1 /* 2 * Copyright (C) 2007 Oracle. All rights reserved. 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public 6 * License v2 as published by the Free Software Foundation. 7 * 8 * This program is distributed in the hope that it will be useful, 9 * but WITHOUT ANY WARRANTY; without even the implied warranty of 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 11 * General Public License for more details. 12 * 13 * You should have received a copy of the GNU General Public 14 * License along with this program; if not, write to the 15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330, 16 * Boston, MA 021110-1307, USA. 17 */ 18 19 #include <linux/kernel.h> 20 #include <linux/bio.h> 21 #include <linux/buffer_head.h> 22 #include <linux/file.h> 23 #include <linux/fs.h> 24 #include <linux/pagemap.h> 25 #include <linux/highmem.h> 26 #include <linux/time.h> 27 #include <linux/init.h> 28 #include <linux/string.h> 29 #include <linux/backing-dev.h> 30 #include <linux/mpage.h> 31 #include <linux/swap.h> 32 #include <linux/writeback.h> 33 #include <linux/statfs.h> 34 #include <linux/compat.h> 35 #include <linux/bit_spinlock.h> 36 #include <linux/xattr.h> 37 #include <linux/posix_acl.h> 38 #include <linux/falloc.h> 39 #include <linux/slab.h> 40 #include <linux/ratelimit.h> 41 #include <linux/mount.h> 42 #include <linux/btrfs.h> 43 #include <linux/blkdev.h> 44 #include <linux/posix_acl_xattr.h> 45 #include <linux/uio.h> 46 #include "ctree.h" 47 #include "disk-io.h" 48 #include "transaction.h" 49 #include "btrfs_inode.h" 50 #include "print-tree.h" 51 #include "ordered-data.h" 52 #include "xattr.h" 53 #include "tree-log.h" 54 #include "volumes.h" 55 #include "compression.h" 56 #include "locking.h" 57 #include "free-space-cache.h" 58 #include "inode-map.h" 59 #include "backref.h" 60 #include "hash.h" 61 #include "props.h" 62 #include "qgroup.h" 63 64 struct btrfs_iget_args { 65 struct btrfs_key *location; 66 struct btrfs_root *root; 67 }; 68 69 static const struct inode_operations btrfs_dir_inode_operations; 70 static const struct inode_operations btrfs_symlink_inode_operations; 71 static const struct inode_operations btrfs_dir_ro_inode_operations; 72 static const struct inode_operations btrfs_special_inode_operations; 73 static const struct inode_operations btrfs_file_inode_operations; 74 static const struct address_space_operations btrfs_aops; 75 static const struct address_space_operations btrfs_symlink_aops; 76 static const struct file_operations btrfs_dir_file_operations; 77 static struct extent_io_ops btrfs_extent_io_ops; 78 79 static struct kmem_cache *btrfs_inode_cachep; 80 static struct kmem_cache *btrfs_delalloc_work_cachep; 81 struct kmem_cache *btrfs_trans_handle_cachep; 82 struct kmem_cache *btrfs_transaction_cachep; 83 struct kmem_cache *btrfs_path_cachep; 84 struct kmem_cache *btrfs_free_space_cachep; 85 86 #define S_SHIFT 12 87 static unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = { 88 [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE, 89 [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR, 90 [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV, 91 [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV, 92 [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO, 93 [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK, 94 [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK, 95 }; 96 97 static int btrfs_setsize(struct inode *inode, struct iattr *attr); 98 static int btrfs_truncate(struct inode *inode); 99 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent); 100 static noinline int cow_file_range(struct inode *inode, 101 struct page *locked_page, 102 u64 start, u64 end, int *page_started, 103 unsigned long *nr_written, int unlock); 104 static struct extent_map *create_pinned_em(struct inode *inode, u64 start, 105 u64 len, u64 orig_start, 106 u64 block_start, u64 block_len, 107 u64 orig_block_len, u64 ram_bytes, 108 int type); 109 110 static int btrfs_dirty_inode(struct inode *inode); 111 112 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS 113 void btrfs_test_inode_set_ops(struct inode *inode) 114 { 115 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops; 116 } 117 #endif 118 119 static int btrfs_init_inode_security(struct btrfs_trans_handle *trans, 120 struct inode *inode, struct inode *dir, 121 const struct qstr *qstr) 122 { 123 int err; 124 125 err = btrfs_init_acl(trans, inode, dir); 126 if (!err) 127 err = btrfs_xattr_security_init(trans, inode, dir, qstr); 128 return err; 129 } 130 131 /* 132 * this does all the hard work for inserting an inline extent into 133 * the btree. The caller should have done a btrfs_drop_extents so that 134 * no overlapping inline items exist in the btree 135 */ 136 static int insert_inline_extent(struct btrfs_trans_handle *trans, 137 struct btrfs_path *path, int extent_inserted, 138 struct btrfs_root *root, struct inode *inode, 139 u64 start, size_t size, size_t compressed_size, 140 int compress_type, 141 struct page **compressed_pages) 142 { 143 struct extent_buffer *leaf; 144 struct page *page = NULL; 145 char *kaddr; 146 unsigned long ptr; 147 struct btrfs_file_extent_item *ei; 148 int err = 0; 149 int ret; 150 size_t cur_size = size; 151 unsigned long offset; 152 153 if (compressed_size && compressed_pages) 154 cur_size = compressed_size; 155 156 inode_add_bytes(inode, size); 157 158 if (!extent_inserted) { 159 struct btrfs_key key; 160 size_t datasize; 161 162 key.objectid = btrfs_ino(inode); 163 key.offset = start; 164 key.type = BTRFS_EXTENT_DATA_KEY; 165 166 datasize = btrfs_file_extent_calc_inline_size(cur_size); 167 path->leave_spinning = 1; 168 ret = btrfs_insert_empty_item(trans, root, path, &key, 169 datasize); 170 if (ret) { 171 err = ret; 172 goto fail; 173 } 174 } 175 leaf = path->nodes[0]; 176 ei = btrfs_item_ptr(leaf, path->slots[0], 177 struct btrfs_file_extent_item); 178 btrfs_set_file_extent_generation(leaf, ei, trans->transid); 179 btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE); 180 btrfs_set_file_extent_encryption(leaf, ei, 0); 181 btrfs_set_file_extent_other_encoding(leaf, ei, 0); 182 btrfs_set_file_extent_ram_bytes(leaf, ei, size); 183 ptr = btrfs_file_extent_inline_start(ei); 184 185 if (compress_type != BTRFS_COMPRESS_NONE) { 186 struct page *cpage; 187 int i = 0; 188 while (compressed_size > 0) { 189 cpage = compressed_pages[i]; 190 cur_size = min_t(unsigned long, compressed_size, 191 PAGE_CACHE_SIZE); 192 193 kaddr = kmap_atomic(cpage); 194 write_extent_buffer(leaf, kaddr, ptr, cur_size); 195 kunmap_atomic(kaddr); 196 197 i++; 198 ptr += cur_size; 199 compressed_size -= cur_size; 200 } 201 btrfs_set_file_extent_compression(leaf, ei, 202 compress_type); 203 } else { 204 page = find_get_page(inode->i_mapping, 205 start >> PAGE_CACHE_SHIFT); 206 btrfs_set_file_extent_compression(leaf, ei, 0); 207 kaddr = kmap_atomic(page); 208 offset = start & (PAGE_CACHE_SIZE - 1); 209 write_extent_buffer(leaf, kaddr + offset, ptr, size); 210 kunmap_atomic(kaddr); 211 page_cache_release(page); 212 } 213 btrfs_mark_buffer_dirty(leaf); 214 btrfs_release_path(path); 215 216 /* 217 * we're an inline extent, so nobody can 218 * extend the file past i_size without locking 219 * a page we already have locked. 220 * 221 * We must do any isize and inode updates 222 * before we unlock the pages. Otherwise we 223 * could end up racing with unlink. 224 */ 225 BTRFS_I(inode)->disk_i_size = inode->i_size; 226 ret = btrfs_update_inode(trans, root, inode); 227 228 return ret; 229 fail: 230 return err; 231 } 232 233 234 /* 235 * conditionally insert an inline extent into the file. This 236 * does the checks required to make sure the data is small enough 237 * to fit as an inline extent. 238 */ 239 static noinline int cow_file_range_inline(struct btrfs_root *root, 240 struct inode *inode, u64 start, 241 u64 end, size_t compressed_size, 242 int compress_type, 243 struct page **compressed_pages) 244 { 245 struct btrfs_trans_handle *trans; 246 u64 isize = i_size_read(inode); 247 u64 actual_end = min(end + 1, isize); 248 u64 inline_len = actual_end - start; 249 u64 aligned_end = ALIGN(end, root->sectorsize); 250 u64 data_len = inline_len; 251 int ret; 252 struct btrfs_path *path; 253 int extent_inserted = 0; 254 u32 extent_item_size; 255 256 if (compressed_size) 257 data_len = compressed_size; 258 259 if (start > 0 || 260 actual_end > PAGE_CACHE_SIZE || 261 data_len > BTRFS_MAX_INLINE_DATA_SIZE(root) || 262 (!compressed_size && 263 (actual_end & (root->sectorsize - 1)) == 0) || 264 end + 1 < isize || 265 data_len > root->fs_info->max_inline) { 266 return 1; 267 } 268 269 path = btrfs_alloc_path(); 270 if (!path) 271 return -ENOMEM; 272 273 trans = btrfs_join_transaction(root); 274 if (IS_ERR(trans)) { 275 btrfs_free_path(path); 276 return PTR_ERR(trans); 277 } 278 trans->block_rsv = &root->fs_info->delalloc_block_rsv; 279 280 if (compressed_size && compressed_pages) 281 extent_item_size = btrfs_file_extent_calc_inline_size( 282 compressed_size); 283 else 284 extent_item_size = btrfs_file_extent_calc_inline_size( 285 inline_len); 286 287 ret = __btrfs_drop_extents(trans, root, inode, path, 288 start, aligned_end, NULL, 289 1, 1, extent_item_size, &extent_inserted); 290 if (ret) { 291 btrfs_abort_transaction(trans, root, ret); 292 goto out; 293 } 294 295 if (isize > actual_end) 296 inline_len = min_t(u64, isize, actual_end); 297 ret = insert_inline_extent(trans, path, extent_inserted, 298 root, inode, start, 299 inline_len, compressed_size, 300 compress_type, compressed_pages); 301 if (ret && ret != -ENOSPC) { 302 btrfs_abort_transaction(trans, root, ret); 303 goto out; 304 } else if (ret == -ENOSPC) { 305 ret = 1; 306 goto out; 307 } 308 309 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags); 310 btrfs_delalloc_release_metadata(inode, end + 1 - start); 311 btrfs_drop_extent_cache(inode, start, aligned_end - 1, 0); 312 out: 313 btrfs_free_path(path); 314 btrfs_end_transaction(trans, root); 315 return ret; 316 } 317 318 struct async_extent { 319 u64 start; 320 u64 ram_size; 321 u64 compressed_size; 322 struct page **pages; 323 unsigned long nr_pages; 324 int compress_type; 325 struct list_head list; 326 }; 327 328 struct async_cow { 329 struct inode *inode; 330 struct btrfs_root *root; 331 struct page *locked_page; 332 u64 start; 333 u64 end; 334 struct list_head extents; 335 struct btrfs_work work; 336 }; 337 338 static noinline int add_async_extent(struct async_cow *cow, 339 u64 start, u64 ram_size, 340 u64 compressed_size, 341 struct page **pages, 342 unsigned long nr_pages, 343 int compress_type) 344 { 345 struct async_extent *async_extent; 346 347 async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS); 348 BUG_ON(!async_extent); /* -ENOMEM */ 349 async_extent->start = start; 350 async_extent->ram_size = ram_size; 351 async_extent->compressed_size = compressed_size; 352 async_extent->pages = pages; 353 async_extent->nr_pages = nr_pages; 354 async_extent->compress_type = compress_type; 355 list_add_tail(&async_extent->list, &cow->extents); 356 return 0; 357 } 358 359 static inline int inode_need_compress(struct inode *inode) 360 { 361 struct btrfs_root *root = BTRFS_I(inode)->root; 362 363 /* force compress */ 364 if (btrfs_test_opt(root, FORCE_COMPRESS)) 365 return 1; 366 /* bad compression ratios */ 367 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS) 368 return 0; 369 if (btrfs_test_opt(root, COMPRESS) || 370 BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS || 371 BTRFS_I(inode)->force_compress) 372 return 1; 373 return 0; 374 } 375 376 /* 377 * we create compressed extents in two phases. The first 378 * phase compresses a range of pages that have already been 379 * locked (both pages and state bits are locked). 380 * 381 * This is done inside an ordered work queue, and the compression 382 * is spread across many cpus. The actual IO submission is step 383 * two, and the ordered work queue takes care of making sure that 384 * happens in the same order things were put onto the queue by 385 * writepages and friends. 386 * 387 * If this code finds it can't get good compression, it puts an 388 * entry onto the work queue to write the uncompressed bytes. This 389 * makes sure that both compressed inodes and uncompressed inodes 390 * are written in the same order that the flusher thread sent them 391 * down. 392 */ 393 static noinline void compress_file_range(struct inode *inode, 394 struct page *locked_page, 395 u64 start, u64 end, 396 struct async_cow *async_cow, 397 int *num_added) 398 { 399 struct btrfs_root *root = BTRFS_I(inode)->root; 400 u64 num_bytes; 401 u64 blocksize = root->sectorsize; 402 u64 actual_end; 403 u64 isize = i_size_read(inode); 404 int ret = 0; 405 struct page **pages = NULL; 406 unsigned long nr_pages; 407 unsigned long nr_pages_ret = 0; 408 unsigned long total_compressed = 0; 409 unsigned long total_in = 0; 410 unsigned long max_compressed = 128 * 1024; 411 unsigned long max_uncompressed = 128 * 1024; 412 int i; 413 int will_compress; 414 int compress_type = root->fs_info->compress_type; 415 int redirty = 0; 416 417 /* if this is a small write inside eof, kick off a defrag */ 418 if ((end - start + 1) < 16 * 1024 && 419 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size)) 420 btrfs_add_inode_defrag(NULL, inode); 421 422 actual_end = min_t(u64, isize, end + 1); 423 again: 424 will_compress = 0; 425 nr_pages = (end >> PAGE_CACHE_SHIFT) - (start >> PAGE_CACHE_SHIFT) + 1; 426 nr_pages = min(nr_pages, (128 * 1024UL) / PAGE_CACHE_SIZE); 427 428 /* 429 * we don't want to send crud past the end of i_size through 430 * compression, that's just a waste of CPU time. So, if the 431 * end of the file is before the start of our current 432 * requested range of bytes, we bail out to the uncompressed 433 * cleanup code that can deal with all of this. 434 * 435 * It isn't really the fastest way to fix things, but this is a 436 * very uncommon corner. 437 */ 438 if (actual_end <= start) 439 goto cleanup_and_bail_uncompressed; 440 441 total_compressed = actual_end - start; 442 443 /* 444 * skip compression for a small file range(<=blocksize) that 445 * isn't an inline extent, since it dosen't save disk space at all. 446 */ 447 if (total_compressed <= blocksize && 448 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size)) 449 goto cleanup_and_bail_uncompressed; 450 451 /* we want to make sure that amount of ram required to uncompress 452 * an extent is reasonable, so we limit the total size in ram 453 * of a compressed extent to 128k. This is a crucial number 454 * because it also controls how easily we can spread reads across 455 * cpus for decompression. 456 * 457 * We also want to make sure the amount of IO required to do 458 * a random read is reasonably small, so we limit the size of 459 * a compressed extent to 128k. 460 */ 461 total_compressed = min(total_compressed, max_uncompressed); 462 num_bytes = ALIGN(end - start + 1, blocksize); 463 num_bytes = max(blocksize, num_bytes); 464 total_in = 0; 465 ret = 0; 466 467 /* 468 * we do compression for mount -o compress and when the 469 * inode has not been flagged as nocompress. This flag can 470 * change at any time if we discover bad compression ratios. 471 */ 472 if (inode_need_compress(inode)) { 473 WARN_ON(pages); 474 pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS); 475 if (!pages) { 476 /* just bail out to the uncompressed code */ 477 goto cont; 478 } 479 480 if (BTRFS_I(inode)->force_compress) 481 compress_type = BTRFS_I(inode)->force_compress; 482 483 /* 484 * we need to call clear_page_dirty_for_io on each 485 * page in the range. Otherwise applications with the file 486 * mmap'd can wander in and change the page contents while 487 * we are compressing them. 488 * 489 * If the compression fails for any reason, we set the pages 490 * dirty again later on. 491 */ 492 extent_range_clear_dirty_for_io(inode, start, end); 493 redirty = 1; 494 ret = btrfs_compress_pages(compress_type, 495 inode->i_mapping, start, 496 total_compressed, pages, 497 nr_pages, &nr_pages_ret, 498 &total_in, 499 &total_compressed, 500 max_compressed); 501 502 if (!ret) { 503 unsigned long offset = total_compressed & 504 (PAGE_CACHE_SIZE - 1); 505 struct page *page = pages[nr_pages_ret - 1]; 506 char *kaddr; 507 508 /* zero the tail end of the last page, we might be 509 * sending it down to disk 510 */ 511 if (offset) { 512 kaddr = kmap_atomic(page); 513 memset(kaddr + offset, 0, 514 PAGE_CACHE_SIZE - offset); 515 kunmap_atomic(kaddr); 516 } 517 will_compress = 1; 518 } 519 } 520 cont: 521 if (start == 0) { 522 /* lets try to make an inline extent */ 523 if (ret || total_in < (actual_end - start)) { 524 /* we didn't compress the entire range, try 525 * to make an uncompressed inline extent. 526 */ 527 ret = cow_file_range_inline(root, inode, start, end, 528 0, 0, NULL); 529 } else { 530 /* try making a compressed inline extent */ 531 ret = cow_file_range_inline(root, inode, start, end, 532 total_compressed, 533 compress_type, pages); 534 } 535 if (ret <= 0) { 536 unsigned long clear_flags = EXTENT_DELALLOC | 537 EXTENT_DEFRAG; 538 unsigned long page_error_op; 539 540 clear_flags |= (ret < 0) ? EXTENT_DO_ACCOUNTING : 0; 541 page_error_op = ret < 0 ? PAGE_SET_ERROR : 0; 542 543 /* 544 * inline extent creation worked or returned error, 545 * we don't need to create any more async work items. 546 * Unlock and free up our temp pages. 547 */ 548 extent_clear_unlock_delalloc(inode, start, end, NULL, 549 clear_flags, PAGE_UNLOCK | 550 PAGE_CLEAR_DIRTY | 551 PAGE_SET_WRITEBACK | 552 page_error_op | 553 PAGE_END_WRITEBACK); 554 goto free_pages_out; 555 } 556 } 557 558 if (will_compress) { 559 /* 560 * we aren't doing an inline extent round the compressed size 561 * up to a block size boundary so the allocator does sane 562 * things 563 */ 564 total_compressed = ALIGN(total_compressed, blocksize); 565 566 /* 567 * one last check to make sure the compression is really a 568 * win, compare the page count read with the blocks on disk 569 */ 570 total_in = ALIGN(total_in, PAGE_CACHE_SIZE); 571 if (total_compressed >= total_in) { 572 will_compress = 0; 573 } else { 574 num_bytes = total_in; 575 } 576 } 577 if (!will_compress && pages) { 578 /* 579 * the compression code ran but failed to make things smaller, 580 * free any pages it allocated and our page pointer array 581 */ 582 for (i = 0; i < nr_pages_ret; i++) { 583 WARN_ON(pages[i]->mapping); 584 page_cache_release(pages[i]); 585 } 586 kfree(pages); 587 pages = NULL; 588 total_compressed = 0; 589 nr_pages_ret = 0; 590 591 /* flag the file so we don't compress in the future */ 592 if (!btrfs_test_opt(root, FORCE_COMPRESS) && 593 !(BTRFS_I(inode)->force_compress)) { 594 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS; 595 } 596 } 597 if (will_compress) { 598 *num_added += 1; 599 600 /* the async work queues will take care of doing actual 601 * allocation on disk for these compressed pages, 602 * and will submit them to the elevator. 603 */ 604 add_async_extent(async_cow, start, num_bytes, 605 total_compressed, pages, nr_pages_ret, 606 compress_type); 607 608 if (start + num_bytes < end) { 609 start += num_bytes; 610 pages = NULL; 611 cond_resched(); 612 goto again; 613 } 614 } else { 615 cleanup_and_bail_uncompressed: 616 /* 617 * No compression, but we still need to write the pages in 618 * the file we've been given so far. redirty the locked 619 * page if it corresponds to our extent and set things up 620 * for the async work queue to run cow_file_range to do 621 * the normal delalloc dance 622 */ 623 if (page_offset(locked_page) >= start && 624 page_offset(locked_page) <= end) { 625 __set_page_dirty_nobuffers(locked_page); 626 /* unlocked later on in the async handlers */ 627 } 628 if (redirty) 629 extent_range_redirty_for_io(inode, start, end); 630 add_async_extent(async_cow, start, end - start + 1, 631 0, NULL, 0, BTRFS_COMPRESS_NONE); 632 *num_added += 1; 633 } 634 635 return; 636 637 free_pages_out: 638 for (i = 0; i < nr_pages_ret; i++) { 639 WARN_ON(pages[i]->mapping); 640 page_cache_release(pages[i]); 641 } 642 kfree(pages); 643 } 644 645 static void free_async_extent_pages(struct async_extent *async_extent) 646 { 647 int i; 648 649 if (!async_extent->pages) 650 return; 651 652 for (i = 0; i < async_extent->nr_pages; i++) { 653 WARN_ON(async_extent->pages[i]->mapping); 654 page_cache_release(async_extent->pages[i]); 655 } 656 kfree(async_extent->pages); 657 async_extent->nr_pages = 0; 658 async_extent->pages = NULL; 659 } 660 661 /* 662 * phase two of compressed writeback. This is the ordered portion 663 * of the code, which only gets called in the order the work was 664 * queued. We walk all the async extents created by compress_file_range 665 * and send them down to the disk. 666 */ 667 static noinline void submit_compressed_extents(struct inode *inode, 668 struct async_cow *async_cow) 669 { 670 struct async_extent *async_extent; 671 u64 alloc_hint = 0; 672 struct btrfs_key ins; 673 struct extent_map *em; 674 struct btrfs_root *root = BTRFS_I(inode)->root; 675 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; 676 struct extent_io_tree *io_tree; 677 int ret = 0; 678 679 again: 680 while (!list_empty(&async_cow->extents)) { 681 async_extent = list_entry(async_cow->extents.next, 682 struct async_extent, list); 683 list_del(&async_extent->list); 684 685 io_tree = &BTRFS_I(inode)->io_tree; 686 687 retry: 688 /* did the compression code fall back to uncompressed IO? */ 689 if (!async_extent->pages) { 690 int page_started = 0; 691 unsigned long nr_written = 0; 692 693 lock_extent(io_tree, async_extent->start, 694 async_extent->start + 695 async_extent->ram_size - 1); 696 697 /* allocate blocks */ 698 ret = cow_file_range(inode, async_cow->locked_page, 699 async_extent->start, 700 async_extent->start + 701 async_extent->ram_size - 1, 702 &page_started, &nr_written, 0); 703 704 /* JDM XXX */ 705 706 /* 707 * if page_started, cow_file_range inserted an 708 * inline extent and took care of all the unlocking 709 * and IO for us. Otherwise, we need to submit 710 * all those pages down to the drive. 711 */ 712 if (!page_started && !ret) 713 extent_write_locked_range(io_tree, 714 inode, async_extent->start, 715 async_extent->start + 716 async_extent->ram_size - 1, 717 btrfs_get_extent, 718 WB_SYNC_ALL); 719 else if (ret) 720 unlock_page(async_cow->locked_page); 721 kfree(async_extent); 722 cond_resched(); 723 continue; 724 } 725 726 lock_extent(io_tree, async_extent->start, 727 async_extent->start + async_extent->ram_size - 1); 728 729 ret = btrfs_reserve_extent(root, 730 async_extent->compressed_size, 731 async_extent->compressed_size, 732 0, alloc_hint, &ins, 1, 1); 733 if (ret) { 734 free_async_extent_pages(async_extent); 735 736 if (ret == -ENOSPC) { 737 unlock_extent(io_tree, async_extent->start, 738 async_extent->start + 739 async_extent->ram_size - 1); 740 741 /* 742 * we need to redirty the pages if we decide to 743 * fallback to uncompressed IO, otherwise we 744 * will not submit these pages down to lower 745 * layers. 746 */ 747 extent_range_redirty_for_io(inode, 748 async_extent->start, 749 async_extent->start + 750 async_extent->ram_size - 1); 751 752 goto retry; 753 } 754 goto out_free; 755 } 756 /* 757 * here we're doing allocation and writeback of the 758 * compressed pages 759 */ 760 btrfs_drop_extent_cache(inode, async_extent->start, 761 async_extent->start + 762 async_extent->ram_size - 1, 0); 763 764 em = alloc_extent_map(); 765 if (!em) { 766 ret = -ENOMEM; 767 goto out_free_reserve; 768 } 769 em->start = async_extent->start; 770 em->len = async_extent->ram_size; 771 em->orig_start = em->start; 772 em->mod_start = em->start; 773 em->mod_len = em->len; 774 775 em->block_start = ins.objectid; 776 em->block_len = ins.offset; 777 em->orig_block_len = ins.offset; 778 em->ram_bytes = async_extent->ram_size; 779 em->bdev = root->fs_info->fs_devices->latest_bdev; 780 em->compress_type = async_extent->compress_type; 781 set_bit(EXTENT_FLAG_PINNED, &em->flags); 782 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags); 783 em->generation = -1; 784 785 while (1) { 786 write_lock(&em_tree->lock); 787 ret = add_extent_mapping(em_tree, em, 1); 788 write_unlock(&em_tree->lock); 789 if (ret != -EEXIST) { 790 free_extent_map(em); 791 break; 792 } 793 btrfs_drop_extent_cache(inode, async_extent->start, 794 async_extent->start + 795 async_extent->ram_size - 1, 0); 796 } 797 798 if (ret) 799 goto out_free_reserve; 800 801 ret = btrfs_add_ordered_extent_compress(inode, 802 async_extent->start, 803 ins.objectid, 804 async_extent->ram_size, 805 ins.offset, 806 BTRFS_ORDERED_COMPRESSED, 807 async_extent->compress_type); 808 if (ret) { 809 btrfs_drop_extent_cache(inode, async_extent->start, 810 async_extent->start + 811 async_extent->ram_size - 1, 0); 812 goto out_free_reserve; 813 } 814 815 /* 816 * clear dirty, set writeback and unlock the pages. 817 */ 818 extent_clear_unlock_delalloc(inode, async_extent->start, 819 async_extent->start + 820 async_extent->ram_size - 1, 821 NULL, EXTENT_LOCKED | EXTENT_DELALLOC, 822 PAGE_UNLOCK | PAGE_CLEAR_DIRTY | 823 PAGE_SET_WRITEBACK); 824 ret = btrfs_submit_compressed_write(inode, 825 async_extent->start, 826 async_extent->ram_size, 827 ins.objectid, 828 ins.offset, async_extent->pages, 829 async_extent->nr_pages); 830 if (ret) { 831 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree; 832 struct page *p = async_extent->pages[0]; 833 const u64 start = async_extent->start; 834 const u64 end = start + async_extent->ram_size - 1; 835 836 p->mapping = inode->i_mapping; 837 tree->ops->writepage_end_io_hook(p, start, end, 838 NULL, 0); 839 p->mapping = NULL; 840 extent_clear_unlock_delalloc(inode, start, end, NULL, 0, 841 PAGE_END_WRITEBACK | 842 PAGE_SET_ERROR); 843 free_async_extent_pages(async_extent); 844 } 845 alloc_hint = ins.objectid + ins.offset; 846 kfree(async_extent); 847 cond_resched(); 848 } 849 return; 850 out_free_reserve: 851 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1); 852 out_free: 853 extent_clear_unlock_delalloc(inode, async_extent->start, 854 async_extent->start + 855 async_extent->ram_size - 1, 856 NULL, EXTENT_LOCKED | EXTENT_DELALLOC | 857 EXTENT_DEFRAG | EXTENT_DO_ACCOUNTING, 858 PAGE_UNLOCK | PAGE_CLEAR_DIRTY | 859 PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK | 860 PAGE_SET_ERROR); 861 free_async_extent_pages(async_extent); 862 kfree(async_extent); 863 goto again; 864 } 865 866 static u64 get_extent_allocation_hint(struct inode *inode, u64 start, 867 u64 num_bytes) 868 { 869 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; 870 struct extent_map *em; 871 u64 alloc_hint = 0; 872 873 read_lock(&em_tree->lock); 874 em = search_extent_mapping(em_tree, start, num_bytes); 875 if (em) { 876 /* 877 * if block start isn't an actual block number then find the 878 * first block in this inode and use that as a hint. If that 879 * block is also bogus then just don't worry about it. 880 */ 881 if (em->block_start >= EXTENT_MAP_LAST_BYTE) { 882 free_extent_map(em); 883 em = search_extent_mapping(em_tree, 0, 0); 884 if (em && em->block_start < EXTENT_MAP_LAST_BYTE) 885 alloc_hint = em->block_start; 886 if (em) 887 free_extent_map(em); 888 } else { 889 alloc_hint = em->block_start; 890 free_extent_map(em); 891 } 892 } 893 read_unlock(&em_tree->lock); 894 895 return alloc_hint; 896 } 897 898 /* 899 * when extent_io.c finds a delayed allocation range in the file, 900 * the call backs end up in this code. The basic idea is to 901 * allocate extents on disk for the range, and create ordered data structs 902 * in ram to track those extents. 903 * 904 * locked_page is the page that writepage had locked already. We use 905 * it to make sure we don't do extra locks or unlocks. 906 * 907 * *page_started is set to one if we unlock locked_page and do everything 908 * required to start IO on it. It may be clean and already done with 909 * IO when we return. 910 */ 911 static noinline int cow_file_range(struct inode *inode, 912 struct page *locked_page, 913 u64 start, u64 end, int *page_started, 914 unsigned long *nr_written, 915 int unlock) 916 { 917 struct btrfs_root *root = BTRFS_I(inode)->root; 918 u64 alloc_hint = 0; 919 u64 num_bytes; 920 unsigned long ram_size; 921 u64 disk_num_bytes; 922 u64 cur_alloc_size; 923 u64 blocksize = root->sectorsize; 924 struct btrfs_key ins; 925 struct extent_map *em; 926 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; 927 int ret = 0; 928 929 if (btrfs_is_free_space_inode(inode)) { 930 WARN_ON_ONCE(1); 931 ret = -EINVAL; 932 goto out_unlock; 933 } 934 935 num_bytes = ALIGN(end - start + 1, blocksize); 936 num_bytes = max(blocksize, num_bytes); 937 disk_num_bytes = num_bytes; 938 939 /* if this is a small write inside eof, kick off defrag */ 940 if (num_bytes < 64 * 1024 && 941 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size)) 942 btrfs_add_inode_defrag(NULL, inode); 943 944 if (start == 0) { 945 /* lets try to make an inline extent */ 946 ret = cow_file_range_inline(root, inode, start, end, 0, 0, 947 NULL); 948 if (ret == 0) { 949 extent_clear_unlock_delalloc(inode, start, end, NULL, 950 EXTENT_LOCKED | EXTENT_DELALLOC | 951 EXTENT_DEFRAG, PAGE_UNLOCK | 952 PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK | 953 PAGE_END_WRITEBACK); 954 955 *nr_written = *nr_written + 956 (end - start + PAGE_CACHE_SIZE) / PAGE_CACHE_SIZE; 957 *page_started = 1; 958 goto out; 959 } else if (ret < 0) { 960 goto out_unlock; 961 } 962 } 963 964 BUG_ON(disk_num_bytes > 965 btrfs_super_total_bytes(root->fs_info->super_copy)); 966 967 alloc_hint = get_extent_allocation_hint(inode, start, num_bytes); 968 btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0); 969 970 while (disk_num_bytes > 0) { 971 unsigned long op; 972 973 cur_alloc_size = disk_num_bytes; 974 ret = btrfs_reserve_extent(root, cur_alloc_size, 975 root->sectorsize, 0, alloc_hint, 976 &ins, 1, 1); 977 if (ret < 0) 978 goto out_unlock; 979 980 em = alloc_extent_map(); 981 if (!em) { 982 ret = -ENOMEM; 983 goto out_reserve; 984 } 985 em->start = start; 986 em->orig_start = em->start; 987 ram_size = ins.offset; 988 em->len = ins.offset; 989 em->mod_start = em->start; 990 em->mod_len = em->len; 991 992 em->block_start = ins.objectid; 993 em->block_len = ins.offset; 994 em->orig_block_len = ins.offset; 995 em->ram_bytes = ram_size; 996 em->bdev = root->fs_info->fs_devices->latest_bdev; 997 set_bit(EXTENT_FLAG_PINNED, &em->flags); 998 em->generation = -1; 999 1000 while (1) { 1001 write_lock(&em_tree->lock); 1002 ret = add_extent_mapping(em_tree, em, 1); 1003 write_unlock(&em_tree->lock); 1004 if (ret != -EEXIST) { 1005 free_extent_map(em); 1006 break; 1007 } 1008 btrfs_drop_extent_cache(inode, start, 1009 start + ram_size - 1, 0); 1010 } 1011 if (ret) 1012 goto out_reserve; 1013 1014 cur_alloc_size = ins.offset; 1015 ret = btrfs_add_ordered_extent(inode, start, ins.objectid, 1016 ram_size, cur_alloc_size, 0); 1017 if (ret) 1018 goto out_drop_extent_cache; 1019 1020 if (root->root_key.objectid == 1021 BTRFS_DATA_RELOC_TREE_OBJECTID) { 1022 ret = btrfs_reloc_clone_csums(inode, start, 1023 cur_alloc_size); 1024 if (ret) 1025 goto out_drop_extent_cache; 1026 } 1027 1028 if (disk_num_bytes < cur_alloc_size) 1029 break; 1030 1031 /* we're not doing compressed IO, don't unlock the first 1032 * page (which the caller expects to stay locked), don't 1033 * clear any dirty bits and don't set any writeback bits 1034 * 1035 * Do set the Private2 bit so we know this page was properly 1036 * setup for writepage 1037 */ 1038 op = unlock ? PAGE_UNLOCK : 0; 1039 op |= PAGE_SET_PRIVATE2; 1040 1041 extent_clear_unlock_delalloc(inode, start, 1042 start + ram_size - 1, locked_page, 1043 EXTENT_LOCKED | EXTENT_DELALLOC, 1044 op); 1045 disk_num_bytes -= cur_alloc_size; 1046 num_bytes -= cur_alloc_size; 1047 alloc_hint = ins.objectid + ins.offset; 1048 start += cur_alloc_size; 1049 } 1050 out: 1051 return ret; 1052 1053 out_drop_extent_cache: 1054 btrfs_drop_extent_cache(inode, start, start + ram_size - 1, 0); 1055 out_reserve: 1056 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1); 1057 out_unlock: 1058 extent_clear_unlock_delalloc(inode, start, end, locked_page, 1059 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING | 1060 EXTENT_DELALLOC | EXTENT_DEFRAG, 1061 PAGE_UNLOCK | PAGE_CLEAR_DIRTY | 1062 PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK); 1063 goto out; 1064 } 1065 1066 /* 1067 * work queue call back to started compression on a file and pages 1068 */ 1069 static noinline void async_cow_start(struct btrfs_work *work) 1070 { 1071 struct async_cow *async_cow; 1072 int num_added = 0; 1073 async_cow = container_of(work, struct async_cow, work); 1074 1075 compress_file_range(async_cow->inode, async_cow->locked_page, 1076 async_cow->start, async_cow->end, async_cow, 1077 &num_added); 1078 if (num_added == 0) { 1079 btrfs_add_delayed_iput(async_cow->inode); 1080 async_cow->inode = NULL; 1081 } 1082 } 1083 1084 /* 1085 * work queue call back to submit previously compressed pages 1086 */ 1087 static noinline void async_cow_submit(struct btrfs_work *work) 1088 { 1089 struct async_cow *async_cow; 1090 struct btrfs_root *root; 1091 unsigned long nr_pages; 1092 1093 async_cow = container_of(work, struct async_cow, work); 1094 1095 root = async_cow->root; 1096 nr_pages = (async_cow->end - async_cow->start + PAGE_CACHE_SIZE) >> 1097 PAGE_CACHE_SHIFT; 1098 1099 if (atomic_sub_return(nr_pages, &root->fs_info->async_delalloc_pages) < 1100 5 * 1024 * 1024 && 1101 waitqueue_active(&root->fs_info->async_submit_wait)) 1102 wake_up(&root->fs_info->async_submit_wait); 1103 1104 if (async_cow->inode) 1105 submit_compressed_extents(async_cow->inode, async_cow); 1106 } 1107 1108 static noinline void async_cow_free(struct btrfs_work *work) 1109 { 1110 struct async_cow *async_cow; 1111 async_cow = container_of(work, struct async_cow, work); 1112 if (async_cow->inode) 1113 btrfs_add_delayed_iput(async_cow->inode); 1114 kfree(async_cow); 1115 } 1116 1117 static int cow_file_range_async(struct inode *inode, struct page *locked_page, 1118 u64 start, u64 end, int *page_started, 1119 unsigned long *nr_written) 1120 { 1121 struct async_cow *async_cow; 1122 struct btrfs_root *root = BTRFS_I(inode)->root; 1123 unsigned long nr_pages; 1124 u64 cur_end; 1125 int limit = 10 * 1024 * 1024; 1126 1127 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED, 1128 1, 0, NULL, GFP_NOFS); 1129 while (start < end) { 1130 async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS); 1131 BUG_ON(!async_cow); /* -ENOMEM */ 1132 async_cow->inode = igrab(inode); 1133 async_cow->root = root; 1134 async_cow->locked_page = locked_page; 1135 async_cow->start = start; 1136 1137 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS && 1138 !btrfs_test_opt(root, FORCE_COMPRESS)) 1139 cur_end = end; 1140 else 1141 cur_end = min(end, start + 512 * 1024 - 1); 1142 1143 async_cow->end = cur_end; 1144 INIT_LIST_HEAD(&async_cow->extents); 1145 1146 btrfs_init_work(&async_cow->work, 1147 btrfs_delalloc_helper, 1148 async_cow_start, async_cow_submit, 1149 async_cow_free); 1150 1151 nr_pages = (cur_end - start + PAGE_CACHE_SIZE) >> 1152 PAGE_CACHE_SHIFT; 1153 atomic_add(nr_pages, &root->fs_info->async_delalloc_pages); 1154 1155 btrfs_queue_work(root->fs_info->delalloc_workers, 1156 &async_cow->work); 1157 1158 if (atomic_read(&root->fs_info->async_delalloc_pages) > limit) { 1159 wait_event(root->fs_info->async_submit_wait, 1160 (atomic_read(&root->fs_info->async_delalloc_pages) < 1161 limit)); 1162 } 1163 1164 while (atomic_read(&root->fs_info->async_submit_draining) && 1165 atomic_read(&root->fs_info->async_delalloc_pages)) { 1166 wait_event(root->fs_info->async_submit_wait, 1167 (atomic_read(&root->fs_info->async_delalloc_pages) == 1168 0)); 1169 } 1170 1171 *nr_written += nr_pages; 1172 start = cur_end + 1; 1173 } 1174 *page_started = 1; 1175 return 0; 1176 } 1177 1178 static noinline int csum_exist_in_range(struct btrfs_root *root, 1179 u64 bytenr, u64 num_bytes) 1180 { 1181 int ret; 1182 struct btrfs_ordered_sum *sums; 1183 LIST_HEAD(list); 1184 1185 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, bytenr, 1186 bytenr + num_bytes - 1, &list, 0); 1187 if (ret == 0 && list_empty(&list)) 1188 return 0; 1189 1190 while (!list_empty(&list)) { 1191 sums = list_entry(list.next, struct btrfs_ordered_sum, list); 1192 list_del(&sums->list); 1193 kfree(sums); 1194 } 1195 return 1; 1196 } 1197 1198 /* 1199 * when nowcow writeback call back. This checks for snapshots or COW copies 1200 * of the extents that exist in the file, and COWs the file as required. 1201 * 1202 * If no cow copies or snapshots exist, we write directly to the existing 1203 * blocks on disk 1204 */ 1205 static noinline int run_delalloc_nocow(struct inode *inode, 1206 struct page *locked_page, 1207 u64 start, u64 end, int *page_started, int force, 1208 unsigned long *nr_written) 1209 { 1210 struct btrfs_root *root = BTRFS_I(inode)->root; 1211 struct btrfs_trans_handle *trans; 1212 struct extent_buffer *leaf; 1213 struct btrfs_path *path; 1214 struct btrfs_file_extent_item *fi; 1215 struct btrfs_key found_key; 1216 u64 cow_start; 1217 u64 cur_offset; 1218 u64 extent_end; 1219 u64 extent_offset; 1220 u64 disk_bytenr; 1221 u64 num_bytes; 1222 u64 disk_num_bytes; 1223 u64 ram_bytes; 1224 int extent_type; 1225 int ret, err; 1226 int type; 1227 int nocow; 1228 int check_prev = 1; 1229 bool nolock; 1230 u64 ino = btrfs_ino(inode); 1231 1232 path = btrfs_alloc_path(); 1233 if (!path) { 1234 extent_clear_unlock_delalloc(inode, start, end, locked_page, 1235 EXTENT_LOCKED | EXTENT_DELALLOC | 1236 EXTENT_DO_ACCOUNTING | 1237 EXTENT_DEFRAG, PAGE_UNLOCK | 1238 PAGE_CLEAR_DIRTY | 1239 PAGE_SET_WRITEBACK | 1240 PAGE_END_WRITEBACK); 1241 return -ENOMEM; 1242 } 1243 1244 nolock = btrfs_is_free_space_inode(inode); 1245 1246 if (nolock) 1247 trans = btrfs_join_transaction_nolock(root); 1248 else 1249 trans = btrfs_join_transaction(root); 1250 1251 if (IS_ERR(trans)) { 1252 extent_clear_unlock_delalloc(inode, start, end, locked_page, 1253 EXTENT_LOCKED | EXTENT_DELALLOC | 1254 EXTENT_DO_ACCOUNTING | 1255 EXTENT_DEFRAG, PAGE_UNLOCK | 1256 PAGE_CLEAR_DIRTY | 1257 PAGE_SET_WRITEBACK | 1258 PAGE_END_WRITEBACK); 1259 btrfs_free_path(path); 1260 return PTR_ERR(trans); 1261 } 1262 1263 trans->block_rsv = &root->fs_info->delalloc_block_rsv; 1264 1265 cow_start = (u64)-1; 1266 cur_offset = start; 1267 while (1) { 1268 ret = btrfs_lookup_file_extent(trans, root, path, ino, 1269 cur_offset, 0); 1270 if (ret < 0) 1271 goto error; 1272 if (ret > 0 && path->slots[0] > 0 && check_prev) { 1273 leaf = path->nodes[0]; 1274 btrfs_item_key_to_cpu(leaf, &found_key, 1275 path->slots[0] - 1); 1276 if (found_key.objectid == ino && 1277 found_key.type == BTRFS_EXTENT_DATA_KEY) 1278 path->slots[0]--; 1279 } 1280 check_prev = 0; 1281 next_slot: 1282 leaf = path->nodes[0]; 1283 if (path->slots[0] >= btrfs_header_nritems(leaf)) { 1284 ret = btrfs_next_leaf(root, path); 1285 if (ret < 0) 1286 goto error; 1287 if (ret > 0) 1288 break; 1289 leaf = path->nodes[0]; 1290 } 1291 1292 nocow = 0; 1293 disk_bytenr = 0; 1294 num_bytes = 0; 1295 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 1296 1297 if (found_key.objectid > ino || 1298 found_key.type > BTRFS_EXTENT_DATA_KEY || 1299 found_key.offset > end) 1300 break; 1301 1302 if (found_key.offset > cur_offset) { 1303 extent_end = found_key.offset; 1304 extent_type = 0; 1305 goto out_check; 1306 } 1307 1308 fi = btrfs_item_ptr(leaf, path->slots[0], 1309 struct btrfs_file_extent_item); 1310 extent_type = btrfs_file_extent_type(leaf, fi); 1311 1312 ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi); 1313 if (extent_type == BTRFS_FILE_EXTENT_REG || 1314 extent_type == BTRFS_FILE_EXTENT_PREALLOC) { 1315 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); 1316 extent_offset = btrfs_file_extent_offset(leaf, fi); 1317 extent_end = found_key.offset + 1318 btrfs_file_extent_num_bytes(leaf, fi); 1319 disk_num_bytes = 1320 btrfs_file_extent_disk_num_bytes(leaf, fi); 1321 if (extent_end <= start) { 1322 path->slots[0]++; 1323 goto next_slot; 1324 } 1325 if (disk_bytenr == 0) 1326 goto out_check; 1327 if (btrfs_file_extent_compression(leaf, fi) || 1328 btrfs_file_extent_encryption(leaf, fi) || 1329 btrfs_file_extent_other_encoding(leaf, fi)) 1330 goto out_check; 1331 if (extent_type == BTRFS_FILE_EXTENT_REG && !force) 1332 goto out_check; 1333 if (btrfs_extent_readonly(root, disk_bytenr)) 1334 goto out_check; 1335 if (btrfs_cross_ref_exist(trans, root, ino, 1336 found_key.offset - 1337 extent_offset, disk_bytenr)) 1338 goto out_check; 1339 disk_bytenr += extent_offset; 1340 disk_bytenr += cur_offset - found_key.offset; 1341 num_bytes = min(end + 1, extent_end) - cur_offset; 1342 /* 1343 * if there are pending snapshots for this root, 1344 * we fall into common COW way. 1345 */ 1346 if (!nolock) { 1347 err = btrfs_start_write_no_snapshoting(root); 1348 if (!err) 1349 goto out_check; 1350 } 1351 /* 1352 * force cow if csum exists in the range. 1353 * this ensure that csum for a given extent are 1354 * either valid or do not exist. 1355 */ 1356 if (csum_exist_in_range(root, disk_bytenr, num_bytes)) 1357 goto out_check; 1358 nocow = 1; 1359 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { 1360 extent_end = found_key.offset + 1361 btrfs_file_extent_inline_len(leaf, 1362 path->slots[0], fi); 1363 extent_end = ALIGN(extent_end, root->sectorsize); 1364 } else { 1365 BUG_ON(1); 1366 } 1367 out_check: 1368 if (extent_end <= start) { 1369 path->slots[0]++; 1370 if (!nolock && nocow) 1371 btrfs_end_write_no_snapshoting(root); 1372 goto next_slot; 1373 } 1374 if (!nocow) { 1375 if (cow_start == (u64)-1) 1376 cow_start = cur_offset; 1377 cur_offset = extent_end; 1378 if (cur_offset > end) 1379 break; 1380 path->slots[0]++; 1381 goto next_slot; 1382 } 1383 1384 btrfs_release_path(path); 1385 if (cow_start != (u64)-1) { 1386 ret = cow_file_range(inode, locked_page, 1387 cow_start, found_key.offset - 1, 1388 page_started, nr_written, 1); 1389 if (ret) { 1390 if (!nolock && nocow) 1391 btrfs_end_write_no_snapshoting(root); 1392 goto error; 1393 } 1394 cow_start = (u64)-1; 1395 } 1396 1397 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) { 1398 struct extent_map *em; 1399 struct extent_map_tree *em_tree; 1400 em_tree = &BTRFS_I(inode)->extent_tree; 1401 em = alloc_extent_map(); 1402 BUG_ON(!em); /* -ENOMEM */ 1403 em->start = cur_offset; 1404 em->orig_start = found_key.offset - extent_offset; 1405 em->len = num_bytes; 1406 em->block_len = num_bytes; 1407 em->block_start = disk_bytenr; 1408 em->orig_block_len = disk_num_bytes; 1409 em->ram_bytes = ram_bytes; 1410 em->bdev = root->fs_info->fs_devices->latest_bdev; 1411 em->mod_start = em->start; 1412 em->mod_len = em->len; 1413 set_bit(EXTENT_FLAG_PINNED, &em->flags); 1414 set_bit(EXTENT_FLAG_FILLING, &em->flags); 1415 em->generation = -1; 1416 while (1) { 1417 write_lock(&em_tree->lock); 1418 ret = add_extent_mapping(em_tree, em, 1); 1419 write_unlock(&em_tree->lock); 1420 if (ret != -EEXIST) { 1421 free_extent_map(em); 1422 break; 1423 } 1424 btrfs_drop_extent_cache(inode, em->start, 1425 em->start + em->len - 1, 0); 1426 } 1427 type = BTRFS_ORDERED_PREALLOC; 1428 } else { 1429 type = BTRFS_ORDERED_NOCOW; 1430 } 1431 1432 ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr, 1433 num_bytes, num_bytes, type); 1434 BUG_ON(ret); /* -ENOMEM */ 1435 1436 if (root->root_key.objectid == 1437 BTRFS_DATA_RELOC_TREE_OBJECTID) { 1438 ret = btrfs_reloc_clone_csums(inode, cur_offset, 1439 num_bytes); 1440 if (ret) { 1441 if (!nolock && nocow) 1442 btrfs_end_write_no_snapshoting(root); 1443 goto error; 1444 } 1445 } 1446 1447 extent_clear_unlock_delalloc(inode, cur_offset, 1448 cur_offset + num_bytes - 1, 1449 locked_page, EXTENT_LOCKED | 1450 EXTENT_DELALLOC, PAGE_UNLOCK | 1451 PAGE_SET_PRIVATE2); 1452 if (!nolock && nocow) 1453 btrfs_end_write_no_snapshoting(root); 1454 cur_offset = extent_end; 1455 if (cur_offset > end) 1456 break; 1457 } 1458 btrfs_release_path(path); 1459 1460 if (cur_offset <= end && cow_start == (u64)-1) { 1461 cow_start = cur_offset; 1462 cur_offset = end; 1463 } 1464 1465 if (cow_start != (u64)-1) { 1466 ret = cow_file_range(inode, locked_page, cow_start, end, 1467 page_started, nr_written, 1); 1468 if (ret) 1469 goto error; 1470 } 1471 1472 error: 1473 err = btrfs_end_transaction(trans, root); 1474 if (!ret) 1475 ret = err; 1476 1477 if (ret && cur_offset < end) 1478 extent_clear_unlock_delalloc(inode, cur_offset, end, 1479 locked_page, EXTENT_LOCKED | 1480 EXTENT_DELALLOC | EXTENT_DEFRAG | 1481 EXTENT_DO_ACCOUNTING, PAGE_UNLOCK | 1482 PAGE_CLEAR_DIRTY | 1483 PAGE_SET_WRITEBACK | 1484 PAGE_END_WRITEBACK); 1485 btrfs_free_path(path); 1486 return ret; 1487 } 1488 1489 static inline int need_force_cow(struct inode *inode, u64 start, u64 end) 1490 { 1491 1492 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) && 1493 !(BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC)) 1494 return 0; 1495 1496 /* 1497 * @defrag_bytes is a hint value, no spinlock held here, 1498 * if is not zero, it means the file is defragging. 1499 * Force cow if given extent needs to be defragged. 1500 */ 1501 if (BTRFS_I(inode)->defrag_bytes && 1502 test_range_bit(&BTRFS_I(inode)->io_tree, start, end, 1503 EXTENT_DEFRAG, 0, NULL)) 1504 return 1; 1505 1506 return 0; 1507 } 1508 1509 /* 1510 * extent_io.c call back to do delayed allocation processing 1511 */ 1512 static int run_delalloc_range(struct inode *inode, struct page *locked_page, 1513 u64 start, u64 end, int *page_started, 1514 unsigned long *nr_written) 1515 { 1516 int ret; 1517 int force_cow = need_force_cow(inode, start, end); 1518 1519 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW && !force_cow) { 1520 ret = run_delalloc_nocow(inode, locked_page, start, end, 1521 page_started, 1, nr_written); 1522 } else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC && !force_cow) { 1523 ret = run_delalloc_nocow(inode, locked_page, start, end, 1524 page_started, 0, nr_written); 1525 } else if (!inode_need_compress(inode)) { 1526 ret = cow_file_range(inode, locked_page, start, end, 1527 page_started, nr_written, 1); 1528 } else { 1529 set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT, 1530 &BTRFS_I(inode)->runtime_flags); 1531 ret = cow_file_range_async(inode, locked_page, start, end, 1532 page_started, nr_written); 1533 } 1534 return ret; 1535 } 1536 1537 static void btrfs_split_extent_hook(struct inode *inode, 1538 struct extent_state *orig, u64 split) 1539 { 1540 u64 size; 1541 1542 /* not delalloc, ignore it */ 1543 if (!(orig->state & EXTENT_DELALLOC)) 1544 return; 1545 1546 size = orig->end - orig->start + 1; 1547 if (size > BTRFS_MAX_EXTENT_SIZE) { 1548 u64 num_extents; 1549 u64 new_size; 1550 1551 /* 1552 * See the explanation in btrfs_merge_extent_hook, the same 1553 * applies here, just in reverse. 1554 */ 1555 new_size = orig->end - split + 1; 1556 num_extents = div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1, 1557 BTRFS_MAX_EXTENT_SIZE); 1558 new_size = split - orig->start; 1559 num_extents += div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1, 1560 BTRFS_MAX_EXTENT_SIZE); 1561 if (div64_u64(size + BTRFS_MAX_EXTENT_SIZE - 1, 1562 BTRFS_MAX_EXTENT_SIZE) >= num_extents) 1563 return; 1564 } 1565 1566 spin_lock(&BTRFS_I(inode)->lock); 1567 BTRFS_I(inode)->outstanding_extents++; 1568 spin_unlock(&BTRFS_I(inode)->lock); 1569 } 1570 1571 /* 1572 * extent_io.c merge_extent_hook, used to track merged delayed allocation 1573 * extents so we can keep track of new extents that are just merged onto old 1574 * extents, such as when we are doing sequential writes, so we can properly 1575 * account for the metadata space we'll need. 1576 */ 1577 static void btrfs_merge_extent_hook(struct inode *inode, 1578 struct extent_state *new, 1579 struct extent_state *other) 1580 { 1581 u64 new_size, old_size; 1582 u64 num_extents; 1583 1584 /* not delalloc, ignore it */ 1585 if (!(other->state & EXTENT_DELALLOC)) 1586 return; 1587 1588 if (new->start > other->start) 1589 new_size = new->end - other->start + 1; 1590 else 1591 new_size = other->end - new->start + 1; 1592 1593 /* we're not bigger than the max, unreserve the space and go */ 1594 if (new_size <= BTRFS_MAX_EXTENT_SIZE) { 1595 spin_lock(&BTRFS_I(inode)->lock); 1596 BTRFS_I(inode)->outstanding_extents--; 1597 spin_unlock(&BTRFS_I(inode)->lock); 1598 return; 1599 } 1600 1601 /* 1602 * We have to add up either side to figure out how many extents were 1603 * accounted for before we merged into one big extent. If the number of 1604 * extents we accounted for is <= the amount we need for the new range 1605 * then we can return, otherwise drop. Think of it like this 1606 * 1607 * [ 4k][MAX_SIZE] 1608 * 1609 * So we've grown the extent by a MAX_SIZE extent, this would mean we 1610 * need 2 outstanding extents, on one side we have 1 and the other side 1611 * we have 1 so they are == and we can return. But in this case 1612 * 1613 * [MAX_SIZE+4k][MAX_SIZE+4k] 1614 * 1615 * Each range on their own accounts for 2 extents, but merged together 1616 * they are only 3 extents worth of accounting, so we need to drop in 1617 * this case. 1618 */ 1619 old_size = other->end - other->start + 1; 1620 num_extents = div64_u64(old_size + BTRFS_MAX_EXTENT_SIZE - 1, 1621 BTRFS_MAX_EXTENT_SIZE); 1622 old_size = new->end - new->start + 1; 1623 num_extents += div64_u64(old_size + BTRFS_MAX_EXTENT_SIZE - 1, 1624 BTRFS_MAX_EXTENT_SIZE); 1625 1626 if (div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1, 1627 BTRFS_MAX_EXTENT_SIZE) >= num_extents) 1628 return; 1629 1630 spin_lock(&BTRFS_I(inode)->lock); 1631 BTRFS_I(inode)->outstanding_extents--; 1632 spin_unlock(&BTRFS_I(inode)->lock); 1633 } 1634 1635 static void btrfs_add_delalloc_inodes(struct btrfs_root *root, 1636 struct inode *inode) 1637 { 1638 spin_lock(&root->delalloc_lock); 1639 if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) { 1640 list_add_tail(&BTRFS_I(inode)->delalloc_inodes, 1641 &root->delalloc_inodes); 1642 set_bit(BTRFS_INODE_IN_DELALLOC_LIST, 1643 &BTRFS_I(inode)->runtime_flags); 1644 root->nr_delalloc_inodes++; 1645 if (root->nr_delalloc_inodes == 1) { 1646 spin_lock(&root->fs_info->delalloc_root_lock); 1647 BUG_ON(!list_empty(&root->delalloc_root)); 1648 list_add_tail(&root->delalloc_root, 1649 &root->fs_info->delalloc_roots); 1650 spin_unlock(&root->fs_info->delalloc_root_lock); 1651 } 1652 } 1653 spin_unlock(&root->delalloc_lock); 1654 } 1655 1656 static void btrfs_del_delalloc_inode(struct btrfs_root *root, 1657 struct inode *inode) 1658 { 1659 spin_lock(&root->delalloc_lock); 1660 if (!list_empty(&BTRFS_I(inode)->delalloc_inodes)) { 1661 list_del_init(&BTRFS_I(inode)->delalloc_inodes); 1662 clear_bit(BTRFS_INODE_IN_DELALLOC_LIST, 1663 &BTRFS_I(inode)->runtime_flags); 1664 root->nr_delalloc_inodes--; 1665 if (!root->nr_delalloc_inodes) { 1666 spin_lock(&root->fs_info->delalloc_root_lock); 1667 BUG_ON(list_empty(&root->delalloc_root)); 1668 list_del_init(&root->delalloc_root); 1669 spin_unlock(&root->fs_info->delalloc_root_lock); 1670 } 1671 } 1672 spin_unlock(&root->delalloc_lock); 1673 } 1674 1675 /* 1676 * extent_io.c set_bit_hook, used to track delayed allocation 1677 * bytes in this file, and to maintain the list of inodes that 1678 * have pending delalloc work to be done. 1679 */ 1680 static void btrfs_set_bit_hook(struct inode *inode, 1681 struct extent_state *state, unsigned *bits) 1682 { 1683 1684 if ((*bits & EXTENT_DEFRAG) && !(*bits & EXTENT_DELALLOC)) 1685 WARN_ON(1); 1686 /* 1687 * set_bit and clear bit hooks normally require _irqsave/restore 1688 * but in this case, we are only testing for the DELALLOC 1689 * bit, which is only set or cleared with irqs on 1690 */ 1691 if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) { 1692 struct btrfs_root *root = BTRFS_I(inode)->root; 1693 u64 len = state->end + 1 - state->start; 1694 bool do_list = !btrfs_is_free_space_inode(inode); 1695 1696 if (*bits & EXTENT_FIRST_DELALLOC) { 1697 *bits &= ~EXTENT_FIRST_DELALLOC; 1698 } else { 1699 spin_lock(&BTRFS_I(inode)->lock); 1700 BTRFS_I(inode)->outstanding_extents++; 1701 spin_unlock(&BTRFS_I(inode)->lock); 1702 } 1703 1704 /* For sanity tests */ 1705 if (btrfs_test_is_dummy_root(root)) 1706 return; 1707 1708 __percpu_counter_add(&root->fs_info->delalloc_bytes, len, 1709 root->fs_info->delalloc_batch); 1710 spin_lock(&BTRFS_I(inode)->lock); 1711 BTRFS_I(inode)->delalloc_bytes += len; 1712 if (*bits & EXTENT_DEFRAG) 1713 BTRFS_I(inode)->defrag_bytes += len; 1714 if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST, 1715 &BTRFS_I(inode)->runtime_flags)) 1716 btrfs_add_delalloc_inodes(root, inode); 1717 spin_unlock(&BTRFS_I(inode)->lock); 1718 } 1719 } 1720 1721 /* 1722 * extent_io.c clear_bit_hook, see set_bit_hook for why 1723 */ 1724 static void btrfs_clear_bit_hook(struct inode *inode, 1725 struct extent_state *state, 1726 unsigned *bits) 1727 { 1728 u64 len = state->end + 1 - state->start; 1729 u64 num_extents = div64_u64(len + BTRFS_MAX_EXTENT_SIZE -1, 1730 BTRFS_MAX_EXTENT_SIZE); 1731 1732 spin_lock(&BTRFS_I(inode)->lock); 1733 if ((state->state & EXTENT_DEFRAG) && (*bits & EXTENT_DEFRAG)) 1734 BTRFS_I(inode)->defrag_bytes -= len; 1735 spin_unlock(&BTRFS_I(inode)->lock); 1736 1737 /* 1738 * set_bit and clear bit hooks normally require _irqsave/restore 1739 * but in this case, we are only testing for the DELALLOC 1740 * bit, which is only set or cleared with irqs on 1741 */ 1742 if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) { 1743 struct btrfs_root *root = BTRFS_I(inode)->root; 1744 bool do_list = !btrfs_is_free_space_inode(inode); 1745 1746 if (*bits & EXTENT_FIRST_DELALLOC) { 1747 *bits &= ~EXTENT_FIRST_DELALLOC; 1748 } else if (!(*bits & EXTENT_DO_ACCOUNTING)) { 1749 spin_lock(&BTRFS_I(inode)->lock); 1750 BTRFS_I(inode)->outstanding_extents -= num_extents; 1751 spin_unlock(&BTRFS_I(inode)->lock); 1752 } 1753 1754 /* 1755 * We don't reserve metadata space for space cache inodes so we 1756 * don't need to call dellalloc_release_metadata if there is an 1757 * error. 1758 */ 1759 if (*bits & EXTENT_DO_ACCOUNTING && 1760 root != root->fs_info->tree_root) 1761 btrfs_delalloc_release_metadata(inode, len); 1762 1763 /* For sanity tests. */ 1764 if (btrfs_test_is_dummy_root(root)) 1765 return; 1766 1767 if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID 1768 && do_list && !(state->state & EXTENT_NORESERVE)) 1769 btrfs_free_reserved_data_space(inode, len); 1770 1771 __percpu_counter_add(&root->fs_info->delalloc_bytes, -len, 1772 root->fs_info->delalloc_batch); 1773 spin_lock(&BTRFS_I(inode)->lock); 1774 BTRFS_I(inode)->delalloc_bytes -= len; 1775 if (do_list && BTRFS_I(inode)->delalloc_bytes == 0 && 1776 test_bit(BTRFS_INODE_IN_DELALLOC_LIST, 1777 &BTRFS_I(inode)->runtime_flags)) 1778 btrfs_del_delalloc_inode(root, inode); 1779 spin_unlock(&BTRFS_I(inode)->lock); 1780 } 1781 } 1782 1783 /* 1784 * extent_io.c merge_bio_hook, this must check the chunk tree to make sure 1785 * we don't create bios that span stripes or chunks 1786 */ 1787 int btrfs_merge_bio_hook(int rw, struct page *page, unsigned long offset, 1788 size_t size, struct bio *bio, 1789 unsigned long bio_flags) 1790 { 1791 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root; 1792 u64 logical = (u64)bio->bi_iter.bi_sector << 9; 1793 u64 length = 0; 1794 u64 map_length; 1795 int ret; 1796 1797 if (bio_flags & EXTENT_BIO_COMPRESSED) 1798 return 0; 1799 1800 length = bio->bi_iter.bi_size; 1801 map_length = length; 1802 ret = btrfs_map_block(root->fs_info, rw, logical, 1803 &map_length, NULL, 0); 1804 /* Will always return 0 with map_multi == NULL */ 1805 BUG_ON(ret < 0); 1806 if (map_length < length + size) 1807 return 1; 1808 return 0; 1809 } 1810 1811 /* 1812 * in order to insert checksums into the metadata in large chunks, 1813 * we wait until bio submission time. All the pages in the bio are 1814 * checksummed and sums are attached onto the ordered extent record. 1815 * 1816 * At IO completion time the cums attached on the ordered extent record 1817 * are inserted into the btree 1818 */ 1819 static int __btrfs_submit_bio_start(struct inode *inode, int rw, 1820 struct bio *bio, int mirror_num, 1821 unsigned long bio_flags, 1822 u64 bio_offset) 1823 { 1824 struct btrfs_root *root = BTRFS_I(inode)->root; 1825 int ret = 0; 1826 1827 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0); 1828 BUG_ON(ret); /* -ENOMEM */ 1829 return 0; 1830 } 1831 1832 /* 1833 * in order to insert checksums into the metadata in large chunks, 1834 * we wait until bio submission time. All the pages in the bio are 1835 * checksummed and sums are attached onto the ordered extent record. 1836 * 1837 * At IO completion time the cums attached on the ordered extent record 1838 * are inserted into the btree 1839 */ 1840 static int __btrfs_submit_bio_done(struct inode *inode, int rw, struct bio *bio, 1841 int mirror_num, unsigned long bio_flags, 1842 u64 bio_offset) 1843 { 1844 struct btrfs_root *root = BTRFS_I(inode)->root; 1845 int ret; 1846 1847 ret = btrfs_map_bio(root, rw, bio, mirror_num, 1); 1848 if (ret) 1849 bio_endio(bio, ret); 1850 return ret; 1851 } 1852 1853 /* 1854 * extent_io.c submission hook. This does the right thing for csum calculation 1855 * on write, or reading the csums from the tree before a read 1856 */ 1857 static int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio, 1858 int mirror_num, unsigned long bio_flags, 1859 u64 bio_offset) 1860 { 1861 struct btrfs_root *root = BTRFS_I(inode)->root; 1862 int ret = 0; 1863 int skip_sum; 1864 int metadata = 0; 1865 int async = !atomic_read(&BTRFS_I(inode)->sync_writers); 1866 1867 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM; 1868 1869 if (btrfs_is_free_space_inode(inode)) 1870 metadata = 2; 1871 1872 if (!(rw & REQ_WRITE)) { 1873 ret = btrfs_bio_wq_end_io(root->fs_info, bio, metadata); 1874 if (ret) 1875 goto out; 1876 1877 if (bio_flags & EXTENT_BIO_COMPRESSED) { 1878 ret = btrfs_submit_compressed_read(inode, bio, 1879 mirror_num, 1880 bio_flags); 1881 goto out; 1882 } else if (!skip_sum) { 1883 ret = btrfs_lookup_bio_sums(root, inode, bio, NULL); 1884 if (ret) 1885 goto out; 1886 } 1887 goto mapit; 1888 } else if (async && !skip_sum) { 1889 /* csum items have already been cloned */ 1890 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID) 1891 goto mapit; 1892 /* we're doing a write, do the async checksumming */ 1893 ret = btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info, 1894 inode, rw, bio, mirror_num, 1895 bio_flags, bio_offset, 1896 __btrfs_submit_bio_start, 1897 __btrfs_submit_bio_done); 1898 goto out; 1899 } else if (!skip_sum) { 1900 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0); 1901 if (ret) 1902 goto out; 1903 } 1904 1905 mapit: 1906 ret = btrfs_map_bio(root, rw, bio, mirror_num, 0); 1907 1908 out: 1909 if (ret < 0) 1910 bio_endio(bio, ret); 1911 return ret; 1912 } 1913 1914 /* 1915 * given a list of ordered sums record them in the inode. This happens 1916 * at IO completion time based on sums calculated at bio submission time. 1917 */ 1918 static noinline int add_pending_csums(struct btrfs_trans_handle *trans, 1919 struct inode *inode, u64 file_offset, 1920 struct list_head *list) 1921 { 1922 struct btrfs_ordered_sum *sum; 1923 1924 list_for_each_entry(sum, list, list) { 1925 trans->adding_csums = 1; 1926 btrfs_csum_file_blocks(trans, 1927 BTRFS_I(inode)->root->fs_info->csum_root, sum); 1928 trans->adding_csums = 0; 1929 } 1930 return 0; 1931 } 1932 1933 int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end, 1934 struct extent_state **cached_state) 1935 { 1936 WARN_ON((end & (PAGE_CACHE_SIZE - 1)) == 0); 1937 return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end, 1938 cached_state, GFP_NOFS); 1939 } 1940 1941 /* see btrfs_writepage_start_hook for details on why this is required */ 1942 struct btrfs_writepage_fixup { 1943 struct page *page; 1944 struct btrfs_work work; 1945 }; 1946 1947 static void btrfs_writepage_fixup_worker(struct btrfs_work *work) 1948 { 1949 struct btrfs_writepage_fixup *fixup; 1950 struct btrfs_ordered_extent *ordered; 1951 struct extent_state *cached_state = NULL; 1952 struct page *page; 1953 struct inode *inode; 1954 u64 page_start; 1955 u64 page_end; 1956 int ret; 1957 1958 fixup = container_of(work, struct btrfs_writepage_fixup, work); 1959 page = fixup->page; 1960 again: 1961 lock_page(page); 1962 if (!page->mapping || !PageDirty(page) || !PageChecked(page)) { 1963 ClearPageChecked(page); 1964 goto out_page; 1965 } 1966 1967 inode = page->mapping->host; 1968 page_start = page_offset(page); 1969 page_end = page_offset(page) + PAGE_CACHE_SIZE - 1; 1970 1971 lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end, 0, 1972 &cached_state); 1973 1974 /* already ordered? We're done */ 1975 if (PagePrivate2(page)) 1976 goto out; 1977 1978 ordered = btrfs_lookup_ordered_extent(inode, page_start); 1979 if (ordered) { 1980 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, 1981 page_end, &cached_state, GFP_NOFS); 1982 unlock_page(page); 1983 btrfs_start_ordered_extent(inode, ordered, 1); 1984 btrfs_put_ordered_extent(ordered); 1985 goto again; 1986 } 1987 1988 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE); 1989 if (ret) { 1990 mapping_set_error(page->mapping, ret); 1991 end_extent_writepage(page, ret, page_start, page_end); 1992 ClearPageChecked(page); 1993 goto out; 1994 } 1995 1996 btrfs_set_extent_delalloc(inode, page_start, page_end, &cached_state); 1997 ClearPageChecked(page); 1998 set_page_dirty(page); 1999 out: 2000 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end, 2001 &cached_state, GFP_NOFS); 2002 out_page: 2003 unlock_page(page); 2004 page_cache_release(page); 2005 kfree(fixup); 2006 } 2007 2008 /* 2009 * There are a few paths in the higher layers of the kernel that directly 2010 * set the page dirty bit without asking the filesystem if it is a 2011 * good idea. This causes problems because we want to make sure COW 2012 * properly happens and the data=ordered rules are followed. 2013 * 2014 * In our case any range that doesn't have the ORDERED bit set 2015 * hasn't been properly setup for IO. We kick off an async process 2016 * to fix it up. The async helper will wait for ordered extents, set 2017 * the delalloc bit and make it safe to write the page. 2018 */ 2019 static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end) 2020 { 2021 struct inode *inode = page->mapping->host; 2022 struct btrfs_writepage_fixup *fixup; 2023 struct btrfs_root *root = BTRFS_I(inode)->root; 2024 2025 /* this page is properly in the ordered list */ 2026 if (TestClearPagePrivate2(page)) 2027 return 0; 2028 2029 if (PageChecked(page)) 2030 return -EAGAIN; 2031 2032 fixup = kzalloc(sizeof(*fixup), GFP_NOFS); 2033 if (!fixup) 2034 return -EAGAIN; 2035 2036 SetPageChecked(page); 2037 page_cache_get(page); 2038 btrfs_init_work(&fixup->work, btrfs_fixup_helper, 2039 btrfs_writepage_fixup_worker, NULL, NULL); 2040 fixup->page = page; 2041 btrfs_queue_work(root->fs_info->fixup_workers, &fixup->work); 2042 return -EBUSY; 2043 } 2044 2045 static int insert_reserved_file_extent(struct btrfs_trans_handle *trans, 2046 struct inode *inode, u64 file_pos, 2047 u64 disk_bytenr, u64 disk_num_bytes, 2048 u64 num_bytes, u64 ram_bytes, 2049 u8 compression, u8 encryption, 2050 u16 other_encoding, int extent_type) 2051 { 2052 struct btrfs_root *root = BTRFS_I(inode)->root; 2053 struct btrfs_file_extent_item *fi; 2054 struct btrfs_path *path; 2055 struct extent_buffer *leaf; 2056 struct btrfs_key ins; 2057 int extent_inserted = 0; 2058 int ret; 2059 2060 path = btrfs_alloc_path(); 2061 if (!path) 2062 return -ENOMEM; 2063 2064 /* 2065 * we may be replacing one extent in the tree with another. 2066 * The new extent is pinned in the extent map, and we don't want 2067 * to drop it from the cache until it is completely in the btree. 2068 * 2069 * So, tell btrfs_drop_extents to leave this extent in the cache. 2070 * the caller is expected to unpin it and allow it to be merged 2071 * with the others. 2072 */ 2073 ret = __btrfs_drop_extents(trans, root, inode, path, file_pos, 2074 file_pos + num_bytes, NULL, 0, 2075 1, sizeof(*fi), &extent_inserted); 2076 if (ret) 2077 goto out; 2078 2079 if (!extent_inserted) { 2080 ins.objectid = btrfs_ino(inode); 2081 ins.offset = file_pos; 2082 ins.type = BTRFS_EXTENT_DATA_KEY; 2083 2084 path->leave_spinning = 1; 2085 ret = btrfs_insert_empty_item(trans, root, path, &ins, 2086 sizeof(*fi)); 2087 if (ret) 2088 goto out; 2089 } 2090 leaf = path->nodes[0]; 2091 fi = btrfs_item_ptr(leaf, path->slots[0], 2092 struct btrfs_file_extent_item); 2093 btrfs_set_file_extent_generation(leaf, fi, trans->transid); 2094 btrfs_set_file_extent_type(leaf, fi, extent_type); 2095 btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr); 2096 btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes); 2097 btrfs_set_file_extent_offset(leaf, fi, 0); 2098 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes); 2099 btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes); 2100 btrfs_set_file_extent_compression(leaf, fi, compression); 2101 btrfs_set_file_extent_encryption(leaf, fi, encryption); 2102 btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding); 2103 2104 btrfs_mark_buffer_dirty(leaf); 2105 btrfs_release_path(path); 2106 2107 inode_add_bytes(inode, num_bytes); 2108 2109 ins.objectid = disk_bytenr; 2110 ins.offset = disk_num_bytes; 2111 ins.type = BTRFS_EXTENT_ITEM_KEY; 2112 ret = btrfs_alloc_reserved_file_extent(trans, root, 2113 root->root_key.objectid, 2114 btrfs_ino(inode), file_pos, &ins); 2115 out: 2116 btrfs_free_path(path); 2117 2118 return ret; 2119 } 2120 2121 /* snapshot-aware defrag */ 2122 struct sa_defrag_extent_backref { 2123 struct rb_node node; 2124 struct old_sa_defrag_extent *old; 2125 u64 root_id; 2126 u64 inum; 2127 u64 file_pos; 2128 u64 extent_offset; 2129 u64 num_bytes; 2130 u64 generation; 2131 }; 2132 2133 struct old_sa_defrag_extent { 2134 struct list_head list; 2135 struct new_sa_defrag_extent *new; 2136 2137 u64 extent_offset; 2138 u64 bytenr; 2139 u64 offset; 2140 u64 len; 2141 int count; 2142 }; 2143 2144 struct new_sa_defrag_extent { 2145 struct rb_root root; 2146 struct list_head head; 2147 struct btrfs_path *path; 2148 struct inode *inode; 2149 u64 file_pos; 2150 u64 len; 2151 u64 bytenr; 2152 u64 disk_len; 2153 u8 compress_type; 2154 }; 2155 2156 static int backref_comp(struct sa_defrag_extent_backref *b1, 2157 struct sa_defrag_extent_backref *b2) 2158 { 2159 if (b1->root_id < b2->root_id) 2160 return -1; 2161 else if (b1->root_id > b2->root_id) 2162 return 1; 2163 2164 if (b1->inum < b2->inum) 2165 return -1; 2166 else if (b1->inum > b2->inum) 2167 return 1; 2168 2169 if (b1->file_pos < b2->file_pos) 2170 return -1; 2171 else if (b1->file_pos > b2->file_pos) 2172 return 1; 2173 2174 /* 2175 * [------------------------------] ===> (a range of space) 2176 * |<--->| |<---->| =============> (fs/file tree A) 2177 * |<---------------------------->| ===> (fs/file tree B) 2178 * 2179 * A range of space can refer to two file extents in one tree while 2180 * refer to only one file extent in another tree. 2181 * 2182 * So we may process a disk offset more than one time(two extents in A) 2183 * and locate at the same extent(one extent in B), then insert two same 2184 * backrefs(both refer to the extent in B). 2185 */ 2186 return 0; 2187 } 2188 2189 static void backref_insert(struct rb_root *root, 2190 struct sa_defrag_extent_backref *backref) 2191 { 2192 struct rb_node **p = &root->rb_node; 2193 struct rb_node *parent = NULL; 2194 struct sa_defrag_extent_backref *entry; 2195 int ret; 2196 2197 while (*p) { 2198 parent = *p; 2199 entry = rb_entry(parent, struct sa_defrag_extent_backref, node); 2200 2201 ret = backref_comp(backref, entry); 2202 if (ret < 0) 2203 p = &(*p)->rb_left; 2204 else 2205 p = &(*p)->rb_right; 2206 } 2207 2208 rb_link_node(&backref->node, parent, p); 2209 rb_insert_color(&backref->node, root); 2210 } 2211 2212 /* 2213 * Note the backref might has changed, and in this case we just return 0. 2214 */ 2215 static noinline int record_one_backref(u64 inum, u64 offset, u64 root_id, 2216 void *ctx) 2217 { 2218 struct btrfs_file_extent_item *extent; 2219 struct btrfs_fs_info *fs_info; 2220 struct old_sa_defrag_extent *old = ctx; 2221 struct new_sa_defrag_extent *new = old->new; 2222 struct btrfs_path *path = new->path; 2223 struct btrfs_key key; 2224 struct btrfs_root *root; 2225 struct sa_defrag_extent_backref *backref; 2226 struct extent_buffer *leaf; 2227 struct inode *inode = new->inode; 2228 int slot; 2229 int ret; 2230 u64 extent_offset; 2231 u64 num_bytes; 2232 2233 if (BTRFS_I(inode)->root->root_key.objectid == root_id && 2234 inum == btrfs_ino(inode)) 2235 return 0; 2236 2237 key.objectid = root_id; 2238 key.type = BTRFS_ROOT_ITEM_KEY; 2239 key.offset = (u64)-1; 2240 2241 fs_info = BTRFS_I(inode)->root->fs_info; 2242 root = btrfs_read_fs_root_no_name(fs_info, &key); 2243 if (IS_ERR(root)) { 2244 if (PTR_ERR(root) == -ENOENT) 2245 return 0; 2246 WARN_ON(1); 2247 pr_debug("inum=%llu, offset=%llu, root_id=%llu\n", 2248 inum, offset, root_id); 2249 return PTR_ERR(root); 2250 } 2251 2252 key.objectid = inum; 2253 key.type = BTRFS_EXTENT_DATA_KEY; 2254 if (offset > (u64)-1 << 32) 2255 key.offset = 0; 2256 else 2257 key.offset = offset; 2258 2259 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 2260 if (WARN_ON(ret < 0)) 2261 return ret; 2262 ret = 0; 2263 2264 while (1) { 2265 cond_resched(); 2266 2267 leaf = path->nodes[0]; 2268 slot = path->slots[0]; 2269 2270 if (slot >= btrfs_header_nritems(leaf)) { 2271 ret = btrfs_next_leaf(root, path); 2272 if (ret < 0) { 2273 goto out; 2274 } else if (ret > 0) { 2275 ret = 0; 2276 goto out; 2277 } 2278 continue; 2279 } 2280 2281 path->slots[0]++; 2282 2283 btrfs_item_key_to_cpu(leaf, &key, slot); 2284 2285 if (key.objectid > inum) 2286 goto out; 2287 2288 if (key.objectid < inum || key.type != BTRFS_EXTENT_DATA_KEY) 2289 continue; 2290 2291 extent = btrfs_item_ptr(leaf, slot, 2292 struct btrfs_file_extent_item); 2293 2294 if (btrfs_file_extent_disk_bytenr(leaf, extent) != old->bytenr) 2295 continue; 2296 2297 /* 2298 * 'offset' refers to the exact key.offset, 2299 * NOT the 'offset' field in btrfs_extent_data_ref, ie. 2300 * (key.offset - extent_offset). 2301 */ 2302 if (key.offset != offset) 2303 continue; 2304 2305 extent_offset = btrfs_file_extent_offset(leaf, extent); 2306 num_bytes = btrfs_file_extent_num_bytes(leaf, extent); 2307 2308 if (extent_offset >= old->extent_offset + old->offset + 2309 old->len || extent_offset + num_bytes <= 2310 old->extent_offset + old->offset) 2311 continue; 2312 break; 2313 } 2314 2315 backref = kmalloc(sizeof(*backref), GFP_NOFS); 2316 if (!backref) { 2317 ret = -ENOENT; 2318 goto out; 2319 } 2320 2321 backref->root_id = root_id; 2322 backref->inum = inum; 2323 backref->file_pos = offset; 2324 backref->num_bytes = num_bytes; 2325 backref->extent_offset = extent_offset; 2326 backref->generation = btrfs_file_extent_generation(leaf, extent); 2327 backref->old = old; 2328 backref_insert(&new->root, backref); 2329 old->count++; 2330 out: 2331 btrfs_release_path(path); 2332 WARN_ON(ret); 2333 return ret; 2334 } 2335 2336 static noinline bool record_extent_backrefs(struct btrfs_path *path, 2337 struct new_sa_defrag_extent *new) 2338 { 2339 struct btrfs_fs_info *fs_info = BTRFS_I(new->inode)->root->fs_info; 2340 struct old_sa_defrag_extent *old, *tmp; 2341 int ret; 2342 2343 new->path = path; 2344 2345 list_for_each_entry_safe(old, tmp, &new->head, list) { 2346 ret = iterate_inodes_from_logical(old->bytenr + 2347 old->extent_offset, fs_info, 2348 path, record_one_backref, 2349 old); 2350 if (ret < 0 && ret != -ENOENT) 2351 return false; 2352 2353 /* no backref to be processed for this extent */ 2354 if (!old->count) { 2355 list_del(&old->list); 2356 kfree(old); 2357 } 2358 } 2359 2360 if (list_empty(&new->head)) 2361 return false; 2362 2363 return true; 2364 } 2365 2366 static int relink_is_mergable(struct extent_buffer *leaf, 2367 struct btrfs_file_extent_item *fi, 2368 struct new_sa_defrag_extent *new) 2369 { 2370 if (btrfs_file_extent_disk_bytenr(leaf, fi) != new->bytenr) 2371 return 0; 2372 2373 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG) 2374 return 0; 2375 2376 if (btrfs_file_extent_compression(leaf, fi) != new->compress_type) 2377 return 0; 2378 2379 if (btrfs_file_extent_encryption(leaf, fi) || 2380 btrfs_file_extent_other_encoding(leaf, fi)) 2381 return 0; 2382 2383 return 1; 2384 } 2385 2386 /* 2387 * Note the backref might has changed, and in this case we just return 0. 2388 */ 2389 static noinline int relink_extent_backref(struct btrfs_path *path, 2390 struct sa_defrag_extent_backref *prev, 2391 struct sa_defrag_extent_backref *backref) 2392 { 2393 struct btrfs_file_extent_item *extent; 2394 struct btrfs_file_extent_item *item; 2395 struct btrfs_ordered_extent *ordered; 2396 struct btrfs_trans_handle *trans; 2397 struct btrfs_fs_info *fs_info; 2398 struct btrfs_root *root; 2399 struct btrfs_key key; 2400 struct extent_buffer *leaf; 2401 struct old_sa_defrag_extent *old = backref->old; 2402 struct new_sa_defrag_extent *new = old->new; 2403 struct inode *src_inode = new->inode; 2404 struct inode *inode; 2405 struct extent_state *cached = NULL; 2406 int ret = 0; 2407 u64 start; 2408 u64 len; 2409 u64 lock_start; 2410 u64 lock_end; 2411 bool merge = false; 2412 int index; 2413 2414 if (prev && prev->root_id == backref->root_id && 2415 prev->inum == backref->inum && 2416 prev->file_pos + prev->num_bytes == backref->file_pos) 2417 merge = true; 2418 2419 /* step 1: get root */ 2420 key.objectid = backref->root_id; 2421 key.type = BTRFS_ROOT_ITEM_KEY; 2422 key.offset = (u64)-1; 2423 2424 fs_info = BTRFS_I(src_inode)->root->fs_info; 2425 index = srcu_read_lock(&fs_info->subvol_srcu); 2426 2427 root = btrfs_read_fs_root_no_name(fs_info, &key); 2428 if (IS_ERR(root)) { 2429 srcu_read_unlock(&fs_info->subvol_srcu, index); 2430 if (PTR_ERR(root) == -ENOENT) 2431 return 0; 2432 return PTR_ERR(root); 2433 } 2434 2435 if (btrfs_root_readonly(root)) { 2436 srcu_read_unlock(&fs_info->subvol_srcu, index); 2437 return 0; 2438 } 2439 2440 /* step 2: get inode */ 2441 key.objectid = backref->inum; 2442 key.type = BTRFS_INODE_ITEM_KEY; 2443 key.offset = 0; 2444 2445 inode = btrfs_iget(fs_info->sb, &key, root, NULL); 2446 if (IS_ERR(inode)) { 2447 srcu_read_unlock(&fs_info->subvol_srcu, index); 2448 return 0; 2449 } 2450 2451 srcu_read_unlock(&fs_info->subvol_srcu, index); 2452 2453 /* step 3: relink backref */ 2454 lock_start = backref->file_pos; 2455 lock_end = backref->file_pos + backref->num_bytes - 1; 2456 lock_extent_bits(&BTRFS_I(inode)->io_tree, lock_start, lock_end, 2457 0, &cached); 2458 2459 ordered = btrfs_lookup_first_ordered_extent(inode, lock_end); 2460 if (ordered) { 2461 btrfs_put_ordered_extent(ordered); 2462 goto out_unlock; 2463 } 2464 2465 trans = btrfs_join_transaction(root); 2466 if (IS_ERR(trans)) { 2467 ret = PTR_ERR(trans); 2468 goto out_unlock; 2469 } 2470 2471 key.objectid = backref->inum; 2472 key.type = BTRFS_EXTENT_DATA_KEY; 2473 key.offset = backref->file_pos; 2474 2475 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 2476 if (ret < 0) { 2477 goto out_free_path; 2478 } else if (ret > 0) { 2479 ret = 0; 2480 goto out_free_path; 2481 } 2482 2483 extent = btrfs_item_ptr(path->nodes[0], path->slots[0], 2484 struct btrfs_file_extent_item); 2485 2486 if (btrfs_file_extent_generation(path->nodes[0], extent) != 2487 backref->generation) 2488 goto out_free_path; 2489 2490 btrfs_release_path(path); 2491 2492 start = backref->file_pos; 2493 if (backref->extent_offset < old->extent_offset + old->offset) 2494 start += old->extent_offset + old->offset - 2495 backref->extent_offset; 2496 2497 len = min(backref->extent_offset + backref->num_bytes, 2498 old->extent_offset + old->offset + old->len); 2499 len -= max(backref->extent_offset, old->extent_offset + old->offset); 2500 2501 ret = btrfs_drop_extents(trans, root, inode, start, 2502 start + len, 1); 2503 if (ret) 2504 goto out_free_path; 2505 again: 2506 key.objectid = btrfs_ino(inode); 2507 key.type = BTRFS_EXTENT_DATA_KEY; 2508 key.offset = start; 2509 2510 path->leave_spinning = 1; 2511 if (merge) { 2512 struct btrfs_file_extent_item *fi; 2513 u64 extent_len; 2514 struct btrfs_key found_key; 2515 2516 ret = btrfs_search_slot(trans, root, &key, path, 0, 1); 2517 if (ret < 0) 2518 goto out_free_path; 2519 2520 path->slots[0]--; 2521 leaf = path->nodes[0]; 2522 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 2523 2524 fi = btrfs_item_ptr(leaf, path->slots[0], 2525 struct btrfs_file_extent_item); 2526 extent_len = btrfs_file_extent_num_bytes(leaf, fi); 2527 2528 if (extent_len + found_key.offset == start && 2529 relink_is_mergable(leaf, fi, new)) { 2530 btrfs_set_file_extent_num_bytes(leaf, fi, 2531 extent_len + len); 2532 btrfs_mark_buffer_dirty(leaf); 2533 inode_add_bytes(inode, len); 2534 2535 ret = 1; 2536 goto out_free_path; 2537 } else { 2538 merge = false; 2539 btrfs_release_path(path); 2540 goto again; 2541 } 2542 } 2543 2544 ret = btrfs_insert_empty_item(trans, root, path, &key, 2545 sizeof(*extent)); 2546 if (ret) { 2547 btrfs_abort_transaction(trans, root, ret); 2548 goto out_free_path; 2549 } 2550 2551 leaf = path->nodes[0]; 2552 item = btrfs_item_ptr(leaf, path->slots[0], 2553 struct btrfs_file_extent_item); 2554 btrfs_set_file_extent_disk_bytenr(leaf, item, new->bytenr); 2555 btrfs_set_file_extent_disk_num_bytes(leaf, item, new->disk_len); 2556 btrfs_set_file_extent_offset(leaf, item, start - new->file_pos); 2557 btrfs_set_file_extent_num_bytes(leaf, item, len); 2558 btrfs_set_file_extent_ram_bytes(leaf, item, new->len); 2559 btrfs_set_file_extent_generation(leaf, item, trans->transid); 2560 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG); 2561 btrfs_set_file_extent_compression(leaf, item, new->compress_type); 2562 btrfs_set_file_extent_encryption(leaf, item, 0); 2563 btrfs_set_file_extent_other_encoding(leaf, item, 0); 2564 2565 btrfs_mark_buffer_dirty(leaf); 2566 inode_add_bytes(inode, len); 2567 btrfs_release_path(path); 2568 2569 ret = btrfs_inc_extent_ref(trans, root, new->bytenr, 2570 new->disk_len, 0, 2571 backref->root_id, backref->inum, 2572 new->file_pos, 0); /* start - extent_offset */ 2573 if (ret) { 2574 btrfs_abort_transaction(trans, root, ret); 2575 goto out_free_path; 2576 } 2577 2578 ret = 1; 2579 out_free_path: 2580 btrfs_release_path(path); 2581 path->leave_spinning = 0; 2582 btrfs_end_transaction(trans, root); 2583 out_unlock: 2584 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lock_start, lock_end, 2585 &cached, GFP_NOFS); 2586 iput(inode); 2587 return ret; 2588 } 2589 2590 static void free_sa_defrag_extent(struct new_sa_defrag_extent *new) 2591 { 2592 struct old_sa_defrag_extent *old, *tmp; 2593 2594 if (!new) 2595 return; 2596 2597 list_for_each_entry_safe(old, tmp, &new->head, list) { 2598 list_del(&old->list); 2599 kfree(old); 2600 } 2601 kfree(new); 2602 } 2603 2604 static void relink_file_extents(struct new_sa_defrag_extent *new) 2605 { 2606 struct btrfs_path *path; 2607 struct sa_defrag_extent_backref *backref; 2608 struct sa_defrag_extent_backref *prev = NULL; 2609 struct inode *inode; 2610 struct btrfs_root *root; 2611 struct rb_node *node; 2612 int ret; 2613 2614 inode = new->inode; 2615 root = BTRFS_I(inode)->root; 2616 2617 path = btrfs_alloc_path(); 2618 if (!path) 2619 return; 2620 2621 if (!record_extent_backrefs(path, new)) { 2622 btrfs_free_path(path); 2623 goto out; 2624 } 2625 btrfs_release_path(path); 2626 2627 while (1) { 2628 node = rb_first(&new->root); 2629 if (!node) 2630 break; 2631 rb_erase(node, &new->root); 2632 2633 backref = rb_entry(node, struct sa_defrag_extent_backref, node); 2634 2635 ret = relink_extent_backref(path, prev, backref); 2636 WARN_ON(ret < 0); 2637 2638 kfree(prev); 2639 2640 if (ret == 1) 2641 prev = backref; 2642 else 2643 prev = NULL; 2644 cond_resched(); 2645 } 2646 kfree(prev); 2647 2648 btrfs_free_path(path); 2649 out: 2650 free_sa_defrag_extent(new); 2651 2652 atomic_dec(&root->fs_info->defrag_running); 2653 wake_up(&root->fs_info->transaction_wait); 2654 } 2655 2656 static struct new_sa_defrag_extent * 2657 record_old_file_extents(struct inode *inode, 2658 struct btrfs_ordered_extent *ordered) 2659 { 2660 struct btrfs_root *root = BTRFS_I(inode)->root; 2661 struct btrfs_path *path; 2662 struct btrfs_key key; 2663 struct old_sa_defrag_extent *old; 2664 struct new_sa_defrag_extent *new; 2665 int ret; 2666 2667 new = kmalloc(sizeof(*new), GFP_NOFS); 2668 if (!new) 2669 return NULL; 2670 2671 new->inode = inode; 2672 new->file_pos = ordered->file_offset; 2673 new->len = ordered->len; 2674 new->bytenr = ordered->start; 2675 new->disk_len = ordered->disk_len; 2676 new->compress_type = ordered->compress_type; 2677 new->root = RB_ROOT; 2678 INIT_LIST_HEAD(&new->head); 2679 2680 path = btrfs_alloc_path(); 2681 if (!path) 2682 goto out_kfree; 2683 2684 key.objectid = btrfs_ino(inode); 2685 key.type = BTRFS_EXTENT_DATA_KEY; 2686 key.offset = new->file_pos; 2687 2688 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 2689 if (ret < 0) 2690 goto out_free_path; 2691 if (ret > 0 && path->slots[0] > 0) 2692 path->slots[0]--; 2693 2694 /* find out all the old extents for the file range */ 2695 while (1) { 2696 struct btrfs_file_extent_item *extent; 2697 struct extent_buffer *l; 2698 int slot; 2699 u64 num_bytes; 2700 u64 offset; 2701 u64 end; 2702 u64 disk_bytenr; 2703 u64 extent_offset; 2704 2705 l = path->nodes[0]; 2706 slot = path->slots[0]; 2707 2708 if (slot >= btrfs_header_nritems(l)) { 2709 ret = btrfs_next_leaf(root, path); 2710 if (ret < 0) 2711 goto out_free_path; 2712 else if (ret > 0) 2713 break; 2714 continue; 2715 } 2716 2717 btrfs_item_key_to_cpu(l, &key, slot); 2718 2719 if (key.objectid != btrfs_ino(inode)) 2720 break; 2721 if (key.type != BTRFS_EXTENT_DATA_KEY) 2722 break; 2723 if (key.offset >= new->file_pos + new->len) 2724 break; 2725 2726 extent = btrfs_item_ptr(l, slot, struct btrfs_file_extent_item); 2727 2728 num_bytes = btrfs_file_extent_num_bytes(l, extent); 2729 if (key.offset + num_bytes < new->file_pos) 2730 goto next; 2731 2732 disk_bytenr = btrfs_file_extent_disk_bytenr(l, extent); 2733 if (!disk_bytenr) 2734 goto next; 2735 2736 extent_offset = btrfs_file_extent_offset(l, extent); 2737 2738 old = kmalloc(sizeof(*old), GFP_NOFS); 2739 if (!old) 2740 goto out_free_path; 2741 2742 offset = max(new->file_pos, key.offset); 2743 end = min(new->file_pos + new->len, key.offset + num_bytes); 2744 2745 old->bytenr = disk_bytenr; 2746 old->extent_offset = extent_offset; 2747 old->offset = offset - key.offset; 2748 old->len = end - offset; 2749 old->new = new; 2750 old->count = 0; 2751 list_add_tail(&old->list, &new->head); 2752 next: 2753 path->slots[0]++; 2754 cond_resched(); 2755 } 2756 2757 btrfs_free_path(path); 2758 atomic_inc(&root->fs_info->defrag_running); 2759 2760 return new; 2761 2762 out_free_path: 2763 btrfs_free_path(path); 2764 out_kfree: 2765 free_sa_defrag_extent(new); 2766 return NULL; 2767 } 2768 2769 static void btrfs_release_delalloc_bytes(struct btrfs_root *root, 2770 u64 start, u64 len) 2771 { 2772 struct btrfs_block_group_cache *cache; 2773 2774 cache = btrfs_lookup_block_group(root->fs_info, start); 2775 ASSERT(cache); 2776 2777 spin_lock(&cache->lock); 2778 cache->delalloc_bytes -= len; 2779 spin_unlock(&cache->lock); 2780 2781 btrfs_put_block_group(cache); 2782 } 2783 2784 /* as ordered data IO finishes, this gets called so we can finish 2785 * an ordered extent if the range of bytes in the file it covers are 2786 * fully written. 2787 */ 2788 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent) 2789 { 2790 struct inode *inode = ordered_extent->inode; 2791 struct btrfs_root *root = BTRFS_I(inode)->root; 2792 struct btrfs_trans_handle *trans = NULL; 2793 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 2794 struct extent_state *cached_state = NULL; 2795 struct new_sa_defrag_extent *new = NULL; 2796 int compress_type = 0; 2797 int ret = 0; 2798 u64 logical_len = ordered_extent->len; 2799 bool nolock; 2800 bool truncated = false; 2801 2802 nolock = btrfs_is_free_space_inode(inode); 2803 2804 if (test_bit(BTRFS_ORDERED_IOERR, &ordered_extent->flags)) { 2805 ret = -EIO; 2806 goto out; 2807 } 2808 2809 btrfs_free_io_failure_record(inode, ordered_extent->file_offset, 2810 ordered_extent->file_offset + 2811 ordered_extent->len - 1); 2812 2813 if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered_extent->flags)) { 2814 truncated = true; 2815 logical_len = ordered_extent->truncated_len; 2816 /* Truncated the entire extent, don't bother adding */ 2817 if (!logical_len) 2818 goto out; 2819 } 2820 2821 if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) { 2822 BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */ 2823 btrfs_ordered_update_i_size(inode, 0, ordered_extent); 2824 if (nolock) 2825 trans = btrfs_join_transaction_nolock(root); 2826 else 2827 trans = btrfs_join_transaction(root); 2828 if (IS_ERR(trans)) { 2829 ret = PTR_ERR(trans); 2830 trans = NULL; 2831 goto out; 2832 } 2833 trans->block_rsv = &root->fs_info->delalloc_block_rsv; 2834 ret = btrfs_update_inode_fallback(trans, root, inode); 2835 if (ret) /* -ENOMEM or corruption */ 2836 btrfs_abort_transaction(trans, root, ret); 2837 goto out; 2838 } 2839 2840 lock_extent_bits(io_tree, ordered_extent->file_offset, 2841 ordered_extent->file_offset + ordered_extent->len - 1, 2842 0, &cached_state); 2843 2844 ret = test_range_bit(io_tree, ordered_extent->file_offset, 2845 ordered_extent->file_offset + ordered_extent->len - 1, 2846 EXTENT_DEFRAG, 1, cached_state); 2847 if (ret) { 2848 u64 last_snapshot = btrfs_root_last_snapshot(&root->root_item); 2849 if (0 && last_snapshot >= BTRFS_I(inode)->generation) 2850 /* the inode is shared */ 2851 new = record_old_file_extents(inode, ordered_extent); 2852 2853 clear_extent_bit(io_tree, ordered_extent->file_offset, 2854 ordered_extent->file_offset + ordered_extent->len - 1, 2855 EXTENT_DEFRAG, 0, 0, &cached_state, GFP_NOFS); 2856 } 2857 2858 if (nolock) 2859 trans = btrfs_join_transaction_nolock(root); 2860 else 2861 trans = btrfs_join_transaction(root); 2862 if (IS_ERR(trans)) { 2863 ret = PTR_ERR(trans); 2864 trans = NULL; 2865 goto out_unlock; 2866 } 2867 2868 trans->block_rsv = &root->fs_info->delalloc_block_rsv; 2869 2870 if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags)) 2871 compress_type = ordered_extent->compress_type; 2872 if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) { 2873 BUG_ON(compress_type); 2874 ret = btrfs_mark_extent_written(trans, inode, 2875 ordered_extent->file_offset, 2876 ordered_extent->file_offset + 2877 logical_len); 2878 } else { 2879 BUG_ON(root == root->fs_info->tree_root); 2880 ret = insert_reserved_file_extent(trans, inode, 2881 ordered_extent->file_offset, 2882 ordered_extent->start, 2883 ordered_extent->disk_len, 2884 logical_len, logical_len, 2885 compress_type, 0, 0, 2886 BTRFS_FILE_EXTENT_REG); 2887 if (!ret) 2888 btrfs_release_delalloc_bytes(root, 2889 ordered_extent->start, 2890 ordered_extent->disk_len); 2891 } 2892 unpin_extent_cache(&BTRFS_I(inode)->extent_tree, 2893 ordered_extent->file_offset, ordered_extent->len, 2894 trans->transid); 2895 if (ret < 0) { 2896 btrfs_abort_transaction(trans, root, ret); 2897 goto out_unlock; 2898 } 2899 2900 add_pending_csums(trans, inode, ordered_extent->file_offset, 2901 &ordered_extent->list); 2902 2903 btrfs_ordered_update_i_size(inode, 0, ordered_extent); 2904 ret = btrfs_update_inode_fallback(trans, root, inode); 2905 if (ret) { /* -ENOMEM or corruption */ 2906 btrfs_abort_transaction(trans, root, ret); 2907 goto out_unlock; 2908 } 2909 ret = 0; 2910 out_unlock: 2911 unlock_extent_cached(io_tree, ordered_extent->file_offset, 2912 ordered_extent->file_offset + 2913 ordered_extent->len - 1, &cached_state, GFP_NOFS); 2914 out: 2915 if (root != root->fs_info->tree_root) 2916 btrfs_delalloc_release_metadata(inode, ordered_extent->len); 2917 if (trans) 2918 btrfs_end_transaction(trans, root); 2919 2920 if (ret || truncated) { 2921 u64 start, end; 2922 2923 if (truncated) 2924 start = ordered_extent->file_offset + logical_len; 2925 else 2926 start = ordered_extent->file_offset; 2927 end = ordered_extent->file_offset + ordered_extent->len - 1; 2928 clear_extent_uptodate(io_tree, start, end, NULL, GFP_NOFS); 2929 2930 /* Drop the cache for the part of the extent we didn't write. */ 2931 btrfs_drop_extent_cache(inode, start, end, 0); 2932 2933 /* 2934 * If the ordered extent had an IOERR or something else went 2935 * wrong we need to return the space for this ordered extent 2936 * back to the allocator. We only free the extent in the 2937 * truncated case if we didn't write out the extent at all. 2938 */ 2939 if ((ret || !logical_len) && 2940 !test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) && 2941 !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) 2942 btrfs_free_reserved_extent(root, ordered_extent->start, 2943 ordered_extent->disk_len, 1); 2944 } 2945 2946 2947 /* 2948 * This needs to be done to make sure anybody waiting knows we are done 2949 * updating everything for this ordered extent. 2950 */ 2951 btrfs_remove_ordered_extent(inode, ordered_extent); 2952 2953 /* for snapshot-aware defrag */ 2954 if (new) { 2955 if (ret) { 2956 free_sa_defrag_extent(new); 2957 atomic_dec(&root->fs_info->defrag_running); 2958 } else { 2959 relink_file_extents(new); 2960 } 2961 } 2962 2963 /* once for us */ 2964 btrfs_put_ordered_extent(ordered_extent); 2965 /* once for the tree */ 2966 btrfs_put_ordered_extent(ordered_extent); 2967 2968 return ret; 2969 } 2970 2971 static void finish_ordered_fn(struct btrfs_work *work) 2972 { 2973 struct btrfs_ordered_extent *ordered_extent; 2974 ordered_extent = container_of(work, struct btrfs_ordered_extent, work); 2975 btrfs_finish_ordered_io(ordered_extent); 2976 } 2977 2978 static int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end, 2979 struct extent_state *state, int uptodate) 2980 { 2981 struct inode *inode = page->mapping->host; 2982 struct btrfs_root *root = BTRFS_I(inode)->root; 2983 struct btrfs_ordered_extent *ordered_extent = NULL; 2984 struct btrfs_workqueue *wq; 2985 btrfs_work_func_t func; 2986 2987 trace_btrfs_writepage_end_io_hook(page, start, end, uptodate); 2988 2989 ClearPagePrivate2(page); 2990 if (!btrfs_dec_test_ordered_pending(inode, &ordered_extent, start, 2991 end - start + 1, uptodate)) 2992 return 0; 2993 2994 if (btrfs_is_free_space_inode(inode)) { 2995 wq = root->fs_info->endio_freespace_worker; 2996 func = btrfs_freespace_write_helper; 2997 } else { 2998 wq = root->fs_info->endio_write_workers; 2999 func = btrfs_endio_write_helper; 3000 } 3001 3002 btrfs_init_work(&ordered_extent->work, func, finish_ordered_fn, NULL, 3003 NULL); 3004 btrfs_queue_work(wq, &ordered_extent->work); 3005 3006 return 0; 3007 } 3008 3009 static int __readpage_endio_check(struct inode *inode, 3010 struct btrfs_io_bio *io_bio, 3011 int icsum, struct page *page, 3012 int pgoff, u64 start, size_t len) 3013 { 3014 char *kaddr; 3015 u32 csum_expected; 3016 u32 csum = ~(u32)0; 3017 static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL, 3018 DEFAULT_RATELIMIT_BURST); 3019 3020 csum_expected = *(((u32 *)io_bio->csum) + icsum); 3021 3022 kaddr = kmap_atomic(page); 3023 csum = btrfs_csum_data(kaddr + pgoff, csum, len); 3024 btrfs_csum_final(csum, (char *)&csum); 3025 if (csum != csum_expected) 3026 goto zeroit; 3027 3028 kunmap_atomic(kaddr); 3029 return 0; 3030 zeroit: 3031 if (__ratelimit(&_rs)) 3032 btrfs_warn(BTRFS_I(inode)->root->fs_info, 3033 "csum failed ino %llu off %llu csum %u expected csum %u", 3034 btrfs_ino(inode), start, csum, csum_expected); 3035 memset(kaddr + pgoff, 1, len); 3036 flush_dcache_page(page); 3037 kunmap_atomic(kaddr); 3038 if (csum_expected == 0) 3039 return 0; 3040 return -EIO; 3041 } 3042 3043 /* 3044 * when reads are done, we need to check csums to verify the data is correct 3045 * if there's a match, we allow the bio to finish. If not, the code in 3046 * extent_io.c will try to find good copies for us. 3047 */ 3048 static int btrfs_readpage_end_io_hook(struct btrfs_io_bio *io_bio, 3049 u64 phy_offset, struct page *page, 3050 u64 start, u64 end, int mirror) 3051 { 3052 size_t offset = start - page_offset(page); 3053 struct inode *inode = page->mapping->host; 3054 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 3055 struct btrfs_root *root = BTRFS_I(inode)->root; 3056 3057 if (PageChecked(page)) { 3058 ClearPageChecked(page); 3059 return 0; 3060 } 3061 3062 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM) 3063 return 0; 3064 3065 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID && 3066 test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) { 3067 clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM, 3068 GFP_NOFS); 3069 return 0; 3070 } 3071 3072 phy_offset >>= inode->i_sb->s_blocksize_bits; 3073 return __readpage_endio_check(inode, io_bio, phy_offset, page, offset, 3074 start, (size_t)(end - start + 1)); 3075 } 3076 3077 struct delayed_iput { 3078 struct list_head list; 3079 struct inode *inode; 3080 }; 3081 3082 /* JDM: If this is fs-wide, why can't we add a pointer to 3083 * btrfs_inode instead and avoid the allocation? */ 3084 void btrfs_add_delayed_iput(struct inode *inode) 3085 { 3086 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info; 3087 struct delayed_iput *delayed; 3088 3089 if (atomic_add_unless(&inode->i_count, -1, 1)) 3090 return; 3091 3092 delayed = kmalloc(sizeof(*delayed), GFP_NOFS | __GFP_NOFAIL); 3093 delayed->inode = inode; 3094 3095 spin_lock(&fs_info->delayed_iput_lock); 3096 list_add_tail(&delayed->list, &fs_info->delayed_iputs); 3097 spin_unlock(&fs_info->delayed_iput_lock); 3098 } 3099 3100 void btrfs_run_delayed_iputs(struct btrfs_root *root) 3101 { 3102 LIST_HEAD(list); 3103 struct btrfs_fs_info *fs_info = root->fs_info; 3104 struct delayed_iput *delayed; 3105 int empty; 3106 3107 spin_lock(&fs_info->delayed_iput_lock); 3108 empty = list_empty(&fs_info->delayed_iputs); 3109 spin_unlock(&fs_info->delayed_iput_lock); 3110 if (empty) 3111 return; 3112 3113 down_read(&fs_info->delayed_iput_sem); 3114 3115 spin_lock(&fs_info->delayed_iput_lock); 3116 list_splice_init(&fs_info->delayed_iputs, &list); 3117 spin_unlock(&fs_info->delayed_iput_lock); 3118 3119 while (!list_empty(&list)) { 3120 delayed = list_entry(list.next, struct delayed_iput, list); 3121 list_del(&delayed->list); 3122 iput(delayed->inode); 3123 kfree(delayed); 3124 } 3125 3126 up_read(&root->fs_info->delayed_iput_sem); 3127 } 3128 3129 /* 3130 * This is called in transaction commit time. If there are no orphan 3131 * files in the subvolume, it removes orphan item and frees block_rsv 3132 * structure. 3133 */ 3134 void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans, 3135 struct btrfs_root *root) 3136 { 3137 struct btrfs_block_rsv *block_rsv; 3138 int ret; 3139 3140 if (atomic_read(&root->orphan_inodes) || 3141 root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) 3142 return; 3143 3144 spin_lock(&root->orphan_lock); 3145 if (atomic_read(&root->orphan_inodes)) { 3146 spin_unlock(&root->orphan_lock); 3147 return; 3148 } 3149 3150 if (root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) { 3151 spin_unlock(&root->orphan_lock); 3152 return; 3153 } 3154 3155 block_rsv = root->orphan_block_rsv; 3156 root->orphan_block_rsv = NULL; 3157 spin_unlock(&root->orphan_lock); 3158 3159 if (test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state) && 3160 btrfs_root_refs(&root->root_item) > 0) { 3161 ret = btrfs_del_orphan_item(trans, root->fs_info->tree_root, 3162 root->root_key.objectid); 3163 if (ret) 3164 btrfs_abort_transaction(trans, root, ret); 3165 else 3166 clear_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, 3167 &root->state); 3168 } 3169 3170 if (block_rsv) { 3171 WARN_ON(block_rsv->size > 0); 3172 btrfs_free_block_rsv(root, block_rsv); 3173 } 3174 } 3175 3176 /* 3177 * This creates an orphan entry for the given inode in case something goes 3178 * wrong in the middle of an unlink/truncate. 3179 * 3180 * NOTE: caller of this function should reserve 5 units of metadata for 3181 * this function. 3182 */ 3183 int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode) 3184 { 3185 struct btrfs_root *root = BTRFS_I(inode)->root; 3186 struct btrfs_block_rsv *block_rsv = NULL; 3187 int reserve = 0; 3188 int insert = 0; 3189 int ret; 3190 3191 if (!root->orphan_block_rsv) { 3192 block_rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP); 3193 if (!block_rsv) 3194 return -ENOMEM; 3195 } 3196 3197 spin_lock(&root->orphan_lock); 3198 if (!root->orphan_block_rsv) { 3199 root->orphan_block_rsv = block_rsv; 3200 } else if (block_rsv) { 3201 btrfs_free_block_rsv(root, block_rsv); 3202 block_rsv = NULL; 3203 } 3204 3205 if (!test_and_set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM, 3206 &BTRFS_I(inode)->runtime_flags)) { 3207 #if 0 3208 /* 3209 * For proper ENOSPC handling, we should do orphan 3210 * cleanup when mounting. But this introduces backward 3211 * compatibility issue. 3212 */ 3213 if (!xchg(&root->orphan_item_inserted, 1)) 3214 insert = 2; 3215 else 3216 insert = 1; 3217 #endif 3218 insert = 1; 3219 atomic_inc(&root->orphan_inodes); 3220 } 3221 3222 if (!test_and_set_bit(BTRFS_INODE_ORPHAN_META_RESERVED, 3223 &BTRFS_I(inode)->runtime_flags)) 3224 reserve = 1; 3225 spin_unlock(&root->orphan_lock); 3226 3227 /* grab metadata reservation from transaction handle */ 3228 if (reserve) { 3229 ret = btrfs_orphan_reserve_metadata(trans, inode); 3230 BUG_ON(ret); /* -ENOSPC in reservation; Logic error? JDM */ 3231 } 3232 3233 /* insert an orphan item to track this unlinked/truncated file */ 3234 if (insert >= 1) { 3235 ret = btrfs_insert_orphan_item(trans, root, btrfs_ino(inode)); 3236 if (ret) { 3237 atomic_dec(&root->orphan_inodes); 3238 if (reserve) { 3239 clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED, 3240 &BTRFS_I(inode)->runtime_flags); 3241 btrfs_orphan_release_metadata(inode); 3242 } 3243 if (ret != -EEXIST) { 3244 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM, 3245 &BTRFS_I(inode)->runtime_flags); 3246 btrfs_abort_transaction(trans, root, ret); 3247 return ret; 3248 } 3249 } 3250 ret = 0; 3251 } 3252 3253 /* insert an orphan item to track subvolume contains orphan files */ 3254 if (insert >= 2) { 3255 ret = btrfs_insert_orphan_item(trans, root->fs_info->tree_root, 3256 root->root_key.objectid); 3257 if (ret && ret != -EEXIST) { 3258 btrfs_abort_transaction(trans, root, ret); 3259 return ret; 3260 } 3261 } 3262 return 0; 3263 } 3264 3265 /* 3266 * We have done the truncate/delete so we can go ahead and remove the orphan 3267 * item for this particular inode. 3268 */ 3269 static int btrfs_orphan_del(struct btrfs_trans_handle *trans, 3270 struct inode *inode) 3271 { 3272 struct btrfs_root *root = BTRFS_I(inode)->root; 3273 int delete_item = 0; 3274 int release_rsv = 0; 3275 int ret = 0; 3276 3277 spin_lock(&root->orphan_lock); 3278 if (test_and_clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM, 3279 &BTRFS_I(inode)->runtime_flags)) 3280 delete_item = 1; 3281 3282 if (test_and_clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED, 3283 &BTRFS_I(inode)->runtime_flags)) 3284 release_rsv = 1; 3285 spin_unlock(&root->orphan_lock); 3286 3287 if (delete_item) { 3288 atomic_dec(&root->orphan_inodes); 3289 if (trans) 3290 ret = btrfs_del_orphan_item(trans, root, 3291 btrfs_ino(inode)); 3292 } 3293 3294 if (release_rsv) 3295 btrfs_orphan_release_metadata(inode); 3296 3297 return ret; 3298 } 3299 3300 /* 3301 * this cleans up any orphans that may be left on the list from the last use 3302 * of this root. 3303 */ 3304 int btrfs_orphan_cleanup(struct btrfs_root *root) 3305 { 3306 struct btrfs_path *path; 3307 struct extent_buffer *leaf; 3308 struct btrfs_key key, found_key; 3309 struct btrfs_trans_handle *trans; 3310 struct inode *inode; 3311 u64 last_objectid = 0; 3312 int ret = 0, nr_unlink = 0, nr_truncate = 0; 3313 3314 if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED)) 3315 return 0; 3316 3317 path = btrfs_alloc_path(); 3318 if (!path) { 3319 ret = -ENOMEM; 3320 goto out; 3321 } 3322 path->reada = -1; 3323 3324 key.objectid = BTRFS_ORPHAN_OBJECTID; 3325 key.type = BTRFS_ORPHAN_ITEM_KEY; 3326 key.offset = (u64)-1; 3327 3328 while (1) { 3329 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 3330 if (ret < 0) 3331 goto out; 3332 3333 /* 3334 * if ret == 0 means we found what we were searching for, which 3335 * is weird, but possible, so only screw with path if we didn't 3336 * find the key and see if we have stuff that matches 3337 */ 3338 if (ret > 0) { 3339 ret = 0; 3340 if (path->slots[0] == 0) 3341 break; 3342 path->slots[0]--; 3343 } 3344 3345 /* pull out the item */ 3346 leaf = path->nodes[0]; 3347 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 3348 3349 /* make sure the item matches what we want */ 3350 if (found_key.objectid != BTRFS_ORPHAN_OBJECTID) 3351 break; 3352 if (found_key.type != BTRFS_ORPHAN_ITEM_KEY) 3353 break; 3354 3355 /* release the path since we're done with it */ 3356 btrfs_release_path(path); 3357 3358 /* 3359 * this is where we are basically btrfs_lookup, without the 3360 * crossing root thing. we store the inode number in the 3361 * offset of the orphan item. 3362 */ 3363 3364 if (found_key.offset == last_objectid) { 3365 btrfs_err(root->fs_info, 3366 "Error removing orphan entry, stopping orphan cleanup"); 3367 ret = -EINVAL; 3368 goto out; 3369 } 3370 3371 last_objectid = found_key.offset; 3372 3373 found_key.objectid = found_key.offset; 3374 found_key.type = BTRFS_INODE_ITEM_KEY; 3375 found_key.offset = 0; 3376 inode = btrfs_iget(root->fs_info->sb, &found_key, root, NULL); 3377 ret = PTR_ERR_OR_ZERO(inode); 3378 if (ret && ret != -ESTALE) 3379 goto out; 3380 3381 if (ret == -ESTALE && root == root->fs_info->tree_root) { 3382 struct btrfs_root *dead_root; 3383 struct btrfs_fs_info *fs_info = root->fs_info; 3384 int is_dead_root = 0; 3385 3386 /* 3387 * this is an orphan in the tree root. Currently these 3388 * could come from 2 sources: 3389 * a) a snapshot deletion in progress 3390 * b) a free space cache inode 3391 * We need to distinguish those two, as the snapshot 3392 * orphan must not get deleted. 3393 * find_dead_roots already ran before us, so if this 3394 * is a snapshot deletion, we should find the root 3395 * in the dead_roots list 3396 */ 3397 spin_lock(&fs_info->trans_lock); 3398 list_for_each_entry(dead_root, &fs_info->dead_roots, 3399 root_list) { 3400 if (dead_root->root_key.objectid == 3401 found_key.objectid) { 3402 is_dead_root = 1; 3403 break; 3404 } 3405 } 3406 spin_unlock(&fs_info->trans_lock); 3407 if (is_dead_root) { 3408 /* prevent this orphan from being found again */ 3409 key.offset = found_key.objectid - 1; 3410 continue; 3411 } 3412 } 3413 /* 3414 * Inode is already gone but the orphan item is still there, 3415 * kill the orphan item. 3416 */ 3417 if (ret == -ESTALE) { 3418 trans = btrfs_start_transaction(root, 1); 3419 if (IS_ERR(trans)) { 3420 ret = PTR_ERR(trans); 3421 goto out; 3422 } 3423 btrfs_debug(root->fs_info, "auto deleting %Lu", 3424 found_key.objectid); 3425 ret = btrfs_del_orphan_item(trans, root, 3426 found_key.objectid); 3427 btrfs_end_transaction(trans, root); 3428 if (ret) 3429 goto out; 3430 continue; 3431 } 3432 3433 /* 3434 * add this inode to the orphan list so btrfs_orphan_del does 3435 * the proper thing when we hit it 3436 */ 3437 set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM, 3438 &BTRFS_I(inode)->runtime_flags); 3439 atomic_inc(&root->orphan_inodes); 3440 3441 /* if we have links, this was a truncate, lets do that */ 3442 if (inode->i_nlink) { 3443 if (WARN_ON(!S_ISREG(inode->i_mode))) { 3444 iput(inode); 3445 continue; 3446 } 3447 nr_truncate++; 3448 3449 /* 1 for the orphan item deletion. */ 3450 trans = btrfs_start_transaction(root, 1); 3451 if (IS_ERR(trans)) { 3452 iput(inode); 3453 ret = PTR_ERR(trans); 3454 goto out; 3455 } 3456 ret = btrfs_orphan_add(trans, inode); 3457 btrfs_end_transaction(trans, root); 3458 if (ret) { 3459 iput(inode); 3460 goto out; 3461 } 3462 3463 ret = btrfs_truncate(inode); 3464 if (ret) 3465 btrfs_orphan_del(NULL, inode); 3466 } else { 3467 nr_unlink++; 3468 } 3469 3470 /* this will do delete_inode and everything for us */ 3471 iput(inode); 3472 if (ret) 3473 goto out; 3474 } 3475 /* release the path since we're done with it */ 3476 btrfs_release_path(path); 3477 3478 root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE; 3479 3480 if (root->orphan_block_rsv) 3481 btrfs_block_rsv_release(root, root->orphan_block_rsv, 3482 (u64)-1); 3483 3484 if (root->orphan_block_rsv || 3485 test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state)) { 3486 trans = btrfs_join_transaction(root); 3487 if (!IS_ERR(trans)) 3488 btrfs_end_transaction(trans, root); 3489 } 3490 3491 if (nr_unlink) 3492 btrfs_debug(root->fs_info, "unlinked %d orphans", nr_unlink); 3493 if (nr_truncate) 3494 btrfs_debug(root->fs_info, "truncated %d orphans", nr_truncate); 3495 3496 out: 3497 if (ret) 3498 btrfs_err(root->fs_info, 3499 "could not do orphan cleanup %d", ret); 3500 btrfs_free_path(path); 3501 return ret; 3502 } 3503 3504 /* 3505 * very simple check to peek ahead in the leaf looking for xattrs. If we 3506 * don't find any xattrs, we know there can't be any acls. 3507 * 3508 * slot is the slot the inode is in, objectid is the objectid of the inode 3509 */ 3510 static noinline int acls_after_inode_item(struct extent_buffer *leaf, 3511 int slot, u64 objectid, 3512 int *first_xattr_slot) 3513 { 3514 u32 nritems = btrfs_header_nritems(leaf); 3515 struct btrfs_key found_key; 3516 static u64 xattr_access = 0; 3517 static u64 xattr_default = 0; 3518 int scanned = 0; 3519 3520 if (!xattr_access) { 3521 xattr_access = btrfs_name_hash(POSIX_ACL_XATTR_ACCESS, 3522 strlen(POSIX_ACL_XATTR_ACCESS)); 3523 xattr_default = btrfs_name_hash(POSIX_ACL_XATTR_DEFAULT, 3524 strlen(POSIX_ACL_XATTR_DEFAULT)); 3525 } 3526 3527 slot++; 3528 *first_xattr_slot = -1; 3529 while (slot < nritems) { 3530 btrfs_item_key_to_cpu(leaf, &found_key, slot); 3531 3532 /* we found a different objectid, there must not be acls */ 3533 if (found_key.objectid != objectid) 3534 return 0; 3535 3536 /* we found an xattr, assume we've got an acl */ 3537 if (found_key.type == BTRFS_XATTR_ITEM_KEY) { 3538 if (*first_xattr_slot == -1) 3539 *first_xattr_slot = slot; 3540 if (found_key.offset == xattr_access || 3541 found_key.offset == xattr_default) 3542 return 1; 3543 } 3544 3545 /* 3546 * we found a key greater than an xattr key, there can't 3547 * be any acls later on 3548 */ 3549 if (found_key.type > BTRFS_XATTR_ITEM_KEY) 3550 return 0; 3551 3552 slot++; 3553 scanned++; 3554 3555 /* 3556 * it goes inode, inode backrefs, xattrs, extents, 3557 * so if there are a ton of hard links to an inode there can 3558 * be a lot of backrefs. Don't waste time searching too hard, 3559 * this is just an optimization 3560 */ 3561 if (scanned >= 8) 3562 break; 3563 } 3564 /* we hit the end of the leaf before we found an xattr or 3565 * something larger than an xattr. We have to assume the inode 3566 * has acls 3567 */ 3568 if (*first_xattr_slot == -1) 3569 *first_xattr_slot = slot; 3570 return 1; 3571 } 3572 3573 /* 3574 * read an inode from the btree into the in-memory inode 3575 */ 3576 static void btrfs_read_locked_inode(struct inode *inode) 3577 { 3578 struct btrfs_path *path; 3579 struct extent_buffer *leaf; 3580 struct btrfs_inode_item *inode_item; 3581 struct btrfs_root *root = BTRFS_I(inode)->root; 3582 struct btrfs_key location; 3583 unsigned long ptr; 3584 int maybe_acls; 3585 u32 rdev; 3586 int ret; 3587 bool filled = false; 3588 int first_xattr_slot; 3589 3590 ret = btrfs_fill_inode(inode, &rdev); 3591 if (!ret) 3592 filled = true; 3593 3594 path = btrfs_alloc_path(); 3595 if (!path) 3596 goto make_bad; 3597 3598 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location)); 3599 3600 ret = btrfs_lookup_inode(NULL, root, path, &location, 0); 3601 if (ret) 3602 goto make_bad; 3603 3604 leaf = path->nodes[0]; 3605 3606 if (filled) 3607 goto cache_index; 3608 3609 inode_item = btrfs_item_ptr(leaf, path->slots[0], 3610 struct btrfs_inode_item); 3611 inode->i_mode = btrfs_inode_mode(leaf, inode_item); 3612 set_nlink(inode, btrfs_inode_nlink(leaf, inode_item)); 3613 i_uid_write(inode, btrfs_inode_uid(leaf, inode_item)); 3614 i_gid_write(inode, btrfs_inode_gid(leaf, inode_item)); 3615 btrfs_i_size_write(inode, btrfs_inode_size(leaf, inode_item)); 3616 3617 inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->atime); 3618 inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->atime); 3619 3620 inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->mtime); 3621 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->mtime); 3622 3623 inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->ctime); 3624 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->ctime); 3625 3626 BTRFS_I(inode)->i_otime.tv_sec = 3627 btrfs_timespec_sec(leaf, &inode_item->otime); 3628 BTRFS_I(inode)->i_otime.tv_nsec = 3629 btrfs_timespec_nsec(leaf, &inode_item->otime); 3630 3631 inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item)); 3632 BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item); 3633 BTRFS_I(inode)->last_trans = btrfs_inode_transid(leaf, inode_item); 3634 3635 inode->i_version = btrfs_inode_sequence(leaf, inode_item); 3636 inode->i_generation = BTRFS_I(inode)->generation; 3637 inode->i_rdev = 0; 3638 rdev = btrfs_inode_rdev(leaf, inode_item); 3639 3640 BTRFS_I(inode)->index_cnt = (u64)-1; 3641 BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item); 3642 3643 cache_index: 3644 /* 3645 * If we were modified in the current generation and evicted from memory 3646 * and then re-read we need to do a full sync since we don't have any 3647 * idea about which extents were modified before we were evicted from 3648 * cache. 3649 * 3650 * This is required for both inode re-read from disk and delayed inode 3651 * in delayed_nodes_tree. 3652 */ 3653 if (BTRFS_I(inode)->last_trans == root->fs_info->generation) 3654 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, 3655 &BTRFS_I(inode)->runtime_flags); 3656 3657 path->slots[0]++; 3658 if (inode->i_nlink != 1 || 3659 path->slots[0] >= btrfs_header_nritems(leaf)) 3660 goto cache_acl; 3661 3662 btrfs_item_key_to_cpu(leaf, &location, path->slots[0]); 3663 if (location.objectid != btrfs_ino(inode)) 3664 goto cache_acl; 3665 3666 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); 3667 if (location.type == BTRFS_INODE_REF_KEY) { 3668 struct btrfs_inode_ref *ref; 3669 3670 ref = (struct btrfs_inode_ref *)ptr; 3671 BTRFS_I(inode)->dir_index = btrfs_inode_ref_index(leaf, ref); 3672 } else if (location.type == BTRFS_INODE_EXTREF_KEY) { 3673 struct btrfs_inode_extref *extref; 3674 3675 extref = (struct btrfs_inode_extref *)ptr; 3676 BTRFS_I(inode)->dir_index = btrfs_inode_extref_index(leaf, 3677 extref); 3678 } 3679 cache_acl: 3680 /* 3681 * try to precache a NULL acl entry for files that don't have 3682 * any xattrs or acls 3683 */ 3684 maybe_acls = acls_after_inode_item(leaf, path->slots[0], 3685 btrfs_ino(inode), &first_xattr_slot); 3686 if (first_xattr_slot != -1) { 3687 path->slots[0] = first_xattr_slot; 3688 ret = btrfs_load_inode_props(inode, path); 3689 if (ret) 3690 btrfs_err(root->fs_info, 3691 "error loading props for ino %llu (root %llu): %d", 3692 btrfs_ino(inode), 3693 root->root_key.objectid, ret); 3694 } 3695 btrfs_free_path(path); 3696 3697 if (!maybe_acls) 3698 cache_no_acl(inode); 3699 3700 switch (inode->i_mode & S_IFMT) { 3701 case S_IFREG: 3702 inode->i_mapping->a_ops = &btrfs_aops; 3703 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops; 3704 inode->i_fop = &btrfs_file_operations; 3705 inode->i_op = &btrfs_file_inode_operations; 3706 break; 3707 case S_IFDIR: 3708 inode->i_fop = &btrfs_dir_file_operations; 3709 if (root == root->fs_info->tree_root) 3710 inode->i_op = &btrfs_dir_ro_inode_operations; 3711 else 3712 inode->i_op = &btrfs_dir_inode_operations; 3713 break; 3714 case S_IFLNK: 3715 inode->i_op = &btrfs_symlink_inode_operations; 3716 inode->i_mapping->a_ops = &btrfs_symlink_aops; 3717 break; 3718 default: 3719 inode->i_op = &btrfs_special_inode_operations; 3720 init_special_inode(inode, inode->i_mode, rdev); 3721 break; 3722 } 3723 3724 btrfs_update_iflags(inode); 3725 return; 3726 3727 make_bad: 3728 btrfs_free_path(path); 3729 make_bad_inode(inode); 3730 } 3731 3732 /* 3733 * given a leaf and an inode, copy the inode fields into the leaf 3734 */ 3735 static void fill_inode_item(struct btrfs_trans_handle *trans, 3736 struct extent_buffer *leaf, 3737 struct btrfs_inode_item *item, 3738 struct inode *inode) 3739 { 3740 struct btrfs_map_token token; 3741 3742 btrfs_init_map_token(&token); 3743 3744 btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token); 3745 btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token); 3746 btrfs_set_token_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size, 3747 &token); 3748 btrfs_set_token_inode_mode(leaf, item, inode->i_mode, &token); 3749 btrfs_set_token_inode_nlink(leaf, item, inode->i_nlink, &token); 3750 3751 btrfs_set_token_timespec_sec(leaf, &item->atime, 3752 inode->i_atime.tv_sec, &token); 3753 btrfs_set_token_timespec_nsec(leaf, &item->atime, 3754 inode->i_atime.tv_nsec, &token); 3755 3756 btrfs_set_token_timespec_sec(leaf, &item->mtime, 3757 inode->i_mtime.tv_sec, &token); 3758 btrfs_set_token_timespec_nsec(leaf, &item->mtime, 3759 inode->i_mtime.tv_nsec, &token); 3760 3761 btrfs_set_token_timespec_sec(leaf, &item->ctime, 3762 inode->i_ctime.tv_sec, &token); 3763 btrfs_set_token_timespec_nsec(leaf, &item->ctime, 3764 inode->i_ctime.tv_nsec, &token); 3765 3766 btrfs_set_token_timespec_sec(leaf, &item->otime, 3767 BTRFS_I(inode)->i_otime.tv_sec, &token); 3768 btrfs_set_token_timespec_nsec(leaf, &item->otime, 3769 BTRFS_I(inode)->i_otime.tv_nsec, &token); 3770 3771 btrfs_set_token_inode_nbytes(leaf, item, inode_get_bytes(inode), 3772 &token); 3773 btrfs_set_token_inode_generation(leaf, item, BTRFS_I(inode)->generation, 3774 &token); 3775 btrfs_set_token_inode_sequence(leaf, item, inode->i_version, &token); 3776 btrfs_set_token_inode_transid(leaf, item, trans->transid, &token); 3777 btrfs_set_token_inode_rdev(leaf, item, inode->i_rdev, &token); 3778 btrfs_set_token_inode_flags(leaf, item, BTRFS_I(inode)->flags, &token); 3779 btrfs_set_token_inode_block_group(leaf, item, 0, &token); 3780 } 3781 3782 /* 3783 * copy everything in the in-memory inode into the btree. 3784 */ 3785 static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans, 3786 struct btrfs_root *root, struct inode *inode) 3787 { 3788 struct btrfs_inode_item *inode_item; 3789 struct btrfs_path *path; 3790 struct extent_buffer *leaf; 3791 int ret; 3792 3793 path = btrfs_alloc_path(); 3794 if (!path) 3795 return -ENOMEM; 3796 3797 path->leave_spinning = 1; 3798 ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location, 3799 1); 3800 if (ret) { 3801 if (ret > 0) 3802 ret = -ENOENT; 3803 goto failed; 3804 } 3805 3806 leaf = path->nodes[0]; 3807 inode_item = btrfs_item_ptr(leaf, path->slots[0], 3808 struct btrfs_inode_item); 3809 3810 fill_inode_item(trans, leaf, inode_item, inode); 3811 btrfs_mark_buffer_dirty(leaf); 3812 btrfs_set_inode_last_trans(trans, inode); 3813 ret = 0; 3814 failed: 3815 btrfs_free_path(path); 3816 return ret; 3817 } 3818 3819 /* 3820 * copy everything in the in-memory inode into the btree. 3821 */ 3822 noinline int btrfs_update_inode(struct btrfs_trans_handle *trans, 3823 struct btrfs_root *root, struct inode *inode) 3824 { 3825 int ret; 3826 3827 /* 3828 * If the inode is a free space inode, we can deadlock during commit 3829 * if we put it into the delayed code. 3830 * 3831 * The data relocation inode should also be directly updated 3832 * without delay 3833 */ 3834 if (!btrfs_is_free_space_inode(inode) 3835 && root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID 3836 && !root->fs_info->log_root_recovering) { 3837 btrfs_update_root_times(trans, root); 3838 3839 ret = btrfs_delayed_update_inode(trans, root, inode); 3840 if (!ret) 3841 btrfs_set_inode_last_trans(trans, inode); 3842 return ret; 3843 } 3844 3845 return btrfs_update_inode_item(trans, root, inode); 3846 } 3847 3848 noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans, 3849 struct btrfs_root *root, 3850 struct inode *inode) 3851 { 3852 int ret; 3853 3854 ret = btrfs_update_inode(trans, root, inode); 3855 if (ret == -ENOSPC) 3856 return btrfs_update_inode_item(trans, root, inode); 3857 return ret; 3858 } 3859 3860 /* 3861 * unlink helper that gets used here in inode.c and in the tree logging 3862 * recovery code. It remove a link in a directory with a given name, and 3863 * also drops the back refs in the inode to the directory 3864 */ 3865 static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans, 3866 struct btrfs_root *root, 3867 struct inode *dir, struct inode *inode, 3868 const char *name, int name_len) 3869 { 3870 struct btrfs_path *path; 3871 int ret = 0; 3872 struct extent_buffer *leaf; 3873 struct btrfs_dir_item *di; 3874 struct btrfs_key key; 3875 u64 index; 3876 u64 ino = btrfs_ino(inode); 3877 u64 dir_ino = btrfs_ino(dir); 3878 3879 path = btrfs_alloc_path(); 3880 if (!path) { 3881 ret = -ENOMEM; 3882 goto out; 3883 } 3884 3885 path->leave_spinning = 1; 3886 di = btrfs_lookup_dir_item(trans, root, path, dir_ino, 3887 name, name_len, -1); 3888 if (IS_ERR(di)) { 3889 ret = PTR_ERR(di); 3890 goto err; 3891 } 3892 if (!di) { 3893 ret = -ENOENT; 3894 goto err; 3895 } 3896 leaf = path->nodes[0]; 3897 btrfs_dir_item_key_to_cpu(leaf, di, &key); 3898 ret = btrfs_delete_one_dir_name(trans, root, path, di); 3899 if (ret) 3900 goto err; 3901 btrfs_release_path(path); 3902 3903 /* 3904 * If we don't have dir index, we have to get it by looking up 3905 * the inode ref, since we get the inode ref, remove it directly, 3906 * it is unnecessary to do delayed deletion. 3907 * 3908 * But if we have dir index, needn't search inode ref to get it. 3909 * Since the inode ref is close to the inode item, it is better 3910 * that we delay to delete it, and just do this deletion when 3911 * we update the inode item. 3912 */ 3913 if (BTRFS_I(inode)->dir_index) { 3914 ret = btrfs_delayed_delete_inode_ref(inode); 3915 if (!ret) { 3916 index = BTRFS_I(inode)->dir_index; 3917 goto skip_backref; 3918 } 3919 } 3920 3921 ret = btrfs_del_inode_ref(trans, root, name, name_len, ino, 3922 dir_ino, &index); 3923 if (ret) { 3924 btrfs_info(root->fs_info, 3925 "failed to delete reference to %.*s, inode %llu parent %llu", 3926 name_len, name, ino, dir_ino); 3927 btrfs_abort_transaction(trans, root, ret); 3928 goto err; 3929 } 3930 skip_backref: 3931 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index); 3932 if (ret) { 3933 btrfs_abort_transaction(trans, root, ret); 3934 goto err; 3935 } 3936 3937 ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len, 3938 inode, dir_ino); 3939 if (ret != 0 && ret != -ENOENT) { 3940 btrfs_abort_transaction(trans, root, ret); 3941 goto err; 3942 } 3943 3944 ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len, 3945 dir, index); 3946 if (ret == -ENOENT) 3947 ret = 0; 3948 else if (ret) 3949 btrfs_abort_transaction(trans, root, ret); 3950 err: 3951 btrfs_free_path(path); 3952 if (ret) 3953 goto out; 3954 3955 btrfs_i_size_write(dir, dir->i_size - name_len * 2); 3956 inode_inc_iversion(inode); 3957 inode_inc_iversion(dir); 3958 inode->i_ctime = dir->i_mtime = dir->i_ctime = CURRENT_TIME; 3959 ret = btrfs_update_inode(trans, root, dir); 3960 out: 3961 return ret; 3962 } 3963 3964 int btrfs_unlink_inode(struct btrfs_trans_handle *trans, 3965 struct btrfs_root *root, 3966 struct inode *dir, struct inode *inode, 3967 const char *name, int name_len) 3968 { 3969 int ret; 3970 ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len); 3971 if (!ret) { 3972 drop_nlink(inode); 3973 ret = btrfs_update_inode(trans, root, inode); 3974 } 3975 return ret; 3976 } 3977 3978 /* 3979 * helper to start transaction for unlink and rmdir. 3980 * 3981 * unlink and rmdir are special in btrfs, they do not always free space, so 3982 * if we cannot make our reservations the normal way try and see if there is 3983 * plenty of slack room in the global reserve to migrate, otherwise we cannot 3984 * allow the unlink to occur. 3985 */ 3986 static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir) 3987 { 3988 struct btrfs_trans_handle *trans; 3989 struct btrfs_root *root = BTRFS_I(dir)->root; 3990 int ret; 3991 3992 /* 3993 * 1 for the possible orphan item 3994 * 1 for the dir item 3995 * 1 for the dir index 3996 * 1 for the inode ref 3997 * 1 for the inode 3998 */ 3999 trans = btrfs_start_transaction(root, 5); 4000 if (!IS_ERR(trans) || PTR_ERR(trans) != -ENOSPC) 4001 return trans; 4002 4003 if (PTR_ERR(trans) == -ENOSPC) { 4004 u64 num_bytes = btrfs_calc_trans_metadata_size(root, 5); 4005 4006 trans = btrfs_start_transaction(root, 0); 4007 if (IS_ERR(trans)) 4008 return trans; 4009 ret = btrfs_cond_migrate_bytes(root->fs_info, 4010 &root->fs_info->trans_block_rsv, 4011 num_bytes, 5); 4012 if (ret) { 4013 btrfs_end_transaction(trans, root); 4014 return ERR_PTR(ret); 4015 } 4016 trans->block_rsv = &root->fs_info->trans_block_rsv; 4017 trans->bytes_reserved = num_bytes; 4018 } 4019 return trans; 4020 } 4021 4022 static int btrfs_unlink(struct inode *dir, struct dentry *dentry) 4023 { 4024 struct btrfs_root *root = BTRFS_I(dir)->root; 4025 struct btrfs_trans_handle *trans; 4026 struct inode *inode = d_inode(dentry); 4027 int ret; 4028 4029 trans = __unlink_start_trans(dir); 4030 if (IS_ERR(trans)) 4031 return PTR_ERR(trans); 4032 4033 btrfs_record_unlink_dir(trans, dir, d_inode(dentry), 0); 4034 4035 ret = btrfs_unlink_inode(trans, root, dir, d_inode(dentry), 4036 dentry->d_name.name, dentry->d_name.len); 4037 if (ret) 4038 goto out; 4039 4040 if (inode->i_nlink == 0) { 4041 ret = btrfs_orphan_add(trans, inode); 4042 if (ret) 4043 goto out; 4044 } 4045 4046 out: 4047 btrfs_end_transaction(trans, root); 4048 btrfs_btree_balance_dirty(root); 4049 return ret; 4050 } 4051 4052 int btrfs_unlink_subvol(struct btrfs_trans_handle *trans, 4053 struct btrfs_root *root, 4054 struct inode *dir, u64 objectid, 4055 const char *name, int name_len) 4056 { 4057 struct btrfs_path *path; 4058 struct extent_buffer *leaf; 4059 struct btrfs_dir_item *di; 4060 struct btrfs_key key; 4061 u64 index; 4062 int ret; 4063 u64 dir_ino = btrfs_ino(dir); 4064 4065 path = btrfs_alloc_path(); 4066 if (!path) 4067 return -ENOMEM; 4068 4069 di = btrfs_lookup_dir_item(trans, root, path, dir_ino, 4070 name, name_len, -1); 4071 if (IS_ERR_OR_NULL(di)) { 4072 if (!di) 4073 ret = -ENOENT; 4074 else 4075 ret = PTR_ERR(di); 4076 goto out; 4077 } 4078 4079 leaf = path->nodes[0]; 4080 btrfs_dir_item_key_to_cpu(leaf, di, &key); 4081 WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid); 4082 ret = btrfs_delete_one_dir_name(trans, root, path, di); 4083 if (ret) { 4084 btrfs_abort_transaction(trans, root, ret); 4085 goto out; 4086 } 4087 btrfs_release_path(path); 4088 4089 ret = btrfs_del_root_ref(trans, root->fs_info->tree_root, 4090 objectid, root->root_key.objectid, 4091 dir_ino, &index, name, name_len); 4092 if (ret < 0) { 4093 if (ret != -ENOENT) { 4094 btrfs_abort_transaction(trans, root, ret); 4095 goto out; 4096 } 4097 di = btrfs_search_dir_index_item(root, path, dir_ino, 4098 name, name_len); 4099 if (IS_ERR_OR_NULL(di)) { 4100 if (!di) 4101 ret = -ENOENT; 4102 else 4103 ret = PTR_ERR(di); 4104 btrfs_abort_transaction(trans, root, ret); 4105 goto out; 4106 } 4107 4108 leaf = path->nodes[0]; 4109 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); 4110 btrfs_release_path(path); 4111 index = key.offset; 4112 } 4113 btrfs_release_path(path); 4114 4115 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index); 4116 if (ret) { 4117 btrfs_abort_transaction(trans, root, ret); 4118 goto out; 4119 } 4120 4121 btrfs_i_size_write(dir, dir->i_size - name_len * 2); 4122 inode_inc_iversion(dir); 4123 dir->i_mtime = dir->i_ctime = CURRENT_TIME; 4124 ret = btrfs_update_inode_fallback(trans, root, dir); 4125 if (ret) 4126 btrfs_abort_transaction(trans, root, ret); 4127 out: 4128 btrfs_free_path(path); 4129 return ret; 4130 } 4131 4132 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry) 4133 { 4134 struct inode *inode = d_inode(dentry); 4135 int err = 0; 4136 struct btrfs_root *root = BTRFS_I(dir)->root; 4137 struct btrfs_trans_handle *trans; 4138 4139 if (inode->i_size > BTRFS_EMPTY_DIR_SIZE) 4140 return -ENOTEMPTY; 4141 if (btrfs_ino(inode) == BTRFS_FIRST_FREE_OBJECTID) 4142 return -EPERM; 4143 4144 trans = __unlink_start_trans(dir); 4145 if (IS_ERR(trans)) 4146 return PTR_ERR(trans); 4147 4148 if (unlikely(btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) { 4149 err = btrfs_unlink_subvol(trans, root, dir, 4150 BTRFS_I(inode)->location.objectid, 4151 dentry->d_name.name, 4152 dentry->d_name.len); 4153 goto out; 4154 } 4155 4156 err = btrfs_orphan_add(trans, inode); 4157 if (err) 4158 goto out; 4159 4160 /* now the directory is empty */ 4161 err = btrfs_unlink_inode(trans, root, dir, d_inode(dentry), 4162 dentry->d_name.name, dentry->d_name.len); 4163 if (!err) 4164 btrfs_i_size_write(inode, 0); 4165 out: 4166 btrfs_end_transaction(trans, root); 4167 btrfs_btree_balance_dirty(root); 4168 4169 return err; 4170 } 4171 4172 static int truncate_space_check(struct btrfs_trans_handle *trans, 4173 struct btrfs_root *root, 4174 u64 bytes_deleted) 4175 { 4176 int ret; 4177 4178 bytes_deleted = btrfs_csum_bytes_to_leaves(root, bytes_deleted); 4179 ret = btrfs_block_rsv_add(root, &root->fs_info->trans_block_rsv, 4180 bytes_deleted, BTRFS_RESERVE_NO_FLUSH); 4181 if (!ret) 4182 trans->bytes_reserved += bytes_deleted; 4183 return ret; 4184 4185 } 4186 4187 /* 4188 * this can truncate away extent items, csum items and directory items. 4189 * It starts at a high offset and removes keys until it can't find 4190 * any higher than new_size 4191 * 4192 * csum items that cross the new i_size are truncated to the new size 4193 * as well. 4194 * 4195 * min_type is the minimum key type to truncate down to. If set to 0, this 4196 * will kill all the items on this inode, including the INODE_ITEM_KEY. 4197 */ 4198 int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans, 4199 struct btrfs_root *root, 4200 struct inode *inode, 4201 u64 new_size, u32 min_type) 4202 { 4203 struct btrfs_path *path; 4204 struct extent_buffer *leaf; 4205 struct btrfs_file_extent_item *fi; 4206 struct btrfs_key key; 4207 struct btrfs_key found_key; 4208 u64 extent_start = 0; 4209 u64 extent_num_bytes = 0; 4210 u64 extent_offset = 0; 4211 u64 item_end = 0; 4212 u64 last_size = (u64)-1; 4213 u32 found_type = (u8)-1; 4214 int found_extent; 4215 int del_item; 4216 int pending_del_nr = 0; 4217 int pending_del_slot = 0; 4218 int extent_type = -1; 4219 int ret; 4220 int err = 0; 4221 u64 ino = btrfs_ino(inode); 4222 u64 bytes_deleted = 0; 4223 bool be_nice = 0; 4224 bool should_throttle = 0; 4225 bool should_end = 0; 4226 4227 BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY); 4228 4229 /* 4230 * for non-free space inodes and ref cows, we want to back off from 4231 * time to time 4232 */ 4233 if (!btrfs_is_free_space_inode(inode) && 4234 test_bit(BTRFS_ROOT_REF_COWS, &root->state)) 4235 be_nice = 1; 4236 4237 path = btrfs_alloc_path(); 4238 if (!path) 4239 return -ENOMEM; 4240 path->reada = -1; 4241 4242 /* 4243 * We want to drop from the next block forward in case this new size is 4244 * not block aligned since we will be keeping the last block of the 4245 * extent just the way it is. 4246 */ 4247 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) || 4248 root == root->fs_info->tree_root) 4249 btrfs_drop_extent_cache(inode, ALIGN(new_size, 4250 root->sectorsize), (u64)-1, 0); 4251 4252 /* 4253 * This function is also used to drop the items in the log tree before 4254 * we relog the inode, so if root != BTRFS_I(inode)->root, it means 4255 * it is used to drop the loged items. So we shouldn't kill the delayed 4256 * items. 4257 */ 4258 if (min_type == 0 && root == BTRFS_I(inode)->root) 4259 btrfs_kill_delayed_inode_items(inode); 4260 4261 key.objectid = ino; 4262 key.offset = (u64)-1; 4263 key.type = (u8)-1; 4264 4265 search_again: 4266 /* 4267 * with a 16K leaf size and 128MB extents, you can actually queue 4268 * up a huge file in a single leaf. Most of the time that 4269 * bytes_deleted is > 0, it will be huge by the time we get here 4270 */ 4271 if (be_nice && bytes_deleted > 32 * 1024 * 1024) { 4272 if (btrfs_should_end_transaction(trans, root)) { 4273 err = -EAGAIN; 4274 goto error; 4275 } 4276 } 4277 4278 4279 path->leave_spinning = 1; 4280 ret = btrfs_search_slot(trans, root, &key, path, -1, 1); 4281 if (ret < 0) { 4282 err = ret; 4283 goto out; 4284 } 4285 4286 if (ret > 0) { 4287 /* there are no items in the tree for us to truncate, we're 4288 * done 4289 */ 4290 if (path->slots[0] == 0) 4291 goto out; 4292 path->slots[0]--; 4293 } 4294 4295 while (1) { 4296 fi = NULL; 4297 leaf = path->nodes[0]; 4298 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 4299 found_type = found_key.type; 4300 4301 if (found_key.objectid != ino) 4302 break; 4303 4304 if (found_type < min_type) 4305 break; 4306 4307 item_end = found_key.offset; 4308 if (found_type == BTRFS_EXTENT_DATA_KEY) { 4309 fi = btrfs_item_ptr(leaf, path->slots[0], 4310 struct btrfs_file_extent_item); 4311 extent_type = btrfs_file_extent_type(leaf, fi); 4312 if (extent_type != BTRFS_FILE_EXTENT_INLINE) { 4313 item_end += 4314 btrfs_file_extent_num_bytes(leaf, fi); 4315 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { 4316 item_end += btrfs_file_extent_inline_len(leaf, 4317 path->slots[0], fi); 4318 } 4319 item_end--; 4320 } 4321 if (found_type > min_type) { 4322 del_item = 1; 4323 } else { 4324 if (item_end < new_size) 4325 break; 4326 if (found_key.offset >= new_size) 4327 del_item = 1; 4328 else 4329 del_item = 0; 4330 } 4331 found_extent = 0; 4332 /* FIXME, shrink the extent if the ref count is only 1 */ 4333 if (found_type != BTRFS_EXTENT_DATA_KEY) 4334 goto delete; 4335 4336 if (del_item) 4337 last_size = found_key.offset; 4338 else 4339 last_size = new_size; 4340 4341 if (extent_type != BTRFS_FILE_EXTENT_INLINE) { 4342 u64 num_dec; 4343 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi); 4344 if (!del_item) { 4345 u64 orig_num_bytes = 4346 btrfs_file_extent_num_bytes(leaf, fi); 4347 extent_num_bytes = ALIGN(new_size - 4348 found_key.offset, 4349 root->sectorsize); 4350 btrfs_set_file_extent_num_bytes(leaf, fi, 4351 extent_num_bytes); 4352 num_dec = (orig_num_bytes - 4353 extent_num_bytes); 4354 if (test_bit(BTRFS_ROOT_REF_COWS, 4355 &root->state) && 4356 extent_start != 0) 4357 inode_sub_bytes(inode, num_dec); 4358 btrfs_mark_buffer_dirty(leaf); 4359 } else { 4360 extent_num_bytes = 4361 btrfs_file_extent_disk_num_bytes(leaf, 4362 fi); 4363 extent_offset = found_key.offset - 4364 btrfs_file_extent_offset(leaf, fi); 4365 4366 /* FIXME blocksize != 4096 */ 4367 num_dec = btrfs_file_extent_num_bytes(leaf, fi); 4368 if (extent_start != 0) { 4369 found_extent = 1; 4370 if (test_bit(BTRFS_ROOT_REF_COWS, 4371 &root->state)) 4372 inode_sub_bytes(inode, num_dec); 4373 } 4374 } 4375 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { 4376 /* 4377 * we can't truncate inline items that have had 4378 * special encodings 4379 */ 4380 if (!del_item && 4381 btrfs_file_extent_compression(leaf, fi) == 0 && 4382 btrfs_file_extent_encryption(leaf, fi) == 0 && 4383 btrfs_file_extent_other_encoding(leaf, fi) == 0) { 4384 u32 size = new_size - found_key.offset; 4385 4386 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state)) 4387 inode_sub_bytes(inode, item_end + 1 - 4388 new_size); 4389 4390 /* 4391 * update the ram bytes to properly reflect 4392 * the new size of our item 4393 */ 4394 btrfs_set_file_extent_ram_bytes(leaf, fi, size); 4395 size = 4396 btrfs_file_extent_calc_inline_size(size); 4397 btrfs_truncate_item(root, path, size, 1); 4398 } else if (test_bit(BTRFS_ROOT_REF_COWS, 4399 &root->state)) { 4400 inode_sub_bytes(inode, item_end + 1 - 4401 found_key.offset); 4402 } 4403 } 4404 delete: 4405 if (del_item) { 4406 if (!pending_del_nr) { 4407 /* no pending yet, add ourselves */ 4408 pending_del_slot = path->slots[0]; 4409 pending_del_nr = 1; 4410 } else if (pending_del_nr && 4411 path->slots[0] + 1 == pending_del_slot) { 4412 /* hop on the pending chunk */ 4413 pending_del_nr++; 4414 pending_del_slot = path->slots[0]; 4415 } else { 4416 BUG(); 4417 } 4418 } else { 4419 break; 4420 } 4421 should_throttle = 0; 4422 4423 if (found_extent && 4424 (test_bit(BTRFS_ROOT_REF_COWS, &root->state) || 4425 root == root->fs_info->tree_root)) { 4426 btrfs_set_path_blocking(path); 4427 bytes_deleted += extent_num_bytes; 4428 ret = btrfs_free_extent(trans, root, extent_start, 4429 extent_num_bytes, 0, 4430 btrfs_header_owner(leaf), 4431 ino, extent_offset, 0); 4432 BUG_ON(ret); 4433 if (btrfs_should_throttle_delayed_refs(trans, root)) 4434 btrfs_async_run_delayed_refs(root, 4435 trans->delayed_ref_updates * 2, 0); 4436 if (be_nice) { 4437 if (truncate_space_check(trans, root, 4438 extent_num_bytes)) { 4439 should_end = 1; 4440 } 4441 if (btrfs_should_throttle_delayed_refs(trans, 4442 root)) { 4443 should_throttle = 1; 4444 } 4445 } 4446 } 4447 4448 if (found_type == BTRFS_INODE_ITEM_KEY) 4449 break; 4450 4451 if (path->slots[0] == 0 || 4452 path->slots[0] != pending_del_slot || 4453 should_throttle || should_end) { 4454 if (pending_del_nr) { 4455 ret = btrfs_del_items(trans, root, path, 4456 pending_del_slot, 4457 pending_del_nr); 4458 if (ret) { 4459 btrfs_abort_transaction(trans, 4460 root, ret); 4461 goto error; 4462 } 4463 pending_del_nr = 0; 4464 } 4465 btrfs_release_path(path); 4466 if (should_throttle) { 4467 unsigned long updates = trans->delayed_ref_updates; 4468 if (updates) { 4469 trans->delayed_ref_updates = 0; 4470 ret = btrfs_run_delayed_refs(trans, root, updates * 2); 4471 if (ret && !err) 4472 err = ret; 4473 } 4474 } 4475 /* 4476 * if we failed to refill our space rsv, bail out 4477 * and let the transaction restart 4478 */ 4479 if (should_end) { 4480 err = -EAGAIN; 4481 goto error; 4482 } 4483 goto search_again; 4484 } else { 4485 path->slots[0]--; 4486 } 4487 } 4488 out: 4489 if (pending_del_nr) { 4490 ret = btrfs_del_items(trans, root, path, pending_del_slot, 4491 pending_del_nr); 4492 if (ret) 4493 btrfs_abort_transaction(trans, root, ret); 4494 } 4495 error: 4496 if (last_size != (u64)-1 && 4497 root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) 4498 btrfs_ordered_update_i_size(inode, last_size, NULL); 4499 4500 btrfs_free_path(path); 4501 4502 if (be_nice && bytes_deleted > 32 * 1024 * 1024) { 4503 unsigned long updates = trans->delayed_ref_updates; 4504 if (updates) { 4505 trans->delayed_ref_updates = 0; 4506 ret = btrfs_run_delayed_refs(trans, root, updates * 2); 4507 if (ret && !err) 4508 err = ret; 4509 } 4510 } 4511 return err; 4512 } 4513 4514 /* 4515 * btrfs_truncate_page - read, zero a chunk and write a page 4516 * @inode - inode that we're zeroing 4517 * @from - the offset to start zeroing 4518 * @len - the length to zero, 0 to zero the entire range respective to the 4519 * offset 4520 * @front - zero up to the offset instead of from the offset on 4521 * 4522 * This will find the page for the "from" offset and cow the page and zero the 4523 * part we want to zero. This is used with truncate and hole punching. 4524 */ 4525 int btrfs_truncate_page(struct inode *inode, loff_t from, loff_t len, 4526 int front) 4527 { 4528 struct address_space *mapping = inode->i_mapping; 4529 struct btrfs_root *root = BTRFS_I(inode)->root; 4530 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 4531 struct btrfs_ordered_extent *ordered; 4532 struct extent_state *cached_state = NULL; 4533 char *kaddr; 4534 u32 blocksize = root->sectorsize; 4535 pgoff_t index = from >> PAGE_CACHE_SHIFT; 4536 unsigned offset = from & (PAGE_CACHE_SIZE-1); 4537 struct page *page; 4538 gfp_t mask = btrfs_alloc_write_mask(mapping); 4539 int ret = 0; 4540 u64 page_start; 4541 u64 page_end; 4542 4543 if ((offset & (blocksize - 1)) == 0 && 4544 (!len || ((len & (blocksize - 1)) == 0))) 4545 goto out; 4546 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE); 4547 if (ret) 4548 goto out; 4549 4550 again: 4551 page = find_or_create_page(mapping, index, mask); 4552 if (!page) { 4553 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE); 4554 ret = -ENOMEM; 4555 goto out; 4556 } 4557 4558 page_start = page_offset(page); 4559 page_end = page_start + PAGE_CACHE_SIZE - 1; 4560 4561 if (!PageUptodate(page)) { 4562 ret = btrfs_readpage(NULL, page); 4563 lock_page(page); 4564 if (page->mapping != mapping) { 4565 unlock_page(page); 4566 page_cache_release(page); 4567 goto again; 4568 } 4569 if (!PageUptodate(page)) { 4570 ret = -EIO; 4571 goto out_unlock; 4572 } 4573 } 4574 wait_on_page_writeback(page); 4575 4576 lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state); 4577 set_page_extent_mapped(page); 4578 4579 ordered = btrfs_lookup_ordered_extent(inode, page_start); 4580 if (ordered) { 4581 unlock_extent_cached(io_tree, page_start, page_end, 4582 &cached_state, GFP_NOFS); 4583 unlock_page(page); 4584 page_cache_release(page); 4585 btrfs_start_ordered_extent(inode, ordered, 1); 4586 btrfs_put_ordered_extent(ordered); 4587 goto again; 4588 } 4589 4590 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end, 4591 EXTENT_DIRTY | EXTENT_DELALLOC | 4592 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 4593 0, 0, &cached_state, GFP_NOFS); 4594 4595 ret = btrfs_set_extent_delalloc(inode, page_start, page_end, 4596 &cached_state); 4597 if (ret) { 4598 unlock_extent_cached(io_tree, page_start, page_end, 4599 &cached_state, GFP_NOFS); 4600 goto out_unlock; 4601 } 4602 4603 if (offset != PAGE_CACHE_SIZE) { 4604 if (!len) 4605 len = PAGE_CACHE_SIZE - offset; 4606 kaddr = kmap(page); 4607 if (front) 4608 memset(kaddr, 0, offset); 4609 else 4610 memset(kaddr + offset, 0, len); 4611 flush_dcache_page(page); 4612 kunmap(page); 4613 } 4614 ClearPageChecked(page); 4615 set_page_dirty(page); 4616 unlock_extent_cached(io_tree, page_start, page_end, &cached_state, 4617 GFP_NOFS); 4618 4619 out_unlock: 4620 if (ret) 4621 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE); 4622 unlock_page(page); 4623 page_cache_release(page); 4624 out: 4625 return ret; 4626 } 4627 4628 static int maybe_insert_hole(struct btrfs_root *root, struct inode *inode, 4629 u64 offset, u64 len) 4630 { 4631 struct btrfs_trans_handle *trans; 4632 int ret; 4633 4634 /* 4635 * Still need to make sure the inode looks like it's been updated so 4636 * that any holes get logged if we fsync. 4637 */ 4638 if (btrfs_fs_incompat(root->fs_info, NO_HOLES)) { 4639 BTRFS_I(inode)->last_trans = root->fs_info->generation; 4640 BTRFS_I(inode)->last_sub_trans = root->log_transid; 4641 BTRFS_I(inode)->last_log_commit = root->last_log_commit; 4642 return 0; 4643 } 4644 4645 /* 4646 * 1 - for the one we're dropping 4647 * 1 - for the one we're adding 4648 * 1 - for updating the inode. 4649 */ 4650 trans = btrfs_start_transaction(root, 3); 4651 if (IS_ERR(trans)) 4652 return PTR_ERR(trans); 4653 4654 ret = btrfs_drop_extents(trans, root, inode, offset, offset + len, 1); 4655 if (ret) { 4656 btrfs_abort_transaction(trans, root, ret); 4657 btrfs_end_transaction(trans, root); 4658 return ret; 4659 } 4660 4661 ret = btrfs_insert_file_extent(trans, root, btrfs_ino(inode), offset, 4662 0, 0, len, 0, len, 0, 0, 0); 4663 if (ret) 4664 btrfs_abort_transaction(trans, root, ret); 4665 else 4666 btrfs_update_inode(trans, root, inode); 4667 btrfs_end_transaction(trans, root); 4668 return ret; 4669 } 4670 4671 /* 4672 * This function puts in dummy file extents for the area we're creating a hole 4673 * for. So if we are truncating this file to a larger size we need to insert 4674 * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for 4675 * the range between oldsize and size 4676 */ 4677 int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size) 4678 { 4679 struct btrfs_root *root = BTRFS_I(inode)->root; 4680 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 4681 struct extent_map *em = NULL; 4682 struct extent_state *cached_state = NULL; 4683 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; 4684 u64 hole_start = ALIGN(oldsize, root->sectorsize); 4685 u64 block_end = ALIGN(size, root->sectorsize); 4686 u64 last_byte; 4687 u64 cur_offset; 4688 u64 hole_size; 4689 int err = 0; 4690 4691 /* 4692 * If our size started in the middle of a page we need to zero out the 4693 * rest of the page before we expand the i_size, otherwise we could 4694 * expose stale data. 4695 */ 4696 err = btrfs_truncate_page(inode, oldsize, 0, 0); 4697 if (err) 4698 return err; 4699 4700 if (size <= hole_start) 4701 return 0; 4702 4703 while (1) { 4704 struct btrfs_ordered_extent *ordered; 4705 4706 lock_extent_bits(io_tree, hole_start, block_end - 1, 0, 4707 &cached_state); 4708 ordered = btrfs_lookup_ordered_range(inode, hole_start, 4709 block_end - hole_start); 4710 if (!ordered) 4711 break; 4712 unlock_extent_cached(io_tree, hole_start, block_end - 1, 4713 &cached_state, GFP_NOFS); 4714 btrfs_start_ordered_extent(inode, ordered, 1); 4715 btrfs_put_ordered_extent(ordered); 4716 } 4717 4718 cur_offset = hole_start; 4719 while (1) { 4720 em = btrfs_get_extent(inode, NULL, 0, cur_offset, 4721 block_end - cur_offset, 0); 4722 if (IS_ERR(em)) { 4723 err = PTR_ERR(em); 4724 em = NULL; 4725 break; 4726 } 4727 last_byte = min(extent_map_end(em), block_end); 4728 last_byte = ALIGN(last_byte , root->sectorsize); 4729 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) { 4730 struct extent_map *hole_em; 4731 hole_size = last_byte - cur_offset; 4732 4733 err = maybe_insert_hole(root, inode, cur_offset, 4734 hole_size); 4735 if (err) 4736 break; 4737 btrfs_drop_extent_cache(inode, cur_offset, 4738 cur_offset + hole_size - 1, 0); 4739 hole_em = alloc_extent_map(); 4740 if (!hole_em) { 4741 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, 4742 &BTRFS_I(inode)->runtime_flags); 4743 goto next; 4744 } 4745 hole_em->start = cur_offset; 4746 hole_em->len = hole_size; 4747 hole_em->orig_start = cur_offset; 4748 4749 hole_em->block_start = EXTENT_MAP_HOLE; 4750 hole_em->block_len = 0; 4751 hole_em->orig_block_len = 0; 4752 hole_em->ram_bytes = hole_size; 4753 hole_em->bdev = root->fs_info->fs_devices->latest_bdev; 4754 hole_em->compress_type = BTRFS_COMPRESS_NONE; 4755 hole_em->generation = root->fs_info->generation; 4756 4757 while (1) { 4758 write_lock(&em_tree->lock); 4759 err = add_extent_mapping(em_tree, hole_em, 1); 4760 write_unlock(&em_tree->lock); 4761 if (err != -EEXIST) 4762 break; 4763 btrfs_drop_extent_cache(inode, cur_offset, 4764 cur_offset + 4765 hole_size - 1, 0); 4766 } 4767 free_extent_map(hole_em); 4768 } 4769 next: 4770 free_extent_map(em); 4771 em = NULL; 4772 cur_offset = last_byte; 4773 if (cur_offset >= block_end) 4774 break; 4775 } 4776 free_extent_map(em); 4777 unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state, 4778 GFP_NOFS); 4779 return err; 4780 } 4781 4782 static int wait_snapshoting_atomic_t(atomic_t *a) 4783 { 4784 schedule(); 4785 return 0; 4786 } 4787 4788 static void wait_for_snapshot_creation(struct btrfs_root *root) 4789 { 4790 while (true) { 4791 int ret; 4792 4793 ret = btrfs_start_write_no_snapshoting(root); 4794 if (ret) 4795 break; 4796 wait_on_atomic_t(&root->will_be_snapshoted, 4797 wait_snapshoting_atomic_t, 4798 TASK_UNINTERRUPTIBLE); 4799 } 4800 } 4801 4802 static int btrfs_setsize(struct inode *inode, struct iattr *attr) 4803 { 4804 struct btrfs_root *root = BTRFS_I(inode)->root; 4805 struct btrfs_trans_handle *trans; 4806 loff_t oldsize = i_size_read(inode); 4807 loff_t newsize = attr->ia_size; 4808 int mask = attr->ia_valid; 4809 int ret; 4810 4811 /* 4812 * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a 4813 * special case where we need to update the times despite not having 4814 * these flags set. For all other operations the VFS set these flags 4815 * explicitly if it wants a timestamp update. 4816 */ 4817 if (newsize != oldsize) { 4818 inode_inc_iversion(inode); 4819 if (!(mask & (ATTR_CTIME | ATTR_MTIME))) 4820 inode->i_ctime = inode->i_mtime = 4821 current_fs_time(inode->i_sb); 4822 } 4823 4824 if (newsize > oldsize) { 4825 truncate_pagecache(inode, newsize); 4826 /* 4827 * Don't do an expanding truncate while snapshoting is ongoing. 4828 * This is to ensure the snapshot captures a fully consistent 4829 * state of this file - if the snapshot captures this expanding 4830 * truncation, it must capture all writes that happened before 4831 * this truncation. 4832 */ 4833 wait_for_snapshot_creation(root); 4834 ret = btrfs_cont_expand(inode, oldsize, newsize); 4835 if (ret) { 4836 btrfs_end_write_no_snapshoting(root); 4837 return ret; 4838 } 4839 4840 trans = btrfs_start_transaction(root, 1); 4841 if (IS_ERR(trans)) { 4842 btrfs_end_write_no_snapshoting(root); 4843 return PTR_ERR(trans); 4844 } 4845 4846 i_size_write(inode, newsize); 4847 btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL); 4848 ret = btrfs_update_inode(trans, root, inode); 4849 btrfs_end_write_no_snapshoting(root); 4850 btrfs_end_transaction(trans, root); 4851 } else { 4852 4853 /* 4854 * We're truncating a file that used to have good data down to 4855 * zero. Make sure it gets into the ordered flush list so that 4856 * any new writes get down to disk quickly. 4857 */ 4858 if (newsize == 0) 4859 set_bit(BTRFS_INODE_ORDERED_DATA_CLOSE, 4860 &BTRFS_I(inode)->runtime_flags); 4861 4862 /* 4863 * 1 for the orphan item we're going to add 4864 * 1 for the orphan item deletion. 4865 */ 4866 trans = btrfs_start_transaction(root, 2); 4867 if (IS_ERR(trans)) 4868 return PTR_ERR(trans); 4869 4870 /* 4871 * We need to do this in case we fail at _any_ point during the 4872 * actual truncate. Once we do the truncate_setsize we could 4873 * invalidate pages which forces any outstanding ordered io to 4874 * be instantly completed which will give us extents that need 4875 * to be truncated. If we fail to get an orphan inode down we 4876 * could have left over extents that were never meant to live, 4877 * so we need to garuntee from this point on that everything 4878 * will be consistent. 4879 */ 4880 ret = btrfs_orphan_add(trans, inode); 4881 btrfs_end_transaction(trans, root); 4882 if (ret) 4883 return ret; 4884 4885 /* we don't support swapfiles, so vmtruncate shouldn't fail */ 4886 truncate_setsize(inode, newsize); 4887 4888 /* Disable nonlocked read DIO to avoid the end less truncate */ 4889 btrfs_inode_block_unlocked_dio(inode); 4890 inode_dio_wait(inode); 4891 btrfs_inode_resume_unlocked_dio(inode); 4892 4893 ret = btrfs_truncate(inode); 4894 if (ret && inode->i_nlink) { 4895 int err; 4896 4897 /* 4898 * failed to truncate, disk_i_size is only adjusted down 4899 * as we remove extents, so it should represent the true 4900 * size of the inode, so reset the in memory size and 4901 * delete our orphan entry. 4902 */ 4903 trans = btrfs_join_transaction(root); 4904 if (IS_ERR(trans)) { 4905 btrfs_orphan_del(NULL, inode); 4906 return ret; 4907 } 4908 i_size_write(inode, BTRFS_I(inode)->disk_i_size); 4909 err = btrfs_orphan_del(trans, inode); 4910 if (err) 4911 btrfs_abort_transaction(trans, root, err); 4912 btrfs_end_transaction(trans, root); 4913 } 4914 } 4915 4916 return ret; 4917 } 4918 4919 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr) 4920 { 4921 struct inode *inode = d_inode(dentry); 4922 struct btrfs_root *root = BTRFS_I(inode)->root; 4923 int err; 4924 4925 if (btrfs_root_readonly(root)) 4926 return -EROFS; 4927 4928 err = inode_change_ok(inode, attr); 4929 if (err) 4930 return err; 4931 4932 if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) { 4933 err = btrfs_setsize(inode, attr); 4934 if (err) 4935 return err; 4936 } 4937 4938 if (attr->ia_valid) { 4939 setattr_copy(inode, attr); 4940 inode_inc_iversion(inode); 4941 err = btrfs_dirty_inode(inode); 4942 4943 if (!err && attr->ia_valid & ATTR_MODE) 4944 err = posix_acl_chmod(inode, inode->i_mode); 4945 } 4946 4947 return err; 4948 } 4949 4950 /* 4951 * While truncating the inode pages during eviction, we get the VFS calling 4952 * btrfs_invalidatepage() against each page of the inode. This is slow because 4953 * the calls to btrfs_invalidatepage() result in a huge amount of calls to 4954 * lock_extent_bits() and clear_extent_bit(), which keep merging and splitting 4955 * extent_state structures over and over, wasting lots of time. 4956 * 4957 * Therefore if the inode is being evicted, let btrfs_invalidatepage() skip all 4958 * those expensive operations on a per page basis and do only the ordered io 4959 * finishing, while we release here the extent_map and extent_state structures, 4960 * without the excessive merging and splitting. 4961 */ 4962 static void evict_inode_truncate_pages(struct inode *inode) 4963 { 4964 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 4965 struct extent_map_tree *map_tree = &BTRFS_I(inode)->extent_tree; 4966 struct rb_node *node; 4967 4968 ASSERT(inode->i_state & I_FREEING); 4969 truncate_inode_pages_final(&inode->i_data); 4970 4971 write_lock(&map_tree->lock); 4972 while (!RB_EMPTY_ROOT(&map_tree->map)) { 4973 struct extent_map *em; 4974 4975 node = rb_first(&map_tree->map); 4976 em = rb_entry(node, struct extent_map, rb_node); 4977 clear_bit(EXTENT_FLAG_PINNED, &em->flags); 4978 clear_bit(EXTENT_FLAG_LOGGING, &em->flags); 4979 remove_extent_mapping(map_tree, em); 4980 free_extent_map(em); 4981 if (need_resched()) { 4982 write_unlock(&map_tree->lock); 4983 cond_resched(); 4984 write_lock(&map_tree->lock); 4985 } 4986 } 4987 write_unlock(&map_tree->lock); 4988 4989 spin_lock(&io_tree->lock); 4990 while (!RB_EMPTY_ROOT(&io_tree->state)) { 4991 struct extent_state *state; 4992 struct extent_state *cached_state = NULL; 4993 4994 node = rb_first(&io_tree->state); 4995 state = rb_entry(node, struct extent_state, rb_node); 4996 atomic_inc(&state->refs); 4997 spin_unlock(&io_tree->lock); 4998 4999 lock_extent_bits(io_tree, state->start, state->end, 5000 0, &cached_state); 5001 clear_extent_bit(io_tree, state->start, state->end, 5002 EXTENT_LOCKED | EXTENT_DIRTY | 5003 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING | 5004 EXTENT_DEFRAG, 1, 1, 5005 &cached_state, GFP_NOFS); 5006 free_extent_state(state); 5007 5008 cond_resched(); 5009 spin_lock(&io_tree->lock); 5010 } 5011 spin_unlock(&io_tree->lock); 5012 } 5013 5014 void btrfs_evict_inode(struct inode *inode) 5015 { 5016 struct btrfs_trans_handle *trans; 5017 struct btrfs_root *root = BTRFS_I(inode)->root; 5018 struct btrfs_block_rsv *rsv, *global_rsv; 5019 int steal_from_global = 0; 5020 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1); 5021 int ret; 5022 5023 trace_btrfs_inode_evict(inode); 5024 5025 evict_inode_truncate_pages(inode); 5026 5027 if (inode->i_nlink && 5028 ((btrfs_root_refs(&root->root_item) != 0 && 5029 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID) || 5030 btrfs_is_free_space_inode(inode))) 5031 goto no_delete; 5032 5033 if (is_bad_inode(inode)) { 5034 btrfs_orphan_del(NULL, inode); 5035 goto no_delete; 5036 } 5037 /* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */ 5038 btrfs_wait_ordered_range(inode, 0, (u64)-1); 5039 5040 btrfs_free_io_failure_record(inode, 0, (u64)-1); 5041 5042 if (root->fs_info->log_root_recovering) { 5043 BUG_ON(test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM, 5044 &BTRFS_I(inode)->runtime_flags)); 5045 goto no_delete; 5046 } 5047 5048 if (inode->i_nlink > 0) { 5049 BUG_ON(btrfs_root_refs(&root->root_item) != 0 && 5050 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID); 5051 goto no_delete; 5052 } 5053 5054 ret = btrfs_commit_inode_delayed_inode(inode); 5055 if (ret) { 5056 btrfs_orphan_del(NULL, inode); 5057 goto no_delete; 5058 } 5059 5060 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP); 5061 if (!rsv) { 5062 btrfs_orphan_del(NULL, inode); 5063 goto no_delete; 5064 } 5065 rsv->size = min_size; 5066 rsv->failfast = 1; 5067 global_rsv = &root->fs_info->global_block_rsv; 5068 5069 btrfs_i_size_write(inode, 0); 5070 5071 /* 5072 * This is a bit simpler than btrfs_truncate since we've already 5073 * reserved our space for our orphan item in the unlink, so we just 5074 * need to reserve some slack space in case we add bytes and update 5075 * inode item when doing the truncate. 5076 */ 5077 while (1) { 5078 ret = btrfs_block_rsv_refill(root, rsv, min_size, 5079 BTRFS_RESERVE_FLUSH_LIMIT); 5080 5081 /* 5082 * Try and steal from the global reserve since we will 5083 * likely not use this space anyway, we want to try as 5084 * hard as possible to get this to work. 5085 */ 5086 if (ret) 5087 steal_from_global++; 5088 else 5089 steal_from_global = 0; 5090 ret = 0; 5091 5092 /* 5093 * steal_from_global == 0: we reserved stuff, hooray! 5094 * steal_from_global == 1: we didn't reserve stuff, boo! 5095 * steal_from_global == 2: we've committed, still not a lot of 5096 * room but maybe we'll have room in the global reserve this 5097 * time. 5098 * steal_from_global == 3: abandon all hope! 5099 */ 5100 if (steal_from_global > 2) { 5101 btrfs_warn(root->fs_info, 5102 "Could not get space for a delete, will truncate on mount %d", 5103 ret); 5104 btrfs_orphan_del(NULL, inode); 5105 btrfs_free_block_rsv(root, rsv); 5106 goto no_delete; 5107 } 5108 5109 trans = btrfs_join_transaction(root); 5110 if (IS_ERR(trans)) { 5111 btrfs_orphan_del(NULL, inode); 5112 btrfs_free_block_rsv(root, rsv); 5113 goto no_delete; 5114 } 5115 5116 /* 5117 * We can't just steal from the global reserve, we need tomake 5118 * sure there is room to do it, if not we need to commit and try 5119 * again. 5120 */ 5121 if (steal_from_global) { 5122 if (!btrfs_check_space_for_delayed_refs(trans, root)) 5123 ret = btrfs_block_rsv_migrate(global_rsv, rsv, 5124 min_size); 5125 else 5126 ret = -ENOSPC; 5127 } 5128 5129 /* 5130 * Couldn't steal from the global reserve, we have too much 5131 * pending stuff built up, commit the transaction and try it 5132 * again. 5133 */ 5134 if (ret) { 5135 ret = btrfs_commit_transaction(trans, root); 5136 if (ret) { 5137 btrfs_orphan_del(NULL, inode); 5138 btrfs_free_block_rsv(root, rsv); 5139 goto no_delete; 5140 } 5141 continue; 5142 } else { 5143 steal_from_global = 0; 5144 } 5145 5146 trans->block_rsv = rsv; 5147 5148 ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0); 5149 if (ret != -ENOSPC && ret != -EAGAIN) 5150 break; 5151 5152 trans->block_rsv = &root->fs_info->trans_block_rsv; 5153 btrfs_end_transaction(trans, root); 5154 trans = NULL; 5155 btrfs_btree_balance_dirty(root); 5156 } 5157 5158 btrfs_free_block_rsv(root, rsv); 5159 5160 /* 5161 * Errors here aren't a big deal, it just means we leave orphan items 5162 * in the tree. They will be cleaned up on the next mount. 5163 */ 5164 if (ret == 0) { 5165 trans->block_rsv = root->orphan_block_rsv; 5166 btrfs_orphan_del(trans, inode); 5167 } else { 5168 btrfs_orphan_del(NULL, inode); 5169 } 5170 5171 trans->block_rsv = &root->fs_info->trans_block_rsv; 5172 if (!(root == root->fs_info->tree_root || 5173 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)) 5174 btrfs_return_ino(root, btrfs_ino(inode)); 5175 5176 btrfs_end_transaction(trans, root); 5177 btrfs_btree_balance_dirty(root); 5178 no_delete: 5179 btrfs_remove_delayed_node(inode); 5180 clear_inode(inode); 5181 return; 5182 } 5183 5184 /* 5185 * this returns the key found in the dir entry in the location pointer. 5186 * If no dir entries were found, location->objectid is 0. 5187 */ 5188 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry, 5189 struct btrfs_key *location) 5190 { 5191 const char *name = dentry->d_name.name; 5192 int namelen = dentry->d_name.len; 5193 struct btrfs_dir_item *di; 5194 struct btrfs_path *path; 5195 struct btrfs_root *root = BTRFS_I(dir)->root; 5196 int ret = 0; 5197 5198 path = btrfs_alloc_path(); 5199 if (!path) 5200 return -ENOMEM; 5201 5202 di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(dir), name, 5203 namelen, 0); 5204 if (IS_ERR(di)) 5205 ret = PTR_ERR(di); 5206 5207 if (IS_ERR_OR_NULL(di)) 5208 goto out_err; 5209 5210 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location); 5211 out: 5212 btrfs_free_path(path); 5213 return ret; 5214 out_err: 5215 location->objectid = 0; 5216 goto out; 5217 } 5218 5219 /* 5220 * when we hit a tree root in a directory, the btrfs part of the inode 5221 * needs to be changed to reflect the root directory of the tree root. This 5222 * is kind of like crossing a mount point. 5223 */ 5224 static int fixup_tree_root_location(struct btrfs_root *root, 5225 struct inode *dir, 5226 struct dentry *dentry, 5227 struct btrfs_key *location, 5228 struct btrfs_root **sub_root) 5229 { 5230 struct btrfs_path *path; 5231 struct btrfs_root *new_root; 5232 struct btrfs_root_ref *ref; 5233 struct extent_buffer *leaf; 5234 struct btrfs_key key; 5235 int ret; 5236 int err = 0; 5237 5238 path = btrfs_alloc_path(); 5239 if (!path) { 5240 err = -ENOMEM; 5241 goto out; 5242 } 5243 5244 err = -ENOENT; 5245 key.objectid = BTRFS_I(dir)->root->root_key.objectid; 5246 key.type = BTRFS_ROOT_REF_KEY; 5247 key.offset = location->objectid; 5248 5249 ret = btrfs_search_slot(NULL, root->fs_info->tree_root, &key, path, 5250 0, 0); 5251 if (ret) { 5252 if (ret < 0) 5253 err = ret; 5254 goto out; 5255 } 5256 5257 leaf = path->nodes[0]; 5258 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref); 5259 if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(dir) || 5260 btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len) 5261 goto out; 5262 5263 ret = memcmp_extent_buffer(leaf, dentry->d_name.name, 5264 (unsigned long)(ref + 1), 5265 dentry->d_name.len); 5266 if (ret) 5267 goto out; 5268 5269 btrfs_release_path(path); 5270 5271 new_root = btrfs_read_fs_root_no_name(root->fs_info, location); 5272 if (IS_ERR(new_root)) { 5273 err = PTR_ERR(new_root); 5274 goto out; 5275 } 5276 5277 *sub_root = new_root; 5278 location->objectid = btrfs_root_dirid(&new_root->root_item); 5279 location->type = BTRFS_INODE_ITEM_KEY; 5280 location->offset = 0; 5281 err = 0; 5282 out: 5283 btrfs_free_path(path); 5284 return err; 5285 } 5286 5287 static void inode_tree_add(struct inode *inode) 5288 { 5289 struct btrfs_root *root = BTRFS_I(inode)->root; 5290 struct btrfs_inode *entry; 5291 struct rb_node **p; 5292 struct rb_node *parent; 5293 struct rb_node *new = &BTRFS_I(inode)->rb_node; 5294 u64 ino = btrfs_ino(inode); 5295 5296 if (inode_unhashed(inode)) 5297 return; 5298 parent = NULL; 5299 spin_lock(&root->inode_lock); 5300 p = &root->inode_tree.rb_node; 5301 while (*p) { 5302 parent = *p; 5303 entry = rb_entry(parent, struct btrfs_inode, rb_node); 5304 5305 if (ino < btrfs_ino(&entry->vfs_inode)) 5306 p = &parent->rb_left; 5307 else if (ino > btrfs_ino(&entry->vfs_inode)) 5308 p = &parent->rb_right; 5309 else { 5310 WARN_ON(!(entry->vfs_inode.i_state & 5311 (I_WILL_FREE | I_FREEING))); 5312 rb_replace_node(parent, new, &root->inode_tree); 5313 RB_CLEAR_NODE(parent); 5314 spin_unlock(&root->inode_lock); 5315 return; 5316 } 5317 } 5318 rb_link_node(new, parent, p); 5319 rb_insert_color(new, &root->inode_tree); 5320 spin_unlock(&root->inode_lock); 5321 } 5322 5323 static void inode_tree_del(struct inode *inode) 5324 { 5325 struct btrfs_root *root = BTRFS_I(inode)->root; 5326 int empty = 0; 5327 5328 spin_lock(&root->inode_lock); 5329 if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) { 5330 rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree); 5331 RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node); 5332 empty = RB_EMPTY_ROOT(&root->inode_tree); 5333 } 5334 spin_unlock(&root->inode_lock); 5335 5336 if (empty && btrfs_root_refs(&root->root_item) == 0) { 5337 synchronize_srcu(&root->fs_info->subvol_srcu); 5338 spin_lock(&root->inode_lock); 5339 empty = RB_EMPTY_ROOT(&root->inode_tree); 5340 spin_unlock(&root->inode_lock); 5341 if (empty) 5342 btrfs_add_dead_root(root); 5343 } 5344 } 5345 5346 void btrfs_invalidate_inodes(struct btrfs_root *root) 5347 { 5348 struct rb_node *node; 5349 struct rb_node *prev; 5350 struct btrfs_inode *entry; 5351 struct inode *inode; 5352 u64 objectid = 0; 5353 5354 if (!test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state)) 5355 WARN_ON(btrfs_root_refs(&root->root_item) != 0); 5356 5357 spin_lock(&root->inode_lock); 5358 again: 5359 node = root->inode_tree.rb_node; 5360 prev = NULL; 5361 while (node) { 5362 prev = node; 5363 entry = rb_entry(node, struct btrfs_inode, rb_node); 5364 5365 if (objectid < btrfs_ino(&entry->vfs_inode)) 5366 node = node->rb_left; 5367 else if (objectid > btrfs_ino(&entry->vfs_inode)) 5368 node = node->rb_right; 5369 else 5370 break; 5371 } 5372 if (!node) { 5373 while (prev) { 5374 entry = rb_entry(prev, struct btrfs_inode, rb_node); 5375 if (objectid <= btrfs_ino(&entry->vfs_inode)) { 5376 node = prev; 5377 break; 5378 } 5379 prev = rb_next(prev); 5380 } 5381 } 5382 while (node) { 5383 entry = rb_entry(node, struct btrfs_inode, rb_node); 5384 objectid = btrfs_ino(&entry->vfs_inode) + 1; 5385 inode = igrab(&entry->vfs_inode); 5386 if (inode) { 5387 spin_unlock(&root->inode_lock); 5388 if (atomic_read(&inode->i_count) > 1) 5389 d_prune_aliases(inode); 5390 /* 5391 * btrfs_drop_inode will have it removed from 5392 * the inode cache when its usage count 5393 * hits zero. 5394 */ 5395 iput(inode); 5396 cond_resched(); 5397 spin_lock(&root->inode_lock); 5398 goto again; 5399 } 5400 5401 if (cond_resched_lock(&root->inode_lock)) 5402 goto again; 5403 5404 node = rb_next(node); 5405 } 5406 spin_unlock(&root->inode_lock); 5407 } 5408 5409 static int btrfs_init_locked_inode(struct inode *inode, void *p) 5410 { 5411 struct btrfs_iget_args *args = p; 5412 inode->i_ino = args->location->objectid; 5413 memcpy(&BTRFS_I(inode)->location, args->location, 5414 sizeof(*args->location)); 5415 BTRFS_I(inode)->root = args->root; 5416 return 0; 5417 } 5418 5419 static int btrfs_find_actor(struct inode *inode, void *opaque) 5420 { 5421 struct btrfs_iget_args *args = opaque; 5422 return args->location->objectid == BTRFS_I(inode)->location.objectid && 5423 args->root == BTRFS_I(inode)->root; 5424 } 5425 5426 static struct inode *btrfs_iget_locked(struct super_block *s, 5427 struct btrfs_key *location, 5428 struct btrfs_root *root) 5429 { 5430 struct inode *inode; 5431 struct btrfs_iget_args args; 5432 unsigned long hashval = btrfs_inode_hash(location->objectid, root); 5433 5434 args.location = location; 5435 args.root = root; 5436 5437 inode = iget5_locked(s, hashval, btrfs_find_actor, 5438 btrfs_init_locked_inode, 5439 (void *)&args); 5440 return inode; 5441 } 5442 5443 /* Get an inode object given its location and corresponding root. 5444 * Returns in *is_new if the inode was read from disk 5445 */ 5446 struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location, 5447 struct btrfs_root *root, int *new) 5448 { 5449 struct inode *inode; 5450 5451 inode = btrfs_iget_locked(s, location, root); 5452 if (!inode) 5453 return ERR_PTR(-ENOMEM); 5454 5455 if (inode->i_state & I_NEW) { 5456 btrfs_read_locked_inode(inode); 5457 if (!is_bad_inode(inode)) { 5458 inode_tree_add(inode); 5459 unlock_new_inode(inode); 5460 if (new) 5461 *new = 1; 5462 } else { 5463 unlock_new_inode(inode); 5464 iput(inode); 5465 inode = ERR_PTR(-ESTALE); 5466 } 5467 } 5468 5469 return inode; 5470 } 5471 5472 static struct inode *new_simple_dir(struct super_block *s, 5473 struct btrfs_key *key, 5474 struct btrfs_root *root) 5475 { 5476 struct inode *inode = new_inode(s); 5477 5478 if (!inode) 5479 return ERR_PTR(-ENOMEM); 5480 5481 BTRFS_I(inode)->root = root; 5482 memcpy(&BTRFS_I(inode)->location, key, sizeof(*key)); 5483 set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags); 5484 5485 inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID; 5486 inode->i_op = &btrfs_dir_ro_inode_operations; 5487 inode->i_fop = &simple_dir_operations; 5488 inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO; 5489 inode->i_mtime = CURRENT_TIME; 5490 inode->i_atime = inode->i_mtime; 5491 inode->i_ctime = inode->i_mtime; 5492 BTRFS_I(inode)->i_otime = inode->i_mtime; 5493 5494 return inode; 5495 } 5496 5497 struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry) 5498 { 5499 struct inode *inode; 5500 struct btrfs_root *root = BTRFS_I(dir)->root; 5501 struct btrfs_root *sub_root = root; 5502 struct btrfs_key location; 5503 int index; 5504 int ret = 0; 5505 5506 if (dentry->d_name.len > BTRFS_NAME_LEN) 5507 return ERR_PTR(-ENAMETOOLONG); 5508 5509 ret = btrfs_inode_by_name(dir, dentry, &location); 5510 if (ret < 0) 5511 return ERR_PTR(ret); 5512 5513 if (location.objectid == 0) 5514 return ERR_PTR(-ENOENT); 5515 5516 if (location.type == BTRFS_INODE_ITEM_KEY) { 5517 inode = btrfs_iget(dir->i_sb, &location, root, NULL); 5518 return inode; 5519 } 5520 5521 BUG_ON(location.type != BTRFS_ROOT_ITEM_KEY); 5522 5523 index = srcu_read_lock(&root->fs_info->subvol_srcu); 5524 ret = fixup_tree_root_location(root, dir, dentry, 5525 &location, &sub_root); 5526 if (ret < 0) { 5527 if (ret != -ENOENT) 5528 inode = ERR_PTR(ret); 5529 else 5530 inode = new_simple_dir(dir->i_sb, &location, sub_root); 5531 } else { 5532 inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL); 5533 } 5534 srcu_read_unlock(&root->fs_info->subvol_srcu, index); 5535 5536 if (!IS_ERR(inode) && root != sub_root) { 5537 down_read(&root->fs_info->cleanup_work_sem); 5538 if (!(inode->i_sb->s_flags & MS_RDONLY)) 5539 ret = btrfs_orphan_cleanup(sub_root); 5540 up_read(&root->fs_info->cleanup_work_sem); 5541 if (ret) { 5542 iput(inode); 5543 inode = ERR_PTR(ret); 5544 } 5545 } 5546 5547 return inode; 5548 } 5549 5550 static int btrfs_dentry_delete(const struct dentry *dentry) 5551 { 5552 struct btrfs_root *root; 5553 struct inode *inode = d_inode(dentry); 5554 5555 if (!inode && !IS_ROOT(dentry)) 5556 inode = d_inode(dentry->d_parent); 5557 5558 if (inode) { 5559 root = BTRFS_I(inode)->root; 5560 if (btrfs_root_refs(&root->root_item) == 0) 5561 return 1; 5562 5563 if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID) 5564 return 1; 5565 } 5566 return 0; 5567 } 5568 5569 static void btrfs_dentry_release(struct dentry *dentry) 5570 { 5571 kfree(dentry->d_fsdata); 5572 } 5573 5574 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry, 5575 unsigned int flags) 5576 { 5577 struct inode *inode; 5578 5579 inode = btrfs_lookup_dentry(dir, dentry); 5580 if (IS_ERR(inode)) { 5581 if (PTR_ERR(inode) == -ENOENT) 5582 inode = NULL; 5583 else 5584 return ERR_CAST(inode); 5585 } 5586 5587 return d_splice_alias(inode, dentry); 5588 } 5589 5590 unsigned char btrfs_filetype_table[] = { 5591 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK 5592 }; 5593 5594 static int btrfs_real_readdir(struct file *file, struct dir_context *ctx) 5595 { 5596 struct inode *inode = file_inode(file); 5597 struct btrfs_root *root = BTRFS_I(inode)->root; 5598 struct btrfs_item *item; 5599 struct btrfs_dir_item *di; 5600 struct btrfs_key key; 5601 struct btrfs_key found_key; 5602 struct btrfs_path *path; 5603 struct list_head ins_list; 5604 struct list_head del_list; 5605 int ret; 5606 struct extent_buffer *leaf; 5607 int slot; 5608 unsigned char d_type; 5609 int over = 0; 5610 u32 di_cur; 5611 u32 di_total; 5612 u32 di_len; 5613 int key_type = BTRFS_DIR_INDEX_KEY; 5614 char tmp_name[32]; 5615 char *name_ptr; 5616 int name_len; 5617 int is_curr = 0; /* ctx->pos points to the current index? */ 5618 5619 /* FIXME, use a real flag for deciding about the key type */ 5620 if (root->fs_info->tree_root == root) 5621 key_type = BTRFS_DIR_ITEM_KEY; 5622 5623 if (!dir_emit_dots(file, ctx)) 5624 return 0; 5625 5626 path = btrfs_alloc_path(); 5627 if (!path) 5628 return -ENOMEM; 5629 5630 path->reada = 1; 5631 5632 if (key_type == BTRFS_DIR_INDEX_KEY) { 5633 INIT_LIST_HEAD(&ins_list); 5634 INIT_LIST_HEAD(&del_list); 5635 btrfs_get_delayed_items(inode, &ins_list, &del_list); 5636 } 5637 5638 key.type = key_type; 5639 key.offset = ctx->pos; 5640 key.objectid = btrfs_ino(inode); 5641 5642 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 5643 if (ret < 0) 5644 goto err; 5645 5646 while (1) { 5647 leaf = path->nodes[0]; 5648 slot = path->slots[0]; 5649 if (slot >= btrfs_header_nritems(leaf)) { 5650 ret = btrfs_next_leaf(root, path); 5651 if (ret < 0) 5652 goto err; 5653 else if (ret > 0) 5654 break; 5655 continue; 5656 } 5657 5658 item = btrfs_item_nr(slot); 5659 btrfs_item_key_to_cpu(leaf, &found_key, slot); 5660 5661 if (found_key.objectid != key.objectid) 5662 break; 5663 if (found_key.type != key_type) 5664 break; 5665 if (found_key.offset < ctx->pos) 5666 goto next; 5667 if (key_type == BTRFS_DIR_INDEX_KEY && 5668 btrfs_should_delete_dir_index(&del_list, 5669 found_key.offset)) 5670 goto next; 5671 5672 ctx->pos = found_key.offset; 5673 is_curr = 1; 5674 5675 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item); 5676 di_cur = 0; 5677 di_total = btrfs_item_size(leaf, item); 5678 5679 while (di_cur < di_total) { 5680 struct btrfs_key location; 5681 5682 if (verify_dir_item(root, leaf, di)) 5683 break; 5684 5685 name_len = btrfs_dir_name_len(leaf, di); 5686 if (name_len <= sizeof(tmp_name)) { 5687 name_ptr = tmp_name; 5688 } else { 5689 name_ptr = kmalloc(name_len, GFP_NOFS); 5690 if (!name_ptr) { 5691 ret = -ENOMEM; 5692 goto err; 5693 } 5694 } 5695 read_extent_buffer(leaf, name_ptr, 5696 (unsigned long)(di + 1), name_len); 5697 5698 d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)]; 5699 btrfs_dir_item_key_to_cpu(leaf, di, &location); 5700 5701 5702 /* is this a reference to our own snapshot? If so 5703 * skip it. 5704 * 5705 * In contrast to old kernels, we insert the snapshot's 5706 * dir item and dir index after it has been created, so 5707 * we won't find a reference to our own snapshot. We 5708 * still keep the following code for backward 5709 * compatibility. 5710 */ 5711 if (location.type == BTRFS_ROOT_ITEM_KEY && 5712 location.objectid == root->root_key.objectid) { 5713 over = 0; 5714 goto skip; 5715 } 5716 over = !dir_emit(ctx, name_ptr, name_len, 5717 location.objectid, d_type); 5718 5719 skip: 5720 if (name_ptr != tmp_name) 5721 kfree(name_ptr); 5722 5723 if (over) 5724 goto nopos; 5725 di_len = btrfs_dir_name_len(leaf, di) + 5726 btrfs_dir_data_len(leaf, di) + sizeof(*di); 5727 di_cur += di_len; 5728 di = (struct btrfs_dir_item *)((char *)di + di_len); 5729 } 5730 next: 5731 path->slots[0]++; 5732 } 5733 5734 if (key_type == BTRFS_DIR_INDEX_KEY) { 5735 if (is_curr) 5736 ctx->pos++; 5737 ret = btrfs_readdir_delayed_dir_index(ctx, &ins_list); 5738 if (ret) 5739 goto nopos; 5740 } 5741 5742 /* Reached end of directory/root. Bump pos past the last item. */ 5743 ctx->pos++; 5744 5745 /* 5746 * Stop new entries from being returned after we return the last 5747 * entry. 5748 * 5749 * New directory entries are assigned a strictly increasing 5750 * offset. This means that new entries created during readdir 5751 * are *guaranteed* to be seen in the future by that readdir. 5752 * This has broken buggy programs which operate on names as 5753 * they're returned by readdir. Until we re-use freed offsets 5754 * we have this hack to stop new entries from being returned 5755 * under the assumption that they'll never reach this huge 5756 * offset. 5757 * 5758 * This is being careful not to overflow 32bit loff_t unless the 5759 * last entry requires it because doing so has broken 32bit apps 5760 * in the past. 5761 */ 5762 if (key_type == BTRFS_DIR_INDEX_KEY) { 5763 if (ctx->pos >= INT_MAX) 5764 ctx->pos = LLONG_MAX; 5765 else 5766 ctx->pos = INT_MAX; 5767 } 5768 nopos: 5769 ret = 0; 5770 err: 5771 if (key_type == BTRFS_DIR_INDEX_KEY) 5772 btrfs_put_delayed_items(&ins_list, &del_list); 5773 btrfs_free_path(path); 5774 return ret; 5775 } 5776 5777 int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc) 5778 { 5779 struct btrfs_root *root = BTRFS_I(inode)->root; 5780 struct btrfs_trans_handle *trans; 5781 int ret = 0; 5782 bool nolock = false; 5783 5784 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags)) 5785 return 0; 5786 5787 if (btrfs_fs_closing(root->fs_info) && btrfs_is_free_space_inode(inode)) 5788 nolock = true; 5789 5790 if (wbc->sync_mode == WB_SYNC_ALL) { 5791 if (nolock) 5792 trans = btrfs_join_transaction_nolock(root); 5793 else 5794 trans = btrfs_join_transaction(root); 5795 if (IS_ERR(trans)) 5796 return PTR_ERR(trans); 5797 ret = btrfs_commit_transaction(trans, root); 5798 } 5799 return ret; 5800 } 5801 5802 /* 5803 * This is somewhat expensive, updating the tree every time the 5804 * inode changes. But, it is most likely to find the inode in cache. 5805 * FIXME, needs more benchmarking...there are no reasons other than performance 5806 * to keep or drop this code. 5807 */ 5808 static int btrfs_dirty_inode(struct inode *inode) 5809 { 5810 struct btrfs_root *root = BTRFS_I(inode)->root; 5811 struct btrfs_trans_handle *trans; 5812 int ret; 5813 5814 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags)) 5815 return 0; 5816 5817 trans = btrfs_join_transaction(root); 5818 if (IS_ERR(trans)) 5819 return PTR_ERR(trans); 5820 5821 ret = btrfs_update_inode(trans, root, inode); 5822 if (ret && ret == -ENOSPC) { 5823 /* whoops, lets try again with the full transaction */ 5824 btrfs_end_transaction(trans, root); 5825 trans = btrfs_start_transaction(root, 1); 5826 if (IS_ERR(trans)) 5827 return PTR_ERR(trans); 5828 5829 ret = btrfs_update_inode(trans, root, inode); 5830 } 5831 btrfs_end_transaction(trans, root); 5832 if (BTRFS_I(inode)->delayed_node) 5833 btrfs_balance_delayed_items(root); 5834 5835 return ret; 5836 } 5837 5838 /* 5839 * This is a copy of file_update_time. We need this so we can return error on 5840 * ENOSPC for updating the inode in the case of file write and mmap writes. 5841 */ 5842 static int btrfs_update_time(struct inode *inode, struct timespec *now, 5843 int flags) 5844 { 5845 struct btrfs_root *root = BTRFS_I(inode)->root; 5846 5847 if (btrfs_root_readonly(root)) 5848 return -EROFS; 5849 5850 if (flags & S_VERSION) 5851 inode_inc_iversion(inode); 5852 if (flags & S_CTIME) 5853 inode->i_ctime = *now; 5854 if (flags & S_MTIME) 5855 inode->i_mtime = *now; 5856 if (flags & S_ATIME) 5857 inode->i_atime = *now; 5858 return btrfs_dirty_inode(inode); 5859 } 5860 5861 /* 5862 * find the highest existing sequence number in a directory 5863 * and then set the in-memory index_cnt variable to reflect 5864 * free sequence numbers 5865 */ 5866 static int btrfs_set_inode_index_count(struct inode *inode) 5867 { 5868 struct btrfs_root *root = BTRFS_I(inode)->root; 5869 struct btrfs_key key, found_key; 5870 struct btrfs_path *path; 5871 struct extent_buffer *leaf; 5872 int ret; 5873 5874 key.objectid = btrfs_ino(inode); 5875 key.type = BTRFS_DIR_INDEX_KEY; 5876 key.offset = (u64)-1; 5877 5878 path = btrfs_alloc_path(); 5879 if (!path) 5880 return -ENOMEM; 5881 5882 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 5883 if (ret < 0) 5884 goto out; 5885 /* FIXME: we should be able to handle this */ 5886 if (ret == 0) 5887 goto out; 5888 ret = 0; 5889 5890 /* 5891 * MAGIC NUMBER EXPLANATION: 5892 * since we search a directory based on f_pos we have to start at 2 5893 * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody 5894 * else has to start at 2 5895 */ 5896 if (path->slots[0] == 0) { 5897 BTRFS_I(inode)->index_cnt = 2; 5898 goto out; 5899 } 5900 5901 path->slots[0]--; 5902 5903 leaf = path->nodes[0]; 5904 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 5905 5906 if (found_key.objectid != btrfs_ino(inode) || 5907 found_key.type != BTRFS_DIR_INDEX_KEY) { 5908 BTRFS_I(inode)->index_cnt = 2; 5909 goto out; 5910 } 5911 5912 BTRFS_I(inode)->index_cnt = found_key.offset + 1; 5913 out: 5914 btrfs_free_path(path); 5915 return ret; 5916 } 5917 5918 /* 5919 * helper to find a free sequence number in a given directory. This current 5920 * code is very simple, later versions will do smarter things in the btree 5921 */ 5922 int btrfs_set_inode_index(struct inode *dir, u64 *index) 5923 { 5924 int ret = 0; 5925 5926 if (BTRFS_I(dir)->index_cnt == (u64)-1) { 5927 ret = btrfs_inode_delayed_dir_index_count(dir); 5928 if (ret) { 5929 ret = btrfs_set_inode_index_count(dir); 5930 if (ret) 5931 return ret; 5932 } 5933 } 5934 5935 *index = BTRFS_I(dir)->index_cnt; 5936 BTRFS_I(dir)->index_cnt++; 5937 5938 return ret; 5939 } 5940 5941 static int btrfs_insert_inode_locked(struct inode *inode) 5942 { 5943 struct btrfs_iget_args args; 5944 args.location = &BTRFS_I(inode)->location; 5945 args.root = BTRFS_I(inode)->root; 5946 5947 return insert_inode_locked4(inode, 5948 btrfs_inode_hash(inode->i_ino, BTRFS_I(inode)->root), 5949 btrfs_find_actor, &args); 5950 } 5951 5952 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans, 5953 struct btrfs_root *root, 5954 struct inode *dir, 5955 const char *name, int name_len, 5956 u64 ref_objectid, u64 objectid, 5957 umode_t mode, u64 *index) 5958 { 5959 struct inode *inode; 5960 struct btrfs_inode_item *inode_item; 5961 struct btrfs_key *location; 5962 struct btrfs_path *path; 5963 struct btrfs_inode_ref *ref; 5964 struct btrfs_key key[2]; 5965 u32 sizes[2]; 5966 int nitems = name ? 2 : 1; 5967 unsigned long ptr; 5968 int ret; 5969 5970 path = btrfs_alloc_path(); 5971 if (!path) 5972 return ERR_PTR(-ENOMEM); 5973 5974 inode = new_inode(root->fs_info->sb); 5975 if (!inode) { 5976 btrfs_free_path(path); 5977 return ERR_PTR(-ENOMEM); 5978 } 5979 5980 /* 5981 * O_TMPFILE, set link count to 0, so that after this point, 5982 * we fill in an inode item with the correct link count. 5983 */ 5984 if (!name) 5985 set_nlink(inode, 0); 5986 5987 /* 5988 * we have to initialize this early, so we can reclaim the inode 5989 * number if we fail afterwards in this function. 5990 */ 5991 inode->i_ino = objectid; 5992 5993 if (dir && name) { 5994 trace_btrfs_inode_request(dir); 5995 5996 ret = btrfs_set_inode_index(dir, index); 5997 if (ret) { 5998 btrfs_free_path(path); 5999 iput(inode); 6000 return ERR_PTR(ret); 6001 } 6002 } else if (dir) { 6003 *index = 0; 6004 } 6005 /* 6006 * index_cnt is ignored for everything but a dir, 6007 * btrfs_get_inode_index_count has an explanation for the magic 6008 * number 6009 */ 6010 BTRFS_I(inode)->index_cnt = 2; 6011 BTRFS_I(inode)->dir_index = *index; 6012 BTRFS_I(inode)->root = root; 6013 BTRFS_I(inode)->generation = trans->transid; 6014 inode->i_generation = BTRFS_I(inode)->generation; 6015 6016 /* 6017 * We could have gotten an inode number from somebody who was fsynced 6018 * and then removed in this same transaction, so let's just set full 6019 * sync since it will be a full sync anyway and this will blow away the 6020 * old info in the log. 6021 */ 6022 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags); 6023 6024 key[0].objectid = objectid; 6025 key[0].type = BTRFS_INODE_ITEM_KEY; 6026 key[0].offset = 0; 6027 6028 sizes[0] = sizeof(struct btrfs_inode_item); 6029 6030 if (name) { 6031 /* 6032 * Start new inodes with an inode_ref. This is slightly more 6033 * efficient for small numbers of hard links since they will 6034 * be packed into one item. Extended refs will kick in if we 6035 * add more hard links than can fit in the ref item. 6036 */ 6037 key[1].objectid = objectid; 6038 key[1].type = BTRFS_INODE_REF_KEY; 6039 key[1].offset = ref_objectid; 6040 6041 sizes[1] = name_len + sizeof(*ref); 6042 } 6043 6044 location = &BTRFS_I(inode)->location; 6045 location->objectid = objectid; 6046 location->offset = 0; 6047 location->type = BTRFS_INODE_ITEM_KEY; 6048 6049 ret = btrfs_insert_inode_locked(inode); 6050 if (ret < 0) 6051 goto fail; 6052 6053 path->leave_spinning = 1; 6054 ret = btrfs_insert_empty_items(trans, root, path, key, sizes, nitems); 6055 if (ret != 0) 6056 goto fail_unlock; 6057 6058 inode_init_owner(inode, dir, mode); 6059 inode_set_bytes(inode, 0); 6060 6061 inode->i_mtime = CURRENT_TIME; 6062 inode->i_atime = inode->i_mtime; 6063 inode->i_ctime = inode->i_mtime; 6064 BTRFS_I(inode)->i_otime = inode->i_mtime; 6065 6066 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0], 6067 struct btrfs_inode_item); 6068 memset_extent_buffer(path->nodes[0], 0, (unsigned long)inode_item, 6069 sizeof(*inode_item)); 6070 fill_inode_item(trans, path->nodes[0], inode_item, inode); 6071 6072 if (name) { 6073 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1, 6074 struct btrfs_inode_ref); 6075 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len); 6076 btrfs_set_inode_ref_index(path->nodes[0], ref, *index); 6077 ptr = (unsigned long)(ref + 1); 6078 write_extent_buffer(path->nodes[0], name, ptr, name_len); 6079 } 6080 6081 btrfs_mark_buffer_dirty(path->nodes[0]); 6082 btrfs_free_path(path); 6083 6084 btrfs_inherit_iflags(inode, dir); 6085 6086 if (S_ISREG(mode)) { 6087 if (btrfs_test_opt(root, NODATASUM)) 6088 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM; 6089 if (btrfs_test_opt(root, NODATACOW)) 6090 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW | 6091 BTRFS_INODE_NODATASUM; 6092 } 6093 6094 inode_tree_add(inode); 6095 6096 trace_btrfs_inode_new(inode); 6097 btrfs_set_inode_last_trans(trans, inode); 6098 6099 btrfs_update_root_times(trans, root); 6100 6101 ret = btrfs_inode_inherit_props(trans, inode, dir); 6102 if (ret) 6103 btrfs_err(root->fs_info, 6104 "error inheriting props for ino %llu (root %llu): %d", 6105 btrfs_ino(inode), root->root_key.objectid, ret); 6106 6107 return inode; 6108 6109 fail_unlock: 6110 unlock_new_inode(inode); 6111 fail: 6112 if (dir && name) 6113 BTRFS_I(dir)->index_cnt--; 6114 btrfs_free_path(path); 6115 iput(inode); 6116 return ERR_PTR(ret); 6117 } 6118 6119 static inline u8 btrfs_inode_type(struct inode *inode) 6120 { 6121 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT]; 6122 } 6123 6124 /* 6125 * utility function to add 'inode' into 'parent_inode' with 6126 * a give name and a given sequence number. 6127 * if 'add_backref' is true, also insert a backref from the 6128 * inode to the parent directory. 6129 */ 6130 int btrfs_add_link(struct btrfs_trans_handle *trans, 6131 struct inode *parent_inode, struct inode *inode, 6132 const char *name, int name_len, int add_backref, u64 index) 6133 { 6134 int ret = 0; 6135 struct btrfs_key key; 6136 struct btrfs_root *root = BTRFS_I(parent_inode)->root; 6137 u64 ino = btrfs_ino(inode); 6138 u64 parent_ino = btrfs_ino(parent_inode); 6139 6140 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) { 6141 memcpy(&key, &BTRFS_I(inode)->root->root_key, sizeof(key)); 6142 } else { 6143 key.objectid = ino; 6144 key.type = BTRFS_INODE_ITEM_KEY; 6145 key.offset = 0; 6146 } 6147 6148 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) { 6149 ret = btrfs_add_root_ref(trans, root->fs_info->tree_root, 6150 key.objectid, root->root_key.objectid, 6151 parent_ino, index, name, name_len); 6152 } else if (add_backref) { 6153 ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino, 6154 parent_ino, index); 6155 } 6156 6157 /* Nothing to clean up yet */ 6158 if (ret) 6159 return ret; 6160 6161 ret = btrfs_insert_dir_item(trans, root, name, name_len, 6162 parent_inode, &key, 6163 btrfs_inode_type(inode), index); 6164 if (ret == -EEXIST || ret == -EOVERFLOW) 6165 goto fail_dir_item; 6166 else if (ret) { 6167 btrfs_abort_transaction(trans, root, ret); 6168 return ret; 6169 } 6170 6171 btrfs_i_size_write(parent_inode, parent_inode->i_size + 6172 name_len * 2); 6173 inode_inc_iversion(parent_inode); 6174 parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME; 6175 ret = btrfs_update_inode(trans, root, parent_inode); 6176 if (ret) 6177 btrfs_abort_transaction(trans, root, ret); 6178 return ret; 6179 6180 fail_dir_item: 6181 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) { 6182 u64 local_index; 6183 int err; 6184 err = btrfs_del_root_ref(trans, root->fs_info->tree_root, 6185 key.objectid, root->root_key.objectid, 6186 parent_ino, &local_index, name, name_len); 6187 6188 } else if (add_backref) { 6189 u64 local_index; 6190 int err; 6191 6192 err = btrfs_del_inode_ref(trans, root, name, name_len, 6193 ino, parent_ino, &local_index); 6194 } 6195 return ret; 6196 } 6197 6198 static int btrfs_add_nondir(struct btrfs_trans_handle *trans, 6199 struct inode *dir, struct dentry *dentry, 6200 struct inode *inode, int backref, u64 index) 6201 { 6202 int err = btrfs_add_link(trans, dir, inode, 6203 dentry->d_name.name, dentry->d_name.len, 6204 backref, index); 6205 if (err > 0) 6206 err = -EEXIST; 6207 return err; 6208 } 6209 6210 static int btrfs_mknod(struct inode *dir, struct dentry *dentry, 6211 umode_t mode, dev_t rdev) 6212 { 6213 struct btrfs_trans_handle *trans; 6214 struct btrfs_root *root = BTRFS_I(dir)->root; 6215 struct inode *inode = NULL; 6216 int err; 6217 int drop_inode = 0; 6218 u64 objectid; 6219 u64 index = 0; 6220 6221 if (!new_valid_dev(rdev)) 6222 return -EINVAL; 6223 6224 /* 6225 * 2 for inode item and ref 6226 * 2 for dir items 6227 * 1 for xattr if selinux is on 6228 */ 6229 trans = btrfs_start_transaction(root, 5); 6230 if (IS_ERR(trans)) 6231 return PTR_ERR(trans); 6232 6233 err = btrfs_find_free_ino(root, &objectid); 6234 if (err) 6235 goto out_unlock; 6236 6237 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name, 6238 dentry->d_name.len, btrfs_ino(dir), objectid, 6239 mode, &index); 6240 if (IS_ERR(inode)) { 6241 err = PTR_ERR(inode); 6242 goto out_unlock; 6243 } 6244 6245 /* 6246 * If the active LSM wants to access the inode during 6247 * d_instantiate it needs these. Smack checks to see 6248 * if the filesystem supports xattrs by looking at the 6249 * ops vector. 6250 */ 6251 inode->i_op = &btrfs_special_inode_operations; 6252 init_special_inode(inode, inode->i_mode, rdev); 6253 6254 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name); 6255 if (err) 6256 goto out_unlock_inode; 6257 6258 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index); 6259 if (err) { 6260 goto out_unlock_inode; 6261 } else { 6262 btrfs_update_inode(trans, root, inode); 6263 unlock_new_inode(inode); 6264 d_instantiate(dentry, inode); 6265 } 6266 6267 out_unlock: 6268 btrfs_end_transaction(trans, root); 6269 btrfs_balance_delayed_items(root); 6270 btrfs_btree_balance_dirty(root); 6271 if (drop_inode) { 6272 inode_dec_link_count(inode); 6273 iput(inode); 6274 } 6275 return err; 6276 6277 out_unlock_inode: 6278 drop_inode = 1; 6279 unlock_new_inode(inode); 6280 goto out_unlock; 6281 6282 } 6283 6284 static int btrfs_create(struct inode *dir, struct dentry *dentry, 6285 umode_t mode, bool excl) 6286 { 6287 struct btrfs_trans_handle *trans; 6288 struct btrfs_root *root = BTRFS_I(dir)->root; 6289 struct inode *inode = NULL; 6290 int drop_inode_on_err = 0; 6291 int err; 6292 u64 objectid; 6293 u64 index = 0; 6294 6295 /* 6296 * 2 for inode item and ref 6297 * 2 for dir items 6298 * 1 for xattr if selinux is on 6299 */ 6300 trans = btrfs_start_transaction(root, 5); 6301 if (IS_ERR(trans)) 6302 return PTR_ERR(trans); 6303 6304 err = btrfs_find_free_ino(root, &objectid); 6305 if (err) 6306 goto out_unlock; 6307 6308 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name, 6309 dentry->d_name.len, btrfs_ino(dir), objectid, 6310 mode, &index); 6311 if (IS_ERR(inode)) { 6312 err = PTR_ERR(inode); 6313 goto out_unlock; 6314 } 6315 drop_inode_on_err = 1; 6316 /* 6317 * If the active LSM wants to access the inode during 6318 * d_instantiate it needs these. Smack checks to see 6319 * if the filesystem supports xattrs by looking at the 6320 * ops vector. 6321 */ 6322 inode->i_fop = &btrfs_file_operations; 6323 inode->i_op = &btrfs_file_inode_operations; 6324 inode->i_mapping->a_ops = &btrfs_aops; 6325 6326 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name); 6327 if (err) 6328 goto out_unlock_inode; 6329 6330 err = btrfs_update_inode(trans, root, inode); 6331 if (err) 6332 goto out_unlock_inode; 6333 6334 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index); 6335 if (err) 6336 goto out_unlock_inode; 6337 6338 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops; 6339 unlock_new_inode(inode); 6340 d_instantiate(dentry, inode); 6341 6342 out_unlock: 6343 btrfs_end_transaction(trans, root); 6344 if (err && drop_inode_on_err) { 6345 inode_dec_link_count(inode); 6346 iput(inode); 6347 } 6348 btrfs_balance_delayed_items(root); 6349 btrfs_btree_balance_dirty(root); 6350 return err; 6351 6352 out_unlock_inode: 6353 unlock_new_inode(inode); 6354 goto out_unlock; 6355 6356 } 6357 6358 static int btrfs_link(struct dentry *old_dentry, struct inode *dir, 6359 struct dentry *dentry) 6360 { 6361 struct btrfs_trans_handle *trans; 6362 struct btrfs_root *root = BTRFS_I(dir)->root; 6363 struct inode *inode = d_inode(old_dentry); 6364 u64 index; 6365 int err; 6366 int drop_inode = 0; 6367 6368 /* do not allow sys_link's with other subvols of the same device */ 6369 if (root->objectid != BTRFS_I(inode)->root->objectid) 6370 return -EXDEV; 6371 6372 if (inode->i_nlink >= BTRFS_LINK_MAX) 6373 return -EMLINK; 6374 6375 err = btrfs_set_inode_index(dir, &index); 6376 if (err) 6377 goto fail; 6378 6379 /* 6380 * 2 items for inode and inode ref 6381 * 2 items for dir items 6382 * 1 item for parent inode 6383 */ 6384 trans = btrfs_start_transaction(root, 5); 6385 if (IS_ERR(trans)) { 6386 err = PTR_ERR(trans); 6387 goto fail; 6388 } 6389 6390 /* There are several dir indexes for this inode, clear the cache. */ 6391 BTRFS_I(inode)->dir_index = 0ULL; 6392 inc_nlink(inode); 6393 inode_inc_iversion(inode); 6394 inode->i_ctime = CURRENT_TIME; 6395 ihold(inode); 6396 set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags); 6397 6398 err = btrfs_add_nondir(trans, dir, dentry, inode, 1, index); 6399 6400 if (err) { 6401 drop_inode = 1; 6402 } else { 6403 struct dentry *parent = dentry->d_parent; 6404 err = btrfs_update_inode(trans, root, inode); 6405 if (err) 6406 goto fail; 6407 if (inode->i_nlink == 1) { 6408 /* 6409 * If new hard link count is 1, it's a file created 6410 * with open(2) O_TMPFILE flag. 6411 */ 6412 err = btrfs_orphan_del(trans, inode); 6413 if (err) 6414 goto fail; 6415 } 6416 d_instantiate(dentry, inode); 6417 btrfs_log_new_name(trans, inode, NULL, parent); 6418 } 6419 6420 btrfs_end_transaction(trans, root); 6421 btrfs_balance_delayed_items(root); 6422 fail: 6423 if (drop_inode) { 6424 inode_dec_link_count(inode); 6425 iput(inode); 6426 } 6427 btrfs_btree_balance_dirty(root); 6428 return err; 6429 } 6430 6431 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) 6432 { 6433 struct inode *inode = NULL; 6434 struct btrfs_trans_handle *trans; 6435 struct btrfs_root *root = BTRFS_I(dir)->root; 6436 int err = 0; 6437 int drop_on_err = 0; 6438 u64 objectid = 0; 6439 u64 index = 0; 6440 6441 /* 6442 * 2 items for inode and ref 6443 * 2 items for dir items 6444 * 1 for xattr if selinux is on 6445 */ 6446 trans = btrfs_start_transaction(root, 5); 6447 if (IS_ERR(trans)) 6448 return PTR_ERR(trans); 6449 6450 err = btrfs_find_free_ino(root, &objectid); 6451 if (err) 6452 goto out_fail; 6453 6454 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name, 6455 dentry->d_name.len, btrfs_ino(dir), objectid, 6456 S_IFDIR | mode, &index); 6457 if (IS_ERR(inode)) { 6458 err = PTR_ERR(inode); 6459 goto out_fail; 6460 } 6461 6462 drop_on_err = 1; 6463 /* these must be set before we unlock the inode */ 6464 inode->i_op = &btrfs_dir_inode_operations; 6465 inode->i_fop = &btrfs_dir_file_operations; 6466 6467 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name); 6468 if (err) 6469 goto out_fail_inode; 6470 6471 btrfs_i_size_write(inode, 0); 6472 err = btrfs_update_inode(trans, root, inode); 6473 if (err) 6474 goto out_fail_inode; 6475 6476 err = btrfs_add_link(trans, dir, inode, dentry->d_name.name, 6477 dentry->d_name.len, 0, index); 6478 if (err) 6479 goto out_fail_inode; 6480 6481 d_instantiate(dentry, inode); 6482 /* 6483 * mkdir is special. We're unlocking after we call d_instantiate 6484 * to avoid a race with nfsd calling d_instantiate. 6485 */ 6486 unlock_new_inode(inode); 6487 drop_on_err = 0; 6488 6489 out_fail: 6490 btrfs_end_transaction(trans, root); 6491 if (drop_on_err) { 6492 inode_dec_link_count(inode); 6493 iput(inode); 6494 } 6495 btrfs_balance_delayed_items(root); 6496 btrfs_btree_balance_dirty(root); 6497 return err; 6498 6499 out_fail_inode: 6500 unlock_new_inode(inode); 6501 goto out_fail; 6502 } 6503 6504 /* Find next extent map of a given extent map, caller needs to ensure locks */ 6505 static struct extent_map *next_extent_map(struct extent_map *em) 6506 { 6507 struct rb_node *next; 6508 6509 next = rb_next(&em->rb_node); 6510 if (!next) 6511 return NULL; 6512 return container_of(next, struct extent_map, rb_node); 6513 } 6514 6515 static struct extent_map *prev_extent_map(struct extent_map *em) 6516 { 6517 struct rb_node *prev; 6518 6519 prev = rb_prev(&em->rb_node); 6520 if (!prev) 6521 return NULL; 6522 return container_of(prev, struct extent_map, rb_node); 6523 } 6524 6525 /* helper for btfs_get_extent. Given an existing extent in the tree, 6526 * the existing extent is the nearest extent to map_start, 6527 * and an extent that you want to insert, deal with overlap and insert 6528 * the best fitted new extent into the tree. 6529 */ 6530 static int merge_extent_mapping(struct extent_map_tree *em_tree, 6531 struct extent_map *existing, 6532 struct extent_map *em, 6533 u64 map_start) 6534 { 6535 struct extent_map *prev; 6536 struct extent_map *next; 6537 u64 start; 6538 u64 end; 6539 u64 start_diff; 6540 6541 BUG_ON(map_start < em->start || map_start >= extent_map_end(em)); 6542 6543 if (existing->start > map_start) { 6544 next = existing; 6545 prev = prev_extent_map(next); 6546 } else { 6547 prev = existing; 6548 next = next_extent_map(prev); 6549 } 6550 6551 start = prev ? extent_map_end(prev) : em->start; 6552 start = max_t(u64, start, em->start); 6553 end = next ? next->start : extent_map_end(em); 6554 end = min_t(u64, end, extent_map_end(em)); 6555 start_diff = start - em->start; 6556 em->start = start; 6557 em->len = end - start; 6558 if (em->block_start < EXTENT_MAP_LAST_BYTE && 6559 !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) { 6560 em->block_start += start_diff; 6561 em->block_len -= start_diff; 6562 } 6563 return add_extent_mapping(em_tree, em, 0); 6564 } 6565 6566 static noinline int uncompress_inline(struct btrfs_path *path, 6567 struct inode *inode, struct page *page, 6568 size_t pg_offset, u64 extent_offset, 6569 struct btrfs_file_extent_item *item) 6570 { 6571 int ret; 6572 struct extent_buffer *leaf = path->nodes[0]; 6573 char *tmp; 6574 size_t max_size; 6575 unsigned long inline_size; 6576 unsigned long ptr; 6577 int compress_type; 6578 6579 WARN_ON(pg_offset != 0); 6580 compress_type = btrfs_file_extent_compression(leaf, item); 6581 max_size = btrfs_file_extent_ram_bytes(leaf, item); 6582 inline_size = btrfs_file_extent_inline_item_len(leaf, 6583 btrfs_item_nr(path->slots[0])); 6584 tmp = kmalloc(inline_size, GFP_NOFS); 6585 if (!tmp) 6586 return -ENOMEM; 6587 ptr = btrfs_file_extent_inline_start(item); 6588 6589 read_extent_buffer(leaf, tmp, ptr, inline_size); 6590 6591 max_size = min_t(unsigned long, PAGE_CACHE_SIZE, max_size); 6592 ret = btrfs_decompress(compress_type, tmp, page, 6593 extent_offset, inline_size, max_size); 6594 kfree(tmp); 6595 return ret; 6596 } 6597 6598 /* 6599 * a bit scary, this does extent mapping from logical file offset to the disk. 6600 * the ugly parts come from merging extents from the disk with the in-ram 6601 * representation. This gets more complex because of the data=ordered code, 6602 * where the in-ram extents might be locked pending data=ordered completion. 6603 * 6604 * This also copies inline extents directly into the page. 6605 */ 6606 6607 struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page, 6608 size_t pg_offset, u64 start, u64 len, 6609 int create) 6610 { 6611 int ret; 6612 int err = 0; 6613 u64 extent_start = 0; 6614 u64 extent_end = 0; 6615 u64 objectid = btrfs_ino(inode); 6616 u32 found_type; 6617 struct btrfs_path *path = NULL; 6618 struct btrfs_root *root = BTRFS_I(inode)->root; 6619 struct btrfs_file_extent_item *item; 6620 struct extent_buffer *leaf; 6621 struct btrfs_key found_key; 6622 struct extent_map *em = NULL; 6623 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; 6624 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 6625 struct btrfs_trans_handle *trans = NULL; 6626 const bool new_inline = !page || create; 6627 6628 again: 6629 read_lock(&em_tree->lock); 6630 em = lookup_extent_mapping(em_tree, start, len); 6631 if (em) 6632 em->bdev = root->fs_info->fs_devices->latest_bdev; 6633 read_unlock(&em_tree->lock); 6634 6635 if (em) { 6636 if (em->start > start || em->start + em->len <= start) 6637 free_extent_map(em); 6638 else if (em->block_start == EXTENT_MAP_INLINE && page) 6639 free_extent_map(em); 6640 else 6641 goto out; 6642 } 6643 em = alloc_extent_map(); 6644 if (!em) { 6645 err = -ENOMEM; 6646 goto out; 6647 } 6648 em->bdev = root->fs_info->fs_devices->latest_bdev; 6649 em->start = EXTENT_MAP_HOLE; 6650 em->orig_start = EXTENT_MAP_HOLE; 6651 em->len = (u64)-1; 6652 em->block_len = (u64)-1; 6653 6654 if (!path) { 6655 path = btrfs_alloc_path(); 6656 if (!path) { 6657 err = -ENOMEM; 6658 goto out; 6659 } 6660 /* 6661 * Chances are we'll be called again, so go ahead and do 6662 * readahead 6663 */ 6664 path->reada = 1; 6665 } 6666 6667 ret = btrfs_lookup_file_extent(trans, root, path, 6668 objectid, start, trans != NULL); 6669 if (ret < 0) { 6670 err = ret; 6671 goto out; 6672 } 6673 6674 if (ret != 0) { 6675 if (path->slots[0] == 0) 6676 goto not_found; 6677 path->slots[0]--; 6678 } 6679 6680 leaf = path->nodes[0]; 6681 item = btrfs_item_ptr(leaf, path->slots[0], 6682 struct btrfs_file_extent_item); 6683 /* are we inside the extent that was found? */ 6684 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 6685 found_type = found_key.type; 6686 if (found_key.objectid != objectid || 6687 found_type != BTRFS_EXTENT_DATA_KEY) { 6688 /* 6689 * If we backup past the first extent we want to move forward 6690 * and see if there is an extent in front of us, otherwise we'll 6691 * say there is a hole for our whole search range which can 6692 * cause problems. 6693 */ 6694 extent_end = start; 6695 goto next; 6696 } 6697 6698 found_type = btrfs_file_extent_type(leaf, item); 6699 extent_start = found_key.offset; 6700 if (found_type == BTRFS_FILE_EXTENT_REG || 6701 found_type == BTRFS_FILE_EXTENT_PREALLOC) { 6702 extent_end = extent_start + 6703 btrfs_file_extent_num_bytes(leaf, item); 6704 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) { 6705 size_t size; 6706 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item); 6707 extent_end = ALIGN(extent_start + size, root->sectorsize); 6708 } 6709 next: 6710 if (start >= extent_end) { 6711 path->slots[0]++; 6712 if (path->slots[0] >= btrfs_header_nritems(leaf)) { 6713 ret = btrfs_next_leaf(root, path); 6714 if (ret < 0) { 6715 err = ret; 6716 goto out; 6717 } 6718 if (ret > 0) 6719 goto not_found; 6720 leaf = path->nodes[0]; 6721 } 6722 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 6723 if (found_key.objectid != objectid || 6724 found_key.type != BTRFS_EXTENT_DATA_KEY) 6725 goto not_found; 6726 if (start + len <= found_key.offset) 6727 goto not_found; 6728 if (start > found_key.offset) 6729 goto next; 6730 em->start = start; 6731 em->orig_start = start; 6732 em->len = found_key.offset - start; 6733 goto not_found_em; 6734 } 6735 6736 btrfs_extent_item_to_extent_map(inode, path, item, new_inline, em); 6737 6738 if (found_type == BTRFS_FILE_EXTENT_REG || 6739 found_type == BTRFS_FILE_EXTENT_PREALLOC) { 6740 goto insert; 6741 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) { 6742 unsigned long ptr; 6743 char *map; 6744 size_t size; 6745 size_t extent_offset; 6746 size_t copy_size; 6747 6748 if (new_inline) 6749 goto out; 6750 6751 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item); 6752 extent_offset = page_offset(page) + pg_offset - extent_start; 6753 copy_size = min_t(u64, PAGE_CACHE_SIZE - pg_offset, 6754 size - extent_offset); 6755 em->start = extent_start + extent_offset; 6756 em->len = ALIGN(copy_size, root->sectorsize); 6757 em->orig_block_len = em->len; 6758 em->orig_start = em->start; 6759 ptr = btrfs_file_extent_inline_start(item) + extent_offset; 6760 if (create == 0 && !PageUptodate(page)) { 6761 if (btrfs_file_extent_compression(leaf, item) != 6762 BTRFS_COMPRESS_NONE) { 6763 ret = uncompress_inline(path, inode, page, 6764 pg_offset, 6765 extent_offset, item); 6766 if (ret) { 6767 err = ret; 6768 goto out; 6769 } 6770 } else { 6771 map = kmap(page); 6772 read_extent_buffer(leaf, map + pg_offset, ptr, 6773 copy_size); 6774 if (pg_offset + copy_size < PAGE_CACHE_SIZE) { 6775 memset(map + pg_offset + copy_size, 0, 6776 PAGE_CACHE_SIZE - pg_offset - 6777 copy_size); 6778 } 6779 kunmap(page); 6780 } 6781 flush_dcache_page(page); 6782 } else if (create && PageUptodate(page)) { 6783 BUG(); 6784 if (!trans) { 6785 kunmap(page); 6786 free_extent_map(em); 6787 em = NULL; 6788 6789 btrfs_release_path(path); 6790 trans = btrfs_join_transaction(root); 6791 6792 if (IS_ERR(trans)) 6793 return ERR_CAST(trans); 6794 goto again; 6795 } 6796 map = kmap(page); 6797 write_extent_buffer(leaf, map + pg_offset, ptr, 6798 copy_size); 6799 kunmap(page); 6800 btrfs_mark_buffer_dirty(leaf); 6801 } 6802 set_extent_uptodate(io_tree, em->start, 6803 extent_map_end(em) - 1, NULL, GFP_NOFS); 6804 goto insert; 6805 } 6806 not_found: 6807 em->start = start; 6808 em->orig_start = start; 6809 em->len = len; 6810 not_found_em: 6811 em->block_start = EXTENT_MAP_HOLE; 6812 set_bit(EXTENT_FLAG_VACANCY, &em->flags); 6813 insert: 6814 btrfs_release_path(path); 6815 if (em->start > start || extent_map_end(em) <= start) { 6816 btrfs_err(root->fs_info, "bad extent! em: [%llu %llu] passed [%llu %llu]", 6817 em->start, em->len, start, len); 6818 err = -EIO; 6819 goto out; 6820 } 6821 6822 err = 0; 6823 write_lock(&em_tree->lock); 6824 ret = add_extent_mapping(em_tree, em, 0); 6825 /* it is possible that someone inserted the extent into the tree 6826 * while we had the lock dropped. It is also possible that 6827 * an overlapping map exists in the tree 6828 */ 6829 if (ret == -EEXIST) { 6830 struct extent_map *existing; 6831 6832 ret = 0; 6833 6834 existing = search_extent_mapping(em_tree, start, len); 6835 /* 6836 * existing will always be non-NULL, since there must be 6837 * extent causing the -EEXIST. 6838 */ 6839 if (start >= extent_map_end(existing) || 6840 start <= existing->start) { 6841 /* 6842 * The existing extent map is the one nearest to 6843 * the [start, start + len) range which overlaps 6844 */ 6845 err = merge_extent_mapping(em_tree, existing, 6846 em, start); 6847 free_extent_map(existing); 6848 if (err) { 6849 free_extent_map(em); 6850 em = NULL; 6851 } 6852 } else { 6853 free_extent_map(em); 6854 em = existing; 6855 err = 0; 6856 } 6857 } 6858 write_unlock(&em_tree->lock); 6859 out: 6860 6861 trace_btrfs_get_extent(root, em); 6862 6863 if (path) 6864 btrfs_free_path(path); 6865 if (trans) { 6866 ret = btrfs_end_transaction(trans, root); 6867 if (!err) 6868 err = ret; 6869 } 6870 if (err) { 6871 free_extent_map(em); 6872 return ERR_PTR(err); 6873 } 6874 BUG_ON(!em); /* Error is always set */ 6875 return em; 6876 } 6877 6878 struct extent_map *btrfs_get_extent_fiemap(struct inode *inode, struct page *page, 6879 size_t pg_offset, u64 start, u64 len, 6880 int create) 6881 { 6882 struct extent_map *em; 6883 struct extent_map *hole_em = NULL; 6884 u64 range_start = start; 6885 u64 end; 6886 u64 found; 6887 u64 found_end; 6888 int err = 0; 6889 6890 em = btrfs_get_extent(inode, page, pg_offset, start, len, create); 6891 if (IS_ERR(em)) 6892 return em; 6893 if (em) { 6894 /* 6895 * if our em maps to 6896 * - a hole or 6897 * - a pre-alloc extent, 6898 * there might actually be delalloc bytes behind it. 6899 */ 6900 if (em->block_start != EXTENT_MAP_HOLE && 6901 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) 6902 return em; 6903 else 6904 hole_em = em; 6905 } 6906 6907 /* check to see if we've wrapped (len == -1 or similar) */ 6908 end = start + len; 6909 if (end < start) 6910 end = (u64)-1; 6911 else 6912 end -= 1; 6913 6914 em = NULL; 6915 6916 /* ok, we didn't find anything, lets look for delalloc */ 6917 found = count_range_bits(&BTRFS_I(inode)->io_tree, &range_start, 6918 end, len, EXTENT_DELALLOC, 1); 6919 found_end = range_start + found; 6920 if (found_end < range_start) 6921 found_end = (u64)-1; 6922 6923 /* 6924 * we didn't find anything useful, return 6925 * the original results from get_extent() 6926 */ 6927 if (range_start > end || found_end <= start) { 6928 em = hole_em; 6929 hole_em = NULL; 6930 goto out; 6931 } 6932 6933 /* adjust the range_start to make sure it doesn't 6934 * go backwards from the start they passed in 6935 */ 6936 range_start = max(start, range_start); 6937 found = found_end - range_start; 6938 6939 if (found > 0) { 6940 u64 hole_start = start; 6941 u64 hole_len = len; 6942 6943 em = alloc_extent_map(); 6944 if (!em) { 6945 err = -ENOMEM; 6946 goto out; 6947 } 6948 /* 6949 * when btrfs_get_extent can't find anything it 6950 * returns one huge hole 6951 * 6952 * make sure what it found really fits our range, and 6953 * adjust to make sure it is based on the start from 6954 * the caller 6955 */ 6956 if (hole_em) { 6957 u64 calc_end = extent_map_end(hole_em); 6958 6959 if (calc_end <= start || (hole_em->start > end)) { 6960 free_extent_map(hole_em); 6961 hole_em = NULL; 6962 } else { 6963 hole_start = max(hole_em->start, start); 6964 hole_len = calc_end - hole_start; 6965 } 6966 } 6967 em->bdev = NULL; 6968 if (hole_em && range_start > hole_start) { 6969 /* our hole starts before our delalloc, so we 6970 * have to return just the parts of the hole 6971 * that go until the delalloc starts 6972 */ 6973 em->len = min(hole_len, 6974 range_start - hole_start); 6975 em->start = hole_start; 6976 em->orig_start = hole_start; 6977 /* 6978 * don't adjust block start at all, 6979 * it is fixed at EXTENT_MAP_HOLE 6980 */ 6981 em->block_start = hole_em->block_start; 6982 em->block_len = hole_len; 6983 if (test_bit(EXTENT_FLAG_PREALLOC, &hole_em->flags)) 6984 set_bit(EXTENT_FLAG_PREALLOC, &em->flags); 6985 } else { 6986 em->start = range_start; 6987 em->len = found; 6988 em->orig_start = range_start; 6989 em->block_start = EXTENT_MAP_DELALLOC; 6990 em->block_len = found; 6991 } 6992 } else if (hole_em) { 6993 return hole_em; 6994 } 6995 out: 6996 6997 free_extent_map(hole_em); 6998 if (err) { 6999 free_extent_map(em); 7000 return ERR_PTR(err); 7001 } 7002 return em; 7003 } 7004 7005 static struct extent_map *btrfs_new_extent_direct(struct inode *inode, 7006 u64 start, u64 len) 7007 { 7008 struct btrfs_root *root = BTRFS_I(inode)->root; 7009 struct extent_map *em; 7010 struct btrfs_key ins; 7011 u64 alloc_hint; 7012 int ret; 7013 7014 alloc_hint = get_extent_allocation_hint(inode, start, len); 7015 ret = btrfs_reserve_extent(root, len, root->sectorsize, 0, 7016 alloc_hint, &ins, 1, 1); 7017 if (ret) 7018 return ERR_PTR(ret); 7019 7020 em = create_pinned_em(inode, start, ins.offset, start, ins.objectid, 7021 ins.offset, ins.offset, ins.offset, 0); 7022 if (IS_ERR(em)) { 7023 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1); 7024 return em; 7025 } 7026 7027 ret = btrfs_add_ordered_extent_dio(inode, start, ins.objectid, 7028 ins.offset, ins.offset, 0); 7029 if (ret) { 7030 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1); 7031 free_extent_map(em); 7032 return ERR_PTR(ret); 7033 } 7034 7035 return em; 7036 } 7037 7038 /* 7039 * returns 1 when the nocow is safe, < 1 on error, 0 if the 7040 * block must be cow'd 7041 */ 7042 noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len, 7043 u64 *orig_start, u64 *orig_block_len, 7044 u64 *ram_bytes) 7045 { 7046 struct btrfs_trans_handle *trans; 7047 struct btrfs_path *path; 7048 int ret; 7049 struct extent_buffer *leaf; 7050 struct btrfs_root *root = BTRFS_I(inode)->root; 7051 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 7052 struct btrfs_file_extent_item *fi; 7053 struct btrfs_key key; 7054 u64 disk_bytenr; 7055 u64 backref_offset; 7056 u64 extent_end; 7057 u64 num_bytes; 7058 int slot; 7059 int found_type; 7060 bool nocow = (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW); 7061 7062 path = btrfs_alloc_path(); 7063 if (!path) 7064 return -ENOMEM; 7065 7066 ret = btrfs_lookup_file_extent(NULL, root, path, btrfs_ino(inode), 7067 offset, 0); 7068 if (ret < 0) 7069 goto out; 7070 7071 slot = path->slots[0]; 7072 if (ret == 1) { 7073 if (slot == 0) { 7074 /* can't find the item, must cow */ 7075 ret = 0; 7076 goto out; 7077 } 7078 slot--; 7079 } 7080 ret = 0; 7081 leaf = path->nodes[0]; 7082 btrfs_item_key_to_cpu(leaf, &key, slot); 7083 if (key.objectid != btrfs_ino(inode) || 7084 key.type != BTRFS_EXTENT_DATA_KEY) { 7085 /* not our file or wrong item type, must cow */ 7086 goto out; 7087 } 7088 7089 if (key.offset > offset) { 7090 /* Wrong offset, must cow */ 7091 goto out; 7092 } 7093 7094 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item); 7095 found_type = btrfs_file_extent_type(leaf, fi); 7096 if (found_type != BTRFS_FILE_EXTENT_REG && 7097 found_type != BTRFS_FILE_EXTENT_PREALLOC) { 7098 /* not a regular extent, must cow */ 7099 goto out; 7100 } 7101 7102 if (!nocow && found_type == BTRFS_FILE_EXTENT_REG) 7103 goto out; 7104 7105 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi); 7106 if (extent_end <= offset) 7107 goto out; 7108 7109 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); 7110 if (disk_bytenr == 0) 7111 goto out; 7112 7113 if (btrfs_file_extent_compression(leaf, fi) || 7114 btrfs_file_extent_encryption(leaf, fi) || 7115 btrfs_file_extent_other_encoding(leaf, fi)) 7116 goto out; 7117 7118 backref_offset = btrfs_file_extent_offset(leaf, fi); 7119 7120 if (orig_start) { 7121 *orig_start = key.offset - backref_offset; 7122 *orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi); 7123 *ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi); 7124 } 7125 7126 if (btrfs_extent_readonly(root, disk_bytenr)) 7127 goto out; 7128 7129 num_bytes = min(offset + *len, extent_end) - offset; 7130 if (!nocow && found_type == BTRFS_FILE_EXTENT_PREALLOC) { 7131 u64 range_end; 7132 7133 range_end = round_up(offset + num_bytes, root->sectorsize) - 1; 7134 ret = test_range_bit(io_tree, offset, range_end, 7135 EXTENT_DELALLOC, 0, NULL); 7136 if (ret) { 7137 ret = -EAGAIN; 7138 goto out; 7139 } 7140 } 7141 7142 btrfs_release_path(path); 7143 7144 /* 7145 * look for other files referencing this extent, if we 7146 * find any we must cow 7147 */ 7148 trans = btrfs_join_transaction(root); 7149 if (IS_ERR(trans)) { 7150 ret = 0; 7151 goto out; 7152 } 7153 7154 ret = btrfs_cross_ref_exist(trans, root, btrfs_ino(inode), 7155 key.offset - backref_offset, disk_bytenr); 7156 btrfs_end_transaction(trans, root); 7157 if (ret) { 7158 ret = 0; 7159 goto out; 7160 } 7161 7162 /* 7163 * adjust disk_bytenr and num_bytes to cover just the bytes 7164 * in this extent we are about to write. If there 7165 * are any csums in that range we have to cow in order 7166 * to keep the csums correct 7167 */ 7168 disk_bytenr += backref_offset; 7169 disk_bytenr += offset - key.offset; 7170 if (csum_exist_in_range(root, disk_bytenr, num_bytes)) 7171 goto out; 7172 /* 7173 * all of the above have passed, it is safe to overwrite this extent 7174 * without cow 7175 */ 7176 *len = num_bytes; 7177 ret = 1; 7178 out: 7179 btrfs_free_path(path); 7180 return ret; 7181 } 7182 7183 bool btrfs_page_exists_in_range(struct inode *inode, loff_t start, loff_t end) 7184 { 7185 struct radix_tree_root *root = &inode->i_mapping->page_tree; 7186 int found = false; 7187 void **pagep = NULL; 7188 struct page *page = NULL; 7189 int start_idx; 7190 int end_idx; 7191 7192 start_idx = start >> PAGE_CACHE_SHIFT; 7193 7194 /* 7195 * end is the last byte in the last page. end == start is legal 7196 */ 7197 end_idx = end >> PAGE_CACHE_SHIFT; 7198 7199 rcu_read_lock(); 7200 7201 /* Most of the code in this while loop is lifted from 7202 * find_get_page. It's been modified to begin searching from a 7203 * page and return just the first page found in that range. If the 7204 * found idx is less than or equal to the end idx then we know that 7205 * a page exists. If no pages are found or if those pages are 7206 * outside of the range then we're fine (yay!) */ 7207 while (page == NULL && 7208 radix_tree_gang_lookup_slot(root, &pagep, NULL, start_idx, 1)) { 7209 page = radix_tree_deref_slot(pagep); 7210 if (unlikely(!page)) 7211 break; 7212 7213 if (radix_tree_exception(page)) { 7214 if (radix_tree_deref_retry(page)) { 7215 page = NULL; 7216 continue; 7217 } 7218 /* 7219 * Otherwise, shmem/tmpfs must be storing a swap entry 7220 * here as an exceptional entry: so return it without 7221 * attempting to raise page count. 7222 */ 7223 page = NULL; 7224 break; /* TODO: Is this relevant for this use case? */ 7225 } 7226 7227 if (!page_cache_get_speculative(page)) { 7228 page = NULL; 7229 continue; 7230 } 7231 7232 /* 7233 * Has the page moved? 7234 * This is part of the lockless pagecache protocol. See 7235 * include/linux/pagemap.h for details. 7236 */ 7237 if (unlikely(page != *pagep)) { 7238 page_cache_release(page); 7239 page = NULL; 7240 } 7241 } 7242 7243 if (page) { 7244 if (page->index <= end_idx) 7245 found = true; 7246 page_cache_release(page); 7247 } 7248 7249 rcu_read_unlock(); 7250 return found; 7251 } 7252 7253 static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend, 7254 struct extent_state **cached_state, int writing) 7255 { 7256 struct btrfs_ordered_extent *ordered; 7257 int ret = 0; 7258 7259 while (1) { 7260 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend, 7261 0, cached_state); 7262 /* 7263 * We're concerned with the entire range that we're going to be 7264 * doing DIO to, so we need to make sure theres no ordered 7265 * extents in this range. 7266 */ 7267 ordered = btrfs_lookup_ordered_range(inode, lockstart, 7268 lockend - lockstart + 1); 7269 7270 /* 7271 * We need to make sure there are no buffered pages in this 7272 * range either, we could have raced between the invalidate in 7273 * generic_file_direct_write and locking the extent. The 7274 * invalidate needs to happen so that reads after a write do not 7275 * get stale data. 7276 */ 7277 if (!ordered && 7278 (!writing || 7279 !btrfs_page_exists_in_range(inode, lockstart, lockend))) 7280 break; 7281 7282 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend, 7283 cached_state, GFP_NOFS); 7284 7285 if (ordered) { 7286 btrfs_start_ordered_extent(inode, ordered, 1); 7287 btrfs_put_ordered_extent(ordered); 7288 } else { 7289 /* Screw you mmap */ 7290 ret = btrfs_fdatawrite_range(inode, lockstart, lockend); 7291 if (ret) 7292 break; 7293 ret = filemap_fdatawait_range(inode->i_mapping, 7294 lockstart, 7295 lockend); 7296 if (ret) 7297 break; 7298 7299 /* 7300 * If we found a page that couldn't be invalidated just 7301 * fall back to buffered. 7302 */ 7303 ret = invalidate_inode_pages2_range(inode->i_mapping, 7304 lockstart >> PAGE_CACHE_SHIFT, 7305 lockend >> PAGE_CACHE_SHIFT); 7306 if (ret) 7307 break; 7308 } 7309 7310 cond_resched(); 7311 } 7312 7313 return ret; 7314 } 7315 7316 static struct extent_map *create_pinned_em(struct inode *inode, u64 start, 7317 u64 len, u64 orig_start, 7318 u64 block_start, u64 block_len, 7319 u64 orig_block_len, u64 ram_bytes, 7320 int type) 7321 { 7322 struct extent_map_tree *em_tree; 7323 struct extent_map *em; 7324 struct btrfs_root *root = BTRFS_I(inode)->root; 7325 int ret; 7326 7327 em_tree = &BTRFS_I(inode)->extent_tree; 7328 em = alloc_extent_map(); 7329 if (!em) 7330 return ERR_PTR(-ENOMEM); 7331 7332 em->start = start; 7333 em->orig_start = orig_start; 7334 em->mod_start = start; 7335 em->mod_len = len; 7336 em->len = len; 7337 em->block_len = block_len; 7338 em->block_start = block_start; 7339 em->bdev = root->fs_info->fs_devices->latest_bdev; 7340 em->orig_block_len = orig_block_len; 7341 em->ram_bytes = ram_bytes; 7342 em->generation = -1; 7343 set_bit(EXTENT_FLAG_PINNED, &em->flags); 7344 if (type == BTRFS_ORDERED_PREALLOC) 7345 set_bit(EXTENT_FLAG_FILLING, &em->flags); 7346 7347 do { 7348 btrfs_drop_extent_cache(inode, em->start, 7349 em->start + em->len - 1, 0); 7350 write_lock(&em_tree->lock); 7351 ret = add_extent_mapping(em_tree, em, 1); 7352 write_unlock(&em_tree->lock); 7353 } while (ret == -EEXIST); 7354 7355 if (ret) { 7356 free_extent_map(em); 7357 return ERR_PTR(ret); 7358 } 7359 7360 return em; 7361 } 7362 7363 7364 static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock, 7365 struct buffer_head *bh_result, int create) 7366 { 7367 struct extent_map *em; 7368 struct btrfs_root *root = BTRFS_I(inode)->root; 7369 struct extent_state *cached_state = NULL; 7370 u64 start = iblock << inode->i_blkbits; 7371 u64 lockstart, lockend; 7372 u64 len = bh_result->b_size; 7373 u64 *outstanding_extents = NULL; 7374 int unlock_bits = EXTENT_LOCKED; 7375 int ret = 0; 7376 7377 if (create) 7378 unlock_bits |= EXTENT_DIRTY; 7379 else 7380 len = min_t(u64, len, root->sectorsize); 7381 7382 lockstart = start; 7383 lockend = start + len - 1; 7384 7385 if (current->journal_info) { 7386 /* 7387 * Need to pull our outstanding extents and set journal_info to NULL so 7388 * that anything that needs to check if there's a transction doesn't get 7389 * confused. 7390 */ 7391 outstanding_extents = current->journal_info; 7392 current->journal_info = NULL; 7393 } 7394 7395 /* 7396 * If this errors out it's because we couldn't invalidate pagecache for 7397 * this range and we need to fallback to buffered. 7398 */ 7399 if (lock_extent_direct(inode, lockstart, lockend, &cached_state, create)) 7400 return -ENOTBLK; 7401 7402 em = btrfs_get_extent(inode, NULL, 0, start, len, 0); 7403 if (IS_ERR(em)) { 7404 ret = PTR_ERR(em); 7405 goto unlock_err; 7406 } 7407 7408 /* 7409 * Ok for INLINE and COMPRESSED extents we need to fallback on buffered 7410 * io. INLINE is special, and we could probably kludge it in here, but 7411 * it's still buffered so for safety lets just fall back to the generic 7412 * buffered path. 7413 * 7414 * For COMPRESSED we _have_ to read the entire extent in so we can 7415 * decompress it, so there will be buffering required no matter what we 7416 * do, so go ahead and fallback to buffered. 7417 * 7418 * We return -ENOTBLK because thats what makes DIO go ahead and go back 7419 * to buffered IO. Don't blame me, this is the price we pay for using 7420 * the generic code. 7421 */ 7422 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) || 7423 em->block_start == EXTENT_MAP_INLINE) { 7424 free_extent_map(em); 7425 ret = -ENOTBLK; 7426 goto unlock_err; 7427 } 7428 7429 /* Just a good old fashioned hole, return */ 7430 if (!create && (em->block_start == EXTENT_MAP_HOLE || 7431 test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) { 7432 free_extent_map(em); 7433 goto unlock_err; 7434 } 7435 7436 /* 7437 * We don't allocate a new extent in the following cases 7438 * 7439 * 1) The inode is marked as NODATACOW. In this case we'll just use the 7440 * existing extent. 7441 * 2) The extent is marked as PREALLOC. We're good to go here and can 7442 * just use the extent. 7443 * 7444 */ 7445 if (!create) { 7446 len = min(len, em->len - (start - em->start)); 7447 lockstart = start + len; 7448 goto unlock; 7449 } 7450 7451 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) || 7452 ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) && 7453 em->block_start != EXTENT_MAP_HOLE)) { 7454 int type; 7455 u64 block_start, orig_start, orig_block_len, ram_bytes; 7456 7457 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) 7458 type = BTRFS_ORDERED_PREALLOC; 7459 else 7460 type = BTRFS_ORDERED_NOCOW; 7461 len = min(len, em->len - (start - em->start)); 7462 block_start = em->block_start + (start - em->start); 7463 7464 if (can_nocow_extent(inode, start, &len, &orig_start, 7465 &orig_block_len, &ram_bytes) == 1) { 7466 if (type == BTRFS_ORDERED_PREALLOC) { 7467 free_extent_map(em); 7468 em = create_pinned_em(inode, start, len, 7469 orig_start, 7470 block_start, len, 7471 orig_block_len, 7472 ram_bytes, type); 7473 if (IS_ERR(em)) { 7474 ret = PTR_ERR(em); 7475 goto unlock_err; 7476 } 7477 } 7478 7479 ret = btrfs_add_ordered_extent_dio(inode, start, 7480 block_start, len, len, type); 7481 if (ret) { 7482 free_extent_map(em); 7483 goto unlock_err; 7484 } 7485 goto unlock; 7486 } 7487 } 7488 7489 /* 7490 * this will cow the extent, reset the len in case we changed 7491 * it above 7492 */ 7493 len = bh_result->b_size; 7494 free_extent_map(em); 7495 em = btrfs_new_extent_direct(inode, start, len); 7496 if (IS_ERR(em)) { 7497 ret = PTR_ERR(em); 7498 goto unlock_err; 7499 } 7500 len = min(len, em->len - (start - em->start)); 7501 unlock: 7502 bh_result->b_blocknr = (em->block_start + (start - em->start)) >> 7503 inode->i_blkbits; 7504 bh_result->b_size = len; 7505 bh_result->b_bdev = em->bdev; 7506 set_buffer_mapped(bh_result); 7507 if (create) { 7508 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) 7509 set_buffer_new(bh_result); 7510 7511 /* 7512 * Need to update the i_size under the extent lock so buffered 7513 * readers will get the updated i_size when we unlock. 7514 */ 7515 if (start + len > i_size_read(inode)) 7516 i_size_write(inode, start + len); 7517 7518 /* 7519 * If we have an outstanding_extents count still set then we're 7520 * within our reservation, otherwise we need to adjust our inode 7521 * counter appropriately. 7522 */ 7523 if (*outstanding_extents) { 7524 (*outstanding_extents)--; 7525 } else { 7526 spin_lock(&BTRFS_I(inode)->lock); 7527 BTRFS_I(inode)->outstanding_extents++; 7528 spin_unlock(&BTRFS_I(inode)->lock); 7529 } 7530 7531 current->journal_info = outstanding_extents; 7532 btrfs_free_reserved_data_space(inode, len); 7533 } 7534 7535 /* 7536 * In the case of write we need to clear and unlock the entire range, 7537 * in the case of read we need to unlock only the end area that we 7538 * aren't using if there is any left over space. 7539 */ 7540 if (lockstart < lockend) { 7541 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, 7542 lockend, unlock_bits, 1, 0, 7543 &cached_state, GFP_NOFS); 7544 } else { 7545 free_extent_state(cached_state); 7546 } 7547 7548 free_extent_map(em); 7549 7550 return 0; 7551 7552 unlock_err: 7553 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend, 7554 unlock_bits, 1, 0, &cached_state, GFP_NOFS); 7555 if (outstanding_extents) 7556 current->journal_info = outstanding_extents; 7557 return ret; 7558 } 7559 7560 static inline int submit_dio_repair_bio(struct inode *inode, struct bio *bio, 7561 int rw, int mirror_num) 7562 { 7563 struct btrfs_root *root = BTRFS_I(inode)->root; 7564 int ret; 7565 7566 BUG_ON(rw & REQ_WRITE); 7567 7568 bio_get(bio); 7569 7570 ret = btrfs_bio_wq_end_io(root->fs_info, bio, 7571 BTRFS_WQ_ENDIO_DIO_REPAIR); 7572 if (ret) 7573 goto err; 7574 7575 ret = btrfs_map_bio(root, rw, bio, mirror_num, 0); 7576 err: 7577 bio_put(bio); 7578 return ret; 7579 } 7580 7581 static int btrfs_check_dio_repairable(struct inode *inode, 7582 struct bio *failed_bio, 7583 struct io_failure_record *failrec, 7584 int failed_mirror) 7585 { 7586 int num_copies; 7587 7588 num_copies = btrfs_num_copies(BTRFS_I(inode)->root->fs_info, 7589 failrec->logical, failrec->len); 7590 if (num_copies == 1) { 7591 /* 7592 * we only have a single copy of the data, so don't bother with 7593 * all the retry and error correction code that follows. no 7594 * matter what the error is, it is very likely to persist. 7595 */ 7596 pr_debug("Check DIO Repairable: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d\n", 7597 num_copies, failrec->this_mirror, failed_mirror); 7598 return 0; 7599 } 7600 7601 failrec->failed_mirror = failed_mirror; 7602 failrec->this_mirror++; 7603 if (failrec->this_mirror == failed_mirror) 7604 failrec->this_mirror++; 7605 7606 if (failrec->this_mirror > num_copies) { 7607 pr_debug("Check DIO Repairable: (fail) num_copies=%d, next_mirror %d, failed_mirror %d\n", 7608 num_copies, failrec->this_mirror, failed_mirror); 7609 return 0; 7610 } 7611 7612 return 1; 7613 } 7614 7615 static int dio_read_error(struct inode *inode, struct bio *failed_bio, 7616 struct page *page, u64 start, u64 end, 7617 int failed_mirror, bio_end_io_t *repair_endio, 7618 void *repair_arg) 7619 { 7620 struct io_failure_record *failrec; 7621 struct bio *bio; 7622 int isector; 7623 int read_mode; 7624 int ret; 7625 7626 BUG_ON(failed_bio->bi_rw & REQ_WRITE); 7627 7628 ret = btrfs_get_io_failure_record(inode, start, end, &failrec); 7629 if (ret) 7630 return ret; 7631 7632 ret = btrfs_check_dio_repairable(inode, failed_bio, failrec, 7633 failed_mirror); 7634 if (!ret) { 7635 free_io_failure(inode, failrec); 7636 return -EIO; 7637 } 7638 7639 if (failed_bio->bi_vcnt > 1) 7640 read_mode = READ_SYNC | REQ_FAILFAST_DEV; 7641 else 7642 read_mode = READ_SYNC; 7643 7644 isector = start - btrfs_io_bio(failed_bio)->logical; 7645 isector >>= inode->i_sb->s_blocksize_bits; 7646 bio = btrfs_create_repair_bio(inode, failed_bio, failrec, page, 7647 0, isector, repair_endio, repair_arg); 7648 if (!bio) { 7649 free_io_failure(inode, failrec); 7650 return -EIO; 7651 } 7652 7653 btrfs_debug(BTRFS_I(inode)->root->fs_info, 7654 "Repair DIO Read Error: submitting new dio read[%#x] to this_mirror=%d, in_validation=%d\n", 7655 read_mode, failrec->this_mirror, failrec->in_validation); 7656 7657 ret = submit_dio_repair_bio(inode, bio, read_mode, 7658 failrec->this_mirror); 7659 if (ret) { 7660 free_io_failure(inode, failrec); 7661 bio_put(bio); 7662 } 7663 7664 return ret; 7665 } 7666 7667 struct btrfs_retry_complete { 7668 struct completion done; 7669 struct inode *inode; 7670 u64 start; 7671 int uptodate; 7672 }; 7673 7674 static void btrfs_retry_endio_nocsum(struct bio *bio, int err) 7675 { 7676 struct btrfs_retry_complete *done = bio->bi_private; 7677 struct bio_vec *bvec; 7678 int i; 7679 7680 if (err) 7681 goto end; 7682 7683 done->uptodate = 1; 7684 bio_for_each_segment_all(bvec, bio, i) 7685 clean_io_failure(done->inode, done->start, bvec->bv_page, 0); 7686 end: 7687 complete(&done->done); 7688 bio_put(bio); 7689 } 7690 7691 static int __btrfs_correct_data_nocsum(struct inode *inode, 7692 struct btrfs_io_bio *io_bio) 7693 { 7694 struct bio_vec *bvec; 7695 struct btrfs_retry_complete done; 7696 u64 start; 7697 int i; 7698 int ret; 7699 7700 start = io_bio->logical; 7701 done.inode = inode; 7702 7703 bio_for_each_segment_all(bvec, &io_bio->bio, i) { 7704 try_again: 7705 done.uptodate = 0; 7706 done.start = start; 7707 init_completion(&done.done); 7708 7709 ret = dio_read_error(inode, &io_bio->bio, bvec->bv_page, start, 7710 start + bvec->bv_len - 1, 7711 io_bio->mirror_num, 7712 btrfs_retry_endio_nocsum, &done); 7713 if (ret) 7714 return ret; 7715 7716 wait_for_completion(&done.done); 7717 7718 if (!done.uptodate) { 7719 /* We might have another mirror, so try again */ 7720 goto try_again; 7721 } 7722 7723 start += bvec->bv_len; 7724 } 7725 7726 return 0; 7727 } 7728 7729 static void btrfs_retry_endio(struct bio *bio, int err) 7730 { 7731 struct btrfs_retry_complete *done = bio->bi_private; 7732 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio); 7733 struct bio_vec *bvec; 7734 int uptodate; 7735 int ret; 7736 int i; 7737 7738 if (err) 7739 goto end; 7740 7741 uptodate = 1; 7742 bio_for_each_segment_all(bvec, bio, i) { 7743 ret = __readpage_endio_check(done->inode, io_bio, i, 7744 bvec->bv_page, 0, 7745 done->start, bvec->bv_len); 7746 if (!ret) 7747 clean_io_failure(done->inode, done->start, 7748 bvec->bv_page, 0); 7749 else 7750 uptodate = 0; 7751 } 7752 7753 done->uptodate = uptodate; 7754 end: 7755 complete(&done->done); 7756 bio_put(bio); 7757 } 7758 7759 static int __btrfs_subio_endio_read(struct inode *inode, 7760 struct btrfs_io_bio *io_bio, int err) 7761 { 7762 struct bio_vec *bvec; 7763 struct btrfs_retry_complete done; 7764 u64 start; 7765 u64 offset = 0; 7766 int i; 7767 int ret; 7768 7769 err = 0; 7770 start = io_bio->logical; 7771 done.inode = inode; 7772 7773 bio_for_each_segment_all(bvec, &io_bio->bio, i) { 7774 ret = __readpage_endio_check(inode, io_bio, i, bvec->bv_page, 7775 0, start, bvec->bv_len); 7776 if (likely(!ret)) 7777 goto next; 7778 try_again: 7779 done.uptodate = 0; 7780 done.start = start; 7781 init_completion(&done.done); 7782 7783 ret = dio_read_error(inode, &io_bio->bio, bvec->bv_page, start, 7784 start + bvec->bv_len - 1, 7785 io_bio->mirror_num, 7786 btrfs_retry_endio, &done); 7787 if (ret) { 7788 err = ret; 7789 goto next; 7790 } 7791 7792 wait_for_completion(&done.done); 7793 7794 if (!done.uptodate) { 7795 /* We might have another mirror, so try again */ 7796 goto try_again; 7797 } 7798 next: 7799 offset += bvec->bv_len; 7800 start += bvec->bv_len; 7801 } 7802 7803 return err; 7804 } 7805 7806 static int btrfs_subio_endio_read(struct inode *inode, 7807 struct btrfs_io_bio *io_bio, int err) 7808 { 7809 bool skip_csum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM; 7810 7811 if (skip_csum) { 7812 if (unlikely(err)) 7813 return __btrfs_correct_data_nocsum(inode, io_bio); 7814 else 7815 return 0; 7816 } else { 7817 return __btrfs_subio_endio_read(inode, io_bio, err); 7818 } 7819 } 7820 7821 static void btrfs_endio_direct_read(struct bio *bio, int err) 7822 { 7823 struct btrfs_dio_private *dip = bio->bi_private; 7824 struct inode *inode = dip->inode; 7825 struct bio *dio_bio; 7826 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio); 7827 7828 if (dip->flags & BTRFS_DIO_ORIG_BIO_SUBMITTED) 7829 err = btrfs_subio_endio_read(inode, io_bio, err); 7830 7831 unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset, 7832 dip->logical_offset + dip->bytes - 1); 7833 dio_bio = dip->dio_bio; 7834 7835 kfree(dip); 7836 7837 /* If we had a csum failure make sure to clear the uptodate flag */ 7838 if (err) 7839 clear_bit(BIO_UPTODATE, &dio_bio->bi_flags); 7840 dio_end_io(dio_bio, err); 7841 7842 if (io_bio->end_io) 7843 io_bio->end_io(io_bio, err); 7844 bio_put(bio); 7845 } 7846 7847 static void btrfs_endio_direct_write(struct bio *bio, int err) 7848 { 7849 struct btrfs_dio_private *dip = bio->bi_private; 7850 struct inode *inode = dip->inode; 7851 struct btrfs_root *root = BTRFS_I(inode)->root; 7852 struct btrfs_ordered_extent *ordered = NULL; 7853 u64 ordered_offset = dip->logical_offset; 7854 u64 ordered_bytes = dip->bytes; 7855 struct bio *dio_bio; 7856 int ret; 7857 7858 if (err) 7859 goto out_done; 7860 again: 7861 ret = btrfs_dec_test_first_ordered_pending(inode, &ordered, 7862 &ordered_offset, 7863 ordered_bytes, !err); 7864 if (!ret) 7865 goto out_test; 7866 7867 btrfs_init_work(&ordered->work, btrfs_endio_write_helper, 7868 finish_ordered_fn, NULL, NULL); 7869 btrfs_queue_work(root->fs_info->endio_write_workers, 7870 &ordered->work); 7871 out_test: 7872 /* 7873 * our bio might span multiple ordered extents. If we haven't 7874 * completed the accounting for the whole dio, go back and try again 7875 */ 7876 if (ordered_offset < dip->logical_offset + dip->bytes) { 7877 ordered_bytes = dip->logical_offset + dip->bytes - 7878 ordered_offset; 7879 ordered = NULL; 7880 goto again; 7881 } 7882 out_done: 7883 dio_bio = dip->dio_bio; 7884 7885 kfree(dip); 7886 7887 /* If we had an error make sure to clear the uptodate flag */ 7888 if (err) 7889 clear_bit(BIO_UPTODATE, &dio_bio->bi_flags); 7890 dio_end_io(dio_bio, err); 7891 bio_put(bio); 7892 } 7893 7894 static int __btrfs_submit_bio_start_direct_io(struct inode *inode, int rw, 7895 struct bio *bio, int mirror_num, 7896 unsigned long bio_flags, u64 offset) 7897 { 7898 int ret; 7899 struct btrfs_root *root = BTRFS_I(inode)->root; 7900 ret = btrfs_csum_one_bio(root, inode, bio, offset, 1); 7901 BUG_ON(ret); /* -ENOMEM */ 7902 return 0; 7903 } 7904 7905 static void btrfs_end_dio_bio(struct bio *bio, int err) 7906 { 7907 struct btrfs_dio_private *dip = bio->bi_private; 7908 7909 if (err) 7910 btrfs_warn(BTRFS_I(dip->inode)->root->fs_info, 7911 "direct IO failed ino %llu rw %lu sector %#Lx len %u err no %d", 7912 btrfs_ino(dip->inode), bio->bi_rw, 7913 (unsigned long long)bio->bi_iter.bi_sector, 7914 bio->bi_iter.bi_size, err); 7915 7916 if (dip->subio_endio) 7917 err = dip->subio_endio(dip->inode, btrfs_io_bio(bio), err); 7918 7919 if (err) { 7920 dip->errors = 1; 7921 7922 /* 7923 * before atomic variable goto zero, we must make sure 7924 * dip->errors is perceived to be set. 7925 */ 7926 smp_mb__before_atomic(); 7927 } 7928 7929 /* if there are more bios still pending for this dio, just exit */ 7930 if (!atomic_dec_and_test(&dip->pending_bios)) 7931 goto out; 7932 7933 if (dip->errors) { 7934 bio_io_error(dip->orig_bio); 7935 } else { 7936 set_bit(BIO_UPTODATE, &dip->dio_bio->bi_flags); 7937 bio_endio(dip->orig_bio, 0); 7938 } 7939 out: 7940 bio_put(bio); 7941 } 7942 7943 static struct bio *btrfs_dio_bio_alloc(struct block_device *bdev, 7944 u64 first_sector, gfp_t gfp_flags) 7945 { 7946 int nr_vecs = bio_get_nr_vecs(bdev); 7947 return btrfs_bio_alloc(bdev, first_sector, nr_vecs, gfp_flags); 7948 } 7949 7950 static inline int btrfs_lookup_and_bind_dio_csum(struct btrfs_root *root, 7951 struct inode *inode, 7952 struct btrfs_dio_private *dip, 7953 struct bio *bio, 7954 u64 file_offset) 7955 { 7956 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio); 7957 struct btrfs_io_bio *orig_io_bio = btrfs_io_bio(dip->orig_bio); 7958 int ret; 7959 7960 /* 7961 * We load all the csum data we need when we submit 7962 * the first bio to reduce the csum tree search and 7963 * contention. 7964 */ 7965 if (dip->logical_offset == file_offset) { 7966 ret = btrfs_lookup_bio_sums_dio(root, inode, dip->orig_bio, 7967 file_offset); 7968 if (ret) 7969 return ret; 7970 } 7971 7972 if (bio == dip->orig_bio) 7973 return 0; 7974 7975 file_offset -= dip->logical_offset; 7976 file_offset >>= inode->i_sb->s_blocksize_bits; 7977 io_bio->csum = (u8 *)(((u32 *)orig_io_bio->csum) + file_offset); 7978 7979 return 0; 7980 } 7981 7982 static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode, 7983 int rw, u64 file_offset, int skip_sum, 7984 int async_submit) 7985 { 7986 struct btrfs_dio_private *dip = bio->bi_private; 7987 int write = rw & REQ_WRITE; 7988 struct btrfs_root *root = BTRFS_I(inode)->root; 7989 int ret; 7990 7991 if (async_submit) 7992 async_submit = !atomic_read(&BTRFS_I(inode)->sync_writers); 7993 7994 bio_get(bio); 7995 7996 if (!write) { 7997 ret = btrfs_bio_wq_end_io(root->fs_info, bio, 7998 BTRFS_WQ_ENDIO_DATA); 7999 if (ret) 8000 goto err; 8001 } 8002 8003 if (skip_sum) 8004 goto map; 8005 8006 if (write && async_submit) { 8007 ret = btrfs_wq_submit_bio(root->fs_info, 8008 inode, rw, bio, 0, 0, 8009 file_offset, 8010 __btrfs_submit_bio_start_direct_io, 8011 __btrfs_submit_bio_done); 8012 goto err; 8013 } else if (write) { 8014 /* 8015 * If we aren't doing async submit, calculate the csum of the 8016 * bio now. 8017 */ 8018 ret = btrfs_csum_one_bio(root, inode, bio, file_offset, 1); 8019 if (ret) 8020 goto err; 8021 } else { 8022 ret = btrfs_lookup_and_bind_dio_csum(root, inode, dip, bio, 8023 file_offset); 8024 if (ret) 8025 goto err; 8026 } 8027 map: 8028 ret = btrfs_map_bio(root, rw, bio, 0, async_submit); 8029 err: 8030 bio_put(bio); 8031 return ret; 8032 } 8033 8034 static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip, 8035 int skip_sum) 8036 { 8037 struct inode *inode = dip->inode; 8038 struct btrfs_root *root = BTRFS_I(inode)->root; 8039 struct bio *bio; 8040 struct bio *orig_bio = dip->orig_bio; 8041 struct bio_vec *bvec = orig_bio->bi_io_vec; 8042 u64 start_sector = orig_bio->bi_iter.bi_sector; 8043 u64 file_offset = dip->logical_offset; 8044 u64 submit_len = 0; 8045 u64 map_length; 8046 int nr_pages = 0; 8047 int ret; 8048 int async_submit = 0; 8049 8050 map_length = orig_bio->bi_iter.bi_size; 8051 ret = btrfs_map_block(root->fs_info, rw, start_sector << 9, 8052 &map_length, NULL, 0); 8053 if (ret) 8054 return -EIO; 8055 8056 if (map_length >= orig_bio->bi_iter.bi_size) { 8057 bio = orig_bio; 8058 dip->flags |= BTRFS_DIO_ORIG_BIO_SUBMITTED; 8059 goto submit; 8060 } 8061 8062 /* async crcs make it difficult to collect full stripe writes. */ 8063 if (btrfs_get_alloc_profile(root, 1) & BTRFS_BLOCK_GROUP_RAID56_MASK) 8064 async_submit = 0; 8065 else 8066 async_submit = 1; 8067 8068 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, start_sector, GFP_NOFS); 8069 if (!bio) 8070 return -ENOMEM; 8071 8072 bio->bi_private = dip; 8073 bio->bi_end_io = btrfs_end_dio_bio; 8074 btrfs_io_bio(bio)->logical = file_offset; 8075 atomic_inc(&dip->pending_bios); 8076 8077 while (bvec <= (orig_bio->bi_io_vec + orig_bio->bi_vcnt - 1)) { 8078 if (map_length < submit_len + bvec->bv_len || 8079 bio_add_page(bio, bvec->bv_page, bvec->bv_len, 8080 bvec->bv_offset) < bvec->bv_len) { 8081 /* 8082 * inc the count before we submit the bio so 8083 * we know the end IO handler won't happen before 8084 * we inc the count. Otherwise, the dip might get freed 8085 * before we're done setting it up 8086 */ 8087 atomic_inc(&dip->pending_bios); 8088 ret = __btrfs_submit_dio_bio(bio, inode, rw, 8089 file_offset, skip_sum, 8090 async_submit); 8091 if (ret) { 8092 bio_put(bio); 8093 atomic_dec(&dip->pending_bios); 8094 goto out_err; 8095 } 8096 8097 start_sector += submit_len >> 9; 8098 file_offset += submit_len; 8099 8100 submit_len = 0; 8101 nr_pages = 0; 8102 8103 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, 8104 start_sector, GFP_NOFS); 8105 if (!bio) 8106 goto out_err; 8107 bio->bi_private = dip; 8108 bio->bi_end_io = btrfs_end_dio_bio; 8109 btrfs_io_bio(bio)->logical = file_offset; 8110 8111 map_length = orig_bio->bi_iter.bi_size; 8112 ret = btrfs_map_block(root->fs_info, rw, 8113 start_sector << 9, 8114 &map_length, NULL, 0); 8115 if (ret) { 8116 bio_put(bio); 8117 goto out_err; 8118 } 8119 } else { 8120 submit_len += bvec->bv_len; 8121 nr_pages++; 8122 bvec++; 8123 } 8124 } 8125 8126 submit: 8127 ret = __btrfs_submit_dio_bio(bio, inode, rw, file_offset, skip_sum, 8128 async_submit); 8129 if (!ret) 8130 return 0; 8131 8132 bio_put(bio); 8133 out_err: 8134 dip->errors = 1; 8135 /* 8136 * before atomic variable goto zero, we must 8137 * make sure dip->errors is perceived to be set. 8138 */ 8139 smp_mb__before_atomic(); 8140 if (atomic_dec_and_test(&dip->pending_bios)) 8141 bio_io_error(dip->orig_bio); 8142 8143 /* bio_end_io() will handle error, so we needn't return it */ 8144 return 0; 8145 } 8146 8147 static void btrfs_submit_direct(int rw, struct bio *dio_bio, 8148 struct inode *inode, loff_t file_offset) 8149 { 8150 struct btrfs_root *root = BTRFS_I(inode)->root; 8151 struct btrfs_dio_private *dip; 8152 struct bio *io_bio; 8153 struct btrfs_io_bio *btrfs_bio; 8154 int skip_sum; 8155 int write = rw & REQ_WRITE; 8156 int ret = 0; 8157 8158 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM; 8159 8160 io_bio = btrfs_bio_clone(dio_bio, GFP_NOFS); 8161 if (!io_bio) { 8162 ret = -ENOMEM; 8163 goto free_ordered; 8164 } 8165 8166 dip = kzalloc(sizeof(*dip), GFP_NOFS); 8167 if (!dip) { 8168 ret = -ENOMEM; 8169 goto free_io_bio; 8170 } 8171 8172 dip->private = dio_bio->bi_private; 8173 dip->inode = inode; 8174 dip->logical_offset = file_offset; 8175 dip->bytes = dio_bio->bi_iter.bi_size; 8176 dip->disk_bytenr = (u64)dio_bio->bi_iter.bi_sector << 9; 8177 io_bio->bi_private = dip; 8178 dip->orig_bio = io_bio; 8179 dip->dio_bio = dio_bio; 8180 atomic_set(&dip->pending_bios, 0); 8181 btrfs_bio = btrfs_io_bio(io_bio); 8182 btrfs_bio->logical = file_offset; 8183 8184 if (write) { 8185 io_bio->bi_end_io = btrfs_endio_direct_write; 8186 } else { 8187 io_bio->bi_end_io = btrfs_endio_direct_read; 8188 dip->subio_endio = btrfs_subio_endio_read; 8189 } 8190 8191 ret = btrfs_submit_direct_hook(rw, dip, skip_sum); 8192 if (!ret) 8193 return; 8194 8195 if (btrfs_bio->end_io) 8196 btrfs_bio->end_io(btrfs_bio, ret); 8197 free_io_bio: 8198 bio_put(io_bio); 8199 8200 free_ordered: 8201 /* 8202 * If this is a write, we need to clean up the reserved space and kill 8203 * the ordered extent. 8204 */ 8205 if (write) { 8206 struct btrfs_ordered_extent *ordered; 8207 ordered = btrfs_lookup_ordered_extent(inode, file_offset); 8208 if (!test_bit(BTRFS_ORDERED_PREALLOC, &ordered->flags) && 8209 !test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags)) 8210 btrfs_free_reserved_extent(root, ordered->start, 8211 ordered->disk_len, 1); 8212 btrfs_put_ordered_extent(ordered); 8213 btrfs_put_ordered_extent(ordered); 8214 } 8215 bio_endio(dio_bio, ret); 8216 } 8217 8218 static ssize_t check_direct_IO(struct btrfs_root *root, struct kiocb *iocb, 8219 const struct iov_iter *iter, loff_t offset) 8220 { 8221 int seg; 8222 int i; 8223 unsigned blocksize_mask = root->sectorsize - 1; 8224 ssize_t retval = -EINVAL; 8225 8226 if (offset & blocksize_mask) 8227 goto out; 8228 8229 if (iov_iter_alignment(iter) & blocksize_mask) 8230 goto out; 8231 8232 /* If this is a write we don't need to check anymore */ 8233 if (iov_iter_rw(iter) == WRITE) 8234 return 0; 8235 /* 8236 * Check to make sure we don't have duplicate iov_base's in this 8237 * iovec, if so return EINVAL, otherwise we'll get csum errors 8238 * when reading back. 8239 */ 8240 for (seg = 0; seg < iter->nr_segs; seg++) { 8241 for (i = seg + 1; i < iter->nr_segs; i++) { 8242 if (iter->iov[seg].iov_base == iter->iov[i].iov_base) 8243 goto out; 8244 } 8245 } 8246 retval = 0; 8247 out: 8248 return retval; 8249 } 8250 8251 static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter, 8252 loff_t offset) 8253 { 8254 struct file *file = iocb->ki_filp; 8255 struct inode *inode = file->f_mapping->host; 8256 u64 outstanding_extents = 0; 8257 size_t count = 0; 8258 int flags = 0; 8259 bool wakeup = true; 8260 bool relock = false; 8261 ssize_t ret; 8262 8263 if (check_direct_IO(BTRFS_I(inode)->root, iocb, iter, offset)) 8264 return 0; 8265 8266 inode_dio_begin(inode); 8267 smp_mb__after_atomic(); 8268 8269 /* 8270 * The generic stuff only does filemap_write_and_wait_range, which 8271 * isn't enough if we've written compressed pages to this area, so 8272 * we need to flush the dirty pages again to make absolutely sure 8273 * that any outstanding dirty pages are on disk. 8274 */ 8275 count = iov_iter_count(iter); 8276 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT, 8277 &BTRFS_I(inode)->runtime_flags)) 8278 filemap_fdatawrite_range(inode->i_mapping, offset, 8279 offset + count - 1); 8280 8281 if (iov_iter_rw(iter) == WRITE) { 8282 /* 8283 * If the write DIO is beyond the EOF, we need update 8284 * the isize, but it is protected by i_mutex. So we can 8285 * not unlock the i_mutex at this case. 8286 */ 8287 if (offset + count <= inode->i_size) { 8288 mutex_unlock(&inode->i_mutex); 8289 relock = true; 8290 } 8291 ret = btrfs_delalloc_reserve_space(inode, count); 8292 if (ret) 8293 goto out; 8294 outstanding_extents = div64_u64(count + 8295 BTRFS_MAX_EXTENT_SIZE - 1, 8296 BTRFS_MAX_EXTENT_SIZE); 8297 8298 /* 8299 * We need to know how many extents we reserved so that we can 8300 * do the accounting properly if we go over the number we 8301 * originally calculated. Abuse current->journal_info for this. 8302 */ 8303 current->journal_info = &outstanding_extents; 8304 } else if (test_bit(BTRFS_INODE_READDIO_NEED_LOCK, 8305 &BTRFS_I(inode)->runtime_flags)) { 8306 inode_dio_end(inode); 8307 flags = DIO_LOCKING | DIO_SKIP_HOLES; 8308 wakeup = false; 8309 } 8310 8311 ret = __blockdev_direct_IO(iocb, inode, 8312 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev, 8313 iter, offset, btrfs_get_blocks_direct, NULL, 8314 btrfs_submit_direct, flags); 8315 if (iov_iter_rw(iter) == WRITE) { 8316 current->journal_info = NULL; 8317 if (ret < 0 && ret != -EIOCBQUEUED) 8318 btrfs_delalloc_release_space(inode, count); 8319 else if (ret >= 0 && (size_t)ret < count) 8320 btrfs_delalloc_release_space(inode, 8321 count - (size_t)ret); 8322 } 8323 out: 8324 if (wakeup) 8325 inode_dio_end(inode); 8326 if (relock) 8327 mutex_lock(&inode->i_mutex); 8328 8329 return ret; 8330 } 8331 8332 #define BTRFS_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC) 8333 8334 static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, 8335 __u64 start, __u64 len) 8336 { 8337 int ret; 8338 8339 ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS); 8340 if (ret) 8341 return ret; 8342 8343 return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent_fiemap); 8344 } 8345 8346 int btrfs_readpage(struct file *file, struct page *page) 8347 { 8348 struct extent_io_tree *tree; 8349 tree = &BTRFS_I(page->mapping->host)->io_tree; 8350 return extent_read_full_page(tree, page, btrfs_get_extent, 0); 8351 } 8352 8353 static int btrfs_writepage(struct page *page, struct writeback_control *wbc) 8354 { 8355 struct extent_io_tree *tree; 8356 8357 8358 if (current->flags & PF_MEMALLOC) { 8359 redirty_page_for_writepage(wbc, page); 8360 unlock_page(page); 8361 return 0; 8362 } 8363 tree = &BTRFS_I(page->mapping->host)->io_tree; 8364 return extent_write_full_page(tree, page, btrfs_get_extent, wbc); 8365 } 8366 8367 static int btrfs_writepages(struct address_space *mapping, 8368 struct writeback_control *wbc) 8369 { 8370 struct extent_io_tree *tree; 8371 8372 tree = &BTRFS_I(mapping->host)->io_tree; 8373 return extent_writepages(tree, mapping, btrfs_get_extent, wbc); 8374 } 8375 8376 static int 8377 btrfs_readpages(struct file *file, struct address_space *mapping, 8378 struct list_head *pages, unsigned nr_pages) 8379 { 8380 struct extent_io_tree *tree; 8381 tree = &BTRFS_I(mapping->host)->io_tree; 8382 return extent_readpages(tree, mapping, pages, nr_pages, 8383 btrfs_get_extent); 8384 } 8385 static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags) 8386 { 8387 struct extent_io_tree *tree; 8388 struct extent_map_tree *map; 8389 int ret; 8390 8391 tree = &BTRFS_I(page->mapping->host)->io_tree; 8392 map = &BTRFS_I(page->mapping->host)->extent_tree; 8393 ret = try_release_extent_mapping(map, tree, page, gfp_flags); 8394 if (ret == 1) { 8395 ClearPagePrivate(page); 8396 set_page_private(page, 0); 8397 page_cache_release(page); 8398 } 8399 return ret; 8400 } 8401 8402 static int btrfs_releasepage(struct page *page, gfp_t gfp_flags) 8403 { 8404 if (PageWriteback(page) || PageDirty(page)) 8405 return 0; 8406 return __btrfs_releasepage(page, gfp_flags & GFP_NOFS); 8407 } 8408 8409 static void btrfs_invalidatepage(struct page *page, unsigned int offset, 8410 unsigned int length) 8411 { 8412 struct inode *inode = page->mapping->host; 8413 struct extent_io_tree *tree; 8414 struct btrfs_ordered_extent *ordered; 8415 struct extent_state *cached_state = NULL; 8416 u64 page_start = page_offset(page); 8417 u64 page_end = page_start + PAGE_CACHE_SIZE - 1; 8418 int inode_evicting = inode->i_state & I_FREEING; 8419 8420 /* 8421 * we have the page locked, so new writeback can't start, 8422 * and the dirty bit won't be cleared while we are here. 8423 * 8424 * Wait for IO on this page so that we can safely clear 8425 * the PagePrivate2 bit and do ordered accounting 8426 */ 8427 wait_on_page_writeback(page); 8428 8429 tree = &BTRFS_I(inode)->io_tree; 8430 if (offset) { 8431 btrfs_releasepage(page, GFP_NOFS); 8432 return; 8433 } 8434 8435 if (!inode_evicting) 8436 lock_extent_bits(tree, page_start, page_end, 0, &cached_state); 8437 ordered = btrfs_lookup_ordered_extent(inode, page_start); 8438 if (ordered) { 8439 /* 8440 * IO on this page will never be started, so we need 8441 * to account for any ordered extents now 8442 */ 8443 if (!inode_evicting) 8444 clear_extent_bit(tree, page_start, page_end, 8445 EXTENT_DIRTY | EXTENT_DELALLOC | 8446 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING | 8447 EXTENT_DEFRAG, 1, 0, &cached_state, 8448 GFP_NOFS); 8449 /* 8450 * whoever cleared the private bit is responsible 8451 * for the finish_ordered_io 8452 */ 8453 if (TestClearPagePrivate2(page)) { 8454 struct btrfs_ordered_inode_tree *tree; 8455 u64 new_len; 8456 8457 tree = &BTRFS_I(inode)->ordered_tree; 8458 8459 spin_lock_irq(&tree->lock); 8460 set_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags); 8461 new_len = page_start - ordered->file_offset; 8462 if (new_len < ordered->truncated_len) 8463 ordered->truncated_len = new_len; 8464 spin_unlock_irq(&tree->lock); 8465 8466 if (btrfs_dec_test_ordered_pending(inode, &ordered, 8467 page_start, 8468 PAGE_CACHE_SIZE, 1)) 8469 btrfs_finish_ordered_io(ordered); 8470 } 8471 btrfs_put_ordered_extent(ordered); 8472 if (!inode_evicting) { 8473 cached_state = NULL; 8474 lock_extent_bits(tree, page_start, page_end, 0, 8475 &cached_state); 8476 } 8477 } 8478 8479 if (!inode_evicting) { 8480 clear_extent_bit(tree, page_start, page_end, 8481 EXTENT_LOCKED | EXTENT_DIRTY | 8482 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING | 8483 EXTENT_DEFRAG, 1, 1, 8484 &cached_state, GFP_NOFS); 8485 8486 __btrfs_releasepage(page, GFP_NOFS); 8487 } 8488 8489 ClearPageChecked(page); 8490 if (PagePrivate(page)) { 8491 ClearPagePrivate(page); 8492 set_page_private(page, 0); 8493 page_cache_release(page); 8494 } 8495 } 8496 8497 /* 8498 * btrfs_page_mkwrite() is not allowed to change the file size as it gets 8499 * called from a page fault handler when a page is first dirtied. Hence we must 8500 * be careful to check for EOF conditions here. We set the page up correctly 8501 * for a written page which means we get ENOSPC checking when writing into 8502 * holes and correct delalloc and unwritten extent mapping on filesystems that 8503 * support these features. 8504 * 8505 * We are not allowed to take the i_mutex here so we have to play games to 8506 * protect against truncate races as the page could now be beyond EOF. Because 8507 * vmtruncate() writes the inode size before removing pages, once we have the 8508 * page lock we can determine safely if the page is beyond EOF. If it is not 8509 * beyond EOF, then the page is guaranteed safe against truncation until we 8510 * unlock the page. 8511 */ 8512 int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) 8513 { 8514 struct page *page = vmf->page; 8515 struct inode *inode = file_inode(vma->vm_file); 8516 struct btrfs_root *root = BTRFS_I(inode)->root; 8517 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 8518 struct btrfs_ordered_extent *ordered; 8519 struct extent_state *cached_state = NULL; 8520 char *kaddr; 8521 unsigned long zero_start; 8522 loff_t size; 8523 int ret; 8524 int reserved = 0; 8525 u64 page_start; 8526 u64 page_end; 8527 8528 sb_start_pagefault(inode->i_sb); 8529 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE); 8530 if (!ret) { 8531 ret = file_update_time(vma->vm_file); 8532 reserved = 1; 8533 } 8534 if (ret) { 8535 if (ret == -ENOMEM) 8536 ret = VM_FAULT_OOM; 8537 else /* -ENOSPC, -EIO, etc */ 8538 ret = VM_FAULT_SIGBUS; 8539 if (reserved) 8540 goto out; 8541 goto out_noreserve; 8542 } 8543 8544 ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */ 8545 again: 8546 lock_page(page); 8547 size = i_size_read(inode); 8548 page_start = page_offset(page); 8549 page_end = page_start + PAGE_CACHE_SIZE - 1; 8550 8551 if ((page->mapping != inode->i_mapping) || 8552 (page_start >= size)) { 8553 /* page got truncated out from underneath us */ 8554 goto out_unlock; 8555 } 8556 wait_on_page_writeback(page); 8557 8558 lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state); 8559 set_page_extent_mapped(page); 8560 8561 /* 8562 * we can't set the delalloc bits if there are pending ordered 8563 * extents. Drop our locks and wait for them to finish 8564 */ 8565 ordered = btrfs_lookup_ordered_extent(inode, page_start); 8566 if (ordered) { 8567 unlock_extent_cached(io_tree, page_start, page_end, 8568 &cached_state, GFP_NOFS); 8569 unlock_page(page); 8570 btrfs_start_ordered_extent(inode, ordered, 1); 8571 btrfs_put_ordered_extent(ordered); 8572 goto again; 8573 } 8574 8575 /* 8576 * XXX - page_mkwrite gets called every time the page is dirtied, even 8577 * if it was already dirty, so for space accounting reasons we need to 8578 * clear any delalloc bits for the range we are fixing to save. There 8579 * is probably a better way to do this, but for now keep consistent with 8580 * prepare_pages in the normal write path. 8581 */ 8582 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end, 8583 EXTENT_DIRTY | EXTENT_DELALLOC | 8584 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 8585 0, 0, &cached_state, GFP_NOFS); 8586 8587 ret = btrfs_set_extent_delalloc(inode, page_start, page_end, 8588 &cached_state); 8589 if (ret) { 8590 unlock_extent_cached(io_tree, page_start, page_end, 8591 &cached_state, GFP_NOFS); 8592 ret = VM_FAULT_SIGBUS; 8593 goto out_unlock; 8594 } 8595 ret = 0; 8596 8597 /* page is wholly or partially inside EOF */ 8598 if (page_start + PAGE_CACHE_SIZE > size) 8599 zero_start = size & ~PAGE_CACHE_MASK; 8600 else 8601 zero_start = PAGE_CACHE_SIZE; 8602 8603 if (zero_start != PAGE_CACHE_SIZE) { 8604 kaddr = kmap(page); 8605 memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start); 8606 flush_dcache_page(page); 8607 kunmap(page); 8608 } 8609 ClearPageChecked(page); 8610 set_page_dirty(page); 8611 SetPageUptodate(page); 8612 8613 BTRFS_I(inode)->last_trans = root->fs_info->generation; 8614 BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid; 8615 BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit; 8616 8617 unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS); 8618 8619 out_unlock: 8620 if (!ret) { 8621 sb_end_pagefault(inode->i_sb); 8622 return VM_FAULT_LOCKED; 8623 } 8624 unlock_page(page); 8625 out: 8626 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE); 8627 out_noreserve: 8628 sb_end_pagefault(inode->i_sb); 8629 return ret; 8630 } 8631 8632 static int btrfs_truncate(struct inode *inode) 8633 { 8634 struct btrfs_root *root = BTRFS_I(inode)->root; 8635 struct btrfs_block_rsv *rsv; 8636 int ret = 0; 8637 int err = 0; 8638 struct btrfs_trans_handle *trans; 8639 u64 mask = root->sectorsize - 1; 8640 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1); 8641 8642 ret = btrfs_wait_ordered_range(inode, inode->i_size & (~mask), 8643 (u64)-1); 8644 if (ret) 8645 return ret; 8646 8647 /* 8648 * Yes ladies and gentelment, this is indeed ugly. The fact is we have 8649 * 3 things going on here 8650 * 8651 * 1) We need to reserve space for our orphan item and the space to 8652 * delete our orphan item. Lord knows we don't want to have a dangling 8653 * orphan item because we didn't reserve space to remove it. 8654 * 8655 * 2) We need to reserve space to update our inode. 8656 * 8657 * 3) We need to have something to cache all the space that is going to 8658 * be free'd up by the truncate operation, but also have some slack 8659 * space reserved in case it uses space during the truncate (thank you 8660 * very much snapshotting). 8661 * 8662 * And we need these to all be seperate. The fact is we can use alot of 8663 * space doing the truncate, and we have no earthly idea how much space 8664 * we will use, so we need the truncate reservation to be seperate so it 8665 * doesn't end up using space reserved for updating the inode or 8666 * removing the orphan item. We also need to be able to stop the 8667 * transaction and start a new one, which means we need to be able to 8668 * update the inode several times, and we have no idea of knowing how 8669 * many times that will be, so we can't just reserve 1 item for the 8670 * entirety of the opration, so that has to be done seperately as well. 8671 * Then there is the orphan item, which does indeed need to be held on 8672 * to for the whole operation, and we need nobody to touch this reserved 8673 * space except the orphan code. 8674 * 8675 * So that leaves us with 8676 * 8677 * 1) root->orphan_block_rsv - for the orphan deletion. 8678 * 2) rsv - for the truncate reservation, which we will steal from the 8679 * transaction reservation. 8680 * 3) fs_info->trans_block_rsv - this will have 1 items worth left for 8681 * updating the inode. 8682 */ 8683 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP); 8684 if (!rsv) 8685 return -ENOMEM; 8686 rsv->size = min_size; 8687 rsv->failfast = 1; 8688 8689 /* 8690 * 1 for the truncate slack space 8691 * 1 for updating the inode. 8692 */ 8693 trans = btrfs_start_transaction(root, 2); 8694 if (IS_ERR(trans)) { 8695 err = PTR_ERR(trans); 8696 goto out; 8697 } 8698 8699 /* Migrate the slack space for the truncate to our reserve */ 8700 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, rsv, 8701 min_size); 8702 BUG_ON(ret); 8703 8704 /* 8705 * So if we truncate and then write and fsync we normally would just 8706 * write the extents that changed, which is a problem if we need to 8707 * first truncate that entire inode. So set this flag so we write out 8708 * all of the extents in the inode to the sync log so we're completely 8709 * safe. 8710 */ 8711 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags); 8712 trans->block_rsv = rsv; 8713 8714 while (1) { 8715 ret = btrfs_truncate_inode_items(trans, root, inode, 8716 inode->i_size, 8717 BTRFS_EXTENT_DATA_KEY); 8718 if (ret != -ENOSPC && ret != -EAGAIN) { 8719 err = ret; 8720 break; 8721 } 8722 8723 trans->block_rsv = &root->fs_info->trans_block_rsv; 8724 ret = btrfs_update_inode(trans, root, inode); 8725 if (ret) { 8726 err = ret; 8727 break; 8728 } 8729 8730 btrfs_end_transaction(trans, root); 8731 btrfs_btree_balance_dirty(root); 8732 8733 trans = btrfs_start_transaction(root, 2); 8734 if (IS_ERR(trans)) { 8735 ret = err = PTR_ERR(trans); 8736 trans = NULL; 8737 break; 8738 } 8739 8740 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, 8741 rsv, min_size); 8742 BUG_ON(ret); /* shouldn't happen */ 8743 trans->block_rsv = rsv; 8744 } 8745 8746 if (ret == 0 && inode->i_nlink > 0) { 8747 trans->block_rsv = root->orphan_block_rsv; 8748 ret = btrfs_orphan_del(trans, inode); 8749 if (ret) 8750 err = ret; 8751 } 8752 8753 if (trans) { 8754 trans->block_rsv = &root->fs_info->trans_block_rsv; 8755 ret = btrfs_update_inode(trans, root, inode); 8756 if (ret && !err) 8757 err = ret; 8758 8759 ret = btrfs_end_transaction(trans, root); 8760 btrfs_btree_balance_dirty(root); 8761 } 8762 8763 out: 8764 btrfs_free_block_rsv(root, rsv); 8765 8766 if (ret && !err) 8767 err = ret; 8768 8769 return err; 8770 } 8771 8772 /* 8773 * create a new subvolume directory/inode (helper for the ioctl). 8774 */ 8775 int btrfs_create_subvol_root(struct btrfs_trans_handle *trans, 8776 struct btrfs_root *new_root, 8777 struct btrfs_root *parent_root, 8778 u64 new_dirid) 8779 { 8780 struct inode *inode; 8781 int err; 8782 u64 index = 0; 8783 8784 inode = btrfs_new_inode(trans, new_root, NULL, "..", 2, 8785 new_dirid, new_dirid, 8786 S_IFDIR | (~current_umask() & S_IRWXUGO), 8787 &index); 8788 if (IS_ERR(inode)) 8789 return PTR_ERR(inode); 8790 inode->i_op = &btrfs_dir_inode_operations; 8791 inode->i_fop = &btrfs_dir_file_operations; 8792 8793 set_nlink(inode, 1); 8794 btrfs_i_size_write(inode, 0); 8795 unlock_new_inode(inode); 8796 8797 err = btrfs_subvol_inherit_props(trans, new_root, parent_root); 8798 if (err) 8799 btrfs_err(new_root->fs_info, 8800 "error inheriting subvolume %llu properties: %d", 8801 new_root->root_key.objectid, err); 8802 8803 err = btrfs_update_inode(trans, new_root, inode); 8804 8805 iput(inode); 8806 return err; 8807 } 8808 8809 struct inode *btrfs_alloc_inode(struct super_block *sb) 8810 { 8811 struct btrfs_inode *ei; 8812 struct inode *inode; 8813 8814 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS); 8815 if (!ei) 8816 return NULL; 8817 8818 ei->root = NULL; 8819 ei->generation = 0; 8820 ei->last_trans = 0; 8821 ei->last_sub_trans = 0; 8822 ei->logged_trans = 0; 8823 ei->delalloc_bytes = 0; 8824 ei->defrag_bytes = 0; 8825 ei->disk_i_size = 0; 8826 ei->flags = 0; 8827 ei->csum_bytes = 0; 8828 ei->index_cnt = (u64)-1; 8829 ei->dir_index = 0; 8830 ei->last_unlink_trans = 0; 8831 ei->last_log_commit = 0; 8832 8833 spin_lock_init(&ei->lock); 8834 ei->outstanding_extents = 0; 8835 ei->reserved_extents = 0; 8836 8837 ei->runtime_flags = 0; 8838 ei->force_compress = BTRFS_COMPRESS_NONE; 8839 8840 ei->delayed_node = NULL; 8841 8842 ei->i_otime.tv_sec = 0; 8843 ei->i_otime.tv_nsec = 0; 8844 8845 inode = &ei->vfs_inode; 8846 extent_map_tree_init(&ei->extent_tree); 8847 extent_io_tree_init(&ei->io_tree, &inode->i_data); 8848 extent_io_tree_init(&ei->io_failure_tree, &inode->i_data); 8849 ei->io_tree.track_uptodate = 1; 8850 ei->io_failure_tree.track_uptodate = 1; 8851 atomic_set(&ei->sync_writers, 0); 8852 mutex_init(&ei->log_mutex); 8853 mutex_init(&ei->delalloc_mutex); 8854 btrfs_ordered_inode_tree_init(&ei->ordered_tree); 8855 INIT_LIST_HEAD(&ei->delalloc_inodes); 8856 RB_CLEAR_NODE(&ei->rb_node); 8857 8858 return inode; 8859 } 8860 8861 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS 8862 void btrfs_test_destroy_inode(struct inode *inode) 8863 { 8864 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0); 8865 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode)); 8866 } 8867 #endif 8868 8869 static void btrfs_i_callback(struct rcu_head *head) 8870 { 8871 struct inode *inode = container_of(head, struct inode, i_rcu); 8872 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode)); 8873 } 8874 8875 void btrfs_destroy_inode(struct inode *inode) 8876 { 8877 struct btrfs_ordered_extent *ordered; 8878 struct btrfs_root *root = BTRFS_I(inode)->root; 8879 8880 WARN_ON(!hlist_empty(&inode->i_dentry)); 8881 WARN_ON(inode->i_data.nrpages); 8882 WARN_ON(BTRFS_I(inode)->outstanding_extents); 8883 WARN_ON(BTRFS_I(inode)->reserved_extents); 8884 WARN_ON(BTRFS_I(inode)->delalloc_bytes); 8885 WARN_ON(BTRFS_I(inode)->csum_bytes); 8886 WARN_ON(BTRFS_I(inode)->defrag_bytes); 8887 8888 /* 8889 * This can happen where we create an inode, but somebody else also 8890 * created the same inode and we need to destroy the one we already 8891 * created. 8892 */ 8893 if (!root) 8894 goto free; 8895 8896 if (test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM, 8897 &BTRFS_I(inode)->runtime_flags)) { 8898 btrfs_info(root->fs_info, "inode %llu still on the orphan list", 8899 btrfs_ino(inode)); 8900 atomic_dec(&root->orphan_inodes); 8901 } 8902 8903 while (1) { 8904 ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1); 8905 if (!ordered) 8906 break; 8907 else { 8908 btrfs_err(root->fs_info, "found ordered extent %llu %llu on inode cleanup", 8909 ordered->file_offset, ordered->len); 8910 btrfs_remove_ordered_extent(inode, ordered); 8911 btrfs_put_ordered_extent(ordered); 8912 btrfs_put_ordered_extent(ordered); 8913 } 8914 } 8915 inode_tree_del(inode); 8916 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0); 8917 free: 8918 call_rcu(&inode->i_rcu, btrfs_i_callback); 8919 } 8920 8921 int btrfs_drop_inode(struct inode *inode) 8922 { 8923 struct btrfs_root *root = BTRFS_I(inode)->root; 8924 8925 if (root == NULL) 8926 return 1; 8927 8928 /* the snap/subvol tree is on deleting */ 8929 if (btrfs_root_refs(&root->root_item) == 0) 8930 return 1; 8931 else 8932 return generic_drop_inode(inode); 8933 } 8934 8935 static void init_once(void *foo) 8936 { 8937 struct btrfs_inode *ei = (struct btrfs_inode *) foo; 8938 8939 inode_init_once(&ei->vfs_inode); 8940 } 8941 8942 void btrfs_destroy_cachep(void) 8943 { 8944 /* 8945 * Make sure all delayed rcu free inodes are flushed before we 8946 * destroy cache. 8947 */ 8948 rcu_barrier(); 8949 if (btrfs_inode_cachep) 8950 kmem_cache_destroy(btrfs_inode_cachep); 8951 if (btrfs_trans_handle_cachep) 8952 kmem_cache_destroy(btrfs_trans_handle_cachep); 8953 if (btrfs_transaction_cachep) 8954 kmem_cache_destroy(btrfs_transaction_cachep); 8955 if (btrfs_path_cachep) 8956 kmem_cache_destroy(btrfs_path_cachep); 8957 if (btrfs_free_space_cachep) 8958 kmem_cache_destroy(btrfs_free_space_cachep); 8959 if (btrfs_delalloc_work_cachep) 8960 kmem_cache_destroy(btrfs_delalloc_work_cachep); 8961 } 8962 8963 int btrfs_init_cachep(void) 8964 { 8965 btrfs_inode_cachep = kmem_cache_create("btrfs_inode", 8966 sizeof(struct btrfs_inode), 0, 8967 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, init_once); 8968 if (!btrfs_inode_cachep) 8969 goto fail; 8970 8971 btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle", 8972 sizeof(struct btrfs_trans_handle), 0, 8973 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL); 8974 if (!btrfs_trans_handle_cachep) 8975 goto fail; 8976 8977 btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction", 8978 sizeof(struct btrfs_transaction), 0, 8979 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL); 8980 if (!btrfs_transaction_cachep) 8981 goto fail; 8982 8983 btrfs_path_cachep = kmem_cache_create("btrfs_path", 8984 sizeof(struct btrfs_path), 0, 8985 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL); 8986 if (!btrfs_path_cachep) 8987 goto fail; 8988 8989 btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space", 8990 sizeof(struct btrfs_free_space), 0, 8991 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL); 8992 if (!btrfs_free_space_cachep) 8993 goto fail; 8994 8995 btrfs_delalloc_work_cachep = kmem_cache_create("btrfs_delalloc_work", 8996 sizeof(struct btrfs_delalloc_work), 0, 8997 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, 8998 NULL); 8999 if (!btrfs_delalloc_work_cachep) 9000 goto fail; 9001 9002 return 0; 9003 fail: 9004 btrfs_destroy_cachep(); 9005 return -ENOMEM; 9006 } 9007 9008 static int btrfs_getattr(struct vfsmount *mnt, 9009 struct dentry *dentry, struct kstat *stat) 9010 { 9011 u64 delalloc_bytes; 9012 struct inode *inode = d_inode(dentry); 9013 u32 blocksize = inode->i_sb->s_blocksize; 9014 9015 generic_fillattr(inode, stat); 9016 stat->dev = BTRFS_I(inode)->root->anon_dev; 9017 stat->blksize = PAGE_CACHE_SIZE; 9018 9019 spin_lock(&BTRFS_I(inode)->lock); 9020 delalloc_bytes = BTRFS_I(inode)->delalloc_bytes; 9021 spin_unlock(&BTRFS_I(inode)->lock); 9022 stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) + 9023 ALIGN(delalloc_bytes, blocksize)) >> 9; 9024 return 0; 9025 } 9026 9027 static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry, 9028 struct inode *new_dir, struct dentry *new_dentry) 9029 { 9030 struct btrfs_trans_handle *trans; 9031 struct btrfs_root *root = BTRFS_I(old_dir)->root; 9032 struct btrfs_root *dest = BTRFS_I(new_dir)->root; 9033 struct inode *new_inode = d_inode(new_dentry); 9034 struct inode *old_inode = d_inode(old_dentry); 9035 struct timespec ctime = CURRENT_TIME; 9036 u64 index = 0; 9037 u64 root_objectid; 9038 int ret; 9039 u64 old_ino = btrfs_ino(old_inode); 9040 9041 if (btrfs_ino(new_dir) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID) 9042 return -EPERM; 9043 9044 /* we only allow rename subvolume link between subvolumes */ 9045 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest) 9046 return -EXDEV; 9047 9048 if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID || 9049 (new_inode && btrfs_ino(new_inode) == BTRFS_FIRST_FREE_OBJECTID)) 9050 return -ENOTEMPTY; 9051 9052 if (S_ISDIR(old_inode->i_mode) && new_inode && 9053 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE) 9054 return -ENOTEMPTY; 9055 9056 9057 /* check for collisions, even if the name isn't there */ 9058 ret = btrfs_check_dir_item_collision(dest, new_dir->i_ino, 9059 new_dentry->d_name.name, 9060 new_dentry->d_name.len); 9061 9062 if (ret) { 9063 if (ret == -EEXIST) { 9064 /* we shouldn't get 9065 * eexist without a new_inode */ 9066 if (WARN_ON(!new_inode)) { 9067 return ret; 9068 } 9069 } else { 9070 /* maybe -EOVERFLOW */ 9071 return ret; 9072 } 9073 } 9074 ret = 0; 9075 9076 /* 9077 * we're using rename to replace one file with another. Start IO on it 9078 * now so we don't add too much work to the end of the transaction 9079 */ 9080 if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size) 9081 filemap_flush(old_inode->i_mapping); 9082 9083 /* close the racy window with snapshot create/destroy ioctl */ 9084 if (old_ino == BTRFS_FIRST_FREE_OBJECTID) 9085 down_read(&root->fs_info->subvol_sem); 9086 /* 9087 * We want to reserve the absolute worst case amount of items. So if 9088 * both inodes are subvols and we need to unlink them then that would 9089 * require 4 item modifications, but if they are both normal inodes it 9090 * would require 5 item modifications, so we'll assume their normal 9091 * inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items 9092 * should cover the worst case number of items we'll modify. 9093 */ 9094 trans = btrfs_start_transaction(root, 11); 9095 if (IS_ERR(trans)) { 9096 ret = PTR_ERR(trans); 9097 goto out_notrans; 9098 } 9099 9100 if (dest != root) 9101 btrfs_record_root_in_trans(trans, dest); 9102 9103 ret = btrfs_set_inode_index(new_dir, &index); 9104 if (ret) 9105 goto out_fail; 9106 9107 BTRFS_I(old_inode)->dir_index = 0ULL; 9108 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) { 9109 /* force full log commit if subvolume involved. */ 9110 btrfs_set_log_full_commit(root->fs_info, trans); 9111 } else { 9112 ret = btrfs_insert_inode_ref(trans, dest, 9113 new_dentry->d_name.name, 9114 new_dentry->d_name.len, 9115 old_ino, 9116 btrfs_ino(new_dir), index); 9117 if (ret) 9118 goto out_fail; 9119 /* 9120 * this is an ugly little race, but the rename is required 9121 * to make sure that if we crash, the inode is either at the 9122 * old name or the new one. pinning the log transaction lets 9123 * us make sure we don't allow a log commit to come in after 9124 * we unlink the name but before we add the new name back in. 9125 */ 9126 btrfs_pin_log_trans(root); 9127 } 9128 9129 inode_inc_iversion(old_dir); 9130 inode_inc_iversion(new_dir); 9131 inode_inc_iversion(old_inode); 9132 old_dir->i_ctime = old_dir->i_mtime = ctime; 9133 new_dir->i_ctime = new_dir->i_mtime = ctime; 9134 old_inode->i_ctime = ctime; 9135 9136 if (old_dentry->d_parent != new_dentry->d_parent) 9137 btrfs_record_unlink_dir(trans, old_dir, old_inode, 1); 9138 9139 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) { 9140 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid; 9141 ret = btrfs_unlink_subvol(trans, root, old_dir, root_objectid, 9142 old_dentry->d_name.name, 9143 old_dentry->d_name.len); 9144 } else { 9145 ret = __btrfs_unlink_inode(trans, root, old_dir, 9146 d_inode(old_dentry), 9147 old_dentry->d_name.name, 9148 old_dentry->d_name.len); 9149 if (!ret) 9150 ret = btrfs_update_inode(trans, root, old_inode); 9151 } 9152 if (ret) { 9153 btrfs_abort_transaction(trans, root, ret); 9154 goto out_fail; 9155 } 9156 9157 if (new_inode) { 9158 inode_inc_iversion(new_inode); 9159 new_inode->i_ctime = CURRENT_TIME; 9160 if (unlikely(btrfs_ino(new_inode) == 9161 BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) { 9162 root_objectid = BTRFS_I(new_inode)->location.objectid; 9163 ret = btrfs_unlink_subvol(trans, dest, new_dir, 9164 root_objectid, 9165 new_dentry->d_name.name, 9166 new_dentry->d_name.len); 9167 BUG_ON(new_inode->i_nlink == 0); 9168 } else { 9169 ret = btrfs_unlink_inode(trans, dest, new_dir, 9170 d_inode(new_dentry), 9171 new_dentry->d_name.name, 9172 new_dentry->d_name.len); 9173 } 9174 if (!ret && new_inode->i_nlink == 0) 9175 ret = btrfs_orphan_add(trans, d_inode(new_dentry)); 9176 if (ret) { 9177 btrfs_abort_transaction(trans, root, ret); 9178 goto out_fail; 9179 } 9180 } 9181 9182 ret = btrfs_add_link(trans, new_dir, old_inode, 9183 new_dentry->d_name.name, 9184 new_dentry->d_name.len, 0, index); 9185 if (ret) { 9186 btrfs_abort_transaction(trans, root, ret); 9187 goto out_fail; 9188 } 9189 9190 if (old_inode->i_nlink == 1) 9191 BTRFS_I(old_inode)->dir_index = index; 9192 9193 if (old_ino != BTRFS_FIRST_FREE_OBJECTID) { 9194 struct dentry *parent = new_dentry->d_parent; 9195 btrfs_log_new_name(trans, old_inode, old_dir, parent); 9196 btrfs_end_log_trans(root); 9197 } 9198 out_fail: 9199 btrfs_end_transaction(trans, root); 9200 out_notrans: 9201 if (old_ino == BTRFS_FIRST_FREE_OBJECTID) 9202 up_read(&root->fs_info->subvol_sem); 9203 9204 return ret; 9205 } 9206 9207 static int btrfs_rename2(struct inode *old_dir, struct dentry *old_dentry, 9208 struct inode *new_dir, struct dentry *new_dentry, 9209 unsigned int flags) 9210 { 9211 if (flags & ~RENAME_NOREPLACE) 9212 return -EINVAL; 9213 9214 return btrfs_rename(old_dir, old_dentry, new_dir, new_dentry); 9215 } 9216 9217 static void btrfs_run_delalloc_work(struct btrfs_work *work) 9218 { 9219 struct btrfs_delalloc_work *delalloc_work; 9220 struct inode *inode; 9221 9222 delalloc_work = container_of(work, struct btrfs_delalloc_work, 9223 work); 9224 inode = delalloc_work->inode; 9225 if (delalloc_work->wait) { 9226 btrfs_wait_ordered_range(inode, 0, (u64)-1); 9227 } else { 9228 filemap_flush(inode->i_mapping); 9229 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT, 9230 &BTRFS_I(inode)->runtime_flags)) 9231 filemap_flush(inode->i_mapping); 9232 } 9233 9234 if (delalloc_work->delay_iput) 9235 btrfs_add_delayed_iput(inode); 9236 else 9237 iput(inode); 9238 complete(&delalloc_work->completion); 9239 } 9240 9241 struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode, 9242 int wait, int delay_iput) 9243 { 9244 struct btrfs_delalloc_work *work; 9245 9246 work = kmem_cache_zalloc(btrfs_delalloc_work_cachep, GFP_NOFS); 9247 if (!work) 9248 return NULL; 9249 9250 init_completion(&work->completion); 9251 INIT_LIST_HEAD(&work->list); 9252 work->inode = inode; 9253 work->wait = wait; 9254 work->delay_iput = delay_iput; 9255 WARN_ON_ONCE(!inode); 9256 btrfs_init_work(&work->work, btrfs_flush_delalloc_helper, 9257 btrfs_run_delalloc_work, NULL, NULL); 9258 9259 return work; 9260 } 9261 9262 void btrfs_wait_and_free_delalloc_work(struct btrfs_delalloc_work *work) 9263 { 9264 wait_for_completion(&work->completion); 9265 kmem_cache_free(btrfs_delalloc_work_cachep, work); 9266 } 9267 9268 /* 9269 * some fairly slow code that needs optimization. This walks the list 9270 * of all the inodes with pending delalloc and forces them to disk. 9271 */ 9272 static int __start_delalloc_inodes(struct btrfs_root *root, int delay_iput, 9273 int nr) 9274 { 9275 struct btrfs_inode *binode; 9276 struct inode *inode; 9277 struct btrfs_delalloc_work *work, *next; 9278 struct list_head works; 9279 struct list_head splice; 9280 int ret = 0; 9281 9282 INIT_LIST_HEAD(&works); 9283 INIT_LIST_HEAD(&splice); 9284 9285 mutex_lock(&root->delalloc_mutex); 9286 spin_lock(&root->delalloc_lock); 9287 list_splice_init(&root->delalloc_inodes, &splice); 9288 while (!list_empty(&splice)) { 9289 binode = list_entry(splice.next, struct btrfs_inode, 9290 delalloc_inodes); 9291 9292 list_move_tail(&binode->delalloc_inodes, 9293 &root->delalloc_inodes); 9294 inode = igrab(&binode->vfs_inode); 9295 if (!inode) { 9296 cond_resched_lock(&root->delalloc_lock); 9297 continue; 9298 } 9299 spin_unlock(&root->delalloc_lock); 9300 9301 work = btrfs_alloc_delalloc_work(inode, 0, delay_iput); 9302 if (!work) { 9303 if (delay_iput) 9304 btrfs_add_delayed_iput(inode); 9305 else 9306 iput(inode); 9307 ret = -ENOMEM; 9308 goto out; 9309 } 9310 list_add_tail(&work->list, &works); 9311 btrfs_queue_work(root->fs_info->flush_workers, 9312 &work->work); 9313 ret++; 9314 if (nr != -1 && ret >= nr) 9315 goto out; 9316 cond_resched(); 9317 spin_lock(&root->delalloc_lock); 9318 } 9319 spin_unlock(&root->delalloc_lock); 9320 9321 out: 9322 list_for_each_entry_safe(work, next, &works, list) { 9323 list_del_init(&work->list); 9324 btrfs_wait_and_free_delalloc_work(work); 9325 } 9326 9327 if (!list_empty_careful(&splice)) { 9328 spin_lock(&root->delalloc_lock); 9329 list_splice_tail(&splice, &root->delalloc_inodes); 9330 spin_unlock(&root->delalloc_lock); 9331 } 9332 mutex_unlock(&root->delalloc_mutex); 9333 return ret; 9334 } 9335 9336 int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput) 9337 { 9338 int ret; 9339 9340 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state)) 9341 return -EROFS; 9342 9343 ret = __start_delalloc_inodes(root, delay_iput, -1); 9344 if (ret > 0) 9345 ret = 0; 9346 /* 9347 * the filemap_flush will queue IO into the worker threads, but 9348 * we have to make sure the IO is actually started and that 9349 * ordered extents get created before we return 9350 */ 9351 atomic_inc(&root->fs_info->async_submit_draining); 9352 while (atomic_read(&root->fs_info->nr_async_submits) || 9353 atomic_read(&root->fs_info->async_delalloc_pages)) { 9354 wait_event(root->fs_info->async_submit_wait, 9355 (atomic_read(&root->fs_info->nr_async_submits) == 0 && 9356 atomic_read(&root->fs_info->async_delalloc_pages) == 0)); 9357 } 9358 atomic_dec(&root->fs_info->async_submit_draining); 9359 return ret; 9360 } 9361 9362 int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, int delay_iput, 9363 int nr) 9364 { 9365 struct btrfs_root *root; 9366 struct list_head splice; 9367 int ret; 9368 9369 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) 9370 return -EROFS; 9371 9372 INIT_LIST_HEAD(&splice); 9373 9374 mutex_lock(&fs_info->delalloc_root_mutex); 9375 spin_lock(&fs_info->delalloc_root_lock); 9376 list_splice_init(&fs_info->delalloc_roots, &splice); 9377 while (!list_empty(&splice) && nr) { 9378 root = list_first_entry(&splice, struct btrfs_root, 9379 delalloc_root); 9380 root = btrfs_grab_fs_root(root); 9381 BUG_ON(!root); 9382 list_move_tail(&root->delalloc_root, 9383 &fs_info->delalloc_roots); 9384 spin_unlock(&fs_info->delalloc_root_lock); 9385 9386 ret = __start_delalloc_inodes(root, delay_iput, nr); 9387 btrfs_put_fs_root(root); 9388 if (ret < 0) 9389 goto out; 9390 9391 if (nr != -1) { 9392 nr -= ret; 9393 WARN_ON(nr < 0); 9394 } 9395 spin_lock(&fs_info->delalloc_root_lock); 9396 } 9397 spin_unlock(&fs_info->delalloc_root_lock); 9398 9399 ret = 0; 9400 atomic_inc(&fs_info->async_submit_draining); 9401 while (atomic_read(&fs_info->nr_async_submits) || 9402 atomic_read(&fs_info->async_delalloc_pages)) { 9403 wait_event(fs_info->async_submit_wait, 9404 (atomic_read(&fs_info->nr_async_submits) == 0 && 9405 atomic_read(&fs_info->async_delalloc_pages) == 0)); 9406 } 9407 atomic_dec(&fs_info->async_submit_draining); 9408 out: 9409 if (!list_empty_careful(&splice)) { 9410 spin_lock(&fs_info->delalloc_root_lock); 9411 list_splice_tail(&splice, &fs_info->delalloc_roots); 9412 spin_unlock(&fs_info->delalloc_root_lock); 9413 } 9414 mutex_unlock(&fs_info->delalloc_root_mutex); 9415 return ret; 9416 } 9417 9418 static int btrfs_symlink(struct inode *dir, struct dentry *dentry, 9419 const char *symname) 9420 { 9421 struct btrfs_trans_handle *trans; 9422 struct btrfs_root *root = BTRFS_I(dir)->root; 9423 struct btrfs_path *path; 9424 struct btrfs_key key; 9425 struct inode *inode = NULL; 9426 int err; 9427 int drop_inode = 0; 9428 u64 objectid; 9429 u64 index = 0; 9430 int name_len; 9431 int datasize; 9432 unsigned long ptr; 9433 struct btrfs_file_extent_item *ei; 9434 struct extent_buffer *leaf; 9435 9436 name_len = strlen(symname); 9437 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root)) 9438 return -ENAMETOOLONG; 9439 9440 /* 9441 * 2 items for inode item and ref 9442 * 2 items for dir items 9443 * 1 item for xattr if selinux is on 9444 */ 9445 trans = btrfs_start_transaction(root, 5); 9446 if (IS_ERR(trans)) 9447 return PTR_ERR(trans); 9448 9449 err = btrfs_find_free_ino(root, &objectid); 9450 if (err) 9451 goto out_unlock; 9452 9453 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name, 9454 dentry->d_name.len, btrfs_ino(dir), objectid, 9455 S_IFLNK|S_IRWXUGO, &index); 9456 if (IS_ERR(inode)) { 9457 err = PTR_ERR(inode); 9458 goto out_unlock; 9459 } 9460 9461 /* 9462 * If the active LSM wants to access the inode during 9463 * d_instantiate it needs these. Smack checks to see 9464 * if the filesystem supports xattrs by looking at the 9465 * ops vector. 9466 */ 9467 inode->i_fop = &btrfs_file_operations; 9468 inode->i_op = &btrfs_file_inode_operations; 9469 inode->i_mapping->a_ops = &btrfs_aops; 9470 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops; 9471 9472 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name); 9473 if (err) 9474 goto out_unlock_inode; 9475 9476 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index); 9477 if (err) 9478 goto out_unlock_inode; 9479 9480 path = btrfs_alloc_path(); 9481 if (!path) { 9482 err = -ENOMEM; 9483 goto out_unlock_inode; 9484 } 9485 key.objectid = btrfs_ino(inode); 9486 key.offset = 0; 9487 key.type = BTRFS_EXTENT_DATA_KEY; 9488 datasize = btrfs_file_extent_calc_inline_size(name_len); 9489 err = btrfs_insert_empty_item(trans, root, path, &key, 9490 datasize); 9491 if (err) { 9492 btrfs_free_path(path); 9493 goto out_unlock_inode; 9494 } 9495 leaf = path->nodes[0]; 9496 ei = btrfs_item_ptr(leaf, path->slots[0], 9497 struct btrfs_file_extent_item); 9498 btrfs_set_file_extent_generation(leaf, ei, trans->transid); 9499 btrfs_set_file_extent_type(leaf, ei, 9500 BTRFS_FILE_EXTENT_INLINE); 9501 btrfs_set_file_extent_encryption(leaf, ei, 0); 9502 btrfs_set_file_extent_compression(leaf, ei, 0); 9503 btrfs_set_file_extent_other_encoding(leaf, ei, 0); 9504 btrfs_set_file_extent_ram_bytes(leaf, ei, name_len); 9505 9506 ptr = btrfs_file_extent_inline_start(ei); 9507 write_extent_buffer(leaf, symname, ptr, name_len); 9508 btrfs_mark_buffer_dirty(leaf); 9509 btrfs_free_path(path); 9510 9511 inode->i_op = &btrfs_symlink_inode_operations; 9512 inode->i_mapping->a_ops = &btrfs_symlink_aops; 9513 inode_set_bytes(inode, name_len); 9514 btrfs_i_size_write(inode, name_len); 9515 err = btrfs_update_inode(trans, root, inode); 9516 if (err) { 9517 drop_inode = 1; 9518 goto out_unlock_inode; 9519 } 9520 9521 unlock_new_inode(inode); 9522 d_instantiate(dentry, inode); 9523 9524 out_unlock: 9525 btrfs_end_transaction(trans, root); 9526 if (drop_inode) { 9527 inode_dec_link_count(inode); 9528 iput(inode); 9529 } 9530 btrfs_btree_balance_dirty(root); 9531 return err; 9532 9533 out_unlock_inode: 9534 drop_inode = 1; 9535 unlock_new_inode(inode); 9536 goto out_unlock; 9537 } 9538 9539 static int __btrfs_prealloc_file_range(struct inode *inode, int mode, 9540 u64 start, u64 num_bytes, u64 min_size, 9541 loff_t actual_len, u64 *alloc_hint, 9542 struct btrfs_trans_handle *trans) 9543 { 9544 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; 9545 struct extent_map *em; 9546 struct btrfs_root *root = BTRFS_I(inode)->root; 9547 struct btrfs_key ins; 9548 u64 cur_offset = start; 9549 u64 i_size; 9550 u64 cur_bytes; 9551 int ret = 0; 9552 bool own_trans = true; 9553 9554 if (trans) 9555 own_trans = false; 9556 while (num_bytes > 0) { 9557 if (own_trans) { 9558 trans = btrfs_start_transaction(root, 3); 9559 if (IS_ERR(trans)) { 9560 ret = PTR_ERR(trans); 9561 break; 9562 } 9563 } 9564 9565 cur_bytes = min(num_bytes, 256ULL * 1024 * 1024); 9566 cur_bytes = max(cur_bytes, min_size); 9567 ret = btrfs_reserve_extent(root, cur_bytes, min_size, 0, 9568 *alloc_hint, &ins, 1, 0); 9569 if (ret) { 9570 if (own_trans) 9571 btrfs_end_transaction(trans, root); 9572 break; 9573 } 9574 9575 ret = insert_reserved_file_extent(trans, inode, 9576 cur_offset, ins.objectid, 9577 ins.offset, ins.offset, 9578 ins.offset, 0, 0, 0, 9579 BTRFS_FILE_EXTENT_PREALLOC); 9580 if (ret) { 9581 btrfs_free_reserved_extent(root, ins.objectid, 9582 ins.offset, 0); 9583 btrfs_abort_transaction(trans, root, ret); 9584 if (own_trans) 9585 btrfs_end_transaction(trans, root); 9586 break; 9587 } 9588 9589 btrfs_drop_extent_cache(inode, cur_offset, 9590 cur_offset + ins.offset -1, 0); 9591 9592 em = alloc_extent_map(); 9593 if (!em) { 9594 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, 9595 &BTRFS_I(inode)->runtime_flags); 9596 goto next; 9597 } 9598 9599 em->start = cur_offset; 9600 em->orig_start = cur_offset; 9601 em->len = ins.offset; 9602 em->block_start = ins.objectid; 9603 em->block_len = ins.offset; 9604 em->orig_block_len = ins.offset; 9605 em->ram_bytes = ins.offset; 9606 em->bdev = root->fs_info->fs_devices->latest_bdev; 9607 set_bit(EXTENT_FLAG_PREALLOC, &em->flags); 9608 em->generation = trans->transid; 9609 9610 while (1) { 9611 write_lock(&em_tree->lock); 9612 ret = add_extent_mapping(em_tree, em, 1); 9613 write_unlock(&em_tree->lock); 9614 if (ret != -EEXIST) 9615 break; 9616 btrfs_drop_extent_cache(inode, cur_offset, 9617 cur_offset + ins.offset - 1, 9618 0); 9619 } 9620 free_extent_map(em); 9621 next: 9622 num_bytes -= ins.offset; 9623 cur_offset += ins.offset; 9624 *alloc_hint = ins.objectid + ins.offset; 9625 9626 inode_inc_iversion(inode); 9627 inode->i_ctime = CURRENT_TIME; 9628 BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC; 9629 if (!(mode & FALLOC_FL_KEEP_SIZE) && 9630 (actual_len > inode->i_size) && 9631 (cur_offset > inode->i_size)) { 9632 if (cur_offset > actual_len) 9633 i_size = actual_len; 9634 else 9635 i_size = cur_offset; 9636 i_size_write(inode, i_size); 9637 btrfs_ordered_update_i_size(inode, i_size, NULL); 9638 } 9639 9640 ret = btrfs_update_inode(trans, root, inode); 9641 9642 if (ret) { 9643 btrfs_abort_transaction(trans, root, ret); 9644 if (own_trans) 9645 btrfs_end_transaction(trans, root); 9646 break; 9647 } 9648 9649 if (own_trans) 9650 btrfs_end_transaction(trans, root); 9651 } 9652 return ret; 9653 } 9654 9655 int btrfs_prealloc_file_range(struct inode *inode, int mode, 9656 u64 start, u64 num_bytes, u64 min_size, 9657 loff_t actual_len, u64 *alloc_hint) 9658 { 9659 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes, 9660 min_size, actual_len, alloc_hint, 9661 NULL); 9662 } 9663 9664 int btrfs_prealloc_file_range_trans(struct inode *inode, 9665 struct btrfs_trans_handle *trans, int mode, 9666 u64 start, u64 num_bytes, u64 min_size, 9667 loff_t actual_len, u64 *alloc_hint) 9668 { 9669 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes, 9670 min_size, actual_len, alloc_hint, trans); 9671 } 9672 9673 static int btrfs_set_page_dirty(struct page *page) 9674 { 9675 return __set_page_dirty_nobuffers(page); 9676 } 9677 9678 static int btrfs_permission(struct inode *inode, int mask) 9679 { 9680 struct btrfs_root *root = BTRFS_I(inode)->root; 9681 umode_t mode = inode->i_mode; 9682 9683 if (mask & MAY_WRITE && 9684 (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) { 9685 if (btrfs_root_readonly(root)) 9686 return -EROFS; 9687 if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY) 9688 return -EACCES; 9689 } 9690 return generic_permission(inode, mask); 9691 } 9692 9693 static int btrfs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode) 9694 { 9695 struct btrfs_trans_handle *trans; 9696 struct btrfs_root *root = BTRFS_I(dir)->root; 9697 struct inode *inode = NULL; 9698 u64 objectid; 9699 u64 index; 9700 int ret = 0; 9701 9702 /* 9703 * 5 units required for adding orphan entry 9704 */ 9705 trans = btrfs_start_transaction(root, 5); 9706 if (IS_ERR(trans)) 9707 return PTR_ERR(trans); 9708 9709 ret = btrfs_find_free_ino(root, &objectid); 9710 if (ret) 9711 goto out; 9712 9713 inode = btrfs_new_inode(trans, root, dir, NULL, 0, 9714 btrfs_ino(dir), objectid, mode, &index); 9715 if (IS_ERR(inode)) { 9716 ret = PTR_ERR(inode); 9717 inode = NULL; 9718 goto out; 9719 } 9720 9721 inode->i_fop = &btrfs_file_operations; 9722 inode->i_op = &btrfs_file_inode_operations; 9723 9724 inode->i_mapping->a_ops = &btrfs_aops; 9725 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops; 9726 9727 ret = btrfs_init_inode_security(trans, inode, dir, NULL); 9728 if (ret) 9729 goto out_inode; 9730 9731 ret = btrfs_update_inode(trans, root, inode); 9732 if (ret) 9733 goto out_inode; 9734 ret = btrfs_orphan_add(trans, inode); 9735 if (ret) 9736 goto out_inode; 9737 9738 /* 9739 * We set number of links to 0 in btrfs_new_inode(), and here we set 9740 * it to 1 because d_tmpfile() will issue a warning if the count is 0, 9741 * through: 9742 * 9743 * d_tmpfile() -> inode_dec_link_count() -> drop_nlink() 9744 */ 9745 set_nlink(inode, 1); 9746 unlock_new_inode(inode); 9747 d_tmpfile(dentry, inode); 9748 mark_inode_dirty(inode); 9749 9750 out: 9751 btrfs_end_transaction(trans, root); 9752 if (ret) 9753 iput(inode); 9754 btrfs_balance_delayed_items(root); 9755 btrfs_btree_balance_dirty(root); 9756 return ret; 9757 9758 out_inode: 9759 unlock_new_inode(inode); 9760 goto out; 9761 9762 } 9763 9764 /* Inspired by filemap_check_errors() */ 9765 int btrfs_inode_check_errors(struct inode *inode) 9766 { 9767 int ret = 0; 9768 9769 if (test_bit(AS_ENOSPC, &inode->i_mapping->flags) && 9770 test_and_clear_bit(AS_ENOSPC, &inode->i_mapping->flags)) 9771 ret = -ENOSPC; 9772 if (test_bit(AS_EIO, &inode->i_mapping->flags) && 9773 test_and_clear_bit(AS_EIO, &inode->i_mapping->flags)) 9774 ret = -EIO; 9775 9776 return ret; 9777 } 9778 9779 static const struct inode_operations btrfs_dir_inode_operations = { 9780 .getattr = btrfs_getattr, 9781 .lookup = btrfs_lookup, 9782 .create = btrfs_create, 9783 .unlink = btrfs_unlink, 9784 .link = btrfs_link, 9785 .mkdir = btrfs_mkdir, 9786 .rmdir = btrfs_rmdir, 9787 .rename2 = btrfs_rename2, 9788 .symlink = btrfs_symlink, 9789 .setattr = btrfs_setattr, 9790 .mknod = btrfs_mknod, 9791 .setxattr = btrfs_setxattr, 9792 .getxattr = btrfs_getxattr, 9793 .listxattr = btrfs_listxattr, 9794 .removexattr = btrfs_removexattr, 9795 .permission = btrfs_permission, 9796 .get_acl = btrfs_get_acl, 9797 .set_acl = btrfs_set_acl, 9798 .update_time = btrfs_update_time, 9799 .tmpfile = btrfs_tmpfile, 9800 }; 9801 static const struct inode_operations btrfs_dir_ro_inode_operations = { 9802 .lookup = btrfs_lookup, 9803 .permission = btrfs_permission, 9804 .get_acl = btrfs_get_acl, 9805 .set_acl = btrfs_set_acl, 9806 .update_time = btrfs_update_time, 9807 }; 9808 9809 static const struct file_operations btrfs_dir_file_operations = { 9810 .llseek = generic_file_llseek, 9811 .read = generic_read_dir, 9812 .iterate = btrfs_real_readdir, 9813 .unlocked_ioctl = btrfs_ioctl, 9814 #ifdef CONFIG_COMPAT 9815 .compat_ioctl = btrfs_ioctl, 9816 #endif 9817 .release = btrfs_release_file, 9818 .fsync = btrfs_sync_file, 9819 }; 9820 9821 static struct extent_io_ops btrfs_extent_io_ops = { 9822 .fill_delalloc = run_delalloc_range, 9823 .submit_bio_hook = btrfs_submit_bio_hook, 9824 .merge_bio_hook = btrfs_merge_bio_hook, 9825 .readpage_end_io_hook = btrfs_readpage_end_io_hook, 9826 .writepage_end_io_hook = btrfs_writepage_end_io_hook, 9827 .writepage_start_hook = btrfs_writepage_start_hook, 9828 .set_bit_hook = btrfs_set_bit_hook, 9829 .clear_bit_hook = btrfs_clear_bit_hook, 9830 .merge_extent_hook = btrfs_merge_extent_hook, 9831 .split_extent_hook = btrfs_split_extent_hook, 9832 }; 9833 9834 /* 9835 * btrfs doesn't support the bmap operation because swapfiles 9836 * use bmap to make a mapping of extents in the file. They assume 9837 * these extents won't change over the life of the file and they 9838 * use the bmap result to do IO directly to the drive. 9839 * 9840 * the btrfs bmap call would return logical addresses that aren't 9841 * suitable for IO and they also will change frequently as COW 9842 * operations happen. So, swapfile + btrfs == corruption. 9843 * 9844 * For now we're avoiding this by dropping bmap. 9845 */ 9846 static const struct address_space_operations btrfs_aops = { 9847 .readpage = btrfs_readpage, 9848 .writepage = btrfs_writepage, 9849 .writepages = btrfs_writepages, 9850 .readpages = btrfs_readpages, 9851 .direct_IO = btrfs_direct_IO, 9852 .invalidatepage = btrfs_invalidatepage, 9853 .releasepage = btrfs_releasepage, 9854 .set_page_dirty = btrfs_set_page_dirty, 9855 .error_remove_page = generic_error_remove_page, 9856 }; 9857 9858 static const struct address_space_operations btrfs_symlink_aops = { 9859 .readpage = btrfs_readpage, 9860 .writepage = btrfs_writepage, 9861 .invalidatepage = btrfs_invalidatepage, 9862 .releasepage = btrfs_releasepage, 9863 }; 9864 9865 static const struct inode_operations btrfs_file_inode_operations = { 9866 .getattr = btrfs_getattr, 9867 .setattr = btrfs_setattr, 9868 .setxattr = btrfs_setxattr, 9869 .getxattr = btrfs_getxattr, 9870 .listxattr = btrfs_listxattr, 9871 .removexattr = btrfs_removexattr, 9872 .permission = btrfs_permission, 9873 .fiemap = btrfs_fiemap, 9874 .get_acl = btrfs_get_acl, 9875 .set_acl = btrfs_set_acl, 9876 .update_time = btrfs_update_time, 9877 }; 9878 static const struct inode_operations btrfs_special_inode_operations = { 9879 .getattr = btrfs_getattr, 9880 .setattr = btrfs_setattr, 9881 .permission = btrfs_permission, 9882 .setxattr = btrfs_setxattr, 9883 .getxattr = btrfs_getxattr, 9884 .listxattr = btrfs_listxattr, 9885 .removexattr = btrfs_removexattr, 9886 .get_acl = btrfs_get_acl, 9887 .set_acl = btrfs_set_acl, 9888 .update_time = btrfs_update_time, 9889 }; 9890 static const struct inode_operations btrfs_symlink_inode_operations = { 9891 .readlink = generic_readlink, 9892 .follow_link = page_follow_link_light, 9893 .put_link = page_put_link, 9894 .getattr = btrfs_getattr, 9895 .setattr = btrfs_setattr, 9896 .permission = btrfs_permission, 9897 .setxattr = btrfs_setxattr, 9898 .getxattr = btrfs_getxattr, 9899 .listxattr = btrfs_listxattr, 9900 .removexattr = btrfs_removexattr, 9901 .update_time = btrfs_update_time, 9902 }; 9903 9904 const struct dentry_operations btrfs_dentry_operations = { 9905 .d_delete = btrfs_dentry_delete, 9906 .d_release = btrfs_dentry_release, 9907 }; 9908