1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (C) 2008 Oracle. All rights reserved. 4 */ 5 6 #include <linux/sched.h> 7 #include <linux/slab.h> 8 #include <linux/blkdev.h> 9 #include <linux/list_sort.h> 10 #include <linux/iversion.h> 11 #include "misc.h" 12 #include "ctree.h" 13 #include "tree-log.h" 14 #include "disk-io.h" 15 #include "locking.h" 16 #include "print-tree.h" 17 #include "backref.h" 18 #include "compression.h" 19 #include "qgroup.h" 20 #include "block-group.h" 21 #include "space-info.h" 22 #include "zoned.h" 23 24 /* magic values for the inode_only field in btrfs_log_inode: 25 * 26 * LOG_INODE_ALL means to log everything 27 * LOG_INODE_EXISTS means to log just enough to recreate the inode 28 * during log replay 29 */ 30 enum { 31 LOG_INODE_ALL, 32 LOG_INODE_EXISTS, 33 LOG_OTHER_INODE, 34 LOG_OTHER_INODE_ALL, 35 }; 36 37 /* 38 * directory trouble cases 39 * 40 * 1) on rename or unlink, if the inode being unlinked isn't in the fsync 41 * log, we must force a full commit before doing an fsync of the directory 42 * where the unlink was done. 43 * ---> record transid of last unlink/rename per directory 44 * 45 * mkdir foo/some_dir 46 * normal commit 47 * rename foo/some_dir foo2/some_dir 48 * mkdir foo/some_dir 49 * fsync foo/some_dir/some_file 50 * 51 * The fsync above will unlink the original some_dir without recording 52 * it in its new location (foo2). After a crash, some_dir will be gone 53 * unless the fsync of some_file forces a full commit 54 * 55 * 2) we must log any new names for any file or dir that is in the fsync 56 * log. ---> check inode while renaming/linking. 57 * 58 * 2a) we must log any new names for any file or dir during rename 59 * when the directory they are being removed from was logged. 60 * ---> check inode and old parent dir during rename 61 * 62 * 2a is actually the more important variant. With the extra logging 63 * a crash might unlink the old name without recreating the new one 64 * 65 * 3) after a crash, we must go through any directories with a link count 66 * of zero and redo the rm -rf 67 * 68 * mkdir f1/foo 69 * normal commit 70 * rm -rf f1/foo 71 * fsync(f1) 72 * 73 * The directory f1 was fully removed from the FS, but fsync was never 74 * called on f1, only its parent dir. After a crash the rm -rf must 75 * be replayed. This must be able to recurse down the entire 76 * directory tree. The inode link count fixup code takes care of the 77 * ugly details. 78 */ 79 80 /* 81 * stages for the tree walking. The first 82 * stage (0) is to only pin down the blocks we find 83 * the second stage (1) is to make sure that all the inodes 84 * we find in the log are created in the subvolume. 85 * 86 * The last stage is to deal with directories and links and extents 87 * and all the other fun semantics 88 */ 89 enum { 90 LOG_WALK_PIN_ONLY, 91 LOG_WALK_REPLAY_INODES, 92 LOG_WALK_REPLAY_DIR_INDEX, 93 LOG_WALK_REPLAY_ALL, 94 }; 95 96 static int btrfs_log_inode(struct btrfs_trans_handle *trans, 97 struct btrfs_inode *inode, 98 int inode_only, 99 struct btrfs_log_ctx *ctx); 100 static int link_to_fixup_dir(struct btrfs_trans_handle *trans, 101 struct btrfs_root *root, 102 struct btrfs_path *path, u64 objectid); 103 static noinline int replay_dir_deletes(struct btrfs_trans_handle *trans, 104 struct btrfs_root *root, 105 struct btrfs_root *log, 106 struct btrfs_path *path, 107 u64 dirid, int del_all); 108 static void wait_log_commit(struct btrfs_root *root, int transid); 109 110 /* 111 * tree logging is a special write ahead log used to make sure that 112 * fsyncs and O_SYNCs can happen without doing full tree commits. 113 * 114 * Full tree commits are expensive because they require commonly 115 * modified blocks to be recowed, creating many dirty pages in the 116 * extent tree an 4x-6x higher write load than ext3. 117 * 118 * Instead of doing a tree commit on every fsync, we use the 119 * key ranges and transaction ids to find items for a given file or directory 120 * that have changed in this transaction. Those items are copied into 121 * a special tree (one per subvolume root), that tree is written to disk 122 * and then the fsync is considered complete. 123 * 124 * After a crash, items are copied out of the log-tree back into the 125 * subvolume tree. Any file data extents found are recorded in the extent 126 * allocation tree, and the log-tree freed. 127 * 128 * The log tree is read three times, once to pin down all the extents it is 129 * using in ram and once, once to create all the inodes logged in the tree 130 * and once to do all the other items. 131 */ 132 133 /* 134 * start a sub transaction and setup the log tree 135 * this increments the log tree writer count to make the people 136 * syncing the tree wait for us to finish 137 */ 138 static int start_log_trans(struct btrfs_trans_handle *trans, 139 struct btrfs_root *root, 140 struct btrfs_log_ctx *ctx) 141 { 142 struct btrfs_fs_info *fs_info = root->fs_info; 143 struct btrfs_root *tree_root = fs_info->tree_root; 144 const bool zoned = btrfs_is_zoned(fs_info); 145 int ret = 0; 146 bool created = false; 147 148 /* 149 * First check if the log root tree was already created. If not, create 150 * it before locking the root's log_mutex, just to keep lockdep happy. 151 */ 152 if (!test_bit(BTRFS_ROOT_HAS_LOG_TREE, &tree_root->state)) { 153 mutex_lock(&tree_root->log_mutex); 154 if (!fs_info->log_root_tree) { 155 ret = btrfs_init_log_root_tree(trans, fs_info); 156 if (!ret) { 157 set_bit(BTRFS_ROOT_HAS_LOG_TREE, &tree_root->state); 158 created = true; 159 } 160 } 161 mutex_unlock(&tree_root->log_mutex); 162 if (ret) 163 return ret; 164 } 165 166 mutex_lock(&root->log_mutex); 167 168 again: 169 if (root->log_root) { 170 int index = (root->log_transid + 1) % 2; 171 172 if (btrfs_need_log_full_commit(trans)) { 173 ret = -EAGAIN; 174 goto out; 175 } 176 177 if (zoned && atomic_read(&root->log_commit[index])) { 178 wait_log_commit(root, root->log_transid - 1); 179 goto again; 180 } 181 182 if (!root->log_start_pid) { 183 clear_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state); 184 root->log_start_pid = current->pid; 185 } else if (root->log_start_pid != current->pid) { 186 set_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state); 187 } 188 } else { 189 /* 190 * This means fs_info->log_root_tree was already created 191 * for some other FS trees. Do the full commit not to mix 192 * nodes from multiple log transactions to do sequential 193 * writing. 194 */ 195 if (zoned && !created) { 196 ret = -EAGAIN; 197 goto out; 198 } 199 200 ret = btrfs_add_log_tree(trans, root); 201 if (ret) 202 goto out; 203 204 set_bit(BTRFS_ROOT_HAS_LOG_TREE, &root->state); 205 clear_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state); 206 root->log_start_pid = current->pid; 207 } 208 209 atomic_inc(&root->log_writers); 210 if (!ctx->logging_new_name) { 211 int index = root->log_transid % 2; 212 list_add_tail(&ctx->list, &root->log_ctxs[index]); 213 ctx->log_transid = root->log_transid; 214 } 215 216 out: 217 mutex_unlock(&root->log_mutex); 218 return ret; 219 } 220 221 /* 222 * returns 0 if there was a log transaction running and we were able 223 * to join, or returns -ENOENT if there were not transactions 224 * in progress 225 */ 226 static int join_running_log_trans(struct btrfs_root *root) 227 { 228 const bool zoned = btrfs_is_zoned(root->fs_info); 229 int ret = -ENOENT; 230 231 if (!test_bit(BTRFS_ROOT_HAS_LOG_TREE, &root->state)) 232 return ret; 233 234 mutex_lock(&root->log_mutex); 235 again: 236 if (root->log_root) { 237 int index = (root->log_transid + 1) % 2; 238 239 ret = 0; 240 if (zoned && atomic_read(&root->log_commit[index])) { 241 wait_log_commit(root, root->log_transid - 1); 242 goto again; 243 } 244 atomic_inc(&root->log_writers); 245 } 246 mutex_unlock(&root->log_mutex); 247 return ret; 248 } 249 250 /* 251 * This either makes the current running log transaction wait 252 * until you call btrfs_end_log_trans() or it makes any future 253 * log transactions wait until you call btrfs_end_log_trans() 254 */ 255 void btrfs_pin_log_trans(struct btrfs_root *root) 256 { 257 atomic_inc(&root->log_writers); 258 } 259 260 /* 261 * indicate we're done making changes to the log tree 262 * and wake up anyone waiting to do a sync 263 */ 264 void btrfs_end_log_trans(struct btrfs_root *root) 265 { 266 if (atomic_dec_and_test(&root->log_writers)) { 267 /* atomic_dec_and_test implies a barrier */ 268 cond_wake_up_nomb(&root->log_writer_wait); 269 } 270 } 271 272 static int btrfs_write_tree_block(struct extent_buffer *buf) 273 { 274 return filemap_fdatawrite_range(buf->pages[0]->mapping, buf->start, 275 buf->start + buf->len - 1); 276 } 277 278 static void btrfs_wait_tree_block_writeback(struct extent_buffer *buf) 279 { 280 filemap_fdatawait_range(buf->pages[0]->mapping, 281 buf->start, buf->start + buf->len - 1); 282 } 283 284 /* 285 * the walk control struct is used to pass state down the chain when 286 * processing the log tree. The stage field tells us which part 287 * of the log tree processing we are currently doing. The others 288 * are state fields used for that specific part 289 */ 290 struct walk_control { 291 /* should we free the extent on disk when done? This is used 292 * at transaction commit time while freeing a log tree 293 */ 294 int free; 295 296 /* should we write out the extent buffer? This is used 297 * while flushing the log tree to disk during a sync 298 */ 299 int write; 300 301 /* should we wait for the extent buffer io to finish? Also used 302 * while flushing the log tree to disk for a sync 303 */ 304 int wait; 305 306 /* pin only walk, we record which extents on disk belong to the 307 * log trees 308 */ 309 int pin; 310 311 /* what stage of the replay code we're currently in */ 312 int stage; 313 314 /* 315 * Ignore any items from the inode currently being processed. Needs 316 * to be set every time we find a BTRFS_INODE_ITEM_KEY and we are in 317 * the LOG_WALK_REPLAY_INODES stage. 318 */ 319 bool ignore_cur_inode; 320 321 /* the root we are currently replaying */ 322 struct btrfs_root *replay_dest; 323 324 /* the trans handle for the current replay */ 325 struct btrfs_trans_handle *trans; 326 327 /* the function that gets used to process blocks we find in the 328 * tree. Note the extent_buffer might not be up to date when it is 329 * passed in, and it must be checked or read if you need the data 330 * inside it 331 */ 332 int (*process_func)(struct btrfs_root *log, struct extent_buffer *eb, 333 struct walk_control *wc, u64 gen, int level); 334 }; 335 336 /* 337 * process_func used to pin down extents, write them or wait on them 338 */ 339 static int process_one_buffer(struct btrfs_root *log, 340 struct extent_buffer *eb, 341 struct walk_control *wc, u64 gen, int level) 342 { 343 struct btrfs_fs_info *fs_info = log->fs_info; 344 int ret = 0; 345 346 /* 347 * If this fs is mixed then we need to be able to process the leaves to 348 * pin down any logged extents, so we have to read the block. 349 */ 350 if (btrfs_fs_incompat(fs_info, MIXED_GROUPS)) { 351 ret = btrfs_read_buffer(eb, gen, level, NULL); 352 if (ret) 353 return ret; 354 } 355 356 if (wc->pin) 357 ret = btrfs_pin_extent_for_log_replay(wc->trans, eb->start, 358 eb->len); 359 360 if (!ret && btrfs_buffer_uptodate(eb, gen, 0)) { 361 if (wc->pin && btrfs_header_level(eb) == 0) 362 ret = btrfs_exclude_logged_extents(eb); 363 if (wc->write) 364 btrfs_write_tree_block(eb); 365 if (wc->wait) 366 btrfs_wait_tree_block_writeback(eb); 367 } 368 return ret; 369 } 370 371 static int do_overwrite_item(struct btrfs_trans_handle *trans, 372 struct btrfs_root *root, 373 struct btrfs_path *path, 374 struct extent_buffer *eb, int slot, 375 struct btrfs_key *key) 376 { 377 int ret; 378 u32 item_size; 379 u64 saved_i_size = 0; 380 int save_old_i_size = 0; 381 unsigned long src_ptr; 382 unsigned long dst_ptr; 383 int overwrite_root = 0; 384 bool inode_item = key->type == BTRFS_INODE_ITEM_KEY; 385 386 if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) 387 overwrite_root = 1; 388 389 item_size = btrfs_item_size_nr(eb, slot); 390 src_ptr = btrfs_item_ptr_offset(eb, slot); 391 392 /* Our caller must have done a search for the key for us. */ 393 ASSERT(path->nodes[0] != NULL); 394 395 /* 396 * And the slot must point to the exact key or the slot where the key 397 * should be at (the first item with a key greater than 'key') 398 */ 399 if (path->slots[0] < btrfs_header_nritems(path->nodes[0])) { 400 struct btrfs_key found_key; 401 402 btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]); 403 ret = btrfs_comp_cpu_keys(&found_key, key); 404 ASSERT(ret >= 0); 405 } else { 406 ret = 1; 407 } 408 409 if (ret == 0) { 410 char *src_copy; 411 char *dst_copy; 412 u32 dst_size = btrfs_item_size_nr(path->nodes[0], 413 path->slots[0]); 414 if (dst_size != item_size) 415 goto insert; 416 417 if (item_size == 0) { 418 btrfs_release_path(path); 419 return 0; 420 } 421 dst_copy = kmalloc(item_size, GFP_NOFS); 422 src_copy = kmalloc(item_size, GFP_NOFS); 423 if (!dst_copy || !src_copy) { 424 btrfs_release_path(path); 425 kfree(dst_copy); 426 kfree(src_copy); 427 return -ENOMEM; 428 } 429 430 read_extent_buffer(eb, src_copy, src_ptr, item_size); 431 432 dst_ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]); 433 read_extent_buffer(path->nodes[0], dst_copy, dst_ptr, 434 item_size); 435 ret = memcmp(dst_copy, src_copy, item_size); 436 437 kfree(dst_copy); 438 kfree(src_copy); 439 /* 440 * they have the same contents, just return, this saves 441 * us from cowing blocks in the destination tree and doing 442 * extra writes that may not have been done by a previous 443 * sync 444 */ 445 if (ret == 0) { 446 btrfs_release_path(path); 447 return 0; 448 } 449 450 /* 451 * We need to load the old nbytes into the inode so when we 452 * replay the extents we've logged we get the right nbytes. 453 */ 454 if (inode_item) { 455 struct btrfs_inode_item *item; 456 u64 nbytes; 457 u32 mode; 458 459 item = btrfs_item_ptr(path->nodes[0], path->slots[0], 460 struct btrfs_inode_item); 461 nbytes = btrfs_inode_nbytes(path->nodes[0], item); 462 item = btrfs_item_ptr(eb, slot, 463 struct btrfs_inode_item); 464 btrfs_set_inode_nbytes(eb, item, nbytes); 465 466 /* 467 * If this is a directory we need to reset the i_size to 468 * 0 so that we can set it up properly when replaying 469 * the rest of the items in this log. 470 */ 471 mode = btrfs_inode_mode(eb, item); 472 if (S_ISDIR(mode)) 473 btrfs_set_inode_size(eb, item, 0); 474 } 475 } else if (inode_item) { 476 struct btrfs_inode_item *item; 477 u32 mode; 478 479 /* 480 * New inode, set nbytes to 0 so that the nbytes comes out 481 * properly when we replay the extents. 482 */ 483 item = btrfs_item_ptr(eb, slot, struct btrfs_inode_item); 484 btrfs_set_inode_nbytes(eb, item, 0); 485 486 /* 487 * If this is a directory we need to reset the i_size to 0 so 488 * that we can set it up properly when replaying the rest of 489 * the items in this log. 490 */ 491 mode = btrfs_inode_mode(eb, item); 492 if (S_ISDIR(mode)) 493 btrfs_set_inode_size(eb, item, 0); 494 } 495 insert: 496 btrfs_release_path(path); 497 /* try to insert the key into the destination tree */ 498 path->skip_release_on_error = 1; 499 ret = btrfs_insert_empty_item(trans, root, path, 500 key, item_size); 501 path->skip_release_on_error = 0; 502 503 /* make sure any existing item is the correct size */ 504 if (ret == -EEXIST || ret == -EOVERFLOW) { 505 u32 found_size; 506 found_size = btrfs_item_size_nr(path->nodes[0], 507 path->slots[0]); 508 if (found_size > item_size) 509 btrfs_truncate_item(path, item_size, 1); 510 else if (found_size < item_size) 511 btrfs_extend_item(path, item_size - found_size); 512 } else if (ret) { 513 return ret; 514 } 515 dst_ptr = btrfs_item_ptr_offset(path->nodes[0], 516 path->slots[0]); 517 518 /* don't overwrite an existing inode if the generation number 519 * was logged as zero. This is done when the tree logging code 520 * is just logging an inode to make sure it exists after recovery. 521 * 522 * Also, don't overwrite i_size on directories during replay. 523 * log replay inserts and removes directory items based on the 524 * state of the tree found in the subvolume, and i_size is modified 525 * as it goes 526 */ 527 if (key->type == BTRFS_INODE_ITEM_KEY && ret == -EEXIST) { 528 struct btrfs_inode_item *src_item; 529 struct btrfs_inode_item *dst_item; 530 531 src_item = (struct btrfs_inode_item *)src_ptr; 532 dst_item = (struct btrfs_inode_item *)dst_ptr; 533 534 if (btrfs_inode_generation(eb, src_item) == 0) { 535 struct extent_buffer *dst_eb = path->nodes[0]; 536 const u64 ino_size = btrfs_inode_size(eb, src_item); 537 538 /* 539 * For regular files an ino_size == 0 is used only when 540 * logging that an inode exists, as part of a directory 541 * fsync, and the inode wasn't fsynced before. In this 542 * case don't set the size of the inode in the fs/subvol 543 * tree, otherwise we would be throwing valid data away. 544 */ 545 if (S_ISREG(btrfs_inode_mode(eb, src_item)) && 546 S_ISREG(btrfs_inode_mode(dst_eb, dst_item)) && 547 ino_size != 0) 548 btrfs_set_inode_size(dst_eb, dst_item, ino_size); 549 goto no_copy; 550 } 551 552 if (overwrite_root && 553 S_ISDIR(btrfs_inode_mode(eb, src_item)) && 554 S_ISDIR(btrfs_inode_mode(path->nodes[0], dst_item))) { 555 save_old_i_size = 1; 556 saved_i_size = btrfs_inode_size(path->nodes[0], 557 dst_item); 558 } 559 } 560 561 copy_extent_buffer(path->nodes[0], eb, dst_ptr, 562 src_ptr, item_size); 563 564 if (save_old_i_size) { 565 struct btrfs_inode_item *dst_item; 566 dst_item = (struct btrfs_inode_item *)dst_ptr; 567 btrfs_set_inode_size(path->nodes[0], dst_item, saved_i_size); 568 } 569 570 /* make sure the generation is filled in */ 571 if (key->type == BTRFS_INODE_ITEM_KEY) { 572 struct btrfs_inode_item *dst_item; 573 dst_item = (struct btrfs_inode_item *)dst_ptr; 574 if (btrfs_inode_generation(path->nodes[0], dst_item) == 0) { 575 btrfs_set_inode_generation(path->nodes[0], dst_item, 576 trans->transid); 577 } 578 } 579 no_copy: 580 btrfs_mark_buffer_dirty(path->nodes[0]); 581 btrfs_release_path(path); 582 return 0; 583 } 584 585 /* 586 * Item overwrite used by replay and tree logging. eb, slot and key all refer 587 * to the src data we are copying out. 588 * 589 * root is the tree we are copying into, and path is a scratch 590 * path for use in this function (it should be released on entry and 591 * will be released on exit). 592 * 593 * If the key is already in the destination tree the existing item is 594 * overwritten. If the existing item isn't big enough, it is extended. 595 * If it is too large, it is truncated. 596 * 597 * If the key isn't in the destination yet, a new item is inserted. 598 */ 599 static int overwrite_item(struct btrfs_trans_handle *trans, 600 struct btrfs_root *root, 601 struct btrfs_path *path, 602 struct extent_buffer *eb, int slot, 603 struct btrfs_key *key) 604 { 605 int ret; 606 607 /* Look for the key in the destination tree. */ 608 ret = btrfs_search_slot(NULL, root, key, path, 0, 0); 609 if (ret < 0) 610 return ret; 611 612 return do_overwrite_item(trans, root, path, eb, slot, key); 613 } 614 615 /* 616 * simple helper to read an inode off the disk from a given root 617 * This can only be called for subvolume roots and not for the log 618 */ 619 static noinline struct inode *read_one_inode(struct btrfs_root *root, 620 u64 objectid) 621 { 622 struct inode *inode; 623 624 inode = btrfs_iget(root->fs_info->sb, objectid, root); 625 if (IS_ERR(inode)) 626 inode = NULL; 627 return inode; 628 } 629 630 /* replays a single extent in 'eb' at 'slot' with 'key' into the 631 * subvolume 'root'. path is released on entry and should be released 632 * on exit. 633 * 634 * extents in the log tree have not been allocated out of the extent 635 * tree yet. So, this completes the allocation, taking a reference 636 * as required if the extent already exists or creating a new extent 637 * if it isn't in the extent allocation tree yet. 638 * 639 * The extent is inserted into the file, dropping any existing extents 640 * from the file that overlap the new one. 641 */ 642 static noinline int replay_one_extent(struct btrfs_trans_handle *trans, 643 struct btrfs_root *root, 644 struct btrfs_path *path, 645 struct extent_buffer *eb, int slot, 646 struct btrfs_key *key) 647 { 648 struct btrfs_drop_extents_args drop_args = { 0 }; 649 struct btrfs_fs_info *fs_info = root->fs_info; 650 int found_type; 651 u64 extent_end; 652 u64 start = key->offset; 653 u64 nbytes = 0; 654 struct btrfs_file_extent_item *item; 655 struct inode *inode = NULL; 656 unsigned long size; 657 int ret = 0; 658 659 item = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item); 660 found_type = btrfs_file_extent_type(eb, item); 661 662 if (found_type == BTRFS_FILE_EXTENT_REG || 663 found_type == BTRFS_FILE_EXTENT_PREALLOC) { 664 nbytes = btrfs_file_extent_num_bytes(eb, item); 665 extent_end = start + nbytes; 666 667 /* 668 * We don't add to the inodes nbytes if we are prealloc or a 669 * hole. 670 */ 671 if (btrfs_file_extent_disk_bytenr(eb, item) == 0) 672 nbytes = 0; 673 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) { 674 size = btrfs_file_extent_ram_bytes(eb, item); 675 nbytes = btrfs_file_extent_ram_bytes(eb, item); 676 extent_end = ALIGN(start + size, 677 fs_info->sectorsize); 678 } else { 679 ret = 0; 680 goto out; 681 } 682 683 inode = read_one_inode(root, key->objectid); 684 if (!inode) { 685 ret = -EIO; 686 goto out; 687 } 688 689 /* 690 * first check to see if we already have this extent in the 691 * file. This must be done before the btrfs_drop_extents run 692 * so we don't try to drop this extent. 693 */ 694 ret = btrfs_lookup_file_extent(trans, root, path, 695 btrfs_ino(BTRFS_I(inode)), start, 0); 696 697 if (ret == 0 && 698 (found_type == BTRFS_FILE_EXTENT_REG || 699 found_type == BTRFS_FILE_EXTENT_PREALLOC)) { 700 struct btrfs_file_extent_item cmp1; 701 struct btrfs_file_extent_item cmp2; 702 struct btrfs_file_extent_item *existing; 703 struct extent_buffer *leaf; 704 705 leaf = path->nodes[0]; 706 existing = btrfs_item_ptr(leaf, path->slots[0], 707 struct btrfs_file_extent_item); 708 709 read_extent_buffer(eb, &cmp1, (unsigned long)item, 710 sizeof(cmp1)); 711 read_extent_buffer(leaf, &cmp2, (unsigned long)existing, 712 sizeof(cmp2)); 713 714 /* 715 * we already have a pointer to this exact extent, 716 * we don't have to do anything 717 */ 718 if (memcmp(&cmp1, &cmp2, sizeof(cmp1)) == 0) { 719 btrfs_release_path(path); 720 goto out; 721 } 722 } 723 btrfs_release_path(path); 724 725 /* drop any overlapping extents */ 726 drop_args.start = start; 727 drop_args.end = extent_end; 728 drop_args.drop_cache = true; 729 ret = btrfs_drop_extents(trans, root, BTRFS_I(inode), &drop_args); 730 if (ret) 731 goto out; 732 733 if (found_type == BTRFS_FILE_EXTENT_REG || 734 found_type == BTRFS_FILE_EXTENT_PREALLOC) { 735 u64 offset; 736 unsigned long dest_offset; 737 struct btrfs_key ins; 738 739 if (btrfs_file_extent_disk_bytenr(eb, item) == 0 && 740 btrfs_fs_incompat(fs_info, NO_HOLES)) 741 goto update_inode; 742 743 ret = btrfs_insert_empty_item(trans, root, path, key, 744 sizeof(*item)); 745 if (ret) 746 goto out; 747 dest_offset = btrfs_item_ptr_offset(path->nodes[0], 748 path->slots[0]); 749 copy_extent_buffer(path->nodes[0], eb, dest_offset, 750 (unsigned long)item, sizeof(*item)); 751 752 ins.objectid = btrfs_file_extent_disk_bytenr(eb, item); 753 ins.offset = btrfs_file_extent_disk_num_bytes(eb, item); 754 ins.type = BTRFS_EXTENT_ITEM_KEY; 755 offset = key->offset - btrfs_file_extent_offset(eb, item); 756 757 /* 758 * Manually record dirty extent, as here we did a shallow 759 * file extent item copy and skip normal backref update, 760 * but modifying extent tree all by ourselves. 761 * So need to manually record dirty extent for qgroup, 762 * as the owner of the file extent changed from log tree 763 * (doesn't affect qgroup) to fs/file tree(affects qgroup) 764 */ 765 ret = btrfs_qgroup_trace_extent(trans, 766 btrfs_file_extent_disk_bytenr(eb, item), 767 btrfs_file_extent_disk_num_bytes(eb, item), 768 GFP_NOFS); 769 if (ret < 0) 770 goto out; 771 772 if (ins.objectid > 0) { 773 struct btrfs_ref ref = { 0 }; 774 u64 csum_start; 775 u64 csum_end; 776 LIST_HEAD(ordered_sums); 777 778 /* 779 * is this extent already allocated in the extent 780 * allocation tree? If so, just add a reference 781 */ 782 ret = btrfs_lookup_data_extent(fs_info, ins.objectid, 783 ins.offset); 784 if (ret < 0) { 785 goto out; 786 } else if (ret == 0) { 787 btrfs_init_generic_ref(&ref, 788 BTRFS_ADD_DELAYED_REF, 789 ins.objectid, ins.offset, 0); 790 btrfs_init_data_ref(&ref, 791 root->root_key.objectid, 792 key->objectid, offset, 0, false); 793 ret = btrfs_inc_extent_ref(trans, &ref); 794 if (ret) 795 goto out; 796 } else { 797 /* 798 * insert the extent pointer in the extent 799 * allocation tree 800 */ 801 ret = btrfs_alloc_logged_file_extent(trans, 802 root->root_key.objectid, 803 key->objectid, offset, &ins); 804 if (ret) 805 goto out; 806 } 807 btrfs_release_path(path); 808 809 if (btrfs_file_extent_compression(eb, item)) { 810 csum_start = ins.objectid; 811 csum_end = csum_start + ins.offset; 812 } else { 813 csum_start = ins.objectid + 814 btrfs_file_extent_offset(eb, item); 815 csum_end = csum_start + 816 btrfs_file_extent_num_bytes(eb, item); 817 } 818 819 ret = btrfs_lookup_csums_range(root->log_root, 820 csum_start, csum_end - 1, 821 &ordered_sums, 0); 822 if (ret) 823 goto out; 824 /* 825 * Now delete all existing cums in the csum root that 826 * cover our range. We do this because we can have an 827 * extent that is completely referenced by one file 828 * extent item and partially referenced by another 829 * file extent item (like after using the clone or 830 * extent_same ioctls). In this case if we end up doing 831 * the replay of the one that partially references the 832 * extent first, and we do not do the csum deletion 833 * below, we can get 2 csum items in the csum tree that 834 * overlap each other. For example, imagine our log has 835 * the two following file extent items: 836 * 837 * key (257 EXTENT_DATA 409600) 838 * extent data disk byte 12845056 nr 102400 839 * extent data offset 20480 nr 20480 ram 102400 840 * 841 * key (257 EXTENT_DATA 819200) 842 * extent data disk byte 12845056 nr 102400 843 * extent data offset 0 nr 102400 ram 102400 844 * 845 * Where the second one fully references the 100K extent 846 * that starts at disk byte 12845056, and the log tree 847 * has a single csum item that covers the entire range 848 * of the extent: 849 * 850 * key (EXTENT_CSUM EXTENT_CSUM 12845056) itemsize 100 851 * 852 * After the first file extent item is replayed, the 853 * csum tree gets the following csum item: 854 * 855 * key (EXTENT_CSUM EXTENT_CSUM 12865536) itemsize 20 856 * 857 * Which covers the 20K sub-range starting at offset 20K 858 * of our extent. Now when we replay the second file 859 * extent item, if we do not delete existing csum items 860 * that cover any of its blocks, we end up getting two 861 * csum items in our csum tree that overlap each other: 862 * 863 * key (EXTENT_CSUM EXTENT_CSUM 12845056) itemsize 100 864 * key (EXTENT_CSUM EXTENT_CSUM 12865536) itemsize 20 865 * 866 * Which is a problem, because after this anyone trying 867 * to lookup up for the checksum of any block of our 868 * extent starting at an offset of 40K or higher, will 869 * end up looking at the second csum item only, which 870 * does not contain the checksum for any block starting 871 * at offset 40K or higher of our extent. 872 */ 873 while (!list_empty(&ordered_sums)) { 874 struct btrfs_ordered_sum *sums; 875 sums = list_entry(ordered_sums.next, 876 struct btrfs_ordered_sum, 877 list); 878 if (!ret) 879 ret = btrfs_del_csums(trans, 880 fs_info->csum_root, 881 sums->bytenr, 882 sums->len); 883 if (!ret) 884 ret = btrfs_csum_file_blocks(trans, 885 fs_info->csum_root, sums); 886 list_del(&sums->list); 887 kfree(sums); 888 } 889 if (ret) 890 goto out; 891 } else { 892 btrfs_release_path(path); 893 } 894 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) { 895 /* inline extents are easy, we just overwrite them */ 896 ret = overwrite_item(trans, root, path, eb, slot, key); 897 if (ret) 898 goto out; 899 } 900 901 ret = btrfs_inode_set_file_extent_range(BTRFS_I(inode), start, 902 extent_end - start); 903 if (ret) 904 goto out; 905 906 update_inode: 907 btrfs_update_inode_bytes(BTRFS_I(inode), nbytes, drop_args.bytes_found); 908 ret = btrfs_update_inode(trans, root, BTRFS_I(inode)); 909 out: 910 if (inode) 911 iput(inode); 912 return ret; 913 } 914 915 /* 916 * when cleaning up conflicts between the directory names in the 917 * subvolume, directory names in the log and directory names in the 918 * inode back references, we may have to unlink inodes from directories. 919 * 920 * This is a helper function to do the unlink of a specific directory 921 * item 922 */ 923 static noinline int drop_one_dir_item(struct btrfs_trans_handle *trans, 924 struct btrfs_path *path, 925 struct btrfs_inode *dir, 926 struct btrfs_dir_item *di) 927 { 928 struct btrfs_root *root = dir->root; 929 struct inode *inode; 930 char *name; 931 int name_len; 932 struct extent_buffer *leaf; 933 struct btrfs_key location; 934 int ret; 935 936 leaf = path->nodes[0]; 937 938 btrfs_dir_item_key_to_cpu(leaf, di, &location); 939 name_len = btrfs_dir_name_len(leaf, di); 940 name = kmalloc(name_len, GFP_NOFS); 941 if (!name) 942 return -ENOMEM; 943 944 read_extent_buffer(leaf, name, (unsigned long)(di + 1), name_len); 945 btrfs_release_path(path); 946 947 inode = read_one_inode(root, location.objectid); 948 if (!inode) { 949 ret = -EIO; 950 goto out; 951 } 952 953 ret = link_to_fixup_dir(trans, root, path, location.objectid); 954 if (ret) 955 goto out; 956 957 ret = btrfs_unlink_inode(trans, dir, BTRFS_I(inode), name, 958 name_len); 959 if (ret) 960 goto out; 961 else 962 ret = btrfs_run_delayed_items(trans); 963 out: 964 kfree(name); 965 iput(inode); 966 return ret; 967 } 968 969 /* 970 * See if a given name and sequence number found in an inode back reference are 971 * already in a directory and correctly point to this inode. 972 * 973 * Returns: < 0 on error, 0 if the directory entry does not exists and 1 if it 974 * exists. 975 */ 976 static noinline int inode_in_dir(struct btrfs_root *root, 977 struct btrfs_path *path, 978 u64 dirid, u64 objectid, u64 index, 979 const char *name, int name_len) 980 { 981 struct btrfs_dir_item *di; 982 struct btrfs_key location; 983 int ret = 0; 984 985 di = btrfs_lookup_dir_index_item(NULL, root, path, dirid, 986 index, name, name_len, 0); 987 if (IS_ERR(di)) { 988 ret = PTR_ERR(di); 989 goto out; 990 } else if (di) { 991 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location); 992 if (location.objectid != objectid) 993 goto out; 994 } else { 995 goto out; 996 } 997 998 btrfs_release_path(path); 999 di = btrfs_lookup_dir_item(NULL, root, path, dirid, name, name_len, 0); 1000 if (IS_ERR(di)) { 1001 ret = PTR_ERR(di); 1002 goto out; 1003 } else if (di) { 1004 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location); 1005 if (location.objectid == objectid) 1006 ret = 1; 1007 } 1008 out: 1009 btrfs_release_path(path); 1010 return ret; 1011 } 1012 1013 /* 1014 * helper function to check a log tree for a named back reference in 1015 * an inode. This is used to decide if a back reference that is 1016 * found in the subvolume conflicts with what we find in the log. 1017 * 1018 * inode backreferences may have multiple refs in a single item, 1019 * during replay we process one reference at a time, and we don't 1020 * want to delete valid links to a file from the subvolume if that 1021 * link is also in the log. 1022 */ 1023 static noinline int backref_in_log(struct btrfs_root *log, 1024 struct btrfs_key *key, 1025 u64 ref_objectid, 1026 const char *name, int namelen) 1027 { 1028 struct btrfs_path *path; 1029 int ret; 1030 1031 path = btrfs_alloc_path(); 1032 if (!path) 1033 return -ENOMEM; 1034 1035 ret = btrfs_search_slot(NULL, log, key, path, 0, 0); 1036 if (ret < 0) { 1037 goto out; 1038 } else if (ret == 1) { 1039 ret = 0; 1040 goto out; 1041 } 1042 1043 if (key->type == BTRFS_INODE_EXTREF_KEY) 1044 ret = !!btrfs_find_name_in_ext_backref(path->nodes[0], 1045 path->slots[0], 1046 ref_objectid, 1047 name, namelen); 1048 else 1049 ret = !!btrfs_find_name_in_backref(path->nodes[0], 1050 path->slots[0], 1051 name, namelen); 1052 out: 1053 btrfs_free_path(path); 1054 return ret; 1055 } 1056 1057 static inline int __add_inode_ref(struct btrfs_trans_handle *trans, 1058 struct btrfs_root *root, 1059 struct btrfs_path *path, 1060 struct btrfs_root *log_root, 1061 struct btrfs_inode *dir, 1062 struct btrfs_inode *inode, 1063 u64 inode_objectid, u64 parent_objectid, 1064 u64 ref_index, char *name, int namelen, 1065 int *search_done) 1066 { 1067 int ret; 1068 char *victim_name; 1069 int victim_name_len; 1070 struct extent_buffer *leaf; 1071 struct btrfs_dir_item *di; 1072 struct btrfs_key search_key; 1073 struct btrfs_inode_extref *extref; 1074 1075 again: 1076 /* Search old style refs */ 1077 search_key.objectid = inode_objectid; 1078 search_key.type = BTRFS_INODE_REF_KEY; 1079 search_key.offset = parent_objectid; 1080 ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0); 1081 if (ret == 0) { 1082 struct btrfs_inode_ref *victim_ref; 1083 unsigned long ptr; 1084 unsigned long ptr_end; 1085 1086 leaf = path->nodes[0]; 1087 1088 /* are we trying to overwrite a back ref for the root directory 1089 * if so, just jump out, we're done 1090 */ 1091 if (search_key.objectid == search_key.offset) 1092 return 1; 1093 1094 /* check all the names in this back reference to see 1095 * if they are in the log. if so, we allow them to stay 1096 * otherwise they must be unlinked as a conflict 1097 */ 1098 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); 1099 ptr_end = ptr + btrfs_item_size_nr(leaf, path->slots[0]); 1100 while (ptr < ptr_end) { 1101 victim_ref = (struct btrfs_inode_ref *)ptr; 1102 victim_name_len = btrfs_inode_ref_name_len(leaf, 1103 victim_ref); 1104 victim_name = kmalloc(victim_name_len, GFP_NOFS); 1105 if (!victim_name) 1106 return -ENOMEM; 1107 1108 read_extent_buffer(leaf, victim_name, 1109 (unsigned long)(victim_ref + 1), 1110 victim_name_len); 1111 1112 ret = backref_in_log(log_root, &search_key, 1113 parent_objectid, victim_name, 1114 victim_name_len); 1115 if (ret < 0) { 1116 kfree(victim_name); 1117 return ret; 1118 } else if (!ret) { 1119 inc_nlink(&inode->vfs_inode); 1120 btrfs_release_path(path); 1121 1122 ret = btrfs_unlink_inode(trans, dir, inode, 1123 victim_name, victim_name_len); 1124 kfree(victim_name); 1125 if (ret) 1126 return ret; 1127 ret = btrfs_run_delayed_items(trans); 1128 if (ret) 1129 return ret; 1130 *search_done = 1; 1131 goto again; 1132 } 1133 kfree(victim_name); 1134 1135 ptr = (unsigned long)(victim_ref + 1) + victim_name_len; 1136 } 1137 1138 /* 1139 * NOTE: we have searched root tree and checked the 1140 * corresponding ref, it does not need to check again. 1141 */ 1142 *search_done = 1; 1143 } 1144 btrfs_release_path(path); 1145 1146 /* Same search but for extended refs */ 1147 extref = btrfs_lookup_inode_extref(NULL, root, path, name, namelen, 1148 inode_objectid, parent_objectid, 0, 1149 0); 1150 if (!IS_ERR_OR_NULL(extref)) { 1151 u32 item_size; 1152 u32 cur_offset = 0; 1153 unsigned long base; 1154 struct inode *victim_parent; 1155 1156 leaf = path->nodes[0]; 1157 1158 item_size = btrfs_item_size_nr(leaf, path->slots[0]); 1159 base = btrfs_item_ptr_offset(leaf, path->slots[0]); 1160 1161 while (cur_offset < item_size) { 1162 extref = (struct btrfs_inode_extref *)(base + cur_offset); 1163 1164 victim_name_len = btrfs_inode_extref_name_len(leaf, extref); 1165 1166 if (btrfs_inode_extref_parent(leaf, extref) != parent_objectid) 1167 goto next; 1168 1169 victim_name = kmalloc(victim_name_len, GFP_NOFS); 1170 if (!victim_name) 1171 return -ENOMEM; 1172 read_extent_buffer(leaf, victim_name, (unsigned long)&extref->name, 1173 victim_name_len); 1174 1175 search_key.objectid = inode_objectid; 1176 search_key.type = BTRFS_INODE_EXTREF_KEY; 1177 search_key.offset = btrfs_extref_hash(parent_objectid, 1178 victim_name, 1179 victim_name_len); 1180 ret = backref_in_log(log_root, &search_key, 1181 parent_objectid, victim_name, 1182 victim_name_len); 1183 if (ret < 0) { 1184 return ret; 1185 } else if (!ret) { 1186 ret = -ENOENT; 1187 victim_parent = read_one_inode(root, 1188 parent_objectid); 1189 if (victim_parent) { 1190 inc_nlink(&inode->vfs_inode); 1191 btrfs_release_path(path); 1192 1193 ret = btrfs_unlink_inode(trans, 1194 BTRFS_I(victim_parent), 1195 inode, 1196 victim_name, 1197 victim_name_len); 1198 if (!ret) 1199 ret = btrfs_run_delayed_items( 1200 trans); 1201 } 1202 iput(victim_parent); 1203 kfree(victim_name); 1204 if (ret) 1205 return ret; 1206 *search_done = 1; 1207 goto again; 1208 } 1209 kfree(victim_name); 1210 next: 1211 cur_offset += victim_name_len + sizeof(*extref); 1212 } 1213 *search_done = 1; 1214 } 1215 btrfs_release_path(path); 1216 1217 /* look for a conflicting sequence number */ 1218 di = btrfs_lookup_dir_index_item(trans, root, path, btrfs_ino(dir), 1219 ref_index, name, namelen, 0); 1220 if (IS_ERR(di)) { 1221 return PTR_ERR(di); 1222 } else if (di) { 1223 ret = drop_one_dir_item(trans, path, dir, di); 1224 if (ret) 1225 return ret; 1226 } 1227 btrfs_release_path(path); 1228 1229 /* look for a conflicting name */ 1230 di = btrfs_lookup_dir_item(trans, root, path, btrfs_ino(dir), 1231 name, namelen, 0); 1232 if (IS_ERR(di)) { 1233 return PTR_ERR(di); 1234 } else if (di) { 1235 ret = drop_one_dir_item(trans, path, dir, di); 1236 if (ret) 1237 return ret; 1238 } 1239 btrfs_release_path(path); 1240 1241 return 0; 1242 } 1243 1244 static int extref_get_fields(struct extent_buffer *eb, unsigned long ref_ptr, 1245 u32 *namelen, char **name, u64 *index, 1246 u64 *parent_objectid) 1247 { 1248 struct btrfs_inode_extref *extref; 1249 1250 extref = (struct btrfs_inode_extref *)ref_ptr; 1251 1252 *namelen = btrfs_inode_extref_name_len(eb, extref); 1253 *name = kmalloc(*namelen, GFP_NOFS); 1254 if (*name == NULL) 1255 return -ENOMEM; 1256 1257 read_extent_buffer(eb, *name, (unsigned long)&extref->name, 1258 *namelen); 1259 1260 if (index) 1261 *index = btrfs_inode_extref_index(eb, extref); 1262 if (parent_objectid) 1263 *parent_objectid = btrfs_inode_extref_parent(eb, extref); 1264 1265 return 0; 1266 } 1267 1268 static int ref_get_fields(struct extent_buffer *eb, unsigned long ref_ptr, 1269 u32 *namelen, char **name, u64 *index) 1270 { 1271 struct btrfs_inode_ref *ref; 1272 1273 ref = (struct btrfs_inode_ref *)ref_ptr; 1274 1275 *namelen = btrfs_inode_ref_name_len(eb, ref); 1276 *name = kmalloc(*namelen, GFP_NOFS); 1277 if (*name == NULL) 1278 return -ENOMEM; 1279 1280 read_extent_buffer(eb, *name, (unsigned long)(ref + 1), *namelen); 1281 1282 if (index) 1283 *index = btrfs_inode_ref_index(eb, ref); 1284 1285 return 0; 1286 } 1287 1288 /* 1289 * Take an inode reference item from the log tree and iterate all names from the 1290 * inode reference item in the subvolume tree with the same key (if it exists). 1291 * For any name that is not in the inode reference item from the log tree, do a 1292 * proper unlink of that name (that is, remove its entry from the inode 1293 * reference item and both dir index keys). 1294 */ 1295 static int unlink_old_inode_refs(struct btrfs_trans_handle *trans, 1296 struct btrfs_root *root, 1297 struct btrfs_path *path, 1298 struct btrfs_inode *inode, 1299 struct extent_buffer *log_eb, 1300 int log_slot, 1301 struct btrfs_key *key) 1302 { 1303 int ret; 1304 unsigned long ref_ptr; 1305 unsigned long ref_end; 1306 struct extent_buffer *eb; 1307 1308 again: 1309 btrfs_release_path(path); 1310 ret = btrfs_search_slot(NULL, root, key, path, 0, 0); 1311 if (ret > 0) { 1312 ret = 0; 1313 goto out; 1314 } 1315 if (ret < 0) 1316 goto out; 1317 1318 eb = path->nodes[0]; 1319 ref_ptr = btrfs_item_ptr_offset(eb, path->slots[0]); 1320 ref_end = ref_ptr + btrfs_item_size_nr(eb, path->slots[0]); 1321 while (ref_ptr < ref_end) { 1322 char *name = NULL; 1323 int namelen; 1324 u64 parent_id; 1325 1326 if (key->type == BTRFS_INODE_EXTREF_KEY) { 1327 ret = extref_get_fields(eb, ref_ptr, &namelen, &name, 1328 NULL, &parent_id); 1329 } else { 1330 parent_id = key->offset; 1331 ret = ref_get_fields(eb, ref_ptr, &namelen, &name, 1332 NULL); 1333 } 1334 if (ret) 1335 goto out; 1336 1337 if (key->type == BTRFS_INODE_EXTREF_KEY) 1338 ret = !!btrfs_find_name_in_ext_backref(log_eb, log_slot, 1339 parent_id, name, 1340 namelen); 1341 else 1342 ret = !!btrfs_find_name_in_backref(log_eb, log_slot, 1343 name, namelen); 1344 1345 if (!ret) { 1346 struct inode *dir; 1347 1348 btrfs_release_path(path); 1349 dir = read_one_inode(root, parent_id); 1350 if (!dir) { 1351 ret = -ENOENT; 1352 kfree(name); 1353 goto out; 1354 } 1355 ret = btrfs_unlink_inode(trans, BTRFS_I(dir), 1356 inode, name, namelen); 1357 kfree(name); 1358 iput(dir); 1359 if (ret) 1360 goto out; 1361 goto again; 1362 } 1363 1364 kfree(name); 1365 ref_ptr += namelen; 1366 if (key->type == BTRFS_INODE_EXTREF_KEY) 1367 ref_ptr += sizeof(struct btrfs_inode_extref); 1368 else 1369 ref_ptr += sizeof(struct btrfs_inode_ref); 1370 } 1371 ret = 0; 1372 out: 1373 btrfs_release_path(path); 1374 return ret; 1375 } 1376 1377 static int btrfs_inode_ref_exists(struct inode *inode, struct inode *dir, 1378 const u8 ref_type, const char *name, 1379 const int namelen) 1380 { 1381 struct btrfs_key key; 1382 struct btrfs_path *path; 1383 const u64 parent_id = btrfs_ino(BTRFS_I(dir)); 1384 int ret; 1385 1386 path = btrfs_alloc_path(); 1387 if (!path) 1388 return -ENOMEM; 1389 1390 key.objectid = btrfs_ino(BTRFS_I(inode)); 1391 key.type = ref_type; 1392 if (key.type == BTRFS_INODE_REF_KEY) 1393 key.offset = parent_id; 1394 else 1395 key.offset = btrfs_extref_hash(parent_id, name, namelen); 1396 1397 ret = btrfs_search_slot(NULL, BTRFS_I(inode)->root, &key, path, 0, 0); 1398 if (ret < 0) 1399 goto out; 1400 if (ret > 0) { 1401 ret = 0; 1402 goto out; 1403 } 1404 if (key.type == BTRFS_INODE_EXTREF_KEY) 1405 ret = !!btrfs_find_name_in_ext_backref(path->nodes[0], 1406 path->slots[0], parent_id, name, namelen); 1407 else 1408 ret = !!btrfs_find_name_in_backref(path->nodes[0], path->slots[0], 1409 name, namelen); 1410 1411 out: 1412 btrfs_free_path(path); 1413 return ret; 1414 } 1415 1416 static int add_link(struct btrfs_trans_handle *trans, 1417 struct inode *dir, struct inode *inode, const char *name, 1418 int namelen, u64 ref_index) 1419 { 1420 struct btrfs_root *root = BTRFS_I(dir)->root; 1421 struct btrfs_dir_item *dir_item; 1422 struct btrfs_key key; 1423 struct btrfs_path *path; 1424 struct inode *other_inode = NULL; 1425 int ret; 1426 1427 path = btrfs_alloc_path(); 1428 if (!path) 1429 return -ENOMEM; 1430 1431 dir_item = btrfs_lookup_dir_item(NULL, root, path, 1432 btrfs_ino(BTRFS_I(dir)), 1433 name, namelen, 0); 1434 if (!dir_item) { 1435 btrfs_release_path(path); 1436 goto add_link; 1437 } else if (IS_ERR(dir_item)) { 1438 ret = PTR_ERR(dir_item); 1439 goto out; 1440 } 1441 1442 /* 1443 * Our inode's dentry collides with the dentry of another inode which is 1444 * in the log but not yet processed since it has a higher inode number. 1445 * So delete that other dentry. 1446 */ 1447 btrfs_dir_item_key_to_cpu(path->nodes[0], dir_item, &key); 1448 btrfs_release_path(path); 1449 other_inode = read_one_inode(root, key.objectid); 1450 if (!other_inode) { 1451 ret = -ENOENT; 1452 goto out; 1453 } 1454 ret = btrfs_unlink_inode(trans, BTRFS_I(dir), BTRFS_I(other_inode), 1455 name, namelen); 1456 if (ret) 1457 goto out; 1458 /* 1459 * If we dropped the link count to 0, bump it so that later the iput() 1460 * on the inode will not free it. We will fixup the link count later. 1461 */ 1462 if (other_inode->i_nlink == 0) 1463 inc_nlink(other_inode); 1464 1465 ret = btrfs_run_delayed_items(trans); 1466 if (ret) 1467 goto out; 1468 add_link: 1469 ret = btrfs_add_link(trans, BTRFS_I(dir), BTRFS_I(inode), 1470 name, namelen, 0, ref_index); 1471 out: 1472 iput(other_inode); 1473 btrfs_free_path(path); 1474 1475 return ret; 1476 } 1477 1478 /* 1479 * replay one inode back reference item found in the log tree. 1480 * eb, slot and key refer to the buffer and key found in the log tree. 1481 * root is the destination we are replaying into, and path is for temp 1482 * use by this function. (it should be released on return). 1483 */ 1484 static noinline int add_inode_ref(struct btrfs_trans_handle *trans, 1485 struct btrfs_root *root, 1486 struct btrfs_root *log, 1487 struct btrfs_path *path, 1488 struct extent_buffer *eb, int slot, 1489 struct btrfs_key *key) 1490 { 1491 struct inode *dir = NULL; 1492 struct inode *inode = NULL; 1493 unsigned long ref_ptr; 1494 unsigned long ref_end; 1495 char *name = NULL; 1496 int namelen; 1497 int ret; 1498 int search_done = 0; 1499 int log_ref_ver = 0; 1500 u64 parent_objectid; 1501 u64 inode_objectid; 1502 u64 ref_index = 0; 1503 int ref_struct_size; 1504 1505 ref_ptr = btrfs_item_ptr_offset(eb, slot); 1506 ref_end = ref_ptr + btrfs_item_size_nr(eb, slot); 1507 1508 if (key->type == BTRFS_INODE_EXTREF_KEY) { 1509 struct btrfs_inode_extref *r; 1510 1511 ref_struct_size = sizeof(struct btrfs_inode_extref); 1512 log_ref_ver = 1; 1513 r = (struct btrfs_inode_extref *)ref_ptr; 1514 parent_objectid = btrfs_inode_extref_parent(eb, r); 1515 } else { 1516 ref_struct_size = sizeof(struct btrfs_inode_ref); 1517 parent_objectid = key->offset; 1518 } 1519 inode_objectid = key->objectid; 1520 1521 /* 1522 * it is possible that we didn't log all the parent directories 1523 * for a given inode. If we don't find the dir, just don't 1524 * copy the back ref in. The link count fixup code will take 1525 * care of the rest 1526 */ 1527 dir = read_one_inode(root, parent_objectid); 1528 if (!dir) { 1529 ret = -ENOENT; 1530 goto out; 1531 } 1532 1533 inode = read_one_inode(root, inode_objectid); 1534 if (!inode) { 1535 ret = -EIO; 1536 goto out; 1537 } 1538 1539 while (ref_ptr < ref_end) { 1540 if (log_ref_ver) { 1541 ret = extref_get_fields(eb, ref_ptr, &namelen, &name, 1542 &ref_index, &parent_objectid); 1543 /* 1544 * parent object can change from one array 1545 * item to another. 1546 */ 1547 if (!dir) 1548 dir = read_one_inode(root, parent_objectid); 1549 if (!dir) { 1550 ret = -ENOENT; 1551 goto out; 1552 } 1553 } else { 1554 ret = ref_get_fields(eb, ref_ptr, &namelen, &name, 1555 &ref_index); 1556 } 1557 if (ret) 1558 goto out; 1559 1560 ret = inode_in_dir(root, path, btrfs_ino(BTRFS_I(dir)), 1561 btrfs_ino(BTRFS_I(inode)), ref_index, 1562 name, namelen); 1563 if (ret < 0) { 1564 goto out; 1565 } else if (ret == 0) { 1566 /* 1567 * look for a conflicting back reference in the 1568 * metadata. if we find one we have to unlink that name 1569 * of the file before we add our new link. Later on, we 1570 * overwrite any existing back reference, and we don't 1571 * want to create dangling pointers in the directory. 1572 */ 1573 1574 if (!search_done) { 1575 ret = __add_inode_ref(trans, root, path, log, 1576 BTRFS_I(dir), 1577 BTRFS_I(inode), 1578 inode_objectid, 1579 parent_objectid, 1580 ref_index, name, namelen, 1581 &search_done); 1582 if (ret) { 1583 if (ret == 1) 1584 ret = 0; 1585 goto out; 1586 } 1587 } 1588 1589 /* 1590 * If a reference item already exists for this inode 1591 * with the same parent and name, but different index, 1592 * drop it and the corresponding directory index entries 1593 * from the parent before adding the new reference item 1594 * and dir index entries, otherwise we would fail with 1595 * -EEXIST returned from btrfs_add_link() below. 1596 */ 1597 ret = btrfs_inode_ref_exists(inode, dir, key->type, 1598 name, namelen); 1599 if (ret > 0) { 1600 ret = btrfs_unlink_inode(trans, 1601 BTRFS_I(dir), 1602 BTRFS_I(inode), 1603 name, namelen); 1604 /* 1605 * If we dropped the link count to 0, bump it so 1606 * that later the iput() on the inode will not 1607 * free it. We will fixup the link count later. 1608 */ 1609 if (!ret && inode->i_nlink == 0) 1610 inc_nlink(inode); 1611 } 1612 if (ret < 0) 1613 goto out; 1614 1615 /* insert our name */ 1616 ret = add_link(trans, dir, inode, name, namelen, 1617 ref_index); 1618 if (ret) 1619 goto out; 1620 1621 ret = btrfs_update_inode(trans, root, BTRFS_I(inode)); 1622 if (ret) 1623 goto out; 1624 } 1625 /* Else, ret == 1, we already have a perfect match, we're done. */ 1626 1627 ref_ptr = (unsigned long)(ref_ptr + ref_struct_size) + namelen; 1628 kfree(name); 1629 name = NULL; 1630 if (log_ref_ver) { 1631 iput(dir); 1632 dir = NULL; 1633 } 1634 } 1635 1636 /* 1637 * Before we overwrite the inode reference item in the subvolume tree 1638 * with the item from the log tree, we must unlink all names from the 1639 * parent directory that are in the subvolume's tree inode reference 1640 * item, otherwise we end up with an inconsistent subvolume tree where 1641 * dir index entries exist for a name but there is no inode reference 1642 * item with the same name. 1643 */ 1644 ret = unlink_old_inode_refs(trans, root, path, BTRFS_I(inode), eb, slot, 1645 key); 1646 if (ret) 1647 goto out; 1648 1649 /* finally write the back reference in the inode */ 1650 ret = overwrite_item(trans, root, path, eb, slot, key); 1651 out: 1652 btrfs_release_path(path); 1653 kfree(name); 1654 iput(dir); 1655 iput(inode); 1656 return ret; 1657 } 1658 1659 static int count_inode_extrefs(struct btrfs_root *root, 1660 struct btrfs_inode *inode, struct btrfs_path *path) 1661 { 1662 int ret = 0; 1663 int name_len; 1664 unsigned int nlink = 0; 1665 u32 item_size; 1666 u32 cur_offset = 0; 1667 u64 inode_objectid = btrfs_ino(inode); 1668 u64 offset = 0; 1669 unsigned long ptr; 1670 struct btrfs_inode_extref *extref; 1671 struct extent_buffer *leaf; 1672 1673 while (1) { 1674 ret = btrfs_find_one_extref(root, inode_objectid, offset, path, 1675 &extref, &offset); 1676 if (ret) 1677 break; 1678 1679 leaf = path->nodes[0]; 1680 item_size = btrfs_item_size_nr(leaf, path->slots[0]); 1681 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); 1682 cur_offset = 0; 1683 1684 while (cur_offset < item_size) { 1685 extref = (struct btrfs_inode_extref *) (ptr + cur_offset); 1686 name_len = btrfs_inode_extref_name_len(leaf, extref); 1687 1688 nlink++; 1689 1690 cur_offset += name_len + sizeof(*extref); 1691 } 1692 1693 offset++; 1694 btrfs_release_path(path); 1695 } 1696 btrfs_release_path(path); 1697 1698 if (ret < 0 && ret != -ENOENT) 1699 return ret; 1700 return nlink; 1701 } 1702 1703 static int count_inode_refs(struct btrfs_root *root, 1704 struct btrfs_inode *inode, struct btrfs_path *path) 1705 { 1706 int ret; 1707 struct btrfs_key key; 1708 unsigned int nlink = 0; 1709 unsigned long ptr; 1710 unsigned long ptr_end; 1711 int name_len; 1712 u64 ino = btrfs_ino(inode); 1713 1714 key.objectid = ino; 1715 key.type = BTRFS_INODE_REF_KEY; 1716 key.offset = (u64)-1; 1717 1718 while (1) { 1719 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 1720 if (ret < 0) 1721 break; 1722 if (ret > 0) { 1723 if (path->slots[0] == 0) 1724 break; 1725 path->slots[0]--; 1726 } 1727 process_slot: 1728 btrfs_item_key_to_cpu(path->nodes[0], &key, 1729 path->slots[0]); 1730 if (key.objectid != ino || 1731 key.type != BTRFS_INODE_REF_KEY) 1732 break; 1733 ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]); 1734 ptr_end = ptr + btrfs_item_size_nr(path->nodes[0], 1735 path->slots[0]); 1736 while (ptr < ptr_end) { 1737 struct btrfs_inode_ref *ref; 1738 1739 ref = (struct btrfs_inode_ref *)ptr; 1740 name_len = btrfs_inode_ref_name_len(path->nodes[0], 1741 ref); 1742 ptr = (unsigned long)(ref + 1) + name_len; 1743 nlink++; 1744 } 1745 1746 if (key.offset == 0) 1747 break; 1748 if (path->slots[0] > 0) { 1749 path->slots[0]--; 1750 goto process_slot; 1751 } 1752 key.offset--; 1753 btrfs_release_path(path); 1754 } 1755 btrfs_release_path(path); 1756 1757 return nlink; 1758 } 1759 1760 /* 1761 * There are a few corners where the link count of the file can't 1762 * be properly maintained during replay. So, instead of adding 1763 * lots of complexity to the log code, we just scan the backrefs 1764 * for any file that has been through replay. 1765 * 1766 * The scan will update the link count on the inode to reflect the 1767 * number of back refs found. If it goes down to zero, the iput 1768 * will free the inode. 1769 */ 1770 static noinline int fixup_inode_link_count(struct btrfs_trans_handle *trans, 1771 struct btrfs_root *root, 1772 struct inode *inode) 1773 { 1774 struct btrfs_path *path; 1775 int ret; 1776 u64 nlink = 0; 1777 u64 ino = btrfs_ino(BTRFS_I(inode)); 1778 1779 path = btrfs_alloc_path(); 1780 if (!path) 1781 return -ENOMEM; 1782 1783 ret = count_inode_refs(root, BTRFS_I(inode), path); 1784 if (ret < 0) 1785 goto out; 1786 1787 nlink = ret; 1788 1789 ret = count_inode_extrefs(root, BTRFS_I(inode), path); 1790 if (ret < 0) 1791 goto out; 1792 1793 nlink += ret; 1794 1795 ret = 0; 1796 1797 if (nlink != inode->i_nlink) { 1798 set_nlink(inode, nlink); 1799 ret = btrfs_update_inode(trans, root, BTRFS_I(inode)); 1800 if (ret) 1801 goto out; 1802 } 1803 BTRFS_I(inode)->index_cnt = (u64)-1; 1804 1805 if (inode->i_nlink == 0) { 1806 if (S_ISDIR(inode->i_mode)) { 1807 ret = replay_dir_deletes(trans, root, NULL, path, 1808 ino, 1); 1809 if (ret) 1810 goto out; 1811 } 1812 ret = btrfs_insert_orphan_item(trans, root, ino); 1813 if (ret == -EEXIST) 1814 ret = 0; 1815 } 1816 1817 out: 1818 btrfs_free_path(path); 1819 return ret; 1820 } 1821 1822 static noinline int fixup_inode_link_counts(struct btrfs_trans_handle *trans, 1823 struct btrfs_root *root, 1824 struct btrfs_path *path) 1825 { 1826 int ret; 1827 struct btrfs_key key; 1828 struct inode *inode; 1829 1830 key.objectid = BTRFS_TREE_LOG_FIXUP_OBJECTID; 1831 key.type = BTRFS_ORPHAN_ITEM_KEY; 1832 key.offset = (u64)-1; 1833 while (1) { 1834 ret = btrfs_search_slot(trans, root, &key, path, -1, 1); 1835 if (ret < 0) 1836 break; 1837 1838 if (ret == 1) { 1839 ret = 0; 1840 if (path->slots[0] == 0) 1841 break; 1842 path->slots[0]--; 1843 } 1844 1845 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); 1846 if (key.objectid != BTRFS_TREE_LOG_FIXUP_OBJECTID || 1847 key.type != BTRFS_ORPHAN_ITEM_KEY) 1848 break; 1849 1850 ret = btrfs_del_item(trans, root, path); 1851 if (ret) 1852 break; 1853 1854 btrfs_release_path(path); 1855 inode = read_one_inode(root, key.offset); 1856 if (!inode) { 1857 ret = -EIO; 1858 break; 1859 } 1860 1861 ret = fixup_inode_link_count(trans, root, inode); 1862 iput(inode); 1863 if (ret) 1864 break; 1865 1866 /* 1867 * fixup on a directory may create new entries, 1868 * make sure we always look for the highset possible 1869 * offset 1870 */ 1871 key.offset = (u64)-1; 1872 } 1873 btrfs_release_path(path); 1874 return ret; 1875 } 1876 1877 1878 /* 1879 * record a given inode in the fixup dir so we can check its link 1880 * count when replay is done. The link count is incremented here 1881 * so the inode won't go away until we check it 1882 */ 1883 static noinline int link_to_fixup_dir(struct btrfs_trans_handle *trans, 1884 struct btrfs_root *root, 1885 struct btrfs_path *path, 1886 u64 objectid) 1887 { 1888 struct btrfs_key key; 1889 int ret = 0; 1890 struct inode *inode; 1891 1892 inode = read_one_inode(root, objectid); 1893 if (!inode) 1894 return -EIO; 1895 1896 key.objectid = BTRFS_TREE_LOG_FIXUP_OBJECTID; 1897 key.type = BTRFS_ORPHAN_ITEM_KEY; 1898 key.offset = objectid; 1899 1900 ret = btrfs_insert_empty_item(trans, root, path, &key, 0); 1901 1902 btrfs_release_path(path); 1903 if (ret == 0) { 1904 if (!inode->i_nlink) 1905 set_nlink(inode, 1); 1906 else 1907 inc_nlink(inode); 1908 ret = btrfs_update_inode(trans, root, BTRFS_I(inode)); 1909 } else if (ret == -EEXIST) { 1910 ret = 0; 1911 } 1912 iput(inode); 1913 1914 return ret; 1915 } 1916 1917 /* 1918 * when replaying the log for a directory, we only insert names 1919 * for inodes that actually exist. This means an fsync on a directory 1920 * does not implicitly fsync all the new files in it 1921 */ 1922 static noinline int insert_one_name(struct btrfs_trans_handle *trans, 1923 struct btrfs_root *root, 1924 u64 dirid, u64 index, 1925 char *name, int name_len, 1926 struct btrfs_key *location) 1927 { 1928 struct inode *inode; 1929 struct inode *dir; 1930 int ret; 1931 1932 inode = read_one_inode(root, location->objectid); 1933 if (!inode) 1934 return -ENOENT; 1935 1936 dir = read_one_inode(root, dirid); 1937 if (!dir) { 1938 iput(inode); 1939 return -EIO; 1940 } 1941 1942 ret = btrfs_add_link(trans, BTRFS_I(dir), BTRFS_I(inode), name, 1943 name_len, 1, index); 1944 1945 /* FIXME, put inode into FIXUP list */ 1946 1947 iput(inode); 1948 iput(dir); 1949 return ret; 1950 } 1951 1952 /* 1953 * take a single entry in a log directory item and replay it into 1954 * the subvolume. 1955 * 1956 * if a conflicting item exists in the subdirectory already, 1957 * the inode it points to is unlinked and put into the link count 1958 * fix up tree. 1959 * 1960 * If a name from the log points to a file or directory that does 1961 * not exist in the FS, it is skipped. fsyncs on directories 1962 * do not force down inodes inside that directory, just changes to the 1963 * names or unlinks in a directory. 1964 * 1965 * Returns < 0 on error, 0 if the name wasn't replayed (dentry points to a 1966 * non-existing inode) and 1 if the name was replayed. 1967 */ 1968 static noinline int replay_one_name(struct btrfs_trans_handle *trans, 1969 struct btrfs_root *root, 1970 struct btrfs_path *path, 1971 struct extent_buffer *eb, 1972 struct btrfs_dir_item *di, 1973 struct btrfs_key *key) 1974 { 1975 char *name; 1976 int name_len; 1977 struct btrfs_dir_item *dst_di; 1978 struct btrfs_key found_key; 1979 struct btrfs_key log_key; 1980 struct inode *dir; 1981 u8 log_type; 1982 bool exists; 1983 int ret; 1984 bool update_size = (key->type == BTRFS_DIR_INDEX_KEY); 1985 bool name_added = false; 1986 1987 dir = read_one_inode(root, key->objectid); 1988 if (!dir) 1989 return -EIO; 1990 1991 name_len = btrfs_dir_name_len(eb, di); 1992 name = kmalloc(name_len, GFP_NOFS); 1993 if (!name) { 1994 ret = -ENOMEM; 1995 goto out; 1996 } 1997 1998 log_type = btrfs_dir_type(eb, di); 1999 read_extent_buffer(eb, name, (unsigned long)(di + 1), 2000 name_len); 2001 2002 btrfs_dir_item_key_to_cpu(eb, di, &log_key); 2003 ret = btrfs_lookup_inode(trans, root, path, &log_key, 0); 2004 btrfs_release_path(path); 2005 if (ret < 0) 2006 goto out; 2007 exists = (ret == 0); 2008 ret = 0; 2009 2010 if (key->type == BTRFS_DIR_ITEM_KEY) { 2011 dst_di = btrfs_lookup_dir_item(trans, root, path, key->objectid, 2012 name, name_len, 1); 2013 } else if (key->type == BTRFS_DIR_INDEX_KEY) { 2014 dst_di = btrfs_lookup_dir_index_item(trans, root, path, 2015 key->objectid, 2016 key->offset, name, 2017 name_len, 1); 2018 } else { 2019 /* Corruption */ 2020 ret = -EINVAL; 2021 goto out; 2022 } 2023 2024 if (IS_ERR(dst_di)) { 2025 ret = PTR_ERR(dst_di); 2026 goto out; 2027 } else if (!dst_di) { 2028 /* we need a sequence number to insert, so we only 2029 * do inserts for the BTRFS_DIR_INDEX_KEY types 2030 */ 2031 if (key->type != BTRFS_DIR_INDEX_KEY) 2032 goto out; 2033 goto insert; 2034 } 2035 2036 btrfs_dir_item_key_to_cpu(path->nodes[0], dst_di, &found_key); 2037 /* the existing item matches the logged item */ 2038 if (found_key.objectid == log_key.objectid && 2039 found_key.type == log_key.type && 2040 found_key.offset == log_key.offset && 2041 btrfs_dir_type(path->nodes[0], dst_di) == log_type) { 2042 update_size = false; 2043 goto out; 2044 } 2045 2046 /* 2047 * don't drop the conflicting directory entry if the inode 2048 * for the new entry doesn't exist 2049 */ 2050 if (!exists) 2051 goto out; 2052 2053 ret = drop_one_dir_item(trans, path, BTRFS_I(dir), dst_di); 2054 if (ret) 2055 goto out; 2056 2057 if (key->type == BTRFS_DIR_INDEX_KEY) 2058 goto insert; 2059 out: 2060 btrfs_release_path(path); 2061 if (!ret && update_size) { 2062 btrfs_i_size_write(BTRFS_I(dir), dir->i_size + name_len * 2); 2063 ret = btrfs_update_inode(trans, root, BTRFS_I(dir)); 2064 } 2065 kfree(name); 2066 iput(dir); 2067 if (!ret && name_added) 2068 ret = 1; 2069 return ret; 2070 2071 insert: 2072 /* 2073 * Check if the inode reference exists in the log for the given name, 2074 * inode and parent inode 2075 */ 2076 found_key.objectid = log_key.objectid; 2077 found_key.type = BTRFS_INODE_REF_KEY; 2078 found_key.offset = key->objectid; 2079 ret = backref_in_log(root->log_root, &found_key, 0, name, name_len); 2080 if (ret < 0) { 2081 goto out; 2082 } else if (ret) { 2083 /* The dentry will be added later. */ 2084 ret = 0; 2085 update_size = false; 2086 goto out; 2087 } 2088 2089 found_key.objectid = log_key.objectid; 2090 found_key.type = BTRFS_INODE_EXTREF_KEY; 2091 found_key.offset = key->objectid; 2092 ret = backref_in_log(root->log_root, &found_key, key->objectid, name, 2093 name_len); 2094 if (ret < 0) { 2095 goto out; 2096 } else if (ret) { 2097 /* The dentry will be added later. */ 2098 ret = 0; 2099 update_size = false; 2100 goto out; 2101 } 2102 btrfs_release_path(path); 2103 ret = insert_one_name(trans, root, key->objectid, key->offset, 2104 name, name_len, &log_key); 2105 if (ret && ret != -ENOENT && ret != -EEXIST) 2106 goto out; 2107 if (!ret) 2108 name_added = true; 2109 update_size = false; 2110 ret = 0; 2111 goto out; 2112 } 2113 2114 /* 2115 * find all the names in a directory item and reconcile them into 2116 * the subvolume. Only BTRFS_DIR_ITEM_KEY types will have more than 2117 * one name in a directory item, but the same code gets used for 2118 * both directory index types 2119 */ 2120 static noinline int replay_one_dir_item(struct btrfs_trans_handle *trans, 2121 struct btrfs_root *root, 2122 struct btrfs_path *path, 2123 struct extent_buffer *eb, int slot, 2124 struct btrfs_key *key) 2125 { 2126 int ret = 0; 2127 u32 item_size = btrfs_item_size_nr(eb, slot); 2128 struct btrfs_dir_item *di; 2129 int name_len; 2130 unsigned long ptr; 2131 unsigned long ptr_end; 2132 struct btrfs_path *fixup_path = NULL; 2133 2134 ptr = btrfs_item_ptr_offset(eb, slot); 2135 ptr_end = ptr + item_size; 2136 while (ptr < ptr_end) { 2137 di = (struct btrfs_dir_item *)ptr; 2138 name_len = btrfs_dir_name_len(eb, di); 2139 ret = replay_one_name(trans, root, path, eb, di, key); 2140 if (ret < 0) 2141 break; 2142 ptr = (unsigned long)(di + 1); 2143 ptr += name_len; 2144 2145 /* 2146 * If this entry refers to a non-directory (directories can not 2147 * have a link count > 1) and it was added in the transaction 2148 * that was not committed, make sure we fixup the link count of 2149 * the inode it the entry points to. Otherwise something like 2150 * the following would result in a directory pointing to an 2151 * inode with a wrong link that does not account for this dir 2152 * entry: 2153 * 2154 * mkdir testdir 2155 * touch testdir/foo 2156 * touch testdir/bar 2157 * sync 2158 * 2159 * ln testdir/bar testdir/bar_link 2160 * ln testdir/foo testdir/foo_link 2161 * xfs_io -c "fsync" testdir/bar 2162 * 2163 * <power failure> 2164 * 2165 * mount fs, log replay happens 2166 * 2167 * File foo would remain with a link count of 1 when it has two 2168 * entries pointing to it in the directory testdir. This would 2169 * make it impossible to ever delete the parent directory has 2170 * it would result in stale dentries that can never be deleted. 2171 */ 2172 if (ret == 1 && btrfs_dir_type(eb, di) != BTRFS_FT_DIR) { 2173 struct btrfs_key di_key; 2174 2175 if (!fixup_path) { 2176 fixup_path = btrfs_alloc_path(); 2177 if (!fixup_path) { 2178 ret = -ENOMEM; 2179 break; 2180 } 2181 } 2182 2183 btrfs_dir_item_key_to_cpu(eb, di, &di_key); 2184 ret = link_to_fixup_dir(trans, root, fixup_path, 2185 di_key.objectid); 2186 if (ret) 2187 break; 2188 } 2189 ret = 0; 2190 } 2191 btrfs_free_path(fixup_path); 2192 return ret; 2193 } 2194 2195 /* 2196 * directory replay has two parts. There are the standard directory 2197 * items in the log copied from the subvolume, and range items 2198 * created in the log while the subvolume was logged. 2199 * 2200 * The range items tell us which parts of the key space the log 2201 * is authoritative for. During replay, if a key in the subvolume 2202 * directory is in a logged range item, but not actually in the log 2203 * that means it was deleted from the directory before the fsync 2204 * and should be removed. 2205 */ 2206 static noinline int find_dir_range(struct btrfs_root *root, 2207 struct btrfs_path *path, 2208 u64 dirid, int key_type, 2209 u64 *start_ret, u64 *end_ret) 2210 { 2211 struct btrfs_key key; 2212 u64 found_end; 2213 struct btrfs_dir_log_item *item; 2214 int ret; 2215 int nritems; 2216 2217 if (*start_ret == (u64)-1) 2218 return 1; 2219 2220 key.objectid = dirid; 2221 key.type = key_type; 2222 key.offset = *start_ret; 2223 2224 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 2225 if (ret < 0) 2226 goto out; 2227 if (ret > 0) { 2228 if (path->slots[0] == 0) 2229 goto out; 2230 path->slots[0]--; 2231 } 2232 if (ret != 0) 2233 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); 2234 2235 if (key.type != key_type || key.objectid != dirid) { 2236 ret = 1; 2237 goto next; 2238 } 2239 item = btrfs_item_ptr(path->nodes[0], path->slots[0], 2240 struct btrfs_dir_log_item); 2241 found_end = btrfs_dir_log_end(path->nodes[0], item); 2242 2243 if (*start_ret >= key.offset && *start_ret <= found_end) { 2244 ret = 0; 2245 *start_ret = key.offset; 2246 *end_ret = found_end; 2247 goto out; 2248 } 2249 ret = 1; 2250 next: 2251 /* check the next slot in the tree to see if it is a valid item */ 2252 nritems = btrfs_header_nritems(path->nodes[0]); 2253 path->slots[0]++; 2254 if (path->slots[0] >= nritems) { 2255 ret = btrfs_next_leaf(root, path); 2256 if (ret) 2257 goto out; 2258 } 2259 2260 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); 2261 2262 if (key.type != key_type || key.objectid != dirid) { 2263 ret = 1; 2264 goto out; 2265 } 2266 item = btrfs_item_ptr(path->nodes[0], path->slots[0], 2267 struct btrfs_dir_log_item); 2268 found_end = btrfs_dir_log_end(path->nodes[0], item); 2269 *start_ret = key.offset; 2270 *end_ret = found_end; 2271 ret = 0; 2272 out: 2273 btrfs_release_path(path); 2274 return ret; 2275 } 2276 2277 /* 2278 * this looks for a given directory item in the log. If the directory 2279 * item is not in the log, the item is removed and the inode it points 2280 * to is unlinked 2281 */ 2282 static noinline int check_item_in_log(struct btrfs_trans_handle *trans, 2283 struct btrfs_root *log, 2284 struct btrfs_path *path, 2285 struct btrfs_path *log_path, 2286 struct inode *dir, 2287 struct btrfs_key *dir_key) 2288 { 2289 struct btrfs_root *root = BTRFS_I(dir)->root; 2290 int ret; 2291 struct extent_buffer *eb; 2292 int slot; 2293 u32 item_size; 2294 struct btrfs_dir_item *di; 2295 struct btrfs_dir_item *log_di; 2296 int name_len; 2297 unsigned long ptr; 2298 unsigned long ptr_end; 2299 char *name; 2300 struct inode *inode; 2301 struct btrfs_key location; 2302 2303 again: 2304 eb = path->nodes[0]; 2305 slot = path->slots[0]; 2306 item_size = btrfs_item_size_nr(eb, slot); 2307 ptr = btrfs_item_ptr_offset(eb, slot); 2308 ptr_end = ptr + item_size; 2309 while (ptr < ptr_end) { 2310 di = (struct btrfs_dir_item *)ptr; 2311 name_len = btrfs_dir_name_len(eb, di); 2312 name = kmalloc(name_len, GFP_NOFS); 2313 if (!name) { 2314 ret = -ENOMEM; 2315 goto out; 2316 } 2317 read_extent_buffer(eb, name, (unsigned long)(di + 1), 2318 name_len); 2319 log_di = NULL; 2320 if (log && dir_key->type == BTRFS_DIR_ITEM_KEY) { 2321 log_di = btrfs_lookup_dir_item(trans, log, log_path, 2322 dir_key->objectid, 2323 name, name_len, 0); 2324 } else if (log && dir_key->type == BTRFS_DIR_INDEX_KEY) { 2325 log_di = btrfs_lookup_dir_index_item(trans, log, 2326 log_path, 2327 dir_key->objectid, 2328 dir_key->offset, 2329 name, name_len, 0); 2330 } 2331 if (!log_di) { 2332 btrfs_dir_item_key_to_cpu(eb, di, &location); 2333 btrfs_release_path(path); 2334 btrfs_release_path(log_path); 2335 inode = read_one_inode(root, location.objectid); 2336 if (!inode) { 2337 kfree(name); 2338 return -EIO; 2339 } 2340 2341 ret = link_to_fixup_dir(trans, root, 2342 path, location.objectid); 2343 if (ret) { 2344 kfree(name); 2345 iput(inode); 2346 goto out; 2347 } 2348 2349 inc_nlink(inode); 2350 ret = btrfs_unlink_inode(trans, BTRFS_I(dir), 2351 BTRFS_I(inode), name, name_len); 2352 if (!ret) 2353 ret = btrfs_run_delayed_items(trans); 2354 kfree(name); 2355 iput(inode); 2356 if (ret) 2357 goto out; 2358 2359 /* there might still be more names under this key 2360 * check and repeat if required 2361 */ 2362 ret = btrfs_search_slot(NULL, root, dir_key, path, 2363 0, 0); 2364 if (ret == 0) 2365 goto again; 2366 ret = 0; 2367 goto out; 2368 } else if (IS_ERR(log_di)) { 2369 kfree(name); 2370 return PTR_ERR(log_di); 2371 } 2372 btrfs_release_path(log_path); 2373 kfree(name); 2374 2375 ptr = (unsigned long)(di + 1); 2376 ptr += name_len; 2377 } 2378 ret = 0; 2379 out: 2380 btrfs_release_path(path); 2381 btrfs_release_path(log_path); 2382 return ret; 2383 } 2384 2385 static int replay_xattr_deletes(struct btrfs_trans_handle *trans, 2386 struct btrfs_root *root, 2387 struct btrfs_root *log, 2388 struct btrfs_path *path, 2389 const u64 ino) 2390 { 2391 struct btrfs_key search_key; 2392 struct btrfs_path *log_path; 2393 int i; 2394 int nritems; 2395 int ret; 2396 2397 log_path = btrfs_alloc_path(); 2398 if (!log_path) 2399 return -ENOMEM; 2400 2401 search_key.objectid = ino; 2402 search_key.type = BTRFS_XATTR_ITEM_KEY; 2403 search_key.offset = 0; 2404 again: 2405 ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0); 2406 if (ret < 0) 2407 goto out; 2408 process_leaf: 2409 nritems = btrfs_header_nritems(path->nodes[0]); 2410 for (i = path->slots[0]; i < nritems; i++) { 2411 struct btrfs_key key; 2412 struct btrfs_dir_item *di; 2413 struct btrfs_dir_item *log_di; 2414 u32 total_size; 2415 u32 cur; 2416 2417 btrfs_item_key_to_cpu(path->nodes[0], &key, i); 2418 if (key.objectid != ino || key.type != BTRFS_XATTR_ITEM_KEY) { 2419 ret = 0; 2420 goto out; 2421 } 2422 2423 di = btrfs_item_ptr(path->nodes[0], i, struct btrfs_dir_item); 2424 total_size = btrfs_item_size_nr(path->nodes[0], i); 2425 cur = 0; 2426 while (cur < total_size) { 2427 u16 name_len = btrfs_dir_name_len(path->nodes[0], di); 2428 u16 data_len = btrfs_dir_data_len(path->nodes[0], di); 2429 u32 this_len = sizeof(*di) + name_len + data_len; 2430 char *name; 2431 2432 name = kmalloc(name_len, GFP_NOFS); 2433 if (!name) { 2434 ret = -ENOMEM; 2435 goto out; 2436 } 2437 read_extent_buffer(path->nodes[0], name, 2438 (unsigned long)(di + 1), name_len); 2439 2440 log_di = btrfs_lookup_xattr(NULL, log, log_path, ino, 2441 name, name_len, 0); 2442 btrfs_release_path(log_path); 2443 if (!log_di) { 2444 /* Doesn't exist in log tree, so delete it. */ 2445 btrfs_release_path(path); 2446 di = btrfs_lookup_xattr(trans, root, path, ino, 2447 name, name_len, -1); 2448 kfree(name); 2449 if (IS_ERR(di)) { 2450 ret = PTR_ERR(di); 2451 goto out; 2452 } 2453 ASSERT(di); 2454 ret = btrfs_delete_one_dir_name(trans, root, 2455 path, di); 2456 if (ret) 2457 goto out; 2458 btrfs_release_path(path); 2459 search_key = key; 2460 goto again; 2461 } 2462 kfree(name); 2463 if (IS_ERR(log_di)) { 2464 ret = PTR_ERR(log_di); 2465 goto out; 2466 } 2467 cur += this_len; 2468 di = (struct btrfs_dir_item *)((char *)di + this_len); 2469 } 2470 } 2471 ret = btrfs_next_leaf(root, path); 2472 if (ret > 0) 2473 ret = 0; 2474 else if (ret == 0) 2475 goto process_leaf; 2476 out: 2477 btrfs_free_path(log_path); 2478 btrfs_release_path(path); 2479 return ret; 2480 } 2481 2482 2483 /* 2484 * deletion replay happens before we copy any new directory items 2485 * out of the log or out of backreferences from inodes. It 2486 * scans the log to find ranges of keys that log is authoritative for, 2487 * and then scans the directory to find items in those ranges that are 2488 * not present in the log. 2489 * 2490 * Anything we don't find in the log is unlinked and removed from the 2491 * directory. 2492 */ 2493 static noinline int replay_dir_deletes(struct btrfs_trans_handle *trans, 2494 struct btrfs_root *root, 2495 struct btrfs_root *log, 2496 struct btrfs_path *path, 2497 u64 dirid, int del_all) 2498 { 2499 u64 range_start; 2500 u64 range_end; 2501 int key_type = BTRFS_DIR_LOG_ITEM_KEY; 2502 int ret = 0; 2503 struct btrfs_key dir_key; 2504 struct btrfs_key found_key; 2505 struct btrfs_path *log_path; 2506 struct inode *dir; 2507 2508 dir_key.objectid = dirid; 2509 dir_key.type = BTRFS_DIR_ITEM_KEY; 2510 log_path = btrfs_alloc_path(); 2511 if (!log_path) 2512 return -ENOMEM; 2513 2514 dir = read_one_inode(root, dirid); 2515 /* it isn't an error if the inode isn't there, that can happen 2516 * because we replay the deletes before we copy in the inode item 2517 * from the log 2518 */ 2519 if (!dir) { 2520 btrfs_free_path(log_path); 2521 return 0; 2522 } 2523 again: 2524 range_start = 0; 2525 range_end = 0; 2526 while (1) { 2527 if (del_all) 2528 range_end = (u64)-1; 2529 else { 2530 ret = find_dir_range(log, path, dirid, key_type, 2531 &range_start, &range_end); 2532 if (ret < 0) 2533 goto out; 2534 else if (ret > 0) 2535 break; 2536 } 2537 2538 dir_key.offset = range_start; 2539 while (1) { 2540 int nritems; 2541 ret = btrfs_search_slot(NULL, root, &dir_key, path, 2542 0, 0); 2543 if (ret < 0) 2544 goto out; 2545 2546 nritems = btrfs_header_nritems(path->nodes[0]); 2547 if (path->slots[0] >= nritems) { 2548 ret = btrfs_next_leaf(root, path); 2549 if (ret == 1) 2550 break; 2551 else if (ret < 0) 2552 goto out; 2553 } 2554 btrfs_item_key_to_cpu(path->nodes[0], &found_key, 2555 path->slots[0]); 2556 if (found_key.objectid != dirid || 2557 found_key.type != dir_key.type) 2558 goto next_type; 2559 2560 if (found_key.offset > range_end) 2561 break; 2562 2563 ret = check_item_in_log(trans, log, path, 2564 log_path, dir, 2565 &found_key); 2566 if (ret) 2567 goto out; 2568 if (found_key.offset == (u64)-1) 2569 break; 2570 dir_key.offset = found_key.offset + 1; 2571 } 2572 btrfs_release_path(path); 2573 if (range_end == (u64)-1) 2574 break; 2575 range_start = range_end + 1; 2576 } 2577 2578 next_type: 2579 ret = 0; 2580 if (key_type == BTRFS_DIR_LOG_ITEM_KEY) { 2581 key_type = BTRFS_DIR_LOG_INDEX_KEY; 2582 dir_key.type = BTRFS_DIR_INDEX_KEY; 2583 btrfs_release_path(path); 2584 goto again; 2585 } 2586 out: 2587 btrfs_release_path(path); 2588 btrfs_free_path(log_path); 2589 iput(dir); 2590 return ret; 2591 } 2592 2593 /* 2594 * the process_func used to replay items from the log tree. This 2595 * gets called in two different stages. The first stage just looks 2596 * for inodes and makes sure they are all copied into the subvolume. 2597 * 2598 * The second stage copies all the other item types from the log into 2599 * the subvolume. The two stage approach is slower, but gets rid of 2600 * lots of complexity around inodes referencing other inodes that exist 2601 * only in the log (references come from either directory items or inode 2602 * back refs). 2603 */ 2604 static int replay_one_buffer(struct btrfs_root *log, struct extent_buffer *eb, 2605 struct walk_control *wc, u64 gen, int level) 2606 { 2607 int nritems; 2608 struct btrfs_path *path; 2609 struct btrfs_root *root = wc->replay_dest; 2610 struct btrfs_key key; 2611 int i; 2612 int ret; 2613 2614 ret = btrfs_read_buffer(eb, gen, level, NULL); 2615 if (ret) 2616 return ret; 2617 2618 level = btrfs_header_level(eb); 2619 2620 if (level != 0) 2621 return 0; 2622 2623 path = btrfs_alloc_path(); 2624 if (!path) 2625 return -ENOMEM; 2626 2627 nritems = btrfs_header_nritems(eb); 2628 for (i = 0; i < nritems; i++) { 2629 btrfs_item_key_to_cpu(eb, &key, i); 2630 2631 /* inode keys are done during the first stage */ 2632 if (key.type == BTRFS_INODE_ITEM_KEY && 2633 wc->stage == LOG_WALK_REPLAY_INODES) { 2634 struct btrfs_inode_item *inode_item; 2635 u32 mode; 2636 2637 inode_item = btrfs_item_ptr(eb, i, 2638 struct btrfs_inode_item); 2639 /* 2640 * If we have a tmpfile (O_TMPFILE) that got fsync'ed 2641 * and never got linked before the fsync, skip it, as 2642 * replaying it is pointless since it would be deleted 2643 * later. We skip logging tmpfiles, but it's always 2644 * possible we are replaying a log created with a kernel 2645 * that used to log tmpfiles. 2646 */ 2647 if (btrfs_inode_nlink(eb, inode_item) == 0) { 2648 wc->ignore_cur_inode = true; 2649 continue; 2650 } else { 2651 wc->ignore_cur_inode = false; 2652 } 2653 ret = replay_xattr_deletes(wc->trans, root, log, 2654 path, key.objectid); 2655 if (ret) 2656 break; 2657 mode = btrfs_inode_mode(eb, inode_item); 2658 if (S_ISDIR(mode)) { 2659 ret = replay_dir_deletes(wc->trans, 2660 root, log, path, key.objectid, 0); 2661 if (ret) 2662 break; 2663 } 2664 ret = overwrite_item(wc->trans, root, path, 2665 eb, i, &key); 2666 if (ret) 2667 break; 2668 2669 /* 2670 * Before replaying extents, truncate the inode to its 2671 * size. We need to do it now and not after log replay 2672 * because before an fsync we can have prealloc extents 2673 * added beyond the inode's i_size. If we did it after, 2674 * through orphan cleanup for example, we would drop 2675 * those prealloc extents just after replaying them. 2676 */ 2677 if (S_ISREG(mode)) { 2678 struct btrfs_drop_extents_args drop_args = { 0 }; 2679 struct inode *inode; 2680 u64 from; 2681 2682 inode = read_one_inode(root, key.objectid); 2683 if (!inode) { 2684 ret = -EIO; 2685 break; 2686 } 2687 from = ALIGN(i_size_read(inode), 2688 root->fs_info->sectorsize); 2689 drop_args.start = from; 2690 drop_args.end = (u64)-1; 2691 drop_args.drop_cache = true; 2692 ret = btrfs_drop_extents(wc->trans, root, 2693 BTRFS_I(inode), 2694 &drop_args); 2695 if (!ret) { 2696 inode_sub_bytes(inode, 2697 drop_args.bytes_found); 2698 /* Update the inode's nbytes. */ 2699 ret = btrfs_update_inode(wc->trans, 2700 root, BTRFS_I(inode)); 2701 } 2702 iput(inode); 2703 if (ret) 2704 break; 2705 } 2706 2707 ret = link_to_fixup_dir(wc->trans, root, 2708 path, key.objectid); 2709 if (ret) 2710 break; 2711 } 2712 2713 if (wc->ignore_cur_inode) 2714 continue; 2715 2716 if (key.type == BTRFS_DIR_INDEX_KEY && 2717 wc->stage == LOG_WALK_REPLAY_DIR_INDEX) { 2718 ret = replay_one_dir_item(wc->trans, root, path, 2719 eb, i, &key); 2720 if (ret) 2721 break; 2722 } 2723 2724 if (wc->stage < LOG_WALK_REPLAY_ALL) 2725 continue; 2726 2727 /* these keys are simply copied */ 2728 if (key.type == BTRFS_XATTR_ITEM_KEY) { 2729 ret = overwrite_item(wc->trans, root, path, 2730 eb, i, &key); 2731 if (ret) 2732 break; 2733 } else if (key.type == BTRFS_INODE_REF_KEY || 2734 key.type == BTRFS_INODE_EXTREF_KEY) { 2735 ret = add_inode_ref(wc->trans, root, log, path, 2736 eb, i, &key); 2737 if (ret && ret != -ENOENT) 2738 break; 2739 ret = 0; 2740 } else if (key.type == BTRFS_EXTENT_DATA_KEY) { 2741 ret = replay_one_extent(wc->trans, root, path, 2742 eb, i, &key); 2743 if (ret) 2744 break; 2745 } else if (key.type == BTRFS_DIR_ITEM_KEY) { 2746 ret = replay_one_dir_item(wc->trans, root, path, 2747 eb, i, &key); 2748 if (ret) 2749 break; 2750 } 2751 } 2752 btrfs_free_path(path); 2753 return ret; 2754 } 2755 2756 /* 2757 * Correctly adjust the reserved bytes occupied by a log tree extent buffer 2758 */ 2759 static void unaccount_log_buffer(struct btrfs_fs_info *fs_info, u64 start) 2760 { 2761 struct btrfs_block_group *cache; 2762 2763 cache = btrfs_lookup_block_group(fs_info, start); 2764 if (!cache) { 2765 btrfs_err(fs_info, "unable to find block group for %llu", start); 2766 return; 2767 } 2768 2769 spin_lock(&cache->space_info->lock); 2770 spin_lock(&cache->lock); 2771 cache->reserved -= fs_info->nodesize; 2772 cache->space_info->bytes_reserved -= fs_info->nodesize; 2773 spin_unlock(&cache->lock); 2774 spin_unlock(&cache->space_info->lock); 2775 2776 btrfs_put_block_group(cache); 2777 } 2778 2779 static noinline int walk_down_log_tree(struct btrfs_trans_handle *trans, 2780 struct btrfs_root *root, 2781 struct btrfs_path *path, int *level, 2782 struct walk_control *wc) 2783 { 2784 struct btrfs_fs_info *fs_info = root->fs_info; 2785 u64 bytenr; 2786 u64 ptr_gen; 2787 struct extent_buffer *next; 2788 struct extent_buffer *cur; 2789 u32 blocksize; 2790 int ret = 0; 2791 2792 while (*level > 0) { 2793 struct btrfs_key first_key; 2794 2795 cur = path->nodes[*level]; 2796 2797 WARN_ON(btrfs_header_level(cur) != *level); 2798 2799 if (path->slots[*level] >= 2800 btrfs_header_nritems(cur)) 2801 break; 2802 2803 bytenr = btrfs_node_blockptr(cur, path->slots[*level]); 2804 ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]); 2805 btrfs_node_key_to_cpu(cur, &first_key, path->slots[*level]); 2806 blocksize = fs_info->nodesize; 2807 2808 next = btrfs_find_create_tree_block(fs_info, bytenr, 2809 btrfs_header_owner(cur), 2810 *level - 1); 2811 if (IS_ERR(next)) 2812 return PTR_ERR(next); 2813 2814 if (*level == 1) { 2815 ret = wc->process_func(root, next, wc, ptr_gen, 2816 *level - 1); 2817 if (ret) { 2818 free_extent_buffer(next); 2819 return ret; 2820 } 2821 2822 path->slots[*level]++; 2823 if (wc->free) { 2824 ret = btrfs_read_buffer(next, ptr_gen, 2825 *level - 1, &first_key); 2826 if (ret) { 2827 free_extent_buffer(next); 2828 return ret; 2829 } 2830 2831 if (trans) { 2832 btrfs_tree_lock(next); 2833 btrfs_clean_tree_block(next); 2834 btrfs_wait_tree_block_writeback(next); 2835 btrfs_tree_unlock(next); 2836 ret = btrfs_pin_reserved_extent(trans, 2837 bytenr, blocksize); 2838 if (ret) { 2839 free_extent_buffer(next); 2840 return ret; 2841 } 2842 btrfs_redirty_list_add( 2843 trans->transaction, next); 2844 } else { 2845 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &next->bflags)) 2846 clear_extent_buffer_dirty(next); 2847 unaccount_log_buffer(fs_info, bytenr); 2848 } 2849 } 2850 free_extent_buffer(next); 2851 continue; 2852 } 2853 ret = btrfs_read_buffer(next, ptr_gen, *level - 1, &first_key); 2854 if (ret) { 2855 free_extent_buffer(next); 2856 return ret; 2857 } 2858 2859 if (path->nodes[*level-1]) 2860 free_extent_buffer(path->nodes[*level-1]); 2861 path->nodes[*level-1] = next; 2862 *level = btrfs_header_level(next); 2863 path->slots[*level] = 0; 2864 cond_resched(); 2865 } 2866 path->slots[*level] = btrfs_header_nritems(path->nodes[*level]); 2867 2868 cond_resched(); 2869 return 0; 2870 } 2871 2872 static noinline int walk_up_log_tree(struct btrfs_trans_handle *trans, 2873 struct btrfs_root *root, 2874 struct btrfs_path *path, int *level, 2875 struct walk_control *wc) 2876 { 2877 struct btrfs_fs_info *fs_info = root->fs_info; 2878 int i; 2879 int slot; 2880 int ret; 2881 2882 for (i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) { 2883 slot = path->slots[i]; 2884 if (slot + 1 < btrfs_header_nritems(path->nodes[i])) { 2885 path->slots[i]++; 2886 *level = i; 2887 WARN_ON(*level == 0); 2888 return 0; 2889 } else { 2890 ret = wc->process_func(root, path->nodes[*level], wc, 2891 btrfs_header_generation(path->nodes[*level]), 2892 *level); 2893 if (ret) 2894 return ret; 2895 2896 if (wc->free) { 2897 struct extent_buffer *next; 2898 2899 next = path->nodes[*level]; 2900 2901 if (trans) { 2902 btrfs_tree_lock(next); 2903 btrfs_clean_tree_block(next); 2904 btrfs_wait_tree_block_writeback(next); 2905 btrfs_tree_unlock(next); 2906 ret = btrfs_pin_reserved_extent(trans, 2907 path->nodes[*level]->start, 2908 path->nodes[*level]->len); 2909 if (ret) 2910 return ret; 2911 btrfs_redirty_list_add(trans->transaction, 2912 next); 2913 } else { 2914 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &next->bflags)) 2915 clear_extent_buffer_dirty(next); 2916 2917 unaccount_log_buffer(fs_info, 2918 path->nodes[*level]->start); 2919 } 2920 } 2921 free_extent_buffer(path->nodes[*level]); 2922 path->nodes[*level] = NULL; 2923 *level = i + 1; 2924 } 2925 } 2926 return 1; 2927 } 2928 2929 /* 2930 * drop the reference count on the tree rooted at 'snap'. This traverses 2931 * the tree freeing any blocks that have a ref count of zero after being 2932 * decremented. 2933 */ 2934 static int walk_log_tree(struct btrfs_trans_handle *trans, 2935 struct btrfs_root *log, struct walk_control *wc) 2936 { 2937 struct btrfs_fs_info *fs_info = log->fs_info; 2938 int ret = 0; 2939 int wret; 2940 int level; 2941 struct btrfs_path *path; 2942 int orig_level; 2943 2944 path = btrfs_alloc_path(); 2945 if (!path) 2946 return -ENOMEM; 2947 2948 level = btrfs_header_level(log->node); 2949 orig_level = level; 2950 path->nodes[level] = log->node; 2951 atomic_inc(&log->node->refs); 2952 path->slots[level] = 0; 2953 2954 while (1) { 2955 wret = walk_down_log_tree(trans, log, path, &level, wc); 2956 if (wret > 0) 2957 break; 2958 if (wret < 0) { 2959 ret = wret; 2960 goto out; 2961 } 2962 2963 wret = walk_up_log_tree(trans, log, path, &level, wc); 2964 if (wret > 0) 2965 break; 2966 if (wret < 0) { 2967 ret = wret; 2968 goto out; 2969 } 2970 } 2971 2972 /* was the root node processed? if not, catch it here */ 2973 if (path->nodes[orig_level]) { 2974 ret = wc->process_func(log, path->nodes[orig_level], wc, 2975 btrfs_header_generation(path->nodes[orig_level]), 2976 orig_level); 2977 if (ret) 2978 goto out; 2979 if (wc->free) { 2980 struct extent_buffer *next; 2981 2982 next = path->nodes[orig_level]; 2983 2984 if (trans) { 2985 btrfs_tree_lock(next); 2986 btrfs_clean_tree_block(next); 2987 btrfs_wait_tree_block_writeback(next); 2988 btrfs_tree_unlock(next); 2989 ret = btrfs_pin_reserved_extent(trans, 2990 next->start, next->len); 2991 if (ret) 2992 goto out; 2993 btrfs_redirty_list_add(trans->transaction, next); 2994 } else { 2995 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &next->bflags)) 2996 clear_extent_buffer_dirty(next); 2997 unaccount_log_buffer(fs_info, next->start); 2998 } 2999 } 3000 } 3001 3002 out: 3003 btrfs_free_path(path); 3004 return ret; 3005 } 3006 3007 /* 3008 * helper function to update the item for a given subvolumes log root 3009 * in the tree of log roots 3010 */ 3011 static int update_log_root(struct btrfs_trans_handle *trans, 3012 struct btrfs_root *log, 3013 struct btrfs_root_item *root_item) 3014 { 3015 struct btrfs_fs_info *fs_info = log->fs_info; 3016 int ret; 3017 3018 if (log->log_transid == 1) { 3019 /* insert root item on the first sync */ 3020 ret = btrfs_insert_root(trans, fs_info->log_root_tree, 3021 &log->root_key, root_item); 3022 } else { 3023 ret = btrfs_update_root(trans, fs_info->log_root_tree, 3024 &log->root_key, root_item); 3025 } 3026 return ret; 3027 } 3028 3029 static void wait_log_commit(struct btrfs_root *root, int transid) 3030 { 3031 DEFINE_WAIT(wait); 3032 int index = transid % 2; 3033 3034 /* 3035 * we only allow two pending log transactions at a time, 3036 * so we know that if ours is more than 2 older than the 3037 * current transaction, we're done 3038 */ 3039 for (;;) { 3040 prepare_to_wait(&root->log_commit_wait[index], 3041 &wait, TASK_UNINTERRUPTIBLE); 3042 3043 if (!(root->log_transid_committed < transid && 3044 atomic_read(&root->log_commit[index]))) 3045 break; 3046 3047 mutex_unlock(&root->log_mutex); 3048 schedule(); 3049 mutex_lock(&root->log_mutex); 3050 } 3051 finish_wait(&root->log_commit_wait[index], &wait); 3052 } 3053 3054 static void wait_for_writer(struct btrfs_root *root) 3055 { 3056 DEFINE_WAIT(wait); 3057 3058 for (;;) { 3059 prepare_to_wait(&root->log_writer_wait, &wait, 3060 TASK_UNINTERRUPTIBLE); 3061 if (!atomic_read(&root->log_writers)) 3062 break; 3063 3064 mutex_unlock(&root->log_mutex); 3065 schedule(); 3066 mutex_lock(&root->log_mutex); 3067 } 3068 finish_wait(&root->log_writer_wait, &wait); 3069 } 3070 3071 static inline void btrfs_remove_log_ctx(struct btrfs_root *root, 3072 struct btrfs_log_ctx *ctx) 3073 { 3074 mutex_lock(&root->log_mutex); 3075 list_del_init(&ctx->list); 3076 mutex_unlock(&root->log_mutex); 3077 } 3078 3079 /* 3080 * Invoked in log mutex context, or be sure there is no other task which 3081 * can access the list. 3082 */ 3083 static inline void btrfs_remove_all_log_ctxs(struct btrfs_root *root, 3084 int index, int error) 3085 { 3086 struct btrfs_log_ctx *ctx; 3087 struct btrfs_log_ctx *safe; 3088 3089 list_for_each_entry_safe(ctx, safe, &root->log_ctxs[index], list) { 3090 list_del_init(&ctx->list); 3091 ctx->log_ret = error; 3092 } 3093 } 3094 3095 /* 3096 * btrfs_sync_log does sends a given tree log down to the disk and 3097 * updates the super blocks to record it. When this call is done, 3098 * you know that any inodes previously logged are safely on disk only 3099 * if it returns 0. 3100 * 3101 * Any other return value means you need to call btrfs_commit_transaction. 3102 * Some of the edge cases for fsyncing directories that have had unlinks 3103 * or renames done in the past mean that sometimes the only safe 3104 * fsync is to commit the whole FS. When btrfs_sync_log returns -EAGAIN, 3105 * that has happened. 3106 */ 3107 int btrfs_sync_log(struct btrfs_trans_handle *trans, 3108 struct btrfs_root *root, struct btrfs_log_ctx *ctx) 3109 { 3110 int index1; 3111 int index2; 3112 int mark; 3113 int ret; 3114 struct btrfs_fs_info *fs_info = root->fs_info; 3115 struct btrfs_root *log = root->log_root; 3116 struct btrfs_root *log_root_tree = fs_info->log_root_tree; 3117 struct btrfs_root_item new_root_item; 3118 int log_transid = 0; 3119 struct btrfs_log_ctx root_log_ctx; 3120 struct blk_plug plug; 3121 u64 log_root_start; 3122 u64 log_root_level; 3123 3124 mutex_lock(&root->log_mutex); 3125 log_transid = ctx->log_transid; 3126 if (root->log_transid_committed >= log_transid) { 3127 mutex_unlock(&root->log_mutex); 3128 return ctx->log_ret; 3129 } 3130 3131 index1 = log_transid % 2; 3132 if (atomic_read(&root->log_commit[index1])) { 3133 wait_log_commit(root, log_transid); 3134 mutex_unlock(&root->log_mutex); 3135 return ctx->log_ret; 3136 } 3137 ASSERT(log_transid == root->log_transid); 3138 atomic_set(&root->log_commit[index1], 1); 3139 3140 /* wait for previous tree log sync to complete */ 3141 if (atomic_read(&root->log_commit[(index1 + 1) % 2])) 3142 wait_log_commit(root, log_transid - 1); 3143 3144 while (1) { 3145 int batch = atomic_read(&root->log_batch); 3146 /* when we're on an ssd, just kick the log commit out */ 3147 if (!btrfs_test_opt(fs_info, SSD) && 3148 test_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state)) { 3149 mutex_unlock(&root->log_mutex); 3150 schedule_timeout_uninterruptible(1); 3151 mutex_lock(&root->log_mutex); 3152 } 3153 wait_for_writer(root); 3154 if (batch == atomic_read(&root->log_batch)) 3155 break; 3156 } 3157 3158 /* bail out if we need to do a full commit */ 3159 if (btrfs_need_log_full_commit(trans)) { 3160 ret = -EAGAIN; 3161 mutex_unlock(&root->log_mutex); 3162 goto out; 3163 } 3164 3165 if (log_transid % 2 == 0) 3166 mark = EXTENT_DIRTY; 3167 else 3168 mark = EXTENT_NEW; 3169 3170 /* we start IO on all the marked extents here, but we don't actually 3171 * wait for them until later. 3172 */ 3173 blk_start_plug(&plug); 3174 ret = btrfs_write_marked_extents(fs_info, &log->dirty_log_pages, mark); 3175 /* 3176 * -EAGAIN happens when someone, e.g., a concurrent transaction 3177 * commit, writes a dirty extent in this tree-log commit. This 3178 * concurrent write will create a hole writing out the extents, 3179 * and we cannot proceed on a zoned filesystem, requiring 3180 * sequential writing. While we can bail out to a full commit 3181 * here, but we can continue hoping the concurrent writing fills 3182 * the hole. 3183 */ 3184 if (ret == -EAGAIN && btrfs_is_zoned(fs_info)) 3185 ret = 0; 3186 if (ret) { 3187 blk_finish_plug(&plug); 3188 btrfs_abort_transaction(trans, ret); 3189 btrfs_set_log_full_commit(trans); 3190 mutex_unlock(&root->log_mutex); 3191 goto out; 3192 } 3193 3194 /* 3195 * We _must_ update under the root->log_mutex in order to make sure we 3196 * have a consistent view of the log root we are trying to commit at 3197 * this moment. 3198 * 3199 * We _must_ copy this into a local copy, because we are not holding the 3200 * log_root_tree->log_mutex yet. This is important because when we 3201 * commit the log_root_tree we must have a consistent view of the 3202 * log_root_tree when we update the super block to point at the 3203 * log_root_tree bytenr. If we update the log_root_tree here we'll race 3204 * with the commit and possibly point at the new block which we may not 3205 * have written out. 3206 */ 3207 btrfs_set_root_node(&log->root_item, log->node); 3208 memcpy(&new_root_item, &log->root_item, sizeof(new_root_item)); 3209 3210 root->log_transid++; 3211 log->log_transid = root->log_transid; 3212 root->log_start_pid = 0; 3213 /* 3214 * IO has been started, blocks of the log tree have WRITTEN flag set 3215 * in their headers. new modifications of the log will be written to 3216 * new positions. so it's safe to allow log writers to go in. 3217 */ 3218 mutex_unlock(&root->log_mutex); 3219 3220 if (btrfs_is_zoned(fs_info)) { 3221 mutex_lock(&fs_info->tree_root->log_mutex); 3222 if (!log_root_tree->node) { 3223 ret = btrfs_alloc_log_tree_node(trans, log_root_tree); 3224 if (ret) { 3225 mutex_unlock(&fs_info->tree_root->log_mutex); 3226 goto out; 3227 } 3228 } 3229 mutex_unlock(&fs_info->tree_root->log_mutex); 3230 } 3231 3232 btrfs_init_log_ctx(&root_log_ctx, NULL); 3233 3234 mutex_lock(&log_root_tree->log_mutex); 3235 3236 index2 = log_root_tree->log_transid % 2; 3237 list_add_tail(&root_log_ctx.list, &log_root_tree->log_ctxs[index2]); 3238 root_log_ctx.log_transid = log_root_tree->log_transid; 3239 3240 /* 3241 * Now we are safe to update the log_root_tree because we're under the 3242 * log_mutex, and we're a current writer so we're holding the commit 3243 * open until we drop the log_mutex. 3244 */ 3245 ret = update_log_root(trans, log, &new_root_item); 3246 if (ret) { 3247 if (!list_empty(&root_log_ctx.list)) 3248 list_del_init(&root_log_ctx.list); 3249 3250 blk_finish_plug(&plug); 3251 btrfs_set_log_full_commit(trans); 3252 3253 if (ret != -ENOSPC) { 3254 btrfs_abort_transaction(trans, ret); 3255 mutex_unlock(&log_root_tree->log_mutex); 3256 goto out; 3257 } 3258 btrfs_wait_tree_log_extents(log, mark); 3259 mutex_unlock(&log_root_tree->log_mutex); 3260 ret = -EAGAIN; 3261 goto out; 3262 } 3263 3264 if (log_root_tree->log_transid_committed >= root_log_ctx.log_transid) { 3265 blk_finish_plug(&plug); 3266 list_del_init(&root_log_ctx.list); 3267 mutex_unlock(&log_root_tree->log_mutex); 3268 ret = root_log_ctx.log_ret; 3269 goto out; 3270 } 3271 3272 index2 = root_log_ctx.log_transid % 2; 3273 if (atomic_read(&log_root_tree->log_commit[index2])) { 3274 blk_finish_plug(&plug); 3275 ret = btrfs_wait_tree_log_extents(log, mark); 3276 wait_log_commit(log_root_tree, 3277 root_log_ctx.log_transid); 3278 mutex_unlock(&log_root_tree->log_mutex); 3279 if (!ret) 3280 ret = root_log_ctx.log_ret; 3281 goto out; 3282 } 3283 ASSERT(root_log_ctx.log_transid == log_root_tree->log_transid); 3284 atomic_set(&log_root_tree->log_commit[index2], 1); 3285 3286 if (atomic_read(&log_root_tree->log_commit[(index2 + 1) % 2])) { 3287 wait_log_commit(log_root_tree, 3288 root_log_ctx.log_transid - 1); 3289 } 3290 3291 /* 3292 * now that we've moved on to the tree of log tree roots, 3293 * check the full commit flag again 3294 */ 3295 if (btrfs_need_log_full_commit(trans)) { 3296 blk_finish_plug(&plug); 3297 btrfs_wait_tree_log_extents(log, mark); 3298 mutex_unlock(&log_root_tree->log_mutex); 3299 ret = -EAGAIN; 3300 goto out_wake_log_root; 3301 } 3302 3303 ret = btrfs_write_marked_extents(fs_info, 3304 &log_root_tree->dirty_log_pages, 3305 EXTENT_DIRTY | EXTENT_NEW); 3306 blk_finish_plug(&plug); 3307 /* 3308 * As described above, -EAGAIN indicates a hole in the extents. We 3309 * cannot wait for these write outs since the waiting cause a 3310 * deadlock. Bail out to the full commit instead. 3311 */ 3312 if (ret == -EAGAIN && btrfs_is_zoned(fs_info)) { 3313 btrfs_set_log_full_commit(trans); 3314 btrfs_wait_tree_log_extents(log, mark); 3315 mutex_unlock(&log_root_tree->log_mutex); 3316 goto out_wake_log_root; 3317 } else if (ret) { 3318 btrfs_set_log_full_commit(trans); 3319 btrfs_abort_transaction(trans, ret); 3320 mutex_unlock(&log_root_tree->log_mutex); 3321 goto out_wake_log_root; 3322 } 3323 ret = btrfs_wait_tree_log_extents(log, mark); 3324 if (!ret) 3325 ret = btrfs_wait_tree_log_extents(log_root_tree, 3326 EXTENT_NEW | EXTENT_DIRTY); 3327 if (ret) { 3328 btrfs_set_log_full_commit(trans); 3329 mutex_unlock(&log_root_tree->log_mutex); 3330 goto out_wake_log_root; 3331 } 3332 3333 log_root_start = log_root_tree->node->start; 3334 log_root_level = btrfs_header_level(log_root_tree->node); 3335 log_root_tree->log_transid++; 3336 mutex_unlock(&log_root_tree->log_mutex); 3337 3338 /* 3339 * Here we are guaranteed that nobody is going to write the superblock 3340 * for the current transaction before us and that neither we do write 3341 * our superblock before the previous transaction finishes its commit 3342 * and writes its superblock, because: 3343 * 3344 * 1) We are holding a handle on the current transaction, so no body 3345 * can commit it until we release the handle; 3346 * 3347 * 2) Before writing our superblock we acquire the tree_log_mutex, so 3348 * if the previous transaction is still committing, and hasn't yet 3349 * written its superblock, we wait for it to do it, because a 3350 * transaction commit acquires the tree_log_mutex when the commit 3351 * begins and releases it only after writing its superblock. 3352 */ 3353 mutex_lock(&fs_info->tree_log_mutex); 3354 3355 /* 3356 * The previous transaction writeout phase could have failed, and thus 3357 * marked the fs in an error state. We must not commit here, as we 3358 * could have updated our generation in the super_for_commit and 3359 * writing the super here would result in transid mismatches. If there 3360 * is an error here just bail. 3361 */ 3362 if (BTRFS_FS_ERROR(fs_info)) { 3363 ret = -EIO; 3364 btrfs_set_log_full_commit(trans); 3365 btrfs_abort_transaction(trans, ret); 3366 mutex_unlock(&fs_info->tree_log_mutex); 3367 goto out_wake_log_root; 3368 } 3369 3370 btrfs_set_super_log_root(fs_info->super_for_commit, log_root_start); 3371 btrfs_set_super_log_root_level(fs_info->super_for_commit, log_root_level); 3372 ret = write_all_supers(fs_info, 1); 3373 mutex_unlock(&fs_info->tree_log_mutex); 3374 if (ret) { 3375 btrfs_set_log_full_commit(trans); 3376 btrfs_abort_transaction(trans, ret); 3377 goto out_wake_log_root; 3378 } 3379 3380 /* 3381 * We know there can only be one task here, since we have not yet set 3382 * root->log_commit[index1] to 0 and any task attempting to sync the 3383 * log must wait for the previous log transaction to commit if it's 3384 * still in progress or wait for the current log transaction commit if 3385 * someone else already started it. We use <= and not < because the 3386 * first log transaction has an ID of 0. 3387 */ 3388 ASSERT(root->last_log_commit <= log_transid); 3389 root->last_log_commit = log_transid; 3390 3391 out_wake_log_root: 3392 mutex_lock(&log_root_tree->log_mutex); 3393 btrfs_remove_all_log_ctxs(log_root_tree, index2, ret); 3394 3395 log_root_tree->log_transid_committed++; 3396 atomic_set(&log_root_tree->log_commit[index2], 0); 3397 mutex_unlock(&log_root_tree->log_mutex); 3398 3399 /* 3400 * The barrier before waitqueue_active (in cond_wake_up) is needed so 3401 * all the updates above are seen by the woken threads. It might not be 3402 * necessary, but proving that seems to be hard. 3403 */ 3404 cond_wake_up(&log_root_tree->log_commit_wait[index2]); 3405 out: 3406 mutex_lock(&root->log_mutex); 3407 btrfs_remove_all_log_ctxs(root, index1, ret); 3408 root->log_transid_committed++; 3409 atomic_set(&root->log_commit[index1], 0); 3410 mutex_unlock(&root->log_mutex); 3411 3412 /* 3413 * The barrier before waitqueue_active (in cond_wake_up) is needed so 3414 * all the updates above are seen by the woken threads. It might not be 3415 * necessary, but proving that seems to be hard. 3416 */ 3417 cond_wake_up(&root->log_commit_wait[index1]); 3418 return ret; 3419 } 3420 3421 static void free_log_tree(struct btrfs_trans_handle *trans, 3422 struct btrfs_root *log) 3423 { 3424 int ret; 3425 struct walk_control wc = { 3426 .free = 1, 3427 .process_func = process_one_buffer 3428 }; 3429 3430 if (log->node) { 3431 ret = walk_log_tree(trans, log, &wc); 3432 if (ret) { 3433 if (trans) 3434 btrfs_abort_transaction(trans, ret); 3435 else 3436 btrfs_handle_fs_error(log->fs_info, ret, NULL); 3437 } 3438 } 3439 3440 clear_extent_bits(&log->dirty_log_pages, 0, (u64)-1, 3441 EXTENT_DIRTY | EXTENT_NEW | EXTENT_NEED_WAIT); 3442 extent_io_tree_release(&log->log_csum_range); 3443 3444 btrfs_put_root(log); 3445 } 3446 3447 /* 3448 * free all the extents used by the tree log. This should be called 3449 * at commit time of the full transaction 3450 */ 3451 int btrfs_free_log(struct btrfs_trans_handle *trans, struct btrfs_root *root) 3452 { 3453 if (root->log_root) { 3454 free_log_tree(trans, root->log_root); 3455 root->log_root = NULL; 3456 clear_bit(BTRFS_ROOT_HAS_LOG_TREE, &root->state); 3457 } 3458 return 0; 3459 } 3460 3461 int btrfs_free_log_root_tree(struct btrfs_trans_handle *trans, 3462 struct btrfs_fs_info *fs_info) 3463 { 3464 if (fs_info->log_root_tree) { 3465 free_log_tree(trans, fs_info->log_root_tree); 3466 fs_info->log_root_tree = NULL; 3467 clear_bit(BTRFS_ROOT_HAS_LOG_TREE, &fs_info->tree_root->state); 3468 } 3469 return 0; 3470 } 3471 3472 /* 3473 * Check if an inode was logged in the current transaction. This may often 3474 * return some false positives, because logged_trans is an in memory only field, 3475 * not persisted anywhere. This is meant to be used in contexts where a false 3476 * positive has no functional consequences. 3477 */ 3478 static bool inode_logged(struct btrfs_trans_handle *trans, 3479 struct btrfs_inode *inode) 3480 { 3481 if (inode->logged_trans == trans->transid) 3482 return true; 3483 3484 if (!test_bit(BTRFS_ROOT_HAS_LOG_TREE, &inode->root->state)) 3485 return false; 3486 3487 /* 3488 * The inode's logged_trans is always 0 when we load it (because it is 3489 * not persisted in the inode item or elsewhere). So if it is 0, the 3490 * inode was last modified in the current transaction then the inode may 3491 * have been logged before in the current transaction, then evicted and 3492 * loaded again in the current transaction - or may have never been logged 3493 * in the current transaction, but since we can not be sure, we have to 3494 * assume it was, otherwise our callers can leave an inconsistent log. 3495 */ 3496 if (inode->logged_trans == 0 && 3497 inode->last_trans == trans->transid && 3498 !test_bit(BTRFS_FS_LOG_RECOVERING, &trans->fs_info->flags)) 3499 return true; 3500 3501 return false; 3502 } 3503 3504 /* 3505 * If both a file and directory are logged, and unlinks or renames are 3506 * mixed in, we have a few interesting corners: 3507 * 3508 * create file X in dir Y 3509 * link file X to X.link in dir Y 3510 * fsync file X 3511 * unlink file X but leave X.link 3512 * fsync dir Y 3513 * 3514 * After a crash we would expect only X.link to exist. But file X 3515 * didn't get fsync'd again so the log has back refs for X and X.link. 3516 * 3517 * We solve this by removing directory entries and inode backrefs from the 3518 * log when a file that was logged in the current transaction is 3519 * unlinked. Any later fsync will include the updated log entries, and 3520 * we'll be able to reconstruct the proper directory items from backrefs. 3521 * 3522 * This optimizations allows us to avoid relogging the entire inode 3523 * or the entire directory. 3524 */ 3525 void btrfs_del_dir_entries_in_log(struct btrfs_trans_handle *trans, 3526 struct btrfs_root *root, 3527 const char *name, int name_len, 3528 struct btrfs_inode *dir, u64 index) 3529 { 3530 struct btrfs_root *log; 3531 struct btrfs_dir_item *di; 3532 struct btrfs_path *path; 3533 int ret; 3534 int err = 0; 3535 u64 dir_ino = btrfs_ino(dir); 3536 3537 if (!inode_logged(trans, dir)) 3538 return; 3539 3540 ret = join_running_log_trans(root); 3541 if (ret) 3542 return; 3543 3544 mutex_lock(&dir->log_mutex); 3545 3546 log = root->log_root; 3547 path = btrfs_alloc_path(); 3548 if (!path) { 3549 err = -ENOMEM; 3550 goto out_unlock; 3551 } 3552 3553 di = btrfs_lookup_dir_item(trans, log, path, dir_ino, 3554 name, name_len, -1); 3555 if (IS_ERR(di)) { 3556 err = PTR_ERR(di); 3557 goto fail; 3558 } 3559 if (di) { 3560 ret = btrfs_delete_one_dir_name(trans, log, path, di); 3561 if (ret) { 3562 err = ret; 3563 goto fail; 3564 } 3565 } 3566 btrfs_release_path(path); 3567 di = btrfs_lookup_dir_index_item(trans, log, path, dir_ino, 3568 index, name, name_len, -1); 3569 if (IS_ERR(di)) { 3570 err = PTR_ERR(di); 3571 goto fail; 3572 } 3573 if (di) { 3574 ret = btrfs_delete_one_dir_name(trans, log, path, di); 3575 if (ret) { 3576 err = ret; 3577 goto fail; 3578 } 3579 } 3580 3581 /* 3582 * We do not need to update the size field of the directory's inode item 3583 * because on log replay we update the field to reflect all existing 3584 * entries in the directory (see overwrite_item()). 3585 */ 3586 fail: 3587 btrfs_free_path(path); 3588 out_unlock: 3589 mutex_unlock(&dir->log_mutex); 3590 if (err < 0) 3591 btrfs_set_log_full_commit(trans); 3592 btrfs_end_log_trans(root); 3593 } 3594 3595 /* see comments for btrfs_del_dir_entries_in_log */ 3596 void btrfs_del_inode_ref_in_log(struct btrfs_trans_handle *trans, 3597 struct btrfs_root *root, 3598 const char *name, int name_len, 3599 struct btrfs_inode *inode, u64 dirid) 3600 { 3601 struct btrfs_root *log; 3602 u64 index; 3603 int ret; 3604 3605 if (!inode_logged(trans, inode)) 3606 return; 3607 3608 ret = join_running_log_trans(root); 3609 if (ret) 3610 return; 3611 log = root->log_root; 3612 mutex_lock(&inode->log_mutex); 3613 3614 ret = btrfs_del_inode_ref(trans, log, name, name_len, btrfs_ino(inode), 3615 dirid, &index); 3616 mutex_unlock(&inode->log_mutex); 3617 if (ret < 0 && ret != -ENOENT) 3618 btrfs_set_log_full_commit(trans); 3619 btrfs_end_log_trans(root); 3620 } 3621 3622 /* 3623 * creates a range item in the log for 'dirid'. first_offset and 3624 * last_offset tell us which parts of the key space the log should 3625 * be considered authoritative for. 3626 */ 3627 static noinline int insert_dir_log_key(struct btrfs_trans_handle *trans, 3628 struct btrfs_root *log, 3629 struct btrfs_path *path, 3630 int key_type, u64 dirid, 3631 u64 first_offset, u64 last_offset) 3632 { 3633 int ret; 3634 struct btrfs_key key; 3635 struct btrfs_dir_log_item *item; 3636 3637 key.objectid = dirid; 3638 key.offset = first_offset; 3639 if (key_type == BTRFS_DIR_ITEM_KEY) 3640 key.type = BTRFS_DIR_LOG_ITEM_KEY; 3641 else 3642 key.type = BTRFS_DIR_LOG_INDEX_KEY; 3643 ret = btrfs_insert_empty_item(trans, log, path, &key, sizeof(*item)); 3644 if (ret) 3645 return ret; 3646 3647 item = btrfs_item_ptr(path->nodes[0], path->slots[0], 3648 struct btrfs_dir_log_item); 3649 btrfs_set_dir_log_end(path->nodes[0], item, last_offset); 3650 btrfs_mark_buffer_dirty(path->nodes[0]); 3651 btrfs_release_path(path); 3652 return 0; 3653 } 3654 3655 static int flush_dir_items_batch(struct btrfs_trans_handle *trans, 3656 struct btrfs_root *log, 3657 struct extent_buffer *src, 3658 struct btrfs_path *dst_path, 3659 int start_slot, 3660 int count) 3661 { 3662 char *ins_data = NULL; 3663 struct btrfs_item_batch batch; 3664 struct extent_buffer *dst; 3665 unsigned long src_offset; 3666 unsigned long dst_offset; 3667 struct btrfs_key key; 3668 u32 item_size; 3669 int ret; 3670 int i; 3671 3672 ASSERT(count > 0); 3673 batch.nr = count; 3674 3675 if (count == 1) { 3676 btrfs_item_key_to_cpu(src, &key, start_slot); 3677 item_size = btrfs_item_size_nr(src, start_slot); 3678 batch.keys = &key; 3679 batch.data_sizes = &item_size; 3680 batch.total_data_size = item_size; 3681 } else { 3682 struct btrfs_key *ins_keys; 3683 u32 *ins_sizes; 3684 3685 ins_data = kmalloc(count * sizeof(u32) + 3686 count * sizeof(struct btrfs_key), GFP_NOFS); 3687 if (!ins_data) 3688 return -ENOMEM; 3689 3690 ins_sizes = (u32 *)ins_data; 3691 ins_keys = (struct btrfs_key *)(ins_data + count * sizeof(u32)); 3692 batch.keys = ins_keys; 3693 batch.data_sizes = ins_sizes; 3694 batch.total_data_size = 0; 3695 3696 for (i = 0; i < count; i++) { 3697 const int slot = start_slot + i; 3698 3699 btrfs_item_key_to_cpu(src, &ins_keys[i], slot); 3700 ins_sizes[i] = btrfs_item_size_nr(src, slot); 3701 batch.total_data_size += ins_sizes[i]; 3702 } 3703 } 3704 3705 ret = btrfs_insert_empty_items(trans, log, dst_path, &batch); 3706 if (ret) 3707 goto out; 3708 3709 dst = dst_path->nodes[0]; 3710 /* 3711 * Copy all the items in bulk, in a single copy operation. Item data is 3712 * organized such that it's placed at the end of a leaf and from right 3713 * to left. For example, the data for the second item ends at an offset 3714 * that matches the offset where the data for the first item starts, the 3715 * data for the third item ends at an offset that matches the offset 3716 * where the data of the second items starts, and so on. 3717 * Therefore our source and destination start offsets for copy match the 3718 * offsets of the last items (highest slots). 3719 */ 3720 dst_offset = btrfs_item_ptr_offset(dst, dst_path->slots[0] + count - 1); 3721 src_offset = btrfs_item_ptr_offset(src, start_slot + count - 1); 3722 copy_extent_buffer(dst, src, dst_offset, src_offset, batch.total_data_size); 3723 btrfs_release_path(dst_path); 3724 out: 3725 kfree(ins_data); 3726 3727 return ret; 3728 } 3729 3730 static int process_dir_items_leaf(struct btrfs_trans_handle *trans, 3731 struct btrfs_inode *inode, 3732 struct btrfs_path *path, 3733 struct btrfs_path *dst_path, 3734 int key_type, 3735 struct btrfs_log_ctx *ctx) 3736 { 3737 struct btrfs_root *log = inode->root->log_root; 3738 struct extent_buffer *src = path->nodes[0]; 3739 const int nritems = btrfs_header_nritems(src); 3740 const u64 ino = btrfs_ino(inode); 3741 const bool inode_logged_before = inode_logged(trans, inode); 3742 u64 last_logged_key_offset; 3743 bool last_found = false; 3744 int batch_start = 0; 3745 int batch_size = 0; 3746 int i; 3747 3748 if (key_type == BTRFS_DIR_ITEM_KEY) 3749 last_logged_key_offset = inode->last_dir_item_offset; 3750 else 3751 last_logged_key_offset = inode->last_dir_index_offset; 3752 3753 for (i = path->slots[0]; i < nritems; i++) { 3754 struct btrfs_key key; 3755 int ret; 3756 3757 btrfs_item_key_to_cpu(src, &key, i); 3758 3759 if (key.objectid != ino || key.type != key_type) { 3760 last_found = true; 3761 break; 3762 } 3763 3764 ctx->last_dir_item_offset = key.offset; 3765 /* 3766 * We must make sure that when we log a directory entry, the 3767 * corresponding inode, after log replay, has a matching link 3768 * count. For example: 3769 * 3770 * touch foo 3771 * mkdir mydir 3772 * sync 3773 * ln foo mydir/bar 3774 * xfs_io -c "fsync" mydir 3775 * <crash> 3776 * <mount fs and log replay> 3777 * 3778 * Would result in a fsync log that when replayed, our file inode 3779 * would have a link count of 1, but we get two directory entries 3780 * pointing to the same inode. After removing one of the names, 3781 * it would not be possible to remove the other name, which 3782 * resulted always in stale file handle errors, and would not be 3783 * possible to rmdir the parent directory, since its i_size could 3784 * never be decremented to the value BTRFS_EMPTY_DIR_SIZE, 3785 * resulting in -ENOTEMPTY errors. 3786 */ 3787 if (!ctx->log_new_dentries) { 3788 struct btrfs_dir_item *di; 3789 struct btrfs_key di_key; 3790 3791 di = btrfs_item_ptr(src, i, struct btrfs_dir_item); 3792 btrfs_dir_item_key_to_cpu(src, di, &di_key); 3793 if ((btrfs_dir_transid(src, di) == trans->transid || 3794 btrfs_dir_type(src, di) == BTRFS_FT_DIR) && 3795 di_key.type != BTRFS_ROOT_ITEM_KEY) 3796 ctx->log_new_dentries = true; 3797 } 3798 3799 if (!inode_logged_before) 3800 goto add_to_batch; 3801 3802 /* 3803 * If we were logged before and have logged dir items, we can skip 3804 * checking if any item with a key offset larger than the last one 3805 * we logged is in the log tree, saving time and avoiding adding 3806 * contention on the log tree. 3807 */ 3808 if (key.offset > last_logged_key_offset) 3809 goto add_to_batch; 3810 /* 3811 * Check if the key was already logged before. If not we can add 3812 * it to a batch for bulk insertion. 3813 */ 3814 ret = btrfs_search_slot(NULL, log, &key, dst_path, 0, 0); 3815 if (ret < 0) { 3816 return ret; 3817 } else if (ret > 0) { 3818 btrfs_release_path(dst_path); 3819 goto add_to_batch; 3820 } 3821 3822 /* 3823 * Item exists in the log. Overwrite the item in the log if it 3824 * has different content or do nothing if it has exactly the same 3825 * content. And then flush the current batch if any - do it after 3826 * overwriting the current item, or we would deadlock otherwise, 3827 * since we are holding a path for the existing item. 3828 */ 3829 ret = do_overwrite_item(trans, log, dst_path, src, i, &key); 3830 if (ret < 0) 3831 return ret; 3832 3833 if (batch_size > 0) { 3834 ret = flush_dir_items_batch(trans, log, src, dst_path, 3835 batch_start, batch_size); 3836 if (ret < 0) 3837 return ret; 3838 batch_size = 0; 3839 } 3840 continue; 3841 add_to_batch: 3842 if (batch_size == 0) 3843 batch_start = i; 3844 batch_size++; 3845 } 3846 3847 if (batch_size > 0) { 3848 int ret; 3849 3850 ret = flush_dir_items_batch(trans, log, src, dst_path, 3851 batch_start, batch_size); 3852 if (ret < 0) 3853 return ret; 3854 } 3855 3856 return last_found ? 1 : 0; 3857 } 3858 3859 /* 3860 * log all the items included in the current transaction for a given 3861 * directory. This also creates the range items in the log tree required 3862 * to replay anything deleted before the fsync 3863 */ 3864 static noinline int log_dir_items(struct btrfs_trans_handle *trans, 3865 struct btrfs_inode *inode, 3866 struct btrfs_path *path, 3867 struct btrfs_path *dst_path, int key_type, 3868 struct btrfs_log_ctx *ctx, 3869 u64 min_offset, u64 *last_offset_ret) 3870 { 3871 struct btrfs_key min_key; 3872 struct btrfs_root *root = inode->root; 3873 struct btrfs_root *log = root->log_root; 3874 int err = 0; 3875 int ret; 3876 u64 first_offset = min_offset; 3877 u64 last_offset = (u64)-1; 3878 u64 ino = btrfs_ino(inode); 3879 3880 min_key.objectid = ino; 3881 min_key.type = key_type; 3882 min_key.offset = min_offset; 3883 3884 ret = btrfs_search_forward(root, &min_key, path, trans->transid); 3885 3886 /* 3887 * we didn't find anything from this transaction, see if there 3888 * is anything at all 3889 */ 3890 if (ret != 0 || min_key.objectid != ino || min_key.type != key_type) { 3891 min_key.objectid = ino; 3892 min_key.type = key_type; 3893 min_key.offset = (u64)-1; 3894 btrfs_release_path(path); 3895 ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0); 3896 if (ret < 0) { 3897 btrfs_release_path(path); 3898 return ret; 3899 } 3900 ret = btrfs_previous_item(root, path, ino, key_type); 3901 3902 /* if ret == 0 there are items for this type, 3903 * create a range to tell us the last key of this type. 3904 * otherwise, there are no items in this directory after 3905 * *min_offset, and we create a range to indicate that. 3906 */ 3907 if (ret == 0) { 3908 struct btrfs_key tmp; 3909 btrfs_item_key_to_cpu(path->nodes[0], &tmp, 3910 path->slots[0]); 3911 if (key_type == tmp.type) 3912 first_offset = max(min_offset, tmp.offset) + 1; 3913 } 3914 goto done; 3915 } 3916 3917 /* go backward to find any previous key */ 3918 ret = btrfs_previous_item(root, path, ino, key_type); 3919 if (ret == 0) { 3920 struct btrfs_key tmp; 3921 btrfs_item_key_to_cpu(path->nodes[0], &tmp, path->slots[0]); 3922 if (key_type == tmp.type) { 3923 first_offset = tmp.offset; 3924 ret = overwrite_item(trans, log, dst_path, 3925 path->nodes[0], path->slots[0], 3926 &tmp); 3927 if (ret) { 3928 err = ret; 3929 goto done; 3930 } 3931 } 3932 } 3933 btrfs_release_path(path); 3934 3935 /* 3936 * Find the first key from this transaction again. See the note for 3937 * log_new_dir_dentries, if we're logging a directory recursively we 3938 * won't be holding its i_mutex, which means we can modify the directory 3939 * while we're logging it. If we remove an entry between our first 3940 * search and this search we'll not find the key again and can just 3941 * bail. 3942 */ 3943 search: 3944 ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0); 3945 if (ret != 0) 3946 goto done; 3947 3948 /* 3949 * we have a block from this transaction, log every item in it 3950 * from our directory 3951 */ 3952 while (1) { 3953 ret = process_dir_items_leaf(trans, inode, path, dst_path, 3954 key_type, ctx); 3955 if (ret != 0) { 3956 if (ret < 0) 3957 err = ret; 3958 goto done; 3959 } 3960 path->slots[0] = btrfs_header_nritems(path->nodes[0]); 3961 3962 /* 3963 * look ahead to the next item and see if it is also 3964 * from this directory and from this transaction 3965 */ 3966 ret = btrfs_next_leaf(root, path); 3967 if (ret) { 3968 if (ret == 1) 3969 last_offset = (u64)-1; 3970 else 3971 err = ret; 3972 goto done; 3973 } 3974 btrfs_item_key_to_cpu(path->nodes[0], &min_key, path->slots[0]); 3975 if (min_key.objectid != ino || min_key.type != key_type) { 3976 last_offset = (u64)-1; 3977 goto done; 3978 } 3979 if (btrfs_header_generation(path->nodes[0]) != trans->transid) { 3980 ret = overwrite_item(trans, log, dst_path, 3981 path->nodes[0], path->slots[0], 3982 &min_key); 3983 if (ret) 3984 err = ret; 3985 else 3986 last_offset = min_key.offset; 3987 goto done; 3988 } 3989 if (need_resched()) { 3990 btrfs_release_path(path); 3991 cond_resched(); 3992 goto search; 3993 } 3994 } 3995 done: 3996 btrfs_release_path(path); 3997 btrfs_release_path(dst_path); 3998 3999 if (err == 0) { 4000 *last_offset_ret = last_offset; 4001 /* 4002 * insert the log range keys to indicate where the log 4003 * is valid 4004 */ 4005 ret = insert_dir_log_key(trans, log, path, key_type, 4006 ino, first_offset, last_offset); 4007 if (ret) 4008 err = ret; 4009 } 4010 return err; 4011 } 4012 4013 /* 4014 * logging directories is very similar to logging inodes, We find all the items 4015 * from the current transaction and write them to the log. 4016 * 4017 * The recovery code scans the directory in the subvolume, and if it finds a 4018 * key in the range logged that is not present in the log tree, then it means 4019 * that dir entry was unlinked during the transaction. 4020 * 4021 * In order for that scan to work, we must include one key smaller than 4022 * the smallest logged by this transaction and one key larger than the largest 4023 * key logged by this transaction. 4024 */ 4025 static noinline int log_directory_changes(struct btrfs_trans_handle *trans, 4026 struct btrfs_inode *inode, 4027 struct btrfs_path *path, 4028 struct btrfs_path *dst_path, 4029 struct btrfs_log_ctx *ctx) 4030 { 4031 u64 min_key; 4032 u64 max_key; 4033 int ret; 4034 int key_type = BTRFS_DIR_ITEM_KEY; 4035 4036 /* 4037 * If this is the first time we are being logged in the current 4038 * transaction, or we were logged before but the inode was evicted and 4039 * reloaded later, in which case its logged_trans is 0, reset the values 4040 * of the last logged key offsets. Note that we don't use the helper 4041 * function inode_logged() here - that is because the function returns 4042 * true after an inode eviction, assuming the worst case as it can not 4043 * know for sure if the inode was logged before. So we can not skip key 4044 * searches in the case the inode was evicted, because it may not have 4045 * been logged in this transaction and may have been logged in a past 4046 * transaction, so we need to reset the last dir item and index offsets 4047 * to (u64)-1. 4048 */ 4049 if (inode->logged_trans != trans->transid) { 4050 inode->last_dir_item_offset = (u64)-1; 4051 inode->last_dir_index_offset = (u64)-1; 4052 } 4053 again: 4054 min_key = 0; 4055 max_key = 0; 4056 if (key_type == BTRFS_DIR_ITEM_KEY) 4057 ctx->last_dir_item_offset = inode->last_dir_item_offset; 4058 else 4059 ctx->last_dir_item_offset = inode->last_dir_index_offset; 4060 4061 while (1) { 4062 ret = log_dir_items(trans, inode, path, dst_path, key_type, 4063 ctx, min_key, &max_key); 4064 if (ret) 4065 return ret; 4066 if (max_key == (u64)-1) 4067 break; 4068 min_key = max_key + 1; 4069 } 4070 4071 if (key_type == BTRFS_DIR_ITEM_KEY) { 4072 inode->last_dir_item_offset = ctx->last_dir_item_offset; 4073 key_type = BTRFS_DIR_INDEX_KEY; 4074 goto again; 4075 } else { 4076 inode->last_dir_index_offset = ctx->last_dir_item_offset; 4077 } 4078 return 0; 4079 } 4080 4081 /* 4082 * a helper function to drop items from the log before we relog an 4083 * inode. max_key_type indicates the highest item type to remove. 4084 * This cannot be run for file data extents because it does not 4085 * free the extents they point to. 4086 */ 4087 static int drop_inode_items(struct btrfs_trans_handle *trans, 4088 struct btrfs_root *log, 4089 struct btrfs_path *path, 4090 struct btrfs_inode *inode, 4091 int max_key_type) 4092 { 4093 int ret; 4094 struct btrfs_key key; 4095 struct btrfs_key found_key; 4096 int start_slot; 4097 4098 if (!inode_logged(trans, inode)) 4099 return 0; 4100 4101 key.objectid = btrfs_ino(inode); 4102 key.type = max_key_type; 4103 key.offset = (u64)-1; 4104 4105 while (1) { 4106 ret = btrfs_search_slot(trans, log, &key, path, -1, 1); 4107 BUG_ON(ret == 0); /* Logic error */ 4108 if (ret < 0) 4109 break; 4110 4111 if (path->slots[0] == 0) 4112 break; 4113 4114 path->slots[0]--; 4115 btrfs_item_key_to_cpu(path->nodes[0], &found_key, 4116 path->slots[0]); 4117 4118 if (found_key.objectid != key.objectid) 4119 break; 4120 4121 found_key.offset = 0; 4122 found_key.type = 0; 4123 ret = btrfs_bin_search(path->nodes[0], &found_key, &start_slot); 4124 if (ret < 0) 4125 break; 4126 4127 ret = btrfs_del_items(trans, log, path, start_slot, 4128 path->slots[0] - start_slot + 1); 4129 /* 4130 * If start slot isn't 0 then we don't need to re-search, we've 4131 * found the last guy with the objectid in this tree. 4132 */ 4133 if (ret || start_slot != 0) 4134 break; 4135 btrfs_release_path(path); 4136 } 4137 btrfs_release_path(path); 4138 if (ret > 0) 4139 ret = 0; 4140 return ret; 4141 } 4142 4143 static int truncate_inode_items(struct btrfs_trans_handle *trans, 4144 struct btrfs_root *log_root, 4145 struct btrfs_inode *inode, 4146 u64 new_size, u32 min_type) 4147 { 4148 int ret; 4149 4150 do { 4151 ret = btrfs_truncate_inode_items(trans, log_root, inode, 4152 new_size, min_type, NULL); 4153 } while (ret == -EAGAIN); 4154 4155 return ret; 4156 } 4157 4158 static void fill_inode_item(struct btrfs_trans_handle *trans, 4159 struct extent_buffer *leaf, 4160 struct btrfs_inode_item *item, 4161 struct inode *inode, int log_inode_only, 4162 u64 logged_isize) 4163 { 4164 struct btrfs_map_token token; 4165 u64 flags; 4166 4167 btrfs_init_map_token(&token, leaf); 4168 4169 if (log_inode_only) { 4170 /* set the generation to zero so the recover code 4171 * can tell the difference between an logging 4172 * just to say 'this inode exists' and a logging 4173 * to say 'update this inode with these values' 4174 */ 4175 btrfs_set_token_inode_generation(&token, item, 0); 4176 btrfs_set_token_inode_size(&token, item, logged_isize); 4177 } else { 4178 btrfs_set_token_inode_generation(&token, item, 4179 BTRFS_I(inode)->generation); 4180 btrfs_set_token_inode_size(&token, item, inode->i_size); 4181 } 4182 4183 btrfs_set_token_inode_uid(&token, item, i_uid_read(inode)); 4184 btrfs_set_token_inode_gid(&token, item, i_gid_read(inode)); 4185 btrfs_set_token_inode_mode(&token, item, inode->i_mode); 4186 btrfs_set_token_inode_nlink(&token, item, inode->i_nlink); 4187 4188 btrfs_set_token_timespec_sec(&token, &item->atime, 4189 inode->i_atime.tv_sec); 4190 btrfs_set_token_timespec_nsec(&token, &item->atime, 4191 inode->i_atime.tv_nsec); 4192 4193 btrfs_set_token_timespec_sec(&token, &item->mtime, 4194 inode->i_mtime.tv_sec); 4195 btrfs_set_token_timespec_nsec(&token, &item->mtime, 4196 inode->i_mtime.tv_nsec); 4197 4198 btrfs_set_token_timespec_sec(&token, &item->ctime, 4199 inode->i_ctime.tv_sec); 4200 btrfs_set_token_timespec_nsec(&token, &item->ctime, 4201 inode->i_ctime.tv_nsec); 4202 4203 /* 4204 * We do not need to set the nbytes field, in fact during a fast fsync 4205 * its value may not even be correct, since a fast fsync does not wait 4206 * for ordered extent completion, which is where we update nbytes, it 4207 * only waits for writeback to complete. During log replay as we find 4208 * file extent items and replay them, we adjust the nbytes field of the 4209 * inode item in subvolume tree as needed (see overwrite_item()). 4210 */ 4211 4212 btrfs_set_token_inode_sequence(&token, item, inode_peek_iversion(inode)); 4213 btrfs_set_token_inode_transid(&token, item, trans->transid); 4214 btrfs_set_token_inode_rdev(&token, item, inode->i_rdev); 4215 flags = btrfs_inode_combine_flags(BTRFS_I(inode)->flags, 4216 BTRFS_I(inode)->ro_flags); 4217 btrfs_set_token_inode_flags(&token, item, flags); 4218 btrfs_set_token_inode_block_group(&token, item, 0); 4219 } 4220 4221 static int log_inode_item(struct btrfs_trans_handle *trans, 4222 struct btrfs_root *log, struct btrfs_path *path, 4223 struct btrfs_inode *inode, bool inode_item_dropped) 4224 { 4225 struct btrfs_inode_item *inode_item; 4226 int ret; 4227 4228 /* 4229 * If we are doing a fast fsync and the inode was logged before in the 4230 * current transaction, then we know the inode was previously logged and 4231 * it exists in the log tree. For performance reasons, in this case use 4232 * btrfs_search_slot() directly with ins_len set to 0 so that we never 4233 * attempt a write lock on the leaf's parent, which adds unnecessary lock 4234 * contention in case there are concurrent fsyncs for other inodes of the 4235 * same subvolume. Using btrfs_insert_empty_item() when the inode item 4236 * already exists can also result in unnecessarily splitting a leaf. 4237 */ 4238 if (!inode_item_dropped && inode->logged_trans == trans->transid) { 4239 ret = btrfs_search_slot(trans, log, &inode->location, path, 0, 1); 4240 ASSERT(ret <= 0); 4241 if (ret > 0) 4242 ret = -ENOENT; 4243 } else { 4244 /* 4245 * This means it is the first fsync in the current transaction, 4246 * so the inode item is not in the log and we need to insert it. 4247 * We can never get -EEXIST because we are only called for a fast 4248 * fsync and in case an inode eviction happens after the inode was 4249 * logged before in the current transaction, when we load again 4250 * the inode, we set BTRFS_INODE_NEEDS_FULL_SYNC on its runtime 4251 * flags and set ->logged_trans to 0. 4252 */ 4253 ret = btrfs_insert_empty_item(trans, log, path, &inode->location, 4254 sizeof(*inode_item)); 4255 ASSERT(ret != -EEXIST); 4256 } 4257 if (ret) 4258 return ret; 4259 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0], 4260 struct btrfs_inode_item); 4261 fill_inode_item(trans, path->nodes[0], inode_item, &inode->vfs_inode, 4262 0, 0); 4263 btrfs_release_path(path); 4264 return 0; 4265 } 4266 4267 static int log_csums(struct btrfs_trans_handle *trans, 4268 struct btrfs_inode *inode, 4269 struct btrfs_root *log_root, 4270 struct btrfs_ordered_sum *sums) 4271 { 4272 const u64 lock_end = sums->bytenr + sums->len - 1; 4273 struct extent_state *cached_state = NULL; 4274 int ret; 4275 4276 /* 4277 * If this inode was not used for reflink operations in the current 4278 * transaction with new extents, then do the fast path, no need to 4279 * worry about logging checksum items with overlapping ranges. 4280 */ 4281 if (inode->last_reflink_trans < trans->transid) 4282 return btrfs_csum_file_blocks(trans, log_root, sums); 4283 4284 /* 4285 * Serialize logging for checksums. This is to avoid racing with the 4286 * same checksum being logged by another task that is logging another 4287 * file which happens to refer to the same extent as well. Such races 4288 * can leave checksum items in the log with overlapping ranges. 4289 */ 4290 ret = lock_extent_bits(&log_root->log_csum_range, sums->bytenr, 4291 lock_end, &cached_state); 4292 if (ret) 4293 return ret; 4294 /* 4295 * Due to extent cloning, we might have logged a csum item that covers a 4296 * subrange of a cloned extent, and later we can end up logging a csum 4297 * item for a larger subrange of the same extent or the entire range. 4298 * This would leave csum items in the log tree that cover the same range 4299 * and break the searches for checksums in the log tree, resulting in 4300 * some checksums missing in the fs/subvolume tree. So just delete (or 4301 * trim and adjust) any existing csum items in the log for this range. 4302 */ 4303 ret = btrfs_del_csums(trans, log_root, sums->bytenr, sums->len); 4304 if (!ret) 4305 ret = btrfs_csum_file_blocks(trans, log_root, sums); 4306 4307 unlock_extent_cached(&log_root->log_csum_range, sums->bytenr, lock_end, 4308 &cached_state); 4309 4310 return ret; 4311 } 4312 4313 static noinline int copy_items(struct btrfs_trans_handle *trans, 4314 struct btrfs_inode *inode, 4315 struct btrfs_path *dst_path, 4316 struct btrfs_path *src_path, 4317 int start_slot, int nr, int inode_only, 4318 u64 logged_isize) 4319 { 4320 struct btrfs_fs_info *fs_info = trans->fs_info; 4321 unsigned long src_offset; 4322 unsigned long dst_offset; 4323 struct btrfs_root *log = inode->root->log_root; 4324 struct btrfs_file_extent_item *extent; 4325 struct btrfs_inode_item *inode_item; 4326 struct extent_buffer *src = src_path->nodes[0]; 4327 int ret; 4328 struct btrfs_key *ins_keys; 4329 u32 *ins_sizes; 4330 struct btrfs_item_batch batch; 4331 char *ins_data; 4332 int i; 4333 struct list_head ordered_sums; 4334 int skip_csum = inode->flags & BTRFS_INODE_NODATASUM; 4335 4336 INIT_LIST_HEAD(&ordered_sums); 4337 4338 ins_data = kmalloc(nr * sizeof(struct btrfs_key) + 4339 nr * sizeof(u32), GFP_NOFS); 4340 if (!ins_data) 4341 return -ENOMEM; 4342 4343 ins_sizes = (u32 *)ins_data; 4344 ins_keys = (struct btrfs_key *)(ins_data + nr * sizeof(u32)); 4345 batch.keys = ins_keys; 4346 batch.data_sizes = ins_sizes; 4347 batch.total_data_size = 0; 4348 batch.nr = nr; 4349 4350 for (i = 0; i < nr; i++) { 4351 ins_sizes[i] = btrfs_item_size_nr(src, i + start_slot); 4352 batch.total_data_size += ins_sizes[i]; 4353 btrfs_item_key_to_cpu(src, ins_keys + i, i + start_slot); 4354 } 4355 ret = btrfs_insert_empty_items(trans, log, dst_path, &batch); 4356 if (ret) { 4357 kfree(ins_data); 4358 return ret; 4359 } 4360 4361 for (i = 0; i < nr; i++, dst_path->slots[0]++) { 4362 dst_offset = btrfs_item_ptr_offset(dst_path->nodes[0], 4363 dst_path->slots[0]); 4364 4365 src_offset = btrfs_item_ptr_offset(src, start_slot + i); 4366 4367 if (ins_keys[i].type == BTRFS_INODE_ITEM_KEY) { 4368 inode_item = btrfs_item_ptr(dst_path->nodes[0], 4369 dst_path->slots[0], 4370 struct btrfs_inode_item); 4371 fill_inode_item(trans, dst_path->nodes[0], inode_item, 4372 &inode->vfs_inode, 4373 inode_only == LOG_INODE_EXISTS, 4374 logged_isize); 4375 } else { 4376 copy_extent_buffer(dst_path->nodes[0], src, dst_offset, 4377 src_offset, ins_sizes[i]); 4378 } 4379 4380 /* take a reference on file data extents so that truncates 4381 * or deletes of this inode don't have to relog the inode 4382 * again 4383 */ 4384 if (ins_keys[i].type == BTRFS_EXTENT_DATA_KEY && 4385 !skip_csum) { 4386 int found_type; 4387 extent = btrfs_item_ptr(src, start_slot + i, 4388 struct btrfs_file_extent_item); 4389 4390 if (btrfs_file_extent_generation(src, extent) < trans->transid) 4391 continue; 4392 4393 found_type = btrfs_file_extent_type(src, extent); 4394 if (found_type == BTRFS_FILE_EXTENT_REG) { 4395 u64 ds, dl, cs, cl; 4396 ds = btrfs_file_extent_disk_bytenr(src, 4397 extent); 4398 /* ds == 0 is a hole */ 4399 if (ds == 0) 4400 continue; 4401 4402 dl = btrfs_file_extent_disk_num_bytes(src, 4403 extent); 4404 cs = btrfs_file_extent_offset(src, extent); 4405 cl = btrfs_file_extent_num_bytes(src, 4406 extent); 4407 if (btrfs_file_extent_compression(src, 4408 extent)) { 4409 cs = 0; 4410 cl = dl; 4411 } 4412 4413 ret = btrfs_lookup_csums_range( 4414 fs_info->csum_root, 4415 ds + cs, ds + cs + cl - 1, 4416 &ordered_sums, 0); 4417 if (ret) 4418 break; 4419 } 4420 } 4421 } 4422 4423 btrfs_mark_buffer_dirty(dst_path->nodes[0]); 4424 btrfs_release_path(dst_path); 4425 kfree(ins_data); 4426 4427 /* 4428 * we have to do this after the loop above to avoid changing the 4429 * log tree while trying to change the log tree. 4430 */ 4431 while (!list_empty(&ordered_sums)) { 4432 struct btrfs_ordered_sum *sums = list_entry(ordered_sums.next, 4433 struct btrfs_ordered_sum, 4434 list); 4435 if (!ret) 4436 ret = log_csums(trans, inode, log, sums); 4437 list_del(&sums->list); 4438 kfree(sums); 4439 } 4440 4441 return ret; 4442 } 4443 4444 static int extent_cmp(void *priv, const struct list_head *a, 4445 const struct list_head *b) 4446 { 4447 const struct extent_map *em1, *em2; 4448 4449 em1 = list_entry(a, struct extent_map, list); 4450 em2 = list_entry(b, struct extent_map, list); 4451 4452 if (em1->start < em2->start) 4453 return -1; 4454 else if (em1->start > em2->start) 4455 return 1; 4456 return 0; 4457 } 4458 4459 static int log_extent_csums(struct btrfs_trans_handle *trans, 4460 struct btrfs_inode *inode, 4461 struct btrfs_root *log_root, 4462 const struct extent_map *em, 4463 struct btrfs_log_ctx *ctx) 4464 { 4465 struct btrfs_ordered_extent *ordered; 4466 u64 csum_offset; 4467 u64 csum_len; 4468 u64 mod_start = em->mod_start; 4469 u64 mod_len = em->mod_len; 4470 LIST_HEAD(ordered_sums); 4471 int ret = 0; 4472 4473 if (inode->flags & BTRFS_INODE_NODATASUM || 4474 test_bit(EXTENT_FLAG_PREALLOC, &em->flags) || 4475 em->block_start == EXTENT_MAP_HOLE) 4476 return 0; 4477 4478 list_for_each_entry(ordered, &ctx->ordered_extents, log_list) { 4479 const u64 ordered_end = ordered->file_offset + ordered->num_bytes; 4480 const u64 mod_end = mod_start + mod_len; 4481 struct btrfs_ordered_sum *sums; 4482 4483 if (mod_len == 0) 4484 break; 4485 4486 if (ordered_end <= mod_start) 4487 continue; 4488 if (mod_end <= ordered->file_offset) 4489 break; 4490 4491 /* 4492 * We are going to copy all the csums on this ordered extent, so 4493 * go ahead and adjust mod_start and mod_len in case this ordered 4494 * extent has already been logged. 4495 */ 4496 if (ordered->file_offset > mod_start) { 4497 if (ordered_end >= mod_end) 4498 mod_len = ordered->file_offset - mod_start; 4499 /* 4500 * If we have this case 4501 * 4502 * |--------- logged extent ---------| 4503 * |----- ordered extent ----| 4504 * 4505 * Just don't mess with mod_start and mod_len, we'll 4506 * just end up logging more csums than we need and it 4507 * will be ok. 4508 */ 4509 } else { 4510 if (ordered_end < mod_end) { 4511 mod_len = mod_end - ordered_end; 4512 mod_start = ordered_end; 4513 } else { 4514 mod_len = 0; 4515 } 4516 } 4517 4518 /* 4519 * To keep us from looping for the above case of an ordered 4520 * extent that falls inside of the logged extent. 4521 */ 4522 if (test_and_set_bit(BTRFS_ORDERED_LOGGED_CSUM, &ordered->flags)) 4523 continue; 4524 4525 list_for_each_entry(sums, &ordered->list, list) { 4526 ret = log_csums(trans, inode, log_root, sums); 4527 if (ret) 4528 return ret; 4529 } 4530 } 4531 4532 /* We're done, found all csums in the ordered extents. */ 4533 if (mod_len == 0) 4534 return 0; 4535 4536 /* If we're compressed we have to save the entire range of csums. */ 4537 if (em->compress_type) { 4538 csum_offset = 0; 4539 csum_len = max(em->block_len, em->orig_block_len); 4540 } else { 4541 csum_offset = mod_start - em->start; 4542 csum_len = mod_len; 4543 } 4544 4545 /* block start is already adjusted for the file extent offset. */ 4546 ret = btrfs_lookup_csums_range(trans->fs_info->csum_root, 4547 em->block_start + csum_offset, 4548 em->block_start + csum_offset + 4549 csum_len - 1, &ordered_sums, 0); 4550 if (ret) 4551 return ret; 4552 4553 while (!list_empty(&ordered_sums)) { 4554 struct btrfs_ordered_sum *sums = list_entry(ordered_sums.next, 4555 struct btrfs_ordered_sum, 4556 list); 4557 if (!ret) 4558 ret = log_csums(trans, inode, log_root, sums); 4559 list_del(&sums->list); 4560 kfree(sums); 4561 } 4562 4563 return ret; 4564 } 4565 4566 static int log_one_extent(struct btrfs_trans_handle *trans, 4567 struct btrfs_inode *inode, 4568 const struct extent_map *em, 4569 struct btrfs_path *path, 4570 struct btrfs_log_ctx *ctx) 4571 { 4572 struct btrfs_drop_extents_args drop_args = { 0 }; 4573 struct btrfs_root *log = inode->root->log_root; 4574 struct btrfs_file_extent_item *fi; 4575 struct extent_buffer *leaf; 4576 struct btrfs_map_token token; 4577 struct btrfs_key key; 4578 u64 extent_offset = em->start - em->orig_start; 4579 u64 block_len; 4580 int ret; 4581 4582 ret = log_extent_csums(trans, inode, log, em, ctx); 4583 if (ret) 4584 return ret; 4585 4586 /* 4587 * If this is the first time we are logging the inode in the current 4588 * transaction, we can avoid btrfs_drop_extents(), which is expensive 4589 * because it does a deletion search, which always acquires write locks 4590 * for extent buffers at levels 2, 1 and 0. This not only wastes time 4591 * but also adds significant contention in a log tree, since log trees 4592 * are small, with a root at level 2 or 3 at most, due to their short 4593 * life span. 4594 */ 4595 if (inode_logged(trans, inode)) { 4596 drop_args.path = path; 4597 drop_args.start = em->start; 4598 drop_args.end = em->start + em->len; 4599 drop_args.replace_extent = true; 4600 drop_args.extent_item_size = sizeof(*fi); 4601 ret = btrfs_drop_extents(trans, log, inode, &drop_args); 4602 if (ret) 4603 return ret; 4604 } 4605 4606 if (!drop_args.extent_inserted) { 4607 key.objectid = btrfs_ino(inode); 4608 key.type = BTRFS_EXTENT_DATA_KEY; 4609 key.offset = em->start; 4610 4611 ret = btrfs_insert_empty_item(trans, log, path, &key, 4612 sizeof(*fi)); 4613 if (ret) 4614 return ret; 4615 } 4616 leaf = path->nodes[0]; 4617 btrfs_init_map_token(&token, leaf); 4618 fi = btrfs_item_ptr(leaf, path->slots[0], 4619 struct btrfs_file_extent_item); 4620 4621 btrfs_set_token_file_extent_generation(&token, fi, trans->transid); 4622 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) 4623 btrfs_set_token_file_extent_type(&token, fi, 4624 BTRFS_FILE_EXTENT_PREALLOC); 4625 else 4626 btrfs_set_token_file_extent_type(&token, fi, 4627 BTRFS_FILE_EXTENT_REG); 4628 4629 block_len = max(em->block_len, em->orig_block_len); 4630 if (em->compress_type != BTRFS_COMPRESS_NONE) { 4631 btrfs_set_token_file_extent_disk_bytenr(&token, fi, 4632 em->block_start); 4633 btrfs_set_token_file_extent_disk_num_bytes(&token, fi, block_len); 4634 } else if (em->block_start < EXTENT_MAP_LAST_BYTE) { 4635 btrfs_set_token_file_extent_disk_bytenr(&token, fi, 4636 em->block_start - 4637 extent_offset); 4638 btrfs_set_token_file_extent_disk_num_bytes(&token, fi, block_len); 4639 } else { 4640 btrfs_set_token_file_extent_disk_bytenr(&token, fi, 0); 4641 btrfs_set_token_file_extent_disk_num_bytes(&token, fi, 0); 4642 } 4643 4644 btrfs_set_token_file_extent_offset(&token, fi, extent_offset); 4645 btrfs_set_token_file_extent_num_bytes(&token, fi, em->len); 4646 btrfs_set_token_file_extent_ram_bytes(&token, fi, em->ram_bytes); 4647 btrfs_set_token_file_extent_compression(&token, fi, em->compress_type); 4648 btrfs_set_token_file_extent_encryption(&token, fi, 0); 4649 btrfs_set_token_file_extent_other_encoding(&token, fi, 0); 4650 btrfs_mark_buffer_dirty(leaf); 4651 4652 btrfs_release_path(path); 4653 4654 return ret; 4655 } 4656 4657 /* 4658 * Log all prealloc extents beyond the inode's i_size to make sure we do not 4659 * lose them after doing a fast fsync and replaying the log. We scan the 4660 * subvolume's root instead of iterating the inode's extent map tree because 4661 * otherwise we can log incorrect extent items based on extent map conversion. 4662 * That can happen due to the fact that extent maps are merged when they 4663 * are not in the extent map tree's list of modified extents. 4664 */ 4665 static int btrfs_log_prealloc_extents(struct btrfs_trans_handle *trans, 4666 struct btrfs_inode *inode, 4667 struct btrfs_path *path) 4668 { 4669 struct btrfs_root *root = inode->root; 4670 struct btrfs_key key; 4671 const u64 i_size = i_size_read(&inode->vfs_inode); 4672 const u64 ino = btrfs_ino(inode); 4673 struct btrfs_path *dst_path = NULL; 4674 bool dropped_extents = false; 4675 u64 truncate_offset = i_size; 4676 struct extent_buffer *leaf; 4677 int slot; 4678 int ins_nr = 0; 4679 int start_slot; 4680 int ret; 4681 4682 if (!(inode->flags & BTRFS_INODE_PREALLOC)) 4683 return 0; 4684 4685 key.objectid = ino; 4686 key.type = BTRFS_EXTENT_DATA_KEY; 4687 key.offset = i_size; 4688 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 4689 if (ret < 0) 4690 goto out; 4691 4692 /* 4693 * We must check if there is a prealloc extent that starts before the 4694 * i_size and crosses the i_size boundary. This is to ensure later we 4695 * truncate down to the end of that extent and not to the i_size, as 4696 * otherwise we end up losing part of the prealloc extent after a log 4697 * replay and with an implicit hole if there is another prealloc extent 4698 * that starts at an offset beyond i_size. 4699 */ 4700 ret = btrfs_previous_item(root, path, ino, BTRFS_EXTENT_DATA_KEY); 4701 if (ret < 0) 4702 goto out; 4703 4704 if (ret == 0) { 4705 struct btrfs_file_extent_item *ei; 4706 4707 leaf = path->nodes[0]; 4708 slot = path->slots[0]; 4709 ei = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item); 4710 4711 if (btrfs_file_extent_type(leaf, ei) == 4712 BTRFS_FILE_EXTENT_PREALLOC) { 4713 u64 extent_end; 4714 4715 btrfs_item_key_to_cpu(leaf, &key, slot); 4716 extent_end = key.offset + 4717 btrfs_file_extent_num_bytes(leaf, ei); 4718 4719 if (extent_end > i_size) 4720 truncate_offset = extent_end; 4721 } 4722 } else { 4723 ret = 0; 4724 } 4725 4726 while (true) { 4727 leaf = path->nodes[0]; 4728 slot = path->slots[0]; 4729 4730 if (slot >= btrfs_header_nritems(leaf)) { 4731 if (ins_nr > 0) { 4732 ret = copy_items(trans, inode, dst_path, path, 4733 start_slot, ins_nr, 1, 0); 4734 if (ret < 0) 4735 goto out; 4736 ins_nr = 0; 4737 } 4738 ret = btrfs_next_leaf(root, path); 4739 if (ret < 0) 4740 goto out; 4741 if (ret > 0) { 4742 ret = 0; 4743 break; 4744 } 4745 continue; 4746 } 4747 4748 btrfs_item_key_to_cpu(leaf, &key, slot); 4749 if (key.objectid > ino) 4750 break; 4751 if (WARN_ON_ONCE(key.objectid < ino) || 4752 key.type < BTRFS_EXTENT_DATA_KEY || 4753 key.offset < i_size) { 4754 path->slots[0]++; 4755 continue; 4756 } 4757 if (!dropped_extents) { 4758 /* 4759 * Avoid logging extent items logged in past fsync calls 4760 * and leading to duplicate keys in the log tree. 4761 */ 4762 ret = truncate_inode_items(trans, root->log_root, inode, 4763 truncate_offset, 4764 BTRFS_EXTENT_DATA_KEY); 4765 if (ret) 4766 goto out; 4767 dropped_extents = true; 4768 } 4769 if (ins_nr == 0) 4770 start_slot = slot; 4771 ins_nr++; 4772 path->slots[0]++; 4773 if (!dst_path) { 4774 dst_path = btrfs_alloc_path(); 4775 if (!dst_path) { 4776 ret = -ENOMEM; 4777 goto out; 4778 } 4779 } 4780 } 4781 if (ins_nr > 0) 4782 ret = copy_items(trans, inode, dst_path, path, 4783 start_slot, ins_nr, 1, 0); 4784 out: 4785 btrfs_release_path(path); 4786 btrfs_free_path(dst_path); 4787 return ret; 4788 } 4789 4790 static int btrfs_log_changed_extents(struct btrfs_trans_handle *trans, 4791 struct btrfs_inode *inode, 4792 struct btrfs_path *path, 4793 struct btrfs_log_ctx *ctx) 4794 { 4795 struct btrfs_ordered_extent *ordered; 4796 struct btrfs_ordered_extent *tmp; 4797 struct extent_map *em, *n; 4798 struct list_head extents; 4799 struct extent_map_tree *tree = &inode->extent_tree; 4800 int ret = 0; 4801 int num = 0; 4802 4803 INIT_LIST_HEAD(&extents); 4804 4805 write_lock(&tree->lock); 4806 4807 list_for_each_entry_safe(em, n, &tree->modified_extents, list) { 4808 list_del_init(&em->list); 4809 /* 4810 * Just an arbitrary number, this can be really CPU intensive 4811 * once we start getting a lot of extents, and really once we 4812 * have a bunch of extents we just want to commit since it will 4813 * be faster. 4814 */ 4815 if (++num > 32768) { 4816 list_del_init(&tree->modified_extents); 4817 ret = -EFBIG; 4818 goto process; 4819 } 4820 4821 if (em->generation < trans->transid) 4822 continue; 4823 4824 /* We log prealloc extents beyond eof later. */ 4825 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) && 4826 em->start >= i_size_read(&inode->vfs_inode)) 4827 continue; 4828 4829 /* Need a ref to keep it from getting evicted from cache */ 4830 refcount_inc(&em->refs); 4831 set_bit(EXTENT_FLAG_LOGGING, &em->flags); 4832 list_add_tail(&em->list, &extents); 4833 num++; 4834 } 4835 4836 list_sort(NULL, &extents, extent_cmp); 4837 process: 4838 while (!list_empty(&extents)) { 4839 em = list_entry(extents.next, struct extent_map, list); 4840 4841 list_del_init(&em->list); 4842 4843 /* 4844 * If we had an error we just need to delete everybody from our 4845 * private list. 4846 */ 4847 if (ret) { 4848 clear_em_logging(tree, em); 4849 free_extent_map(em); 4850 continue; 4851 } 4852 4853 write_unlock(&tree->lock); 4854 4855 ret = log_one_extent(trans, inode, em, path, ctx); 4856 write_lock(&tree->lock); 4857 clear_em_logging(tree, em); 4858 free_extent_map(em); 4859 } 4860 WARN_ON(!list_empty(&extents)); 4861 write_unlock(&tree->lock); 4862 4863 btrfs_release_path(path); 4864 if (!ret) 4865 ret = btrfs_log_prealloc_extents(trans, inode, path); 4866 if (ret) 4867 return ret; 4868 4869 /* 4870 * We have logged all extents successfully, now make sure the commit of 4871 * the current transaction waits for the ordered extents to complete 4872 * before it commits and wipes out the log trees, otherwise we would 4873 * lose data if an ordered extents completes after the transaction 4874 * commits and a power failure happens after the transaction commit. 4875 */ 4876 list_for_each_entry_safe(ordered, tmp, &ctx->ordered_extents, log_list) { 4877 list_del_init(&ordered->log_list); 4878 set_bit(BTRFS_ORDERED_LOGGED, &ordered->flags); 4879 4880 if (!test_bit(BTRFS_ORDERED_COMPLETE, &ordered->flags)) { 4881 spin_lock_irq(&inode->ordered_tree.lock); 4882 if (!test_bit(BTRFS_ORDERED_COMPLETE, &ordered->flags)) { 4883 set_bit(BTRFS_ORDERED_PENDING, &ordered->flags); 4884 atomic_inc(&trans->transaction->pending_ordered); 4885 } 4886 spin_unlock_irq(&inode->ordered_tree.lock); 4887 } 4888 btrfs_put_ordered_extent(ordered); 4889 } 4890 4891 return 0; 4892 } 4893 4894 static int logged_inode_size(struct btrfs_root *log, struct btrfs_inode *inode, 4895 struct btrfs_path *path, u64 *size_ret) 4896 { 4897 struct btrfs_key key; 4898 int ret; 4899 4900 key.objectid = btrfs_ino(inode); 4901 key.type = BTRFS_INODE_ITEM_KEY; 4902 key.offset = 0; 4903 4904 ret = btrfs_search_slot(NULL, log, &key, path, 0, 0); 4905 if (ret < 0) { 4906 return ret; 4907 } else if (ret > 0) { 4908 *size_ret = 0; 4909 } else { 4910 struct btrfs_inode_item *item; 4911 4912 item = btrfs_item_ptr(path->nodes[0], path->slots[0], 4913 struct btrfs_inode_item); 4914 *size_ret = btrfs_inode_size(path->nodes[0], item); 4915 /* 4916 * If the in-memory inode's i_size is smaller then the inode 4917 * size stored in the btree, return the inode's i_size, so 4918 * that we get a correct inode size after replaying the log 4919 * when before a power failure we had a shrinking truncate 4920 * followed by addition of a new name (rename / new hard link). 4921 * Otherwise return the inode size from the btree, to avoid 4922 * data loss when replaying a log due to previously doing a 4923 * write that expands the inode's size and logging a new name 4924 * immediately after. 4925 */ 4926 if (*size_ret > inode->vfs_inode.i_size) 4927 *size_ret = inode->vfs_inode.i_size; 4928 } 4929 4930 btrfs_release_path(path); 4931 return 0; 4932 } 4933 4934 /* 4935 * At the moment we always log all xattrs. This is to figure out at log replay 4936 * time which xattrs must have their deletion replayed. If a xattr is missing 4937 * in the log tree and exists in the fs/subvol tree, we delete it. This is 4938 * because if a xattr is deleted, the inode is fsynced and a power failure 4939 * happens, causing the log to be replayed the next time the fs is mounted, 4940 * we want the xattr to not exist anymore (same behaviour as other filesystems 4941 * with a journal, ext3/4, xfs, f2fs, etc). 4942 */ 4943 static int btrfs_log_all_xattrs(struct btrfs_trans_handle *trans, 4944 struct btrfs_inode *inode, 4945 struct btrfs_path *path, 4946 struct btrfs_path *dst_path) 4947 { 4948 struct btrfs_root *root = inode->root; 4949 int ret; 4950 struct btrfs_key key; 4951 const u64 ino = btrfs_ino(inode); 4952 int ins_nr = 0; 4953 int start_slot = 0; 4954 bool found_xattrs = false; 4955 4956 if (test_bit(BTRFS_INODE_NO_XATTRS, &inode->runtime_flags)) 4957 return 0; 4958 4959 key.objectid = ino; 4960 key.type = BTRFS_XATTR_ITEM_KEY; 4961 key.offset = 0; 4962 4963 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 4964 if (ret < 0) 4965 return ret; 4966 4967 while (true) { 4968 int slot = path->slots[0]; 4969 struct extent_buffer *leaf = path->nodes[0]; 4970 int nritems = btrfs_header_nritems(leaf); 4971 4972 if (slot >= nritems) { 4973 if (ins_nr > 0) { 4974 ret = copy_items(trans, inode, dst_path, path, 4975 start_slot, ins_nr, 1, 0); 4976 if (ret < 0) 4977 return ret; 4978 ins_nr = 0; 4979 } 4980 ret = btrfs_next_leaf(root, path); 4981 if (ret < 0) 4982 return ret; 4983 else if (ret > 0) 4984 break; 4985 continue; 4986 } 4987 4988 btrfs_item_key_to_cpu(leaf, &key, slot); 4989 if (key.objectid != ino || key.type != BTRFS_XATTR_ITEM_KEY) 4990 break; 4991 4992 if (ins_nr == 0) 4993 start_slot = slot; 4994 ins_nr++; 4995 path->slots[0]++; 4996 found_xattrs = true; 4997 cond_resched(); 4998 } 4999 if (ins_nr > 0) { 5000 ret = copy_items(trans, inode, dst_path, path, 5001 start_slot, ins_nr, 1, 0); 5002 if (ret < 0) 5003 return ret; 5004 } 5005 5006 if (!found_xattrs) 5007 set_bit(BTRFS_INODE_NO_XATTRS, &inode->runtime_flags); 5008 5009 return 0; 5010 } 5011 5012 /* 5013 * When using the NO_HOLES feature if we punched a hole that causes the 5014 * deletion of entire leafs or all the extent items of the first leaf (the one 5015 * that contains the inode item and references) we may end up not processing 5016 * any extents, because there are no leafs with a generation matching the 5017 * current transaction that have extent items for our inode. So we need to find 5018 * if any holes exist and then log them. We also need to log holes after any 5019 * truncate operation that changes the inode's size. 5020 */ 5021 static int btrfs_log_holes(struct btrfs_trans_handle *trans, 5022 struct btrfs_inode *inode, 5023 struct btrfs_path *path) 5024 { 5025 struct btrfs_root *root = inode->root; 5026 struct btrfs_fs_info *fs_info = root->fs_info; 5027 struct btrfs_key key; 5028 const u64 ino = btrfs_ino(inode); 5029 const u64 i_size = i_size_read(&inode->vfs_inode); 5030 u64 prev_extent_end = 0; 5031 int ret; 5032 5033 if (!btrfs_fs_incompat(fs_info, NO_HOLES) || i_size == 0) 5034 return 0; 5035 5036 key.objectid = ino; 5037 key.type = BTRFS_EXTENT_DATA_KEY; 5038 key.offset = 0; 5039 5040 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 5041 if (ret < 0) 5042 return ret; 5043 5044 while (true) { 5045 struct extent_buffer *leaf = path->nodes[0]; 5046 5047 if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) { 5048 ret = btrfs_next_leaf(root, path); 5049 if (ret < 0) 5050 return ret; 5051 if (ret > 0) { 5052 ret = 0; 5053 break; 5054 } 5055 leaf = path->nodes[0]; 5056 } 5057 5058 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); 5059 if (key.objectid != ino || key.type != BTRFS_EXTENT_DATA_KEY) 5060 break; 5061 5062 /* We have a hole, log it. */ 5063 if (prev_extent_end < key.offset) { 5064 const u64 hole_len = key.offset - prev_extent_end; 5065 5066 /* 5067 * Release the path to avoid deadlocks with other code 5068 * paths that search the root while holding locks on 5069 * leafs from the log root. 5070 */ 5071 btrfs_release_path(path); 5072 ret = btrfs_insert_file_extent(trans, root->log_root, 5073 ino, prev_extent_end, 0, 5074 0, hole_len, 0, hole_len, 5075 0, 0, 0); 5076 if (ret < 0) 5077 return ret; 5078 5079 /* 5080 * Search for the same key again in the root. Since it's 5081 * an extent item and we are holding the inode lock, the 5082 * key must still exist. If it doesn't just emit warning 5083 * and return an error to fall back to a transaction 5084 * commit. 5085 */ 5086 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 5087 if (ret < 0) 5088 return ret; 5089 if (WARN_ON(ret > 0)) 5090 return -ENOENT; 5091 leaf = path->nodes[0]; 5092 } 5093 5094 prev_extent_end = btrfs_file_extent_end(path); 5095 path->slots[0]++; 5096 cond_resched(); 5097 } 5098 5099 if (prev_extent_end < i_size) { 5100 u64 hole_len; 5101 5102 btrfs_release_path(path); 5103 hole_len = ALIGN(i_size - prev_extent_end, fs_info->sectorsize); 5104 ret = btrfs_insert_file_extent(trans, root->log_root, 5105 ino, prev_extent_end, 0, 0, 5106 hole_len, 0, hole_len, 5107 0, 0, 0); 5108 if (ret < 0) 5109 return ret; 5110 } 5111 5112 return 0; 5113 } 5114 5115 /* 5116 * When we are logging a new inode X, check if it doesn't have a reference that 5117 * matches the reference from some other inode Y created in a past transaction 5118 * and that was renamed in the current transaction. If we don't do this, then at 5119 * log replay time we can lose inode Y (and all its files if it's a directory): 5120 * 5121 * mkdir /mnt/x 5122 * echo "hello world" > /mnt/x/foobar 5123 * sync 5124 * mv /mnt/x /mnt/y 5125 * mkdir /mnt/x # or touch /mnt/x 5126 * xfs_io -c fsync /mnt/x 5127 * <power fail> 5128 * mount fs, trigger log replay 5129 * 5130 * After the log replay procedure, we would lose the first directory and all its 5131 * files (file foobar). 5132 * For the case where inode Y is not a directory we simply end up losing it: 5133 * 5134 * echo "123" > /mnt/foo 5135 * sync 5136 * mv /mnt/foo /mnt/bar 5137 * echo "abc" > /mnt/foo 5138 * xfs_io -c fsync /mnt/foo 5139 * <power fail> 5140 * 5141 * We also need this for cases where a snapshot entry is replaced by some other 5142 * entry (file or directory) otherwise we end up with an unreplayable log due to 5143 * attempts to delete the snapshot entry (entry of type BTRFS_ROOT_ITEM_KEY) as 5144 * if it were a regular entry: 5145 * 5146 * mkdir /mnt/x 5147 * btrfs subvolume snapshot /mnt /mnt/x/snap 5148 * btrfs subvolume delete /mnt/x/snap 5149 * rmdir /mnt/x 5150 * mkdir /mnt/x 5151 * fsync /mnt/x or fsync some new file inside it 5152 * <power fail> 5153 * 5154 * The snapshot delete, rmdir of x, mkdir of a new x and the fsync all happen in 5155 * the same transaction. 5156 */ 5157 static int btrfs_check_ref_name_override(struct extent_buffer *eb, 5158 const int slot, 5159 const struct btrfs_key *key, 5160 struct btrfs_inode *inode, 5161 u64 *other_ino, u64 *other_parent) 5162 { 5163 int ret; 5164 struct btrfs_path *search_path; 5165 char *name = NULL; 5166 u32 name_len = 0; 5167 u32 item_size = btrfs_item_size_nr(eb, slot); 5168 u32 cur_offset = 0; 5169 unsigned long ptr = btrfs_item_ptr_offset(eb, slot); 5170 5171 search_path = btrfs_alloc_path(); 5172 if (!search_path) 5173 return -ENOMEM; 5174 search_path->search_commit_root = 1; 5175 search_path->skip_locking = 1; 5176 5177 while (cur_offset < item_size) { 5178 u64 parent; 5179 u32 this_name_len; 5180 u32 this_len; 5181 unsigned long name_ptr; 5182 struct btrfs_dir_item *di; 5183 5184 if (key->type == BTRFS_INODE_REF_KEY) { 5185 struct btrfs_inode_ref *iref; 5186 5187 iref = (struct btrfs_inode_ref *)(ptr + cur_offset); 5188 parent = key->offset; 5189 this_name_len = btrfs_inode_ref_name_len(eb, iref); 5190 name_ptr = (unsigned long)(iref + 1); 5191 this_len = sizeof(*iref) + this_name_len; 5192 } else { 5193 struct btrfs_inode_extref *extref; 5194 5195 extref = (struct btrfs_inode_extref *)(ptr + 5196 cur_offset); 5197 parent = btrfs_inode_extref_parent(eb, extref); 5198 this_name_len = btrfs_inode_extref_name_len(eb, extref); 5199 name_ptr = (unsigned long)&extref->name; 5200 this_len = sizeof(*extref) + this_name_len; 5201 } 5202 5203 if (this_name_len > name_len) { 5204 char *new_name; 5205 5206 new_name = krealloc(name, this_name_len, GFP_NOFS); 5207 if (!new_name) { 5208 ret = -ENOMEM; 5209 goto out; 5210 } 5211 name_len = this_name_len; 5212 name = new_name; 5213 } 5214 5215 read_extent_buffer(eb, name, name_ptr, this_name_len); 5216 di = btrfs_lookup_dir_item(NULL, inode->root, search_path, 5217 parent, name, this_name_len, 0); 5218 if (di && !IS_ERR(di)) { 5219 struct btrfs_key di_key; 5220 5221 btrfs_dir_item_key_to_cpu(search_path->nodes[0], 5222 di, &di_key); 5223 if (di_key.type == BTRFS_INODE_ITEM_KEY) { 5224 if (di_key.objectid != key->objectid) { 5225 ret = 1; 5226 *other_ino = di_key.objectid; 5227 *other_parent = parent; 5228 } else { 5229 ret = 0; 5230 } 5231 } else { 5232 ret = -EAGAIN; 5233 } 5234 goto out; 5235 } else if (IS_ERR(di)) { 5236 ret = PTR_ERR(di); 5237 goto out; 5238 } 5239 btrfs_release_path(search_path); 5240 5241 cur_offset += this_len; 5242 } 5243 ret = 0; 5244 out: 5245 btrfs_free_path(search_path); 5246 kfree(name); 5247 return ret; 5248 } 5249 5250 struct btrfs_ino_list { 5251 u64 ino; 5252 u64 parent; 5253 struct list_head list; 5254 }; 5255 5256 static int log_conflicting_inodes(struct btrfs_trans_handle *trans, 5257 struct btrfs_root *root, 5258 struct btrfs_path *path, 5259 struct btrfs_log_ctx *ctx, 5260 u64 ino, u64 parent) 5261 { 5262 struct btrfs_ino_list *ino_elem; 5263 LIST_HEAD(inode_list); 5264 int ret = 0; 5265 5266 ino_elem = kmalloc(sizeof(*ino_elem), GFP_NOFS); 5267 if (!ino_elem) 5268 return -ENOMEM; 5269 ino_elem->ino = ino; 5270 ino_elem->parent = parent; 5271 list_add_tail(&ino_elem->list, &inode_list); 5272 5273 while (!list_empty(&inode_list)) { 5274 struct btrfs_fs_info *fs_info = root->fs_info; 5275 struct btrfs_key key; 5276 struct inode *inode; 5277 5278 ino_elem = list_first_entry(&inode_list, struct btrfs_ino_list, 5279 list); 5280 ino = ino_elem->ino; 5281 parent = ino_elem->parent; 5282 list_del(&ino_elem->list); 5283 kfree(ino_elem); 5284 if (ret) 5285 continue; 5286 5287 btrfs_release_path(path); 5288 5289 inode = btrfs_iget(fs_info->sb, ino, root); 5290 /* 5291 * If the other inode that had a conflicting dir entry was 5292 * deleted in the current transaction, we need to log its parent 5293 * directory. 5294 */ 5295 if (IS_ERR(inode)) { 5296 ret = PTR_ERR(inode); 5297 if (ret == -ENOENT) { 5298 inode = btrfs_iget(fs_info->sb, parent, root); 5299 if (IS_ERR(inode)) { 5300 ret = PTR_ERR(inode); 5301 } else { 5302 ret = btrfs_log_inode(trans, 5303 BTRFS_I(inode), 5304 LOG_OTHER_INODE_ALL, 5305 ctx); 5306 btrfs_add_delayed_iput(inode); 5307 } 5308 } 5309 continue; 5310 } 5311 /* 5312 * If the inode was already logged skip it - otherwise we can 5313 * hit an infinite loop. Example: 5314 * 5315 * From the commit root (previous transaction) we have the 5316 * following inodes: 5317 * 5318 * inode 257 a directory 5319 * inode 258 with references "zz" and "zz_link" on inode 257 5320 * inode 259 with reference "a" on inode 257 5321 * 5322 * And in the current (uncommitted) transaction we have: 5323 * 5324 * inode 257 a directory, unchanged 5325 * inode 258 with references "a" and "a2" on inode 257 5326 * inode 259 with reference "zz_link" on inode 257 5327 * inode 261 with reference "zz" on inode 257 5328 * 5329 * When logging inode 261 the following infinite loop could 5330 * happen if we don't skip already logged inodes: 5331 * 5332 * - we detect inode 258 as a conflicting inode, with inode 261 5333 * on reference "zz", and log it; 5334 * 5335 * - we detect inode 259 as a conflicting inode, with inode 258 5336 * on reference "a", and log it; 5337 * 5338 * - we detect inode 258 as a conflicting inode, with inode 259 5339 * on reference "zz_link", and log it - again! After this we 5340 * repeat the above steps forever. 5341 */ 5342 spin_lock(&BTRFS_I(inode)->lock); 5343 /* 5344 * Check the inode's logged_trans only instead of 5345 * btrfs_inode_in_log(). This is because the last_log_commit of 5346 * the inode is not updated when we only log that it exists (see 5347 * btrfs_log_inode()). 5348 */ 5349 if (BTRFS_I(inode)->logged_trans == trans->transid) { 5350 spin_unlock(&BTRFS_I(inode)->lock); 5351 btrfs_add_delayed_iput(inode); 5352 continue; 5353 } 5354 spin_unlock(&BTRFS_I(inode)->lock); 5355 /* 5356 * We are safe logging the other inode without acquiring its 5357 * lock as long as we log with the LOG_INODE_EXISTS mode. We 5358 * are safe against concurrent renames of the other inode as 5359 * well because during a rename we pin the log and update the 5360 * log with the new name before we unpin it. 5361 */ 5362 ret = btrfs_log_inode(trans, BTRFS_I(inode), LOG_OTHER_INODE, ctx); 5363 if (ret) { 5364 btrfs_add_delayed_iput(inode); 5365 continue; 5366 } 5367 5368 key.objectid = ino; 5369 key.type = BTRFS_INODE_REF_KEY; 5370 key.offset = 0; 5371 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 5372 if (ret < 0) { 5373 btrfs_add_delayed_iput(inode); 5374 continue; 5375 } 5376 5377 while (true) { 5378 struct extent_buffer *leaf = path->nodes[0]; 5379 int slot = path->slots[0]; 5380 u64 other_ino = 0; 5381 u64 other_parent = 0; 5382 5383 if (slot >= btrfs_header_nritems(leaf)) { 5384 ret = btrfs_next_leaf(root, path); 5385 if (ret < 0) { 5386 break; 5387 } else if (ret > 0) { 5388 ret = 0; 5389 break; 5390 } 5391 continue; 5392 } 5393 5394 btrfs_item_key_to_cpu(leaf, &key, slot); 5395 if (key.objectid != ino || 5396 (key.type != BTRFS_INODE_REF_KEY && 5397 key.type != BTRFS_INODE_EXTREF_KEY)) { 5398 ret = 0; 5399 break; 5400 } 5401 5402 ret = btrfs_check_ref_name_override(leaf, slot, &key, 5403 BTRFS_I(inode), &other_ino, 5404 &other_parent); 5405 if (ret < 0) 5406 break; 5407 if (ret > 0) { 5408 ino_elem = kmalloc(sizeof(*ino_elem), GFP_NOFS); 5409 if (!ino_elem) { 5410 ret = -ENOMEM; 5411 break; 5412 } 5413 ino_elem->ino = other_ino; 5414 ino_elem->parent = other_parent; 5415 list_add_tail(&ino_elem->list, &inode_list); 5416 ret = 0; 5417 } 5418 path->slots[0]++; 5419 } 5420 btrfs_add_delayed_iput(inode); 5421 } 5422 5423 return ret; 5424 } 5425 5426 static int copy_inode_items_to_log(struct btrfs_trans_handle *trans, 5427 struct btrfs_inode *inode, 5428 struct btrfs_key *min_key, 5429 const struct btrfs_key *max_key, 5430 struct btrfs_path *path, 5431 struct btrfs_path *dst_path, 5432 const u64 logged_isize, 5433 const bool recursive_logging, 5434 const int inode_only, 5435 struct btrfs_log_ctx *ctx, 5436 bool *need_log_inode_item) 5437 { 5438 struct btrfs_root *root = inode->root; 5439 int ins_start_slot = 0; 5440 int ins_nr = 0; 5441 int ret; 5442 5443 while (1) { 5444 ret = btrfs_search_forward(root, min_key, path, trans->transid); 5445 if (ret < 0) 5446 return ret; 5447 if (ret > 0) { 5448 ret = 0; 5449 break; 5450 } 5451 again: 5452 /* Note, ins_nr might be > 0 here, cleanup outside the loop */ 5453 if (min_key->objectid != max_key->objectid) 5454 break; 5455 if (min_key->type > max_key->type) 5456 break; 5457 5458 if (min_key->type == BTRFS_INODE_ITEM_KEY) 5459 *need_log_inode_item = false; 5460 5461 if ((min_key->type == BTRFS_INODE_REF_KEY || 5462 min_key->type == BTRFS_INODE_EXTREF_KEY) && 5463 inode->generation == trans->transid && 5464 !recursive_logging) { 5465 u64 other_ino = 0; 5466 u64 other_parent = 0; 5467 5468 ret = btrfs_check_ref_name_override(path->nodes[0], 5469 path->slots[0], min_key, inode, 5470 &other_ino, &other_parent); 5471 if (ret < 0) { 5472 return ret; 5473 } else if (ret > 0 && 5474 other_ino != btrfs_ino(BTRFS_I(ctx->inode))) { 5475 if (ins_nr > 0) { 5476 ins_nr++; 5477 } else { 5478 ins_nr = 1; 5479 ins_start_slot = path->slots[0]; 5480 } 5481 ret = copy_items(trans, inode, dst_path, path, 5482 ins_start_slot, ins_nr, 5483 inode_only, logged_isize); 5484 if (ret < 0) 5485 return ret; 5486 ins_nr = 0; 5487 5488 ret = log_conflicting_inodes(trans, root, path, 5489 ctx, other_ino, other_parent); 5490 if (ret) 5491 return ret; 5492 btrfs_release_path(path); 5493 goto next_key; 5494 } 5495 } 5496 5497 /* Skip xattrs, we log them later with btrfs_log_all_xattrs() */ 5498 if (min_key->type == BTRFS_XATTR_ITEM_KEY) { 5499 if (ins_nr == 0) 5500 goto next_slot; 5501 ret = copy_items(trans, inode, dst_path, path, 5502 ins_start_slot, 5503 ins_nr, inode_only, logged_isize); 5504 if (ret < 0) 5505 return ret; 5506 ins_nr = 0; 5507 goto next_slot; 5508 } 5509 5510 if (ins_nr && ins_start_slot + ins_nr == path->slots[0]) { 5511 ins_nr++; 5512 goto next_slot; 5513 } else if (!ins_nr) { 5514 ins_start_slot = path->slots[0]; 5515 ins_nr = 1; 5516 goto next_slot; 5517 } 5518 5519 ret = copy_items(trans, inode, dst_path, path, ins_start_slot, 5520 ins_nr, inode_only, logged_isize); 5521 if (ret < 0) 5522 return ret; 5523 ins_nr = 1; 5524 ins_start_slot = path->slots[0]; 5525 next_slot: 5526 path->slots[0]++; 5527 if (path->slots[0] < btrfs_header_nritems(path->nodes[0])) { 5528 btrfs_item_key_to_cpu(path->nodes[0], min_key, 5529 path->slots[0]); 5530 goto again; 5531 } 5532 if (ins_nr) { 5533 ret = copy_items(trans, inode, dst_path, path, 5534 ins_start_slot, ins_nr, inode_only, 5535 logged_isize); 5536 if (ret < 0) 5537 return ret; 5538 ins_nr = 0; 5539 } 5540 btrfs_release_path(path); 5541 next_key: 5542 if (min_key->offset < (u64)-1) { 5543 min_key->offset++; 5544 } else if (min_key->type < max_key->type) { 5545 min_key->type++; 5546 min_key->offset = 0; 5547 } else { 5548 break; 5549 } 5550 } 5551 if (ins_nr) 5552 ret = copy_items(trans, inode, dst_path, path, ins_start_slot, 5553 ins_nr, inode_only, logged_isize); 5554 5555 return ret; 5556 } 5557 5558 /* log a single inode in the tree log. 5559 * At least one parent directory for this inode must exist in the tree 5560 * or be logged already. 5561 * 5562 * Any items from this inode changed by the current transaction are copied 5563 * to the log tree. An extra reference is taken on any extents in this 5564 * file, allowing us to avoid a whole pile of corner cases around logging 5565 * blocks that have been removed from the tree. 5566 * 5567 * See LOG_INODE_ALL and related defines for a description of what inode_only 5568 * does. 5569 * 5570 * This handles both files and directories. 5571 */ 5572 static int btrfs_log_inode(struct btrfs_trans_handle *trans, 5573 struct btrfs_inode *inode, 5574 int inode_only, 5575 struct btrfs_log_ctx *ctx) 5576 { 5577 struct btrfs_path *path; 5578 struct btrfs_path *dst_path; 5579 struct btrfs_key min_key; 5580 struct btrfs_key max_key; 5581 struct btrfs_root *log = inode->root->log_root; 5582 int err = 0; 5583 int ret = 0; 5584 bool fast_search = false; 5585 u64 ino = btrfs_ino(inode); 5586 struct extent_map_tree *em_tree = &inode->extent_tree; 5587 u64 logged_isize = 0; 5588 bool need_log_inode_item = true; 5589 bool xattrs_logged = false; 5590 bool recursive_logging = false; 5591 bool inode_item_dropped = true; 5592 5593 path = btrfs_alloc_path(); 5594 if (!path) 5595 return -ENOMEM; 5596 dst_path = btrfs_alloc_path(); 5597 if (!dst_path) { 5598 btrfs_free_path(path); 5599 return -ENOMEM; 5600 } 5601 5602 min_key.objectid = ino; 5603 min_key.type = BTRFS_INODE_ITEM_KEY; 5604 min_key.offset = 0; 5605 5606 max_key.objectid = ino; 5607 5608 5609 /* today the code can only do partial logging of directories */ 5610 if (S_ISDIR(inode->vfs_inode.i_mode) || 5611 (!test_bit(BTRFS_INODE_NEEDS_FULL_SYNC, 5612 &inode->runtime_flags) && 5613 inode_only >= LOG_INODE_EXISTS)) 5614 max_key.type = BTRFS_XATTR_ITEM_KEY; 5615 else 5616 max_key.type = (u8)-1; 5617 max_key.offset = (u64)-1; 5618 5619 /* 5620 * Only run delayed items if we are a directory. We want to make sure 5621 * all directory indexes hit the fs/subvolume tree so we can find them 5622 * and figure out which index ranges have to be logged. 5623 */ 5624 if (S_ISDIR(inode->vfs_inode.i_mode)) { 5625 err = btrfs_commit_inode_delayed_items(trans, inode); 5626 if (err) 5627 goto out; 5628 } 5629 5630 if (inode_only == LOG_OTHER_INODE || inode_only == LOG_OTHER_INODE_ALL) { 5631 recursive_logging = true; 5632 if (inode_only == LOG_OTHER_INODE) 5633 inode_only = LOG_INODE_EXISTS; 5634 else 5635 inode_only = LOG_INODE_ALL; 5636 mutex_lock_nested(&inode->log_mutex, SINGLE_DEPTH_NESTING); 5637 } else { 5638 mutex_lock(&inode->log_mutex); 5639 } 5640 5641 /* 5642 * This is for cases where logging a directory could result in losing a 5643 * a file after replaying the log. For example, if we move a file from a 5644 * directory A to a directory B, then fsync directory A, we have no way 5645 * to known the file was moved from A to B, so logging just A would 5646 * result in losing the file after a log replay. 5647 */ 5648 if (S_ISDIR(inode->vfs_inode.i_mode) && 5649 inode_only == LOG_INODE_ALL && 5650 inode->last_unlink_trans >= trans->transid) { 5651 btrfs_set_log_full_commit(trans); 5652 err = 1; 5653 goto out_unlock; 5654 } 5655 5656 /* 5657 * a brute force approach to making sure we get the most uptodate 5658 * copies of everything. 5659 */ 5660 if (S_ISDIR(inode->vfs_inode.i_mode)) { 5661 int max_key_type = BTRFS_DIR_LOG_INDEX_KEY; 5662 5663 clear_bit(BTRFS_INODE_COPY_EVERYTHING, &inode->runtime_flags); 5664 if (inode_only == LOG_INODE_EXISTS) 5665 max_key_type = BTRFS_XATTR_ITEM_KEY; 5666 ret = drop_inode_items(trans, log, path, inode, max_key_type); 5667 } else { 5668 if (inode_only == LOG_INODE_EXISTS && inode_logged(trans, inode)) { 5669 /* 5670 * Make sure the new inode item we write to the log has 5671 * the same isize as the current one (if it exists). 5672 * This is necessary to prevent data loss after log 5673 * replay, and also to prevent doing a wrong expanding 5674 * truncate - for e.g. create file, write 4K into offset 5675 * 0, fsync, write 4K into offset 4096, add hard link, 5676 * fsync some other file (to sync log), power fail - if 5677 * we use the inode's current i_size, after log replay 5678 * we get a 8Kb file, with the last 4Kb extent as a hole 5679 * (zeroes), as if an expanding truncate happened, 5680 * instead of getting a file of 4Kb only. 5681 */ 5682 err = logged_inode_size(log, inode, path, &logged_isize); 5683 if (err) 5684 goto out_unlock; 5685 } 5686 if (test_bit(BTRFS_INODE_NEEDS_FULL_SYNC, 5687 &inode->runtime_flags)) { 5688 if (inode_only == LOG_INODE_EXISTS) { 5689 max_key.type = BTRFS_XATTR_ITEM_KEY; 5690 ret = drop_inode_items(trans, log, path, inode, 5691 max_key.type); 5692 } else { 5693 clear_bit(BTRFS_INODE_NEEDS_FULL_SYNC, 5694 &inode->runtime_flags); 5695 clear_bit(BTRFS_INODE_COPY_EVERYTHING, 5696 &inode->runtime_flags); 5697 if (inode_logged(trans, inode)) 5698 ret = truncate_inode_items(trans, log, 5699 inode, 0, 0); 5700 } 5701 } else if (test_and_clear_bit(BTRFS_INODE_COPY_EVERYTHING, 5702 &inode->runtime_flags) || 5703 inode_only == LOG_INODE_EXISTS) { 5704 if (inode_only == LOG_INODE_ALL) 5705 fast_search = true; 5706 max_key.type = BTRFS_XATTR_ITEM_KEY; 5707 ret = drop_inode_items(trans, log, path, inode, 5708 max_key.type); 5709 } else { 5710 if (inode_only == LOG_INODE_ALL) 5711 fast_search = true; 5712 inode_item_dropped = false; 5713 goto log_extents; 5714 } 5715 5716 } 5717 if (ret) { 5718 err = ret; 5719 goto out_unlock; 5720 } 5721 5722 err = copy_inode_items_to_log(trans, inode, &min_key, &max_key, 5723 path, dst_path, logged_isize, 5724 recursive_logging, inode_only, ctx, 5725 &need_log_inode_item); 5726 if (err) 5727 goto out_unlock; 5728 5729 btrfs_release_path(path); 5730 btrfs_release_path(dst_path); 5731 err = btrfs_log_all_xattrs(trans, inode, path, dst_path); 5732 if (err) 5733 goto out_unlock; 5734 xattrs_logged = true; 5735 if (max_key.type >= BTRFS_EXTENT_DATA_KEY && !fast_search) { 5736 btrfs_release_path(path); 5737 btrfs_release_path(dst_path); 5738 err = btrfs_log_holes(trans, inode, path); 5739 if (err) 5740 goto out_unlock; 5741 } 5742 log_extents: 5743 btrfs_release_path(path); 5744 btrfs_release_path(dst_path); 5745 if (need_log_inode_item) { 5746 err = log_inode_item(trans, log, dst_path, inode, inode_item_dropped); 5747 if (err) 5748 goto out_unlock; 5749 /* 5750 * If we are doing a fast fsync and the inode was logged before 5751 * in this transaction, we don't need to log the xattrs because 5752 * they were logged before. If xattrs were added, changed or 5753 * deleted since the last time we logged the inode, then we have 5754 * already logged them because the inode had the runtime flag 5755 * BTRFS_INODE_COPY_EVERYTHING set. 5756 */ 5757 if (!xattrs_logged && inode->logged_trans < trans->transid) { 5758 err = btrfs_log_all_xattrs(trans, inode, path, dst_path); 5759 if (err) 5760 goto out_unlock; 5761 btrfs_release_path(path); 5762 } 5763 } 5764 if (fast_search) { 5765 ret = btrfs_log_changed_extents(trans, inode, dst_path, ctx); 5766 if (ret) { 5767 err = ret; 5768 goto out_unlock; 5769 } 5770 } else if (inode_only == LOG_INODE_ALL) { 5771 struct extent_map *em, *n; 5772 5773 write_lock(&em_tree->lock); 5774 list_for_each_entry_safe(em, n, &em_tree->modified_extents, list) 5775 list_del_init(&em->list); 5776 write_unlock(&em_tree->lock); 5777 } 5778 5779 if (inode_only == LOG_INODE_ALL && S_ISDIR(inode->vfs_inode.i_mode)) { 5780 ret = log_directory_changes(trans, inode, path, dst_path, ctx); 5781 if (ret) { 5782 err = ret; 5783 goto out_unlock; 5784 } 5785 } 5786 5787 spin_lock(&inode->lock); 5788 inode->logged_trans = trans->transid; 5789 /* 5790 * Don't update last_log_commit if we logged that an inode exists. 5791 * We do this for three reasons: 5792 * 5793 * 1) We might have had buffered writes to this inode that were 5794 * flushed and had their ordered extents completed in this 5795 * transaction, but we did not previously log the inode with 5796 * LOG_INODE_ALL. Later the inode was evicted and after that 5797 * it was loaded again and this LOG_INODE_EXISTS log operation 5798 * happened. We must make sure that if an explicit fsync against 5799 * the inode is performed later, it logs the new extents, an 5800 * updated inode item, etc, and syncs the log. The same logic 5801 * applies to direct IO writes instead of buffered writes. 5802 * 5803 * 2) When we log the inode with LOG_INODE_EXISTS, its inode item 5804 * is logged with an i_size of 0 or whatever value was logged 5805 * before. If later the i_size of the inode is increased by a 5806 * truncate operation, the log is synced through an fsync of 5807 * some other inode and then finally an explicit fsync against 5808 * this inode is made, we must make sure this fsync logs the 5809 * inode with the new i_size, the hole between old i_size and 5810 * the new i_size, and syncs the log. 5811 * 5812 * 3) If we are logging that an ancestor inode exists as part of 5813 * logging a new name from a link or rename operation, don't update 5814 * its last_log_commit - otherwise if an explicit fsync is made 5815 * against an ancestor, the fsync considers the inode in the log 5816 * and doesn't sync the log, resulting in the ancestor missing after 5817 * a power failure unless the log was synced as part of an fsync 5818 * against any other unrelated inode. 5819 */ 5820 if (inode_only != LOG_INODE_EXISTS) 5821 inode->last_log_commit = inode->last_sub_trans; 5822 spin_unlock(&inode->lock); 5823 out_unlock: 5824 mutex_unlock(&inode->log_mutex); 5825 out: 5826 btrfs_free_path(path); 5827 btrfs_free_path(dst_path); 5828 return err; 5829 } 5830 5831 /* 5832 * Check if we need to log an inode. This is used in contexts where while 5833 * logging an inode we need to log another inode (either that it exists or in 5834 * full mode). This is used instead of btrfs_inode_in_log() because the later 5835 * requires the inode to be in the log and have the log transaction committed, 5836 * while here we do not care if the log transaction was already committed - our 5837 * caller will commit the log later - and we want to avoid logging an inode 5838 * multiple times when multiple tasks have joined the same log transaction. 5839 */ 5840 static bool need_log_inode(struct btrfs_trans_handle *trans, 5841 struct btrfs_inode *inode) 5842 { 5843 /* 5844 * If a directory was not modified, no dentries added or removed, we can 5845 * and should avoid logging it. 5846 */ 5847 if (S_ISDIR(inode->vfs_inode.i_mode) && inode->last_trans < trans->transid) 5848 return false; 5849 5850 /* 5851 * If this inode does not have new/updated/deleted xattrs since the last 5852 * time it was logged and is flagged as logged in the current transaction, 5853 * we can skip logging it. As for new/deleted names, those are updated in 5854 * the log by link/unlink/rename operations. 5855 * In case the inode was logged and then evicted and reloaded, its 5856 * logged_trans will be 0, in which case we have to fully log it since 5857 * logged_trans is a transient field, not persisted. 5858 */ 5859 if (inode->logged_trans == trans->transid && 5860 !test_bit(BTRFS_INODE_COPY_EVERYTHING, &inode->runtime_flags)) 5861 return false; 5862 5863 return true; 5864 } 5865 5866 struct btrfs_dir_list { 5867 u64 ino; 5868 struct list_head list; 5869 }; 5870 5871 /* 5872 * Log the inodes of the new dentries of a directory. See log_dir_items() for 5873 * details about the why it is needed. 5874 * This is a recursive operation - if an existing dentry corresponds to a 5875 * directory, that directory's new entries are logged too (same behaviour as 5876 * ext3/4, xfs, f2fs, reiserfs, nilfs2). Note that when logging the inodes 5877 * the dentries point to we do not lock their i_mutex, otherwise lockdep 5878 * complains about the following circular lock dependency / possible deadlock: 5879 * 5880 * CPU0 CPU1 5881 * ---- ---- 5882 * lock(&type->i_mutex_dir_key#3/2); 5883 * lock(sb_internal#2); 5884 * lock(&type->i_mutex_dir_key#3/2); 5885 * lock(&sb->s_type->i_mutex_key#14); 5886 * 5887 * Where sb_internal is the lock (a counter that works as a lock) acquired by 5888 * sb_start_intwrite() in btrfs_start_transaction(). 5889 * Not locking i_mutex of the inodes is still safe because: 5890 * 5891 * 1) For regular files we log with a mode of LOG_INODE_EXISTS. It's possible 5892 * that while logging the inode new references (names) are added or removed 5893 * from the inode, leaving the logged inode item with a link count that does 5894 * not match the number of logged inode reference items. This is fine because 5895 * at log replay time we compute the real number of links and correct the 5896 * link count in the inode item (see replay_one_buffer() and 5897 * link_to_fixup_dir()); 5898 * 5899 * 2) For directories we log with a mode of LOG_INODE_ALL. It's possible that 5900 * while logging the inode's items new items with keys BTRFS_DIR_ITEM_KEY and 5901 * BTRFS_DIR_INDEX_KEY are added to fs/subvol tree and the logged inode item 5902 * has a size that doesn't match the sum of the lengths of all the logged 5903 * names. This does not result in a problem because if a dir_item key is 5904 * logged but its matching dir_index key is not logged, at log replay time we 5905 * don't use it to replay the respective name (see replay_one_name()). On the 5906 * other hand if only the dir_index key ends up being logged, the respective 5907 * name is added to the fs/subvol tree with both the dir_item and dir_index 5908 * keys created (see replay_one_name()). 5909 * The directory's inode item with a wrong i_size is not a problem as well, 5910 * since we don't use it at log replay time to set the i_size in the inode 5911 * item of the fs/subvol tree (see overwrite_item()). 5912 */ 5913 static int log_new_dir_dentries(struct btrfs_trans_handle *trans, 5914 struct btrfs_root *root, 5915 struct btrfs_inode *start_inode, 5916 struct btrfs_log_ctx *ctx) 5917 { 5918 struct btrfs_fs_info *fs_info = root->fs_info; 5919 struct btrfs_root *log = root->log_root; 5920 struct btrfs_path *path; 5921 LIST_HEAD(dir_list); 5922 struct btrfs_dir_list *dir_elem; 5923 int ret = 0; 5924 5925 /* 5926 * If we are logging a new name, as part of a link or rename operation, 5927 * don't bother logging new dentries, as we just want to log the names 5928 * of an inode and that any new parents exist. 5929 */ 5930 if (ctx->logging_new_name) 5931 return 0; 5932 5933 path = btrfs_alloc_path(); 5934 if (!path) 5935 return -ENOMEM; 5936 5937 dir_elem = kmalloc(sizeof(*dir_elem), GFP_NOFS); 5938 if (!dir_elem) { 5939 btrfs_free_path(path); 5940 return -ENOMEM; 5941 } 5942 dir_elem->ino = btrfs_ino(start_inode); 5943 list_add_tail(&dir_elem->list, &dir_list); 5944 5945 while (!list_empty(&dir_list)) { 5946 struct extent_buffer *leaf; 5947 struct btrfs_key min_key; 5948 int nritems; 5949 int i; 5950 5951 dir_elem = list_first_entry(&dir_list, struct btrfs_dir_list, 5952 list); 5953 if (ret) 5954 goto next_dir_inode; 5955 5956 min_key.objectid = dir_elem->ino; 5957 min_key.type = BTRFS_DIR_ITEM_KEY; 5958 min_key.offset = 0; 5959 again: 5960 btrfs_release_path(path); 5961 ret = btrfs_search_forward(log, &min_key, path, trans->transid); 5962 if (ret < 0) { 5963 goto next_dir_inode; 5964 } else if (ret > 0) { 5965 ret = 0; 5966 goto next_dir_inode; 5967 } 5968 5969 process_leaf: 5970 leaf = path->nodes[0]; 5971 nritems = btrfs_header_nritems(leaf); 5972 for (i = path->slots[0]; i < nritems; i++) { 5973 struct btrfs_dir_item *di; 5974 struct btrfs_key di_key; 5975 struct inode *di_inode; 5976 struct btrfs_dir_list *new_dir_elem; 5977 int log_mode = LOG_INODE_EXISTS; 5978 int type; 5979 5980 btrfs_item_key_to_cpu(leaf, &min_key, i); 5981 if (min_key.objectid != dir_elem->ino || 5982 min_key.type != BTRFS_DIR_ITEM_KEY) 5983 goto next_dir_inode; 5984 5985 di = btrfs_item_ptr(leaf, i, struct btrfs_dir_item); 5986 type = btrfs_dir_type(leaf, di); 5987 if (btrfs_dir_transid(leaf, di) < trans->transid && 5988 type != BTRFS_FT_DIR) 5989 continue; 5990 btrfs_dir_item_key_to_cpu(leaf, di, &di_key); 5991 if (di_key.type == BTRFS_ROOT_ITEM_KEY) 5992 continue; 5993 5994 btrfs_release_path(path); 5995 di_inode = btrfs_iget(fs_info->sb, di_key.objectid, root); 5996 if (IS_ERR(di_inode)) { 5997 ret = PTR_ERR(di_inode); 5998 goto next_dir_inode; 5999 } 6000 6001 if (!need_log_inode(trans, BTRFS_I(di_inode))) { 6002 btrfs_add_delayed_iput(di_inode); 6003 break; 6004 } 6005 6006 ctx->log_new_dentries = false; 6007 if (type == BTRFS_FT_DIR || type == BTRFS_FT_SYMLINK) 6008 log_mode = LOG_INODE_ALL; 6009 ret = btrfs_log_inode(trans, BTRFS_I(di_inode), 6010 log_mode, ctx); 6011 btrfs_add_delayed_iput(di_inode); 6012 if (ret) 6013 goto next_dir_inode; 6014 if (ctx->log_new_dentries) { 6015 new_dir_elem = kmalloc(sizeof(*new_dir_elem), 6016 GFP_NOFS); 6017 if (!new_dir_elem) { 6018 ret = -ENOMEM; 6019 goto next_dir_inode; 6020 } 6021 new_dir_elem->ino = di_key.objectid; 6022 list_add_tail(&new_dir_elem->list, &dir_list); 6023 } 6024 break; 6025 } 6026 if (i == nritems) { 6027 ret = btrfs_next_leaf(log, path); 6028 if (ret < 0) { 6029 goto next_dir_inode; 6030 } else if (ret > 0) { 6031 ret = 0; 6032 goto next_dir_inode; 6033 } 6034 goto process_leaf; 6035 } 6036 if (min_key.offset < (u64)-1) { 6037 min_key.offset++; 6038 goto again; 6039 } 6040 next_dir_inode: 6041 list_del(&dir_elem->list); 6042 kfree(dir_elem); 6043 } 6044 6045 btrfs_free_path(path); 6046 return ret; 6047 } 6048 6049 static int btrfs_log_all_parents(struct btrfs_trans_handle *trans, 6050 struct btrfs_inode *inode, 6051 struct btrfs_log_ctx *ctx) 6052 { 6053 struct btrfs_fs_info *fs_info = trans->fs_info; 6054 int ret; 6055 struct btrfs_path *path; 6056 struct btrfs_key key; 6057 struct btrfs_root *root = inode->root; 6058 const u64 ino = btrfs_ino(inode); 6059 6060 path = btrfs_alloc_path(); 6061 if (!path) 6062 return -ENOMEM; 6063 path->skip_locking = 1; 6064 path->search_commit_root = 1; 6065 6066 key.objectid = ino; 6067 key.type = BTRFS_INODE_REF_KEY; 6068 key.offset = 0; 6069 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 6070 if (ret < 0) 6071 goto out; 6072 6073 while (true) { 6074 struct extent_buffer *leaf = path->nodes[0]; 6075 int slot = path->slots[0]; 6076 u32 cur_offset = 0; 6077 u32 item_size; 6078 unsigned long ptr; 6079 6080 if (slot >= btrfs_header_nritems(leaf)) { 6081 ret = btrfs_next_leaf(root, path); 6082 if (ret < 0) 6083 goto out; 6084 else if (ret > 0) 6085 break; 6086 continue; 6087 } 6088 6089 btrfs_item_key_to_cpu(leaf, &key, slot); 6090 /* BTRFS_INODE_EXTREF_KEY is BTRFS_INODE_REF_KEY + 1 */ 6091 if (key.objectid != ino || key.type > BTRFS_INODE_EXTREF_KEY) 6092 break; 6093 6094 item_size = btrfs_item_size_nr(leaf, slot); 6095 ptr = btrfs_item_ptr_offset(leaf, slot); 6096 while (cur_offset < item_size) { 6097 struct btrfs_key inode_key; 6098 struct inode *dir_inode; 6099 6100 inode_key.type = BTRFS_INODE_ITEM_KEY; 6101 inode_key.offset = 0; 6102 6103 if (key.type == BTRFS_INODE_EXTREF_KEY) { 6104 struct btrfs_inode_extref *extref; 6105 6106 extref = (struct btrfs_inode_extref *) 6107 (ptr + cur_offset); 6108 inode_key.objectid = btrfs_inode_extref_parent( 6109 leaf, extref); 6110 cur_offset += sizeof(*extref); 6111 cur_offset += btrfs_inode_extref_name_len(leaf, 6112 extref); 6113 } else { 6114 inode_key.objectid = key.offset; 6115 cur_offset = item_size; 6116 } 6117 6118 dir_inode = btrfs_iget(fs_info->sb, inode_key.objectid, 6119 root); 6120 /* 6121 * If the parent inode was deleted, return an error to 6122 * fallback to a transaction commit. This is to prevent 6123 * getting an inode that was moved from one parent A to 6124 * a parent B, got its former parent A deleted and then 6125 * it got fsync'ed, from existing at both parents after 6126 * a log replay (and the old parent still existing). 6127 * Example: 6128 * 6129 * mkdir /mnt/A 6130 * mkdir /mnt/B 6131 * touch /mnt/B/bar 6132 * sync 6133 * mv /mnt/B/bar /mnt/A/bar 6134 * mv -T /mnt/A /mnt/B 6135 * fsync /mnt/B/bar 6136 * <power fail> 6137 * 6138 * If we ignore the old parent B which got deleted, 6139 * after a log replay we would have file bar linked 6140 * at both parents and the old parent B would still 6141 * exist. 6142 */ 6143 if (IS_ERR(dir_inode)) { 6144 ret = PTR_ERR(dir_inode); 6145 goto out; 6146 } 6147 6148 if (!need_log_inode(trans, BTRFS_I(dir_inode))) { 6149 btrfs_add_delayed_iput(dir_inode); 6150 continue; 6151 } 6152 6153 ctx->log_new_dentries = false; 6154 ret = btrfs_log_inode(trans, BTRFS_I(dir_inode), 6155 LOG_INODE_ALL, ctx); 6156 if (!ret && ctx->log_new_dentries) 6157 ret = log_new_dir_dentries(trans, root, 6158 BTRFS_I(dir_inode), ctx); 6159 btrfs_add_delayed_iput(dir_inode); 6160 if (ret) 6161 goto out; 6162 } 6163 path->slots[0]++; 6164 } 6165 ret = 0; 6166 out: 6167 btrfs_free_path(path); 6168 return ret; 6169 } 6170 6171 static int log_new_ancestors(struct btrfs_trans_handle *trans, 6172 struct btrfs_root *root, 6173 struct btrfs_path *path, 6174 struct btrfs_log_ctx *ctx) 6175 { 6176 struct btrfs_key found_key; 6177 6178 btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]); 6179 6180 while (true) { 6181 struct btrfs_fs_info *fs_info = root->fs_info; 6182 struct extent_buffer *leaf = path->nodes[0]; 6183 int slot = path->slots[0]; 6184 struct btrfs_key search_key; 6185 struct inode *inode; 6186 u64 ino; 6187 int ret = 0; 6188 6189 btrfs_release_path(path); 6190 6191 ino = found_key.offset; 6192 6193 search_key.objectid = found_key.offset; 6194 search_key.type = BTRFS_INODE_ITEM_KEY; 6195 search_key.offset = 0; 6196 inode = btrfs_iget(fs_info->sb, ino, root); 6197 if (IS_ERR(inode)) 6198 return PTR_ERR(inode); 6199 6200 if (BTRFS_I(inode)->generation >= trans->transid && 6201 need_log_inode(trans, BTRFS_I(inode))) 6202 ret = btrfs_log_inode(trans, BTRFS_I(inode), 6203 LOG_INODE_EXISTS, ctx); 6204 btrfs_add_delayed_iput(inode); 6205 if (ret) 6206 return ret; 6207 6208 if (search_key.objectid == BTRFS_FIRST_FREE_OBJECTID) 6209 break; 6210 6211 search_key.type = BTRFS_INODE_REF_KEY; 6212 ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0); 6213 if (ret < 0) 6214 return ret; 6215 6216 leaf = path->nodes[0]; 6217 slot = path->slots[0]; 6218 if (slot >= btrfs_header_nritems(leaf)) { 6219 ret = btrfs_next_leaf(root, path); 6220 if (ret < 0) 6221 return ret; 6222 else if (ret > 0) 6223 return -ENOENT; 6224 leaf = path->nodes[0]; 6225 slot = path->slots[0]; 6226 } 6227 6228 btrfs_item_key_to_cpu(leaf, &found_key, slot); 6229 if (found_key.objectid != search_key.objectid || 6230 found_key.type != BTRFS_INODE_REF_KEY) 6231 return -ENOENT; 6232 } 6233 return 0; 6234 } 6235 6236 static int log_new_ancestors_fast(struct btrfs_trans_handle *trans, 6237 struct btrfs_inode *inode, 6238 struct dentry *parent, 6239 struct btrfs_log_ctx *ctx) 6240 { 6241 struct btrfs_root *root = inode->root; 6242 struct dentry *old_parent = NULL; 6243 struct super_block *sb = inode->vfs_inode.i_sb; 6244 int ret = 0; 6245 6246 while (true) { 6247 if (!parent || d_really_is_negative(parent) || 6248 sb != parent->d_sb) 6249 break; 6250 6251 inode = BTRFS_I(d_inode(parent)); 6252 if (root != inode->root) 6253 break; 6254 6255 if (inode->generation >= trans->transid && 6256 need_log_inode(trans, inode)) { 6257 ret = btrfs_log_inode(trans, inode, 6258 LOG_INODE_EXISTS, ctx); 6259 if (ret) 6260 break; 6261 } 6262 if (IS_ROOT(parent)) 6263 break; 6264 6265 parent = dget_parent(parent); 6266 dput(old_parent); 6267 old_parent = parent; 6268 } 6269 dput(old_parent); 6270 6271 return ret; 6272 } 6273 6274 static int log_all_new_ancestors(struct btrfs_trans_handle *trans, 6275 struct btrfs_inode *inode, 6276 struct dentry *parent, 6277 struct btrfs_log_ctx *ctx) 6278 { 6279 struct btrfs_root *root = inode->root; 6280 const u64 ino = btrfs_ino(inode); 6281 struct btrfs_path *path; 6282 struct btrfs_key search_key; 6283 int ret; 6284 6285 /* 6286 * For a single hard link case, go through a fast path that does not 6287 * need to iterate the fs/subvolume tree. 6288 */ 6289 if (inode->vfs_inode.i_nlink < 2) 6290 return log_new_ancestors_fast(trans, inode, parent, ctx); 6291 6292 path = btrfs_alloc_path(); 6293 if (!path) 6294 return -ENOMEM; 6295 6296 search_key.objectid = ino; 6297 search_key.type = BTRFS_INODE_REF_KEY; 6298 search_key.offset = 0; 6299 again: 6300 ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0); 6301 if (ret < 0) 6302 goto out; 6303 if (ret == 0) 6304 path->slots[0]++; 6305 6306 while (true) { 6307 struct extent_buffer *leaf = path->nodes[0]; 6308 int slot = path->slots[0]; 6309 struct btrfs_key found_key; 6310 6311 if (slot >= btrfs_header_nritems(leaf)) { 6312 ret = btrfs_next_leaf(root, path); 6313 if (ret < 0) 6314 goto out; 6315 else if (ret > 0) 6316 break; 6317 continue; 6318 } 6319 6320 btrfs_item_key_to_cpu(leaf, &found_key, slot); 6321 if (found_key.objectid != ino || 6322 found_key.type > BTRFS_INODE_EXTREF_KEY) 6323 break; 6324 6325 /* 6326 * Don't deal with extended references because they are rare 6327 * cases and too complex to deal with (we would need to keep 6328 * track of which subitem we are processing for each item in 6329 * this loop, etc). So just return some error to fallback to 6330 * a transaction commit. 6331 */ 6332 if (found_key.type == BTRFS_INODE_EXTREF_KEY) { 6333 ret = -EMLINK; 6334 goto out; 6335 } 6336 6337 /* 6338 * Logging ancestors needs to do more searches on the fs/subvol 6339 * tree, so it releases the path as needed to avoid deadlocks. 6340 * Keep track of the last inode ref key and resume from that key 6341 * after logging all new ancestors for the current hard link. 6342 */ 6343 memcpy(&search_key, &found_key, sizeof(search_key)); 6344 6345 ret = log_new_ancestors(trans, root, path, ctx); 6346 if (ret) 6347 goto out; 6348 btrfs_release_path(path); 6349 goto again; 6350 } 6351 ret = 0; 6352 out: 6353 btrfs_free_path(path); 6354 return ret; 6355 } 6356 6357 /* 6358 * helper function around btrfs_log_inode to make sure newly created 6359 * parent directories also end up in the log. A minimal inode and backref 6360 * only logging is done of any parent directories that are older than 6361 * the last committed transaction 6362 */ 6363 static int btrfs_log_inode_parent(struct btrfs_trans_handle *trans, 6364 struct btrfs_inode *inode, 6365 struct dentry *parent, 6366 int inode_only, 6367 struct btrfs_log_ctx *ctx) 6368 { 6369 struct btrfs_root *root = inode->root; 6370 struct btrfs_fs_info *fs_info = root->fs_info; 6371 int ret = 0; 6372 bool log_dentries = false; 6373 6374 if (btrfs_test_opt(fs_info, NOTREELOG)) { 6375 ret = 1; 6376 goto end_no_trans; 6377 } 6378 6379 if (btrfs_root_refs(&root->root_item) == 0) { 6380 ret = 1; 6381 goto end_no_trans; 6382 } 6383 6384 /* 6385 * Skip already logged inodes or inodes corresponding to tmpfiles 6386 * (since logging them is pointless, a link count of 0 means they 6387 * will never be accessible). 6388 */ 6389 if ((btrfs_inode_in_log(inode, trans->transid) && 6390 list_empty(&ctx->ordered_extents)) || 6391 inode->vfs_inode.i_nlink == 0) { 6392 ret = BTRFS_NO_LOG_SYNC; 6393 goto end_no_trans; 6394 } 6395 6396 ret = start_log_trans(trans, root, ctx); 6397 if (ret) 6398 goto end_no_trans; 6399 6400 ret = btrfs_log_inode(trans, inode, inode_only, ctx); 6401 if (ret) 6402 goto end_trans; 6403 6404 /* 6405 * for regular files, if its inode is already on disk, we don't 6406 * have to worry about the parents at all. This is because 6407 * we can use the last_unlink_trans field to record renames 6408 * and other fun in this file. 6409 */ 6410 if (S_ISREG(inode->vfs_inode.i_mode) && 6411 inode->generation < trans->transid && 6412 inode->last_unlink_trans < trans->transid) { 6413 ret = 0; 6414 goto end_trans; 6415 } 6416 6417 if (S_ISDIR(inode->vfs_inode.i_mode) && ctx->log_new_dentries) 6418 log_dentries = true; 6419 6420 /* 6421 * On unlink we must make sure all our current and old parent directory 6422 * inodes are fully logged. This is to prevent leaving dangling 6423 * directory index entries in directories that were our parents but are 6424 * not anymore. Not doing this results in old parent directory being 6425 * impossible to delete after log replay (rmdir will always fail with 6426 * error -ENOTEMPTY). 6427 * 6428 * Example 1: 6429 * 6430 * mkdir testdir 6431 * touch testdir/foo 6432 * ln testdir/foo testdir/bar 6433 * sync 6434 * unlink testdir/bar 6435 * xfs_io -c fsync testdir/foo 6436 * <power failure> 6437 * mount fs, triggers log replay 6438 * 6439 * If we don't log the parent directory (testdir), after log replay the 6440 * directory still has an entry pointing to the file inode using the bar 6441 * name, but a matching BTRFS_INODE_[REF|EXTREF]_KEY does not exist and 6442 * the file inode has a link count of 1. 6443 * 6444 * Example 2: 6445 * 6446 * mkdir testdir 6447 * touch foo 6448 * ln foo testdir/foo2 6449 * ln foo testdir/foo3 6450 * sync 6451 * unlink testdir/foo3 6452 * xfs_io -c fsync foo 6453 * <power failure> 6454 * mount fs, triggers log replay 6455 * 6456 * Similar as the first example, after log replay the parent directory 6457 * testdir still has an entry pointing to the inode file with name foo3 6458 * but the file inode does not have a matching BTRFS_INODE_REF_KEY item 6459 * and has a link count of 2. 6460 */ 6461 if (inode->last_unlink_trans >= trans->transid) { 6462 ret = btrfs_log_all_parents(trans, inode, ctx); 6463 if (ret) 6464 goto end_trans; 6465 } 6466 6467 ret = log_all_new_ancestors(trans, inode, parent, ctx); 6468 if (ret) 6469 goto end_trans; 6470 6471 if (log_dentries) 6472 ret = log_new_dir_dentries(trans, root, inode, ctx); 6473 else 6474 ret = 0; 6475 end_trans: 6476 if (ret < 0) { 6477 btrfs_set_log_full_commit(trans); 6478 ret = 1; 6479 } 6480 6481 if (ret) 6482 btrfs_remove_log_ctx(root, ctx); 6483 btrfs_end_log_trans(root); 6484 end_no_trans: 6485 return ret; 6486 } 6487 6488 /* 6489 * it is not safe to log dentry if the chunk root has added new 6490 * chunks. This returns 0 if the dentry was logged, and 1 otherwise. 6491 * If this returns 1, you must commit the transaction to safely get your 6492 * data on disk. 6493 */ 6494 int btrfs_log_dentry_safe(struct btrfs_trans_handle *trans, 6495 struct dentry *dentry, 6496 struct btrfs_log_ctx *ctx) 6497 { 6498 struct dentry *parent = dget_parent(dentry); 6499 int ret; 6500 6501 ret = btrfs_log_inode_parent(trans, BTRFS_I(d_inode(dentry)), parent, 6502 LOG_INODE_ALL, ctx); 6503 dput(parent); 6504 6505 return ret; 6506 } 6507 6508 /* 6509 * should be called during mount to recover any replay any log trees 6510 * from the FS 6511 */ 6512 int btrfs_recover_log_trees(struct btrfs_root *log_root_tree) 6513 { 6514 int ret; 6515 struct btrfs_path *path; 6516 struct btrfs_trans_handle *trans; 6517 struct btrfs_key key; 6518 struct btrfs_key found_key; 6519 struct btrfs_root *log; 6520 struct btrfs_fs_info *fs_info = log_root_tree->fs_info; 6521 struct walk_control wc = { 6522 .process_func = process_one_buffer, 6523 .stage = LOG_WALK_PIN_ONLY, 6524 }; 6525 6526 path = btrfs_alloc_path(); 6527 if (!path) 6528 return -ENOMEM; 6529 6530 set_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags); 6531 6532 trans = btrfs_start_transaction(fs_info->tree_root, 0); 6533 if (IS_ERR(trans)) { 6534 ret = PTR_ERR(trans); 6535 goto error; 6536 } 6537 6538 wc.trans = trans; 6539 wc.pin = 1; 6540 6541 ret = walk_log_tree(trans, log_root_tree, &wc); 6542 if (ret) { 6543 btrfs_abort_transaction(trans, ret); 6544 goto error; 6545 } 6546 6547 again: 6548 key.objectid = BTRFS_TREE_LOG_OBJECTID; 6549 key.offset = (u64)-1; 6550 key.type = BTRFS_ROOT_ITEM_KEY; 6551 6552 while (1) { 6553 ret = btrfs_search_slot(NULL, log_root_tree, &key, path, 0, 0); 6554 6555 if (ret < 0) { 6556 btrfs_abort_transaction(trans, ret); 6557 goto error; 6558 } 6559 if (ret > 0) { 6560 if (path->slots[0] == 0) 6561 break; 6562 path->slots[0]--; 6563 } 6564 btrfs_item_key_to_cpu(path->nodes[0], &found_key, 6565 path->slots[0]); 6566 btrfs_release_path(path); 6567 if (found_key.objectid != BTRFS_TREE_LOG_OBJECTID) 6568 break; 6569 6570 log = btrfs_read_tree_root(log_root_tree, &found_key); 6571 if (IS_ERR(log)) { 6572 ret = PTR_ERR(log); 6573 btrfs_abort_transaction(trans, ret); 6574 goto error; 6575 } 6576 6577 wc.replay_dest = btrfs_get_fs_root(fs_info, found_key.offset, 6578 true); 6579 if (IS_ERR(wc.replay_dest)) { 6580 ret = PTR_ERR(wc.replay_dest); 6581 6582 /* 6583 * We didn't find the subvol, likely because it was 6584 * deleted. This is ok, simply skip this log and go to 6585 * the next one. 6586 * 6587 * We need to exclude the root because we can't have 6588 * other log replays overwriting this log as we'll read 6589 * it back in a few more times. This will keep our 6590 * block from being modified, and we'll just bail for 6591 * each subsequent pass. 6592 */ 6593 if (ret == -ENOENT) 6594 ret = btrfs_pin_extent_for_log_replay(trans, 6595 log->node->start, 6596 log->node->len); 6597 btrfs_put_root(log); 6598 6599 if (!ret) 6600 goto next; 6601 btrfs_abort_transaction(trans, ret); 6602 goto error; 6603 } 6604 6605 wc.replay_dest->log_root = log; 6606 ret = btrfs_record_root_in_trans(trans, wc.replay_dest); 6607 if (ret) 6608 /* The loop needs to continue due to the root refs */ 6609 btrfs_abort_transaction(trans, ret); 6610 else 6611 ret = walk_log_tree(trans, log, &wc); 6612 6613 if (!ret && wc.stage == LOG_WALK_REPLAY_ALL) { 6614 ret = fixup_inode_link_counts(trans, wc.replay_dest, 6615 path); 6616 if (ret) 6617 btrfs_abort_transaction(trans, ret); 6618 } 6619 6620 if (!ret && wc.stage == LOG_WALK_REPLAY_ALL) { 6621 struct btrfs_root *root = wc.replay_dest; 6622 6623 btrfs_release_path(path); 6624 6625 /* 6626 * We have just replayed everything, and the highest 6627 * objectid of fs roots probably has changed in case 6628 * some inode_item's got replayed. 6629 * 6630 * root->objectid_mutex is not acquired as log replay 6631 * could only happen during mount. 6632 */ 6633 ret = btrfs_init_root_free_objectid(root); 6634 if (ret) 6635 btrfs_abort_transaction(trans, ret); 6636 } 6637 6638 wc.replay_dest->log_root = NULL; 6639 btrfs_put_root(wc.replay_dest); 6640 btrfs_put_root(log); 6641 6642 if (ret) 6643 goto error; 6644 next: 6645 if (found_key.offset == 0) 6646 break; 6647 key.offset = found_key.offset - 1; 6648 } 6649 btrfs_release_path(path); 6650 6651 /* step one is to pin it all, step two is to replay just inodes */ 6652 if (wc.pin) { 6653 wc.pin = 0; 6654 wc.process_func = replay_one_buffer; 6655 wc.stage = LOG_WALK_REPLAY_INODES; 6656 goto again; 6657 } 6658 /* step three is to replay everything */ 6659 if (wc.stage < LOG_WALK_REPLAY_ALL) { 6660 wc.stage++; 6661 goto again; 6662 } 6663 6664 btrfs_free_path(path); 6665 6666 /* step 4: commit the transaction, which also unpins the blocks */ 6667 ret = btrfs_commit_transaction(trans); 6668 if (ret) 6669 return ret; 6670 6671 log_root_tree->log_root = NULL; 6672 clear_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags); 6673 btrfs_put_root(log_root_tree); 6674 6675 return 0; 6676 error: 6677 if (wc.trans) 6678 btrfs_end_transaction(wc.trans); 6679 clear_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags); 6680 btrfs_free_path(path); 6681 return ret; 6682 } 6683 6684 /* 6685 * there are some corner cases where we want to force a full 6686 * commit instead of allowing a directory to be logged. 6687 * 6688 * They revolve around files there were unlinked from the directory, and 6689 * this function updates the parent directory so that a full commit is 6690 * properly done if it is fsync'd later after the unlinks are done. 6691 * 6692 * Must be called before the unlink operations (updates to the subvolume tree, 6693 * inodes, etc) are done. 6694 */ 6695 void btrfs_record_unlink_dir(struct btrfs_trans_handle *trans, 6696 struct btrfs_inode *dir, struct btrfs_inode *inode, 6697 int for_rename) 6698 { 6699 /* 6700 * when we're logging a file, if it hasn't been renamed 6701 * or unlinked, and its inode is fully committed on disk, 6702 * we don't have to worry about walking up the directory chain 6703 * to log its parents. 6704 * 6705 * So, we use the last_unlink_trans field to put this transid 6706 * into the file. When the file is logged we check it and 6707 * don't log the parents if the file is fully on disk. 6708 */ 6709 mutex_lock(&inode->log_mutex); 6710 inode->last_unlink_trans = trans->transid; 6711 mutex_unlock(&inode->log_mutex); 6712 6713 /* 6714 * if this directory was already logged any new 6715 * names for this file/dir will get recorded 6716 */ 6717 if (dir->logged_trans == trans->transid) 6718 return; 6719 6720 /* 6721 * if the inode we're about to unlink was logged, 6722 * the log will be properly updated for any new names 6723 */ 6724 if (inode->logged_trans == trans->transid) 6725 return; 6726 6727 /* 6728 * when renaming files across directories, if the directory 6729 * there we're unlinking from gets fsync'd later on, there's 6730 * no way to find the destination directory later and fsync it 6731 * properly. So, we have to be conservative and force commits 6732 * so the new name gets discovered. 6733 */ 6734 if (for_rename) 6735 goto record; 6736 6737 /* we can safely do the unlink without any special recording */ 6738 return; 6739 6740 record: 6741 mutex_lock(&dir->log_mutex); 6742 dir->last_unlink_trans = trans->transid; 6743 mutex_unlock(&dir->log_mutex); 6744 } 6745 6746 /* 6747 * Make sure that if someone attempts to fsync the parent directory of a deleted 6748 * snapshot, it ends up triggering a transaction commit. This is to guarantee 6749 * that after replaying the log tree of the parent directory's root we will not 6750 * see the snapshot anymore and at log replay time we will not see any log tree 6751 * corresponding to the deleted snapshot's root, which could lead to replaying 6752 * it after replaying the log tree of the parent directory (which would replay 6753 * the snapshot delete operation). 6754 * 6755 * Must be called before the actual snapshot destroy operation (updates to the 6756 * parent root and tree of tree roots trees, etc) are done. 6757 */ 6758 void btrfs_record_snapshot_destroy(struct btrfs_trans_handle *trans, 6759 struct btrfs_inode *dir) 6760 { 6761 mutex_lock(&dir->log_mutex); 6762 dir->last_unlink_trans = trans->transid; 6763 mutex_unlock(&dir->log_mutex); 6764 } 6765 6766 /* 6767 * Call this after adding a new name for a file and it will properly 6768 * update the log to reflect the new name. 6769 */ 6770 void btrfs_log_new_name(struct btrfs_trans_handle *trans, 6771 struct btrfs_inode *inode, struct btrfs_inode *old_dir, 6772 struct dentry *parent) 6773 { 6774 struct btrfs_log_ctx ctx; 6775 6776 /* 6777 * this will force the logging code to walk the dentry chain 6778 * up for the file 6779 */ 6780 if (!S_ISDIR(inode->vfs_inode.i_mode)) 6781 inode->last_unlink_trans = trans->transid; 6782 6783 /* 6784 * if this inode hasn't been logged and directory we're renaming it 6785 * from hasn't been logged, we don't need to log it 6786 */ 6787 if (!inode_logged(trans, inode) && 6788 (!old_dir || !inode_logged(trans, old_dir))) 6789 return; 6790 6791 /* 6792 * If we are doing a rename (old_dir is not NULL) from a directory that 6793 * was previously logged, make sure the next log attempt on the directory 6794 * is not skipped and logs the inode again. This is because the log may 6795 * not currently be authoritative for a range including the old 6796 * BTRFS_DIR_ITEM_KEY and BTRFS_DIR_INDEX_KEY keys, so we want to make 6797 * sure after a log replay we do not end up with both the new and old 6798 * dentries around (in case the inode is a directory we would have a 6799 * directory with two hard links and 2 inode references for different 6800 * parents). The next log attempt of old_dir will happen at 6801 * btrfs_log_all_parents(), called through btrfs_log_inode_parent() 6802 * below, because we have previously set inode->last_unlink_trans to the 6803 * current transaction ID, either here or at btrfs_record_unlink_dir() in 6804 * case inode is a directory. 6805 */ 6806 if (old_dir) 6807 old_dir->logged_trans = 0; 6808 6809 btrfs_init_log_ctx(&ctx, &inode->vfs_inode); 6810 ctx.logging_new_name = true; 6811 /* 6812 * We don't care about the return value. If we fail to log the new name 6813 * then we know the next attempt to sync the log will fallback to a full 6814 * transaction commit (due to a call to btrfs_set_log_full_commit()), so 6815 * we don't need to worry about getting a log committed that has an 6816 * inconsistent state after a rename operation. 6817 */ 6818 btrfs_log_inode_parent(trans, inode, parent, LOG_INODE_EXISTS, &ctx); 6819 } 6820 6821