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 "compat.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 61 struct btrfs_iget_args { 62 u64 ino; 63 struct btrfs_root *root; 64 }; 65 66 static const struct inode_operations btrfs_dir_inode_operations; 67 static const struct inode_operations btrfs_symlink_inode_operations; 68 static const struct inode_operations btrfs_dir_ro_inode_operations; 69 static const struct inode_operations btrfs_special_inode_operations; 70 static const struct inode_operations btrfs_file_inode_operations; 71 static const struct address_space_operations btrfs_aops; 72 static const struct address_space_operations btrfs_symlink_aops; 73 static const struct file_operations btrfs_dir_file_operations; 74 static struct extent_io_ops btrfs_extent_io_ops; 75 76 static struct kmem_cache *btrfs_inode_cachep; 77 static struct kmem_cache *btrfs_delalloc_work_cachep; 78 struct kmem_cache *btrfs_trans_handle_cachep; 79 struct kmem_cache *btrfs_transaction_cachep; 80 struct kmem_cache *btrfs_path_cachep; 81 struct kmem_cache *btrfs_free_space_cachep; 82 83 #define S_SHIFT 12 84 static unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = { 85 [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE, 86 [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR, 87 [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV, 88 [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV, 89 [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO, 90 [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK, 91 [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK, 92 }; 93 94 static int btrfs_setsize(struct inode *inode, struct iattr *attr); 95 static int btrfs_truncate(struct inode *inode); 96 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent); 97 static noinline int cow_file_range(struct inode *inode, 98 struct page *locked_page, 99 u64 start, u64 end, int *page_started, 100 unsigned long *nr_written, int unlock); 101 static struct extent_map *create_pinned_em(struct inode *inode, u64 start, 102 u64 len, u64 orig_start, 103 u64 block_start, u64 block_len, 104 u64 orig_block_len, u64 ram_bytes, 105 int type); 106 107 static int btrfs_dirty_inode(struct inode *inode); 108 109 static int btrfs_init_inode_security(struct btrfs_trans_handle *trans, 110 struct inode *inode, struct inode *dir, 111 const struct qstr *qstr) 112 { 113 int err; 114 115 err = btrfs_init_acl(trans, inode, dir); 116 if (!err) 117 err = btrfs_xattr_security_init(trans, inode, dir, qstr); 118 return err; 119 } 120 121 /* 122 * this does all the hard work for inserting an inline extent into 123 * the btree. The caller should have done a btrfs_drop_extents so that 124 * no overlapping inline items exist in the btree 125 */ 126 static noinline int insert_inline_extent(struct btrfs_trans_handle *trans, 127 struct btrfs_root *root, struct inode *inode, 128 u64 start, size_t size, size_t compressed_size, 129 int compress_type, 130 struct page **compressed_pages) 131 { 132 struct btrfs_key key; 133 struct btrfs_path *path; 134 struct extent_buffer *leaf; 135 struct page *page = NULL; 136 char *kaddr; 137 unsigned long ptr; 138 struct btrfs_file_extent_item *ei; 139 int err = 0; 140 int ret; 141 size_t cur_size = size; 142 size_t datasize; 143 unsigned long offset; 144 145 if (compressed_size && compressed_pages) 146 cur_size = compressed_size; 147 148 path = btrfs_alloc_path(); 149 if (!path) 150 return -ENOMEM; 151 152 path->leave_spinning = 1; 153 154 key.objectid = btrfs_ino(inode); 155 key.offset = start; 156 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY); 157 datasize = btrfs_file_extent_calc_inline_size(cur_size); 158 159 inode_add_bytes(inode, size); 160 ret = btrfs_insert_empty_item(trans, root, path, &key, 161 datasize); 162 if (ret) { 163 err = ret; 164 goto fail; 165 } 166 leaf = path->nodes[0]; 167 ei = btrfs_item_ptr(leaf, path->slots[0], 168 struct btrfs_file_extent_item); 169 btrfs_set_file_extent_generation(leaf, ei, trans->transid); 170 btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE); 171 btrfs_set_file_extent_encryption(leaf, ei, 0); 172 btrfs_set_file_extent_other_encoding(leaf, ei, 0); 173 btrfs_set_file_extent_ram_bytes(leaf, ei, size); 174 ptr = btrfs_file_extent_inline_start(ei); 175 176 if (compress_type != BTRFS_COMPRESS_NONE) { 177 struct page *cpage; 178 int i = 0; 179 while (compressed_size > 0) { 180 cpage = compressed_pages[i]; 181 cur_size = min_t(unsigned long, compressed_size, 182 PAGE_CACHE_SIZE); 183 184 kaddr = kmap_atomic(cpage); 185 write_extent_buffer(leaf, kaddr, ptr, cur_size); 186 kunmap_atomic(kaddr); 187 188 i++; 189 ptr += cur_size; 190 compressed_size -= cur_size; 191 } 192 btrfs_set_file_extent_compression(leaf, ei, 193 compress_type); 194 } else { 195 page = find_get_page(inode->i_mapping, 196 start >> PAGE_CACHE_SHIFT); 197 btrfs_set_file_extent_compression(leaf, ei, 0); 198 kaddr = kmap_atomic(page); 199 offset = start & (PAGE_CACHE_SIZE - 1); 200 write_extent_buffer(leaf, kaddr + offset, ptr, size); 201 kunmap_atomic(kaddr); 202 page_cache_release(page); 203 } 204 btrfs_mark_buffer_dirty(leaf); 205 btrfs_free_path(path); 206 207 /* 208 * we're an inline extent, so nobody can 209 * extend the file past i_size without locking 210 * a page we already have locked. 211 * 212 * We must do any isize and inode updates 213 * before we unlock the pages. Otherwise we 214 * could end up racing with unlink. 215 */ 216 BTRFS_I(inode)->disk_i_size = inode->i_size; 217 ret = btrfs_update_inode(trans, root, inode); 218 219 return ret; 220 fail: 221 btrfs_free_path(path); 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_trans_handle *trans, 232 struct btrfs_root *root, 233 struct inode *inode, u64 start, u64 end, 234 size_t compressed_size, int compress_type, 235 struct page **compressed_pages) 236 { 237 u64 isize = i_size_read(inode); 238 u64 actual_end = min(end + 1, isize); 239 u64 inline_len = actual_end - start; 240 u64 aligned_end = ALIGN(end, root->sectorsize); 241 u64 data_len = inline_len; 242 int ret; 243 244 if (compressed_size) 245 data_len = compressed_size; 246 247 if (start > 0 || 248 actual_end >= PAGE_CACHE_SIZE || 249 data_len >= BTRFS_MAX_INLINE_DATA_SIZE(root) || 250 (!compressed_size && 251 (actual_end & (root->sectorsize - 1)) == 0) || 252 end + 1 < isize || 253 data_len > root->fs_info->max_inline) { 254 return 1; 255 } 256 257 ret = btrfs_drop_extents(trans, root, inode, start, aligned_end, 1); 258 if (ret) 259 return ret; 260 261 if (isize > actual_end) 262 inline_len = min_t(u64, isize, actual_end); 263 ret = insert_inline_extent(trans, root, inode, start, 264 inline_len, compressed_size, 265 compress_type, compressed_pages); 266 if (ret && ret != -ENOSPC) { 267 btrfs_abort_transaction(trans, root, ret); 268 return ret; 269 } else if (ret == -ENOSPC) { 270 return 1; 271 } 272 273 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags); 274 btrfs_delalloc_release_metadata(inode, end + 1 - start); 275 btrfs_drop_extent_cache(inode, start, aligned_end - 1, 0); 276 return 0; 277 } 278 279 struct async_extent { 280 u64 start; 281 u64 ram_size; 282 u64 compressed_size; 283 struct page **pages; 284 unsigned long nr_pages; 285 int compress_type; 286 struct list_head list; 287 }; 288 289 struct async_cow { 290 struct inode *inode; 291 struct btrfs_root *root; 292 struct page *locked_page; 293 u64 start; 294 u64 end; 295 struct list_head extents; 296 struct btrfs_work work; 297 }; 298 299 static noinline int add_async_extent(struct async_cow *cow, 300 u64 start, u64 ram_size, 301 u64 compressed_size, 302 struct page **pages, 303 unsigned long nr_pages, 304 int compress_type) 305 { 306 struct async_extent *async_extent; 307 308 async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS); 309 BUG_ON(!async_extent); /* -ENOMEM */ 310 async_extent->start = start; 311 async_extent->ram_size = ram_size; 312 async_extent->compressed_size = compressed_size; 313 async_extent->pages = pages; 314 async_extent->nr_pages = nr_pages; 315 async_extent->compress_type = compress_type; 316 list_add_tail(&async_extent->list, &cow->extents); 317 return 0; 318 } 319 320 /* 321 * we create compressed extents in two phases. The first 322 * phase compresses a range of pages that have already been 323 * locked (both pages and state bits are locked). 324 * 325 * This is done inside an ordered work queue, and the compression 326 * is spread across many cpus. The actual IO submission is step 327 * two, and the ordered work queue takes care of making sure that 328 * happens in the same order things were put onto the queue by 329 * writepages and friends. 330 * 331 * If this code finds it can't get good compression, it puts an 332 * entry onto the work queue to write the uncompressed bytes. This 333 * makes sure that both compressed inodes and uncompressed inodes 334 * are written in the same order that the flusher thread sent them 335 * down. 336 */ 337 static noinline int compress_file_range(struct inode *inode, 338 struct page *locked_page, 339 u64 start, u64 end, 340 struct async_cow *async_cow, 341 int *num_added) 342 { 343 struct btrfs_root *root = BTRFS_I(inode)->root; 344 struct btrfs_trans_handle *trans; 345 u64 num_bytes; 346 u64 blocksize = root->sectorsize; 347 u64 actual_end; 348 u64 isize = i_size_read(inode); 349 int ret = 0; 350 struct page **pages = NULL; 351 unsigned long nr_pages; 352 unsigned long nr_pages_ret = 0; 353 unsigned long total_compressed = 0; 354 unsigned long total_in = 0; 355 unsigned long max_compressed = 128 * 1024; 356 unsigned long max_uncompressed = 128 * 1024; 357 int i; 358 int will_compress; 359 int compress_type = root->fs_info->compress_type; 360 int redirty = 0; 361 362 /* if this is a small write inside eof, kick off a defrag */ 363 if ((end - start + 1) < 16 * 1024 && 364 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size)) 365 btrfs_add_inode_defrag(NULL, inode); 366 367 actual_end = min_t(u64, isize, end + 1); 368 again: 369 will_compress = 0; 370 nr_pages = (end >> PAGE_CACHE_SHIFT) - (start >> PAGE_CACHE_SHIFT) + 1; 371 nr_pages = min(nr_pages, (128 * 1024UL) / PAGE_CACHE_SIZE); 372 373 /* 374 * we don't want to send crud past the end of i_size through 375 * compression, that's just a waste of CPU time. So, if the 376 * end of the file is before the start of our current 377 * requested range of bytes, we bail out to the uncompressed 378 * cleanup code that can deal with all of this. 379 * 380 * It isn't really the fastest way to fix things, but this is a 381 * very uncommon corner. 382 */ 383 if (actual_end <= start) 384 goto cleanup_and_bail_uncompressed; 385 386 total_compressed = actual_end - start; 387 388 /* we want to make sure that amount of ram required to uncompress 389 * an extent is reasonable, so we limit the total size in ram 390 * of a compressed extent to 128k. This is a crucial number 391 * because it also controls how easily we can spread reads across 392 * cpus for decompression. 393 * 394 * We also want to make sure the amount of IO required to do 395 * a random read is reasonably small, so we limit the size of 396 * a compressed extent to 128k. 397 */ 398 total_compressed = min(total_compressed, max_uncompressed); 399 num_bytes = ALIGN(end - start + 1, blocksize); 400 num_bytes = max(blocksize, num_bytes); 401 total_in = 0; 402 ret = 0; 403 404 /* 405 * we do compression for mount -o compress and when the 406 * inode has not been flagged as nocompress. This flag can 407 * change at any time if we discover bad compression ratios. 408 */ 409 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS) && 410 (btrfs_test_opt(root, COMPRESS) || 411 (BTRFS_I(inode)->force_compress) || 412 (BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS))) { 413 WARN_ON(pages); 414 pages = kzalloc(sizeof(struct page *) * nr_pages, GFP_NOFS); 415 if (!pages) { 416 /* just bail out to the uncompressed code */ 417 goto cont; 418 } 419 420 if (BTRFS_I(inode)->force_compress) 421 compress_type = BTRFS_I(inode)->force_compress; 422 423 /* 424 * we need to call clear_page_dirty_for_io on each 425 * page in the range. Otherwise applications with the file 426 * mmap'd can wander in and change the page contents while 427 * we are compressing them. 428 * 429 * If the compression fails for any reason, we set the pages 430 * dirty again later on. 431 */ 432 extent_range_clear_dirty_for_io(inode, start, end); 433 redirty = 1; 434 ret = btrfs_compress_pages(compress_type, 435 inode->i_mapping, start, 436 total_compressed, pages, 437 nr_pages, &nr_pages_ret, 438 &total_in, 439 &total_compressed, 440 max_compressed); 441 442 if (!ret) { 443 unsigned long offset = total_compressed & 444 (PAGE_CACHE_SIZE - 1); 445 struct page *page = pages[nr_pages_ret - 1]; 446 char *kaddr; 447 448 /* zero the tail end of the last page, we might be 449 * sending it down to disk 450 */ 451 if (offset) { 452 kaddr = kmap_atomic(page); 453 memset(kaddr + offset, 0, 454 PAGE_CACHE_SIZE - offset); 455 kunmap_atomic(kaddr); 456 } 457 will_compress = 1; 458 } 459 } 460 cont: 461 if (start == 0) { 462 trans = btrfs_join_transaction(root); 463 if (IS_ERR(trans)) { 464 ret = PTR_ERR(trans); 465 trans = NULL; 466 goto cleanup_and_out; 467 } 468 trans->block_rsv = &root->fs_info->delalloc_block_rsv; 469 470 /* lets try to make an inline extent */ 471 if (ret || total_in < (actual_end - start)) { 472 /* we didn't compress the entire range, try 473 * to make an uncompressed inline extent. 474 */ 475 ret = cow_file_range_inline(trans, root, inode, 476 start, end, 0, 0, NULL); 477 } else { 478 /* try making a compressed inline extent */ 479 ret = cow_file_range_inline(trans, root, inode, 480 start, end, 481 total_compressed, 482 compress_type, pages); 483 } 484 if (ret <= 0) { 485 /* 486 * inline extent creation worked or returned error, 487 * we don't need to create any more async work items. 488 * Unlock and free up our temp pages. 489 */ 490 extent_clear_unlock_delalloc(inode, 491 &BTRFS_I(inode)->io_tree, 492 start, end, NULL, 493 EXTENT_CLEAR_UNLOCK_PAGE | EXTENT_CLEAR_DIRTY | 494 EXTENT_CLEAR_DELALLOC | 495 EXTENT_SET_WRITEBACK | EXTENT_END_WRITEBACK); 496 497 btrfs_end_transaction(trans, root); 498 goto free_pages_out; 499 } 500 btrfs_end_transaction(trans, root); 501 } 502 503 if (will_compress) { 504 /* 505 * we aren't doing an inline extent round the compressed size 506 * up to a block size boundary so the allocator does sane 507 * things 508 */ 509 total_compressed = ALIGN(total_compressed, blocksize); 510 511 /* 512 * one last check to make sure the compression is really a 513 * win, compare the page count read with the blocks on disk 514 */ 515 total_in = ALIGN(total_in, PAGE_CACHE_SIZE); 516 if (total_compressed >= total_in) { 517 will_compress = 0; 518 } else { 519 num_bytes = total_in; 520 } 521 } 522 if (!will_compress && pages) { 523 /* 524 * the compression code ran but failed to make things smaller, 525 * free any pages it allocated and our page pointer array 526 */ 527 for (i = 0; i < nr_pages_ret; i++) { 528 WARN_ON(pages[i]->mapping); 529 page_cache_release(pages[i]); 530 } 531 kfree(pages); 532 pages = NULL; 533 total_compressed = 0; 534 nr_pages_ret = 0; 535 536 /* flag the file so we don't compress in the future */ 537 if (!btrfs_test_opt(root, FORCE_COMPRESS) && 538 !(BTRFS_I(inode)->force_compress)) { 539 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS; 540 } 541 } 542 if (will_compress) { 543 *num_added += 1; 544 545 /* the async work queues will take care of doing actual 546 * allocation on disk for these compressed pages, 547 * and will submit them to the elevator. 548 */ 549 add_async_extent(async_cow, start, num_bytes, 550 total_compressed, pages, nr_pages_ret, 551 compress_type); 552 553 if (start + num_bytes < end) { 554 start += num_bytes; 555 pages = NULL; 556 cond_resched(); 557 goto again; 558 } 559 } else { 560 cleanup_and_bail_uncompressed: 561 /* 562 * No compression, but we still need to write the pages in 563 * the file we've been given so far. redirty the locked 564 * page if it corresponds to our extent and set things up 565 * for the async work queue to run cow_file_range to do 566 * the normal delalloc dance 567 */ 568 if (page_offset(locked_page) >= start && 569 page_offset(locked_page) <= end) { 570 __set_page_dirty_nobuffers(locked_page); 571 /* unlocked later on in the async handlers */ 572 } 573 if (redirty) 574 extent_range_redirty_for_io(inode, start, end); 575 add_async_extent(async_cow, start, end - start + 1, 576 0, NULL, 0, BTRFS_COMPRESS_NONE); 577 *num_added += 1; 578 } 579 580 out: 581 return ret; 582 583 free_pages_out: 584 for (i = 0; i < nr_pages_ret; i++) { 585 WARN_ON(pages[i]->mapping); 586 page_cache_release(pages[i]); 587 } 588 kfree(pages); 589 590 goto out; 591 592 cleanup_and_out: 593 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree, 594 start, end, NULL, 595 EXTENT_CLEAR_UNLOCK_PAGE | 596 EXTENT_CLEAR_DIRTY | 597 EXTENT_CLEAR_DELALLOC | 598 EXTENT_SET_WRITEBACK | 599 EXTENT_END_WRITEBACK); 600 if (!trans || IS_ERR(trans)) 601 btrfs_error(root->fs_info, ret, "Failed to join transaction"); 602 else 603 btrfs_abort_transaction(trans, root, ret); 604 goto free_pages_out; 605 } 606 607 /* 608 * phase two of compressed writeback. This is the ordered portion 609 * of the code, which only gets called in the order the work was 610 * queued. We walk all the async extents created by compress_file_range 611 * and send them down to the disk. 612 */ 613 static noinline int submit_compressed_extents(struct inode *inode, 614 struct async_cow *async_cow) 615 { 616 struct async_extent *async_extent; 617 u64 alloc_hint = 0; 618 struct btrfs_trans_handle *trans; 619 struct btrfs_key ins; 620 struct extent_map *em; 621 struct btrfs_root *root = BTRFS_I(inode)->root; 622 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; 623 struct extent_io_tree *io_tree; 624 int ret = 0; 625 626 if (list_empty(&async_cow->extents)) 627 return 0; 628 629 again: 630 while (!list_empty(&async_cow->extents)) { 631 async_extent = list_entry(async_cow->extents.next, 632 struct async_extent, list); 633 list_del(&async_extent->list); 634 635 io_tree = &BTRFS_I(inode)->io_tree; 636 637 retry: 638 /* did the compression code fall back to uncompressed IO? */ 639 if (!async_extent->pages) { 640 int page_started = 0; 641 unsigned long nr_written = 0; 642 643 lock_extent(io_tree, async_extent->start, 644 async_extent->start + 645 async_extent->ram_size - 1); 646 647 /* allocate blocks */ 648 ret = cow_file_range(inode, async_cow->locked_page, 649 async_extent->start, 650 async_extent->start + 651 async_extent->ram_size - 1, 652 &page_started, &nr_written, 0); 653 654 /* JDM XXX */ 655 656 /* 657 * if page_started, cow_file_range inserted an 658 * inline extent and took care of all the unlocking 659 * and IO for us. Otherwise, we need to submit 660 * all those pages down to the drive. 661 */ 662 if (!page_started && !ret) 663 extent_write_locked_range(io_tree, 664 inode, async_extent->start, 665 async_extent->start + 666 async_extent->ram_size - 1, 667 btrfs_get_extent, 668 WB_SYNC_ALL); 669 else if (ret) 670 unlock_page(async_cow->locked_page); 671 kfree(async_extent); 672 cond_resched(); 673 continue; 674 } 675 676 lock_extent(io_tree, async_extent->start, 677 async_extent->start + async_extent->ram_size - 1); 678 679 trans = btrfs_join_transaction(root); 680 if (IS_ERR(trans)) { 681 ret = PTR_ERR(trans); 682 } else { 683 trans->block_rsv = &root->fs_info->delalloc_block_rsv; 684 ret = btrfs_reserve_extent(trans, root, 685 async_extent->compressed_size, 686 async_extent->compressed_size, 687 0, alloc_hint, &ins, 1); 688 if (ret && ret != -ENOSPC) 689 btrfs_abort_transaction(trans, root, ret); 690 btrfs_end_transaction(trans, root); 691 } 692 693 if (ret) { 694 int i; 695 696 for (i = 0; i < async_extent->nr_pages; i++) { 697 WARN_ON(async_extent->pages[i]->mapping); 698 page_cache_release(async_extent->pages[i]); 699 } 700 kfree(async_extent->pages); 701 async_extent->nr_pages = 0; 702 async_extent->pages = NULL; 703 704 if (ret == -ENOSPC) 705 goto retry; 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 goto out_free_reserve; 720 em->start = async_extent->start; 721 em->len = async_extent->ram_size; 722 em->orig_start = em->start; 723 em->mod_start = em->start; 724 em->mod_len = em->len; 725 726 em->block_start = ins.objectid; 727 em->block_len = ins.offset; 728 em->orig_block_len = ins.offset; 729 em->ram_bytes = async_extent->ram_size; 730 em->bdev = root->fs_info->fs_devices->latest_bdev; 731 em->compress_type = async_extent->compress_type; 732 set_bit(EXTENT_FLAG_PINNED, &em->flags); 733 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags); 734 em->generation = -1; 735 736 while (1) { 737 write_lock(&em_tree->lock); 738 ret = add_extent_mapping(em_tree, em, 1); 739 write_unlock(&em_tree->lock); 740 if (ret != -EEXIST) { 741 free_extent_map(em); 742 break; 743 } 744 btrfs_drop_extent_cache(inode, async_extent->start, 745 async_extent->start + 746 async_extent->ram_size - 1, 0); 747 } 748 749 if (ret) 750 goto out_free_reserve; 751 752 ret = btrfs_add_ordered_extent_compress(inode, 753 async_extent->start, 754 ins.objectid, 755 async_extent->ram_size, 756 ins.offset, 757 BTRFS_ORDERED_COMPRESSED, 758 async_extent->compress_type); 759 if (ret) 760 goto out_free_reserve; 761 762 /* 763 * clear dirty, set writeback and unlock the pages. 764 */ 765 extent_clear_unlock_delalloc(inode, 766 &BTRFS_I(inode)->io_tree, 767 async_extent->start, 768 async_extent->start + 769 async_extent->ram_size - 1, 770 NULL, EXTENT_CLEAR_UNLOCK_PAGE | 771 EXTENT_CLEAR_UNLOCK | 772 EXTENT_CLEAR_DELALLOC | 773 EXTENT_CLEAR_DIRTY | EXTENT_SET_WRITEBACK); 774 775 ret = btrfs_submit_compressed_write(inode, 776 async_extent->start, 777 async_extent->ram_size, 778 ins.objectid, 779 ins.offset, async_extent->pages, 780 async_extent->nr_pages); 781 alloc_hint = ins.objectid + ins.offset; 782 kfree(async_extent); 783 if (ret) 784 goto out; 785 cond_resched(); 786 } 787 ret = 0; 788 out: 789 return ret; 790 out_free_reserve: 791 btrfs_free_reserved_extent(root, ins.objectid, ins.offset); 792 out_free: 793 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree, 794 async_extent->start, 795 async_extent->start + 796 async_extent->ram_size - 1, 797 NULL, EXTENT_CLEAR_UNLOCK_PAGE | 798 EXTENT_CLEAR_UNLOCK | 799 EXTENT_CLEAR_DELALLOC | 800 EXTENT_CLEAR_DIRTY | 801 EXTENT_SET_WRITEBACK | 802 EXTENT_END_WRITEBACK); 803 kfree(async_extent); 804 goto again; 805 } 806 807 static u64 get_extent_allocation_hint(struct inode *inode, u64 start, 808 u64 num_bytes) 809 { 810 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; 811 struct extent_map *em; 812 u64 alloc_hint = 0; 813 814 read_lock(&em_tree->lock); 815 em = search_extent_mapping(em_tree, start, num_bytes); 816 if (em) { 817 /* 818 * if block start isn't an actual block number then find the 819 * first block in this inode and use that as a hint. If that 820 * block is also bogus then just don't worry about it. 821 */ 822 if (em->block_start >= EXTENT_MAP_LAST_BYTE) { 823 free_extent_map(em); 824 em = search_extent_mapping(em_tree, 0, 0); 825 if (em && em->block_start < EXTENT_MAP_LAST_BYTE) 826 alloc_hint = em->block_start; 827 if (em) 828 free_extent_map(em); 829 } else { 830 alloc_hint = em->block_start; 831 free_extent_map(em); 832 } 833 } 834 read_unlock(&em_tree->lock); 835 836 return alloc_hint; 837 } 838 839 /* 840 * when extent_io.c finds a delayed allocation range in the file, 841 * the call backs end up in this code. The basic idea is to 842 * allocate extents on disk for the range, and create ordered data structs 843 * in ram to track those extents. 844 * 845 * locked_page is the page that writepage had locked already. We use 846 * it to make sure we don't do extra locks or unlocks. 847 * 848 * *page_started is set to one if we unlock locked_page and do everything 849 * required to start IO on it. It may be clean and already done with 850 * IO when we return. 851 */ 852 static noinline int __cow_file_range(struct btrfs_trans_handle *trans, 853 struct inode *inode, 854 struct btrfs_root *root, 855 struct page *locked_page, 856 u64 start, u64 end, int *page_started, 857 unsigned long *nr_written, 858 int unlock) 859 { 860 u64 alloc_hint = 0; 861 u64 num_bytes; 862 unsigned long ram_size; 863 u64 disk_num_bytes; 864 u64 cur_alloc_size; 865 u64 blocksize = root->sectorsize; 866 struct btrfs_key ins; 867 struct extent_map *em; 868 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; 869 int ret = 0; 870 871 BUG_ON(btrfs_is_free_space_inode(inode)); 872 873 num_bytes = ALIGN(end - start + 1, blocksize); 874 num_bytes = max(blocksize, num_bytes); 875 disk_num_bytes = num_bytes; 876 877 /* if this is a small write inside eof, kick off defrag */ 878 if (num_bytes < 64 * 1024 && 879 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size)) 880 btrfs_add_inode_defrag(trans, inode); 881 882 if (start == 0) { 883 /* lets try to make an inline extent */ 884 ret = cow_file_range_inline(trans, root, inode, 885 start, end, 0, 0, NULL); 886 if (ret == 0) { 887 extent_clear_unlock_delalloc(inode, 888 &BTRFS_I(inode)->io_tree, 889 start, end, NULL, 890 EXTENT_CLEAR_UNLOCK_PAGE | 891 EXTENT_CLEAR_UNLOCK | 892 EXTENT_CLEAR_DELALLOC | 893 EXTENT_CLEAR_DIRTY | 894 EXTENT_SET_WRITEBACK | 895 EXTENT_END_WRITEBACK); 896 897 *nr_written = *nr_written + 898 (end - start + PAGE_CACHE_SIZE) / PAGE_CACHE_SIZE; 899 *page_started = 1; 900 goto out; 901 } else if (ret < 0) { 902 btrfs_abort_transaction(trans, root, ret); 903 goto out_unlock; 904 } 905 } 906 907 BUG_ON(disk_num_bytes > 908 btrfs_super_total_bytes(root->fs_info->super_copy)); 909 910 alloc_hint = get_extent_allocation_hint(inode, start, num_bytes); 911 btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0); 912 913 while (disk_num_bytes > 0) { 914 unsigned long op; 915 916 cur_alloc_size = disk_num_bytes; 917 ret = btrfs_reserve_extent(trans, root, cur_alloc_size, 918 root->sectorsize, 0, alloc_hint, 919 &ins, 1); 920 if (ret < 0) { 921 btrfs_abort_transaction(trans, root, ret); 922 goto out_unlock; 923 } 924 925 em = alloc_extent_map(); 926 if (!em) 927 goto out_reserve; 928 em->start = start; 929 em->orig_start = em->start; 930 ram_size = ins.offset; 931 em->len = ins.offset; 932 em->mod_start = em->start; 933 em->mod_len = em->len; 934 935 em->block_start = ins.objectid; 936 em->block_len = ins.offset; 937 em->orig_block_len = ins.offset; 938 em->ram_bytes = ram_size; 939 em->bdev = root->fs_info->fs_devices->latest_bdev; 940 set_bit(EXTENT_FLAG_PINNED, &em->flags); 941 em->generation = -1; 942 943 while (1) { 944 write_lock(&em_tree->lock); 945 ret = add_extent_mapping(em_tree, em, 1); 946 write_unlock(&em_tree->lock); 947 if (ret != -EEXIST) { 948 free_extent_map(em); 949 break; 950 } 951 btrfs_drop_extent_cache(inode, start, 952 start + ram_size - 1, 0); 953 } 954 if (ret) 955 goto out_reserve; 956 957 cur_alloc_size = ins.offset; 958 ret = btrfs_add_ordered_extent(inode, start, ins.objectid, 959 ram_size, cur_alloc_size, 0); 960 if (ret) 961 goto out_reserve; 962 963 if (root->root_key.objectid == 964 BTRFS_DATA_RELOC_TREE_OBJECTID) { 965 ret = btrfs_reloc_clone_csums(inode, start, 966 cur_alloc_size); 967 if (ret) { 968 btrfs_abort_transaction(trans, root, ret); 969 goto out_reserve; 970 } 971 } 972 973 if (disk_num_bytes < cur_alloc_size) 974 break; 975 976 /* we're not doing compressed IO, don't unlock the first 977 * page (which the caller expects to stay locked), don't 978 * clear any dirty bits and don't set any writeback bits 979 * 980 * Do set the Private2 bit so we know this page was properly 981 * setup for writepage 982 */ 983 op = unlock ? EXTENT_CLEAR_UNLOCK_PAGE : 0; 984 op |= EXTENT_CLEAR_UNLOCK | EXTENT_CLEAR_DELALLOC | 985 EXTENT_SET_PRIVATE2; 986 987 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree, 988 start, start + ram_size - 1, 989 locked_page, op); 990 disk_num_bytes -= cur_alloc_size; 991 num_bytes -= cur_alloc_size; 992 alloc_hint = ins.objectid + ins.offset; 993 start += cur_alloc_size; 994 } 995 out: 996 return ret; 997 998 out_reserve: 999 btrfs_free_reserved_extent(root, ins.objectid, ins.offset); 1000 out_unlock: 1001 extent_clear_unlock_delalloc(inode, 1002 &BTRFS_I(inode)->io_tree, 1003 start, end, locked_page, 1004 EXTENT_CLEAR_UNLOCK_PAGE | 1005 EXTENT_CLEAR_UNLOCK | 1006 EXTENT_CLEAR_DELALLOC | 1007 EXTENT_CLEAR_DIRTY | 1008 EXTENT_SET_WRITEBACK | 1009 EXTENT_END_WRITEBACK); 1010 1011 goto out; 1012 } 1013 1014 static noinline int cow_file_range(struct inode *inode, 1015 struct page *locked_page, 1016 u64 start, u64 end, int *page_started, 1017 unsigned long *nr_written, 1018 int unlock) 1019 { 1020 struct btrfs_trans_handle *trans; 1021 struct btrfs_root *root = BTRFS_I(inode)->root; 1022 int ret; 1023 1024 trans = btrfs_join_transaction(root); 1025 if (IS_ERR(trans)) { 1026 extent_clear_unlock_delalloc(inode, 1027 &BTRFS_I(inode)->io_tree, 1028 start, end, locked_page, 1029 EXTENT_CLEAR_UNLOCK_PAGE | 1030 EXTENT_CLEAR_UNLOCK | 1031 EXTENT_CLEAR_DELALLOC | 1032 EXTENT_CLEAR_DIRTY | 1033 EXTENT_SET_WRITEBACK | 1034 EXTENT_END_WRITEBACK); 1035 return PTR_ERR(trans); 1036 } 1037 trans->block_rsv = &root->fs_info->delalloc_block_rsv; 1038 1039 ret = __cow_file_range(trans, inode, root, locked_page, start, end, 1040 page_started, nr_written, unlock); 1041 1042 btrfs_end_transaction(trans, root); 1043 1044 return ret; 1045 } 1046 1047 /* 1048 * work queue call back to started compression on a file and pages 1049 */ 1050 static noinline void async_cow_start(struct btrfs_work *work) 1051 { 1052 struct async_cow *async_cow; 1053 int num_added = 0; 1054 async_cow = container_of(work, struct async_cow, work); 1055 1056 compress_file_range(async_cow->inode, async_cow->locked_page, 1057 async_cow->start, async_cow->end, async_cow, 1058 &num_added); 1059 if (num_added == 0) { 1060 btrfs_add_delayed_iput(async_cow->inode); 1061 async_cow->inode = NULL; 1062 } 1063 } 1064 1065 /* 1066 * work queue call back to submit previously compressed pages 1067 */ 1068 static noinline void async_cow_submit(struct btrfs_work *work) 1069 { 1070 struct async_cow *async_cow; 1071 struct btrfs_root *root; 1072 unsigned long nr_pages; 1073 1074 async_cow = container_of(work, struct async_cow, work); 1075 1076 root = async_cow->root; 1077 nr_pages = (async_cow->end - async_cow->start + PAGE_CACHE_SIZE) >> 1078 PAGE_CACHE_SHIFT; 1079 1080 if (atomic_sub_return(nr_pages, &root->fs_info->async_delalloc_pages) < 1081 5 * 1024 * 1024 && 1082 waitqueue_active(&root->fs_info->async_submit_wait)) 1083 wake_up(&root->fs_info->async_submit_wait); 1084 1085 if (async_cow->inode) 1086 submit_compressed_extents(async_cow->inode, async_cow); 1087 } 1088 1089 static noinline void async_cow_free(struct btrfs_work *work) 1090 { 1091 struct async_cow *async_cow; 1092 async_cow = container_of(work, struct async_cow, work); 1093 if (async_cow->inode) 1094 btrfs_add_delayed_iput(async_cow->inode); 1095 kfree(async_cow); 1096 } 1097 1098 static int cow_file_range_async(struct inode *inode, struct page *locked_page, 1099 u64 start, u64 end, int *page_started, 1100 unsigned long *nr_written) 1101 { 1102 struct async_cow *async_cow; 1103 struct btrfs_root *root = BTRFS_I(inode)->root; 1104 unsigned long nr_pages; 1105 u64 cur_end; 1106 int limit = 10 * 1024 * 1024; 1107 1108 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED, 1109 1, 0, NULL, GFP_NOFS); 1110 while (start < end) { 1111 async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS); 1112 BUG_ON(!async_cow); /* -ENOMEM */ 1113 async_cow->inode = igrab(inode); 1114 async_cow->root = root; 1115 async_cow->locked_page = locked_page; 1116 async_cow->start = start; 1117 1118 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS) 1119 cur_end = end; 1120 else 1121 cur_end = min(end, start + 512 * 1024 - 1); 1122 1123 async_cow->end = cur_end; 1124 INIT_LIST_HEAD(&async_cow->extents); 1125 1126 async_cow->work.func = async_cow_start; 1127 async_cow->work.ordered_func = async_cow_submit; 1128 async_cow->work.ordered_free = async_cow_free; 1129 async_cow->work.flags = 0; 1130 1131 nr_pages = (cur_end - start + PAGE_CACHE_SIZE) >> 1132 PAGE_CACHE_SHIFT; 1133 atomic_add(nr_pages, &root->fs_info->async_delalloc_pages); 1134 1135 btrfs_queue_worker(&root->fs_info->delalloc_workers, 1136 &async_cow->work); 1137 1138 if (atomic_read(&root->fs_info->async_delalloc_pages) > limit) { 1139 wait_event(root->fs_info->async_submit_wait, 1140 (atomic_read(&root->fs_info->async_delalloc_pages) < 1141 limit)); 1142 } 1143 1144 while (atomic_read(&root->fs_info->async_submit_draining) && 1145 atomic_read(&root->fs_info->async_delalloc_pages)) { 1146 wait_event(root->fs_info->async_submit_wait, 1147 (atomic_read(&root->fs_info->async_delalloc_pages) == 1148 0)); 1149 } 1150 1151 *nr_written += nr_pages; 1152 start = cur_end + 1; 1153 } 1154 *page_started = 1; 1155 return 0; 1156 } 1157 1158 static noinline int csum_exist_in_range(struct btrfs_root *root, 1159 u64 bytenr, u64 num_bytes) 1160 { 1161 int ret; 1162 struct btrfs_ordered_sum *sums; 1163 LIST_HEAD(list); 1164 1165 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, bytenr, 1166 bytenr + num_bytes - 1, &list, 0); 1167 if (ret == 0 && list_empty(&list)) 1168 return 0; 1169 1170 while (!list_empty(&list)) { 1171 sums = list_entry(list.next, struct btrfs_ordered_sum, list); 1172 list_del(&sums->list); 1173 kfree(sums); 1174 } 1175 return 1; 1176 } 1177 1178 /* 1179 * when nowcow writeback call back. This checks for snapshots or COW copies 1180 * of the extents that exist in the file, and COWs the file as required. 1181 * 1182 * If no cow copies or snapshots exist, we write directly to the existing 1183 * blocks on disk 1184 */ 1185 static noinline int run_delalloc_nocow(struct inode *inode, 1186 struct page *locked_page, 1187 u64 start, u64 end, int *page_started, int force, 1188 unsigned long *nr_written) 1189 { 1190 struct btrfs_root *root = BTRFS_I(inode)->root; 1191 struct btrfs_trans_handle *trans; 1192 struct extent_buffer *leaf; 1193 struct btrfs_path *path; 1194 struct btrfs_file_extent_item *fi; 1195 struct btrfs_key found_key; 1196 u64 cow_start; 1197 u64 cur_offset; 1198 u64 extent_end; 1199 u64 extent_offset; 1200 u64 disk_bytenr; 1201 u64 num_bytes; 1202 u64 disk_num_bytes; 1203 u64 ram_bytes; 1204 int extent_type; 1205 int ret, err; 1206 int type; 1207 int nocow; 1208 int check_prev = 1; 1209 bool nolock; 1210 u64 ino = btrfs_ino(inode); 1211 1212 path = btrfs_alloc_path(); 1213 if (!path) { 1214 extent_clear_unlock_delalloc(inode, 1215 &BTRFS_I(inode)->io_tree, 1216 start, end, locked_page, 1217 EXTENT_CLEAR_UNLOCK_PAGE | 1218 EXTENT_CLEAR_UNLOCK | 1219 EXTENT_CLEAR_DELALLOC | 1220 EXTENT_CLEAR_DIRTY | 1221 EXTENT_SET_WRITEBACK | 1222 EXTENT_END_WRITEBACK); 1223 return -ENOMEM; 1224 } 1225 1226 nolock = btrfs_is_free_space_inode(inode); 1227 1228 if (nolock) 1229 trans = btrfs_join_transaction_nolock(root); 1230 else 1231 trans = btrfs_join_transaction(root); 1232 1233 if (IS_ERR(trans)) { 1234 extent_clear_unlock_delalloc(inode, 1235 &BTRFS_I(inode)->io_tree, 1236 start, end, locked_page, 1237 EXTENT_CLEAR_UNLOCK_PAGE | 1238 EXTENT_CLEAR_UNLOCK | 1239 EXTENT_CLEAR_DELALLOC | 1240 EXTENT_CLEAR_DIRTY | 1241 EXTENT_SET_WRITEBACK | 1242 EXTENT_END_WRITEBACK); 1243 btrfs_free_path(path); 1244 return PTR_ERR(trans); 1245 } 1246 1247 trans->block_rsv = &root->fs_info->delalloc_block_rsv; 1248 1249 cow_start = (u64)-1; 1250 cur_offset = start; 1251 while (1) { 1252 ret = btrfs_lookup_file_extent(trans, root, path, ino, 1253 cur_offset, 0); 1254 if (ret < 0) { 1255 btrfs_abort_transaction(trans, root, ret); 1256 goto error; 1257 } 1258 if (ret > 0 && path->slots[0] > 0 && check_prev) { 1259 leaf = path->nodes[0]; 1260 btrfs_item_key_to_cpu(leaf, &found_key, 1261 path->slots[0] - 1); 1262 if (found_key.objectid == ino && 1263 found_key.type == BTRFS_EXTENT_DATA_KEY) 1264 path->slots[0]--; 1265 } 1266 check_prev = 0; 1267 next_slot: 1268 leaf = path->nodes[0]; 1269 if (path->slots[0] >= btrfs_header_nritems(leaf)) { 1270 ret = btrfs_next_leaf(root, path); 1271 if (ret < 0) { 1272 btrfs_abort_transaction(trans, root, ret); 1273 goto error; 1274 } 1275 if (ret > 0) 1276 break; 1277 leaf = path->nodes[0]; 1278 } 1279 1280 nocow = 0; 1281 disk_bytenr = 0; 1282 num_bytes = 0; 1283 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 1284 1285 if (found_key.objectid > ino || 1286 found_key.type > BTRFS_EXTENT_DATA_KEY || 1287 found_key.offset > end) 1288 break; 1289 1290 if (found_key.offset > cur_offset) { 1291 extent_end = found_key.offset; 1292 extent_type = 0; 1293 goto out_check; 1294 } 1295 1296 fi = btrfs_item_ptr(leaf, path->slots[0], 1297 struct btrfs_file_extent_item); 1298 extent_type = btrfs_file_extent_type(leaf, fi); 1299 1300 ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi); 1301 if (extent_type == BTRFS_FILE_EXTENT_REG || 1302 extent_type == BTRFS_FILE_EXTENT_PREALLOC) { 1303 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); 1304 extent_offset = btrfs_file_extent_offset(leaf, fi); 1305 extent_end = found_key.offset + 1306 btrfs_file_extent_num_bytes(leaf, fi); 1307 disk_num_bytes = 1308 btrfs_file_extent_disk_num_bytes(leaf, fi); 1309 if (extent_end <= start) { 1310 path->slots[0]++; 1311 goto next_slot; 1312 } 1313 if (disk_bytenr == 0) 1314 goto out_check; 1315 if (btrfs_file_extent_compression(leaf, fi) || 1316 btrfs_file_extent_encryption(leaf, fi) || 1317 btrfs_file_extent_other_encoding(leaf, fi)) 1318 goto out_check; 1319 if (extent_type == BTRFS_FILE_EXTENT_REG && !force) 1320 goto out_check; 1321 if (btrfs_extent_readonly(root, disk_bytenr)) 1322 goto out_check; 1323 if (btrfs_cross_ref_exist(trans, root, ino, 1324 found_key.offset - 1325 extent_offset, disk_bytenr)) 1326 goto out_check; 1327 disk_bytenr += extent_offset; 1328 disk_bytenr += cur_offset - found_key.offset; 1329 num_bytes = min(end + 1, extent_end) - cur_offset; 1330 /* 1331 * force cow if csum exists in the range. 1332 * this ensure that csum for a given extent are 1333 * either valid or do not exist. 1334 */ 1335 if (csum_exist_in_range(root, disk_bytenr, num_bytes)) 1336 goto out_check; 1337 nocow = 1; 1338 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { 1339 extent_end = found_key.offset + 1340 btrfs_file_extent_inline_len(leaf, fi); 1341 extent_end = ALIGN(extent_end, root->sectorsize); 1342 } else { 1343 BUG_ON(1); 1344 } 1345 out_check: 1346 if (extent_end <= start) { 1347 path->slots[0]++; 1348 goto next_slot; 1349 } 1350 if (!nocow) { 1351 if (cow_start == (u64)-1) 1352 cow_start = cur_offset; 1353 cur_offset = extent_end; 1354 if (cur_offset > end) 1355 break; 1356 path->slots[0]++; 1357 goto next_slot; 1358 } 1359 1360 btrfs_release_path(path); 1361 if (cow_start != (u64)-1) { 1362 ret = __cow_file_range(trans, inode, root, locked_page, 1363 cow_start, found_key.offset - 1, 1364 page_started, nr_written, 1); 1365 if (ret) { 1366 btrfs_abort_transaction(trans, root, ret); 1367 goto error; 1368 } 1369 cow_start = (u64)-1; 1370 } 1371 1372 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) { 1373 struct extent_map *em; 1374 struct extent_map_tree *em_tree; 1375 em_tree = &BTRFS_I(inode)->extent_tree; 1376 em = alloc_extent_map(); 1377 BUG_ON(!em); /* -ENOMEM */ 1378 em->start = cur_offset; 1379 em->orig_start = found_key.offset - extent_offset; 1380 em->len = num_bytes; 1381 em->block_len = num_bytes; 1382 em->block_start = disk_bytenr; 1383 em->orig_block_len = disk_num_bytes; 1384 em->ram_bytes = ram_bytes; 1385 em->bdev = root->fs_info->fs_devices->latest_bdev; 1386 em->mod_start = em->start; 1387 em->mod_len = em->len; 1388 set_bit(EXTENT_FLAG_PINNED, &em->flags); 1389 set_bit(EXTENT_FLAG_FILLING, &em->flags); 1390 em->generation = -1; 1391 while (1) { 1392 write_lock(&em_tree->lock); 1393 ret = add_extent_mapping(em_tree, em, 1); 1394 write_unlock(&em_tree->lock); 1395 if (ret != -EEXIST) { 1396 free_extent_map(em); 1397 break; 1398 } 1399 btrfs_drop_extent_cache(inode, em->start, 1400 em->start + em->len - 1, 0); 1401 } 1402 type = BTRFS_ORDERED_PREALLOC; 1403 } else { 1404 type = BTRFS_ORDERED_NOCOW; 1405 } 1406 1407 ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr, 1408 num_bytes, num_bytes, type); 1409 BUG_ON(ret); /* -ENOMEM */ 1410 1411 if (root->root_key.objectid == 1412 BTRFS_DATA_RELOC_TREE_OBJECTID) { 1413 ret = btrfs_reloc_clone_csums(inode, cur_offset, 1414 num_bytes); 1415 if (ret) { 1416 btrfs_abort_transaction(trans, root, ret); 1417 goto error; 1418 } 1419 } 1420 1421 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree, 1422 cur_offset, cur_offset + num_bytes - 1, 1423 locked_page, EXTENT_CLEAR_UNLOCK_PAGE | 1424 EXTENT_CLEAR_UNLOCK | EXTENT_CLEAR_DELALLOC | 1425 EXTENT_SET_PRIVATE2); 1426 cur_offset = extent_end; 1427 if (cur_offset > end) 1428 break; 1429 } 1430 btrfs_release_path(path); 1431 1432 if (cur_offset <= end && cow_start == (u64)-1) { 1433 cow_start = cur_offset; 1434 cur_offset = end; 1435 } 1436 1437 if (cow_start != (u64)-1) { 1438 ret = __cow_file_range(trans, inode, root, locked_page, 1439 cow_start, end, 1440 page_started, nr_written, 1); 1441 if (ret) { 1442 btrfs_abort_transaction(trans, root, ret); 1443 goto error; 1444 } 1445 } 1446 1447 error: 1448 err = btrfs_end_transaction(trans, root); 1449 if (!ret) 1450 ret = err; 1451 1452 if (ret && cur_offset < end) 1453 extent_clear_unlock_delalloc(inode, 1454 &BTRFS_I(inode)->io_tree, 1455 cur_offset, end, locked_page, 1456 EXTENT_CLEAR_UNLOCK_PAGE | 1457 EXTENT_CLEAR_UNLOCK | 1458 EXTENT_CLEAR_DELALLOC | 1459 EXTENT_CLEAR_DIRTY | 1460 EXTENT_SET_WRITEBACK | 1461 EXTENT_END_WRITEBACK); 1462 1463 btrfs_free_path(path); 1464 return ret; 1465 } 1466 1467 /* 1468 * extent_io.c call back to do delayed allocation processing 1469 */ 1470 static int run_delalloc_range(struct inode *inode, struct page *locked_page, 1471 u64 start, u64 end, int *page_started, 1472 unsigned long *nr_written) 1473 { 1474 int ret; 1475 struct btrfs_root *root = BTRFS_I(inode)->root; 1476 1477 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) { 1478 ret = run_delalloc_nocow(inode, locked_page, start, end, 1479 page_started, 1, nr_written); 1480 } else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC) { 1481 ret = run_delalloc_nocow(inode, locked_page, start, end, 1482 page_started, 0, nr_written); 1483 } else if (!btrfs_test_opt(root, COMPRESS) && 1484 !(BTRFS_I(inode)->force_compress) && 1485 !(BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS)) { 1486 ret = cow_file_range(inode, locked_page, start, end, 1487 page_started, nr_written, 1); 1488 } else { 1489 set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT, 1490 &BTRFS_I(inode)->runtime_flags); 1491 ret = cow_file_range_async(inode, locked_page, start, end, 1492 page_started, nr_written); 1493 } 1494 return ret; 1495 } 1496 1497 static void btrfs_split_extent_hook(struct inode *inode, 1498 struct extent_state *orig, u64 split) 1499 { 1500 /* not delalloc, ignore it */ 1501 if (!(orig->state & EXTENT_DELALLOC)) 1502 return; 1503 1504 spin_lock(&BTRFS_I(inode)->lock); 1505 BTRFS_I(inode)->outstanding_extents++; 1506 spin_unlock(&BTRFS_I(inode)->lock); 1507 } 1508 1509 /* 1510 * extent_io.c merge_extent_hook, used to track merged delayed allocation 1511 * extents so we can keep track of new extents that are just merged onto old 1512 * extents, such as when we are doing sequential writes, so we can properly 1513 * account for the metadata space we'll need. 1514 */ 1515 static void btrfs_merge_extent_hook(struct inode *inode, 1516 struct extent_state *new, 1517 struct extent_state *other) 1518 { 1519 /* not delalloc, ignore it */ 1520 if (!(other->state & EXTENT_DELALLOC)) 1521 return; 1522 1523 spin_lock(&BTRFS_I(inode)->lock); 1524 BTRFS_I(inode)->outstanding_extents--; 1525 spin_unlock(&BTRFS_I(inode)->lock); 1526 } 1527 1528 /* 1529 * extent_io.c set_bit_hook, used to track delayed allocation 1530 * bytes in this file, and to maintain the list of inodes that 1531 * have pending delalloc work to be done. 1532 */ 1533 static void btrfs_set_bit_hook(struct inode *inode, 1534 struct extent_state *state, unsigned long *bits) 1535 { 1536 1537 /* 1538 * set_bit and clear bit hooks normally require _irqsave/restore 1539 * but in this case, we are only testing for the DELALLOC 1540 * bit, which is only set or cleared with irqs on 1541 */ 1542 if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) { 1543 struct btrfs_root *root = BTRFS_I(inode)->root; 1544 u64 len = state->end + 1 - state->start; 1545 bool do_list = !btrfs_is_free_space_inode(inode); 1546 1547 if (*bits & EXTENT_FIRST_DELALLOC) { 1548 *bits &= ~EXTENT_FIRST_DELALLOC; 1549 } else { 1550 spin_lock(&BTRFS_I(inode)->lock); 1551 BTRFS_I(inode)->outstanding_extents++; 1552 spin_unlock(&BTRFS_I(inode)->lock); 1553 } 1554 1555 __percpu_counter_add(&root->fs_info->delalloc_bytes, len, 1556 root->fs_info->delalloc_batch); 1557 spin_lock(&BTRFS_I(inode)->lock); 1558 BTRFS_I(inode)->delalloc_bytes += len; 1559 if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST, 1560 &BTRFS_I(inode)->runtime_flags)) { 1561 spin_lock(&root->fs_info->delalloc_lock); 1562 if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) { 1563 list_add_tail(&BTRFS_I(inode)->delalloc_inodes, 1564 &root->fs_info->delalloc_inodes); 1565 set_bit(BTRFS_INODE_IN_DELALLOC_LIST, 1566 &BTRFS_I(inode)->runtime_flags); 1567 } 1568 spin_unlock(&root->fs_info->delalloc_lock); 1569 } 1570 spin_unlock(&BTRFS_I(inode)->lock); 1571 } 1572 } 1573 1574 /* 1575 * extent_io.c clear_bit_hook, see set_bit_hook for why 1576 */ 1577 static void btrfs_clear_bit_hook(struct inode *inode, 1578 struct extent_state *state, 1579 unsigned long *bits) 1580 { 1581 /* 1582 * set_bit and clear bit hooks normally require _irqsave/restore 1583 * but in this case, we are only testing for the DELALLOC 1584 * bit, which is only set or cleared with irqs on 1585 */ 1586 if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) { 1587 struct btrfs_root *root = BTRFS_I(inode)->root; 1588 u64 len = state->end + 1 - state->start; 1589 bool do_list = !btrfs_is_free_space_inode(inode); 1590 1591 if (*bits & EXTENT_FIRST_DELALLOC) { 1592 *bits &= ~EXTENT_FIRST_DELALLOC; 1593 } else if (!(*bits & EXTENT_DO_ACCOUNTING)) { 1594 spin_lock(&BTRFS_I(inode)->lock); 1595 BTRFS_I(inode)->outstanding_extents--; 1596 spin_unlock(&BTRFS_I(inode)->lock); 1597 } 1598 1599 if (*bits & EXTENT_DO_ACCOUNTING) 1600 btrfs_delalloc_release_metadata(inode, len); 1601 1602 if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID 1603 && do_list) 1604 btrfs_free_reserved_data_space(inode, len); 1605 1606 __percpu_counter_add(&root->fs_info->delalloc_bytes, -len, 1607 root->fs_info->delalloc_batch); 1608 spin_lock(&BTRFS_I(inode)->lock); 1609 BTRFS_I(inode)->delalloc_bytes -= len; 1610 if (do_list && BTRFS_I(inode)->delalloc_bytes == 0 && 1611 test_bit(BTRFS_INODE_IN_DELALLOC_LIST, 1612 &BTRFS_I(inode)->runtime_flags)) { 1613 spin_lock(&root->fs_info->delalloc_lock); 1614 if (!list_empty(&BTRFS_I(inode)->delalloc_inodes)) { 1615 list_del_init(&BTRFS_I(inode)->delalloc_inodes); 1616 clear_bit(BTRFS_INODE_IN_DELALLOC_LIST, 1617 &BTRFS_I(inode)->runtime_flags); 1618 } 1619 spin_unlock(&root->fs_info->delalloc_lock); 1620 } 1621 spin_unlock(&BTRFS_I(inode)->lock); 1622 } 1623 } 1624 1625 /* 1626 * extent_io.c merge_bio_hook, this must check the chunk tree to make sure 1627 * we don't create bios that span stripes or chunks 1628 */ 1629 int btrfs_merge_bio_hook(int rw, struct page *page, unsigned long offset, 1630 size_t size, struct bio *bio, 1631 unsigned long bio_flags) 1632 { 1633 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root; 1634 u64 logical = (u64)bio->bi_sector << 9; 1635 u64 length = 0; 1636 u64 map_length; 1637 int ret; 1638 1639 if (bio_flags & EXTENT_BIO_COMPRESSED) 1640 return 0; 1641 1642 length = bio->bi_size; 1643 map_length = length; 1644 ret = btrfs_map_block(root->fs_info, rw, logical, 1645 &map_length, NULL, 0); 1646 /* Will always return 0 with map_multi == NULL */ 1647 BUG_ON(ret < 0); 1648 if (map_length < length + size) 1649 return 1; 1650 return 0; 1651 } 1652 1653 /* 1654 * in order to insert checksums into the metadata in large chunks, 1655 * we wait until bio submission time. All the pages in the bio are 1656 * checksummed and sums are attached onto the ordered extent record. 1657 * 1658 * At IO completion time the cums attached on the ordered extent record 1659 * are inserted into the btree 1660 */ 1661 static int __btrfs_submit_bio_start(struct inode *inode, int rw, 1662 struct bio *bio, int mirror_num, 1663 unsigned long bio_flags, 1664 u64 bio_offset) 1665 { 1666 struct btrfs_root *root = BTRFS_I(inode)->root; 1667 int ret = 0; 1668 1669 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0); 1670 BUG_ON(ret); /* -ENOMEM */ 1671 return 0; 1672 } 1673 1674 /* 1675 * in order to insert checksums into the metadata in large chunks, 1676 * we wait until bio submission time. All the pages in the bio are 1677 * checksummed and sums are attached onto the ordered extent record. 1678 * 1679 * At IO completion time the cums attached on the ordered extent record 1680 * are inserted into the btree 1681 */ 1682 static int __btrfs_submit_bio_done(struct inode *inode, int rw, struct bio *bio, 1683 int mirror_num, unsigned long bio_flags, 1684 u64 bio_offset) 1685 { 1686 struct btrfs_root *root = BTRFS_I(inode)->root; 1687 int ret; 1688 1689 ret = btrfs_map_bio(root, rw, bio, mirror_num, 1); 1690 if (ret) 1691 bio_endio(bio, ret); 1692 return ret; 1693 } 1694 1695 /* 1696 * extent_io.c submission hook. This does the right thing for csum calculation 1697 * on write, or reading the csums from the tree before a read 1698 */ 1699 static int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio, 1700 int mirror_num, unsigned long bio_flags, 1701 u64 bio_offset) 1702 { 1703 struct btrfs_root *root = BTRFS_I(inode)->root; 1704 int ret = 0; 1705 int skip_sum; 1706 int metadata = 0; 1707 int async = !atomic_read(&BTRFS_I(inode)->sync_writers); 1708 1709 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM; 1710 1711 if (btrfs_is_free_space_inode(inode)) 1712 metadata = 2; 1713 1714 if (!(rw & REQ_WRITE)) { 1715 ret = btrfs_bio_wq_end_io(root->fs_info, bio, metadata); 1716 if (ret) 1717 goto out; 1718 1719 if (bio_flags & EXTENT_BIO_COMPRESSED) { 1720 ret = btrfs_submit_compressed_read(inode, bio, 1721 mirror_num, 1722 bio_flags); 1723 goto out; 1724 } else if (!skip_sum) { 1725 ret = btrfs_lookup_bio_sums(root, inode, bio, NULL); 1726 if (ret) 1727 goto out; 1728 } 1729 goto mapit; 1730 } else if (async && !skip_sum) { 1731 /* csum items have already been cloned */ 1732 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID) 1733 goto mapit; 1734 /* we're doing a write, do the async checksumming */ 1735 ret = btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info, 1736 inode, rw, bio, mirror_num, 1737 bio_flags, bio_offset, 1738 __btrfs_submit_bio_start, 1739 __btrfs_submit_bio_done); 1740 goto out; 1741 } else if (!skip_sum) { 1742 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0); 1743 if (ret) 1744 goto out; 1745 } 1746 1747 mapit: 1748 ret = btrfs_map_bio(root, rw, bio, mirror_num, 0); 1749 1750 out: 1751 if (ret < 0) 1752 bio_endio(bio, ret); 1753 return ret; 1754 } 1755 1756 /* 1757 * given a list of ordered sums record them in the inode. This happens 1758 * at IO completion time based on sums calculated at bio submission time. 1759 */ 1760 static noinline int add_pending_csums(struct btrfs_trans_handle *trans, 1761 struct inode *inode, u64 file_offset, 1762 struct list_head *list) 1763 { 1764 struct btrfs_ordered_sum *sum; 1765 1766 list_for_each_entry(sum, list, list) { 1767 trans->adding_csums = 1; 1768 btrfs_csum_file_blocks(trans, 1769 BTRFS_I(inode)->root->fs_info->csum_root, sum); 1770 trans->adding_csums = 0; 1771 } 1772 return 0; 1773 } 1774 1775 int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end, 1776 struct extent_state **cached_state) 1777 { 1778 WARN_ON((end & (PAGE_CACHE_SIZE - 1)) == 0); 1779 return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end, 1780 cached_state, GFP_NOFS); 1781 } 1782 1783 /* see btrfs_writepage_start_hook for details on why this is required */ 1784 struct btrfs_writepage_fixup { 1785 struct page *page; 1786 struct btrfs_work work; 1787 }; 1788 1789 static void btrfs_writepage_fixup_worker(struct btrfs_work *work) 1790 { 1791 struct btrfs_writepage_fixup *fixup; 1792 struct btrfs_ordered_extent *ordered; 1793 struct extent_state *cached_state = NULL; 1794 struct page *page; 1795 struct inode *inode; 1796 u64 page_start; 1797 u64 page_end; 1798 int ret; 1799 1800 fixup = container_of(work, struct btrfs_writepage_fixup, work); 1801 page = fixup->page; 1802 again: 1803 lock_page(page); 1804 if (!page->mapping || !PageDirty(page) || !PageChecked(page)) { 1805 ClearPageChecked(page); 1806 goto out_page; 1807 } 1808 1809 inode = page->mapping->host; 1810 page_start = page_offset(page); 1811 page_end = page_offset(page) + PAGE_CACHE_SIZE - 1; 1812 1813 lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end, 0, 1814 &cached_state); 1815 1816 /* already ordered? We're done */ 1817 if (PagePrivate2(page)) 1818 goto out; 1819 1820 ordered = btrfs_lookup_ordered_extent(inode, page_start); 1821 if (ordered) { 1822 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, 1823 page_end, &cached_state, GFP_NOFS); 1824 unlock_page(page); 1825 btrfs_start_ordered_extent(inode, ordered, 1); 1826 btrfs_put_ordered_extent(ordered); 1827 goto again; 1828 } 1829 1830 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE); 1831 if (ret) { 1832 mapping_set_error(page->mapping, ret); 1833 end_extent_writepage(page, ret, page_start, page_end); 1834 ClearPageChecked(page); 1835 goto out; 1836 } 1837 1838 btrfs_set_extent_delalloc(inode, page_start, page_end, &cached_state); 1839 ClearPageChecked(page); 1840 set_page_dirty(page); 1841 out: 1842 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end, 1843 &cached_state, GFP_NOFS); 1844 out_page: 1845 unlock_page(page); 1846 page_cache_release(page); 1847 kfree(fixup); 1848 } 1849 1850 /* 1851 * There are a few paths in the higher layers of the kernel that directly 1852 * set the page dirty bit without asking the filesystem if it is a 1853 * good idea. This causes problems because we want to make sure COW 1854 * properly happens and the data=ordered rules are followed. 1855 * 1856 * In our case any range that doesn't have the ORDERED bit set 1857 * hasn't been properly setup for IO. We kick off an async process 1858 * to fix it up. The async helper will wait for ordered extents, set 1859 * the delalloc bit and make it safe to write the page. 1860 */ 1861 static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end) 1862 { 1863 struct inode *inode = page->mapping->host; 1864 struct btrfs_writepage_fixup *fixup; 1865 struct btrfs_root *root = BTRFS_I(inode)->root; 1866 1867 /* this page is properly in the ordered list */ 1868 if (TestClearPagePrivate2(page)) 1869 return 0; 1870 1871 if (PageChecked(page)) 1872 return -EAGAIN; 1873 1874 fixup = kzalloc(sizeof(*fixup), GFP_NOFS); 1875 if (!fixup) 1876 return -EAGAIN; 1877 1878 SetPageChecked(page); 1879 page_cache_get(page); 1880 fixup->work.func = btrfs_writepage_fixup_worker; 1881 fixup->page = page; 1882 btrfs_queue_worker(&root->fs_info->fixup_workers, &fixup->work); 1883 return -EBUSY; 1884 } 1885 1886 static int insert_reserved_file_extent(struct btrfs_trans_handle *trans, 1887 struct inode *inode, u64 file_pos, 1888 u64 disk_bytenr, u64 disk_num_bytes, 1889 u64 num_bytes, u64 ram_bytes, 1890 u8 compression, u8 encryption, 1891 u16 other_encoding, int extent_type) 1892 { 1893 struct btrfs_root *root = BTRFS_I(inode)->root; 1894 struct btrfs_file_extent_item *fi; 1895 struct btrfs_path *path; 1896 struct extent_buffer *leaf; 1897 struct btrfs_key ins; 1898 int ret; 1899 1900 path = btrfs_alloc_path(); 1901 if (!path) 1902 return -ENOMEM; 1903 1904 path->leave_spinning = 1; 1905 1906 /* 1907 * we may be replacing one extent in the tree with another. 1908 * The new extent is pinned in the extent map, and we don't want 1909 * to drop it from the cache until it is completely in the btree. 1910 * 1911 * So, tell btrfs_drop_extents to leave this extent in the cache. 1912 * the caller is expected to unpin it and allow it to be merged 1913 * with the others. 1914 */ 1915 ret = btrfs_drop_extents(trans, root, inode, file_pos, 1916 file_pos + num_bytes, 0); 1917 if (ret) 1918 goto out; 1919 1920 ins.objectid = btrfs_ino(inode); 1921 ins.offset = file_pos; 1922 ins.type = BTRFS_EXTENT_DATA_KEY; 1923 ret = btrfs_insert_empty_item(trans, root, path, &ins, sizeof(*fi)); 1924 if (ret) 1925 goto out; 1926 leaf = path->nodes[0]; 1927 fi = btrfs_item_ptr(leaf, path->slots[0], 1928 struct btrfs_file_extent_item); 1929 btrfs_set_file_extent_generation(leaf, fi, trans->transid); 1930 btrfs_set_file_extent_type(leaf, fi, extent_type); 1931 btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr); 1932 btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes); 1933 btrfs_set_file_extent_offset(leaf, fi, 0); 1934 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes); 1935 btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes); 1936 btrfs_set_file_extent_compression(leaf, fi, compression); 1937 btrfs_set_file_extent_encryption(leaf, fi, encryption); 1938 btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding); 1939 1940 btrfs_mark_buffer_dirty(leaf); 1941 btrfs_release_path(path); 1942 1943 inode_add_bytes(inode, num_bytes); 1944 1945 ins.objectid = disk_bytenr; 1946 ins.offset = disk_num_bytes; 1947 ins.type = BTRFS_EXTENT_ITEM_KEY; 1948 ret = btrfs_alloc_reserved_file_extent(trans, root, 1949 root->root_key.objectid, 1950 btrfs_ino(inode), file_pos, &ins); 1951 out: 1952 btrfs_free_path(path); 1953 1954 return ret; 1955 } 1956 1957 /* snapshot-aware defrag */ 1958 struct sa_defrag_extent_backref { 1959 struct rb_node node; 1960 struct old_sa_defrag_extent *old; 1961 u64 root_id; 1962 u64 inum; 1963 u64 file_pos; 1964 u64 extent_offset; 1965 u64 num_bytes; 1966 u64 generation; 1967 }; 1968 1969 struct old_sa_defrag_extent { 1970 struct list_head list; 1971 struct new_sa_defrag_extent *new; 1972 1973 u64 extent_offset; 1974 u64 bytenr; 1975 u64 offset; 1976 u64 len; 1977 int count; 1978 }; 1979 1980 struct new_sa_defrag_extent { 1981 struct rb_root root; 1982 struct list_head head; 1983 struct btrfs_path *path; 1984 struct inode *inode; 1985 u64 file_pos; 1986 u64 len; 1987 u64 bytenr; 1988 u64 disk_len; 1989 u8 compress_type; 1990 }; 1991 1992 static int backref_comp(struct sa_defrag_extent_backref *b1, 1993 struct sa_defrag_extent_backref *b2) 1994 { 1995 if (b1->root_id < b2->root_id) 1996 return -1; 1997 else if (b1->root_id > b2->root_id) 1998 return 1; 1999 2000 if (b1->inum < b2->inum) 2001 return -1; 2002 else if (b1->inum > b2->inum) 2003 return 1; 2004 2005 if (b1->file_pos < b2->file_pos) 2006 return -1; 2007 else if (b1->file_pos > b2->file_pos) 2008 return 1; 2009 2010 /* 2011 * [------------------------------] ===> (a range of space) 2012 * |<--->| |<---->| =============> (fs/file tree A) 2013 * |<---------------------------->| ===> (fs/file tree B) 2014 * 2015 * A range of space can refer to two file extents in one tree while 2016 * refer to only one file extent in another tree. 2017 * 2018 * So we may process a disk offset more than one time(two extents in A) 2019 * and locate at the same extent(one extent in B), then insert two same 2020 * backrefs(both refer to the extent in B). 2021 */ 2022 return 0; 2023 } 2024 2025 static void backref_insert(struct rb_root *root, 2026 struct sa_defrag_extent_backref *backref) 2027 { 2028 struct rb_node **p = &root->rb_node; 2029 struct rb_node *parent = NULL; 2030 struct sa_defrag_extent_backref *entry; 2031 int ret; 2032 2033 while (*p) { 2034 parent = *p; 2035 entry = rb_entry(parent, struct sa_defrag_extent_backref, node); 2036 2037 ret = backref_comp(backref, entry); 2038 if (ret < 0) 2039 p = &(*p)->rb_left; 2040 else 2041 p = &(*p)->rb_right; 2042 } 2043 2044 rb_link_node(&backref->node, parent, p); 2045 rb_insert_color(&backref->node, root); 2046 } 2047 2048 /* 2049 * Note the backref might has changed, and in this case we just return 0. 2050 */ 2051 static noinline int record_one_backref(u64 inum, u64 offset, u64 root_id, 2052 void *ctx) 2053 { 2054 struct btrfs_file_extent_item *extent; 2055 struct btrfs_fs_info *fs_info; 2056 struct old_sa_defrag_extent *old = ctx; 2057 struct new_sa_defrag_extent *new = old->new; 2058 struct btrfs_path *path = new->path; 2059 struct btrfs_key key; 2060 struct btrfs_root *root; 2061 struct sa_defrag_extent_backref *backref; 2062 struct extent_buffer *leaf; 2063 struct inode *inode = new->inode; 2064 int slot; 2065 int ret; 2066 u64 extent_offset; 2067 u64 num_bytes; 2068 2069 if (BTRFS_I(inode)->root->root_key.objectid == root_id && 2070 inum == btrfs_ino(inode)) 2071 return 0; 2072 2073 key.objectid = root_id; 2074 key.type = BTRFS_ROOT_ITEM_KEY; 2075 key.offset = (u64)-1; 2076 2077 fs_info = BTRFS_I(inode)->root->fs_info; 2078 root = btrfs_read_fs_root_no_name(fs_info, &key); 2079 if (IS_ERR(root)) { 2080 if (PTR_ERR(root) == -ENOENT) 2081 return 0; 2082 WARN_ON(1); 2083 pr_debug("inum=%llu, offset=%llu, root_id=%llu\n", 2084 inum, offset, root_id); 2085 return PTR_ERR(root); 2086 } 2087 2088 key.objectid = inum; 2089 key.type = BTRFS_EXTENT_DATA_KEY; 2090 if (offset > (u64)-1 << 32) 2091 key.offset = 0; 2092 else 2093 key.offset = offset; 2094 2095 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 2096 if (ret < 0) { 2097 WARN_ON(1); 2098 return ret; 2099 } 2100 2101 while (1) { 2102 cond_resched(); 2103 2104 leaf = path->nodes[0]; 2105 slot = path->slots[0]; 2106 2107 if (slot >= btrfs_header_nritems(leaf)) { 2108 ret = btrfs_next_leaf(root, path); 2109 if (ret < 0) { 2110 goto out; 2111 } else if (ret > 0) { 2112 ret = 0; 2113 goto out; 2114 } 2115 continue; 2116 } 2117 2118 path->slots[0]++; 2119 2120 btrfs_item_key_to_cpu(leaf, &key, slot); 2121 2122 if (key.objectid > inum) 2123 goto out; 2124 2125 if (key.objectid < inum || key.type != BTRFS_EXTENT_DATA_KEY) 2126 continue; 2127 2128 extent = btrfs_item_ptr(leaf, slot, 2129 struct btrfs_file_extent_item); 2130 2131 if (btrfs_file_extent_disk_bytenr(leaf, extent) != old->bytenr) 2132 continue; 2133 2134 extent_offset = btrfs_file_extent_offset(leaf, extent); 2135 if (key.offset - extent_offset != offset) 2136 continue; 2137 2138 num_bytes = btrfs_file_extent_num_bytes(leaf, extent); 2139 if (extent_offset >= old->extent_offset + old->offset + 2140 old->len || extent_offset + num_bytes <= 2141 old->extent_offset + old->offset) 2142 continue; 2143 2144 break; 2145 } 2146 2147 backref = kmalloc(sizeof(*backref), GFP_NOFS); 2148 if (!backref) { 2149 ret = -ENOENT; 2150 goto out; 2151 } 2152 2153 backref->root_id = root_id; 2154 backref->inum = inum; 2155 backref->file_pos = offset + extent_offset; 2156 backref->num_bytes = num_bytes; 2157 backref->extent_offset = extent_offset; 2158 backref->generation = btrfs_file_extent_generation(leaf, extent); 2159 backref->old = old; 2160 backref_insert(&new->root, backref); 2161 old->count++; 2162 out: 2163 btrfs_release_path(path); 2164 WARN_ON(ret); 2165 return ret; 2166 } 2167 2168 static noinline bool record_extent_backrefs(struct btrfs_path *path, 2169 struct new_sa_defrag_extent *new) 2170 { 2171 struct btrfs_fs_info *fs_info = BTRFS_I(new->inode)->root->fs_info; 2172 struct old_sa_defrag_extent *old, *tmp; 2173 int ret; 2174 2175 new->path = path; 2176 2177 list_for_each_entry_safe(old, tmp, &new->head, list) { 2178 ret = iterate_inodes_from_logical(old->bytenr, fs_info, 2179 path, record_one_backref, 2180 old); 2181 BUG_ON(ret < 0 && ret != -ENOENT); 2182 2183 /* no backref to be processed for this extent */ 2184 if (!old->count) { 2185 list_del(&old->list); 2186 kfree(old); 2187 } 2188 } 2189 2190 if (list_empty(&new->head)) 2191 return false; 2192 2193 return true; 2194 } 2195 2196 static int relink_is_mergable(struct extent_buffer *leaf, 2197 struct btrfs_file_extent_item *fi, 2198 u64 disk_bytenr) 2199 { 2200 if (btrfs_file_extent_disk_bytenr(leaf, fi) != disk_bytenr) 2201 return 0; 2202 2203 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG) 2204 return 0; 2205 2206 if (btrfs_file_extent_compression(leaf, fi) || 2207 btrfs_file_extent_encryption(leaf, fi) || 2208 btrfs_file_extent_other_encoding(leaf, fi)) 2209 return 0; 2210 2211 return 1; 2212 } 2213 2214 /* 2215 * Note the backref might has changed, and in this case we just return 0. 2216 */ 2217 static noinline int relink_extent_backref(struct btrfs_path *path, 2218 struct sa_defrag_extent_backref *prev, 2219 struct sa_defrag_extent_backref *backref) 2220 { 2221 struct btrfs_file_extent_item *extent; 2222 struct btrfs_file_extent_item *item; 2223 struct btrfs_ordered_extent *ordered; 2224 struct btrfs_trans_handle *trans; 2225 struct btrfs_fs_info *fs_info; 2226 struct btrfs_root *root; 2227 struct btrfs_key key; 2228 struct extent_buffer *leaf; 2229 struct old_sa_defrag_extent *old = backref->old; 2230 struct new_sa_defrag_extent *new = old->new; 2231 struct inode *src_inode = new->inode; 2232 struct inode *inode; 2233 struct extent_state *cached = NULL; 2234 int ret = 0; 2235 u64 start; 2236 u64 len; 2237 u64 lock_start; 2238 u64 lock_end; 2239 bool merge = false; 2240 int index; 2241 2242 if (prev && prev->root_id == backref->root_id && 2243 prev->inum == backref->inum && 2244 prev->file_pos + prev->num_bytes == backref->file_pos) 2245 merge = true; 2246 2247 /* step 1: get root */ 2248 key.objectid = backref->root_id; 2249 key.type = BTRFS_ROOT_ITEM_KEY; 2250 key.offset = (u64)-1; 2251 2252 fs_info = BTRFS_I(src_inode)->root->fs_info; 2253 index = srcu_read_lock(&fs_info->subvol_srcu); 2254 2255 root = btrfs_read_fs_root_no_name(fs_info, &key); 2256 if (IS_ERR(root)) { 2257 srcu_read_unlock(&fs_info->subvol_srcu, index); 2258 if (PTR_ERR(root) == -ENOENT) 2259 return 0; 2260 return PTR_ERR(root); 2261 } 2262 if (btrfs_root_refs(&root->root_item) == 0) { 2263 srcu_read_unlock(&fs_info->subvol_srcu, index); 2264 /* parse ENOENT to 0 */ 2265 return 0; 2266 } 2267 2268 /* step 2: get inode */ 2269 key.objectid = backref->inum; 2270 key.type = BTRFS_INODE_ITEM_KEY; 2271 key.offset = 0; 2272 2273 inode = btrfs_iget(fs_info->sb, &key, root, NULL); 2274 if (IS_ERR(inode)) { 2275 srcu_read_unlock(&fs_info->subvol_srcu, index); 2276 return 0; 2277 } 2278 2279 srcu_read_unlock(&fs_info->subvol_srcu, index); 2280 2281 /* step 3: relink backref */ 2282 lock_start = backref->file_pos; 2283 lock_end = backref->file_pos + backref->num_bytes - 1; 2284 lock_extent_bits(&BTRFS_I(inode)->io_tree, lock_start, lock_end, 2285 0, &cached); 2286 2287 ordered = btrfs_lookup_first_ordered_extent(inode, lock_end); 2288 if (ordered) { 2289 btrfs_put_ordered_extent(ordered); 2290 goto out_unlock; 2291 } 2292 2293 trans = btrfs_join_transaction(root); 2294 if (IS_ERR(trans)) { 2295 ret = PTR_ERR(trans); 2296 goto out_unlock; 2297 } 2298 2299 key.objectid = backref->inum; 2300 key.type = BTRFS_EXTENT_DATA_KEY; 2301 key.offset = backref->file_pos; 2302 2303 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 2304 if (ret < 0) { 2305 goto out_free_path; 2306 } else if (ret > 0) { 2307 ret = 0; 2308 goto out_free_path; 2309 } 2310 2311 extent = btrfs_item_ptr(path->nodes[0], path->slots[0], 2312 struct btrfs_file_extent_item); 2313 2314 if (btrfs_file_extent_generation(path->nodes[0], extent) != 2315 backref->generation) 2316 goto out_free_path; 2317 2318 btrfs_release_path(path); 2319 2320 start = backref->file_pos; 2321 if (backref->extent_offset < old->extent_offset + old->offset) 2322 start += old->extent_offset + old->offset - 2323 backref->extent_offset; 2324 2325 len = min(backref->extent_offset + backref->num_bytes, 2326 old->extent_offset + old->offset + old->len); 2327 len -= max(backref->extent_offset, old->extent_offset + old->offset); 2328 2329 ret = btrfs_drop_extents(trans, root, inode, start, 2330 start + len, 1); 2331 if (ret) 2332 goto out_free_path; 2333 again: 2334 key.objectid = btrfs_ino(inode); 2335 key.type = BTRFS_EXTENT_DATA_KEY; 2336 key.offset = start; 2337 2338 path->leave_spinning = 1; 2339 if (merge) { 2340 struct btrfs_file_extent_item *fi; 2341 u64 extent_len; 2342 struct btrfs_key found_key; 2343 2344 ret = btrfs_search_slot(trans, root, &key, path, 1, 1); 2345 if (ret < 0) 2346 goto out_free_path; 2347 2348 path->slots[0]--; 2349 leaf = path->nodes[0]; 2350 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 2351 2352 fi = btrfs_item_ptr(leaf, path->slots[0], 2353 struct btrfs_file_extent_item); 2354 extent_len = btrfs_file_extent_num_bytes(leaf, fi); 2355 2356 if (relink_is_mergable(leaf, fi, new->bytenr) && 2357 extent_len + found_key.offset == start) { 2358 btrfs_set_file_extent_num_bytes(leaf, fi, 2359 extent_len + len); 2360 btrfs_mark_buffer_dirty(leaf); 2361 inode_add_bytes(inode, len); 2362 2363 ret = 1; 2364 goto out_free_path; 2365 } else { 2366 merge = false; 2367 btrfs_release_path(path); 2368 goto again; 2369 } 2370 } 2371 2372 ret = btrfs_insert_empty_item(trans, root, path, &key, 2373 sizeof(*extent)); 2374 if (ret) { 2375 btrfs_abort_transaction(trans, root, ret); 2376 goto out_free_path; 2377 } 2378 2379 leaf = path->nodes[0]; 2380 item = btrfs_item_ptr(leaf, path->slots[0], 2381 struct btrfs_file_extent_item); 2382 btrfs_set_file_extent_disk_bytenr(leaf, item, new->bytenr); 2383 btrfs_set_file_extent_disk_num_bytes(leaf, item, new->disk_len); 2384 btrfs_set_file_extent_offset(leaf, item, start - new->file_pos); 2385 btrfs_set_file_extent_num_bytes(leaf, item, len); 2386 btrfs_set_file_extent_ram_bytes(leaf, item, new->len); 2387 btrfs_set_file_extent_generation(leaf, item, trans->transid); 2388 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG); 2389 btrfs_set_file_extent_compression(leaf, item, new->compress_type); 2390 btrfs_set_file_extent_encryption(leaf, item, 0); 2391 btrfs_set_file_extent_other_encoding(leaf, item, 0); 2392 2393 btrfs_mark_buffer_dirty(leaf); 2394 inode_add_bytes(inode, len); 2395 btrfs_release_path(path); 2396 2397 ret = btrfs_inc_extent_ref(trans, root, new->bytenr, 2398 new->disk_len, 0, 2399 backref->root_id, backref->inum, 2400 new->file_pos, 0); /* start - extent_offset */ 2401 if (ret) { 2402 btrfs_abort_transaction(trans, root, ret); 2403 goto out_free_path; 2404 } 2405 2406 ret = 1; 2407 out_free_path: 2408 btrfs_release_path(path); 2409 path->leave_spinning = 0; 2410 btrfs_end_transaction(trans, root); 2411 out_unlock: 2412 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lock_start, lock_end, 2413 &cached, GFP_NOFS); 2414 iput(inode); 2415 return ret; 2416 } 2417 2418 static void relink_file_extents(struct new_sa_defrag_extent *new) 2419 { 2420 struct btrfs_path *path; 2421 struct old_sa_defrag_extent *old, *tmp; 2422 struct sa_defrag_extent_backref *backref; 2423 struct sa_defrag_extent_backref *prev = NULL; 2424 struct inode *inode; 2425 struct btrfs_root *root; 2426 struct rb_node *node; 2427 int ret; 2428 2429 inode = new->inode; 2430 root = BTRFS_I(inode)->root; 2431 2432 path = btrfs_alloc_path(); 2433 if (!path) 2434 return; 2435 2436 if (!record_extent_backrefs(path, new)) { 2437 btrfs_free_path(path); 2438 goto out; 2439 } 2440 btrfs_release_path(path); 2441 2442 while (1) { 2443 node = rb_first(&new->root); 2444 if (!node) 2445 break; 2446 rb_erase(node, &new->root); 2447 2448 backref = rb_entry(node, struct sa_defrag_extent_backref, node); 2449 2450 ret = relink_extent_backref(path, prev, backref); 2451 WARN_ON(ret < 0); 2452 2453 kfree(prev); 2454 2455 if (ret == 1) 2456 prev = backref; 2457 else 2458 prev = NULL; 2459 cond_resched(); 2460 } 2461 kfree(prev); 2462 2463 btrfs_free_path(path); 2464 2465 list_for_each_entry_safe(old, tmp, &new->head, list) { 2466 list_del(&old->list); 2467 kfree(old); 2468 } 2469 out: 2470 atomic_dec(&root->fs_info->defrag_running); 2471 wake_up(&root->fs_info->transaction_wait); 2472 2473 kfree(new); 2474 } 2475 2476 static struct new_sa_defrag_extent * 2477 record_old_file_extents(struct inode *inode, 2478 struct btrfs_ordered_extent *ordered) 2479 { 2480 struct btrfs_root *root = BTRFS_I(inode)->root; 2481 struct btrfs_path *path; 2482 struct btrfs_key key; 2483 struct old_sa_defrag_extent *old, *tmp; 2484 struct new_sa_defrag_extent *new; 2485 int ret; 2486 2487 new = kmalloc(sizeof(*new), GFP_NOFS); 2488 if (!new) 2489 return NULL; 2490 2491 new->inode = inode; 2492 new->file_pos = ordered->file_offset; 2493 new->len = ordered->len; 2494 new->bytenr = ordered->start; 2495 new->disk_len = ordered->disk_len; 2496 new->compress_type = ordered->compress_type; 2497 new->root = RB_ROOT; 2498 INIT_LIST_HEAD(&new->head); 2499 2500 path = btrfs_alloc_path(); 2501 if (!path) 2502 goto out_kfree; 2503 2504 key.objectid = btrfs_ino(inode); 2505 key.type = BTRFS_EXTENT_DATA_KEY; 2506 key.offset = new->file_pos; 2507 2508 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 2509 if (ret < 0) 2510 goto out_free_path; 2511 if (ret > 0 && path->slots[0] > 0) 2512 path->slots[0]--; 2513 2514 /* find out all the old extents for the file range */ 2515 while (1) { 2516 struct btrfs_file_extent_item *extent; 2517 struct extent_buffer *l; 2518 int slot; 2519 u64 num_bytes; 2520 u64 offset; 2521 u64 end; 2522 u64 disk_bytenr; 2523 u64 extent_offset; 2524 2525 l = path->nodes[0]; 2526 slot = path->slots[0]; 2527 2528 if (slot >= btrfs_header_nritems(l)) { 2529 ret = btrfs_next_leaf(root, path); 2530 if (ret < 0) 2531 goto out_free_list; 2532 else if (ret > 0) 2533 break; 2534 continue; 2535 } 2536 2537 btrfs_item_key_to_cpu(l, &key, slot); 2538 2539 if (key.objectid != btrfs_ino(inode)) 2540 break; 2541 if (key.type != BTRFS_EXTENT_DATA_KEY) 2542 break; 2543 if (key.offset >= new->file_pos + new->len) 2544 break; 2545 2546 extent = btrfs_item_ptr(l, slot, struct btrfs_file_extent_item); 2547 2548 num_bytes = btrfs_file_extent_num_bytes(l, extent); 2549 if (key.offset + num_bytes < new->file_pos) 2550 goto next; 2551 2552 disk_bytenr = btrfs_file_extent_disk_bytenr(l, extent); 2553 if (!disk_bytenr) 2554 goto next; 2555 2556 extent_offset = btrfs_file_extent_offset(l, extent); 2557 2558 old = kmalloc(sizeof(*old), GFP_NOFS); 2559 if (!old) 2560 goto out_free_list; 2561 2562 offset = max(new->file_pos, key.offset); 2563 end = min(new->file_pos + new->len, key.offset + num_bytes); 2564 2565 old->bytenr = disk_bytenr; 2566 old->extent_offset = extent_offset; 2567 old->offset = offset - key.offset; 2568 old->len = end - offset; 2569 old->new = new; 2570 old->count = 0; 2571 list_add_tail(&old->list, &new->head); 2572 next: 2573 path->slots[0]++; 2574 cond_resched(); 2575 } 2576 2577 btrfs_free_path(path); 2578 atomic_inc(&root->fs_info->defrag_running); 2579 2580 return new; 2581 2582 out_free_list: 2583 list_for_each_entry_safe(old, tmp, &new->head, list) { 2584 list_del(&old->list); 2585 kfree(old); 2586 } 2587 out_free_path: 2588 btrfs_free_path(path); 2589 out_kfree: 2590 kfree(new); 2591 return NULL; 2592 } 2593 2594 /* 2595 * helper function for btrfs_finish_ordered_io, this 2596 * just reads in some of the csum leaves to prime them into ram 2597 * before we start the transaction. It limits the amount of btree 2598 * reads required while inside the transaction. 2599 */ 2600 /* as ordered data IO finishes, this gets called so we can finish 2601 * an ordered extent if the range of bytes in the file it covers are 2602 * fully written. 2603 */ 2604 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent) 2605 { 2606 struct inode *inode = ordered_extent->inode; 2607 struct btrfs_root *root = BTRFS_I(inode)->root; 2608 struct btrfs_trans_handle *trans = NULL; 2609 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 2610 struct extent_state *cached_state = NULL; 2611 struct new_sa_defrag_extent *new = NULL; 2612 int compress_type = 0; 2613 int ret; 2614 bool nolock; 2615 2616 nolock = btrfs_is_free_space_inode(inode); 2617 2618 if (test_bit(BTRFS_ORDERED_IOERR, &ordered_extent->flags)) { 2619 ret = -EIO; 2620 goto out; 2621 } 2622 2623 if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) { 2624 BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */ 2625 btrfs_ordered_update_i_size(inode, 0, ordered_extent); 2626 if (nolock) 2627 trans = btrfs_join_transaction_nolock(root); 2628 else 2629 trans = btrfs_join_transaction(root); 2630 if (IS_ERR(trans)) { 2631 ret = PTR_ERR(trans); 2632 trans = NULL; 2633 goto out; 2634 } 2635 trans->block_rsv = &root->fs_info->delalloc_block_rsv; 2636 ret = btrfs_update_inode_fallback(trans, root, inode); 2637 if (ret) /* -ENOMEM or corruption */ 2638 btrfs_abort_transaction(trans, root, ret); 2639 goto out; 2640 } 2641 2642 lock_extent_bits(io_tree, ordered_extent->file_offset, 2643 ordered_extent->file_offset + ordered_extent->len - 1, 2644 0, &cached_state); 2645 2646 ret = test_range_bit(io_tree, ordered_extent->file_offset, 2647 ordered_extent->file_offset + ordered_extent->len - 1, 2648 EXTENT_DEFRAG, 1, cached_state); 2649 if (ret) { 2650 u64 last_snapshot = btrfs_root_last_snapshot(&root->root_item); 2651 if (last_snapshot >= BTRFS_I(inode)->generation) 2652 /* the inode is shared */ 2653 new = record_old_file_extents(inode, ordered_extent); 2654 2655 clear_extent_bit(io_tree, ordered_extent->file_offset, 2656 ordered_extent->file_offset + ordered_extent->len - 1, 2657 EXTENT_DEFRAG, 0, 0, &cached_state, GFP_NOFS); 2658 } 2659 2660 if (nolock) 2661 trans = btrfs_join_transaction_nolock(root); 2662 else 2663 trans = btrfs_join_transaction(root); 2664 if (IS_ERR(trans)) { 2665 ret = PTR_ERR(trans); 2666 trans = NULL; 2667 goto out_unlock; 2668 } 2669 trans->block_rsv = &root->fs_info->delalloc_block_rsv; 2670 2671 if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags)) 2672 compress_type = ordered_extent->compress_type; 2673 if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) { 2674 BUG_ON(compress_type); 2675 ret = btrfs_mark_extent_written(trans, inode, 2676 ordered_extent->file_offset, 2677 ordered_extent->file_offset + 2678 ordered_extent->len); 2679 } else { 2680 BUG_ON(root == root->fs_info->tree_root); 2681 ret = insert_reserved_file_extent(trans, inode, 2682 ordered_extent->file_offset, 2683 ordered_extent->start, 2684 ordered_extent->disk_len, 2685 ordered_extent->len, 2686 ordered_extent->len, 2687 compress_type, 0, 0, 2688 BTRFS_FILE_EXTENT_REG); 2689 } 2690 unpin_extent_cache(&BTRFS_I(inode)->extent_tree, 2691 ordered_extent->file_offset, ordered_extent->len, 2692 trans->transid); 2693 if (ret < 0) { 2694 btrfs_abort_transaction(trans, root, ret); 2695 goto out_unlock; 2696 } 2697 2698 add_pending_csums(trans, inode, ordered_extent->file_offset, 2699 &ordered_extent->list); 2700 2701 btrfs_ordered_update_i_size(inode, 0, ordered_extent); 2702 ret = btrfs_update_inode_fallback(trans, root, inode); 2703 if (ret) { /* -ENOMEM or corruption */ 2704 btrfs_abort_transaction(trans, root, ret); 2705 goto out_unlock; 2706 } 2707 ret = 0; 2708 out_unlock: 2709 unlock_extent_cached(io_tree, ordered_extent->file_offset, 2710 ordered_extent->file_offset + 2711 ordered_extent->len - 1, &cached_state, GFP_NOFS); 2712 out: 2713 if (root != root->fs_info->tree_root) 2714 btrfs_delalloc_release_metadata(inode, ordered_extent->len); 2715 if (trans) 2716 btrfs_end_transaction(trans, root); 2717 2718 if (ret) { 2719 clear_extent_uptodate(io_tree, ordered_extent->file_offset, 2720 ordered_extent->file_offset + 2721 ordered_extent->len - 1, NULL, GFP_NOFS); 2722 2723 /* 2724 * If the ordered extent had an IOERR or something else went 2725 * wrong we need to return the space for this ordered extent 2726 * back to the allocator. 2727 */ 2728 if (!test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) && 2729 !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) 2730 btrfs_free_reserved_extent(root, ordered_extent->start, 2731 ordered_extent->disk_len); 2732 } 2733 2734 2735 /* 2736 * This needs to be done to make sure anybody waiting knows we are done 2737 * updating everything for this ordered extent. 2738 */ 2739 btrfs_remove_ordered_extent(inode, ordered_extent); 2740 2741 /* for snapshot-aware defrag */ 2742 if (new) 2743 relink_file_extents(new); 2744 2745 /* once for us */ 2746 btrfs_put_ordered_extent(ordered_extent); 2747 /* once for the tree */ 2748 btrfs_put_ordered_extent(ordered_extent); 2749 2750 return ret; 2751 } 2752 2753 static void finish_ordered_fn(struct btrfs_work *work) 2754 { 2755 struct btrfs_ordered_extent *ordered_extent; 2756 ordered_extent = container_of(work, struct btrfs_ordered_extent, work); 2757 btrfs_finish_ordered_io(ordered_extent); 2758 } 2759 2760 static int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end, 2761 struct extent_state *state, int uptodate) 2762 { 2763 struct inode *inode = page->mapping->host; 2764 struct btrfs_root *root = BTRFS_I(inode)->root; 2765 struct btrfs_ordered_extent *ordered_extent = NULL; 2766 struct btrfs_workers *workers; 2767 2768 trace_btrfs_writepage_end_io_hook(page, start, end, uptodate); 2769 2770 ClearPagePrivate2(page); 2771 if (!btrfs_dec_test_ordered_pending(inode, &ordered_extent, start, 2772 end - start + 1, uptodate)) 2773 return 0; 2774 2775 ordered_extent->work.func = finish_ordered_fn; 2776 ordered_extent->work.flags = 0; 2777 2778 if (btrfs_is_free_space_inode(inode)) 2779 workers = &root->fs_info->endio_freespace_worker; 2780 else 2781 workers = &root->fs_info->endio_write_workers; 2782 btrfs_queue_worker(workers, &ordered_extent->work); 2783 2784 return 0; 2785 } 2786 2787 /* 2788 * when reads are done, we need to check csums to verify the data is correct 2789 * if there's a match, we allow the bio to finish. If not, the code in 2790 * extent_io.c will try to find good copies for us. 2791 */ 2792 static int btrfs_readpage_end_io_hook(struct page *page, u64 start, u64 end, 2793 struct extent_state *state, int mirror) 2794 { 2795 size_t offset = start - page_offset(page); 2796 struct inode *inode = page->mapping->host; 2797 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 2798 char *kaddr; 2799 u64 private = ~(u32)0; 2800 int ret; 2801 struct btrfs_root *root = BTRFS_I(inode)->root; 2802 u32 csum = ~(u32)0; 2803 static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL, 2804 DEFAULT_RATELIMIT_BURST); 2805 2806 if (PageChecked(page)) { 2807 ClearPageChecked(page); 2808 goto good; 2809 } 2810 2811 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM) 2812 goto good; 2813 2814 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID && 2815 test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) { 2816 clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM, 2817 GFP_NOFS); 2818 return 0; 2819 } 2820 2821 if (state && state->start == start) { 2822 private = state->private; 2823 ret = 0; 2824 } else { 2825 ret = get_state_private(io_tree, start, &private); 2826 } 2827 kaddr = kmap_atomic(page); 2828 if (ret) 2829 goto zeroit; 2830 2831 csum = btrfs_csum_data(kaddr + offset, csum, end - start + 1); 2832 btrfs_csum_final(csum, (char *)&csum); 2833 if (csum != private) 2834 goto zeroit; 2835 2836 kunmap_atomic(kaddr); 2837 good: 2838 return 0; 2839 2840 zeroit: 2841 if (__ratelimit(&_rs)) 2842 btrfs_info(root->fs_info, "csum failed ino %llu off %llu csum %u private %llu", 2843 (unsigned long long)btrfs_ino(page->mapping->host), 2844 (unsigned long long)start, csum, 2845 (unsigned long long)private); 2846 memset(kaddr + offset, 1, end - start + 1); 2847 flush_dcache_page(page); 2848 kunmap_atomic(kaddr); 2849 if (private == 0) 2850 return 0; 2851 return -EIO; 2852 } 2853 2854 struct delayed_iput { 2855 struct list_head list; 2856 struct inode *inode; 2857 }; 2858 2859 /* JDM: If this is fs-wide, why can't we add a pointer to 2860 * btrfs_inode instead and avoid the allocation? */ 2861 void btrfs_add_delayed_iput(struct inode *inode) 2862 { 2863 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info; 2864 struct delayed_iput *delayed; 2865 2866 if (atomic_add_unless(&inode->i_count, -1, 1)) 2867 return; 2868 2869 delayed = kmalloc(sizeof(*delayed), GFP_NOFS | __GFP_NOFAIL); 2870 delayed->inode = inode; 2871 2872 spin_lock(&fs_info->delayed_iput_lock); 2873 list_add_tail(&delayed->list, &fs_info->delayed_iputs); 2874 spin_unlock(&fs_info->delayed_iput_lock); 2875 } 2876 2877 void btrfs_run_delayed_iputs(struct btrfs_root *root) 2878 { 2879 LIST_HEAD(list); 2880 struct btrfs_fs_info *fs_info = root->fs_info; 2881 struct delayed_iput *delayed; 2882 int empty; 2883 2884 spin_lock(&fs_info->delayed_iput_lock); 2885 empty = list_empty(&fs_info->delayed_iputs); 2886 spin_unlock(&fs_info->delayed_iput_lock); 2887 if (empty) 2888 return; 2889 2890 spin_lock(&fs_info->delayed_iput_lock); 2891 list_splice_init(&fs_info->delayed_iputs, &list); 2892 spin_unlock(&fs_info->delayed_iput_lock); 2893 2894 while (!list_empty(&list)) { 2895 delayed = list_entry(list.next, struct delayed_iput, list); 2896 list_del(&delayed->list); 2897 iput(delayed->inode); 2898 kfree(delayed); 2899 } 2900 } 2901 2902 /* 2903 * This is called in transaction commit time. If there are no orphan 2904 * files in the subvolume, it removes orphan item and frees block_rsv 2905 * structure. 2906 */ 2907 void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans, 2908 struct btrfs_root *root) 2909 { 2910 struct btrfs_block_rsv *block_rsv; 2911 int ret; 2912 2913 if (atomic_read(&root->orphan_inodes) || 2914 root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) 2915 return; 2916 2917 spin_lock(&root->orphan_lock); 2918 if (atomic_read(&root->orphan_inodes)) { 2919 spin_unlock(&root->orphan_lock); 2920 return; 2921 } 2922 2923 if (root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) { 2924 spin_unlock(&root->orphan_lock); 2925 return; 2926 } 2927 2928 block_rsv = root->orphan_block_rsv; 2929 root->orphan_block_rsv = NULL; 2930 spin_unlock(&root->orphan_lock); 2931 2932 if (root->orphan_item_inserted && 2933 btrfs_root_refs(&root->root_item) > 0) { 2934 ret = btrfs_del_orphan_item(trans, root->fs_info->tree_root, 2935 root->root_key.objectid); 2936 BUG_ON(ret); 2937 root->orphan_item_inserted = 0; 2938 } 2939 2940 if (block_rsv) { 2941 WARN_ON(block_rsv->size > 0); 2942 btrfs_free_block_rsv(root, block_rsv); 2943 } 2944 } 2945 2946 /* 2947 * This creates an orphan entry for the given inode in case something goes 2948 * wrong in the middle of an unlink/truncate. 2949 * 2950 * NOTE: caller of this function should reserve 5 units of metadata for 2951 * this function. 2952 */ 2953 int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode) 2954 { 2955 struct btrfs_root *root = BTRFS_I(inode)->root; 2956 struct btrfs_block_rsv *block_rsv = NULL; 2957 int reserve = 0; 2958 int insert = 0; 2959 int ret; 2960 2961 if (!root->orphan_block_rsv) { 2962 block_rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP); 2963 if (!block_rsv) 2964 return -ENOMEM; 2965 } 2966 2967 spin_lock(&root->orphan_lock); 2968 if (!root->orphan_block_rsv) { 2969 root->orphan_block_rsv = block_rsv; 2970 } else if (block_rsv) { 2971 btrfs_free_block_rsv(root, block_rsv); 2972 block_rsv = NULL; 2973 } 2974 2975 if (!test_and_set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM, 2976 &BTRFS_I(inode)->runtime_flags)) { 2977 #if 0 2978 /* 2979 * For proper ENOSPC handling, we should do orphan 2980 * cleanup when mounting. But this introduces backward 2981 * compatibility issue. 2982 */ 2983 if (!xchg(&root->orphan_item_inserted, 1)) 2984 insert = 2; 2985 else 2986 insert = 1; 2987 #endif 2988 insert = 1; 2989 atomic_inc(&root->orphan_inodes); 2990 } 2991 2992 if (!test_and_set_bit(BTRFS_INODE_ORPHAN_META_RESERVED, 2993 &BTRFS_I(inode)->runtime_flags)) 2994 reserve = 1; 2995 spin_unlock(&root->orphan_lock); 2996 2997 /* grab metadata reservation from transaction handle */ 2998 if (reserve) { 2999 ret = btrfs_orphan_reserve_metadata(trans, inode); 3000 BUG_ON(ret); /* -ENOSPC in reservation; Logic error? JDM */ 3001 } 3002 3003 /* insert an orphan item to track this unlinked/truncated file */ 3004 if (insert >= 1) { 3005 ret = btrfs_insert_orphan_item(trans, root, btrfs_ino(inode)); 3006 if (ret && ret != -EEXIST) { 3007 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM, 3008 &BTRFS_I(inode)->runtime_flags); 3009 btrfs_abort_transaction(trans, root, ret); 3010 return ret; 3011 } 3012 ret = 0; 3013 } 3014 3015 /* insert an orphan item to track subvolume contains orphan files */ 3016 if (insert >= 2) { 3017 ret = btrfs_insert_orphan_item(trans, root->fs_info->tree_root, 3018 root->root_key.objectid); 3019 if (ret && ret != -EEXIST) { 3020 btrfs_abort_transaction(trans, root, ret); 3021 return ret; 3022 } 3023 } 3024 return 0; 3025 } 3026 3027 /* 3028 * We have done the truncate/delete so we can go ahead and remove the orphan 3029 * item for this particular inode. 3030 */ 3031 static int btrfs_orphan_del(struct btrfs_trans_handle *trans, 3032 struct inode *inode) 3033 { 3034 struct btrfs_root *root = BTRFS_I(inode)->root; 3035 int delete_item = 0; 3036 int release_rsv = 0; 3037 int ret = 0; 3038 3039 spin_lock(&root->orphan_lock); 3040 if (test_and_clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM, 3041 &BTRFS_I(inode)->runtime_flags)) 3042 delete_item = 1; 3043 3044 if (test_and_clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED, 3045 &BTRFS_I(inode)->runtime_flags)) 3046 release_rsv = 1; 3047 spin_unlock(&root->orphan_lock); 3048 3049 if (trans && delete_item) { 3050 ret = btrfs_del_orphan_item(trans, root, btrfs_ino(inode)); 3051 BUG_ON(ret); /* -ENOMEM or corruption (JDM: Recheck) */ 3052 } 3053 3054 if (release_rsv) { 3055 btrfs_orphan_release_metadata(inode); 3056 atomic_dec(&root->orphan_inodes); 3057 } 3058 3059 return 0; 3060 } 3061 3062 /* 3063 * this cleans up any orphans that may be left on the list from the last use 3064 * of this root. 3065 */ 3066 int btrfs_orphan_cleanup(struct btrfs_root *root) 3067 { 3068 struct btrfs_path *path; 3069 struct extent_buffer *leaf; 3070 struct btrfs_key key, found_key; 3071 struct btrfs_trans_handle *trans; 3072 struct inode *inode; 3073 u64 last_objectid = 0; 3074 int ret = 0, nr_unlink = 0, nr_truncate = 0; 3075 3076 if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED)) 3077 return 0; 3078 3079 path = btrfs_alloc_path(); 3080 if (!path) { 3081 ret = -ENOMEM; 3082 goto out; 3083 } 3084 path->reada = -1; 3085 3086 key.objectid = BTRFS_ORPHAN_OBJECTID; 3087 btrfs_set_key_type(&key, BTRFS_ORPHAN_ITEM_KEY); 3088 key.offset = (u64)-1; 3089 3090 while (1) { 3091 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 3092 if (ret < 0) 3093 goto out; 3094 3095 /* 3096 * if ret == 0 means we found what we were searching for, which 3097 * is weird, but possible, so only screw with path if we didn't 3098 * find the key and see if we have stuff that matches 3099 */ 3100 if (ret > 0) { 3101 ret = 0; 3102 if (path->slots[0] == 0) 3103 break; 3104 path->slots[0]--; 3105 } 3106 3107 /* pull out the item */ 3108 leaf = path->nodes[0]; 3109 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 3110 3111 /* make sure the item matches what we want */ 3112 if (found_key.objectid != BTRFS_ORPHAN_OBJECTID) 3113 break; 3114 if (btrfs_key_type(&found_key) != BTRFS_ORPHAN_ITEM_KEY) 3115 break; 3116 3117 /* release the path since we're done with it */ 3118 btrfs_release_path(path); 3119 3120 /* 3121 * this is where we are basically btrfs_lookup, without the 3122 * crossing root thing. we store the inode number in the 3123 * offset of the orphan item. 3124 */ 3125 3126 if (found_key.offset == last_objectid) { 3127 btrfs_err(root->fs_info, 3128 "Error removing orphan entry, stopping orphan cleanup"); 3129 ret = -EINVAL; 3130 goto out; 3131 } 3132 3133 last_objectid = found_key.offset; 3134 3135 found_key.objectid = found_key.offset; 3136 found_key.type = BTRFS_INODE_ITEM_KEY; 3137 found_key.offset = 0; 3138 inode = btrfs_iget(root->fs_info->sb, &found_key, root, NULL); 3139 ret = PTR_RET(inode); 3140 if (ret && ret != -ESTALE) 3141 goto out; 3142 3143 if (ret == -ESTALE && root == root->fs_info->tree_root) { 3144 struct btrfs_root *dead_root; 3145 struct btrfs_fs_info *fs_info = root->fs_info; 3146 int is_dead_root = 0; 3147 3148 /* 3149 * this is an orphan in the tree root. Currently these 3150 * could come from 2 sources: 3151 * a) a snapshot deletion in progress 3152 * b) a free space cache inode 3153 * We need to distinguish those two, as the snapshot 3154 * orphan must not get deleted. 3155 * find_dead_roots already ran before us, so if this 3156 * is a snapshot deletion, we should find the root 3157 * in the dead_roots list 3158 */ 3159 spin_lock(&fs_info->trans_lock); 3160 list_for_each_entry(dead_root, &fs_info->dead_roots, 3161 root_list) { 3162 if (dead_root->root_key.objectid == 3163 found_key.objectid) { 3164 is_dead_root = 1; 3165 break; 3166 } 3167 } 3168 spin_unlock(&fs_info->trans_lock); 3169 if (is_dead_root) { 3170 /* prevent this orphan from being found again */ 3171 key.offset = found_key.objectid - 1; 3172 continue; 3173 } 3174 } 3175 /* 3176 * Inode is already gone but the orphan item is still there, 3177 * kill the orphan item. 3178 */ 3179 if (ret == -ESTALE) { 3180 trans = btrfs_start_transaction(root, 1); 3181 if (IS_ERR(trans)) { 3182 ret = PTR_ERR(trans); 3183 goto out; 3184 } 3185 btrfs_debug(root->fs_info, "auto deleting %Lu", 3186 found_key.objectid); 3187 ret = btrfs_del_orphan_item(trans, root, 3188 found_key.objectid); 3189 BUG_ON(ret); /* -ENOMEM or corruption (JDM: Recheck) */ 3190 btrfs_end_transaction(trans, root); 3191 continue; 3192 } 3193 3194 /* 3195 * add this inode to the orphan list so btrfs_orphan_del does 3196 * the proper thing when we hit it 3197 */ 3198 set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM, 3199 &BTRFS_I(inode)->runtime_flags); 3200 atomic_inc(&root->orphan_inodes); 3201 3202 /* if we have links, this was a truncate, lets do that */ 3203 if (inode->i_nlink) { 3204 if (!S_ISREG(inode->i_mode)) { 3205 WARN_ON(1); 3206 iput(inode); 3207 continue; 3208 } 3209 nr_truncate++; 3210 3211 /* 1 for the orphan item deletion. */ 3212 trans = btrfs_start_transaction(root, 1); 3213 if (IS_ERR(trans)) { 3214 ret = PTR_ERR(trans); 3215 goto out; 3216 } 3217 ret = btrfs_orphan_add(trans, inode); 3218 btrfs_end_transaction(trans, root); 3219 if (ret) 3220 goto out; 3221 3222 ret = btrfs_truncate(inode); 3223 if (ret) 3224 btrfs_orphan_del(NULL, inode); 3225 } else { 3226 nr_unlink++; 3227 } 3228 3229 /* this will do delete_inode and everything for us */ 3230 iput(inode); 3231 if (ret) 3232 goto out; 3233 } 3234 /* release the path since we're done with it */ 3235 btrfs_release_path(path); 3236 3237 root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE; 3238 3239 if (root->orphan_block_rsv) 3240 btrfs_block_rsv_release(root, root->orphan_block_rsv, 3241 (u64)-1); 3242 3243 if (root->orphan_block_rsv || root->orphan_item_inserted) { 3244 trans = btrfs_join_transaction(root); 3245 if (!IS_ERR(trans)) 3246 btrfs_end_transaction(trans, root); 3247 } 3248 3249 if (nr_unlink) 3250 btrfs_debug(root->fs_info, "unlinked %d orphans", nr_unlink); 3251 if (nr_truncate) 3252 btrfs_debug(root->fs_info, "truncated %d orphans", nr_truncate); 3253 3254 out: 3255 if (ret) 3256 btrfs_crit(root->fs_info, 3257 "could not do orphan cleanup %d", ret); 3258 btrfs_free_path(path); 3259 return ret; 3260 } 3261 3262 /* 3263 * very simple check to peek ahead in the leaf looking for xattrs. If we 3264 * don't find any xattrs, we know there can't be any acls. 3265 * 3266 * slot is the slot the inode is in, objectid is the objectid of the inode 3267 */ 3268 static noinline int acls_after_inode_item(struct extent_buffer *leaf, 3269 int slot, u64 objectid) 3270 { 3271 u32 nritems = btrfs_header_nritems(leaf); 3272 struct btrfs_key found_key; 3273 int scanned = 0; 3274 3275 slot++; 3276 while (slot < nritems) { 3277 btrfs_item_key_to_cpu(leaf, &found_key, slot); 3278 3279 /* we found a different objectid, there must not be acls */ 3280 if (found_key.objectid != objectid) 3281 return 0; 3282 3283 /* we found an xattr, assume we've got an acl */ 3284 if (found_key.type == BTRFS_XATTR_ITEM_KEY) 3285 return 1; 3286 3287 /* 3288 * we found a key greater than an xattr key, there can't 3289 * be any acls later on 3290 */ 3291 if (found_key.type > BTRFS_XATTR_ITEM_KEY) 3292 return 0; 3293 3294 slot++; 3295 scanned++; 3296 3297 /* 3298 * it goes inode, inode backrefs, xattrs, extents, 3299 * so if there are a ton of hard links to an inode there can 3300 * be a lot of backrefs. Don't waste time searching too hard, 3301 * this is just an optimization 3302 */ 3303 if (scanned >= 8) 3304 break; 3305 } 3306 /* we hit the end of the leaf before we found an xattr or 3307 * something larger than an xattr. We have to assume the inode 3308 * has acls 3309 */ 3310 return 1; 3311 } 3312 3313 /* 3314 * read an inode from the btree into the in-memory inode 3315 */ 3316 static void btrfs_read_locked_inode(struct inode *inode) 3317 { 3318 struct btrfs_path *path; 3319 struct extent_buffer *leaf; 3320 struct btrfs_inode_item *inode_item; 3321 struct btrfs_timespec *tspec; 3322 struct btrfs_root *root = BTRFS_I(inode)->root; 3323 struct btrfs_key location; 3324 int maybe_acls; 3325 u32 rdev; 3326 int ret; 3327 bool filled = false; 3328 3329 ret = btrfs_fill_inode(inode, &rdev); 3330 if (!ret) 3331 filled = true; 3332 3333 path = btrfs_alloc_path(); 3334 if (!path) 3335 goto make_bad; 3336 3337 path->leave_spinning = 1; 3338 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location)); 3339 3340 ret = btrfs_lookup_inode(NULL, root, path, &location, 0); 3341 if (ret) 3342 goto make_bad; 3343 3344 leaf = path->nodes[0]; 3345 3346 if (filled) 3347 goto cache_acl; 3348 3349 inode_item = btrfs_item_ptr(leaf, path->slots[0], 3350 struct btrfs_inode_item); 3351 inode->i_mode = btrfs_inode_mode(leaf, inode_item); 3352 set_nlink(inode, btrfs_inode_nlink(leaf, inode_item)); 3353 i_uid_write(inode, btrfs_inode_uid(leaf, inode_item)); 3354 i_gid_write(inode, btrfs_inode_gid(leaf, inode_item)); 3355 btrfs_i_size_write(inode, btrfs_inode_size(leaf, inode_item)); 3356 3357 tspec = btrfs_inode_atime(inode_item); 3358 inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, tspec); 3359 inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, tspec); 3360 3361 tspec = btrfs_inode_mtime(inode_item); 3362 inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, tspec); 3363 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, tspec); 3364 3365 tspec = btrfs_inode_ctime(inode_item); 3366 inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, tspec); 3367 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, tspec); 3368 3369 inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item)); 3370 BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item); 3371 BTRFS_I(inode)->last_trans = btrfs_inode_transid(leaf, inode_item); 3372 3373 /* 3374 * If we were modified in the current generation and evicted from memory 3375 * and then re-read we need to do a full sync since we don't have any 3376 * idea about which extents were modified before we were evicted from 3377 * cache. 3378 */ 3379 if (BTRFS_I(inode)->last_trans == root->fs_info->generation) 3380 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, 3381 &BTRFS_I(inode)->runtime_flags); 3382 3383 inode->i_version = btrfs_inode_sequence(leaf, inode_item); 3384 inode->i_generation = BTRFS_I(inode)->generation; 3385 inode->i_rdev = 0; 3386 rdev = btrfs_inode_rdev(leaf, inode_item); 3387 3388 BTRFS_I(inode)->index_cnt = (u64)-1; 3389 BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item); 3390 cache_acl: 3391 /* 3392 * try to precache a NULL acl entry for files that don't have 3393 * any xattrs or acls 3394 */ 3395 maybe_acls = acls_after_inode_item(leaf, path->slots[0], 3396 btrfs_ino(inode)); 3397 if (!maybe_acls) 3398 cache_no_acl(inode); 3399 3400 btrfs_free_path(path); 3401 3402 switch (inode->i_mode & S_IFMT) { 3403 case S_IFREG: 3404 inode->i_mapping->a_ops = &btrfs_aops; 3405 inode->i_mapping->backing_dev_info = &root->fs_info->bdi; 3406 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops; 3407 inode->i_fop = &btrfs_file_operations; 3408 inode->i_op = &btrfs_file_inode_operations; 3409 break; 3410 case S_IFDIR: 3411 inode->i_fop = &btrfs_dir_file_operations; 3412 if (root == root->fs_info->tree_root) 3413 inode->i_op = &btrfs_dir_ro_inode_operations; 3414 else 3415 inode->i_op = &btrfs_dir_inode_operations; 3416 break; 3417 case S_IFLNK: 3418 inode->i_op = &btrfs_symlink_inode_operations; 3419 inode->i_mapping->a_ops = &btrfs_symlink_aops; 3420 inode->i_mapping->backing_dev_info = &root->fs_info->bdi; 3421 break; 3422 default: 3423 inode->i_op = &btrfs_special_inode_operations; 3424 init_special_inode(inode, inode->i_mode, rdev); 3425 break; 3426 } 3427 3428 btrfs_update_iflags(inode); 3429 return; 3430 3431 make_bad: 3432 btrfs_free_path(path); 3433 make_bad_inode(inode); 3434 } 3435 3436 /* 3437 * given a leaf and an inode, copy the inode fields into the leaf 3438 */ 3439 static void fill_inode_item(struct btrfs_trans_handle *trans, 3440 struct extent_buffer *leaf, 3441 struct btrfs_inode_item *item, 3442 struct inode *inode) 3443 { 3444 struct btrfs_map_token token; 3445 3446 btrfs_init_map_token(&token); 3447 3448 btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token); 3449 btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token); 3450 btrfs_set_token_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size, 3451 &token); 3452 btrfs_set_token_inode_mode(leaf, item, inode->i_mode, &token); 3453 btrfs_set_token_inode_nlink(leaf, item, inode->i_nlink, &token); 3454 3455 btrfs_set_token_timespec_sec(leaf, btrfs_inode_atime(item), 3456 inode->i_atime.tv_sec, &token); 3457 btrfs_set_token_timespec_nsec(leaf, btrfs_inode_atime(item), 3458 inode->i_atime.tv_nsec, &token); 3459 3460 btrfs_set_token_timespec_sec(leaf, btrfs_inode_mtime(item), 3461 inode->i_mtime.tv_sec, &token); 3462 btrfs_set_token_timespec_nsec(leaf, btrfs_inode_mtime(item), 3463 inode->i_mtime.tv_nsec, &token); 3464 3465 btrfs_set_token_timespec_sec(leaf, btrfs_inode_ctime(item), 3466 inode->i_ctime.tv_sec, &token); 3467 btrfs_set_token_timespec_nsec(leaf, btrfs_inode_ctime(item), 3468 inode->i_ctime.tv_nsec, &token); 3469 3470 btrfs_set_token_inode_nbytes(leaf, item, inode_get_bytes(inode), 3471 &token); 3472 btrfs_set_token_inode_generation(leaf, item, BTRFS_I(inode)->generation, 3473 &token); 3474 btrfs_set_token_inode_sequence(leaf, item, inode->i_version, &token); 3475 btrfs_set_token_inode_transid(leaf, item, trans->transid, &token); 3476 btrfs_set_token_inode_rdev(leaf, item, inode->i_rdev, &token); 3477 btrfs_set_token_inode_flags(leaf, item, BTRFS_I(inode)->flags, &token); 3478 btrfs_set_token_inode_block_group(leaf, item, 0, &token); 3479 } 3480 3481 /* 3482 * copy everything in the in-memory inode into the btree. 3483 */ 3484 static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans, 3485 struct btrfs_root *root, struct inode *inode) 3486 { 3487 struct btrfs_inode_item *inode_item; 3488 struct btrfs_path *path; 3489 struct extent_buffer *leaf; 3490 int ret; 3491 3492 path = btrfs_alloc_path(); 3493 if (!path) 3494 return -ENOMEM; 3495 3496 path->leave_spinning = 1; 3497 ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location, 3498 1); 3499 if (ret) { 3500 if (ret > 0) 3501 ret = -ENOENT; 3502 goto failed; 3503 } 3504 3505 btrfs_unlock_up_safe(path, 1); 3506 leaf = path->nodes[0]; 3507 inode_item = btrfs_item_ptr(leaf, path->slots[0], 3508 struct btrfs_inode_item); 3509 3510 fill_inode_item(trans, leaf, inode_item, inode); 3511 btrfs_mark_buffer_dirty(leaf); 3512 btrfs_set_inode_last_trans(trans, inode); 3513 ret = 0; 3514 failed: 3515 btrfs_free_path(path); 3516 return ret; 3517 } 3518 3519 /* 3520 * copy everything in the in-memory inode into the btree. 3521 */ 3522 noinline int btrfs_update_inode(struct btrfs_trans_handle *trans, 3523 struct btrfs_root *root, struct inode *inode) 3524 { 3525 int ret; 3526 3527 /* 3528 * If the inode is a free space inode, we can deadlock during commit 3529 * if we put it into the delayed code. 3530 * 3531 * The data relocation inode should also be directly updated 3532 * without delay 3533 */ 3534 if (!btrfs_is_free_space_inode(inode) 3535 && root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID) { 3536 btrfs_update_root_times(trans, root); 3537 3538 ret = btrfs_delayed_update_inode(trans, root, inode); 3539 if (!ret) 3540 btrfs_set_inode_last_trans(trans, inode); 3541 return ret; 3542 } 3543 3544 return btrfs_update_inode_item(trans, root, inode); 3545 } 3546 3547 noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans, 3548 struct btrfs_root *root, 3549 struct inode *inode) 3550 { 3551 int ret; 3552 3553 ret = btrfs_update_inode(trans, root, inode); 3554 if (ret == -ENOSPC) 3555 return btrfs_update_inode_item(trans, root, inode); 3556 return ret; 3557 } 3558 3559 /* 3560 * unlink helper that gets used here in inode.c and in the tree logging 3561 * recovery code. It remove a link in a directory with a given name, and 3562 * also drops the back refs in the inode to the directory 3563 */ 3564 static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans, 3565 struct btrfs_root *root, 3566 struct inode *dir, struct inode *inode, 3567 const char *name, int name_len) 3568 { 3569 struct btrfs_path *path; 3570 int ret = 0; 3571 struct extent_buffer *leaf; 3572 struct btrfs_dir_item *di; 3573 struct btrfs_key key; 3574 u64 index; 3575 u64 ino = btrfs_ino(inode); 3576 u64 dir_ino = btrfs_ino(dir); 3577 3578 path = btrfs_alloc_path(); 3579 if (!path) { 3580 ret = -ENOMEM; 3581 goto out; 3582 } 3583 3584 path->leave_spinning = 1; 3585 di = btrfs_lookup_dir_item(trans, root, path, dir_ino, 3586 name, name_len, -1); 3587 if (IS_ERR(di)) { 3588 ret = PTR_ERR(di); 3589 goto err; 3590 } 3591 if (!di) { 3592 ret = -ENOENT; 3593 goto err; 3594 } 3595 leaf = path->nodes[0]; 3596 btrfs_dir_item_key_to_cpu(leaf, di, &key); 3597 ret = btrfs_delete_one_dir_name(trans, root, path, di); 3598 if (ret) 3599 goto err; 3600 btrfs_release_path(path); 3601 3602 ret = btrfs_del_inode_ref(trans, root, name, name_len, ino, 3603 dir_ino, &index); 3604 if (ret) { 3605 btrfs_info(root->fs_info, 3606 "failed to delete reference to %.*s, inode %llu parent %llu", 3607 name_len, name, 3608 (unsigned long long)ino, (unsigned long long)dir_ino); 3609 btrfs_abort_transaction(trans, root, ret); 3610 goto err; 3611 } 3612 3613 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index); 3614 if (ret) { 3615 btrfs_abort_transaction(trans, root, ret); 3616 goto err; 3617 } 3618 3619 ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len, 3620 inode, dir_ino); 3621 if (ret != 0 && ret != -ENOENT) { 3622 btrfs_abort_transaction(trans, root, ret); 3623 goto err; 3624 } 3625 3626 ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len, 3627 dir, index); 3628 if (ret == -ENOENT) 3629 ret = 0; 3630 else if (ret) 3631 btrfs_abort_transaction(trans, root, ret); 3632 err: 3633 btrfs_free_path(path); 3634 if (ret) 3635 goto out; 3636 3637 btrfs_i_size_write(dir, dir->i_size - name_len * 2); 3638 inode_inc_iversion(inode); 3639 inode_inc_iversion(dir); 3640 inode->i_ctime = dir->i_mtime = dir->i_ctime = CURRENT_TIME; 3641 ret = btrfs_update_inode(trans, root, dir); 3642 out: 3643 return ret; 3644 } 3645 3646 int btrfs_unlink_inode(struct btrfs_trans_handle *trans, 3647 struct btrfs_root *root, 3648 struct inode *dir, struct inode *inode, 3649 const char *name, int name_len) 3650 { 3651 int ret; 3652 ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len); 3653 if (!ret) { 3654 btrfs_drop_nlink(inode); 3655 ret = btrfs_update_inode(trans, root, inode); 3656 } 3657 return ret; 3658 } 3659 3660 3661 /* helper to check if there is any shared block in the path */ 3662 static int check_path_shared(struct btrfs_root *root, 3663 struct btrfs_path *path) 3664 { 3665 struct extent_buffer *eb; 3666 int level; 3667 u64 refs = 1; 3668 3669 for (level = 0; level < BTRFS_MAX_LEVEL; level++) { 3670 int ret; 3671 3672 if (!path->nodes[level]) 3673 break; 3674 eb = path->nodes[level]; 3675 if (!btrfs_block_can_be_shared(root, eb)) 3676 continue; 3677 ret = btrfs_lookup_extent_info(NULL, root, eb->start, level, 1, 3678 &refs, NULL); 3679 if (refs > 1) 3680 return 1; 3681 } 3682 return 0; 3683 } 3684 3685 /* 3686 * helper to start transaction for unlink and rmdir. 3687 * 3688 * unlink and rmdir are special in btrfs, they do not always free space. 3689 * so in enospc case, we should make sure they will free space before 3690 * allowing them to use the global metadata reservation. 3691 */ 3692 static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir, 3693 struct dentry *dentry) 3694 { 3695 struct btrfs_trans_handle *trans; 3696 struct btrfs_root *root = BTRFS_I(dir)->root; 3697 struct btrfs_path *path; 3698 struct btrfs_dir_item *di; 3699 struct inode *inode = dentry->d_inode; 3700 u64 index; 3701 int check_link = 1; 3702 int err = -ENOSPC; 3703 int ret; 3704 u64 ino = btrfs_ino(inode); 3705 u64 dir_ino = btrfs_ino(dir); 3706 3707 /* 3708 * 1 for the possible orphan item 3709 * 1 for the dir item 3710 * 1 for the dir index 3711 * 1 for the inode ref 3712 * 1 for the inode 3713 */ 3714 trans = btrfs_start_transaction(root, 5); 3715 if (!IS_ERR(trans) || PTR_ERR(trans) != -ENOSPC) 3716 return trans; 3717 3718 if (ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID) 3719 return ERR_PTR(-ENOSPC); 3720 3721 /* check if there is someone else holds reference */ 3722 if (S_ISDIR(inode->i_mode) && atomic_read(&inode->i_count) > 1) 3723 return ERR_PTR(-ENOSPC); 3724 3725 if (atomic_read(&inode->i_count) > 2) 3726 return ERR_PTR(-ENOSPC); 3727 3728 if (xchg(&root->fs_info->enospc_unlink, 1)) 3729 return ERR_PTR(-ENOSPC); 3730 3731 path = btrfs_alloc_path(); 3732 if (!path) { 3733 root->fs_info->enospc_unlink = 0; 3734 return ERR_PTR(-ENOMEM); 3735 } 3736 3737 /* 1 for the orphan item */ 3738 trans = btrfs_start_transaction(root, 1); 3739 if (IS_ERR(trans)) { 3740 btrfs_free_path(path); 3741 root->fs_info->enospc_unlink = 0; 3742 return trans; 3743 } 3744 3745 path->skip_locking = 1; 3746 path->search_commit_root = 1; 3747 3748 ret = btrfs_lookup_inode(trans, root, path, 3749 &BTRFS_I(dir)->location, 0); 3750 if (ret < 0) { 3751 err = ret; 3752 goto out; 3753 } 3754 if (ret == 0) { 3755 if (check_path_shared(root, path)) 3756 goto out; 3757 } else { 3758 check_link = 0; 3759 } 3760 btrfs_release_path(path); 3761 3762 ret = btrfs_lookup_inode(trans, root, path, 3763 &BTRFS_I(inode)->location, 0); 3764 if (ret < 0) { 3765 err = ret; 3766 goto out; 3767 } 3768 if (ret == 0) { 3769 if (check_path_shared(root, path)) 3770 goto out; 3771 } else { 3772 check_link = 0; 3773 } 3774 btrfs_release_path(path); 3775 3776 if (ret == 0 && S_ISREG(inode->i_mode)) { 3777 ret = btrfs_lookup_file_extent(trans, root, path, 3778 ino, (u64)-1, 0); 3779 if (ret < 0) { 3780 err = ret; 3781 goto out; 3782 } 3783 BUG_ON(ret == 0); /* Corruption */ 3784 if (check_path_shared(root, path)) 3785 goto out; 3786 btrfs_release_path(path); 3787 } 3788 3789 if (!check_link) { 3790 err = 0; 3791 goto out; 3792 } 3793 3794 di = btrfs_lookup_dir_item(trans, root, path, dir_ino, 3795 dentry->d_name.name, dentry->d_name.len, 0); 3796 if (IS_ERR(di)) { 3797 err = PTR_ERR(di); 3798 goto out; 3799 } 3800 if (di) { 3801 if (check_path_shared(root, path)) 3802 goto out; 3803 } else { 3804 err = 0; 3805 goto out; 3806 } 3807 btrfs_release_path(path); 3808 3809 ret = btrfs_get_inode_ref_index(trans, root, path, dentry->d_name.name, 3810 dentry->d_name.len, ino, dir_ino, 0, 3811 &index); 3812 if (ret) { 3813 err = ret; 3814 goto out; 3815 } 3816 3817 if (check_path_shared(root, path)) 3818 goto out; 3819 3820 btrfs_release_path(path); 3821 3822 /* 3823 * This is a commit root search, if we can lookup inode item and other 3824 * relative items in the commit root, it means the transaction of 3825 * dir/file creation has been committed, and the dir index item that we 3826 * delay to insert has also been inserted into the commit root. So 3827 * we needn't worry about the delayed insertion of the dir index item 3828 * here. 3829 */ 3830 di = btrfs_lookup_dir_index_item(trans, root, path, dir_ino, index, 3831 dentry->d_name.name, dentry->d_name.len, 0); 3832 if (IS_ERR(di)) { 3833 err = PTR_ERR(di); 3834 goto out; 3835 } 3836 BUG_ON(ret == -ENOENT); 3837 if (check_path_shared(root, path)) 3838 goto out; 3839 3840 err = 0; 3841 out: 3842 btrfs_free_path(path); 3843 /* Migrate the orphan reservation over */ 3844 if (!err) 3845 err = btrfs_block_rsv_migrate(trans->block_rsv, 3846 &root->fs_info->global_block_rsv, 3847 trans->bytes_reserved); 3848 3849 if (err) { 3850 btrfs_end_transaction(trans, root); 3851 root->fs_info->enospc_unlink = 0; 3852 return ERR_PTR(err); 3853 } 3854 3855 trans->block_rsv = &root->fs_info->global_block_rsv; 3856 return trans; 3857 } 3858 3859 static void __unlink_end_trans(struct btrfs_trans_handle *trans, 3860 struct btrfs_root *root) 3861 { 3862 if (trans->block_rsv->type == BTRFS_BLOCK_RSV_GLOBAL) { 3863 btrfs_block_rsv_release(root, trans->block_rsv, 3864 trans->bytes_reserved); 3865 trans->block_rsv = &root->fs_info->trans_block_rsv; 3866 BUG_ON(!root->fs_info->enospc_unlink); 3867 root->fs_info->enospc_unlink = 0; 3868 } 3869 btrfs_end_transaction(trans, root); 3870 } 3871 3872 static int btrfs_unlink(struct inode *dir, struct dentry *dentry) 3873 { 3874 struct btrfs_root *root = BTRFS_I(dir)->root; 3875 struct btrfs_trans_handle *trans; 3876 struct inode *inode = dentry->d_inode; 3877 int ret; 3878 3879 trans = __unlink_start_trans(dir, dentry); 3880 if (IS_ERR(trans)) 3881 return PTR_ERR(trans); 3882 3883 btrfs_record_unlink_dir(trans, dir, dentry->d_inode, 0); 3884 3885 ret = btrfs_unlink_inode(trans, root, dir, dentry->d_inode, 3886 dentry->d_name.name, dentry->d_name.len); 3887 if (ret) 3888 goto out; 3889 3890 if (inode->i_nlink == 0) { 3891 ret = btrfs_orphan_add(trans, inode); 3892 if (ret) 3893 goto out; 3894 } 3895 3896 out: 3897 __unlink_end_trans(trans, root); 3898 btrfs_btree_balance_dirty(root); 3899 return ret; 3900 } 3901 3902 int btrfs_unlink_subvol(struct btrfs_trans_handle *trans, 3903 struct btrfs_root *root, 3904 struct inode *dir, u64 objectid, 3905 const char *name, int name_len) 3906 { 3907 struct btrfs_path *path; 3908 struct extent_buffer *leaf; 3909 struct btrfs_dir_item *di; 3910 struct btrfs_key key; 3911 u64 index; 3912 int ret; 3913 u64 dir_ino = btrfs_ino(dir); 3914 3915 path = btrfs_alloc_path(); 3916 if (!path) 3917 return -ENOMEM; 3918 3919 di = btrfs_lookup_dir_item(trans, root, path, dir_ino, 3920 name, name_len, -1); 3921 if (IS_ERR_OR_NULL(di)) { 3922 if (!di) 3923 ret = -ENOENT; 3924 else 3925 ret = PTR_ERR(di); 3926 goto out; 3927 } 3928 3929 leaf = path->nodes[0]; 3930 btrfs_dir_item_key_to_cpu(leaf, di, &key); 3931 WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid); 3932 ret = btrfs_delete_one_dir_name(trans, root, path, di); 3933 if (ret) { 3934 btrfs_abort_transaction(trans, root, ret); 3935 goto out; 3936 } 3937 btrfs_release_path(path); 3938 3939 ret = btrfs_del_root_ref(trans, root->fs_info->tree_root, 3940 objectid, root->root_key.objectid, 3941 dir_ino, &index, name, name_len); 3942 if (ret < 0) { 3943 if (ret != -ENOENT) { 3944 btrfs_abort_transaction(trans, root, ret); 3945 goto out; 3946 } 3947 di = btrfs_search_dir_index_item(root, path, dir_ino, 3948 name, name_len); 3949 if (IS_ERR_OR_NULL(di)) { 3950 if (!di) 3951 ret = -ENOENT; 3952 else 3953 ret = PTR_ERR(di); 3954 btrfs_abort_transaction(trans, root, ret); 3955 goto out; 3956 } 3957 3958 leaf = path->nodes[0]; 3959 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); 3960 btrfs_release_path(path); 3961 index = key.offset; 3962 } 3963 btrfs_release_path(path); 3964 3965 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index); 3966 if (ret) { 3967 btrfs_abort_transaction(trans, root, ret); 3968 goto out; 3969 } 3970 3971 btrfs_i_size_write(dir, dir->i_size - name_len * 2); 3972 inode_inc_iversion(dir); 3973 dir->i_mtime = dir->i_ctime = CURRENT_TIME; 3974 ret = btrfs_update_inode_fallback(trans, root, dir); 3975 if (ret) 3976 btrfs_abort_transaction(trans, root, ret); 3977 out: 3978 btrfs_free_path(path); 3979 return ret; 3980 } 3981 3982 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry) 3983 { 3984 struct inode *inode = dentry->d_inode; 3985 int err = 0; 3986 struct btrfs_root *root = BTRFS_I(dir)->root; 3987 struct btrfs_trans_handle *trans; 3988 3989 if (inode->i_size > BTRFS_EMPTY_DIR_SIZE) 3990 return -ENOTEMPTY; 3991 if (btrfs_ino(inode) == BTRFS_FIRST_FREE_OBJECTID) 3992 return -EPERM; 3993 3994 trans = __unlink_start_trans(dir, dentry); 3995 if (IS_ERR(trans)) 3996 return PTR_ERR(trans); 3997 3998 if (unlikely(btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) { 3999 err = btrfs_unlink_subvol(trans, root, dir, 4000 BTRFS_I(inode)->location.objectid, 4001 dentry->d_name.name, 4002 dentry->d_name.len); 4003 goto out; 4004 } 4005 4006 err = btrfs_orphan_add(trans, inode); 4007 if (err) 4008 goto out; 4009 4010 /* now the directory is empty */ 4011 err = btrfs_unlink_inode(trans, root, dir, dentry->d_inode, 4012 dentry->d_name.name, dentry->d_name.len); 4013 if (!err) 4014 btrfs_i_size_write(inode, 0); 4015 out: 4016 __unlink_end_trans(trans, root); 4017 btrfs_btree_balance_dirty(root); 4018 4019 return err; 4020 } 4021 4022 /* 4023 * this can truncate away extent items, csum items and directory items. 4024 * It starts at a high offset and removes keys until it can't find 4025 * any higher than new_size 4026 * 4027 * csum items that cross the new i_size are truncated to the new size 4028 * as well. 4029 * 4030 * min_type is the minimum key type to truncate down to. If set to 0, this 4031 * will kill all the items on this inode, including the INODE_ITEM_KEY. 4032 */ 4033 int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans, 4034 struct btrfs_root *root, 4035 struct inode *inode, 4036 u64 new_size, u32 min_type) 4037 { 4038 struct btrfs_path *path; 4039 struct extent_buffer *leaf; 4040 struct btrfs_file_extent_item *fi; 4041 struct btrfs_key key; 4042 struct btrfs_key found_key; 4043 u64 extent_start = 0; 4044 u64 extent_num_bytes = 0; 4045 u64 extent_offset = 0; 4046 u64 item_end = 0; 4047 u32 found_type = (u8)-1; 4048 int found_extent; 4049 int del_item; 4050 int pending_del_nr = 0; 4051 int pending_del_slot = 0; 4052 int extent_type = -1; 4053 int ret; 4054 int err = 0; 4055 u64 ino = btrfs_ino(inode); 4056 4057 BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY); 4058 4059 path = btrfs_alloc_path(); 4060 if (!path) 4061 return -ENOMEM; 4062 path->reada = -1; 4063 4064 /* 4065 * We want to drop from the next block forward in case this new size is 4066 * not block aligned since we will be keeping the last block of the 4067 * extent just the way it is. 4068 */ 4069 if (root->ref_cows || root == root->fs_info->tree_root) 4070 btrfs_drop_extent_cache(inode, ALIGN(new_size, 4071 root->sectorsize), (u64)-1, 0); 4072 4073 /* 4074 * This function is also used to drop the items in the log tree before 4075 * we relog the inode, so if root != BTRFS_I(inode)->root, it means 4076 * it is used to drop the loged items. So we shouldn't kill the delayed 4077 * items. 4078 */ 4079 if (min_type == 0 && root == BTRFS_I(inode)->root) 4080 btrfs_kill_delayed_inode_items(inode); 4081 4082 key.objectid = ino; 4083 key.offset = (u64)-1; 4084 key.type = (u8)-1; 4085 4086 search_again: 4087 path->leave_spinning = 1; 4088 ret = btrfs_search_slot(trans, root, &key, path, -1, 1); 4089 if (ret < 0) { 4090 err = ret; 4091 goto out; 4092 } 4093 4094 if (ret > 0) { 4095 /* there are no items in the tree for us to truncate, we're 4096 * done 4097 */ 4098 if (path->slots[0] == 0) 4099 goto out; 4100 path->slots[0]--; 4101 } 4102 4103 while (1) { 4104 fi = NULL; 4105 leaf = path->nodes[0]; 4106 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 4107 found_type = btrfs_key_type(&found_key); 4108 4109 if (found_key.objectid != ino) 4110 break; 4111 4112 if (found_type < min_type) 4113 break; 4114 4115 item_end = found_key.offset; 4116 if (found_type == BTRFS_EXTENT_DATA_KEY) { 4117 fi = btrfs_item_ptr(leaf, path->slots[0], 4118 struct btrfs_file_extent_item); 4119 extent_type = btrfs_file_extent_type(leaf, fi); 4120 if (extent_type != BTRFS_FILE_EXTENT_INLINE) { 4121 item_end += 4122 btrfs_file_extent_num_bytes(leaf, fi); 4123 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { 4124 item_end += btrfs_file_extent_inline_len(leaf, 4125 fi); 4126 } 4127 item_end--; 4128 } 4129 if (found_type > min_type) { 4130 del_item = 1; 4131 } else { 4132 if (item_end < new_size) 4133 break; 4134 if (found_key.offset >= new_size) 4135 del_item = 1; 4136 else 4137 del_item = 0; 4138 } 4139 found_extent = 0; 4140 /* FIXME, shrink the extent if the ref count is only 1 */ 4141 if (found_type != BTRFS_EXTENT_DATA_KEY) 4142 goto delete; 4143 4144 if (extent_type != BTRFS_FILE_EXTENT_INLINE) { 4145 u64 num_dec; 4146 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi); 4147 if (!del_item) { 4148 u64 orig_num_bytes = 4149 btrfs_file_extent_num_bytes(leaf, fi); 4150 extent_num_bytes = ALIGN(new_size - 4151 found_key.offset, 4152 root->sectorsize); 4153 btrfs_set_file_extent_num_bytes(leaf, fi, 4154 extent_num_bytes); 4155 num_dec = (orig_num_bytes - 4156 extent_num_bytes); 4157 if (root->ref_cows && extent_start != 0) 4158 inode_sub_bytes(inode, num_dec); 4159 btrfs_mark_buffer_dirty(leaf); 4160 } else { 4161 extent_num_bytes = 4162 btrfs_file_extent_disk_num_bytes(leaf, 4163 fi); 4164 extent_offset = found_key.offset - 4165 btrfs_file_extent_offset(leaf, fi); 4166 4167 /* FIXME blocksize != 4096 */ 4168 num_dec = btrfs_file_extent_num_bytes(leaf, fi); 4169 if (extent_start != 0) { 4170 found_extent = 1; 4171 if (root->ref_cows) 4172 inode_sub_bytes(inode, num_dec); 4173 } 4174 } 4175 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { 4176 /* 4177 * we can't truncate inline items that have had 4178 * special encodings 4179 */ 4180 if (!del_item && 4181 btrfs_file_extent_compression(leaf, fi) == 0 && 4182 btrfs_file_extent_encryption(leaf, fi) == 0 && 4183 btrfs_file_extent_other_encoding(leaf, fi) == 0) { 4184 u32 size = new_size - found_key.offset; 4185 4186 if (root->ref_cows) { 4187 inode_sub_bytes(inode, item_end + 1 - 4188 new_size); 4189 } 4190 size = 4191 btrfs_file_extent_calc_inline_size(size); 4192 btrfs_truncate_item(root, path, size, 1); 4193 } else if (root->ref_cows) { 4194 inode_sub_bytes(inode, item_end + 1 - 4195 found_key.offset); 4196 } 4197 } 4198 delete: 4199 if (del_item) { 4200 if (!pending_del_nr) { 4201 /* no pending yet, add ourselves */ 4202 pending_del_slot = path->slots[0]; 4203 pending_del_nr = 1; 4204 } else if (pending_del_nr && 4205 path->slots[0] + 1 == pending_del_slot) { 4206 /* hop on the pending chunk */ 4207 pending_del_nr++; 4208 pending_del_slot = path->slots[0]; 4209 } else { 4210 BUG(); 4211 } 4212 } else { 4213 break; 4214 } 4215 if (found_extent && (root->ref_cows || 4216 root == root->fs_info->tree_root)) { 4217 btrfs_set_path_blocking(path); 4218 ret = btrfs_free_extent(trans, root, extent_start, 4219 extent_num_bytes, 0, 4220 btrfs_header_owner(leaf), 4221 ino, extent_offset, 0); 4222 BUG_ON(ret); 4223 } 4224 4225 if (found_type == BTRFS_INODE_ITEM_KEY) 4226 break; 4227 4228 if (path->slots[0] == 0 || 4229 path->slots[0] != pending_del_slot) { 4230 if (pending_del_nr) { 4231 ret = btrfs_del_items(trans, root, path, 4232 pending_del_slot, 4233 pending_del_nr); 4234 if (ret) { 4235 btrfs_abort_transaction(trans, 4236 root, ret); 4237 goto error; 4238 } 4239 pending_del_nr = 0; 4240 } 4241 btrfs_release_path(path); 4242 goto search_again; 4243 } else { 4244 path->slots[0]--; 4245 } 4246 } 4247 out: 4248 if (pending_del_nr) { 4249 ret = btrfs_del_items(trans, root, path, pending_del_slot, 4250 pending_del_nr); 4251 if (ret) 4252 btrfs_abort_transaction(trans, root, ret); 4253 } 4254 error: 4255 btrfs_free_path(path); 4256 return err; 4257 } 4258 4259 /* 4260 * btrfs_truncate_page - read, zero a chunk and write a page 4261 * @inode - inode that we're zeroing 4262 * @from - the offset to start zeroing 4263 * @len - the length to zero, 0 to zero the entire range respective to the 4264 * offset 4265 * @front - zero up to the offset instead of from the offset on 4266 * 4267 * This will find the page for the "from" offset and cow the page and zero the 4268 * part we want to zero. This is used with truncate and hole punching. 4269 */ 4270 int btrfs_truncate_page(struct inode *inode, loff_t from, loff_t len, 4271 int front) 4272 { 4273 struct address_space *mapping = inode->i_mapping; 4274 struct btrfs_root *root = BTRFS_I(inode)->root; 4275 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 4276 struct btrfs_ordered_extent *ordered; 4277 struct extent_state *cached_state = NULL; 4278 char *kaddr; 4279 u32 blocksize = root->sectorsize; 4280 pgoff_t index = from >> PAGE_CACHE_SHIFT; 4281 unsigned offset = from & (PAGE_CACHE_SIZE-1); 4282 struct page *page; 4283 gfp_t mask = btrfs_alloc_write_mask(mapping); 4284 int ret = 0; 4285 u64 page_start; 4286 u64 page_end; 4287 4288 if ((offset & (blocksize - 1)) == 0 && 4289 (!len || ((len & (blocksize - 1)) == 0))) 4290 goto out; 4291 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE); 4292 if (ret) 4293 goto out; 4294 4295 again: 4296 page = find_or_create_page(mapping, index, mask); 4297 if (!page) { 4298 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE); 4299 ret = -ENOMEM; 4300 goto out; 4301 } 4302 4303 page_start = page_offset(page); 4304 page_end = page_start + PAGE_CACHE_SIZE - 1; 4305 4306 if (!PageUptodate(page)) { 4307 ret = btrfs_readpage(NULL, page); 4308 lock_page(page); 4309 if (page->mapping != mapping) { 4310 unlock_page(page); 4311 page_cache_release(page); 4312 goto again; 4313 } 4314 if (!PageUptodate(page)) { 4315 ret = -EIO; 4316 goto out_unlock; 4317 } 4318 } 4319 wait_on_page_writeback(page); 4320 4321 lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state); 4322 set_page_extent_mapped(page); 4323 4324 ordered = btrfs_lookup_ordered_extent(inode, page_start); 4325 if (ordered) { 4326 unlock_extent_cached(io_tree, page_start, page_end, 4327 &cached_state, GFP_NOFS); 4328 unlock_page(page); 4329 page_cache_release(page); 4330 btrfs_start_ordered_extent(inode, ordered, 1); 4331 btrfs_put_ordered_extent(ordered); 4332 goto again; 4333 } 4334 4335 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end, 4336 EXTENT_DIRTY | EXTENT_DELALLOC | 4337 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 4338 0, 0, &cached_state, GFP_NOFS); 4339 4340 ret = btrfs_set_extent_delalloc(inode, page_start, page_end, 4341 &cached_state); 4342 if (ret) { 4343 unlock_extent_cached(io_tree, page_start, page_end, 4344 &cached_state, GFP_NOFS); 4345 goto out_unlock; 4346 } 4347 4348 if (offset != PAGE_CACHE_SIZE) { 4349 if (!len) 4350 len = PAGE_CACHE_SIZE - offset; 4351 kaddr = kmap(page); 4352 if (front) 4353 memset(kaddr, 0, offset); 4354 else 4355 memset(kaddr + offset, 0, len); 4356 flush_dcache_page(page); 4357 kunmap(page); 4358 } 4359 ClearPageChecked(page); 4360 set_page_dirty(page); 4361 unlock_extent_cached(io_tree, page_start, page_end, &cached_state, 4362 GFP_NOFS); 4363 4364 out_unlock: 4365 if (ret) 4366 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE); 4367 unlock_page(page); 4368 page_cache_release(page); 4369 out: 4370 return ret; 4371 } 4372 4373 /* 4374 * This function puts in dummy file extents for the area we're creating a hole 4375 * for. So if we are truncating this file to a larger size we need to insert 4376 * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for 4377 * the range between oldsize and size 4378 */ 4379 int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size) 4380 { 4381 struct btrfs_trans_handle *trans; 4382 struct btrfs_root *root = BTRFS_I(inode)->root; 4383 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 4384 struct extent_map *em = NULL; 4385 struct extent_state *cached_state = NULL; 4386 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; 4387 u64 hole_start = ALIGN(oldsize, root->sectorsize); 4388 u64 block_end = ALIGN(size, root->sectorsize); 4389 u64 last_byte; 4390 u64 cur_offset; 4391 u64 hole_size; 4392 int err = 0; 4393 4394 if (size <= hole_start) 4395 return 0; 4396 4397 while (1) { 4398 struct btrfs_ordered_extent *ordered; 4399 btrfs_wait_ordered_range(inode, hole_start, 4400 block_end - hole_start); 4401 lock_extent_bits(io_tree, hole_start, block_end - 1, 0, 4402 &cached_state); 4403 ordered = btrfs_lookup_ordered_extent(inode, hole_start); 4404 if (!ordered) 4405 break; 4406 unlock_extent_cached(io_tree, hole_start, block_end - 1, 4407 &cached_state, GFP_NOFS); 4408 btrfs_put_ordered_extent(ordered); 4409 } 4410 4411 cur_offset = hole_start; 4412 while (1) { 4413 em = btrfs_get_extent(inode, NULL, 0, cur_offset, 4414 block_end - cur_offset, 0); 4415 if (IS_ERR(em)) { 4416 err = PTR_ERR(em); 4417 em = NULL; 4418 break; 4419 } 4420 last_byte = min(extent_map_end(em), block_end); 4421 last_byte = ALIGN(last_byte , root->sectorsize); 4422 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) { 4423 struct extent_map *hole_em; 4424 hole_size = last_byte - cur_offset; 4425 4426 trans = btrfs_start_transaction(root, 3); 4427 if (IS_ERR(trans)) { 4428 err = PTR_ERR(trans); 4429 break; 4430 } 4431 4432 err = btrfs_drop_extents(trans, root, inode, 4433 cur_offset, 4434 cur_offset + hole_size, 1); 4435 if (err) { 4436 btrfs_abort_transaction(trans, root, err); 4437 btrfs_end_transaction(trans, root); 4438 break; 4439 } 4440 4441 err = btrfs_insert_file_extent(trans, root, 4442 btrfs_ino(inode), cur_offset, 0, 4443 0, hole_size, 0, hole_size, 4444 0, 0, 0); 4445 if (err) { 4446 btrfs_abort_transaction(trans, root, err); 4447 btrfs_end_transaction(trans, root); 4448 break; 4449 } 4450 4451 btrfs_drop_extent_cache(inode, cur_offset, 4452 cur_offset + hole_size - 1, 0); 4453 hole_em = alloc_extent_map(); 4454 if (!hole_em) { 4455 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, 4456 &BTRFS_I(inode)->runtime_flags); 4457 goto next; 4458 } 4459 hole_em->start = cur_offset; 4460 hole_em->len = hole_size; 4461 hole_em->orig_start = cur_offset; 4462 4463 hole_em->block_start = EXTENT_MAP_HOLE; 4464 hole_em->block_len = 0; 4465 hole_em->orig_block_len = 0; 4466 hole_em->ram_bytes = hole_size; 4467 hole_em->bdev = root->fs_info->fs_devices->latest_bdev; 4468 hole_em->compress_type = BTRFS_COMPRESS_NONE; 4469 hole_em->generation = trans->transid; 4470 4471 while (1) { 4472 write_lock(&em_tree->lock); 4473 err = add_extent_mapping(em_tree, hole_em, 1); 4474 write_unlock(&em_tree->lock); 4475 if (err != -EEXIST) 4476 break; 4477 btrfs_drop_extent_cache(inode, cur_offset, 4478 cur_offset + 4479 hole_size - 1, 0); 4480 } 4481 free_extent_map(hole_em); 4482 next: 4483 btrfs_update_inode(trans, root, inode); 4484 btrfs_end_transaction(trans, root); 4485 } 4486 free_extent_map(em); 4487 em = NULL; 4488 cur_offset = last_byte; 4489 if (cur_offset >= block_end) 4490 break; 4491 } 4492 4493 free_extent_map(em); 4494 unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state, 4495 GFP_NOFS); 4496 return err; 4497 } 4498 4499 static int btrfs_setsize(struct inode *inode, struct iattr *attr) 4500 { 4501 struct btrfs_root *root = BTRFS_I(inode)->root; 4502 struct btrfs_trans_handle *trans; 4503 loff_t oldsize = i_size_read(inode); 4504 loff_t newsize = attr->ia_size; 4505 int mask = attr->ia_valid; 4506 int ret; 4507 4508 if (newsize == oldsize) 4509 return 0; 4510 4511 /* 4512 * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a 4513 * special case where we need to update the times despite not having 4514 * these flags set. For all other operations the VFS set these flags 4515 * explicitly if it wants a timestamp update. 4516 */ 4517 if (newsize != oldsize && (!(mask & (ATTR_CTIME | ATTR_MTIME)))) 4518 inode->i_ctime = inode->i_mtime = current_fs_time(inode->i_sb); 4519 4520 if (newsize > oldsize) { 4521 truncate_pagecache(inode, oldsize, newsize); 4522 ret = btrfs_cont_expand(inode, oldsize, newsize); 4523 if (ret) 4524 return ret; 4525 4526 trans = btrfs_start_transaction(root, 1); 4527 if (IS_ERR(trans)) 4528 return PTR_ERR(trans); 4529 4530 i_size_write(inode, newsize); 4531 btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL); 4532 ret = btrfs_update_inode(trans, root, inode); 4533 btrfs_end_transaction(trans, root); 4534 } else { 4535 4536 /* 4537 * We're truncating a file that used to have good data down to 4538 * zero. Make sure it gets into the ordered flush list so that 4539 * any new writes get down to disk quickly. 4540 */ 4541 if (newsize == 0) 4542 set_bit(BTRFS_INODE_ORDERED_DATA_CLOSE, 4543 &BTRFS_I(inode)->runtime_flags); 4544 4545 /* 4546 * 1 for the orphan item we're going to add 4547 * 1 for the orphan item deletion. 4548 */ 4549 trans = btrfs_start_transaction(root, 2); 4550 if (IS_ERR(trans)) 4551 return PTR_ERR(trans); 4552 4553 /* 4554 * We need to do this in case we fail at _any_ point during the 4555 * actual truncate. Once we do the truncate_setsize we could 4556 * invalidate pages which forces any outstanding ordered io to 4557 * be instantly completed which will give us extents that need 4558 * to be truncated. If we fail to get an orphan inode down we 4559 * could have left over extents that were never meant to live, 4560 * so we need to garuntee from this point on that everything 4561 * will be consistent. 4562 */ 4563 ret = btrfs_orphan_add(trans, inode); 4564 btrfs_end_transaction(trans, root); 4565 if (ret) 4566 return ret; 4567 4568 /* we don't support swapfiles, so vmtruncate shouldn't fail */ 4569 truncate_setsize(inode, newsize); 4570 4571 /* Disable nonlocked read DIO to avoid the end less truncate */ 4572 btrfs_inode_block_unlocked_dio(inode); 4573 inode_dio_wait(inode); 4574 btrfs_inode_resume_unlocked_dio(inode); 4575 4576 ret = btrfs_truncate(inode); 4577 if (ret && inode->i_nlink) 4578 btrfs_orphan_del(NULL, inode); 4579 } 4580 4581 return ret; 4582 } 4583 4584 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr) 4585 { 4586 struct inode *inode = dentry->d_inode; 4587 struct btrfs_root *root = BTRFS_I(inode)->root; 4588 int err; 4589 4590 if (btrfs_root_readonly(root)) 4591 return -EROFS; 4592 4593 err = inode_change_ok(inode, attr); 4594 if (err) 4595 return err; 4596 4597 if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) { 4598 err = btrfs_setsize(inode, attr); 4599 if (err) 4600 return err; 4601 } 4602 4603 if (attr->ia_valid) { 4604 setattr_copy(inode, attr); 4605 inode_inc_iversion(inode); 4606 err = btrfs_dirty_inode(inode); 4607 4608 if (!err && attr->ia_valid & ATTR_MODE) 4609 err = btrfs_acl_chmod(inode); 4610 } 4611 4612 return err; 4613 } 4614 4615 void btrfs_evict_inode(struct inode *inode) 4616 { 4617 struct btrfs_trans_handle *trans; 4618 struct btrfs_root *root = BTRFS_I(inode)->root; 4619 struct btrfs_block_rsv *rsv, *global_rsv; 4620 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1); 4621 int ret; 4622 4623 trace_btrfs_inode_evict(inode); 4624 4625 truncate_inode_pages(&inode->i_data, 0); 4626 if (inode->i_nlink && (btrfs_root_refs(&root->root_item) != 0 || 4627 btrfs_is_free_space_inode(inode))) 4628 goto no_delete; 4629 4630 if (is_bad_inode(inode)) { 4631 btrfs_orphan_del(NULL, inode); 4632 goto no_delete; 4633 } 4634 /* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */ 4635 btrfs_wait_ordered_range(inode, 0, (u64)-1); 4636 4637 if (root->fs_info->log_root_recovering) { 4638 BUG_ON(test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM, 4639 &BTRFS_I(inode)->runtime_flags)); 4640 goto no_delete; 4641 } 4642 4643 if (inode->i_nlink > 0) { 4644 BUG_ON(btrfs_root_refs(&root->root_item) != 0); 4645 goto no_delete; 4646 } 4647 4648 ret = btrfs_commit_inode_delayed_inode(inode); 4649 if (ret) { 4650 btrfs_orphan_del(NULL, inode); 4651 goto no_delete; 4652 } 4653 4654 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP); 4655 if (!rsv) { 4656 btrfs_orphan_del(NULL, inode); 4657 goto no_delete; 4658 } 4659 rsv->size = min_size; 4660 rsv->failfast = 1; 4661 global_rsv = &root->fs_info->global_block_rsv; 4662 4663 btrfs_i_size_write(inode, 0); 4664 4665 /* 4666 * This is a bit simpler than btrfs_truncate since we've already 4667 * reserved our space for our orphan item in the unlink, so we just 4668 * need to reserve some slack space in case we add bytes and update 4669 * inode item when doing the truncate. 4670 */ 4671 while (1) { 4672 ret = btrfs_block_rsv_refill(root, rsv, min_size, 4673 BTRFS_RESERVE_FLUSH_LIMIT); 4674 4675 /* 4676 * Try and steal from the global reserve since we will 4677 * likely not use this space anyway, we want to try as 4678 * hard as possible to get this to work. 4679 */ 4680 if (ret) 4681 ret = btrfs_block_rsv_migrate(global_rsv, rsv, min_size); 4682 4683 if (ret) { 4684 btrfs_warn(root->fs_info, 4685 "Could not get space for a delete, will truncate on mount %d", 4686 ret); 4687 btrfs_orphan_del(NULL, inode); 4688 btrfs_free_block_rsv(root, rsv); 4689 goto no_delete; 4690 } 4691 4692 trans = btrfs_join_transaction(root); 4693 if (IS_ERR(trans)) { 4694 btrfs_orphan_del(NULL, inode); 4695 btrfs_free_block_rsv(root, rsv); 4696 goto no_delete; 4697 } 4698 4699 trans->block_rsv = rsv; 4700 4701 ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0); 4702 if (ret != -ENOSPC) 4703 break; 4704 4705 trans->block_rsv = &root->fs_info->trans_block_rsv; 4706 btrfs_end_transaction(trans, root); 4707 trans = NULL; 4708 btrfs_btree_balance_dirty(root); 4709 } 4710 4711 btrfs_free_block_rsv(root, rsv); 4712 4713 if (ret == 0) { 4714 trans->block_rsv = root->orphan_block_rsv; 4715 ret = btrfs_orphan_del(trans, inode); 4716 BUG_ON(ret); 4717 } 4718 4719 trans->block_rsv = &root->fs_info->trans_block_rsv; 4720 if (!(root == root->fs_info->tree_root || 4721 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)) 4722 btrfs_return_ino(root, btrfs_ino(inode)); 4723 4724 btrfs_end_transaction(trans, root); 4725 btrfs_btree_balance_dirty(root); 4726 no_delete: 4727 clear_inode(inode); 4728 return; 4729 } 4730 4731 /* 4732 * this returns the key found in the dir entry in the location pointer. 4733 * If no dir entries were found, location->objectid is 0. 4734 */ 4735 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry, 4736 struct btrfs_key *location) 4737 { 4738 const char *name = dentry->d_name.name; 4739 int namelen = dentry->d_name.len; 4740 struct btrfs_dir_item *di; 4741 struct btrfs_path *path; 4742 struct btrfs_root *root = BTRFS_I(dir)->root; 4743 int ret = 0; 4744 4745 path = btrfs_alloc_path(); 4746 if (!path) 4747 return -ENOMEM; 4748 4749 di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(dir), name, 4750 namelen, 0); 4751 if (IS_ERR(di)) 4752 ret = PTR_ERR(di); 4753 4754 if (IS_ERR_OR_NULL(di)) 4755 goto out_err; 4756 4757 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location); 4758 out: 4759 btrfs_free_path(path); 4760 return ret; 4761 out_err: 4762 location->objectid = 0; 4763 goto out; 4764 } 4765 4766 /* 4767 * when we hit a tree root in a directory, the btrfs part of the inode 4768 * needs to be changed to reflect the root directory of the tree root. This 4769 * is kind of like crossing a mount point. 4770 */ 4771 static int fixup_tree_root_location(struct btrfs_root *root, 4772 struct inode *dir, 4773 struct dentry *dentry, 4774 struct btrfs_key *location, 4775 struct btrfs_root **sub_root) 4776 { 4777 struct btrfs_path *path; 4778 struct btrfs_root *new_root; 4779 struct btrfs_root_ref *ref; 4780 struct extent_buffer *leaf; 4781 int ret; 4782 int err = 0; 4783 4784 path = btrfs_alloc_path(); 4785 if (!path) { 4786 err = -ENOMEM; 4787 goto out; 4788 } 4789 4790 err = -ENOENT; 4791 ret = btrfs_find_root_ref(root->fs_info->tree_root, path, 4792 BTRFS_I(dir)->root->root_key.objectid, 4793 location->objectid); 4794 if (ret) { 4795 if (ret < 0) 4796 err = ret; 4797 goto out; 4798 } 4799 4800 leaf = path->nodes[0]; 4801 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref); 4802 if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(dir) || 4803 btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len) 4804 goto out; 4805 4806 ret = memcmp_extent_buffer(leaf, dentry->d_name.name, 4807 (unsigned long)(ref + 1), 4808 dentry->d_name.len); 4809 if (ret) 4810 goto out; 4811 4812 btrfs_release_path(path); 4813 4814 new_root = btrfs_read_fs_root_no_name(root->fs_info, location); 4815 if (IS_ERR(new_root)) { 4816 err = PTR_ERR(new_root); 4817 goto out; 4818 } 4819 4820 if (btrfs_root_refs(&new_root->root_item) == 0) { 4821 err = -ENOENT; 4822 goto out; 4823 } 4824 4825 *sub_root = new_root; 4826 location->objectid = btrfs_root_dirid(&new_root->root_item); 4827 location->type = BTRFS_INODE_ITEM_KEY; 4828 location->offset = 0; 4829 err = 0; 4830 out: 4831 btrfs_free_path(path); 4832 return err; 4833 } 4834 4835 static void inode_tree_add(struct inode *inode) 4836 { 4837 struct btrfs_root *root = BTRFS_I(inode)->root; 4838 struct btrfs_inode *entry; 4839 struct rb_node **p; 4840 struct rb_node *parent; 4841 u64 ino = btrfs_ino(inode); 4842 again: 4843 p = &root->inode_tree.rb_node; 4844 parent = NULL; 4845 4846 if (inode_unhashed(inode)) 4847 return; 4848 4849 spin_lock(&root->inode_lock); 4850 while (*p) { 4851 parent = *p; 4852 entry = rb_entry(parent, struct btrfs_inode, rb_node); 4853 4854 if (ino < btrfs_ino(&entry->vfs_inode)) 4855 p = &parent->rb_left; 4856 else if (ino > btrfs_ino(&entry->vfs_inode)) 4857 p = &parent->rb_right; 4858 else { 4859 WARN_ON(!(entry->vfs_inode.i_state & 4860 (I_WILL_FREE | I_FREEING))); 4861 rb_erase(parent, &root->inode_tree); 4862 RB_CLEAR_NODE(parent); 4863 spin_unlock(&root->inode_lock); 4864 goto again; 4865 } 4866 } 4867 rb_link_node(&BTRFS_I(inode)->rb_node, parent, p); 4868 rb_insert_color(&BTRFS_I(inode)->rb_node, &root->inode_tree); 4869 spin_unlock(&root->inode_lock); 4870 } 4871 4872 static void inode_tree_del(struct inode *inode) 4873 { 4874 struct btrfs_root *root = BTRFS_I(inode)->root; 4875 int empty = 0; 4876 4877 spin_lock(&root->inode_lock); 4878 if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) { 4879 rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree); 4880 RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node); 4881 empty = RB_EMPTY_ROOT(&root->inode_tree); 4882 } 4883 spin_unlock(&root->inode_lock); 4884 4885 /* 4886 * Free space cache has inodes in the tree root, but the tree root has a 4887 * root_refs of 0, so this could end up dropping the tree root as a 4888 * snapshot, so we need the extra !root->fs_info->tree_root check to 4889 * make sure we don't drop it. 4890 */ 4891 if (empty && btrfs_root_refs(&root->root_item) == 0 && 4892 root != root->fs_info->tree_root) { 4893 synchronize_srcu(&root->fs_info->subvol_srcu); 4894 spin_lock(&root->inode_lock); 4895 empty = RB_EMPTY_ROOT(&root->inode_tree); 4896 spin_unlock(&root->inode_lock); 4897 if (empty) 4898 btrfs_add_dead_root(root); 4899 } 4900 } 4901 4902 void btrfs_invalidate_inodes(struct btrfs_root *root) 4903 { 4904 struct rb_node *node; 4905 struct rb_node *prev; 4906 struct btrfs_inode *entry; 4907 struct inode *inode; 4908 u64 objectid = 0; 4909 4910 WARN_ON(btrfs_root_refs(&root->root_item) != 0); 4911 4912 spin_lock(&root->inode_lock); 4913 again: 4914 node = root->inode_tree.rb_node; 4915 prev = NULL; 4916 while (node) { 4917 prev = node; 4918 entry = rb_entry(node, struct btrfs_inode, rb_node); 4919 4920 if (objectid < btrfs_ino(&entry->vfs_inode)) 4921 node = node->rb_left; 4922 else if (objectid > btrfs_ino(&entry->vfs_inode)) 4923 node = node->rb_right; 4924 else 4925 break; 4926 } 4927 if (!node) { 4928 while (prev) { 4929 entry = rb_entry(prev, struct btrfs_inode, rb_node); 4930 if (objectid <= btrfs_ino(&entry->vfs_inode)) { 4931 node = prev; 4932 break; 4933 } 4934 prev = rb_next(prev); 4935 } 4936 } 4937 while (node) { 4938 entry = rb_entry(node, struct btrfs_inode, rb_node); 4939 objectid = btrfs_ino(&entry->vfs_inode) + 1; 4940 inode = igrab(&entry->vfs_inode); 4941 if (inode) { 4942 spin_unlock(&root->inode_lock); 4943 if (atomic_read(&inode->i_count) > 1) 4944 d_prune_aliases(inode); 4945 /* 4946 * btrfs_drop_inode will have it removed from 4947 * the inode cache when its usage count 4948 * hits zero. 4949 */ 4950 iput(inode); 4951 cond_resched(); 4952 spin_lock(&root->inode_lock); 4953 goto again; 4954 } 4955 4956 if (cond_resched_lock(&root->inode_lock)) 4957 goto again; 4958 4959 node = rb_next(node); 4960 } 4961 spin_unlock(&root->inode_lock); 4962 } 4963 4964 static int btrfs_init_locked_inode(struct inode *inode, void *p) 4965 { 4966 struct btrfs_iget_args *args = p; 4967 inode->i_ino = args->ino; 4968 BTRFS_I(inode)->root = args->root; 4969 return 0; 4970 } 4971 4972 static int btrfs_find_actor(struct inode *inode, void *opaque) 4973 { 4974 struct btrfs_iget_args *args = opaque; 4975 return args->ino == btrfs_ino(inode) && 4976 args->root == BTRFS_I(inode)->root; 4977 } 4978 4979 static struct inode *btrfs_iget_locked(struct super_block *s, 4980 u64 objectid, 4981 struct btrfs_root *root) 4982 { 4983 struct inode *inode; 4984 struct btrfs_iget_args args; 4985 args.ino = objectid; 4986 args.root = root; 4987 4988 inode = iget5_locked(s, objectid, btrfs_find_actor, 4989 btrfs_init_locked_inode, 4990 (void *)&args); 4991 return inode; 4992 } 4993 4994 /* Get an inode object given its location and corresponding root. 4995 * Returns in *is_new if the inode was read from disk 4996 */ 4997 struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location, 4998 struct btrfs_root *root, int *new) 4999 { 5000 struct inode *inode; 5001 5002 inode = btrfs_iget_locked(s, location->objectid, root); 5003 if (!inode) 5004 return ERR_PTR(-ENOMEM); 5005 5006 if (inode->i_state & I_NEW) { 5007 BTRFS_I(inode)->root = root; 5008 memcpy(&BTRFS_I(inode)->location, location, sizeof(*location)); 5009 btrfs_read_locked_inode(inode); 5010 if (!is_bad_inode(inode)) { 5011 inode_tree_add(inode); 5012 unlock_new_inode(inode); 5013 if (new) 5014 *new = 1; 5015 } else { 5016 unlock_new_inode(inode); 5017 iput(inode); 5018 inode = ERR_PTR(-ESTALE); 5019 } 5020 } 5021 5022 return inode; 5023 } 5024 5025 static struct inode *new_simple_dir(struct super_block *s, 5026 struct btrfs_key *key, 5027 struct btrfs_root *root) 5028 { 5029 struct inode *inode = new_inode(s); 5030 5031 if (!inode) 5032 return ERR_PTR(-ENOMEM); 5033 5034 BTRFS_I(inode)->root = root; 5035 memcpy(&BTRFS_I(inode)->location, key, sizeof(*key)); 5036 set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags); 5037 5038 inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID; 5039 inode->i_op = &btrfs_dir_ro_inode_operations; 5040 inode->i_fop = &simple_dir_operations; 5041 inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO; 5042 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 5043 5044 return inode; 5045 } 5046 5047 struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry) 5048 { 5049 struct inode *inode; 5050 struct btrfs_root *root = BTRFS_I(dir)->root; 5051 struct btrfs_root *sub_root = root; 5052 struct btrfs_key location; 5053 int index; 5054 int ret = 0; 5055 5056 if (dentry->d_name.len > BTRFS_NAME_LEN) 5057 return ERR_PTR(-ENAMETOOLONG); 5058 5059 ret = btrfs_inode_by_name(dir, dentry, &location); 5060 if (ret < 0) 5061 return ERR_PTR(ret); 5062 5063 if (location.objectid == 0) 5064 return NULL; 5065 5066 if (location.type == BTRFS_INODE_ITEM_KEY) { 5067 inode = btrfs_iget(dir->i_sb, &location, root, NULL); 5068 return inode; 5069 } 5070 5071 BUG_ON(location.type != BTRFS_ROOT_ITEM_KEY); 5072 5073 index = srcu_read_lock(&root->fs_info->subvol_srcu); 5074 ret = fixup_tree_root_location(root, dir, dentry, 5075 &location, &sub_root); 5076 if (ret < 0) { 5077 if (ret != -ENOENT) 5078 inode = ERR_PTR(ret); 5079 else 5080 inode = new_simple_dir(dir->i_sb, &location, sub_root); 5081 } else { 5082 inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL); 5083 } 5084 srcu_read_unlock(&root->fs_info->subvol_srcu, index); 5085 5086 if (!IS_ERR(inode) && root != sub_root) { 5087 down_read(&root->fs_info->cleanup_work_sem); 5088 if (!(inode->i_sb->s_flags & MS_RDONLY)) 5089 ret = btrfs_orphan_cleanup(sub_root); 5090 up_read(&root->fs_info->cleanup_work_sem); 5091 if (ret) 5092 inode = ERR_PTR(ret); 5093 } 5094 5095 return inode; 5096 } 5097 5098 static int btrfs_dentry_delete(const struct dentry *dentry) 5099 { 5100 struct btrfs_root *root; 5101 struct inode *inode = dentry->d_inode; 5102 5103 if (!inode && !IS_ROOT(dentry)) 5104 inode = dentry->d_parent->d_inode; 5105 5106 if (inode) { 5107 root = BTRFS_I(inode)->root; 5108 if (btrfs_root_refs(&root->root_item) == 0) 5109 return 1; 5110 5111 if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID) 5112 return 1; 5113 } 5114 return 0; 5115 } 5116 5117 static void btrfs_dentry_release(struct dentry *dentry) 5118 { 5119 if (dentry->d_fsdata) 5120 kfree(dentry->d_fsdata); 5121 } 5122 5123 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry, 5124 unsigned int flags) 5125 { 5126 struct dentry *ret; 5127 5128 ret = d_splice_alias(btrfs_lookup_dentry(dir, dentry), dentry); 5129 return ret; 5130 } 5131 5132 unsigned char btrfs_filetype_table[] = { 5133 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK 5134 }; 5135 5136 static int btrfs_real_readdir(struct file *filp, void *dirent, 5137 filldir_t filldir) 5138 { 5139 struct inode *inode = file_inode(filp); 5140 struct btrfs_root *root = BTRFS_I(inode)->root; 5141 struct btrfs_item *item; 5142 struct btrfs_dir_item *di; 5143 struct btrfs_key key; 5144 struct btrfs_key found_key; 5145 struct btrfs_path *path; 5146 struct list_head ins_list; 5147 struct list_head del_list; 5148 int ret; 5149 struct extent_buffer *leaf; 5150 int slot; 5151 unsigned char d_type; 5152 int over = 0; 5153 u32 di_cur; 5154 u32 di_total; 5155 u32 di_len; 5156 int key_type = BTRFS_DIR_INDEX_KEY; 5157 char tmp_name[32]; 5158 char *name_ptr; 5159 int name_len; 5160 int is_curr = 0; /* filp->f_pos points to the current index? */ 5161 5162 /* FIXME, use a real flag for deciding about the key type */ 5163 if (root->fs_info->tree_root == root) 5164 key_type = BTRFS_DIR_ITEM_KEY; 5165 5166 /* special case for "." */ 5167 if (filp->f_pos == 0) { 5168 over = filldir(dirent, ".", 1, 5169 filp->f_pos, btrfs_ino(inode), DT_DIR); 5170 if (over) 5171 return 0; 5172 filp->f_pos = 1; 5173 } 5174 /* special case for .., just use the back ref */ 5175 if (filp->f_pos == 1) { 5176 u64 pino = parent_ino(filp->f_path.dentry); 5177 over = filldir(dirent, "..", 2, 5178 filp->f_pos, pino, DT_DIR); 5179 if (over) 5180 return 0; 5181 filp->f_pos = 2; 5182 } 5183 path = btrfs_alloc_path(); 5184 if (!path) 5185 return -ENOMEM; 5186 5187 path->reada = 1; 5188 5189 if (key_type == BTRFS_DIR_INDEX_KEY) { 5190 INIT_LIST_HEAD(&ins_list); 5191 INIT_LIST_HEAD(&del_list); 5192 btrfs_get_delayed_items(inode, &ins_list, &del_list); 5193 } 5194 5195 btrfs_set_key_type(&key, key_type); 5196 key.offset = filp->f_pos; 5197 key.objectid = btrfs_ino(inode); 5198 5199 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 5200 if (ret < 0) 5201 goto err; 5202 5203 while (1) { 5204 leaf = path->nodes[0]; 5205 slot = path->slots[0]; 5206 if (slot >= btrfs_header_nritems(leaf)) { 5207 ret = btrfs_next_leaf(root, path); 5208 if (ret < 0) 5209 goto err; 5210 else if (ret > 0) 5211 break; 5212 continue; 5213 } 5214 5215 item = btrfs_item_nr(leaf, slot); 5216 btrfs_item_key_to_cpu(leaf, &found_key, slot); 5217 5218 if (found_key.objectid != key.objectid) 5219 break; 5220 if (btrfs_key_type(&found_key) != key_type) 5221 break; 5222 if (found_key.offset < filp->f_pos) 5223 goto next; 5224 if (key_type == BTRFS_DIR_INDEX_KEY && 5225 btrfs_should_delete_dir_index(&del_list, 5226 found_key.offset)) 5227 goto next; 5228 5229 filp->f_pos = found_key.offset; 5230 is_curr = 1; 5231 5232 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item); 5233 di_cur = 0; 5234 di_total = btrfs_item_size(leaf, item); 5235 5236 while (di_cur < di_total) { 5237 struct btrfs_key location; 5238 5239 if (verify_dir_item(root, leaf, di)) 5240 break; 5241 5242 name_len = btrfs_dir_name_len(leaf, di); 5243 if (name_len <= sizeof(tmp_name)) { 5244 name_ptr = tmp_name; 5245 } else { 5246 name_ptr = kmalloc(name_len, GFP_NOFS); 5247 if (!name_ptr) { 5248 ret = -ENOMEM; 5249 goto err; 5250 } 5251 } 5252 read_extent_buffer(leaf, name_ptr, 5253 (unsigned long)(di + 1), name_len); 5254 5255 d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)]; 5256 btrfs_dir_item_key_to_cpu(leaf, di, &location); 5257 5258 5259 /* is this a reference to our own snapshot? If so 5260 * skip it. 5261 * 5262 * In contrast to old kernels, we insert the snapshot's 5263 * dir item and dir index after it has been created, so 5264 * we won't find a reference to our own snapshot. We 5265 * still keep the following code for backward 5266 * compatibility. 5267 */ 5268 if (location.type == BTRFS_ROOT_ITEM_KEY && 5269 location.objectid == root->root_key.objectid) { 5270 over = 0; 5271 goto skip; 5272 } 5273 over = filldir(dirent, name_ptr, name_len, 5274 found_key.offset, location.objectid, 5275 d_type); 5276 5277 skip: 5278 if (name_ptr != tmp_name) 5279 kfree(name_ptr); 5280 5281 if (over) 5282 goto nopos; 5283 di_len = btrfs_dir_name_len(leaf, di) + 5284 btrfs_dir_data_len(leaf, di) + sizeof(*di); 5285 di_cur += di_len; 5286 di = (struct btrfs_dir_item *)((char *)di + di_len); 5287 } 5288 next: 5289 path->slots[0]++; 5290 } 5291 5292 if (key_type == BTRFS_DIR_INDEX_KEY) { 5293 if (is_curr) 5294 filp->f_pos++; 5295 ret = btrfs_readdir_delayed_dir_index(filp, dirent, filldir, 5296 &ins_list); 5297 if (ret) 5298 goto nopos; 5299 } 5300 5301 /* Reached end of directory/root. Bump pos past the last item. */ 5302 if (key_type == BTRFS_DIR_INDEX_KEY) 5303 /* 5304 * 32-bit glibc will use getdents64, but then strtol - 5305 * so the last number we can serve is this. 5306 */ 5307 filp->f_pos = 0x7fffffff; 5308 else 5309 filp->f_pos++; 5310 nopos: 5311 ret = 0; 5312 err: 5313 if (key_type == BTRFS_DIR_INDEX_KEY) 5314 btrfs_put_delayed_items(&ins_list, &del_list); 5315 btrfs_free_path(path); 5316 return ret; 5317 } 5318 5319 int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc) 5320 { 5321 struct btrfs_root *root = BTRFS_I(inode)->root; 5322 struct btrfs_trans_handle *trans; 5323 int ret = 0; 5324 bool nolock = false; 5325 5326 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags)) 5327 return 0; 5328 5329 if (btrfs_fs_closing(root->fs_info) && btrfs_is_free_space_inode(inode)) 5330 nolock = true; 5331 5332 if (wbc->sync_mode == WB_SYNC_ALL) { 5333 if (nolock) 5334 trans = btrfs_join_transaction_nolock(root); 5335 else 5336 trans = btrfs_join_transaction(root); 5337 if (IS_ERR(trans)) 5338 return PTR_ERR(trans); 5339 ret = btrfs_commit_transaction(trans, root); 5340 } 5341 return ret; 5342 } 5343 5344 /* 5345 * This is somewhat expensive, updating the tree every time the 5346 * inode changes. But, it is most likely to find the inode in cache. 5347 * FIXME, needs more benchmarking...there are no reasons other than performance 5348 * to keep or drop this code. 5349 */ 5350 static int btrfs_dirty_inode(struct inode *inode) 5351 { 5352 struct btrfs_root *root = BTRFS_I(inode)->root; 5353 struct btrfs_trans_handle *trans; 5354 int ret; 5355 5356 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags)) 5357 return 0; 5358 5359 trans = btrfs_join_transaction(root); 5360 if (IS_ERR(trans)) 5361 return PTR_ERR(trans); 5362 5363 ret = btrfs_update_inode(trans, root, inode); 5364 if (ret && ret == -ENOSPC) { 5365 /* whoops, lets try again with the full transaction */ 5366 btrfs_end_transaction(trans, root); 5367 trans = btrfs_start_transaction(root, 1); 5368 if (IS_ERR(trans)) 5369 return PTR_ERR(trans); 5370 5371 ret = btrfs_update_inode(trans, root, inode); 5372 } 5373 btrfs_end_transaction(trans, root); 5374 if (BTRFS_I(inode)->delayed_node) 5375 btrfs_balance_delayed_items(root); 5376 5377 return ret; 5378 } 5379 5380 /* 5381 * This is a copy of file_update_time. We need this so we can return error on 5382 * ENOSPC for updating the inode in the case of file write and mmap writes. 5383 */ 5384 static int btrfs_update_time(struct inode *inode, struct timespec *now, 5385 int flags) 5386 { 5387 struct btrfs_root *root = BTRFS_I(inode)->root; 5388 5389 if (btrfs_root_readonly(root)) 5390 return -EROFS; 5391 5392 if (flags & S_VERSION) 5393 inode_inc_iversion(inode); 5394 if (flags & S_CTIME) 5395 inode->i_ctime = *now; 5396 if (flags & S_MTIME) 5397 inode->i_mtime = *now; 5398 if (flags & S_ATIME) 5399 inode->i_atime = *now; 5400 return btrfs_dirty_inode(inode); 5401 } 5402 5403 /* 5404 * find the highest existing sequence number in a directory 5405 * and then set the in-memory index_cnt variable to reflect 5406 * free sequence numbers 5407 */ 5408 static int btrfs_set_inode_index_count(struct inode *inode) 5409 { 5410 struct btrfs_root *root = BTRFS_I(inode)->root; 5411 struct btrfs_key key, found_key; 5412 struct btrfs_path *path; 5413 struct extent_buffer *leaf; 5414 int ret; 5415 5416 key.objectid = btrfs_ino(inode); 5417 btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY); 5418 key.offset = (u64)-1; 5419 5420 path = btrfs_alloc_path(); 5421 if (!path) 5422 return -ENOMEM; 5423 5424 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 5425 if (ret < 0) 5426 goto out; 5427 /* FIXME: we should be able to handle this */ 5428 if (ret == 0) 5429 goto out; 5430 ret = 0; 5431 5432 /* 5433 * MAGIC NUMBER EXPLANATION: 5434 * since we search a directory based on f_pos we have to start at 2 5435 * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody 5436 * else has to start at 2 5437 */ 5438 if (path->slots[0] == 0) { 5439 BTRFS_I(inode)->index_cnt = 2; 5440 goto out; 5441 } 5442 5443 path->slots[0]--; 5444 5445 leaf = path->nodes[0]; 5446 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 5447 5448 if (found_key.objectid != btrfs_ino(inode) || 5449 btrfs_key_type(&found_key) != BTRFS_DIR_INDEX_KEY) { 5450 BTRFS_I(inode)->index_cnt = 2; 5451 goto out; 5452 } 5453 5454 BTRFS_I(inode)->index_cnt = found_key.offset + 1; 5455 out: 5456 btrfs_free_path(path); 5457 return ret; 5458 } 5459 5460 /* 5461 * helper to find a free sequence number in a given directory. This current 5462 * code is very simple, later versions will do smarter things in the btree 5463 */ 5464 int btrfs_set_inode_index(struct inode *dir, u64 *index) 5465 { 5466 int ret = 0; 5467 5468 if (BTRFS_I(dir)->index_cnt == (u64)-1) { 5469 ret = btrfs_inode_delayed_dir_index_count(dir); 5470 if (ret) { 5471 ret = btrfs_set_inode_index_count(dir); 5472 if (ret) 5473 return ret; 5474 } 5475 } 5476 5477 *index = BTRFS_I(dir)->index_cnt; 5478 BTRFS_I(dir)->index_cnt++; 5479 5480 return ret; 5481 } 5482 5483 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans, 5484 struct btrfs_root *root, 5485 struct inode *dir, 5486 const char *name, int name_len, 5487 u64 ref_objectid, u64 objectid, 5488 umode_t mode, u64 *index) 5489 { 5490 struct inode *inode; 5491 struct btrfs_inode_item *inode_item; 5492 struct btrfs_key *location; 5493 struct btrfs_path *path; 5494 struct btrfs_inode_ref *ref; 5495 struct btrfs_key key[2]; 5496 u32 sizes[2]; 5497 unsigned long ptr; 5498 int ret; 5499 int owner; 5500 5501 path = btrfs_alloc_path(); 5502 if (!path) 5503 return ERR_PTR(-ENOMEM); 5504 5505 inode = new_inode(root->fs_info->sb); 5506 if (!inode) { 5507 btrfs_free_path(path); 5508 return ERR_PTR(-ENOMEM); 5509 } 5510 5511 /* 5512 * we have to initialize this early, so we can reclaim the inode 5513 * number if we fail afterwards in this function. 5514 */ 5515 inode->i_ino = objectid; 5516 5517 if (dir) { 5518 trace_btrfs_inode_request(dir); 5519 5520 ret = btrfs_set_inode_index(dir, index); 5521 if (ret) { 5522 btrfs_free_path(path); 5523 iput(inode); 5524 return ERR_PTR(ret); 5525 } 5526 } 5527 /* 5528 * index_cnt is ignored for everything but a dir, 5529 * btrfs_get_inode_index_count has an explanation for the magic 5530 * number 5531 */ 5532 BTRFS_I(inode)->index_cnt = 2; 5533 BTRFS_I(inode)->root = root; 5534 BTRFS_I(inode)->generation = trans->transid; 5535 inode->i_generation = BTRFS_I(inode)->generation; 5536 5537 /* 5538 * We could have gotten an inode number from somebody who was fsynced 5539 * and then removed in this same transaction, so let's just set full 5540 * sync since it will be a full sync anyway and this will blow away the 5541 * old info in the log. 5542 */ 5543 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags); 5544 5545 if (S_ISDIR(mode)) 5546 owner = 0; 5547 else 5548 owner = 1; 5549 5550 key[0].objectid = objectid; 5551 btrfs_set_key_type(&key[0], BTRFS_INODE_ITEM_KEY); 5552 key[0].offset = 0; 5553 5554 /* 5555 * Start new inodes with an inode_ref. This is slightly more 5556 * efficient for small numbers of hard links since they will 5557 * be packed into one item. Extended refs will kick in if we 5558 * add more hard links than can fit in the ref item. 5559 */ 5560 key[1].objectid = objectid; 5561 btrfs_set_key_type(&key[1], BTRFS_INODE_REF_KEY); 5562 key[1].offset = ref_objectid; 5563 5564 sizes[0] = sizeof(struct btrfs_inode_item); 5565 sizes[1] = name_len + sizeof(*ref); 5566 5567 path->leave_spinning = 1; 5568 ret = btrfs_insert_empty_items(trans, root, path, key, sizes, 2); 5569 if (ret != 0) 5570 goto fail; 5571 5572 inode_init_owner(inode, dir, mode); 5573 inode_set_bytes(inode, 0); 5574 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; 5575 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0], 5576 struct btrfs_inode_item); 5577 memset_extent_buffer(path->nodes[0], 0, (unsigned long)inode_item, 5578 sizeof(*inode_item)); 5579 fill_inode_item(trans, path->nodes[0], inode_item, inode); 5580 5581 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1, 5582 struct btrfs_inode_ref); 5583 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len); 5584 btrfs_set_inode_ref_index(path->nodes[0], ref, *index); 5585 ptr = (unsigned long)(ref + 1); 5586 write_extent_buffer(path->nodes[0], name, ptr, name_len); 5587 5588 btrfs_mark_buffer_dirty(path->nodes[0]); 5589 btrfs_free_path(path); 5590 5591 location = &BTRFS_I(inode)->location; 5592 location->objectid = objectid; 5593 location->offset = 0; 5594 btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY); 5595 5596 btrfs_inherit_iflags(inode, dir); 5597 5598 if (S_ISREG(mode)) { 5599 if (btrfs_test_opt(root, NODATASUM)) 5600 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM; 5601 if (btrfs_test_opt(root, NODATACOW)) 5602 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW | 5603 BTRFS_INODE_NODATASUM; 5604 } 5605 5606 insert_inode_hash(inode); 5607 inode_tree_add(inode); 5608 5609 trace_btrfs_inode_new(inode); 5610 btrfs_set_inode_last_trans(trans, inode); 5611 5612 btrfs_update_root_times(trans, root); 5613 5614 return inode; 5615 fail: 5616 if (dir) 5617 BTRFS_I(dir)->index_cnt--; 5618 btrfs_free_path(path); 5619 iput(inode); 5620 return ERR_PTR(ret); 5621 } 5622 5623 static inline u8 btrfs_inode_type(struct inode *inode) 5624 { 5625 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT]; 5626 } 5627 5628 /* 5629 * utility function to add 'inode' into 'parent_inode' with 5630 * a give name and a given sequence number. 5631 * if 'add_backref' is true, also insert a backref from the 5632 * inode to the parent directory. 5633 */ 5634 int btrfs_add_link(struct btrfs_trans_handle *trans, 5635 struct inode *parent_inode, struct inode *inode, 5636 const char *name, int name_len, int add_backref, u64 index) 5637 { 5638 int ret = 0; 5639 struct btrfs_key key; 5640 struct btrfs_root *root = BTRFS_I(parent_inode)->root; 5641 u64 ino = btrfs_ino(inode); 5642 u64 parent_ino = btrfs_ino(parent_inode); 5643 5644 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) { 5645 memcpy(&key, &BTRFS_I(inode)->root->root_key, sizeof(key)); 5646 } else { 5647 key.objectid = ino; 5648 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY); 5649 key.offset = 0; 5650 } 5651 5652 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) { 5653 ret = btrfs_add_root_ref(trans, root->fs_info->tree_root, 5654 key.objectid, root->root_key.objectid, 5655 parent_ino, index, name, name_len); 5656 } else if (add_backref) { 5657 ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino, 5658 parent_ino, index); 5659 } 5660 5661 /* Nothing to clean up yet */ 5662 if (ret) 5663 return ret; 5664 5665 ret = btrfs_insert_dir_item(trans, root, name, name_len, 5666 parent_inode, &key, 5667 btrfs_inode_type(inode), index); 5668 if (ret == -EEXIST || ret == -EOVERFLOW) 5669 goto fail_dir_item; 5670 else if (ret) { 5671 btrfs_abort_transaction(trans, root, ret); 5672 return ret; 5673 } 5674 5675 btrfs_i_size_write(parent_inode, parent_inode->i_size + 5676 name_len * 2); 5677 inode_inc_iversion(parent_inode); 5678 parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME; 5679 ret = btrfs_update_inode(trans, root, parent_inode); 5680 if (ret) 5681 btrfs_abort_transaction(trans, root, ret); 5682 return ret; 5683 5684 fail_dir_item: 5685 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) { 5686 u64 local_index; 5687 int err; 5688 err = btrfs_del_root_ref(trans, root->fs_info->tree_root, 5689 key.objectid, root->root_key.objectid, 5690 parent_ino, &local_index, name, name_len); 5691 5692 } else if (add_backref) { 5693 u64 local_index; 5694 int err; 5695 5696 err = btrfs_del_inode_ref(trans, root, name, name_len, 5697 ino, parent_ino, &local_index); 5698 } 5699 return ret; 5700 } 5701 5702 static int btrfs_add_nondir(struct btrfs_trans_handle *trans, 5703 struct inode *dir, struct dentry *dentry, 5704 struct inode *inode, int backref, u64 index) 5705 { 5706 int err = btrfs_add_link(trans, dir, inode, 5707 dentry->d_name.name, dentry->d_name.len, 5708 backref, index); 5709 if (err > 0) 5710 err = -EEXIST; 5711 return err; 5712 } 5713 5714 static int btrfs_mknod(struct inode *dir, struct dentry *dentry, 5715 umode_t mode, dev_t rdev) 5716 { 5717 struct btrfs_trans_handle *trans; 5718 struct btrfs_root *root = BTRFS_I(dir)->root; 5719 struct inode *inode = NULL; 5720 int err; 5721 int drop_inode = 0; 5722 u64 objectid; 5723 u64 index = 0; 5724 5725 if (!new_valid_dev(rdev)) 5726 return -EINVAL; 5727 5728 /* 5729 * 2 for inode item and ref 5730 * 2 for dir items 5731 * 1 for xattr if selinux is on 5732 */ 5733 trans = btrfs_start_transaction(root, 5); 5734 if (IS_ERR(trans)) 5735 return PTR_ERR(trans); 5736 5737 err = btrfs_find_free_ino(root, &objectid); 5738 if (err) 5739 goto out_unlock; 5740 5741 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name, 5742 dentry->d_name.len, btrfs_ino(dir), objectid, 5743 mode, &index); 5744 if (IS_ERR(inode)) { 5745 err = PTR_ERR(inode); 5746 goto out_unlock; 5747 } 5748 5749 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name); 5750 if (err) { 5751 drop_inode = 1; 5752 goto out_unlock; 5753 } 5754 5755 /* 5756 * If the active LSM wants to access the inode during 5757 * d_instantiate it needs these. Smack checks to see 5758 * if the filesystem supports xattrs by looking at the 5759 * ops vector. 5760 */ 5761 5762 inode->i_op = &btrfs_special_inode_operations; 5763 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index); 5764 if (err) 5765 drop_inode = 1; 5766 else { 5767 init_special_inode(inode, inode->i_mode, rdev); 5768 btrfs_update_inode(trans, root, inode); 5769 d_instantiate(dentry, inode); 5770 } 5771 out_unlock: 5772 btrfs_end_transaction(trans, root); 5773 btrfs_btree_balance_dirty(root); 5774 if (drop_inode) { 5775 inode_dec_link_count(inode); 5776 iput(inode); 5777 } 5778 return err; 5779 } 5780 5781 static int btrfs_create(struct inode *dir, struct dentry *dentry, 5782 umode_t mode, bool excl) 5783 { 5784 struct btrfs_trans_handle *trans; 5785 struct btrfs_root *root = BTRFS_I(dir)->root; 5786 struct inode *inode = NULL; 5787 int drop_inode_on_err = 0; 5788 int err; 5789 u64 objectid; 5790 u64 index = 0; 5791 5792 /* 5793 * 2 for inode item and ref 5794 * 2 for dir items 5795 * 1 for xattr if selinux is on 5796 */ 5797 trans = btrfs_start_transaction(root, 5); 5798 if (IS_ERR(trans)) 5799 return PTR_ERR(trans); 5800 5801 err = btrfs_find_free_ino(root, &objectid); 5802 if (err) 5803 goto out_unlock; 5804 5805 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name, 5806 dentry->d_name.len, btrfs_ino(dir), objectid, 5807 mode, &index); 5808 if (IS_ERR(inode)) { 5809 err = PTR_ERR(inode); 5810 goto out_unlock; 5811 } 5812 drop_inode_on_err = 1; 5813 5814 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name); 5815 if (err) 5816 goto out_unlock; 5817 5818 err = btrfs_update_inode(trans, root, inode); 5819 if (err) 5820 goto out_unlock; 5821 5822 /* 5823 * If the active LSM wants to access the inode during 5824 * d_instantiate it needs these. Smack checks to see 5825 * if the filesystem supports xattrs by looking at the 5826 * ops vector. 5827 */ 5828 inode->i_fop = &btrfs_file_operations; 5829 inode->i_op = &btrfs_file_inode_operations; 5830 5831 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index); 5832 if (err) 5833 goto out_unlock; 5834 5835 inode->i_mapping->a_ops = &btrfs_aops; 5836 inode->i_mapping->backing_dev_info = &root->fs_info->bdi; 5837 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops; 5838 d_instantiate(dentry, inode); 5839 5840 out_unlock: 5841 btrfs_end_transaction(trans, root); 5842 if (err && drop_inode_on_err) { 5843 inode_dec_link_count(inode); 5844 iput(inode); 5845 } 5846 btrfs_btree_balance_dirty(root); 5847 return err; 5848 } 5849 5850 static int btrfs_link(struct dentry *old_dentry, struct inode *dir, 5851 struct dentry *dentry) 5852 { 5853 struct btrfs_trans_handle *trans; 5854 struct btrfs_root *root = BTRFS_I(dir)->root; 5855 struct inode *inode = old_dentry->d_inode; 5856 u64 index; 5857 int err; 5858 int drop_inode = 0; 5859 5860 /* do not allow sys_link's with other subvols of the same device */ 5861 if (root->objectid != BTRFS_I(inode)->root->objectid) 5862 return -EXDEV; 5863 5864 if (inode->i_nlink >= BTRFS_LINK_MAX) 5865 return -EMLINK; 5866 5867 err = btrfs_set_inode_index(dir, &index); 5868 if (err) 5869 goto fail; 5870 5871 /* 5872 * 2 items for inode and inode ref 5873 * 2 items for dir items 5874 * 1 item for parent inode 5875 */ 5876 trans = btrfs_start_transaction(root, 5); 5877 if (IS_ERR(trans)) { 5878 err = PTR_ERR(trans); 5879 goto fail; 5880 } 5881 5882 btrfs_inc_nlink(inode); 5883 inode_inc_iversion(inode); 5884 inode->i_ctime = CURRENT_TIME; 5885 ihold(inode); 5886 set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags); 5887 5888 err = btrfs_add_nondir(trans, dir, dentry, inode, 1, index); 5889 5890 if (err) { 5891 drop_inode = 1; 5892 } else { 5893 struct dentry *parent = dentry->d_parent; 5894 err = btrfs_update_inode(trans, root, inode); 5895 if (err) 5896 goto fail; 5897 d_instantiate(dentry, inode); 5898 btrfs_log_new_name(trans, inode, NULL, parent); 5899 } 5900 5901 btrfs_end_transaction(trans, root); 5902 fail: 5903 if (drop_inode) { 5904 inode_dec_link_count(inode); 5905 iput(inode); 5906 } 5907 btrfs_btree_balance_dirty(root); 5908 return err; 5909 } 5910 5911 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) 5912 { 5913 struct inode *inode = NULL; 5914 struct btrfs_trans_handle *trans; 5915 struct btrfs_root *root = BTRFS_I(dir)->root; 5916 int err = 0; 5917 int drop_on_err = 0; 5918 u64 objectid = 0; 5919 u64 index = 0; 5920 5921 /* 5922 * 2 items for inode and ref 5923 * 2 items for dir items 5924 * 1 for xattr if selinux is on 5925 */ 5926 trans = btrfs_start_transaction(root, 5); 5927 if (IS_ERR(trans)) 5928 return PTR_ERR(trans); 5929 5930 err = btrfs_find_free_ino(root, &objectid); 5931 if (err) 5932 goto out_fail; 5933 5934 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name, 5935 dentry->d_name.len, btrfs_ino(dir), objectid, 5936 S_IFDIR | mode, &index); 5937 if (IS_ERR(inode)) { 5938 err = PTR_ERR(inode); 5939 goto out_fail; 5940 } 5941 5942 drop_on_err = 1; 5943 5944 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name); 5945 if (err) 5946 goto out_fail; 5947 5948 inode->i_op = &btrfs_dir_inode_operations; 5949 inode->i_fop = &btrfs_dir_file_operations; 5950 5951 btrfs_i_size_write(inode, 0); 5952 err = btrfs_update_inode(trans, root, inode); 5953 if (err) 5954 goto out_fail; 5955 5956 err = btrfs_add_link(trans, dir, inode, dentry->d_name.name, 5957 dentry->d_name.len, 0, index); 5958 if (err) 5959 goto out_fail; 5960 5961 d_instantiate(dentry, inode); 5962 drop_on_err = 0; 5963 5964 out_fail: 5965 btrfs_end_transaction(trans, root); 5966 if (drop_on_err) 5967 iput(inode); 5968 btrfs_btree_balance_dirty(root); 5969 return err; 5970 } 5971 5972 /* helper for btfs_get_extent. Given an existing extent in the tree, 5973 * and an extent that you want to insert, deal with overlap and insert 5974 * the new extent into the tree. 5975 */ 5976 static int merge_extent_mapping(struct extent_map_tree *em_tree, 5977 struct extent_map *existing, 5978 struct extent_map *em, 5979 u64 map_start, u64 map_len) 5980 { 5981 u64 start_diff; 5982 5983 BUG_ON(map_start < em->start || map_start >= extent_map_end(em)); 5984 start_diff = map_start - em->start; 5985 em->start = map_start; 5986 em->len = map_len; 5987 if (em->block_start < EXTENT_MAP_LAST_BYTE && 5988 !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) { 5989 em->block_start += start_diff; 5990 em->block_len -= start_diff; 5991 } 5992 return add_extent_mapping(em_tree, em, 0); 5993 } 5994 5995 static noinline int uncompress_inline(struct btrfs_path *path, 5996 struct inode *inode, struct page *page, 5997 size_t pg_offset, u64 extent_offset, 5998 struct btrfs_file_extent_item *item) 5999 { 6000 int ret; 6001 struct extent_buffer *leaf = path->nodes[0]; 6002 char *tmp; 6003 size_t max_size; 6004 unsigned long inline_size; 6005 unsigned long ptr; 6006 int compress_type; 6007 6008 WARN_ON(pg_offset != 0); 6009 compress_type = btrfs_file_extent_compression(leaf, item); 6010 max_size = btrfs_file_extent_ram_bytes(leaf, item); 6011 inline_size = btrfs_file_extent_inline_item_len(leaf, 6012 btrfs_item_nr(leaf, path->slots[0])); 6013 tmp = kmalloc(inline_size, GFP_NOFS); 6014 if (!tmp) 6015 return -ENOMEM; 6016 ptr = btrfs_file_extent_inline_start(item); 6017 6018 read_extent_buffer(leaf, tmp, ptr, inline_size); 6019 6020 max_size = min_t(unsigned long, PAGE_CACHE_SIZE, max_size); 6021 ret = btrfs_decompress(compress_type, tmp, page, 6022 extent_offset, inline_size, max_size); 6023 if (ret) { 6024 char *kaddr = kmap_atomic(page); 6025 unsigned long copy_size = min_t(u64, 6026 PAGE_CACHE_SIZE - pg_offset, 6027 max_size - extent_offset); 6028 memset(kaddr + pg_offset, 0, copy_size); 6029 kunmap_atomic(kaddr); 6030 } 6031 kfree(tmp); 6032 return 0; 6033 } 6034 6035 /* 6036 * a bit scary, this does extent mapping from logical file offset to the disk. 6037 * the ugly parts come from merging extents from the disk with the in-ram 6038 * representation. This gets more complex because of the data=ordered code, 6039 * where the in-ram extents might be locked pending data=ordered completion. 6040 * 6041 * This also copies inline extents directly into the page. 6042 */ 6043 6044 struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page, 6045 size_t pg_offset, u64 start, u64 len, 6046 int create) 6047 { 6048 int ret; 6049 int err = 0; 6050 u64 bytenr; 6051 u64 extent_start = 0; 6052 u64 extent_end = 0; 6053 u64 objectid = btrfs_ino(inode); 6054 u32 found_type; 6055 struct btrfs_path *path = NULL; 6056 struct btrfs_root *root = BTRFS_I(inode)->root; 6057 struct btrfs_file_extent_item *item; 6058 struct extent_buffer *leaf; 6059 struct btrfs_key found_key; 6060 struct extent_map *em = NULL; 6061 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; 6062 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 6063 struct btrfs_trans_handle *trans = NULL; 6064 int compress_type; 6065 6066 again: 6067 read_lock(&em_tree->lock); 6068 em = lookup_extent_mapping(em_tree, start, len); 6069 if (em) 6070 em->bdev = root->fs_info->fs_devices->latest_bdev; 6071 read_unlock(&em_tree->lock); 6072 6073 if (em) { 6074 if (em->start > start || em->start + em->len <= start) 6075 free_extent_map(em); 6076 else if (em->block_start == EXTENT_MAP_INLINE && page) 6077 free_extent_map(em); 6078 else 6079 goto out; 6080 } 6081 em = alloc_extent_map(); 6082 if (!em) { 6083 err = -ENOMEM; 6084 goto out; 6085 } 6086 em->bdev = root->fs_info->fs_devices->latest_bdev; 6087 em->start = EXTENT_MAP_HOLE; 6088 em->orig_start = EXTENT_MAP_HOLE; 6089 em->len = (u64)-1; 6090 em->block_len = (u64)-1; 6091 6092 if (!path) { 6093 path = btrfs_alloc_path(); 6094 if (!path) { 6095 err = -ENOMEM; 6096 goto out; 6097 } 6098 /* 6099 * Chances are we'll be called again, so go ahead and do 6100 * readahead 6101 */ 6102 path->reada = 1; 6103 } 6104 6105 ret = btrfs_lookup_file_extent(trans, root, path, 6106 objectid, start, trans != NULL); 6107 if (ret < 0) { 6108 err = ret; 6109 goto out; 6110 } 6111 6112 if (ret != 0) { 6113 if (path->slots[0] == 0) 6114 goto not_found; 6115 path->slots[0]--; 6116 } 6117 6118 leaf = path->nodes[0]; 6119 item = btrfs_item_ptr(leaf, path->slots[0], 6120 struct btrfs_file_extent_item); 6121 /* are we inside the extent that was found? */ 6122 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 6123 found_type = btrfs_key_type(&found_key); 6124 if (found_key.objectid != objectid || 6125 found_type != BTRFS_EXTENT_DATA_KEY) { 6126 goto not_found; 6127 } 6128 6129 found_type = btrfs_file_extent_type(leaf, item); 6130 extent_start = found_key.offset; 6131 compress_type = btrfs_file_extent_compression(leaf, item); 6132 if (found_type == BTRFS_FILE_EXTENT_REG || 6133 found_type == BTRFS_FILE_EXTENT_PREALLOC) { 6134 extent_end = extent_start + 6135 btrfs_file_extent_num_bytes(leaf, item); 6136 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) { 6137 size_t size; 6138 size = btrfs_file_extent_inline_len(leaf, item); 6139 extent_end = ALIGN(extent_start + size, root->sectorsize); 6140 } 6141 6142 if (start >= extent_end) { 6143 path->slots[0]++; 6144 if (path->slots[0] >= btrfs_header_nritems(leaf)) { 6145 ret = btrfs_next_leaf(root, path); 6146 if (ret < 0) { 6147 err = ret; 6148 goto out; 6149 } 6150 if (ret > 0) 6151 goto not_found; 6152 leaf = path->nodes[0]; 6153 } 6154 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 6155 if (found_key.objectid != objectid || 6156 found_key.type != BTRFS_EXTENT_DATA_KEY) 6157 goto not_found; 6158 if (start + len <= found_key.offset) 6159 goto not_found; 6160 em->start = start; 6161 em->orig_start = start; 6162 em->len = found_key.offset - start; 6163 goto not_found_em; 6164 } 6165 6166 em->ram_bytes = btrfs_file_extent_ram_bytes(leaf, item); 6167 if (found_type == BTRFS_FILE_EXTENT_REG || 6168 found_type == BTRFS_FILE_EXTENT_PREALLOC) { 6169 em->start = extent_start; 6170 em->len = extent_end - extent_start; 6171 em->orig_start = extent_start - 6172 btrfs_file_extent_offset(leaf, item); 6173 em->orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, 6174 item); 6175 bytenr = btrfs_file_extent_disk_bytenr(leaf, item); 6176 if (bytenr == 0) { 6177 em->block_start = EXTENT_MAP_HOLE; 6178 goto insert; 6179 } 6180 if (compress_type != BTRFS_COMPRESS_NONE) { 6181 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags); 6182 em->compress_type = compress_type; 6183 em->block_start = bytenr; 6184 em->block_len = em->orig_block_len; 6185 } else { 6186 bytenr += btrfs_file_extent_offset(leaf, item); 6187 em->block_start = bytenr; 6188 em->block_len = em->len; 6189 if (found_type == BTRFS_FILE_EXTENT_PREALLOC) 6190 set_bit(EXTENT_FLAG_PREALLOC, &em->flags); 6191 } 6192 goto insert; 6193 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) { 6194 unsigned long ptr; 6195 char *map; 6196 size_t size; 6197 size_t extent_offset; 6198 size_t copy_size; 6199 6200 em->block_start = EXTENT_MAP_INLINE; 6201 if (!page || create) { 6202 em->start = extent_start; 6203 em->len = extent_end - extent_start; 6204 goto out; 6205 } 6206 6207 size = btrfs_file_extent_inline_len(leaf, item); 6208 extent_offset = page_offset(page) + pg_offset - extent_start; 6209 copy_size = min_t(u64, PAGE_CACHE_SIZE - pg_offset, 6210 size - extent_offset); 6211 em->start = extent_start + extent_offset; 6212 em->len = ALIGN(copy_size, root->sectorsize); 6213 em->orig_block_len = em->len; 6214 em->orig_start = em->start; 6215 if (compress_type) { 6216 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags); 6217 em->compress_type = compress_type; 6218 } 6219 ptr = btrfs_file_extent_inline_start(item) + extent_offset; 6220 if (create == 0 && !PageUptodate(page)) { 6221 if (btrfs_file_extent_compression(leaf, item) != 6222 BTRFS_COMPRESS_NONE) { 6223 ret = uncompress_inline(path, inode, page, 6224 pg_offset, 6225 extent_offset, item); 6226 BUG_ON(ret); /* -ENOMEM */ 6227 } else { 6228 map = kmap(page); 6229 read_extent_buffer(leaf, map + pg_offset, ptr, 6230 copy_size); 6231 if (pg_offset + copy_size < PAGE_CACHE_SIZE) { 6232 memset(map + pg_offset + copy_size, 0, 6233 PAGE_CACHE_SIZE - pg_offset - 6234 copy_size); 6235 } 6236 kunmap(page); 6237 } 6238 flush_dcache_page(page); 6239 } else if (create && PageUptodate(page)) { 6240 BUG(); 6241 if (!trans) { 6242 kunmap(page); 6243 free_extent_map(em); 6244 em = NULL; 6245 6246 btrfs_release_path(path); 6247 trans = btrfs_join_transaction(root); 6248 6249 if (IS_ERR(trans)) 6250 return ERR_CAST(trans); 6251 goto again; 6252 } 6253 map = kmap(page); 6254 write_extent_buffer(leaf, map + pg_offset, ptr, 6255 copy_size); 6256 kunmap(page); 6257 btrfs_mark_buffer_dirty(leaf); 6258 } 6259 set_extent_uptodate(io_tree, em->start, 6260 extent_map_end(em) - 1, NULL, GFP_NOFS); 6261 goto insert; 6262 } else { 6263 WARN(1, KERN_ERR "btrfs unknown found_type %d\n", found_type); 6264 } 6265 not_found: 6266 em->start = start; 6267 em->orig_start = start; 6268 em->len = len; 6269 not_found_em: 6270 em->block_start = EXTENT_MAP_HOLE; 6271 set_bit(EXTENT_FLAG_VACANCY, &em->flags); 6272 insert: 6273 btrfs_release_path(path); 6274 if (em->start > start || extent_map_end(em) <= start) { 6275 btrfs_err(root->fs_info, "bad extent! em: [%llu %llu] passed [%llu %llu]", 6276 (unsigned long long)em->start, 6277 (unsigned long long)em->len, 6278 (unsigned long long)start, 6279 (unsigned long long)len); 6280 err = -EIO; 6281 goto out; 6282 } 6283 6284 err = 0; 6285 write_lock(&em_tree->lock); 6286 ret = add_extent_mapping(em_tree, em, 0); 6287 /* it is possible that someone inserted the extent into the tree 6288 * while we had the lock dropped. It is also possible that 6289 * an overlapping map exists in the tree 6290 */ 6291 if (ret == -EEXIST) { 6292 struct extent_map *existing; 6293 6294 ret = 0; 6295 6296 existing = lookup_extent_mapping(em_tree, start, len); 6297 if (existing && (existing->start > start || 6298 existing->start + existing->len <= start)) { 6299 free_extent_map(existing); 6300 existing = NULL; 6301 } 6302 if (!existing) { 6303 existing = lookup_extent_mapping(em_tree, em->start, 6304 em->len); 6305 if (existing) { 6306 err = merge_extent_mapping(em_tree, existing, 6307 em, start, 6308 root->sectorsize); 6309 free_extent_map(existing); 6310 if (err) { 6311 free_extent_map(em); 6312 em = NULL; 6313 } 6314 } else { 6315 err = -EIO; 6316 free_extent_map(em); 6317 em = NULL; 6318 } 6319 } else { 6320 free_extent_map(em); 6321 em = existing; 6322 err = 0; 6323 } 6324 } 6325 write_unlock(&em_tree->lock); 6326 out: 6327 6328 if (em) 6329 trace_btrfs_get_extent(root, em); 6330 6331 if (path) 6332 btrfs_free_path(path); 6333 if (trans) { 6334 ret = btrfs_end_transaction(trans, root); 6335 if (!err) 6336 err = ret; 6337 } 6338 if (err) { 6339 free_extent_map(em); 6340 return ERR_PTR(err); 6341 } 6342 BUG_ON(!em); /* Error is always set */ 6343 return em; 6344 } 6345 6346 struct extent_map *btrfs_get_extent_fiemap(struct inode *inode, struct page *page, 6347 size_t pg_offset, u64 start, u64 len, 6348 int create) 6349 { 6350 struct extent_map *em; 6351 struct extent_map *hole_em = NULL; 6352 u64 range_start = start; 6353 u64 end; 6354 u64 found; 6355 u64 found_end; 6356 int err = 0; 6357 6358 em = btrfs_get_extent(inode, page, pg_offset, start, len, create); 6359 if (IS_ERR(em)) 6360 return em; 6361 if (em) { 6362 /* 6363 * if our em maps to 6364 * - a hole or 6365 * - a pre-alloc extent, 6366 * there might actually be delalloc bytes behind it. 6367 */ 6368 if (em->block_start != EXTENT_MAP_HOLE && 6369 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) 6370 return em; 6371 else 6372 hole_em = em; 6373 } 6374 6375 /* check to see if we've wrapped (len == -1 or similar) */ 6376 end = start + len; 6377 if (end < start) 6378 end = (u64)-1; 6379 else 6380 end -= 1; 6381 6382 em = NULL; 6383 6384 /* ok, we didn't find anything, lets look for delalloc */ 6385 found = count_range_bits(&BTRFS_I(inode)->io_tree, &range_start, 6386 end, len, EXTENT_DELALLOC, 1); 6387 found_end = range_start + found; 6388 if (found_end < range_start) 6389 found_end = (u64)-1; 6390 6391 /* 6392 * we didn't find anything useful, return 6393 * the original results from get_extent() 6394 */ 6395 if (range_start > end || found_end <= start) { 6396 em = hole_em; 6397 hole_em = NULL; 6398 goto out; 6399 } 6400 6401 /* adjust the range_start to make sure it doesn't 6402 * go backwards from the start they passed in 6403 */ 6404 range_start = max(start,range_start); 6405 found = found_end - range_start; 6406 6407 if (found > 0) { 6408 u64 hole_start = start; 6409 u64 hole_len = len; 6410 6411 em = alloc_extent_map(); 6412 if (!em) { 6413 err = -ENOMEM; 6414 goto out; 6415 } 6416 /* 6417 * when btrfs_get_extent can't find anything it 6418 * returns one huge hole 6419 * 6420 * make sure what it found really fits our range, and 6421 * adjust to make sure it is based on the start from 6422 * the caller 6423 */ 6424 if (hole_em) { 6425 u64 calc_end = extent_map_end(hole_em); 6426 6427 if (calc_end <= start || (hole_em->start > end)) { 6428 free_extent_map(hole_em); 6429 hole_em = NULL; 6430 } else { 6431 hole_start = max(hole_em->start, start); 6432 hole_len = calc_end - hole_start; 6433 } 6434 } 6435 em->bdev = NULL; 6436 if (hole_em && range_start > hole_start) { 6437 /* our hole starts before our delalloc, so we 6438 * have to return just the parts of the hole 6439 * that go until the delalloc starts 6440 */ 6441 em->len = min(hole_len, 6442 range_start - hole_start); 6443 em->start = hole_start; 6444 em->orig_start = hole_start; 6445 /* 6446 * don't adjust block start at all, 6447 * it is fixed at EXTENT_MAP_HOLE 6448 */ 6449 em->block_start = hole_em->block_start; 6450 em->block_len = hole_len; 6451 if (test_bit(EXTENT_FLAG_PREALLOC, &hole_em->flags)) 6452 set_bit(EXTENT_FLAG_PREALLOC, &em->flags); 6453 } else { 6454 em->start = range_start; 6455 em->len = found; 6456 em->orig_start = range_start; 6457 em->block_start = EXTENT_MAP_DELALLOC; 6458 em->block_len = found; 6459 } 6460 } else if (hole_em) { 6461 return hole_em; 6462 } 6463 out: 6464 6465 free_extent_map(hole_em); 6466 if (err) { 6467 free_extent_map(em); 6468 return ERR_PTR(err); 6469 } 6470 return em; 6471 } 6472 6473 static struct extent_map *btrfs_new_extent_direct(struct inode *inode, 6474 u64 start, u64 len) 6475 { 6476 struct btrfs_root *root = BTRFS_I(inode)->root; 6477 struct btrfs_trans_handle *trans; 6478 struct extent_map *em; 6479 struct btrfs_key ins; 6480 u64 alloc_hint; 6481 int ret; 6482 6483 trans = btrfs_join_transaction(root); 6484 if (IS_ERR(trans)) 6485 return ERR_CAST(trans); 6486 6487 trans->block_rsv = &root->fs_info->delalloc_block_rsv; 6488 6489 alloc_hint = get_extent_allocation_hint(inode, start, len); 6490 ret = btrfs_reserve_extent(trans, root, len, root->sectorsize, 0, 6491 alloc_hint, &ins, 1); 6492 if (ret) { 6493 em = ERR_PTR(ret); 6494 goto out; 6495 } 6496 6497 em = create_pinned_em(inode, start, ins.offset, start, ins.objectid, 6498 ins.offset, ins.offset, ins.offset, 0); 6499 if (IS_ERR(em)) 6500 goto out; 6501 6502 ret = btrfs_add_ordered_extent_dio(inode, start, ins.objectid, 6503 ins.offset, ins.offset, 0); 6504 if (ret) { 6505 btrfs_free_reserved_extent(root, ins.objectid, ins.offset); 6506 em = ERR_PTR(ret); 6507 } 6508 out: 6509 btrfs_end_transaction(trans, root); 6510 return em; 6511 } 6512 6513 /* 6514 * returns 1 when the nocow is safe, < 1 on error, 0 if the 6515 * block must be cow'd 6516 */ 6517 static noinline int can_nocow_odirect(struct btrfs_trans_handle *trans, 6518 struct inode *inode, u64 offset, u64 *len, 6519 u64 *orig_start, u64 *orig_block_len, 6520 u64 *ram_bytes) 6521 { 6522 struct btrfs_path *path; 6523 int ret; 6524 struct extent_buffer *leaf; 6525 struct btrfs_root *root = BTRFS_I(inode)->root; 6526 struct btrfs_file_extent_item *fi; 6527 struct btrfs_key key; 6528 u64 disk_bytenr; 6529 u64 backref_offset; 6530 u64 extent_end; 6531 u64 num_bytes; 6532 int slot; 6533 int found_type; 6534 6535 path = btrfs_alloc_path(); 6536 if (!path) 6537 return -ENOMEM; 6538 6539 ret = btrfs_lookup_file_extent(trans, root, path, btrfs_ino(inode), 6540 offset, 0); 6541 if (ret < 0) 6542 goto out; 6543 6544 slot = path->slots[0]; 6545 if (ret == 1) { 6546 if (slot == 0) { 6547 /* can't find the item, must cow */ 6548 ret = 0; 6549 goto out; 6550 } 6551 slot--; 6552 } 6553 ret = 0; 6554 leaf = path->nodes[0]; 6555 btrfs_item_key_to_cpu(leaf, &key, slot); 6556 if (key.objectid != btrfs_ino(inode) || 6557 key.type != BTRFS_EXTENT_DATA_KEY) { 6558 /* not our file or wrong item type, must cow */ 6559 goto out; 6560 } 6561 6562 if (key.offset > offset) { 6563 /* Wrong offset, must cow */ 6564 goto out; 6565 } 6566 6567 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item); 6568 found_type = btrfs_file_extent_type(leaf, fi); 6569 if (found_type != BTRFS_FILE_EXTENT_REG && 6570 found_type != BTRFS_FILE_EXTENT_PREALLOC) { 6571 /* not a regular extent, must cow */ 6572 goto out; 6573 } 6574 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); 6575 backref_offset = btrfs_file_extent_offset(leaf, fi); 6576 6577 *orig_start = key.offset - backref_offset; 6578 *orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi); 6579 *ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi); 6580 6581 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi); 6582 if (extent_end < offset + *len) { 6583 /* extent doesn't include our full range, must cow */ 6584 goto out; 6585 } 6586 6587 if (btrfs_extent_readonly(root, disk_bytenr)) 6588 goto out; 6589 6590 /* 6591 * look for other files referencing this extent, if we 6592 * find any we must cow 6593 */ 6594 if (btrfs_cross_ref_exist(trans, root, btrfs_ino(inode), 6595 key.offset - backref_offset, disk_bytenr)) 6596 goto out; 6597 6598 /* 6599 * adjust disk_bytenr and num_bytes to cover just the bytes 6600 * in this extent we are about to write. If there 6601 * are any csums in that range we have to cow in order 6602 * to keep the csums correct 6603 */ 6604 disk_bytenr += backref_offset; 6605 disk_bytenr += offset - key.offset; 6606 num_bytes = min(offset + *len, extent_end) - offset; 6607 if (csum_exist_in_range(root, disk_bytenr, num_bytes)) 6608 goto out; 6609 /* 6610 * all of the above have passed, it is safe to overwrite this extent 6611 * without cow 6612 */ 6613 *len = num_bytes; 6614 ret = 1; 6615 out: 6616 btrfs_free_path(path); 6617 return ret; 6618 } 6619 6620 static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend, 6621 struct extent_state **cached_state, int writing) 6622 { 6623 struct btrfs_ordered_extent *ordered; 6624 int ret = 0; 6625 6626 while (1) { 6627 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend, 6628 0, cached_state); 6629 /* 6630 * We're concerned with the entire range that we're going to be 6631 * doing DIO to, so we need to make sure theres no ordered 6632 * extents in this range. 6633 */ 6634 ordered = btrfs_lookup_ordered_range(inode, lockstart, 6635 lockend - lockstart + 1); 6636 6637 /* 6638 * We need to make sure there are no buffered pages in this 6639 * range either, we could have raced between the invalidate in 6640 * generic_file_direct_write and locking the extent. The 6641 * invalidate needs to happen so that reads after a write do not 6642 * get stale data. 6643 */ 6644 if (!ordered && (!writing || 6645 !test_range_bit(&BTRFS_I(inode)->io_tree, 6646 lockstart, lockend, EXTENT_UPTODATE, 0, 6647 *cached_state))) 6648 break; 6649 6650 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend, 6651 cached_state, GFP_NOFS); 6652 6653 if (ordered) { 6654 btrfs_start_ordered_extent(inode, ordered, 1); 6655 btrfs_put_ordered_extent(ordered); 6656 } else { 6657 /* Screw you mmap */ 6658 ret = filemap_write_and_wait_range(inode->i_mapping, 6659 lockstart, 6660 lockend); 6661 if (ret) 6662 break; 6663 6664 /* 6665 * If we found a page that couldn't be invalidated just 6666 * fall back to buffered. 6667 */ 6668 ret = invalidate_inode_pages2_range(inode->i_mapping, 6669 lockstart >> PAGE_CACHE_SHIFT, 6670 lockend >> PAGE_CACHE_SHIFT); 6671 if (ret) 6672 break; 6673 } 6674 6675 cond_resched(); 6676 } 6677 6678 return ret; 6679 } 6680 6681 static struct extent_map *create_pinned_em(struct inode *inode, u64 start, 6682 u64 len, u64 orig_start, 6683 u64 block_start, u64 block_len, 6684 u64 orig_block_len, u64 ram_bytes, 6685 int type) 6686 { 6687 struct extent_map_tree *em_tree; 6688 struct extent_map *em; 6689 struct btrfs_root *root = BTRFS_I(inode)->root; 6690 int ret; 6691 6692 em_tree = &BTRFS_I(inode)->extent_tree; 6693 em = alloc_extent_map(); 6694 if (!em) 6695 return ERR_PTR(-ENOMEM); 6696 6697 em->start = start; 6698 em->orig_start = orig_start; 6699 em->mod_start = start; 6700 em->mod_len = len; 6701 em->len = len; 6702 em->block_len = block_len; 6703 em->block_start = block_start; 6704 em->bdev = root->fs_info->fs_devices->latest_bdev; 6705 em->orig_block_len = orig_block_len; 6706 em->ram_bytes = ram_bytes; 6707 em->generation = -1; 6708 set_bit(EXTENT_FLAG_PINNED, &em->flags); 6709 if (type == BTRFS_ORDERED_PREALLOC) 6710 set_bit(EXTENT_FLAG_FILLING, &em->flags); 6711 6712 do { 6713 btrfs_drop_extent_cache(inode, em->start, 6714 em->start + em->len - 1, 0); 6715 write_lock(&em_tree->lock); 6716 ret = add_extent_mapping(em_tree, em, 1); 6717 write_unlock(&em_tree->lock); 6718 } while (ret == -EEXIST); 6719 6720 if (ret) { 6721 free_extent_map(em); 6722 return ERR_PTR(ret); 6723 } 6724 6725 return em; 6726 } 6727 6728 6729 static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock, 6730 struct buffer_head *bh_result, int create) 6731 { 6732 struct extent_map *em; 6733 struct btrfs_root *root = BTRFS_I(inode)->root; 6734 struct extent_state *cached_state = NULL; 6735 u64 start = iblock << inode->i_blkbits; 6736 u64 lockstart, lockend; 6737 u64 len = bh_result->b_size; 6738 struct btrfs_trans_handle *trans; 6739 int unlock_bits = EXTENT_LOCKED; 6740 int ret = 0; 6741 6742 if (create) 6743 unlock_bits |= EXTENT_DELALLOC | EXTENT_DIRTY; 6744 else 6745 len = min_t(u64, len, root->sectorsize); 6746 6747 lockstart = start; 6748 lockend = start + len - 1; 6749 6750 /* 6751 * If this errors out it's because we couldn't invalidate pagecache for 6752 * this range and we need to fallback to buffered. 6753 */ 6754 if (lock_extent_direct(inode, lockstart, lockend, &cached_state, create)) 6755 return -ENOTBLK; 6756 6757 em = btrfs_get_extent(inode, NULL, 0, start, len, 0); 6758 if (IS_ERR(em)) { 6759 ret = PTR_ERR(em); 6760 goto unlock_err; 6761 } 6762 6763 /* 6764 * Ok for INLINE and COMPRESSED extents we need to fallback on buffered 6765 * io. INLINE is special, and we could probably kludge it in here, but 6766 * it's still buffered so for safety lets just fall back to the generic 6767 * buffered path. 6768 * 6769 * For COMPRESSED we _have_ to read the entire extent in so we can 6770 * decompress it, so there will be buffering required no matter what we 6771 * do, so go ahead and fallback to buffered. 6772 * 6773 * We return -ENOTBLK because thats what makes DIO go ahead and go back 6774 * to buffered IO. Don't blame me, this is the price we pay for using 6775 * the generic code. 6776 */ 6777 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) || 6778 em->block_start == EXTENT_MAP_INLINE) { 6779 free_extent_map(em); 6780 ret = -ENOTBLK; 6781 goto unlock_err; 6782 } 6783 6784 /* Just a good old fashioned hole, return */ 6785 if (!create && (em->block_start == EXTENT_MAP_HOLE || 6786 test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) { 6787 free_extent_map(em); 6788 goto unlock_err; 6789 } 6790 6791 /* 6792 * We don't allocate a new extent in the following cases 6793 * 6794 * 1) The inode is marked as NODATACOW. In this case we'll just use the 6795 * existing extent. 6796 * 2) The extent is marked as PREALLOC. We're good to go here and can 6797 * just use the extent. 6798 * 6799 */ 6800 if (!create) { 6801 len = min(len, em->len - (start - em->start)); 6802 lockstart = start + len; 6803 goto unlock; 6804 } 6805 6806 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) || 6807 ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) && 6808 em->block_start != EXTENT_MAP_HOLE)) { 6809 int type; 6810 int ret; 6811 u64 block_start, orig_start, orig_block_len, ram_bytes; 6812 6813 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) 6814 type = BTRFS_ORDERED_PREALLOC; 6815 else 6816 type = BTRFS_ORDERED_NOCOW; 6817 len = min(len, em->len - (start - em->start)); 6818 block_start = em->block_start + (start - em->start); 6819 6820 /* 6821 * we're not going to log anything, but we do need 6822 * to make sure the current transaction stays open 6823 * while we look for nocow cross refs 6824 */ 6825 trans = btrfs_join_transaction(root); 6826 if (IS_ERR(trans)) 6827 goto must_cow; 6828 6829 if (can_nocow_odirect(trans, inode, start, &len, &orig_start, 6830 &orig_block_len, &ram_bytes) == 1) { 6831 if (type == BTRFS_ORDERED_PREALLOC) { 6832 free_extent_map(em); 6833 em = create_pinned_em(inode, start, len, 6834 orig_start, 6835 block_start, len, 6836 orig_block_len, 6837 ram_bytes, type); 6838 if (IS_ERR(em)) { 6839 btrfs_end_transaction(trans, root); 6840 goto unlock_err; 6841 } 6842 } 6843 6844 ret = btrfs_add_ordered_extent_dio(inode, start, 6845 block_start, len, len, type); 6846 btrfs_end_transaction(trans, root); 6847 if (ret) { 6848 free_extent_map(em); 6849 goto unlock_err; 6850 } 6851 goto unlock; 6852 } 6853 btrfs_end_transaction(trans, root); 6854 } 6855 must_cow: 6856 /* 6857 * this will cow the extent, reset the len in case we changed 6858 * it above 6859 */ 6860 len = bh_result->b_size; 6861 free_extent_map(em); 6862 em = btrfs_new_extent_direct(inode, start, len); 6863 if (IS_ERR(em)) { 6864 ret = PTR_ERR(em); 6865 goto unlock_err; 6866 } 6867 len = min(len, em->len - (start - em->start)); 6868 unlock: 6869 bh_result->b_blocknr = (em->block_start + (start - em->start)) >> 6870 inode->i_blkbits; 6871 bh_result->b_size = len; 6872 bh_result->b_bdev = em->bdev; 6873 set_buffer_mapped(bh_result); 6874 if (create) { 6875 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) 6876 set_buffer_new(bh_result); 6877 6878 /* 6879 * Need to update the i_size under the extent lock so buffered 6880 * readers will get the updated i_size when we unlock. 6881 */ 6882 if (start + len > i_size_read(inode)) 6883 i_size_write(inode, start + len); 6884 6885 spin_lock(&BTRFS_I(inode)->lock); 6886 BTRFS_I(inode)->outstanding_extents++; 6887 spin_unlock(&BTRFS_I(inode)->lock); 6888 6889 ret = set_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, 6890 lockstart + len - 1, EXTENT_DELALLOC, NULL, 6891 &cached_state, GFP_NOFS); 6892 BUG_ON(ret); 6893 } 6894 6895 /* 6896 * In the case of write we need to clear and unlock the entire range, 6897 * in the case of read we need to unlock only the end area that we 6898 * aren't using if there is any left over space. 6899 */ 6900 if (lockstart < lockend) { 6901 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, 6902 lockend, unlock_bits, 1, 0, 6903 &cached_state, GFP_NOFS); 6904 } else { 6905 free_extent_state(cached_state); 6906 } 6907 6908 free_extent_map(em); 6909 6910 return 0; 6911 6912 unlock_err: 6913 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend, 6914 unlock_bits, 1, 0, &cached_state, GFP_NOFS); 6915 return ret; 6916 } 6917 6918 struct btrfs_dio_private { 6919 struct inode *inode; 6920 u64 logical_offset; 6921 u64 disk_bytenr; 6922 u64 bytes; 6923 void *private; 6924 6925 /* number of bios pending for this dio */ 6926 atomic_t pending_bios; 6927 6928 /* IO errors */ 6929 int errors; 6930 6931 struct bio *orig_bio; 6932 }; 6933 6934 static void btrfs_endio_direct_read(struct bio *bio, int err) 6935 { 6936 struct btrfs_dio_private *dip = bio->bi_private; 6937 struct bio_vec *bvec_end = bio->bi_io_vec + bio->bi_vcnt - 1; 6938 struct bio_vec *bvec = bio->bi_io_vec; 6939 struct inode *inode = dip->inode; 6940 struct btrfs_root *root = BTRFS_I(inode)->root; 6941 u64 start; 6942 6943 start = dip->logical_offset; 6944 do { 6945 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) { 6946 struct page *page = bvec->bv_page; 6947 char *kaddr; 6948 u32 csum = ~(u32)0; 6949 u64 private = ~(u32)0; 6950 unsigned long flags; 6951 6952 if (get_state_private(&BTRFS_I(inode)->io_tree, 6953 start, &private)) 6954 goto failed; 6955 local_irq_save(flags); 6956 kaddr = kmap_atomic(page); 6957 csum = btrfs_csum_data(kaddr + bvec->bv_offset, 6958 csum, bvec->bv_len); 6959 btrfs_csum_final(csum, (char *)&csum); 6960 kunmap_atomic(kaddr); 6961 local_irq_restore(flags); 6962 6963 flush_dcache_page(bvec->bv_page); 6964 if (csum != private) { 6965 failed: 6966 btrfs_err(root->fs_info, "csum failed ino %llu off %llu csum %u private %u", 6967 (unsigned long long)btrfs_ino(inode), 6968 (unsigned long long)start, 6969 csum, (unsigned)private); 6970 err = -EIO; 6971 } 6972 } 6973 6974 start += bvec->bv_len; 6975 bvec++; 6976 } while (bvec <= bvec_end); 6977 6978 unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset, 6979 dip->logical_offset + dip->bytes - 1); 6980 bio->bi_private = dip->private; 6981 6982 kfree(dip); 6983 6984 /* If we had a csum failure make sure to clear the uptodate flag */ 6985 if (err) 6986 clear_bit(BIO_UPTODATE, &bio->bi_flags); 6987 dio_end_io(bio, err); 6988 } 6989 6990 static void btrfs_endio_direct_write(struct bio *bio, int err) 6991 { 6992 struct btrfs_dio_private *dip = bio->bi_private; 6993 struct inode *inode = dip->inode; 6994 struct btrfs_root *root = BTRFS_I(inode)->root; 6995 struct btrfs_ordered_extent *ordered = NULL; 6996 u64 ordered_offset = dip->logical_offset; 6997 u64 ordered_bytes = dip->bytes; 6998 int ret; 6999 7000 if (err) 7001 goto out_done; 7002 again: 7003 ret = btrfs_dec_test_first_ordered_pending(inode, &ordered, 7004 &ordered_offset, 7005 ordered_bytes, !err); 7006 if (!ret) 7007 goto out_test; 7008 7009 ordered->work.func = finish_ordered_fn; 7010 ordered->work.flags = 0; 7011 btrfs_queue_worker(&root->fs_info->endio_write_workers, 7012 &ordered->work); 7013 out_test: 7014 /* 7015 * our bio might span multiple ordered extents. If we haven't 7016 * completed the accounting for the whole dio, go back and try again 7017 */ 7018 if (ordered_offset < dip->logical_offset + dip->bytes) { 7019 ordered_bytes = dip->logical_offset + dip->bytes - 7020 ordered_offset; 7021 ordered = NULL; 7022 goto again; 7023 } 7024 out_done: 7025 bio->bi_private = dip->private; 7026 7027 kfree(dip); 7028 7029 /* If we had an error make sure to clear the uptodate flag */ 7030 if (err) 7031 clear_bit(BIO_UPTODATE, &bio->bi_flags); 7032 dio_end_io(bio, err); 7033 } 7034 7035 static int __btrfs_submit_bio_start_direct_io(struct inode *inode, int rw, 7036 struct bio *bio, int mirror_num, 7037 unsigned long bio_flags, u64 offset) 7038 { 7039 int ret; 7040 struct btrfs_root *root = BTRFS_I(inode)->root; 7041 ret = btrfs_csum_one_bio(root, inode, bio, offset, 1); 7042 BUG_ON(ret); /* -ENOMEM */ 7043 return 0; 7044 } 7045 7046 static void btrfs_end_dio_bio(struct bio *bio, int err) 7047 { 7048 struct btrfs_dio_private *dip = bio->bi_private; 7049 7050 if (err) { 7051 printk(KERN_ERR "btrfs direct IO failed ino %llu rw %lu " 7052 "sector %#Lx len %u err no %d\n", 7053 (unsigned long long)btrfs_ino(dip->inode), bio->bi_rw, 7054 (unsigned long long)bio->bi_sector, bio->bi_size, err); 7055 dip->errors = 1; 7056 7057 /* 7058 * before atomic variable goto zero, we must make sure 7059 * dip->errors is perceived to be set. 7060 */ 7061 smp_mb__before_atomic_dec(); 7062 } 7063 7064 /* if there are more bios still pending for this dio, just exit */ 7065 if (!atomic_dec_and_test(&dip->pending_bios)) 7066 goto out; 7067 7068 if (dip->errors) 7069 bio_io_error(dip->orig_bio); 7070 else { 7071 set_bit(BIO_UPTODATE, &dip->orig_bio->bi_flags); 7072 bio_endio(dip->orig_bio, 0); 7073 } 7074 out: 7075 bio_put(bio); 7076 } 7077 7078 static struct bio *btrfs_dio_bio_alloc(struct block_device *bdev, 7079 u64 first_sector, gfp_t gfp_flags) 7080 { 7081 int nr_vecs = bio_get_nr_vecs(bdev); 7082 return btrfs_bio_alloc(bdev, first_sector, nr_vecs, gfp_flags); 7083 } 7084 7085 static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode, 7086 int rw, u64 file_offset, int skip_sum, 7087 int async_submit) 7088 { 7089 int write = rw & REQ_WRITE; 7090 struct btrfs_root *root = BTRFS_I(inode)->root; 7091 int ret; 7092 7093 if (async_submit) 7094 async_submit = !atomic_read(&BTRFS_I(inode)->sync_writers); 7095 7096 bio_get(bio); 7097 7098 if (!write) { 7099 ret = btrfs_bio_wq_end_io(root->fs_info, bio, 0); 7100 if (ret) 7101 goto err; 7102 } 7103 7104 if (skip_sum) 7105 goto map; 7106 7107 if (write && async_submit) { 7108 ret = btrfs_wq_submit_bio(root->fs_info, 7109 inode, rw, bio, 0, 0, 7110 file_offset, 7111 __btrfs_submit_bio_start_direct_io, 7112 __btrfs_submit_bio_done); 7113 goto err; 7114 } else if (write) { 7115 /* 7116 * If we aren't doing async submit, calculate the csum of the 7117 * bio now. 7118 */ 7119 ret = btrfs_csum_one_bio(root, inode, bio, file_offset, 1); 7120 if (ret) 7121 goto err; 7122 } else if (!skip_sum) { 7123 ret = btrfs_lookup_bio_sums_dio(root, inode, bio, file_offset); 7124 if (ret) 7125 goto err; 7126 } 7127 7128 map: 7129 ret = btrfs_map_bio(root, rw, bio, 0, async_submit); 7130 err: 7131 bio_put(bio); 7132 return ret; 7133 } 7134 7135 static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip, 7136 int skip_sum) 7137 { 7138 struct inode *inode = dip->inode; 7139 struct btrfs_root *root = BTRFS_I(inode)->root; 7140 struct bio *bio; 7141 struct bio *orig_bio = dip->orig_bio; 7142 struct bio_vec *bvec = orig_bio->bi_io_vec; 7143 u64 start_sector = orig_bio->bi_sector; 7144 u64 file_offset = dip->logical_offset; 7145 u64 submit_len = 0; 7146 u64 map_length; 7147 int nr_pages = 0; 7148 int ret = 0; 7149 int async_submit = 0; 7150 7151 map_length = orig_bio->bi_size; 7152 ret = btrfs_map_block(root->fs_info, rw, start_sector << 9, 7153 &map_length, NULL, 0); 7154 if (ret) { 7155 bio_put(orig_bio); 7156 return -EIO; 7157 } 7158 if (map_length >= orig_bio->bi_size) { 7159 bio = orig_bio; 7160 goto submit; 7161 } 7162 7163 /* async crcs make it difficult to collect full stripe writes. */ 7164 if (btrfs_get_alloc_profile(root, 1) & 7165 (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6)) 7166 async_submit = 0; 7167 else 7168 async_submit = 1; 7169 7170 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, start_sector, GFP_NOFS); 7171 if (!bio) 7172 return -ENOMEM; 7173 bio->bi_private = dip; 7174 bio->bi_end_io = btrfs_end_dio_bio; 7175 atomic_inc(&dip->pending_bios); 7176 7177 while (bvec <= (orig_bio->bi_io_vec + orig_bio->bi_vcnt - 1)) { 7178 if (unlikely(map_length < submit_len + bvec->bv_len || 7179 bio_add_page(bio, bvec->bv_page, bvec->bv_len, 7180 bvec->bv_offset) < bvec->bv_len)) { 7181 /* 7182 * inc the count before we submit the bio so 7183 * we know the end IO handler won't happen before 7184 * we inc the count. Otherwise, the dip might get freed 7185 * before we're done setting it up 7186 */ 7187 atomic_inc(&dip->pending_bios); 7188 ret = __btrfs_submit_dio_bio(bio, inode, rw, 7189 file_offset, skip_sum, 7190 async_submit); 7191 if (ret) { 7192 bio_put(bio); 7193 atomic_dec(&dip->pending_bios); 7194 goto out_err; 7195 } 7196 7197 start_sector += submit_len >> 9; 7198 file_offset += submit_len; 7199 7200 submit_len = 0; 7201 nr_pages = 0; 7202 7203 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, 7204 start_sector, GFP_NOFS); 7205 if (!bio) 7206 goto out_err; 7207 bio->bi_private = dip; 7208 bio->bi_end_io = btrfs_end_dio_bio; 7209 7210 map_length = orig_bio->bi_size; 7211 ret = btrfs_map_block(root->fs_info, rw, 7212 start_sector << 9, 7213 &map_length, NULL, 0); 7214 if (ret) { 7215 bio_put(bio); 7216 goto out_err; 7217 } 7218 } else { 7219 submit_len += bvec->bv_len; 7220 nr_pages ++; 7221 bvec++; 7222 } 7223 } 7224 7225 submit: 7226 ret = __btrfs_submit_dio_bio(bio, inode, rw, file_offset, skip_sum, 7227 async_submit); 7228 if (!ret) 7229 return 0; 7230 7231 bio_put(bio); 7232 out_err: 7233 dip->errors = 1; 7234 /* 7235 * before atomic variable goto zero, we must 7236 * make sure dip->errors is perceived to be set. 7237 */ 7238 smp_mb__before_atomic_dec(); 7239 if (atomic_dec_and_test(&dip->pending_bios)) 7240 bio_io_error(dip->orig_bio); 7241 7242 /* bio_end_io() will handle error, so we needn't return it */ 7243 return 0; 7244 } 7245 7246 static void btrfs_submit_direct(int rw, struct bio *bio, struct inode *inode, 7247 loff_t file_offset) 7248 { 7249 struct btrfs_root *root = BTRFS_I(inode)->root; 7250 struct btrfs_dio_private *dip; 7251 struct bio_vec *bvec = bio->bi_io_vec; 7252 int skip_sum; 7253 int write = rw & REQ_WRITE; 7254 int ret = 0; 7255 7256 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM; 7257 7258 dip = kmalloc(sizeof(*dip), GFP_NOFS); 7259 if (!dip) { 7260 ret = -ENOMEM; 7261 goto free_ordered; 7262 } 7263 7264 dip->private = bio->bi_private; 7265 dip->inode = inode; 7266 dip->logical_offset = file_offset; 7267 7268 dip->bytes = 0; 7269 do { 7270 dip->bytes += bvec->bv_len; 7271 bvec++; 7272 } while (bvec <= (bio->bi_io_vec + bio->bi_vcnt - 1)); 7273 7274 dip->disk_bytenr = (u64)bio->bi_sector << 9; 7275 bio->bi_private = dip; 7276 dip->errors = 0; 7277 dip->orig_bio = bio; 7278 atomic_set(&dip->pending_bios, 0); 7279 7280 if (write) 7281 bio->bi_end_io = btrfs_endio_direct_write; 7282 else 7283 bio->bi_end_io = btrfs_endio_direct_read; 7284 7285 ret = btrfs_submit_direct_hook(rw, dip, skip_sum); 7286 if (!ret) 7287 return; 7288 free_ordered: 7289 /* 7290 * If this is a write, we need to clean up the reserved space and kill 7291 * the ordered extent. 7292 */ 7293 if (write) { 7294 struct btrfs_ordered_extent *ordered; 7295 ordered = btrfs_lookup_ordered_extent(inode, file_offset); 7296 if (!test_bit(BTRFS_ORDERED_PREALLOC, &ordered->flags) && 7297 !test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags)) 7298 btrfs_free_reserved_extent(root, ordered->start, 7299 ordered->disk_len); 7300 btrfs_put_ordered_extent(ordered); 7301 btrfs_put_ordered_extent(ordered); 7302 } 7303 bio_endio(bio, ret); 7304 } 7305 7306 static ssize_t check_direct_IO(struct btrfs_root *root, int rw, struct kiocb *iocb, 7307 const struct iovec *iov, loff_t offset, 7308 unsigned long nr_segs) 7309 { 7310 int seg; 7311 int i; 7312 size_t size; 7313 unsigned long addr; 7314 unsigned blocksize_mask = root->sectorsize - 1; 7315 ssize_t retval = -EINVAL; 7316 loff_t end = offset; 7317 7318 if (offset & blocksize_mask) 7319 goto out; 7320 7321 /* Check the memory alignment. Blocks cannot straddle pages */ 7322 for (seg = 0; seg < nr_segs; seg++) { 7323 addr = (unsigned long)iov[seg].iov_base; 7324 size = iov[seg].iov_len; 7325 end += size; 7326 if ((addr & blocksize_mask) || (size & blocksize_mask)) 7327 goto out; 7328 7329 /* If this is a write we don't need to check anymore */ 7330 if (rw & WRITE) 7331 continue; 7332 7333 /* 7334 * Check to make sure we don't have duplicate iov_base's in this 7335 * iovec, if so return EINVAL, otherwise we'll get csum errors 7336 * when reading back. 7337 */ 7338 for (i = seg + 1; i < nr_segs; i++) { 7339 if (iov[seg].iov_base == iov[i].iov_base) 7340 goto out; 7341 } 7342 } 7343 retval = 0; 7344 out: 7345 return retval; 7346 } 7347 7348 static ssize_t btrfs_direct_IO(int rw, struct kiocb *iocb, 7349 const struct iovec *iov, loff_t offset, 7350 unsigned long nr_segs) 7351 { 7352 struct file *file = iocb->ki_filp; 7353 struct inode *inode = file->f_mapping->host; 7354 size_t count = 0; 7355 int flags = 0; 7356 bool wakeup = true; 7357 bool relock = false; 7358 ssize_t ret; 7359 7360 if (check_direct_IO(BTRFS_I(inode)->root, rw, iocb, iov, 7361 offset, nr_segs)) 7362 return 0; 7363 7364 atomic_inc(&inode->i_dio_count); 7365 smp_mb__after_atomic_inc(); 7366 7367 if (rw & WRITE) { 7368 count = iov_length(iov, nr_segs); 7369 /* 7370 * If the write DIO is beyond the EOF, we need update 7371 * the isize, but it is protected by i_mutex. So we can 7372 * not unlock the i_mutex at this case. 7373 */ 7374 if (offset + count <= inode->i_size) { 7375 mutex_unlock(&inode->i_mutex); 7376 relock = true; 7377 } 7378 ret = btrfs_delalloc_reserve_space(inode, count); 7379 if (ret) 7380 goto out; 7381 } else if (unlikely(test_bit(BTRFS_INODE_READDIO_NEED_LOCK, 7382 &BTRFS_I(inode)->runtime_flags))) { 7383 inode_dio_done(inode); 7384 flags = DIO_LOCKING | DIO_SKIP_HOLES; 7385 wakeup = false; 7386 } 7387 7388 ret = __blockdev_direct_IO(rw, iocb, inode, 7389 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev, 7390 iov, offset, nr_segs, btrfs_get_blocks_direct, NULL, 7391 btrfs_submit_direct, flags); 7392 if (rw & WRITE) { 7393 if (ret < 0 && ret != -EIOCBQUEUED) 7394 btrfs_delalloc_release_space(inode, count); 7395 else if (ret >= 0 && (size_t)ret < count) 7396 btrfs_delalloc_release_space(inode, 7397 count - (size_t)ret); 7398 else 7399 btrfs_delalloc_release_metadata(inode, 0); 7400 } 7401 out: 7402 if (wakeup) 7403 inode_dio_done(inode); 7404 if (relock) 7405 mutex_lock(&inode->i_mutex); 7406 7407 return ret; 7408 } 7409 7410 #define BTRFS_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC) 7411 7412 static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, 7413 __u64 start, __u64 len) 7414 { 7415 int ret; 7416 7417 ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS); 7418 if (ret) 7419 return ret; 7420 7421 return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent_fiemap); 7422 } 7423 7424 int btrfs_readpage(struct file *file, struct page *page) 7425 { 7426 struct extent_io_tree *tree; 7427 tree = &BTRFS_I(page->mapping->host)->io_tree; 7428 return extent_read_full_page(tree, page, btrfs_get_extent, 0); 7429 } 7430 7431 static int btrfs_writepage(struct page *page, struct writeback_control *wbc) 7432 { 7433 struct extent_io_tree *tree; 7434 7435 7436 if (current->flags & PF_MEMALLOC) { 7437 redirty_page_for_writepage(wbc, page); 7438 unlock_page(page); 7439 return 0; 7440 } 7441 tree = &BTRFS_I(page->mapping->host)->io_tree; 7442 return extent_write_full_page(tree, page, btrfs_get_extent, wbc); 7443 } 7444 7445 static int btrfs_writepages(struct address_space *mapping, 7446 struct writeback_control *wbc) 7447 { 7448 struct extent_io_tree *tree; 7449 7450 tree = &BTRFS_I(mapping->host)->io_tree; 7451 return extent_writepages(tree, mapping, btrfs_get_extent, wbc); 7452 } 7453 7454 static int 7455 btrfs_readpages(struct file *file, struct address_space *mapping, 7456 struct list_head *pages, unsigned nr_pages) 7457 { 7458 struct extent_io_tree *tree; 7459 tree = &BTRFS_I(mapping->host)->io_tree; 7460 return extent_readpages(tree, mapping, pages, nr_pages, 7461 btrfs_get_extent); 7462 } 7463 static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags) 7464 { 7465 struct extent_io_tree *tree; 7466 struct extent_map_tree *map; 7467 int ret; 7468 7469 tree = &BTRFS_I(page->mapping->host)->io_tree; 7470 map = &BTRFS_I(page->mapping->host)->extent_tree; 7471 ret = try_release_extent_mapping(map, tree, page, gfp_flags); 7472 if (ret == 1) { 7473 ClearPagePrivate(page); 7474 set_page_private(page, 0); 7475 page_cache_release(page); 7476 } 7477 return ret; 7478 } 7479 7480 static int btrfs_releasepage(struct page *page, gfp_t gfp_flags) 7481 { 7482 if (PageWriteback(page) || PageDirty(page)) 7483 return 0; 7484 return __btrfs_releasepage(page, gfp_flags & GFP_NOFS); 7485 } 7486 7487 static void btrfs_invalidatepage(struct page *page, unsigned long offset) 7488 { 7489 struct inode *inode = page->mapping->host; 7490 struct extent_io_tree *tree; 7491 struct btrfs_ordered_extent *ordered; 7492 struct extent_state *cached_state = NULL; 7493 u64 page_start = page_offset(page); 7494 u64 page_end = page_start + PAGE_CACHE_SIZE - 1; 7495 7496 /* 7497 * we have the page locked, so new writeback can't start, 7498 * and the dirty bit won't be cleared while we are here. 7499 * 7500 * Wait for IO on this page so that we can safely clear 7501 * the PagePrivate2 bit and do ordered accounting 7502 */ 7503 wait_on_page_writeback(page); 7504 7505 tree = &BTRFS_I(inode)->io_tree; 7506 if (offset) { 7507 btrfs_releasepage(page, GFP_NOFS); 7508 return; 7509 } 7510 lock_extent_bits(tree, page_start, page_end, 0, &cached_state); 7511 ordered = btrfs_lookup_ordered_extent(inode, page_offset(page)); 7512 if (ordered) { 7513 /* 7514 * IO on this page will never be started, so we need 7515 * to account for any ordered extents now 7516 */ 7517 clear_extent_bit(tree, page_start, page_end, 7518 EXTENT_DIRTY | EXTENT_DELALLOC | 7519 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING | 7520 EXTENT_DEFRAG, 1, 0, &cached_state, GFP_NOFS); 7521 /* 7522 * whoever cleared the private bit is responsible 7523 * for the finish_ordered_io 7524 */ 7525 if (TestClearPagePrivate2(page) && 7526 btrfs_dec_test_ordered_pending(inode, &ordered, page_start, 7527 PAGE_CACHE_SIZE, 1)) { 7528 btrfs_finish_ordered_io(ordered); 7529 } 7530 btrfs_put_ordered_extent(ordered); 7531 cached_state = NULL; 7532 lock_extent_bits(tree, page_start, page_end, 0, &cached_state); 7533 } 7534 clear_extent_bit(tree, page_start, page_end, 7535 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC | 7536 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 1, 1, 7537 &cached_state, GFP_NOFS); 7538 __btrfs_releasepage(page, GFP_NOFS); 7539 7540 ClearPageChecked(page); 7541 if (PagePrivate(page)) { 7542 ClearPagePrivate(page); 7543 set_page_private(page, 0); 7544 page_cache_release(page); 7545 } 7546 } 7547 7548 /* 7549 * btrfs_page_mkwrite() is not allowed to change the file size as it gets 7550 * called from a page fault handler when a page is first dirtied. Hence we must 7551 * be careful to check for EOF conditions here. We set the page up correctly 7552 * for a written page which means we get ENOSPC checking when writing into 7553 * holes and correct delalloc and unwritten extent mapping on filesystems that 7554 * support these features. 7555 * 7556 * We are not allowed to take the i_mutex here so we have to play games to 7557 * protect against truncate races as the page could now be beyond EOF. Because 7558 * vmtruncate() writes the inode size before removing pages, once we have the 7559 * page lock we can determine safely if the page is beyond EOF. If it is not 7560 * beyond EOF, then the page is guaranteed safe against truncation until we 7561 * unlock the page. 7562 */ 7563 int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) 7564 { 7565 struct page *page = vmf->page; 7566 struct inode *inode = file_inode(vma->vm_file); 7567 struct btrfs_root *root = BTRFS_I(inode)->root; 7568 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 7569 struct btrfs_ordered_extent *ordered; 7570 struct extent_state *cached_state = NULL; 7571 char *kaddr; 7572 unsigned long zero_start; 7573 loff_t size; 7574 int ret; 7575 int reserved = 0; 7576 u64 page_start; 7577 u64 page_end; 7578 7579 sb_start_pagefault(inode->i_sb); 7580 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE); 7581 if (!ret) { 7582 ret = file_update_time(vma->vm_file); 7583 reserved = 1; 7584 } 7585 if (ret) { 7586 if (ret == -ENOMEM) 7587 ret = VM_FAULT_OOM; 7588 else /* -ENOSPC, -EIO, etc */ 7589 ret = VM_FAULT_SIGBUS; 7590 if (reserved) 7591 goto out; 7592 goto out_noreserve; 7593 } 7594 7595 ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */ 7596 again: 7597 lock_page(page); 7598 size = i_size_read(inode); 7599 page_start = page_offset(page); 7600 page_end = page_start + PAGE_CACHE_SIZE - 1; 7601 7602 if ((page->mapping != inode->i_mapping) || 7603 (page_start >= size)) { 7604 /* page got truncated out from underneath us */ 7605 goto out_unlock; 7606 } 7607 wait_on_page_writeback(page); 7608 7609 lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state); 7610 set_page_extent_mapped(page); 7611 7612 /* 7613 * we can't set the delalloc bits if there are pending ordered 7614 * extents. Drop our locks and wait for them to finish 7615 */ 7616 ordered = btrfs_lookup_ordered_extent(inode, page_start); 7617 if (ordered) { 7618 unlock_extent_cached(io_tree, page_start, page_end, 7619 &cached_state, GFP_NOFS); 7620 unlock_page(page); 7621 btrfs_start_ordered_extent(inode, ordered, 1); 7622 btrfs_put_ordered_extent(ordered); 7623 goto again; 7624 } 7625 7626 /* 7627 * XXX - page_mkwrite gets called every time the page is dirtied, even 7628 * if it was already dirty, so for space accounting reasons we need to 7629 * clear any delalloc bits for the range we are fixing to save. There 7630 * is probably a better way to do this, but for now keep consistent with 7631 * prepare_pages in the normal write path. 7632 */ 7633 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end, 7634 EXTENT_DIRTY | EXTENT_DELALLOC | 7635 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 7636 0, 0, &cached_state, GFP_NOFS); 7637 7638 ret = btrfs_set_extent_delalloc(inode, page_start, page_end, 7639 &cached_state); 7640 if (ret) { 7641 unlock_extent_cached(io_tree, page_start, page_end, 7642 &cached_state, GFP_NOFS); 7643 ret = VM_FAULT_SIGBUS; 7644 goto out_unlock; 7645 } 7646 ret = 0; 7647 7648 /* page is wholly or partially inside EOF */ 7649 if (page_start + PAGE_CACHE_SIZE > size) 7650 zero_start = size & ~PAGE_CACHE_MASK; 7651 else 7652 zero_start = PAGE_CACHE_SIZE; 7653 7654 if (zero_start != PAGE_CACHE_SIZE) { 7655 kaddr = kmap(page); 7656 memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start); 7657 flush_dcache_page(page); 7658 kunmap(page); 7659 } 7660 ClearPageChecked(page); 7661 set_page_dirty(page); 7662 SetPageUptodate(page); 7663 7664 BTRFS_I(inode)->last_trans = root->fs_info->generation; 7665 BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid; 7666 BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit; 7667 7668 unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS); 7669 7670 out_unlock: 7671 if (!ret) { 7672 sb_end_pagefault(inode->i_sb); 7673 return VM_FAULT_LOCKED; 7674 } 7675 unlock_page(page); 7676 out: 7677 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE); 7678 out_noreserve: 7679 sb_end_pagefault(inode->i_sb); 7680 return ret; 7681 } 7682 7683 static int btrfs_truncate(struct inode *inode) 7684 { 7685 struct btrfs_root *root = BTRFS_I(inode)->root; 7686 struct btrfs_block_rsv *rsv; 7687 int ret; 7688 int err = 0; 7689 struct btrfs_trans_handle *trans; 7690 u64 mask = root->sectorsize - 1; 7691 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1); 7692 7693 ret = btrfs_truncate_page(inode, inode->i_size, 0, 0); 7694 if (ret) 7695 return ret; 7696 7697 btrfs_wait_ordered_range(inode, inode->i_size & (~mask), (u64)-1); 7698 btrfs_ordered_update_i_size(inode, inode->i_size, NULL); 7699 7700 /* 7701 * Yes ladies and gentelment, this is indeed ugly. The fact is we have 7702 * 3 things going on here 7703 * 7704 * 1) We need to reserve space for our orphan item and the space to 7705 * delete our orphan item. Lord knows we don't want to have a dangling 7706 * orphan item because we didn't reserve space to remove it. 7707 * 7708 * 2) We need to reserve space to update our inode. 7709 * 7710 * 3) We need to have something to cache all the space that is going to 7711 * be free'd up by the truncate operation, but also have some slack 7712 * space reserved in case it uses space during the truncate (thank you 7713 * very much snapshotting). 7714 * 7715 * And we need these to all be seperate. The fact is we can use alot of 7716 * space doing the truncate, and we have no earthly idea how much space 7717 * we will use, so we need the truncate reservation to be seperate so it 7718 * doesn't end up using space reserved for updating the inode or 7719 * removing the orphan item. We also need to be able to stop the 7720 * transaction and start a new one, which means we need to be able to 7721 * update the inode several times, and we have no idea of knowing how 7722 * many times that will be, so we can't just reserve 1 item for the 7723 * entirety of the opration, so that has to be done seperately as well. 7724 * Then there is the orphan item, which does indeed need to be held on 7725 * to for the whole operation, and we need nobody to touch this reserved 7726 * space except the orphan code. 7727 * 7728 * So that leaves us with 7729 * 7730 * 1) root->orphan_block_rsv - for the orphan deletion. 7731 * 2) rsv - for the truncate reservation, which we will steal from the 7732 * transaction reservation. 7733 * 3) fs_info->trans_block_rsv - this will have 1 items worth left for 7734 * updating the inode. 7735 */ 7736 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP); 7737 if (!rsv) 7738 return -ENOMEM; 7739 rsv->size = min_size; 7740 rsv->failfast = 1; 7741 7742 /* 7743 * 1 for the truncate slack space 7744 * 1 for updating the inode. 7745 */ 7746 trans = btrfs_start_transaction(root, 2); 7747 if (IS_ERR(trans)) { 7748 err = PTR_ERR(trans); 7749 goto out; 7750 } 7751 7752 /* Migrate the slack space for the truncate to our reserve */ 7753 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, rsv, 7754 min_size); 7755 BUG_ON(ret); 7756 7757 /* 7758 * setattr is responsible for setting the ordered_data_close flag, 7759 * but that is only tested during the last file release. That 7760 * could happen well after the next commit, leaving a great big 7761 * window where new writes may get lost if someone chooses to write 7762 * to this file after truncating to zero 7763 * 7764 * The inode doesn't have any dirty data here, and so if we commit 7765 * this is a noop. If someone immediately starts writing to the inode 7766 * it is very likely we'll catch some of their writes in this 7767 * transaction, and the commit will find this file on the ordered 7768 * data list with good things to send down. 7769 * 7770 * This is a best effort solution, there is still a window where 7771 * using truncate to replace the contents of the file will 7772 * end up with a zero length file after a crash. 7773 */ 7774 if (inode->i_size == 0 && test_bit(BTRFS_INODE_ORDERED_DATA_CLOSE, 7775 &BTRFS_I(inode)->runtime_flags)) 7776 btrfs_add_ordered_operation(trans, root, inode); 7777 7778 /* 7779 * So if we truncate and then write and fsync we normally would just 7780 * write the extents that changed, which is a problem if we need to 7781 * first truncate that entire inode. So set this flag so we write out 7782 * all of the extents in the inode to the sync log so we're completely 7783 * safe. 7784 */ 7785 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags); 7786 trans->block_rsv = rsv; 7787 7788 while (1) { 7789 ret = btrfs_truncate_inode_items(trans, root, inode, 7790 inode->i_size, 7791 BTRFS_EXTENT_DATA_KEY); 7792 if (ret != -ENOSPC) { 7793 err = ret; 7794 break; 7795 } 7796 7797 trans->block_rsv = &root->fs_info->trans_block_rsv; 7798 ret = btrfs_update_inode(trans, root, inode); 7799 if (ret) { 7800 err = ret; 7801 break; 7802 } 7803 7804 btrfs_end_transaction(trans, root); 7805 btrfs_btree_balance_dirty(root); 7806 7807 trans = btrfs_start_transaction(root, 2); 7808 if (IS_ERR(trans)) { 7809 ret = err = PTR_ERR(trans); 7810 trans = NULL; 7811 break; 7812 } 7813 7814 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, 7815 rsv, min_size); 7816 BUG_ON(ret); /* shouldn't happen */ 7817 trans->block_rsv = rsv; 7818 } 7819 7820 if (ret == 0 && inode->i_nlink > 0) { 7821 trans->block_rsv = root->orphan_block_rsv; 7822 ret = btrfs_orphan_del(trans, inode); 7823 if (ret) 7824 err = ret; 7825 } 7826 7827 if (trans) { 7828 trans->block_rsv = &root->fs_info->trans_block_rsv; 7829 ret = btrfs_update_inode(trans, root, inode); 7830 if (ret && !err) 7831 err = ret; 7832 7833 ret = btrfs_end_transaction(trans, root); 7834 btrfs_btree_balance_dirty(root); 7835 } 7836 7837 out: 7838 btrfs_free_block_rsv(root, rsv); 7839 7840 if (ret && !err) 7841 err = ret; 7842 7843 return err; 7844 } 7845 7846 /* 7847 * create a new subvolume directory/inode (helper for the ioctl). 7848 */ 7849 int btrfs_create_subvol_root(struct btrfs_trans_handle *trans, 7850 struct btrfs_root *new_root, u64 new_dirid) 7851 { 7852 struct inode *inode; 7853 int err; 7854 u64 index = 0; 7855 7856 inode = btrfs_new_inode(trans, new_root, NULL, "..", 2, 7857 new_dirid, new_dirid, 7858 S_IFDIR | (~current_umask() & S_IRWXUGO), 7859 &index); 7860 if (IS_ERR(inode)) 7861 return PTR_ERR(inode); 7862 inode->i_op = &btrfs_dir_inode_operations; 7863 inode->i_fop = &btrfs_dir_file_operations; 7864 7865 set_nlink(inode, 1); 7866 btrfs_i_size_write(inode, 0); 7867 7868 err = btrfs_update_inode(trans, new_root, inode); 7869 7870 iput(inode); 7871 return err; 7872 } 7873 7874 struct inode *btrfs_alloc_inode(struct super_block *sb) 7875 { 7876 struct btrfs_inode *ei; 7877 struct inode *inode; 7878 7879 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS); 7880 if (!ei) 7881 return NULL; 7882 7883 ei->root = NULL; 7884 ei->generation = 0; 7885 ei->last_trans = 0; 7886 ei->last_sub_trans = 0; 7887 ei->logged_trans = 0; 7888 ei->delalloc_bytes = 0; 7889 ei->disk_i_size = 0; 7890 ei->flags = 0; 7891 ei->csum_bytes = 0; 7892 ei->index_cnt = (u64)-1; 7893 ei->last_unlink_trans = 0; 7894 ei->last_log_commit = 0; 7895 7896 spin_lock_init(&ei->lock); 7897 ei->outstanding_extents = 0; 7898 ei->reserved_extents = 0; 7899 7900 ei->runtime_flags = 0; 7901 ei->force_compress = BTRFS_COMPRESS_NONE; 7902 7903 ei->delayed_node = NULL; 7904 7905 inode = &ei->vfs_inode; 7906 extent_map_tree_init(&ei->extent_tree); 7907 extent_io_tree_init(&ei->io_tree, &inode->i_data); 7908 extent_io_tree_init(&ei->io_failure_tree, &inode->i_data); 7909 ei->io_tree.track_uptodate = 1; 7910 ei->io_failure_tree.track_uptodate = 1; 7911 atomic_set(&ei->sync_writers, 0); 7912 mutex_init(&ei->log_mutex); 7913 mutex_init(&ei->delalloc_mutex); 7914 btrfs_ordered_inode_tree_init(&ei->ordered_tree); 7915 INIT_LIST_HEAD(&ei->delalloc_inodes); 7916 INIT_LIST_HEAD(&ei->ordered_operations); 7917 RB_CLEAR_NODE(&ei->rb_node); 7918 7919 return inode; 7920 } 7921 7922 static void btrfs_i_callback(struct rcu_head *head) 7923 { 7924 struct inode *inode = container_of(head, struct inode, i_rcu); 7925 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode)); 7926 } 7927 7928 void btrfs_destroy_inode(struct inode *inode) 7929 { 7930 struct btrfs_ordered_extent *ordered; 7931 struct btrfs_root *root = BTRFS_I(inode)->root; 7932 7933 WARN_ON(!hlist_empty(&inode->i_dentry)); 7934 WARN_ON(inode->i_data.nrpages); 7935 WARN_ON(BTRFS_I(inode)->outstanding_extents); 7936 WARN_ON(BTRFS_I(inode)->reserved_extents); 7937 WARN_ON(BTRFS_I(inode)->delalloc_bytes); 7938 WARN_ON(BTRFS_I(inode)->csum_bytes); 7939 7940 /* 7941 * This can happen where we create an inode, but somebody else also 7942 * created the same inode and we need to destroy the one we already 7943 * created. 7944 */ 7945 if (!root) 7946 goto free; 7947 7948 /* 7949 * Make sure we're properly removed from the ordered operation 7950 * lists. 7951 */ 7952 smp_mb(); 7953 if (!list_empty(&BTRFS_I(inode)->ordered_operations)) { 7954 spin_lock(&root->fs_info->ordered_extent_lock); 7955 list_del_init(&BTRFS_I(inode)->ordered_operations); 7956 spin_unlock(&root->fs_info->ordered_extent_lock); 7957 } 7958 7959 if (test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM, 7960 &BTRFS_I(inode)->runtime_flags)) { 7961 btrfs_info(root->fs_info, "inode %llu still on the orphan list", 7962 (unsigned long long)btrfs_ino(inode)); 7963 atomic_dec(&root->orphan_inodes); 7964 } 7965 7966 while (1) { 7967 ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1); 7968 if (!ordered) 7969 break; 7970 else { 7971 btrfs_err(root->fs_info, "found ordered extent %llu %llu on inode cleanup", 7972 (unsigned long long)ordered->file_offset, 7973 (unsigned long long)ordered->len); 7974 btrfs_remove_ordered_extent(inode, ordered); 7975 btrfs_put_ordered_extent(ordered); 7976 btrfs_put_ordered_extent(ordered); 7977 } 7978 } 7979 inode_tree_del(inode); 7980 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0); 7981 free: 7982 btrfs_remove_delayed_node(inode); 7983 call_rcu(&inode->i_rcu, btrfs_i_callback); 7984 } 7985 7986 int btrfs_drop_inode(struct inode *inode) 7987 { 7988 struct btrfs_root *root = BTRFS_I(inode)->root; 7989 7990 /* the snap/subvol tree is on deleting */ 7991 if (btrfs_root_refs(&root->root_item) == 0 && 7992 root != root->fs_info->tree_root) 7993 return 1; 7994 else 7995 return generic_drop_inode(inode); 7996 } 7997 7998 static void init_once(void *foo) 7999 { 8000 struct btrfs_inode *ei = (struct btrfs_inode *) foo; 8001 8002 inode_init_once(&ei->vfs_inode); 8003 } 8004 8005 void btrfs_destroy_cachep(void) 8006 { 8007 /* 8008 * Make sure all delayed rcu free inodes are flushed before we 8009 * destroy cache. 8010 */ 8011 rcu_barrier(); 8012 if (btrfs_inode_cachep) 8013 kmem_cache_destroy(btrfs_inode_cachep); 8014 if (btrfs_trans_handle_cachep) 8015 kmem_cache_destroy(btrfs_trans_handle_cachep); 8016 if (btrfs_transaction_cachep) 8017 kmem_cache_destroy(btrfs_transaction_cachep); 8018 if (btrfs_path_cachep) 8019 kmem_cache_destroy(btrfs_path_cachep); 8020 if (btrfs_free_space_cachep) 8021 kmem_cache_destroy(btrfs_free_space_cachep); 8022 if (btrfs_delalloc_work_cachep) 8023 kmem_cache_destroy(btrfs_delalloc_work_cachep); 8024 } 8025 8026 int btrfs_init_cachep(void) 8027 { 8028 btrfs_inode_cachep = kmem_cache_create("btrfs_inode", 8029 sizeof(struct btrfs_inode), 0, 8030 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, init_once); 8031 if (!btrfs_inode_cachep) 8032 goto fail; 8033 8034 btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle", 8035 sizeof(struct btrfs_trans_handle), 0, 8036 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL); 8037 if (!btrfs_trans_handle_cachep) 8038 goto fail; 8039 8040 btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction", 8041 sizeof(struct btrfs_transaction), 0, 8042 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL); 8043 if (!btrfs_transaction_cachep) 8044 goto fail; 8045 8046 btrfs_path_cachep = kmem_cache_create("btrfs_path", 8047 sizeof(struct btrfs_path), 0, 8048 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL); 8049 if (!btrfs_path_cachep) 8050 goto fail; 8051 8052 btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space", 8053 sizeof(struct btrfs_free_space), 0, 8054 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL); 8055 if (!btrfs_free_space_cachep) 8056 goto fail; 8057 8058 btrfs_delalloc_work_cachep = kmem_cache_create("btrfs_delalloc_work", 8059 sizeof(struct btrfs_delalloc_work), 0, 8060 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, 8061 NULL); 8062 if (!btrfs_delalloc_work_cachep) 8063 goto fail; 8064 8065 return 0; 8066 fail: 8067 btrfs_destroy_cachep(); 8068 return -ENOMEM; 8069 } 8070 8071 static int btrfs_getattr(struct vfsmount *mnt, 8072 struct dentry *dentry, struct kstat *stat) 8073 { 8074 u64 delalloc_bytes; 8075 struct inode *inode = dentry->d_inode; 8076 u32 blocksize = inode->i_sb->s_blocksize; 8077 8078 generic_fillattr(inode, stat); 8079 stat->dev = BTRFS_I(inode)->root->anon_dev; 8080 stat->blksize = PAGE_CACHE_SIZE; 8081 8082 spin_lock(&BTRFS_I(inode)->lock); 8083 delalloc_bytes = BTRFS_I(inode)->delalloc_bytes; 8084 spin_unlock(&BTRFS_I(inode)->lock); 8085 stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) + 8086 ALIGN(delalloc_bytes, blocksize)) >> 9; 8087 return 0; 8088 } 8089 8090 static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry, 8091 struct inode *new_dir, struct dentry *new_dentry) 8092 { 8093 struct btrfs_trans_handle *trans; 8094 struct btrfs_root *root = BTRFS_I(old_dir)->root; 8095 struct btrfs_root *dest = BTRFS_I(new_dir)->root; 8096 struct inode *new_inode = new_dentry->d_inode; 8097 struct inode *old_inode = old_dentry->d_inode; 8098 struct timespec ctime = CURRENT_TIME; 8099 u64 index = 0; 8100 u64 root_objectid; 8101 int ret; 8102 u64 old_ino = btrfs_ino(old_inode); 8103 8104 if (btrfs_ino(new_dir) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID) 8105 return -EPERM; 8106 8107 /* we only allow rename subvolume link between subvolumes */ 8108 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest) 8109 return -EXDEV; 8110 8111 if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID || 8112 (new_inode && btrfs_ino(new_inode) == BTRFS_FIRST_FREE_OBJECTID)) 8113 return -ENOTEMPTY; 8114 8115 if (S_ISDIR(old_inode->i_mode) && new_inode && 8116 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE) 8117 return -ENOTEMPTY; 8118 8119 8120 /* check for collisions, even if the name isn't there */ 8121 ret = btrfs_check_dir_item_collision(root, new_dir->i_ino, 8122 new_dentry->d_name.name, 8123 new_dentry->d_name.len); 8124 8125 if (ret) { 8126 if (ret == -EEXIST) { 8127 /* we shouldn't get 8128 * eexist without a new_inode */ 8129 if (!new_inode) { 8130 WARN_ON(1); 8131 return ret; 8132 } 8133 } else { 8134 /* maybe -EOVERFLOW */ 8135 return ret; 8136 } 8137 } 8138 ret = 0; 8139 8140 /* 8141 * we're using rename to replace one file with another. 8142 * and the replacement file is large. Start IO on it now so 8143 * we don't add too much work to the end of the transaction 8144 */ 8145 if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size && 8146 old_inode->i_size > BTRFS_ORDERED_OPERATIONS_FLUSH_LIMIT) 8147 filemap_flush(old_inode->i_mapping); 8148 8149 /* close the racy window with snapshot create/destroy ioctl */ 8150 if (old_ino == BTRFS_FIRST_FREE_OBJECTID) 8151 down_read(&root->fs_info->subvol_sem); 8152 /* 8153 * We want to reserve the absolute worst case amount of items. So if 8154 * both inodes are subvols and we need to unlink them then that would 8155 * require 4 item modifications, but if they are both normal inodes it 8156 * would require 5 item modifications, so we'll assume their normal 8157 * inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items 8158 * should cover the worst case number of items we'll modify. 8159 */ 8160 trans = btrfs_start_transaction(root, 11); 8161 if (IS_ERR(trans)) { 8162 ret = PTR_ERR(trans); 8163 goto out_notrans; 8164 } 8165 8166 if (dest != root) 8167 btrfs_record_root_in_trans(trans, dest); 8168 8169 ret = btrfs_set_inode_index(new_dir, &index); 8170 if (ret) 8171 goto out_fail; 8172 8173 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) { 8174 /* force full log commit if subvolume involved. */ 8175 root->fs_info->last_trans_log_full_commit = trans->transid; 8176 } else { 8177 ret = btrfs_insert_inode_ref(trans, dest, 8178 new_dentry->d_name.name, 8179 new_dentry->d_name.len, 8180 old_ino, 8181 btrfs_ino(new_dir), index); 8182 if (ret) 8183 goto out_fail; 8184 /* 8185 * this is an ugly little race, but the rename is required 8186 * to make sure that if we crash, the inode is either at the 8187 * old name or the new one. pinning the log transaction lets 8188 * us make sure we don't allow a log commit to come in after 8189 * we unlink the name but before we add the new name back in. 8190 */ 8191 btrfs_pin_log_trans(root); 8192 } 8193 /* 8194 * make sure the inode gets flushed if it is replacing 8195 * something. 8196 */ 8197 if (new_inode && new_inode->i_size && S_ISREG(old_inode->i_mode)) 8198 btrfs_add_ordered_operation(trans, root, old_inode); 8199 8200 inode_inc_iversion(old_dir); 8201 inode_inc_iversion(new_dir); 8202 inode_inc_iversion(old_inode); 8203 old_dir->i_ctime = old_dir->i_mtime = ctime; 8204 new_dir->i_ctime = new_dir->i_mtime = ctime; 8205 old_inode->i_ctime = ctime; 8206 8207 if (old_dentry->d_parent != new_dentry->d_parent) 8208 btrfs_record_unlink_dir(trans, old_dir, old_inode, 1); 8209 8210 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) { 8211 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid; 8212 ret = btrfs_unlink_subvol(trans, root, old_dir, root_objectid, 8213 old_dentry->d_name.name, 8214 old_dentry->d_name.len); 8215 } else { 8216 ret = __btrfs_unlink_inode(trans, root, old_dir, 8217 old_dentry->d_inode, 8218 old_dentry->d_name.name, 8219 old_dentry->d_name.len); 8220 if (!ret) 8221 ret = btrfs_update_inode(trans, root, old_inode); 8222 } 8223 if (ret) { 8224 btrfs_abort_transaction(trans, root, ret); 8225 goto out_fail; 8226 } 8227 8228 if (new_inode) { 8229 inode_inc_iversion(new_inode); 8230 new_inode->i_ctime = CURRENT_TIME; 8231 if (unlikely(btrfs_ino(new_inode) == 8232 BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) { 8233 root_objectid = BTRFS_I(new_inode)->location.objectid; 8234 ret = btrfs_unlink_subvol(trans, dest, new_dir, 8235 root_objectid, 8236 new_dentry->d_name.name, 8237 new_dentry->d_name.len); 8238 BUG_ON(new_inode->i_nlink == 0); 8239 } else { 8240 ret = btrfs_unlink_inode(trans, dest, new_dir, 8241 new_dentry->d_inode, 8242 new_dentry->d_name.name, 8243 new_dentry->d_name.len); 8244 } 8245 if (!ret && new_inode->i_nlink == 0) { 8246 ret = btrfs_orphan_add(trans, new_dentry->d_inode); 8247 BUG_ON(ret); 8248 } 8249 if (ret) { 8250 btrfs_abort_transaction(trans, root, ret); 8251 goto out_fail; 8252 } 8253 } 8254 8255 ret = btrfs_add_link(trans, new_dir, old_inode, 8256 new_dentry->d_name.name, 8257 new_dentry->d_name.len, 0, index); 8258 if (ret) { 8259 btrfs_abort_transaction(trans, root, ret); 8260 goto out_fail; 8261 } 8262 8263 if (old_ino != BTRFS_FIRST_FREE_OBJECTID) { 8264 struct dentry *parent = new_dentry->d_parent; 8265 btrfs_log_new_name(trans, old_inode, old_dir, parent); 8266 btrfs_end_log_trans(root); 8267 } 8268 out_fail: 8269 btrfs_end_transaction(trans, root); 8270 out_notrans: 8271 if (old_ino == BTRFS_FIRST_FREE_OBJECTID) 8272 up_read(&root->fs_info->subvol_sem); 8273 8274 return ret; 8275 } 8276 8277 static void btrfs_run_delalloc_work(struct btrfs_work *work) 8278 { 8279 struct btrfs_delalloc_work *delalloc_work; 8280 8281 delalloc_work = container_of(work, struct btrfs_delalloc_work, 8282 work); 8283 if (delalloc_work->wait) 8284 btrfs_wait_ordered_range(delalloc_work->inode, 0, (u64)-1); 8285 else 8286 filemap_flush(delalloc_work->inode->i_mapping); 8287 8288 if (delalloc_work->delay_iput) 8289 btrfs_add_delayed_iput(delalloc_work->inode); 8290 else 8291 iput(delalloc_work->inode); 8292 complete(&delalloc_work->completion); 8293 } 8294 8295 struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode, 8296 int wait, int delay_iput) 8297 { 8298 struct btrfs_delalloc_work *work; 8299 8300 work = kmem_cache_zalloc(btrfs_delalloc_work_cachep, GFP_NOFS); 8301 if (!work) 8302 return NULL; 8303 8304 init_completion(&work->completion); 8305 INIT_LIST_HEAD(&work->list); 8306 work->inode = inode; 8307 work->wait = wait; 8308 work->delay_iput = delay_iput; 8309 work->work.func = btrfs_run_delalloc_work; 8310 8311 return work; 8312 } 8313 8314 void btrfs_wait_and_free_delalloc_work(struct btrfs_delalloc_work *work) 8315 { 8316 wait_for_completion(&work->completion); 8317 kmem_cache_free(btrfs_delalloc_work_cachep, work); 8318 } 8319 8320 /* 8321 * some fairly slow code that needs optimization. This walks the list 8322 * of all the inodes with pending delalloc and forces them to disk. 8323 */ 8324 int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput) 8325 { 8326 struct btrfs_inode *binode; 8327 struct inode *inode; 8328 struct btrfs_delalloc_work *work, *next; 8329 struct list_head works; 8330 struct list_head splice; 8331 int ret = 0; 8332 8333 if (root->fs_info->sb->s_flags & MS_RDONLY) 8334 return -EROFS; 8335 8336 INIT_LIST_HEAD(&works); 8337 INIT_LIST_HEAD(&splice); 8338 8339 spin_lock(&root->fs_info->delalloc_lock); 8340 list_splice_init(&root->fs_info->delalloc_inodes, &splice); 8341 while (!list_empty(&splice)) { 8342 binode = list_entry(splice.next, struct btrfs_inode, 8343 delalloc_inodes); 8344 8345 list_del_init(&binode->delalloc_inodes); 8346 8347 inode = igrab(&binode->vfs_inode); 8348 if (!inode) { 8349 clear_bit(BTRFS_INODE_IN_DELALLOC_LIST, 8350 &binode->runtime_flags); 8351 continue; 8352 } 8353 8354 list_add_tail(&binode->delalloc_inodes, 8355 &root->fs_info->delalloc_inodes); 8356 spin_unlock(&root->fs_info->delalloc_lock); 8357 8358 work = btrfs_alloc_delalloc_work(inode, 0, delay_iput); 8359 if (unlikely(!work)) { 8360 ret = -ENOMEM; 8361 goto out; 8362 } 8363 list_add_tail(&work->list, &works); 8364 btrfs_queue_worker(&root->fs_info->flush_workers, 8365 &work->work); 8366 8367 cond_resched(); 8368 spin_lock(&root->fs_info->delalloc_lock); 8369 } 8370 spin_unlock(&root->fs_info->delalloc_lock); 8371 8372 list_for_each_entry_safe(work, next, &works, list) { 8373 list_del_init(&work->list); 8374 btrfs_wait_and_free_delalloc_work(work); 8375 } 8376 8377 /* the filemap_flush will queue IO into the worker threads, but 8378 * we have to make sure the IO is actually started and that 8379 * ordered extents get created before we return 8380 */ 8381 atomic_inc(&root->fs_info->async_submit_draining); 8382 while (atomic_read(&root->fs_info->nr_async_submits) || 8383 atomic_read(&root->fs_info->async_delalloc_pages)) { 8384 wait_event(root->fs_info->async_submit_wait, 8385 (atomic_read(&root->fs_info->nr_async_submits) == 0 && 8386 atomic_read(&root->fs_info->async_delalloc_pages) == 0)); 8387 } 8388 atomic_dec(&root->fs_info->async_submit_draining); 8389 return 0; 8390 out: 8391 list_for_each_entry_safe(work, next, &works, list) { 8392 list_del_init(&work->list); 8393 btrfs_wait_and_free_delalloc_work(work); 8394 } 8395 8396 if (!list_empty_careful(&splice)) { 8397 spin_lock(&root->fs_info->delalloc_lock); 8398 list_splice_tail(&splice, &root->fs_info->delalloc_inodes); 8399 spin_unlock(&root->fs_info->delalloc_lock); 8400 } 8401 return ret; 8402 } 8403 8404 static int btrfs_symlink(struct inode *dir, struct dentry *dentry, 8405 const char *symname) 8406 { 8407 struct btrfs_trans_handle *trans; 8408 struct btrfs_root *root = BTRFS_I(dir)->root; 8409 struct btrfs_path *path; 8410 struct btrfs_key key; 8411 struct inode *inode = NULL; 8412 int err; 8413 int drop_inode = 0; 8414 u64 objectid; 8415 u64 index = 0 ; 8416 int name_len; 8417 int datasize; 8418 unsigned long ptr; 8419 struct btrfs_file_extent_item *ei; 8420 struct extent_buffer *leaf; 8421 8422 name_len = strlen(symname) + 1; 8423 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root)) 8424 return -ENAMETOOLONG; 8425 8426 /* 8427 * 2 items for inode item and ref 8428 * 2 items for dir items 8429 * 1 item for xattr if selinux is on 8430 */ 8431 trans = btrfs_start_transaction(root, 5); 8432 if (IS_ERR(trans)) 8433 return PTR_ERR(trans); 8434 8435 err = btrfs_find_free_ino(root, &objectid); 8436 if (err) 8437 goto out_unlock; 8438 8439 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name, 8440 dentry->d_name.len, btrfs_ino(dir), objectid, 8441 S_IFLNK|S_IRWXUGO, &index); 8442 if (IS_ERR(inode)) { 8443 err = PTR_ERR(inode); 8444 goto out_unlock; 8445 } 8446 8447 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name); 8448 if (err) { 8449 drop_inode = 1; 8450 goto out_unlock; 8451 } 8452 8453 /* 8454 * If the active LSM wants to access the inode during 8455 * d_instantiate it needs these. Smack checks to see 8456 * if the filesystem supports xattrs by looking at the 8457 * ops vector. 8458 */ 8459 inode->i_fop = &btrfs_file_operations; 8460 inode->i_op = &btrfs_file_inode_operations; 8461 8462 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index); 8463 if (err) 8464 drop_inode = 1; 8465 else { 8466 inode->i_mapping->a_ops = &btrfs_aops; 8467 inode->i_mapping->backing_dev_info = &root->fs_info->bdi; 8468 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops; 8469 } 8470 if (drop_inode) 8471 goto out_unlock; 8472 8473 path = btrfs_alloc_path(); 8474 if (!path) { 8475 err = -ENOMEM; 8476 drop_inode = 1; 8477 goto out_unlock; 8478 } 8479 key.objectid = btrfs_ino(inode); 8480 key.offset = 0; 8481 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY); 8482 datasize = btrfs_file_extent_calc_inline_size(name_len); 8483 err = btrfs_insert_empty_item(trans, root, path, &key, 8484 datasize); 8485 if (err) { 8486 drop_inode = 1; 8487 btrfs_free_path(path); 8488 goto out_unlock; 8489 } 8490 leaf = path->nodes[0]; 8491 ei = btrfs_item_ptr(leaf, path->slots[0], 8492 struct btrfs_file_extent_item); 8493 btrfs_set_file_extent_generation(leaf, ei, trans->transid); 8494 btrfs_set_file_extent_type(leaf, ei, 8495 BTRFS_FILE_EXTENT_INLINE); 8496 btrfs_set_file_extent_encryption(leaf, ei, 0); 8497 btrfs_set_file_extent_compression(leaf, ei, 0); 8498 btrfs_set_file_extent_other_encoding(leaf, ei, 0); 8499 btrfs_set_file_extent_ram_bytes(leaf, ei, name_len); 8500 8501 ptr = btrfs_file_extent_inline_start(ei); 8502 write_extent_buffer(leaf, symname, ptr, name_len); 8503 btrfs_mark_buffer_dirty(leaf); 8504 btrfs_free_path(path); 8505 8506 inode->i_op = &btrfs_symlink_inode_operations; 8507 inode->i_mapping->a_ops = &btrfs_symlink_aops; 8508 inode->i_mapping->backing_dev_info = &root->fs_info->bdi; 8509 inode_set_bytes(inode, name_len); 8510 btrfs_i_size_write(inode, name_len - 1); 8511 err = btrfs_update_inode(trans, root, inode); 8512 if (err) 8513 drop_inode = 1; 8514 8515 out_unlock: 8516 if (!err) 8517 d_instantiate(dentry, inode); 8518 btrfs_end_transaction(trans, root); 8519 if (drop_inode) { 8520 inode_dec_link_count(inode); 8521 iput(inode); 8522 } 8523 btrfs_btree_balance_dirty(root); 8524 return err; 8525 } 8526 8527 static int __btrfs_prealloc_file_range(struct inode *inode, int mode, 8528 u64 start, u64 num_bytes, u64 min_size, 8529 loff_t actual_len, u64 *alloc_hint, 8530 struct btrfs_trans_handle *trans) 8531 { 8532 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; 8533 struct extent_map *em; 8534 struct btrfs_root *root = BTRFS_I(inode)->root; 8535 struct btrfs_key ins; 8536 u64 cur_offset = start; 8537 u64 i_size; 8538 u64 cur_bytes; 8539 int ret = 0; 8540 bool own_trans = true; 8541 8542 if (trans) 8543 own_trans = false; 8544 while (num_bytes > 0) { 8545 if (own_trans) { 8546 trans = btrfs_start_transaction(root, 3); 8547 if (IS_ERR(trans)) { 8548 ret = PTR_ERR(trans); 8549 break; 8550 } 8551 } 8552 8553 cur_bytes = min(num_bytes, 256ULL * 1024 * 1024); 8554 cur_bytes = max(cur_bytes, min_size); 8555 ret = btrfs_reserve_extent(trans, root, cur_bytes, 8556 min_size, 0, *alloc_hint, &ins, 1); 8557 if (ret) { 8558 if (own_trans) 8559 btrfs_end_transaction(trans, root); 8560 break; 8561 } 8562 8563 ret = insert_reserved_file_extent(trans, inode, 8564 cur_offset, ins.objectid, 8565 ins.offset, ins.offset, 8566 ins.offset, 0, 0, 0, 8567 BTRFS_FILE_EXTENT_PREALLOC); 8568 if (ret) { 8569 btrfs_abort_transaction(trans, root, ret); 8570 if (own_trans) 8571 btrfs_end_transaction(trans, root); 8572 break; 8573 } 8574 btrfs_drop_extent_cache(inode, cur_offset, 8575 cur_offset + ins.offset -1, 0); 8576 8577 em = alloc_extent_map(); 8578 if (!em) { 8579 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, 8580 &BTRFS_I(inode)->runtime_flags); 8581 goto next; 8582 } 8583 8584 em->start = cur_offset; 8585 em->orig_start = cur_offset; 8586 em->len = ins.offset; 8587 em->block_start = ins.objectid; 8588 em->block_len = ins.offset; 8589 em->orig_block_len = ins.offset; 8590 em->ram_bytes = ins.offset; 8591 em->bdev = root->fs_info->fs_devices->latest_bdev; 8592 set_bit(EXTENT_FLAG_PREALLOC, &em->flags); 8593 em->generation = trans->transid; 8594 8595 while (1) { 8596 write_lock(&em_tree->lock); 8597 ret = add_extent_mapping(em_tree, em, 1); 8598 write_unlock(&em_tree->lock); 8599 if (ret != -EEXIST) 8600 break; 8601 btrfs_drop_extent_cache(inode, cur_offset, 8602 cur_offset + ins.offset - 1, 8603 0); 8604 } 8605 free_extent_map(em); 8606 next: 8607 num_bytes -= ins.offset; 8608 cur_offset += ins.offset; 8609 *alloc_hint = ins.objectid + ins.offset; 8610 8611 inode_inc_iversion(inode); 8612 inode->i_ctime = CURRENT_TIME; 8613 BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC; 8614 if (!(mode & FALLOC_FL_KEEP_SIZE) && 8615 (actual_len > inode->i_size) && 8616 (cur_offset > inode->i_size)) { 8617 if (cur_offset > actual_len) 8618 i_size = actual_len; 8619 else 8620 i_size = cur_offset; 8621 i_size_write(inode, i_size); 8622 btrfs_ordered_update_i_size(inode, i_size, NULL); 8623 } 8624 8625 ret = btrfs_update_inode(trans, root, inode); 8626 8627 if (ret) { 8628 btrfs_abort_transaction(trans, root, ret); 8629 if (own_trans) 8630 btrfs_end_transaction(trans, root); 8631 break; 8632 } 8633 8634 if (own_trans) 8635 btrfs_end_transaction(trans, root); 8636 } 8637 return ret; 8638 } 8639 8640 int btrfs_prealloc_file_range(struct inode *inode, int mode, 8641 u64 start, u64 num_bytes, u64 min_size, 8642 loff_t actual_len, u64 *alloc_hint) 8643 { 8644 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes, 8645 min_size, actual_len, alloc_hint, 8646 NULL); 8647 } 8648 8649 int btrfs_prealloc_file_range_trans(struct inode *inode, 8650 struct btrfs_trans_handle *trans, int mode, 8651 u64 start, u64 num_bytes, u64 min_size, 8652 loff_t actual_len, u64 *alloc_hint) 8653 { 8654 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes, 8655 min_size, actual_len, alloc_hint, trans); 8656 } 8657 8658 static int btrfs_set_page_dirty(struct page *page) 8659 { 8660 return __set_page_dirty_nobuffers(page); 8661 } 8662 8663 static int btrfs_permission(struct inode *inode, int mask) 8664 { 8665 struct btrfs_root *root = BTRFS_I(inode)->root; 8666 umode_t mode = inode->i_mode; 8667 8668 if (mask & MAY_WRITE && 8669 (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) { 8670 if (btrfs_root_readonly(root)) 8671 return -EROFS; 8672 if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY) 8673 return -EACCES; 8674 } 8675 return generic_permission(inode, mask); 8676 } 8677 8678 static const struct inode_operations btrfs_dir_inode_operations = { 8679 .getattr = btrfs_getattr, 8680 .lookup = btrfs_lookup, 8681 .create = btrfs_create, 8682 .unlink = btrfs_unlink, 8683 .link = btrfs_link, 8684 .mkdir = btrfs_mkdir, 8685 .rmdir = btrfs_rmdir, 8686 .rename = btrfs_rename, 8687 .symlink = btrfs_symlink, 8688 .setattr = btrfs_setattr, 8689 .mknod = btrfs_mknod, 8690 .setxattr = btrfs_setxattr, 8691 .getxattr = btrfs_getxattr, 8692 .listxattr = btrfs_listxattr, 8693 .removexattr = btrfs_removexattr, 8694 .permission = btrfs_permission, 8695 .get_acl = btrfs_get_acl, 8696 }; 8697 static const struct inode_operations btrfs_dir_ro_inode_operations = { 8698 .lookup = btrfs_lookup, 8699 .permission = btrfs_permission, 8700 .get_acl = btrfs_get_acl, 8701 }; 8702 8703 static const struct file_operations btrfs_dir_file_operations = { 8704 .llseek = generic_file_llseek, 8705 .read = generic_read_dir, 8706 .readdir = btrfs_real_readdir, 8707 .unlocked_ioctl = btrfs_ioctl, 8708 #ifdef CONFIG_COMPAT 8709 .compat_ioctl = btrfs_ioctl, 8710 #endif 8711 .release = btrfs_release_file, 8712 .fsync = btrfs_sync_file, 8713 }; 8714 8715 static struct extent_io_ops btrfs_extent_io_ops = { 8716 .fill_delalloc = run_delalloc_range, 8717 .submit_bio_hook = btrfs_submit_bio_hook, 8718 .merge_bio_hook = btrfs_merge_bio_hook, 8719 .readpage_end_io_hook = btrfs_readpage_end_io_hook, 8720 .writepage_end_io_hook = btrfs_writepage_end_io_hook, 8721 .writepage_start_hook = btrfs_writepage_start_hook, 8722 .set_bit_hook = btrfs_set_bit_hook, 8723 .clear_bit_hook = btrfs_clear_bit_hook, 8724 .merge_extent_hook = btrfs_merge_extent_hook, 8725 .split_extent_hook = btrfs_split_extent_hook, 8726 }; 8727 8728 /* 8729 * btrfs doesn't support the bmap operation because swapfiles 8730 * use bmap to make a mapping of extents in the file. They assume 8731 * these extents won't change over the life of the file and they 8732 * use the bmap result to do IO directly to the drive. 8733 * 8734 * the btrfs bmap call would return logical addresses that aren't 8735 * suitable for IO and they also will change frequently as COW 8736 * operations happen. So, swapfile + btrfs == corruption. 8737 * 8738 * For now we're avoiding this by dropping bmap. 8739 */ 8740 static const struct address_space_operations btrfs_aops = { 8741 .readpage = btrfs_readpage, 8742 .writepage = btrfs_writepage, 8743 .writepages = btrfs_writepages, 8744 .readpages = btrfs_readpages, 8745 .direct_IO = btrfs_direct_IO, 8746 .invalidatepage = btrfs_invalidatepage, 8747 .releasepage = btrfs_releasepage, 8748 .set_page_dirty = btrfs_set_page_dirty, 8749 .error_remove_page = generic_error_remove_page, 8750 }; 8751 8752 static const struct address_space_operations btrfs_symlink_aops = { 8753 .readpage = btrfs_readpage, 8754 .writepage = btrfs_writepage, 8755 .invalidatepage = btrfs_invalidatepage, 8756 .releasepage = btrfs_releasepage, 8757 }; 8758 8759 static const struct inode_operations btrfs_file_inode_operations = { 8760 .getattr = btrfs_getattr, 8761 .setattr = btrfs_setattr, 8762 .setxattr = btrfs_setxattr, 8763 .getxattr = btrfs_getxattr, 8764 .listxattr = btrfs_listxattr, 8765 .removexattr = btrfs_removexattr, 8766 .permission = btrfs_permission, 8767 .fiemap = btrfs_fiemap, 8768 .get_acl = btrfs_get_acl, 8769 .update_time = btrfs_update_time, 8770 }; 8771 static const struct inode_operations btrfs_special_inode_operations = { 8772 .getattr = btrfs_getattr, 8773 .setattr = btrfs_setattr, 8774 .permission = btrfs_permission, 8775 .setxattr = btrfs_setxattr, 8776 .getxattr = btrfs_getxattr, 8777 .listxattr = btrfs_listxattr, 8778 .removexattr = btrfs_removexattr, 8779 .get_acl = btrfs_get_acl, 8780 .update_time = btrfs_update_time, 8781 }; 8782 static const struct inode_operations btrfs_symlink_inode_operations = { 8783 .readlink = generic_readlink, 8784 .follow_link = page_follow_link_light, 8785 .put_link = page_put_link, 8786 .getattr = btrfs_getattr, 8787 .setattr = btrfs_setattr, 8788 .permission = btrfs_permission, 8789 .setxattr = btrfs_setxattr, 8790 .getxattr = btrfs_getxattr, 8791 .listxattr = btrfs_listxattr, 8792 .removexattr = btrfs_removexattr, 8793 .get_acl = btrfs_get_acl, 8794 .update_time = btrfs_update_time, 8795 }; 8796 8797 const struct dentry_operations btrfs_dentry_operations = { 8798 .d_delete = btrfs_dentry_delete, 8799 .d_release = btrfs_dentry_release, 8800 }; 8801