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1/*
2 * Copyright (C) 2008 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19#include <linux/sched.h>
20#include <linux/slab.h>
21#include "ctree.h"
22#include "transaction.h"
23#include "disk-io.h"
24#include "locking.h"
25#include "print-tree.h"
26#include "compat.h"
27#include "tree-log.h"
28
29/* magic values for the inode_only field in btrfs_log_inode:
30 *
31 * LOG_INODE_ALL means to log everything
32 * LOG_INODE_EXISTS means to log just enough to recreate the inode
33 * during log replay
34 */
35#define LOG_INODE_ALL 0
36#define LOG_INODE_EXISTS 1
37
38/*
39 * directory trouble cases
40 *
41 * 1) on rename or unlink, if the inode being unlinked isn't in the fsync
42 * log, we must force a full commit before doing an fsync of the directory
43 * where the unlink was done.
44 * ---> record transid of last unlink/rename per directory
45 *
46 * mkdir foo/some_dir
47 * normal commit
48 * rename foo/some_dir foo2/some_dir
49 * mkdir foo/some_dir
50 * fsync foo/some_dir/some_file
51 *
52 * The fsync above will unlink the original some_dir without recording
53 * it in its new location (foo2). After a crash, some_dir will be gone
54 * unless the fsync of some_file forces a full commit
55 *
56 * 2) we must log any new names for any file or dir that is in the fsync
57 * log. ---> check inode while renaming/linking.
58 *
59 * 2a) we must log any new names for any file or dir during rename
60 * when the directory they are being removed from was logged.
61 * ---> check inode and old parent dir during rename
62 *
63 * 2a is actually the more important variant. With the extra logging
64 * a crash might unlink the old name without recreating the new one
65 *
66 * 3) after a crash, we must go through any directories with a link count
67 * of zero and redo the rm -rf
68 *
69 * mkdir f1/foo
70 * normal commit
71 * rm -rf f1/foo
72 * fsync(f1)
73 *
74 * The directory f1 was fully removed from the FS, but fsync was never
75 * called on f1, only its parent dir. After a crash the rm -rf must
76 * be replayed. This must be able to recurse down the entire
77 * directory tree. The inode link count fixup code takes care of the
78 * ugly details.
79 */
80
81/*
82 * stages for the tree walking. The first
83 * stage (0) is to only pin down the blocks we find
84 * the second stage (1) is to make sure that all the inodes
85 * we find in the log are created in the subvolume.
86 *
87 * The last stage is to deal with directories and links and extents
88 * and all the other fun semantics
89 */
90#define LOG_WALK_PIN_ONLY 0
91#define LOG_WALK_REPLAY_INODES 1
92#define LOG_WALK_REPLAY_ALL 2
93
94static int btrfs_log_inode(struct btrfs_trans_handle *trans,
95 struct btrfs_root *root, struct inode *inode,
96 int inode_only);
97static int link_to_fixup_dir(struct btrfs_trans_handle *trans,
98 struct btrfs_root *root,
99 struct btrfs_path *path, u64 objectid);
100static noinline int replay_dir_deletes(struct btrfs_trans_handle *trans,
101 struct btrfs_root *root,
102 struct btrfs_root *log,
103 struct btrfs_path *path,
104 u64 dirid, int del_all);
105
106/*
107 * tree logging is a special write ahead log used to make sure that
108 * fsyncs and O_SYNCs can happen without doing full tree commits.
109 *
110 * Full tree commits are expensive because they require commonly
111 * modified blocks to be recowed, creating many dirty pages in the
112 * extent tree an 4x-6x higher write load than ext3.
113 *
114 * Instead of doing a tree commit on every fsync, we use the
115 * key ranges and transaction ids to find items for a given file or directory
116 * that have changed in this transaction. Those items are copied into
117 * a special tree (one per subvolume root), that tree is written to disk
118 * and then the fsync is considered complete.
119 *
120 * After a crash, items are copied out of the log-tree back into the
121 * subvolume tree. Any file data extents found are recorded in the extent
122 * allocation tree, and the log-tree freed.
123 *
124 * The log tree is read three times, once to pin down all the extents it is
125 * using in ram and once, once to create all the inodes logged in the tree
126 * and once to do all the other items.
127 */
128
129/*
130 * start a sub transaction and setup the log tree
131 * this increments the log tree writer count to make the people
132 * syncing the tree wait for us to finish
133 */
134static int start_log_trans(struct btrfs_trans_handle *trans,
135 struct btrfs_root *root)
136{
137 int ret;
138 int err = 0;
139
140 mutex_lock(&root->log_mutex);
141 if (root->log_root) {
142 if (!root->log_start_pid) {
143 root->log_start_pid = current->pid;
144 root->log_multiple_pids = false;
145 } else if (root->log_start_pid != current->pid) {
146 root->log_multiple_pids = true;
147 }
148
149 root->log_batch++;
150 atomic_inc(&root->log_writers);
151 mutex_unlock(&root->log_mutex);
152 return 0;
153 }
154 root->log_multiple_pids = false;
155 root->log_start_pid = current->pid;
156 mutex_lock(&root->fs_info->tree_log_mutex);
157 if (!root->fs_info->log_root_tree) {
158 ret = btrfs_init_log_root_tree(trans, root->fs_info);
159 if (ret)
160 err = ret;
161 }
162 if (err == 0 && !root->log_root) {
163 ret = btrfs_add_log_tree(trans, root);
164 if (ret)
165 err = ret;
166 }
167 mutex_unlock(&root->fs_info->tree_log_mutex);
168 root->log_batch++;
169 atomic_inc(&root->log_writers);
170 mutex_unlock(&root->log_mutex);
171 return err;
172}
173
174/*
175 * returns 0 if there was a log transaction running and we were able
176 * to join, or returns -ENOENT if there were not transactions
177 * in progress
178 */
179static int join_running_log_trans(struct btrfs_root *root)
180{
181 int ret = -ENOENT;
182
183 smp_mb();
184 if (!root->log_root)
185 return -ENOENT;
186
187 mutex_lock(&root->log_mutex);
188 if (root->log_root) {
189 ret = 0;
190 atomic_inc(&root->log_writers);
191 }
192 mutex_unlock(&root->log_mutex);
193 return ret;
194}
195
196/*
197 * This either makes the current running log transaction wait
198 * until you call btrfs_end_log_trans() or it makes any future
199 * log transactions wait until you call btrfs_end_log_trans()
200 */
201int btrfs_pin_log_trans(struct btrfs_root *root)
202{
203 int ret = -ENOENT;
204
205 mutex_lock(&root->log_mutex);
206 atomic_inc(&root->log_writers);
207 mutex_unlock(&root->log_mutex);
208 return ret;
209}
210
211/*
212 * indicate we're done making changes to the log tree
213 * and wake up anyone waiting to do a sync
214 */
215int btrfs_end_log_trans(struct btrfs_root *root)
216{
217 if (atomic_dec_and_test(&root->log_writers)) {
218 smp_mb();
219 if (waitqueue_active(&root->log_writer_wait))
220 wake_up(&root->log_writer_wait);
221 }
222 return 0;
223}
224
225
226/*
227 * the walk control struct is used to pass state down the chain when
228 * processing the log tree. The stage field tells us which part
229 * of the log tree processing we are currently doing. The others
230 * are state fields used for that specific part
231 */
232struct walk_control {
233 /* should we free the extent on disk when done? This is used
234 * at transaction commit time while freeing a log tree
235 */
236 int free;
237
238 /* should we write out the extent buffer? This is used
239 * while flushing the log tree to disk during a sync
240 */
241 int write;
242
243 /* should we wait for the extent buffer io to finish? Also used
244 * while flushing the log tree to disk for a sync
245 */
246 int wait;
247
248 /* pin only walk, we record which extents on disk belong to the
249 * log trees
250 */
251 int pin;
252
253 /* what stage of the replay code we're currently in */
254 int stage;
255
256 /* the root we are currently replaying */
257 struct btrfs_root *replay_dest;
258
259 /* the trans handle for the current replay */
260 struct btrfs_trans_handle *trans;
261
262 /* the function that gets used to process blocks we find in the
263 * tree. Note the extent_buffer might not be up to date when it is
264 * passed in, and it must be checked or read if you need the data
265 * inside it
266 */
267 int (*process_func)(struct btrfs_root *log, struct extent_buffer *eb,
268 struct walk_control *wc, u64 gen);
269};
270
271/*
272 * process_func used to pin down extents, write them or wait on them
273 */
274static int process_one_buffer(struct btrfs_root *log,
275 struct extent_buffer *eb,
276 struct walk_control *wc, u64 gen)
277{
278 if (wc->pin)
279 btrfs_pin_extent(log->fs_info->extent_root,
280 eb->start, eb->len, 0);
281
282 if (btrfs_buffer_uptodate(eb, gen)) {
283 if (wc->write)
284 btrfs_write_tree_block(eb);
285 if (wc->wait)
286 btrfs_wait_tree_block_writeback(eb);
287 }
288 return 0;
289}
290
291/*
292 * Item overwrite used by replay and tree logging. eb, slot and key all refer
293 * to the src data we are copying out.
294 *
295 * root is the tree we are copying into, and path is a scratch
296 * path for use in this function (it should be released on entry and
297 * will be released on exit).
298 *
299 * If the key is already in the destination tree the existing item is
300 * overwritten. If the existing item isn't big enough, it is extended.
301 * If it is too large, it is truncated.
302 *
303 * If the key isn't in the destination yet, a new item is inserted.
304 */
305static noinline int overwrite_item(struct btrfs_trans_handle *trans,
306 struct btrfs_root *root,
307 struct btrfs_path *path,
308 struct extent_buffer *eb, int slot,
309 struct btrfs_key *key)
310{
311 int ret;
312 u32 item_size;
313 u64 saved_i_size = 0;
314 int save_old_i_size = 0;
315 unsigned long src_ptr;
316 unsigned long dst_ptr;
317 int overwrite_root = 0;
318
319 if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
320 overwrite_root = 1;
321
322 item_size = btrfs_item_size_nr(eb, slot);
323 src_ptr = btrfs_item_ptr_offset(eb, slot);
324
325 /* look for the key in the destination tree */
326 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
327 if (ret == 0) {
328 char *src_copy;
329 char *dst_copy;
330 u32 dst_size = btrfs_item_size_nr(path->nodes[0],
331 path->slots[0]);
332 if (dst_size != item_size)
333 goto insert;
334
335 if (item_size == 0) {
336 btrfs_release_path(path);
337 return 0;
338 }
339 dst_copy = kmalloc(item_size, GFP_NOFS);
340 src_copy = kmalloc(item_size, GFP_NOFS);
341 if (!dst_copy || !src_copy) {
342 btrfs_release_path(path);
343 kfree(dst_copy);
344 kfree(src_copy);
345 return -ENOMEM;
346 }
347
348 read_extent_buffer(eb, src_copy, src_ptr, item_size);
349
350 dst_ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
351 read_extent_buffer(path->nodes[0], dst_copy, dst_ptr,
352 item_size);
353 ret = memcmp(dst_copy, src_copy, item_size);
354
355 kfree(dst_copy);
356 kfree(src_copy);
357 /*
358 * they have the same contents, just return, this saves
359 * us from cowing blocks in the destination tree and doing
360 * extra writes that may not have been done by a previous
361 * sync
362 */
363 if (ret == 0) {
364 btrfs_release_path(path);
365 return 0;
366 }
367
368 }
369insert:
370 btrfs_release_path(path);
371 /* try to insert the key into the destination tree */
372 ret = btrfs_insert_empty_item(trans, root, path,
373 key, item_size);
374
375 /* make sure any existing item is the correct size */
376 if (ret == -EEXIST) {
377 u32 found_size;
378 found_size = btrfs_item_size_nr(path->nodes[0],
379 path->slots[0]);
380 if (found_size > item_size) {
381 btrfs_truncate_item(trans, root, path, item_size, 1);
382 } else if (found_size < item_size) {
383 ret = btrfs_extend_item(trans, root, path,
384 item_size - found_size);
385 }
386 } else if (ret) {
387 return ret;
388 }
389 dst_ptr = btrfs_item_ptr_offset(path->nodes[0],
390 path->slots[0]);
391
392 /* don't overwrite an existing inode if the generation number
393 * was logged as zero. This is done when the tree logging code
394 * is just logging an inode to make sure it exists after recovery.
395 *
396 * Also, don't overwrite i_size on directories during replay.
397 * log replay inserts and removes directory items based on the
398 * state of the tree found in the subvolume, and i_size is modified
399 * as it goes
400 */
401 if (key->type == BTRFS_INODE_ITEM_KEY && ret == -EEXIST) {
402 struct btrfs_inode_item *src_item;
403 struct btrfs_inode_item *dst_item;
404
405 src_item = (struct btrfs_inode_item *)src_ptr;
406 dst_item = (struct btrfs_inode_item *)dst_ptr;
407
408 if (btrfs_inode_generation(eb, src_item) == 0)
409 goto no_copy;
410
411 if (overwrite_root &&
412 S_ISDIR(btrfs_inode_mode(eb, src_item)) &&
413 S_ISDIR(btrfs_inode_mode(path->nodes[0], dst_item))) {
414 save_old_i_size = 1;
415 saved_i_size = btrfs_inode_size(path->nodes[0],
416 dst_item);
417 }
418 }
419
420 copy_extent_buffer(path->nodes[0], eb, dst_ptr,
421 src_ptr, item_size);
422
423 if (save_old_i_size) {
424 struct btrfs_inode_item *dst_item;
425 dst_item = (struct btrfs_inode_item *)dst_ptr;
426 btrfs_set_inode_size(path->nodes[0], dst_item, saved_i_size);
427 }
428
429 /* make sure the generation is filled in */
430 if (key->type == BTRFS_INODE_ITEM_KEY) {
431 struct btrfs_inode_item *dst_item;
432 dst_item = (struct btrfs_inode_item *)dst_ptr;
433 if (btrfs_inode_generation(path->nodes[0], dst_item) == 0) {
434 btrfs_set_inode_generation(path->nodes[0], dst_item,
435 trans->transid);
436 }
437 }
438no_copy:
439 btrfs_mark_buffer_dirty(path->nodes[0]);
440 btrfs_release_path(path);
441 return 0;
442}
443
444/*
445 * simple helper to read an inode off the disk from a given root
446 * This can only be called for subvolume roots and not for the log
447 */
448static noinline struct inode *read_one_inode(struct btrfs_root *root,
449 u64 objectid)
450{
451 struct btrfs_key key;
452 struct inode *inode;
453
454 key.objectid = objectid;
455 key.type = BTRFS_INODE_ITEM_KEY;
456 key.offset = 0;
457 inode = btrfs_iget(root->fs_info->sb, &key, root, NULL);
458 if (IS_ERR(inode)) {
459 inode = NULL;
460 } else if (is_bad_inode(inode)) {
461 iput(inode);
462 inode = NULL;
463 }
464 return inode;
465}
466
467/* replays a single extent in 'eb' at 'slot' with 'key' into the
468 * subvolume 'root'. path is released on entry and should be released
469 * on exit.
470 *
471 * extents in the log tree have not been allocated out of the extent
472 * tree yet. So, this completes the allocation, taking a reference
473 * as required if the extent already exists or creating a new extent
474 * if it isn't in the extent allocation tree yet.
475 *
476 * The extent is inserted into the file, dropping any existing extents
477 * from the file that overlap the new one.
478 */
479static noinline int replay_one_extent(struct btrfs_trans_handle *trans,
480 struct btrfs_root *root,
481 struct btrfs_path *path,
482 struct extent_buffer *eb, int slot,
483 struct btrfs_key *key)
484{
485 int found_type;
486 u64 mask = root->sectorsize - 1;
487 u64 extent_end;
488 u64 alloc_hint;
489 u64 start = key->offset;
490 u64 saved_nbytes;
491 struct btrfs_file_extent_item *item;
492 struct inode *inode = NULL;
493 unsigned long size;
494 int ret = 0;
495
496 item = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item);
497 found_type = btrfs_file_extent_type(eb, item);
498
499 if (found_type == BTRFS_FILE_EXTENT_REG ||
500 found_type == BTRFS_FILE_EXTENT_PREALLOC)
501 extent_end = start + btrfs_file_extent_num_bytes(eb, item);
502 else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
503 size = btrfs_file_extent_inline_len(eb, item);
504 extent_end = (start + size + mask) & ~mask;
505 } else {
506 ret = 0;
507 goto out;
508 }
509
510 inode = read_one_inode(root, key->objectid);
511 if (!inode) {
512 ret = -EIO;
513 goto out;
514 }
515
516 /*
517 * first check to see if we already have this extent in the
518 * file. This must be done before the btrfs_drop_extents run
519 * so we don't try to drop this extent.
520 */
521 ret = btrfs_lookup_file_extent(trans, root, path, btrfs_ino(inode),
522 start, 0);
523
524 if (ret == 0 &&
525 (found_type == BTRFS_FILE_EXTENT_REG ||
526 found_type == BTRFS_FILE_EXTENT_PREALLOC)) {
527 struct btrfs_file_extent_item cmp1;
528 struct btrfs_file_extent_item cmp2;
529 struct btrfs_file_extent_item *existing;
530 struct extent_buffer *leaf;
531
532 leaf = path->nodes[0];
533 existing = btrfs_item_ptr(leaf, path->slots[0],
534 struct btrfs_file_extent_item);
535
536 read_extent_buffer(eb, &cmp1, (unsigned long)item,
537 sizeof(cmp1));
538 read_extent_buffer(leaf, &cmp2, (unsigned long)existing,
539 sizeof(cmp2));
540
541 /*
542 * we already have a pointer to this exact extent,
543 * we don't have to do anything
544 */
545 if (memcmp(&cmp1, &cmp2, sizeof(cmp1)) == 0) {
546 btrfs_release_path(path);
547 goto out;
548 }
549 }
550 btrfs_release_path(path);
551
552 saved_nbytes = inode_get_bytes(inode);
553 /* drop any overlapping extents */
554 ret = btrfs_drop_extents(trans, inode, start, extent_end,
555 &alloc_hint, 1);
556 BUG_ON(ret);
557
558 if (found_type == BTRFS_FILE_EXTENT_REG ||
559 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
560 u64 offset;
561 unsigned long dest_offset;
562 struct btrfs_key ins;
563
564 ret = btrfs_insert_empty_item(trans, root, path, key,
565 sizeof(*item));
566 BUG_ON(ret);
567 dest_offset = btrfs_item_ptr_offset(path->nodes[0],
568 path->slots[0]);
569 copy_extent_buffer(path->nodes[0], eb, dest_offset,
570 (unsigned long)item, sizeof(*item));
571
572 ins.objectid = btrfs_file_extent_disk_bytenr(eb, item);
573 ins.offset = btrfs_file_extent_disk_num_bytes(eb, item);
574 ins.type = BTRFS_EXTENT_ITEM_KEY;
575 offset = key->offset - btrfs_file_extent_offset(eb, item);
576
577 if (ins.objectid > 0) {
578 u64 csum_start;
579 u64 csum_end;
580 LIST_HEAD(ordered_sums);
581 /*
582 * is this extent already allocated in the extent
583 * allocation tree? If so, just add a reference
584 */
585 ret = btrfs_lookup_extent(root, ins.objectid,
586 ins.offset);
587 if (ret == 0) {
588 ret = btrfs_inc_extent_ref(trans, root,
589 ins.objectid, ins.offset,
590 0, root->root_key.objectid,
591 key->objectid, offset);
592 BUG_ON(ret);
593 } else {
594 /*
595 * insert the extent pointer in the extent
596 * allocation tree
597 */
598 ret = btrfs_alloc_logged_file_extent(trans,
599 root, root->root_key.objectid,
600 key->objectid, offset, &ins);
601 BUG_ON(ret);
602 }
603 btrfs_release_path(path);
604
605 if (btrfs_file_extent_compression(eb, item)) {
606 csum_start = ins.objectid;
607 csum_end = csum_start + ins.offset;
608 } else {
609 csum_start = ins.objectid +
610 btrfs_file_extent_offset(eb, item);
611 csum_end = csum_start +
612 btrfs_file_extent_num_bytes(eb, item);
613 }
614
615 ret = btrfs_lookup_csums_range(root->log_root,
616 csum_start, csum_end - 1,
617 &ordered_sums, 0);
618 BUG_ON(ret);
619 while (!list_empty(&ordered_sums)) {
620 struct btrfs_ordered_sum *sums;
621 sums = list_entry(ordered_sums.next,
622 struct btrfs_ordered_sum,
623 list);
624 ret = btrfs_csum_file_blocks(trans,
625 root->fs_info->csum_root,
626 sums);
627 BUG_ON(ret);
628 list_del(&sums->list);
629 kfree(sums);
630 }
631 } else {
632 btrfs_release_path(path);
633 }
634 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
635 /* inline extents are easy, we just overwrite them */
636 ret = overwrite_item(trans, root, path, eb, slot, key);
637 BUG_ON(ret);
638 }
639
640 inode_set_bytes(inode, saved_nbytes);
641 btrfs_update_inode(trans, root, inode);
642out:
643 if (inode)
644 iput(inode);
645 return ret;
646}
647
648/*
649 * when cleaning up conflicts between the directory names in the
650 * subvolume, directory names in the log and directory names in the
651 * inode back references, we may have to unlink inodes from directories.
652 *
653 * This is a helper function to do the unlink of a specific directory
654 * item
655 */
656static noinline int drop_one_dir_item(struct btrfs_trans_handle *trans,
657 struct btrfs_root *root,
658 struct btrfs_path *path,
659 struct inode *dir,
660 struct btrfs_dir_item *di)
661{
662 struct inode *inode;
663 char *name;
664 int name_len;
665 struct extent_buffer *leaf;
666 struct btrfs_key location;
667 int ret;
668
669 leaf = path->nodes[0];
670
671 btrfs_dir_item_key_to_cpu(leaf, di, &location);
672 name_len = btrfs_dir_name_len(leaf, di);
673 name = kmalloc(name_len, GFP_NOFS);
674 if (!name)
675 return -ENOMEM;
676
677 read_extent_buffer(leaf, name, (unsigned long)(di + 1), name_len);
678 btrfs_release_path(path);
679
680 inode = read_one_inode(root, location.objectid);
681 if (!inode) {
682 kfree(name);
683 return -EIO;
684 }
685
686 ret = link_to_fixup_dir(trans, root, path, location.objectid);
687 BUG_ON(ret);
688
689 ret = btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
690 BUG_ON(ret);
691 kfree(name);
692
693 iput(inode);
694 return ret;
695}
696
697/*
698 * helper function to see if a given name and sequence number found
699 * in an inode back reference are already in a directory and correctly
700 * point to this inode
701 */
702static noinline int inode_in_dir(struct btrfs_root *root,
703 struct btrfs_path *path,
704 u64 dirid, u64 objectid, u64 index,
705 const char *name, int name_len)
706{
707 struct btrfs_dir_item *di;
708 struct btrfs_key location;
709 int match = 0;
710
711 di = btrfs_lookup_dir_index_item(NULL, root, path, dirid,
712 index, name, name_len, 0);
713 if (di && !IS_ERR(di)) {
714 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
715 if (location.objectid != objectid)
716 goto out;
717 } else
718 goto out;
719 btrfs_release_path(path);
720
721 di = btrfs_lookup_dir_item(NULL, root, path, dirid, name, name_len, 0);
722 if (di && !IS_ERR(di)) {
723 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
724 if (location.objectid != objectid)
725 goto out;
726 } else
727 goto out;
728 match = 1;
729out:
730 btrfs_release_path(path);
731 return match;
732}
733
734/*
735 * helper function to check a log tree for a named back reference in
736 * an inode. This is used to decide if a back reference that is
737 * found in the subvolume conflicts with what we find in the log.
738 *
739 * inode backreferences may have multiple refs in a single item,
740 * during replay we process one reference at a time, and we don't
741 * want to delete valid links to a file from the subvolume if that
742 * link is also in the log.
743 */
744static noinline int backref_in_log(struct btrfs_root *log,
745 struct btrfs_key *key,
746 char *name, int namelen)
747{
748 struct btrfs_path *path;
749 struct btrfs_inode_ref *ref;
750 unsigned long ptr;
751 unsigned long ptr_end;
752 unsigned long name_ptr;
753 int found_name_len;
754 int item_size;
755 int ret;
756 int match = 0;
757
758 path = btrfs_alloc_path();
759 if (!path)
760 return -ENOMEM;
761
762 ret = btrfs_search_slot(NULL, log, key, path, 0, 0);
763 if (ret != 0)
764 goto out;
765
766 item_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
767 ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
768 ptr_end = ptr + item_size;
769 while (ptr < ptr_end) {
770 ref = (struct btrfs_inode_ref *)ptr;
771 found_name_len = btrfs_inode_ref_name_len(path->nodes[0], ref);
772 if (found_name_len == namelen) {
773 name_ptr = (unsigned long)(ref + 1);
774 ret = memcmp_extent_buffer(path->nodes[0], name,
775 name_ptr, namelen);
776 if (ret == 0) {
777 match = 1;
778 goto out;
779 }
780 }
781 ptr = (unsigned long)(ref + 1) + found_name_len;
782 }
783out:
784 btrfs_free_path(path);
785 return match;
786}
787
788
789/*
790 * replay one inode back reference item found in the log tree.
791 * eb, slot and key refer to the buffer and key found in the log tree.
792 * root is the destination we are replaying into, and path is for temp
793 * use by this function. (it should be released on return).
794 */
795static noinline int add_inode_ref(struct btrfs_trans_handle *trans,
796 struct btrfs_root *root,
797 struct btrfs_root *log,
798 struct btrfs_path *path,
799 struct extent_buffer *eb, int slot,
800 struct btrfs_key *key)
801{
802 struct btrfs_inode_ref *ref;
803 struct btrfs_dir_item *di;
804 struct inode *dir;
805 struct inode *inode;
806 unsigned long ref_ptr;
807 unsigned long ref_end;
808 char *name;
809 int namelen;
810 int ret;
811 int search_done = 0;
812
813 /*
814 * it is possible that we didn't log all the parent directories
815 * for a given inode. If we don't find the dir, just don't
816 * copy the back ref in. The link count fixup code will take
817 * care of the rest
818 */
819 dir = read_one_inode(root, key->offset);
820 if (!dir)
821 return -ENOENT;
822
823 inode = read_one_inode(root, key->objectid);
824 if (!inode) {
825 iput(dir);
826 return -EIO;
827 }
828
829 ref_ptr = btrfs_item_ptr_offset(eb, slot);
830 ref_end = ref_ptr + btrfs_item_size_nr(eb, slot);
831
832again:
833 ref = (struct btrfs_inode_ref *)ref_ptr;
834
835 namelen = btrfs_inode_ref_name_len(eb, ref);
836 name = kmalloc(namelen, GFP_NOFS);
837 BUG_ON(!name);
838
839 read_extent_buffer(eb, name, (unsigned long)(ref + 1), namelen);
840
841 /* if we already have a perfect match, we're done */
842 if (inode_in_dir(root, path, btrfs_ino(dir), btrfs_ino(inode),
843 btrfs_inode_ref_index(eb, ref),
844 name, namelen)) {
845 goto out;
846 }
847
848 /*
849 * look for a conflicting back reference in the metadata.
850 * if we find one we have to unlink that name of the file
851 * before we add our new link. Later on, we overwrite any
852 * existing back reference, and we don't want to create
853 * dangling pointers in the directory.
854 */
855
856 if (search_done)
857 goto insert;
858
859 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
860 if (ret == 0) {
861 char *victim_name;
862 int victim_name_len;
863 struct btrfs_inode_ref *victim_ref;
864 unsigned long ptr;
865 unsigned long ptr_end;
866 struct extent_buffer *leaf = path->nodes[0];
867
868 /* are we trying to overwrite a back ref for the root directory
869 * if so, just jump out, we're done
870 */
871 if (key->objectid == key->offset)
872 goto out_nowrite;
873
874 /* check all the names in this back reference to see
875 * if they are in the log. if so, we allow them to stay
876 * otherwise they must be unlinked as a conflict
877 */
878 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
879 ptr_end = ptr + btrfs_item_size_nr(leaf, path->slots[0]);
880 while (ptr < ptr_end) {
881 victim_ref = (struct btrfs_inode_ref *)ptr;
882 victim_name_len = btrfs_inode_ref_name_len(leaf,
883 victim_ref);
884 victim_name = kmalloc(victim_name_len, GFP_NOFS);
885 BUG_ON(!victim_name);
886
887 read_extent_buffer(leaf, victim_name,
888 (unsigned long)(victim_ref + 1),
889 victim_name_len);
890
891 if (!backref_in_log(log, key, victim_name,
892 victim_name_len)) {
893 btrfs_inc_nlink(inode);
894 btrfs_release_path(path);
895
896 ret = btrfs_unlink_inode(trans, root, dir,
897 inode, victim_name,
898 victim_name_len);
899 }
900 kfree(victim_name);
901 ptr = (unsigned long)(victim_ref + 1) + victim_name_len;
902 }
903 BUG_ON(ret);
904
905 /*
906 * NOTE: we have searched root tree and checked the
907 * coresponding ref, it does not need to check again.
908 */
909 search_done = 1;
910 }
911 btrfs_release_path(path);
912
913 /* look for a conflicting sequence number */
914 di = btrfs_lookup_dir_index_item(trans, root, path, btrfs_ino(dir),
915 btrfs_inode_ref_index(eb, ref),
916 name, namelen, 0);
917 if (di && !IS_ERR(di)) {
918 ret = drop_one_dir_item(trans, root, path, dir, di);
919 BUG_ON(ret);
920 }
921 btrfs_release_path(path);
922
923 /* look for a conflicing name */
924 di = btrfs_lookup_dir_item(trans, root, path, btrfs_ino(dir),
925 name, namelen, 0);
926 if (di && !IS_ERR(di)) {
927 ret = drop_one_dir_item(trans, root, path, dir, di);
928 BUG_ON(ret);
929 }
930 btrfs_release_path(path);
931
932insert:
933 /* insert our name */
934 ret = btrfs_add_link(trans, dir, inode, name, namelen, 0,
935 btrfs_inode_ref_index(eb, ref));
936 BUG_ON(ret);
937
938 btrfs_update_inode(trans, root, inode);
939
940out:
941 ref_ptr = (unsigned long)(ref + 1) + namelen;
942 kfree(name);
943 if (ref_ptr < ref_end)
944 goto again;
945
946 /* finally write the back reference in the inode */
947 ret = overwrite_item(trans, root, path, eb, slot, key);
948 BUG_ON(ret);
949
950out_nowrite:
951 btrfs_release_path(path);
952 iput(dir);
953 iput(inode);
954 return 0;
955}
956
957static int insert_orphan_item(struct btrfs_trans_handle *trans,
958 struct btrfs_root *root, u64 offset)
959{
960 int ret;
961 ret = btrfs_find_orphan_item(root, offset);
962 if (ret > 0)
963 ret = btrfs_insert_orphan_item(trans, root, offset);
964 return ret;
965}
966
967
968/*
969 * There are a few corners where the link count of the file can't
970 * be properly maintained during replay. So, instead of adding
971 * lots of complexity to the log code, we just scan the backrefs
972 * for any file that has been through replay.
973 *
974 * The scan will update the link count on the inode to reflect the
975 * number of back refs found. If it goes down to zero, the iput
976 * will free the inode.
977 */
978static noinline int fixup_inode_link_count(struct btrfs_trans_handle *trans,
979 struct btrfs_root *root,
980 struct inode *inode)
981{
982 struct btrfs_path *path;
983 int ret;
984 struct btrfs_key key;
985 u64 nlink = 0;
986 unsigned long ptr;
987 unsigned long ptr_end;
988 int name_len;
989 u64 ino = btrfs_ino(inode);
990
991 key.objectid = ino;
992 key.type = BTRFS_INODE_REF_KEY;
993 key.offset = (u64)-1;
994
995 path = btrfs_alloc_path();
996 if (!path)
997 return -ENOMEM;
998
999 while (1) {
1000 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1001 if (ret < 0)
1002 break;
1003 if (ret > 0) {
1004 if (path->slots[0] == 0)
1005 break;
1006 path->slots[0]--;
1007 }
1008 btrfs_item_key_to_cpu(path->nodes[0], &key,
1009 path->slots[0]);
1010 if (key.objectid != ino ||
1011 key.type != BTRFS_INODE_REF_KEY)
1012 break;
1013 ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
1014 ptr_end = ptr + btrfs_item_size_nr(path->nodes[0],
1015 path->slots[0]);
1016 while (ptr < ptr_end) {
1017 struct btrfs_inode_ref *ref;
1018
1019 ref = (struct btrfs_inode_ref *)ptr;
1020 name_len = btrfs_inode_ref_name_len(path->nodes[0],
1021 ref);
1022 ptr = (unsigned long)(ref + 1) + name_len;
1023 nlink++;
1024 }
1025
1026 if (key.offset == 0)
1027 break;
1028 key.offset--;
1029 btrfs_release_path(path);
1030 }
1031 btrfs_release_path(path);
1032 if (nlink != inode->i_nlink) {
1033 inode->i_nlink = nlink;
1034 btrfs_update_inode(trans, root, inode);
1035 }
1036 BTRFS_I(inode)->index_cnt = (u64)-1;
1037
1038 if (inode->i_nlink == 0) {
1039 if (S_ISDIR(inode->i_mode)) {
1040 ret = replay_dir_deletes(trans, root, NULL, path,
1041 ino, 1);
1042 BUG_ON(ret);
1043 }
1044 ret = insert_orphan_item(trans, root, ino);
1045 BUG_ON(ret);
1046 }
1047 btrfs_free_path(path);
1048
1049 return 0;
1050}
1051
1052static noinline int fixup_inode_link_counts(struct btrfs_trans_handle *trans,
1053 struct btrfs_root *root,
1054 struct btrfs_path *path)
1055{
1056 int ret;
1057 struct btrfs_key key;
1058 struct inode *inode;
1059
1060 key.objectid = BTRFS_TREE_LOG_FIXUP_OBJECTID;
1061 key.type = BTRFS_ORPHAN_ITEM_KEY;
1062 key.offset = (u64)-1;
1063 while (1) {
1064 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1065 if (ret < 0)
1066 break;
1067
1068 if (ret == 1) {
1069 if (path->slots[0] == 0)
1070 break;
1071 path->slots[0]--;
1072 }
1073
1074 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1075 if (key.objectid != BTRFS_TREE_LOG_FIXUP_OBJECTID ||
1076 key.type != BTRFS_ORPHAN_ITEM_KEY)
1077 break;
1078
1079 ret = btrfs_del_item(trans, root, path);
1080 if (ret)
1081 goto out;
1082
1083 btrfs_release_path(path);
1084 inode = read_one_inode(root, key.offset);
1085 if (!inode)
1086 return -EIO;
1087
1088 ret = fixup_inode_link_count(trans, root, inode);
1089 BUG_ON(ret);
1090
1091 iput(inode);
1092
1093 /*
1094 * fixup on a directory may create new entries,
1095 * make sure we always look for the highset possible
1096 * offset
1097 */
1098 key.offset = (u64)-1;
1099 }
1100 ret = 0;
1101out:
1102 btrfs_release_path(path);
1103 return ret;
1104}
1105
1106
1107/*
1108 * record a given inode in the fixup dir so we can check its link
1109 * count when replay is done. The link count is incremented here
1110 * so the inode won't go away until we check it
1111 */
1112static noinline int link_to_fixup_dir(struct btrfs_trans_handle *trans,
1113 struct btrfs_root *root,
1114 struct btrfs_path *path,
1115 u64 objectid)
1116{
1117 struct btrfs_key key;
1118 int ret = 0;
1119 struct inode *inode;
1120
1121 inode = read_one_inode(root, objectid);
1122 if (!inode)
1123 return -EIO;
1124
1125 key.objectid = BTRFS_TREE_LOG_FIXUP_OBJECTID;
1126 btrfs_set_key_type(&key, BTRFS_ORPHAN_ITEM_KEY);
1127 key.offset = objectid;
1128
1129 ret = btrfs_insert_empty_item(trans, root, path, &key, 0);
1130
1131 btrfs_release_path(path);
1132 if (ret == 0) {
1133 btrfs_inc_nlink(inode);
1134 btrfs_update_inode(trans, root, inode);
1135 } else if (ret == -EEXIST) {
1136 ret = 0;
1137 } else {
1138 BUG();
1139 }
1140 iput(inode);
1141
1142 return ret;
1143}
1144
1145/*
1146 * when replaying the log for a directory, we only insert names
1147 * for inodes that actually exist. This means an fsync on a directory
1148 * does not implicitly fsync all the new files in it
1149 */
1150static noinline int insert_one_name(struct btrfs_trans_handle *trans,
1151 struct btrfs_root *root,
1152 struct btrfs_path *path,
1153 u64 dirid, u64 index,
1154 char *name, int name_len, u8 type,
1155 struct btrfs_key *location)
1156{
1157 struct inode *inode;
1158 struct inode *dir;
1159 int ret;
1160
1161 inode = read_one_inode(root, location->objectid);
1162 if (!inode)
1163 return -ENOENT;
1164
1165 dir = read_one_inode(root, dirid);
1166 if (!dir) {
1167 iput(inode);
1168 return -EIO;
1169 }
1170 ret = btrfs_add_link(trans, dir, inode, name, name_len, 1, index);
1171
1172 /* FIXME, put inode into FIXUP list */
1173
1174 iput(inode);
1175 iput(dir);
1176 return ret;
1177}
1178
1179/*
1180 * take a single entry in a log directory item and replay it into
1181 * the subvolume.
1182 *
1183 * if a conflicting item exists in the subdirectory already,
1184 * the inode it points to is unlinked and put into the link count
1185 * fix up tree.
1186 *
1187 * If a name from the log points to a file or directory that does
1188 * not exist in the FS, it is skipped. fsyncs on directories
1189 * do not force down inodes inside that directory, just changes to the
1190 * names or unlinks in a directory.
1191 */
1192static noinline int replay_one_name(struct btrfs_trans_handle *trans,
1193 struct btrfs_root *root,
1194 struct btrfs_path *path,
1195 struct extent_buffer *eb,
1196 struct btrfs_dir_item *di,
1197 struct btrfs_key *key)
1198{
1199 char *name;
1200 int name_len;
1201 struct btrfs_dir_item *dst_di;
1202 struct btrfs_key found_key;
1203 struct btrfs_key log_key;
1204 struct inode *dir;
1205 u8 log_type;
1206 int exists;
1207 int ret;
1208
1209 dir = read_one_inode(root, key->objectid);
1210 if (!dir)
1211 return -EIO;
1212
1213 name_len = btrfs_dir_name_len(eb, di);
1214 name = kmalloc(name_len, GFP_NOFS);
1215 if (!name)
1216 return -ENOMEM;
1217
1218 log_type = btrfs_dir_type(eb, di);
1219 read_extent_buffer(eb, name, (unsigned long)(di + 1),
1220 name_len);
1221
1222 btrfs_dir_item_key_to_cpu(eb, di, &log_key);
1223 exists = btrfs_lookup_inode(trans, root, path, &log_key, 0);
1224 if (exists == 0)
1225 exists = 1;
1226 else
1227 exists = 0;
1228 btrfs_release_path(path);
1229
1230 if (key->type == BTRFS_DIR_ITEM_KEY) {
1231 dst_di = btrfs_lookup_dir_item(trans, root, path, key->objectid,
1232 name, name_len, 1);
1233 } else if (key->type == BTRFS_DIR_INDEX_KEY) {
1234 dst_di = btrfs_lookup_dir_index_item(trans, root, path,
1235 key->objectid,
1236 key->offset, name,
1237 name_len, 1);
1238 } else {
1239 BUG();
1240 }
1241 if (IS_ERR_OR_NULL(dst_di)) {
1242 /* we need a sequence number to insert, so we only
1243 * do inserts for the BTRFS_DIR_INDEX_KEY types
1244 */
1245 if (key->type != BTRFS_DIR_INDEX_KEY)
1246 goto out;
1247 goto insert;
1248 }
1249
1250 btrfs_dir_item_key_to_cpu(path->nodes[0], dst_di, &found_key);
1251 /* the existing item matches the logged item */
1252 if (found_key.objectid == log_key.objectid &&
1253 found_key.type == log_key.type &&
1254 found_key.offset == log_key.offset &&
1255 btrfs_dir_type(path->nodes[0], dst_di) == log_type) {
1256 goto out;
1257 }
1258
1259 /*
1260 * don't drop the conflicting directory entry if the inode
1261 * for the new entry doesn't exist
1262 */
1263 if (!exists)
1264 goto out;
1265
1266 ret = drop_one_dir_item(trans, root, path, dir, dst_di);
1267 BUG_ON(ret);
1268
1269 if (key->type == BTRFS_DIR_INDEX_KEY)
1270 goto insert;
1271out:
1272 btrfs_release_path(path);
1273 kfree(name);
1274 iput(dir);
1275 return 0;
1276
1277insert:
1278 btrfs_release_path(path);
1279 ret = insert_one_name(trans, root, path, key->objectid, key->offset,
1280 name, name_len, log_type, &log_key);
1281
1282 BUG_ON(ret && ret != -ENOENT);
1283 goto out;
1284}
1285
1286/*
1287 * find all the names in a directory item and reconcile them into
1288 * the subvolume. Only BTRFS_DIR_ITEM_KEY types will have more than
1289 * one name in a directory item, but the same code gets used for
1290 * both directory index types
1291 */
1292static noinline int replay_one_dir_item(struct btrfs_trans_handle *trans,
1293 struct btrfs_root *root,
1294 struct btrfs_path *path,
1295 struct extent_buffer *eb, int slot,
1296 struct btrfs_key *key)
1297{
1298 int ret;
1299 u32 item_size = btrfs_item_size_nr(eb, slot);
1300 struct btrfs_dir_item *di;
1301 int name_len;
1302 unsigned long ptr;
1303 unsigned long ptr_end;
1304
1305 ptr = btrfs_item_ptr_offset(eb, slot);
1306 ptr_end = ptr + item_size;
1307 while (ptr < ptr_end) {
1308 di = (struct btrfs_dir_item *)ptr;
1309 if (verify_dir_item(root, eb, di))
1310 return -EIO;
1311 name_len = btrfs_dir_name_len(eb, di);
1312 ret = replay_one_name(trans, root, path, eb, di, key);
1313 BUG_ON(ret);
1314 ptr = (unsigned long)(di + 1);
1315 ptr += name_len;
1316 }
1317 return 0;
1318}
1319
1320/*
1321 * directory replay has two parts. There are the standard directory
1322 * items in the log copied from the subvolume, and range items
1323 * created in the log while the subvolume was logged.
1324 *
1325 * The range items tell us which parts of the key space the log
1326 * is authoritative for. During replay, if a key in the subvolume
1327 * directory is in a logged range item, but not actually in the log
1328 * that means it was deleted from the directory before the fsync
1329 * and should be removed.
1330 */
1331static noinline int find_dir_range(struct btrfs_root *root,
1332 struct btrfs_path *path,
1333 u64 dirid, int key_type,
1334 u64 *start_ret, u64 *end_ret)
1335{
1336 struct btrfs_key key;
1337 u64 found_end;
1338 struct btrfs_dir_log_item *item;
1339 int ret;
1340 int nritems;
1341
1342 if (*start_ret == (u64)-1)
1343 return 1;
1344
1345 key.objectid = dirid;
1346 key.type = key_type;
1347 key.offset = *start_ret;
1348
1349 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1350 if (ret < 0)
1351 goto out;
1352 if (ret > 0) {
1353 if (path->slots[0] == 0)
1354 goto out;
1355 path->slots[0]--;
1356 }
1357 if (ret != 0)
1358 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1359
1360 if (key.type != key_type || key.objectid != dirid) {
1361 ret = 1;
1362 goto next;
1363 }
1364 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
1365 struct btrfs_dir_log_item);
1366 found_end = btrfs_dir_log_end(path->nodes[0], item);
1367
1368 if (*start_ret >= key.offset && *start_ret <= found_end) {
1369 ret = 0;
1370 *start_ret = key.offset;
1371 *end_ret = found_end;
1372 goto out;
1373 }
1374 ret = 1;
1375next:
1376 /* check the next slot in the tree to see if it is a valid item */
1377 nritems = btrfs_header_nritems(path->nodes[0]);
1378 if (path->slots[0] >= nritems) {
1379 ret = btrfs_next_leaf(root, path);
1380 if (ret)
1381 goto out;
1382 } else {
1383 path->slots[0]++;
1384 }
1385
1386 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1387
1388 if (key.type != key_type || key.objectid != dirid) {
1389 ret = 1;
1390 goto out;
1391 }
1392 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
1393 struct btrfs_dir_log_item);
1394 found_end = btrfs_dir_log_end(path->nodes[0], item);
1395 *start_ret = key.offset;
1396 *end_ret = found_end;
1397 ret = 0;
1398out:
1399 btrfs_release_path(path);
1400 return ret;
1401}
1402
1403/*
1404 * this looks for a given directory item in the log. If the directory
1405 * item is not in the log, the item is removed and the inode it points
1406 * to is unlinked
1407 */
1408static noinline int check_item_in_log(struct btrfs_trans_handle *trans,
1409 struct btrfs_root *root,
1410 struct btrfs_root *log,
1411 struct btrfs_path *path,
1412 struct btrfs_path *log_path,
1413 struct inode *dir,
1414 struct btrfs_key *dir_key)
1415{
1416 int ret;
1417 struct extent_buffer *eb;
1418 int slot;
1419 u32 item_size;
1420 struct btrfs_dir_item *di;
1421 struct btrfs_dir_item *log_di;
1422 int name_len;
1423 unsigned long ptr;
1424 unsigned long ptr_end;
1425 char *name;
1426 struct inode *inode;
1427 struct btrfs_key location;
1428
1429again:
1430 eb = path->nodes[0];
1431 slot = path->slots[0];
1432 item_size = btrfs_item_size_nr(eb, slot);
1433 ptr = btrfs_item_ptr_offset(eb, slot);
1434 ptr_end = ptr + item_size;
1435 while (ptr < ptr_end) {
1436 di = (struct btrfs_dir_item *)ptr;
1437 if (verify_dir_item(root, eb, di)) {
1438 ret = -EIO;
1439 goto out;
1440 }
1441
1442 name_len = btrfs_dir_name_len(eb, di);
1443 name = kmalloc(name_len, GFP_NOFS);
1444 if (!name) {
1445 ret = -ENOMEM;
1446 goto out;
1447 }
1448 read_extent_buffer(eb, name, (unsigned long)(di + 1),
1449 name_len);
1450 log_di = NULL;
1451 if (log && dir_key->type == BTRFS_DIR_ITEM_KEY) {
1452 log_di = btrfs_lookup_dir_item(trans, log, log_path,
1453 dir_key->objectid,
1454 name, name_len, 0);
1455 } else if (log && dir_key->type == BTRFS_DIR_INDEX_KEY) {
1456 log_di = btrfs_lookup_dir_index_item(trans, log,
1457 log_path,
1458 dir_key->objectid,
1459 dir_key->offset,
1460 name, name_len, 0);
1461 }
1462 if (IS_ERR_OR_NULL(log_di)) {
1463 btrfs_dir_item_key_to_cpu(eb, di, &location);
1464 btrfs_release_path(path);
1465 btrfs_release_path(log_path);
1466 inode = read_one_inode(root, location.objectid);
1467 if (!inode) {
1468 kfree(name);
1469 return -EIO;
1470 }
1471
1472 ret = link_to_fixup_dir(trans, root,
1473 path, location.objectid);
1474 BUG_ON(ret);
1475 btrfs_inc_nlink(inode);
1476 ret = btrfs_unlink_inode(trans, root, dir, inode,
1477 name, name_len);
1478 BUG_ON(ret);
1479 kfree(name);
1480 iput(inode);
1481
1482 /* there might still be more names under this key
1483 * check and repeat if required
1484 */
1485 ret = btrfs_search_slot(NULL, root, dir_key, path,
1486 0, 0);
1487 if (ret == 0)
1488 goto again;
1489 ret = 0;
1490 goto out;
1491 }
1492 btrfs_release_path(log_path);
1493 kfree(name);
1494
1495 ptr = (unsigned long)(di + 1);
1496 ptr += name_len;
1497 }
1498 ret = 0;
1499out:
1500 btrfs_release_path(path);
1501 btrfs_release_path(log_path);
1502 return ret;
1503}
1504
1505/*
1506 * deletion replay happens before we copy any new directory items
1507 * out of the log or out of backreferences from inodes. It
1508 * scans the log to find ranges of keys that log is authoritative for,
1509 * and then scans the directory to find items in those ranges that are
1510 * not present in the log.
1511 *
1512 * Anything we don't find in the log is unlinked and removed from the
1513 * directory.
1514 */
1515static noinline int replay_dir_deletes(struct btrfs_trans_handle *trans,
1516 struct btrfs_root *root,
1517 struct btrfs_root *log,
1518 struct btrfs_path *path,
1519 u64 dirid, int del_all)
1520{
1521 u64 range_start;
1522 u64 range_end;
1523 int key_type = BTRFS_DIR_LOG_ITEM_KEY;
1524 int ret = 0;
1525 struct btrfs_key dir_key;
1526 struct btrfs_key found_key;
1527 struct btrfs_path *log_path;
1528 struct inode *dir;
1529
1530 dir_key.objectid = dirid;
1531 dir_key.type = BTRFS_DIR_ITEM_KEY;
1532 log_path = btrfs_alloc_path();
1533 if (!log_path)
1534 return -ENOMEM;
1535
1536 dir = read_one_inode(root, dirid);
1537 /* it isn't an error if the inode isn't there, that can happen
1538 * because we replay the deletes before we copy in the inode item
1539 * from the log
1540 */
1541 if (!dir) {
1542 btrfs_free_path(log_path);
1543 return 0;
1544 }
1545again:
1546 range_start = 0;
1547 range_end = 0;
1548 while (1) {
1549 if (del_all)
1550 range_end = (u64)-1;
1551 else {
1552 ret = find_dir_range(log, path, dirid, key_type,
1553 &range_start, &range_end);
1554 if (ret != 0)
1555 break;
1556 }
1557
1558 dir_key.offset = range_start;
1559 while (1) {
1560 int nritems;
1561 ret = btrfs_search_slot(NULL, root, &dir_key, path,
1562 0, 0);
1563 if (ret < 0)
1564 goto out;
1565
1566 nritems = btrfs_header_nritems(path->nodes[0]);
1567 if (path->slots[0] >= nritems) {
1568 ret = btrfs_next_leaf(root, path);
1569 if (ret)
1570 break;
1571 }
1572 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1573 path->slots[0]);
1574 if (found_key.objectid != dirid ||
1575 found_key.type != dir_key.type)
1576 goto next_type;
1577
1578 if (found_key.offset > range_end)
1579 break;
1580
1581 ret = check_item_in_log(trans, root, log, path,
1582 log_path, dir,
1583 &found_key);
1584 BUG_ON(ret);
1585 if (found_key.offset == (u64)-1)
1586 break;
1587 dir_key.offset = found_key.offset + 1;
1588 }
1589 btrfs_release_path(path);
1590 if (range_end == (u64)-1)
1591 break;
1592 range_start = range_end + 1;
1593 }
1594
1595next_type:
1596 ret = 0;
1597 if (key_type == BTRFS_DIR_LOG_ITEM_KEY) {
1598 key_type = BTRFS_DIR_LOG_INDEX_KEY;
1599 dir_key.type = BTRFS_DIR_INDEX_KEY;
1600 btrfs_release_path(path);
1601 goto again;
1602 }
1603out:
1604 btrfs_release_path(path);
1605 btrfs_free_path(log_path);
1606 iput(dir);
1607 return ret;
1608}
1609
1610/*
1611 * the process_func used to replay items from the log tree. This
1612 * gets called in two different stages. The first stage just looks
1613 * for inodes and makes sure they are all copied into the subvolume.
1614 *
1615 * The second stage copies all the other item types from the log into
1616 * the subvolume. The two stage approach is slower, but gets rid of
1617 * lots of complexity around inodes referencing other inodes that exist
1618 * only in the log (references come from either directory items or inode
1619 * back refs).
1620 */
1621static int replay_one_buffer(struct btrfs_root *log, struct extent_buffer *eb,
1622 struct walk_control *wc, u64 gen)
1623{
1624 int nritems;
1625 struct btrfs_path *path;
1626 struct btrfs_root *root = wc->replay_dest;
1627 struct btrfs_key key;
1628 int level;
1629 int i;
1630 int ret;
1631
1632 btrfs_read_buffer(eb, gen);
1633
1634 level = btrfs_header_level(eb);
1635
1636 if (level != 0)
1637 return 0;
1638
1639 path = btrfs_alloc_path();
1640 if (!path)
1641 return -ENOMEM;
1642
1643 nritems = btrfs_header_nritems(eb);
1644 for (i = 0; i < nritems; i++) {
1645 btrfs_item_key_to_cpu(eb, &key, i);
1646
1647 /* inode keys are done during the first stage */
1648 if (key.type == BTRFS_INODE_ITEM_KEY &&
1649 wc->stage == LOG_WALK_REPLAY_INODES) {
1650 struct btrfs_inode_item *inode_item;
1651 u32 mode;
1652
1653 inode_item = btrfs_item_ptr(eb, i,
1654 struct btrfs_inode_item);
1655 mode = btrfs_inode_mode(eb, inode_item);
1656 if (S_ISDIR(mode)) {
1657 ret = replay_dir_deletes(wc->trans,
1658 root, log, path, key.objectid, 0);
1659 BUG_ON(ret);
1660 }
1661 ret = overwrite_item(wc->trans, root, path,
1662 eb, i, &key);
1663 BUG_ON(ret);
1664
1665 /* for regular files, make sure corresponding
1666 * orhpan item exist. extents past the new EOF
1667 * will be truncated later by orphan cleanup.
1668 */
1669 if (S_ISREG(mode)) {
1670 ret = insert_orphan_item(wc->trans, root,
1671 key.objectid);
1672 BUG_ON(ret);
1673 }
1674
1675 ret = link_to_fixup_dir(wc->trans, root,
1676 path, key.objectid);
1677 BUG_ON(ret);
1678 }
1679 if (wc->stage < LOG_WALK_REPLAY_ALL)
1680 continue;
1681
1682 /* these keys are simply copied */
1683 if (key.type == BTRFS_XATTR_ITEM_KEY) {
1684 ret = overwrite_item(wc->trans, root, path,
1685 eb, i, &key);
1686 BUG_ON(ret);
1687 } else if (key.type == BTRFS_INODE_REF_KEY) {
1688 ret = add_inode_ref(wc->trans, root, log, path,
1689 eb, i, &key);
1690 BUG_ON(ret && ret != -ENOENT);
1691 } else if (key.type == BTRFS_EXTENT_DATA_KEY) {
1692 ret = replay_one_extent(wc->trans, root, path,
1693 eb, i, &key);
1694 BUG_ON(ret);
1695 } else if (key.type == BTRFS_DIR_ITEM_KEY ||
1696 key.type == BTRFS_DIR_INDEX_KEY) {
1697 ret = replay_one_dir_item(wc->trans, root, path,
1698 eb, i, &key);
1699 BUG_ON(ret);
1700 }
1701 }
1702 btrfs_free_path(path);
1703 return 0;
1704}
1705
1706static noinline int walk_down_log_tree(struct btrfs_trans_handle *trans,
1707 struct btrfs_root *root,
1708 struct btrfs_path *path, int *level,
1709 struct walk_control *wc)
1710{
1711 u64 root_owner;
1712 u64 bytenr;
1713 u64 ptr_gen;
1714 struct extent_buffer *next;
1715 struct extent_buffer *cur;
1716 struct extent_buffer *parent;
1717 u32 blocksize;
1718 int ret = 0;
1719
1720 WARN_ON(*level < 0);
1721 WARN_ON(*level >= BTRFS_MAX_LEVEL);
1722
1723 while (*level > 0) {
1724 WARN_ON(*level < 0);
1725 WARN_ON(*level >= BTRFS_MAX_LEVEL);
1726 cur = path->nodes[*level];
1727
1728 if (btrfs_header_level(cur) != *level)
1729 WARN_ON(1);
1730
1731 if (path->slots[*level] >=
1732 btrfs_header_nritems(cur))
1733 break;
1734
1735 bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
1736 ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
1737 blocksize = btrfs_level_size(root, *level - 1);
1738
1739 parent = path->nodes[*level];
1740 root_owner = btrfs_header_owner(parent);
1741
1742 next = btrfs_find_create_tree_block(root, bytenr, blocksize);
1743 if (!next)
1744 return -ENOMEM;
1745
1746 if (*level == 1) {
1747 ret = wc->process_func(root, next, wc, ptr_gen);
1748 if (ret)
1749 return ret;
1750
1751 path->slots[*level]++;
1752 if (wc->free) {
1753 btrfs_read_buffer(next, ptr_gen);
1754
1755 btrfs_tree_lock(next);
1756 btrfs_set_lock_blocking(next);
1757 clean_tree_block(trans, root, next);
1758 btrfs_wait_tree_block_writeback(next);
1759 btrfs_tree_unlock(next);
1760
1761 WARN_ON(root_owner !=
1762 BTRFS_TREE_LOG_OBJECTID);
1763 ret = btrfs_free_reserved_extent(root,
1764 bytenr, blocksize);
1765 BUG_ON(ret);
1766 }
1767 free_extent_buffer(next);
1768 continue;
1769 }
1770 btrfs_read_buffer(next, ptr_gen);
1771
1772 WARN_ON(*level <= 0);
1773 if (path->nodes[*level-1])
1774 free_extent_buffer(path->nodes[*level-1]);
1775 path->nodes[*level-1] = next;
1776 *level = btrfs_header_level(next);
1777 path->slots[*level] = 0;
1778 cond_resched();
1779 }
1780 WARN_ON(*level < 0);
1781 WARN_ON(*level >= BTRFS_MAX_LEVEL);
1782
1783 path->slots[*level] = btrfs_header_nritems(path->nodes[*level]);
1784
1785 cond_resched();
1786 return 0;
1787}
1788
1789static noinline int walk_up_log_tree(struct btrfs_trans_handle *trans,
1790 struct btrfs_root *root,
1791 struct btrfs_path *path, int *level,
1792 struct walk_control *wc)
1793{
1794 u64 root_owner;
1795 int i;
1796 int slot;
1797 int ret;
1798
1799 for (i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
1800 slot = path->slots[i];
1801 if (slot + 1 < btrfs_header_nritems(path->nodes[i])) {
1802 path->slots[i]++;
1803 *level = i;
1804 WARN_ON(*level == 0);
1805 return 0;
1806 } else {
1807 struct extent_buffer *parent;
1808 if (path->nodes[*level] == root->node)
1809 parent = path->nodes[*level];
1810 else
1811 parent = path->nodes[*level + 1];
1812
1813 root_owner = btrfs_header_owner(parent);
1814 ret = wc->process_func(root, path->nodes[*level], wc,
1815 btrfs_header_generation(path->nodes[*level]));
1816 if (ret)
1817 return ret;
1818
1819 if (wc->free) {
1820 struct extent_buffer *next;
1821
1822 next = path->nodes[*level];
1823
1824 btrfs_tree_lock(next);
1825 btrfs_set_lock_blocking(next);
1826 clean_tree_block(trans, root, next);
1827 btrfs_wait_tree_block_writeback(next);
1828 btrfs_tree_unlock(next);
1829
1830 WARN_ON(root_owner != BTRFS_TREE_LOG_OBJECTID);
1831 ret = btrfs_free_reserved_extent(root,
1832 path->nodes[*level]->start,
1833 path->nodes[*level]->len);
1834 BUG_ON(ret);
1835 }
1836 free_extent_buffer(path->nodes[*level]);
1837 path->nodes[*level] = NULL;
1838 *level = i + 1;
1839 }
1840 }
1841 return 1;
1842}
1843
1844/*
1845 * drop the reference count on the tree rooted at 'snap'. This traverses
1846 * the tree freeing any blocks that have a ref count of zero after being
1847 * decremented.
1848 */
1849static int walk_log_tree(struct btrfs_trans_handle *trans,
1850 struct btrfs_root *log, struct walk_control *wc)
1851{
1852 int ret = 0;
1853 int wret;
1854 int level;
1855 struct btrfs_path *path;
1856 int i;
1857 int orig_level;
1858
1859 path = btrfs_alloc_path();
1860 if (!path)
1861 return -ENOMEM;
1862
1863 level = btrfs_header_level(log->node);
1864 orig_level = level;
1865 path->nodes[level] = log->node;
1866 extent_buffer_get(log->node);
1867 path->slots[level] = 0;
1868
1869 while (1) {
1870 wret = walk_down_log_tree(trans, log, path, &level, wc);
1871 if (wret > 0)
1872 break;
1873 if (wret < 0)
1874 ret = wret;
1875
1876 wret = walk_up_log_tree(trans, log, path, &level, wc);
1877 if (wret > 0)
1878 break;
1879 if (wret < 0)
1880 ret = wret;
1881 }
1882
1883 /* was the root node processed? if not, catch it here */
1884 if (path->nodes[orig_level]) {
1885 wc->process_func(log, path->nodes[orig_level], wc,
1886 btrfs_header_generation(path->nodes[orig_level]));
1887 if (wc->free) {
1888 struct extent_buffer *next;
1889
1890 next = path->nodes[orig_level];
1891
1892 btrfs_tree_lock(next);
1893 btrfs_set_lock_blocking(next);
1894 clean_tree_block(trans, log, next);
1895 btrfs_wait_tree_block_writeback(next);
1896 btrfs_tree_unlock(next);
1897
1898 WARN_ON(log->root_key.objectid !=
1899 BTRFS_TREE_LOG_OBJECTID);
1900 ret = btrfs_free_reserved_extent(log, next->start,
1901 next->len);
1902 BUG_ON(ret);
1903 }
1904 }
1905
1906 for (i = 0; i <= orig_level; i++) {
1907 if (path->nodes[i]) {
1908 free_extent_buffer(path->nodes[i]);
1909 path->nodes[i] = NULL;
1910 }
1911 }
1912 btrfs_free_path(path);
1913 return ret;
1914}
1915
1916/*
1917 * helper function to update the item for a given subvolumes log root
1918 * in the tree of log roots
1919 */
1920static int update_log_root(struct btrfs_trans_handle *trans,
1921 struct btrfs_root *log)
1922{
1923 int ret;
1924
1925 if (log->log_transid == 1) {
1926 /* insert root item on the first sync */
1927 ret = btrfs_insert_root(trans, log->fs_info->log_root_tree,
1928 &log->root_key, &log->root_item);
1929 } else {
1930 ret = btrfs_update_root(trans, log->fs_info->log_root_tree,
1931 &log->root_key, &log->root_item);
1932 }
1933 return ret;
1934}
1935
1936static int wait_log_commit(struct btrfs_trans_handle *trans,
1937 struct btrfs_root *root, unsigned long transid)
1938{
1939 DEFINE_WAIT(wait);
1940 int index = transid % 2;
1941
1942 /*
1943 * we only allow two pending log transactions at a time,
1944 * so we know that if ours is more than 2 older than the
1945 * current transaction, we're done
1946 */
1947 do {
1948 prepare_to_wait(&root->log_commit_wait[index],
1949 &wait, TASK_UNINTERRUPTIBLE);
1950 mutex_unlock(&root->log_mutex);
1951
1952 if (root->fs_info->last_trans_log_full_commit !=
1953 trans->transid && root->log_transid < transid + 2 &&
1954 atomic_read(&root->log_commit[index]))
1955 schedule();
1956
1957 finish_wait(&root->log_commit_wait[index], &wait);
1958 mutex_lock(&root->log_mutex);
1959 } while (root->log_transid < transid + 2 &&
1960 atomic_read(&root->log_commit[index]));
1961 return 0;
1962}
1963
1964static int wait_for_writer(struct btrfs_trans_handle *trans,
1965 struct btrfs_root *root)
1966{
1967 DEFINE_WAIT(wait);
1968 while (atomic_read(&root->log_writers)) {
1969 prepare_to_wait(&root->log_writer_wait,
1970 &wait, TASK_UNINTERRUPTIBLE);
1971 mutex_unlock(&root->log_mutex);
1972 if (root->fs_info->last_trans_log_full_commit !=
1973 trans->transid && atomic_read(&root->log_writers))
1974 schedule();
1975 mutex_lock(&root->log_mutex);
1976 finish_wait(&root->log_writer_wait, &wait);
1977 }
1978 return 0;
1979}
1980
1981/*
1982 * btrfs_sync_log does sends a given tree log down to the disk and
1983 * updates the super blocks to record it. When this call is done,
1984 * you know that any inodes previously logged are safely on disk only
1985 * if it returns 0.
1986 *
1987 * Any other return value means you need to call btrfs_commit_transaction.
1988 * Some of the edge cases for fsyncing directories that have had unlinks
1989 * or renames done in the past mean that sometimes the only safe
1990 * fsync is to commit the whole FS. When btrfs_sync_log returns -EAGAIN,
1991 * that has happened.
1992 */
1993int btrfs_sync_log(struct btrfs_trans_handle *trans,
1994 struct btrfs_root *root)
1995{
1996 int index1;
1997 int index2;
1998 int mark;
1999 int ret;
2000 struct btrfs_root *log = root->log_root;
2001 struct btrfs_root *log_root_tree = root->fs_info->log_root_tree;
2002 unsigned long log_transid = 0;
2003
2004 mutex_lock(&root->log_mutex);
2005 index1 = root->log_transid % 2;
2006 if (atomic_read(&root->log_commit[index1])) {
2007 wait_log_commit(trans, root, root->log_transid);
2008 mutex_unlock(&root->log_mutex);
2009 return 0;
2010 }
2011 atomic_set(&root->log_commit[index1], 1);
2012
2013 /* wait for previous tree log sync to complete */
2014 if (atomic_read(&root->log_commit[(index1 + 1) % 2]))
2015 wait_log_commit(trans, root, root->log_transid - 1);
2016
2017 while (1) {
2018 unsigned long batch = root->log_batch;
2019 if (root->log_multiple_pids) {
2020 mutex_unlock(&root->log_mutex);
2021 schedule_timeout_uninterruptible(1);
2022 mutex_lock(&root->log_mutex);
2023 }
2024 wait_for_writer(trans, root);
2025 if (batch == root->log_batch)
2026 break;
2027 }
2028
2029 /* bail out if we need to do a full commit */
2030 if (root->fs_info->last_trans_log_full_commit == trans->transid) {
2031 ret = -EAGAIN;
2032 mutex_unlock(&root->log_mutex);
2033 goto out;
2034 }
2035
2036 log_transid = root->log_transid;
2037 if (log_transid % 2 == 0)
2038 mark = EXTENT_DIRTY;
2039 else
2040 mark = EXTENT_NEW;
2041
2042 /* we start IO on all the marked extents here, but we don't actually
2043 * wait for them until later.
2044 */
2045 ret = btrfs_write_marked_extents(log, &log->dirty_log_pages, mark);
2046 BUG_ON(ret);
2047
2048 btrfs_set_root_node(&log->root_item, log->node);
2049
2050 root->log_batch = 0;
2051 root->log_transid++;
2052 log->log_transid = root->log_transid;
2053 root->log_start_pid = 0;
2054 smp_mb();
2055 /*
2056 * IO has been started, blocks of the log tree have WRITTEN flag set
2057 * in their headers. new modifications of the log will be written to
2058 * new positions. so it's safe to allow log writers to go in.
2059 */
2060 mutex_unlock(&root->log_mutex);
2061
2062 mutex_lock(&log_root_tree->log_mutex);
2063 log_root_tree->log_batch++;
2064 atomic_inc(&log_root_tree->log_writers);
2065 mutex_unlock(&log_root_tree->log_mutex);
2066
2067 ret = update_log_root(trans, log);
2068
2069 mutex_lock(&log_root_tree->log_mutex);
2070 if (atomic_dec_and_test(&log_root_tree->log_writers)) {
2071 smp_mb();
2072 if (waitqueue_active(&log_root_tree->log_writer_wait))
2073 wake_up(&log_root_tree->log_writer_wait);
2074 }
2075
2076 if (ret) {
2077 BUG_ON(ret != -ENOSPC);
2078 root->fs_info->last_trans_log_full_commit = trans->transid;
2079 btrfs_wait_marked_extents(log, &log->dirty_log_pages, mark);
2080 mutex_unlock(&log_root_tree->log_mutex);
2081 ret = -EAGAIN;
2082 goto out;
2083 }
2084
2085 index2 = log_root_tree->log_transid % 2;
2086 if (atomic_read(&log_root_tree->log_commit[index2])) {
2087 btrfs_wait_marked_extents(log, &log->dirty_log_pages, mark);
2088 wait_log_commit(trans, log_root_tree,
2089 log_root_tree->log_transid);
2090 mutex_unlock(&log_root_tree->log_mutex);
2091 ret = 0;
2092 goto out;
2093 }
2094 atomic_set(&log_root_tree->log_commit[index2], 1);
2095
2096 if (atomic_read(&log_root_tree->log_commit[(index2 + 1) % 2])) {
2097 wait_log_commit(trans, log_root_tree,
2098 log_root_tree->log_transid - 1);
2099 }
2100
2101 wait_for_writer(trans, log_root_tree);
2102
2103 /*
2104 * now that we've moved on to the tree of log tree roots,
2105 * check the full commit flag again
2106 */
2107 if (root->fs_info->last_trans_log_full_commit == trans->transid) {
2108 btrfs_wait_marked_extents(log, &log->dirty_log_pages, mark);
2109 mutex_unlock(&log_root_tree->log_mutex);
2110 ret = -EAGAIN;
2111 goto out_wake_log_root;
2112 }
2113
2114 ret = btrfs_write_and_wait_marked_extents(log_root_tree,
2115 &log_root_tree->dirty_log_pages,
2116 EXTENT_DIRTY | EXTENT_NEW);
2117 BUG_ON(ret);
2118 btrfs_wait_marked_extents(log, &log->dirty_log_pages, mark);
2119
2120 btrfs_set_super_log_root(&root->fs_info->super_for_commit,
2121 log_root_tree->node->start);
2122 btrfs_set_super_log_root_level(&root->fs_info->super_for_commit,
2123 btrfs_header_level(log_root_tree->node));
2124
2125 log_root_tree->log_batch = 0;
2126 log_root_tree->log_transid++;
2127 smp_mb();
2128
2129 mutex_unlock(&log_root_tree->log_mutex);
2130
2131 /*
2132 * nobody else is going to jump in and write the the ctree
2133 * super here because the log_commit atomic below is protecting
2134 * us. We must be called with a transaction handle pinning
2135 * the running transaction open, so a full commit can't hop
2136 * in and cause problems either.
2137 */
2138 btrfs_scrub_pause_super(root);
2139 write_ctree_super(trans, root->fs_info->tree_root, 1);
2140 btrfs_scrub_continue_super(root);
2141 ret = 0;
2142
2143 mutex_lock(&root->log_mutex);
2144 if (root->last_log_commit < log_transid)
2145 root->last_log_commit = log_transid;
2146 mutex_unlock(&root->log_mutex);
2147
2148out_wake_log_root:
2149 atomic_set(&log_root_tree->log_commit[index2], 0);
2150 smp_mb();
2151 if (waitqueue_active(&log_root_tree->log_commit_wait[index2]))
2152 wake_up(&log_root_tree->log_commit_wait[index2]);
2153out:
2154 atomic_set(&root->log_commit[index1], 0);
2155 smp_mb();
2156 if (waitqueue_active(&root->log_commit_wait[index1]))
2157 wake_up(&root->log_commit_wait[index1]);
2158 return ret;
2159}
2160
2161static void free_log_tree(struct btrfs_trans_handle *trans,
2162 struct btrfs_root *log)
2163{
2164 int ret;
2165 u64 start;
2166 u64 end;
2167 struct walk_control wc = {
2168 .free = 1,
2169 .process_func = process_one_buffer
2170 };
2171
2172 ret = walk_log_tree(trans, log, &wc);
2173 BUG_ON(ret);
2174
2175 while (1) {
2176 ret = find_first_extent_bit(&log->dirty_log_pages,
2177 0, &start, &end, EXTENT_DIRTY | EXTENT_NEW);
2178 if (ret)
2179 break;
2180
2181 clear_extent_bits(&log->dirty_log_pages, start, end,
2182 EXTENT_DIRTY | EXTENT_NEW, GFP_NOFS);
2183 }
2184
2185 free_extent_buffer(log->node);
2186 kfree(log);
2187}
2188
2189/*
2190 * free all the extents used by the tree log. This should be called
2191 * at commit time of the full transaction
2192 */
2193int btrfs_free_log(struct btrfs_trans_handle *trans, struct btrfs_root *root)
2194{
2195 if (root->log_root) {
2196 free_log_tree(trans, root->log_root);
2197 root->log_root = NULL;
2198 }
2199 return 0;
2200}
2201
2202int btrfs_free_log_root_tree(struct btrfs_trans_handle *trans,
2203 struct btrfs_fs_info *fs_info)
2204{
2205 if (fs_info->log_root_tree) {
2206 free_log_tree(trans, fs_info->log_root_tree);
2207 fs_info->log_root_tree = NULL;
2208 }
2209 return 0;
2210}
2211
2212/*
2213 * If both a file and directory are logged, and unlinks or renames are
2214 * mixed in, we have a few interesting corners:
2215 *
2216 * create file X in dir Y
2217 * link file X to X.link in dir Y
2218 * fsync file X
2219 * unlink file X but leave X.link
2220 * fsync dir Y
2221 *
2222 * After a crash we would expect only X.link to exist. But file X
2223 * didn't get fsync'd again so the log has back refs for X and X.link.
2224 *
2225 * We solve this by removing directory entries and inode backrefs from the
2226 * log when a file that was logged in the current transaction is
2227 * unlinked. Any later fsync will include the updated log entries, and
2228 * we'll be able to reconstruct the proper directory items from backrefs.
2229 *
2230 * This optimizations allows us to avoid relogging the entire inode
2231 * or the entire directory.
2232 */
2233int btrfs_del_dir_entries_in_log(struct btrfs_trans_handle *trans,
2234 struct btrfs_root *root,
2235 const char *name, int name_len,
2236 struct inode *dir, u64 index)
2237{
2238 struct btrfs_root *log;
2239 struct btrfs_dir_item *di;
2240 struct btrfs_path *path;
2241 int ret;
2242 int err = 0;
2243 int bytes_del = 0;
2244 u64 dir_ino = btrfs_ino(dir);
2245
2246 if (BTRFS_I(dir)->logged_trans < trans->transid)
2247 return 0;
2248
2249 ret = join_running_log_trans(root);
2250 if (ret)
2251 return 0;
2252
2253 mutex_lock(&BTRFS_I(dir)->log_mutex);
2254
2255 log = root->log_root;
2256 path = btrfs_alloc_path();
2257 if (!path) {
2258 err = -ENOMEM;
2259 goto out_unlock;
2260 }
2261
2262 di = btrfs_lookup_dir_item(trans, log, path, dir_ino,
2263 name, name_len, -1);
2264 if (IS_ERR(di)) {
2265 err = PTR_ERR(di);
2266 goto fail;
2267 }
2268 if (di) {
2269 ret = btrfs_delete_one_dir_name(trans, log, path, di);
2270 bytes_del += name_len;
2271 BUG_ON(ret);
2272 }
2273 btrfs_release_path(path);
2274 di = btrfs_lookup_dir_index_item(trans, log, path, dir_ino,
2275 index, name, name_len, -1);
2276 if (IS_ERR(di)) {
2277 err = PTR_ERR(di);
2278 goto fail;
2279 }
2280 if (di) {
2281 ret = btrfs_delete_one_dir_name(trans, log, path, di);
2282 bytes_del += name_len;
2283 BUG_ON(ret);
2284 }
2285
2286 /* update the directory size in the log to reflect the names
2287 * we have removed
2288 */
2289 if (bytes_del) {
2290 struct btrfs_key key;
2291
2292 key.objectid = dir_ino;
2293 key.offset = 0;
2294 key.type = BTRFS_INODE_ITEM_KEY;
2295 btrfs_release_path(path);
2296
2297 ret = btrfs_search_slot(trans, log, &key, path, 0, 1);
2298 if (ret < 0) {
2299 err = ret;
2300 goto fail;
2301 }
2302 if (ret == 0) {
2303 struct btrfs_inode_item *item;
2304 u64 i_size;
2305
2306 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
2307 struct btrfs_inode_item);
2308 i_size = btrfs_inode_size(path->nodes[0], item);
2309 if (i_size > bytes_del)
2310 i_size -= bytes_del;
2311 else
2312 i_size = 0;
2313 btrfs_set_inode_size(path->nodes[0], item, i_size);
2314 btrfs_mark_buffer_dirty(path->nodes[0]);
2315 } else
2316 ret = 0;
2317 btrfs_release_path(path);
2318 }
2319fail:
2320 btrfs_free_path(path);
2321out_unlock:
2322 mutex_unlock(&BTRFS_I(dir)->log_mutex);
2323 if (ret == -ENOSPC) {
2324 root->fs_info->last_trans_log_full_commit = trans->transid;
2325 ret = 0;
2326 }
2327 btrfs_end_log_trans(root);
2328
2329 return err;
2330}
2331
2332/* see comments for btrfs_del_dir_entries_in_log */
2333int btrfs_del_inode_ref_in_log(struct btrfs_trans_handle *trans,
2334 struct btrfs_root *root,
2335 const char *name, int name_len,
2336 struct inode *inode, u64 dirid)
2337{
2338 struct btrfs_root *log;
2339 u64 index;
2340 int ret;
2341
2342 if (BTRFS_I(inode)->logged_trans < trans->transid)
2343 return 0;
2344
2345 ret = join_running_log_trans(root);
2346 if (ret)
2347 return 0;
2348 log = root->log_root;
2349 mutex_lock(&BTRFS_I(inode)->log_mutex);
2350
2351 ret = btrfs_del_inode_ref(trans, log, name, name_len, btrfs_ino(inode),
2352 dirid, &index);
2353 mutex_unlock(&BTRFS_I(inode)->log_mutex);
2354 if (ret == -ENOSPC) {
2355 root->fs_info->last_trans_log_full_commit = trans->transid;
2356 ret = 0;
2357 }
2358 btrfs_end_log_trans(root);
2359
2360 return ret;
2361}
2362
2363/*
2364 * creates a range item in the log for 'dirid'. first_offset and
2365 * last_offset tell us which parts of the key space the log should
2366 * be considered authoritative for.
2367 */
2368static noinline int insert_dir_log_key(struct btrfs_trans_handle *trans,
2369 struct btrfs_root *log,
2370 struct btrfs_path *path,
2371 int key_type, u64 dirid,
2372 u64 first_offset, u64 last_offset)
2373{
2374 int ret;
2375 struct btrfs_key key;
2376 struct btrfs_dir_log_item *item;
2377
2378 key.objectid = dirid;
2379 key.offset = first_offset;
2380 if (key_type == BTRFS_DIR_ITEM_KEY)
2381 key.type = BTRFS_DIR_LOG_ITEM_KEY;
2382 else
2383 key.type = BTRFS_DIR_LOG_INDEX_KEY;
2384 ret = btrfs_insert_empty_item(trans, log, path, &key, sizeof(*item));
2385 if (ret)
2386 return ret;
2387
2388 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
2389 struct btrfs_dir_log_item);
2390 btrfs_set_dir_log_end(path->nodes[0], item, last_offset);
2391 btrfs_mark_buffer_dirty(path->nodes[0]);
2392 btrfs_release_path(path);
2393 return 0;
2394}
2395
2396/*
2397 * log all the items included in the current transaction for a given
2398 * directory. This also creates the range items in the log tree required
2399 * to replay anything deleted before the fsync
2400 */
2401static noinline int log_dir_items(struct btrfs_trans_handle *trans,
2402 struct btrfs_root *root, struct inode *inode,
2403 struct btrfs_path *path,
2404 struct btrfs_path *dst_path, int key_type,
2405 u64 min_offset, u64 *last_offset_ret)
2406{
2407 struct btrfs_key min_key;
2408 struct btrfs_key max_key;
2409 struct btrfs_root *log = root->log_root;
2410 struct extent_buffer *src;
2411 int err = 0;
2412 int ret;
2413 int i;
2414 int nritems;
2415 u64 first_offset = min_offset;
2416 u64 last_offset = (u64)-1;
2417 u64 ino = btrfs_ino(inode);
2418
2419 log = root->log_root;
2420 max_key.objectid = ino;
2421 max_key.offset = (u64)-1;
2422 max_key.type = key_type;
2423
2424 min_key.objectid = ino;
2425 min_key.type = key_type;
2426 min_key.offset = min_offset;
2427
2428 path->keep_locks = 1;
2429
2430 ret = btrfs_search_forward(root, &min_key, &max_key,
2431 path, 0, trans->transid);
2432
2433 /*
2434 * we didn't find anything from this transaction, see if there
2435 * is anything at all
2436 */
2437 if (ret != 0 || min_key.objectid != ino || min_key.type != key_type) {
2438 min_key.objectid = ino;
2439 min_key.type = key_type;
2440 min_key.offset = (u64)-1;
2441 btrfs_release_path(path);
2442 ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0);
2443 if (ret < 0) {
2444 btrfs_release_path(path);
2445 return ret;
2446 }
2447 ret = btrfs_previous_item(root, path, ino, key_type);
2448
2449 /* if ret == 0 there are items for this type,
2450 * create a range to tell us the last key of this type.
2451 * otherwise, there are no items in this directory after
2452 * *min_offset, and we create a range to indicate that.
2453 */
2454 if (ret == 0) {
2455 struct btrfs_key tmp;
2456 btrfs_item_key_to_cpu(path->nodes[0], &tmp,
2457 path->slots[0]);
2458 if (key_type == tmp.type)
2459 first_offset = max(min_offset, tmp.offset) + 1;
2460 }
2461 goto done;
2462 }
2463
2464 /* go backward to find any previous key */
2465 ret = btrfs_previous_item(root, path, ino, key_type);
2466 if (ret == 0) {
2467 struct btrfs_key tmp;
2468 btrfs_item_key_to_cpu(path->nodes[0], &tmp, path->slots[0]);
2469 if (key_type == tmp.type) {
2470 first_offset = tmp.offset;
2471 ret = overwrite_item(trans, log, dst_path,
2472 path->nodes[0], path->slots[0],
2473 &tmp);
2474 if (ret) {
2475 err = ret;
2476 goto done;
2477 }
2478 }
2479 }
2480 btrfs_release_path(path);
2481
2482 /* find the first key from this transaction again */
2483 ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0);
2484 if (ret != 0) {
2485 WARN_ON(1);
2486 goto done;
2487 }
2488
2489 /*
2490 * we have a block from this transaction, log every item in it
2491 * from our directory
2492 */
2493 while (1) {
2494 struct btrfs_key tmp;
2495 src = path->nodes[0];
2496 nritems = btrfs_header_nritems(src);
2497 for (i = path->slots[0]; i < nritems; i++) {
2498 btrfs_item_key_to_cpu(src, &min_key, i);
2499
2500 if (min_key.objectid != ino || min_key.type != key_type)
2501 goto done;
2502 ret = overwrite_item(trans, log, dst_path, src, i,
2503 &min_key);
2504 if (ret) {
2505 err = ret;
2506 goto done;
2507 }
2508 }
2509 path->slots[0] = nritems;
2510
2511 /*
2512 * look ahead to the next item and see if it is also
2513 * from this directory and from this transaction
2514 */
2515 ret = btrfs_next_leaf(root, path);
2516 if (ret == 1) {
2517 last_offset = (u64)-1;
2518 goto done;
2519 }
2520 btrfs_item_key_to_cpu(path->nodes[0], &tmp, path->slots[0]);
2521 if (tmp.objectid != ino || tmp.type != key_type) {
2522 last_offset = (u64)-1;
2523 goto done;
2524 }
2525 if (btrfs_header_generation(path->nodes[0]) != trans->transid) {
2526 ret = overwrite_item(trans, log, dst_path,
2527 path->nodes[0], path->slots[0],
2528 &tmp);
2529 if (ret)
2530 err = ret;
2531 else
2532 last_offset = tmp.offset;
2533 goto done;
2534 }
2535 }
2536done:
2537 btrfs_release_path(path);
2538 btrfs_release_path(dst_path);
2539
2540 if (err == 0) {
2541 *last_offset_ret = last_offset;
2542 /*
2543 * insert the log range keys to indicate where the log
2544 * is valid
2545 */
2546 ret = insert_dir_log_key(trans, log, path, key_type,
2547 ino, first_offset, last_offset);
2548 if (ret)
2549 err = ret;
2550 }
2551 return err;
2552}
2553
2554/*
2555 * logging directories is very similar to logging inodes, We find all the items
2556 * from the current transaction and write them to the log.
2557 *
2558 * The recovery code scans the directory in the subvolume, and if it finds a
2559 * key in the range logged that is not present in the log tree, then it means
2560 * that dir entry was unlinked during the transaction.
2561 *
2562 * In order for that scan to work, we must include one key smaller than
2563 * the smallest logged by this transaction and one key larger than the largest
2564 * key logged by this transaction.
2565 */
2566static noinline int log_directory_changes(struct btrfs_trans_handle *trans,
2567 struct btrfs_root *root, struct inode *inode,
2568 struct btrfs_path *path,
2569 struct btrfs_path *dst_path)
2570{
2571 u64 min_key;
2572 u64 max_key;
2573 int ret;
2574 int key_type = BTRFS_DIR_ITEM_KEY;
2575
2576again:
2577 min_key = 0;
2578 max_key = 0;
2579 while (1) {
2580 ret = log_dir_items(trans, root, inode, path,
2581 dst_path, key_type, min_key,
2582 &max_key);
2583 if (ret)
2584 return ret;
2585 if (max_key == (u64)-1)
2586 break;
2587 min_key = max_key + 1;
2588 }
2589
2590 if (key_type == BTRFS_DIR_ITEM_KEY) {
2591 key_type = BTRFS_DIR_INDEX_KEY;
2592 goto again;
2593 }
2594 return 0;
2595}
2596
2597/*
2598 * a helper function to drop items from the log before we relog an
2599 * inode. max_key_type indicates the highest item type to remove.
2600 * This cannot be run for file data extents because it does not
2601 * free the extents they point to.
2602 */
2603static int drop_objectid_items(struct btrfs_trans_handle *trans,
2604 struct btrfs_root *log,
2605 struct btrfs_path *path,
2606 u64 objectid, int max_key_type)
2607{
2608 int ret;
2609 struct btrfs_key key;
2610 struct btrfs_key found_key;
2611
2612 key.objectid = objectid;
2613 key.type = max_key_type;
2614 key.offset = (u64)-1;
2615
2616 while (1) {
2617 ret = btrfs_search_slot(trans, log, &key, path, -1, 1);
2618 BUG_ON(ret == 0);
2619 if (ret < 0)
2620 break;
2621
2622 if (path->slots[0] == 0)
2623 break;
2624
2625 path->slots[0]--;
2626 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
2627 path->slots[0]);
2628
2629 if (found_key.objectid != objectid)
2630 break;
2631
2632 ret = btrfs_del_item(trans, log, path);
2633 if (ret)
2634 break;
2635 btrfs_release_path(path);
2636 }
2637 btrfs_release_path(path);
2638 return ret;
2639}
2640
2641static noinline int copy_items(struct btrfs_trans_handle *trans,
2642 struct btrfs_root *log,
2643 struct btrfs_path *dst_path,
2644 struct extent_buffer *src,
2645 int start_slot, int nr, int inode_only)
2646{
2647 unsigned long src_offset;
2648 unsigned long dst_offset;
2649 struct btrfs_file_extent_item *extent;
2650 struct btrfs_inode_item *inode_item;
2651 int ret;
2652 struct btrfs_key *ins_keys;
2653 u32 *ins_sizes;
2654 char *ins_data;
2655 int i;
2656 struct list_head ordered_sums;
2657
2658 INIT_LIST_HEAD(&ordered_sums);
2659
2660 ins_data = kmalloc(nr * sizeof(struct btrfs_key) +
2661 nr * sizeof(u32), GFP_NOFS);
2662 if (!ins_data)
2663 return -ENOMEM;
2664
2665 ins_sizes = (u32 *)ins_data;
2666 ins_keys = (struct btrfs_key *)(ins_data + nr * sizeof(u32));
2667
2668 for (i = 0; i < nr; i++) {
2669 ins_sizes[i] = btrfs_item_size_nr(src, i + start_slot);
2670 btrfs_item_key_to_cpu(src, ins_keys + i, i + start_slot);
2671 }
2672 ret = btrfs_insert_empty_items(trans, log, dst_path,
2673 ins_keys, ins_sizes, nr);
2674 if (ret) {
2675 kfree(ins_data);
2676 return ret;
2677 }
2678
2679 for (i = 0; i < nr; i++, dst_path->slots[0]++) {
2680 dst_offset = btrfs_item_ptr_offset(dst_path->nodes[0],
2681 dst_path->slots[0]);
2682
2683 src_offset = btrfs_item_ptr_offset(src, start_slot + i);
2684
2685 copy_extent_buffer(dst_path->nodes[0], src, dst_offset,
2686 src_offset, ins_sizes[i]);
2687
2688 if (inode_only == LOG_INODE_EXISTS &&
2689 ins_keys[i].type == BTRFS_INODE_ITEM_KEY) {
2690 inode_item = btrfs_item_ptr(dst_path->nodes[0],
2691 dst_path->slots[0],
2692 struct btrfs_inode_item);
2693 btrfs_set_inode_size(dst_path->nodes[0], inode_item, 0);
2694
2695 /* set the generation to zero so the recover code
2696 * can tell the difference between an logging
2697 * just to say 'this inode exists' and a logging
2698 * to say 'update this inode with these values'
2699 */
2700 btrfs_set_inode_generation(dst_path->nodes[0],
2701 inode_item, 0);
2702 }
2703 /* take a reference on file data extents so that truncates
2704 * or deletes of this inode don't have to relog the inode
2705 * again
2706 */
2707 if (btrfs_key_type(ins_keys + i) == BTRFS_EXTENT_DATA_KEY) {
2708 int found_type;
2709 extent = btrfs_item_ptr(src, start_slot + i,
2710 struct btrfs_file_extent_item);
2711
2712 if (btrfs_file_extent_generation(src, extent) < trans->transid)
2713 continue;
2714
2715 found_type = btrfs_file_extent_type(src, extent);
2716 if (found_type == BTRFS_FILE_EXTENT_REG ||
2717 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
2718 u64 ds, dl, cs, cl;
2719 ds = btrfs_file_extent_disk_bytenr(src,
2720 extent);
2721 /* ds == 0 is a hole */
2722 if (ds == 0)
2723 continue;
2724
2725 dl = btrfs_file_extent_disk_num_bytes(src,
2726 extent);
2727 cs = btrfs_file_extent_offset(src, extent);
2728 cl = btrfs_file_extent_num_bytes(src,
2729 extent);
2730 if (btrfs_file_extent_compression(src,
2731 extent)) {
2732 cs = 0;
2733 cl = dl;
2734 }
2735
2736 ret = btrfs_lookup_csums_range(
2737 log->fs_info->csum_root,
2738 ds + cs, ds + cs + cl - 1,
2739 &ordered_sums, 0);
2740 BUG_ON(ret);
2741 }
2742 }
2743 }
2744
2745 btrfs_mark_buffer_dirty(dst_path->nodes[0]);
2746 btrfs_release_path(dst_path);
2747 kfree(ins_data);
2748
2749 /*
2750 * we have to do this after the loop above to avoid changing the
2751 * log tree while trying to change the log tree.
2752 */
2753 ret = 0;
2754 while (!list_empty(&ordered_sums)) {
2755 struct btrfs_ordered_sum *sums = list_entry(ordered_sums.next,
2756 struct btrfs_ordered_sum,
2757 list);
2758 if (!ret)
2759 ret = btrfs_csum_file_blocks(trans, log, sums);
2760 list_del(&sums->list);
2761 kfree(sums);
2762 }
2763 return ret;
2764}
2765
2766/* log a single inode in the tree log.
2767 * At least one parent directory for this inode must exist in the tree
2768 * or be logged already.
2769 *
2770 * Any items from this inode changed by the current transaction are copied
2771 * to the log tree. An extra reference is taken on any extents in this
2772 * file, allowing us to avoid a whole pile of corner cases around logging
2773 * blocks that have been removed from the tree.
2774 *
2775 * See LOG_INODE_ALL and related defines for a description of what inode_only
2776 * does.
2777 *
2778 * This handles both files and directories.
2779 */
2780static int btrfs_log_inode(struct btrfs_trans_handle *trans,
2781 struct btrfs_root *root, struct inode *inode,
2782 int inode_only)
2783{
2784 struct btrfs_path *path;
2785 struct btrfs_path *dst_path;
2786 struct btrfs_key min_key;
2787 struct btrfs_key max_key;
2788 struct btrfs_root *log = root->log_root;
2789 struct extent_buffer *src = NULL;
2790 int err = 0;
2791 int ret;
2792 int nritems;
2793 int ins_start_slot = 0;
2794 int ins_nr;
2795 u64 ino = btrfs_ino(inode);
2796
2797 log = root->log_root;
2798
2799 path = btrfs_alloc_path();
2800 if (!path)
2801 return -ENOMEM;
2802 dst_path = btrfs_alloc_path();
2803 if (!dst_path) {
2804 btrfs_free_path(path);
2805 return -ENOMEM;
2806 }
2807
2808 min_key.objectid = ino;
2809 min_key.type = BTRFS_INODE_ITEM_KEY;
2810 min_key.offset = 0;
2811
2812 max_key.objectid = ino;
2813
2814 /* today the code can only do partial logging of directories */
2815 if (!S_ISDIR(inode->i_mode))
2816 inode_only = LOG_INODE_ALL;
2817
2818 if (inode_only == LOG_INODE_EXISTS || S_ISDIR(inode->i_mode))
2819 max_key.type = BTRFS_XATTR_ITEM_KEY;
2820 else
2821 max_key.type = (u8)-1;
2822 max_key.offset = (u64)-1;
2823
2824 ret = btrfs_commit_inode_delayed_items(trans, inode);
2825 if (ret) {
2826 btrfs_free_path(path);
2827 btrfs_free_path(dst_path);
2828 return ret;
2829 }
2830
2831 mutex_lock(&BTRFS_I(inode)->log_mutex);
2832
2833 /*
2834 * a brute force approach to making sure we get the most uptodate
2835 * copies of everything.
2836 */
2837 if (S_ISDIR(inode->i_mode)) {
2838 int max_key_type = BTRFS_DIR_LOG_INDEX_KEY;
2839
2840 if (inode_only == LOG_INODE_EXISTS)
2841 max_key_type = BTRFS_XATTR_ITEM_KEY;
2842 ret = drop_objectid_items(trans, log, path, ino, max_key_type);
2843 } else {
2844 ret = btrfs_truncate_inode_items(trans, log, inode, 0, 0);
2845 }
2846 if (ret) {
2847 err = ret;
2848 goto out_unlock;
2849 }
2850 path->keep_locks = 1;
2851
2852 while (1) {
2853 ins_nr = 0;
2854 ret = btrfs_search_forward(root, &min_key, &max_key,
2855 path, 0, trans->transid);
2856 if (ret != 0)
2857 break;
2858again:
2859 /* note, ins_nr might be > 0 here, cleanup outside the loop */
2860 if (min_key.objectid != ino)
2861 break;
2862 if (min_key.type > max_key.type)
2863 break;
2864
2865 src = path->nodes[0];
2866 if (ins_nr && ins_start_slot + ins_nr == path->slots[0]) {
2867 ins_nr++;
2868 goto next_slot;
2869 } else if (!ins_nr) {
2870 ins_start_slot = path->slots[0];
2871 ins_nr = 1;
2872 goto next_slot;
2873 }
2874
2875 ret = copy_items(trans, log, dst_path, src, ins_start_slot,
2876 ins_nr, inode_only);
2877 if (ret) {
2878 err = ret;
2879 goto out_unlock;
2880 }
2881 ins_nr = 1;
2882 ins_start_slot = path->slots[0];
2883next_slot:
2884
2885 nritems = btrfs_header_nritems(path->nodes[0]);
2886 path->slots[0]++;
2887 if (path->slots[0] < nritems) {
2888 btrfs_item_key_to_cpu(path->nodes[0], &min_key,
2889 path->slots[0]);
2890 goto again;
2891 }
2892 if (ins_nr) {
2893 ret = copy_items(trans, log, dst_path, src,
2894 ins_start_slot,
2895 ins_nr, inode_only);
2896 if (ret) {
2897 err = ret;
2898 goto out_unlock;
2899 }
2900 ins_nr = 0;
2901 }
2902 btrfs_release_path(path);
2903
2904 if (min_key.offset < (u64)-1)
2905 min_key.offset++;
2906 else if (min_key.type < (u8)-1)
2907 min_key.type++;
2908 else if (min_key.objectid < (u64)-1)
2909 min_key.objectid++;
2910 else
2911 break;
2912 }
2913 if (ins_nr) {
2914 ret = copy_items(trans, log, dst_path, src,
2915 ins_start_slot,
2916 ins_nr, inode_only);
2917 if (ret) {
2918 err = ret;
2919 goto out_unlock;
2920 }
2921 ins_nr = 0;
2922 }
2923 WARN_ON(ins_nr);
2924 if (inode_only == LOG_INODE_ALL && S_ISDIR(inode->i_mode)) {
2925 btrfs_release_path(path);
2926 btrfs_release_path(dst_path);
2927 ret = log_directory_changes(trans, root, inode, path, dst_path);
2928 if (ret) {
2929 err = ret;
2930 goto out_unlock;
2931 }
2932 }
2933 BTRFS_I(inode)->logged_trans = trans->transid;
2934out_unlock:
2935 mutex_unlock(&BTRFS_I(inode)->log_mutex);
2936
2937 btrfs_free_path(path);
2938 btrfs_free_path(dst_path);
2939 return err;
2940}
2941
2942/*
2943 * follow the dentry parent pointers up the chain and see if any
2944 * of the directories in it require a full commit before they can
2945 * be logged. Returns zero if nothing special needs to be done or 1 if
2946 * a full commit is required.
2947 */
2948static noinline int check_parent_dirs_for_sync(struct btrfs_trans_handle *trans,
2949 struct inode *inode,
2950 struct dentry *parent,
2951 struct super_block *sb,
2952 u64 last_committed)
2953{
2954 int ret = 0;
2955 struct btrfs_root *root;
2956 struct dentry *old_parent = NULL;
2957
2958 /*
2959 * for regular files, if its inode is already on disk, we don't
2960 * have to worry about the parents at all. This is because
2961 * we can use the last_unlink_trans field to record renames
2962 * and other fun in this file.
2963 */
2964 if (S_ISREG(inode->i_mode) &&
2965 BTRFS_I(inode)->generation <= last_committed &&
2966 BTRFS_I(inode)->last_unlink_trans <= last_committed)
2967 goto out;
2968
2969 if (!S_ISDIR(inode->i_mode)) {
2970 if (!parent || !parent->d_inode || sb != parent->d_inode->i_sb)
2971 goto out;
2972 inode = parent->d_inode;
2973 }
2974
2975 while (1) {
2976 BTRFS_I(inode)->logged_trans = trans->transid;
2977 smp_mb();
2978
2979 if (BTRFS_I(inode)->last_unlink_trans > last_committed) {
2980 root = BTRFS_I(inode)->root;
2981
2982 /*
2983 * make sure any commits to the log are forced
2984 * to be full commits
2985 */
2986 root->fs_info->last_trans_log_full_commit =
2987 trans->transid;
2988 ret = 1;
2989 break;
2990 }
2991
2992 if (!parent || !parent->d_inode || sb != parent->d_inode->i_sb)
2993 break;
2994
2995 if (IS_ROOT(parent))
2996 break;
2997
2998 parent = dget_parent(parent);
2999 dput(old_parent);
3000 old_parent = parent;
3001 inode = parent->d_inode;
3002
3003 }
3004 dput(old_parent);
3005out:
3006 return ret;
3007}
3008
3009static int inode_in_log(struct btrfs_trans_handle *trans,
3010 struct inode *inode)
3011{
3012 struct btrfs_root *root = BTRFS_I(inode)->root;
3013 int ret = 0;
3014
3015 mutex_lock(&root->log_mutex);
3016 if (BTRFS_I(inode)->logged_trans == trans->transid &&
3017 BTRFS_I(inode)->last_sub_trans <= root->last_log_commit)
3018 ret = 1;
3019 mutex_unlock(&root->log_mutex);
3020 return ret;
3021}
3022
3023
3024/*
3025 * helper function around btrfs_log_inode to make sure newly created
3026 * parent directories also end up in the log. A minimal inode and backref
3027 * only logging is done of any parent directories that are older than
3028 * the last committed transaction
3029 */
3030int btrfs_log_inode_parent(struct btrfs_trans_handle *trans,
3031 struct btrfs_root *root, struct inode *inode,
3032 struct dentry *parent, int exists_only)
3033{
3034 int inode_only = exists_only ? LOG_INODE_EXISTS : LOG_INODE_ALL;
3035 struct super_block *sb;
3036 struct dentry *old_parent = NULL;
3037 int ret = 0;
3038 u64 last_committed = root->fs_info->last_trans_committed;
3039
3040 sb = inode->i_sb;
3041
3042 if (btrfs_test_opt(root, NOTREELOG)) {
3043 ret = 1;
3044 goto end_no_trans;
3045 }
3046
3047 if (root->fs_info->last_trans_log_full_commit >
3048 root->fs_info->last_trans_committed) {
3049 ret = 1;
3050 goto end_no_trans;
3051 }
3052
3053 if (root != BTRFS_I(inode)->root ||
3054 btrfs_root_refs(&root->root_item) == 0) {
3055 ret = 1;
3056 goto end_no_trans;
3057 }
3058
3059 ret = check_parent_dirs_for_sync(trans, inode, parent,
3060 sb, last_committed);
3061 if (ret)
3062 goto end_no_trans;
3063
3064 if (inode_in_log(trans, inode)) {
3065 ret = BTRFS_NO_LOG_SYNC;
3066 goto end_no_trans;
3067 }
3068
3069 ret = start_log_trans(trans, root);
3070 if (ret)
3071 goto end_trans;
3072
3073 ret = btrfs_log_inode(trans, root, inode, inode_only);
3074 if (ret)
3075 goto end_trans;
3076
3077 /*
3078 * for regular files, if its inode is already on disk, we don't
3079 * have to worry about the parents at all. This is because
3080 * we can use the last_unlink_trans field to record renames
3081 * and other fun in this file.
3082 */
3083 if (S_ISREG(inode->i_mode) &&
3084 BTRFS_I(inode)->generation <= last_committed &&
3085 BTRFS_I(inode)->last_unlink_trans <= last_committed) {
3086 ret = 0;
3087 goto end_trans;
3088 }
3089
3090 inode_only = LOG_INODE_EXISTS;
3091 while (1) {
3092 if (!parent || !parent->d_inode || sb != parent->d_inode->i_sb)
3093 break;
3094
3095 inode = parent->d_inode;
3096 if (root != BTRFS_I(inode)->root)
3097 break;
3098
3099 if (BTRFS_I(inode)->generation >
3100 root->fs_info->last_trans_committed) {
3101 ret = btrfs_log_inode(trans, root, inode, inode_only);
3102 if (ret)
3103 goto end_trans;
3104 }
3105 if (IS_ROOT(parent))
3106 break;
3107
3108 parent = dget_parent(parent);
3109 dput(old_parent);
3110 old_parent = parent;
3111 }
3112 ret = 0;
3113end_trans:
3114 dput(old_parent);
3115 if (ret < 0) {
3116 BUG_ON(ret != -ENOSPC);
3117 root->fs_info->last_trans_log_full_commit = trans->transid;
3118 ret = 1;
3119 }
3120 btrfs_end_log_trans(root);
3121end_no_trans:
3122 return ret;
3123}
3124
3125/*
3126 * it is not safe to log dentry if the chunk root has added new
3127 * chunks. This returns 0 if the dentry was logged, and 1 otherwise.
3128 * If this returns 1, you must commit the transaction to safely get your
3129 * data on disk.
3130 */
3131int btrfs_log_dentry_safe(struct btrfs_trans_handle *trans,
3132 struct btrfs_root *root, struct dentry *dentry)
3133{
3134 struct dentry *parent = dget_parent(dentry);
3135 int ret;
3136
3137 ret = btrfs_log_inode_parent(trans, root, dentry->d_inode, parent, 0);
3138 dput(parent);
3139
3140 return ret;
3141}
3142
3143/*
3144 * should be called during mount to recover any replay any log trees
3145 * from the FS
3146 */
3147int btrfs_recover_log_trees(struct btrfs_root *log_root_tree)
3148{
3149 int ret;
3150 struct btrfs_path *path;
3151 struct btrfs_trans_handle *trans;
3152 struct btrfs_key key;
3153 struct btrfs_key found_key;
3154 struct btrfs_key tmp_key;
3155 struct btrfs_root *log;
3156 struct btrfs_fs_info *fs_info = log_root_tree->fs_info;
3157 struct walk_control wc = {
3158 .process_func = process_one_buffer,
3159 .stage = 0,
3160 };
3161
3162 path = btrfs_alloc_path();
3163 if (!path)
3164 return -ENOMEM;
3165
3166 fs_info->log_root_recovering = 1;
3167
3168 trans = btrfs_start_transaction(fs_info->tree_root, 0);
3169 BUG_ON(IS_ERR(trans));
3170
3171 wc.trans = trans;
3172 wc.pin = 1;
3173
3174 ret = walk_log_tree(trans, log_root_tree, &wc);
3175 BUG_ON(ret);
3176
3177again:
3178 key.objectid = BTRFS_TREE_LOG_OBJECTID;
3179 key.offset = (u64)-1;
3180 btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
3181
3182 while (1) {
3183 ret = btrfs_search_slot(NULL, log_root_tree, &key, path, 0, 0);
3184 if (ret < 0)
3185 break;
3186 if (ret > 0) {
3187 if (path->slots[0] == 0)
3188 break;
3189 path->slots[0]--;
3190 }
3191 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
3192 path->slots[0]);
3193 btrfs_release_path(path);
3194 if (found_key.objectid != BTRFS_TREE_LOG_OBJECTID)
3195 break;
3196
3197 log = btrfs_read_fs_root_no_radix(log_root_tree,
3198 &found_key);
3199 BUG_ON(IS_ERR(log));
3200
3201 tmp_key.objectid = found_key.offset;
3202 tmp_key.type = BTRFS_ROOT_ITEM_KEY;
3203 tmp_key.offset = (u64)-1;
3204
3205 wc.replay_dest = btrfs_read_fs_root_no_name(fs_info, &tmp_key);
3206 BUG_ON(IS_ERR_OR_NULL(wc.replay_dest));
3207
3208 wc.replay_dest->log_root = log;
3209 btrfs_record_root_in_trans(trans, wc.replay_dest);
3210 ret = walk_log_tree(trans, log, &wc);
3211 BUG_ON(ret);
3212
3213 if (wc.stage == LOG_WALK_REPLAY_ALL) {
3214 ret = fixup_inode_link_counts(trans, wc.replay_dest,
3215 path);
3216 BUG_ON(ret);
3217 }
3218
3219 key.offset = found_key.offset - 1;
3220 wc.replay_dest->log_root = NULL;
3221 free_extent_buffer(log->node);
3222 free_extent_buffer(log->commit_root);
3223 kfree(log);
3224
3225 if (found_key.offset == 0)
3226 break;
3227 }
3228 btrfs_release_path(path);
3229
3230 /* step one is to pin it all, step two is to replay just inodes */
3231 if (wc.pin) {
3232 wc.pin = 0;
3233 wc.process_func = replay_one_buffer;
3234 wc.stage = LOG_WALK_REPLAY_INODES;
3235 goto again;
3236 }
3237 /* step three is to replay everything */
3238 if (wc.stage < LOG_WALK_REPLAY_ALL) {
3239 wc.stage++;
3240 goto again;
3241 }
3242
3243 btrfs_free_path(path);
3244
3245 free_extent_buffer(log_root_tree->node);
3246 log_root_tree->log_root = NULL;
3247 fs_info->log_root_recovering = 0;
3248
3249 /* step 4: commit the transaction, which also unpins the blocks */
3250 btrfs_commit_transaction(trans, fs_info->tree_root);
3251
3252 kfree(log_root_tree);
3253 return 0;
3254}
3255
3256/*
3257 * there are some corner cases where we want to force a full
3258 * commit instead of allowing a directory to be logged.
3259 *
3260 * They revolve around files there were unlinked from the directory, and
3261 * this function updates the parent directory so that a full commit is
3262 * properly done if it is fsync'd later after the unlinks are done.
3263 */
3264void btrfs_record_unlink_dir(struct btrfs_trans_handle *trans,
3265 struct inode *dir, struct inode *inode,
3266 int for_rename)
3267{
3268 /*
3269 * when we're logging a file, if it hasn't been renamed
3270 * or unlinked, and its inode is fully committed on disk,
3271 * we don't have to worry about walking up the directory chain
3272 * to log its parents.
3273 *
3274 * So, we use the last_unlink_trans field to put this transid
3275 * into the file. When the file is logged we check it and
3276 * don't log the parents if the file is fully on disk.
3277 */
3278 if (S_ISREG(inode->i_mode))
3279 BTRFS_I(inode)->last_unlink_trans = trans->transid;
3280
3281 /*
3282 * if this directory was already logged any new
3283 * names for this file/dir will get recorded
3284 */
3285 smp_mb();
3286 if (BTRFS_I(dir)->logged_trans == trans->transid)
3287 return;
3288
3289 /*
3290 * if the inode we're about to unlink was logged,
3291 * the log will be properly updated for any new names
3292 */
3293 if (BTRFS_I(inode)->logged_trans == trans->transid)
3294 return;
3295
3296 /*
3297 * when renaming files across directories, if the directory
3298 * there we're unlinking from gets fsync'd later on, there's
3299 * no way to find the destination directory later and fsync it
3300 * properly. So, we have to be conservative and force commits
3301 * so the new name gets discovered.
3302 */
3303 if (for_rename)
3304 goto record;
3305
3306 /* we can safely do the unlink without any special recording */
3307 return;
3308
3309record:
3310 BTRFS_I(dir)->last_unlink_trans = trans->transid;
3311}
3312
3313/*
3314 * Call this after adding a new name for a file and it will properly
3315 * update the log to reflect the new name.
3316 *
3317 * It will return zero if all goes well, and it will return 1 if a
3318 * full transaction commit is required.
3319 */
3320int btrfs_log_new_name(struct btrfs_trans_handle *trans,
3321 struct inode *inode, struct inode *old_dir,
3322 struct dentry *parent)
3323{
3324 struct btrfs_root * root = BTRFS_I(inode)->root;
3325
3326 /*
3327 * this will force the logging code to walk the dentry chain
3328 * up for the file
3329 */
3330 if (S_ISREG(inode->i_mode))
3331 BTRFS_I(inode)->last_unlink_trans = trans->transid;
3332
3333 /*
3334 * if this inode hasn't been logged and directory we're renaming it
3335 * from hasn't been logged, we don't need to log it
3336 */
3337 if (BTRFS_I(inode)->logged_trans <=
3338 root->fs_info->last_trans_committed &&
3339 (!old_dir || BTRFS_I(old_dir)->logged_trans <=
3340 root->fs_info->last_trans_committed))
3341 return 0;
3342
3343 return btrfs_log_inode_parent(trans, root, inode, parent, 1);
3344}
3345
1/*
2 * Copyright (C) 2008 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19#include <linux/sched.h>
20#include <linux/slab.h>
21#include "ctree.h"
22#include "transaction.h"
23#include "disk-io.h"
24#include "locking.h"
25#include "print-tree.h"
26#include "compat.h"
27#include "tree-log.h"
28
29/* magic values for the inode_only field in btrfs_log_inode:
30 *
31 * LOG_INODE_ALL means to log everything
32 * LOG_INODE_EXISTS means to log just enough to recreate the inode
33 * during log replay
34 */
35#define LOG_INODE_ALL 0
36#define LOG_INODE_EXISTS 1
37
38/*
39 * directory trouble cases
40 *
41 * 1) on rename or unlink, if the inode being unlinked isn't in the fsync
42 * log, we must force a full commit before doing an fsync of the directory
43 * where the unlink was done.
44 * ---> record transid of last unlink/rename per directory
45 *
46 * mkdir foo/some_dir
47 * normal commit
48 * rename foo/some_dir foo2/some_dir
49 * mkdir foo/some_dir
50 * fsync foo/some_dir/some_file
51 *
52 * The fsync above will unlink the original some_dir without recording
53 * it in its new location (foo2). After a crash, some_dir will be gone
54 * unless the fsync of some_file forces a full commit
55 *
56 * 2) we must log any new names for any file or dir that is in the fsync
57 * log. ---> check inode while renaming/linking.
58 *
59 * 2a) we must log any new names for any file or dir during rename
60 * when the directory they are being removed from was logged.
61 * ---> check inode and old parent dir during rename
62 *
63 * 2a is actually the more important variant. With the extra logging
64 * a crash might unlink the old name without recreating the new one
65 *
66 * 3) after a crash, we must go through any directories with a link count
67 * of zero and redo the rm -rf
68 *
69 * mkdir f1/foo
70 * normal commit
71 * rm -rf f1/foo
72 * fsync(f1)
73 *
74 * The directory f1 was fully removed from the FS, but fsync was never
75 * called on f1, only its parent dir. After a crash the rm -rf must
76 * be replayed. This must be able to recurse down the entire
77 * directory tree. The inode link count fixup code takes care of the
78 * ugly details.
79 */
80
81/*
82 * stages for the tree walking. The first
83 * stage (0) is to only pin down the blocks we find
84 * the second stage (1) is to make sure that all the inodes
85 * we find in the log are created in the subvolume.
86 *
87 * The last stage is to deal with directories and links and extents
88 * and all the other fun semantics
89 */
90#define LOG_WALK_PIN_ONLY 0
91#define LOG_WALK_REPLAY_INODES 1
92#define LOG_WALK_REPLAY_ALL 2
93
94static int btrfs_log_inode(struct btrfs_trans_handle *trans,
95 struct btrfs_root *root, struct inode *inode,
96 int inode_only);
97static int link_to_fixup_dir(struct btrfs_trans_handle *trans,
98 struct btrfs_root *root,
99 struct btrfs_path *path, u64 objectid);
100static noinline int replay_dir_deletes(struct btrfs_trans_handle *trans,
101 struct btrfs_root *root,
102 struct btrfs_root *log,
103 struct btrfs_path *path,
104 u64 dirid, int del_all);
105
106/*
107 * tree logging is a special write ahead log used to make sure that
108 * fsyncs and O_SYNCs can happen without doing full tree commits.
109 *
110 * Full tree commits are expensive because they require commonly
111 * modified blocks to be recowed, creating many dirty pages in the
112 * extent tree an 4x-6x higher write load than ext3.
113 *
114 * Instead of doing a tree commit on every fsync, we use the
115 * key ranges and transaction ids to find items for a given file or directory
116 * that have changed in this transaction. Those items are copied into
117 * a special tree (one per subvolume root), that tree is written to disk
118 * and then the fsync is considered complete.
119 *
120 * After a crash, items are copied out of the log-tree back into the
121 * subvolume tree. Any file data extents found are recorded in the extent
122 * allocation tree, and the log-tree freed.
123 *
124 * The log tree is read three times, once to pin down all the extents it is
125 * using in ram and once, once to create all the inodes logged in the tree
126 * and once to do all the other items.
127 */
128
129/*
130 * start a sub transaction and setup the log tree
131 * this increments the log tree writer count to make the people
132 * syncing the tree wait for us to finish
133 */
134static int start_log_trans(struct btrfs_trans_handle *trans,
135 struct btrfs_root *root)
136{
137 int ret;
138 int err = 0;
139
140 mutex_lock(&root->log_mutex);
141 if (root->log_root) {
142 if (!root->log_start_pid) {
143 root->log_start_pid = current->pid;
144 root->log_multiple_pids = false;
145 } else if (root->log_start_pid != current->pid) {
146 root->log_multiple_pids = true;
147 }
148
149 root->log_batch++;
150 atomic_inc(&root->log_writers);
151 mutex_unlock(&root->log_mutex);
152 return 0;
153 }
154 root->log_multiple_pids = false;
155 root->log_start_pid = current->pid;
156 mutex_lock(&root->fs_info->tree_log_mutex);
157 if (!root->fs_info->log_root_tree) {
158 ret = btrfs_init_log_root_tree(trans, root->fs_info);
159 if (ret)
160 err = ret;
161 }
162 if (err == 0 && !root->log_root) {
163 ret = btrfs_add_log_tree(trans, root);
164 if (ret)
165 err = ret;
166 }
167 mutex_unlock(&root->fs_info->tree_log_mutex);
168 root->log_batch++;
169 atomic_inc(&root->log_writers);
170 mutex_unlock(&root->log_mutex);
171 return err;
172}
173
174/*
175 * returns 0 if there was a log transaction running and we were able
176 * to join, or returns -ENOENT if there were not transactions
177 * in progress
178 */
179static int join_running_log_trans(struct btrfs_root *root)
180{
181 int ret = -ENOENT;
182
183 smp_mb();
184 if (!root->log_root)
185 return -ENOENT;
186
187 mutex_lock(&root->log_mutex);
188 if (root->log_root) {
189 ret = 0;
190 atomic_inc(&root->log_writers);
191 }
192 mutex_unlock(&root->log_mutex);
193 return ret;
194}
195
196/*
197 * This either makes the current running log transaction wait
198 * until you call btrfs_end_log_trans() or it makes any future
199 * log transactions wait until you call btrfs_end_log_trans()
200 */
201int btrfs_pin_log_trans(struct btrfs_root *root)
202{
203 int ret = -ENOENT;
204
205 mutex_lock(&root->log_mutex);
206 atomic_inc(&root->log_writers);
207 mutex_unlock(&root->log_mutex);
208 return ret;
209}
210
211/*
212 * indicate we're done making changes to the log tree
213 * and wake up anyone waiting to do a sync
214 */
215void btrfs_end_log_trans(struct btrfs_root *root)
216{
217 if (atomic_dec_and_test(&root->log_writers)) {
218 smp_mb();
219 if (waitqueue_active(&root->log_writer_wait))
220 wake_up(&root->log_writer_wait);
221 }
222}
223
224
225/*
226 * the walk control struct is used to pass state down the chain when
227 * processing the log tree. The stage field tells us which part
228 * of the log tree processing we are currently doing. The others
229 * are state fields used for that specific part
230 */
231struct walk_control {
232 /* should we free the extent on disk when done? This is used
233 * at transaction commit time while freeing a log tree
234 */
235 int free;
236
237 /* should we write out the extent buffer? This is used
238 * while flushing the log tree to disk during a sync
239 */
240 int write;
241
242 /* should we wait for the extent buffer io to finish? Also used
243 * while flushing the log tree to disk for a sync
244 */
245 int wait;
246
247 /* pin only walk, we record which extents on disk belong to the
248 * log trees
249 */
250 int pin;
251
252 /* what stage of the replay code we're currently in */
253 int stage;
254
255 /* the root we are currently replaying */
256 struct btrfs_root *replay_dest;
257
258 /* the trans handle for the current replay */
259 struct btrfs_trans_handle *trans;
260
261 /* the function that gets used to process blocks we find in the
262 * tree. Note the extent_buffer might not be up to date when it is
263 * passed in, and it must be checked or read if you need the data
264 * inside it
265 */
266 int (*process_func)(struct btrfs_root *log, struct extent_buffer *eb,
267 struct walk_control *wc, u64 gen);
268};
269
270/*
271 * process_func used to pin down extents, write them or wait on them
272 */
273static int process_one_buffer(struct btrfs_root *log,
274 struct extent_buffer *eb,
275 struct walk_control *wc, u64 gen)
276{
277 if (wc->pin)
278 btrfs_pin_extent_for_log_replay(wc->trans,
279 log->fs_info->extent_root,
280 eb->start, eb->len);
281
282 if (btrfs_buffer_uptodate(eb, gen, 0)) {
283 if (wc->write)
284 btrfs_write_tree_block(eb);
285 if (wc->wait)
286 btrfs_wait_tree_block_writeback(eb);
287 }
288 return 0;
289}
290
291/*
292 * Item overwrite used by replay and tree logging. eb, slot and key all refer
293 * to the src data we are copying out.
294 *
295 * root is the tree we are copying into, and path is a scratch
296 * path for use in this function (it should be released on entry and
297 * will be released on exit).
298 *
299 * If the key is already in the destination tree the existing item is
300 * overwritten. If the existing item isn't big enough, it is extended.
301 * If it is too large, it is truncated.
302 *
303 * If the key isn't in the destination yet, a new item is inserted.
304 */
305static noinline int overwrite_item(struct btrfs_trans_handle *trans,
306 struct btrfs_root *root,
307 struct btrfs_path *path,
308 struct extent_buffer *eb, int slot,
309 struct btrfs_key *key)
310{
311 int ret;
312 u32 item_size;
313 u64 saved_i_size = 0;
314 int save_old_i_size = 0;
315 unsigned long src_ptr;
316 unsigned long dst_ptr;
317 int overwrite_root = 0;
318
319 if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
320 overwrite_root = 1;
321
322 item_size = btrfs_item_size_nr(eb, slot);
323 src_ptr = btrfs_item_ptr_offset(eb, slot);
324
325 /* look for the key in the destination tree */
326 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
327 if (ret == 0) {
328 char *src_copy;
329 char *dst_copy;
330 u32 dst_size = btrfs_item_size_nr(path->nodes[0],
331 path->slots[0]);
332 if (dst_size != item_size)
333 goto insert;
334
335 if (item_size == 0) {
336 btrfs_release_path(path);
337 return 0;
338 }
339 dst_copy = kmalloc(item_size, GFP_NOFS);
340 src_copy = kmalloc(item_size, GFP_NOFS);
341 if (!dst_copy || !src_copy) {
342 btrfs_release_path(path);
343 kfree(dst_copy);
344 kfree(src_copy);
345 return -ENOMEM;
346 }
347
348 read_extent_buffer(eb, src_copy, src_ptr, item_size);
349
350 dst_ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
351 read_extent_buffer(path->nodes[0], dst_copy, dst_ptr,
352 item_size);
353 ret = memcmp(dst_copy, src_copy, item_size);
354
355 kfree(dst_copy);
356 kfree(src_copy);
357 /*
358 * they have the same contents, just return, this saves
359 * us from cowing blocks in the destination tree and doing
360 * extra writes that may not have been done by a previous
361 * sync
362 */
363 if (ret == 0) {
364 btrfs_release_path(path);
365 return 0;
366 }
367
368 }
369insert:
370 btrfs_release_path(path);
371 /* try to insert the key into the destination tree */
372 ret = btrfs_insert_empty_item(trans, root, path,
373 key, item_size);
374
375 /* make sure any existing item is the correct size */
376 if (ret == -EEXIST) {
377 u32 found_size;
378 found_size = btrfs_item_size_nr(path->nodes[0],
379 path->slots[0]);
380 if (found_size > item_size)
381 btrfs_truncate_item(trans, root, path, item_size, 1);
382 else if (found_size < item_size)
383 btrfs_extend_item(trans, root, path,
384 item_size - found_size);
385 } else if (ret) {
386 return ret;
387 }
388 dst_ptr = btrfs_item_ptr_offset(path->nodes[0],
389 path->slots[0]);
390
391 /* don't overwrite an existing inode if the generation number
392 * was logged as zero. This is done when the tree logging code
393 * is just logging an inode to make sure it exists after recovery.
394 *
395 * Also, don't overwrite i_size on directories during replay.
396 * log replay inserts and removes directory items based on the
397 * state of the tree found in the subvolume, and i_size is modified
398 * as it goes
399 */
400 if (key->type == BTRFS_INODE_ITEM_KEY && ret == -EEXIST) {
401 struct btrfs_inode_item *src_item;
402 struct btrfs_inode_item *dst_item;
403
404 src_item = (struct btrfs_inode_item *)src_ptr;
405 dst_item = (struct btrfs_inode_item *)dst_ptr;
406
407 if (btrfs_inode_generation(eb, src_item) == 0)
408 goto no_copy;
409
410 if (overwrite_root &&
411 S_ISDIR(btrfs_inode_mode(eb, src_item)) &&
412 S_ISDIR(btrfs_inode_mode(path->nodes[0], dst_item))) {
413 save_old_i_size = 1;
414 saved_i_size = btrfs_inode_size(path->nodes[0],
415 dst_item);
416 }
417 }
418
419 copy_extent_buffer(path->nodes[0], eb, dst_ptr,
420 src_ptr, item_size);
421
422 if (save_old_i_size) {
423 struct btrfs_inode_item *dst_item;
424 dst_item = (struct btrfs_inode_item *)dst_ptr;
425 btrfs_set_inode_size(path->nodes[0], dst_item, saved_i_size);
426 }
427
428 /* make sure the generation is filled in */
429 if (key->type == BTRFS_INODE_ITEM_KEY) {
430 struct btrfs_inode_item *dst_item;
431 dst_item = (struct btrfs_inode_item *)dst_ptr;
432 if (btrfs_inode_generation(path->nodes[0], dst_item) == 0) {
433 btrfs_set_inode_generation(path->nodes[0], dst_item,
434 trans->transid);
435 }
436 }
437no_copy:
438 btrfs_mark_buffer_dirty(path->nodes[0]);
439 btrfs_release_path(path);
440 return 0;
441}
442
443/*
444 * simple helper to read an inode off the disk from a given root
445 * This can only be called for subvolume roots and not for the log
446 */
447static noinline struct inode *read_one_inode(struct btrfs_root *root,
448 u64 objectid)
449{
450 struct btrfs_key key;
451 struct inode *inode;
452
453 key.objectid = objectid;
454 key.type = BTRFS_INODE_ITEM_KEY;
455 key.offset = 0;
456 inode = btrfs_iget(root->fs_info->sb, &key, root, NULL);
457 if (IS_ERR(inode)) {
458 inode = NULL;
459 } else if (is_bad_inode(inode)) {
460 iput(inode);
461 inode = NULL;
462 }
463 return inode;
464}
465
466/* replays a single extent in 'eb' at 'slot' with 'key' into the
467 * subvolume 'root'. path is released on entry and should be released
468 * on exit.
469 *
470 * extents in the log tree have not been allocated out of the extent
471 * tree yet. So, this completes the allocation, taking a reference
472 * as required if the extent already exists or creating a new extent
473 * if it isn't in the extent allocation tree yet.
474 *
475 * The extent is inserted into the file, dropping any existing extents
476 * from the file that overlap the new one.
477 */
478static noinline int replay_one_extent(struct btrfs_trans_handle *trans,
479 struct btrfs_root *root,
480 struct btrfs_path *path,
481 struct extent_buffer *eb, int slot,
482 struct btrfs_key *key)
483{
484 int found_type;
485 u64 mask = root->sectorsize - 1;
486 u64 extent_end;
487 u64 alloc_hint;
488 u64 start = key->offset;
489 u64 saved_nbytes;
490 struct btrfs_file_extent_item *item;
491 struct inode *inode = NULL;
492 unsigned long size;
493 int ret = 0;
494
495 item = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item);
496 found_type = btrfs_file_extent_type(eb, item);
497
498 if (found_type == BTRFS_FILE_EXTENT_REG ||
499 found_type == BTRFS_FILE_EXTENT_PREALLOC)
500 extent_end = start + btrfs_file_extent_num_bytes(eb, item);
501 else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
502 size = btrfs_file_extent_inline_len(eb, item);
503 extent_end = (start + size + mask) & ~mask;
504 } else {
505 ret = 0;
506 goto out;
507 }
508
509 inode = read_one_inode(root, key->objectid);
510 if (!inode) {
511 ret = -EIO;
512 goto out;
513 }
514
515 /*
516 * first check to see if we already have this extent in the
517 * file. This must be done before the btrfs_drop_extents run
518 * so we don't try to drop this extent.
519 */
520 ret = btrfs_lookup_file_extent(trans, root, path, btrfs_ino(inode),
521 start, 0);
522
523 if (ret == 0 &&
524 (found_type == BTRFS_FILE_EXTENT_REG ||
525 found_type == BTRFS_FILE_EXTENT_PREALLOC)) {
526 struct btrfs_file_extent_item cmp1;
527 struct btrfs_file_extent_item cmp2;
528 struct btrfs_file_extent_item *existing;
529 struct extent_buffer *leaf;
530
531 leaf = path->nodes[0];
532 existing = btrfs_item_ptr(leaf, path->slots[0],
533 struct btrfs_file_extent_item);
534
535 read_extent_buffer(eb, &cmp1, (unsigned long)item,
536 sizeof(cmp1));
537 read_extent_buffer(leaf, &cmp2, (unsigned long)existing,
538 sizeof(cmp2));
539
540 /*
541 * we already have a pointer to this exact extent,
542 * we don't have to do anything
543 */
544 if (memcmp(&cmp1, &cmp2, sizeof(cmp1)) == 0) {
545 btrfs_release_path(path);
546 goto out;
547 }
548 }
549 btrfs_release_path(path);
550
551 saved_nbytes = inode_get_bytes(inode);
552 /* drop any overlapping extents */
553 ret = btrfs_drop_extents(trans, inode, start, extent_end,
554 &alloc_hint, 1);
555 BUG_ON(ret);
556
557 if (found_type == BTRFS_FILE_EXTENT_REG ||
558 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
559 u64 offset;
560 unsigned long dest_offset;
561 struct btrfs_key ins;
562
563 ret = btrfs_insert_empty_item(trans, root, path, key,
564 sizeof(*item));
565 BUG_ON(ret);
566 dest_offset = btrfs_item_ptr_offset(path->nodes[0],
567 path->slots[0]);
568 copy_extent_buffer(path->nodes[0], eb, dest_offset,
569 (unsigned long)item, sizeof(*item));
570
571 ins.objectid = btrfs_file_extent_disk_bytenr(eb, item);
572 ins.offset = btrfs_file_extent_disk_num_bytes(eb, item);
573 ins.type = BTRFS_EXTENT_ITEM_KEY;
574 offset = key->offset - btrfs_file_extent_offset(eb, item);
575
576 if (ins.objectid > 0) {
577 u64 csum_start;
578 u64 csum_end;
579 LIST_HEAD(ordered_sums);
580 /*
581 * is this extent already allocated in the extent
582 * allocation tree? If so, just add a reference
583 */
584 ret = btrfs_lookup_extent(root, ins.objectid,
585 ins.offset);
586 if (ret == 0) {
587 ret = btrfs_inc_extent_ref(trans, root,
588 ins.objectid, ins.offset,
589 0, root->root_key.objectid,
590 key->objectid, offset, 0);
591 BUG_ON(ret);
592 } else {
593 /*
594 * insert the extent pointer in the extent
595 * allocation tree
596 */
597 ret = btrfs_alloc_logged_file_extent(trans,
598 root, root->root_key.objectid,
599 key->objectid, offset, &ins);
600 BUG_ON(ret);
601 }
602 btrfs_release_path(path);
603
604 if (btrfs_file_extent_compression(eb, item)) {
605 csum_start = ins.objectid;
606 csum_end = csum_start + ins.offset;
607 } else {
608 csum_start = ins.objectid +
609 btrfs_file_extent_offset(eb, item);
610 csum_end = csum_start +
611 btrfs_file_extent_num_bytes(eb, item);
612 }
613
614 ret = btrfs_lookup_csums_range(root->log_root,
615 csum_start, csum_end - 1,
616 &ordered_sums, 0);
617 BUG_ON(ret);
618 while (!list_empty(&ordered_sums)) {
619 struct btrfs_ordered_sum *sums;
620 sums = list_entry(ordered_sums.next,
621 struct btrfs_ordered_sum,
622 list);
623 ret = btrfs_csum_file_blocks(trans,
624 root->fs_info->csum_root,
625 sums);
626 BUG_ON(ret);
627 list_del(&sums->list);
628 kfree(sums);
629 }
630 } else {
631 btrfs_release_path(path);
632 }
633 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
634 /* inline extents are easy, we just overwrite them */
635 ret = overwrite_item(trans, root, path, eb, slot, key);
636 BUG_ON(ret);
637 }
638
639 inode_set_bytes(inode, saved_nbytes);
640 btrfs_update_inode(trans, root, inode);
641out:
642 if (inode)
643 iput(inode);
644 return ret;
645}
646
647/*
648 * when cleaning up conflicts between the directory names in the
649 * subvolume, directory names in the log and directory names in the
650 * inode back references, we may have to unlink inodes from directories.
651 *
652 * This is a helper function to do the unlink of a specific directory
653 * item
654 */
655static noinline int drop_one_dir_item(struct btrfs_trans_handle *trans,
656 struct btrfs_root *root,
657 struct btrfs_path *path,
658 struct inode *dir,
659 struct btrfs_dir_item *di)
660{
661 struct inode *inode;
662 char *name;
663 int name_len;
664 struct extent_buffer *leaf;
665 struct btrfs_key location;
666 int ret;
667
668 leaf = path->nodes[0];
669
670 btrfs_dir_item_key_to_cpu(leaf, di, &location);
671 name_len = btrfs_dir_name_len(leaf, di);
672 name = kmalloc(name_len, GFP_NOFS);
673 if (!name)
674 return -ENOMEM;
675
676 read_extent_buffer(leaf, name, (unsigned long)(di + 1), name_len);
677 btrfs_release_path(path);
678
679 inode = read_one_inode(root, location.objectid);
680 if (!inode) {
681 kfree(name);
682 return -EIO;
683 }
684
685 ret = link_to_fixup_dir(trans, root, path, location.objectid);
686 BUG_ON(ret);
687
688 ret = btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
689 BUG_ON(ret);
690 kfree(name);
691
692 iput(inode);
693
694 btrfs_run_delayed_items(trans, root);
695 return ret;
696}
697
698/*
699 * helper function to see if a given name and sequence number found
700 * in an inode back reference are already in a directory and correctly
701 * point to this inode
702 */
703static noinline int inode_in_dir(struct btrfs_root *root,
704 struct btrfs_path *path,
705 u64 dirid, u64 objectid, u64 index,
706 const char *name, int name_len)
707{
708 struct btrfs_dir_item *di;
709 struct btrfs_key location;
710 int match = 0;
711
712 di = btrfs_lookup_dir_index_item(NULL, root, path, dirid,
713 index, name, name_len, 0);
714 if (di && !IS_ERR(di)) {
715 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
716 if (location.objectid != objectid)
717 goto out;
718 } else
719 goto out;
720 btrfs_release_path(path);
721
722 di = btrfs_lookup_dir_item(NULL, root, path, dirid, name, name_len, 0);
723 if (di && !IS_ERR(di)) {
724 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
725 if (location.objectid != objectid)
726 goto out;
727 } else
728 goto out;
729 match = 1;
730out:
731 btrfs_release_path(path);
732 return match;
733}
734
735/*
736 * helper function to check a log tree for a named back reference in
737 * an inode. This is used to decide if a back reference that is
738 * found in the subvolume conflicts with what we find in the log.
739 *
740 * inode backreferences may have multiple refs in a single item,
741 * during replay we process one reference at a time, and we don't
742 * want to delete valid links to a file from the subvolume if that
743 * link is also in the log.
744 */
745static noinline int backref_in_log(struct btrfs_root *log,
746 struct btrfs_key *key,
747 char *name, int namelen)
748{
749 struct btrfs_path *path;
750 struct btrfs_inode_ref *ref;
751 unsigned long ptr;
752 unsigned long ptr_end;
753 unsigned long name_ptr;
754 int found_name_len;
755 int item_size;
756 int ret;
757 int match = 0;
758
759 path = btrfs_alloc_path();
760 if (!path)
761 return -ENOMEM;
762
763 ret = btrfs_search_slot(NULL, log, key, path, 0, 0);
764 if (ret != 0)
765 goto out;
766
767 item_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
768 ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
769 ptr_end = ptr + item_size;
770 while (ptr < ptr_end) {
771 ref = (struct btrfs_inode_ref *)ptr;
772 found_name_len = btrfs_inode_ref_name_len(path->nodes[0], ref);
773 if (found_name_len == namelen) {
774 name_ptr = (unsigned long)(ref + 1);
775 ret = memcmp_extent_buffer(path->nodes[0], name,
776 name_ptr, namelen);
777 if (ret == 0) {
778 match = 1;
779 goto out;
780 }
781 }
782 ptr = (unsigned long)(ref + 1) + found_name_len;
783 }
784out:
785 btrfs_free_path(path);
786 return match;
787}
788
789
790/*
791 * replay one inode back reference item found in the log tree.
792 * eb, slot and key refer to the buffer and key found in the log tree.
793 * root is the destination we are replaying into, and path is for temp
794 * use by this function. (it should be released on return).
795 */
796static noinline int add_inode_ref(struct btrfs_trans_handle *trans,
797 struct btrfs_root *root,
798 struct btrfs_root *log,
799 struct btrfs_path *path,
800 struct extent_buffer *eb, int slot,
801 struct btrfs_key *key)
802{
803 struct btrfs_inode_ref *ref;
804 struct btrfs_dir_item *di;
805 struct inode *dir;
806 struct inode *inode;
807 unsigned long ref_ptr;
808 unsigned long ref_end;
809 char *name;
810 int namelen;
811 int ret;
812 int search_done = 0;
813
814 /*
815 * it is possible that we didn't log all the parent directories
816 * for a given inode. If we don't find the dir, just don't
817 * copy the back ref in. The link count fixup code will take
818 * care of the rest
819 */
820 dir = read_one_inode(root, key->offset);
821 if (!dir)
822 return -ENOENT;
823
824 inode = read_one_inode(root, key->objectid);
825 if (!inode) {
826 iput(dir);
827 return -EIO;
828 }
829
830 ref_ptr = btrfs_item_ptr_offset(eb, slot);
831 ref_end = ref_ptr + btrfs_item_size_nr(eb, slot);
832
833again:
834 ref = (struct btrfs_inode_ref *)ref_ptr;
835
836 namelen = btrfs_inode_ref_name_len(eb, ref);
837 name = kmalloc(namelen, GFP_NOFS);
838 BUG_ON(!name);
839
840 read_extent_buffer(eb, name, (unsigned long)(ref + 1), namelen);
841
842 /* if we already have a perfect match, we're done */
843 if (inode_in_dir(root, path, btrfs_ino(dir), btrfs_ino(inode),
844 btrfs_inode_ref_index(eb, ref),
845 name, namelen)) {
846 goto out;
847 }
848
849 /*
850 * look for a conflicting back reference in the metadata.
851 * if we find one we have to unlink that name of the file
852 * before we add our new link. Later on, we overwrite any
853 * existing back reference, and we don't want to create
854 * dangling pointers in the directory.
855 */
856
857 if (search_done)
858 goto insert;
859
860 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
861 if (ret == 0) {
862 char *victim_name;
863 int victim_name_len;
864 struct btrfs_inode_ref *victim_ref;
865 unsigned long ptr;
866 unsigned long ptr_end;
867 struct extent_buffer *leaf = path->nodes[0];
868
869 /* are we trying to overwrite a back ref for the root directory
870 * if so, just jump out, we're done
871 */
872 if (key->objectid == key->offset)
873 goto out_nowrite;
874
875 /* check all the names in this back reference to see
876 * if they are in the log. if so, we allow them to stay
877 * otherwise they must be unlinked as a conflict
878 */
879 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
880 ptr_end = ptr + btrfs_item_size_nr(leaf, path->slots[0]);
881 while (ptr < ptr_end) {
882 victim_ref = (struct btrfs_inode_ref *)ptr;
883 victim_name_len = btrfs_inode_ref_name_len(leaf,
884 victim_ref);
885 victim_name = kmalloc(victim_name_len, GFP_NOFS);
886 BUG_ON(!victim_name);
887
888 read_extent_buffer(leaf, victim_name,
889 (unsigned long)(victim_ref + 1),
890 victim_name_len);
891
892 if (!backref_in_log(log, key, victim_name,
893 victim_name_len)) {
894 btrfs_inc_nlink(inode);
895 btrfs_release_path(path);
896
897 ret = btrfs_unlink_inode(trans, root, dir,
898 inode, victim_name,
899 victim_name_len);
900 btrfs_run_delayed_items(trans, root);
901 }
902 kfree(victim_name);
903 ptr = (unsigned long)(victim_ref + 1) + victim_name_len;
904 }
905 BUG_ON(ret);
906
907 /*
908 * NOTE: we have searched root tree and checked the
909 * coresponding ref, it does not need to check again.
910 */
911 search_done = 1;
912 }
913 btrfs_release_path(path);
914
915 /* look for a conflicting sequence number */
916 di = btrfs_lookup_dir_index_item(trans, root, path, btrfs_ino(dir),
917 btrfs_inode_ref_index(eb, ref),
918 name, namelen, 0);
919 if (di && !IS_ERR(di)) {
920 ret = drop_one_dir_item(trans, root, path, dir, di);
921 BUG_ON(ret);
922 }
923 btrfs_release_path(path);
924
925 /* look for a conflicing name */
926 di = btrfs_lookup_dir_item(trans, root, path, btrfs_ino(dir),
927 name, namelen, 0);
928 if (di && !IS_ERR(di)) {
929 ret = drop_one_dir_item(trans, root, path, dir, di);
930 BUG_ON(ret);
931 }
932 btrfs_release_path(path);
933
934insert:
935 /* insert our name */
936 ret = btrfs_add_link(trans, dir, inode, name, namelen, 0,
937 btrfs_inode_ref_index(eb, ref));
938 BUG_ON(ret);
939
940 btrfs_update_inode(trans, root, inode);
941
942out:
943 ref_ptr = (unsigned long)(ref + 1) + namelen;
944 kfree(name);
945 if (ref_ptr < ref_end)
946 goto again;
947
948 /* finally write the back reference in the inode */
949 ret = overwrite_item(trans, root, path, eb, slot, key);
950 BUG_ON(ret);
951
952out_nowrite:
953 btrfs_release_path(path);
954 iput(dir);
955 iput(inode);
956 return 0;
957}
958
959static int insert_orphan_item(struct btrfs_trans_handle *trans,
960 struct btrfs_root *root, u64 offset)
961{
962 int ret;
963 ret = btrfs_find_orphan_item(root, offset);
964 if (ret > 0)
965 ret = btrfs_insert_orphan_item(trans, root, offset);
966 return ret;
967}
968
969
970/*
971 * There are a few corners where the link count of the file can't
972 * be properly maintained during replay. So, instead of adding
973 * lots of complexity to the log code, we just scan the backrefs
974 * for any file that has been through replay.
975 *
976 * The scan will update the link count on the inode to reflect the
977 * number of back refs found. If it goes down to zero, the iput
978 * will free the inode.
979 */
980static noinline int fixup_inode_link_count(struct btrfs_trans_handle *trans,
981 struct btrfs_root *root,
982 struct inode *inode)
983{
984 struct btrfs_path *path;
985 int ret;
986 struct btrfs_key key;
987 u64 nlink = 0;
988 unsigned long ptr;
989 unsigned long ptr_end;
990 int name_len;
991 u64 ino = btrfs_ino(inode);
992
993 key.objectid = ino;
994 key.type = BTRFS_INODE_REF_KEY;
995 key.offset = (u64)-1;
996
997 path = btrfs_alloc_path();
998 if (!path)
999 return -ENOMEM;
1000
1001 while (1) {
1002 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1003 if (ret < 0)
1004 break;
1005 if (ret > 0) {
1006 if (path->slots[0] == 0)
1007 break;
1008 path->slots[0]--;
1009 }
1010 btrfs_item_key_to_cpu(path->nodes[0], &key,
1011 path->slots[0]);
1012 if (key.objectid != ino ||
1013 key.type != BTRFS_INODE_REF_KEY)
1014 break;
1015 ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
1016 ptr_end = ptr + btrfs_item_size_nr(path->nodes[0],
1017 path->slots[0]);
1018 while (ptr < ptr_end) {
1019 struct btrfs_inode_ref *ref;
1020
1021 ref = (struct btrfs_inode_ref *)ptr;
1022 name_len = btrfs_inode_ref_name_len(path->nodes[0],
1023 ref);
1024 ptr = (unsigned long)(ref + 1) + name_len;
1025 nlink++;
1026 }
1027
1028 if (key.offset == 0)
1029 break;
1030 key.offset--;
1031 btrfs_release_path(path);
1032 }
1033 btrfs_release_path(path);
1034 if (nlink != inode->i_nlink) {
1035 set_nlink(inode, nlink);
1036 btrfs_update_inode(trans, root, inode);
1037 }
1038 BTRFS_I(inode)->index_cnt = (u64)-1;
1039
1040 if (inode->i_nlink == 0) {
1041 if (S_ISDIR(inode->i_mode)) {
1042 ret = replay_dir_deletes(trans, root, NULL, path,
1043 ino, 1);
1044 BUG_ON(ret);
1045 }
1046 ret = insert_orphan_item(trans, root, ino);
1047 BUG_ON(ret);
1048 }
1049 btrfs_free_path(path);
1050
1051 return 0;
1052}
1053
1054static noinline int fixup_inode_link_counts(struct btrfs_trans_handle *trans,
1055 struct btrfs_root *root,
1056 struct btrfs_path *path)
1057{
1058 int ret;
1059 struct btrfs_key key;
1060 struct inode *inode;
1061
1062 key.objectid = BTRFS_TREE_LOG_FIXUP_OBJECTID;
1063 key.type = BTRFS_ORPHAN_ITEM_KEY;
1064 key.offset = (u64)-1;
1065 while (1) {
1066 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1067 if (ret < 0)
1068 break;
1069
1070 if (ret == 1) {
1071 if (path->slots[0] == 0)
1072 break;
1073 path->slots[0]--;
1074 }
1075
1076 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1077 if (key.objectid != BTRFS_TREE_LOG_FIXUP_OBJECTID ||
1078 key.type != BTRFS_ORPHAN_ITEM_KEY)
1079 break;
1080
1081 ret = btrfs_del_item(trans, root, path);
1082 if (ret)
1083 goto out;
1084
1085 btrfs_release_path(path);
1086 inode = read_one_inode(root, key.offset);
1087 if (!inode)
1088 return -EIO;
1089
1090 ret = fixup_inode_link_count(trans, root, inode);
1091 BUG_ON(ret);
1092
1093 iput(inode);
1094
1095 /*
1096 * fixup on a directory may create new entries,
1097 * make sure we always look for the highset possible
1098 * offset
1099 */
1100 key.offset = (u64)-1;
1101 }
1102 ret = 0;
1103out:
1104 btrfs_release_path(path);
1105 return ret;
1106}
1107
1108
1109/*
1110 * record a given inode in the fixup dir so we can check its link
1111 * count when replay is done. The link count is incremented here
1112 * so the inode won't go away until we check it
1113 */
1114static noinline int link_to_fixup_dir(struct btrfs_trans_handle *trans,
1115 struct btrfs_root *root,
1116 struct btrfs_path *path,
1117 u64 objectid)
1118{
1119 struct btrfs_key key;
1120 int ret = 0;
1121 struct inode *inode;
1122
1123 inode = read_one_inode(root, objectid);
1124 if (!inode)
1125 return -EIO;
1126
1127 key.objectid = BTRFS_TREE_LOG_FIXUP_OBJECTID;
1128 btrfs_set_key_type(&key, BTRFS_ORPHAN_ITEM_KEY);
1129 key.offset = objectid;
1130
1131 ret = btrfs_insert_empty_item(trans, root, path, &key, 0);
1132
1133 btrfs_release_path(path);
1134 if (ret == 0) {
1135 btrfs_inc_nlink(inode);
1136 btrfs_update_inode(trans, root, inode);
1137 } else if (ret == -EEXIST) {
1138 ret = 0;
1139 } else {
1140 BUG();
1141 }
1142 iput(inode);
1143
1144 return ret;
1145}
1146
1147/*
1148 * when replaying the log for a directory, we only insert names
1149 * for inodes that actually exist. This means an fsync on a directory
1150 * does not implicitly fsync all the new files in it
1151 */
1152static noinline int insert_one_name(struct btrfs_trans_handle *trans,
1153 struct btrfs_root *root,
1154 struct btrfs_path *path,
1155 u64 dirid, u64 index,
1156 char *name, int name_len, u8 type,
1157 struct btrfs_key *location)
1158{
1159 struct inode *inode;
1160 struct inode *dir;
1161 int ret;
1162
1163 inode = read_one_inode(root, location->objectid);
1164 if (!inode)
1165 return -ENOENT;
1166
1167 dir = read_one_inode(root, dirid);
1168 if (!dir) {
1169 iput(inode);
1170 return -EIO;
1171 }
1172 ret = btrfs_add_link(trans, dir, inode, name, name_len, 1, index);
1173
1174 /* FIXME, put inode into FIXUP list */
1175
1176 iput(inode);
1177 iput(dir);
1178 return ret;
1179}
1180
1181/*
1182 * take a single entry in a log directory item and replay it into
1183 * the subvolume.
1184 *
1185 * if a conflicting item exists in the subdirectory already,
1186 * the inode it points to is unlinked and put into the link count
1187 * fix up tree.
1188 *
1189 * If a name from the log points to a file or directory that does
1190 * not exist in the FS, it is skipped. fsyncs on directories
1191 * do not force down inodes inside that directory, just changes to the
1192 * names or unlinks in a directory.
1193 */
1194static noinline int replay_one_name(struct btrfs_trans_handle *trans,
1195 struct btrfs_root *root,
1196 struct btrfs_path *path,
1197 struct extent_buffer *eb,
1198 struct btrfs_dir_item *di,
1199 struct btrfs_key *key)
1200{
1201 char *name;
1202 int name_len;
1203 struct btrfs_dir_item *dst_di;
1204 struct btrfs_key found_key;
1205 struct btrfs_key log_key;
1206 struct inode *dir;
1207 u8 log_type;
1208 int exists;
1209 int ret;
1210
1211 dir = read_one_inode(root, key->objectid);
1212 if (!dir)
1213 return -EIO;
1214
1215 name_len = btrfs_dir_name_len(eb, di);
1216 name = kmalloc(name_len, GFP_NOFS);
1217 if (!name)
1218 return -ENOMEM;
1219
1220 log_type = btrfs_dir_type(eb, di);
1221 read_extent_buffer(eb, name, (unsigned long)(di + 1),
1222 name_len);
1223
1224 btrfs_dir_item_key_to_cpu(eb, di, &log_key);
1225 exists = btrfs_lookup_inode(trans, root, path, &log_key, 0);
1226 if (exists == 0)
1227 exists = 1;
1228 else
1229 exists = 0;
1230 btrfs_release_path(path);
1231
1232 if (key->type == BTRFS_DIR_ITEM_KEY) {
1233 dst_di = btrfs_lookup_dir_item(trans, root, path, key->objectid,
1234 name, name_len, 1);
1235 } else if (key->type == BTRFS_DIR_INDEX_KEY) {
1236 dst_di = btrfs_lookup_dir_index_item(trans, root, path,
1237 key->objectid,
1238 key->offset, name,
1239 name_len, 1);
1240 } else {
1241 BUG();
1242 }
1243 if (IS_ERR_OR_NULL(dst_di)) {
1244 /* we need a sequence number to insert, so we only
1245 * do inserts for the BTRFS_DIR_INDEX_KEY types
1246 */
1247 if (key->type != BTRFS_DIR_INDEX_KEY)
1248 goto out;
1249 goto insert;
1250 }
1251
1252 btrfs_dir_item_key_to_cpu(path->nodes[0], dst_di, &found_key);
1253 /* the existing item matches the logged item */
1254 if (found_key.objectid == log_key.objectid &&
1255 found_key.type == log_key.type &&
1256 found_key.offset == log_key.offset &&
1257 btrfs_dir_type(path->nodes[0], dst_di) == log_type) {
1258 goto out;
1259 }
1260
1261 /*
1262 * don't drop the conflicting directory entry if the inode
1263 * for the new entry doesn't exist
1264 */
1265 if (!exists)
1266 goto out;
1267
1268 ret = drop_one_dir_item(trans, root, path, dir, dst_di);
1269 BUG_ON(ret);
1270
1271 if (key->type == BTRFS_DIR_INDEX_KEY)
1272 goto insert;
1273out:
1274 btrfs_release_path(path);
1275 kfree(name);
1276 iput(dir);
1277 return 0;
1278
1279insert:
1280 btrfs_release_path(path);
1281 ret = insert_one_name(trans, root, path, key->objectid, key->offset,
1282 name, name_len, log_type, &log_key);
1283
1284 BUG_ON(ret && ret != -ENOENT);
1285 goto out;
1286}
1287
1288/*
1289 * find all the names in a directory item and reconcile them into
1290 * the subvolume. Only BTRFS_DIR_ITEM_KEY types will have more than
1291 * one name in a directory item, but the same code gets used for
1292 * both directory index types
1293 */
1294static noinline int replay_one_dir_item(struct btrfs_trans_handle *trans,
1295 struct btrfs_root *root,
1296 struct btrfs_path *path,
1297 struct extent_buffer *eb, int slot,
1298 struct btrfs_key *key)
1299{
1300 int ret;
1301 u32 item_size = btrfs_item_size_nr(eb, slot);
1302 struct btrfs_dir_item *di;
1303 int name_len;
1304 unsigned long ptr;
1305 unsigned long ptr_end;
1306
1307 ptr = btrfs_item_ptr_offset(eb, slot);
1308 ptr_end = ptr + item_size;
1309 while (ptr < ptr_end) {
1310 di = (struct btrfs_dir_item *)ptr;
1311 if (verify_dir_item(root, eb, di))
1312 return -EIO;
1313 name_len = btrfs_dir_name_len(eb, di);
1314 ret = replay_one_name(trans, root, path, eb, di, key);
1315 BUG_ON(ret);
1316 ptr = (unsigned long)(di + 1);
1317 ptr += name_len;
1318 }
1319 return 0;
1320}
1321
1322/*
1323 * directory replay has two parts. There are the standard directory
1324 * items in the log copied from the subvolume, and range items
1325 * created in the log while the subvolume was logged.
1326 *
1327 * The range items tell us which parts of the key space the log
1328 * is authoritative for. During replay, if a key in the subvolume
1329 * directory is in a logged range item, but not actually in the log
1330 * that means it was deleted from the directory before the fsync
1331 * and should be removed.
1332 */
1333static noinline int find_dir_range(struct btrfs_root *root,
1334 struct btrfs_path *path,
1335 u64 dirid, int key_type,
1336 u64 *start_ret, u64 *end_ret)
1337{
1338 struct btrfs_key key;
1339 u64 found_end;
1340 struct btrfs_dir_log_item *item;
1341 int ret;
1342 int nritems;
1343
1344 if (*start_ret == (u64)-1)
1345 return 1;
1346
1347 key.objectid = dirid;
1348 key.type = key_type;
1349 key.offset = *start_ret;
1350
1351 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1352 if (ret < 0)
1353 goto out;
1354 if (ret > 0) {
1355 if (path->slots[0] == 0)
1356 goto out;
1357 path->slots[0]--;
1358 }
1359 if (ret != 0)
1360 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1361
1362 if (key.type != key_type || key.objectid != dirid) {
1363 ret = 1;
1364 goto next;
1365 }
1366 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
1367 struct btrfs_dir_log_item);
1368 found_end = btrfs_dir_log_end(path->nodes[0], item);
1369
1370 if (*start_ret >= key.offset && *start_ret <= found_end) {
1371 ret = 0;
1372 *start_ret = key.offset;
1373 *end_ret = found_end;
1374 goto out;
1375 }
1376 ret = 1;
1377next:
1378 /* check the next slot in the tree to see if it is a valid item */
1379 nritems = btrfs_header_nritems(path->nodes[0]);
1380 if (path->slots[0] >= nritems) {
1381 ret = btrfs_next_leaf(root, path);
1382 if (ret)
1383 goto out;
1384 } else {
1385 path->slots[0]++;
1386 }
1387
1388 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1389
1390 if (key.type != key_type || key.objectid != dirid) {
1391 ret = 1;
1392 goto out;
1393 }
1394 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
1395 struct btrfs_dir_log_item);
1396 found_end = btrfs_dir_log_end(path->nodes[0], item);
1397 *start_ret = key.offset;
1398 *end_ret = found_end;
1399 ret = 0;
1400out:
1401 btrfs_release_path(path);
1402 return ret;
1403}
1404
1405/*
1406 * this looks for a given directory item in the log. If the directory
1407 * item is not in the log, the item is removed and the inode it points
1408 * to is unlinked
1409 */
1410static noinline int check_item_in_log(struct btrfs_trans_handle *trans,
1411 struct btrfs_root *root,
1412 struct btrfs_root *log,
1413 struct btrfs_path *path,
1414 struct btrfs_path *log_path,
1415 struct inode *dir,
1416 struct btrfs_key *dir_key)
1417{
1418 int ret;
1419 struct extent_buffer *eb;
1420 int slot;
1421 u32 item_size;
1422 struct btrfs_dir_item *di;
1423 struct btrfs_dir_item *log_di;
1424 int name_len;
1425 unsigned long ptr;
1426 unsigned long ptr_end;
1427 char *name;
1428 struct inode *inode;
1429 struct btrfs_key location;
1430
1431again:
1432 eb = path->nodes[0];
1433 slot = path->slots[0];
1434 item_size = btrfs_item_size_nr(eb, slot);
1435 ptr = btrfs_item_ptr_offset(eb, slot);
1436 ptr_end = ptr + item_size;
1437 while (ptr < ptr_end) {
1438 di = (struct btrfs_dir_item *)ptr;
1439 if (verify_dir_item(root, eb, di)) {
1440 ret = -EIO;
1441 goto out;
1442 }
1443
1444 name_len = btrfs_dir_name_len(eb, di);
1445 name = kmalloc(name_len, GFP_NOFS);
1446 if (!name) {
1447 ret = -ENOMEM;
1448 goto out;
1449 }
1450 read_extent_buffer(eb, name, (unsigned long)(di + 1),
1451 name_len);
1452 log_di = NULL;
1453 if (log && dir_key->type == BTRFS_DIR_ITEM_KEY) {
1454 log_di = btrfs_lookup_dir_item(trans, log, log_path,
1455 dir_key->objectid,
1456 name, name_len, 0);
1457 } else if (log && dir_key->type == BTRFS_DIR_INDEX_KEY) {
1458 log_di = btrfs_lookup_dir_index_item(trans, log,
1459 log_path,
1460 dir_key->objectid,
1461 dir_key->offset,
1462 name, name_len, 0);
1463 }
1464 if (IS_ERR_OR_NULL(log_di)) {
1465 btrfs_dir_item_key_to_cpu(eb, di, &location);
1466 btrfs_release_path(path);
1467 btrfs_release_path(log_path);
1468 inode = read_one_inode(root, location.objectid);
1469 if (!inode) {
1470 kfree(name);
1471 return -EIO;
1472 }
1473
1474 ret = link_to_fixup_dir(trans, root,
1475 path, location.objectid);
1476 BUG_ON(ret);
1477 btrfs_inc_nlink(inode);
1478 ret = btrfs_unlink_inode(trans, root, dir, inode,
1479 name, name_len);
1480 BUG_ON(ret);
1481
1482 btrfs_run_delayed_items(trans, root);
1483
1484 kfree(name);
1485 iput(inode);
1486
1487 /* there might still be more names under this key
1488 * check and repeat if required
1489 */
1490 ret = btrfs_search_slot(NULL, root, dir_key, path,
1491 0, 0);
1492 if (ret == 0)
1493 goto again;
1494 ret = 0;
1495 goto out;
1496 }
1497 btrfs_release_path(log_path);
1498 kfree(name);
1499
1500 ptr = (unsigned long)(di + 1);
1501 ptr += name_len;
1502 }
1503 ret = 0;
1504out:
1505 btrfs_release_path(path);
1506 btrfs_release_path(log_path);
1507 return ret;
1508}
1509
1510/*
1511 * deletion replay happens before we copy any new directory items
1512 * out of the log or out of backreferences from inodes. It
1513 * scans the log to find ranges of keys that log is authoritative for,
1514 * and then scans the directory to find items in those ranges that are
1515 * not present in the log.
1516 *
1517 * Anything we don't find in the log is unlinked and removed from the
1518 * directory.
1519 */
1520static noinline int replay_dir_deletes(struct btrfs_trans_handle *trans,
1521 struct btrfs_root *root,
1522 struct btrfs_root *log,
1523 struct btrfs_path *path,
1524 u64 dirid, int del_all)
1525{
1526 u64 range_start;
1527 u64 range_end;
1528 int key_type = BTRFS_DIR_LOG_ITEM_KEY;
1529 int ret = 0;
1530 struct btrfs_key dir_key;
1531 struct btrfs_key found_key;
1532 struct btrfs_path *log_path;
1533 struct inode *dir;
1534
1535 dir_key.objectid = dirid;
1536 dir_key.type = BTRFS_DIR_ITEM_KEY;
1537 log_path = btrfs_alloc_path();
1538 if (!log_path)
1539 return -ENOMEM;
1540
1541 dir = read_one_inode(root, dirid);
1542 /* it isn't an error if the inode isn't there, that can happen
1543 * because we replay the deletes before we copy in the inode item
1544 * from the log
1545 */
1546 if (!dir) {
1547 btrfs_free_path(log_path);
1548 return 0;
1549 }
1550again:
1551 range_start = 0;
1552 range_end = 0;
1553 while (1) {
1554 if (del_all)
1555 range_end = (u64)-1;
1556 else {
1557 ret = find_dir_range(log, path, dirid, key_type,
1558 &range_start, &range_end);
1559 if (ret != 0)
1560 break;
1561 }
1562
1563 dir_key.offset = range_start;
1564 while (1) {
1565 int nritems;
1566 ret = btrfs_search_slot(NULL, root, &dir_key, path,
1567 0, 0);
1568 if (ret < 0)
1569 goto out;
1570
1571 nritems = btrfs_header_nritems(path->nodes[0]);
1572 if (path->slots[0] >= nritems) {
1573 ret = btrfs_next_leaf(root, path);
1574 if (ret)
1575 break;
1576 }
1577 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1578 path->slots[0]);
1579 if (found_key.objectid != dirid ||
1580 found_key.type != dir_key.type)
1581 goto next_type;
1582
1583 if (found_key.offset > range_end)
1584 break;
1585
1586 ret = check_item_in_log(trans, root, log, path,
1587 log_path, dir,
1588 &found_key);
1589 BUG_ON(ret);
1590 if (found_key.offset == (u64)-1)
1591 break;
1592 dir_key.offset = found_key.offset + 1;
1593 }
1594 btrfs_release_path(path);
1595 if (range_end == (u64)-1)
1596 break;
1597 range_start = range_end + 1;
1598 }
1599
1600next_type:
1601 ret = 0;
1602 if (key_type == BTRFS_DIR_LOG_ITEM_KEY) {
1603 key_type = BTRFS_DIR_LOG_INDEX_KEY;
1604 dir_key.type = BTRFS_DIR_INDEX_KEY;
1605 btrfs_release_path(path);
1606 goto again;
1607 }
1608out:
1609 btrfs_release_path(path);
1610 btrfs_free_path(log_path);
1611 iput(dir);
1612 return ret;
1613}
1614
1615/*
1616 * the process_func used to replay items from the log tree. This
1617 * gets called in two different stages. The first stage just looks
1618 * for inodes and makes sure they are all copied into the subvolume.
1619 *
1620 * The second stage copies all the other item types from the log into
1621 * the subvolume. The two stage approach is slower, but gets rid of
1622 * lots of complexity around inodes referencing other inodes that exist
1623 * only in the log (references come from either directory items or inode
1624 * back refs).
1625 */
1626static int replay_one_buffer(struct btrfs_root *log, struct extent_buffer *eb,
1627 struct walk_control *wc, u64 gen)
1628{
1629 int nritems;
1630 struct btrfs_path *path;
1631 struct btrfs_root *root = wc->replay_dest;
1632 struct btrfs_key key;
1633 int level;
1634 int i;
1635 int ret;
1636
1637 ret = btrfs_read_buffer(eb, gen);
1638 if (ret)
1639 return ret;
1640
1641 level = btrfs_header_level(eb);
1642
1643 if (level != 0)
1644 return 0;
1645
1646 path = btrfs_alloc_path();
1647 if (!path)
1648 return -ENOMEM;
1649
1650 nritems = btrfs_header_nritems(eb);
1651 for (i = 0; i < nritems; i++) {
1652 btrfs_item_key_to_cpu(eb, &key, i);
1653
1654 /* inode keys are done during the first stage */
1655 if (key.type == BTRFS_INODE_ITEM_KEY &&
1656 wc->stage == LOG_WALK_REPLAY_INODES) {
1657 struct btrfs_inode_item *inode_item;
1658 u32 mode;
1659
1660 inode_item = btrfs_item_ptr(eb, i,
1661 struct btrfs_inode_item);
1662 mode = btrfs_inode_mode(eb, inode_item);
1663 if (S_ISDIR(mode)) {
1664 ret = replay_dir_deletes(wc->trans,
1665 root, log, path, key.objectid, 0);
1666 BUG_ON(ret);
1667 }
1668 ret = overwrite_item(wc->trans, root, path,
1669 eb, i, &key);
1670 BUG_ON(ret);
1671
1672 /* for regular files, make sure corresponding
1673 * orhpan item exist. extents past the new EOF
1674 * will be truncated later by orphan cleanup.
1675 */
1676 if (S_ISREG(mode)) {
1677 ret = insert_orphan_item(wc->trans, root,
1678 key.objectid);
1679 BUG_ON(ret);
1680 }
1681
1682 ret = link_to_fixup_dir(wc->trans, root,
1683 path, key.objectid);
1684 BUG_ON(ret);
1685 }
1686 if (wc->stage < LOG_WALK_REPLAY_ALL)
1687 continue;
1688
1689 /* these keys are simply copied */
1690 if (key.type == BTRFS_XATTR_ITEM_KEY) {
1691 ret = overwrite_item(wc->trans, root, path,
1692 eb, i, &key);
1693 BUG_ON(ret);
1694 } else if (key.type == BTRFS_INODE_REF_KEY) {
1695 ret = add_inode_ref(wc->trans, root, log, path,
1696 eb, i, &key);
1697 BUG_ON(ret && ret != -ENOENT);
1698 } else if (key.type == BTRFS_EXTENT_DATA_KEY) {
1699 ret = replay_one_extent(wc->trans, root, path,
1700 eb, i, &key);
1701 BUG_ON(ret);
1702 } else if (key.type == BTRFS_DIR_ITEM_KEY ||
1703 key.type == BTRFS_DIR_INDEX_KEY) {
1704 ret = replay_one_dir_item(wc->trans, root, path,
1705 eb, i, &key);
1706 BUG_ON(ret);
1707 }
1708 }
1709 btrfs_free_path(path);
1710 return 0;
1711}
1712
1713static noinline int walk_down_log_tree(struct btrfs_trans_handle *trans,
1714 struct btrfs_root *root,
1715 struct btrfs_path *path, int *level,
1716 struct walk_control *wc)
1717{
1718 u64 root_owner;
1719 u64 bytenr;
1720 u64 ptr_gen;
1721 struct extent_buffer *next;
1722 struct extent_buffer *cur;
1723 struct extent_buffer *parent;
1724 u32 blocksize;
1725 int ret = 0;
1726
1727 WARN_ON(*level < 0);
1728 WARN_ON(*level >= BTRFS_MAX_LEVEL);
1729
1730 while (*level > 0) {
1731 WARN_ON(*level < 0);
1732 WARN_ON(*level >= BTRFS_MAX_LEVEL);
1733 cur = path->nodes[*level];
1734
1735 if (btrfs_header_level(cur) != *level)
1736 WARN_ON(1);
1737
1738 if (path->slots[*level] >=
1739 btrfs_header_nritems(cur))
1740 break;
1741
1742 bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
1743 ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
1744 blocksize = btrfs_level_size(root, *level - 1);
1745
1746 parent = path->nodes[*level];
1747 root_owner = btrfs_header_owner(parent);
1748
1749 next = btrfs_find_create_tree_block(root, bytenr, blocksize);
1750 if (!next)
1751 return -ENOMEM;
1752
1753 if (*level == 1) {
1754 ret = wc->process_func(root, next, wc, ptr_gen);
1755 if (ret)
1756 return ret;
1757
1758 path->slots[*level]++;
1759 if (wc->free) {
1760 ret = btrfs_read_buffer(next, ptr_gen);
1761 if (ret) {
1762 free_extent_buffer(next);
1763 return ret;
1764 }
1765
1766 btrfs_tree_lock(next);
1767 btrfs_set_lock_blocking(next);
1768 clean_tree_block(trans, root, next);
1769 btrfs_wait_tree_block_writeback(next);
1770 btrfs_tree_unlock(next);
1771
1772 WARN_ON(root_owner !=
1773 BTRFS_TREE_LOG_OBJECTID);
1774 ret = btrfs_free_and_pin_reserved_extent(root,
1775 bytenr, blocksize);
1776 BUG_ON(ret); /* -ENOMEM or logic errors */
1777 }
1778 free_extent_buffer(next);
1779 continue;
1780 }
1781 ret = btrfs_read_buffer(next, ptr_gen);
1782 if (ret) {
1783 free_extent_buffer(next);
1784 return ret;
1785 }
1786
1787 WARN_ON(*level <= 0);
1788 if (path->nodes[*level-1])
1789 free_extent_buffer(path->nodes[*level-1]);
1790 path->nodes[*level-1] = next;
1791 *level = btrfs_header_level(next);
1792 path->slots[*level] = 0;
1793 cond_resched();
1794 }
1795 WARN_ON(*level < 0);
1796 WARN_ON(*level >= BTRFS_MAX_LEVEL);
1797
1798 path->slots[*level] = btrfs_header_nritems(path->nodes[*level]);
1799
1800 cond_resched();
1801 return 0;
1802}
1803
1804static noinline int walk_up_log_tree(struct btrfs_trans_handle *trans,
1805 struct btrfs_root *root,
1806 struct btrfs_path *path, int *level,
1807 struct walk_control *wc)
1808{
1809 u64 root_owner;
1810 int i;
1811 int slot;
1812 int ret;
1813
1814 for (i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
1815 slot = path->slots[i];
1816 if (slot + 1 < btrfs_header_nritems(path->nodes[i])) {
1817 path->slots[i]++;
1818 *level = i;
1819 WARN_ON(*level == 0);
1820 return 0;
1821 } else {
1822 struct extent_buffer *parent;
1823 if (path->nodes[*level] == root->node)
1824 parent = path->nodes[*level];
1825 else
1826 parent = path->nodes[*level + 1];
1827
1828 root_owner = btrfs_header_owner(parent);
1829 ret = wc->process_func(root, path->nodes[*level], wc,
1830 btrfs_header_generation(path->nodes[*level]));
1831 if (ret)
1832 return ret;
1833
1834 if (wc->free) {
1835 struct extent_buffer *next;
1836
1837 next = path->nodes[*level];
1838
1839 btrfs_tree_lock(next);
1840 btrfs_set_lock_blocking(next);
1841 clean_tree_block(trans, root, next);
1842 btrfs_wait_tree_block_writeback(next);
1843 btrfs_tree_unlock(next);
1844
1845 WARN_ON(root_owner != BTRFS_TREE_LOG_OBJECTID);
1846 ret = btrfs_free_and_pin_reserved_extent(root,
1847 path->nodes[*level]->start,
1848 path->nodes[*level]->len);
1849 BUG_ON(ret);
1850 }
1851 free_extent_buffer(path->nodes[*level]);
1852 path->nodes[*level] = NULL;
1853 *level = i + 1;
1854 }
1855 }
1856 return 1;
1857}
1858
1859/*
1860 * drop the reference count on the tree rooted at 'snap'. This traverses
1861 * the tree freeing any blocks that have a ref count of zero after being
1862 * decremented.
1863 */
1864static int walk_log_tree(struct btrfs_trans_handle *trans,
1865 struct btrfs_root *log, struct walk_control *wc)
1866{
1867 int ret = 0;
1868 int wret;
1869 int level;
1870 struct btrfs_path *path;
1871 int i;
1872 int orig_level;
1873
1874 path = btrfs_alloc_path();
1875 if (!path)
1876 return -ENOMEM;
1877
1878 level = btrfs_header_level(log->node);
1879 orig_level = level;
1880 path->nodes[level] = log->node;
1881 extent_buffer_get(log->node);
1882 path->slots[level] = 0;
1883
1884 while (1) {
1885 wret = walk_down_log_tree(trans, log, path, &level, wc);
1886 if (wret > 0)
1887 break;
1888 if (wret < 0) {
1889 ret = wret;
1890 goto out;
1891 }
1892
1893 wret = walk_up_log_tree(trans, log, path, &level, wc);
1894 if (wret > 0)
1895 break;
1896 if (wret < 0) {
1897 ret = wret;
1898 goto out;
1899 }
1900 }
1901
1902 /* was the root node processed? if not, catch it here */
1903 if (path->nodes[orig_level]) {
1904 ret = wc->process_func(log, path->nodes[orig_level], wc,
1905 btrfs_header_generation(path->nodes[orig_level]));
1906 if (ret)
1907 goto out;
1908 if (wc->free) {
1909 struct extent_buffer *next;
1910
1911 next = path->nodes[orig_level];
1912
1913 btrfs_tree_lock(next);
1914 btrfs_set_lock_blocking(next);
1915 clean_tree_block(trans, log, next);
1916 btrfs_wait_tree_block_writeback(next);
1917 btrfs_tree_unlock(next);
1918
1919 WARN_ON(log->root_key.objectid !=
1920 BTRFS_TREE_LOG_OBJECTID);
1921 ret = btrfs_free_and_pin_reserved_extent(log, next->start,
1922 next->len);
1923 BUG_ON(ret); /* -ENOMEM or logic errors */
1924 }
1925 }
1926
1927out:
1928 for (i = 0; i <= orig_level; i++) {
1929 if (path->nodes[i]) {
1930 free_extent_buffer(path->nodes[i]);
1931 path->nodes[i] = NULL;
1932 }
1933 }
1934 btrfs_free_path(path);
1935 return ret;
1936}
1937
1938/*
1939 * helper function to update the item for a given subvolumes log root
1940 * in the tree of log roots
1941 */
1942static int update_log_root(struct btrfs_trans_handle *trans,
1943 struct btrfs_root *log)
1944{
1945 int ret;
1946
1947 if (log->log_transid == 1) {
1948 /* insert root item on the first sync */
1949 ret = btrfs_insert_root(trans, log->fs_info->log_root_tree,
1950 &log->root_key, &log->root_item);
1951 } else {
1952 ret = btrfs_update_root(trans, log->fs_info->log_root_tree,
1953 &log->root_key, &log->root_item);
1954 }
1955 return ret;
1956}
1957
1958static int wait_log_commit(struct btrfs_trans_handle *trans,
1959 struct btrfs_root *root, unsigned long transid)
1960{
1961 DEFINE_WAIT(wait);
1962 int index = transid % 2;
1963
1964 /*
1965 * we only allow two pending log transactions at a time,
1966 * so we know that if ours is more than 2 older than the
1967 * current transaction, we're done
1968 */
1969 do {
1970 prepare_to_wait(&root->log_commit_wait[index],
1971 &wait, TASK_UNINTERRUPTIBLE);
1972 mutex_unlock(&root->log_mutex);
1973
1974 if (root->fs_info->last_trans_log_full_commit !=
1975 trans->transid && root->log_transid < transid + 2 &&
1976 atomic_read(&root->log_commit[index]))
1977 schedule();
1978
1979 finish_wait(&root->log_commit_wait[index], &wait);
1980 mutex_lock(&root->log_mutex);
1981 } while (root->fs_info->last_trans_log_full_commit !=
1982 trans->transid && root->log_transid < transid + 2 &&
1983 atomic_read(&root->log_commit[index]));
1984 return 0;
1985}
1986
1987static void wait_for_writer(struct btrfs_trans_handle *trans,
1988 struct btrfs_root *root)
1989{
1990 DEFINE_WAIT(wait);
1991 while (root->fs_info->last_trans_log_full_commit !=
1992 trans->transid && atomic_read(&root->log_writers)) {
1993 prepare_to_wait(&root->log_writer_wait,
1994 &wait, TASK_UNINTERRUPTIBLE);
1995 mutex_unlock(&root->log_mutex);
1996 if (root->fs_info->last_trans_log_full_commit !=
1997 trans->transid && atomic_read(&root->log_writers))
1998 schedule();
1999 mutex_lock(&root->log_mutex);
2000 finish_wait(&root->log_writer_wait, &wait);
2001 }
2002}
2003
2004/*
2005 * btrfs_sync_log does sends a given tree log down to the disk and
2006 * updates the super blocks to record it. When this call is done,
2007 * you know that any inodes previously logged are safely on disk only
2008 * if it returns 0.
2009 *
2010 * Any other return value means you need to call btrfs_commit_transaction.
2011 * Some of the edge cases for fsyncing directories that have had unlinks
2012 * or renames done in the past mean that sometimes the only safe
2013 * fsync is to commit the whole FS. When btrfs_sync_log returns -EAGAIN,
2014 * that has happened.
2015 */
2016int btrfs_sync_log(struct btrfs_trans_handle *trans,
2017 struct btrfs_root *root)
2018{
2019 int index1;
2020 int index2;
2021 int mark;
2022 int ret;
2023 struct btrfs_root *log = root->log_root;
2024 struct btrfs_root *log_root_tree = root->fs_info->log_root_tree;
2025 unsigned long log_transid = 0;
2026
2027 mutex_lock(&root->log_mutex);
2028 index1 = root->log_transid % 2;
2029 if (atomic_read(&root->log_commit[index1])) {
2030 wait_log_commit(trans, root, root->log_transid);
2031 mutex_unlock(&root->log_mutex);
2032 return 0;
2033 }
2034 atomic_set(&root->log_commit[index1], 1);
2035
2036 /* wait for previous tree log sync to complete */
2037 if (atomic_read(&root->log_commit[(index1 + 1) % 2]))
2038 wait_log_commit(trans, root, root->log_transid - 1);
2039 while (1) {
2040 unsigned long batch = root->log_batch;
2041 /* when we're on an ssd, just kick the log commit out */
2042 if (!btrfs_test_opt(root, SSD) && root->log_multiple_pids) {
2043 mutex_unlock(&root->log_mutex);
2044 schedule_timeout_uninterruptible(1);
2045 mutex_lock(&root->log_mutex);
2046 }
2047 wait_for_writer(trans, root);
2048 if (batch == root->log_batch)
2049 break;
2050 }
2051
2052 /* bail out if we need to do a full commit */
2053 if (root->fs_info->last_trans_log_full_commit == trans->transid) {
2054 ret = -EAGAIN;
2055 mutex_unlock(&root->log_mutex);
2056 goto out;
2057 }
2058
2059 log_transid = root->log_transid;
2060 if (log_transid % 2 == 0)
2061 mark = EXTENT_DIRTY;
2062 else
2063 mark = EXTENT_NEW;
2064
2065 /* we start IO on all the marked extents here, but we don't actually
2066 * wait for them until later.
2067 */
2068 ret = btrfs_write_marked_extents(log, &log->dirty_log_pages, mark);
2069 if (ret) {
2070 btrfs_abort_transaction(trans, root, ret);
2071 mutex_unlock(&root->log_mutex);
2072 goto out;
2073 }
2074
2075 btrfs_set_root_node(&log->root_item, log->node);
2076
2077 root->log_batch = 0;
2078 root->log_transid++;
2079 log->log_transid = root->log_transid;
2080 root->log_start_pid = 0;
2081 smp_mb();
2082 /*
2083 * IO has been started, blocks of the log tree have WRITTEN flag set
2084 * in their headers. new modifications of the log will be written to
2085 * new positions. so it's safe to allow log writers to go in.
2086 */
2087 mutex_unlock(&root->log_mutex);
2088
2089 mutex_lock(&log_root_tree->log_mutex);
2090 log_root_tree->log_batch++;
2091 atomic_inc(&log_root_tree->log_writers);
2092 mutex_unlock(&log_root_tree->log_mutex);
2093
2094 ret = update_log_root(trans, log);
2095
2096 mutex_lock(&log_root_tree->log_mutex);
2097 if (atomic_dec_and_test(&log_root_tree->log_writers)) {
2098 smp_mb();
2099 if (waitqueue_active(&log_root_tree->log_writer_wait))
2100 wake_up(&log_root_tree->log_writer_wait);
2101 }
2102
2103 if (ret) {
2104 if (ret != -ENOSPC) {
2105 btrfs_abort_transaction(trans, root, ret);
2106 mutex_unlock(&log_root_tree->log_mutex);
2107 goto out;
2108 }
2109 root->fs_info->last_trans_log_full_commit = trans->transid;
2110 btrfs_wait_marked_extents(log, &log->dirty_log_pages, mark);
2111 mutex_unlock(&log_root_tree->log_mutex);
2112 ret = -EAGAIN;
2113 goto out;
2114 }
2115
2116 index2 = log_root_tree->log_transid % 2;
2117 if (atomic_read(&log_root_tree->log_commit[index2])) {
2118 btrfs_wait_marked_extents(log, &log->dirty_log_pages, mark);
2119 wait_log_commit(trans, log_root_tree,
2120 log_root_tree->log_transid);
2121 mutex_unlock(&log_root_tree->log_mutex);
2122 ret = 0;
2123 goto out;
2124 }
2125 atomic_set(&log_root_tree->log_commit[index2], 1);
2126
2127 if (atomic_read(&log_root_tree->log_commit[(index2 + 1) % 2])) {
2128 wait_log_commit(trans, log_root_tree,
2129 log_root_tree->log_transid - 1);
2130 }
2131
2132 wait_for_writer(trans, log_root_tree);
2133
2134 /*
2135 * now that we've moved on to the tree of log tree roots,
2136 * check the full commit flag again
2137 */
2138 if (root->fs_info->last_trans_log_full_commit == trans->transid) {
2139 btrfs_wait_marked_extents(log, &log->dirty_log_pages, mark);
2140 mutex_unlock(&log_root_tree->log_mutex);
2141 ret = -EAGAIN;
2142 goto out_wake_log_root;
2143 }
2144
2145 ret = btrfs_write_and_wait_marked_extents(log_root_tree,
2146 &log_root_tree->dirty_log_pages,
2147 EXTENT_DIRTY | EXTENT_NEW);
2148 if (ret) {
2149 btrfs_abort_transaction(trans, root, ret);
2150 mutex_unlock(&log_root_tree->log_mutex);
2151 goto out_wake_log_root;
2152 }
2153 btrfs_wait_marked_extents(log, &log->dirty_log_pages, mark);
2154
2155 btrfs_set_super_log_root(root->fs_info->super_for_commit,
2156 log_root_tree->node->start);
2157 btrfs_set_super_log_root_level(root->fs_info->super_for_commit,
2158 btrfs_header_level(log_root_tree->node));
2159
2160 log_root_tree->log_batch = 0;
2161 log_root_tree->log_transid++;
2162 smp_mb();
2163
2164 mutex_unlock(&log_root_tree->log_mutex);
2165
2166 /*
2167 * nobody else is going to jump in and write the the ctree
2168 * super here because the log_commit atomic below is protecting
2169 * us. We must be called with a transaction handle pinning
2170 * the running transaction open, so a full commit can't hop
2171 * in and cause problems either.
2172 */
2173 btrfs_scrub_pause_super(root);
2174 write_ctree_super(trans, root->fs_info->tree_root, 1);
2175 btrfs_scrub_continue_super(root);
2176 ret = 0;
2177
2178 mutex_lock(&root->log_mutex);
2179 if (root->last_log_commit < log_transid)
2180 root->last_log_commit = log_transid;
2181 mutex_unlock(&root->log_mutex);
2182
2183out_wake_log_root:
2184 atomic_set(&log_root_tree->log_commit[index2], 0);
2185 smp_mb();
2186 if (waitqueue_active(&log_root_tree->log_commit_wait[index2]))
2187 wake_up(&log_root_tree->log_commit_wait[index2]);
2188out:
2189 atomic_set(&root->log_commit[index1], 0);
2190 smp_mb();
2191 if (waitqueue_active(&root->log_commit_wait[index1]))
2192 wake_up(&root->log_commit_wait[index1]);
2193 return ret;
2194}
2195
2196static void free_log_tree(struct btrfs_trans_handle *trans,
2197 struct btrfs_root *log)
2198{
2199 int ret;
2200 u64 start;
2201 u64 end;
2202 struct walk_control wc = {
2203 .free = 1,
2204 .process_func = process_one_buffer
2205 };
2206
2207 ret = walk_log_tree(trans, log, &wc);
2208 BUG_ON(ret);
2209
2210 while (1) {
2211 ret = find_first_extent_bit(&log->dirty_log_pages,
2212 0, &start, &end, EXTENT_DIRTY | EXTENT_NEW);
2213 if (ret)
2214 break;
2215
2216 clear_extent_bits(&log->dirty_log_pages, start, end,
2217 EXTENT_DIRTY | EXTENT_NEW, GFP_NOFS);
2218 }
2219
2220 free_extent_buffer(log->node);
2221 kfree(log);
2222}
2223
2224/*
2225 * free all the extents used by the tree log. This should be called
2226 * at commit time of the full transaction
2227 */
2228int btrfs_free_log(struct btrfs_trans_handle *trans, struct btrfs_root *root)
2229{
2230 if (root->log_root) {
2231 free_log_tree(trans, root->log_root);
2232 root->log_root = NULL;
2233 }
2234 return 0;
2235}
2236
2237int btrfs_free_log_root_tree(struct btrfs_trans_handle *trans,
2238 struct btrfs_fs_info *fs_info)
2239{
2240 if (fs_info->log_root_tree) {
2241 free_log_tree(trans, fs_info->log_root_tree);
2242 fs_info->log_root_tree = NULL;
2243 }
2244 return 0;
2245}
2246
2247/*
2248 * If both a file and directory are logged, and unlinks or renames are
2249 * mixed in, we have a few interesting corners:
2250 *
2251 * create file X in dir Y
2252 * link file X to X.link in dir Y
2253 * fsync file X
2254 * unlink file X but leave X.link
2255 * fsync dir Y
2256 *
2257 * After a crash we would expect only X.link to exist. But file X
2258 * didn't get fsync'd again so the log has back refs for X and X.link.
2259 *
2260 * We solve this by removing directory entries and inode backrefs from the
2261 * log when a file that was logged in the current transaction is
2262 * unlinked. Any later fsync will include the updated log entries, and
2263 * we'll be able to reconstruct the proper directory items from backrefs.
2264 *
2265 * This optimizations allows us to avoid relogging the entire inode
2266 * or the entire directory.
2267 */
2268int btrfs_del_dir_entries_in_log(struct btrfs_trans_handle *trans,
2269 struct btrfs_root *root,
2270 const char *name, int name_len,
2271 struct inode *dir, u64 index)
2272{
2273 struct btrfs_root *log;
2274 struct btrfs_dir_item *di;
2275 struct btrfs_path *path;
2276 int ret;
2277 int err = 0;
2278 int bytes_del = 0;
2279 u64 dir_ino = btrfs_ino(dir);
2280
2281 if (BTRFS_I(dir)->logged_trans < trans->transid)
2282 return 0;
2283
2284 ret = join_running_log_trans(root);
2285 if (ret)
2286 return 0;
2287
2288 mutex_lock(&BTRFS_I(dir)->log_mutex);
2289
2290 log = root->log_root;
2291 path = btrfs_alloc_path();
2292 if (!path) {
2293 err = -ENOMEM;
2294 goto out_unlock;
2295 }
2296
2297 di = btrfs_lookup_dir_item(trans, log, path, dir_ino,
2298 name, name_len, -1);
2299 if (IS_ERR(di)) {
2300 err = PTR_ERR(di);
2301 goto fail;
2302 }
2303 if (di) {
2304 ret = btrfs_delete_one_dir_name(trans, log, path, di);
2305 bytes_del += name_len;
2306 BUG_ON(ret);
2307 }
2308 btrfs_release_path(path);
2309 di = btrfs_lookup_dir_index_item(trans, log, path, dir_ino,
2310 index, name, name_len, -1);
2311 if (IS_ERR(di)) {
2312 err = PTR_ERR(di);
2313 goto fail;
2314 }
2315 if (di) {
2316 ret = btrfs_delete_one_dir_name(trans, log, path, di);
2317 bytes_del += name_len;
2318 BUG_ON(ret);
2319 }
2320
2321 /* update the directory size in the log to reflect the names
2322 * we have removed
2323 */
2324 if (bytes_del) {
2325 struct btrfs_key key;
2326
2327 key.objectid = dir_ino;
2328 key.offset = 0;
2329 key.type = BTRFS_INODE_ITEM_KEY;
2330 btrfs_release_path(path);
2331
2332 ret = btrfs_search_slot(trans, log, &key, path, 0, 1);
2333 if (ret < 0) {
2334 err = ret;
2335 goto fail;
2336 }
2337 if (ret == 0) {
2338 struct btrfs_inode_item *item;
2339 u64 i_size;
2340
2341 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
2342 struct btrfs_inode_item);
2343 i_size = btrfs_inode_size(path->nodes[0], item);
2344 if (i_size > bytes_del)
2345 i_size -= bytes_del;
2346 else
2347 i_size = 0;
2348 btrfs_set_inode_size(path->nodes[0], item, i_size);
2349 btrfs_mark_buffer_dirty(path->nodes[0]);
2350 } else
2351 ret = 0;
2352 btrfs_release_path(path);
2353 }
2354fail:
2355 btrfs_free_path(path);
2356out_unlock:
2357 mutex_unlock(&BTRFS_I(dir)->log_mutex);
2358 if (ret == -ENOSPC) {
2359 root->fs_info->last_trans_log_full_commit = trans->transid;
2360 ret = 0;
2361 } else if (ret < 0)
2362 btrfs_abort_transaction(trans, root, ret);
2363
2364 btrfs_end_log_trans(root);
2365
2366 return err;
2367}
2368
2369/* see comments for btrfs_del_dir_entries_in_log */
2370int btrfs_del_inode_ref_in_log(struct btrfs_trans_handle *trans,
2371 struct btrfs_root *root,
2372 const char *name, int name_len,
2373 struct inode *inode, u64 dirid)
2374{
2375 struct btrfs_root *log;
2376 u64 index;
2377 int ret;
2378
2379 if (BTRFS_I(inode)->logged_trans < trans->transid)
2380 return 0;
2381
2382 ret = join_running_log_trans(root);
2383 if (ret)
2384 return 0;
2385 log = root->log_root;
2386 mutex_lock(&BTRFS_I(inode)->log_mutex);
2387
2388 ret = btrfs_del_inode_ref(trans, log, name, name_len, btrfs_ino(inode),
2389 dirid, &index);
2390 mutex_unlock(&BTRFS_I(inode)->log_mutex);
2391 if (ret == -ENOSPC) {
2392 root->fs_info->last_trans_log_full_commit = trans->transid;
2393 ret = 0;
2394 } else if (ret < 0 && ret != -ENOENT)
2395 btrfs_abort_transaction(trans, root, ret);
2396 btrfs_end_log_trans(root);
2397
2398 return ret;
2399}
2400
2401/*
2402 * creates a range item in the log for 'dirid'. first_offset and
2403 * last_offset tell us which parts of the key space the log should
2404 * be considered authoritative for.
2405 */
2406static noinline int insert_dir_log_key(struct btrfs_trans_handle *trans,
2407 struct btrfs_root *log,
2408 struct btrfs_path *path,
2409 int key_type, u64 dirid,
2410 u64 first_offset, u64 last_offset)
2411{
2412 int ret;
2413 struct btrfs_key key;
2414 struct btrfs_dir_log_item *item;
2415
2416 key.objectid = dirid;
2417 key.offset = first_offset;
2418 if (key_type == BTRFS_DIR_ITEM_KEY)
2419 key.type = BTRFS_DIR_LOG_ITEM_KEY;
2420 else
2421 key.type = BTRFS_DIR_LOG_INDEX_KEY;
2422 ret = btrfs_insert_empty_item(trans, log, path, &key, sizeof(*item));
2423 if (ret)
2424 return ret;
2425
2426 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
2427 struct btrfs_dir_log_item);
2428 btrfs_set_dir_log_end(path->nodes[0], item, last_offset);
2429 btrfs_mark_buffer_dirty(path->nodes[0]);
2430 btrfs_release_path(path);
2431 return 0;
2432}
2433
2434/*
2435 * log all the items included in the current transaction for a given
2436 * directory. This also creates the range items in the log tree required
2437 * to replay anything deleted before the fsync
2438 */
2439static noinline int log_dir_items(struct btrfs_trans_handle *trans,
2440 struct btrfs_root *root, struct inode *inode,
2441 struct btrfs_path *path,
2442 struct btrfs_path *dst_path, int key_type,
2443 u64 min_offset, u64 *last_offset_ret)
2444{
2445 struct btrfs_key min_key;
2446 struct btrfs_key max_key;
2447 struct btrfs_root *log = root->log_root;
2448 struct extent_buffer *src;
2449 int err = 0;
2450 int ret;
2451 int i;
2452 int nritems;
2453 u64 first_offset = min_offset;
2454 u64 last_offset = (u64)-1;
2455 u64 ino = btrfs_ino(inode);
2456
2457 log = root->log_root;
2458 max_key.objectid = ino;
2459 max_key.offset = (u64)-1;
2460 max_key.type = key_type;
2461
2462 min_key.objectid = ino;
2463 min_key.type = key_type;
2464 min_key.offset = min_offset;
2465
2466 path->keep_locks = 1;
2467
2468 ret = btrfs_search_forward(root, &min_key, &max_key,
2469 path, 0, trans->transid);
2470
2471 /*
2472 * we didn't find anything from this transaction, see if there
2473 * is anything at all
2474 */
2475 if (ret != 0 || min_key.objectid != ino || min_key.type != key_type) {
2476 min_key.objectid = ino;
2477 min_key.type = key_type;
2478 min_key.offset = (u64)-1;
2479 btrfs_release_path(path);
2480 ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0);
2481 if (ret < 0) {
2482 btrfs_release_path(path);
2483 return ret;
2484 }
2485 ret = btrfs_previous_item(root, path, ino, key_type);
2486
2487 /* if ret == 0 there are items for this type,
2488 * create a range to tell us the last key of this type.
2489 * otherwise, there are no items in this directory after
2490 * *min_offset, and we create a range to indicate that.
2491 */
2492 if (ret == 0) {
2493 struct btrfs_key tmp;
2494 btrfs_item_key_to_cpu(path->nodes[0], &tmp,
2495 path->slots[0]);
2496 if (key_type == tmp.type)
2497 first_offset = max(min_offset, tmp.offset) + 1;
2498 }
2499 goto done;
2500 }
2501
2502 /* go backward to find any previous key */
2503 ret = btrfs_previous_item(root, path, ino, key_type);
2504 if (ret == 0) {
2505 struct btrfs_key tmp;
2506 btrfs_item_key_to_cpu(path->nodes[0], &tmp, path->slots[0]);
2507 if (key_type == tmp.type) {
2508 first_offset = tmp.offset;
2509 ret = overwrite_item(trans, log, dst_path,
2510 path->nodes[0], path->slots[0],
2511 &tmp);
2512 if (ret) {
2513 err = ret;
2514 goto done;
2515 }
2516 }
2517 }
2518 btrfs_release_path(path);
2519
2520 /* find the first key from this transaction again */
2521 ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0);
2522 if (ret != 0) {
2523 WARN_ON(1);
2524 goto done;
2525 }
2526
2527 /*
2528 * we have a block from this transaction, log every item in it
2529 * from our directory
2530 */
2531 while (1) {
2532 struct btrfs_key tmp;
2533 src = path->nodes[0];
2534 nritems = btrfs_header_nritems(src);
2535 for (i = path->slots[0]; i < nritems; i++) {
2536 btrfs_item_key_to_cpu(src, &min_key, i);
2537
2538 if (min_key.objectid != ino || min_key.type != key_type)
2539 goto done;
2540 ret = overwrite_item(trans, log, dst_path, src, i,
2541 &min_key);
2542 if (ret) {
2543 err = ret;
2544 goto done;
2545 }
2546 }
2547 path->slots[0] = nritems;
2548
2549 /*
2550 * look ahead to the next item and see if it is also
2551 * from this directory and from this transaction
2552 */
2553 ret = btrfs_next_leaf(root, path);
2554 if (ret == 1) {
2555 last_offset = (u64)-1;
2556 goto done;
2557 }
2558 btrfs_item_key_to_cpu(path->nodes[0], &tmp, path->slots[0]);
2559 if (tmp.objectid != ino || tmp.type != key_type) {
2560 last_offset = (u64)-1;
2561 goto done;
2562 }
2563 if (btrfs_header_generation(path->nodes[0]) != trans->transid) {
2564 ret = overwrite_item(trans, log, dst_path,
2565 path->nodes[0], path->slots[0],
2566 &tmp);
2567 if (ret)
2568 err = ret;
2569 else
2570 last_offset = tmp.offset;
2571 goto done;
2572 }
2573 }
2574done:
2575 btrfs_release_path(path);
2576 btrfs_release_path(dst_path);
2577
2578 if (err == 0) {
2579 *last_offset_ret = last_offset;
2580 /*
2581 * insert the log range keys to indicate where the log
2582 * is valid
2583 */
2584 ret = insert_dir_log_key(trans, log, path, key_type,
2585 ino, first_offset, last_offset);
2586 if (ret)
2587 err = ret;
2588 }
2589 return err;
2590}
2591
2592/*
2593 * logging directories is very similar to logging inodes, We find all the items
2594 * from the current transaction and write them to the log.
2595 *
2596 * The recovery code scans the directory in the subvolume, and if it finds a
2597 * key in the range logged that is not present in the log tree, then it means
2598 * that dir entry was unlinked during the transaction.
2599 *
2600 * In order for that scan to work, we must include one key smaller than
2601 * the smallest logged by this transaction and one key larger than the largest
2602 * key logged by this transaction.
2603 */
2604static noinline int log_directory_changes(struct btrfs_trans_handle *trans,
2605 struct btrfs_root *root, struct inode *inode,
2606 struct btrfs_path *path,
2607 struct btrfs_path *dst_path)
2608{
2609 u64 min_key;
2610 u64 max_key;
2611 int ret;
2612 int key_type = BTRFS_DIR_ITEM_KEY;
2613
2614again:
2615 min_key = 0;
2616 max_key = 0;
2617 while (1) {
2618 ret = log_dir_items(trans, root, inode, path,
2619 dst_path, key_type, min_key,
2620 &max_key);
2621 if (ret)
2622 return ret;
2623 if (max_key == (u64)-1)
2624 break;
2625 min_key = max_key + 1;
2626 }
2627
2628 if (key_type == BTRFS_DIR_ITEM_KEY) {
2629 key_type = BTRFS_DIR_INDEX_KEY;
2630 goto again;
2631 }
2632 return 0;
2633}
2634
2635/*
2636 * a helper function to drop items from the log before we relog an
2637 * inode. max_key_type indicates the highest item type to remove.
2638 * This cannot be run for file data extents because it does not
2639 * free the extents they point to.
2640 */
2641static int drop_objectid_items(struct btrfs_trans_handle *trans,
2642 struct btrfs_root *log,
2643 struct btrfs_path *path,
2644 u64 objectid, int max_key_type)
2645{
2646 int ret;
2647 struct btrfs_key key;
2648 struct btrfs_key found_key;
2649
2650 key.objectid = objectid;
2651 key.type = max_key_type;
2652 key.offset = (u64)-1;
2653
2654 while (1) {
2655 ret = btrfs_search_slot(trans, log, &key, path, -1, 1);
2656 BUG_ON(ret == 0);
2657 if (ret < 0)
2658 break;
2659
2660 if (path->slots[0] == 0)
2661 break;
2662
2663 path->slots[0]--;
2664 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
2665 path->slots[0]);
2666
2667 if (found_key.objectid != objectid)
2668 break;
2669
2670 ret = btrfs_del_item(trans, log, path);
2671 if (ret)
2672 break;
2673 btrfs_release_path(path);
2674 }
2675 btrfs_release_path(path);
2676 if (ret > 0)
2677 ret = 0;
2678 return ret;
2679}
2680
2681static noinline int copy_items(struct btrfs_trans_handle *trans,
2682 struct btrfs_root *log,
2683 struct btrfs_path *dst_path,
2684 struct extent_buffer *src,
2685 int start_slot, int nr, int inode_only)
2686{
2687 unsigned long src_offset;
2688 unsigned long dst_offset;
2689 struct btrfs_file_extent_item *extent;
2690 struct btrfs_inode_item *inode_item;
2691 int ret;
2692 struct btrfs_key *ins_keys;
2693 u32 *ins_sizes;
2694 char *ins_data;
2695 int i;
2696 struct list_head ordered_sums;
2697
2698 INIT_LIST_HEAD(&ordered_sums);
2699
2700 ins_data = kmalloc(nr * sizeof(struct btrfs_key) +
2701 nr * sizeof(u32), GFP_NOFS);
2702 if (!ins_data)
2703 return -ENOMEM;
2704
2705 ins_sizes = (u32 *)ins_data;
2706 ins_keys = (struct btrfs_key *)(ins_data + nr * sizeof(u32));
2707
2708 for (i = 0; i < nr; i++) {
2709 ins_sizes[i] = btrfs_item_size_nr(src, i + start_slot);
2710 btrfs_item_key_to_cpu(src, ins_keys + i, i + start_slot);
2711 }
2712 ret = btrfs_insert_empty_items(trans, log, dst_path,
2713 ins_keys, ins_sizes, nr);
2714 if (ret) {
2715 kfree(ins_data);
2716 return ret;
2717 }
2718
2719 for (i = 0; i < nr; i++, dst_path->slots[0]++) {
2720 dst_offset = btrfs_item_ptr_offset(dst_path->nodes[0],
2721 dst_path->slots[0]);
2722
2723 src_offset = btrfs_item_ptr_offset(src, start_slot + i);
2724
2725 copy_extent_buffer(dst_path->nodes[0], src, dst_offset,
2726 src_offset, ins_sizes[i]);
2727
2728 if (inode_only == LOG_INODE_EXISTS &&
2729 ins_keys[i].type == BTRFS_INODE_ITEM_KEY) {
2730 inode_item = btrfs_item_ptr(dst_path->nodes[0],
2731 dst_path->slots[0],
2732 struct btrfs_inode_item);
2733 btrfs_set_inode_size(dst_path->nodes[0], inode_item, 0);
2734
2735 /* set the generation to zero so the recover code
2736 * can tell the difference between an logging
2737 * just to say 'this inode exists' and a logging
2738 * to say 'update this inode with these values'
2739 */
2740 btrfs_set_inode_generation(dst_path->nodes[0],
2741 inode_item, 0);
2742 }
2743 /* take a reference on file data extents so that truncates
2744 * or deletes of this inode don't have to relog the inode
2745 * again
2746 */
2747 if (btrfs_key_type(ins_keys + i) == BTRFS_EXTENT_DATA_KEY) {
2748 int found_type;
2749 extent = btrfs_item_ptr(src, start_slot + i,
2750 struct btrfs_file_extent_item);
2751
2752 if (btrfs_file_extent_generation(src, extent) < trans->transid)
2753 continue;
2754
2755 found_type = btrfs_file_extent_type(src, extent);
2756 if (found_type == BTRFS_FILE_EXTENT_REG ||
2757 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
2758 u64 ds, dl, cs, cl;
2759 ds = btrfs_file_extent_disk_bytenr(src,
2760 extent);
2761 /* ds == 0 is a hole */
2762 if (ds == 0)
2763 continue;
2764
2765 dl = btrfs_file_extent_disk_num_bytes(src,
2766 extent);
2767 cs = btrfs_file_extent_offset(src, extent);
2768 cl = btrfs_file_extent_num_bytes(src,
2769 extent);
2770 if (btrfs_file_extent_compression(src,
2771 extent)) {
2772 cs = 0;
2773 cl = dl;
2774 }
2775
2776 ret = btrfs_lookup_csums_range(
2777 log->fs_info->csum_root,
2778 ds + cs, ds + cs + cl - 1,
2779 &ordered_sums, 0);
2780 BUG_ON(ret);
2781 }
2782 }
2783 }
2784
2785 btrfs_mark_buffer_dirty(dst_path->nodes[0]);
2786 btrfs_release_path(dst_path);
2787 kfree(ins_data);
2788
2789 /*
2790 * we have to do this after the loop above to avoid changing the
2791 * log tree while trying to change the log tree.
2792 */
2793 ret = 0;
2794 while (!list_empty(&ordered_sums)) {
2795 struct btrfs_ordered_sum *sums = list_entry(ordered_sums.next,
2796 struct btrfs_ordered_sum,
2797 list);
2798 if (!ret)
2799 ret = btrfs_csum_file_blocks(trans, log, sums);
2800 list_del(&sums->list);
2801 kfree(sums);
2802 }
2803 return ret;
2804}
2805
2806/* log a single inode in the tree log.
2807 * At least one parent directory for this inode must exist in the tree
2808 * or be logged already.
2809 *
2810 * Any items from this inode changed by the current transaction are copied
2811 * to the log tree. An extra reference is taken on any extents in this
2812 * file, allowing us to avoid a whole pile of corner cases around logging
2813 * blocks that have been removed from the tree.
2814 *
2815 * See LOG_INODE_ALL and related defines for a description of what inode_only
2816 * does.
2817 *
2818 * This handles both files and directories.
2819 */
2820static int btrfs_log_inode(struct btrfs_trans_handle *trans,
2821 struct btrfs_root *root, struct inode *inode,
2822 int inode_only)
2823{
2824 struct btrfs_path *path;
2825 struct btrfs_path *dst_path;
2826 struct btrfs_key min_key;
2827 struct btrfs_key max_key;
2828 struct btrfs_root *log = root->log_root;
2829 struct extent_buffer *src = NULL;
2830 int err = 0;
2831 int ret;
2832 int nritems;
2833 int ins_start_slot = 0;
2834 int ins_nr;
2835 u64 ino = btrfs_ino(inode);
2836
2837 log = root->log_root;
2838
2839 path = btrfs_alloc_path();
2840 if (!path)
2841 return -ENOMEM;
2842 dst_path = btrfs_alloc_path();
2843 if (!dst_path) {
2844 btrfs_free_path(path);
2845 return -ENOMEM;
2846 }
2847
2848 min_key.objectid = ino;
2849 min_key.type = BTRFS_INODE_ITEM_KEY;
2850 min_key.offset = 0;
2851
2852 max_key.objectid = ino;
2853
2854 /* today the code can only do partial logging of directories */
2855 if (!S_ISDIR(inode->i_mode))
2856 inode_only = LOG_INODE_ALL;
2857
2858 if (inode_only == LOG_INODE_EXISTS || S_ISDIR(inode->i_mode))
2859 max_key.type = BTRFS_XATTR_ITEM_KEY;
2860 else
2861 max_key.type = (u8)-1;
2862 max_key.offset = (u64)-1;
2863
2864 ret = btrfs_commit_inode_delayed_items(trans, inode);
2865 if (ret) {
2866 btrfs_free_path(path);
2867 btrfs_free_path(dst_path);
2868 return ret;
2869 }
2870
2871 mutex_lock(&BTRFS_I(inode)->log_mutex);
2872
2873 /*
2874 * a brute force approach to making sure we get the most uptodate
2875 * copies of everything.
2876 */
2877 if (S_ISDIR(inode->i_mode)) {
2878 int max_key_type = BTRFS_DIR_LOG_INDEX_KEY;
2879
2880 if (inode_only == LOG_INODE_EXISTS)
2881 max_key_type = BTRFS_XATTR_ITEM_KEY;
2882 ret = drop_objectid_items(trans, log, path, ino, max_key_type);
2883 } else {
2884 ret = btrfs_truncate_inode_items(trans, log, inode, 0, 0);
2885 }
2886 if (ret) {
2887 err = ret;
2888 goto out_unlock;
2889 }
2890 path->keep_locks = 1;
2891
2892 while (1) {
2893 ins_nr = 0;
2894 ret = btrfs_search_forward(root, &min_key, &max_key,
2895 path, 0, trans->transid);
2896 if (ret != 0)
2897 break;
2898again:
2899 /* note, ins_nr might be > 0 here, cleanup outside the loop */
2900 if (min_key.objectid != ino)
2901 break;
2902 if (min_key.type > max_key.type)
2903 break;
2904
2905 src = path->nodes[0];
2906 if (ins_nr && ins_start_slot + ins_nr == path->slots[0]) {
2907 ins_nr++;
2908 goto next_slot;
2909 } else if (!ins_nr) {
2910 ins_start_slot = path->slots[0];
2911 ins_nr = 1;
2912 goto next_slot;
2913 }
2914
2915 ret = copy_items(trans, log, dst_path, src, ins_start_slot,
2916 ins_nr, inode_only);
2917 if (ret) {
2918 err = ret;
2919 goto out_unlock;
2920 }
2921 ins_nr = 1;
2922 ins_start_slot = path->slots[0];
2923next_slot:
2924
2925 nritems = btrfs_header_nritems(path->nodes[0]);
2926 path->slots[0]++;
2927 if (path->slots[0] < nritems) {
2928 btrfs_item_key_to_cpu(path->nodes[0], &min_key,
2929 path->slots[0]);
2930 goto again;
2931 }
2932 if (ins_nr) {
2933 ret = copy_items(trans, log, dst_path, src,
2934 ins_start_slot,
2935 ins_nr, inode_only);
2936 if (ret) {
2937 err = ret;
2938 goto out_unlock;
2939 }
2940 ins_nr = 0;
2941 }
2942 btrfs_release_path(path);
2943
2944 if (min_key.offset < (u64)-1)
2945 min_key.offset++;
2946 else if (min_key.type < (u8)-1)
2947 min_key.type++;
2948 else if (min_key.objectid < (u64)-1)
2949 min_key.objectid++;
2950 else
2951 break;
2952 }
2953 if (ins_nr) {
2954 ret = copy_items(trans, log, dst_path, src,
2955 ins_start_slot,
2956 ins_nr, inode_only);
2957 if (ret) {
2958 err = ret;
2959 goto out_unlock;
2960 }
2961 ins_nr = 0;
2962 }
2963 WARN_ON(ins_nr);
2964 if (inode_only == LOG_INODE_ALL && S_ISDIR(inode->i_mode)) {
2965 btrfs_release_path(path);
2966 btrfs_release_path(dst_path);
2967 ret = log_directory_changes(trans, root, inode, path, dst_path);
2968 if (ret) {
2969 err = ret;
2970 goto out_unlock;
2971 }
2972 }
2973 BTRFS_I(inode)->logged_trans = trans->transid;
2974out_unlock:
2975 mutex_unlock(&BTRFS_I(inode)->log_mutex);
2976
2977 btrfs_free_path(path);
2978 btrfs_free_path(dst_path);
2979 return err;
2980}
2981
2982/*
2983 * follow the dentry parent pointers up the chain and see if any
2984 * of the directories in it require a full commit before they can
2985 * be logged. Returns zero if nothing special needs to be done or 1 if
2986 * a full commit is required.
2987 */
2988static noinline int check_parent_dirs_for_sync(struct btrfs_trans_handle *trans,
2989 struct inode *inode,
2990 struct dentry *parent,
2991 struct super_block *sb,
2992 u64 last_committed)
2993{
2994 int ret = 0;
2995 struct btrfs_root *root;
2996 struct dentry *old_parent = NULL;
2997
2998 /*
2999 * for regular files, if its inode is already on disk, we don't
3000 * have to worry about the parents at all. This is because
3001 * we can use the last_unlink_trans field to record renames
3002 * and other fun in this file.
3003 */
3004 if (S_ISREG(inode->i_mode) &&
3005 BTRFS_I(inode)->generation <= last_committed &&
3006 BTRFS_I(inode)->last_unlink_trans <= last_committed)
3007 goto out;
3008
3009 if (!S_ISDIR(inode->i_mode)) {
3010 if (!parent || !parent->d_inode || sb != parent->d_inode->i_sb)
3011 goto out;
3012 inode = parent->d_inode;
3013 }
3014
3015 while (1) {
3016 BTRFS_I(inode)->logged_trans = trans->transid;
3017 smp_mb();
3018
3019 if (BTRFS_I(inode)->last_unlink_trans > last_committed) {
3020 root = BTRFS_I(inode)->root;
3021
3022 /*
3023 * make sure any commits to the log are forced
3024 * to be full commits
3025 */
3026 root->fs_info->last_trans_log_full_commit =
3027 trans->transid;
3028 ret = 1;
3029 break;
3030 }
3031
3032 if (!parent || !parent->d_inode || sb != parent->d_inode->i_sb)
3033 break;
3034
3035 if (IS_ROOT(parent))
3036 break;
3037
3038 parent = dget_parent(parent);
3039 dput(old_parent);
3040 old_parent = parent;
3041 inode = parent->d_inode;
3042
3043 }
3044 dput(old_parent);
3045out:
3046 return ret;
3047}
3048
3049/*
3050 * helper function around btrfs_log_inode to make sure newly created
3051 * parent directories also end up in the log. A minimal inode and backref
3052 * only logging is done of any parent directories that are older than
3053 * the last committed transaction
3054 */
3055int btrfs_log_inode_parent(struct btrfs_trans_handle *trans,
3056 struct btrfs_root *root, struct inode *inode,
3057 struct dentry *parent, int exists_only)
3058{
3059 int inode_only = exists_only ? LOG_INODE_EXISTS : LOG_INODE_ALL;
3060 struct super_block *sb;
3061 struct dentry *old_parent = NULL;
3062 int ret = 0;
3063 u64 last_committed = root->fs_info->last_trans_committed;
3064
3065 sb = inode->i_sb;
3066
3067 if (btrfs_test_opt(root, NOTREELOG)) {
3068 ret = 1;
3069 goto end_no_trans;
3070 }
3071
3072 if (root->fs_info->last_trans_log_full_commit >
3073 root->fs_info->last_trans_committed) {
3074 ret = 1;
3075 goto end_no_trans;
3076 }
3077
3078 if (root != BTRFS_I(inode)->root ||
3079 btrfs_root_refs(&root->root_item) == 0) {
3080 ret = 1;
3081 goto end_no_trans;
3082 }
3083
3084 ret = check_parent_dirs_for_sync(trans, inode, parent,
3085 sb, last_committed);
3086 if (ret)
3087 goto end_no_trans;
3088
3089 if (btrfs_inode_in_log(inode, trans->transid)) {
3090 ret = BTRFS_NO_LOG_SYNC;
3091 goto end_no_trans;
3092 }
3093
3094 ret = start_log_trans(trans, root);
3095 if (ret)
3096 goto end_trans;
3097
3098 ret = btrfs_log_inode(trans, root, inode, inode_only);
3099 if (ret)
3100 goto end_trans;
3101
3102 /*
3103 * for regular files, if its inode is already on disk, we don't
3104 * have to worry about the parents at all. This is because
3105 * we can use the last_unlink_trans field to record renames
3106 * and other fun in this file.
3107 */
3108 if (S_ISREG(inode->i_mode) &&
3109 BTRFS_I(inode)->generation <= last_committed &&
3110 BTRFS_I(inode)->last_unlink_trans <= last_committed) {
3111 ret = 0;
3112 goto end_trans;
3113 }
3114
3115 inode_only = LOG_INODE_EXISTS;
3116 while (1) {
3117 if (!parent || !parent->d_inode || sb != parent->d_inode->i_sb)
3118 break;
3119
3120 inode = parent->d_inode;
3121 if (root != BTRFS_I(inode)->root)
3122 break;
3123
3124 if (BTRFS_I(inode)->generation >
3125 root->fs_info->last_trans_committed) {
3126 ret = btrfs_log_inode(trans, root, inode, inode_only);
3127 if (ret)
3128 goto end_trans;
3129 }
3130 if (IS_ROOT(parent))
3131 break;
3132
3133 parent = dget_parent(parent);
3134 dput(old_parent);
3135 old_parent = parent;
3136 }
3137 ret = 0;
3138end_trans:
3139 dput(old_parent);
3140 if (ret < 0) {
3141 BUG_ON(ret != -ENOSPC);
3142 root->fs_info->last_trans_log_full_commit = trans->transid;
3143 ret = 1;
3144 }
3145 btrfs_end_log_trans(root);
3146end_no_trans:
3147 return ret;
3148}
3149
3150/*
3151 * it is not safe to log dentry if the chunk root has added new
3152 * chunks. This returns 0 if the dentry was logged, and 1 otherwise.
3153 * If this returns 1, you must commit the transaction to safely get your
3154 * data on disk.
3155 */
3156int btrfs_log_dentry_safe(struct btrfs_trans_handle *trans,
3157 struct btrfs_root *root, struct dentry *dentry)
3158{
3159 struct dentry *parent = dget_parent(dentry);
3160 int ret;
3161
3162 ret = btrfs_log_inode_parent(trans, root, dentry->d_inode, parent, 0);
3163 dput(parent);
3164
3165 return ret;
3166}
3167
3168/*
3169 * should be called during mount to recover any replay any log trees
3170 * from the FS
3171 */
3172int btrfs_recover_log_trees(struct btrfs_root *log_root_tree)
3173{
3174 int ret;
3175 struct btrfs_path *path;
3176 struct btrfs_trans_handle *trans;
3177 struct btrfs_key key;
3178 struct btrfs_key found_key;
3179 struct btrfs_key tmp_key;
3180 struct btrfs_root *log;
3181 struct btrfs_fs_info *fs_info = log_root_tree->fs_info;
3182 struct walk_control wc = {
3183 .process_func = process_one_buffer,
3184 .stage = 0,
3185 };
3186
3187 path = btrfs_alloc_path();
3188 if (!path)
3189 return -ENOMEM;
3190
3191 fs_info->log_root_recovering = 1;
3192
3193 trans = btrfs_start_transaction(fs_info->tree_root, 0);
3194 if (IS_ERR(trans)) {
3195 ret = PTR_ERR(trans);
3196 goto error;
3197 }
3198
3199 wc.trans = trans;
3200 wc.pin = 1;
3201
3202 ret = walk_log_tree(trans, log_root_tree, &wc);
3203 if (ret) {
3204 btrfs_error(fs_info, ret, "Failed to pin buffers while "
3205 "recovering log root tree.");
3206 goto error;
3207 }
3208
3209again:
3210 key.objectid = BTRFS_TREE_LOG_OBJECTID;
3211 key.offset = (u64)-1;
3212 btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
3213
3214 while (1) {
3215 ret = btrfs_search_slot(NULL, log_root_tree, &key, path, 0, 0);
3216
3217 if (ret < 0) {
3218 btrfs_error(fs_info, ret,
3219 "Couldn't find tree log root.");
3220 goto error;
3221 }
3222 if (ret > 0) {
3223 if (path->slots[0] == 0)
3224 break;
3225 path->slots[0]--;
3226 }
3227 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
3228 path->slots[0]);
3229 btrfs_release_path(path);
3230 if (found_key.objectid != BTRFS_TREE_LOG_OBJECTID)
3231 break;
3232
3233 log = btrfs_read_fs_root_no_radix(log_root_tree,
3234 &found_key);
3235 if (IS_ERR(log)) {
3236 ret = PTR_ERR(log);
3237 btrfs_error(fs_info, ret,
3238 "Couldn't read tree log root.");
3239 goto error;
3240 }
3241
3242 tmp_key.objectid = found_key.offset;
3243 tmp_key.type = BTRFS_ROOT_ITEM_KEY;
3244 tmp_key.offset = (u64)-1;
3245
3246 wc.replay_dest = btrfs_read_fs_root_no_name(fs_info, &tmp_key);
3247 if (IS_ERR(wc.replay_dest)) {
3248 ret = PTR_ERR(wc.replay_dest);
3249 btrfs_error(fs_info, ret, "Couldn't read target root "
3250 "for tree log recovery.");
3251 goto error;
3252 }
3253
3254 wc.replay_dest->log_root = log;
3255 btrfs_record_root_in_trans(trans, wc.replay_dest);
3256 ret = walk_log_tree(trans, log, &wc);
3257 BUG_ON(ret);
3258
3259 if (wc.stage == LOG_WALK_REPLAY_ALL) {
3260 ret = fixup_inode_link_counts(trans, wc.replay_dest,
3261 path);
3262 BUG_ON(ret);
3263 }
3264
3265 key.offset = found_key.offset - 1;
3266 wc.replay_dest->log_root = NULL;
3267 free_extent_buffer(log->node);
3268 free_extent_buffer(log->commit_root);
3269 kfree(log);
3270
3271 if (found_key.offset == 0)
3272 break;
3273 }
3274 btrfs_release_path(path);
3275
3276 /* step one is to pin it all, step two is to replay just inodes */
3277 if (wc.pin) {
3278 wc.pin = 0;
3279 wc.process_func = replay_one_buffer;
3280 wc.stage = LOG_WALK_REPLAY_INODES;
3281 goto again;
3282 }
3283 /* step three is to replay everything */
3284 if (wc.stage < LOG_WALK_REPLAY_ALL) {
3285 wc.stage++;
3286 goto again;
3287 }
3288
3289 btrfs_free_path(path);
3290
3291 free_extent_buffer(log_root_tree->node);
3292 log_root_tree->log_root = NULL;
3293 fs_info->log_root_recovering = 0;
3294
3295 /* step 4: commit the transaction, which also unpins the blocks */
3296 btrfs_commit_transaction(trans, fs_info->tree_root);
3297
3298 kfree(log_root_tree);
3299 return 0;
3300
3301error:
3302 btrfs_free_path(path);
3303 return ret;
3304}
3305
3306/*
3307 * there are some corner cases where we want to force a full
3308 * commit instead of allowing a directory to be logged.
3309 *
3310 * They revolve around files there were unlinked from the directory, and
3311 * this function updates the parent directory so that a full commit is
3312 * properly done if it is fsync'd later after the unlinks are done.
3313 */
3314void btrfs_record_unlink_dir(struct btrfs_trans_handle *trans,
3315 struct inode *dir, struct inode *inode,
3316 int for_rename)
3317{
3318 /*
3319 * when we're logging a file, if it hasn't been renamed
3320 * or unlinked, and its inode is fully committed on disk,
3321 * we don't have to worry about walking up the directory chain
3322 * to log its parents.
3323 *
3324 * So, we use the last_unlink_trans field to put this transid
3325 * into the file. When the file is logged we check it and
3326 * don't log the parents if the file is fully on disk.
3327 */
3328 if (S_ISREG(inode->i_mode))
3329 BTRFS_I(inode)->last_unlink_trans = trans->transid;
3330
3331 /*
3332 * if this directory was already logged any new
3333 * names for this file/dir will get recorded
3334 */
3335 smp_mb();
3336 if (BTRFS_I(dir)->logged_trans == trans->transid)
3337 return;
3338
3339 /*
3340 * if the inode we're about to unlink was logged,
3341 * the log will be properly updated for any new names
3342 */
3343 if (BTRFS_I(inode)->logged_trans == trans->transid)
3344 return;
3345
3346 /*
3347 * when renaming files across directories, if the directory
3348 * there we're unlinking from gets fsync'd later on, there's
3349 * no way to find the destination directory later and fsync it
3350 * properly. So, we have to be conservative and force commits
3351 * so the new name gets discovered.
3352 */
3353 if (for_rename)
3354 goto record;
3355
3356 /* we can safely do the unlink without any special recording */
3357 return;
3358
3359record:
3360 BTRFS_I(dir)->last_unlink_trans = trans->transid;
3361}
3362
3363/*
3364 * Call this after adding a new name for a file and it will properly
3365 * update the log to reflect the new name.
3366 *
3367 * It will return zero if all goes well, and it will return 1 if a
3368 * full transaction commit is required.
3369 */
3370int btrfs_log_new_name(struct btrfs_trans_handle *trans,
3371 struct inode *inode, struct inode *old_dir,
3372 struct dentry *parent)
3373{
3374 struct btrfs_root * root = BTRFS_I(inode)->root;
3375
3376 /*
3377 * this will force the logging code to walk the dentry chain
3378 * up for the file
3379 */
3380 if (S_ISREG(inode->i_mode))
3381 BTRFS_I(inode)->last_unlink_trans = trans->transid;
3382
3383 /*
3384 * if this inode hasn't been logged and directory we're renaming it
3385 * from hasn't been logged, we don't need to log it
3386 */
3387 if (BTRFS_I(inode)->logged_trans <=
3388 root->fs_info->last_trans_committed &&
3389 (!old_dir || BTRFS_I(old_dir)->logged_trans <=
3390 root->fs_info->last_trans_committed))
3391 return 0;
3392
3393 return btrfs_log_inode_parent(trans, root, inode, parent, 1);
3394}
3395