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authorChris Mason <chris.mason@oracle.com>2008-10-16 10:12:58 -0400
committerChris Mason <chris.mason@oracle.com>2008-10-16 10:12:58 -0400
commit26ce34a9c47334ff7984769e4661b2f1883594ff (patch)
treefbc1da082a0b9f4adc7a2560811bbd6e6c47e420 /fs/btrfs/tree-log.c
parent3fa8749e584b55f1180411ab1b51117190bac1e5 (diff)
parent37d3cdddf5378606f6eab99982ca16819745d8f4 (diff)
Merge branch 'master' of ssh://mason@master.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable
Diffstat (limited to 'fs/btrfs/tree-log.c')
-rw-r--r--fs/btrfs/tree-log.c2890
1 files changed, 2890 insertions, 0 deletions
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
new file mode 100644
index 000000000000..cf618cc8b34a
--- /dev/null
+++ b/fs/btrfs/tree-log.c
@@ -0,0 +1,2890 @@
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 "ctree.h"
21#include "transaction.h"
22#include "disk-io.h"
23#include "locking.h"
24#include "print-tree.h"
25#include "compat.h"
26
27/* magic values for the inode_only field in btrfs_log_inode:
28 *
29 * LOG_INODE_ALL means to log everything
30 * LOG_INODE_EXISTS means to log just enough to recreate the inode
31 * during log replay
32 */
33#define LOG_INODE_ALL 0
34#define LOG_INODE_EXISTS 1
35
36/*
37 * stages for the tree walking. The first
38 * stage (0) is to only pin down the blocks we find
39 * the second stage (1) is to make sure that all the inodes
40 * we find in the log are created in the subvolume.
41 *
42 * The last stage is to deal with directories and links and extents
43 * and all the other fun semantics
44 */
45#define LOG_WALK_PIN_ONLY 0
46#define LOG_WALK_REPLAY_INODES 1
47#define LOG_WALK_REPLAY_ALL 2
48
49static int __btrfs_log_inode(struct btrfs_trans_handle *trans,
50 struct btrfs_root *root, struct inode *inode,
51 int inode_only);
52
53/*
54 * tree logging is a special write ahead log used to make sure that
55 * fsyncs and O_SYNCs can happen without doing full tree commits.
56 *
57 * Full tree commits are expensive because they require commonly
58 * modified blocks to be recowed, creating many dirty pages in the
59 * extent tree an 4x-6x higher write load than ext3.
60 *
61 * Instead of doing a tree commit on every fsync, we use the
62 * key ranges and transaction ids to find items for a given file or directory
63 * that have changed in this transaction. Those items are copied into
64 * a special tree (one per subvolume root), that tree is written to disk
65 * and then the fsync is considered complete.
66 *
67 * After a crash, items are copied out of the log-tree back into the
68 * subvolume tree. Any file data extents found are recorded in the extent
69 * allocation tree, and the log-tree freed.
70 *
71 * The log tree is read three times, once to pin down all the extents it is
72 * using in ram and once, once to create all the inodes logged in the tree
73 * and once to do all the other items.
74 */
75
76/*
77 * btrfs_add_log_tree adds a new per-subvolume log tree into the
78 * tree of log tree roots. This must be called with a tree log transaction
79 * running (see start_log_trans).
80 */
81int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
82 struct btrfs_root *root)
83{
84 struct btrfs_key key;
85 struct btrfs_root_item root_item;
86 struct btrfs_inode_item *inode_item;
87 struct extent_buffer *leaf;
88 struct btrfs_root *new_root = root;
89 int ret;
90 u64 objectid = root->root_key.objectid;
91
92 leaf = btrfs_alloc_free_block(trans, root, root->leafsize, 0,
93 BTRFS_TREE_LOG_OBJECTID,
94 trans->transid, 0, 0, 0);
95 if (IS_ERR(leaf)) {
96 ret = PTR_ERR(leaf);
97 return ret;
98 }
99
100 btrfs_set_header_nritems(leaf, 0);
101 btrfs_set_header_level(leaf, 0);
102 btrfs_set_header_bytenr(leaf, leaf->start);
103 btrfs_set_header_generation(leaf, trans->transid);
104 btrfs_set_header_owner(leaf, BTRFS_TREE_LOG_OBJECTID);
105
106 write_extent_buffer(leaf, root->fs_info->fsid,
107 (unsigned long)btrfs_header_fsid(leaf),
108 BTRFS_FSID_SIZE);
109 btrfs_mark_buffer_dirty(leaf);
110
111 inode_item = &root_item.inode;
112 memset(inode_item, 0, sizeof(*inode_item));
113 inode_item->generation = cpu_to_le64(1);
114 inode_item->size = cpu_to_le64(3);
115 inode_item->nlink = cpu_to_le32(1);
116 inode_item->nbytes = cpu_to_le64(root->leafsize);
117 inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
118
119 btrfs_set_root_bytenr(&root_item, leaf->start);
120 btrfs_set_root_level(&root_item, 0);
121 btrfs_set_root_refs(&root_item, 0);
122 btrfs_set_root_used(&root_item, 0);
123
124 memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress));
125 root_item.drop_level = 0;
126
127 btrfs_tree_unlock(leaf);
128 free_extent_buffer(leaf);
129 leaf = NULL;
130
131 btrfs_set_root_dirid(&root_item, 0);
132
133 key.objectid = BTRFS_TREE_LOG_OBJECTID;
134 key.offset = objectid;
135 btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
136 ret = btrfs_insert_root(trans, root->fs_info->log_root_tree, &key,
137 &root_item);
138 if (ret)
139 goto fail;
140
141 new_root = btrfs_read_fs_root_no_radix(root->fs_info->log_root_tree,
142 &key);
143 BUG_ON(!new_root);
144
145 WARN_ON(root->log_root);
146 root->log_root = new_root;
147
148 /*
149 * log trees do not get reference counted because they go away
150 * before a real commit is actually done. They do store pointers
151 * to file data extents, and those reference counts still get
152 * updated (along with back refs to the log tree).
153 */
154 new_root->ref_cows = 0;
155 new_root->last_trans = trans->transid;
156fail:
157 return ret;
158}
159
160/*
161 * start a sub transaction and setup the log tree
162 * this increments the log tree writer count to make the people
163 * syncing the tree wait for us to finish
164 */
165static int start_log_trans(struct btrfs_trans_handle *trans,
166 struct btrfs_root *root)
167{
168 int ret;
169 mutex_lock(&root->fs_info->tree_log_mutex);
170 if (!root->fs_info->log_root_tree) {
171 ret = btrfs_init_log_root_tree(trans, root->fs_info);
172 BUG_ON(ret);
173 }
174 if (!root->log_root) {
175 ret = btrfs_add_log_tree(trans, root);
176 BUG_ON(ret);
177 }
178 atomic_inc(&root->fs_info->tree_log_writers);
179 root->fs_info->tree_log_batch++;
180 mutex_unlock(&root->fs_info->tree_log_mutex);
181 return 0;
182}
183
184/*
185 * returns 0 if there was a log transaction running and we were able
186 * to join, or returns -ENOENT if there were not transactions
187 * in progress
188 */
189static int join_running_log_trans(struct btrfs_root *root)
190{
191 int ret = -ENOENT;
192
193 smp_mb();
194 if (!root->log_root)
195 return -ENOENT;
196
197 mutex_lock(&root->fs_info->tree_log_mutex);
198 if (root->log_root) {
199 ret = 0;
200 atomic_inc(&root->fs_info->tree_log_writers);
201 root->fs_info->tree_log_batch++;
202 }
203 mutex_unlock(&root->fs_info->tree_log_mutex);
204 return ret;
205}
206
207/*
208 * indicate we're done making changes to the log tree
209 * and wake up anyone waiting to do a sync
210 */
211static int end_log_trans(struct btrfs_root *root)
212{
213 atomic_dec(&root->fs_info->tree_log_writers);
214 smp_mb();
215 if (waitqueue_active(&root->fs_info->tree_log_wait))
216 wake_up(&root->fs_info->tree_log_wait);
217 return 0;
218}
219
220
221/*
222 * the walk control struct is used to pass state down the chain when
223 * processing the log tree. The stage field tells us which part
224 * of the log tree processing we are currently doing. The others
225 * are state fields used for that specific part
226 */
227struct walk_control {
228 /* should we free the extent on disk when done? This is used
229 * at transaction commit time while freeing a log tree
230 */
231 int free;
232
233 /* should we write out the extent buffer? This is used
234 * while flushing the log tree to disk during a sync
235 */
236 int write;
237
238 /* should we wait for the extent buffer io to finish? Also used
239 * while flushing the log tree to disk for a sync
240 */
241 int wait;
242
243 /* pin only walk, we record which extents on disk belong to the
244 * log trees
245 */
246 int pin;
247
248 /* what stage of the replay code we're currently in */
249 int stage;
250
251 /* the root we are currently replaying */
252 struct btrfs_root *replay_dest;
253
254 /* the trans handle for the current replay */
255 struct btrfs_trans_handle *trans;
256
257 /* the function that gets used to process blocks we find in the
258 * tree. Note the extent_buffer might not be up to date when it is
259 * passed in, and it must be checked or read if you need the data
260 * inside it
261 */
262 int (*process_func)(struct btrfs_root *log, struct extent_buffer *eb,
263 struct walk_control *wc, u64 gen);
264};
265
266/*
267 * process_func used to pin down extents, write them or wait on them
268 */
269static int process_one_buffer(struct btrfs_root *log,
270 struct extent_buffer *eb,
271 struct walk_control *wc, u64 gen)
272{
273 if (wc->pin) {
274 mutex_lock(&log->fs_info->alloc_mutex);
275 btrfs_update_pinned_extents(log->fs_info->extent_root,
276 eb->start, eb->len, 1);
277 mutex_unlock(&log->fs_info->alloc_mutex);
278 }
279
280 if (btrfs_buffer_uptodate(eb, gen)) {
281 if (wc->write)
282 btrfs_write_tree_block(eb);
283 if (wc->wait)
284 btrfs_wait_tree_block_writeback(eb);
285 }
286 return 0;
287}
288
289/*
290 * Item overwrite used by replay and tree logging. eb, slot and key all refer
291 * to the src data we are copying out.
292 *
293 * root is the tree we are copying into, and path is a scratch
294 * path for use in this function (it should be released on entry and
295 * will be released on exit).
296 *
297 * If the key is already in the destination tree the existing item is
298 * overwritten. If the existing item isn't big enough, it is extended.
299 * If it is too large, it is truncated.
300 *
301 * If the key isn't in the destination yet, a new item is inserted.
302 */
303static noinline int overwrite_item(struct btrfs_trans_handle *trans,
304 struct btrfs_root *root,
305 struct btrfs_path *path,
306 struct extent_buffer *eb, int slot,
307 struct btrfs_key *key)
308{
309 int ret;
310 u32 item_size;
311 u64 saved_i_size = 0;
312 int save_old_i_size = 0;
313 unsigned long src_ptr;
314 unsigned long dst_ptr;
315 int overwrite_root = 0;
316
317 if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
318 overwrite_root = 1;
319
320 item_size = btrfs_item_size_nr(eb, slot);
321 src_ptr = btrfs_item_ptr_offset(eb, slot);
322
323 /* look for the key in the destination tree */
324 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
325 if (ret == 0) {
326 char *src_copy;
327 char *dst_copy;
328 u32 dst_size = btrfs_item_size_nr(path->nodes[0],
329 path->slots[0]);
330 if (dst_size != item_size)
331 goto insert;
332
333 if (item_size == 0) {
334 btrfs_release_path(root, path);
335 return 0;
336 }
337 dst_copy = kmalloc(item_size, GFP_NOFS);
338 src_copy = kmalloc(item_size, GFP_NOFS);
339
340 read_extent_buffer(eb, src_copy, src_ptr, item_size);
341
342 dst_ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
343 read_extent_buffer(path->nodes[0], dst_copy, dst_ptr,
344 item_size);
345 ret = memcmp(dst_copy, src_copy, item_size);
346
347 kfree(dst_copy);
348 kfree(src_copy);
349 /*
350 * they have the same contents, just return, this saves
351 * us from cowing blocks in the destination tree and doing
352 * extra writes that may not have been done by a previous
353 * sync
354 */
355 if (ret == 0) {
356 btrfs_release_path(root, path);
357 return 0;
358 }
359
360 }
361insert:
362 btrfs_release_path(root, path);
363 /* try to insert the key into the destination tree */
364 ret = btrfs_insert_empty_item(trans, root, path,
365 key, item_size);
366
367 /* make sure any existing item is the correct size */
368 if (ret == -EEXIST) {
369 u32 found_size;
370 found_size = btrfs_item_size_nr(path->nodes[0],
371 path->slots[0]);
372 if (found_size > item_size) {
373 btrfs_truncate_item(trans, root, path, item_size, 1);
374 } else if (found_size < item_size) {
375 ret = btrfs_del_item(trans, root,
376 path);
377 BUG_ON(ret);
378
379 btrfs_release_path(root, path);
380 ret = btrfs_insert_empty_item(trans,
381 root, path, key, item_size);
382 BUG_ON(ret);
383 }
384 } else if (ret) {
385 BUG();
386 }
387 dst_ptr = btrfs_item_ptr_offset(path->nodes[0],
388 path->slots[0]);
389
390 /* don't overwrite an existing inode if the generation number
391 * was logged as zero. This is done when the tree logging code
392 * is just logging an inode to make sure it exists after recovery.
393 *
394 * Also, don't overwrite i_size on directories during replay.
395 * log replay inserts and removes directory items based on the
396 * state of the tree found in the subvolume, and i_size is modified
397 * as it goes
398 */
399 if (key->type == BTRFS_INODE_ITEM_KEY && ret == -EEXIST) {
400 struct btrfs_inode_item *src_item;
401 struct btrfs_inode_item *dst_item;
402
403 src_item = (struct btrfs_inode_item *)src_ptr;
404 dst_item = (struct btrfs_inode_item *)dst_ptr;
405
406 if (btrfs_inode_generation(eb, src_item) == 0)
407 goto no_copy;
408
409 if (overwrite_root &&
410 S_ISDIR(btrfs_inode_mode(eb, src_item)) &&
411 S_ISDIR(btrfs_inode_mode(path->nodes[0], dst_item))) {
412 save_old_i_size = 1;
413 saved_i_size = btrfs_inode_size(path->nodes[0],
414 dst_item);
415 }
416 }
417
418 copy_extent_buffer(path->nodes[0], eb, dst_ptr,
419 src_ptr, item_size);
420
421 if (save_old_i_size) {
422 struct btrfs_inode_item *dst_item;
423 dst_item = (struct btrfs_inode_item *)dst_ptr;
424 btrfs_set_inode_size(path->nodes[0], dst_item, saved_i_size);
425 }
426
427 /* make sure the generation is filled in */
428 if (key->type == BTRFS_INODE_ITEM_KEY) {
429 struct btrfs_inode_item *dst_item;
430 dst_item = (struct btrfs_inode_item *)dst_ptr;
431 if (btrfs_inode_generation(path->nodes[0], dst_item) == 0) {
432 btrfs_set_inode_generation(path->nodes[0], dst_item,
433 trans->transid);
434 }
435 }
436
437 if (overwrite_root &&
438 key->type == BTRFS_EXTENT_DATA_KEY) {
439 int extent_type;
440 struct btrfs_file_extent_item *fi;
441
442 fi = (struct btrfs_file_extent_item *)dst_ptr;
443 extent_type = btrfs_file_extent_type(path->nodes[0], fi);
444 if (extent_type == BTRFS_FILE_EXTENT_REG) {
445 struct btrfs_key ins;
446 ins.objectid = btrfs_file_extent_disk_bytenr(
447 path->nodes[0], fi);
448 ins.offset = btrfs_file_extent_disk_num_bytes(
449 path->nodes[0], fi);
450 ins.type = BTRFS_EXTENT_ITEM_KEY;
451
452 /*
453 * is this extent already allocated in the extent
454 * allocation tree? If so, just add a reference
455 */
456 ret = btrfs_lookup_extent(root, ins.objectid,
457 ins.offset);
458 if (ret == 0) {
459 ret = btrfs_inc_extent_ref(trans, root,
460 ins.objectid, ins.offset,
461 path->nodes[0]->start,
462 root->root_key.objectid,
463 trans->transid, key->objectid);
464 } else {
465 /*
466 * insert the extent pointer in the extent
467 * allocation tree
468 */
469 ret = btrfs_alloc_logged_extent(trans, root,
470 path->nodes[0]->start,
471 root->root_key.objectid,
472 trans->transid, key->objectid,
473 &ins);
474 BUG_ON(ret);
475 }
476 }
477 }
478no_copy:
479 btrfs_mark_buffer_dirty(path->nodes[0]);
480 btrfs_release_path(root, path);
481 return 0;
482}
483
484/*
485 * simple helper to read an inode off the disk from a given root
486 * This can only be called for subvolume roots and not for the log
487 */
488static noinline struct inode *read_one_inode(struct btrfs_root *root,
489 u64 objectid)
490{
491 struct inode *inode;
492 inode = btrfs_iget_locked(root->fs_info->sb, objectid, root);
493 if (inode->i_state & I_NEW) {
494 BTRFS_I(inode)->root = root;
495 BTRFS_I(inode)->location.objectid = objectid;
496 BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY;
497 BTRFS_I(inode)->location.offset = 0;
498 btrfs_read_locked_inode(inode);
499 unlock_new_inode(inode);
500
501 }
502 if (is_bad_inode(inode)) {
503 iput(inode);
504 inode = NULL;
505 }
506 return inode;
507}
508
509/* replays a single extent in 'eb' at 'slot' with 'key' into the
510 * subvolume 'root'. path is released on entry and should be released
511 * on exit.
512 *
513 * extents in the log tree have not been allocated out of the extent
514 * tree yet. So, this completes the allocation, taking a reference
515 * as required if the extent already exists or creating a new extent
516 * if it isn't in the extent allocation tree yet.
517 *
518 * The extent is inserted into the file, dropping any existing extents
519 * from the file that overlap the new one.
520 */
521static noinline int replay_one_extent(struct btrfs_trans_handle *trans,
522 struct btrfs_root *root,
523 struct btrfs_path *path,
524 struct extent_buffer *eb, int slot,
525 struct btrfs_key *key)
526{
527 int found_type;
528 u64 mask = root->sectorsize - 1;
529 u64 extent_end;
530 u64 alloc_hint;
531 u64 start = key->offset;
532 struct btrfs_file_extent_item *item;
533 struct inode *inode = NULL;
534 unsigned long size;
535 int ret = 0;
536
537 item = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item);
538 found_type = btrfs_file_extent_type(eb, item);
539
540 if (found_type == BTRFS_FILE_EXTENT_REG)
541 extent_end = start + btrfs_file_extent_num_bytes(eb, item);
542 else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
543 size = btrfs_file_extent_inline_len(eb,
544 btrfs_item_nr(eb, slot));
545 extent_end = (start + size + mask) & ~mask;
546 } else {
547 ret = 0;
548 goto out;
549 }
550
551 inode = read_one_inode(root, key->objectid);
552 if (!inode) {
553 ret = -EIO;
554 goto out;
555 }
556
557 /*
558 * first check to see if we already have this extent in the
559 * file. This must be done before the btrfs_drop_extents run
560 * so we don't try to drop this extent.
561 */
562 ret = btrfs_lookup_file_extent(trans, root, path, inode->i_ino,
563 start, 0);
564
565 if (ret == 0 && found_type == BTRFS_FILE_EXTENT_REG) {
566 struct btrfs_file_extent_item cmp1;
567 struct btrfs_file_extent_item cmp2;
568 struct btrfs_file_extent_item *existing;
569 struct extent_buffer *leaf;
570
571 leaf = path->nodes[0];
572 existing = btrfs_item_ptr(leaf, path->slots[0],
573 struct btrfs_file_extent_item);
574
575 read_extent_buffer(eb, &cmp1, (unsigned long)item,
576 sizeof(cmp1));
577 read_extent_buffer(leaf, &cmp2, (unsigned long)existing,
578 sizeof(cmp2));
579
580 /*
581 * we already have a pointer to this exact extent,
582 * we don't have to do anything
583 */
584 if (memcmp(&cmp1, &cmp2, sizeof(cmp1)) == 0) {
585 btrfs_release_path(root, path);
586 goto out;
587 }
588 }
589 btrfs_release_path(root, path);
590
591 /* drop any overlapping extents */
592 ret = btrfs_drop_extents(trans, root, inode,
593 start, extent_end, start, &alloc_hint);
594 BUG_ON(ret);
595
596 /* insert the extent */
597 ret = overwrite_item(trans, root, path, eb, slot, key);
598 BUG_ON(ret);
599
600 /* btrfs_drop_extents changes i_bytes & i_blocks, update it here */
601 inode_add_bytes(inode, extent_end - start);
602 btrfs_update_inode(trans, root, inode);
603out:
604 if (inode)
605 iput(inode);
606 return ret;
607}
608
609/*
610 * when cleaning up conflicts between the directory names in the
611 * subvolume, directory names in the log and directory names in the
612 * inode back references, we may have to unlink inodes from directories.
613 *
614 * This is a helper function to do the unlink of a specific directory
615 * item
616 */
617static noinline int drop_one_dir_item(struct btrfs_trans_handle *trans,
618 struct btrfs_root *root,
619 struct btrfs_path *path,
620 struct inode *dir,
621 struct btrfs_dir_item *di)
622{
623 struct inode *inode;
624 char *name;
625 int name_len;
626 struct extent_buffer *leaf;
627 struct btrfs_key location;
628 int ret;
629
630 leaf = path->nodes[0];
631
632 btrfs_dir_item_key_to_cpu(leaf, di, &location);
633 name_len = btrfs_dir_name_len(leaf, di);
634 name = kmalloc(name_len, GFP_NOFS);
635 read_extent_buffer(leaf, name, (unsigned long)(di + 1), name_len);
636 btrfs_release_path(root, path);
637
638 inode = read_one_inode(root, location.objectid);
639 BUG_ON(!inode);
640
641 btrfs_inc_nlink(inode);
642 ret = btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
643 kfree(name);
644
645 iput(inode);
646 return ret;
647}
648
649/*
650 * helper function to see if a given name and sequence number found
651 * in an inode back reference are already in a directory and correctly
652 * point to this inode
653 */
654static noinline int inode_in_dir(struct btrfs_root *root,
655 struct btrfs_path *path,
656 u64 dirid, u64 objectid, u64 index,
657 const char *name, int name_len)
658{
659 struct btrfs_dir_item *di;
660 struct btrfs_key location;
661 int match = 0;
662
663 di = btrfs_lookup_dir_index_item(NULL, root, path, dirid,
664 index, name, name_len, 0);
665 if (di && !IS_ERR(di)) {
666 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
667 if (location.objectid != objectid)
668 goto out;
669 } else
670 goto out;
671 btrfs_release_path(root, path);
672
673 di = btrfs_lookup_dir_item(NULL, root, path, dirid, name, name_len, 0);
674 if (di && !IS_ERR(di)) {
675 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
676 if (location.objectid != objectid)
677 goto out;
678 } else
679 goto out;
680 match = 1;
681out:
682 btrfs_release_path(root, path);
683 return match;
684}
685
686/*
687 * helper function to check a log tree for a named back reference in
688 * an inode. This is used to decide if a back reference that is
689 * found in the subvolume conflicts with what we find in the log.
690 *
691 * inode backreferences may have multiple refs in a single item,
692 * during replay we process one reference at a time, and we don't
693 * want to delete valid links to a file from the subvolume if that
694 * link is also in the log.
695 */
696static noinline int backref_in_log(struct btrfs_root *log,
697 struct btrfs_key *key,
698 char *name, int namelen)
699{
700 struct btrfs_path *path;
701 struct btrfs_inode_ref *ref;
702 unsigned long ptr;
703 unsigned long ptr_end;
704 unsigned long name_ptr;
705 int found_name_len;
706 int item_size;
707 int ret;
708 int match = 0;
709
710 path = btrfs_alloc_path();
711 ret = btrfs_search_slot(NULL, log, key, path, 0, 0);
712 if (ret != 0)
713 goto out;
714
715 item_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
716 ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
717 ptr_end = ptr + item_size;
718 while (ptr < ptr_end) {
719 ref = (struct btrfs_inode_ref *)ptr;
720 found_name_len = btrfs_inode_ref_name_len(path->nodes[0], ref);
721 if (found_name_len == namelen) {
722 name_ptr = (unsigned long)(ref + 1);
723 ret = memcmp_extent_buffer(path->nodes[0], name,
724 name_ptr, namelen);
725 if (ret == 0) {
726 match = 1;
727 goto out;
728 }
729 }
730 ptr = (unsigned long)(ref + 1) + found_name_len;
731 }
732out:
733 btrfs_free_path(path);
734 return match;
735}
736
737
738/*
739 * replay one inode back reference item found in the log tree.
740 * eb, slot and key refer to the buffer and key found in the log tree.
741 * root is the destination we are replaying into, and path is for temp
742 * use by this function. (it should be released on return).
743 */
744static noinline int add_inode_ref(struct btrfs_trans_handle *trans,
745 struct btrfs_root *root,
746 struct btrfs_root *log,
747 struct btrfs_path *path,
748 struct extent_buffer *eb, int slot,
749 struct btrfs_key *key)
750{
751 struct inode *dir;
752 int ret;
753 struct btrfs_key location;
754 struct btrfs_inode_ref *ref;
755 struct btrfs_dir_item *di;
756 struct inode *inode;
757 char *name;
758 int namelen;
759 unsigned long ref_ptr;
760 unsigned long ref_end;
761
762 location.objectid = key->objectid;
763 location.type = BTRFS_INODE_ITEM_KEY;
764 location.offset = 0;
765
766 /*
767 * it is possible that we didn't log all the parent directories
768 * for a given inode. If we don't find the dir, just don't
769 * copy the back ref in. The link count fixup code will take
770 * care of the rest
771 */
772 dir = read_one_inode(root, key->offset);
773 if (!dir)
774 return -ENOENT;
775
776 inode = read_one_inode(root, key->objectid);
777 BUG_ON(!dir);
778
779 ref_ptr = btrfs_item_ptr_offset(eb, slot);
780 ref_end = ref_ptr + btrfs_item_size_nr(eb, slot);
781
782again:
783 ref = (struct btrfs_inode_ref *)ref_ptr;
784
785 namelen = btrfs_inode_ref_name_len(eb, ref);
786 name = kmalloc(namelen, GFP_NOFS);
787 BUG_ON(!name);
788
789 read_extent_buffer(eb, name, (unsigned long)(ref + 1), namelen);
790
791 /* if we already have a perfect match, we're done */
792 if (inode_in_dir(root, path, dir->i_ino, inode->i_ino,
793 btrfs_inode_ref_index(eb, ref),
794 name, namelen)) {
795 goto out;
796 }
797
798 /*
799 * look for a conflicting back reference in the metadata.
800 * if we find one we have to unlink that name of the file
801 * before we add our new link. Later on, we overwrite any
802 * existing back reference, and we don't want to create
803 * dangling pointers in the directory.
804 */
805conflict_again:
806 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
807 if (ret == 0) {
808 char *victim_name;
809 int victim_name_len;
810 struct btrfs_inode_ref *victim_ref;
811 unsigned long ptr;
812 unsigned long ptr_end;
813 struct extent_buffer *leaf = path->nodes[0];
814
815 /* are we trying to overwrite a back ref for the root directory
816 * if so, just jump out, we're done
817 */
818 if (key->objectid == key->offset)
819 goto out_nowrite;
820
821 /* check all the names in this back reference to see
822 * if they are in the log. if so, we allow them to stay
823 * otherwise they must be unlinked as a conflict
824 */
825 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
826 ptr_end = ptr + btrfs_item_size_nr(leaf, path->slots[0]);
827 while(ptr < ptr_end) {
828 victim_ref = (struct btrfs_inode_ref *)ptr;
829 victim_name_len = btrfs_inode_ref_name_len(leaf,
830 victim_ref);
831 victim_name = kmalloc(victim_name_len, GFP_NOFS);
832 BUG_ON(!victim_name);
833
834 read_extent_buffer(leaf, victim_name,
835 (unsigned long)(victim_ref + 1),
836 victim_name_len);
837
838 if (!backref_in_log(log, key, victim_name,
839 victim_name_len)) {
840 btrfs_inc_nlink(inode);
841 btrfs_release_path(root, path);
842 ret = btrfs_unlink_inode(trans, root, dir,
843 inode, victim_name,
844 victim_name_len);
845 kfree(victim_name);
846 btrfs_release_path(root, path);
847 goto conflict_again;
848 }
849 kfree(victim_name);
850 ptr = (unsigned long)(victim_ref + 1) + victim_name_len;
851 }
852 BUG_ON(ret);
853 }
854 btrfs_release_path(root, path);
855
856 /* look for a conflicting sequence number */
857 di = btrfs_lookup_dir_index_item(trans, root, path, dir->i_ino,
858 btrfs_inode_ref_index(eb, ref),
859 name, namelen, 0);
860 if (di && !IS_ERR(di)) {
861 ret = drop_one_dir_item(trans, root, path, dir, di);
862 BUG_ON(ret);
863 }
864 btrfs_release_path(root, path);
865
866
867 /* look for a conflicting name */
868 di = btrfs_lookup_dir_item(trans, root, path, dir->i_ino,
869 name, namelen, 0);
870 if (di && !IS_ERR(di)) {
871 ret = drop_one_dir_item(trans, root, path, dir, di);
872 BUG_ON(ret);
873 }
874 btrfs_release_path(root, path);
875
876 /* insert our name */
877 ret = btrfs_add_link(trans, dir, inode, name, namelen, 0,
878 btrfs_inode_ref_index(eb, ref));
879 BUG_ON(ret);
880
881 btrfs_update_inode(trans, root, inode);
882
883out:
884 ref_ptr = (unsigned long)(ref + 1) + namelen;
885 kfree(name);
886 if (ref_ptr < ref_end)
887 goto again;
888
889 /* finally write the back reference in the inode */
890 ret = overwrite_item(trans, root, path, eb, slot, key);
891 BUG_ON(ret);
892
893out_nowrite:
894 btrfs_release_path(root, path);
895 iput(dir);
896 iput(inode);
897 return 0;
898}
899
900/*
901 * replay one csum item from the log tree into the subvolume 'root'
902 * eb, slot and key all refer to the log tree
903 * path is for temp use by this function and should be released on return
904 *
905 * This copies the checksums out of the log tree and inserts them into
906 * the subvolume. Any existing checksums for this range in the file
907 * are overwritten, and new items are added where required.
908 *
909 * We keep this simple by reusing the btrfs_ordered_sum code from
910 * the data=ordered mode. This basically means making a copy
911 * of all the checksums in ram, which we have to do anyway for kmap
912 * rules.
913 *
914 * The copy is then sent down to btrfs_csum_file_blocks, which
915 * does all the hard work of finding existing items in the file
916 * or adding new ones.
917 */
918static noinline int replay_one_csum(struct btrfs_trans_handle *trans,
919 struct btrfs_root *root,
920 struct btrfs_path *path,
921 struct extent_buffer *eb, int slot,
922 struct btrfs_key *key)
923{
924 int ret;
925 u32 item_size = btrfs_item_size_nr(eb, slot);
926 u64 cur_offset;
927 unsigned long file_bytes;
928 struct btrfs_ordered_sum *sums;
929 struct btrfs_sector_sum *sector_sum;
930 struct inode *inode;
931 unsigned long ptr;
932
933 file_bytes = (item_size / BTRFS_CRC32_SIZE) * root->sectorsize;
934 inode = read_one_inode(root, key->objectid);
935 if (!inode) {
936 return -EIO;
937 }
938
939 sums = kzalloc(btrfs_ordered_sum_size(root, file_bytes), GFP_NOFS);
940 if (!sums) {
941 iput(inode);
942 return -ENOMEM;
943 }
944
945 INIT_LIST_HEAD(&sums->list);
946 sums->len = file_bytes;
947 sums->file_offset = key->offset;
948
949 /*
950 * copy all the sums into the ordered sum struct
951 */
952 sector_sum = sums->sums;
953 cur_offset = key->offset;
954 ptr = btrfs_item_ptr_offset(eb, slot);
955 while(item_size > 0) {
956 sector_sum->offset = cur_offset;
957 read_extent_buffer(eb, &sector_sum->sum, ptr, BTRFS_CRC32_SIZE);
958 sector_sum++;
959 item_size -= BTRFS_CRC32_SIZE;
960 ptr += BTRFS_CRC32_SIZE;
961 cur_offset += root->sectorsize;
962 }
963
964 /* let btrfs_csum_file_blocks add them into the file */
965 ret = btrfs_csum_file_blocks(trans, root, inode, sums);
966 BUG_ON(ret);
967 kfree(sums);
968 iput(inode);
969
970 return 0;
971}
972/*
973 * There are a few corners where the link count of the file can't
974 * be properly maintained during replay. So, instead of adding
975 * lots of complexity to the log code, we just scan the backrefs
976 * for any file that has been through replay.
977 *
978 * The scan will update the link count on the inode to reflect the
979 * number of back refs found. If it goes down to zero, the iput
980 * will free the inode.
981 */
982static noinline int fixup_inode_link_count(struct btrfs_trans_handle *trans,
983 struct btrfs_root *root,
984 struct inode *inode)
985{
986 struct btrfs_path *path;
987 int ret;
988 struct btrfs_key key;
989 u64 nlink = 0;
990 unsigned long ptr;
991 unsigned long ptr_end;
992 int name_len;
993
994 key.objectid = inode->i_ino;
995 key.type = BTRFS_INODE_REF_KEY;
996 key.offset = (u64)-1;
997
998 path = btrfs_alloc_path();
999
1000 while(1) {
1001 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1002 if (ret < 0)
1003 break;
1004 if (ret > 0) {
1005 if (path->slots[0] == 0)
1006 break;
1007 path->slots[0]--;
1008 }
1009 btrfs_item_key_to_cpu(path->nodes[0], &key,
1010 path->slots[0]);
1011 if (key.objectid != inode->i_ino ||
1012 key.type != BTRFS_INODE_REF_KEY)
1013 break;
1014 ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
1015 ptr_end = ptr + btrfs_item_size_nr(path->nodes[0],
1016 path->slots[0]);
1017 while(ptr < ptr_end) {
1018 struct btrfs_inode_ref *ref;
1019
1020 ref = (struct btrfs_inode_ref *)ptr;
1021 name_len = btrfs_inode_ref_name_len(path->nodes[0],
1022 ref);
1023 ptr = (unsigned long)(ref + 1) + name_len;
1024 nlink++;
1025 }
1026
1027 if (key.offset == 0)
1028 break;
1029 key.offset--;
1030 btrfs_release_path(root, path);
1031 }
1032 btrfs_free_path(path);
1033 if (nlink != inode->i_nlink) {
1034 inode->i_nlink = nlink;
1035 btrfs_update_inode(trans, root, inode);
1036 }
1037 BTRFS_I(inode)->index_cnt = (u64)-1;
1038
1039 return 0;
1040}
1041
1042static noinline int fixup_inode_link_counts(struct btrfs_trans_handle *trans,
1043 struct btrfs_root *root,
1044 struct btrfs_path *path)
1045{
1046 int ret;
1047 struct btrfs_key key;
1048 struct inode *inode;
1049
1050 key.objectid = BTRFS_TREE_LOG_FIXUP_OBJECTID;
1051 key.type = BTRFS_ORPHAN_ITEM_KEY;
1052 key.offset = (u64)-1;
1053 while(1) {
1054 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1055 if (ret < 0)
1056 break;
1057
1058 if (ret == 1) {
1059 if (path->slots[0] == 0)
1060 break;
1061 path->slots[0]--;
1062 }
1063
1064 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1065 if (key.objectid != BTRFS_TREE_LOG_FIXUP_OBJECTID ||
1066 key.type != BTRFS_ORPHAN_ITEM_KEY)
1067 break;
1068
1069 ret = btrfs_del_item(trans, root, path);
1070 BUG_ON(ret);
1071
1072 btrfs_release_path(root, path);
1073 inode = read_one_inode(root, key.offset);
1074 BUG_ON(!inode);
1075
1076 ret = fixup_inode_link_count(trans, root, inode);
1077 BUG_ON(ret);
1078
1079 iput(inode);
1080
1081 if (key.offset == 0)
1082 break;
1083 key.offset--;
1084 }
1085 btrfs_release_path(root, path);
1086 return 0;
1087}
1088
1089
1090/*
1091 * record a given inode in the fixup dir so we can check its link
1092 * count when replay is done. The link count is incremented here
1093 * so the inode won't go away until we check it
1094 */
1095static noinline int link_to_fixup_dir(struct btrfs_trans_handle *trans,
1096 struct btrfs_root *root,
1097 struct btrfs_path *path,
1098 u64 objectid)
1099{
1100 struct btrfs_key key;
1101 int ret = 0;
1102 struct inode *inode;
1103
1104 inode = read_one_inode(root, objectid);
1105 BUG_ON(!inode);
1106
1107 key.objectid = BTRFS_TREE_LOG_FIXUP_OBJECTID;
1108 btrfs_set_key_type(&key, BTRFS_ORPHAN_ITEM_KEY);
1109 key.offset = objectid;
1110
1111 ret = btrfs_insert_empty_item(trans, root, path, &key, 0);
1112
1113 btrfs_release_path(root, path);
1114 if (ret == 0) {
1115 btrfs_inc_nlink(inode);
1116 btrfs_update_inode(trans, root, inode);
1117 } else if (ret == -EEXIST) {
1118 ret = 0;
1119 } else {
1120 BUG();
1121 }
1122 iput(inode);
1123
1124 return ret;
1125}
1126
1127/*
1128 * when replaying the log for a directory, we only insert names
1129 * for inodes that actually exist. This means an fsync on a directory
1130 * does not implicitly fsync all the new files in it
1131 */
1132static noinline int insert_one_name(struct btrfs_trans_handle *trans,
1133 struct btrfs_root *root,
1134 struct btrfs_path *path,
1135 u64 dirid, u64 index,
1136 char *name, int name_len, u8 type,
1137 struct btrfs_key *location)
1138{
1139 struct inode *inode;
1140 struct inode *dir;
1141 int ret;
1142
1143 inode = read_one_inode(root, location->objectid);
1144 if (!inode)
1145 return -ENOENT;
1146
1147 dir = read_one_inode(root, dirid);
1148 if (!dir) {
1149 iput(inode);
1150 return -EIO;
1151 }
1152 ret = btrfs_add_link(trans, dir, inode, name, name_len, 1, index);
1153
1154 /* FIXME, put inode into FIXUP list */
1155
1156 iput(inode);
1157 iput(dir);
1158 return ret;
1159}
1160
1161/*
1162 * take a single entry in a log directory item and replay it into
1163 * the subvolume.
1164 *
1165 * if a conflicting item exists in the subdirectory already,
1166 * the inode it points to is unlinked and put into the link count
1167 * fix up tree.
1168 *
1169 * If a name from the log points to a file or directory that does
1170 * not exist in the FS, it is skipped. fsyncs on directories
1171 * do not force down inodes inside that directory, just changes to the
1172 * names or unlinks in a directory.
1173 */
1174static noinline int replay_one_name(struct btrfs_trans_handle *trans,
1175 struct btrfs_root *root,
1176 struct btrfs_path *path,
1177 struct extent_buffer *eb,
1178 struct btrfs_dir_item *di,
1179 struct btrfs_key *key)
1180{
1181 char *name;
1182 int name_len;
1183 struct btrfs_dir_item *dst_di;
1184 struct btrfs_key found_key;
1185 struct btrfs_key log_key;
1186 struct inode *dir;
1187 u8 log_type;
1188 int exists;
1189 int ret;
1190
1191 dir = read_one_inode(root, key->objectid);
1192 BUG_ON(!dir);
1193
1194 name_len = btrfs_dir_name_len(eb, di);
1195 name = kmalloc(name_len, GFP_NOFS);
1196 log_type = btrfs_dir_type(eb, di);
1197 read_extent_buffer(eb, name, (unsigned long)(di + 1),
1198 name_len);
1199
1200 btrfs_dir_item_key_to_cpu(eb, di, &log_key);
1201 exists = btrfs_lookup_inode(trans, root, path, &log_key, 0);
1202 if (exists == 0)
1203 exists = 1;
1204 else
1205 exists = 0;
1206 btrfs_release_path(root, path);
1207
1208 if (key->type == BTRFS_DIR_ITEM_KEY) {
1209 dst_di = btrfs_lookup_dir_item(trans, root, path, key->objectid,
1210 name, name_len, 1);
1211 }
1212 else if (key->type == BTRFS_DIR_INDEX_KEY) {
1213 dst_di = btrfs_lookup_dir_index_item(trans, root, path,
1214 key->objectid,
1215 key->offset, name,
1216 name_len, 1);
1217 } else {
1218 BUG();
1219 }
1220 if (!dst_di || IS_ERR(dst_di)) {
1221 /* we need a sequence number to insert, so we only
1222 * do inserts for the BTRFS_DIR_INDEX_KEY types
1223 */
1224 if (key->type != BTRFS_DIR_INDEX_KEY)
1225 goto out;
1226 goto insert;
1227 }
1228
1229 btrfs_dir_item_key_to_cpu(path->nodes[0], dst_di, &found_key);
1230 /* the existing item matches the logged item */
1231 if (found_key.objectid == log_key.objectid &&
1232 found_key.type == log_key.type &&
1233 found_key.offset == log_key.offset &&
1234 btrfs_dir_type(path->nodes[0], dst_di) == log_type) {
1235 goto out;
1236 }
1237
1238 /*
1239 * don't drop the conflicting directory entry if the inode
1240 * for the new entry doesn't exist
1241 */
1242 if (!exists)
1243 goto out;
1244
1245 ret = drop_one_dir_item(trans, root, path, dir, dst_di);
1246 BUG_ON(ret);
1247
1248 if (key->type == BTRFS_DIR_INDEX_KEY)
1249 goto insert;
1250out:
1251 btrfs_release_path(root, path);
1252 kfree(name);
1253 iput(dir);
1254 return 0;
1255
1256insert:
1257 btrfs_release_path(root, path);
1258 ret = insert_one_name(trans, root, path, key->objectid, key->offset,
1259 name, name_len, log_type, &log_key);
1260
1261 if (ret && ret != -ENOENT)
1262 BUG();
1263 goto out;
1264}
1265
1266/*
1267 * find all the names in a directory item and reconcile them into
1268 * the subvolume. Only BTRFS_DIR_ITEM_KEY types will have more than
1269 * one name in a directory item, but the same code gets used for
1270 * both directory index types
1271 */
1272static noinline int replay_one_dir_item(struct btrfs_trans_handle *trans,
1273 struct btrfs_root *root,
1274 struct btrfs_path *path,
1275 struct extent_buffer *eb, int slot,
1276 struct btrfs_key *key)
1277{
1278 int ret;
1279 u32 item_size = btrfs_item_size_nr(eb, slot);
1280 struct btrfs_dir_item *di;
1281 int name_len;
1282 unsigned long ptr;
1283 unsigned long ptr_end;
1284
1285 ptr = btrfs_item_ptr_offset(eb, slot);
1286 ptr_end = ptr + item_size;
1287 while(ptr < ptr_end) {
1288 di = (struct btrfs_dir_item *)ptr;
1289 name_len = btrfs_dir_name_len(eb, di);
1290 ret = replay_one_name(trans, root, path, eb, di, key);
1291 BUG_ON(ret);
1292 ptr = (unsigned long)(di + 1);
1293 ptr += name_len;
1294 }
1295 return 0;
1296}
1297
1298/*
1299 * directory replay has two parts. There are the standard directory
1300 * items in the log copied from the subvolume, and range items
1301 * created in the log while the subvolume was logged.
1302 *
1303 * The range items tell us which parts of the key space the log
1304 * is authoritative for. During replay, if a key in the subvolume
1305 * directory is in a logged range item, but not actually in the log
1306 * that means it was deleted from the directory before the fsync
1307 * and should be removed.
1308 */
1309static noinline int find_dir_range(struct btrfs_root *root,
1310 struct btrfs_path *path,
1311 u64 dirid, int key_type,
1312 u64 *start_ret, u64 *end_ret)
1313{
1314 struct btrfs_key key;
1315 u64 found_end;
1316 struct btrfs_dir_log_item *item;
1317 int ret;
1318 int nritems;
1319
1320 if (*start_ret == (u64)-1)
1321 return 1;
1322
1323 key.objectid = dirid;
1324 key.type = key_type;
1325 key.offset = *start_ret;
1326
1327 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1328 if (ret < 0)
1329 goto out;
1330 if (ret > 0) {
1331 if (path->slots[0] == 0)
1332 goto out;
1333 path->slots[0]--;
1334 }
1335 if (ret != 0)
1336 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1337
1338 if (key.type != key_type || key.objectid != dirid) {
1339 ret = 1;
1340 goto next;
1341 }
1342 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
1343 struct btrfs_dir_log_item);
1344 found_end = btrfs_dir_log_end(path->nodes[0], item);
1345
1346 if (*start_ret >= key.offset && *start_ret <= found_end) {
1347 ret = 0;
1348 *start_ret = key.offset;
1349 *end_ret = found_end;
1350 goto out;
1351 }
1352 ret = 1;
1353next:
1354 /* check the next slot in the tree to see if it is a valid item */
1355 nritems = btrfs_header_nritems(path->nodes[0]);
1356 if (path->slots[0] >= nritems) {
1357 ret = btrfs_next_leaf(root, path);
1358 if (ret)
1359 goto out;
1360 } else {
1361 path->slots[0]++;
1362 }
1363
1364 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1365
1366 if (key.type != key_type || key.objectid != dirid) {
1367 ret = 1;
1368 goto out;
1369 }
1370 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
1371 struct btrfs_dir_log_item);
1372 found_end = btrfs_dir_log_end(path->nodes[0], item);
1373 *start_ret = key.offset;
1374 *end_ret = found_end;
1375 ret = 0;
1376out:
1377 btrfs_release_path(root, path);
1378 return ret;
1379}
1380
1381/*
1382 * this looks for a given directory item in the log. If the directory
1383 * item is not in the log, the item is removed and the inode it points
1384 * to is unlinked
1385 */
1386static noinline int check_item_in_log(struct btrfs_trans_handle *trans,
1387 struct btrfs_root *root,
1388 struct btrfs_root *log,
1389 struct btrfs_path *path,
1390 struct btrfs_path *log_path,
1391 struct inode *dir,
1392 struct btrfs_key *dir_key)
1393{
1394 int ret;
1395 struct extent_buffer *eb;
1396 int slot;
1397 u32 item_size;
1398 struct btrfs_dir_item *di;
1399 struct btrfs_dir_item *log_di;
1400 int name_len;
1401 unsigned long ptr;
1402 unsigned long ptr_end;
1403 char *name;
1404 struct inode *inode;
1405 struct btrfs_key location;
1406
1407again:
1408 eb = path->nodes[0];
1409 slot = path->slots[0];
1410 item_size = btrfs_item_size_nr(eb, slot);
1411 ptr = btrfs_item_ptr_offset(eb, slot);
1412 ptr_end = ptr + item_size;
1413 while(ptr < ptr_end) {
1414 di = (struct btrfs_dir_item *)ptr;
1415 name_len = btrfs_dir_name_len(eb, di);
1416 name = kmalloc(name_len, GFP_NOFS);
1417 if (!name) {
1418 ret = -ENOMEM;
1419 goto out;
1420 }
1421 read_extent_buffer(eb, name, (unsigned long)(di + 1),
1422 name_len);
1423 log_di = NULL;
1424 if (dir_key->type == BTRFS_DIR_ITEM_KEY) {
1425 log_di = btrfs_lookup_dir_item(trans, log, log_path,
1426 dir_key->objectid,
1427 name, name_len, 0);
1428 } else if (dir_key->type == BTRFS_DIR_INDEX_KEY) {
1429 log_di = btrfs_lookup_dir_index_item(trans, log,
1430 log_path,
1431 dir_key->objectid,
1432 dir_key->offset,
1433 name, name_len, 0);
1434 }
1435 if (!log_di || IS_ERR(log_di)) {
1436 btrfs_dir_item_key_to_cpu(eb, di, &location);
1437 btrfs_release_path(root, path);
1438 btrfs_release_path(log, log_path);
1439 inode = read_one_inode(root, location.objectid);
1440 BUG_ON(!inode);
1441
1442 ret = link_to_fixup_dir(trans, root,
1443 path, location.objectid);
1444 BUG_ON(ret);
1445 btrfs_inc_nlink(inode);
1446 ret = btrfs_unlink_inode(trans, root, dir, inode,
1447 name, name_len);
1448 BUG_ON(ret);
1449 kfree(name);
1450 iput(inode);
1451
1452 /* there might still be more names under this key
1453 * check and repeat if required
1454 */
1455 ret = btrfs_search_slot(NULL, root, dir_key, path,
1456 0, 0);
1457 if (ret == 0)
1458 goto again;
1459 ret = 0;
1460 goto out;
1461 }
1462 btrfs_release_path(log, log_path);
1463 kfree(name);
1464
1465 ptr = (unsigned long)(di + 1);
1466 ptr += name_len;
1467 }
1468 ret = 0;
1469out:
1470 btrfs_release_path(root, path);
1471 btrfs_release_path(log, log_path);
1472 return ret;
1473}
1474
1475/*
1476 * deletion replay happens before we copy any new directory items
1477 * out of the log or out of backreferences from inodes. It
1478 * scans the log to find ranges of keys that log is authoritative for,
1479 * and then scans the directory to find items in those ranges that are
1480 * not present in the log.
1481 *
1482 * Anything we don't find in the log is unlinked and removed from the
1483 * directory.
1484 */
1485static noinline int replay_dir_deletes(struct btrfs_trans_handle *trans,
1486 struct btrfs_root *root,
1487 struct btrfs_root *log,
1488 struct btrfs_path *path,
1489 u64 dirid)
1490{
1491 u64 range_start;
1492 u64 range_end;
1493 int key_type = BTRFS_DIR_LOG_ITEM_KEY;
1494 int ret = 0;
1495 struct btrfs_key dir_key;
1496 struct btrfs_key found_key;
1497 struct btrfs_path *log_path;
1498 struct inode *dir;
1499
1500 dir_key.objectid = dirid;
1501 dir_key.type = BTRFS_DIR_ITEM_KEY;
1502 log_path = btrfs_alloc_path();
1503 if (!log_path)
1504 return -ENOMEM;
1505
1506 dir = read_one_inode(root, dirid);
1507 /* it isn't an error if the inode isn't there, that can happen
1508 * because we replay the deletes before we copy in the inode item
1509 * from the log
1510 */
1511 if (!dir) {
1512 btrfs_free_path(log_path);
1513 return 0;
1514 }
1515again:
1516 range_start = 0;
1517 range_end = 0;
1518 while(1) {
1519 ret = find_dir_range(log, path, dirid, key_type,
1520 &range_start, &range_end);
1521 if (ret != 0)
1522 break;
1523
1524 dir_key.offset = range_start;
1525 while(1) {
1526 int nritems;
1527 ret = btrfs_search_slot(NULL, root, &dir_key, path,
1528 0, 0);
1529 if (ret < 0)
1530 goto out;
1531
1532 nritems = btrfs_header_nritems(path->nodes[0]);
1533 if (path->slots[0] >= nritems) {
1534 ret = btrfs_next_leaf(root, path);
1535 if (ret)
1536 break;
1537 }
1538 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1539 path->slots[0]);
1540 if (found_key.objectid != dirid ||
1541 found_key.type != dir_key.type)
1542 goto next_type;
1543
1544 if (found_key.offset > range_end)
1545 break;
1546
1547 ret = check_item_in_log(trans, root, log, path,
1548 log_path, dir, &found_key);
1549 BUG_ON(ret);
1550 if (found_key.offset == (u64)-1)
1551 break;
1552 dir_key.offset = found_key.offset + 1;
1553 }
1554 btrfs_release_path(root, path);
1555 if (range_end == (u64)-1)
1556 break;
1557 range_start = range_end + 1;
1558 }
1559
1560next_type:
1561 ret = 0;
1562 if (key_type == BTRFS_DIR_LOG_ITEM_KEY) {
1563 key_type = BTRFS_DIR_LOG_INDEX_KEY;
1564 dir_key.type = BTRFS_DIR_INDEX_KEY;
1565 btrfs_release_path(root, path);
1566 goto again;
1567 }
1568out:
1569 btrfs_release_path(root, path);
1570 btrfs_free_path(log_path);
1571 iput(dir);
1572 return ret;
1573}
1574
1575/*
1576 * the process_func used to replay items from the log tree. This
1577 * gets called in two different stages. The first stage just looks
1578 * for inodes and makes sure they are all copied into the subvolume.
1579 *
1580 * The second stage copies all the other item types from the log into
1581 * the subvolume. The two stage approach is slower, but gets rid of
1582 * lots of complexity around inodes referencing other inodes that exist
1583 * only in the log (references come from either directory items or inode
1584 * back refs).
1585 */
1586static int replay_one_buffer(struct btrfs_root *log, struct extent_buffer *eb,
1587 struct walk_control *wc, u64 gen)
1588{
1589 int nritems;
1590 struct btrfs_path *path;
1591 struct btrfs_root *root = wc->replay_dest;
1592 struct btrfs_key key;
1593 u32 item_size;
1594 int level;
1595 int i;
1596 int ret;
1597
1598 btrfs_read_buffer(eb, gen);
1599
1600 level = btrfs_header_level(eb);
1601
1602 if (level != 0)
1603 return 0;
1604
1605 path = btrfs_alloc_path();
1606 BUG_ON(!path);
1607
1608 nritems = btrfs_header_nritems(eb);
1609 for (i = 0; i < nritems; i++) {
1610 btrfs_item_key_to_cpu(eb, &key, i);
1611 item_size = btrfs_item_size_nr(eb, i);
1612
1613 /* inode keys are done during the first stage */
1614 if (key.type == BTRFS_INODE_ITEM_KEY &&
1615 wc->stage == LOG_WALK_REPLAY_INODES) {
1616 struct inode *inode;
1617 struct btrfs_inode_item *inode_item;
1618 u32 mode;
1619
1620 inode_item = btrfs_item_ptr(eb, i,
1621 struct btrfs_inode_item);
1622 mode = btrfs_inode_mode(eb, inode_item);
1623 if (S_ISDIR(mode)) {
1624 ret = replay_dir_deletes(wc->trans,
1625 root, log, path, key.objectid);
1626 BUG_ON(ret);
1627 }
1628 ret = overwrite_item(wc->trans, root, path,
1629 eb, i, &key);
1630 BUG_ON(ret);
1631
1632 /* for regular files, truncate away
1633 * extents past the new EOF
1634 */
1635 if (S_ISREG(mode)) {
1636 inode = read_one_inode(root,
1637 key.objectid);
1638 BUG_ON(!inode);
1639
1640 ret = btrfs_truncate_inode_items(wc->trans,
1641 root, inode, inode->i_size,
1642 BTRFS_EXTENT_DATA_KEY);
1643 BUG_ON(ret);
1644 iput(inode);
1645 }
1646 ret = link_to_fixup_dir(wc->trans, root,
1647 path, key.objectid);
1648 BUG_ON(ret);
1649 }
1650 if (wc->stage < LOG_WALK_REPLAY_ALL)
1651 continue;
1652
1653 /* these keys are simply copied */
1654 if (key.type == BTRFS_XATTR_ITEM_KEY) {
1655 ret = overwrite_item(wc->trans, root, path,
1656 eb, i, &key);
1657 BUG_ON(ret);
1658 } else if (key.type == BTRFS_INODE_REF_KEY) {
1659 ret = add_inode_ref(wc->trans, root, log, path,
1660 eb, i, &key);
1661 BUG_ON(ret && ret != -ENOENT);
1662 } else if (key.type == BTRFS_EXTENT_DATA_KEY) {
1663 ret = replay_one_extent(wc->trans, root, path,
1664 eb, i, &key);
1665 BUG_ON(ret);
1666 } else if (key.type == BTRFS_CSUM_ITEM_KEY) {
1667 ret = replay_one_csum(wc->trans, root, path,
1668 eb, i, &key);
1669 BUG_ON(ret);
1670 } else if (key.type == BTRFS_DIR_ITEM_KEY ||
1671 key.type == BTRFS_DIR_INDEX_KEY) {
1672 ret = replay_one_dir_item(wc->trans, root, path,
1673 eb, i, &key);
1674 BUG_ON(ret);
1675 }
1676 }
1677 btrfs_free_path(path);
1678 return 0;
1679}
1680
1681static int noinline walk_down_log_tree(struct btrfs_trans_handle *trans,
1682 struct btrfs_root *root,
1683 struct btrfs_path *path, int *level,
1684 struct walk_control *wc)
1685{
1686 u64 root_owner;
1687 u64 root_gen;
1688 u64 bytenr;
1689 u64 ptr_gen;
1690 struct extent_buffer *next;
1691 struct extent_buffer *cur;
1692 struct extent_buffer *parent;
1693 u32 blocksize;
1694 int ret = 0;
1695
1696 WARN_ON(*level < 0);
1697 WARN_ON(*level >= BTRFS_MAX_LEVEL);
1698
1699 while(*level > 0) {
1700 WARN_ON(*level < 0);
1701 WARN_ON(*level >= BTRFS_MAX_LEVEL);
1702 cur = path->nodes[*level];
1703
1704 if (btrfs_header_level(cur) != *level)
1705 WARN_ON(1);
1706
1707 if (path->slots[*level] >=
1708 btrfs_header_nritems(cur))
1709 break;
1710
1711 bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
1712 ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
1713 blocksize = btrfs_level_size(root, *level - 1);
1714
1715 parent = path->nodes[*level];
1716 root_owner = btrfs_header_owner(parent);
1717 root_gen = btrfs_header_generation(parent);
1718
1719 next = btrfs_find_create_tree_block(root, bytenr, blocksize);
1720
1721 wc->process_func(root, next, wc, ptr_gen);
1722
1723 if (*level == 1) {
1724 path->slots[*level]++;
1725 if (wc->free) {
1726 btrfs_read_buffer(next, ptr_gen);
1727
1728 btrfs_tree_lock(next);
1729 clean_tree_block(trans, root, next);
1730 btrfs_wait_tree_block_writeback(next);
1731 btrfs_tree_unlock(next);
1732
1733 ret = btrfs_drop_leaf_ref(trans, root, next);
1734 BUG_ON(ret);
1735
1736 WARN_ON(root_owner !=
1737 BTRFS_TREE_LOG_OBJECTID);
1738 ret = btrfs_free_reserved_extent(root,
1739 bytenr, blocksize);
1740 BUG_ON(ret);
1741 }
1742 free_extent_buffer(next);
1743 continue;
1744 }
1745 btrfs_read_buffer(next, ptr_gen);
1746
1747 WARN_ON(*level <= 0);
1748 if (path->nodes[*level-1])
1749 free_extent_buffer(path->nodes[*level-1]);
1750 path->nodes[*level-1] = next;
1751 *level = btrfs_header_level(next);
1752 path->slots[*level] = 0;
1753 cond_resched();
1754 }
1755 WARN_ON(*level < 0);
1756 WARN_ON(*level >= BTRFS_MAX_LEVEL);
1757
1758 if (path->nodes[*level] == root->node) {
1759 parent = path->nodes[*level];
1760 } else {
1761 parent = path->nodes[*level + 1];
1762 }
1763 bytenr = path->nodes[*level]->start;
1764
1765 blocksize = btrfs_level_size(root, *level);
1766 root_owner = btrfs_header_owner(parent);
1767 root_gen = btrfs_header_generation(parent);
1768
1769 wc->process_func(root, path->nodes[*level], wc,
1770 btrfs_header_generation(path->nodes[*level]));
1771
1772 if (wc->free) {
1773 next = path->nodes[*level];
1774 btrfs_tree_lock(next);
1775 clean_tree_block(trans, root, next);
1776 btrfs_wait_tree_block_writeback(next);
1777 btrfs_tree_unlock(next);
1778
1779 if (*level == 0) {
1780 ret = btrfs_drop_leaf_ref(trans, root, next);
1781 BUG_ON(ret);
1782 }
1783 WARN_ON(root_owner != BTRFS_TREE_LOG_OBJECTID);
1784 ret = btrfs_free_reserved_extent(root, bytenr, blocksize);
1785 BUG_ON(ret);
1786 }
1787 free_extent_buffer(path->nodes[*level]);
1788 path->nodes[*level] = NULL;
1789 *level += 1;
1790
1791 cond_resched();
1792 return 0;
1793}
1794
1795static int noinline walk_up_log_tree(struct btrfs_trans_handle *trans,
1796 struct btrfs_root *root,
1797 struct btrfs_path *path, int *level,
1798 struct walk_control *wc)
1799{
1800 u64 root_owner;
1801 u64 root_gen;
1802 int i;
1803 int slot;
1804 int ret;
1805
1806 for(i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
1807 slot = path->slots[i];
1808 if (slot < btrfs_header_nritems(path->nodes[i]) - 1) {
1809 struct extent_buffer *node;
1810 node = path->nodes[i];
1811 path->slots[i]++;
1812 *level = i;
1813 WARN_ON(*level == 0);
1814 return 0;
1815 } else {
1816 struct extent_buffer *parent;
1817 if (path->nodes[*level] == root->node)
1818 parent = path->nodes[*level];
1819 else
1820 parent = path->nodes[*level + 1];
1821
1822 root_owner = btrfs_header_owner(parent);
1823 root_gen = btrfs_header_generation(parent);
1824 wc->process_func(root, path->nodes[*level], wc,
1825 btrfs_header_generation(path->nodes[*level]));
1826 if (wc->free) {
1827 struct extent_buffer *next;
1828
1829 next = path->nodes[*level];
1830
1831 btrfs_tree_lock(next);
1832 clean_tree_block(trans, root, next);
1833 btrfs_wait_tree_block_writeback(next);
1834 btrfs_tree_unlock(next);
1835
1836 if (*level == 0) {
1837 ret = btrfs_drop_leaf_ref(trans, root,
1838 next);
1839 BUG_ON(ret);
1840 }
1841
1842 WARN_ON(root_owner != BTRFS_TREE_LOG_OBJECTID);
1843 ret = btrfs_free_reserved_extent(root,
1844 path->nodes[*level]->start,
1845 path->nodes[*level]->len);
1846 BUG_ON(ret);
1847 }
1848 free_extent_buffer(path->nodes[*level]);
1849 path->nodes[*level] = NULL;
1850 *level = i + 1;
1851 }
1852 }
1853 return 1;
1854}
1855
1856/*
1857 * drop the reference count on the tree rooted at 'snap'. This traverses
1858 * the tree freeing any blocks that have a ref count of zero after being
1859 * decremented.
1860 */
1861static int walk_log_tree(struct btrfs_trans_handle *trans,
1862 struct btrfs_root *log, struct walk_control *wc)
1863{
1864 int ret = 0;
1865 int wret;
1866 int level;
1867 struct btrfs_path *path;
1868 int i;
1869 int orig_level;
1870
1871 path = btrfs_alloc_path();
1872 BUG_ON(!path);
1873
1874 level = btrfs_header_level(log->node);
1875 orig_level = level;
1876 path->nodes[level] = log->node;
1877 extent_buffer_get(log->node);
1878 path->slots[level] = 0;
1879
1880 while(1) {
1881 wret = walk_down_log_tree(trans, log, path, &level, wc);
1882 if (wret > 0)
1883 break;
1884 if (wret < 0)
1885 ret = wret;
1886
1887 wret = walk_up_log_tree(trans, log, path, &level, wc);
1888 if (wret > 0)
1889 break;
1890 if (wret < 0)
1891 ret = wret;
1892 }
1893
1894 /* was the root node processed? if not, catch it here */
1895 if (path->nodes[orig_level]) {
1896 wc->process_func(log, path->nodes[orig_level], wc,
1897 btrfs_header_generation(path->nodes[orig_level]));
1898 if (wc->free) {
1899 struct extent_buffer *next;
1900
1901 next = path->nodes[orig_level];
1902
1903 btrfs_tree_lock(next);
1904 clean_tree_block(trans, log, next);
1905 btrfs_wait_tree_block_writeback(next);
1906 btrfs_tree_unlock(next);
1907
1908 if (orig_level == 0) {
1909 ret = btrfs_drop_leaf_ref(trans, log,
1910 next);
1911 BUG_ON(ret);
1912 }
1913 WARN_ON(log->root_key.objectid !=
1914 BTRFS_TREE_LOG_OBJECTID);
1915 ret = btrfs_free_reserved_extent(log, next->start,
1916 next->len);
1917 BUG_ON(ret);
1918 }
1919 }
1920
1921 for (i = 0; i <= orig_level; i++) {
1922 if (path->nodes[i]) {
1923 free_extent_buffer(path->nodes[i]);
1924 path->nodes[i] = NULL;
1925 }
1926 }
1927 btrfs_free_path(path);
1928 if (wc->free)
1929 free_extent_buffer(log->node);
1930 return ret;
1931}
1932
1933int wait_log_commit(struct btrfs_root *log)
1934{
1935 DEFINE_WAIT(wait);
1936 u64 transid = log->fs_info->tree_log_transid;
1937
1938 do {
1939 prepare_to_wait(&log->fs_info->tree_log_wait, &wait,
1940 TASK_UNINTERRUPTIBLE);
1941 mutex_unlock(&log->fs_info->tree_log_mutex);
1942 if (atomic_read(&log->fs_info->tree_log_commit))
1943 schedule();
1944 finish_wait(&log->fs_info->tree_log_wait, &wait);
1945 mutex_lock(&log->fs_info->tree_log_mutex);
1946 } while(transid == log->fs_info->tree_log_transid &&
1947 atomic_read(&log->fs_info->tree_log_commit));
1948 return 0;
1949}
1950
1951/*
1952 * btrfs_sync_log does sends a given tree log down to the disk and
1953 * updates the super blocks to record it. When this call is done,
1954 * you know that any inodes previously logged are safely on disk
1955 */
1956int btrfs_sync_log(struct btrfs_trans_handle *trans,
1957 struct btrfs_root *root)
1958{
1959 int ret;
1960 unsigned long batch;
1961 struct btrfs_root *log = root->log_root;
1962
1963 mutex_lock(&log->fs_info->tree_log_mutex);
1964 if (atomic_read(&log->fs_info->tree_log_commit)) {
1965 wait_log_commit(log);
1966 goto out;
1967 }
1968 atomic_set(&log->fs_info->tree_log_commit, 1);
1969
1970 while(1) {
1971 batch = log->fs_info->tree_log_batch;
1972 mutex_unlock(&log->fs_info->tree_log_mutex);
1973 schedule_timeout_uninterruptible(1);
1974 mutex_lock(&log->fs_info->tree_log_mutex);
1975
1976 while(atomic_read(&log->fs_info->tree_log_writers)) {
1977 DEFINE_WAIT(wait);
1978 prepare_to_wait(&log->fs_info->tree_log_wait, &wait,
1979 TASK_UNINTERRUPTIBLE);
1980 mutex_unlock(&log->fs_info->tree_log_mutex);
1981 if (atomic_read(&log->fs_info->tree_log_writers))
1982 schedule();
1983 mutex_lock(&log->fs_info->tree_log_mutex);
1984 finish_wait(&log->fs_info->tree_log_wait, &wait);
1985 }
1986 if (batch == log->fs_info->tree_log_batch)
1987 break;
1988 }
1989
1990 ret = btrfs_write_and_wait_marked_extents(log, &log->dirty_log_pages);
1991 BUG_ON(ret);
1992 ret = btrfs_write_and_wait_marked_extents(root->fs_info->log_root_tree,
1993 &root->fs_info->log_root_tree->dirty_log_pages);
1994 BUG_ON(ret);
1995
1996 btrfs_set_super_log_root(&root->fs_info->super_for_commit,
1997 log->fs_info->log_root_tree->node->start);
1998 btrfs_set_super_log_root_level(&root->fs_info->super_for_commit,
1999 btrfs_header_level(log->fs_info->log_root_tree->node));
2000
2001 write_ctree_super(trans, log->fs_info->tree_root);
2002 log->fs_info->tree_log_transid++;
2003 log->fs_info->tree_log_batch = 0;
2004 atomic_set(&log->fs_info->tree_log_commit, 0);
2005 smp_mb();
2006 if (waitqueue_active(&log->fs_info->tree_log_wait))
2007 wake_up(&log->fs_info->tree_log_wait);
2008out:
2009 mutex_unlock(&log->fs_info->tree_log_mutex);
2010 return 0;
2011
2012}
2013
2014/* * free all the extents used by the tree log. This should be called
2015 * at commit time of the full transaction
2016 */
2017int btrfs_free_log(struct btrfs_trans_handle *trans, struct btrfs_root *root)
2018{
2019 int ret;
2020 struct btrfs_root *log;
2021 struct key;
2022 u64 start;
2023 u64 end;
2024 struct walk_control wc = {
2025 .free = 1,
2026 .process_func = process_one_buffer
2027 };
2028
2029 if (!root->log_root)
2030 return 0;
2031
2032 log = root->log_root;
2033 ret = walk_log_tree(trans, log, &wc);
2034 BUG_ON(ret);
2035
2036 while(1) {
2037 ret = find_first_extent_bit(&log->dirty_log_pages,
2038 0, &start, &end, EXTENT_DIRTY);
2039 if (ret)
2040 break;
2041
2042 clear_extent_dirty(&log->dirty_log_pages,
2043 start, end, GFP_NOFS);
2044 }
2045
2046 log = root->log_root;
2047 ret = btrfs_del_root(trans, root->fs_info->log_root_tree,
2048 &log->root_key);
2049 BUG_ON(ret);
2050 root->log_root = NULL;
2051 kfree(root->log_root);
2052 return 0;
2053}
2054
2055/*
2056 * helper function to update the item for a given subvolumes log root
2057 * in the tree of log roots
2058 */
2059static int update_log_root(struct btrfs_trans_handle *trans,
2060 struct btrfs_root *log)
2061{
2062 u64 bytenr = btrfs_root_bytenr(&log->root_item);
2063 int ret;
2064
2065 if (log->node->start == bytenr)
2066 return 0;
2067
2068 btrfs_set_root_bytenr(&log->root_item, log->node->start);
2069 btrfs_set_root_level(&log->root_item, btrfs_header_level(log->node));
2070 ret = btrfs_update_root(trans, log->fs_info->log_root_tree,
2071 &log->root_key, &log->root_item);
2072 BUG_ON(ret);
2073 return ret;
2074}
2075
2076/*
2077 * If both a file and directory are logged, and unlinks or renames are
2078 * mixed in, we have a few interesting corners:
2079 *
2080 * create file X in dir Y
2081 * link file X to X.link in dir Y
2082 * fsync file X
2083 * unlink file X but leave X.link
2084 * fsync dir Y
2085 *
2086 * After a crash we would expect only X.link to exist. But file X
2087 * didn't get fsync'd again so the log has back refs for X and X.link.
2088 *
2089 * We solve this by removing directory entries and inode backrefs from the
2090 * log when a file that was logged in the current transaction is
2091 * unlinked. Any later fsync will include the updated log entries, and
2092 * we'll be able to reconstruct the proper directory items from backrefs.
2093 *
2094 * This optimizations allows us to avoid relogging the entire inode
2095 * or the entire directory.
2096 */
2097int btrfs_del_dir_entries_in_log(struct btrfs_trans_handle *trans,
2098 struct btrfs_root *root,
2099 const char *name, int name_len,
2100 struct inode *dir, u64 index)
2101{
2102 struct btrfs_root *log;
2103 struct btrfs_dir_item *di;
2104 struct btrfs_path *path;
2105 int ret;
2106 int bytes_del = 0;
2107
2108 if (BTRFS_I(dir)->logged_trans < trans->transid)
2109 return 0;
2110
2111 ret = join_running_log_trans(root);
2112 if (ret)
2113 return 0;
2114
2115 mutex_lock(&BTRFS_I(dir)->log_mutex);
2116
2117 log = root->log_root;
2118 path = btrfs_alloc_path();
2119 di = btrfs_lookup_dir_item(trans, log, path, dir->i_ino,
2120 name, name_len, -1);
2121 if (di && !IS_ERR(di)) {
2122 ret = btrfs_delete_one_dir_name(trans, log, path, di);
2123 bytes_del += name_len;
2124 BUG_ON(ret);
2125 }
2126 btrfs_release_path(log, path);
2127 di = btrfs_lookup_dir_index_item(trans, log, path, dir->i_ino,
2128 index, name, name_len, -1);
2129 if (di && !IS_ERR(di)) {
2130 ret = btrfs_delete_one_dir_name(trans, log, path, di);
2131 bytes_del += name_len;
2132 BUG_ON(ret);
2133 }
2134
2135 /* update the directory size in the log to reflect the names
2136 * we have removed
2137 */
2138 if (bytes_del) {
2139 struct btrfs_key key;
2140
2141 key.objectid = dir->i_ino;
2142 key.offset = 0;
2143 key.type = BTRFS_INODE_ITEM_KEY;
2144 btrfs_release_path(log, path);
2145
2146 ret = btrfs_search_slot(trans, log, &key, path, 0, 1);
2147 if (ret == 0) {
2148 struct btrfs_inode_item *item;
2149 u64 i_size;
2150
2151 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
2152 struct btrfs_inode_item);
2153 i_size = btrfs_inode_size(path->nodes[0], item);
2154 if (i_size > bytes_del)
2155 i_size -= bytes_del;
2156 else
2157 i_size = 0;
2158 btrfs_set_inode_size(path->nodes[0], item, i_size);
2159 btrfs_mark_buffer_dirty(path->nodes[0]);
2160 } else
2161 ret = 0;
2162 btrfs_release_path(log, path);
2163 }
2164
2165 btrfs_free_path(path);
2166 mutex_unlock(&BTRFS_I(dir)->log_mutex);
2167 end_log_trans(root);
2168
2169 return 0;
2170}
2171
2172/* see comments for btrfs_del_dir_entries_in_log */
2173int btrfs_del_inode_ref_in_log(struct btrfs_trans_handle *trans,
2174 struct btrfs_root *root,
2175 const char *name, int name_len,
2176 struct inode *inode, u64 dirid)
2177{
2178 struct btrfs_root *log;
2179 u64 index;
2180 int ret;
2181
2182 if (BTRFS_I(inode)->logged_trans < trans->transid)
2183 return 0;
2184
2185 ret = join_running_log_trans(root);
2186 if (ret)
2187 return 0;
2188 log = root->log_root;
2189 mutex_lock(&BTRFS_I(inode)->log_mutex);
2190
2191 ret = btrfs_del_inode_ref(trans, log, name, name_len, inode->i_ino,
2192 dirid, &index);
2193 mutex_unlock(&BTRFS_I(inode)->log_mutex);
2194 end_log_trans(root);
2195
2196 return ret;
2197}
2198
2199/*
2200 * creates a range item in the log for 'dirid'. first_offset and
2201 * last_offset tell us which parts of the key space the log should
2202 * be considered authoritative for.
2203 */
2204static noinline int insert_dir_log_key(struct btrfs_trans_handle *trans,
2205 struct btrfs_root *log,
2206 struct btrfs_path *path,
2207 int key_type, u64 dirid,
2208 u64 first_offset, u64 last_offset)
2209{
2210 int ret;
2211 struct btrfs_key key;
2212 struct btrfs_dir_log_item *item;
2213
2214 key.objectid = dirid;
2215 key.offset = first_offset;
2216 if (key_type == BTRFS_DIR_ITEM_KEY)
2217 key.type = BTRFS_DIR_LOG_ITEM_KEY;
2218 else
2219 key.type = BTRFS_DIR_LOG_INDEX_KEY;
2220 ret = btrfs_insert_empty_item(trans, log, path, &key, sizeof(*item));
2221 BUG_ON(ret);
2222
2223 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
2224 struct btrfs_dir_log_item);
2225 btrfs_set_dir_log_end(path->nodes[0], item, last_offset);
2226 btrfs_mark_buffer_dirty(path->nodes[0]);
2227 btrfs_release_path(log, path);
2228 return 0;
2229}
2230
2231/*
2232 * log all the items included in the current transaction for a given
2233 * directory. This also creates the range items in the log tree required
2234 * to replay anything deleted before the fsync
2235 */
2236static noinline int log_dir_items(struct btrfs_trans_handle *trans,
2237 struct btrfs_root *root, struct inode *inode,
2238 struct btrfs_path *path,
2239 struct btrfs_path *dst_path, int key_type,
2240 u64 min_offset, u64 *last_offset_ret)
2241{
2242 struct btrfs_key min_key;
2243 struct btrfs_key max_key;
2244 struct btrfs_root *log = root->log_root;
2245 struct extent_buffer *src;
2246 int ret;
2247 int i;
2248 int nritems;
2249 u64 first_offset = min_offset;
2250 u64 last_offset = (u64)-1;
2251
2252 log = root->log_root;
2253 max_key.objectid = inode->i_ino;
2254 max_key.offset = (u64)-1;
2255 max_key.type = key_type;
2256
2257 min_key.objectid = inode->i_ino;
2258 min_key.type = key_type;
2259 min_key.offset = min_offset;
2260
2261 path->keep_locks = 1;
2262
2263 ret = btrfs_search_forward(root, &min_key, &max_key,
2264 path, 0, trans->transid);
2265
2266 /*
2267 * we didn't find anything from this transaction, see if there
2268 * is anything at all
2269 */
2270 if (ret != 0 || min_key.objectid != inode->i_ino ||
2271 min_key.type != key_type) {
2272 min_key.objectid = inode->i_ino;
2273 min_key.type = key_type;
2274 min_key.offset = (u64)-1;
2275 btrfs_release_path(root, path);
2276 ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0);
2277 if (ret < 0) {
2278 btrfs_release_path(root, path);
2279 return ret;
2280 }
2281 ret = btrfs_previous_item(root, path, inode->i_ino, key_type);
2282
2283 /* if ret == 0 there are items for this type,
2284 * create a range to tell us the last key of this type.
2285 * otherwise, there are no items in this directory after
2286 * *min_offset, and we create a range to indicate that.
2287 */
2288 if (ret == 0) {
2289 struct btrfs_key tmp;
2290 btrfs_item_key_to_cpu(path->nodes[0], &tmp,
2291 path->slots[0]);
2292 if (key_type == tmp.type) {
2293 first_offset = max(min_offset, tmp.offset) + 1;
2294 }
2295 }
2296 goto done;
2297 }
2298
2299 /* go backward to find any previous key */
2300 ret = btrfs_previous_item(root, path, inode->i_ino, key_type);
2301 if (ret == 0) {
2302 struct btrfs_key tmp;
2303 btrfs_item_key_to_cpu(path->nodes[0], &tmp, path->slots[0]);
2304 if (key_type == tmp.type) {
2305 first_offset = tmp.offset;
2306 ret = overwrite_item(trans, log, dst_path,
2307 path->nodes[0], path->slots[0],
2308 &tmp);
2309 }
2310 }
2311 btrfs_release_path(root, path);
2312
2313 /* find the first key from this transaction again */
2314 ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0);
2315 if (ret != 0) {
2316 WARN_ON(1);
2317 goto done;
2318 }
2319
2320 /*
2321 * we have a block from this transaction, log every item in it
2322 * from our directory
2323 */
2324 while(1) {
2325 struct btrfs_key tmp;
2326 src = path->nodes[0];
2327 nritems = btrfs_header_nritems(src);
2328 for (i = path->slots[0]; i < nritems; i++) {
2329 btrfs_item_key_to_cpu(src, &min_key, i);
2330
2331 if (min_key.objectid != inode->i_ino ||
2332 min_key.type != key_type)
2333 goto done;
2334 ret = overwrite_item(trans, log, dst_path, src, i,
2335 &min_key);
2336 BUG_ON(ret);
2337 }
2338 path->slots[0] = nritems;
2339
2340 /*
2341 * look ahead to the next item and see if it is also
2342 * from this directory and from this transaction
2343 */
2344 ret = btrfs_next_leaf(root, path);
2345 if (ret == 1) {
2346 last_offset = (u64)-1;
2347 goto done;
2348 }
2349 btrfs_item_key_to_cpu(path->nodes[0], &tmp, path->slots[0]);
2350 if (tmp.objectid != inode->i_ino || tmp.type != key_type) {
2351 last_offset = (u64)-1;
2352 goto done;
2353 }
2354 if (btrfs_header_generation(path->nodes[0]) != trans->transid) {
2355 ret = overwrite_item(trans, log, dst_path,
2356 path->nodes[0], path->slots[0],
2357 &tmp);
2358
2359 BUG_ON(ret);
2360 last_offset = tmp.offset;
2361 goto done;
2362 }
2363 }
2364done:
2365 *last_offset_ret = last_offset;
2366 btrfs_release_path(root, path);
2367 btrfs_release_path(log, dst_path);
2368
2369 /* insert the log range keys to indicate where the log is valid */
2370 ret = insert_dir_log_key(trans, log, path, key_type, inode->i_ino,
2371 first_offset, last_offset);
2372 BUG_ON(ret);
2373 return 0;
2374}
2375
2376/*
2377 * logging directories is very similar to logging inodes, We find all the items
2378 * from the current transaction and write them to the log.
2379 *
2380 * The recovery code scans the directory in the subvolume, and if it finds a
2381 * key in the range logged that is not present in the log tree, then it means
2382 * that dir entry was unlinked during the transaction.
2383 *
2384 * In order for that scan to work, we must include one key smaller than
2385 * the smallest logged by this transaction and one key larger than the largest
2386 * key logged by this transaction.
2387 */
2388static noinline int log_directory_changes(struct btrfs_trans_handle *trans,
2389 struct btrfs_root *root, struct inode *inode,
2390 struct btrfs_path *path,
2391 struct btrfs_path *dst_path)
2392{
2393 u64 min_key;
2394 u64 max_key;
2395 int ret;
2396 int key_type = BTRFS_DIR_ITEM_KEY;
2397
2398again:
2399 min_key = 0;
2400 max_key = 0;
2401 while(1) {
2402 ret = log_dir_items(trans, root, inode, path,
2403 dst_path, key_type, min_key,
2404 &max_key);
2405 BUG_ON(ret);
2406 if (max_key == (u64)-1)
2407 break;
2408 min_key = max_key + 1;
2409 }
2410
2411 if (key_type == BTRFS_DIR_ITEM_KEY) {
2412 key_type = BTRFS_DIR_INDEX_KEY;
2413 goto again;
2414 }
2415 return 0;
2416}
2417
2418/*
2419 * a helper function to drop items from the log before we relog an
2420 * inode. max_key_type indicates the highest item type to remove.
2421 * This cannot be run for file data extents because it does not
2422 * free the extents they point to.
2423 */
2424static int drop_objectid_items(struct btrfs_trans_handle *trans,
2425 struct btrfs_root *log,
2426 struct btrfs_path *path,
2427 u64 objectid, int max_key_type)
2428{
2429 int ret;
2430 struct btrfs_key key;
2431 struct btrfs_key found_key;
2432
2433 key.objectid = objectid;
2434 key.type = max_key_type;
2435 key.offset = (u64)-1;
2436
2437 while(1) {
2438 ret = btrfs_search_slot(trans, log, &key, path, -1, 1);
2439
2440 if (ret != 1)
2441 break;
2442
2443 if (path->slots[0] == 0)
2444 break;
2445
2446 path->slots[0]--;
2447 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
2448 path->slots[0]);
2449
2450 if (found_key.objectid != objectid)
2451 break;
2452
2453 ret = btrfs_del_item(trans, log, path);
2454 BUG_ON(ret);
2455 btrfs_release_path(log, path);
2456 }
2457 btrfs_release_path(log, path);
2458 return 0;
2459}
2460
2461static noinline int copy_items(struct btrfs_trans_handle *trans,
2462 struct btrfs_root *log,
2463 struct btrfs_path *dst_path,
2464 struct extent_buffer *src,
2465 int start_slot, int nr, int inode_only)
2466{
2467 unsigned long src_offset;
2468 unsigned long dst_offset;
2469 struct btrfs_file_extent_item *extent;
2470 struct btrfs_inode_item *inode_item;
2471 int ret;
2472 struct btrfs_key *ins_keys;
2473 u32 *ins_sizes;
2474 char *ins_data;
2475 int i;
2476
2477 ins_data = kmalloc(nr * sizeof(struct btrfs_key) +
2478 nr * sizeof(u32), GFP_NOFS);
2479 ins_sizes = (u32 *)ins_data;
2480 ins_keys = (struct btrfs_key *)(ins_data + nr * sizeof(u32));
2481
2482 for (i = 0; i < nr; i++) {
2483 ins_sizes[i] = btrfs_item_size_nr(src, i + start_slot);
2484 btrfs_item_key_to_cpu(src, ins_keys + i, i + start_slot);
2485 }
2486 ret = btrfs_insert_empty_items(trans, log, dst_path,
2487 ins_keys, ins_sizes, nr);
2488 BUG_ON(ret);
2489
2490 for (i = 0; i < nr; i++) {
2491 dst_offset = btrfs_item_ptr_offset(dst_path->nodes[0],
2492 dst_path->slots[0]);
2493
2494 src_offset = btrfs_item_ptr_offset(src, start_slot + i);
2495
2496 copy_extent_buffer(dst_path->nodes[0], src, dst_offset,
2497 src_offset, ins_sizes[i]);
2498
2499 if (inode_only == LOG_INODE_EXISTS &&
2500 ins_keys[i].type == BTRFS_INODE_ITEM_KEY) {
2501 inode_item = btrfs_item_ptr(dst_path->nodes[0],
2502 dst_path->slots[0],
2503 struct btrfs_inode_item);
2504 btrfs_set_inode_size(dst_path->nodes[0], inode_item, 0);
2505
2506 /* set the generation to zero so the recover code
2507 * can tell the difference between an logging
2508 * just to say 'this inode exists' and a logging
2509 * to say 'update this inode with these values'
2510 */
2511 btrfs_set_inode_generation(dst_path->nodes[0],
2512 inode_item, 0);
2513 }
2514 /* take a reference on file data extents so that truncates
2515 * or deletes of this inode don't have to relog the inode
2516 * again
2517 */
2518 if (btrfs_key_type(ins_keys + i) == BTRFS_EXTENT_DATA_KEY) {
2519 int found_type;
2520 extent = btrfs_item_ptr(src, start_slot + i,
2521 struct btrfs_file_extent_item);
2522
2523 found_type = btrfs_file_extent_type(src, extent);
2524 if (found_type == BTRFS_FILE_EXTENT_REG) {
2525 u64 ds = btrfs_file_extent_disk_bytenr(src,
2526 extent);
2527 u64 dl = btrfs_file_extent_disk_num_bytes(src,
2528 extent);
2529 /* ds == 0 is a hole */
2530 if (ds != 0) {
2531 ret = btrfs_inc_extent_ref(trans, log,
2532 ds, dl,
2533 dst_path->nodes[0]->start,
2534 BTRFS_TREE_LOG_OBJECTID,
2535 trans->transid,
2536 ins_keys[i].objectid);
2537 BUG_ON(ret);
2538 }
2539 }
2540 }
2541 dst_path->slots[0]++;
2542 }
2543
2544 btrfs_mark_buffer_dirty(dst_path->nodes[0]);
2545 btrfs_release_path(log, dst_path);
2546 kfree(ins_data);
2547 return 0;
2548}
2549
2550/* log a single inode in the tree log.
2551 * At least one parent directory for this inode must exist in the tree
2552 * or be logged already.
2553 *
2554 * Any items from this inode changed by the current transaction are copied
2555 * to the log tree. An extra reference is taken on any extents in this
2556 * file, allowing us to avoid a whole pile of corner cases around logging
2557 * blocks that have been removed from the tree.
2558 *
2559 * See LOG_INODE_ALL and related defines for a description of what inode_only
2560 * does.
2561 *
2562 * This handles both files and directories.
2563 */
2564static int __btrfs_log_inode(struct btrfs_trans_handle *trans,
2565 struct btrfs_root *root, struct inode *inode,
2566 int inode_only)
2567{
2568 struct btrfs_path *path;
2569 struct btrfs_path *dst_path;
2570 struct btrfs_key min_key;
2571 struct btrfs_key max_key;
2572 struct btrfs_root *log = root->log_root;
2573 struct extent_buffer *src = NULL;
2574 u32 size;
2575 int ret;
2576 int nritems;
2577 int ins_start_slot = 0;
2578 int ins_nr;
2579
2580 log = root->log_root;
2581
2582 path = btrfs_alloc_path();
2583 dst_path = btrfs_alloc_path();
2584
2585 min_key.objectid = inode->i_ino;
2586 min_key.type = BTRFS_INODE_ITEM_KEY;
2587 min_key.offset = 0;
2588
2589 max_key.objectid = inode->i_ino;
2590 if (inode_only == LOG_INODE_EXISTS || S_ISDIR(inode->i_mode))
2591 max_key.type = BTRFS_XATTR_ITEM_KEY;
2592 else
2593 max_key.type = (u8)-1;
2594 max_key.offset = (u64)-1;
2595
2596 /*
2597 * if this inode has already been logged and we're in inode_only
2598 * mode, we don't want to delete the things that have already
2599 * been written to the log.
2600 *
2601 * But, if the inode has been through an inode_only log,
2602 * the logged_trans field is not set. This allows us to catch
2603 * any new names for this inode in the backrefs by logging it
2604 * again
2605 */
2606 if (inode_only == LOG_INODE_EXISTS &&
2607 BTRFS_I(inode)->logged_trans == trans->transid) {
2608 btrfs_free_path(path);
2609 btrfs_free_path(dst_path);
2610 goto out;
2611 }
2612 mutex_lock(&BTRFS_I(inode)->log_mutex);
2613
2614 /*
2615 * a brute force approach to making sure we get the most uptodate
2616 * copies of everything.
2617 */
2618 if (S_ISDIR(inode->i_mode)) {
2619 int max_key_type = BTRFS_DIR_LOG_INDEX_KEY;
2620
2621 if (inode_only == LOG_INODE_EXISTS)
2622 max_key_type = BTRFS_XATTR_ITEM_KEY;
2623 ret = drop_objectid_items(trans, log, path,
2624 inode->i_ino, max_key_type);
2625 } else {
2626 ret = btrfs_truncate_inode_items(trans, log, inode, 0, 0);
2627 }
2628 BUG_ON(ret);
2629 path->keep_locks = 1;
2630
2631 while(1) {
2632 ins_nr = 0;
2633 ret = btrfs_search_forward(root, &min_key, &max_key,
2634 path, 0, trans->transid);
2635 if (ret != 0)
2636 break;
2637again:
2638 /* note, ins_nr might be > 0 here, cleanup outside the loop */
2639 if (min_key.objectid != inode->i_ino)
2640 break;
2641 if (min_key.type > max_key.type)
2642 break;
2643
2644 src = path->nodes[0];
2645 size = btrfs_item_size_nr(src, path->slots[0]);
2646 if (ins_nr && ins_start_slot + ins_nr == path->slots[0]) {
2647 ins_nr++;
2648 goto next_slot;
2649 } else if (!ins_nr) {
2650 ins_start_slot = path->slots[0];
2651 ins_nr = 1;
2652 goto next_slot;
2653 }
2654
2655 ret = copy_items(trans, log, dst_path, src, ins_start_slot,
2656 ins_nr, inode_only);
2657 BUG_ON(ret);
2658 ins_nr = 1;
2659 ins_start_slot = path->slots[0];
2660next_slot:
2661
2662 nritems = btrfs_header_nritems(path->nodes[0]);
2663 path->slots[0]++;
2664 if (path->slots[0] < nritems) {
2665 btrfs_item_key_to_cpu(path->nodes[0], &min_key,
2666 path->slots[0]);
2667 goto again;
2668 }
2669 if (ins_nr) {
2670 ret = copy_items(trans, log, dst_path, src,
2671 ins_start_slot,
2672 ins_nr, inode_only);
2673 BUG_ON(ret);
2674 ins_nr = 0;
2675 }
2676 btrfs_release_path(root, path);
2677
2678 if (min_key.offset < (u64)-1)
2679 min_key.offset++;
2680 else if (min_key.type < (u8)-1)
2681 min_key.type++;
2682 else if (min_key.objectid < (u64)-1)
2683 min_key.objectid++;
2684 else
2685 break;
2686 }
2687 if (ins_nr) {
2688 ret = copy_items(trans, log, dst_path, src,
2689 ins_start_slot,
2690 ins_nr, inode_only);
2691 BUG_ON(ret);
2692 ins_nr = 0;
2693 }
2694 WARN_ON(ins_nr);
2695 if (inode_only == LOG_INODE_ALL && S_ISDIR(inode->i_mode)) {
2696 btrfs_release_path(root, path);
2697 btrfs_release_path(log, dst_path);
2698 BTRFS_I(inode)->log_dirty_trans = 0;
2699 ret = log_directory_changes(trans, root, inode, path, dst_path);
2700 BUG_ON(ret);
2701 }
2702 BTRFS_I(inode)->logged_trans = trans->transid;
2703 mutex_unlock(&BTRFS_I(inode)->log_mutex);
2704
2705 btrfs_free_path(path);
2706 btrfs_free_path(dst_path);
2707
2708 mutex_lock(&root->fs_info->tree_log_mutex);
2709 ret = update_log_root(trans, log);
2710 BUG_ON(ret);
2711 mutex_unlock(&root->fs_info->tree_log_mutex);
2712out:
2713 return 0;
2714}
2715
2716int btrfs_log_inode(struct btrfs_trans_handle *trans,
2717 struct btrfs_root *root, struct inode *inode,
2718 int inode_only)
2719{
2720 int ret;
2721
2722 start_log_trans(trans, root);
2723 ret = __btrfs_log_inode(trans, root, inode, inode_only);
2724 end_log_trans(root);
2725 return ret;
2726}
2727
2728/*
2729 * helper function around btrfs_log_inode to make sure newly created
2730 * parent directories also end up in the log. A minimal inode and backref
2731 * only logging is done of any parent directories that are older than
2732 * the last committed transaction
2733 */
2734int btrfs_log_dentry(struct btrfs_trans_handle *trans,
2735 struct btrfs_root *root, struct dentry *dentry)
2736{
2737 int inode_only = LOG_INODE_ALL;
2738 struct super_block *sb;
2739 int ret;
2740
2741 start_log_trans(trans, root);
2742 sb = dentry->d_inode->i_sb;
2743 while(1) {
2744 ret = __btrfs_log_inode(trans, root, dentry->d_inode,
2745 inode_only);
2746 BUG_ON(ret);
2747 inode_only = LOG_INODE_EXISTS;
2748
2749 dentry = dentry->d_parent;
2750 if (!dentry || !dentry->d_inode || sb != dentry->d_inode->i_sb)
2751 break;
2752
2753 if (BTRFS_I(dentry->d_inode)->generation <=
2754 root->fs_info->last_trans_committed)
2755 break;
2756 }
2757 end_log_trans(root);
2758 return 0;
2759}
2760
2761/*
2762 * it is not safe to log dentry if the chunk root has added new
2763 * chunks. This returns 0 if the dentry was logged, and 1 otherwise.
2764 * If this returns 1, you must commit the transaction to safely get your
2765 * data on disk.
2766 */
2767int btrfs_log_dentry_safe(struct btrfs_trans_handle *trans,
2768 struct btrfs_root *root, struct dentry *dentry)
2769{
2770 u64 gen;
2771 gen = root->fs_info->last_trans_new_blockgroup;
2772 if (gen > root->fs_info->last_trans_committed)
2773 return 1;
2774 else
2775 return btrfs_log_dentry(trans, root, dentry);
2776}
2777
2778/*
2779 * should be called during mount to recover any replay any log trees
2780 * from the FS
2781 */
2782int btrfs_recover_log_trees(struct btrfs_root *log_root_tree)
2783{
2784 int ret;
2785 struct btrfs_path *path;
2786 struct btrfs_trans_handle *trans;
2787 struct btrfs_key key;
2788 struct btrfs_key found_key;
2789 struct btrfs_key tmp_key;
2790 struct btrfs_root *log;
2791 struct btrfs_fs_info *fs_info = log_root_tree->fs_info;
2792 u64 highest_inode;
2793 struct walk_control wc = {
2794 .process_func = process_one_buffer,
2795 .stage = 0,
2796 };
2797
2798 fs_info->log_root_recovering = 1;
2799 path = btrfs_alloc_path();
2800 BUG_ON(!path);
2801
2802 trans = btrfs_start_transaction(fs_info->tree_root, 1);
2803
2804 wc.trans = trans;
2805 wc.pin = 1;
2806
2807 walk_log_tree(trans, log_root_tree, &wc);
2808
2809again:
2810 key.objectid = BTRFS_TREE_LOG_OBJECTID;
2811 key.offset = (u64)-1;
2812 btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
2813
2814 while(1) {
2815 ret = btrfs_search_slot(NULL, log_root_tree, &key, path, 0, 0);
2816 if (ret < 0)
2817 break;
2818 if (ret > 0) {
2819 if (path->slots[0] == 0)
2820 break;
2821 path->slots[0]--;
2822 }
2823 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
2824 path->slots[0]);
2825 btrfs_release_path(log_root_tree, path);
2826 if (found_key.objectid != BTRFS_TREE_LOG_OBJECTID)
2827 break;
2828
2829 log = btrfs_read_fs_root_no_radix(log_root_tree,
2830 &found_key);
2831 BUG_ON(!log);
2832
2833
2834 tmp_key.objectid = found_key.offset;
2835 tmp_key.type = BTRFS_ROOT_ITEM_KEY;
2836 tmp_key.offset = (u64)-1;
2837
2838 wc.replay_dest = btrfs_read_fs_root_no_name(fs_info, &tmp_key);
2839
2840 BUG_ON(!wc.replay_dest);
2841
2842 btrfs_record_root_in_trans(wc.replay_dest);
2843 ret = walk_log_tree(trans, log, &wc);
2844 BUG_ON(ret);
2845
2846 if (wc.stage == LOG_WALK_REPLAY_ALL) {
2847 ret = fixup_inode_link_counts(trans, wc.replay_dest,
2848 path);
2849 BUG_ON(ret);
2850 }
2851 ret = btrfs_find_highest_inode(wc.replay_dest, &highest_inode);
2852 if (ret == 0) {
2853 wc.replay_dest->highest_inode = highest_inode;
2854 wc.replay_dest->last_inode_alloc = highest_inode;
2855 }
2856
2857 key.offset = found_key.offset - 1;
2858 free_extent_buffer(log->node);
2859 kfree(log);
2860
2861 if (found_key.offset == 0)
2862 break;
2863 }
2864 btrfs_release_path(log_root_tree, path);
2865
2866 /* step one is to pin it all, step two is to replay just inodes */
2867 if (wc.pin) {
2868 wc.pin = 0;
2869 wc.process_func = replay_one_buffer;
2870 wc.stage = LOG_WALK_REPLAY_INODES;
2871 goto again;
2872 }
2873 /* step three is to replay everything */
2874 if (wc.stage < LOG_WALK_REPLAY_ALL) {
2875 wc.stage++;
2876 goto again;
2877 }
2878
2879 btrfs_free_path(path);
2880
2881 free_extent_buffer(log_root_tree->node);
2882 log_root_tree->log_root = NULL;
2883 fs_info->log_root_recovering = 0;
2884
2885 /* step 4: commit the transaction, which also unpins the blocks */
2886 btrfs_commit_transaction(trans, fs_info->tree_root);
2887
2888 kfree(log_root_tree);
2889 return 0;
2890}
generated by cgit v1.2.2 (git 2.25.0) at 2025-01-01 08:23:48 -0500