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/aio.h> 36 #include <linux/bit_spinlock.h> 37 #include <linux/xattr.h> 38 #include <linux/posix_acl.h> 39 #include <linux/falloc.h> 40 #include <linux/slab.h> 41 #include <linux/ratelimit.h> 42 #include <linux/mount.h> 43 #include <linux/btrfs.h> 44 #include <linux/blkdev.h> 45 #include <linux/posix_acl_xattr.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 63 struct btrfs_iget_args { 64 struct btrfs_key *location; 65 struct btrfs_root *root; 66 }; 67 68 static const struct inode_operations btrfs_dir_inode_operations; 69 static const struct inode_operations btrfs_symlink_inode_operations; 70 static const struct inode_operations btrfs_dir_ro_inode_operations; 71 static const struct inode_operations btrfs_special_inode_operations; 72 static const struct inode_operations btrfs_file_inode_operations; 73 static const struct address_space_operations btrfs_aops; 74 static const struct address_space_operations btrfs_symlink_aops; 75 static const struct file_operations btrfs_dir_file_operations; 76 static struct extent_io_ops btrfs_extent_io_ops; 77 78 static struct kmem_cache *btrfs_inode_cachep; 79 static struct kmem_cache *btrfs_delalloc_work_cachep; 80 struct kmem_cache *btrfs_trans_handle_cachep; 81 struct kmem_cache *btrfs_transaction_cachep; 82 struct kmem_cache *btrfs_path_cachep; 83 struct kmem_cache *btrfs_free_space_cachep; 84 85 #define S_SHIFT 12 86 static unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = { 87 [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE, 88 [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR, 89 [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV, 90 [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV, 91 [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO, 92 [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK, 93 [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK, 94 }; 95 96 static int btrfs_setsize(struct inode *inode, struct iattr *attr); 97 static int btrfs_truncate(struct inode *inode); 98 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent); 99 static noinline int cow_file_range(struct inode *inode, 100 struct page *locked_page, 101 u64 start, u64 end, int *page_started, 102 unsigned long *nr_written, int unlock); 103 static struct extent_map *create_pinned_em(struct inode *inode, u64 start, 104 u64 len, u64 orig_start, 105 u64 block_start, u64 block_len, 106 u64 orig_block_len, u64 ram_bytes, 107 int type); 108 109 static int btrfs_dirty_inode(struct inode *inode); 110 111 static int btrfs_init_inode_security(struct btrfs_trans_handle *trans, 112 struct inode *inode, struct inode *dir, 113 const struct qstr *qstr) 114 { 115 int err; 116 117 err = btrfs_init_acl(trans, inode, dir); 118 if (!err) 119 err = btrfs_xattr_security_init(trans, inode, dir, qstr); 120 return err; 121 } 122 123 /* 124 * this does all the hard work for inserting an inline extent into 125 * the btree. The caller should have done a btrfs_drop_extents so that 126 * no overlapping inline items exist in the btree 127 */ 128 static noinline int insert_inline_extent(struct btrfs_trans_handle *trans, 129 struct btrfs_path *path, int extent_inserted, 130 struct btrfs_root *root, struct inode *inode, 131 u64 start, size_t size, size_t compressed_size, 132 int compress_type, 133 struct page **compressed_pages) 134 { 135 struct extent_buffer *leaf; 136 struct page *page = NULL; 137 char *kaddr; 138 unsigned long ptr; 139 struct btrfs_file_extent_item *ei; 140 int err = 0; 141 int ret; 142 size_t cur_size = size; 143 unsigned long offset; 144 145 if (compressed_size && compressed_pages) 146 cur_size = compressed_size; 147 148 inode_add_bytes(inode, size); 149 150 if (!extent_inserted) { 151 struct btrfs_key key; 152 size_t datasize; 153 154 key.objectid = btrfs_ino(inode); 155 key.offset = start; 156 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY); 157 158 datasize = btrfs_file_extent_calc_inline_size(cur_size); 159 path->leave_spinning = 1; 160 ret = btrfs_insert_empty_item(trans, root, path, &key, 161 datasize); 162 if (ret) { 163 err = ret; 164 goto fail; 165 } 166 } 167 leaf = path->nodes[0]; 168 ei = btrfs_item_ptr(leaf, path->slots[0], 169 struct btrfs_file_extent_item); 170 btrfs_set_file_extent_generation(leaf, ei, trans->transid); 171 btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE); 172 btrfs_set_file_extent_encryption(leaf, ei, 0); 173 btrfs_set_file_extent_other_encoding(leaf, ei, 0); 174 btrfs_set_file_extent_ram_bytes(leaf, ei, size); 175 ptr = btrfs_file_extent_inline_start(ei); 176 177 if (compress_type != BTRFS_COMPRESS_NONE) { 178 struct page *cpage; 179 int i = 0; 180 while (compressed_size > 0) { 181 cpage = compressed_pages[i]; 182 cur_size = min_t(unsigned long, compressed_size, 183 PAGE_CACHE_SIZE); 184 185 kaddr = kmap_atomic(cpage); 186 write_extent_buffer(leaf, kaddr, ptr, cur_size); 187 kunmap_atomic(kaddr); 188 189 i++; 190 ptr += cur_size; 191 compressed_size -= cur_size; 192 } 193 btrfs_set_file_extent_compression(leaf, ei, 194 compress_type); 195 } else { 196 page = find_get_page(inode->i_mapping, 197 start >> PAGE_CACHE_SHIFT); 198 btrfs_set_file_extent_compression(leaf, ei, 0); 199 kaddr = kmap_atomic(page); 200 offset = start & (PAGE_CACHE_SIZE - 1); 201 write_extent_buffer(leaf, kaddr + offset, ptr, size); 202 kunmap_atomic(kaddr); 203 page_cache_release(page); 204 } 205 btrfs_mark_buffer_dirty(leaf); 206 btrfs_release_path(path); 207 208 /* 209 * we're an inline extent, so nobody can 210 * extend the file past i_size without locking 211 * a page we already have locked. 212 * 213 * We must do any isize and inode updates 214 * before we unlock the pages. Otherwise we 215 * could end up racing with unlink. 216 */ 217 BTRFS_I(inode)->disk_i_size = inode->i_size; 218 ret = btrfs_update_inode(trans, root, inode); 219 220 return ret; 221 fail: 222 return err; 223 } 224 225 226 /* 227 * conditionally insert an inline extent into the file. This 228 * does the checks required to make sure the data is small enough 229 * to fit as an inline extent. 230 */ 231 static noinline int cow_file_range_inline(struct btrfs_root *root, 232 struct inode *inode, u64 start, 233 u64 end, size_t compressed_size, 234 int compress_type, 235 struct page **compressed_pages) 236 { 237 struct btrfs_trans_handle *trans; 238 u64 isize = i_size_read(inode); 239 u64 actual_end = min(end + 1, isize); 240 u64 inline_len = actual_end - start; 241 u64 aligned_end = ALIGN(end, root->sectorsize); 242 u64 data_len = inline_len; 243 int ret; 244 struct btrfs_path *path; 245 int extent_inserted = 0; 246 u32 extent_item_size; 247 248 if (compressed_size) 249 data_len = compressed_size; 250 251 if (start > 0 || 252 actual_end >= PAGE_CACHE_SIZE || 253 data_len >= BTRFS_MAX_INLINE_DATA_SIZE(root) || 254 (!compressed_size && 255 (actual_end & (root->sectorsize - 1)) == 0) || 256 end + 1 < isize || 257 data_len > root->fs_info->max_inline) { 258 return 1; 259 } 260 261 path = btrfs_alloc_path(); 262 if (!path) 263 return -ENOMEM; 264 265 trans = btrfs_join_transaction(root); 266 if (IS_ERR(trans)) { 267 btrfs_free_path(path); 268 return PTR_ERR(trans); 269 } 270 trans->block_rsv = &root->fs_info->delalloc_block_rsv; 271 272 if (compressed_size && compressed_pages) 273 extent_item_size = btrfs_file_extent_calc_inline_size( 274 compressed_size); 275 else 276 extent_item_size = btrfs_file_extent_calc_inline_size( 277 inline_len); 278 279 ret = __btrfs_drop_extents(trans, root, inode, path, 280 start, aligned_end, NULL, 281 1, 1, extent_item_size, &extent_inserted); 282 if (ret) { 283 btrfs_abort_transaction(trans, root, ret); 284 goto out; 285 } 286 287 if (isize > actual_end) 288 inline_len = min_t(u64, isize, actual_end); 289 ret = insert_inline_extent(trans, path, extent_inserted, 290 root, inode, start, 291 inline_len, compressed_size, 292 compress_type, compressed_pages); 293 if (ret && ret != -ENOSPC) { 294 btrfs_abort_transaction(trans, root, ret); 295 goto out; 296 } else if (ret == -ENOSPC) { 297 ret = 1; 298 goto out; 299 } 300 301 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags); 302 btrfs_delalloc_release_metadata(inode, end + 1 - start); 303 btrfs_drop_extent_cache(inode, start, aligned_end - 1, 0); 304 out: 305 btrfs_free_path(path); 306 btrfs_end_transaction(trans, root); 307 return ret; 308 } 309 310 struct async_extent { 311 u64 start; 312 u64 ram_size; 313 u64 compressed_size; 314 struct page **pages; 315 unsigned long nr_pages; 316 int compress_type; 317 struct list_head list; 318 }; 319 320 struct async_cow { 321 struct inode *inode; 322 struct btrfs_root *root; 323 struct page *locked_page; 324 u64 start; 325 u64 end; 326 struct list_head extents; 327 struct btrfs_work work; 328 }; 329 330 static noinline int add_async_extent(struct async_cow *cow, 331 u64 start, u64 ram_size, 332 u64 compressed_size, 333 struct page **pages, 334 unsigned long nr_pages, 335 int compress_type) 336 { 337 struct async_extent *async_extent; 338 339 async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS); 340 BUG_ON(!async_extent); /* -ENOMEM */ 341 async_extent->start = start; 342 async_extent->ram_size = ram_size; 343 async_extent->compressed_size = compressed_size; 344 async_extent->pages = pages; 345 async_extent->nr_pages = nr_pages; 346 async_extent->compress_type = compress_type; 347 list_add_tail(&async_extent->list, &cow->extents); 348 return 0; 349 } 350 351 /* 352 * we create compressed extents in two phases. The first 353 * phase compresses a range of pages that have already been 354 * locked (both pages and state bits are locked). 355 * 356 * This is done inside an ordered work queue, and the compression 357 * is spread across many cpus. The actual IO submission is step 358 * two, and the ordered work queue takes care of making sure that 359 * happens in the same order things were put onto the queue by 360 * writepages and friends. 361 * 362 * If this code finds it can't get good compression, it puts an 363 * entry onto the work queue to write the uncompressed bytes. This 364 * makes sure that both compressed inodes and uncompressed inodes 365 * are written in the same order that the flusher thread sent them 366 * down. 367 */ 368 static noinline int compress_file_range(struct inode *inode, 369 struct page *locked_page, 370 u64 start, u64 end, 371 struct async_cow *async_cow, 372 int *num_added) 373 { 374 struct btrfs_root *root = BTRFS_I(inode)->root; 375 u64 num_bytes; 376 u64 blocksize = root->sectorsize; 377 u64 actual_end; 378 u64 isize = i_size_read(inode); 379 int ret = 0; 380 struct page **pages = NULL; 381 unsigned long nr_pages; 382 unsigned long nr_pages_ret = 0; 383 unsigned long total_compressed = 0; 384 unsigned long total_in = 0; 385 unsigned long max_compressed = 128 * 1024; 386 unsigned long max_uncompressed = 128 * 1024; 387 int i; 388 int will_compress; 389 int compress_type = root->fs_info->compress_type; 390 int redirty = 0; 391 392 /* if this is a small write inside eof, kick off a defrag */ 393 if ((end - start + 1) < 16 * 1024 && 394 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size)) 395 btrfs_add_inode_defrag(NULL, inode); 396 397 actual_end = min_t(u64, isize, end + 1); 398 again: 399 will_compress = 0; 400 nr_pages = (end >> PAGE_CACHE_SHIFT) - (start >> PAGE_CACHE_SHIFT) + 1; 401 nr_pages = min(nr_pages, (128 * 1024UL) / PAGE_CACHE_SIZE); 402 403 /* 404 * we don't want to send crud past the end of i_size through 405 * compression, that's just a waste of CPU time. So, if the 406 * end of the file is before the start of our current 407 * requested range of bytes, we bail out to the uncompressed 408 * cleanup code that can deal with all of this. 409 * 410 * It isn't really the fastest way to fix things, but this is a 411 * very uncommon corner. 412 */ 413 if (actual_end <= start) 414 goto cleanup_and_bail_uncompressed; 415 416 total_compressed = actual_end - start; 417 418 /* we want to make sure that amount of ram required to uncompress 419 * an extent is reasonable, so we limit the total size in ram 420 * of a compressed extent to 128k. This is a crucial number 421 * because it also controls how easily we can spread reads across 422 * cpus for decompression. 423 * 424 * We also want to make sure the amount of IO required to do 425 * a random read is reasonably small, so we limit the size of 426 * a compressed extent to 128k. 427 */ 428 total_compressed = min(total_compressed, max_uncompressed); 429 num_bytes = ALIGN(end - start + 1, blocksize); 430 num_bytes = max(blocksize, num_bytes); 431 total_in = 0; 432 ret = 0; 433 434 /* 435 * we do compression for mount -o compress and when the 436 * inode has not been flagged as nocompress. This flag can 437 * change at any time if we discover bad compression ratios. 438 */ 439 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS) && 440 (btrfs_test_opt(root, COMPRESS) || 441 (BTRFS_I(inode)->force_compress) || 442 (BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS))) { 443 WARN_ON(pages); 444 pages = kzalloc(sizeof(struct page *) * nr_pages, GFP_NOFS); 445 if (!pages) { 446 /* just bail out to the uncompressed code */ 447 goto cont; 448 } 449 450 if (BTRFS_I(inode)->force_compress) 451 compress_type = BTRFS_I(inode)->force_compress; 452 453 /* 454 * we need to call clear_page_dirty_for_io on each 455 * page in the range. Otherwise applications with the file 456 * mmap'd can wander in and change the page contents while 457 * we are compressing them. 458 * 459 * If the compression fails for any reason, we set the pages 460 * dirty again later on. 461 */ 462 extent_range_clear_dirty_for_io(inode, start, end); 463 redirty = 1; 464 ret = btrfs_compress_pages(compress_type, 465 inode->i_mapping, start, 466 total_compressed, pages, 467 nr_pages, &nr_pages_ret, 468 &total_in, 469 &total_compressed, 470 max_compressed); 471 472 if (!ret) { 473 unsigned long offset = total_compressed & 474 (PAGE_CACHE_SIZE - 1); 475 struct page *page = pages[nr_pages_ret - 1]; 476 char *kaddr; 477 478 /* zero the tail end of the last page, we might be 479 * sending it down to disk 480 */ 481 if (offset) { 482 kaddr = kmap_atomic(page); 483 memset(kaddr + offset, 0, 484 PAGE_CACHE_SIZE - offset); 485 kunmap_atomic(kaddr); 486 } 487 will_compress = 1; 488 } 489 } 490 cont: 491 if (start == 0) { 492 /* lets try to make an inline extent */ 493 if (ret || total_in < (actual_end - start)) { 494 /* we didn't compress the entire range, try 495 * to make an uncompressed inline extent. 496 */ 497 ret = cow_file_range_inline(root, inode, start, end, 498 0, 0, NULL); 499 } else { 500 /* try making a compressed inline extent */ 501 ret = cow_file_range_inline(root, inode, start, end, 502 total_compressed, 503 compress_type, pages); 504 } 505 if (ret <= 0) { 506 unsigned long clear_flags = EXTENT_DELALLOC | 507 EXTENT_DEFRAG; 508 clear_flags |= (ret < 0) ? EXTENT_DO_ACCOUNTING : 0; 509 510 /* 511 * inline extent creation worked or returned error, 512 * we don't need to create any more async work items. 513 * Unlock and free up our temp pages. 514 */ 515 extent_clear_unlock_delalloc(inode, start, end, NULL, 516 clear_flags, PAGE_UNLOCK | 517 PAGE_CLEAR_DIRTY | 518 PAGE_SET_WRITEBACK | 519 PAGE_END_WRITEBACK); 520 goto free_pages_out; 521 } 522 } 523 524 if (will_compress) { 525 /* 526 * we aren't doing an inline extent round the compressed size 527 * up to a block size boundary so the allocator does sane 528 * things 529 */ 530 total_compressed = ALIGN(total_compressed, blocksize); 531 532 /* 533 * one last check to make sure the compression is really a 534 * win, compare the page count read with the blocks on disk 535 */ 536 total_in = ALIGN(total_in, PAGE_CACHE_SIZE); 537 if (total_compressed >= total_in) { 538 will_compress = 0; 539 } else { 540 num_bytes = total_in; 541 } 542 } 543 if (!will_compress && pages) { 544 /* 545 * the compression code ran but failed to make things smaller, 546 * free any pages it allocated and our page pointer array 547 */ 548 for (i = 0; i < nr_pages_ret; i++) { 549 WARN_ON(pages[i]->mapping); 550 page_cache_release(pages[i]); 551 } 552 kfree(pages); 553 pages = NULL; 554 total_compressed = 0; 555 nr_pages_ret = 0; 556 557 /* flag the file so we don't compress in the future */ 558 if (!btrfs_test_opt(root, FORCE_COMPRESS) && 559 !(BTRFS_I(inode)->force_compress)) { 560 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS; 561 } 562 } 563 if (will_compress) { 564 *num_added += 1; 565 566 /* the async work queues will take care of doing actual 567 * allocation on disk for these compressed pages, 568 * and will submit them to the elevator. 569 */ 570 add_async_extent(async_cow, start, num_bytes, 571 total_compressed, pages, nr_pages_ret, 572 compress_type); 573 574 if (start + num_bytes < end) { 575 start += num_bytes; 576 pages = NULL; 577 cond_resched(); 578 goto again; 579 } 580 } else { 581 cleanup_and_bail_uncompressed: 582 /* 583 * No compression, but we still need to write the pages in 584 * the file we've been given so far. redirty the locked 585 * page if it corresponds to our extent and set things up 586 * for the async work queue to run cow_file_range to do 587 * the normal delalloc dance 588 */ 589 if (page_offset(locked_page) >= start && 590 page_offset(locked_page) <= end) { 591 __set_page_dirty_nobuffers(locked_page); 592 /* unlocked later on in the async handlers */ 593 } 594 if (redirty) 595 extent_range_redirty_for_io(inode, start, end); 596 add_async_extent(async_cow, start, end - start + 1, 597 0, NULL, 0, BTRFS_COMPRESS_NONE); 598 *num_added += 1; 599 } 600 601 out: 602 return ret; 603 604 free_pages_out: 605 for (i = 0; i < nr_pages_ret; i++) { 606 WARN_ON(pages[i]->mapping); 607 page_cache_release(pages[i]); 608 } 609 kfree(pages); 610 611 goto out; 612 } 613 614 /* 615 * phase two of compressed writeback. This is the ordered portion 616 * of the code, which only gets called in the order the work was 617 * queued. We walk all the async extents created by compress_file_range 618 * and send them down to the disk. 619 */ 620 static noinline int submit_compressed_extents(struct inode *inode, 621 struct async_cow *async_cow) 622 { 623 struct async_extent *async_extent; 624 u64 alloc_hint = 0; 625 struct btrfs_key ins; 626 struct extent_map *em; 627 struct btrfs_root *root = BTRFS_I(inode)->root; 628 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; 629 struct extent_io_tree *io_tree; 630 int ret = 0; 631 632 if (list_empty(&async_cow->extents)) 633 return 0; 634 635 again: 636 while (!list_empty(&async_cow->extents)) { 637 async_extent = list_entry(async_cow->extents.next, 638 struct async_extent, list); 639 list_del(&async_extent->list); 640 641 io_tree = &BTRFS_I(inode)->io_tree; 642 643 retry: 644 /* did the compression code fall back to uncompressed IO? */ 645 if (!async_extent->pages) { 646 int page_started = 0; 647 unsigned long nr_written = 0; 648 649 lock_extent(io_tree, async_extent->start, 650 async_extent->start + 651 async_extent->ram_size - 1); 652 653 /* allocate blocks */ 654 ret = cow_file_range(inode, async_cow->locked_page, 655 async_extent->start, 656 async_extent->start + 657 async_extent->ram_size - 1, 658 &page_started, &nr_written, 0); 659 660 /* JDM XXX */ 661 662 /* 663 * if page_started, cow_file_range inserted an 664 * inline extent and took care of all the unlocking 665 * and IO for us. Otherwise, we need to submit 666 * all those pages down to the drive. 667 */ 668 if (!page_started && !ret) 669 extent_write_locked_range(io_tree, 670 inode, async_extent->start, 671 async_extent->start + 672 async_extent->ram_size - 1, 673 btrfs_get_extent, 674 WB_SYNC_ALL); 675 else if (ret) 676 unlock_page(async_cow->locked_page); 677 kfree(async_extent); 678 cond_resched(); 679 continue; 680 } 681 682 lock_extent(io_tree, async_extent->start, 683 async_extent->start + async_extent->ram_size - 1); 684 685 ret = btrfs_reserve_extent(root, 686 async_extent->compressed_size, 687 async_extent->compressed_size, 688 0, alloc_hint, &ins, 1); 689 if (ret) { 690 int i; 691 692 for (i = 0; i < async_extent->nr_pages; i++) { 693 WARN_ON(async_extent->pages[i]->mapping); 694 page_cache_release(async_extent->pages[i]); 695 } 696 kfree(async_extent->pages); 697 async_extent->nr_pages = 0; 698 async_extent->pages = NULL; 699 700 if (ret == -ENOSPC) { 701 unlock_extent(io_tree, async_extent->start, 702 async_extent->start + 703 async_extent->ram_size - 1); 704 goto retry; 705 } 706 goto out_free; 707 } 708 709 /* 710 * here we're doing allocation and writeback of the 711 * compressed pages 712 */ 713 btrfs_drop_extent_cache(inode, async_extent->start, 714 async_extent->start + 715 async_extent->ram_size - 1, 0); 716 717 em = alloc_extent_map(); 718 if (!em) { 719 ret = -ENOMEM; 720 goto out_free_reserve; 721 } 722 em->start = async_extent->start; 723 em->len = async_extent->ram_size; 724 em->orig_start = em->start; 725 em->mod_start = em->start; 726 em->mod_len = em->len; 727 728 em->block_start = ins.objectid; 729 em->block_len = ins.offset; 730 em->orig_block_len = ins.offset; 731 em->ram_bytes = async_extent->ram_size; 732 em->bdev = root->fs_info->fs_devices->latest_bdev; 733 em->compress_type = async_extent->compress_type; 734 set_bit(EXTENT_FLAG_PINNED, &em->flags); 735 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags); 736 em->generation = -1; 737 738 while (1) { 739 write_lock(&em_tree->lock); 740 ret = add_extent_mapping(em_tree, em, 1); 741 write_unlock(&em_tree->lock); 742 if (ret != -EEXIST) { 743 free_extent_map(em); 744 break; 745 } 746 btrfs_drop_extent_cache(inode, async_extent->start, 747 async_extent->start + 748 async_extent->ram_size - 1, 0); 749 } 750 751 if (ret) 752 goto out_free_reserve; 753 754 ret = btrfs_add_ordered_extent_compress(inode, 755 async_extent->start, 756 ins.objectid, 757 async_extent->ram_size, 758 ins.offset, 759 BTRFS_ORDERED_COMPRESSED, 760 async_extent->compress_type); 761 if (ret) 762 goto out_free_reserve; 763 764 /* 765 * clear dirty, set writeback and unlock the pages. 766 */ 767 extent_clear_unlock_delalloc(inode, async_extent->start, 768 async_extent->start + 769 async_extent->ram_size - 1, 770 NULL, EXTENT_LOCKED | EXTENT_DELALLOC, 771 PAGE_UNLOCK | PAGE_CLEAR_DIRTY | 772 PAGE_SET_WRITEBACK); 773 ret = btrfs_submit_compressed_write(inode, 774 async_extent->start, 775 async_extent->ram_size, 776 ins.objectid, 777 ins.offset, async_extent->pages, 778 async_extent->nr_pages); 779 alloc_hint = ins.objectid + ins.offset; 780 kfree(async_extent); 781 if (ret) 782 goto out; 783 cond_resched(); 784 } 785 ret = 0; 786 out: 787 return ret; 788 out_free_reserve: 789 btrfs_free_reserved_extent(root, ins.objectid, ins.offset); 790 out_free: 791 extent_clear_unlock_delalloc(inode, async_extent->start, 792 async_extent->start + 793 async_extent->ram_size - 1, 794 NULL, EXTENT_LOCKED | EXTENT_DELALLOC | 795 EXTENT_DEFRAG | EXTENT_DO_ACCOUNTING, 796 PAGE_UNLOCK | PAGE_CLEAR_DIRTY | 797 PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK); 798 kfree(async_extent); 799 goto again; 800 } 801 802 static u64 get_extent_allocation_hint(struct inode *inode, u64 start, 803 u64 num_bytes) 804 { 805 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; 806 struct extent_map *em; 807 u64 alloc_hint = 0; 808 809 read_lock(&em_tree->lock); 810 em = search_extent_mapping(em_tree, start, num_bytes); 811 if (em) { 812 /* 813 * if block start isn't an actual block number then find the 814 * first block in this inode and use that as a hint. If that 815 * block is also bogus then just don't worry about it. 816 */ 817 if (em->block_start >= EXTENT_MAP_LAST_BYTE) { 818 free_extent_map(em); 819 em = search_extent_mapping(em_tree, 0, 0); 820 if (em && em->block_start < EXTENT_MAP_LAST_BYTE) 821 alloc_hint = em->block_start; 822 if (em) 823 free_extent_map(em); 824 } else { 825 alloc_hint = em->block_start; 826 free_extent_map(em); 827 } 828 } 829 read_unlock(&em_tree->lock); 830 831 return alloc_hint; 832 } 833 834 /* 835 * when extent_io.c finds a delayed allocation range in the file, 836 * the call backs end up in this code. The basic idea is to 837 * allocate extents on disk for the range, and create ordered data structs 838 * in ram to track those extents. 839 * 840 * locked_page is the page that writepage had locked already. We use 841 * it to make sure we don't do extra locks or unlocks. 842 * 843 * *page_started is set to one if we unlock locked_page and do everything 844 * required to start IO on it. It may be clean and already done with 845 * IO when we return. 846 */ 847 static noinline int cow_file_range(struct inode *inode, 848 struct page *locked_page, 849 u64 start, u64 end, int *page_started, 850 unsigned long *nr_written, 851 int unlock) 852 { 853 struct btrfs_root *root = BTRFS_I(inode)->root; 854 u64 alloc_hint = 0; 855 u64 num_bytes; 856 unsigned long ram_size; 857 u64 disk_num_bytes; 858 u64 cur_alloc_size; 859 u64 blocksize = root->sectorsize; 860 struct btrfs_key ins; 861 struct extent_map *em; 862 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; 863 int ret = 0; 864 865 if (btrfs_is_free_space_inode(inode)) { 866 WARN_ON_ONCE(1); 867 return -EINVAL; 868 } 869 870 num_bytes = ALIGN(end - start + 1, blocksize); 871 num_bytes = max(blocksize, num_bytes); 872 disk_num_bytes = num_bytes; 873 874 /* if this is a small write inside eof, kick off defrag */ 875 if (num_bytes < 64 * 1024 && 876 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size)) 877 btrfs_add_inode_defrag(NULL, inode); 878 879 if (start == 0) { 880 /* lets try to make an inline extent */ 881 ret = cow_file_range_inline(root, inode, start, end, 0, 0, 882 NULL); 883 if (ret == 0) { 884 extent_clear_unlock_delalloc(inode, start, end, NULL, 885 EXTENT_LOCKED | EXTENT_DELALLOC | 886 EXTENT_DEFRAG, PAGE_UNLOCK | 887 PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK | 888 PAGE_END_WRITEBACK); 889 890 *nr_written = *nr_written + 891 (end - start + PAGE_CACHE_SIZE) / PAGE_CACHE_SIZE; 892 *page_started = 1; 893 goto out; 894 } else if (ret < 0) { 895 goto out_unlock; 896 } 897 } 898 899 BUG_ON(disk_num_bytes > 900 btrfs_super_total_bytes(root->fs_info->super_copy)); 901 902 alloc_hint = get_extent_allocation_hint(inode, start, num_bytes); 903 btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0); 904 905 while (disk_num_bytes > 0) { 906 unsigned long op; 907 908 cur_alloc_size = disk_num_bytes; 909 ret = btrfs_reserve_extent(root, cur_alloc_size, 910 root->sectorsize, 0, alloc_hint, 911 &ins, 1); 912 if (ret < 0) 913 goto out_unlock; 914 915 em = alloc_extent_map(); 916 if (!em) { 917 ret = -ENOMEM; 918 goto out_reserve; 919 } 920 em->start = start; 921 em->orig_start = em->start; 922 ram_size = ins.offset; 923 em->len = ins.offset; 924 em->mod_start = em->start; 925 em->mod_len = em->len; 926 927 em->block_start = ins.objectid; 928 em->block_len = ins.offset; 929 em->orig_block_len = ins.offset; 930 em->ram_bytes = ram_size; 931 em->bdev = root->fs_info->fs_devices->latest_bdev; 932 set_bit(EXTENT_FLAG_PINNED, &em->flags); 933 em->generation = -1; 934 935 while (1) { 936 write_lock(&em_tree->lock); 937 ret = add_extent_mapping(em_tree, em, 1); 938 write_unlock(&em_tree->lock); 939 if (ret != -EEXIST) { 940 free_extent_map(em); 941 break; 942 } 943 btrfs_drop_extent_cache(inode, start, 944 start + ram_size - 1, 0); 945 } 946 if (ret) 947 goto out_reserve; 948 949 cur_alloc_size = ins.offset; 950 ret = btrfs_add_ordered_extent(inode, start, ins.objectid, 951 ram_size, cur_alloc_size, 0); 952 if (ret) 953 goto out_reserve; 954 955 if (root->root_key.objectid == 956 BTRFS_DATA_RELOC_TREE_OBJECTID) { 957 ret = btrfs_reloc_clone_csums(inode, start, 958 cur_alloc_size); 959 if (ret) 960 goto out_reserve; 961 } 962 963 if (disk_num_bytes < cur_alloc_size) 964 break; 965 966 /* we're not doing compressed IO, don't unlock the first 967 * page (which the caller expects to stay locked), don't 968 * clear any dirty bits and don't set any writeback bits 969 * 970 * Do set the Private2 bit so we know this page was properly 971 * setup for writepage 972 */ 973 op = unlock ? PAGE_UNLOCK : 0; 974 op |= PAGE_SET_PRIVATE2; 975 976 extent_clear_unlock_delalloc(inode, start, 977 start + ram_size - 1, locked_page, 978 EXTENT_LOCKED | EXTENT_DELALLOC, 979 op); 980 disk_num_bytes -= cur_alloc_size; 981 num_bytes -= cur_alloc_size; 982 alloc_hint = ins.objectid + ins.offset; 983 start += cur_alloc_size; 984 } 985 out: 986 return ret; 987 988 out_reserve: 989 btrfs_free_reserved_extent(root, ins.objectid, ins.offset); 990 out_unlock: 991 extent_clear_unlock_delalloc(inode, start, end, locked_page, 992 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING | 993 EXTENT_DELALLOC | EXTENT_DEFRAG, 994 PAGE_UNLOCK | PAGE_CLEAR_DIRTY | 995 PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK); 996 goto out; 997 } 998 999 /* 1000 * work queue call back to started compression on a file and pages 1001 */ 1002 static noinline void async_cow_start(struct btrfs_work *work) 1003 { 1004 struct async_cow *async_cow; 1005 int num_added = 0; 1006 async_cow = container_of(work, struct async_cow, work); 1007 1008 compress_file_range(async_cow->inode, async_cow->locked_page, 1009 async_cow->start, async_cow->end, async_cow, 1010 &num_added); 1011 if (num_added == 0) { 1012 btrfs_add_delayed_iput(async_cow->inode); 1013 async_cow->inode = NULL; 1014 } 1015 } 1016 1017 /* 1018 * work queue call back to submit previously compressed pages 1019 */ 1020 static noinline void async_cow_submit(struct btrfs_work *work) 1021 { 1022 struct async_cow *async_cow; 1023 struct btrfs_root *root; 1024 unsigned long nr_pages; 1025 1026 async_cow = container_of(work, struct async_cow, work); 1027 1028 root = async_cow->root; 1029 nr_pages = (async_cow->end - async_cow->start + PAGE_CACHE_SIZE) >> 1030 PAGE_CACHE_SHIFT; 1031 1032 if (atomic_sub_return(nr_pages, &root->fs_info->async_delalloc_pages) < 1033 5 * 1024 * 1024 && 1034 waitqueue_active(&root->fs_info->async_submit_wait)) 1035 wake_up(&root->fs_info->async_submit_wait); 1036 1037 if (async_cow->inode) 1038 submit_compressed_extents(async_cow->inode, async_cow); 1039 } 1040 1041 static noinline void async_cow_free(struct btrfs_work *work) 1042 { 1043 struct async_cow *async_cow; 1044 async_cow = container_of(work, struct async_cow, work); 1045 if (async_cow->inode) 1046 btrfs_add_delayed_iput(async_cow->inode); 1047 kfree(async_cow); 1048 } 1049 1050 static int cow_file_range_async(struct inode *inode, struct page *locked_page, 1051 u64 start, u64 end, int *page_started, 1052 unsigned long *nr_written) 1053 { 1054 struct async_cow *async_cow; 1055 struct btrfs_root *root = BTRFS_I(inode)->root; 1056 unsigned long nr_pages; 1057 u64 cur_end; 1058 int limit = 10 * 1024 * 1024; 1059 1060 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED, 1061 1, 0, NULL, GFP_NOFS); 1062 while (start < end) { 1063 async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS); 1064 BUG_ON(!async_cow); /* -ENOMEM */ 1065 async_cow->inode = igrab(inode); 1066 async_cow->root = root; 1067 async_cow->locked_page = locked_page; 1068 async_cow->start = start; 1069 1070 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS) 1071 cur_end = end; 1072 else 1073 cur_end = min(end, start + 512 * 1024 - 1); 1074 1075 async_cow->end = cur_end; 1076 INIT_LIST_HEAD(&async_cow->extents); 1077 1078 async_cow->work.func = async_cow_start; 1079 async_cow->work.ordered_func = async_cow_submit; 1080 async_cow->work.ordered_free = async_cow_free; 1081 async_cow->work.flags = 0; 1082 1083 nr_pages = (cur_end - start + PAGE_CACHE_SIZE) >> 1084 PAGE_CACHE_SHIFT; 1085 atomic_add(nr_pages, &root->fs_info->async_delalloc_pages); 1086 1087 btrfs_queue_worker(&root->fs_info->delalloc_workers, 1088 &async_cow->work); 1089 1090 if (atomic_read(&root->fs_info->async_delalloc_pages) > limit) { 1091 wait_event(root->fs_info->async_submit_wait, 1092 (atomic_read(&root->fs_info->async_delalloc_pages) < 1093 limit)); 1094 } 1095 1096 while (atomic_read(&root->fs_info->async_submit_draining) && 1097 atomic_read(&root->fs_info->async_delalloc_pages)) { 1098 wait_event(root->fs_info->async_submit_wait, 1099 (atomic_read(&root->fs_info->async_delalloc_pages) == 1100 0)); 1101 } 1102 1103 *nr_written += nr_pages; 1104 start = cur_end + 1; 1105 } 1106 *page_started = 1; 1107 return 0; 1108 } 1109 1110 static noinline int csum_exist_in_range(struct btrfs_root *root, 1111 u64 bytenr, u64 num_bytes) 1112 { 1113 int ret; 1114 struct btrfs_ordered_sum *sums; 1115 LIST_HEAD(list); 1116 1117 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, bytenr, 1118 bytenr + num_bytes - 1, &list, 0); 1119 if (ret == 0 && list_empty(&list)) 1120 return 0; 1121 1122 while (!list_empty(&list)) { 1123 sums = list_entry(list.next, struct btrfs_ordered_sum, list); 1124 list_del(&sums->list); 1125 kfree(sums); 1126 } 1127 return 1; 1128 } 1129 1130 /* 1131 * when nowcow writeback call back. This checks for snapshots or COW copies 1132 * of the extents that exist in the file, and COWs the file as required. 1133 * 1134 * If no cow copies or snapshots exist, we write directly to the existing 1135 * blocks on disk 1136 */ 1137 static noinline int run_delalloc_nocow(struct inode *inode, 1138 struct page *locked_page, 1139 u64 start, u64 end, int *page_started, int force, 1140 unsigned long *nr_written) 1141 { 1142 struct btrfs_root *root = BTRFS_I(inode)->root; 1143 struct btrfs_trans_handle *trans; 1144 struct extent_buffer *leaf; 1145 struct btrfs_path *path; 1146 struct btrfs_file_extent_item *fi; 1147 struct btrfs_key found_key; 1148 u64 cow_start; 1149 u64 cur_offset; 1150 u64 extent_end; 1151 u64 extent_offset; 1152 u64 disk_bytenr; 1153 u64 num_bytes; 1154 u64 disk_num_bytes; 1155 u64 ram_bytes; 1156 int extent_type; 1157 int ret, err; 1158 int type; 1159 int nocow; 1160 int check_prev = 1; 1161 bool nolock; 1162 u64 ino = btrfs_ino(inode); 1163 1164 path = btrfs_alloc_path(); 1165 if (!path) { 1166 extent_clear_unlock_delalloc(inode, start, end, locked_page, 1167 EXTENT_LOCKED | EXTENT_DELALLOC | 1168 EXTENT_DO_ACCOUNTING | 1169 EXTENT_DEFRAG, PAGE_UNLOCK | 1170 PAGE_CLEAR_DIRTY | 1171 PAGE_SET_WRITEBACK | 1172 PAGE_END_WRITEBACK); 1173 return -ENOMEM; 1174 } 1175 1176 nolock = btrfs_is_free_space_inode(inode); 1177 1178 if (nolock) 1179 trans = btrfs_join_transaction_nolock(root); 1180 else 1181 trans = btrfs_join_transaction(root); 1182 1183 if (IS_ERR(trans)) { 1184 extent_clear_unlock_delalloc(inode, start, end, locked_page, 1185 EXTENT_LOCKED | EXTENT_DELALLOC | 1186 EXTENT_DO_ACCOUNTING | 1187 EXTENT_DEFRAG, PAGE_UNLOCK | 1188 PAGE_CLEAR_DIRTY | 1189 PAGE_SET_WRITEBACK | 1190 PAGE_END_WRITEBACK); 1191 btrfs_free_path(path); 1192 return PTR_ERR(trans); 1193 } 1194 1195 trans->block_rsv = &root->fs_info->delalloc_block_rsv; 1196 1197 cow_start = (u64)-1; 1198 cur_offset = start; 1199 while (1) { 1200 ret = btrfs_lookup_file_extent(trans, root, path, ino, 1201 cur_offset, 0); 1202 if (ret < 0) 1203 goto error; 1204 if (ret > 0 && path->slots[0] > 0 && check_prev) { 1205 leaf = path->nodes[0]; 1206 btrfs_item_key_to_cpu(leaf, &found_key, 1207 path->slots[0] - 1); 1208 if (found_key.objectid == ino && 1209 found_key.type == BTRFS_EXTENT_DATA_KEY) 1210 path->slots[0]--; 1211 } 1212 check_prev = 0; 1213 next_slot: 1214 leaf = path->nodes[0]; 1215 if (path->slots[0] >= btrfs_header_nritems(leaf)) { 1216 ret = btrfs_next_leaf(root, path); 1217 if (ret < 0) 1218 goto error; 1219 if (ret > 0) 1220 break; 1221 leaf = path->nodes[0]; 1222 } 1223 1224 nocow = 0; 1225 disk_bytenr = 0; 1226 num_bytes = 0; 1227 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 1228 1229 if (found_key.objectid > ino || 1230 found_key.type > BTRFS_EXTENT_DATA_KEY || 1231 found_key.offset > end) 1232 break; 1233 1234 if (found_key.offset > cur_offset) { 1235 extent_end = found_key.offset; 1236 extent_type = 0; 1237 goto out_check; 1238 } 1239 1240 fi = btrfs_item_ptr(leaf, path->slots[0], 1241 struct btrfs_file_extent_item); 1242 extent_type = btrfs_file_extent_type(leaf, fi); 1243 1244 ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi); 1245 if (extent_type == BTRFS_FILE_EXTENT_REG || 1246 extent_type == BTRFS_FILE_EXTENT_PREALLOC) { 1247 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); 1248 extent_offset = btrfs_file_extent_offset(leaf, fi); 1249 extent_end = found_key.offset + 1250 btrfs_file_extent_num_bytes(leaf, fi); 1251 disk_num_bytes = 1252 btrfs_file_extent_disk_num_bytes(leaf, fi); 1253 if (extent_end <= start) { 1254 path->slots[0]++; 1255 goto next_slot; 1256 } 1257 if (disk_bytenr == 0) 1258 goto out_check; 1259 if (btrfs_file_extent_compression(leaf, fi) || 1260 btrfs_file_extent_encryption(leaf, fi) || 1261 btrfs_file_extent_other_encoding(leaf, fi)) 1262 goto out_check; 1263 if (extent_type == BTRFS_FILE_EXTENT_REG && !force) 1264 goto out_check; 1265 if (btrfs_extent_readonly(root, disk_bytenr)) 1266 goto out_check; 1267 if (btrfs_cross_ref_exist(trans, root, ino, 1268 found_key.offset - 1269 extent_offset, disk_bytenr)) 1270 goto out_check; 1271 disk_bytenr += extent_offset; 1272 disk_bytenr += cur_offset - found_key.offset; 1273 num_bytes = min(end + 1, extent_end) - cur_offset; 1274 /* 1275 * force cow if csum exists in the range. 1276 * this ensure that csum for a given extent are 1277 * either valid or do not exist. 1278 */ 1279 if (csum_exist_in_range(root, disk_bytenr, num_bytes)) 1280 goto out_check; 1281 nocow = 1; 1282 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { 1283 extent_end = found_key.offset + 1284 btrfs_file_extent_inline_len(leaf, 1285 path->slots[0], fi); 1286 extent_end = ALIGN(extent_end, root->sectorsize); 1287 } else { 1288 BUG_ON(1); 1289 } 1290 out_check: 1291 if (extent_end <= start) { 1292 path->slots[0]++; 1293 goto next_slot; 1294 } 1295 if (!nocow) { 1296 if (cow_start == (u64)-1) 1297 cow_start = cur_offset; 1298 cur_offset = extent_end; 1299 if (cur_offset > end) 1300 break; 1301 path->slots[0]++; 1302 goto next_slot; 1303 } 1304 1305 btrfs_release_path(path); 1306 if (cow_start != (u64)-1) { 1307 ret = cow_file_range(inode, locked_page, 1308 cow_start, found_key.offset - 1, 1309 page_started, nr_written, 1); 1310 if (ret) 1311 goto error; 1312 cow_start = (u64)-1; 1313 } 1314 1315 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) { 1316 struct extent_map *em; 1317 struct extent_map_tree *em_tree; 1318 em_tree = &BTRFS_I(inode)->extent_tree; 1319 em = alloc_extent_map(); 1320 BUG_ON(!em); /* -ENOMEM */ 1321 em->start = cur_offset; 1322 em->orig_start = found_key.offset - extent_offset; 1323 em->len = num_bytes; 1324 em->block_len = num_bytes; 1325 em->block_start = disk_bytenr; 1326 em->orig_block_len = disk_num_bytes; 1327 em->ram_bytes = ram_bytes; 1328 em->bdev = root->fs_info->fs_devices->latest_bdev; 1329 em->mod_start = em->start; 1330 em->mod_len = em->len; 1331 set_bit(EXTENT_FLAG_PINNED, &em->flags); 1332 set_bit(EXTENT_FLAG_FILLING, &em->flags); 1333 em->generation = -1; 1334 while (1) { 1335 write_lock(&em_tree->lock); 1336 ret = add_extent_mapping(em_tree, em, 1); 1337 write_unlock(&em_tree->lock); 1338 if (ret != -EEXIST) { 1339 free_extent_map(em); 1340 break; 1341 } 1342 btrfs_drop_extent_cache(inode, em->start, 1343 em->start + em->len - 1, 0); 1344 } 1345 type = BTRFS_ORDERED_PREALLOC; 1346 } else { 1347 type = BTRFS_ORDERED_NOCOW; 1348 } 1349 1350 ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr, 1351 num_bytes, num_bytes, type); 1352 BUG_ON(ret); /* -ENOMEM */ 1353 1354 if (root->root_key.objectid == 1355 BTRFS_DATA_RELOC_TREE_OBJECTID) { 1356 ret = btrfs_reloc_clone_csums(inode, cur_offset, 1357 num_bytes); 1358 if (ret) 1359 goto error; 1360 } 1361 1362 extent_clear_unlock_delalloc(inode, cur_offset, 1363 cur_offset + num_bytes - 1, 1364 locked_page, EXTENT_LOCKED | 1365 EXTENT_DELALLOC, PAGE_UNLOCK | 1366 PAGE_SET_PRIVATE2); 1367 cur_offset = extent_end; 1368 if (cur_offset > end) 1369 break; 1370 } 1371 btrfs_release_path(path); 1372 1373 if (cur_offset <= end && cow_start == (u64)-1) { 1374 cow_start = cur_offset; 1375 cur_offset = end; 1376 } 1377 1378 if (cow_start != (u64)-1) { 1379 ret = cow_file_range(inode, locked_page, cow_start, end, 1380 page_started, nr_written, 1); 1381 if (ret) 1382 goto error; 1383 } 1384 1385 error: 1386 err = btrfs_end_transaction(trans, root); 1387 if (!ret) 1388 ret = err; 1389 1390 if (ret && cur_offset < end) 1391 extent_clear_unlock_delalloc(inode, cur_offset, end, 1392 locked_page, EXTENT_LOCKED | 1393 EXTENT_DELALLOC | EXTENT_DEFRAG | 1394 EXTENT_DO_ACCOUNTING, PAGE_UNLOCK | 1395 PAGE_CLEAR_DIRTY | 1396 PAGE_SET_WRITEBACK | 1397 PAGE_END_WRITEBACK); 1398 btrfs_free_path(path); 1399 return ret; 1400 } 1401 1402 /* 1403 * extent_io.c call back to do delayed allocation processing 1404 */ 1405 static int run_delalloc_range(struct inode *inode, struct page *locked_page, 1406 u64 start, u64 end, int *page_started, 1407 unsigned long *nr_written) 1408 { 1409 int ret; 1410 struct btrfs_root *root = BTRFS_I(inode)->root; 1411 1412 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) { 1413 ret = run_delalloc_nocow(inode, locked_page, start, end, 1414 page_started, 1, nr_written); 1415 } else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC) { 1416 ret = run_delalloc_nocow(inode, locked_page, start, end, 1417 page_started, 0, nr_written); 1418 } else if (!btrfs_test_opt(root, COMPRESS) && 1419 !(BTRFS_I(inode)->force_compress) && 1420 !(BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS)) { 1421 ret = cow_file_range(inode, locked_page, start, end, 1422 page_started, nr_written, 1); 1423 } else { 1424 set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT, 1425 &BTRFS_I(inode)->runtime_flags); 1426 ret = cow_file_range_async(inode, locked_page, start, end, 1427 page_started, nr_written); 1428 } 1429 return ret; 1430 } 1431 1432 static void btrfs_split_extent_hook(struct inode *inode, 1433 struct extent_state *orig, u64 split) 1434 { 1435 /* not delalloc, ignore it */ 1436 if (!(orig->state & EXTENT_DELALLOC)) 1437 return; 1438 1439 spin_lock(&BTRFS_I(inode)->lock); 1440 BTRFS_I(inode)->outstanding_extents++; 1441 spin_unlock(&BTRFS_I(inode)->lock); 1442 } 1443 1444 /* 1445 * extent_io.c merge_extent_hook, used to track merged delayed allocation 1446 * extents so we can keep track of new extents that are just merged onto old 1447 * extents, such as when we are doing sequential writes, so we can properly 1448 * account for the metadata space we'll need. 1449 */ 1450 static void btrfs_merge_extent_hook(struct inode *inode, 1451 struct extent_state *new, 1452 struct extent_state *other) 1453 { 1454 /* not delalloc, ignore it */ 1455 if (!(other->state & EXTENT_DELALLOC)) 1456 return; 1457 1458 spin_lock(&BTRFS_I(inode)->lock); 1459 BTRFS_I(inode)->outstanding_extents--; 1460 spin_unlock(&BTRFS_I(inode)->lock); 1461 } 1462 1463 static void btrfs_add_delalloc_inodes(struct btrfs_root *root, 1464 struct inode *inode) 1465 { 1466 spin_lock(&root->delalloc_lock); 1467 if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) { 1468 list_add_tail(&BTRFS_I(inode)->delalloc_inodes, 1469 &root->delalloc_inodes); 1470 set_bit(BTRFS_INODE_IN_DELALLOC_LIST, 1471 &BTRFS_I(inode)->runtime_flags); 1472 root->nr_delalloc_inodes++; 1473 if (root->nr_delalloc_inodes == 1) { 1474 spin_lock(&root->fs_info->delalloc_root_lock); 1475 BUG_ON(!list_empty(&root->delalloc_root)); 1476 list_add_tail(&root->delalloc_root, 1477 &root->fs_info->delalloc_roots); 1478 spin_unlock(&root->fs_info->delalloc_root_lock); 1479 } 1480 } 1481 spin_unlock(&root->delalloc_lock); 1482 } 1483 1484 static void btrfs_del_delalloc_inode(struct btrfs_root *root, 1485 struct inode *inode) 1486 { 1487 spin_lock(&root->delalloc_lock); 1488 if (!list_empty(&BTRFS_I(inode)->delalloc_inodes)) { 1489 list_del_init(&BTRFS_I(inode)->delalloc_inodes); 1490 clear_bit(BTRFS_INODE_IN_DELALLOC_LIST, 1491 &BTRFS_I(inode)->runtime_flags); 1492 root->nr_delalloc_inodes--; 1493 if (!root->nr_delalloc_inodes) { 1494 spin_lock(&root->fs_info->delalloc_root_lock); 1495 BUG_ON(list_empty(&root->delalloc_root)); 1496 list_del_init(&root->delalloc_root); 1497 spin_unlock(&root->fs_info->delalloc_root_lock); 1498 } 1499 } 1500 spin_unlock(&root->delalloc_lock); 1501 } 1502 1503 /* 1504 * extent_io.c set_bit_hook, used to track delayed allocation 1505 * bytes in this file, and to maintain the list of inodes that 1506 * have pending delalloc work to be done. 1507 */ 1508 static void btrfs_set_bit_hook(struct inode *inode, 1509 struct extent_state *state, unsigned long *bits) 1510 { 1511 1512 /* 1513 * set_bit and clear bit hooks normally require _irqsave/restore 1514 * but in this case, we are only testing for the DELALLOC 1515 * bit, which is only set or cleared with irqs on 1516 */ 1517 if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) { 1518 struct btrfs_root *root = BTRFS_I(inode)->root; 1519 u64 len = state->end + 1 - state->start; 1520 bool do_list = !btrfs_is_free_space_inode(inode); 1521 1522 if (*bits & EXTENT_FIRST_DELALLOC) { 1523 *bits &= ~EXTENT_FIRST_DELALLOC; 1524 } else { 1525 spin_lock(&BTRFS_I(inode)->lock); 1526 BTRFS_I(inode)->outstanding_extents++; 1527 spin_unlock(&BTRFS_I(inode)->lock); 1528 } 1529 1530 __percpu_counter_add(&root->fs_info->delalloc_bytes, len, 1531 root->fs_info->delalloc_batch); 1532 spin_lock(&BTRFS_I(inode)->lock); 1533 BTRFS_I(inode)->delalloc_bytes += len; 1534 if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST, 1535 &BTRFS_I(inode)->runtime_flags)) 1536 btrfs_add_delalloc_inodes(root, inode); 1537 spin_unlock(&BTRFS_I(inode)->lock); 1538 } 1539 } 1540 1541 /* 1542 * extent_io.c clear_bit_hook, see set_bit_hook for why 1543 */ 1544 static void btrfs_clear_bit_hook(struct inode *inode, 1545 struct extent_state *state, 1546 unsigned long *bits) 1547 { 1548 /* 1549 * set_bit and clear bit hooks normally require _irqsave/restore 1550 * but in this case, we are only testing for the DELALLOC 1551 * bit, which is only set or cleared with irqs on 1552 */ 1553 if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) { 1554 struct btrfs_root *root = BTRFS_I(inode)->root; 1555 u64 len = state->end + 1 - state->start; 1556 bool do_list = !btrfs_is_free_space_inode(inode); 1557 1558 if (*bits & EXTENT_FIRST_DELALLOC) { 1559 *bits &= ~EXTENT_FIRST_DELALLOC; 1560 } else if (!(*bits & EXTENT_DO_ACCOUNTING)) { 1561 spin_lock(&BTRFS_I(inode)->lock); 1562 BTRFS_I(inode)->outstanding_extents--; 1563 spin_unlock(&BTRFS_I(inode)->lock); 1564 } 1565 1566 /* 1567 * We don't reserve metadata space for space cache inodes so we 1568 * don't need to call dellalloc_release_metadata if there is an 1569 * error. 1570 */ 1571 if (*bits & EXTENT_DO_ACCOUNTING && 1572 root != root->fs_info->tree_root) 1573 btrfs_delalloc_release_metadata(inode, len); 1574 1575 if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID 1576 && do_list && !(state->state & EXTENT_NORESERVE)) 1577 btrfs_free_reserved_data_space(inode, len); 1578 1579 __percpu_counter_add(&root->fs_info->delalloc_bytes, -len, 1580 root->fs_info->delalloc_batch); 1581 spin_lock(&BTRFS_I(inode)->lock); 1582 BTRFS_I(inode)->delalloc_bytes -= len; 1583 if (do_list && BTRFS_I(inode)->delalloc_bytes == 0 && 1584 test_bit(BTRFS_INODE_IN_DELALLOC_LIST, 1585 &BTRFS_I(inode)->runtime_flags)) 1586 btrfs_del_delalloc_inode(root, inode); 1587 spin_unlock(&BTRFS_I(inode)->lock); 1588 } 1589 } 1590 1591 /* 1592 * extent_io.c merge_bio_hook, this must check the chunk tree to make sure 1593 * we don't create bios that span stripes or chunks 1594 */ 1595 int btrfs_merge_bio_hook(int rw, struct page *page, unsigned long offset, 1596 size_t size, struct bio *bio, 1597 unsigned long bio_flags) 1598 { 1599 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root; 1600 u64 logical = (u64)bio->bi_iter.bi_sector << 9; 1601 u64 length = 0; 1602 u64 map_length; 1603 int ret; 1604 1605 if (bio_flags & EXTENT_BIO_COMPRESSED) 1606 return 0; 1607 1608 length = bio->bi_iter.bi_size; 1609 map_length = length; 1610 ret = btrfs_map_block(root->fs_info, rw, logical, 1611 &map_length, NULL, 0); 1612 /* Will always return 0 with map_multi == NULL */ 1613 BUG_ON(ret < 0); 1614 if (map_length < length + size) 1615 return 1; 1616 return 0; 1617 } 1618 1619 /* 1620 * in order to insert checksums into the metadata in large chunks, 1621 * we wait until bio submission time. All the pages in the bio are 1622 * checksummed and sums are attached onto the ordered extent record. 1623 * 1624 * At IO completion time the cums attached on the ordered extent record 1625 * are inserted into the btree 1626 */ 1627 static int __btrfs_submit_bio_start(struct inode *inode, int rw, 1628 struct bio *bio, int mirror_num, 1629 unsigned long bio_flags, 1630 u64 bio_offset) 1631 { 1632 struct btrfs_root *root = BTRFS_I(inode)->root; 1633 int ret = 0; 1634 1635 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0); 1636 BUG_ON(ret); /* -ENOMEM */ 1637 return 0; 1638 } 1639 1640 /* 1641 * in order to insert checksums into the metadata in large chunks, 1642 * we wait until bio submission time. All the pages in the bio are 1643 * checksummed and sums are attached onto the ordered extent record. 1644 * 1645 * At IO completion time the cums attached on the ordered extent record 1646 * are inserted into the btree 1647 */ 1648 static int __btrfs_submit_bio_done(struct inode *inode, int rw, struct bio *bio, 1649 int mirror_num, unsigned long bio_flags, 1650 u64 bio_offset) 1651 { 1652 struct btrfs_root *root = BTRFS_I(inode)->root; 1653 int ret; 1654 1655 ret = btrfs_map_bio(root, rw, bio, mirror_num, 1); 1656 if (ret) 1657 bio_endio(bio, ret); 1658 return ret; 1659 } 1660 1661 /* 1662 * extent_io.c submission hook. This does the right thing for csum calculation 1663 * on write, or reading the csums from the tree before a read 1664 */ 1665 static int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio, 1666 int mirror_num, unsigned long bio_flags, 1667 u64 bio_offset) 1668 { 1669 struct btrfs_root *root = BTRFS_I(inode)->root; 1670 int ret = 0; 1671 int skip_sum; 1672 int metadata = 0; 1673 int async = !atomic_read(&BTRFS_I(inode)->sync_writers); 1674 1675 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM; 1676 1677 if (btrfs_is_free_space_inode(inode)) 1678 metadata = 2; 1679 1680 if (!(rw & REQ_WRITE)) { 1681 ret = btrfs_bio_wq_end_io(root->fs_info, bio, metadata); 1682 if (ret) 1683 goto out; 1684 1685 if (bio_flags & EXTENT_BIO_COMPRESSED) { 1686 ret = btrfs_submit_compressed_read(inode, bio, 1687 mirror_num, 1688 bio_flags); 1689 goto out; 1690 } else if (!skip_sum) { 1691 ret = btrfs_lookup_bio_sums(root, inode, bio, NULL); 1692 if (ret) 1693 goto out; 1694 } 1695 goto mapit; 1696 } else if (async && !skip_sum) { 1697 /* csum items have already been cloned */ 1698 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID) 1699 goto mapit; 1700 /* we're doing a write, do the async checksumming */ 1701 ret = btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info, 1702 inode, rw, bio, mirror_num, 1703 bio_flags, bio_offset, 1704 __btrfs_submit_bio_start, 1705 __btrfs_submit_bio_done); 1706 goto out; 1707 } else if (!skip_sum) { 1708 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0); 1709 if (ret) 1710 goto out; 1711 } 1712 1713 mapit: 1714 ret = btrfs_map_bio(root, rw, bio, mirror_num, 0); 1715 1716 out: 1717 if (ret < 0) 1718 bio_endio(bio, ret); 1719 return ret; 1720 } 1721 1722 /* 1723 * given a list of ordered sums record them in the inode. This happens 1724 * at IO completion time based on sums calculated at bio submission time. 1725 */ 1726 static noinline int add_pending_csums(struct btrfs_trans_handle *trans, 1727 struct inode *inode, u64 file_offset, 1728 struct list_head *list) 1729 { 1730 struct btrfs_ordered_sum *sum; 1731 1732 list_for_each_entry(sum, list, list) { 1733 trans->adding_csums = 1; 1734 btrfs_csum_file_blocks(trans, 1735 BTRFS_I(inode)->root->fs_info->csum_root, sum); 1736 trans->adding_csums = 0; 1737 } 1738 return 0; 1739 } 1740 1741 int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end, 1742 struct extent_state **cached_state) 1743 { 1744 WARN_ON((end & (PAGE_CACHE_SIZE - 1)) == 0); 1745 return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end, 1746 cached_state, GFP_NOFS); 1747 } 1748 1749 /* see btrfs_writepage_start_hook for details on why this is required */ 1750 struct btrfs_writepage_fixup { 1751 struct page *page; 1752 struct btrfs_work work; 1753 }; 1754 1755 static void btrfs_writepage_fixup_worker(struct btrfs_work *work) 1756 { 1757 struct btrfs_writepage_fixup *fixup; 1758 struct btrfs_ordered_extent *ordered; 1759 struct extent_state *cached_state = NULL; 1760 struct page *page; 1761 struct inode *inode; 1762 u64 page_start; 1763 u64 page_end; 1764 int ret; 1765 1766 fixup = container_of(work, struct btrfs_writepage_fixup, work); 1767 page = fixup->page; 1768 again: 1769 lock_page(page); 1770 if (!page->mapping || !PageDirty(page) || !PageChecked(page)) { 1771 ClearPageChecked(page); 1772 goto out_page; 1773 } 1774 1775 inode = page->mapping->host; 1776 page_start = page_offset(page); 1777 page_end = page_offset(page) + PAGE_CACHE_SIZE - 1; 1778 1779 lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end, 0, 1780 &cached_state); 1781 1782 /* already ordered? We're done */ 1783 if (PagePrivate2(page)) 1784 goto out; 1785 1786 ordered = btrfs_lookup_ordered_extent(inode, page_start); 1787 if (ordered) { 1788 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, 1789 page_end, &cached_state, GFP_NOFS); 1790 unlock_page(page); 1791 btrfs_start_ordered_extent(inode, ordered, 1); 1792 btrfs_put_ordered_extent(ordered); 1793 goto again; 1794 } 1795 1796 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE); 1797 if (ret) { 1798 mapping_set_error(page->mapping, ret); 1799 end_extent_writepage(page, ret, page_start, page_end); 1800 ClearPageChecked(page); 1801 goto out; 1802 } 1803 1804 btrfs_set_extent_delalloc(inode, page_start, page_end, &cached_state); 1805 ClearPageChecked(page); 1806 set_page_dirty(page); 1807 out: 1808 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end, 1809 &cached_state, GFP_NOFS); 1810 out_page: 1811 unlock_page(page); 1812 page_cache_release(page); 1813 kfree(fixup); 1814 } 1815 1816 /* 1817 * There are a few paths in the higher layers of the kernel that directly 1818 * set the page dirty bit without asking the filesystem if it is a 1819 * good idea. This causes problems because we want to make sure COW 1820 * properly happens and the data=ordered rules are followed. 1821 * 1822 * In our case any range that doesn't have the ORDERED bit set 1823 * hasn't been properly setup for IO. We kick off an async process 1824 * to fix it up. The async helper will wait for ordered extents, set 1825 * the delalloc bit and make it safe to write the page. 1826 */ 1827 static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end) 1828 { 1829 struct inode *inode = page->mapping->host; 1830 struct btrfs_writepage_fixup *fixup; 1831 struct btrfs_root *root = BTRFS_I(inode)->root; 1832 1833 /* this page is properly in the ordered list */ 1834 if (TestClearPagePrivate2(page)) 1835 return 0; 1836 1837 if (PageChecked(page)) 1838 return -EAGAIN; 1839 1840 fixup = kzalloc(sizeof(*fixup), GFP_NOFS); 1841 if (!fixup) 1842 return -EAGAIN; 1843 1844 SetPageChecked(page); 1845 page_cache_get(page); 1846 fixup->work.func = btrfs_writepage_fixup_worker; 1847 fixup->page = page; 1848 btrfs_queue_worker(&root->fs_info->fixup_workers, &fixup->work); 1849 return -EBUSY; 1850 } 1851 1852 static int insert_reserved_file_extent(struct btrfs_trans_handle *trans, 1853 struct inode *inode, u64 file_pos, 1854 u64 disk_bytenr, u64 disk_num_bytes, 1855 u64 num_bytes, u64 ram_bytes, 1856 u8 compression, u8 encryption, 1857 u16 other_encoding, int extent_type) 1858 { 1859 struct btrfs_root *root = BTRFS_I(inode)->root; 1860 struct btrfs_file_extent_item *fi; 1861 struct btrfs_path *path; 1862 struct extent_buffer *leaf; 1863 struct btrfs_key ins; 1864 int extent_inserted = 0; 1865 int ret; 1866 1867 path = btrfs_alloc_path(); 1868 if (!path) 1869 return -ENOMEM; 1870 1871 /* 1872 * we may be replacing one extent in the tree with another. 1873 * The new extent is pinned in the extent map, and we don't want 1874 * to drop it from the cache until it is completely in the btree. 1875 * 1876 * So, tell btrfs_drop_extents to leave this extent in the cache. 1877 * the caller is expected to unpin it and allow it to be merged 1878 * with the others. 1879 */ 1880 ret = __btrfs_drop_extents(trans, root, inode, path, file_pos, 1881 file_pos + num_bytes, NULL, 0, 1882 1, sizeof(*fi), &extent_inserted); 1883 if (ret) 1884 goto out; 1885 1886 if (!extent_inserted) { 1887 ins.objectid = btrfs_ino(inode); 1888 ins.offset = file_pos; 1889 ins.type = BTRFS_EXTENT_DATA_KEY; 1890 1891 path->leave_spinning = 1; 1892 ret = btrfs_insert_empty_item(trans, root, path, &ins, 1893 sizeof(*fi)); 1894 if (ret) 1895 goto out; 1896 } 1897 leaf = path->nodes[0]; 1898 fi = btrfs_item_ptr(leaf, path->slots[0], 1899 struct btrfs_file_extent_item); 1900 btrfs_set_file_extent_generation(leaf, fi, trans->transid); 1901 btrfs_set_file_extent_type(leaf, fi, extent_type); 1902 btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr); 1903 btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes); 1904 btrfs_set_file_extent_offset(leaf, fi, 0); 1905 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes); 1906 btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes); 1907 btrfs_set_file_extent_compression(leaf, fi, compression); 1908 btrfs_set_file_extent_encryption(leaf, fi, encryption); 1909 btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding); 1910 1911 btrfs_mark_buffer_dirty(leaf); 1912 btrfs_release_path(path); 1913 1914 inode_add_bytes(inode, num_bytes); 1915 1916 ins.objectid = disk_bytenr; 1917 ins.offset = disk_num_bytes; 1918 ins.type = BTRFS_EXTENT_ITEM_KEY; 1919 ret = btrfs_alloc_reserved_file_extent(trans, root, 1920 root->root_key.objectid, 1921 btrfs_ino(inode), file_pos, &ins); 1922 out: 1923 btrfs_free_path(path); 1924 1925 return ret; 1926 } 1927 1928 /* snapshot-aware defrag */ 1929 struct sa_defrag_extent_backref { 1930 struct rb_node node; 1931 struct old_sa_defrag_extent *old; 1932 u64 root_id; 1933 u64 inum; 1934 u64 file_pos; 1935 u64 extent_offset; 1936 u64 num_bytes; 1937 u64 generation; 1938 }; 1939 1940 struct old_sa_defrag_extent { 1941 struct list_head list; 1942 struct new_sa_defrag_extent *new; 1943 1944 u64 extent_offset; 1945 u64 bytenr; 1946 u64 offset; 1947 u64 len; 1948 int count; 1949 }; 1950 1951 struct new_sa_defrag_extent { 1952 struct rb_root root; 1953 struct list_head head; 1954 struct btrfs_path *path; 1955 struct inode *inode; 1956 u64 file_pos; 1957 u64 len; 1958 u64 bytenr; 1959 u64 disk_len; 1960 u8 compress_type; 1961 }; 1962 1963 static int backref_comp(struct sa_defrag_extent_backref *b1, 1964 struct sa_defrag_extent_backref *b2) 1965 { 1966 if (b1->root_id < b2->root_id) 1967 return -1; 1968 else if (b1->root_id > b2->root_id) 1969 return 1; 1970 1971 if (b1->inum < b2->inum) 1972 return -1; 1973 else if (b1->inum > b2->inum) 1974 return 1; 1975 1976 if (b1->file_pos < b2->file_pos) 1977 return -1; 1978 else if (b1->file_pos > b2->file_pos) 1979 return 1; 1980 1981 /* 1982 * [------------------------------] ===> (a range of space) 1983 * |<--->| |<---->| =============> (fs/file tree A) 1984 * |<---------------------------->| ===> (fs/file tree B) 1985 * 1986 * A range of space can refer to two file extents in one tree while 1987 * refer to only one file extent in another tree. 1988 * 1989 * So we may process a disk offset more than one time(two extents in A) 1990 * and locate at the same extent(one extent in B), then insert two same 1991 * backrefs(both refer to the extent in B). 1992 */ 1993 return 0; 1994 } 1995 1996 static void backref_insert(struct rb_root *root, 1997 struct sa_defrag_extent_backref *backref) 1998 { 1999 struct rb_node **p = &root->rb_node; 2000 struct rb_node *parent = NULL; 2001 struct sa_defrag_extent_backref *entry; 2002 int ret; 2003 2004 while (*p) { 2005 parent = *p; 2006 entry = rb_entry(parent, struct sa_defrag_extent_backref, node); 2007 2008 ret = backref_comp(backref, entry); 2009 if (ret < 0) 2010 p = &(*p)->rb_left; 2011 else 2012 p = &(*p)->rb_right; 2013 } 2014 2015 rb_link_node(&backref->node, parent, p); 2016 rb_insert_color(&backref->node, root); 2017 } 2018 2019 /* 2020 * Note the backref might has changed, and in this case we just return 0. 2021 */ 2022 static noinline int record_one_backref(u64 inum, u64 offset, u64 root_id, 2023 void *ctx) 2024 { 2025 struct btrfs_file_extent_item *extent; 2026 struct btrfs_fs_info *fs_info; 2027 struct old_sa_defrag_extent *old = ctx; 2028 struct new_sa_defrag_extent *new = old->new; 2029 struct btrfs_path *path = new->path; 2030 struct btrfs_key key; 2031 struct btrfs_root *root; 2032 struct sa_defrag_extent_backref *backref; 2033 struct extent_buffer *leaf; 2034 struct inode *inode = new->inode; 2035 int slot; 2036 int ret; 2037 u64 extent_offset; 2038 u64 num_bytes; 2039 2040 if (BTRFS_I(inode)->root->root_key.objectid == root_id && 2041 inum == btrfs_ino(inode)) 2042 return 0; 2043 2044 key.objectid = root_id; 2045 key.type = BTRFS_ROOT_ITEM_KEY; 2046 key.offset = (u64)-1; 2047 2048 fs_info = BTRFS_I(inode)->root->fs_info; 2049 root = btrfs_read_fs_root_no_name(fs_info, &key); 2050 if (IS_ERR(root)) { 2051 if (PTR_ERR(root) == -ENOENT) 2052 return 0; 2053 WARN_ON(1); 2054 pr_debug("inum=%llu, offset=%llu, root_id=%llu\n", 2055 inum, offset, root_id); 2056 return PTR_ERR(root); 2057 } 2058 2059 key.objectid = inum; 2060 key.type = BTRFS_EXTENT_DATA_KEY; 2061 if (offset > (u64)-1 << 32) 2062 key.offset = 0; 2063 else 2064 key.offset = offset; 2065 2066 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 2067 if (WARN_ON(ret < 0)) 2068 return ret; 2069 ret = 0; 2070 2071 while (1) { 2072 cond_resched(); 2073 2074 leaf = path->nodes[0]; 2075 slot = path->slots[0]; 2076 2077 if (slot >= btrfs_header_nritems(leaf)) { 2078 ret = btrfs_next_leaf(root, path); 2079 if (ret < 0) { 2080 goto out; 2081 } else if (ret > 0) { 2082 ret = 0; 2083 goto out; 2084 } 2085 continue; 2086 } 2087 2088 path->slots[0]++; 2089 2090 btrfs_item_key_to_cpu(leaf, &key, slot); 2091 2092 if (key.objectid > inum) 2093 goto out; 2094 2095 if (key.objectid < inum || key.type != BTRFS_EXTENT_DATA_KEY) 2096 continue; 2097 2098 extent = btrfs_item_ptr(leaf, slot, 2099 struct btrfs_file_extent_item); 2100 2101 if (btrfs_file_extent_disk_bytenr(leaf, extent) != old->bytenr) 2102 continue; 2103 2104 /* 2105 * 'offset' refers to the exact key.offset, 2106 * NOT the 'offset' field in btrfs_extent_data_ref, ie. 2107 * (key.offset - extent_offset). 2108 */ 2109 if (key.offset != offset) 2110 continue; 2111 2112 extent_offset = btrfs_file_extent_offset(leaf, extent); 2113 num_bytes = btrfs_file_extent_num_bytes(leaf, extent); 2114 2115 if (extent_offset >= old->extent_offset + old->offset + 2116 old->len || extent_offset + num_bytes <= 2117 old->extent_offset + old->offset) 2118 continue; 2119 break; 2120 } 2121 2122 backref = kmalloc(sizeof(*backref), GFP_NOFS); 2123 if (!backref) { 2124 ret = -ENOENT; 2125 goto out; 2126 } 2127 2128 backref->root_id = root_id; 2129 backref->inum = inum; 2130 backref->file_pos = offset; 2131 backref->num_bytes = num_bytes; 2132 backref->extent_offset = extent_offset; 2133 backref->generation = btrfs_file_extent_generation(leaf, extent); 2134 backref->old = old; 2135 backref_insert(&new->root, backref); 2136 old->count++; 2137 out: 2138 btrfs_release_path(path); 2139 WARN_ON(ret); 2140 return ret; 2141 } 2142 2143 static noinline bool record_extent_backrefs(struct btrfs_path *path, 2144 struct new_sa_defrag_extent *new) 2145 { 2146 struct btrfs_fs_info *fs_info = BTRFS_I(new->inode)->root->fs_info; 2147 struct old_sa_defrag_extent *old, *tmp; 2148 int ret; 2149 2150 new->path = path; 2151 2152 list_for_each_entry_safe(old, tmp, &new->head, list) { 2153 ret = iterate_inodes_from_logical(old->bytenr + 2154 old->extent_offset, fs_info, 2155 path, record_one_backref, 2156 old); 2157 if (ret < 0 && ret != -ENOENT) 2158 return false; 2159 2160 /* no backref to be processed for this extent */ 2161 if (!old->count) { 2162 list_del(&old->list); 2163 kfree(old); 2164 } 2165 } 2166 2167 if (list_empty(&new->head)) 2168 return false; 2169 2170 return true; 2171 } 2172 2173 static int relink_is_mergable(struct extent_buffer *leaf, 2174 struct btrfs_file_extent_item *fi, 2175 struct new_sa_defrag_extent *new) 2176 { 2177 if (btrfs_file_extent_disk_bytenr(leaf, fi) != new->bytenr) 2178 return 0; 2179 2180 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG) 2181 return 0; 2182 2183 if (btrfs_file_extent_compression(leaf, fi) != new->compress_type) 2184 return 0; 2185 2186 if (btrfs_file_extent_encryption(leaf, fi) || 2187 btrfs_file_extent_other_encoding(leaf, fi)) 2188 return 0; 2189 2190 return 1; 2191 } 2192 2193 /* 2194 * Note the backref might has changed, and in this case we just return 0. 2195 */ 2196 static noinline int relink_extent_backref(struct btrfs_path *path, 2197 struct sa_defrag_extent_backref *prev, 2198 struct sa_defrag_extent_backref *backref) 2199 { 2200 struct btrfs_file_extent_item *extent; 2201 struct btrfs_file_extent_item *item; 2202 struct btrfs_ordered_extent *ordered; 2203 struct btrfs_trans_handle *trans; 2204 struct btrfs_fs_info *fs_info; 2205 struct btrfs_root *root; 2206 struct btrfs_key key; 2207 struct extent_buffer *leaf; 2208 struct old_sa_defrag_extent *old = backref->old; 2209 struct new_sa_defrag_extent *new = old->new; 2210 struct inode *src_inode = new->inode; 2211 struct inode *inode; 2212 struct extent_state *cached = NULL; 2213 int ret = 0; 2214 u64 start; 2215 u64 len; 2216 u64 lock_start; 2217 u64 lock_end; 2218 bool merge = false; 2219 int index; 2220 2221 if (prev && prev->root_id == backref->root_id && 2222 prev->inum == backref->inum && 2223 prev->file_pos + prev->num_bytes == backref->file_pos) 2224 merge = true; 2225 2226 /* step 1: get root */ 2227 key.objectid = backref->root_id; 2228 key.type = BTRFS_ROOT_ITEM_KEY; 2229 key.offset = (u64)-1; 2230 2231 fs_info = BTRFS_I(src_inode)->root->fs_info; 2232 index = srcu_read_lock(&fs_info->subvol_srcu); 2233 2234 root = btrfs_read_fs_root_no_name(fs_info, &key); 2235 if (IS_ERR(root)) { 2236 srcu_read_unlock(&fs_info->subvol_srcu, index); 2237 if (PTR_ERR(root) == -ENOENT) 2238 return 0; 2239 return PTR_ERR(root); 2240 } 2241 2242 /* step 2: get inode */ 2243 key.objectid = backref->inum; 2244 key.type = BTRFS_INODE_ITEM_KEY; 2245 key.offset = 0; 2246 2247 inode = btrfs_iget(fs_info->sb, &key, root, NULL); 2248 if (IS_ERR(inode)) { 2249 srcu_read_unlock(&fs_info->subvol_srcu, index); 2250 return 0; 2251 } 2252 2253 srcu_read_unlock(&fs_info->subvol_srcu, index); 2254 2255 /* step 3: relink backref */ 2256 lock_start = backref->file_pos; 2257 lock_end = backref->file_pos + backref->num_bytes - 1; 2258 lock_extent_bits(&BTRFS_I(inode)->io_tree, lock_start, lock_end, 2259 0, &cached); 2260 2261 ordered = btrfs_lookup_first_ordered_extent(inode, lock_end); 2262 if (ordered) { 2263 btrfs_put_ordered_extent(ordered); 2264 goto out_unlock; 2265 } 2266 2267 trans = btrfs_join_transaction(root); 2268 if (IS_ERR(trans)) { 2269 ret = PTR_ERR(trans); 2270 goto out_unlock; 2271 } 2272 2273 key.objectid = backref->inum; 2274 key.type = BTRFS_EXTENT_DATA_KEY; 2275 key.offset = backref->file_pos; 2276 2277 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 2278 if (ret < 0) { 2279 goto out_free_path; 2280 } else if (ret > 0) { 2281 ret = 0; 2282 goto out_free_path; 2283 } 2284 2285 extent = btrfs_item_ptr(path->nodes[0], path->slots[0], 2286 struct btrfs_file_extent_item); 2287 2288 if (btrfs_file_extent_generation(path->nodes[0], extent) != 2289 backref->generation) 2290 goto out_free_path; 2291 2292 btrfs_release_path(path); 2293 2294 start = backref->file_pos; 2295 if (backref->extent_offset < old->extent_offset + old->offset) 2296 start += old->extent_offset + old->offset - 2297 backref->extent_offset; 2298 2299 len = min(backref->extent_offset + backref->num_bytes, 2300 old->extent_offset + old->offset + old->len); 2301 len -= max(backref->extent_offset, old->extent_offset + old->offset); 2302 2303 ret = btrfs_drop_extents(trans, root, inode, start, 2304 start + len, 1); 2305 if (ret) 2306 goto out_free_path; 2307 again: 2308 key.objectid = btrfs_ino(inode); 2309 key.type = BTRFS_EXTENT_DATA_KEY; 2310 key.offset = start; 2311 2312 path->leave_spinning = 1; 2313 if (merge) { 2314 struct btrfs_file_extent_item *fi; 2315 u64 extent_len; 2316 struct btrfs_key found_key; 2317 2318 ret = btrfs_search_slot(trans, root, &key, path, 0, 1); 2319 if (ret < 0) 2320 goto out_free_path; 2321 2322 path->slots[0]--; 2323 leaf = path->nodes[0]; 2324 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 2325 2326 fi = btrfs_item_ptr(leaf, path->slots[0], 2327 struct btrfs_file_extent_item); 2328 extent_len = btrfs_file_extent_num_bytes(leaf, fi); 2329 2330 if (extent_len + found_key.offset == start && 2331 relink_is_mergable(leaf, fi, new)) { 2332 btrfs_set_file_extent_num_bytes(leaf, fi, 2333 extent_len + len); 2334 btrfs_mark_buffer_dirty(leaf); 2335 inode_add_bytes(inode, len); 2336 2337 ret = 1; 2338 goto out_free_path; 2339 } else { 2340 merge = false; 2341 btrfs_release_path(path); 2342 goto again; 2343 } 2344 } 2345 2346 ret = btrfs_insert_empty_item(trans, root, path, &key, 2347 sizeof(*extent)); 2348 if (ret) { 2349 btrfs_abort_transaction(trans, root, ret); 2350 goto out_free_path; 2351 } 2352 2353 leaf = path->nodes[0]; 2354 item = btrfs_item_ptr(leaf, path->slots[0], 2355 struct btrfs_file_extent_item); 2356 btrfs_set_file_extent_disk_bytenr(leaf, item, new->bytenr); 2357 btrfs_set_file_extent_disk_num_bytes(leaf, item, new->disk_len); 2358 btrfs_set_file_extent_offset(leaf, item, start - new->file_pos); 2359 btrfs_set_file_extent_num_bytes(leaf, item, len); 2360 btrfs_set_file_extent_ram_bytes(leaf, item, new->len); 2361 btrfs_set_file_extent_generation(leaf, item, trans->transid); 2362 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG); 2363 btrfs_set_file_extent_compression(leaf, item, new->compress_type); 2364 btrfs_set_file_extent_encryption(leaf, item, 0); 2365 btrfs_set_file_extent_other_encoding(leaf, item, 0); 2366 2367 btrfs_mark_buffer_dirty(leaf); 2368 inode_add_bytes(inode, len); 2369 btrfs_release_path(path); 2370 2371 ret = btrfs_inc_extent_ref(trans, root, new->bytenr, 2372 new->disk_len, 0, 2373 backref->root_id, backref->inum, 2374 new->file_pos, 0); /* start - extent_offset */ 2375 if (ret) { 2376 btrfs_abort_transaction(trans, root, ret); 2377 goto out_free_path; 2378 } 2379 2380 ret = 1; 2381 out_free_path: 2382 btrfs_release_path(path); 2383 path->leave_spinning = 0; 2384 btrfs_end_transaction(trans, root); 2385 out_unlock: 2386 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lock_start, lock_end, 2387 &cached, GFP_NOFS); 2388 iput(inode); 2389 return ret; 2390 } 2391 2392 static void free_sa_defrag_extent(struct new_sa_defrag_extent *new) 2393 { 2394 struct old_sa_defrag_extent *old, *tmp; 2395 2396 if (!new) 2397 return; 2398 2399 list_for_each_entry_safe(old, tmp, &new->head, list) { 2400 list_del(&old->list); 2401 kfree(old); 2402 } 2403 kfree(new); 2404 } 2405 2406 static void relink_file_extents(struct new_sa_defrag_extent *new) 2407 { 2408 struct btrfs_path *path; 2409 struct sa_defrag_extent_backref *backref; 2410 struct sa_defrag_extent_backref *prev = NULL; 2411 struct inode *inode; 2412 struct btrfs_root *root; 2413 struct rb_node *node; 2414 int ret; 2415 2416 inode = new->inode; 2417 root = BTRFS_I(inode)->root; 2418 2419 path = btrfs_alloc_path(); 2420 if (!path) 2421 return; 2422 2423 if (!record_extent_backrefs(path, new)) { 2424 btrfs_free_path(path); 2425 goto out; 2426 } 2427 btrfs_release_path(path); 2428 2429 while (1) { 2430 node = rb_first(&new->root); 2431 if (!node) 2432 break; 2433 rb_erase(node, &new->root); 2434 2435 backref = rb_entry(node, struct sa_defrag_extent_backref, node); 2436 2437 ret = relink_extent_backref(path, prev, backref); 2438 WARN_ON(ret < 0); 2439 2440 kfree(prev); 2441 2442 if (ret == 1) 2443 prev = backref; 2444 else 2445 prev = NULL; 2446 cond_resched(); 2447 } 2448 kfree(prev); 2449 2450 btrfs_free_path(path); 2451 out: 2452 free_sa_defrag_extent(new); 2453 2454 atomic_dec(&root->fs_info->defrag_running); 2455 wake_up(&root->fs_info->transaction_wait); 2456 } 2457 2458 static struct new_sa_defrag_extent * 2459 record_old_file_extents(struct inode *inode, 2460 struct btrfs_ordered_extent *ordered) 2461 { 2462 struct btrfs_root *root = BTRFS_I(inode)->root; 2463 struct btrfs_path *path; 2464 struct btrfs_key key; 2465 struct old_sa_defrag_extent *old; 2466 struct new_sa_defrag_extent *new; 2467 int ret; 2468 2469 new = kmalloc(sizeof(*new), GFP_NOFS); 2470 if (!new) 2471 return NULL; 2472 2473 new->inode = inode; 2474 new->file_pos = ordered->file_offset; 2475 new->len = ordered->len; 2476 new->bytenr = ordered->start; 2477 new->disk_len = ordered->disk_len; 2478 new->compress_type = ordered->compress_type; 2479 new->root = RB_ROOT; 2480 INIT_LIST_HEAD(&new->head); 2481 2482 path = btrfs_alloc_path(); 2483 if (!path) 2484 goto out_kfree; 2485 2486 key.objectid = btrfs_ino(inode); 2487 key.type = BTRFS_EXTENT_DATA_KEY; 2488 key.offset = new->file_pos; 2489 2490 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 2491 if (ret < 0) 2492 goto out_free_path; 2493 if (ret > 0 && path->slots[0] > 0) 2494 path->slots[0]--; 2495 2496 /* find out all the old extents for the file range */ 2497 while (1) { 2498 struct btrfs_file_extent_item *extent; 2499 struct extent_buffer *l; 2500 int slot; 2501 u64 num_bytes; 2502 u64 offset; 2503 u64 end; 2504 u64 disk_bytenr; 2505 u64 extent_offset; 2506 2507 l = path->nodes[0]; 2508 slot = path->slots[0]; 2509 2510 if (slot >= btrfs_header_nritems(l)) { 2511 ret = btrfs_next_leaf(root, path); 2512 if (ret < 0) 2513 goto out_free_path; 2514 else if (ret > 0) 2515 break; 2516 continue; 2517 } 2518 2519 btrfs_item_key_to_cpu(l, &key, slot); 2520 2521 if (key.objectid != btrfs_ino(inode)) 2522 break; 2523 if (key.type != BTRFS_EXTENT_DATA_KEY) 2524 break; 2525 if (key.offset >= new->file_pos + new->len) 2526 break; 2527 2528 extent = btrfs_item_ptr(l, slot, struct btrfs_file_extent_item); 2529 2530 num_bytes = btrfs_file_extent_num_bytes(l, extent); 2531 if (key.offset + num_bytes < new->file_pos) 2532 goto next; 2533 2534 disk_bytenr = btrfs_file_extent_disk_bytenr(l, extent); 2535 if (!disk_bytenr) 2536 goto next; 2537 2538 extent_offset = btrfs_file_extent_offset(l, extent); 2539 2540 old = kmalloc(sizeof(*old), GFP_NOFS); 2541 if (!old) 2542 goto out_free_path; 2543 2544 offset = max(new->file_pos, key.offset); 2545 end = min(new->file_pos + new->len, key.offset + num_bytes); 2546 2547 old->bytenr = disk_bytenr; 2548 old->extent_offset = extent_offset; 2549 old->offset = offset - key.offset; 2550 old->len = end - offset; 2551 old->new = new; 2552 old->count = 0; 2553 list_add_tail(&old->list, &new->head); 2554 next: 2555 path->slots[0]++; 2556 cond_resched(); 2557 } 2558 2559 btrfs_free_path(path); 2560 atomic_inc(&root->fs_info->defrag_running); 2561 2562 return new; 2563 2564 out_free_path: 2565 btrfs_free_path(path); 2566 out_kfree: 2567 free_sa_defrag_extent(new); 2568 return NULL; 2569 } 2570 2571 /* as ordered data IO finishes, this gets called so we can finish 2572 * an ordered extent if the range of bytes in the file it covers are 2573 * fully written. 2574 */ 2575 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent) 2576 { 2577 struct inode *inode = ordered_extent->inode; 2578 struct btrfs_root *root = BTRFS_I(inode)->root; 2579 struct btrfs_trans_handle *trans = NULL; 2580 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 2581 struct extent_state *cached_state = NULL; 2582 struct new_sa_defrag_extent *new = NULL; 2583 int compress_type = 0; 2584 int ret = 0; 2585 u64 logical_len = ordered_extent->len; 2586 bool nolock; 2587 bool truncated = false; 2588 2589 nolock = btrfs_is_free_space_inode(inode); 2590 2591 if (test_bit(BTRFS_ORDERED_IOERR, &ordered_extent->flags)) { 2592 ret = -EIO; 2593 goto out; 2594 } 2595 2596 if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered_extent->flags)) { 2597 truncated = true; 2598 logical_len = ordered_extent->truncated_len; 2599 /* Truncated the entire extent, don't bother adding */ 2600 if (!logical_len) 2601 goto out; 2602 } 2603 2604 if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) { 2605 BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */ 2606 btrfs_ordered_update_i_size(inode, 0, ordered_extent); 2607 if (nolock) 2608 trans = btrfs_join_transaction_nolock(root); 2609 else 2610 trans = btrfs_join_transaction(root); 2611 if (IS_ERR(trans)) { 2612 ret = PTR_ERR(trans); 2613 trans = NULL; 2614 goto out; 2615 } 2616 trans->block_rsv = &root->fs_info->delalloc_block_rsv; 2617 ret = btrfs_update_inode_fallback(trans, root, inode); 2618 if (ret) /* -ENOMEM or corruption */ 2619 btrfs_abort_transaction(trans, root, ret); 2620 goto out; 2621 } 2622 2623 lock_extent_bits(io_tree, ordered_extent->file_offset, 2624 ordered_extent->file_offset + ordered_extent->len - 1, 2625 0, &cached_state); 2626 2627 ret = test_range_bit(io_tree, ordered_extent->file_offset, 2628 ordered_extent->file_offset + ordered_extent->len - 1, 2629 EXTENT_DEFRAG, 1, cached_state); 2630 if (ret) { 2631 u64 last_snapshot = btrfs_root_last_snapshot(&root->root_item); 2632 if (0 && last_snapshot >= BTRFS_I(inode)->generation) 2633 /* the inode is shared */ 2634 new = record_old_file_extents(inode, ordered_extent); 2635 2636 clear_extent_bit(io_tree, ordered_extent->file_offset, 2637 ordered_extent->file_offset + ordered_extent->len - 1, 2638 EXTENT_DEFRAG, 0, 0, &cached_state, GFP_NOFS); 2639 } 2640 2641 if (nolock) 2642 trans = btrfs_join_transaction_nolock(root); 2643 else 2644 trans = btrfs_join_transaction(root); 2645 if (IS_ERR(trans)) { 2646 ret = PTR_ERR(trans); 2647 trans = NULL; 2648 goto out_unlock; 2649 } 2650 trans->block_rsv = &root->fs_info->delalloc_block_rsv; 2651 2652 if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags)) 2653 compress_type = ordered_extent->compress_type; 2654 if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) { 2655 BUG_ON(compress_type); 2656 ret = btrfs_mark_extent_written(trans, inode, 2657 ordered_extent->file_offset, 2658 ordered_extent->file_offset + 2659 logical_len); 2660 } else { 2661 BUG_ON(root == root->fs_info->tree_root); 2662 ret = insert_reserved_file_extent(trans, inode, 2663 ordered_extent->file_offset, 2664 ordered_extent->start, 2665 ordered_extent->disk_len, 2666 logical_len, logical_len, 2667 compress_type, 0, 0, 2668 BTRFS_FILE_EXTENT_REG); 2669 } 2670 unpin_extent_cache(&BTRFS_I(inode)->extent_tree, 2671 ordered_extent->file_offset, ordered_extent->len, 2672 trans->transid); 2673 if (ret < 0) { 2674 btrfs_abort_transaction(trans, root, ret); 2675 goto out_unlock; 2676 } 2677 2678 add_pending_csums(trans, inode, ordered_extent->file_offset, 2679 &ordered_extent->list); 2680 2681 btrfs_ordered_update_i_size(inode, 0, ordered_extent); 2682 ret = btrfs_update_inode_fallback(trans, root, inode); 2683 if (ret) { /* -ENOMEM or corruption */ 2684 btrfs_abort_transaction(trans, root, ret); 2685 goto out_unlock; 2686 } 2687 ret = 0; 2688 out_unlock: 2689 unlock_extent_cached(io_tree, ordered_extent->file_offset, 2690 ordered_extent->file_offset + 2691 ordered_extent->len - 1, &cached_state, GFP_NOFS); 2692 out: 2693 if (root != root->fs_info->tree_root) 2694 btrfs_delalloc_release_metadata(inode, ordered_extent->len); 2695 if (trans) 2696 btrfs_end_transaction(trans, root); 2697 2698 if (ret || truncated) { 2699 u64 start, end; 2700 2701 if (truncated) 2702 start = ordered_extent->file_offset + logical_len; 2703 else 2704 start = ordered_extent->file_offset; 2705 end = ordered_extent->file_offset + ordered_extent->len - 1; 2706 clear_extent_uptodate(io_tree, start, end, NULL, GFP_NOFS); 2707 2708 /* Drop the cache for the part of the extent we didn't write. */ 2709 btrfs_drop_extent_cache(inode, start, end, 0); 2710 2711 /* 2712 * If the ordered extent had an IOERR or something else went 2713 * wrong we need to return the space for this ordered extent 2714 * back to the allocator. We only free the extent in the 2715 * truncated case if we didn't write out the extent at all. 2716 */ 2717 if ((ret || !logical_len) && 2718 !test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) && 2719 !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) 2720 btrfs_free_reserved_extent(root, ordered_extent->start, 2721 ordered_extent->disk_len); 2722 } 2723 2724 2725 /* 2726 * This needs to be done to make sure anybody waiting knows we are done 2727 * updating everything for this ordered extent. 2728 */ 2729 btrfs_remove_ordered_extent(inode, ordered_extent); 2730 2731 /* for snapshot-aware defrag */ 2732 if (new) { 2733 if (ret) { 2734 free_sa_defrag_extent(new); 2735 atomic_dec(&root->fs_info->defrag_running); 2736 } else { 2737 relink_file_extents(new); 2738 } 2739 } 2740 2741 /* once for us */ 2742 btrfs_put_ordered_extent(ordered_extent); 2743 /* once for the tree */ 2744 btrfs_put_ordered_extent(ordered_extent); 2745 2746 return ret; 2747 } 2748 2749 static void finish_ordered_fn(struct btrfs_work *work) 2750 { 2751 struct btrfs_ordered_extent *ordered_extent; 2752 ordered_extent = container_of(work, struct btrfs_ordered_extent, work); 2753 btrfs_finish_ordered_io(ordered_extent); 2754 } 2755 2756 static int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end, 2757 struct extent_state *state, int uptodate) 2758 { 2759 struct inode *inode = page->mapping->host; 2760 struct btrfs_root *root = BTRFS_I(inode)->root; 2761 struct btrfs_ordered_extent *ordered_extent = NULL; 2762 struct btrfs_workers *workers; 2763 2764 trace_btrfs_writepage_end_io_hook(page, start, end, uptodate); 2765 2766 ClearPagePrivate2(page); 2767 if (!btrfs_dec_test_ordered_pending(inode, &ordered_extent, start, 2768 end - start + 1, uptodate)) 2769 return 0; 2770 2771 ordered_extent->work.func = finish_ordered_fn; 2772 ordered_extent->work.flags = 0; 2773 2774 if (btrfs_is_free_space_inode(inode)) 2775 workers = &root->fs_info->endio_freespace_worker; 2776 else 2777 workers = &root->fs_info->endio_write_workers; 2778 btrfs_queue_worker(workers, &ordered_extent->work); 2779 2780 return 0; 2781 } 2782 2783 /* 2784 * when reads are done, we need to check csums to verify the data is correct 2785 * if there's a match, we allow the bio to finish. If not, the code in 2786 * extent_io.c will try to find good copies for us. 2787 */ 2788 static int btrfs_readpage_end_io_hook(struct btrfs_io_bio *io_bio, 2789 u64 phy_offset, struct page *page, 2790 u64 start, u64 end, int mirror) 2791 { 2792 size_t offset = start - page_offset(page); 2793 struct inode *inode = page->mapping->host; 2794 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 2795 char *kaddr; 2796 struct btrfs_root *root = BTRFS_I(inode)->root; 2797 u32 csum_expected; 2798 u32 csum = ~(u32)0; 2799 static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL, 2800 DEFAULT_RATELIMIT_BURST); 2801 2802 if (PageChecked(page)) { 2803 ClearPageChecked(page); 2804 goto good; 2805 } 2806 2807 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM) 2808 goto good; 2809 2810 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID && 2811 test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) { 2812 clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM, 2813 GFP_NOFS); 2814 return 0; 2815 } 2816 2817 phy_offset >>= inode->i_sb->s_blocksize_bits; 2818 csum_expected = *(((u32 *)io_bio->csum) + phy_offset); 2819 2820 kaddr = kmap_atomic(page); 2821 csum = btrfs_csum_data(kaddr + offset, csum, end - start + 1); 2822 btrfs_csum_final(csum, (char *)&csum); 2823 if (csum != csum_expected) 2824 goto zeroit; 2825 2826 kunmap_atomic(kaddr); 2827 good: 2828 return 0; 2829 2830 zeroit: 2831 if (__ratelimit(&_rs)) 2832 btrfs_info(root->fs_info, "csum failed ino %llu off %llu csum %u expected csum %u", 2833 btrfs_ino(page->mapping->host), start, csum, csum_expected); 2834 memset(kaddr + offset, 1, end - start + 1); 2835 flush_dcache_page(page); 2836 kunmap_atomic(kaddr); 2837 if (csum_expected == 0) 2838 return 0; 2839 return -EIO; 2840 } 2841 2842 struct delayed_iput { 2843 struct list_head list; 2844 struct inode *inode; 2845 }; 2846 2847 /* JDM: If this is fs-wide, why can't we add a pointer to 2848 * btrfs_inode instead and avoid the allocation? */ 2849 void btrfs_add_delayed_iput(struct inode *inode) 2850 { 2851 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info; 2852 struct delayed_iput *delayed; 2853 2854 if (atomic_add_unless(&inode->i_count, -1, 1)) 2855 return; 2856 2857 delayed = kmalloc(sizeof(*delayed), GFP_NOFS | __GFP_NOFAIL); 2858 delayed->inode = inode; 2859 2860 spin_lock(&fs_info->delayed_iput_lock); 2861 list_add_tail(&delayed->list, &fs_info->delayed_iputs); 2862 spin_unlock(&fs_info->delayed_iput_lock); 2863 } 2864 2865 void btrfs_run_delayed_iputs(struct btrfs_root *root) 2866 { 2867 LIST_HEAD(list); 2868 struct btrfs_fs_info *fs_info = root->fs_info; 2869 struct delayed_iput *delayed; 2870 int empty; 2871 2872 spin_lock(&fs_info->delayed_iput_lock); 2873 empty = list_empty(&fs_info->delayed_iputs); 2874 spin_unlock(&fs_info->delayed_iput_lock); 2875 if (empty) 2876 return; 2877 2878 spin_lock(&fs_info->delayed_iput_lock); 2879 list_splice_init(&fs_info->delayed_iputs, &list); 2880 spin_unlock(&fs_info->delayed_iput_lock); 2881 2882 while (!list_empty(&list)) { 2883 delayed = list_entry(list.next, struct delayed_iput, list); 2884 list_del(&delayed->list); 2885 iput(delayed->inode); 2886 kfree(delayed); 2887 } 2888 } 2889 2890 /* 2891 * This is called in transaction commit time. If there are no orphan 2892 * files in the subvolume, it removes orphan item and frees block_rsv 2893 * structure. 2894 */ 2895 void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans, 2896 struct btrfs_root *root) 2897 { 2898 struct btrfs_block_rsv *block_rsv; 2899 int ret; 2900 2901 if (atomic_read(&root->orphan_inodes) || 2902 root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) 2903 return; 2904 2905 spin_lock(&root->orphan_lock); 2906 if (atomic_read(&root->orphan_inodes)) { 2907 spin_unlock(&root->orphan_lock); 2908 return; 2909 } 2910 2911 if (root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) { 2912 spin_unlock(&root->orphan_lock); 2913 return; 2914 } 2915 2916 block_rsv = root->orphan_block_rsv; 2917 root->orphan_block_rsv = NULL; 2918 spin_unlock(&root->orphan_lock); 2919 2920 if (root->orphan_item_inserted && 2921 btrfs_root_refs(&root->root_item) > 0) { 2922 ret = btrfs_del_orphan_item(trans, root->fs_info->tree_root, 2923 root->root_key.objectid); 2924 if (ret) 2925 btrfs_abort_transaction(trans, root, ret); 2926 else 2927 root->orphan_item_inserted = 0; 2928 } 2929 2930 if (block_rsv) { 2931 WARN_ON(block_rsv->size > 0); 2932 btrfs_free_block_rsv(root, block_rsv); 2933 } 2934 } 2935 2936 /* 2937 * This creates an orphan entry for the given inode in case something goes 2938 * wrong in the middle of an unlink/truncate. 2939 * 2940 * NOTE: caller of this function should reserve 5 units of metadata for 2941 * this function. 2942 */ 2943 int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode) 2944 { 2945 struct btrfs_root *root = BTRFS_I(inode)->root; 2946 struct btrfs_block_rsv *block_rsv = NULL; 2947 int reserve = 0; 2948 int insert = 0; 2949 int ret; 2950 2951 if (!root->orphan_block_rsv) { 2952 block_rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP); 2953 if (!block_rsv) 2954 return -ENOMEM; 2955 } 2956 2957 spin_lock(&root->orphan_lock); 2958 if (!root->orphan_block_rsv) { 2959 root->orphan_block_rsv = block_rsv; 2960 } else if (block_rsv) { 2961 btrfs_free_block_rsv(root, block_rsv); 2962 block_rsv = NULL; 2963 } 2964 2965 if (!test_and_set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM, 2966 &BTRFS_I(inode)->runtime_flags)) { 2967 #if 0 2968 /* 2969 * For proper ENOSPC handling, we should do orphan 2970 * cleanup when mounting. But this introduces backward 2971 * compatibility issue. 2972 */ 2973 if (!xchg(&root->orphan_item_inserted, 1)) 2974 insert = 2; 2975 else 2976 insert = 1; 2977 #endif 2978 insert = 1; 2979 atomic_inc(&root->orphan_inodes); 2980 } 2981 2982 if (!test_and_set_bit(BTRFS_INODE_ORPHAN_META_RESERVED, 2983 &BTRFS_I(inode)->runtime_flags)) 2984 reserve = 1; 2985 spin_unlock(&root->orphan_lock); 2986 2987 /* grab metadata reservation from transaction handle */ 2988 if (reserve) { 2989 ret = btrfs_orphan_reserve_metadata(trans, inode); 2990 BUG_ON(ret); /* -ENOSPC in reservation; Logic error? JDM */ 2991 } 2992 2993 /* insert an orphan item to track this unlinked/truncated file */ 2994 if (insert >= 1) { 2995 ret = btrfs_insert_orphan_item(trans, root, btrfs_ino(inode)); 2996 if (ret) { 2997 atomic_dec(&root->orphan_inodes); 2998 if (reserve) { 2999 clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED, 3000 &BTRFS_I(inode)->runtime_flags); 3001 btrfs_orphan_release_metadata(inode); 3002 } 3003 if (ret != -EEXIST) { 3004 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM, 3005 &BTRFS_I(inode)->runtime_flags); 3006 btrfs_abort_transaction(trans, root, ret); 3007 return ret; 3008 } 3009 } 3010 ret = 0; 3011 } 3012 3013 /* insert an orphan item to track subvolume contains orphan files */ 3014 if (insert >= 2) { 3015 ret = btrfs_insert_orphan_item(trans, root->fs_info->tree_root, 3016 root->root_key.objectid); 3017 if (ret && ret != -EEXIST) { 3018 btrfs_abort_transaction(trans, root, ret); 3019 return ret; 3020 } 3021 } 3022 return 0; 3023 } 3024 3025 /* 3026 * We have done the truncate/delete so we can go ahead and remove the orphan 3027 * item for this particular inode. 3028 */ 3029 static int btrfs_orphan_del(struct btrfs_trans_handle *trans, 3030 struct inode *inode) 3031 { 3032 struct btrfs_root *root = BTRFS_I(inode)->root; 3033 int delete_item = 0; 3034 int release_rsv = 0; 3035 int ret = 0; 3036 3037 spin_lock(&root->orphan_lock); 3038 if (test_and_clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM, 3039 &BTRFS_I(inode)->runtime_flags)) 3040 delete_item = 1; 3041 3042 if (test_and_clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED, 3043 &BTRFS_I(inode)->runtime_flags)) 3044 release_rsv = 1; 3045 spin_unlock(&root->orphan_lock); 3046 3047 if (delete_item) { 3048 atomic_dec(&root->orphan_inodes); 3049 if (trans) 3050 ret = btrfs_del_orphan_item(trans, root, 3051 btrfs_ino(inode)); 3052 } 3053 3054 if (release_rsv) 3055 btrfs_orphan_release_metadata(inode); 3056 3057 return ret; 3058 } 3059 3060 /* 3061 * this cleans up any orphans that may be left on the list from the last use 3062 * of this root. 3063 */ 3064 int btrfs_orphan_cleanup(struct btrfs_root *root) 3065 { 3066 struct btrfs_path *path; 3067 struct extent_buffer *leaf; 3068 struct btrfs_key key, found_key; 3069 struct btrfs_trans_handle *trans; 3070 struct inode *inode; 3071 u64 last_objectid = 0; 3072 int ret = 0, nr_unlink = 0, nr_truncate = 0; 3073 3074 if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED)) 3075 return 0; 3076 3077 path = btrfs_alloc_path(); 3078 if (!path) { 3079 ret = -ENOMEM; 3080 goto out; 3081 } 3082 path->reada = -1; 3083 3084 key.objectid = BTRFS_ORPHAN_OBJECTID; 3085 btrfs_set_key_type(&key, BTRFS_ORPHAN_ITEM_KEY); 3086 key.offset = (u64)-1; 3087 3088 while (1) { 3089 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 3090 if (ret < 0) 3091 goto out; 3092 3093 /* 3094 * if ret == 0 means we found what we were searching for, which 3095 * is weird, but possible, so only screw with path if we didn't 3096 * find the key and see if we have stuff that matches 3097 */ 3098 if (ret > 0) { 3099 ret = 0; 3100 if (path->slots[0] == 0) 3101 break; 3102 path->slots[0]--; 3103 } 3104 3105 /* pull out the item */ 3106 leaf = path->nodes[0]; 3107 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 3108 3109 /* make sure the item matches what we want */ 3110 if (found_key.objectid != BTRFS_ORPHAN_OBJECTID) 3111 break; 3112 if (btrfs_key_type(&found_key) != BTRFS_ORPHAN_ITEM_KEY) 3113 break; 3114 3115 /* release the path since we're done with it */ 3116 btrfs_release_path(path); 3117 3118 /* 3119 * this is where we are basically btrfs_lookup, without the 3120 * crossing root thing. we store the inode number in the 3121 * offset of the orphan item. 3122 */ 3123 3124 if (found_key.offset == last_objectid) { 3125 btrfs_err(root->fs_info, 3126 "Error removing orphan entry, stopping orphan cleanup"); 3127 ret = -EINVAL; 3128 goto out; 3129 } 3130 3131 last_objectid = found_key.offset; 3132 3133 found_key.objectid = found_key.offset; 3134 found_key.type = BTRFS_INODE_ITEM_KEY; 3135 found_key.offset = 0; 3136 inode = btrfs_iget(root->fs_info->sb, &found_key, root, NULL); 3137 ret = PTR_ERR_OR_ZERO(inode); 3138 if (ret && ret != -ESTALE) 3139 goto out; 3140 3141 if (ret == -ESTALE && root == root->fs_info->tree_root) { 3142 struct btrfs_root *dead_root; 3143 struct btrfs_fs_info *fs_info = root->fs_info; 3144 int is_dead_root = 0; 3145 3146 /* 3147 * this is an orphan in the tree root. Currently these 3148 * could come from 2 sources: 3149 * a) a snapshot deletion in progress 3150 * b) a free space cache inode 3151 * We need to distinguish those two, as the snapshot 3152 * orphan must not get deleted. 3153 * find_dead_roots already ran before us, so if this 3154 * is a snapshot deletion, we should find the root 3155 * in the dead_roots list 3156 */ 3157 spin_lock(&fs_info->trans_lock); 3158 list_for_each_entry(dead_root, &fs_info->dead_roots, 3159 root_list) { 3160 if (dead_root->root_key.objectid == 3161 found_key.objectid) { 3162 is_dead_root = 1; 3163 break; 3164 } 3165 } 3166 spin_unlock(&fs_info->trans_lock); 3167 if (is_dead_root) { 3168 /* prevent this orphan from being found again */ 3169 key.offset = found_key.objectid - 1; 3170 continue; 3171 } 3172 } 3173 /* 3174 * Inode is already gone but the orphan item is still there, 3175 * kill the orphan item. 3176 */ 3177 if (ret == -ESTALE) { 3178 trans = btrfs_start_transaction(root, 1); 3179 if (IS_ERR(trans)) { 3180 ret = PTR_ERR(trans); 3181 goto out; 3182 } 3183 btrfs_debug(root->fs_info, "auto deleting %Lu", 3184 found_key.objectid); 3185 ret = btrfs_del_orphan_item(trans, root, 3186 found_key.objectid); 3187 btrfs_end_transaction(trans, root); 3188 if (ret) 3189 goto out; 3190 continue; 3191 } 3192 3193 /* 3194 * add this inode to the orphan list so btrfs_orphan_del does 3195 * the proper thing when we hit it 3196 */ 3197 set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM, 3198 &BTRFS_I(inode)->runtime_flags); 3199 atomic_inc(&root->orphan_inodes); 3200 3201 /* if we have links, this was a truncate, lets do that */ 3202 if (inode->i_nlink) { 3203 if (WARN_ON(!S_ISREG(inode->i_mode))) { 3204 iput(inode); 3205 continue; 3206 } 3207 nr_truncate++; 3208 3209 /* 1 for the orphan item deletion. */ 3210 trans = btrfs_start_transaction(root, 1); 3211 if (IS_ERR(trans)) { 3212 iput(inode); 3213 ret = PTR_ERR(trans); 3214 goto out; 3215 } 3216 ret = btrfs_orphan_add(trans, inode); 3217 btrfs_end_transaction(trans, root); 3218 if (ret) { 3219 iput(inode); 3220 goto out; 3221 } 3222 3223 ret = btrfs_truncate(inode); 3224 if (ret) 3225 btrfs_orphan_del(NULL, inode); 3226 } else { 3227 nr_unlink++; 3228 } 3229 3230 /* this will do delete_inode and everything for us */ 3231 iput(inode); 3232 if (ret) 3233 goto out; 3234 } 3235 /* release the path since we're done with it */ 3236 btrfs_release_path(path); 3237 3238 root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE; 3239 3240 if (root->orphan_block_rsv) 3241 btrfs_block_rsv_release(root, root->orphan_block_rsv, 3242 (u64)-1); 3243 3244 if (root->orphan_block_rsv || root->orphan_item_inserted) { 3245 trans = btrfs_join_transaction(root); 3246 if (!IS_ERR(trans)) 3247 btrfs_end_transaction(trans, root); 3248 } 3249 3250 if (nr_unlink) 3251 btrfs_debug(root->fs_info, "unlinked %d orphans", nr_unlink); 3252 if (nr_truncate) 3253 btrfs_debug(root->fs_info, "truncated %d orphans", nr_truncate); 3254 3255 out: 3256 if (ret) 3257 btrfs_crit(root->fs_info, 3258 "could not do orphan cleanup %d", ret); 3259 btrfs_free_path(path); 3260 return ret; 3261 } 3262 3263 /* 3264 * very simple check to peek ahead in the leaf looking for xattrs. If we 3265 * don't find any xattrs, we know there can't be any acls. 3266 * 3267 * slot is the slot the inode is in, objectid is the objectid of the inode 3268 */ 3269 static noinline int acls_after_inode_item(struct extent_buffer *leaf, 3270 int slot, u64 objectid, 3271 int *first_xattr_slot) 3272 { 3273 u32 nritems = btrfs_header_nritems(leaf); 3274 struct btrfs_key found_key; 3275 static u64 xattr_access = 0; 3276 static u64 xattr_default = 0; 3277 int scanned = 0; 3278 3279 if (!xattr_access) { 3280 xattr_access = btrfs_name_hash(POSIX_ACL_XATTR_ACCESS, 3281 strlen(POSIX_ACL_XATTR_ACCESS)); 3282 xattr_default = btrfs_name_hash(POSIX_ACL_XATTR_DEFAULT, 3283 strlen(POSIX_ACL_XATTR_DEFAULT)); 3284 } 3285 3286 slot++; 3287 *first_xattr_slot = -1; 3288 while (slot < nritems) { 3289 btrfs_item_key_to_cpu(leaf, &found_key, slot); 3290 3291 /* we found a different objectid, there must not be acls */ 3292 if (found_key.objectid != objectid) 3293 return 0; 3294 3295 /* we found an xattr, assume we've got an acl */ 3296 if (found_key.type == BTRFS_XATTR_ITEM_KEY) { 3297 if (*first_xattr_slot == -1) 3298 *first_xattr_slot = slot; 3299 if (found_key.offset == xattr_access || 3300 found_key.offset == xattr_default) 3301 return 1; 3302 } 3303 3304 /* 3305 * we found a key greater than an xattr key, there can't 3306 * be any acls later on 3307 */ 3308 if (found_key.type > BTRFS_XATTR_ITEM_KEY) 3309 return 0; 3310 3311 slot++; 3312 scanned++; 3313 3314 /* 3315 * it goes inode, inode backrefs, xattrs, extents, 3316 * so if there are a ton of hard links to an inode there can 3317 * be a lot of backrefs. Don't waste time searching too hard, 3318 * this is just an optimization 3319 */ 3320 if (scanned >= 8) 3321 break; 3322 } 3323 /* we hit the end of the leaf before we found an xattr or 3324 * something larger than an xattr. We have to assume the inode 3325 * has acls 3326 */ 3327 if (*first_xattr_slot == -1) 3328 *first_xattr_slot = slot; 3329 return 1; 3330 } 3331 3332 /* 3333 * read an inode from the btree into the in-memory inode 3334 */ 3335 static void btrfs_read_locked_inode(struct inode *inode) 3336 { 3337 struct btrfs_path *path; 3338 struct extent_buffer *leaf; 3339 struct btrfs_inode_item *inode_item; 3340 struct btrfs_timespec *tspec; 3341 struct btrfs_root *root = BTRFS_I(inode)->root; 3342 struct btrfs_key location; 3343 unsigned long ptr; 3344 int maybe_acls; 3345 u32 rdev; 3346 int ret; 3347 bool filled = false; 3348 int first_xattr_slot; 3349 3350 ret = btrfs_fill_inode(inode, &rdev); 3351 if (!ret) 3352 filled = true; 3353 3354 path = btrfs_alloc_path(); 3355 if (!path) 3356 goto make_bad; 3357 3358 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location)); 3359 3360 ret = btrfs_lookup_inode(NULL, root, path, &location, 0); 3361 if (ret) 3362 goto make_bad; 3363 3364 leaf = path->nodes[0]; 3365 3366 if (filled) 3367 goto cache_index; 3368 3369 inode_item = btrfs_item_ptr(leaf, path->slots[0], 3370 struct btrfs_inode_item); 3371 inode->i_mode = btrfs_inode_mode(leaf, inode_item); 3372 set_nlink(inode, btrfs_inode_nlink(leaf, inode_item)); 3373 i_uid_write(inode, btrfs_inode_uid(leaf, inode_item)); 3374 i_gid_write(inode, btrfs_inode_gid(leaf, inode_item)); 3375 btrfs_i_size_write(inode, btrfs_inode_size(leaf, inode_item)); 3376 3377 tspec = btrfs_inode_atime(inode_item); 3378 inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, tspec); 3379 inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, tspec); 3380 3381 tspec = btrfs_inode_mtime(inode_item); 3382 inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, tspec); 3383 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, tspec); 3384 3385 tspec = btrfs_inode_ctime(inode_item); 3386 inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, tspec); 3387 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, tspec); 3388 3389 inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item)); 3390 BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item); 3391 BTRFS_I(inode)->last_trans = btrfs_inode_transid(leaf, inode_item); 3392 3393 /* 3394 * If we were modified in the current generation and evicted from memory 3395 * and then re-read we need to do a full sync since we don't have any 3396 * idea about which extents were modified before we were evicted from 3397 * cache. 3398 */ 3399 if (BTRFS_I(inode)->last_trans == root->fs_info->generation) 3400 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, 3401 &BTRFS_I(inode)->runtime_flags); 3402 3403 inode->i_version = btrfs_inode_sequence(leaf, inode_item); 3404 inode->i_generation = BTRFS_I(inode)->generation; 3405 inode->i_rdev = 0; 3406 rdev = btrfs_inode_rdev(leaf, inode_item); 3407 3408 BTRFS_I(inode)->index_cnt = (u64)-1; 3409 BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item); 3410 3411 cache_index: 3412 path->slots[0]++; 3413 if (inode->i_nlink != 1 || 3414 path->slots[0] >= btrfs_header_nritems(leaf)) 3415 goto cache_acl; 3416 3417 btrfs_item_key_to_cpu(leaf, &location, path->slots[0]); 3418 if (location.objectid != btrfs_ino(inode)) 3419 goto cache_acl; 3420 3421 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); 3422 if (location.type == BTRFS_INODE_REF_KEY) { 3423 struct btrfs_inode_ref *ref; 3424 3425 ref = (struct btrfs_inode_ref *)ptr; 3426 BTRFS_I(inode)->dir_index = btrfs_inode_ref_index(leaf, ref); 3427 } else if (location.type == BTRFS_INODE_EXTREF_KEY) { 3428 struct btrfs_inode_extref *extref; 3429 3430 extref = (struct btrfs_inode_extref *)ptr; 3431 BTRFS_I(inode)->dir_index = btrfs_inode_extref_index(leaf, 3432 extref); 3433 } 3434 cache_acl: 3435 /* 3436 * try to precache a NULL acl entry for files that don't have 3437 * any xattrs or acls 3438 */ 3439 maybe_acls = acls_after_inode_item(leaf, path->slots[0], 3440 btrfs_ino(inode), &first_xattr_slot); 3441 if (first_xattr_slot != -1) { 3442 path->slots[0] = first_xattr_slot; 3443 ret = btrfs_load_inode_props(inode, path); 3444 if (ret) 3445 btrfs_err(root->fs_info, 3446 "error loading props for ino %llu (root %llu): %d\n", 3447 btrfs_ino(inode), 3448 root->root_key.objectid, ret); 3449 } 3450 btrfs_free_path(path); 3451 3452 if (!maybe_acls) 3453 cache_no_acl(inode); 3454 3455 switch (inode->i_mode & S_IFMT) { 3456 case S_IFREG: 3457 inode->i_mapping->a_ops = &btrfs_aops; 3458 inode->i_mapping->backing_dev_info = &root->fs_info->bdi; 3459 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops; 3460 inode->i_fop = &btrfs_file_operations; 3461 inode->i_op = &btrfs_file_inode_operations; 3462 break; 3463 case S_IFDIR: 3464 inode->i_fop = &btrfs_dir_file_operations; 3465 if (root == root->fs_info->tree_root) 3466 inode->i_op = &btrfs_dir_ro_inode_operations; 3467 else 3468 inode->i_op = &btrfs_dir_inode_operations; 3469 break; 3470 case S_IFLNK: 3471 inode->i_op = &btrfs_symlink_inode_operations; 3472 inode->i_mapping->a_ops = &btrfs_symlink_aops; 3473 inode->i_mapping->backing_dev_info = &root->fs_info->bdi; 3474 break; 3475 default: 3476 inode->i_op = &btrfs_special_inode_operations; 3477 init_special_inode(inode, inode->i_mode, rdev); 3478 break; 3479 } 3480 3481 btrfs_update_iflags(inode); 3482 return; 3483 3484 make_bad: 3485 btrfs_free_path(path); 3486 make_bad_inode(inode); 3487 } 3488 3489 /* 3490 * given a leaf and an inode, copy the inode fields into the leaf 3491 */ 3492 static void fill_inode_item(struct btrfs_trans_handle *trans, 3493 struct extent_buffer *leaf, 3494 struct btrfs_inode_item *item, 3495 struct inode *inode) 3496 { 3497 struct btrfs_map_token token; 3498 3499 btrfs_init_map_token(&token); 3500 3501 btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token); 3502 btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token); 3503 btrfs_set_token_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size, 3504 &token); 3505 btrfs_set_token_inode_mode(leaf, item, inode->i_mode, &token); 3506 btrfs_set_token_inode_nlink(leaf, item, inode->i_nlink, &token); 3507 3508 btrfs_set_token_timespec_sec(leaf, btrfs_inode_atime(item), 3509 inode->i_atime.tv_sec, &token); 3510 btrfs_set_token_timespec_nsec(leaf, btrfs_inode_atime(item), 3511 inode->i_atime.tv_nsec, &token); 3512 3513 btrfs_set_token_timespec_sec(leaf, btrfs_inode_mtime(item), 3514 inode->i_mtime.tv_sec, &token); 3515 btrfs_set_token_timespec_nsec(leaf, btrfs_inode_mtime(item), 3516 inode->i_mtime.tv_nsec, &token); 3517 3518 btrfs_set_token_timespec_sec(leaf, btrfs_inode_ctime(item), 3519 inode->i_ctime.tv_sec, &token); 3520 btrfs_set_token_timespec_nsec(leaf, btrfs_inode_ctime(item), 3521 inode->i_ctime.tv_nsec, &token); 3522 3523 btrfs_set_token_inode_nbytes(leaf, item, inode_get_bytes(inode), 3524 &token); 3525 btrfs_set_token_inode_generation(leaf, item, BTRFS_I(inode)->generation, 3526 &token); 3527 btrfs_set_token_inode_sequence(leaf, item, inode->i_version, &token); 3528 btrfs_set_token_inode_transid(leaf, item, trans->transid, &token); 3529 btrfs_set_token_inode_rdev(leaf, item, inode->i_rdev, &token); 3530 btrfs_set_token_inode_flags(leaf, item, BTRFS_I(inode)->flags, &token); 3531 btrfs_set_token_inode_block_group(leaf, item, 0, &token); 3532 } 3533 3534 /* 3535 * copy everything in the in-memory inode into the btree. 3536 */ 3537 static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans, 3538 struct btrfs_root *root, struct inode *inode) 3539 { 3540 struct btrfs_inode_item *inode_item; 3541 struct btrfs_path *path; 3542 struct extent_buffer *leaf; 3543 int ret; 3544 3545 path = btrfs_alloc_path(); 3546 if (!path) 3547 return -ENOMEM; 3548 3549 path->leave_spinning = 1; 3550 ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location, 3551 1); 3552 if (ret) { 3553 if (ret > 0) 3554 ret = -ENOENT; 3555 goto failed; 3556 } 3557 3558 leaf = path->nodes[0]; 3559 inode_item = btrfs_item_ptr(leaf, path->slots[0], 3560 struct btrfs_inode_item); 3561 3562 fill_inode_item(trans, leaf, inode_item, inode); 3563 btrfs_mark_buffer_dirty(leaf); 3564 btrfs_set_inode_last_trans(trans, inode); 3565 ret = 0; 3566 failed: 3567 btrfs_free_path(path); 3568 return ret; 3569 } 3570 3571 /* 3572 * copy everything in the in-memory inode into the btree. 3573 */ 3574 noinline int btrfs_update_inode(struct btrfs_trans_handle *trans, 3575 struct btrfs_root *root, struct inode *inode) 3576 { 3577 int ret; 3578 3579 /* 3580 * If the inode is a free space inode, we can deadlock during commit 3581 * if we put it into the delayed code. 3582 * 3583 * The data relocation inode should also be directly updated 3584 * without delay 3585 */ 3586 if (!btrfs_is_free_space_inode(inode) 3587 && root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID) { 3588 btrfs_update_root_times(trans, root); 3589 3590 ret = btrfs_delayed_update_inode(trans, root, inode); 3591 if (!ret) 3592 btrfs_set_inode_last_trans(trans, inode); 3593 return ret; 3594 } 3595 3596 return btrfs_update_inode_item(trans, root, inode); 3597 } 3598 3599 noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans, 3600 struct btrfs_root *root, 3601 struct inode *inode) 3602 { 3603 int ret; 3604 3605 ret = btrfs_update_inode(trans, root, inode); 3606 if (ret == -ENOSPC) 3607 return btrfs_update_inode_item(trans, root, inode); 3608 return ret; 3609 } 3610 3611 /* 3612 * unlink helper that gets used here in inode.c and in the tree logging 3613 * recovery code. It remove a link in a directory with a given name, and 3614 * also drops the back refs in the inode to the directory 3615 */ 3616 static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans, 3617 struct btrfs_root *root, 3618 struct inode *dir, struct inode *inode, 3619 const char *name, int name_len) 3620 { 3621 struct btrfs_path *path; 3622 int ret = 0; 3623 struct extent_buffer *leaf; 3624 struct btrfs_dir_item *di; 3625 struct btrfs_key key; 3626 u64 index; 3627 u64 ino = btrfs_ino(inode); 3628 u64 dir_ino = btrfs_ino(dir); 3629 3630 path = btrfs_alloc_path(); 3631 if (!path) { 3632 ret = -ENOMEM; 3633 goto out; 3634 } 3635 3636 path->leave_spinning = 1; 3637 di = btrfs_lookup_dir_item(trans, root, path, dir_ino, 3638 name, name_len, -1); 3639 if (IS_ERR(di)) { 3640 ret = PTR_ERR(di); 3641 goto err; 3642 } 3643 if (!di) { 3644 ret = -ENOENT; 3645 goto err; 3646 } 3647 leaf = path->nodes[0]; 3648 btrfs_dir_item_key_to_cpu(leaf, di, &key); 3649 ret = btrfs_delete_one_dir_name(trans, root, path, di); 3650 if (ret) 3651 goto err; 3652 btrfs_release_path(path); 3653 3654 /* 3655 * If we don't have dir index, we have to get it by looking up 3656 * the inode ref, since we get the inode ref, remove it directly, 3657 * it is unnecessary to do delayed deletion. 3658 * 3659 * But if we have dir index, needn't search inode ref to get it. 3660 * Since the inode ref is close to the inode item, it is better 3661 * that we delay to delete it, and just do this deletion when 3662 * we update the inode item. 3663 */ 3664 if (BTRFS_I(inode)->dir_index) { 3665 ret = btrfs_delayed_delete_inode_ref(inode); 3666 if (!ret) { 3667 index = BTRFS_I(inode)->dir_index; 3668 goto skip_backref; 3669 } 3670 } 3671 3672 ret = btrfs_del_inode_ref(trans, root, name, name_len, ino, 3673 dir_ino, &index); 3674 if (ret) { 3675 btrfs_info(root->fs_info, 3676 "failed to delete reference to %.*s, inode %llu parent %llu", 3677 name_len, name, ino, dir_ino); 3678 btrfs_abort_transaction(trans, root, ret); 3679 goto err; 3680 } 3681 skip_backref: 3682 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index); 3683 if (ret) { 3684 btrfs_abort_transaction(trans, root, ret); 3685 goto err; 3686 } 3687 3688 ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len, 3689 inode, dir_ino); 3690 if (ret != 0 && ret != -ENOENT) { 3691 btrfs_abort_transaction(trans, root, ret); 3692 goto err; 3693 } 3694 3695 ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len, 3696 dir, index); 3697 if (ret == -ENOENT) 3698 ret = 0; 3699 else if (ret) 3700 btrfs_abort_transaction(trans, root, ret); 3701 err: 3702 btrfs_free_path(path); 3703 if (ret) 3704 goto out; 3705 3706 btrfs_i_size_write(dir, dir->i_size - name_len * 2); 3707 inode_inc_iversion(inode); 3708 inode_inc_iversion(dir); 3709 inode->i_ctime = dir->i_mtime = dir->i_ctime = CURRENT_TIME; 3710 ret = btrfs_update_inode(trans, root, dir); 3711 out: 3712 return ret; 3713 } 3714 3715 int btrfs_unlink_inode(struct btrfs_trans_handle *trans, 3716 struct btrfs_root *root, 3717 struct inode *dir, struct inode *inode, 3718 const char *name, int name_len) 3719 { 3720 int ret; 3721 ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len); 3722 if (!ret) { 3723 drop_nlink(inode); 3724 ret = btrfs_update_inode(trans, root, inode); 3725 } 3726 return ret; 3727 } 3728 3729 /* 3730 * helper to start transaction for unlink and rmdir. 3731 * 3732 * unlink and rmdir are special in btrfs, they do not always free space, so 3733 * if we cannot make our reservations the normal way try and see if there is 3734 * plenty of slack room in the global reserve to migrate, otherwise we cannot 3735 * allow the unlink to occur. 3736 */ 3737 static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir) 3738 { 3739 struct btrfs_trans_handle *trans; 3740 struct btrfs_root *root = BTRFS_I(dir)->root; 3741 int ret; 3742 3743 /* 3744 * 1 for the possible orphan item 3745 * 1 for the dir item 3746 * 1 for the dir index 3747 * 1 for the inode ref 3748 * 1 for the inode 3749 */ 3750 trans = btrfs_start_transaction(root, 5); 3751 if (!IS_ERR(trans) || PTR_ERR(trans) != -ENOSPC) 3752 return trans; 3753 3754 if (PTR_ERR(trans) == -ENOSPC) { 3755 u64 num_bytes = btrfs_calc_trans_metadata_size(root, 5); 3756 3757 trans = btrfs_start_transaction(root, 0); 3758 if (IS_ERR(trans)) 3759 return trans; 3760 ret = btrfs_cond_migrate_bytes(root->fs_info, 3761 &root->fs_info->trans_block_rsv, 3762 num_bytes, 5); 3763 if (ret) { 3764 btrfs_end_transaction(trans, root); 3765 return ERR_PTR(ret); 3766 } 3767 trans->block_rsv = &root->fs_info->trans_block_rsv; 3768 trans->bytes_reserved = num_bytes; 3769 } 3770 return trans; 3771 } 3772 3773 static int btrfs_unlink(struct inode *dir, struct dentry *dentry) 3774 { 3775 struct btrfs_root *root = BTRFS_I(dir)->root; 3776 struct btrfs_trans_handle *trans; 3777 struct inode *inode = dentry->d_inode; 3778 int ret; 3779 3780 trans = __unlink_start_trans(dir); 3781 if (IS_ERR(trans)) 3782 return PTR_ERR(trans); 3783 3784 btrfs_record_unlink_dir(trans, dir, dentry->d_inode, 0); 3785 3786 ret = btrfs_unlink_inode(trans, root, dir, dentry->d_inode, 3787 dentry->d_name.name, dentry->d_name.len); 3788 if (ret) 3789 goto out; 3790 3791 if (inode->i_nlink == 0) { 3792 ret = btrfs_orphan_add(trans, inode); 3793 if (ret) 3794 goto out; 3795 } 3796 3797 out: 3798 btrfs_end_transaction(trans, root); 3799 btrfs_btree_balance_dirty(root); 3800 return ret; 3801 } 3802 3803 int btrfs_unlink_subvol(struct btrfs_trans_handle *trans, 3804 struct btrfs_root *root, 3805 struct inode *dir, u64 objectid, 3806 const char *name, int name_len) 3807 { 3808 struct btrfs_path *path; 3809 struct extent_buffer *leaf; 3810 struct btrfs_dir_item *di; 3811 struct btrfs_key key; 3812 u64 index; 3813 int ret; 3814 u64 dir_ino = btrfs_ino(dir); 3815 3816 path = btrfs_alloc_path(); 3817 if (!path) 3818 return -ENOMEM; 3819 3820 di = btrfs_lookup_dir_item(trans, root, path, dir_ino, 3821 name, name_len, -1); 3822 if (IS_ERR_OR_NULL(di)) { 3823 if (!di) 3824 ret = -ENOENT; 3825 else 3826 ret = PTR_ERR(di); 3827 goto out; 3828 } 3829 3830 leaf = path->nodes[0]; 3831 btrfs_dir_item_key_to_cpu(leaf, di, &key); 3832 WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid); 3833 ret = btrfs_delete_one_dir_name(trans, root, path, di); 3834 if (ret) { 3835 btrfs_abort_transaction(trans, root, ret); 3836 goto out; 3837 } 3838 btrfs_release_path(path); 3839 3840 ret = btrfs_del_root_ref(trans, root->fs_info->tree_root, 3841 objectid, root->root_key.objectid, 3842 dir_ino, &index, name, name_len); 3843 if (ret < 0) { 3844 if (ret != -ENOENT) { 3845 btrfs_abort_transaction(trans, root, ret); 3846 goto out; 3847 } 3848 di = btrfs_search_dir_index_item(root, path, dir_ino, 3849 name, name_len); 3850 if (IS_ERR_OR_NULL(di)) { 3851 if (!di) 3852 ret = -ENOENT; 3853 else 3854 ret = PTR_ERR(di); 3855 btrfs_abort_transaction(trans, root, ret); 3856 goto out; 3857 } 3858 3859 leaf = path->nodes[0]; 3860 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); 3861 btrfs_release_path(path); 3862 index = key.offset; 3863 } 3864 btrfs_release_path(path); 3865 3866 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index); 3867 if (ret) { 3868 btrfs_abort_transaction(trans, root, ret); 3869 goto out; 3870 } 3871 3872 btrfs_i_size_write(dir, dir->i_size - name_len * 2); 3873 inode_inc_iversion(dir); 3874 dir->i_mtime = dir->i_ctime = CURRENT_TIME; 3875 ret = btrfs_update_inode_fallback(trans, root, dir); 3876 if (ret) 3877 btrfs_abort_transaction(trans, root, ret); 3878 out: 3879 btrfs_free_path(path); 3880 return ret; 3881 } 3882 3883 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry) 3884 { 3885 struct inode *inode = dentry->d_inode; 3886 int err = 0; 3887 struct btrfs_root *root = BTRFS_I(dir)->root; 3888 struct btrfs_trans_handle *trans; 3889 3890 if (inode->i_size > BTRFS_EMPTY_DIR_SIZE) 3891 return -ENOTEMPTY; 3892 if (btrfs_ino(inode) == BTRFS_FIRST_FREE_OBJECTID) 3893 return -EPERM; 3894 3895 trans = __unlink_start_trans(dir); 3896 if (IS_ERR(trans)) 3897 return PTR_ERR(trans); 3898 3899 if (unlikely(btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) { 3900 err = btrfs_unlink_subvol(trans, root, dir, 3901 BTRFS_I(inode)->location.objectid, 3902 dentry->d_name.name, 3903 dentry->d_name.len); 3904 goto out; 3905 } 3906 3907 err = btrfs_orphan_add(trans, inode); 3908 if (err) 3909 goto out; 3910 3911 /* now the directory is empty */ 3912 err = btrfs_unlink_inode(trans, root, dir, dentry->d_inode, 3913 dentry->d_name.name, dentry->d_name.len); 3914 if (!err) 3915 btrfs_i_size_write(inode, 0); 3916 out: 3917 btrfs_end_transaction(trans, root); 3918 btrfs_btree_balance_dirty(root); 3919 3920 return err; 3921 } 3922 3923 /* 3924 * this can truncate away extent items, csum items and directory items. 3925 * It starts at a high offset and removes keys until it can't find 3926 * any higher than new_size 3927 * 3928 * csum items that cross the new i_size are truncated to the new size 3929 * as well. 3930 * 3931 * min_type is the minimum key type to truncate down to. If set to 0, this 3932 * will kill all the items on this inode, including the INODE_ITEM_KEY. 3933 */ 3934 int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans, 3935 struct btrfs_root *root, 3936 struct inode *inode, 3937 u64 new_size, u32 min_type) 3938 { 3939 struct btrfs_path *path; 3940 struct extent_buffer *leaf; 3941 struct btrfs_file_extent_item *fi; 3942 struct btrfs_key key; 3943 struct btrfs_key found_key; 3944 u64 extent_start = 0; 3945 u64 extent_num_bytes = 0; 3946 u64 extent_offset = 0; 3947 u64 item_end = 0; 3948 u64 last_size = (u64)-1; 3949 u32 found_type = (u8)-1; 3950 int found_extent; 3951 int del_item; 3952 int pending_del_nr = 0; 3953 int pending_del_slot = 0; 3954 int extent_type = -1; 3955 int ret; 3956 int err = 0; 3957 u64 ino = btrfs_ino(inode); 3958 3959 BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY); 3960 3961 path = btrfs_alloc_path(); 3962 if (!path) 3963 return -ENOMEM; 3964 path->reada = -1; 3965 3966 /* 3967 * We want to drop from the next block forward in case this new size is 3968 * not block aligned since we will be keeping the last block of the 3969 * extent just the way it is. 3970 */ 3971 if (root->ref_cows || root == root->fs_info->tree_root) 3972 btrfs_drop_extent_cache(inode, ALIGN(new_size, 3973 root->sectorsize), (u64)-1, 0); 3974 3975 /* 3976 * This function is also used to drop the items in the log tree before 3977 * we relog the inode, so if root != BTRFS_I(inode)->root, it means 3978 * it is used to drop the loged items. So we shouldn't kill the delayed 3979 * items. 3980 */ 3981 if (min_type == 0 && root == BTRFS_I(inode)->root) 3982 btrfs_kill_delayed_inode_items(inode); 3983 3984 key.objectid = ino; 3985 key.offset = (u64)-1; 3986 key.type = (u8)-1; 3987 3988 search_again: 3989 path->leave_spinning = 1; 3990 ret = btrfs_search_slot(trans, root, &key, path, -1, 1); 3991 if (ret < 0) { 3992 err = ret; 3993 goto out; 3994 } 3995 3996 if (ret > 0) { 3997 /* there are no items in the tree for us to truncate, we're 3998 * done 3999 */ 4000 if (path->slots[0] == 0) 4001 goto out; 4002 path->slots[0]--; 4003 } 4004 4005 while (1) { 4006 fi = NULL; 4007 leaf = path->nodes[0]; 4008 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 4009 found_type = btrfs_key_type(&found_key); 4010 4011 if (found_key.objectid != ino) 4012 break; 4013 4014 if (found_type < min_type) 4015 break; 4016 4017 item_end = found_key.offset; 4018 if (found_type == BTRFS_EXTENT_DATA_KEY) { 4019 fi = btrfs_item_ptr(leaf, path->slots[0], 4020 struct btrfs_file_extent_item); 4021 extent_type = btrfs_file_extent_type(leaf, fi); 4022 if (extent_type != BTRFS_FILE_EXTENT_INLINE) { 4023 item_end += 4024 btrfs_file_extent_num_bytes(leaf, fi); 4025 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { 4026 item_end += btrfs_file_extent_inline_len(leaf, 4027 path->slots[0], fi); 4028 } 4029 item_end--; 4030 } 4031 if (found_type > min_type) { 4032 del_item = 1; 4033 } else { 4034 if (item_end < new_size) 4035 break; 4036 if (found_key.offset >= new_size) 4037 del_item = 1; 4038 else 4039 del_item = 0; 4040 } 4041 found_extent = 0; 4042 /* FIXME, shrink the extent if the ref count is only 1 */ 4043 if (found_type != BTRFS_EXTENT_DATA_KEY) 4044 goto delete; 4045 4046 if (del_item) 4047 last_size = found_key.offset; 4048 else 4049 last_size = new_size; 4050 4051 if (extent_type != BTRFS_FILE_EXTENT_INLINE) { 4052 u64 num_dec; 4053 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi); 4054 if (!del_item) { 4055 u64 orig_num_bytes = 4056 btrfs_file_extent_num_bytes(leaf, fi); 4057 extent_num_bytes = ALIGN(new_size - 4058 found_key.offset, 4059 root->sectorsize); 4060 btrfs_set_file_extent_num_bytes(leaf, fi, 4061 extent_num_bytes); 4062 num_dec = (orig_num_bytes - 4063 extent_num_bytes); 4064 if (root->ref_cows && extent_start != 0) 4065 inode_sub_bytes(inode, num_dec); 4066 btrfs_mark_buffer_dirty(leaf); 4067 } else { 4068 extent_num_bytes = 4069 btrfs_file_extent_disk_num_bytes(leaf, 4070 fi); 4071 extent_offset = found_key.offset - 4072 btrfs_file_extent_offset(leaf, fi); 4073 4074 /* FIXME blocksize != 4096 */ 4075 num_dec = btrfs_file_extent_num_bytes(leaf, fi); 4076 if (extent_start != 0) { 4077 found_extent = 1; 4078 if (root->ref_cows) 4079 inode_sub_bytes(inode, num_dec); 4080 } 4081 } 4082 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { 4083 /* 4084 * we can't truncate inline items that have had 4085 * special encodings 4086 */ 4087 if (!del_item && 4088 btrfs_file_extent_compression(leaf, fi) == 0 && 4089 btrfs_file_extent_encryption(leaf, fi) == 0 && 4090 btrfs_file_extent_other_encoding(leaf, fi) == 0) { 4091 u32 size = new_size - found_key.offset; 4092 4093 if (root->ref_cows) { 4094 inode_sub_bytes(inode, item_end + 1 - 4095 new_size); 4096 } 4097 4098 /* 4099 * update the ram bytes to properly reflect 4100 * the new size of our item 4101 */ 4102 btrfs_set_file_extent_ram_bytes(leaf, fi, size); 4103 size = 4104 btrfs_file_extent_calc_inline_size(size); 4105 btrfs_truncate_item(root, path, size, 1); 4106 } else if (root->ref_cows) { 4107 inode_sub_bytes(inode, item_end + 1 - 4108 found_key.offset); 4109 } 4110 } 4111 delete: 4112 if (del_item) { 4113 if (!pending_del_nr) { 4114 /* no pending yet, add ourselves */ 4115 pending_del_slot = path->slots[0]; 4116 pending_del_nr = 1; 4117 } else if (pending_del_nr && 4118 path->slots[0] + 1 == pending_del_slot) { 4119 /* hop on the pending chunk */ 4120 pending_del_nr++; 4121 pending_del_slot = path->slots[0]; 4122 } else { 4123 BUG(); 4124 } 4125 } else { 4126 break; 4127 } 4128 if (found_extent && (root->ref_cows || 4129 root == root->fs_info->tree_root)) { 4130 btrfs_set_path_blocking(path); 4131 ret = btrfs_free_extent(trans, root, extent_start, 4132 extent_num_bytes, 0, 4133 btrfs_header_owner(leaf), 4134 ino, extent_offset, 0); 4135 BUG_ON(ret); 4136 } 4137 4138 if (found_type == BTRFS_INODE_ITEM_KEY) 4139 break; 4140 4141 if (path->slots[0] == 0 || 4142 path->slots[0] != pending_del_slot) { 4143 if (pending_del_nr) { 4144 ret = btrfs_del_items(trans, root, path, 4145 pending_del_slot, 4146 pending_del_nr); 4147 if (ret) { 4148 btrfs_abort_transaction(trans, 4149 root, ret); 4150 goto error; 4151 } 4152 pending_del_nr = 0; 4153 } 4154 btrfs_release_path(path); 4155 goto search_again; 4156 } else { 4157 path->slots[0]--; 4158 } 4159 } 4160 out: 4161 if (pending_del_nr) { 4162 ret = btrfs_del_items(trans, root, path, pending_del_slot, 4163 pending_del_nr); 4164 if (ret) 4165 btrfs_abort_transaction(trans, root, ret); 4166 } 4167 error: 4168 if (last_size != (u64)-1) 4169 btrfs_ordered_update_i_size(inode, last_size, NULL); 4170 btrfs_free_path(path); 4171 return err; 4172 } 4173 4174 /* 4175 * btrfs_truncate_page - read, zero a chunk and write a page 4176 * @inode - inode that we're zeroing 4177 * @from - the offset to start zeroing 4178 * @len - the length to zero, 0 to zero the entire range respective to the 4179 * offset 4180 * @front - zero up to the offset instead of from the offset on 4181 * 4182 * This will find the page for the "from" offset and cow the page and zero the 4183 * part we want to zero. This is used with truncate and hole punching. 4184 */ 4185 int btrfs_truncate_page(struct inode *inode, loff_t from, loff_t len, 4186 int front) 4187 { 4188 struct address_space *mapping = inode->i_mapping; 4189 struct btrfs_root *root = BTRFS_I(inode)->root; 4190 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 4191 struct btrfs_ordered_extent *ordered; 4192 struct extent_state *cached_state = NULL; 4193 char *kaddr; 4194 u32 blocksize = root->sectorsize; 4195 pgoff_t index = from >> PAGE_CACHE_SHIFT; 4196 unsigned offset = from & (PAGE_CACHE_SIZE-1); 4197 struct page *page; 4198 gfp_t mask = btrfs_alloc_write_mask(mapping); 4199 int ret = 0; 4200 u64 page_start; 4201 u64 page_end; 4202 4203 if ((offset & (blocksize - 1)) == 0 && 4204 (!len || ((len & (blocksize - 1)) == 0))) 4205 goto out; 4206 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE); 4207 if (ret) 4208 goto out; 4209 4210 again: 4211 page = find_or_create_page(mapping, index, mask); 4212 if (!page) { 4213 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE); 4214 ret = -ENOMEM; 4215 goto out; 4216 } 4217 4218 page_start = page_offset(page); 4219 page_end = page_start + PAGE_CACHE_SIZE - 1; 4220 4221 if (!PageUptodate(page)) { 4222 ret = btrfs_readpage(NULL, page); 4223 lock_page(page); 4224 if (page->mapping != mapping) { 4225 unlock_page(page); 4226 page_cache_release(page); 4227 goto again; 4228 } 4229 if (!PageUptodate(page)) { 4230 ret = -EIO; 4231 goto out_unlock; 4232 } 4233 } 4234 wait_on_page_writeback(page); 4235 4236 lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state); 4237 set_page_extent_mapped(page); 4238 4239 ordered = btrfs_lookup_ordered_extent(inode, page_start); 4240 if (ordered) { 4241 unlock_extent_cached(io_tree, page_start, page_end, 4242 &cached_state, GFP_NOFS); 4243 unlock_page(page); 4244 page_cache_release(page); 4245 btrfs_start_ordered_extent(inode, ordered, 1); 4246 btrfs_put_ordered_extent(ordered); 4247 goto again; 4248 } 4249 4250 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end, 4251 EXTENT_DIRTY | EXTENT_DELALLOC | 4252 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 4253 0, 0, &cached_state, GFP_NOFS); 4254 4255 ret = btrfs_set_extent_delalloc(inode, page_start, page_end, 4256 &cached_state); 4257 if (ret) { 4258 unlock_extent_cached(io_tree, page_start, page_end, 4259 &cached_state, GFP_NOFS); 4260 goto out_unlock; 4261 } 4262 4263 if (offset != PAGE_CACHE_SIZE) { 4264 if (!len) 4265 len = PAGE_CACHE_SIZE - offset; 4266 kaddr = kmap(page); 4267 if (front) 4268 memset(kaddr, 0, offset); 4269 else 4270 memset(kaddr + offset, 0, len); 4271 flush_dcache_page(page); 4272 kunmap(page); 4273 } 4274 ClearPageChecked(page); 4275 set_page_dirty(page); 4276 unlock_extent_cached(io_tree, page_start, page_end, &cached_state, 4277 GFP_NOFS); 4278 4279 out_unlock: 4280 if (ret) 4281 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE); 4282 unlock_page(page); 4283 page_cache_release(page); 4284 out: 4285 return ret; 4286 } 4287 4288 static int maybe_insert_hole(struct btrfs_root *root, struct inode *inode, 4289 u64 offset, u64 len) 4290 { 4291 struct btrfs_trans_handle *trans; 4292 int ret; 4293 4294 /* 4295 * Still need to make sure the inode looks like it's been updated so 4296 * that any holes get logged if we fsync. 4297 */ 4298 if (btrfs_fs_incompat(root->fs_info, NO_HOLES)) { 4299 BTRFS_I(inode)->last_trans = root->fs_info->generation; 4300 BTRFS_I(inode)->last_sub_trans = root->log_transid; 4301 BTRFS_I(inode)->last_log_commit = root->last_log_commit; 4302 return 0; 4303 } 4304 4305 /* 4306 * 1 - for the one we're dropping 4307 * 1 - for the one we're adding 4308 * 1 - for updating the inode. 4309 */ 4310 trans = btrfs_start_transaction(root, 3); 4311 if (IS_ERR(trans)) 4312 return PTR_ERR(trans); 4313 4314 ret = btrfs_drop_extents(trans, root, inode, offset, offset + len, 1); 4315 if (ret) { 4316 btrfs_abort_transaction(trans, root, ret); 4317 btrfs_end_transaction(trans, root); 4318 return ret; 4319 } 4320 4321 ret = btrfs_insert_file_extent(trans, root, btrfs_ino(inode), offset, 4322 0, 0, len, 0, len, 0, 0, 0); 4323 if (ret) 4324 btrfs_abort_transaction(trans, root, ret); 4325 else 4326 btrfs_update_inode(trans, root, inode); 4327 btrfs_end_transaction(trans, root); 4328 return ret; 4329 } 4330 4331 /* 4332 * This function puts in dummy file extents for the area we're creating a hole 4333 * for. So if we are truncating this file to a larger size we need to insert 4334 * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for 4335 * the range between oldsize and size 4336 */ 4337 int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size) 4338 { 4339 struct btrfs_root *root = BTRFS_I(inode)->root; 4340 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 4341 struct extent_map *em = NULL; 4342 struct extent_state *cached_state = NULL; 4343 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; 4344 u64 hole_start = ALIGN(oldsize, root->sectorsize); 4345 u64 block_end = ALIGN(size, root->sectorsize); 4346 u64 last_byte; 4347 u64 cur_offset; 4348 u64 hole_size; 4349 int err = 0; 4350 4351 /* 4352 * If our size started in the middle of a page we need to zero out the 4353 * rest of the page before we expand the i_size, otherwise we could 4354 * expose stale data. 4355 */ 4356 err = btrfs_truncate_page(inode, oldsize, 0, 0); 4357 if (err) 4358 return err; 4359 4360 if (size <= hole_start) 4361 return 0; 4362 4363 while (1) { 4364 struct btrfs_ordered_extent *ordered; 4365 4366 lock_extent_bits(io_tree, hole_start, block_end - 1, 0, 4367 &cached_state); 4368 ordered = btrfs_lookup_ordered_range(inode, hole_start, 4369 block_end - hole_start); 4370 if (!ordered) 4371 break; 4372 unlock_extent_cached(io_tree, hole_start, block_end - 1, 4373 &cached_state, GFP_NOFS); 4374 btrfs_start_ordered_extent(inode, ordered, 1); 4375 btrfs_put_ordered_extent(ordered); 4376 } 4377 4378 cur_offset = hole_start; 4379 while (1) { 4380 em = btrfs_get_extent(inode, NULL, 0, cur_offset, 4381 block_end - cur_offset, 0); 4382 if (IS_ERR(em)) { 4383 err = PTR_ERR(em); 4384 em = NULL; 4385 break; 4386 } 4387 last_byte = min(extent_map_end(em), block_end); 4388 last_byte = ALIGN(last_byte , root->sectorsize); 4389 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) { 4390 struct extent_map *hole_em; 4391 hole_size = last_byte - cur_offset; 4392 4393 err = maybe_insert_hole(root, inode, cur_offset, 4394 hole_size); 4395 if (err) 4396 break; 4397 btrfs_drop_extent_cache(inode, cur_offset, 4398 cur_offset + hole_size - 1, 0); 4399 hole_em = alloc_extent_map(); 4400 if (!hole_em) { 4401 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, 4402 &BTRFS_I(inode)->runtime_flags); 4403 goto next; 4404 } 4405 hole_em->start = cur_offset; 4406 hole_em->len = hole_size; 4407 hole_em->orig_start = cur_offset; 4408 4409 hole_em->block_start = EXTENT_MAP_HOLE; 4410 hole_em->block_len = 0; 4411 hole_em->orig_block_len = 0; 4412 hole_em->ram_bytes = hole_size; 4413 hole_em->bdev = root->fs_info->fs_devices->latest_bdev; 4414 hole_em->compress_type = BTRFS_COMPRESS_NONE; 4415 hole_em->generation = root->fs_info->generation; 4416 4417 while (1) { 4418 write_lock(&em_tree->lock); 4419 err = add_extent_mapping(em_tree, hole_em, 1); 4420 write_unlock(&em_tree->lock); 4421 if (err != -EEXIST) 4422 break; 4423 btrfs_drop_extent_cache(inode, cur_offset, 4424 cur_offset + 4425 hole_size - 1, 0); 4426 } 4427 free_extent_map(hole_em); 4428 } 4429 next: 4430 free_extent_map(em); 4431 em = NULL; 4432 cur_offset = last_byte; 4433 if (cur_offset >= block_end) 4434 break; 4435 } 4436 free_extent_map(em); 4437 unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state, 4438 GFP_NOFS); 4439 return err; 4440 } 4441 4442 static int btrfs_setsize(struct inode *inode, struct iattr *attr) 4443 { 4444 struct btrfs_root *root = BTRFS_I(inode)->root; 4445 struct btrfs_trans_handle *trans; 4446 loff_t oldsize = i_size_read(inode); 4447 loff_t newsize = attr->ia_size; 4448 int mask = attr->ia_valid; 4449 int ret; 4450 4451 /* 4452 * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a 4453 * special case where we need to update the times despite not having 4454 * these flags set. For all other operations the VFS set these flags 4455 * explicitly if it wants a timestamp update. 4456 */ 4457 if (newsize != oldsize) { 4458 inode_inc_iversion(inode); 4459 if (!(mask & (ATTR_CTIME | ATTR_MTIME))) 4460 inode->i_ctime = inode->i_mtime = 4461 current_fs_time(inode->i_sb); 4462 } 4463 4464 if (newsize > oldsize) { 4465 truncate_pagecache(inode, newsize); 4466 ret = btrfs_cont_expand(inode, oldsize, newsize); 4467 if (ret) 4468 return ret; 4469 4470 trans = btrfs_start_transaction(root, 1); 4471 if (IS_ERR(trans)) 4472 return PTR_ERR(trans); 4473 4474 i_size_write(inode, newsize); 4475 btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL); 4476 ret = btrfs_update_inode(trans, root, inode); 4477 btrfs_end_transaction(trans, root); 4478 } else { 4479 4480 /* 4481 * We're truncating a file that used to have good data down to 4482 * zero. Make sure it gets into the ordered flush list so that 4483 * any new writes get down to disk quickly. 4484 */ 4485 if (newsize == 0) 4486 set_bit(BTRFS_INODE_ORDERED_DATA_CLOSE, 4487 &BTRFS_I(inode)->runtime_flags); 4488 4489 /* 4490 * 1 for the orphan item we're going to add 4491 * 1 for the orphan item deletion. 4492 */ 4493 trans = btrfs_start_transaction(root, 2); 4494 if (IS_ERR(trans)) 4495 return PTR_ERR(trans); 4496 4497 /* 4498 * We need to do this in case we fail at _any_ point during the 4499 * actual truncate. Once we do the truncate_setsize we could 4500 * invalidate pages which forces any outstanding ordered io to 4501 * be instantly completed which will give us extents that need 4502 * to be truncated. If we fail to get an orphan inode down we 4503 * could have left over extents that were never meant to live, 4504 * so we need to garuntee from this point on that everything 4505 * will be consistent. 4506 */ 4507 ret = btrfs_orphan_add(trans, inode); 4508 btrfs_end_transaction(trans, root); 4509 if (ret) 4510 return ret; 4511 4512 /* we don't support swapfiles, so vmtruncate shouldn't fail */ 4513 truncate_setsize(inode, newsize); 4514 4515 /* Disable nonlocked read DIO to avoid the end less truncate */ 4516 btrfs_inode_block_unlocked_dio(inode); 4517 inode_dio_wait(inode); 4518 btrfs_inode_resume_unlocked_dio(inode); 4519 4520 ret = btrfs_truncate(inode); 4521 if (ret && inode->i_nlink) { 4522 int err; 4523 4524 /* 4525 * failed to truncate, disk_i_size is only adjusted down 4526 * as we remove extents, so it should represent the true 4527 * size of the inode, so reset the in memory size and 4528 * delete our orphan entry. 4529 */ 4530 trans = btrfs_join_transaction(root); 4531 if (IS_ERR(trans)) { 4532 btrfs_orphan_del(NULL, inode); 4533 return ret; 4534 } 4535 i_size_write(inode, BTRFS_I(inode)->disk_i_size); 4536 err = btrfs_orphan_del(trans, inode); 4537 if (err) 4538 btrfs_abort_transaction(trans, root, err); 4539 btrfs_end_transaction(trans, root); 4540 } 4541 } 4542 4543 return ret; 4544 } 4545 4546 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr) 4547 { 4548 struct inode *inode = dentry->d_inode; 4549 struct btrfs_root *root = BTRFS_I(inode)->root; 4550 int err; 4551 4552 if (btrfs_root_readonly(root)) 4553 return -EROFS; 4554 4555 err = inode_change_ok(inode, attr); 4556 if (err) 4557 return err; 4558 4559 if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) { 4560 err = btrfs_setsize(inode, attr); 4561 if (err) 4562 return err; 4563 } 4564 4565 if (attr->ia_valid) { 4566 setattr_copy(inode, attr); 4567 inode_inc_iversion(inode); 4568 err = btrfs_dirty_inode(inode); 4569 4570 if (!err && attr->ia_valid & ATTR_MODE) 4571 err = posix_acl_chmod(inode, inode->i_mode); 4572 } 4573 4574 return err; 4575 } 4576 4577 /* 4578 * While truncating the inode pages during eviction, we get the VFS calling 4579 * btrfs_invalidatepage() against each page of the inode. This is slow because 4580 * the calls to btrfs_invalidatepage() result in a huge amount of calls to 4581 * lock_extent_bits() and clear_extent_bit(), which keep merging and splitting 4582 * extent_state structures over and over, wasting lots of time. 4583 * 4584 * Therefore if the inode is being evicted, let btrfs_invalidatepage() skip all 4585 * those expensive operations on a per page basis and do only the ordered io 4586 * finishing, while we release here the extent_map and extent_state structures, 4587 * without the excessive merging and splitting. 4588 */ 4589 static void evict_inode_truncate_pages(struct inode *inode) 4590 { 4591 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 4592 struct extent_map_tree *map_tree = &BTRFS_I(inode)->extent_tree; 4593 struct rb_node *node; 4594 4595 ASSERT(inode->i_state & I_FREEING); 4596 truncate_inode_pages(&inode->i_data, 0); 4597 4598 write_lock(&map_tree->lock); 4599 while (!RB_EMPTY_ROOT(&map_tree->map)) { 4600 struct extent_map *em; 4601 4602 node = rb_first(&map_tree->map); 4603 em = rb_entry(node, struct extent_map, rb_node); 4604 clear_bit(EXTENT_FLAG_PINNED, &em->flags); 4605 clear_bit(EXTENT_FLAG_LOGGING, &em->flags); 4606 remove_extent_mapping(map_tree, em); 4607 free_extent_map(em); 4608 } 4609 write_unlock(&map_tree->lock); 4610 4611 spin_lock(&io_tree->lock); 4612 while (!RB_EMPTY_ROOT(&io_tree->state)) { 4613 struct extent_state *state; 4614 struct extent_state *cached_state = NULL; 4615 4616 node = rb_first(&io_tree->state); 4617 state = rb_entry(node, struct extent_state, rb_node); 4618 atomic_inc(&state->refs); 4619 spin_unlock(&io_tree->lock); 4620 4621 lock_extent_bits(io_tree, state->start, state->end, 4622 0, &cached_state); 4623 clear_extent_bit(io_tree, state->start, state->end, 4624 EXTENT_LOCKED | EXTENT_DIRTY | 4625 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING | 4626 EXTENT_DEFRAG, 1, 1, 4627 &cached_state, GFP_NOFS); 4628 free_extent_state(state); 4629 4630 spin_lock(&io_tree->lock); 4631 } 4632 spin_unlock(&io_tree->lock); 4633 } 4634 4635 void btrfs_evict_inode(struct inode *inode) 4636 { 4637 struct btrfs_trans_handle *trans; 4638 struct btrfs_root *root = BTRFS_I(inode)->root; 4639 struct btrfs_block_rsv *rsv, *global_rsv; 4640 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1); 4641 int ret; 4642 4643 trace_btrfs_inode_evict(inode); 4644 4645 evict_inode_truncate_pages(inode); 4646 4647 if (inode->i_nlink && 4648 ((btrfs_root_refs(&root->root_item) != 0 && 4649 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID) || 4650 btrfs_is_free_space_inode(inode))) 4651 goto no_delete; 4652 4653 if (is_bad_inode(inode)) { 4654 btrfs_orphan_del(NULL, inode); 4655 goto no_delete; 4656 } 4657 /* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */ 4658 btrfs_wait_ordered_range(inode, 0, (u64)-1); 4659 4660 if (root->fs_info->log_root_recovering) { 4661 BUG_ON(test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM, 4662 &BTRFS_I(inode)->runtime_flags)); 4663 goto no_delete; 4664 } 4665 4666 if (inode->i_nlink > 0) { 4667 BUG_ON(btrfs_root_refs(&root->root_item) != 0 && 4668 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID); 4669 goto no_delete; 4670 } 4671 4672 ret = btrfs_commit_inode_delayed_inode(inode); 4673 if (ret) { 4674 btrfs_orphan_del(NULL, inode); 4675 goto no_delete; 4676 } 4677 4678 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP); 4679 if (!rsv) { 4680 btrfs_orphan_del(NULL, inode); 4681 goto no_delete; 4682 } 4683 rsv->size = min_size; 4684 rsv->failfast = 1; 4685 global_rsv = &root->fs_info->global_block_rsv; 4686 4687 btrfs_i_size_write(inode, 0); 4688 4689 /* 4690 * This is a bit simpler than btrfs_truncate since we've already 4691 * reserved our space for our orphan item in the unlink, so we just 4692 * need to reserve some slack space in case we add bytes and update 4693 * inode item when doing the truncate. 4694 */ 4695 while (1) { 4696 ret = btrfs_block_rsv_refill(root, rsv, min_size, 4697 BTRFS_RESERVE_FLUSH_LIMIT); 4698 4699 /* 4700 * Try and steal from the global reserve since we will 4701 * likely not use this space anyway, we want to try as 4702 * hard as possible to get this to work. 4703 */ 4704 if (ret) 4705 ret = btrfs_block_rsv_migrate(global_rsv, rsv, min_size); 4706 4707 if (ret) { 4708 btrfs_warn(root->fs_info, 4709 "Could not get space for a delete, will truncate on mount %d", 4710 ret); 4711 btrfs_orphan_del(NULL, inode); 4712 btrfs_free_block_rsv(root, rsv); 4713 goto no_delete; 4714 } 4715 4716 trans = btrfs_join_transaction(root); 4717 if (IS_ERR(trans)) { 4718 btrfs_orphan_del(NULL, inode); 4719 btrfs_free_block_rsv(root, rsv); 4720 goto no_delete; 4721 } 4722 4723 trans->block_rsv = rsv; 4724 4725 ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0); 4726 if (ret != -ENOSPC) 4727 break; 4728 4729 trans->block_rsv = &root->fs_info->trans_block_rsv; 4730 btrfs_end_transaction(trans, root); 4731 trans = NULL; 4732 btrfs_btree_balance_dirty(root); 4733 } 4734 4735 btrfs_free_block_rsv(root, rsv); 4736 4737 /* 4738 * Errors here aren't a big deal, it just means we leave orphan items 4739 * in the tree. They will be cleaned up on the next mount. 4740 */ 4741 if (ret == 0) { 4742 trans->block_rsv = root->orphan_block_rsv; 4743 btrfs_orphan_del(trans, inode); 4744 } else { 4745 btrfs_orphan_del(NULL, inode); 4746 } 4747 4748 trans->block_rsv = &root->fs_info->trans_block_rsv; 4749 if (!(root == root->fs_info->tree_root || 4750 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)) 4751 btrfs_return_ino(root, btrfs_ino(inode)); 4752 4753 btrfs_end_transaction(trans, root); 4754 btrfs_btree_balance_dirty(root); 4755 no_delete: 4756 btrfs_remove_delayed_node(inode); 4757 clear_inode(inode); 4758 return; 4759 } 4760 4761 /* 4762 * this returns the key found in the dir entry in the location pointer. 4763 * If no dir entries were found, location->objectid is 0. 4764 */ 4765 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry, 4766 struct btrfs_key *location) 4767 { 4768 const char *name = dentry->d_name.name; 4769 int namelen = dentry->d_name.len; 4770 struct btrfs_dir_item *di; 4771 struct btrfs_path *path; 4772 struct btrfs_root *root = BTRFS_I(dir)->root; 4773 int ret = 0; 4774 4775 path = btrfs_alloc_path(); 4776 if (!path) 4777 return -ENOMEM; 4778 4779 di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(dir), name, 4780 namelen, 0); 4781 if (IS_ERR(di)) 4782 ret = PTR_ERR(di); 4783 4784 if (IS_ERR_OR_NULL(di)) 4785 goto out_err; 4786 4787 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location); 4788 out: 4789 btrfs_free_path(path); 4790 return ret; 4791 out_err: 4792 location->objectid = 0; 4793 goto out; 4794 } 4795 4796 /* 4797 * when we hit a tree root in a directory, the btrfs part of the inode 4798 * needs to be changed to reflect the root directory of the tree root. This 4799 * is kind of like crossing a mount point. 4800 */ 4801 static int fixup_tree_root_location(struct btrfs_root *root, 4802 struct inode *dir, 4803 struct dentry *dentry, 4804 struct btrfs_key *location, 4805 struct btrfs_root **sub_root) 4806 { 4807 struct btrfs_path *path; 4808 struct btrfs_root *new_root; 4809 struct btrfs_root_ref *ref; 4810 struct extent_buffer *leaf; 4811 int ret; 4812 int err = 0; 4813 4814 path = btrfs_alloc_path(); 4815 if (!path) { 4816 err = -ENOMEM; 4817 goto out; 4818 } 4819 4820 err = -ENOENT; 4821 ret = btrfs_find_item(root->fs_info->tree_root, path, 4822 BTRFS_I(dir)->root->root_key.objectid, 4823 location->objectid, BTRFS_ROOT_REF_KEY, NULL); 4824 if (ret) { 4825 if (ret < 0) 4826 err = ret; 4827 goto out; 4828 } 4829 4830 leaf = path->nodes[0]; 4831 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref); 4832 if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(dir) || 4833 btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len) 4834 goto out; 4835 4836 ret = memcmp_extent_buffer(leaf, dentry->d_name.name, 4837 (unsigned long)(ref + 1), 4838 dentry->d_name.len); 4839 if (ret) 4840 goto out; 4841 4842 btrfs_release_path(path); 4843 4844 new_root = btrfs_read_fs_root_no_name(root->fs_info, location); 4845 if (IS_ERR(new_root)) { 4846 err = PTR_ERR(new_root); 4847 goto out; 4848 } 4849 4850 *sub_root = new_root; 4851 location->objectid = btrfs_root_dirid(&new_root->root_item); 4852 location->type = BTRFS_INODE_ITEM_KEY; 4853 location->offset = 0; 4854 err = 0; 4855 out: 4856 btrfs_free_path(path); 4857 return err; 4858 } 4859 4860 static void inode_tree_add(struct inode *inode) 4861 { 4862 struct btrfs_root *root = BTRFS_I(inode)->root; 4863 struct btrfs_inode *entry; 4864 struct rb_node **p; 4865 struct rb_node *parent; 4866 struct rb_node *new = &BTRFS_I(inode)->rb_node; 4867 u64 ino = btrfs_ino(inode); 4868 4869 if (inode_unhashed(inode)) 4870 return; 4871 parent = NULL; 4872 spin_lock(&root->inode_lock); 4873 p = &root->inode_tree.rb_node; 4874 while (*p) { 4875 parent = *p; 4876 entry = rb_entry(parent, struct btrfs_inode, rb_node); 4877 4878 if (ino < btrfs_ino(&entry->vfs_inode)) 4879 p = &parent->rb_left; 4880 else if (ino > btrfs_ino(&entry->vfs_inode)) 4881 p = &parent->rb_right; 4882 else { 4883 WARN_ON(!(entry->vfs_inode.i_state & 4884 (I_WILL_FREE | I_FREEING))); 4885 rb_replace_node(parent, new, &root->inode_tree); 4886 RB_CLEAR_NODE(parent); 4887 spin_unlock(&root->inode_lock); 4888 return; 4889 } 4890 } 4891 rb_link_node(new, parent, p); 4892 rb_insert_color(new, &root->inode_tree); 4893 spin_unlock(&root->inode_lock); 4894 } 4895 4896 static void inode_tree_del(struct inode *inode) 4897 { 4898 struct btrfs_root *root = BTRFS_I(inode)->root; 4899 int empty = 0; 4900 4901 spin_lock(&root->inode_lock); 4902 if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) { 4903 rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree); 4904 RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node); 4905 empty = RB_EMPTY_ROOT(&root->inode_tree); 4906 } 4907 spin_unlock(&root->inode_lock); 4908 4909 if (empty && btrfs_root_refs(&root->root_item) == 0) { 4910 synchronize_srcu(&root->fs_info->subvol_srcu); 4911 spin_lock(&root->inode_lock); 4912 empty = RB_EMPTY_ROOT(&root->inode_tree); 4913 spin_unlock(&root->inode_lock); 4914 if (empty) 4915 btrfs_add_dead_root(root); 4916 } 4917 } 4918 4919 void btrfs_invalidate_inodes(struct btrfs_root *root) 4920 { 4921 struct rb_node *node; 4922 struct rb_node *prev; 4923 struct btrfs_inode *entry; 4924 struct inode *inode; 4925 u64 objectid = 0; 4926 4927 WARN_ON(btrfs_root_refs(&root->root_item) != 0); 4928 4929 spin_lock(&root->inode_lock); 4930 again: 4931 node = root->inode_tree.rb_node; 4932 prev = NULL; 4933 while (node) { 4934 prev = node; 4935 entry = rb_entry(node, struct btrfs_inode, rb_node); 4936 4937 if (objectid < btrfs_ino(&entry->vfs_inode)) 4938 node = node->rb_left; 4939 else if (objectid > btrfs_ino(&entry->vfs_inode)) 4940 node = node->rb_right; 4941 else 4942 break; 4943 } 4944 if (!node) { 4945 while (prev) { 4946 entry = rb_entry(prev, struct btrfs_inode, rb_node); 4947 if (objectid <= btrfs_ino(&entry->vfs_inode)) { 4948 node = prev; 4949 break; 4950 } 4951 prev = rb_next(prev); 4952 } 4953 } 4954 while (node) { 4955 entry = rb_entry(node, struct btrfs_inode, rb_node); 4956 objectid = btrfs_ino(&entry->vfs_inode) + 1; 4957 inode = igrab(&entry->vfs_inode); 4958 if (inode) { 4959 spin_unlock(&root->inode_lock); 4960 if (atomic_read(&inode->i_count) > 1) 4961 d_prune_aliases(inode); 4962 /* 4963 * btrfs_drop_inode will have it removed from 4964 * the inode cache when its usage count 4965 * hits zero. 4966 */ 4967 iput(inode); 4968 cond_resched(); 4969 spin_lock(&root->inode_lock); 4970 goto again; 4971 } 4972 4973 if (cond_resched_lock(&root->inode_lock)) 4974 goto again; 4975 4976 node = rb_next(node); 4977 } 4978 spin_unlock(&root->inode_lock); 4979 } 4980 4981 static int btrfs_init_locked_inode(struct inode *inode, void *p) 4982 { 4983 struct btrfs_iget_args *args = p; 4984 inode->i_ino = args->location->objectid; 4985 memcpy(&BTRFS_I(inode)->location, args->location, 4986 sizeof(*args->location)); 4987 BTRFS_I(inode)->root = args->root; 4988 return 0; 4989 } 4990 4991 static int btrfs_find_actor(struct inode *inode, void *opaque) 4992 { 4993 struct btrfs_iget_args *args = opaque; 4994 return args->location->objectid == BTRFS_I(inode)->location.objectid && 4995 args->root == BTRFS_I(inode)->root; 4996 } 4997 4998 static struct inode *btrfs_iget_locked(struct super_block *s, 4999 struct btrfs_key *location, 5000 struct btrfs_root *root) 5001 { 5002 struct inode *inode; 5003 struct btrfs_iget_args args; 5004 unsigned long hashval = btrfs_inode_hash(location->objectid, root); 5005 5006 args.location = location; 5007 args.root = root; 5008 5009 inode = iget5_locked(s, hashval, btrfs_find_actor, 5010 btrfs_init_locked_inode, 5011 (void *)&args); 5012 return inode; 5013 } 5014 5015 /* Get an inode object given its location and corresponding root. 5016 * Returns in *is_new if the inode was read from disk 5017 */ 5018 struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location, 5019 struct btrfs_root *root, int *new) 5020 { 5021 struct inode *inode; 5022 5023 inode = btrfs_iget_locked(s, location, root); 5024 if (!inode) 5025 return ERR_PTR(-ENOMEM); 5026 5027 if (inode->i_state & I_NEW) { 5028 btrfs_read_locked_inode(inode); 5029 if (!is_bad_inode(inode)) { 5030 inode_tree_add(inode); 5031 unlock_new_inode(inode); 5032 if (new) 5033 *new = 1; 5034 } else { 5035 unlock_new_inode(inode); 5036 iput(inode); 5037 inode = ERR_PTR(-ESTALE); 5038 } 5039 } 5040 5041 return inode; 5042 } 5043 5044 static struct inode *new_simple_dir(struct super_block *s, 5045 struct btrfs_key *key, 5046 struct btrfs_root *root) 5047 { 5048 struct inode *inode = new_inode(s); 5049 5050 if (!inode) 5051 return ERR_PTR(-ENOMEM); 5052 5053 BTRFS_I(inode)->root = root; 5054 memcpy(&BTRFS_I(inode)->location, key, sizeof(*key)); 5055 set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags); 5056 5057 inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID; 5058 inode->i_op = &btrfs_dir_ro_inode_operations; 5059 inode->i_fop = &simple_dir_operations; 5060 inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO; 5061 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 5062 5063 return inode; 5064 } 5065 5066 struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry) 5067 { 5068 struct inode *inode; 5069 struct btrfs_root *root = BTRFS_I(dir)->root; 5070 struct btrfs_root *sub_root = root; 5071 struct btrfs_key location; 5072 int index; 5073 int ret = 0; 5074 5075 if (dentry->d_name.len > BTRFS_NAME_LEN) 5076 return ERR_PTR(-ENAMETOOLONG); 5077 5078 ret = btrfs_inode_by_name(dir, dentry, &location); 5079 if (ret < 0) 5080 return ERR_PTR(ret); 5081 5082 if (location.objectid == 0) 5083 return ERR_PTR(-ENOENT); 5084 5085 if (location.type == BTRFS_INODE_ITEM_KEY) { 5086 inode = btrfs_iget(dir->i_sb, &location, root, NULL); 5087 return inode; 5088 } 5089 5090 BUG_ON(location.type != BTRFS_ROOT_ITEM_KEY); 5091 5092 index = srcu_read_lock(&root->fs_info->subvol_srcu); 5093 ret = fixup_tree_root_location(root, dir, dentry, 5094 &location, &sub_root); 5095 if (ret < 0) { 5096 if (ret != -ENOENT) 5097 inode = ERR_PTR(ret); 5098 else 5099 inode = new_simple_dir(dir->i_sb, &location, sub_root); 5100 } else { 5101 inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL); 5102 } 5103 srcu_read_unlock(&root->fs_info->subvol_srcu, index); 5104 5105 if (!IS_ERR(inode) && root != sub_root) { 5106 down_read(&root->fs_info->cleanup_work_sem); 5107 if (!(inode->i_sb->s_flags & MS_RDONLY)) 5108 ret = btrfs_orphan_cleanup(sub_root); 5109 up_read(&root->fs_info->cleanup_work_sem); 5110 if (ret) { 5111 iput(inode); 5112 inode = ERR_PTR(ret); 5113 } 5114 } 5115 5116 return inode; 5117 } 5118 5119 static int btrfs_dentry_delete(const struct dentry *dentry) 5120 { 5121 struct btrfs_root *root; 5122 struct inode *inode = dentry->d_inode; 5123 5124 if (!inode && !IS_ROOT(dentry)) 5125 inode = dentry->d_parent->d_inode; 5126 5127 if (inode) { 5128 root = BTRFS_I(inode)->root; 5129 if (btrfs_root_refs(&root->root_item) == 0) 5130 return 1; 5131 5132 if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID) 5133 return 1; 5134 } 5135 return 0; 5136 } 5137 5138 static void btrfs_dentry_release(struct dentry *dentry) 5139 { 5140 if (dentry->d_fsdata) 5141 kfree(dentry->d_fsdata); 5142 } 5143 5144 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry, 5145 unsigned int flags) 5146 { 5147 struct inode *inode; 5148 5149 inode = btrfs_lookup_dentry(dir, dentry); 5150 if (IS_ERR(inode)) { 5151 if (PTR_ERR(inode) == -ENOENT) 5152 inode = NULL; 5153 else 5154 return ERR_CAST(inode); 5155 } 5156 5157 return d_materialise_unique(dentry, inode); 5158 } 5159 5160 unsigned char btrfs_filetype_table[] = { 5161 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK 5162 }; 5163 5164 static int btrfs_real_readdir(struct file *file, struct dir_context *ctx) 5165 { 5166 struct inode *inode = file_inode(file); 5167 struct btrfs_root *root = BTRFS_I(inode)->root; 5168 struct btrfs_item *item; 5169 struct btrfs_dir_item *di; 5170 struct btrfs_key key; 5171 struct btrfs_key found_key; 5172 struct btrfs_path *path; 5173 struct list_head ins_list; 5174 struct list_head del_list; 5175 int ret; 5176 struct extent_buffer *leaf; 5177 int slot; 5178 unsigned char d_type; 5179 int over = 0; 5180 u32 di_cur; 5181 u32 di_total; 5182 u32 di_len; 5183 int key_type = BTRFS_DIR_INDEX_KEY; 5184 char tmp_name[32]; 5185 char *name_ptr; 5186 int name_len; 5187 int is_curr = 0; /* ctx->pos points to the current index? */ 5188 5189 /* FIXME, use a real flag for deciding about the key type */ 5190 if (root->fs_info->tree_root == root) 5191 key_type = BTRFS_DIR_ITEM_KEY; 5192 5193 if (!dir_emit_dots(file, ctx)) 5194 return 0; 5195 5196 path = btrfs_alloc_path(); 5197 if (!path) 5198 return -ENOMEM; 5199 5200 path->reada = 1; 5201 5202 if (key_type == BTRFS_DIR_INDEX_KEY) { 5203 INIT_LIST_HEAD(&ins_list); 5204 INIT_LIST_HEAD(&del_list); 5205 btrfs_get_delayed_items(inode, &ins_list, &del_list); 5206 } 5207 5208 btrfs_set_key_type(&key, key_type); 5209 key.offset = ctx->pos; 5210 key.objectid = btrfs_ino(inode); 5211 5212 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 5213 if (ret < 0) 5214 goto err; 5215 5216 while (1) { 5217 leaf = path->nodes[0]; 5218 slot = path->slots[0]; 5219 if (slot >= btrfs_header_nritems(leaf)) { 5220 ret = btrfs_next_leaf(root, path); 5221 if (ret < 0) 5222 goto err; 5223 else if (ret > 0) 5224 break; 5225 continue; 5226 } 5227 5228 item = btrfs_item_nr(slot); 5229 btrfs_item_key_to_cpu(leaf, &found_key, slot); 5230 5231 if (found_key.objectid != key.objectid) 5232 break; 5233 if (btrfs_key_type(&found_key) != key_type) 5234 break; 5235 if (found_key.offset < ctx->pos) 5236 goto next; 5237 if (key_type == BTRFS_DIR_INDEX_KEY && 5238 btrfs_should_delete_dir_index(&del_list, 5239 found_key.offset)) 5240 goto next; 5241 5242 ctx->pos = found_key.offset; 5243 is_curr = 1; 5244 5245 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item); 5246 di_cur = 0; 5247 di_total = btrfs_item_size(leaf, item); 5248 5249 while (di_cur < di_total) { 5250 struct btrfs_key location; 5251 5252 if (verify_dir_item(root, leaf, di)) 5253 break; 5254 5255 name_len = btrfs_dir_name_len(leaf, di); 5256 if (name_len <= sizeof(tmp_name)) { 5257 name_ptr = tmp_name; 5258 } else { 5259 name_ptr = kmalloc(name_len, GFP_NOFS); 5260 if (!name_ptr) { 5261 ret = -ENOMEM; 5262 goto err; 5263 } 5264 } 5265 read_extent_buffer(leaf, name_ptr, 5266 (unsigned long)(di + 1), name_len); 5267 5268 d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)]; 5269 btrfs_dir_item_key_to_cpu(leaf, di, &location); 5270 5271 5272 /* is this a reference to our own snapshot? If so 5273 * skip it. 5274 * 5275 * In contrast to old kernels, we insert the snapshot's 5276 * dir item and dir index after it has been created, so 5277 * we won't find a reference to our own snapshot. We 5278 * still keep the following code for backward 5279 * compatibility. 5280 */ 5281 if (location.type == BTRFS_ROOT_ITEM_KEY && 5282 location.objectid == root->root_key.objectid) { 5283 over = 0; 5284 goto skip; 5285 } 5286 over = !dir_emit(ctx, name_ptr, name_len, 5287 location.objectid, d_type); 5288 5289 skip: 5290 if (name_ptr != tmp_name) 5291 kfree(name_ptr); 5292 5293 if (over) 5294 goto nopos; 5295 di_len = btrfs_dir_name_len(leaf, di) + 5296 btrfs_dir_data_len(leaf, di) + sizeof(*di); 5297 di_cur += di_len; 5298 di = (struct btrfs_dir_item *)((char *)di + di_len); 5299 } 5300 next: 5301 path->slots[0]++; 5302 } 5303 5304 if (key_type == BTRFS_DIR_INDEX_KEY) { 5305 if (is_curr) 5306 ctx->pos++; 5307 ret = btrfs_readdir_delayed_dir_index(ctx, &ins_list); 5308 if (ret) 5309 goto nopos; 5310 } 5311 5312 /* Reached end of directory/root. Bump pos past the last item. */ 5313 ctx->pos++; 5314 5315 /* 5316 * Stop new entries from being returned after we return the last 5317 * entry. 5318 * 5319 * New directory entries are assigned a strictly increasing 5320 * offset. This means that new entries created during readdir 5321 * are *guaranteed* to be seen in the future by that readdir. 5322 * This has broken buggy programs which operate on names as 5323 * they're returned by readdir. Until we re-use freed offsets 5324 * we have this hack to stop new entries from being returned 5325 * under the assumption that they'll never reach this huge 5326 * offset. 5327 * 5328 * This is being careful not to overflow 32bit loff_t unless the 5329 * last entry requires it because doing so has broken 32bit apps 5330 * in the past. 5331 */ 5332 if (key_type == BTRFS_DIR_INDEX_KEY) { 5333 if (ctx->pos >= INT_MAX) 5334 ctx->pos = LLONG_MAX; 5335 else 5336 ctx->pos = INT_MAX; 5337 } 5338 nopos: 5339 ret = 0; 5340 err: 5341 if (key_type == BTRFS_DIR_INDEX_KEY) 5342 btrfs_put_delayed_items(&ins_list, &del_list); 5343 btrfs_free_path(path); 5344 return ret; 5345 } 5346 5347 int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc) 5348 { 5349 struct btrfs_root *root = BTRFS_I(inode)->root; 5350 struct btrfs_trans_handle *trans; 5351 int ret = 0; 5352 bool nolock = false; 5353 5354 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags)) 5355 return 0; 5356 5357 if (btrfs_fs_closing(root->fs_info) && btrfs_is_free_space_inode(inode)) 5358 nolock = true; 5359 5360 if (wbc->sync_mode == WB_SYNC_ALL) { 5361 if (nolock) 5362 trans = btrfs_join_transaction_nolock(root); 5363 else 5364 trans = btrfs_join_transaction(root); 5365 if (IS_ERR(trans)) 5366 return PTR_ERR(trans); 5367 ret = btrfs_commit_transaction(trans, root); 5368 } 5369 return ret; 5370 } 5371 5372 /* 5373 * This is somewhat expensive, updating the tree every time the 5374 * inode changes. But, it is most likely to find the inode in cache. 5375 * FIXME, needs more benchmarking...there are no reasons other than performance 5376 * to keep or drop this code. 5377 */ 5378 static int btrfs_dirty_inode(struct inode *inode) 5379 { 5380 struct btrfs_root *root = BTRFS_I(inode)->root; 5381 struct btrfs_trans_handle *trans; 5382 int ret; 5383 5384 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags)) 5385 return 0; 5386 5387 trans = btrfs_join_transaction(root); 5388 if (IS_ERR(trans)) 5389 return PTR_ERR(trans); 5390 5391 ret = btrfs_update_inode(trans, root, inode); 5392 if (ret && ret == -ENOSPC) { 5393 /* whoops, lets try again with the full transaction */ 5394 btrfs_end_transaction(trans, root); 5395 trans = btrfs_start_transaction(root, 1); 5396 if (IS_ERR(trans)) 5397 return PTR_ERR(trans); 5398 5399 ret = btrfs_update_inode(trans, root, inode); 5400 } 5401 btrfs_end_transaction(trans, root); 5402 if (BTRFS_I(inode)->delayed_node) 5403 btrfs_balance_delayed_items(root); 5404 5405 return ret; 5406 } 5407 5408 /* 5409 * This is a copy of file_update_time. We need this so we can return error on 5410 * ENOSPC for updating the inode in the case of file write and mmap writes. 5411 */ 5412 static int btrfs_update_time(struct inode *inode, struct timespec *now, 5413 int flags) 5414 { 5415 struct btrfs_root *root = BTRFS_I(inode)->root; 5416 5417 if (btrfs_root_readonly(root)) 5418 return -EROFS; 5419 5420 if (flags & S_VERSION) 5421 inode_inc_iversion(inode); 5422 if (flags & S_CTIME) 5423 inode->i_ctime = *now; 5424 if (flags & S_MTIME) 5425 inode->i_mtime = *now; 5426 if (flags & S_ATIME) 5427 inode->i_atime = *now; 5428 return btrfs_dirty_inode(inode); 5429 } 5430 5431 /* 5432 * find the highest existing sequence number in a directory 5433 * and then set the in-memory index_cnt variable to reflect 5434 * free sequence numbers 5435 */ 5436 static int btrfs_set_inode_index_count(struct inode *inode) 5437 { 5438 struct btrfs_root *root = BTRFS_I(inode)->root; 5439 struct btrfs_key key, found_key; 5440 struct btrfs_path *path; 5441 struct extent_buffer *leaf; 5442 int ret; 5443 5444 key.objectid = btrfs_ino(inode); 5445 btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY); 5446 key.offset = (u64)-1; 5447 5448 path = btrfs_alloc_path(); 5449 if (!path) 5450 return -ENOMEM; 5451 5452 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 5453 if (ret < 0) 5454 goto out; 5455 /* FIXME: we should be able to handle this */ 5456 if (ret == 0) 5457 goto out; 5458 ret = 0; 5459 5460 /* 5461 * MAGIC NUMBER EXPLANATION: 5462 * since we search a directory based on f_pos we have to start at 2 5463 * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody 5464 * else has to start at 2 5465 */ 5466 if (path->slots[0] == 0) { 5467 BTRFS_I(inode)->index_cnt = 2; 5468 goto out; 5469 } 5470 5471 path->slots[0]--; 5472 5473 leaf = path->nodes[0]; 5474 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 5475 5476 if (found_key.objectid != btrfs_ino(inode) || 5477 btrfs_key_type(&found_key) != BTRFS_DIR_INDEX_KEY) { 5478 BTRFS_I(inode)->index_cnt = 2; 5479 goto out; 5480 } 5481 5482 BTRFS_I(inode)->index_cnt = found_key.offset + 1; 5483 out: 5484 btrfs_free_path(path); 5485 return ret; 5486 } 5487 5488 /* 5489 * helper to find a free sequence number in a given directory. This current 5490 * code is very simple, later versions will do smarter things in the btree 5491 */ 5492 int btrfs_set_inode_index(struct inode *dir, u64 *index) 5493 { 5494 int ret = 0; 5495 5496 if (BTRFS_I(dir)->index_cnt == (u64)-1) { 5497 ret = btrfs_inode_delayed_dir_index_count(dir); 5498 if (ret) { 5499 ret = btrfs_set_inode_index_count(dir); 5500 if (ret) 5501 return ret; 5502 } 5503 } 5504 5505 *index = BTRFS_I(dir)->index_cnt; 5506 BTRFS_I(dir)->index_cnt++; 5507 5508 return ret; 5509 } 5510 5511 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans, 5512 struct btrfs_root *root, 5513 struct inode *dir, 5514 const char *name, int name_len, 5515 u64 ref_objectid, u64 objectid, 5516 umode_t mode, u64 *index) 5517 { 5518 struct inode *inode; 5519 struct btrfs_inode_item *inode_item; 5520 struct btrfs_key *location; 5521 struct btrfs_path *path; 5522 struct btrfs_inode_ref *ref; 5523 struct btrfs_key key[2]; 5524 u32 sizes[2]; 5525 unsigned long ptr; 5526 int ret; 5527 5528 path = btrfs_alloc_path(); 5529 if (!path) 5530 return ERR_PTR(-ENOMEM); 5531 5532 inode = new_inode(root->fs_info->sb); 5533 if (!inode) { 5534 btrfs_free_path(path); 5535 return ERR_PTR(-ENOMEM); 5536 } 5537 5538 /* 5539 * we have to initialize this early, so we can reclaim the inode 5540 * number if we fail afterwards in this function. 5541 */ 5542 inode->i_ino = objectid; 5543 5544 if (dir) { 5545 trace_btrfs_inode_request(dir); 5546 5547 ret = btrfs_set_inode_index(dir, index); 5548 if (ret) { 5549 btrfs_free_path(path); 5550 iput(inode); 5551 return ERR_PTR(ret); 5552 } 5553 } 5554 /* 5555 * index_cnt is ignored for everything but a dir, 5556 * btrfs_get_inode_index_count has an explanation for the magic 5557 * number 5558 */ 5559 BTRFS_I(inode)->index_cnt = 2; 5560 BTRFS_I(inode)->dir_index = *index; 5561 BTRFS_I(inode)->root = root; 5562 BTRFS_I(inode)->generation = trans->transid; 5563 inode->i_generation = BTRFS_I(inode)->generation; 5564 5565 /* 5566 * We could have gotten an inode number from somebody who was fsynced 5567 * and then removed in this same transaction, so let's just set full 5568 * sync since it will be a full sync anyway and this will blow away the 5569 * old info in the log. 5570 */ 5571 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags); 5572 5573 key[0].objectid = objectid; 5574 btrfs_set_key_type(&key[0], BTRFS_INODE_ITEM_KEY); 5575 key[0].offset = 0; 5576 5577 /* 5578 * Start new inodes with an inode_ref. This is slightly more 5579 * efficient for small numbers of hard links since they will 5580 * be packed into one item. Extended refs will kick in if we 5581 * add more hard links than can fit in the ref item. 5582 */ 5583 key[1].objectid = objectid; 5584 btrfs_set_key_type(&key[1], BTRFS_INODE_REF_KEY); 5585 key[1].offset = ref_objectid; 5586 5587 sizes[0] = sizeof(struct btrfs_inode_item); 5588 sizes[1] = name_len + sizeof(*ref); 5589 5590 path->leave_spinning = 1; 5591 ret = btrfs_insert_empty_items(trans, root, path, key, sizes, 2); 5592 if (ret != 0) 5593 goto fail; 5594 5595 inode_init_owner(inode, dir, mode); 5596 inode_set_bytes(inode, 0); 5597 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 5598 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0], 5599 struct btrfs_inode_item); 5600 memset_extent_buffer(path->nodes[0], 0, (unsigned long)inode_item, 5601 sizeof(*inode_item)); 5602 fill_inode_item(trans, path->nodes[0], inode_item, inode); 5603 5604 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1, 5605 struct btrfs_inode_ref); 5606 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len); 5607 btrfs_set_inode_ref_index(path->nodes[0], ref, *index); 5608 ptr = (unsigned long)(ref + 1); 5609 write_extent_buffer(path->nodes[0], name, ptr, name_len); 5610 5611 btrfs_mark_buffer_dirty(path->nodes[0]); 5612 btrfs_free_path(path); 5613 5614 location = &BTRFS_I(inode)->location; 5615 location->objectid = objectid; 5616 location->offset = 0; 5617 btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY); 5618 5619 btrfs_inherit_iflags(inode, dir); 5620 5621 if (S_ISREG(mode)) { 5622 if (btrfs_test_opt(root, NODATASUM)) 5623 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM; 5624 if (btrfs_test_opt(root, NODATACOW)) 5625 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW | 5626 BTRFS_INODE_NODATASUM; 5627 } 5628 5629 btrfs_insert_inode_hash(inode); 5630 inode_tree_add(inode); 5631 5632 trace_btrfs_inode_new(inode); 5633 btrfs_set_inode_last_trans(trans, inode); 5634 5635 btrfs_update_root_times(trans, root); 5636 5637 ret = btrfs_inode_inherit_props(trans, inode, dir); 5638 if (ret) 5639 btrfs_err(root->fs_info, 5640 "error inheriting props for ino %llu (root %llu): %d", 5641 btrfs_ino(inode), root->root_key.objectid, ret); 5642 5643 return inode; 5644 fail: 5645 if (dir) 5646 BTRFS_I(dir)->index_cnt--; 5647 btrfs_free_path(path); 5648 iput(inode); 5649 return ERR_PTR(ret); 5650 } 5651 5652 static inline u8 btrfs_inode_type(struct inode *inode) 5653 { 5654 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT]; 5655 } 5656 5657 /* 5658 * utility function to add 'inode' into 'parent_inode' with 5659 * a give name and a given sequence number. 5660 * if 'add_backref' is true, also insert a backref from the 5661 * inode to the parent directory. 5662 */ 5663 int btrfs_add_link(struct btrfs_trans_handle *trans, 5664 struct inode *parent_inode, struct inode *inode, 5665 const char *name, int name_len, int add_backref, u64 index) 5666 { 5667 int ret = 0; 5668 struct btrfs_key key; 5669 struct btrfs_root *root = BTRFS_I(parent_inode)->root; 5670 u64 ino = btrfs_ino(inode); 5671 u64 parent_ino = btrfs_ino(parent_inode); 5672 5673 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) { 5674 memcpy(&key, &BTRFS_I(inode)->root->root_key, sizeof(key)); 5675 } else { 5676 key.objectid = ino; 5677 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY); 5678 key.offset = 0; 5679 } 5680 5681 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) { 5682 ret = btrfs_add_root_ref(trans, root->fs_info->tree_root, 5683 key.objectid, root->root_key.objectid, 5684 parent_ino, index, name, name_len); 5685 } else if (add_backref) { 5686 ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino, 5687 parent_ino, index); 5688 } 5689 5690 /* Nothing to clean up yet */ 5691 if (ret) 5692 return ret; 5693 5694 ret = btrfs_insert_dir_item(trans, root, name, name_len, 5695 parent_inode, &key, 5696 btrfs_inode_type(inode), index); 5697 if (ret == -EEXIST || ret == -EOVERFLOW) 5698 goto fail_dir_item; 5699 else if (ret) { 5700 btrfs_abort_transaction(trans, root, ret); 5701 return ret; 5702 } 5703 5704 btrfs_i_size_write(parent_inode, parent_inode->i_size + 5705 name_len * 2); 5706 inode_inc_iversion(parent_inode); 5707 parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME; 5708 ret = btrfs_update_inode(trans, root, parent_inode); 5709 if (ret) 5710 btrfs_abort_transaction(trans, root, ret); 5711 return ret; 5712 5713 fail_dir_item: 5714 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) { 5715 u64 local_index; 5716 int err; 5717 err = btrfs_del_root_ref(trans, root->fs_info->tree_root, 5718 key.objectid, root->root_key.objectid, 5719 parent_ino, &local_index, name, name_len); 5720 5721 } else if (add_backref) { 5722 u64 local_index; 5723 int err; 5724 5725 err = btrfs_del_inode_ref(trans, root, name, name_len, 5726 ino, parent_ino, &local_index); 5727 } 5728 return ret; 5729 } 5730 5731 static int btrfs_add_nondir(struct btrfs_trans_handle *trans, 5732 struct inode *dir, struct dentry *dentry, 5733 struct inode *inode, int backref, u64 index) 5734 { 5735 int err = btrfs_add_link(trans, dir, inode, 5736 dentry->d_name.name, dentry->d_name.len, 5737 backref, index); 5738 if (err > 0) 5739 err = -EEXIST; 5740 return err; 5741 } 5742 5743 static int btrfs_mknod(struct inode *dir, struct dentry *dentry, 5744 umode_t mode, dev_t rdev) 5745 { 5746 struct btrfs_trans_handle *trans; 5747 struct btrfs_root *root = BTRFS_I(dir)->root; 5748 struct inode *inode = NULL; 5749 int err; 5750 int drop_inode = 0; 5751 u64 objectid; 5752 u64 index = 0; 5753 5754 if (!new_valid_dev(rdev)) 5755 return -EINVAL; 5756 5757 /* 5758 * 2 for inode item and ref 5759 * 2 for dir items 5760 * 1 for xattr if selinux is on 5761 */ 5762 trans = btrfs_start_transaction(root, 5); 5763 if (IS_ERR(trans)) 5764 return PTR_ERR(trans); 5765 5766 err = btrfs_find_free_ino(root, &objectid); 5767 if (err) 5768 goto out_unlock; 5769 5770 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name, 5771 dentry->d_name.len, btrfs_ino(dir), objectid, 5772 mode, &index); 5773 if (IS_ERR(inode)) { 5774 err = PTR_ERR(inode); 5775 goto out_unlock; 5776 } 5777 5778 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name); 5779 if (err) { 5780 drop_inode = 1; 5781 goto out_unlock; 5782 } 5783 5784 /* 5785 * If the active LSM wants to access the inode during 5786 * d_instantiate it needs these. Smack checks to see 5787 * if the filesystem supports xattrs by looking at the 5788 * ops vector. 5789 */ 5790 5791 inode->i_op = &btrfs_special_inode_operations; 5792 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index); 5793 if (err) 5794 drop_inode = 1; 5795 else { 5796 init_special_inode(inode, inode->i_mode, rdev); 5797 btrfs_update_inode(trans, root, inode); 5798 d_instantiate(dentry, inode); 5799 } 5800 out_unlock: 5801 btrfs_end_transaction(trans, root); 5802 btrfs_btree_balance_dirty(root); 5803 if (drop_inode) { 5804 inode_dec_link_count(inode); 5805 iput(inode); 5806 } 5807 return err; 5808 } 5809 5810 static int btrfs_create(struct inode *dir, struct dentry *dentry, 5811 umode_t mode, bool excl) 5812 { 5813 struct btrfs_trans_handle *trans; 5814 struct btrfs_root *root = BTRFS_I(dir)->root; 5815 struct inode *inode = NULL; 5816 int drop_inode_on_err = 0; 5817 int err; 5818 u64 objectid; 5819 u64 index = 0; 5820 5821 /* 5822 * 2 for inode item and ref 5823 * 2 for dir items 5824 * 1 for xattr if selinux is on 5825 */ 5826 trans = btrfs_start_transaction(root, 5); 5827 if (IS_ERR(trans)) 5828 return PTR_ERR(trans); 5829 5830 err = btrfs_find_free_ino(root, &objectid); 5831 if (err) 5832 goto out_unlock; 5833 5834 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name, 5835 dentry->d_name.len, btrfs_ino(dir), objectid, 5836 mode, &index); 5837 if (IS_ERR(inode)) { 5838 err = PTR_ERR(inode); 5839 goto out_unlock; 5840 } 5841 drop_inode_on_err = 1; 5842 5843 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name); 5844 if (err) 5845 goto out_unlock; 5846 5847 err = btrfs_update_inode(trans, root, inode); 5848 if (err) 5849 goto out_unlock; 5850 5851 /* 5852 * If the active LSM wants to access the inode during 5853 * d_instantiate it needs these. Smack checks to see 5854 * if the filesystem supports xattrs by looking at the 5855 * ops vector. 5856 */ 5857 inode->i_fop = &btrfs_file_operations; 5858 inode->i_op = &btrfs_file_inode_operations; 5859 5860 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index); 5861 if (err) 5862 goto out_unlock; 5863 5864 inode->i_mapping->a_ops = &btrfs_aops; 5865 inode->i_mapping->backing_dev_info = &root->fs_info->bdi; 5866 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops; 5867 d_instantiate(dentry, inode); 5868 5869 out_unlock: 5870 btrfs_end_transaction(trans, root); 5871 if (err && drop_inode_on_err) { 5872 inode_dec_link_count(inode); 5873 iput(inode); 5874 } 5875 btrfs_btree_balance_dirty(root); 5876 return err; 5877 } 5878 5879 static int btrfs_link(struct dentry *old_dentry, struct inode *dir, 5880 struct dentry *dentry) 5881 { 5882 struct btrfs_trans_handle *trans; 5883 struct btrfs_root *root = BTRFS_I(dir)->root; 5884 struct inode *inode = old_dentry->d_inode; 5885 u64 index; 5886 int err; 5887 int drop_inode = 0; 5888 5889 /* do not allow sys_link's with other subvols of the same device */ 5890 if (root->objectid != BTRFS_I(inode)->root->objectid) 5891 return -EXDEV; 5892 5893 if (inode->i_nlink >= BTRFS_LINK_MAX) 5894 return -EMLINK; 5895 5896 err = btrfs_set_inode_index(dir, &index); 5897 if (err) 5898 goto fail; 5899 5900 /* 5901 * 2 items for inode and inode ref 5902 * 2 items for dir items 5903 * 1 item for parent inode 5904 */ 5905 trans = btrfs_start_transaction(root, 5); 5906 if (IS_ERR(trans)) { 5907 err = PTR_ERR(trans); 5908 goto fail; 5909 } 5910 5911 /* There are several dir indexes for this inode, clear the cache. */ 5912 BTRFS_I(inode)->dir_index = 0ULL; 5913 inc_nlink(inode); 5914 inode_inc_iversion(inode); 5915 inode->i_ctime = CURRENT_TIME; 5916 ihold(inode); 5917 set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags); 5918 5919 err = btrfs_add_nondir(trans, dir, dentry, inode, 1, index); 5920 5921 if (err) { 5922 drop_inode = 1; 5923 } else { 5924 struct dentry *parent = dentry->d_parent; 5925 err = btrfs_update_inode(trans, root, inode); 5926 if (err) 5927 goto fail; 5928 d_instantiate(dentry, inode); 5929 btrfs_log_new_name(trans, inode, NULL, parent); 5930 } 5931 5932 btrfs_end_transaction(trans, root); 5933 fail: 5934 if (drop_inode) { 5935 inode_dec_link_count(inode); 5936 iput(inode); 5937 } 5938 btrfs_btree_balance_dirty(root); 5939 return err; 5940 } 5941 5942 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) 5943 { 5944 struct inode *inode = NULL; 5945 struct btrfs_trans_handle *trans; 5946 struct btrfs_root *root = BTRFS_I(dir)->root; 5947 int err = 0; 5948 int drop_on_err = 0; 5949 u64 objectid = 0; 5950 u64 index = 0; 5951 5952 /* 5953 * 2 items for inode and ref 5954 * 2 items for dir items 5955 * 1 for xattr if selinux is on 5956 */ 5957 trans = btrfs_start_transaction(root, 5); 5958 if (IS_ERR(trans)) 5959 return PTR_ERR(trans); 5960 5961 err = btrfs_find_free_ino(root, &objectid); 5962 if (err) 5963 goto out_fail; 5964 5965 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name, 5966 dentry->d_name.len, btrfs_ino(dir), objectid, 5967 S_IFDIR | mode, &index); 5968 if (IS_ERR(inode)) { 5969 err = PTR_ERR(inode); 5970 goto out_fail; 5971 } 5972 5973 drop_on_err = 1; 5974 5975 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name); 5976 if (err) 5977 goto out_fail; 5978 5979 inode->i_op = &btrfs_dir_inode_operations; 5980 inode->i_fop = &btrfs_dir_file_operations; 5981 5982 btrfs_i_size_write(inode, 0); 5983 err = btrfs_update_inode(trans, root, inode); 5984 if (err) 5985 goto out_fail; 5986 5987 err = btrfs_add_link(trans, dir, inode, dentry->d_name.name, 5988 dentry->d_name.len, 0, index); 5989 if (err) 5990 goto out_fail; 5991 5992 d_instantiate(dentry, inode); 5993 drop_on_err = 0; 5994 5995 out_fail: 5996 btrfs_end_transaction(trans, root); 5997 if (drop_on_err) 5998 iput(inode); 5999 btrfs_btree_balance_dirty(root); 6000 return err; 6001 } 6002 6003 /* helper for btfs_get_extent. Given an existing extent in the tree, 6004 * and an extent that you want to insert, deal with overlap and insert 6005 * the new extent into the tree. 6006 */ 6007 static int merge_extent_mapping(struct extent_map_tree *em_tree, 6008 struct extent_map *existing, 6009 struct extent_map *em, 6010 u64 map_start, u64 map_len) 6011 { 6012 u64 start_diff; 6013 6014 BUG_ON(map_start < em->start || map_start >= extent_map_end(em)); 6015 start_diff = map_start - em->start; 6016 em->start = map_start; 6017 em->len = map_len; 6018 if (em->block_start < EXTENT_MAP_LAST_BYTE && 6019 !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) { 6020 em->block_start += start_diff; 6021 em->block_len -= start_diff; 6022 } 6023 return add_extent_mapping(em_tree, em, 0); 6024 } 6025 6026 static noinline int uncompress_inline(struct btrfs_path *path, 6027 struct inode *inode, struct page *page, 6028 size_t pg_offset, u64 extent_offset, 6029 struct btrfs_file_extent_item *item) 6030 { 6031 int ret; 6032 struct extent_buffer *leaf = path->nodes[0]; 6033 char *tmp; 6034 size_t max_size; 6035 unsigned long inline_size; 6036 unsigned long ptr; 6037 int compress_type; 6038 6039 WARN_ON(pg_offset != 0); 6040 compress_type = btrfs_file_extent_compression(leaf, item); 6041 max_size = btrfs_file_extent_ram_bytes(leaf, item); 6042 inline_size = btrfs_file_extent_inline_item_len(leaf, 6043 btrfs_item_nr(path->slots[0])); 6044 tmp = kmalloc(inline_size, GFP_NOFS); 6045 if (!tmp) 6046 return -ENOMEM; 6047 ptr = btrfs_file_extent_inline_start(item); 6048 6049 read_extent_buffer(leaf, tmp, ptr, inline_size); 6050 6051 max_size = min_t(unsigned long, PAGE_CACHE_SIZE, max_size); 6052 ret = btrfs_decompress(compress_type, tmp, page, 6053 extent_offset, inline_size, max_size); 6054 if (ret) { 6055 char *kaddr = kmap_atomic(page); 6056 unsigned long copy_size = min_t(u64, 6057 PAGE_CACHE_SIZE - pg_offset, 6058 max_size - extent_offset); 6059 memset(kaddr + pg_offset, 0, copy_size); 6060 kunmap_atomic(kaddr); 6061 } 6062 kfree(tmp); 6063 return 0; 6064 } 6065 6066 /* 6067 * a bit scary, this does extent mapping from logical file offset to the disk. 6068 * the ugly parts come from merging extents from the disk with the in-ram 6069 * representation. This gets more complex because of the data=ordered code, 6070 * where the in-ram extents might be locked pending data=ordered completion. 6071 * 6072 * This also copies inline extents directly into the page. 6073 */ 6074 6075 struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page, 6076 size_t pg_offset, u64 start, u64 len, 6077 int create) 6078 { 6079 int ret; 6080 int err = 0; 6081 u64 bytenr; 6082 u64 extent_start = 0; 6083 u64 extent_end = 0; 6084 u64 objectid = btrfs_ino(inode); 6085 u32 found_type; 6086 struct btrfs_path *path = NULL; 6087 struct btrfs_root *root = BTRFS_I(inode)->root; 6088 struct btrfs_file_extent_item *item; 6089 struct extent_buffer *leaf; 6090 struct btrfs_key found_key; 6091 struct extent_map *em = NULL; 6092 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; 6093 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 6094 struct btrfs_trans_handle *trans = NULL; 6095 int compress_type; 6096 6097 again: 6098 read_lock(&em_tree->lock); 6099 em = lookup_extent_mapping(em_tree, start, len); 6100 if (em) 6101 em->bdev = root->fs_info->fs_devices->latest_bdev; 6102 read_unlock(&em_tree->lock); 6103 6104 if (em) { 6105 if (em->start > start || em->start + em->len <= start) 6106 free_extent_map(em); 6107 else if (em->block_start == EXTENT_MAP_INLINE && page) 6108 free_extent_map(em); 6109 else 6110 goto out; 6111 } 6112 em = alloc_extent_map(); 6113 if (!em) { 6114 err = -ENOMEM; 6115 goto out; 6116 } 6117 em->bdev = root->fs_info->fs_devices->latest_bdev; 6118 em->start = EXTENT_MAP_HOLE; 6119 em->orig_start = EXTENT_MAP_HOLE; 6120 em->len = (u64)-1; 6121 em->block_len = (u64)-1; 6122 6123 if (!path) { 6124 path = btrfs_alloc_path(); 6125 if (!path) { 6126 err = -ENOMEM; 6127 goto out; 6128 } 6129 /* 6130 * Chances are we'll be called again, so go ahead and do 6131 * readahead 6132 */ 6133 path->reada = 1; 6134 } 6135 6136 ret = btrfs_lookup_file_extent(trans, root, path, 6137 objectid, start, trans != NULL); 6138 if (ret < 0) { 6139 err = ret; 6140 goto out; 6141 } 6142 6143 if (ret != 0) { 6144 if (path->slots[0] == 0) 6145 goto not_found; 6146 path->slots[0]--; 6147 } 6148 6149 leaf = path->nodes[0]; 6150 item = btrfs_item_ptr(leaf, path->slots[0], 6151 struct btrfs_file_extent_item); 6152 /* are we inside the extent that was found? */ 6153 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 6154 found_type = btrfs_key_type(&found_key); 6155 if (found_key.objectid != objectid || 6156 found_type != BTRFS_EXTENT_DATA_KEY) { 6157 /* 6158 * If we backup past the first extent we want to move forward 6159 * and see if there is an extent in front of us, otherwise we'll 6160 * say there is a hole for our whole search range which can 6161 * cause problems. 6162 */ 6163 extent_end = start; 6164 goto next; 6165 } 6166 6167 found_type = btrfs_file_extent_type(leaf, item); 6168 extent_start = found_key.offset; 6169 compress_type = btrfs_file_extent_compression(leaf, item); 6170 if (found_type == BTRFS_FILE_EXTENT_REG || 6171 found_type == BTRFS_FILE_EXTENT_PREALLOC) { 6172 extent_end = extent_start + 6173 btrfs_file_extent_num_bytes(leaf, item); 6174 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) { 6175 size_t size; 6176 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item); 6177 extent_end = ALIGN(extent_start + size, root->sectorsize); 6178 } 6179 next: 6180 if (start >= extent_end) { 6181 path->slots[0]++; 6182 if (path->slots[0] >= btrfs_header_nritems(leaf)) { 6183 ret = btrfs_next_leaf(root, path); 6184 if (ret < 0) { 6185 err = ret; 6186 goto out; 6187 } 6188 if (ret > 0) 6189 goto not_found; 6190 leaf = path->nodes[0]; 6191 } 6192 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 6193 if (found_key.objectid != objectid || 6194 found_key.type != BTRFS_EXTENT_DATA_KEY) 6195 goto not_found; 6196 if (start + len <= found_key.offset) 6197 goto not_found; 6198 em->start = start; 6199 em->orig_start = start; 6200 em->len = found_key.offset - start; 6201 goto not_found_em; 6202 } 6203 6204 em->ram_bytes = btrfs_file_extent_ram_bytes(leaf, item); 6205 if (found_type == BTRFS_FILE_EXTENT_REG || 6206 found_type == BTRFS_FILE_EXTENT_PREALLOC) { 6207 em->start = extent_start; 6208 em->len = extent_end - extent_start; 6209 em->orig_start = extent_start - 6210 btrfs_file_extent_offset(leaf, item); 6211 em->orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, 6212 item); 6213 bytenr = btrfs_file_extent_disk_bytenr(leaf, item); 6214 if (bytenr == 0) { 6215 em->block_start = EXTENT_MAP_HOLE; 6216 goto insert; 6217 } 6218 if (compress_type != BTRFS_COMPRESS_NONE) { 6219 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags); 6220 em->compress_type = compress_type; 6221 em->block_start = bytenr; 6222 em->block_len = em->orig_block_len; 6223 } else { 6224 bytenr += btrfs_file_extent_offset(leaf, item); 6225 em->block_start = bytenr; 6226 em->block_len = em->len; 6227 if (found_type == BTRFS_FILE_EXTENT_PREALLOC) 6228 set_bit(EXTENT_FLAG_PREALLOC, &em->flags); 6229 } 6230 goto insert; 6231 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) { 6232 unsigned long ptr; 6233 char *map; 6234 size_t size; 6235 size_t extent_offset; 6236 size_t copy_size; 6237 6238 em->block_start = EXTENT_MAP_INLINE; 6239 if (!page || create) { 6240 em->start = extent_start; 6241 em->len = extent_end - extent_start; 6242 goto out; 6243 } 6244 6245 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item); 6246 extent_offset = page_offset(page) + pg_offset - extent_start; 6247 copy_size = min_t(u64, PAGE_CACHE_SIZE - pg_offset, 6248 size - extent_offset); 6249 em->start = extent_start + extent_offset; 6250 em->len = ALIGN(copy_size, root->sectorsize); 6251 em->orig_block_len = em->len; 6252 em->orig_start = em->start; 6253 if (compress_type) { 6254 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags); 6255 em->compress_type = compress_type; 6256 } 6257 ptr = btrfs_file_extent_inline_start(item) + extent_offset; 6258 if (create == 0 && !PageUptodate(page)) { 6259 if (btrfs_file_extent_compression(leaf, item) != 6260 BTRFS_COMPRESS_NONE) { 6261 ret = uncompress_inline(path, inode, page, 6262 pg_offset, 6263 extent_offset, item); 6264 BUG_ON(ret); /* -ENOMEM */ 6265 } else { 6266 map = kmap(page); 6267 read_extent_buffer(leaf, map + pg_offset, ptr, 6268 copy_size); 6269 if (pg_offset + copy_size < PAGE_CACHE_SIZE) { 6270 memset(map + pg_offset + copy_size, 0, 6271 PAGE_CACHE_SIZE - pg_offset - 6272 copy_size); 6273 } 6274 kunmap(page); 6275 } 6276 flush_dcache_page(page); 6277 } else if (create && PageUptodate(page)) { 6278 BUG(); 6279 if (!trans) { 6280 kunmap(page); 6281 free_extent_map(em); 6282 em = NULL; 6283 6284 btrfs_release_path(path); 6285 trans = btrfs_join_transaction(root); 6286 6287 if (IS_ERR(trans)) 6288 return ERR_CAST(trans); 6289 goto again; 6290 } 6291 map = kmap(page); 6292 write_extent_buffer(leaf, map + pg_offset, ptr, 6293 copy_size); 6294 kunmap(page); 6295 btrfs_mark_buffer_dirty(leaf); 6296 } 6297 set_extent_uptodate(io_tree, em->start, 6298 extent_map_end(em) - 1, NULL, GFP_NOFS); 6299 goto insert; 6300 } else { 6301 WARN(1, KERN_ERR "btrfs unknown found_type %d\n", found_type); 6302 } 6303 not_found: 6304 em->start = start; 6305 em->orig_start = start; 6306 em->len = len; 6307 not_found_em: 6308 em->block_start = EXTENT_MAP_HOLE; 6309 set_bit(EXTENT_FLAG_VACANCY, &em->flags); 6310 insert: 6311 btrfs_release_path(path); 6312 if (em->start > start || extent_map_end(em) <= start) { 6313 btrfs_err(root->fs_info, "bad extent! em: [%llu %llu] passed [%llu %llu]", 6314 em->start, em->len, start, len); 6315 err = -EIO; 6316 goto out; 6317 } 6318 6319 err = 0; 6320 write_lock(&em_tree->lock); 6321 ret = add_extent_mapping(em_tree, em, 0); 6322 /* it is possible that someone inserted the extent into the tree 6323 * while we had the lock dropped. It is also possible that 6324 * an overlapping map exists in the tree 6325 */ 6326 if (ret == -EEXIST) { 6327 struct extent_map *existing; 6328 6329 ret = 0; 6330 6331 existing = lookup_extent_mapping(em_tree, start, len); 6332 if (existing && (existing->start > start || 6333 existing->start + existing->len <= start)) { 6334 free_extent_map(existing); 6335 existing = NULL; 6336 } 6337 if (!existing) { 6338 existing = lookup_extent_mapping(em_tree, em->start, 6339 em->len); 6340 if (existing) { 6341 err = merge_extent_mapping(em_tree, existing, 6342 em, start, 6343 root->sectorsize); 6344 free_extent_map(existing); 6345 if (err) { 6346 free_extent_map(em); 6347 em = NULL; 6348 } 6349 } else { 6350 err = -EIO; 6351 free_extent_map(em); 6352 em = NULL; 6353 } 6354 } else { 6355 free_extent_map(em); 6356 em = existing; 6357 err = 0; 6358 } 6359 } 6360 write_unlock(&em_tree->lock); 6361 out: 6362 6363 trace_btrfs_get_extent(root, em); 6364 6365 if (path) 6366 btrfs_free_path(path); 6367 if (trans) { 6368 ret = btrfs_end_transaction(trans, root); 6369 if (!err) 6370 err = ret; 6371 } 6372 if (err) { 6373 free_extent_map(em); 6374 return ERR_PTR(err); 6375 } 6376 BUG_ON(!em); /* Error is always set */ 6377 return em; 6378 } 6379 6380 struct extent_map *btrfs_get_extent_fiemap(struct inode *inode, struct page *page, 6381 size_t pg_offset, u64 start, u64 len, 6382 int create) 6383 { 6384 struct extent_map *em; 6385 struct extent_map *hole_em = NULL; 6386 u64 range_start = start; 6387 u64 end; 6388 u64 found; 6389 u64 found_end; 6390 int err = 0; 6391 6392 em = btrfs_get_extent(inode, page, pg_offset, start, len, create); 6393 if (IS_ERR(em)) 6394 return em; 6395 if (em) { 6396 /* 6397 * if our em maps to 6398 * - a hole or 6399 * - a pre-alloc extent, 6400 * there might actually be delalloc bytes behind it. 6401 */ 6402 if (em->block_start != EXTENT_MAP_HOLE && 6403 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) 6404 return em; 6405 else 6406 hole_em = em; 6407 } 6408 6409 /* check to see if we've wrapped (len == -1 or similar) */ 6410 end = start + len; 6411 if (end < start) 6412 end = (u64)-1; 6413 else 6414 end -= 1; 6415 6416 em = NULL; 6417 6418 /* ok, we didn't find anything, lets look for delalloc */ 6419 found = count_range_bits(&BTRFS_I(inode)->io_tree, &range_start, 6420 end, len, EXTENT_DELALLOC, 1); 6421 found_end = range_start + found; 6422 if (found_end < range_start) 6423 found_end = (u64)-1; 6424 6425 /* 6426 * we didn't find anything useful, return 6427 * the original results from get_extent() 6428 */ 6429 if (range_start > end || found_end <= start) { 6430 em = hole_em; 6431 hole_em = NULL; 6432 goto out; 6433 } 6434 6435 /* adjust the range_start to make sure it doesn't 6436 * go backwards from the start they passed in 6437 */ 6438 range_start = max(start, range_start); 6439 found = found_end - range_start; 6440 6441 if (found > 0) { 6442 u64 hole_start = start; 6443 u64 hole_len = len; 6444 6445 em = alloc_extent_map(); 6446 if (!em) { 6447 err = -ENOMEM; 6448 goto out; 6449 } 6450 /* 6451 * when btrfs_get_extent can't find anything it 6452 * returns one huge hole 6453 * 6454 * make sure what it found really fits our range, and 6455 * adjust to make sure it is based on the start from 6456 * the caller 6457 */ 6458 if (hole_em) { 6459 u64 calc_end = extent_map_end(hole_em); 6460 6461 if (calc_end <= start || (hole_em->start > end)) { 6462 free_extent_map(hole_em); 6463 hole_em = NULL; 6464 } else { 6465 hole_start = max(hole_em->start, start); 6466 hole_len = calc_end - hole_start; 6467 } 6468 } 6469 em->bdev = NULL; 6470 if (hole_em && range_start > hole_start) { 6471 /* our hole starts before our delalloc, so we 6472 * have to return just the parts of the hole 6473 * that go until the delalloc starts 6474 */ 6475 em->len = min(hole_len, 6476 range_start - hole_start); 6477 em->start = hole_start; 6478 em->orig_start = hole_start; 6479 /* 6480 * don't adjust block start at all, 6481 * it is fixed at EXTENT_MAP_HOLE 6482 */ 6483 em->block_start = hole_em->block_start; 6484 em->block_len = hole_len; 6485 if (test_bit(EXTENT_FLAG_PREALLOC, &hole_em->flags)) 6486 set_bit(EXTENT_FLAG_PREALLOC, &em->flags); 6487 } else { 6488 em->start = range_start; 6489 em->len = found; 6490 em->orig_start = range_start; 6491 em->block_start = EXTENT_MAP_DELALLOC; 6492 em->block_len = found; 6493 } 6494 } else if (hole_em) { 6495 return hole_em; 6496 } 6497 out: 6498 6499 free_extent_map(hole_em); 6500 if (err) { 6501 free_extent_map(em); 6502 return ERR_PTR(err); 6503 } 6504 return em; 6505 } 6506 6507 static struct extent_map *btrfs_new_extent_direct(struct inode *inode, 6508 u64 start, u64 len) 6509 { 6510 struct btrfs_root *root = BTRFS_I(inode)->root; 6511 struct extent_map *em; 6512 struct btrfs_key ins; 6513 u64 alloc_hint; 6514 int ret; 6515 6516 alloc_hint = get_extent_allocation_hint(inode, start, len); 6517 ret = btrfs_reserve_extent(root, len, root->sectorsize, 0, 6518 alloc_hint, &ins, 1); 6519 if (ret) 6520 return ERR_PTR(ret); 6521 6522 em = create_pinned_em(inode, start, ins.offset, start, ins.objectid, 6523 ins.offset, ins.offset, ins.offset, 0); 6524 if (IS_ERR(em)) { 6525 btrfs_free_reserved_extent(root, ins.objectid, ins.offset); 6526 return em; 6527 } 6528 6529 ret = btrfs_add_ordered_extent_dio(inode, start, ins.objectid, 6530 ins.offset, ins.offset, 0); 6531 if (ret) { 6532 btrfs_free_reserved_extent(root, ins.objectid, ins.offset); 6533 free_extent_map(em); 6534 return ERR_PTR(ret); 6535 } 6536 6537 return em; 6538 } 6539 6540 /* 6541 * returns 1 when the nocow is safe, < 1 on error, 0 if the 6542 * block must be cow'd 6543 */ 6544 noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len, 6545 u64 *orig_start, u64 *orig_block_len, 6546 u64 *ram_bytes) 6547 { 6548 struct btrfs_trans_handle *trans; 6549 struct btrfs_path *path; 6550 int ret; 6551 struct extent_buffer *leaf; 6552 struct btrfs_root *root = BTRFS_I(inode)->root; 6553 struct btrfs_file_extent_item *fi; 6554 struct btrfs_key key; 6555 u64 disk_bytenr; 6556 u64 backref_offset; 6557 u64 extent_end; 6558 u64 num_bytes; 6559 int slot; 6560 int found_type; 6561 bool nocow = (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW); 6562 6563 path = btrfs_alloc_path(); 6564 if (!path) 6565 return -ENOMEM; 6566 6567 ret = btrfs_lookup_file_extent(NULL, root, path, btrfs_ino(inode), 6568 offset, 0); 6569 if (ret < 0) 6570 goto out; 6571 6572 slot = path->slots[0]; 6573 if (ret == 1) { 6574 if (slot == 0) { 6575 /* can't find the item, must cow */ 6576 ret = 0; 6577 goto out; 6578 } 6579 slot--; 6580 } 6581 ret = 0; 6582 leaf = path->nodes[0]; 6583 btrfs_item_key_to_cpu(leaf, &key, slot); 6584 if (key.objectid != btrfs_ino(inode) || 6585 key.type != BTRFS_EXTENT_DATA_KEY) { 6586 /* not our file or wrong item type, must cow */ 6587 goto out; 6588 } 6589 6590 if (key.offset > offset) { 6591 /* Wrong offset, must cow */ 6592 goto out; 6593 } 6594 6595 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item); 6596 found_type = btrfs_file_extent_type(leaf, fi); 6597 if (found_type != BTRFS_FILE_EXTENT_REG && 6598 found_type != BTRFS_FILE_EXTENT_PREALLOC) { 6599 /* not a regular extent, must cow */ 6600 goto out; 6601 } 6602 6603 if (!nocow && found_type == BTRFS_FILE_EXTENT_REG) 6604 goto out; 6605 6606 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi); 6607 if (extent_end <= offset) 6608 goto out; 6609 6610 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); 6611 if (disk_bytenr == 0) 6612 goto out; 6613 6614 if (btrfs_file_extent_compression(leaf, fi) || 6615 btrfs_file_extent_encryption(leaf, fi) || 6616 btrfs_file_extent_other_encoding(leaf, fi)) 6617 goto out; 6618 6619 backref_offset = btrfs_file_extent_offset(leaf, fi); 6620 6621 if (orig_start) { 6622 *orig_start = key.offset - backref_offset; 6623 *orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi); 6624 *ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi); 6625 } 6626 6627 if (btrfs_extent_readonly(root, disk_bytenr)) 6628 goto out; 6629 btrfs_release_path(path); 6630 6631 /* 6632 * look for other files referencing this extent, if we 6633 * find any we must cow 6634 */ 6635 trans = btrfs_join_transaction(root); 6636 if (IS_ERR(trans)) { 6637 ret = 0; 6638 goto out; 6639 } 6640 6641 ret = btrfs_cross_ref_exist(trans, root, btrfs_ino(inode), 6642 key.offset - backref_offset, disk_bytenr); 6643 btrfs_end_transaction(trans, root); 6644 if (ret) { 6645 ret = 0; 6646 goto out; 6647 } 6648 6649 /* 6650 * adjust disk_bytenr and num_bytes to cover just the bytes 6651 * in this extent we are about to write. If there 6652 * are any csums in that range we have to cow in order 6653 * to keep the csums correct 6654 */ 6655 disk_bytenr += backref_offset; 6656 disk_bytenr += offset - key.offset; 6657 num_bytes = min(offset + *len, extent_end) - offset; 6658 if (csum_exist_in_range(root, disk_bytenr, num_bytes)) 6659 goto out; 6660 /* 6661 * all of the above have passed, it is safe to overwrite this extent 6662 * without cow 6663 */ 6664 *len = num_bytes; 6665 ret = 1; 6666 out: 6667 btrfs_free_path(path); 6668 return ret; 6669 } 6670 6671 static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend, 6672 struct extent_state **cached_state, int writing) 6673 { 6674 struct btrfs_ordered_extent *ordered; 6675 int ret = 0; 6676 6677 while (1) { 6678 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend, 6679 0, cached_state); 6680 /* 6681 * We're concerned with the entire range that we're going to be 6682 * doing DIO to, so we need to make sure theres no ordered 6683 * extents in this range. 6684 */ 6685 ordered = btrfs_lookup_ordered_range(inode, lockstart, 6686 lockend - lockstart + 1); 6687 6688 /* 6689 * We need to make sure there are no buffered pages in this 6690 * range either, we could have raced between the invalidate in 6691 * generic_file_direct_write and locking the extent. The 6692 * invalidate needs to happen so that reads after a write do not 6693 * get stale data. 6694 */ 6695 if (!ordered && (!writing || 6696 !test_range_bit(&BTRFS_I(inode)->io_tree, 6697 lockstart, lockend, EXTENT_UPTODATE, 0, 6698 *cached_state))) 6699 break; 6700 6701 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend, 6702 cached_state, GFP_NOFS); 6703 6704 if (ordered) { 6705 btrfs_start_ordered_extent(inode, ordered, 1); 6706 btrfs_put_ordered_extent(ordered); 6707 } else { 6708 /* Screw you mmap */ 6709 ret = filemap_write_and_wait_range(inode->i_mapping, 6710 lockstart, 6711 lockend); 6712 if (ret) 6713 break; 6714 6715 /* 6716 * If we found a page that couldn't be invalidated just 6717 * fall back to buffered. 6718 */ 6719 ret = invalidate_inode_pages2_range(inode->i_mapping, 6720 lockstart >> PAGE_CACHE_SHIFT, 6721 lockend >> PAGE_CACHE_SHIFT); 6722 if (ret) 6723 break; 6724 } 6725 6726 cond_resched(); 6727 } 6728 6729 return ret; 6730 } 6731 6732 static struct extent_map *create_pinned_em(struct inode *inode, u64 start, 6733 u64 len, u64 orig_start, 6734 u64 block_start, u64 block_len, 6735 u64 orig_block_len, u64 ram_bytes, 6736 int type) 6737 { 6738 struct extent_map_tree *em_tree; 6739 struct extent_map *em; 6740 struct btrfs_root *root = BTRFS_I(inode)->root; 6741 int ret; 6742 6743 em_tree = &BTRFS_I(inode)->extent_tree; 6744 em = alloc_extent_map(); 6745 if (!em) 6746 return ERR_PTR(-ENOMEM); 6747 6748 em->start = start; 6749 em->orig_start = orig_start; 6750 em->mod_start = start; 6751 em->mod_len = len; 6752 em->len = len; 6753 em->block_len = block_len; 6754 em->block_start = block_start; 6755 em->bdev = root->fs_info->fs_devices->latest_bdev; 6756 em->orig_block_len = orig_block_len; 6757 em->ram_bytes = ram_bytes; 6758 em->generation = -1; 6759 set_bit(EXTENT_FLAG_PINNED, &em->flags); 6760 if (type == BTRFS_ORDERED_PREALLOC) 6761 set_bit(EXTENT_FLAG_FILLING, &em->flags); 6762 6763 do { 6764 btrfs_drop_extent_cache(inode, em->start, 6765 em->start + em->len - 1, 0); 6766 write_lock(&em_tree->lock); 6767 ret = add_extent_mapping(em_tree, em, 1); 6768 write_unlock(&em_tree->lock); 6769 } while (ret == -EEXIST); 6770 6771 if (ret) { 6772 free_extent_map(em); 6773 return ERR_PTR(ret); 6774 } 6775 6776 return em; 6777 } 6778 6779 6780 static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock, 6781 struct buffer_head *bh_result, int create) 6782 { 6783 struct extent_map *em; 6784 struct btrfs_root *root = BTRFS_I(inode)->root; 6785 struct extent_state *cached_state = NULL; 6786 u64 start = iblock << inode->i_blkbits; 6787 u64 lockstart, lockend; 6788 u64 len = bh_result->b_size; 6789 int unlock_bits = EXTENT_LOCKED; 6790 int ret = 0; 6791 6792 if (create) 6793 unlock_bits |= EXTENT_DELALLOC | EXTENT_DIRTY; 6794 else 6795 len = min_t(u64, len, root->sectorsize); 6796 6797 lockstart = start; 6798 lockend = start + len - 1; 6799 6800 /* 6801 * If this errors out it's because we couldn't invalidate pagecache for 6802 * this range and we need to fallback to buffered. 6803 */ 6804 if (lock_extent_direct(inode, lockstart, lockend, &cached_state, create)) 6805 return -ENOTBLK; 6806 6807 em = btrfs_get_extent(inode, NULL, 0, start, len, 0); 6808 if (IS_ERR(em)) { 6809 ret = PTR_ERR(em); 6810 goto unlock_err; 6811 } 6812 6813 /* 6814 * Ok for INLINE and COMPRESSED extents we need to fallback on buffered 6815 * io. INLINE is special, and we could probably kludge it in here, but 6816 * it's still buffered so for safety lets just fall back to the generic 6817 * buffered path. 6818 * 6819 * For COMPRESSED we _have_ to read the entire extent in so we can 6820 * decompress it, so there will be buffering required no matter what we 6821 * do, so go ahead and fallback to buffered. 6822 * 6823 * We return -ENOTBLK because thats what makes DIO go ahead and go back 6824 * to buffered IO. Don't blame me, this is the price we pay for using 6825 * the generic code. 6826 */ 6827 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) || 6828 em->block_start == EXTENT_MAP_INLINE) { 6829 free_extent_map(em); 6830 ret = -ENOTBLK; 6831 goto unlock_err; 6832 } 6833 6834 /* Just a good old fashioned hole, return */ 6835 if (!create && (em->block_start == EXTENT_MAP_HOLE || 6836 test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) { 6837 free_extent_map(em); 6838 goto unlock_err; 6839 } 6840 6841 /* 6842 * We don't allocate a new extent in the following cases 6843 * 6844 * 1) The inode is marked as NODATACOW. In this case we'll just use the 6845 * existing extent. 6846 * 2) The extent is marked as PREALLOC. We're good to go here and can 6847 * just use the extent. 6848 * 6849 */ 6850 if (!create) { 6851 len = min(len, em->len - (start - em->start)); 6852 lockstart = start + len; 6853 goto unlock; 6854 } 6855 6856 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) || 6857 ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) && 6858 em->block_start != EXTENT_MAP_HOLE)) { 6859 int type; 6860 int ret; 6861 u64 block_start, orig_start, orig_block_len, ram_bytes; 6862 6863 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) 6864 type = BTRFS_ORDERED_PREALLOC; 6865 else 6866 type = BTRFS_ORDERED_NOCOW; 6867 len = min(len, em->len - (start - em->start)); 6868 block_start = em->block_start + (start - em->start); 6869 6870 if (can_nocow_extent(inode, start, &len, &orig_start, 6871 &orig_block_len, &ram_bytes) == 1) { 6872 if (type == BTRFS_ORDERED_PREALLOC) { 6873 free_extent_map(em); 6874 em = create_pinned_em(inode, start, len, 6875 orig_start, 6876 block_start, len, 6877 orig_block_len, 6878 ram_bytes, type); 6879 if (IS_ERR(em)) 6880 goto unlock_err; 6881 } 6882 6883 ret = btrfs_add_ordered_extent_dio(inode, start, 6884 block_start, len, len, type); 6885 if (ret) { 6886 free_extent_map(em); 6887 goto unlock_err; 6888 } 6889 goto unlock; 6890 } 6891 } 6892 6893 /* 6894 * this will cow the extent, reset the len in case we changed 6895 * it above 6896 */ 6897 len = bh_result->b_size; 6898 free_extent_map(em); 6899 em = btrfs_new_extent_direct(inode, start, len); 6900 if (IS_ERR(em)) { 6901 ret = PTR_ERR(em); 6902 goto unlock_err; 6903 } 6904 len = min(len, em->len - (start - em->start)); 6905 unlock: 6906 bh_result->b_blocknr = (em->block_start + (start - em->start)) >> 6907 inode->i_blkbits; 6908 bh_result->b_size = len; 6909 bh_result->b_bdev = em->bdev; 6910 set_buffer_mapped(bh_result); 6911 if (create) { 6912 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) 6913 set_buffer_new(bh_result); 6914 6915 /* 6916 * Need to update the i_size under the extent lock so buffered 6917 * readers will get the updated i_size when we unlock. 6918 */ 6919 if (start + len > i_size_read(inode)) 6920 i_size_write(inode, start + len); 6921 6922 spin_lock(&BTRFS_I(inode)->lock); 6923 BTRFS_I(inode)->outstanding_extents++; 6924 spin_unlock(&BTRFS_I(inode)->lock); 6925 6926 ret = set_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, 6927 lockstart + len - 1, EXTENT_DELALLOC, NULL, 6928 &cached_state, GFP_NOFS); 6929 BUG_ON(ret); 6930 } 6931 6932 /* 6933 * In the case of write we need to clear and unlock the entire range, 6934 * in the case of read we need to unlock only the end area that we 6935 * aren't using if there is any left over space. 6936 */ 6937 if (lockstart < lockend) { 6938 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, 6939 lockend, unlock_bits, 1, 0, 6940 &cached_state, GFP_NOFS); 6941 } else { 6942 free_extent_state(cached_state); 6943 } 6944 6945 free_extent_map(em); 6946 6947 return 0; 6948 6949 unlock_err: 6950 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend, 6951 unlock_bits, 1, 0, &cached_state, GFP_NOFS); 6952 return ret; 6953 } 6954 6955 static void btrfs_endio_direct_read(struct bio *bio, int err) 6956 { 6957 struct btrfs_dio_private *dip = bio->bi_private; 6958 struct bio_vec *bvec; 6959 struct inode *inode = dip->inode; 6960 struct btrfs_root *root = BTRFS_I(inode)->root; 6961 struct bio *dio_bio; 6962 u32 *csums = (u32 *)dip->csum; 6963 u64 start; 6964 int i; 6965 6966 start = dip->logical_offset; 6967 bio_for_each_segment_all(bvec, bio, i) { 6968 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) { 6969 struct page *page = bvec->bv_page; 6970 char *kaddr; 6971 u32 csum = ~(u32)0; 6972 unsigned long flags; 6973 6974 local_irq_save(flags); 6975 kaddr = kmap_atomic(page); 6976 csum = btrfs_csum_data(kaddr + bvec->bv_offset, 6977 csum, bvec->bv_len); 6978 btrfs_csum_final(csum, (char *)&csum); 6979 kunmap_atomic(kaddr); 6980 local_irq_restore(flags); 6981 6982 flush_dcache_page(bvec->bv_page); 6983 if (csum != csums[i]) { 6984 btrfs_err(root->fs_info, "csum failed ino %llu off %llu csum %u expected csum %u", 6985 btrfs_ino(inode), start, csum, 6986 csums[i]); 6987 err = -EIO; 6988 } 6989 } 6990 6991 start += bvec->bv_len; 6992 } 6993 6994 unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset, 6995 dip->logical_offset + dip->bytes - 1); 6996 dio_bio = dip->dio_bio; 6997 6998 kfree(dip); 6999 7000 /* If we had a csum failure make sure to clear the uptodate flag */ 7001 if (err) 7002 clear_bit(BIO_UPTODATE, &dio_bio->bi_flags); 7003 dio_end_io(dio_bio, err); 7004 bio_put(bio); 7005 } 7006 7007 static void btrfs_endio_direct_write(struct bio *bio, int err) 7008 { 7009 struct btrfs_dio_private *dip = bio->bi_private; 7010 struct inode *inode = dip->inode; 7011 struct btrfs_root *root = BTRFS_I(inode)->root; 7012 struct btrfs_ordered_extent *ordered = NULL; 7013 u64 ordered_offset = dip->logical_offset; 7014 u64 ordered_bytes = dip->bytes; 7015 struct bio *dio_bio; 7016 int ret; 7017 7018 if (err) 7019 goto out_done; 7020 again: 7021 ret = btrfs_dec_test_first_ordered_pending(inode, &ordered, 7022 &ordered_offset, 7023 ordered_bytes, !err); 7024 if (!ret) 7025 goto out_test; 7026 7027 ordered->work.func = finish_ordered_fn; 7028 ordered->work.flags = 0; 7029 btrfs_queue_worker(&root->fs_info->endio_write_workers, 7030 &ordered->work); 7031 out_test: 7032 /* 7033 * our bio might span multiple ordered extents. If we haven't 7034 * completed the accounting for the whole dio, go back and try again 7035 */ 7036 if (ordered_offset < dip->logical_offset + dip->bytes) { 7037 ordered_bytes = dip->logical_offset + dip->bytes - 7038 ordered_offset; 7039 ordered = NULL; 7040 goto again; 7041 } 7042 out_done: 7043 dio_bio = dip->dio_bio; 7044 7045 kfree(dip); 7046 7047 /* If we had an error make sure to clear the uptodate flag */ 7048 if (err) 7049 clear_bit(BIO_UPTODATE, &dio_bio->bi_flags); 7050 dio_end_io(dio_bio, err); 7051 bio_put(bio); 7052 } 7053 7054 static int __btrfs_submit_bio_start_direct_io(struct inode *inode, int rw, 7055 struct bio *bio, int mirror_num, 7056 unsigned long bio_flags, u64 offset) 7057 { 7058 int ret; 7059 struct btrfs_root *root = BTRFS_I(inode)->root; 7060 ret = btrfs_csum_one_bio(root, inode, bio, offset, 1); 7061 BUG_ON(ret); /* -ENOMEM */ 7062 return 0; 7063 } 7064 7065 static void btrfs_end_dio_bio(struct bio *bio, int err) 7066 { 7067 struct btrfs_dio_private *dip = bio->bi_private; 7068 7069 if (err) { 7070 btrfs_err(BTRFS_I(dip->inode)->root->fs_info, 7071 "direct IO failed ino %llu rw %lu sector %#Lx len %u err no %d", 7072 btrfs_ino(dip->inode), bio->bi_rw, 7073 (unsigned long long)bio->bi_iter.bi_sector, 7074 bio->bi_iter.bi_size, err); 7075 dip->errors = 1; 7076 7077 /* 7078 * before atomic variable goto zero, we must make sure 7079 * dip->errors is perceived to be set. 7080 */ 7081 smp_mb__before_atomic_dec(); 7082 } 7083 7084 /* if there are more bios still pending for this dio, just exit */ 7085 if (!atomic_dec_and_test(&dip->pending_bios)) 7086 goto out; 7087 7088 if (dip->errors) { 7089 bio_io_error(dip->orig_bio); 7090 } else { 7091 set_bit(BIO_UPTODATE, &dip->dio_bio->bi_flags); 7092 bio_endio(dip->orig_bio, 0); 7093 } 7094 out: 7095 bio_put(bio); 7096 } 7097 7098 static struct bio *btrfs_dio_bio_alloc(struct block_device *bdev, 7099 u64 first_sector, gfp_t gfp_flags) 7100 { 7101 int nr_vecs = bio_get_nr_vecs(bdev); 7102 return btrfs_bio_alloc(bdev, first_sector, nr_vecs, gfp_flags); 7103 } 7104 7105 static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode, 7106 int rw, u64 file_offset, int skip_sum, 7107 int async_submit) 7108 { 7109 struct btrfs_dio_private *dip = bio->bi_private; 7110 int write = rw & REQ_WRITE; 7111 struct btrfs_root *root = BTRFS_I(inode)->root; 7112 int ret; 7113 7114 if (async_submit) 7115 async_submit = !atomic_read(&BTRFS_I(inode)->sync_writers); 7116 7117 bio_get(bio); 7118 7119 if (!write) { 7120 ret = btrfs_bio_wq_end_io(root->fs_info, bio, 0); 7121 if (ret) 7122 goto err; 7123 } 7124 7125 if (skip_sum) 7126 goto map; 7127 7128 if (write && async_submit) { 7129 ret = btrfs_wq_submit_bio(root->fs_info, 7130 inode, rw, bio, 0, 0, 7131 file_offset, 7132 __btrfs_submit_bio_start_direct_io, 7133 __btrfs_submit_bio_done); 7134 goto err; 7135 } else if (write) { 7136 /* 7137 * If we aren't doing async submit, calculate the csum of the 7138 * bio now. 7139 */ 7140 ret = btrfs_csum_one_bio(root, inode, bio, file_offset, 1); 7141 if (ret) 7142 goto err; 7143 } else if (!skip_sum) { 7144 ret = btrfs_lookup_bio_sums_dio(root, inode, dip, bio, 7145 file_offset); 7146 if (ret) 7147 goto err; 7148 } 7149 7150 map: 7151 ret = btrfs_map_bio(root, rw, bio, 0, async_submit); 7152 err: 7153 bio_put(bio); 7154 return ret; 7155 } 7156 7157 static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip, 7158 int skip_sum) 7159 { 7160 struct inode *inode = dip->inode; 7161 struct btrfs_root *root = BTRFS_I(inode)->root; 7162 struct bio *bio; 7163 struct bio *orig_bio = dip->orig_bio; 7164 struct bio_vec *bvec = orig_bio->bi_io_vec; 7165 u64 start_sector = orig_bio->bi_iter.bi_sector; 7166 u64 file_offset = dip->logical_offset; 7167 u64 submit_len = 0; 7168 u64 map_length; 7169 int nr_pages = 0; 7170 int ret = 0; 7171 int async_submit = 0; 7172 7173 map_length = orig_bio->bi_iter.bi_size; 7174 ret = btrfs_map_block(root->fs_info, rw, start_sector << 9, 7175 &map_length, NULL, 0); 7176 if (ret) { 7177 bio_put(orig_bio); 7178 return -EIO; 7179 } 7180 7181 if (map_length >= orig_bio->bi_iter.bi_size) { 7182 bio = orig_bio; 7183 goto submit; 7184 } 7185 7186 /* async crcs make it difficult to collect full stripe writes. */ 7187 if (btrfs_get_alloc_profile(root, 1) & 7188 (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6)) 7189 async_submit = 0; 7190 else 7191 async_submit = 1; 7192 7193 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, start_sector, GFP_NOFS); 7194 if (!bio) 7195 return -ENOMEM; 7196 bio->bi_private = dip; 7197 bio->bi_end_io = btrfs_end_dio_bio; 7198 atomic_inc(&dip->pending_bios); 7199 7200 while (bvec <= (orig_bio->bi_io_vec + orig_bio->bi_vcnt - 1)) { 7201 if (unlikely(map_length < submit_len + bvec->bv_len || 7202 bio_add_page(bio, bvec->bv_page, bvec->bv_len, 7203 bvec->bv_offset) < bvec->bv_len)) { 7204 /* 7205 * inc the count before we submit the bio so 7206 * we know the end IO handler won't happen before 7207 * we inc the count. Otherwise, the dip might get freed 7208 * before we're done setting it up 7209 */ 7210 atomic_inc(&dip->pending_bios); 7211 ret = __btrfs_submit_dio_bio(bio, inode, rw, 7212 file_offset, skip_sum, 7213 async_submit); 7214 if (ret) { 7215 bio_put(bio); 7216 atomic_dec(&dip->pending_bios); 7217 goto out_err; 7218 } 7219 7220 start_sector += submit_len >> 9; 7221 file_offset += submit_len; 7222 7223 submit_len = 0; 7224 nr_pages = 0; 7225 7226 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, 7227 start_sector, GFP_NOFS); 7228 if (!bio) 7229 goto out_err; 7230 bio->bi_private = dip; 7231 bio->bi_end_io = btrfs_end_dio_bio; 7232 7233 map_length = orig_bio->bi_iter.bi_size; 7234 ret = btrfs_map_block(root->fs_info, rw, 7235 start_sector << 9, 7236 &map_length, NULL, 0); 7237 if (ret) { 7238 bio_put(bio); 7239 goto out_err; 7240 } 7241 } else { 7242 submit_len += bvec->bv_len; 7243 nr_pages++; 7244 bvec++; 7245 } 7246 } 7247 7248 submit: 7249 ret = __btrfs_submit_dio_bio(bio, inode, rw, file_offset, skip_sum, 7250 async_submit); 7251 if (!ret) 7252 return 0; 7253 7254 bio_put(bio); 7255 out_err: 7256 dip->errors = 1; 7257 /* 7258 * before atomic variable goto zero, we must 7259 * make sure dip->errors is perceived to be set. 7260 */ 7261 smp_mb__before_atomic_dec(); 7262 if (atomic_dec_and_test(&dip->pending_bios)) 7263 bio_io_error(dip->orig_bio); 7264 7265 /* bio_end_io() will handle error, so we needn't return it */ 7266 return 0; 7267 } 7268 7269 static void btrfs_submit_direct(int rw, struct bio *dio_bio, 7270 struct inode *inode, loff_t file_offset) 7271 { 7272 struct btrfs_root *root = BTRFS_I(inode)->root; 7273 struct btrfs_dio_private *dip; 7274 struct bio *io_bio; 7275 int skip_sum; 7276 int sum_len; 7277 int write = rw & REQ_WRITE; 7278 int ret = 0; 7279 u16 csum_size; 7280 7281 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM; 7282 7283 io_bio = btrfs_bio_clone(dio_bio, GFP_NOFS); 7284 if (!io_bio) { 7285 ret = -ENOMEM; 7286 goto free_ordered; 7287 } 7288 7289 if (!skip_sum && !write) { 7290 csum_size = btrfs_super_csum_size(root->fs_info->super_copy); 7291 sum_len = dio_bio->bi_iter.bi_size >> 7292 inode->i_sb->s_blocksize_bits; 7293 sum_len *= csum_size; 7294 } else { 7295 sum_len = 0; 7296 } 7297 7298 dip = kmalloc(sizeof(*dip) + sum_len, GFP_NOFS); 7299 if (!dip) { 7300 ret = -ENOMEM; 7301 goto free_io_bio; 7302 } 7303 7304 dip->private = dio_bio->bi_private; 7305 dip->inode = inode; 7306 dip->logical_offset = file_offset; 7307 dip->bytes = dio_bio->bi_iter.bi_size; 7308 dip->disk_bytenr = (u64)dio_bio->bi_iter.bi_sector << 9; 7309 io_bio->bi_private = dip; 7310 dip->errors = 0; 7311 dip->orig_bio = io_bio; 7312 dip->dio_bio = dio_bio; 7313 atomic_set(&dip->pending_bios, 0); 7314 7315 if (write) 7316 io_bio->bi_end_io = btrfs_endio_direct_write; 7317 else 7318 io_bio->bi_end_io = btrfs_endio_direct_read; 7319 7320 ret = btrfs_submit_direct_hook(rw, dip, skip_sum); 7321 if (!ret) 7322 return; 7323 7324 free_io_bio: 7325 bio_put(io_bio); 7326 7327 free_ordered: 7328 /* 7329 * If this is a write, we need to clean up the reserved space and kill 7330 * the ordered extent. 7331 */ 7332 if (write) { 7333 struct btrfs_ordered_extent *ordered; 7334 ordered = btrfs_lookup_ordered_extent(inode, file_offset); 7335 if (!test_bit(BTRFS_ORDERED_PREALLOC, &ordered->flags) && 7336 !test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags)) 7337 btrfs_free_reserved_extent(root, ordered->start, 7338 ordered->disk_len); 7339 btrfs_put_ordered_extent(ordered); 7340 btrfs_put_ordered_extent(ordered); 7341 } 7342 bio_endio(dio_bio, ret); 7343 } 7344 7345 static ssize_t check_direct_IO(struct btrfs_root *root, int rw, struct kiocb *iocb, 7346 const struct iovec *iov, loff_t offset, 7347 unsigned long nr_segs) 7348 { 7349 int seg; 7350 int i; 7351 size_t size; 7352 unsigned long addr; 7353 unsigned blocksize_mask = root->sectorsize - 1; 7354 ssize_t retval = -EINVAL; 7355 loff_t end = offset; 7356 7357 if (offset & blocksize_mask) 7358 goto out; 7359 7360 /* Check the memory alignment. Blocks cannot straddle pages */ 7361 for (seg = 0; seg < nr_segs; seg++) { 7362 addr = (unsigned long)iov[seg].iov_base; 7363 size = iov[seg].iov_len; 7364 end += size; 7365 if ((addr & blocksize_mask) || (size & blocksize_mask)) 7366 goto out; 7367 7368 /* If this is a write we don't need to check anymore */ 7369 if (rw & WRITE) 7370 continue; 7371 7372 /* 7373 * Check to make sure we don't have duplicate iov_base's in this 7374 * iovec, if so return EINVAL, otherwise we'll get csum errors 7375 * when reading back. 7376 */ 7377 for (i = seg + 1; i < nr_segs; i++) { 7378 if (iov[seg].iov_base == iov[i].iov_base) 7379 goto out; 7380 } 7381 } 7382 retval = 0; 7383 out: 7384 return retval; 7385 } 7386 7387 static ssize_t btrfs_direct_IO(int rw, struct kiocb *iocb, 7388 const struct iovec *iov, loff_t offset, 7389 unsigned long nr_segs) 7390 { 7391 struct file *file = iocb->ki_filp; 7392 struct inode *inode = file->f_mapping->host; 7393 size_t count = 0; 7394 int flags = 0; 7395 bool wakeup = true; 7396 bool relock = false; 7397 ssize_t ret; 7398 7399 if (check_direct_IO(BTRFS_I(inode)->root, rw, iocb, iov, 7400 offset, nr_segs)) 7401 return 0; 7402 7403 atomic_inc(&inode->i_dio_count); 7404 smp_mb__after_atomic_inc(); 7405 7406 /* 7407 * The generic stuff only does filemap_write_and_wait_range, which isn't 7408 * enough if we've written compressed pages to this area, so we need to 7409 * call btrfs_wait_ordered_range to make absolutely sure that any 7410 * outstanding dirty pages are on disk. 7411 */ 7412 count = iov_length(iov, nr_segs); 7413 ret = btrfs_wait_ordered_range(inode, offset, count); 7414 if (ret) 7415 return ret; 7416 7417 if (rw & WRITE) { 7418 /* 7419 * If the write DIO is beyond the EOF, we need update 7420 * the isize, but it is protected by i_mutex. So we can 7421 * not unlock the i_mutex at this case. 7422 */ 7423 if (offset + count <= inode->i_size) { 7424 mutex_unlock(&inode->i_mutex); 7425 relock = true; 7426 } 7427 ret = btrfs_delalloc_reserve_space(inode, count); 7428 if (ret) 7429 goto out; 7430 } else if (unlikely(test_bit(BTRFS_INODE_READDIO_NEED_LOCK, 7431 &BTRFS_I(inode)->runtime_flags))) { 7432 inode_dio_done(inode); 7433 flags = DIO_LOCKING | DIO_SKIP_HOLES; 7434 wakeup = false; 7435 } 7436 7437 ret = __blockdev_direct_IO(rw, iocb, inode, 7438 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev, 7439 iov, offset, nr_segs, btrfs_get_blocks_direct, NULL, 7440 btrfs_submit_direct, flags); 7441 if (rw & WRITE) { 7442 if (ret < 0 && ret != -EIOCBQUEUED) 7443 btrfs_delalloc_release_space(inode, count); 7444 else if (ret >= 0 && (size_t)ret < count) 7445 btrfs_delalloc_release_space(inode, 7446 count - (size_t)ret); 7447 else 7448 btrfs_delalloc_release_metadata(inode, 0); 7449 } 7450 out: 7451 if (wakeup) 7452 inode_dio_done(inode); 7453 if (relock) 7454 mutex_lock(&inode->i_mutex); 7455 7456 return ret; 7457 } 7458 7459 #define BTRFS_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC) 7460 7461 static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, 7462 __u64 start, __u64 len) 7463 { 7464 int ret; 7465 7466 ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS); 7467 if (ret) 7468 return ret; 7469 7470 return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent_fiemap); 7471 } 7472 7473 int btrfs_readpage(struct file *file, struct page *page) 7474 { 7475 struct extent_io_tree *tree; 7476 tree = &BTRFS_I(page->mapping->host)->io_tree; 7477 return extent_read_full_page(tree, page, btrfs_get_extent, 0); 7478 } 7479 7480 static int btrfs_writepage(struct page *page, struct writeback_control *wbc) 7481 { 7482 struct extent_io_tree *tree; 7483 7484 7485 if (current->flags & PF_MEMALLOC) { 7486 redirty_page_for_writepage(wbc, page); 7487 unlock_page(page); 7488 return 0; 7489 } 7490 tree = &BTRFS_I(page->mapping->host)->io_tree; 7491 return extent_write_full_page(tree, page, btrfs_get_extent, wbc); 7492 } 7493 7494 static int btrfs_writepages(struct address_space *mapping, 7495 struct writeback_control *wbc) 7496 { 7497 struct extent_io_tree *tree; 7498 7499 tree = &BTRFS_I(mapping->host)->io_tree; 7500 return extent_writepages(tree, mapping, btrfs_get_extent, wbc); 7501 } 7502 7503 static int 7504 btrfs_readpages(struct file *file, struct address_space *mapping, 7505 struct list_head *pages, unsigned nr_pages) 7506 { 7507 struct extent_io_tree *tree; 7508 tree = &BTRFS_I(mapping->host)->io_tree; 7509 return extent_readpages(tree, mapping, pages, nr_pages, 7510 btrfs_get_extent); 7511 } 7512 static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags) 7513 { 7514 struct extent_io_tree *tree; 7515 struct extent_map_tree *map; 7516 int ret; 7517 7518 tree = &BTRFS_I(page->mapping->host)->io_tree; 7519 map = &BTRFS_I(page->mapping->host)->extent_tree; 7520 ret = try_release_extent_mapping(map, tree, page, gfp_flags); 7521 if (ret == 1) { 7522 ClearPagePrivate(page); 7523 set_page_private(page, 0); 7524 page_cache_release(page); 7525 } 7526 return ret; 7527 } 7528 7529 static int btrfs_releasepage(struct page *page, gfp_t gfp_flags) 7530 { 7531 if (PageWriteback(page) || PageDirty(page)) 7532 return 0; 7533 return __btrfs_releasepage(page, gfp_flags & GFP_NOFS); 7534 } 7535 7536 static void btrfs_invalidatepage(struct page *page, unsigned int offset, 7537 unsigned int length) 7538 { 7539 struct inode *inode = page->mapping->host; 7540 struct extent_io_tree *tree; 7541 struct btrfs_ordered_extent *ordered; 7542 struct extent_state *cached_state = NULL; 7543 u64 page_start = page_offset(page); 7544 u64 page_end = page_start + PAGE_CACHE_SIZE - 1; 7545 int inode_evicting = inode->i_state & I_FREEING; 7546 7547 /* 7548 * we have the page locked, so new writeback can't start, 7549 * and the dirty bit won't be cleared while we are here. 7550 * 7551 * Wait for IO on this page so that we can safely clear 7552 * the PagePrivate2 bit and do ordered accounting 7553 */ 7554 wait_on_page_writeback(page); 7555 7556 tree = &BTRFS_I(inode)->io_tree; 7557 if (offset) { 7558 btrfs_releasepage(page, GFP_NOFS); 7559 return; 7560 } 7561 7562 if (!inode_evicting) 7563 lock_extent_bits(tree, page_start, page_end, 0, &cached_state); 7564 ordered = btrfs_lookup_ordered_extent(inode, page_start); 7565 if (ordered) { 7566 /* 7567 * IO on this page will never be started, so we need 7568 * to account for any ordered extents now 7569 */ 7570 if (!inode_evicting) 7571 clear_extent_bit(tree, page_start, page_end, 7572 EXTENT_DIRTY | EXTENT_DELALLOC | 7573 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING | 7574 EXTENT_DEFRAG, 1, 0, &cached_state, 7575 GFP_NOFS); 7576 /* 7577 * whoever cleared the private bit is responsible 7578 * for the finish_ordered_io 7579 */ 7580 if (TestClearPagePrivate2(page)) { 7581 struct btrfs_ordered_inode_tree *tree; 7582 u64 new_len; 7583 7584 tree = &BTRFS_I(inode)->ordered_tree; 7585 7586 spin_lock_irq(&tree->lock); 7587 set_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags); 7588 new_len = page_start - ordered->file_offset; 7589 if (new_len < ordered->truncated_len) 7590 ordered->truncated_len = new_len; 7591 spin_unlock_irq(&tree->lock); 7592 7593 if (btrfs_dec_test_ordered_pending(inode, &ordered, 7594 page_start, 7595 PAGE_CACHE_SIZE, 1)) 7596 btrfs_finish_ordered_io(ordered); 7597 } 7598 btrfs_put_ordered_extent(ordered); 7599 if (!inode_evicting) { 7600 cached_state = NULL; 7601 lock_extent_bits(tree, page_start, page_end, 0, 7602 &cached_state); 7603 } 7604 } 7605 7606 if (!inode_evicting) { 7607 clear_extent_bit(tree, page_start, page_end, 7608 EXTENT_LOCKED | EXTENT_DIRTY | 7609 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING | 7610 EXTENT_DEFRAG, 1, 1, 7611 &cached_state, GFP_NOFS); 7612 7613 __btrfs_releasepage(page, GFP_NOFS); 7614 } 7615 7616 ClearPageChecked(page); 7617 if (PagePrivate(page)) { 7618 ClearPagePrivate(page); 7619 set_page_private(page, 0); 7620 page_cache_release(page); 7621 } 7622 } 7623 7624 /* 7625 * btrfs_page_mkwrite() is not allowed to change the file size as it gets 7626 * called from a page fault handler when a page is first dirtied. Hence we must 7627 * be careful to check for EOF conditions here. We set the page up correctly 7628 * for a written page which means we get ENOSPC checking when writing into 7629 * holes and correct delalloc and unwritten extent mapping on filesystems that 7630 * support these features. 7631 * 7632 * We are not allowed to take the i_mutex here so we have to play games to 7633 * protect against truncate races as the page could now be beyond EOF. Because 7634 * vmtruncate() writes the inode size before removing pages, once we have the 7635 * page lock we can determine safely if the page is beyond EOF. If it is not 7636 * beyond EOF, then the page is guaranteed safe against truncation until we 7637 * unlock the page. 7638 */ 7639 int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) 7640 { 7641 struct page *page = vmf->page; 7642 struct inode *inode = file_inode(vma->vm_file); 7643 struct btrfs_root *root = BTRFS_I(inode)->root; 7644 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 7645 struct btrfs_ordered_extent *ordered; 7646 struct extent_state *cached_state = NULL; 7647 char *kaddr; 7648 unsigned long zero_start; 7649 loff_t size; 7650 int ret; 7651 int reserved = 0; 7652 u64 page_start; 7653 u64 page_end; 7654 7655 sb_start_pagefault(inode->i_sb); 7656 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE); 7657 if (!ret) { 7658 ret = file_update_time(vma->vm_file); 7659 reserved = 1; 7660 } 7661 if (ret) { 7662 if (ret == -ENOMEM) 7663 ret = VM_FAULT_OOM; 7664 else /* -ENOSPC, -EIO, etc */ 7665 ret = VM_FAULT_SIGBUS; 7666 if (reserved) 7667 goto out; 7668 goto out_noreserve; 7669 } 7670 7671 ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */ 7672 again: 7673 lock_page(page); 7674 size = i_size_read(inode); 7675 page_start = page_offset(page); 7676 page_end = page_start + PAGE_CACHE_SIZE - 1; 7677 7678 if ((page->mapping != inode->i_mapping) || 7679 (page_start >= size)) { 7680 /* page got truncated out from underneath us */ 7681 goto out_unlock; 7682 } 7683 wait_on_page_writeback(page); 7684 7685 lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state); 7686 set_page_extent_mapped(page); 7687 7688 /* 7689 * we can't set the delalloc bits if there are pending ordered 7690 * extents. Drop our locks and wait for them to finish 7691 */ 7692 ordered = btrfs_lookup_ordered_extent(inode, page_start); 7693 if (ordered) { 7694 unlock_extent_cached(io_tree, page_start, page_end, 7695 &cached_state, GFP_NOFS); 7696 unlock_page(page); 7697 btrfs_start_ordered_extent(inode, ordered, 1); 7698 btrfs_put_ordered_extent(ordered); 7699 goto again; 7700 } 7701 7702 /* 7703 * XXX - page_mkwrite gets called every time the page is dirtied, even 7704 * if it was already dirty, so for space accounting reasons we need to 7705 * clear any delalloc bits for the range we are fixing to save. There 7706 * is probably a better way to do this, but for now keep consistent with 7707 * prepare_pages in the normal write path. 7708 */ 7709 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end, 7710 EXTENT_DIRTY | EXTENT_DELALLOC | 7711 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 7712 0, 0, &cached_state, GFP_NOFS); 7713 7714 ret = btrfs_set_extent_delalloc(inode, page_start, page_end, 7715 &cached_state); 7716 if (ret) { 7717 unlock_extent_cached(io_tree, page_start, page_end, 7718 &cached_state, GFP_NOFS); 7719 ret = VM_FAULT_SIGBUS; 7720 goto out_unlock; 7721 } 7722 ret = 0; 7723 7724 /* page is wholly or partially inside EOF */ 7725 if (page_start + PAGE_CACHE_SIZE > size) 7726 zero_start = size & ~PAGE_CACHE_MASK; 7727 else 7728 zero_start = PAGE_CACHE_SIZE; 7729 7730 if (zero_start != PAGE_CACHE_SIZE) { 7731 kaddr = kmap(page); 7732 memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start); 7733 flush_dcache_page(page); 7734 kunmap(page); 7735 } 7736 ClearPageChecked(page); 7737 set_page_dirty(page); 7738 SetPageUptodate(page); 7739 7740 BTRFS_I(inode)->last_trans = root->fs_info->generation; 7741 BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid; 7742 BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit; 7743 7744 unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS); 7745 7746 out_unlock: 7747 if (!ret) { 7748 sb_end_pagefault(inode->i_sb); 7749 return VM_FAULT_LOCKED; 7750 } 7751 unlock_page(page); 7752 out: 7753 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE); 7754 out_noreserve: 7755 sb_end_pagefault(inode->i_sb); 7756 return ret; 7757 } 7758 7759 static int btrfs_truncate(struct inode *inode) 7760 { 7761 struct btrfs_root *root = BTRFS_I(inode)->root; 7762 struct btrfs_block_rsv *rsv; 7763 int ret = 0; 7764 int err = 0; 7765 struct btrfs_trans_handle *trans; 7766 u64 mask = root->sectorsize - 1; 7767 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1); 7768 7769 ret = btrfs_wait_ordered_range(inode, inode->i_size & (~mask), 7770 (u64)-1); 7771 if (ret) 7772 return ret; 7773 7774 /* 7775 * Yes ladies and gentelment, this is indeed ugly. The fact is we have 7776 * 3 things going on here 7777 * 7778 * 1) We need to reserve space for our orphan item and the space to 7779 * delete our orphan item. Lord knows we don't want to have a dangling 7780 * orphan item because we didn't reserve space to remove it. 7781 * 7782 * 2) We need to reserve space to update our inode. 7783 * 7784 * 3) We need to have something to cache all the space that is going to 7785 * be free'd up by the truncate operation, but also have some slack 7786 * space reserved in case it uses space during the truncate (thank you 7787 * very much snapshotting). 7788 * 7789 * And we need these to all be seperate. The fact is we can use alot of 7790 * space doing the truncate, and we have no earthly idea how much space 7791 * we will use, so we need the truncate reservation to be seperate so it 7792 * doesn't end up using space reserved for updating the inode or 7793 * removing the orphan item. We also need to be able to stop the 7794 * transaction and start a new one, which means we need to be able to 7795 * update the inode several times, and we have no idea of knowing how 7796 * many times that will be, so we can't just reserve 1 item for the 7797 * entirety of the opration, so that has to be done seperately as well. 7798 * Then there is the orphan item, which does indeed need to be held on 7799 * to for the whole operation, and we need nobody to touch this reserved 7800 * space except the orphan code. 7801 * 7802 * So that leaves us with 7803 * 7804 * 1) root->orphan_block_rsv - for the orphan deletion. 7805 * 2) rsv - for the truncate reservation, which we will steal from the 7806 * transaction reservation. 7807 * 3) fs_info->trans_block_rsv - this will have 1 items worth left for 7808 * updating the inode. 7809 */ 7810 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP); 7811 if (!rsv) 7812 return -ENOMEM; 7813 rsv->size = min_size; 7814 rsv->failfast = 1; 7815 7816 /* 7817 * 1 for the truncate slack space 7818 * 1 for updating the inode. 7819 */ 7820 trans = btrfs_start_transaction(root, 2); 7821 if (IS_ERR(trans)) { 7822 err = PTR_ERR(trans); 7823 goto out; 7824 } 7825 7826 /* Migrate the slack space for the truncate to our reserve */ 7827 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, rsv, 7828 min_size); 7829 BUG_ON(ret); 7830 7831 /* 7832 * setattr is responsible for setting the ordered_data_close flag, 7833 * but that is only tested during the last file release. That 7834 * could happen well after the next commit, leaving a great big 7835 * window where new writes may get lost if someone chooses to write 7836 * to this file after truncating to zero 7837 * 7838 * The inode doesn't have any dirty data here, and so if we commit 7839 * this is a noop. If someone immediately starts writing to the inode 7840 * it is very likely we'll catch some of their writes in this 7841 * transaction, and the commit will find this file on the ordered 7842 * data list with good things to send down. 7843 * 7844 * This is a best effort solution, there is still a window where 7845 * using truncate to replace the contents of the file will 7846 * end up with a zero length file after a crash. 7847 */ 7848 if (inode->i_size == 0 && test_bit(BTRFS_INODE_ORDERED_DATA_CLOSE, 7849 &BTRFS_I(inode)->runtime_flags)) 7850 btrfs_add_ordered_operation(trans, root, inode); 7851 7852 /* 7853 * So if we truncate and then write and fsync we normally would just 7854 * write the extents that changed, which is a problem if we need to 7855 * first truncate that entire inode. So set this flag so we write out 7856 * all of the extents in the inode to the sync log so we're completely 7857 * safe. 7858 */ 7859 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags); 7860 trans->block_rsv = rsv; 7861 7862 while (1) { 7863 ret = btrfs_truncate_inode_items(trans, root, inode, 7864 inode->i_size, 7865 BTRFS_EXTENT_DATA_KEY); 7866 if (ret != -ENOSPC) { 7867 err = ret; 7868 break; 7869 } 7870 7871 trans->block_rsv = &root->fs_info->trans_block_rsv; 7872 ret = btrfs_update_inode(trans, root, inode); 7873 if (ret) { 7874 err = ret; 7875 break; 7876 } 7877 7878 btrfs_end_transaction(trans, root); 7879 btrfs_btree_balance_dirty(root); 7880 7881 trans = btrfs_start_transaction(root, 2); 7882 if (IS_ERR(trans)) { 7883 ret = err = PTR_ERR(trans); 7884 trans = NULL; 7885 break; 7886 } 7887 7888 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, 7889 rsv, min_size); 7890 BUG_ON(ret); /* shouldn't happen */ 7891 trans->block_rsv = rsv; 7892 } 7893 7894 if (ret == 0 && inode->i_nlink > 0) { 7895 trans->block_rsv = root->orphan_block_rsv; 7896 ret = btrfs_orphan_del(trans, inode); 7897 if (ret) 7898 err = ret; 7899 } 7900 7901 if (trans) { 7902 trans->block_rsv = &root->fs_info->trans_block_rsv; 7903 ret = btrfs_update_inode(trans, root, inode); 7904 if (ret && !err) 7905 err = ret; 7906 7907 ret = btrfs_end_transaction(trans, root); 7908 btrfs_btree_balance_dirty(root); 7909 } 7910 7911 out: 7912 btrfs_free_block_rsv(root, rsv); 7913 7914 if (ret && !err) 7915 err = ret; 7916 7917 return err; 7918 } 7919 7920 /* 7921 * create a new subvolume directory/inode (helper for the ioctl). 7922 */ 7923 int btrfs_create_subvol_root(struct btrfs_trans_handle *trans, 7924 struct btrfs_root *new_root, 7925 struct btrfs_root *parent_root, 7926 u64 new_dirid) 7927 { 7928 struct inode *inode; 7929 int err; 7930 u64 index = 0; 7931 7932 inode = btrfs_new_inode(trans, new_root, NULL, "..", 2, 7933 new_dirid, new_dirid, 7934 S_IFDIR | (~current_umask() & S_IRWXUGO), 7935 &index); 7936 if (IS_ERR(inode)) 7937 return PTR_ERR(inode); 7938 inode->i_op = &btrfs_dir_inode_operations; 7939 inode->i_fop = &btrfs_dir_file_operations; 7940 7941 set_nlink(inode, 1); 7942 btrfs_i_size_write(inode, 0); 7943 7944 err = btrfs_subvol_inherit_props(trans, new_root, parent_root); 7945 if (err) 7946 btrfs_err(new_root->fs_info, 7947 "error inheriting subvolume %llu properties: %d\n", 7948 new_root->root_key.objectid, err); 7949 7950 err = btrfs_update_inode(trans, new_root, inode); 7951 7952 iput(inode); 7953 return err; 7954 } 7955 7956 struct inode *btrfs_alloc_inode(struct super_block *sb) 7957 { 7958 struct btrfs_inode *ei; 7959 struct inode *inode; 7960 7961 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS); 7962 if (!ei) 7963 return NULL; 7964 7965 ei->root = NULL; 7966 ei->generation = 0; 7967 ei->last_trans = 0; 7968 ei->last_sub_trans = 0; 7969 ei->logged_trans = 0; 7970 ei->delalloc_bytes = 0; 7971 ei->disk_i_size = 0; 7972 ei->flags = 0; 7973 ei->csum_bytes = 0; 7974 ei->index_cnt = (u64)-1; 7975 ei->dir_index = 0; 7976 ei->last_unlink_trans = 0; 7977 ei->last_log_commit = 0; 7978 7979 spin_lock_init(&ei->lock); 7980 ei->outstanding_extents = 0; 7981 ei->reserved_extents = 0; 7982 7983 ei->runtime_flags = 0; 7984 ei->force_compress = BTRFS_COMPRESS_NONE; 7985 7986 ei->delayed_node = NULL; 7987 7988 inode = &ei->vfs_inode; 7989 extent_map_tree_init(&ei->extent_tree); 7990 extent_io_tree_init(&ei->io_tree, &inode->i_data); 7991 extent_io_tree_init(&ei->io_failure_tree, &inode->i_data); 7992 ei->io_tree.track_uptodate = 1; 7993 ei->io_failure_tree.track_uptodate = 1; 7994 atomic_set(&ei->sync_writers, 0); 7995 mutex_init(&ei->log_mutex); 7996 mutex_init(&ei->delalloc_mutex); 7997 btrfs_ordered_inode_tree_init(&ei->ordered_tree); 7998 INIT_LIST_HEAD(&ei->delalloc_inodes); 7999 INIT_LIST_HEAD(&ei->ordered_operations); 8000 RB_CLEAR_NODE(&ei->rb_node); 8001 8002 return inode; 8003 } 8004 8005 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS 8006 void btrfs_test_destroy_inode(struct inode *inode) 8007 { 8008 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0); 8009 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode)); 8010 } 8011 #endif 8012 8013 static void btrfs_i_callback(struct rcu_head *head) 8014 { 8015 struct inode *inode = container_of(head, struct inode, i_rcu); 8016 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode)); 8017 } 8018 8019 void btrfs_destroy_inode(struct inode *inode) 8020 { 8021 struct btrfs_ordered_extent *ordered; 8022 struct btrfs_root *root = BTRFS_I(inode)->root; 8023 8024 WARN_ON(!hlist_empty(&inode->i_dentry)); 8025 WARN_ON(inode->i_data.nrpages); 8026 WARN_ON(BTRFS_I(inode)->outstanding_extents); 8027 WARN_ON(BTRFS_I(inode)->reserved_extents); 8028 WARN_ON(BTRFS_I(inode)->delalloc_bytes); 8029 WARN_ON(BTRFS_I(inode)->csum_bytes); 8030 8031 /* 8032 * This can happen where we create an inode, but somebody else also 8033 * created the same inode and we need to destroy the one we already 8034 * created. 8035 */ 8036 if (!root) 8037 goto free; 8038 8039 /* 8040 * Make sure we're properly removed from the ordered operation 8041 * lists. 8042 */ 8043 smp_mb(); 8044 if (!list_empty(&BTRFS_I(inode)->ordered_operations)) { 8045 spin_lock(&root->fs_info->ordered_root_lock); 8046 list_del_init(&BTRFS_I(inode)->ordered_operations); 8047 spin_unlock(&root->fs_info->ordered_root_lock); 8048 } 8049 8050 if (test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM, 8051 &BTRFS_I(inode)->runtime_flags)) { 8052 btrfs_info(root->fs_info, "inode %llu still on the orphan list", 8053 btrfs_ino(inode)); 8054 atomic_dec(&root->orphan_inodes); 8055 } 8056 8057 while (1) { 8058 ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1); 8059 if (!ordered) 8060 break; 8061 else { 8062 btrfs_err(root->fs_info, "found ordered extent %llu %llu on inode cleanup", 8063 ordered->file_offset, ordered->len); 8064 btrfs_remove_ordered_extent(inode, ordered); 8065 btrfs_put_ordered_extent(ordered); 8066 btrfs_put_ordered_extent(ordered); 8067 } 8068 } 8069 inode_tree_del(inode); 8070 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0); 8071 free: 8072 call_rcu(&inode->i_rcu, btrfs_i_callback); 8073 } 8074 8075 int btrfs_drop_inode(struct inode *inode) 8076 { 8077 struct btrfs_root *root = BTRFS_I(inode)->root; 8078 8079 if (root == NULL) 8080 return 1; 8081 8082 /* the snap/subvol tree is on deleting */ 8083 if (btrfs_root_refs(&root->root_item) == 0) 8084 return 1; 8085 else 8086 return generic_drop_inode(inode); 8087 } 8088 8089 static void init_once(void *foo) 8090 { 8091 struct btrfs_inode *ei = (struct btrfs_inode *) foo; 8092 8093 inode_init_once(&ei->vfs_inode); 8094 } 8095 8096 void btrfs_destroy_cachep(void) 8097 { 8098 /* 8099 * Make sure all delayed rcu free inodes are flushed before we 8100 * destroy cache. 8101 */ 8102 rcu_barrier(); 8103 if (btrfs_inode_cachep) 8104 kmem_cache_destroy(btrfs_inode_cachep); 8105 if (btrfs_trans_handle_cachep) 8106 kmem_cache_destroy(btrfs_trans_handle_cachep); 8107 if (btrfs_transaction_cachep) 8108 kmem_cache_destroy(btrfs_transaction_cachep); 8109 if (btrfs_path_cachep) 8110 kmem_cache_destroy(btrfs_path_cachep); 8111 if (btrfs_free_space_cachep) 8112 kmem_cache_destroy(btrfs_free_space_cachep); 8113 if (btrfs_delalloc_work_cachep) 8114 kmem_cache_destroy(btrfs_delalloc_work_cachep); 8115 } 8116 8117 int btrfs_init_cachep(void) 8118 { 8119 btrfs_inode_cachep = kmem_cache_create("btrfs_inode", 8120 sizeof(struct btrfs_inode), 0, 8121 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, init_once); 8122 if (!btrfs_inode_cachep) 8123 goto fail; 8124 8125 btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle", 8126 sizeof(struct btrfs_trans_handle), 0, 8127 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL); 8128 if (!btrfs_trans_handle_cachep) 8129 goto fail; 8130 8131 btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction", 8132 sizeof(struct btrfs_transaction), 0, 8133 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL); 8134 if (!btrfs_transaction_cachep) 8135 goto fail; 8136 8137 btrfs_path_cachep = kmem_cache_create("btrfs_path", 8138 sizeof(struct btrfs_path), 0, 8139 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL); 8140 if (!btrfs_path_cachep) 8141 goto fail; 8142 8143 btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space", 8144 sizeof(struct btrfs_free_space), 0, 8145 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL); 8146 if (!btrfs_free_space_cachep) 8147 goto fail; 8148 8149 btrfs_delalloc_work_cachep = kmem_cache_create("btrfs_delalloc_work", 8150 sizeof(struct btrfs_delalloc_work), 0, 8151 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, 8152 NULL); 8153 if (!btrfs_delalloc_work_cachep) 8154 goto fail; 8155 8156 return 0; 8157 fail: 8158 btrfs_destroy_cachep(); 8159 return -ENOMEM; 8160 } 8161 8162 static int btrfs_getattr(struct vfsmount *mnt, 8163 struct dentry *dentry, struct kstat *stat) 8164 { 8165 u64 delalloc_bytes; 8166 struct inode *inode = dentry->d_inode; 8167 u32 blocksize = inode->i_sb->s_blocksize; 8168 8169 generic_fillattr(inode, stat); 8170 stat->dev = BTRFS_I(inode)->root->anon_dev; 8171 stat->blksize = PAGE_CACHE_SIZE; 8172 8173 spin_lock(&BTRFS_I(inode)->lock); 8174 delalloc_bytes = BTRFS_I(inode)->delalloc_bytes; 8175 spin_unlock(&BTRFS_I(inode)->lock); 8176 stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) + 8177 ALIGN(delalloc_bytes, blocksize)) >> 9; 8178 return 0; 8179 } 8180 8181 static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry, 8182 struct inode *new_dir, struct dentry *new_dentry) 8183 { 8184 struct btrfs_trans_handle *trans; 8185 struct btrfs_root *root = BTRFS_I(old_dir)->root; 8186 struct btrfs_root *dest = BTRFS_I(new_dir)->root; 8187 struct inode *new_inode = new_dentry->d_inode; 8188 struct inode *old_inode = old_dentry->d_inode; 8189 struct timespec ctime = CURRENT_TIME; 8190 u64 index = 0; 8191 u64 root_objectid; 8192 int ret; 8193 u64 old_ino = btrfs_ino(old_inode); 8194 8195 if (btrfs_ino(new_dir) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID) 8196 return -EPERM; 8197 8198 /* we only allow rename subvolume link between subvolumes */ 8199 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest) 8200 return -EXDEV; 8201 8202 if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID || 8203 (new_inode && btrfs_ino(new_inode) == BTRFS_FIRST_FREE_OBJECTID)) 8204 return -ENOTEMPTY; 8205 8206 if (S_ISDIR(old_inode->i_mode) && new_inode && 8207 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE) 8208 return -ENOTEMPTY; 8209 8210 8211 /* check for collisions, even if the name isn't there */ 8212 ret = btrfs_check_dir_item_collision(dest, new_dir->i_ino, 8213 new_dentry->d_name.name, 8214 new_dentry->d_name.len); 8215 8216 if (ret) { 8217 if (ret == -EEXIST) { 8218 /* we shouldn't get 8219 * eexist without a new_inode */ 8220 if (WARN_ON(!new_inode)) { 8221 return ret; 8222 } 8223 } else { 8224 /* maybe -EOVERFLOW */ 8225 return ret; 8226 } 8227 } 8228 ret = 0; 8229 8230 /* 8231 * we're using rename to replace one file with another. 8232 * and the replacement file is large. Start IO on it now so 8233 * we don't add too much work to the end of the transaction 8234 */ 8235 if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size && 8236 old_inode->i_size > BTRFS_ORDERED_OPERATIONS_FLUSH_LIMIT) 8237 filemap_flush(old_inode->i_mapping); 8238 8239 /* close the racy window with snapshot create/destroy ioctl */ 8240 if (old_ino == BTRFS_FIRST_FREE_OBJECTID) 8241 down_read(&root->fs_info->subvol_sem); 8242 /* 8243 * We want to reserve the absolute worst case amount of items. So if 8244 * both inodes are subvols and we need to unlink them then that would 8245 * require 4 item modifications, but if they are both normal inodes it 8246 * would require 5 item modifications, so we'll assume their normal 8247 * inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items 8248 * should cover the worst case number of items we'll modify. 8249 */ 8250 trans = btrfs_start_transaction(root, 11); 8251 if (IS_ERR(trans)) { 8252 ret = PTR_ERR(trans); 8253 goto out_notrans; 8254 } 8255 8256 if (dest != root) 8257 btrfs_record_root_in_trans(trans, dest); 8258 8259 ret = btrfs_set_inode_index(new_dir, &index); 8260 if (ret) 8261 goto out_fail; 8262 8263 BTRFS_I(old_inode)->dir_index = 0ULL; 8264 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) { 8265 /* force full log commit if subvolume involved. */ 8266 root->fs_info->last_trans_log_full_commit = trans->transid; 8267 } else { 8268 ret = btrfs_insert_inode_ref(trans, dest, 8269 new_dentry->d_name.name, 8270 new_dentry->d_name.len, 8271 old_ino, 8272 btrfs_ino(new_dir), index); 8273 if (ret) 8274 goto out_fail; 8275 /* 8276 * this is an ugly little race, but the rename is required 8277 * to make sure that if we crash, the inode is either at the 8278 * old name or the new one. pinning the log transaction lets 8279 * us make sure we don't allow a log commit to come in after 8280 * we unlink the name but before we add the new name back in. 8281 */ 8282 btrfs_pin_log_trans(root); 8283 } 8284 /* 8285 * make sure the inode gets flushed if it is replacing 8286 * something. 8287 */ 8288 if (new_inode && new_inode->i_size && S_ISREG(old_inode->i_mode)) 8289 btrfs_add_ordered_operation(trans, root, old_inode); 8290 8291 inode_inc_iversion(old_dir); 8292 inode_inc_iversion(new_dir); 8293 inode_inc_iversion(old_inode); 8294 old_dir->i_ctime = old_dir->i_mtime = ctime; 8295 new_dir->i_ctime = new_dir->i_mtime = ctime; 8296 old_inode->i_ctime = ctime; 8297 8298 if (old_dentry->d_parent != new_dentry->d_parent) 8299 btrfs_record_unlink_dir(trans, old_dir, old_inode, 1); 8300 8301 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) { 8302 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid; 8303 ret = btrfs_unlink_subvol(trans, root, old_dir, root_objectid, 8304 old_dentry->d_name.name, 8305 old_dentry->d_name.len); 8306 } else { 8307 ret = __btrfs_unlink_inode(trans, root, old_dir, 8308 old_dentry->d_inode, 8309 old_dentry->d_name.name, 8310 old_dentry->d_name.len); 8311 if (!ret) 8312 ret = btrfs_update_inode(trans, root, old_inode); 8313 } 8314 if (ret) { 8315 btrfs_abort_transaction(trans, root, ret); 8316 goto out_fail; 8317 } 8318 8319 if (new_inode) { 8320 inode_inc_iversion(new_inode); 8321 new_inode->i_ctime = CURRENT_TIME; 8322 if (unlikely(btrfs_ino(new_inode) == 8323 BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) { 8324 root_objectid = BTRFS_I(new_inode)->location.objectid; 8325 ret = btrfs_unlink_subvol(trans, dest, new_dir, 8326 root_objectid, 8327 new_dentry->d_name.name, 8328 new_dentry->d_name.len); 8329 BUG_ON(new_inode->i_nlink == 0); 8330 } else { 8331 ret = btrfs_unlink_inode(trans, dest, new_dir, 8332 new_dentry->d_inode, 8333 new_dentry->d_name.name, 8334 new_dentry->d_name.len); 8335 } 8336 if (!ret && new_inode->i_nlink == 0) 8337 ret = btrfs_orphan_add(trans, new_dentry->d_inode); 8338 if (ret) { 8339 btrfs_abort_transaction(trans, root, ret); 8340 goto out_fail; 8341 } 8342 } 8343 8344 ret = btrfs_add_link(trans, new_dir, old_inode, 8345 new_dentry->d_name.name, 8346 new_dentry->d_name.len, 0, index); 8347 if (ret) { 8348 btrfs_abort_transaction(trans, root, ret); 8349 goto out_fail; 8350 } 8351 8352 if (old_inode->i_nlink == 1) 8353 BTRFS_I(old_inode)->dir_index = index; 8354 8355 if (old_ino != BTRFS_FIRST_FREE_OBJECTID) { 8356 struct dentry *parent = new_dentry->d_parent; 8357 btrfs_log_new_name(trans, old_inode, old_dir, parent); 8358 btrfs_end_log_trans(root); 8359 } 8360 out_fail: 8361 btrfs_end_transaction(trans, root); 8362 out_notrans: 8363 if (old_ino == BTRFS_FIRST_FREE_OBJECTID) 8364 up_read(&root->fs_info->subvol_sem); 8365 8366 return ret; 8367 } 8368 8369 static void btrfs_run_delalloc_work(struct btrfs_work *work) 8370 { 8371 struct btrfs_delalloc_work *delalloc_work; 8372 struct inode *inode; 8373 8374 delalloc_work = container_of(work, struct btrfs_delalloc_work, 8375 work); 8376 inode = delalloc_work->inode; 8377 if (delalloc_work->wait) { 8378 btrfs_wait_ordered_range(inode, 0, (u64)-1); 8379 } else { 8380 filemap_flush(inode->i_mapping); 8381 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT, 8382 &BTRFS_I(inode)->runtime_flags)) 8383 filemap_flush(inode->i_mapping); 8384 } 8385 8386 if (delalloc_work->delay_iput) 8387 btrfs_add_delayed_iput(inode); 8388 else 8389 iput(inode); 8390 complete(&delalloc_work->completion); 8391 } 8392 8393 struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode, 8394 int wait, int delay_iput) 8395 { 8396 struct btrfs_delalloc_work *work; 8397 8398 work = kmem_cache_zalloc(btrfs_delalloc_work_cachep, GFP_NOFS); 8399 if (!work) 8400 return NULL; 8401 8402 init_completion(&work->completion); 8403 INIT_LIST_HEAD(&work->list); 8404 work->inode = inode; 8405 work->wait = wait; 8406 work->delay_iput = delay_iput; 8407 work->work.func = btrfs_run_delalloc_work; 8408 8409 return work; 8410 } 8411 8412 void btrfs_wait_and_free_delalloc_work(struct btrfs_delalloc_work *work) 8413 { 8414 wait_for_completion(&work->completion); 8415 kmem_cache_free(btrfs_delalloc_work_cachep, work); 8416 } 8417 8418 /* 8419 * some fairly slow code that needs optimization. This walks the list 8420 * of all the inodes with pending delalloc and forces them to disk. 8421 */ 8422 static int __start_delalloc_inodes(struct btrfs_root *root, int delay_iput) 8423 { 8424 struct btrfs_inode *binode; 8425 struct inode *inode; 8426 struct btrfs_delalloc_work *work, *next; 8427 struct list_head works; 8428 struct list_head splice; 8429 int ret = 0; 8430 8431 INIT_LIST_HEAD(&works); 8432 INIT_LIST_HEAD(&splice); 8433 8434 spin_lock(&root->delalloc_lock); 8435 list_splice_init(&root->delalloc_inodes, &splice); 8436 while (!list_empty(&splice)) { 8437 binode = list_entry(splice.next, struct btrfs_inode, 8438 delalloc_inodes); 8439 8440 list_move_tail(&binode->delalloc_inodes, 8441 &root->delalloc_inodes); 8442 inode = igrab(&binode->vfs_inode); 8443 if (!inode) { 8444 cond_resched_lock(&root->delalloc_lock); 8445 continue; 8446 } 8447 spin_unlock(&root->delalloc_lock); 8448 8449 work = btrfs_alloc_delalloc_work(inode, 0, delay_iput); 8450 if (unlikely(!work)) { 8451 if (delay_iput) 8452 btrfs_add_delayed_iput(inode); 8453 else 8454 iput(inode); 8455 ret = -ENOMEM; 8456 goto out; 8457 } 8458 list_add_tail(&work->list, &works); 8459 btrfs_queue_worker(&root->fs_info->flush_workers, 8460 &work->work); 8461 8462 cond_resched(); 8463 spin_lock(&root->delalloc_lock); 8464 } 8465 spin_unlock(&root->delalloc_lock); 8466 8467 list_for_each_entry_safe(work, next, &works, list) { 8468 list_del_init(&work->list); 8469 btrfs_wait_and_free_delalloc_work(work); 8470 } 8471 return 0; 8472 out: 8473 list_for_each_entry_safe(work, next, &works, list) { 8474 list_del_init(&work->list); 8475 btrfs_wait_and_free_delalloc_work(work); 8476 } 8477 8478 if (!list_empty_careful(&splice)) { 8479 spin_lock(&root->delalloc_lock); 8480 list_splice_tail(&splice, &root->delalloc_inodes); 8481 spin_unlock(&root->delalloc_lock); 8482 } 8483 return ret; 8484 } 8485 8486 int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput) 8487 { 8488 int ret; 8489 8490 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state)) 8491 return -EROFS; 8492 8493 ret = __start_delalloc_inodes(root, delay_iput); 8494 /* 8495 * the filemap_flush will queue IO into the worker threads, but 8496 * we have to make sure the IO is actually started and that 8497 * ordered extents get created before we return 8498 */ 8499 atomic_inc(&root->fs_info->async_submit_draining); 8500 while (atomic_read(&root->fs_info->nr_async_submits) || 8501 atomic_read(&root->fs_info->async_delalloc_pages)) { 8502 wait_event(root->fs_info->async_submit_wait, 8503 (atomic_read(&root->fs_info->nr_async_submits) == 0 && 8504 atomic_read(&root->fs_info->async_delalloc_pages) == 0)); 8505 } 8506 atomic_dec(&root->fs_info->async_submit_draining); 8507 return ret; 8508 } 8509 8510 int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, int delay_iput) 8511 { 8512 struct btrfs_root *root; 8513 struct list_head splice; 8514 int ret; 8515 8516 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) 8517 return -EROFS; 8518 8519 INIT_LIST_HEAD(&splice); 8520 8521 spin_lock(&fs_info->delalloc_root_lock); 8522 list_splice_init(&fs_info->delalloc_roots, &splice); 8523 while (!list_empty(&splice)) { 8524 root = list_first_entry(&splice, struct btrfs_root, 8525 delalloc_root); 8526 root = btrfs_grab_fs_root(root); 8527 BUG_ON(!root); 8528 list_move_tail(&root->delalloc_root, 8529 &fs_info->delalloc_roots); 8530 spin_unlock(&fs_info->delalloc_root_lock); 8531 8532 ret = __start_delalloc_inodes(root, delay_iput); 8533 btrfs_put_fs_root(root); 8534 if (ret) 8535 goto out; 8536 8537 spin_lock(&fs_info->delalloc_root_lock); 8538 } 8539 spin_unlock(&fs_info->delalloc_root_lock); 8540 8541 atomic_inc(&fs_info->async_submit_draining); 8542 while (atomic_read(&fs_info->nr_async_submits) || 8543 atomic_read(&fs_info->async_delalloc_pages)) { 8544 wait_event(fs_info->async_submit_wait, 8545 (atomic_read(&fs_info->nr_async_submits) == 0 && 8546 atomic_read(&fs_info->async_delalloc_pages) == 0)); 8547 } 8548 atomic_dec(&fs_info->async_submit_draining); 8549 return 0; 8550 out: 8551 if (!list_empty_careful(&splice)) { 8552 spin_lock(&fs_info->delalloc_root_lock); 8553 list_splice_tail(&splice, &fs_info->delalloc_roots); 8554 spin_unlock(&fs_info->delalloc_root_lock); 8555 } 8556 return ret; 8557 } 8558 8559 static int btrfs_symlink(struct inode *dir, struct dentry *dentry, 8560 const char *symname) 8561 { 8562 struct btrfs_trans_handle *trans; 8563 struct btrfs_root *root = BTRFS_I(dir)->root; 8564 struct btrfs_path *path; 8565 struct btrfs_key key; 8566 struct inode *inode = NULL; 8567 int err; 8568 int drop_inode = 0; 8569 u64 objectid; 8570 u64 index = 0; 8571 int name_len; 8572 int datasize; 8573 unsigned long ptr; 8574 struct btrfs_file_extent_item *ei; 8575 struct extent_buffer *leaf; 8576 8577 name_len = strlen(symname); 8578 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root)) 8579 return -ENAMETOOLONG; 8580 8581 /* 8582 * 2 items for inode item and ref 8583 * 2 items for dir items 8584 * 1 item for xattr if selinux is on 8585 */ 8586 trans = btrfs_start_transaction(root, 5); 8587 if (IS_ERR(trans)) 8588 return PTR_ERR(trans); 8589 8590 err = btrfs_find_free_ino(root, &objectid); 8591 if (err) 8592 goto out_unlock; 8593 8594 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name, 8595 dentry->d_name.len, btrfs_ino(dir), objectid, 8596 S_IFLNK|S_IRWXUGO, &index); 8597 if (IS_ERR(inode)) { 8598 err = PTR_ERR(inode); 8599 goto out_unlock; 8600 } 8601 8602 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name); 8603 if (err) { 8604 drop_inode = 1; 8605 goto out_unlock; 8606 } 8607 8608 /* 8609 * If the active LSM wants to access the inode during 8610 * d_instantiate it needs these. Smack checks to see 8611 * if the filesystem supports xattrs by looking at the 8612 * ops vector. 8613 */ 8614 inode->i_fop = &btrfs_file_operations; 8615 inode->i_op = &btrfs_file_inode_operations; 8616 8617 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index); 8618 if (err) 8619 drop_inode = 1; 8620 else { 8621 inode->i_mapping->a_ops = &btrfs_aops; 8622 inode->i_mapping->backing_dev_info = &root->fs_info->bdi; 8623 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops; 8624 } 8625 if (drop_inode) 8626 goto out_unlock; 8627 8628 path = btrfs_alloc_path(); 8629 if (!path) { 8630 err = -ENOMEM; 8631 drop_inode = 1; 8632 goto out_unlock; 8633 } 8634 key.objectid = btrfs_ino(inode); 8635 key.offset = 0; 8636 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY); 8637 datasize = btrfs_file_extent_calc_inline_size(name_len); 8638 err = btrfs_insert_empty_item(trans, root, path, &key, 8639 datasize); 8640 if (err) { 8641 drop_inode = 1; 8642 btrfs_free_path(path); 8643 goto out_unlock; 8644 } 8645 leaf = path->nodes[0]; 8646 ei = btrfs_item_ptr(leaf, path->slots[0], 8647 struct btrfs_file_extent_item); 8648 btrfs_set_file_extent_generation(leaf, ei, trans->transid); 8649 btrfs_set_file_extent_type(leaf, ei, 8650 BTRFS_FILE_EXTENT_INLINE); 8651 btrfs_set_file_extent_encryption(leaf, ei, 0); 8652 btrfs_set_file_extent_compression(leaf, ei, 0); 8653 btrfs_set_file_extent_other_encoding(leaf, ei, 0); 8654 btrfs_set_file_extent_ram_bytes(leaf, ei, name_len); 8655 8656 ptr = btrfs_file_extent_inline_start(ei); 8657 write_extent_buffer(leaf, symname, ptr, name_len); 8658 btrfs_mark_buffer_dirty(leaf); 8659 btrfs_free_path(path); 8660 8661 inode->i_op = &btrfs_symlink_inode_operations; 8662 inode->i_mapping->a_ops = &btrfs_symlink_aops; 8663 inode->i_mapping->backing_dev_info = &root->fs_info->bdi; 8664 inode_set_bytes(inode, name_len); 8665 btrfs_i_size_write(inode, name_len); 8666 err = btrfs_update_inode(trans, root, inode); 8667 if (err) 8668 drop_inode = 1; 8669 8670 out_unlock: 8671 if (!err) 8672 d_instantiate(dentry, inode); 8673 btrfs_end_transaction(trans, root); 8674 if (drop_inode) { 8675 inode_dec_link_count(inode); 8676 iput(inode); 8677 } 8678 btrfs_btree_balance_dirty(root); 8679 return err; 8680 } 8681 8682 static int __btrfs_prealloc_file_range(struct inode *inode, int mode, 8683 u64 start, u64 num_bytes, u64 min_size, 8684 loff_t actual_len, u64 *alloc_hint, 8685 struct btrfs_trans_handle *trans) 8686 { 8687 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; 8688 struct extent_map *em; 8689 struct btrfs_root *root = BTRFS_I(inode)->root; 8690 struct btrfs_key ins; 8691 u64 cur_offset = start; 8692 u64 i_size; 8693 u64 cur_bytes; 8694 int ret = 0; 8695 bool own_trans = true; 8696 8697 if (trans) 8698 own_trans = false; 8699 while (num_bytes > 0) { 8700 if (own_trans) { 8701 trans = btrfs_start_transaction(root, 3); 8702 if (IS_ERR(trans)) { 8703 ret = PTR_ERR(trans); 8704 break; 8705 } 8706 } 8707 8708 cur_bytes = min(num_bytes, 256ULL * 1024 * 1024); 8709 cur_bytes = max(cur_bytes, min_size); 8710 ret = btrfs_reserve_extent(root, cur_bytes, min_size, 0, 8711 *alloc_hint, &ins, 1); 8712 if (ret) { 8713 if (own_trans) 8714 btrfs_end_transaction(trans, root); 8715 break; 8716 } 8717 8718 ret = insert_reserved_file_extent(trans, inode, 8719 cur_offset, ins.objectid, 8720 ins.offset, ins.offset, 8721 ins.offset, 0, 0, 0, 8722 BTRFS_FILE_EXTENT_PREALLOC); 8723 if (ret) { 8724 btrfs_free_reserved_extent(root, ins.objectid, 8725 ins.offset); 8726 btrfs_abort_transaction(trans, root, ret); 8727 if (own_trans) 8728 btrfs_end_transaction(trans, root); 8729 break; 8730 } 8731 btrfs_drop_extent_cache(inode, cur_offset, 8732 cur_offset + ins.offset -1, 0); 8733 8734 em = alloc_extent_map(); 8735 if (!em) { 8736 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, 8737 &BTRFS_I(inode)->runtime_flags); 8738 goto next; 8739 } 8740 8741 em->start = cur_offset; 8742 em->orig_start = cur_offset; 8743 em->len = ins.offset; 8744 em->block_start = ins.objectid; 8745 em->block_len = ins.offset; 8746 em->orig_block_len = ins.offset; 8747 em->ram_bytes = ins.offset; 8748 em->bdev = root->fs_info->fs_devices->latest_bdev; 8749 set_bit(EXTENT_FLAG_PREALLOC, &em->flags); 8750 em->generation = trans->transid; 8751 8752 while (1) { 8753 write_lock(&em_tree->lock); 8754 ret = add_extent_mapping(em_tree, em, 1); 8755 write_unlock(&em_tree->lock); 8756 if (ret != -EEXIST) 8757 break; 8758 btrfs_drop_extent_cache(inode, cur_offset, 8759 cur_offset + ins.offset - 1, 8760 0); 8761 } 8762 free_extent_map(em); 8763 next: 8764 num_bytes -= ins.offset; 8765 cur_offset += ins.offset; 8766 *alloc_hint = ins.objectid + ins.offset; 8767 8768 inode_inc_iversion(inode); 8769 inode->i_ctime = CURRENT_TIME; 8770 BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC; 8771 if (!(mode & FALLOC_FL_KEEP_SIZE) && 8772 (actual_len > inode->i_size) && 8773 (cur_offset > inode->i_size)) { 8774 if (cur_offset > actual_len) 8775 i_size = actual_len; 8776 else 8777 i_size = cur_offset; 8778 i_size_write(inode, i_size); 8779 btrfs_ordered_update_i_size(inode, i_size, NULL); 8780 } 8781 8782 ret = btrfs_update_inode(trans, root, inode); 8783 8784 if (ret) { 8785 btrfs_abort_transaction(trans, root, ret); 8786 if (own_trans) 8787 btrfs_end_transaction(trans, root); 8788 break; 8789 } 8790 8791 if (own_trans) 8792 btrfs_end_transaction(trans, root); 8793 } 8794 return ret; 8795 } 8796 8797 int btrfs_prealloc_file_range(struct inode *inode, int mode, 8798 u64 start, u64 num_bytes, u64 min_size, 8799 loff_t actual_len, u64 *alloc_hint) 8800 { 8801 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes, 8802 min_size, actual_len, alloc_hint, 8803 NULL); 8804 } 8805 8806 int btrfs_prealloc_file_range_trans(struct inode *inode, 8807 struct btrfs_trans_handle *trans, int mode, 8808 u64 start, u64 num_bytes, u64 min_size, 8809 loff_t actual_len, u64 *alloc_hint) 8810 { 8811 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes, 8812 min_size, actual_len, alloc_hint, trans); 8813 } 8814 8815 static int btrfs_set_page_dirty(struct page *page) 8816 { 8817 return __set_page_dirty_nobuffers(page); 8818 } 8819 8820 static int btrfs_permission(struct inode *inode, int mask) 8821 { 8822 struct btrfs_root *root = BTRFS_I(inode)->root; 8823 umode_t mode = inode->i_mode; 8824 8825 if (mask & MAY_WRITE && 8826 (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) { 8827 if (btrfs_root_readonly(root)) 8828 return -EROFS; 8829 if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY) 8830 return -EACCES; 8831 } 8832 return generic_permission(inode, mask); 8833 } 8834 8835 static const struct inode_operations btrfs_dir_inode_operations = { 8836 .getattr = btrfs_getattr, 8837 .lookup = btrfs_lookup, 8838 .create = btrfs_create, 8839 .unlink = btrfs_unlink, 8840 .link = btrfs_link, 8841 .mkdir = btrfs_mkdir, 8842 .rmdir = btrfs_rmdir, 8843 .rename = btrfs_rename, 8844 .symlink = btrfs_symlink, 8845 .setattr = btrfs_setattr, 8846 .mknod = btrfs_mknod, 8847 .setxattr = btrfs_setxattr, 8848 .getxattr = btrfs_getxattr, 8849 .listxattr = btrfs_listxattr, 8850 .removexattr = btrfs_removexattr, 8851 .permission = btrfs_permission, 8852 .get_acl = btrfs_get_acl, 8853 .set_acl = btrfs_set_acl, 8854 .update_time = btrfs_update_time, 8855 }; 8856 static const struct inode_operations btrfs_dir_ro_inode_operations = { 8857 .lookup = btrfs_lookup, 8858 .permission = btrfs_permission, 8859 .get_acl = btrfs_get_acl, 8860 .set_acl = btrfs_set_acl, 8861 .update_time = btrfs_update_time, 8862 }; 8863 8864 static const struct file_operations btrfs_dir_file_operations = { 8865 .llseek = generic_file_llseek, 8866 .read = generic_read_dir, 8867 .iterate = btrfs_real_readdir, 8868 .unlocked_ioctl = btrfs_ioctl, 8869 #ifdef CONFIG_COMPAT 8870 .compat_ioctl = btrfs_ioctl, 8871 #endif 8872 .release = btrfs_release_file, 8873 .fsync = btrfs_sync_file, 8874 }; 8875 8876 static struct extent_io_ops btrfs_extent_io_ops = { 8877 .fill_delalloc = run_delalloc_range, 8878 .submit_bio_hook = btrfs_submit_bio_hook, 8879 .merge_bio_hook = btrfs_merge_bio_hook, 8880 .readpage_end_io_hook = btrfs_readpage_end_io_hook, 8881 .writepage_end_io_hook = btrfs_writepage_end_io_hook, 8882 .writepage_start_hook = btrfs_writepage_start_hook, 8883 .set_bit_hook = btrfs_set_bit_hook, 8884 .clear_bit_hook = btrfs_clear_bit_hook, 8885 .merge_extent_hook = btrfs_merge_extent_hook, 8886 .split_extent_hook = btrfs_split_extent_hook, 8887 }; 8888 8889 /* 8890 * btrfs doesn't support the bmap operation because swapfiles 8891 * use bmap to make a mapping of extents in the file. They assume 8892 * these extents won't change over the life of the file and they 8893 * use the bmap result to do IO directly to the drive. 8894 * 8895 * the btrfs bmap call would return logical addresses that aren't 8896 * suitable for IO and they also will change frequently as COW 8897 * operations happen. So, swapfile + btrfs == corruption. 8898 * 8899 * For now we're avoiding this by dropping bmap. 8900 */ 8901 static const struct address_space_operations btrfs_aops = { 8902 .readpage = btrfs_readpage, 8903 .writepage = btrfs_writepage, 8904 .writepages = btrfs_writepages, 8905 .readpages = btrfs_readpages, 8906 .direct_IO = btrfs_direct_IO, 8907 .invalidatepage = btrfs_invalidatepage, 8908 .releasepage = btrfs_releasepage, 8909 .set_page_dirty = btrfs_set_page_dirty, 8910 .error_remove_page = generic_error_remove_page, 8911 }; 8912 8913 static const struct address_space_operations btrfs_symlink_aops = { 8914 .readpage = btrfs_readpage, 8915 .writepage = btrfs_writepage, 8916 .invalidatepage = btrfs_invalidatepage, 8917 .releasepage = btrfs_releasepage, 8918 }; 8919 8920 static const struct inode_operations btrfs_file_inode_operations = { 8921 .getattr = btrfs_getattr, 8922 .setattr = btrfs_setattr, 8923 .setxattr = btrfs_setxattr, 8924 .getxattr = btrfs_getxattr, 8925 .listxattr = btrfs_listxattr, 8926 .removexattr = btrfs_removexattr, 8927 .permission = btrfs_permission, 8928 .fiemap = btrfs_fiemap, 8929 .get_acl = btrfs_get_acl, 8930 .set_acl = btrfs_set_acl, 8931 .update_time = btrfs_update_time, 8932 }; 8933 static const struct inode_operations btrfs_special_inode_operations = { 8934 .getattr = btrfs_getattr, 8935 .setattr = btrfs_setattr, 8936 .permission = btrfs_permission, 8937 .setxattr = btrfs_setxattr, 8938 .getxattr = btrfs_getxattr, 8939 .listxattr = btrfs_listxattr, 8940 .removexattr = btrfs_removexattr, 8941 .get_acl = btrfs_get_acl, 8942 .set_acl = btrfs_set_acl, 8943 .update_time = btrfs_update_time, 8944 }; 8945 static const struct inode_operations btrfs_symlink_inode_operations = { 8946 .readlink = generic_readlink, 8947 .follow_link = page_follow_link_light, 8948 .put_link = page_put_link, 8949 .getattr = btrfs_getattr, 8950 .setattr = btrfs_setattr, 8951 .permission = btrfs_permission, 8952 .setxattr = btrfs_setxattr, 8953 .getxattr = btrfs_getxattr, 8954 .listxattr = btrfs_listxattr, 8955 .removexattr = btrfs_removexattr, 8956 .update_time = btrfs_update_time, 8957 }; 8958 8959 const struct dentry_operations btrfs_dentry_operations = { 8960 .d_delete = btrfs_dentry_delete, 8961 .d_release = btrfs_dentry_release, 8962 }; 8963