Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux...
[~shefty/rdma-dev.git] / fs / btrfs / disk-io.c
1 /*
2  * Copyright (C) 2007 Oracle.  All rights reserved.
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public
6  * License v2 as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
11  * General Public License for more details.
12  *
13  * You should have received a copy of the GNU General Public
14  * License along with this program; if not, write to the
15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16  * Boston, MA 021110-1307, USA.
17  */
18
19 #include <linux/fs.h>
20 #include <linux/blkdev.h>
21 #include <linux/scatterlist.h>
22 #include <linux/swap.h>
23 #include <linux/radix-tree.h>
24 #include <linux/writeback.h>
25 #include <linux/buffer_head.h>
26 #include <linux/workqueue.h>
27 #include <linux/kthread.h>
28 #include <linux/freezer.h>
29 #include <linux/crc32c.h>
30 #include <linux/slab.h>
31 #include <linux/migrate.h>
32 #include <linux/ratelimit.h>
33 #include <asm/unaligned.h>
34 #include "compat.h"
35 #include "ctree.h"
36 #include "disk-io.h"
37 #include "transaction.h"
38 #include "btrfs_inode.h"
39 #include "volumes.h"
40 #include "print-tree.h"
41 #include "async-thread.h"
42 #include "locking.h"
43 #include "tree-log.h"
44 #include "free-space-cache.h"
45 #include "inode-map.h"
46 #include "check-integrity.h"
47
48 static struct extent_io_ops btree_extent_io_ops;
49 static void end_workqueue_fn(struct btrfs_work *work);
50 static void free_fs_root(struct btrfs_root *root);
51 static void btrfs_check_super_valid(struct btrfs_fs_info *fs_info,
52                                     int read_only);
53 static int btrfs_destroy_ordered_operations(struct btrfs_root *root);
54 static int btrfs_destroy_ordered_extents(struct btrfs_root *root);
55 static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
56                                       struct btrfs_root *root);
57 static int btrfs_destroy_pending_snapshots(struct btrfs_transaction *t);
58 static int btrfs_destroy_delalloc_inodes(struct btrfs_root *root);
59 static int btrfs_destroy_marked_extents(struct btrfs_root *root,
60                                         struct extent_io_tree *dirty_pages,
61                                         int mark);
62 static int btrfs_destroy_pinned_extent(struct btrfs_root *root,
63                                        struct extent_io_tree *pinned_extents);
64 static int btrfs_cleanup_transaction(struct btrfs_root *root);
65
66 /*
67  * end_io_wq structs are used to do processing in task context when an IO is
68  * complete.  This is used during reads to verify checksums, and it is used
69  * by writes to insert metadata for new file extents after IO is complete.
70  */
71 struct end_io_wq {
72         struct bio *bio;
73         bio_end_io_t *end_io;
74         void *private;
75         struct btrfs_fs_info *info;
76         int error;
77         int metadata;
78         struct list_head list;
79         struct btrfs_work work;
80 };
81
82 /*
83  * async submit bios are used to offload expensive checksumming
84  * onto the worker threads.  They checksum file and metadata bios
85  * just before they are sent down the IO stack.
86  */
87 struct async_submit_bio {
88         struct inode *inode;
89         struct bio *bio;
90         struct list_head list;
91         extent_submit_bio_hook_t *submit_bio_start;
92         extent_submit_bio_hook_t *submit_bio_done;
93         int rw;
94         int mirror_num;
95         unsigned long bio_flags;
96         /*
97          * bio_offset is optional, can be used if the pages in the bio
98          * can't tell us where in the file the bio should go
99          */
100         u64 bio_offset;
101         struct btrfs_work work;
102 };
103
104 /*
105  * Lockdep class keys for extent_buffer->lock's in this root.  For a given
106  * eb, the lockdep key is determined by the btrfs_root it belongs to and
107  * the level the eb occupies in the tree.
108  *
109  * Different roots are used for different purposes and may nest inside each
110  * other and they require separate keysets.  As lockdep keys should be
111  * static, assign keysets according to the purpose of the root as indicated
112  * by btrfs_root->objectid.  This ensures that all special purpose roots
113  * have separate keysets.
114  *
115  * Lock-nesting across peer nodes is always done with the immediate parent
116  * node locked thus preventing deadlock.  As lockdep doesn't know this, use
117  * subclass to avoid triggering lockdep warning in such cases.
118  *
119  * The key is set by the readpage_end_io_hook after the buffer has passed
120  * csum validation but before the pages are unlocked.  It is also set by
121  * btrfs_init_new_buffer on freshly allocated blocks.
122  *
123  * We also add a check to make sure the highest level of the tree is the
124  * same as our lockdep setup here.  If BTRFS_MAX_LEVEL changes, this code
125  * needs update as well.
126  */
127 #ifdef CONFIG_DEBUG_LOCK_ALLOC
128 # if BTRFS_MAX_LEVEL != 8
129 #  error
130 # endif
131
132 static struct btrfs_lockdep_keyset {
133         u64                     id;             /* root objectid */
134         const char              *name_stem;     /* lock name stem */
135         char                    names[BTRFS_MAX_LEVEL + 1][20];
136         struct lock_class_key   keys[BTRFS_MAX_LEVEL + 1];
137 } btrfs_lockdep_keysets[] = {
138         { .id = BTRFS_ROOT_TREE_OBJECTID,       .name_stem = "root"     },
139         { .id = BTRFS_EXTENT_TREE_OBJECTID,     .name_stem = "extent"   },
140         { .id = BTRFS_CHUNK_TREE_OBJECTID,      .name_stem = "chunk"    },
141         { .id = BTRFS_DEV_TREE_OBJECTID,        .name_stem = "dev"      },
142         { .id = BTRFS_FS_TREE_OBJECTID,         .name_stem = "fs"       },
143         { .id = BTRFS_CSUM_TREE_OBJECTID,       .name_stem = "csum"     },
144         { .id = BTRFS_ORPHAN_OBJECTID,          .name_stem = "orphan"   },
145         { .id = BTRFS_TREE_LOG_OBJECTID,        .name_stem = "log"      },
146         { .id = BTRFS_TREE_RELOC_OBJECTID,      .name_stem = "treloc"   },
147         { .id = BTRFS_DATA_RELOC_TREE_OBJECTID, .name_stem = "dreloc"   },
148         { .id = 0,                              .name_stem = "tree"     },
149 };
150
151 void __init btrfs_init_lockdep(void)
152 {
153         int i, j;
154
155         /* initialize lockdep class names */
156         for (i = 0; i < ARRAY_SIZE(btrfs_lockdep_keysets); i++) {
157                 struct btrfs_lockdep_keyset *ks = &btrfs_lockdep_keysets[i];
158
159                 for (j = 0; j < ARRAY_SIZE(ks->names); j++)
160                         snprintf(ks->names[j], sizeof(ks->names[j]),
161                                  "btrfs-%s-%02d", ks->name_stem, j);
162         }
163 }
164
165 void btrfs_set_buffer_lockdep_class(u64 objectid, struct extent_buffer *eb,
166                                     int level)
167 {
168         struct btrfs_lockdep_keyset *ks;
169
170         BUG_ON(level >= ARRAY_SIZE(ks->keys));
171
172         /* find the matching keyset, id 0 is the default entry */
173         for (ks = btrfs_lockdep_keysets; ks->id; ks++)
174                 if (ks->id == objectid)
175                         break;
176
177         lockdep_set_class_and_name(&eb->lock,
178                                    &ks->keys[level], ks->names[level]);
179 }
180
181 #endif
182
183 /*
184  * extents on the btree inode are pretty simple, there's one extent
185  * that covers the entire device
186  */
187 static struct extent_map *btree_get_extent(struct inode *inode,
188                 struct page *page, size_t pg_offset, u64 start, u64 len,
189                 int create)
190 {
191         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
192         struct extent_map *em;
193         int ret;
194
195         read_lock(&em_tree->lock);
196         em = lookup_extent_mapping(em_tree, start, len);
197         if (em) {
198                 em->bdev =
199                         BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
200                 read_unlock(&em_tree->lock);
201                 goto out;
202         }
203         read_unlock(&em_tree->lock);
204
205         em = alloc_extent_map();
206         if (!em) {
207                 em = ERR_PTR(-ENOMEM);
208                 goto out;
209         }
210         em->start = 0;
211         em->len = (u64)-1;
212         em->block_len = (u64)-1;
213         em->block_start = 0;
214         em->bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
215
216         write_lock(&em_tree->lock);
217         ret = add_extent_mapping(em_tree, em);
218         if (ret == -EEXIST) {
219                 u64 failed_start = em->start;
220                 u64 failed_len = em->len;
221
222                 free_extent_map(em);
223                 em = lookup_extent_mapping(em_tree, start, len);
224                 if (em) {
225                         ret = 0;
226                 } else {
227                         em = lookup_extent_mapping(em_tree, failed_start,
228                                                    failed_len);
229                         ret = -EIO;
230                 }
231         } else if (ret) {
232                 free_extent_map(em);
233                 em = NULL;
234         }
235         write_unlock(&em_tree->lock);
236
237         if (ret)
238                 em = ERR_PTR(ret);
239 out:
240         return em;
241 }
242
243 u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len)
244 {
245         return crc32c(seed, data, len);
246 }
247
248 void btrfs_csum_final(u32 crc, char *result)
249 {
250         put_unaligned_le32(~crc, result);
251 }
252
253 /*
254  * compute the csum for a btree block, and either verify it or write it
255  * into the csum field of the block.
256  */
257 static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
258                            int verify)
259 {
260         u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
261         char *result = NULL;
262         unsigned long len;
263         unsigned long cur_len;
264         unsigned long offset = BTRFS_CSUM_SIZE;
265         char *kaddr;
266         unsigned long map_start;
267         unsigned long map_len;
268         int err;
269         u32 crc = ~(u32)0;
270         unsigned long inline_result;
271
272         len = buf->len - offset;
273         while (len > 0) {
274                 err = map_private_extent_buffer(buf, offset, 32,
275                                         &kaddr, &map_start, &map_len);
276                 if (err)
277                         return 1;
278                 cur_len = min(len, map_len - (offset - map_start));
279                 crc = btrfs_csum_data(root, kaddr + offset - map_start,
280                                       crc, cur_len);
281                 len -= cur_len;
282                 offset += cur_len;
283         }
284         if (csum_size > sizeof(inline_result)) {
285                 result = kzalloc(csum_size * sizeof(char), GFP_NOFS);
286                 if (!result)
287                         return 1;
288         } else {
289                 result = (char *)&inline_result;
290         }
291
292         btrfs_csum_final(crc, result);
293
294         if (verify) {
295                 if (memcmp_extent_buffer(buf, result, 0, csum_size)) {
296                         u32 val;
297                         u32 found = 0;
298                         memcpy(&found, result, csum_size);
299
300                         read_extent_buffer(buf, &val, 0, csum_size);
301                         printk_ratelimited(KERN_INFO "btrfs: %s checksum verify "
302                                        "failed on %llu wanted %X found %X "
303                                        "level %d\n",
304                                        root->fs_info->sb->s_id,
305                                        (unsigned long long)buf->start, val, found,
306                                        btrfs_header_level(buf));
307                         if (result != (char *)&inline_result)
308                                 kfree(result);
309                         return 1;
310                 }
311         } else {
312                 write_extent_buffer(buf, result, 0, csum_size);
313         }
314         if (result != (char *)&inline_result)
315                 kfree(result);
316         return 0;
317 }
318
319 /*
320  * we can't consider a given block up to date unless the transid of the
321  * block matches the transid in the parent node's pointer.  This is how we
322  * detect blocks that either didn't get written at all or got written
323  * in the wrong place.
324  */
325 static int verify_parent_transid(struct extent_io_tree *io_tree,
326                                  struct extent_buffer *eb, u64 parent_transid)
327 {
328         struct extent_state *cached_state = NULL;
329         int ret;
330
331         if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
332                 return 0;
333
334         lock_extent_bits(io_tree, eb->start, eb->start + eb->len - 1,
335                          0, &cached_state, GFP_NOFS);
336         if (extent_buffer_uptodate(io_tree, eb, cached_state) &&
337             btrfs_header_generation(eb) == parent_transid) {
338                 ret = 0;
339                 goto out;
340         }
341         printk_ratelimited("parent transid verify failed on %llu wanted %llu "
342                        "found %llu\n",
343                        (unsigned long long)eb->start,
344                        (unsigned long long)parent_transid,
345                        (unsigned long long)btrfs_header_generation(eb));
346         ret = 1;
347         clear_extent_buffer_uptodate(io_tree, eb, &cached_state);
348 out:
349         unlock_extent_cached(io_tree, eb->start, eb->start + eb->len - 1,
350                              &cached_state, GFP_NOFS);
351         return ret;
352 }
353
354 /*
355  * helper to read a given tree block, doing retries as required when
356  * the checksums don't match and we have alternate mirrors to try.
357  */
358 static int btree_read_extent_buffer_pages(struct btrfs_root *root,
359                                           struct extent_buffer *eb,
360                                           u64 start, u64 parent_transid)
361 {
362         struct extent_io_tree *io_tree;
363         int ret;
364         int num_copies = 0;
365         int mirror_num = 0;
366
367         clear_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
368         io_tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
369         while (1) {
370                 ret = read_extent_buffer_pages(io_tree, eb, start,
371                                                WAIT_COMPLETE,
372                                                btree_get_extent, mirror_num);
373                 if (!ret &&
374                     !verify_parent_transid(io_tree, eb, parent_transid))
375                         return ret;
376
377                 /*
378                  * This buffer's crc is fine, but its contents are corrupted, so
379                  * there is no reason to read the other copies, they won't be
380                  * any less wrong.
381                  */
382                 if (test_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags))
383                         return ret;
384
385                 num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
386                                               eb->start, eb->len);
387                 if (num_copies == 1)
388                         return ret;
389
390                 mirror_num++;
391                 if (mirror_num > num_copies)
392                         return ret;
393         }
394         return -EIO;
395 }
396
397 /*
398  * checksum a dirty tree block before IO.  This has extra checks to make sure
399  * we only fill in the checksum field in the first page of a multi-page block
400  */
401
402 static int csum_dirty_buffer(struct btrfs_root *root, struct page *page)
403 {
404         struct extent_io_tree *tree;
405         u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
406         u64 found_start;
407         unsigned long len;
408         struct extent_buffer *eb;
409         int ret;
410
411         tree = &BTRFS_I(page->mapping->host)->io_tree;
412
413         if (page->private == EXTENT_PAGE_PRIVATE) {
414                 WARN_ON(1);
415                 goto out;
416         }
417         if (!page->private) {
418                 WARN_ON(1);
419                 goto out;
420         }
421         len = page->private >> 2;
422         WARN_ON(len == 0);
423
424         eb = alloc_extent_buffer(tree, start, len, page);
425         if (eb == NULL) {
426                 WARN_ON(1);
427                 goto out;
428         }
429         ret = btree_read_extent_buffer_pages(root, eb, start + PAGE_CACHE_SIZE,
430                                              btrfs_header_generation(eb));
431         BUG_ON(ret);
432         WARN_ON(!btrfs_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN));
433
434         found_start = btrfs_header_bytenr(eb);
435         if (found_start != start) {
436                 WARN_ON(1);
437                 goto err;
438         }
439         if (eb->first_page != page) {
440                 WARN_ON(1);
441                 goto err;
442         }
443         if (!PageUptodate(page)) {
444                 WARN_ON(1);
445                 goto err;
446         }
447         csum_tree_block(root, eb, 0);
448 err:
449         free_extent_buffer(eb);
450 out:
451         return 0;
452 }
453
454 static int check_tree_block_fsid(struct btrfs_root *root,
455                                  struct extent_buffer *eb)
456 {
457         struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
458         u8 fsid[BTRFS_UUID_SIZE];
459         int ret = 1;
460
461         read_extent_buffer(eb, fsid, (unsigned long)btrfs_header_fsid(eb),
462                            BTRFS_FSID_SIZE);
463         while (fs_devices) {
464                 if (!memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE)) {
465                         ret = 0;
466                         break;
467                 }
468                 fs_devices = fs_devices->seed;
469         }
470         return ret;
471 }
472
473 #define CORRUPT(reason, eb, root, slot)                         \
474         printk(KERN_CRIT "btrfs: corrupt leaf, %s: block=%llu," \
475                "root=%llu, slot=%d\n", reason,                  \
476                (unsigned long long)btrfs_header_bytenr(eb),     \
477                (unsigned long long)root->objectid, slot)
478
479 static noinline int check_leaf(struct btrfs_root *root,
480                                struct extent_buffer *leaf)
481 {
482         struct btrfs_key key;
483         struct btrfs_key leaf_key;
484         u32 nritems = btrfs_header_nritems(leaf);
485         int slot;
486
487         if (nritems == 0)
488                 return 0;
489
490         /* Check the 0 item */
491         if (btrfs_item_offset_nr(leaf, 0) + btrfs_item_size_nr(leaf, 0) !=
492             BTRFS_LEAF_DATA_SIZE(root)) {
493                 CORRUPT("invalid item offset size pair", leaf, root, 0);
494                 return -EIO;
495         }
496
497         /*
498          * Check to make sure each items keys are in the correct order and their
499          * offsets make sense.  We only have to loop through nritems-1 because
500          * we check the current slot against the next slot, which verifies the
501          * next slot's offset+size makes sense and that the current's slot
502          * offset is correct.
503          */
504         for (slot = 0; slot < nritems - 1; slot++) {
505                 btrfs_item_key_to_cpu(leaf, &leaf_key, slot);
506                 btrfs_item_key_to_cpu(leaf, &key, slot + 1);
507
508                 /* Make sure the keys are in the right order */
509                 if (btrfs_comp_cpu_keys(&leaf_key, &key) >= 0) {
510                         CORRUPT("bad key order", leaf, root, slot);
511                         return -EIO;
512                 }
513
514                 /*
515                  * Make sure the offset and ends are right, remember that the
516                  * item data starts at the end of the leaf and grows towards the
517                  * front.
518                  */
519                 if (btrfs_item_offset_nr(leaf, slot) !=
520                         btrfs_item_end_nr(leaf, slot + 1)) {
521                         CORRUPT("slot offset bad", leaf, root, slot);
522                         return -EIO;
523                 }
524
525                 /*
526                  * Check to make sure that we don't point outside of the leaf,
527                  * just incase all the items are consistent to eachother, but
528                  * all point outside of the leaf.
529                  */
530                 if (btrfs_item_end_nr(leaf, slot) >
531                     BTRFS_LEAF_DATA_SIZE(root)) {
532                         CORRUPT("slot end outside of leaf", leaf, root, slot);
533                         return -EIO;
534                 }
535         }
536
537         return 0;
538 }
539
540 static int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end,
541                                struct extent_state *state)
542 {
543         struct extent_io_tree *tree;
544         u64 found_start;
545         int found_level;
546         unsigned long len;
547         struct extent_buffer *eb;
548         struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
549         int ret = 0;
550
551         tree = &BTRFS_I(page->mapping->host)->io_tree;
552         if (page->private == EXTENT_PAGE_PRIVATE)
553                 goto out;
554         if (!page->private)
555                 goto out;
556
557         len = page->private >> 2;
558         WARN_ON(len == 0);
559
560         eb = alloc_extent_buffer(tree, start, len, page);
561         if (eb == NULL) {
562                 ret = -EIO;
563                 goto out;
564         }
565
566         found_start = btrfs_header_bytenr(eb);
567         if (found_start != start) {
568                 printk_ratelimited(KERN_INFO "btrfs bad tree block start "
569                                "%llu %llu\n",
570                                (unsigned long long)found_start,
571                                (unsigned long long)eb->start);
572                 ret = -EIO;
573                 goto err;
574         }
575         if (eb->first_page != page) {
576                 printk(KERN_INFO "btrfs bad first page %lu %lu\n",
577                        eb->first_page->index, page->index);
578                 WARN_ON(1);
579                 ret = -EIO;
580                 goto err;
581         }
582         if (check_tree_block_fsid(root, eb)) {
583                 printk_ratelimited(KERN_INFO "btrfs bad fsid on block %llu\n",
584                                (unsigned long long)eb->start);
585                 ret = -EIO;
586                 goto err;
587         }
588         found_level = btrfs_header_level(eb);
589
590         btrfs_set_buffer_lockdep_class(btrfs_header_owner(eb),
591                                        eb, found_level);
592
593         ret = csum_tree_block(root, eb, 1);
594         if (ret) {
595                 ret = -EIO;
596                 goto err;
597         }
598
599         /*
600          * If this is a leaf block and it is corrupt, set the corrupt bit so
601          * that we don't try and read the other copies of this block, just
602          * return -EIO.
603          */
604         if (found_level == 0 && check_leaf(root, eb)) {
605                 set_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
606                 ret = -EIO;
607         }
608
609         end = min_t(u64, eb->len, PAGE_CACHE_SIZE);
610         end = eb->start + end - 1;
611 err:
612         if (test_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags)) {
613                 clear_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags);
614                 btree_readahead_hook(root, eb, eb->start, ret);
615         }
616
617         free_extent_buffer(eb);
618 out:
619         return ret;
620 }
621
622 static int btree_io_failed_hook(struct bio *failed_bio,
623                          struct page *page, u64 start, u64 end,
624                          int mirror_num, struct extent_state *state)
625 {
626         struct extent_io_tree *tree;
627         unsigned long len;
628         struct extent_buffer *eb;
629         struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
630
631         tree = &BTRFS_I(page->mapping->host)->io_tree;
632         if (page->private == EXTENT_PAGE_PRIVATE)
633                 goto out;
634         if (!page->private)
635                 goto out;
636
637         len = page->private >> 2;
638         WARN_ON(len == 0);
639
640         eb = alloc_extent_buffer(tree, start, len, page);
641         if (eb == NULL)
642                 goto out;
643
644         if (test_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags)) {
645                 clear_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags);
646                 btree_readahead_hook(root, eb, eb->start, -EIO);
647         }
648         free_extent_buffer(eb);
649
650 out:
651         return -EIO;    /* we fixed nothing */
652 }
653
654 static void end_workqueue_bio(struct bio *bio, int err)
655 {
656         struct end_io_wq *end_io_wq = bio->bi_private;
657         struct btrfs_fs_info *fs_info;
658
659         fs_info = end_io_wq->info;
660         end_io_wq->error = err;
661         end_io_wq->work.func = end_workqueue_fn;
662         end_io_wq->work.flags = 0;
663
664         if (bio->bi_rw & REQ_WRITE) {
665                 if (end_io_wq->metadata == 1)
666                         btrfs_queue_worker(&fs_info->endio_meta_write_workers,
667                                            &end_io_wq->work);
668                 else if (end_io_wq->metadata == 2)
669                         btrfs_queue_worker(&fs_info->endio_freespace_worker,
670                                            &end_io_wq->work);
671                 else
672                         btrfs_queue_worker(&fs_info->endio_write_workers,
673                                            &end_io_wq->work);
674         } else {
675                 if (end_io_wq->metadata)
676                         btrfs_queue_worker(&fs_info->endio_meta_workers,
677                                            &end_io_wq->work);
678                 else
679                         btrfs_queue_worker(&fs_info->endio_workers,
680                                            &end_io_wq->work);
681         }
682 }
683
684 /*
685  * For the metadata arg you want
686  *
687  * 0 - if data
688  * 1 - if normal metadta
689  * 2 - if writing to the free space cache area
690  */
691 int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
692                         int metadata)
693 {
694         struct end_io_wq *end_io_wq;
695         end_io_wq = kmalloc(sizeof(*end_io_wq), GFP_NOFS);
696         if (!end_io_wq)
697                 return -ENOMEM;
698
699         end_io_wq->private = bio->bi_private;
700         end_io_wq->end_io = bio->bi_end_io;
701         end_io_wq->info = info;
702         end_io_wq->error = 0;
703         end_io_wq->bio = bio;
704         end_io_wq->metadata = metadata;
705
706         bio->bi_private = end_io_wq;
707         bio->bi_end_io = end_workqueue_bio;
708         return 0;
709 }
710
711 unsigned long btrfs_async_submit_limit(struct btrfs_fs_info *info)
712 {
713         unsigned long limit = min_t(unsigned long,
714                                     info->workers.max_workers,
715                                     info->fs_devices->open_devices);
716         return 256 * limit;
717 }
718
719 static void run_one_async_start(struct btrfs_work *work)
720 {
721         struct async_submit_bio *async;
722
723         async = container_of(work, struct  async_submit_bio, work);
724         async->submit_bio_start(async->inode, async->rw, async->bio,
725                                async->mirror_num, async->bio_flags,
726                                async->bio_offset);
727 }
728
729 static void run_one_async_done(struct btrfs_work *work)
730 {
731         struct btrfs_fs_info *fs_info;
732         struct async_submit_bio *async;
733         int limit;
734
735         async = container_of(work, struct  async_submit_bio, work);
736         fs_info = BTRFS_I(async->inode)->root->fs_info;
737
738         limit = btrfs_async_submit_limit(fs_info);
739         limit = limit * 2 / 3;
740
741         atomic_dec(&fs_info->nr_async_submits);
742
743         if (atomic_read(&fs_info->nr_async_submits) < limit &&
744             waitqueue_active(&fs_info->async_submit_wait))
745                 wake_up(&fs_info->async_submit_wait);
746
747         async->submit_bio_done(async->inode, async->rw, async->bio,
748                                async->mirror_num, async->bio_flags,
749                                async->bio_offset);
750 }
751
752 static void run_one_async_free(struct btrfs_work *work)
753 {
754         struct async_submit_bio *async;
755
756         async = container_of(work, struct  async_submit_bio, work);
757         kfree(async);
758 }
759
760 int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
761                         int rw, struct bio *bio, int mirror_num,
762                         unsigned long bio_flags,
763                         u64 bio_offset,
764                         extent_submit_bio_hook_t *submit_bio_start,
765                         extent_submit_bio_hook_t *submit_bio_done)
766 {
767         struct async_submit_bio *async;
768
769         async = kmalloc(sizeof(*async), GFP_NOFS);
770         if (!async)
771                 return -ENOMEM;
772
773         async->inode = inode;
774         async->rw = rw;
775         async->bio = bio;
776         async->mirror_num = mirror_num;
777         async->submit_bio_start = submit_bio_start;
778         async->submit_bio_done = submit_bio_done;
779
780         async->work.func = run_one_async_start;
781         async->work.ordered_func = run_one_async_done;
782         async->work.ordered_free = run_one_async_free;
783
784         async->work.flags = 0;
785         async->bio_flags = bio_flags;
786         async->bio_offset = bio_offset;
787
788         atomic_inc(&fs_info->nr_async_submits);
789
790         if (rw & REQ_SYNC)
791                 btrfs_set_work_high_prio(&async->work);
792
793         btrfs_queue_worker(&fs_info->workers, &async->work);
794
795         while (atomic_read(&fs_info->async_submit_draining) &&
796               atomic_read(&fs_info->nr_async_submits)) {
797                 wait_event(fs_info->async_submit_wait,
798                            (atomic_read(&fs_info->nr_async_submits) == 0));
799         }
800
801         return 0;
802 }
803
804 static int btree_csum_one_bio(struct bio *bio)
805 {
806         struct bio_vec *bvec = bio->bi_io_vec;
807         int bio_index = 0;
808         struct btrfs_root *root;
809
810         WARN_ON(bio->bi_vcnt <= 0);
811         while (bio_index < bio->bi_vcnt) {
812                 root = BTRFS_I(bvec->bv_page->mapping->host)->root;
813                 csum_dirty_buffer(root, bvec->bv_page);
814                 bio_index++;
815                 bvec++;
816         }
817         return 0;
818 }
819
820 static int __btree_submit_bio_start(struct inode *inode, int rw,
821                                     struct bio *bio, int mirror_num,
822                                     unsigned long bio_flags,
823                                     u64 bio_offset)
824 {
825         /*
826          * when we're called for a write, we're already in the async
827          * submission context.  Just jump into btrfs_map_bio
828          */
829         btree_csum_one_bio(bio);
830         return 0;
831 }
832
833 static int __btree_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
834                                  int mirror_num, unsigned long bio_flags,
835                                  u64 bio_offset)
836 {
837         /*
838          * when we're called for a write, we're already in the async
839          * submission context.  Just jump into btrfs_map_bio
840          */
841         return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio, mirror_num, 1);
842 }
843
844 static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
845                                  int mirror_num, unsigned long bio_flags,
846                                  u64 bio_offset)
847 {
848         int ret;
849
850         ret = btrfs_bio_wq_end_io(BTRFS_I(inode)->root->fs_info,
851                                           bio, 1);
852         BUG_ON(ret);
853
854         if (!(rw & REQ_WRITE)) {
855                 /*
856                  * called for a read, do the setup so that checksum validation
857                  * can happen in the async kernel threads
858                  */
859                 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio,
860                                      mirror_num, 0);
861         }
862
863         /*
864          * kthread helpers are used to submit writes so that checksumming
865          * can happen in parallel across all CPUs
866          */
867         return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
868                                    inode, rw, bio, mirror_num, 0,
869                                    bio_offset,
870                                    __btree_submit_bio_start,
871                                    __btree_submit_bio_done);
872 }
873
874 #ifdef CONFIG_MIGRATION
875 static int btree_migratepage(struct address_space *mapping,
876                         struct page *newpage, struct page *page,
877                         enum migrate_mode mode)
878 {
879         /*
880          * we can't safely write a btree page from here,
881          * we haven't done the locking hook
882          */
883         if (PageDirty(page))
884                 return -EAGAIN;
885         /*
886          * Buffers may be managed in a filesystem specific way.
887          * We must have no buffers or drop them.
888          */
889         if (page_has_private(page) &&
890             !try_to_release_page(page, GFP_KERNEL))
891                 return -EAGAIN;
892         return migrate_page(mapping, newpage, page, mode);
893 }
894 #endif
895
896 static int btree_writepage(struct page *page, struct writeback_control *wbc)
897 {
898         struct extent_io_tree *tree;
899         struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
900         struct extent_buffer *eb;
901         int was_dirty;
902
903         tree = &BTRFS_I(page->mapping->host)->io_tree;
904         if (!(current->flags & PF_MEMALLOC)) {
905                 return extent_write_full_page(tree, page,
906                                               btree_get_extent, wbc);
907         }
908
909         redirty_page_for_writepage(wbc, page);
910         eb = btrfs_find_tree_block(root, page_offset(page), PAGE_CACHE_SIZE);
911         WARN_ON(!eb);
912
913         was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
914         if (!was_dirty) {
915                 spin_lock(&root->fs_info->delalloc_lock);
916                 root->fs_info->dirty_metadata_bytes += PAGE_CACHE_SIZE;
917                 spin_unlock(&root->fs_info->delalloc_lock);
918         }
919         free_extent_buffer(eb);
920
921         unlock_page(page);
922         return 0;
923 }
924
925 static int btree_writepages(struct address_space *mapping,
926                             struct writeback_control *wbc)
927 {
928         struct extent_io_tree *tree;
929         tree = &BTRFS_I(mapping->host)->io_tree;
930         if (wbc->sync_mode == WB_SYNC_NONE) {
931                 struct btrfs_root *root = BTRFS_I(mapping->host)->root;
932                 u64 num_dirty;
933                 unsigned long thresh = 32 * 1024 * 1024;
934
935                 if (wbc->for_kupdate)
936                         return 0;
937
938                 /* this is a bit racy, but that's ok */
939                 num_dirty = root->fs_info->dirty_metadata_bytes;
940                 if (num_dirty < thresh)
941                         return 0;
942         }
943         return extent_writepages(tree, mapping, btree_get_extent, wbc);
944 }
945
946 static int btree_readpage(struct file *file, struct page *page)
947 {
948         struct extent_io_tree *tree;
949         tree = &BTRFS_I(page->mapping->host)->io_tree;
950         return extent_read_full_page(tree, page, btree_get_extent, 0);
951 }
952
953 static int btree_releasepage(struct page *page, gfp_t gfp_flags)
954 {
955         struct extent_io_tree *tree;
956         struct extent_map_tree *map;
957         int ret;
958
959         if (PageWriteback(page) || PageDirty(page))
960                 return 0;
961
962         tree = &BTRFS_I(page->mapping->host)->io_tree;
963         map = &BTRFS_I(page->mapping->host)->extent_tree;
964
965         ret = try_release_extent_state(map, tree, page, gfp_flags);
966         if (!ret)
967                 return 0;
968
969         ret = try_release_extent_buffer(tree, page);
970         if (ret == 1) {
971                 ClearPagePrivate(page);
972                 set_page_private(page, 0);
973                 page_cache_release(page);
974         }
975
976         return ret;
977 }
978
979 static void btree_invalidatepage(struct page *page, unsigned long offset)
980 {
981         struct extent_io_tree *tree;
982         tree = &BTRFS_I(page->mapping->host)->io_tree;
983         extent_invalidatepage(tree, page, offset);
984         btree_releasepage(page, GFP_NOFS);
985         if (PagePrivate(page)) {
986                 printk(KERN_WARNING "btrfs warning page private not zero "
987                        "on page %llu\n", (unsigned long long)page_offset(page));
988                 ClearPagePrivate(page);
989                 set_page_private(page, 0);
990                 page_cache_release(page);
991         }
992 }
993
994 static const struct address_space_operations btree_aops = {
995         .readpage       = btree_readpage,
996         .writepage      = btree_writepage,
997         .writepages     = btree_writepages,
998         .releasepage    = btree_releasepage,
999         .invalidatepage = btree_invalidatepage,
1000 #ifdef CONFIG_MIGRATION
1001         .migratepage    = btree_migratepage,
1002 #endif
1003 };
1004
1005 int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
1006                          u64 parent_transid)
1007 {
1008         struct extent_buffer *buf = NULL;
1009         struct inode *btree_inode = root->fs_info->btree_inode;
1010         int ret = 0;
1011
1012         buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
1013         if (!buf)
1014                 return 0;
1015         read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
1016                                  buf, 0, WAIT_NONE, btree_get_extent, 0);
1017         free_extent_buffer(buf);
1018         return ret;
1019 }
1020
1021 int reada_tree_block_flagged(struct btrfs_root *root, u64 bytenr, u32 blocksize,
1022                          int mirror_num, struct extent_buffer **eb)
1023 {
1024         struct extent_buffer *buf = NULL;
1025         struct inode *btree_inode = root->fs_info->btree_inode;
1026         struct extent_io_tree *io_tree = &BTRFS_I(btree_inode)->io_tree;
1027         int ret;
1028
1029         buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
1030         if (!buf)
1031                 return 0;
1032
1033         set_bit(EXTENT_BUFFER_READAHEAD, &buf->bflags);
1034
1035         ret = read_extent_buffer_pages(io_tree, buf, 0, WAIT_PAGE_LOCK,
1036                                        btree_get_extent, mirror_num);
1037         if (ret) {
1038                 free_extent_buffer(buf);
1039                 return ret;
1040         }
1041
1042         if (test_bit(EXTENT_BUFFER_CORRUPT, &buf->bflags)) {
1043                 free_extent_buffer(buf);
1044                 return -EIO;
1045         } else if (extent_buffer_uptodate(io_tree, buf, NULL)) {
1046                 *eb = buf;
1047         } else {
1048                 free_extent_buffer(buf);
1049         }
1050         return 0;
1051 }
1052
1053 struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
1054                                             u64 bytenr, u32 blocksize)
1055 {
1056         struct inode *btree_inode = root->fs_info->btree_inode;
1057         struct extent_buffer *eb;
1058         eb = find_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
1059                                 bytenr, blocksize);
1060         return eb;
1061 }
1062
1063 struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
1064                                                  u64 bytenr, u32 blocksize)
1065 {
1066         struct inode *btree_inode = root->fs_info->btree_inode;
1067         struct extent_buffer *eb;
1068
1069         eb = alloc_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
1070                                  bytenr, blocksize, NULL);
1071         return eb;
1072 }
1073
1074
1075 int btrfs_write_tree_block(struct extent_buffer *buf)
1076 {
1077         return filemap_fdatawrite_range(buf->first_page->mapping, buf->start,
1078                                         buf->start + buf->len - 1);
1079 }
1080
1081 int btrfs_wait_tree_block_writeback(struct extent_buffer *buf)
1082 {
1083         return filemap_fdatawait_range(buf->first_page->mapping,
1084                                        buf->start, buf->start + buf->len - 1);
1085 }
1086
1087 struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
1088                                       u32 blocksize, u64 parent_transid)
1089 {
1090         struct extent_buffer *buf = NULL;
1091         int ret;
1092
1093         buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
1094         if (!buf)
1095                 return NULL;
1096
1097         ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
1098
1099         if (ret == 0)
1100                 set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
1101         return buf;
1102
1103 }
1104
1105 int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
1106                      struct extent_buffer *buf)
1107 {
1108         struct inode *btree_inode = root->fs_info->btree_inode;
1109         if (btrfs_header_generation(buf) ==
1110             root->fs_info->running_transaction->transid) {
1111                 btrfs_assert_tree_locked(buf);
1112
1113                 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &buf->bflags)) {
1114                         spin_lock(&root->fs_info->delalloc_lock);
1115                         if (root->fs_info->dirty_metadata_bytes >= buf->len)
1116                                 root->fs_info->dirty_metadata_bytes -= buf->len;
1117                         else
1118                                 WARN_ON(1);
1119                         spin_unlock(&root->fs_info->delalloc_lock);
1120                 }
1121
1122                 /* ugh, clear_extent_buffer_dirty needs to lock the page */
1123                 btrfs_set_lock_blocking(buf);
1124                 clear_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
1125                                           buf);
1126         }
1127         return 0;
1128 }
1129
1130 static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
1131                         u32 stripesize, struct btrfs_root *root,
1132                         struct btrfs_fs_info *fs_info,
1133                         u64 objectid)
1134 {
1135         root->node = NULL;
1136         root->commit_root = NULL;
1137         root->sectorsize = sectorsize;
1138         root->nodesize = nodesize;
1139         root->leafsize = leafsize;
1140         root->stripesize = stripesize;
1141         root->ref_cows = 0;
1142         root->track_dirty = 0;
1143         root->in_radix = 0;
1144         root->orphan_item_inserted = 0;
1145         root->orphan_cleanup_state = 0;
1146
1147         root->fs_info = fs_info;
1148         root->objectid = objectid;
1149         root->last_trans = 0;
1150         root->highest_objectid = 0;
1151         root->name = NULL;
1152         root->inode_tree = RB_ROOT;
1153         INIT_RADIX_TREE(&root->delayed_nodes_tree, GFP_ATOMIC);
1154         root->block_rsv = NULL;
1155         root->orphan_block_rsv = NULL;
1156
1157         INIT_LIST_HEAD(&root->dirty_list);
1158         INIT_LIST_HEAD(&root->orphan_list);
1159         INIT_LIST_HEAD(&root->root_list);
1160         spin_lock_init(&root->orphan_lock);
1161         spin_lock_init(&root->inode_lock);
1162         spin_lock_init(&root->accounting_lock);
1163         mutex_init(&root->objectid_mutex);
1164         mutex_init(&root->log_mutex);
1165         init_waitqueue_head(&root->log_writer_wait);
1166         init_waitqueue_head(&root->log_commit_wait[0]);
1167         init_waitqueue_head(&root->log_commit_wait[1]);
1168         atomic_set(&root->log_commit[0], 0);
1169         atomic_set(&root->log_commit[1], 0);
1170         atomic_set(&root->log_writers, 0);
1171         root->log_batch = 0;
1172         root->log_transid = 0;
1173         root->last_log_commit = 0;
1174         extent_io_tree_init(&root->dirty_log_pages,
1175                              fs_info->btree_inode->i_mapping);
1176
1177         memset(&root->root_key, 0, sizeof(root->root_key));
1178         memset(&root->root_item, 0, sizeof(root->root_item));
1179         memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
1180         memset(&root->root_kobj, 0, sizeof(root->root_kobj));
1181         root->defrag_trans_start = fs_info->generation;
1182         init_completion(&root->kobj_unregister);
1183         root->defrag_running = 0;
1184         root->root_key.objectid = objectid;
1185         root->anon_dev = 0;
1186         return 0;
1187 }
1188
1189 static int find_and_setup_root(struct btrfs_root *tree_root,
1190                                struct btrfs_fs_info *fs_info,
1191                                u64 objectid,
1192                                struct btrfs_root *root)
1193 {
1194         int ret;
1195         u32 blocksize;
1196         u64 generation;
1197
1198         __setup_root(tree_root->nodesize, tree_root->leafsize,
1199                      tree_root->sectorsize, tree_root->stripesize,
1200                      root, fs_info, objectid);
1201         ret = btrfs_find_last_root(tree_root, objectid,
1202                                    &root->root_item, &root->root_key);
1203         if (ret > 0)
1204                 return -ENOENT;
1205         BUG_ON(ret);
1206
1207         generation = btrfs_root_generation(&root->root_item);
1208         blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
1209         root->commit_root = NULL;
1210         root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
1211                                      blocksize, generation);
1212         if (!root->node || !btrfs_buffer_uptodate(root->node, generation)) {
1213                 free_extent_buffer(root->node);
1214                 root->node = NULL;
1215                 return -EIO;
1216         }
1217         root->commit_root = btrfs_root_node(root);
1218         return 0;
1219 }
1220
1221 static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
1222                                          struct btrfs_fs_info *fs_info)
1223 {
1224         struct btrfs_root *root;
1225         struct btrfs_root *tree_root = fs_info->tree_root;
1226         struct extent_buffer *leaf;
1227
1228         root = kzalloc(sizeof(*root), GFP_NOFS);
1229         if (!root)
1230                 return ERR_PTR(-ENOMEM);
1231
1232         __setup_root(tree_root->nodesize, tree_root->leafsize,
1233                      tree_root->sectorsize, tree_root->stripesize,
1234                      root, fs_info, BTRFS_TREE_LOG_OBJECTID);
1235
1236         root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID;
1237         root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1238         root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
1239         /*
1240          * log trees do not get reference counted because they go away
1241          * before a real commit is actually done.  They do store pointers
1242          * to file data extents, and those reference counts still get
1243          * updated (along with back refs to the log tree).
1244          */
1245         root->ref_cows = 0;
1246
1247         leaf = btrfs_alloc_free_block(trans, root, root->leafsize, 0,
1248                                       BTRFS_TREE_LOG_OBJECTID, NULL,
1249                                       0, 0, 0, 0);
1250         if (IS_ERR(leaf)) {
1251                 kfree(root);
1252                 return ERR_CAST(leaf);
1253         }
1254
1255         memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
1256         btrfs_set_header_bytenr(leaf, leaf->start);
1257         btrfs_set_header_generation(leaf, trans->transid);
1258         btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
1259         btrfs_set_header_owner(leaf, BTRFS_TREE_LOG_OBJECTID);
1260         root->node = leaf;
1261
1262         write_extent_buffer(root->node, root->fs_info->fsid,
1263                             (unsigned long)btrfs_header_fsid(root->node),
1264                             BTRFS_FSID_SIZE);
1265         btrfs_mark_buffer_dirty(root->node);
1266         btrfs_tree_unlock(root->node);
1267         return root;
1268 }
1269
1270 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
1271                              struct btrfs_fs_info *fs_info)
1272 {
1273         struct btrfs_root *log_root;
1274
1275         log_root = alloc_log_tree(trans, fs_info);
1276         if (IS_ERR(log_root))
1277                 return PTR_ERR(log_root);
1278         WARN_ON(fs_info->log_root_tree);
1279         fs_info->log_root_tree = log_root;
1280         return 0;
1281 }
1282
1283 int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
1284                        struct btrfs_root *root)
1285 {
1286         struct btrfs_root *log_root;
1287         struct btrfs_inode_item *inode_item;
1288
1289         log_root = alloc_log_tree(trans, root->fs_info);
1290         if (IS_ERR(log_root))
1291                 return PTR_ERR(log_root);
1292
1293         log_root->last_trans = trans->transid;
1294         log_root->root_key.offset = root->root_key.objectid;
1295
1296         inode_item = &log_root->root_item.inode;
1297         inode_item->generation = cpu_to_le64(1);
1298         inode_item->size = cpu_to_le64(3);
1299         inode_item->nlink = cpu_to_le32(1);
1300         inode_item->nbytes = cpu_to_le64(root->leafsize);
1301         inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
1302
1303         btrfs_set_root_node(&log_root->root_item, log_root->node);
1304
1305         WARN_ON(root->log_root);
1306         root->log_root = log_root;
1307         root->log_transid = 0;
1308         root->last_log_commit = 0;
1309         return 0;
1310 }
1311
1312 struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root,
1313                                                struct btrfs_key *location)
1314 {
1315         struct btrfs_root *root;
1316         struct btrfs_fs_info *fs_info = tree_root->fs_info;
1317         struct btrfs_path *path;
1318         struct extent_buffer *l;
1319         u64 generation;
1320         u32 blocksize;
1321         int ret = 0;
1322
1323         root = kzalloc(sizeof(*root), GFP_NOFS);
1324         if (!root)
1325                 return ERR_PTR(-ENOMEM);
1326         if (location->offset == (u64)-1) {
1327                 ret = find_and_setup_root(tree_root, fs_info,
1328                                           location->objectid, root);
1329                 if (ret) {
1330                         kfree(root);
1331                         return ERR_PTR(ret);
1332                 }
1333                 goto out;
1334         }
1335
1336         __setup_root(tree_root->nodesize, tree_root->leafsize,
1337                      tree_root->sectorsize, tree_root->stripesize,
1338                      root, fs_info, location->objectid);
1339
1340         path = btrfs_alloc_path();
1341         if (!path) {
1342                 kfree(root);
1343                 return ERR_PTR(-ENOMEM);
1344         }
1345         ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
1346         if (ret == 0) {
1347                 l = path->nodes[0];
1348                 read_extent_buffer(l, &root->root_item,
1349                                 btrfs_item_ptr_offset(l, path->slots[0]),
1350                                 sizeof(root->root_item));
1351                 memcpy(&root->root_key, location, sizeof(*location));
1352         }
1353         btrfs_free_path(path);
1354         if (ret) {
1355                 kfree(root);
1356                 if (ret > 0)
1357                         ret = -ENOENT;
1358                 return ERR_PTR(ret);
1359         }
1360
1361         generation = btrfs_root_generation(&root->root_item);
1362         blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
1363         root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
1364                                      blocksize, generation);
1365         root->commit_root = btrfs_root_node(root);
1366         BUG_ON(!root->node);
1367 out:
1368         if (location->objectid != BTRFS_TREE_LOG_OBJECTID) {
1369                 root->ref_cows = 1;
1370                 btrfs_check_and_init_root_item(&root->root_item);
1371         }
1372
1373         return root;
1374 }
1375
1376 struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
1377                                               struct btrfs_key *location)
1378 {
1379         struct btrfs_root *root;
1380         int ret;
1381
1382         if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
1383                 return fs_info->tree_root;
1384         if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
1385                 return fs_info->extent_root;
1386         if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
1387                 return fs_info->chunk_root;
1388         if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
1389                 return fs_info->dev_root;
1390         if (location->objectid == BTRFS_CSUM_TREE_OBJECTID)
1391                 return fs_info->csum_root;
1392 again:
1393         spin_lock(&fs_info->fs_roots_radix_lock);
1394         root = radix_tree_lookup(&fs_info->fs_roots_radix,
1395                                  (unsigned long)location->objectid);
1396         spin_unlock(&fs_info->fs_roots_radix_lock);
1397         if (root)
1398                 return root;
1399
1400         root = btrfs_read_fs_root_no_radix(fs_info->tree_root, location);
1401         if (IS_ERR(root))
1402                 return root;
1403
1404         root->free_ino_ctl = kzalloc(sizeof(*root->free_ino_ctl), GFP_NOFS);
1405         root->free_ino_pinned = kzalloc(sizeof(*root->free_ino_pinned),
1406                                         GFP_NOFS);
1407         if (!root->free_ino_pinned || !root->free_ino_ctl) {
1408                 ret = -ENOMEM;
1409                 goto fail;
1410         }
1411
1412         btrfs_init_free_ino_ctl(root);
1413         mutex_init(&root->fs_commit_mutex);
1414         spin_lock_init(&root->cache_lock);
1415         init_waitqueue_head(&root->cache_wait);
1416
1417         ret = get_anon_bdev(&root->anon_dev);
1418         if (ret)
1419                 goto fail;
1420
1421         if (btrfs_root_refs(&root->root_item) == 0) {
1422                 ret = -ENOENT;
1423                 goto fail;
1424         }
1425
1426         ret = btrfs_find_orphan_item(fs_info->tree_root, location->objectid);
1427         if (ret < 0)
1428                 goto fail;
1429         if (ret == 0)
1430                 root->orphan_item_inserted = 1;
1431
1432         ret = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
1433         if (ret)
1434                 goto fail;
1435
1436         spin_lock(&fs_info->fs_roots_radix_lock);
1437         ret = radix_tree_insert(&fs_info->fs_roots_radix,
1438                                 (unsigned long)root->root_key.objectid,
1439                                 root);
1440         if (ret == 0)
1441                 root->in_radix = 1;
1442
1443         spin_unlock(&fs_info->fs_roots_radix_lock);
1444         radix_tree_preload_end();
1445         if (ret) {
1446                 if (ret == -EEXIST) {
1447                         free_fs_root(root);
1448                         goto again;
1449                 }
1450                 goto fail;
1451         }
1452
1453         ret = btrfs_find_dead_roots(fs_info->tree_root,
1454                                     root->root_key.objectid);
1455         WARN_ON(ret);
1456         return root;
1457 fail:
1458         free_fs_root(root);
1459         return ERR_PTR(ret);
1460 }
1461
1462 static int btrfs_congested_fn(void *congested_data, int bdi_bits)
1463 {
1464         struct btrfs_fs_info *info = (struct btrfs_fs_info *)congested_data;
1465         int ret = 0;
1466         struct btrfs_device *device;
1467         struct backing_dev_info *bdi;
1468
1469         rcu_read_lock();
1470         list_for_each_entry_rcu(device, &info->fs_devices->devices, dev_list) {
1471                 if (!device->bdev)
1472                         continue;
1473                 bdi = blk_get_backing_dev_info(device->bdev);
1474                 if (bdi && bdi_congested(bdi, bdi_bits)) {
1475                         ret = 1;
1476                         break;
1477                 }
1478         }
1479         rcu_read_unlock();
1480         return ret;
1481 }
1482
1483 /*
1484  * If this fails, caller must call bdi_destroy() to get rid of the
1485  * bdi again.
1486  */
1487 static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
1488 {
1489         int err;
1490
1491         bdi->capabilities = BDI_CAP_MAP_COPY;
1492         err = bdi_setup_and_register(bdi, "btrfs", BDI_CAP_MAP_COPY);
1493         if (err)
1494                 return err;
1495
1496         bdi->ra_pages   = default_backing_dev_info.ra_pages;
1497         bdi->congested_fn       = btrfs_congested_fn;
1498         bdi->congested_data     = info;
1499         return 0;
1500 }
1501
1502 static int bio_ready_for_csum(struct bio *bio)
1503 {
1504         u64 length = 0;
1505         u64 buf_len = 0;
1506         u64 start = 0;
1507         struct page *page;
1508         struct extent_io_tree *io_tree = NULL;
1509         struct bio_vec *bvec;
1510         int i;
1511         int ret;
1512
1513         bio_for_each_segment(bvec, bio, i) {
1514                 page = bvec->bv_page;
1515                 if (page->private == EXTENT_PAGE_PRIVATE) {
1516                         length += bvec->bv_len;
1517                         continue;
1518                 }
1519                 if (!page->private) {
1520                         length += bvec->bv_len;
1521                         continue;
1522                 }
1523                 length = bvec->bv_len;
1524                 buf_len = page->private >> 2;
1525                 start = page_offset(page) + bvec->bv_offset;
1526                 io_tree = &BTRFS_I(page->mapping->host)->io_tree;
1527         }
1528         /* are we fully contained in this bio? */
1529         if (buf_len <= length)
1530                 return 1;
1531
1532         ret = extent_range_uptodate(io_tree, start + length,
1533                                     start + buf_len - 1);
1534         return ret;
1535 }
1536
1537 /*
1538  * called by the kthread helper functions to finally call the bio end_io
1539  * functions.  This is where read checksum verification actually happens
1540  */
1541 static void end_workqueue_fn(struct btrfs_work *work)
1542 {
1543         struct bio *bio;
1544         struct end_io_wq *end_io_wq;
1545         struct btrfs_fs_info *fs_info;
1546         int error;
1547
1548         end_io_wq = container_of(work, struct end_io_wq, work);
1549         bio = end_io_wq->bio;
1550         fs_info = end_io_wq->info;
1551
1552         /* metadata bio reads are special because the whole tree block must
1553          * be checksummed at once.  This makes sure the entire block is in
1554          * ram and up to date before trying to verify things.  For
1555          * blocksize <= pagesize, it is basically a noop
1556          */
1557         if (!(bio->bi_rw & REQ_WRITE) && end_io_wq->metadata &&
1558             !bio_ready_for_csum(bio)) {
1559                 btrfs_queue_worker(&fs_info->endio_meta_workers,
1560                                    &end_io_wq->work);
1561                 return;
1562         }
1563         error = end_io_wq->error;
1564         bio->bi_private = end_io_wq->private;
1565         bio->bi_end_io = end_io_wq->end_io;
1566         kfree(end_io_wq);
1567         bio_endio(bio, error);
1568 }
1569
1570 static int cleaner_kthread(void *arg)
1571 {
1572         struct btrfs_root *root = arg;
1573
1574         do {
1575                 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1576
1577                 if (!(root->fs_info->sb->s_flags & MS_RDONLY) &&
1578                     mutex_trylock(&root->fs_info->cleaner_mutex)) {
1579                         btrfs_run_delayed_iputs(root);
1580                         btrfs_clean_old_snapshots(root);
1581                         mutex_unlock(&root->fs_info->cleaner_mutex);
1582                         btrfs_run_defrag_inodes(root->fs_info);
1583                 }
1584
1585                 if (!try_to_freeze()) {
1586                         set_current_state(TASK_INTERRUPTIBLE);
1587                         if (!kthread_should_stop())
1588                                 schedule();
1589                         __set_current_state(TASK_RUNNING);
1590                 }
1591         } while (!kthread_should_stop());
1592         return 0;
1593 }
1594
1595 static int transaction_kthread(void *arg)
1596 {
1597         struct btrfs_root *root = arg;
1598         struct btrfs_trans_handle *trans;
1599         struct btrfs_transaction *cur;
1600         u64 transid;
1601         unsigned long now;
1602         unsigned long delay;
1603         int ret;
1604
1605         do {
1606                 delay = HZ * 30;
1607                 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1608                 mutex_lock(&root->fs_info->transaction_kthread_mutex);
1609
1610                 spin_lock(&root->fs_info->trans_lock);
1611                 cur = root->fs_info->running_transaction;
1612                 if (!cur) {
1613                         spin_unlock(&root->fs_info->trans_lock);
1614                         goto sleep;
1615                 }
1616
1617                 now = get_seconds();
1618                 if (!cur->blocked &&
1619                     (now < cur->start_time || now - cur->start_time < 30)) {
1620                         spin_unlock(&root->fs_info->trans_lock);
1621                         delay = HZ * 5;
1622                         goto sleep;
1623                 }
1624                 transid = cur->transid;
1625                 spin_unlock(&root->fs_info->trans_lock);
1626
1627                 trans = btrfs_join_transaction(root);
1628                 BUG_ON(IS_ERR(trans));
1629                 if (transid == trans->transid) {
1630                         ret = btrfs_commit_transaction(trans, root);
1631                         BUG_ON(ret);
1632                 } else {
1633                         btrfs_end_transaction(trans, root);
1634                 }
1635 sleep:
1636                 wake_up_process(root->fs_info->cleaner_kthread);
1637                 mutex_unlock(&root->fs_info->transaction_kthread_mutex);
1638
1639                 if (!try_to_freeze()) {
1640                         set_current_state(TASK_INTERRUPTIBLE);
1641                         if (!kthread_should_stop() &&
1642                             !btrfs_transaction_blocked(root->fs_info))
1643                                 schedule_timeout(delay);
1644                         __set_current_state(TASK_RUNNING);
1645                 }
1646         } while (!kthread_should_stop());
1647         return 0;
1648 }
1649
1650 /*
1651  * this will find the highest generation in the array of
1652  * root backups.  The index of the highest array is returned,
1653  * or -1 if we can't find anything.
1654  *
1655  * We check to make sure the array is valid by comparing the
1656  * generation of the latest  root in the array with the generation
1657  * in the super block.  If they don't match we pitch it.
1658  */
1659 static int find_newest_super_backup(struct btrfs_fs_info *info, u64 newest_gen)
1660 {
1661         u64 cur;
1662         int newest_index = -1;
1663         struct btrfs_root_backup *root_backup;
1664         int i;
1665
1666         for (i = 0; i < BTRFS_NUM_BACKUP_ROOTS; i++) {
1667                 root_backup = info->super_copy->super_roots + i;
1668                 cur = btrfs_backup_tree_root_gen(root_backup);
1669                 if (cur == newest_gen)
1670                         newest_index = i;
1671         }
1672
1673         /* check to see if we actually wrapped around */
1674         if (newest_index == BTRFS_NUM_BACKUP_ROOTS - 1) {
1675                 root_backup = info->super_copy->super_roots;
1676                 cur = btrfs_backup_tree_root_gen(root_backup);
1677                 if (cur == newest_gen)
1678                         newest_index = 0;
1679         }
1680         return newest_index;
1681 }
1682
1683
1684 /*
1685  * find the oldest backup so we know where to store new entries
1686  * in the backup array.  This will set the backup_root_index
1687  * field in the fs_info struct
1688  */
1689 static void find_oldest_super_backup(struct btrfs_fs_info *info,
1690                                      u64 newest_gen)
1691 {
1692         int newest_index = -1;
1693
1694         newest_index = find_newest_super_backup(info, newest_gen);
1695         /* if there was garbage in there, just move along */
1696         if (newest_index == -1) {
1697                 info->backup_root_index = 0;
1698         } else {
1699                 info->backup_root_index = (newest_index + 1) % BTRFS_NUM_BACKUP_ROOTS;
1700         }
1701 }
1702
1703 /*
1704  * copy all the root pointers into the super backup array.
1705  * this will bump the backup pointer by one when it is
1706  * done
1707  */
1708 static void backup_super_roots(struct btrfs_fs_info *info)
1709 {
1710         int next_backup;
1711         struct btrfs_root_backup *root_backup;
1712         int last_backup;
1713
1714         next_backup = info->backup_root_index;
1715         last_backup = (next_backup + BTRFS_NUM_BACKUP_ROOTS - 1) %
1716                 BTRFS_NUM_BACKUP_ROOTS;
1717
1718         /*
1719          * just overwrite the last backup if we're at the same generation
1720          * this happens only at umount
1721          */
1722         root_backup = info->super_for_commit->super_roots + last_backup;
1723         if (btrfs_backup_tree_root_gen(root_backup) ==
1724             btrfs_header_generation(info->tree_root->node))
1725                 next_backup = last_backup;
1726
1727         root_backup = info->super_for_commit->super_roots + next_backup;
1728
1729         /*
1730          * make sure all of our padding and empty slots get zero filled
1731          * regardless of which ones we use today
1732          */
1733         memset(root_backup, 0, sizeof(*root_backup));
1734
1735         info->backup_root_index = (next_backup + 1) % BTRFS_NUM_BACKUP_ROOTS;
1736
1737         btrfs_set_backup_tree_root(root_backup, info->tree_root->node->start);
1738         btrfs_set_backup_tree_root_gen(root_backup,
1739                                btrfs_header_generation(info->tree_root->node));
1740
1741         btrfs_set_backup_tree_root_level(root_backup,
1742                                btrfs_header_level(info->tree_root->node));
1743
1744         btrfs_set_backup_chunk_root(root_backup, info->chunk_root->node->start);
1745         btrfs_set_backup_chunk_root_gen(root_backup,
1746                                btrfs_header_generation(info->chunk_root->node));
1747         btrfs_set_backup_chunk_root_level(root_backup,
1748                                btrfs_header_level(info->chunk_root->node));
1749
1750         btrfs_set_backup_extent_root(root_backup, info->extent_root->node->start);
1751         btrfs_set_backup_extent_root_gen(root_backup,
1752                                btrfs_header_generation(info->extent_root->node));
1753         btrfs_set_backup_extent_root_level(root_backup,
1754                                btrfs_header_level(info->extent_root->node));
1755
1756         /*
1757          * we might commit during log recovery, which happens before we set
1758          * the fs_root.  Make sure it is valid before we fill it in.
1759          */
1760         if (info->fs_root && info->fs_root->node) {
1761                 btrfs_set_backup_fs_root(root_backup,
1762                                          info->fs_root->node->start);
1763                 btrfs_set_backup_fs_root_gen(root_backup,
1764                                btrfs_header_generation(info->fs_root->node));
1765                 btrfs_set_backup_fs_root_level(root_backup,
1766                                btrfs_header_level(info->fs_root->node));
1767         }
1768
1769         btrfs_set_backup_dev_root(root_backup, info->dev_root->node->start);
1770         btrfs_set_backup_dev_root_gen(root_backup,
1771                                btrfs_header_generation(info->dev_root->node));
1772         btrfs_set_backup_dev_root_level(root_backup,
1773                                        btrfs_header_level(info->dev_root->node));
1774
1775         btrfs_set_backup_csum_root(root_backup, info->csum_root->node->start);
1776         btrfs_set_backup_csum_root_gen(root_backup,
1777                                btrfs_header_generation(info->csum_root->node));
1778         btrfs_set_backup_csum_root_level(root_backup,
1779                                btrfs_header_level(info->csum_root->node));
1780
1781         btrfs_set_backup_total_bytes(root_backup,
1782                              btrfs_super_total_bytes(info->super_copy));
1783         btrfs_set_backup_bytes_used(root_backup,
1784                              btrfs_super_bytes_used(info->super_copy));
1785         btrfs_set_backup_num_devices(root_backup,
1786                              btrfs_super_num_devices(info->super_copy));
1787
1788         /*
1789          * if we don't copy this out to the super_copy, it won't get remembered
1790          * for the next commit
1791          */
1792         memcpy(&info->super_copy->super_roots,
1793                &info->super_for_commit->super_roots,
1794                sizeof(*root_backup) * BTRFS_NUM_BACKUP_ROOTS);
1795 }
1796
1797 /*
1798  * this copies info out of the root backup array and back into
1799  * the in-memory super block.  It is meant to help iterate through
1800  * the array, so you send it the number of backups you've already
1801  * tried and the last backup index you used.
1802  *
1803  * this returns -1 when it has tried all the backups
1804  */
1805 static noinline int next_root_backup(struct btrfs_fs_info *info,
1806                                      struct btrfs_super_block *super,
1807                                      int *num_backups_tried, int *backup_index)
1808 {
1809         struct btrfs_root_backup *root_backup;
1810         int newest = *backup_index;
1811
1812         if (*num_backups_tried == 0) {
1813                 u64 gen = btrfs_super_generation(super);
1814
1815                 newest = find_newest_super_backup(info, gen);
1816                 if (newest == -1)
1817                         return -1;
1818
1819                 *backup_index = newest;
1820                 *num_backups_tried = 1;
1821         } else if (*num_backups_tried == BTRFS_NUM_BACKUP_ROOTS) {
1822                 /* we've tried all the backups, all done */
1823                 return -1;
1824         } else {
1825                 /* jump to the next oldest backup */
1826                 newest = (*backup_index + BTRFS_NUM_BACKUP_ROOTS - 1) %
1827                         BTRFS_NUM_BACKUP_ROOTS;
1828                 *backup_index = newest;
1829                 *num_backups_tried += 1;
1830         }
1831         root_backup = super->super_roots + newest;
1832
1833         btrfs_set_super_generation(super,
1834                                    btrfs_backup_tree_root_gen(root_backup));
1835         btrfs_set_super_root(super, btrfs_backup_tree_root(root_backup));
1836         btrfs_set_super_root_level(super,
1837                                    btrfs_backup_tree_root_level(root_backup));
1838         btrfs_set_super_bytes_used(super, btrfs_backup_bytes_used(root_backup));
1839
1840         /*
1841          * fixme: the total bytes and num_devices need to match or we should
1842          * need a fsck
1843          */
1844         btrfs_set_super_total_bytes(super, btrfs_backup_total_bytes(root_backup));
1845         btrfs_set_super_num_devices(super, btrfs_backup_num_devices(root_backup));
1846         return 0;
1847 }
1848
1849 /* helper to cleanup tree roots */
1850 static void free_root_pointers(struct btrfs_fs_info *info, int chunk_root)
1851 {
1852         free_extent_buffer(info->tree_root->node);
1853         free_extent_buffer(info->tree_root->commit_root);
1854         free_extent_buffer(info->dev_root->node);
1855         free_extent_buffer(info->dev_root->commit_root);
1856         free_extent_buffer(info->extent_root->node);
1857         free_extent_buffer(info->extent_root->commit_root);
1858         free_extent_buffer(info->csum_root->node);
1859         free_extent_buffer(info->csum_root->commit_root);
1860
1861         info->tree_root->node = NULL;
1862         info->tree_root->commit_root = NULL;
1863         info->dev_root->node = NULL;
1864         info->dev_root->commit_root = NULL;
1865         info->extent_root->node = NULL;
1866         info->extent_root->commit_root = NULL;
1867         info->csum_root->node = NULL;
1868         info->csum_root->commit_root = NULL;
1869
1870         if (chunk_root) {
1871                 free_extent_buffer(info->chunk_root->node);
1872                 free_extent_buffer(info->chunk_root->commit_root);
1873                 info->chunk_root->node = NULL;
1874                 info->chunk_root->commit_root = NULL;
1875         }
1876 }
1877
1878
1879 struct btrfs_root *open_ctree(struct super_block *sb,
1880                               struct btrfs_fs_devices *fs_devices,
1881                               char *options)
1882 {
1883         u32 sectorsize;
1884         u32 nodesize;
1885         u32 leafsize;
1886         u32 blocksize;
1887         u32 stripesize;
1888         u64 generation;
1889         u64 features;
1890         struct btrfs_key location;
1891         struct buffer_head *bh;
1892         struct btrfs_super_block *disk_super;
1893         struct btrfs_root *tree_root = btrfs_sb(sb);
1894         struct btrfs_fs_info *fs_info = tree_root->fs_info;
1895         struct btrfs_root *extent_root;
1896         struct btrfs_root *csum_root;
1897         struct btrfs_root *chunk_root;
1898         struct btrfs_root *dev_root;
1899         struct btrfs_root *log_tree_root;
1900         int ret;
1901         int err = -EINVAL;
1902         int num_backups_tried = 0;
1903         int backup_index = 0;
1904
1905         extent_root = fs_info->extent_root =
1906                 kzalloc(sizeof(struct btrfs_root), GFP_NOFS);
1907         csum_root = fs_info->csum_root =
1908                 kzalloc(sizeof(struct btrfs_root), GFP_NOFS);
1909         chunk_root = fs_info->chunk_root =
1910                 kzalloc(sizeof(struct btrfs_root), GFP_NOFS);
1911         dev_root = fs_info->dev_root =
1912                 kzalloc(sizeof(struct btrfs_root), GFP_NOFS);
1913
1914         if (!extent_root || !csum_root || !chunk_root || !dev_root) {
1915                 err = -ENOMEM;
1916                 goto fail;
1917         }
1918
1919         ret = init_srcu_struct(&fs_info->subvol_srcu);
1920         if (ret) {
1921                 err = ret;
1922                 goto fail;
1923         }
1924
1925         ret = setup_bdi(fs_info, &fs_info->bdi);
1926         if (ret) {
1927                 err = ret;
1928                 goto fail_srcu;
1929         }
1930
1931         fs_info->btree_inode = new_inode(sb);
1932         if (!fs_info->btree_inode) {
1933                 err = -ENOMEM;
1934                 goto fail_bdi;
1935         }
1936
1937         mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
1938
1939         INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_ATOMIC);
1940         INIT_LIST_HEAD(&fs_info->trans_list);
1941         INIT_LIST_HEAD(&fs_info->dead_roots);
1942         INIT_LIST_HEAD(&fs_info->delayed_iputs);
1943         INIT_LIST_HEAD(&fs_info->hashers);
1944         INIT_LIST_HEAD(&fs_info->delalloc_inodes);
1945         INIT_LIST_HEAD(&fs_info->ordered_operations);
1946         INIT_LIST_HEAD(&fs_info->caching_block_groups);
1947         spin_lock_init(&fs_info->delalloc_lock);
1948         spin_lock_init(&fs_info->trans_lock);
1949         spin_lock_init(&fs_info->ref_cache_lock);
1950         spin_lock_init(&fs_info->fs_roots_radix_lock);
1951         spin_lock_init(&fs_info->delayed_iput_lock);
1952         spin_lock_init(&fs_info->defrag_inodes_lock);
1953         spin_lock_init(&fs_info->free_chunk_lock);
1954         mutex_init(&fs_info->reloc_mutex);
1955
1956         init_completion(&fs_info->kobj_unregister);
1957         INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
1958         INIT_LIST_HEAD(&fs_info->space_info);
1959         btrfs_mapping_init(&fs_info->mapping_tree);
1960         btrfs_init_block_rsv(&fs_info->global_block_rsv);
1961         btrfs_init_block_rsv(&fs_info->delalloc_block_rsv);
1962         btrfs_init_block_rsv(&fs_info->trans_block_rsv);
1963         btrfs_init_block_rsv(&fs_info->chunk_block_rsv);
1964         btrfs_init_block_rsv(&fs_info->empty_block_rsv);
1965         btrfs_init_block_rsv(&fs_info->delayed_block_rsv);
1966         atomic_set(&fs_info->nr_async_submits, 0);
1967         atomic_set(&fs_info->async_delalloc_pages, 0);
1968         atomic_set(&fs_info->async_submit_draining, 0);
1969         atomic_set(&fs_info->nr_async_bios, 0);
1970         atomic_set(&fs_info->defrag_running, 0);
1971         fs_info->sb = sb;
1972         fs_info->max_inline = 8192 * 1024;
1973         fs_info->metadata_ratio = 0;
1974         fs_info->defrag_inodes = RB_ROOT;
1975         fs_info->trans_no_join = 0;
1976         fs_info->free_chunk_space = 0;
1977
1978         /* readahead state */
1979         INIT_RADIX_TREE(&fs_info->reada_tree, GFP_NOFS & ~__GFP_WAIT);
1980         spin_lock_init(&fs_info->reada_lock);
1981
1982         fs_info->thread_pool_size = min_t(unsigned long,
1983                                           num_online_cpus() + 2, 8);
1984
1985         INIT_LIST_HEAD(&fs_info->ordered_extents);
1986         spin_lock_init(&fs_info->ordered_extent_lock);
1987         fs_info->delayed_root = kmalloc(sizeof(struct btrfs_delayed_root),
1988                                         GFP_NOFS);
1989         if (!fs_info->delayed_root) {
1990                 err = -ENOMEM;
1991                 goto fail_iput;
1992         }
1993         btrfs_init_delayed_root(fs_info->delayed_root);
1994
1995         mutex_init(&fs_info->scrub_lock);
1996         atomic_set(&fs_info->scrubs_running, 0);
1997         atomic_set(&fs_info->scrub_pause_req, 0);
1998         atomic_set(&fs_info->scrubs_paused, 0);
1999         atomic_set(&fs_info->scrub_cancel_req, 0);
2000         init_waitqueue_head(&fs_info->scrub_pause_wait);
2001         init_rwsem(&fs_info->scrub_super_lock);
2002         fs_info->scrub_workers_refcnt = 0;
2003 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
2004         fs_info->check_integrity_print_mask = 0;
2005 #endif
2006
2007         spin_lock_init(&fs_info->balance_lock);
2008         mutex_init(&fs_info->balance_mutex);
2009         atomic_set(&fs_info->balance_running, 0);
2010         atomic_set(&fs_info->balance_pause_req, 0);
2011         atomic_set(&fs_info->balance_cancel_req, 0);
2012         fs_info->balance_ctl = NULL;
2013         init_waitqueue_head(&fs_info->balance_wait_q);
2014
2015         sb->s_blocksize = 4096;
2016         sb->s_blocksize_bits = blksize_bits(4096);
2017         sb->s_bdi = &fs_info->bdi;
2018
2019         fs_info->btree_inode->i_ino = BTRFS_BTREE_INODE_OBJECTID;
2020         set_nlink(fs_info->btree_inode, 1);
2021         /*
2022          * we set the i_size on the btree inode to the max possible int.
2023          * the real end of the address space is determined by all of
2024          * the devices in the system
2025          */
2026         fs_info->btree_inode->i_size = OFFSET_MAX;
2027         fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
2028         fs_info->btree_inode->i_mapping->backing_dev_info = &fs_info->bdi;
2029
2030         RB_CLEAR_NODE(&BTRFS_I(fs_info->btree_inode)->rb_node);
2031         extent_io_tree_init(&BTRFS_I(fs_info->btree_inode)->io_tree,
2032                              fs_info->btree_inode->i_mapping);
2033         extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree);
2034
2035         BTRFS_I(fs_info->btree_inode)->io_tree.ops = &btree_extent_io_ops;
2036
2037         BTRFS_I(fs_info->btree_inode)->root = tree_root;
2038         memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
2039                sizeof(struct btrfs_key));
2040         BTRFS_I(fs_info->btree_inode)->dummy_inode = 1;
2041         insert_inode_hash(fs_info->btree_inode);
2042
2043         spin_lock_init(&fs_info->block_group_cache_lock);
2044         fs_info->block_group_cache_tree = RB_ROOT;
2045
2046         extent_io_tree_init(&fs_info->freed_extents[0],
2047                              fs_info->btree_inode->i_mapping);
2048         extent_io_tree_init(&fs_info->freed_extents[1],
2049                              fs_info->btree_inode->i_mapping);
2050         fs_info->pinned_extents = &fs_info->freed_extents[0];
2051         fs_info->do_barriers = 1;
2052
2053
2054         mutex_init(&fs_info->ordered_operations_mutex);
2055         mutex_init(&fs_info->tree_log_mutex);
2056         mutex_init(&fs_info->chunk_mutex);
2057         mutex_init(&fs_info->transaction_kthread_mutex);
2058         mutex_init(&fs_info->cleaner_mutex);
2059         mutex_init(&fs_info->volume_mutex);
2060         init_rwsem(&fs_info->extent_commit_sem);
2061         init_rwsem(&fs_info->cleanup_work_sem);
2062         init_rwsem(&fs_info->subvol_sem);
2063
2064         btrfs_init_free_cluster(&fs_info->meta_alloc_cluster);
2065         btrfs_init_free_cluster(&fs_info->data_alloc_cluster);
2066
2067         init_waitqueue_head(&fs_info->transaction_throttle);
2068         init_waitqueue_head(&fs_info->transaction_wait);
2069         init_waitqueue_head(&fs_info->transaction_blocked_wait);
2070         init_waitqueue_head(&fs_info->async_submit_wait);
2071
2072         __setup_root(4096, 4096, 4096, 4096, tree_root,
2073                      fs_info, BTRFS_ROOT_TREE_OBJECTID);
2074
2075         bh = btrfs_read_dev_super(fs_devices->latest_bdev);
2076         if (!bh) {
2077                 err = -EINVAL;
2078                 goto fail_alloc;
2079         }
2080
2081         memcpy(fs_info->super_copy, bh->b_data, sizeof(*fs_info->super_copy));
2082         memcpy(fs_info->super_for_commit, fs_info->super_copy,
2083                sizeof(*fs_info->super_for_commit));
2084         brelse(bh);
2085
2086         memcpy(fs_info->fsid, fs_info->super_copy->fsid, BTRFS_FSID_SIZE);
2087
2088         disk_super = fs_info->super_copy;
2089         if (!btrfs_super_root(disk_super))
2090                 goto fail_alloc;
2091
2092         /* check FS state, whether FS is broken. */
2093         fs_info->fs_state |= btrfs_super_flags(disk_super);
2094
2095         btrfs_check_super_valid(fs_info, sb->s_flags & MS_RDONLY);
2096
2097         /*
2098          * run through our array of backup supers and setup
2099          * our ring pointer to the oldest one
2100          */
2101         generation = btrfs_super_generation(disk_super);
2102         find_oldest_super_backup(fs_info, generation);
2103
2104         /*
2105          * In the long term, we'll store the compression type in the super
2106          * block, and it'll be used for per file compression control.
2107          */
2108         fs_info->compress_type = BTRFS_COMPRESS_ZLIB;
2109
2110         ret = btrfs_parse_options(tree_root, options);
2111         if (ret) {
2112                 err = ret;
2113                 goto fail_alloc;
2114         }
2115
2116         features = btrfs_super_incompat_flags(disk_super) &
2117                 ~BTRFS_FEATURE_INCOMPAT_SUPP;
2118         if (features) {
2119                 printk(KERN_ERR "BTRFS: couldn't mount because of "
2120                        "unsupported optional features (%Lx).\n",
2121                        (unsigned long long)features);
2122                 err = -EINVAL;
2123                 goto fail_alloc;
2124         }
2125
2126         features = btrfs_super_incompat_flags(disk_super);
2127         features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
2128         if (tree_root->fs_info->compress_type & BTRFS_COMPRESS_LZO)
2129                 features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO;
2130         btrfs_set_super_incompat_flags(disk_super, features);
2131
2132         features = btrfs_super_compat_ro_flags(disk_super) &
2133                 ~BTRFS_FEATURE_COMPAT_RO_SUPP;
2134         if (!(sb->s_flags & MS_RDONLY) && features) {
2135                 printk(KERN_ERR "BTRFS: couldn't mount RDWR because of "
2136                        "unsupported option features (%Lx).\n",
2137                        (unsigned long long)features);
2138                 err = -EINVAL;
2139                 goto fail_alloc;
2140         }
2141
2142         btrfs_init_workers(&fs_info->generic_worker,
2143                            "genwork", 1, NULL);
2144
2145         btrfs_init_workers(&fs_info->workers, "worker",
2146                            fs_info->thread_pool_size,
2147                            &fs_info->generic_worker);
2148
2149         btrfs_init_workers(&fs_info->delalloc_workers, "delalloc",
2150                            fs_info->thread_pool_size,
2151                            &fs_info->generic_worker);
2152
2153         btrfs_init_workers(&fs_info->submit_workers, "submit",
2154                            min_t(u64, fs_devices->num_devices,
2155                            fs_info->thread_pool_size),
2156                            &fs_info->generic_worker);
2157
2158         btrfs_init_workers(&fs_info->caching_workers, "cache",
2159                            2, &fs_info->generic_worker);
2160
2161         /* a higher idle thresh on the submit workers makes it much more
2162          * likely that bios will be send down in a sane order to the
2163          * devices
2164          */
2165         fs_info->submit_workers.idle_thresh = 64;
2166
2167         fs_info->workers.idle_thresh = 16;
2168         fs_info->workers.ordered = 1;
2169
2170         fs_info->delalloc_workers.idle_thresh = 2;
2171         fs_info->delalloc_workers.ordered = 1;
2172
2173         btrfs_init_workers(&fs_info->fixup_workers, "fixup", 1,
2174                            &fs_info->generic_worker);
2175         btrfs_init_workers(&fs_info->endio_workers, "endio",
2176                            fs_info->thread_pool_size,
2177                            &fs_info->generic_worker);
2178         btrfs_init_workers(&fs_info->endio_meta_workers, "endio-meta",
2179                            fs_info->thread_pool_size,
2180                            &fs_info->generic_worker);
2181         btrfs_init_workers(&fs_info->endio_meta_write_workers,
2182                            "endio-meta-write", fs_info->thread_pool_size,
2183                            &fs_info->generic_worker);
2184         btrfs_init_workers(&fs_info->endio_write_workers, "endio-write",
2185                            fs_info->thread_pool_size,
2186                            &fs_info->generic_worker);
2187         btrfs_init_workers(&fs_info->endio_freespace_worker, "freespace-write",
2188                            1, &fs_info->generic_worker);
2189         btrfs_init_workers(&fs_info->delayed_workers, "delayed-meta",
2190                            fs_info->thread_pool_size,
2191                            &fs_info->generic_worker);
2192         btrfs_init_workers(&fs_info->readahead_workers, "readahead",
2193                            fs_info->thread_pool_size,
2194                            &fs_info->generic_worker);
2195
2196         /*
2197          * endios are largely parallel and should have a very
2198          * low idle thresh
2199          */
2200         fs_info->endio_workers.idle_thresh = 4;
2201         fs_info->endio_meta_workers.idle_thresh = 4;
2202
2203         fs_info->endio_write_workers.idle_thresh = 2;
2204         fs_info->endio_meta_write_workers.idle_thresh = 2;
2205         fs_info->readahead_workers.idle_thresh = 2;
2206
2207         /*
2208          * btrfs_start_workers can really only fail because of ENOMEM so just
2209          * return -ENOMEM if any of these fail.
2210          */
2211         ret = btrfs_start_workers(&fs_info->workers);
2212         ret |= btrfs_start_workers(&fs_info->generic_worker);
2213         ret |= btrfs_start_workers(&fs_info->submit_workers);
2214         ret |= btrfs_start_workers(&fs_info->delalloc_workers);
2215         ret |= btrfs_start_workers(&fs_info->fixup_workers);
2216         ret |= btrfs_start_workers(&fs_info->endio_workers);
2217         ret |= btrfs_start_workers(&fs_info->endio_meta_workers);
2218         ret |= btrfs_start_workers(&fs_info->endio_meta_write_workers);
2219         ret |= btrfs_start_workers(&fs_info->endio_write_workers);
2220         ret |= btrfs_start_workers(&fs_info->endio_freespace_worker);
2221         ret |= btrfs_start_workers(&fs_info->delayed_workers);
2222         ret |= btrfs_start_workers(&fs_info->caching_workers);
2223         ret |= btrfs_start_workers(&fs_info->readahead_workers);
2224         if (ret) {
2225                 ret = -ENOMEM;
2226                 goto fail_sb_buffer;
2227         }
2228
2229         fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super);
2230         fs_info->bdi.ra_pages = max(fs_info->bdi.ra_pages,
2231                                     4 * 1024 * 1024 / PAGE_CACHE_SIZE);
2232
2233         nodesize = btrfs_super_nodesize(disk_super);
2234         leafsize = btrfs_super_leafsize(disk_super);
2235         sectorsize = btrfs_super_sectorsize(disk_super);
2236         stripesize = btrfs_super_stripesize(disk_super);
2237         tree_root->nodesize = nodesize;
2238         tree_root->leafsize = leafsize;
2239         tree_root->sectorsize = sectorsize;
2240         tree_root->stripesize = stripesize;
2241
2242         sb->s_blocksize = sectorsize;
2243         sb->s_blocksize_bits = blksize_bits(sectorsize);
2244
2245         if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
2246                     sizeof(disk_super->magic))) {
2247                 printk(KERN_INFO "btrfs: valid FS not found on %s\n", sb->s_id);
2248                 goto fail_sb_buffer;
2249         }
2250
2251         mutex_lock(&fs_info->chunk_mutex);
2252         ret = btrfs_read_sys_array(tree_root);
2253         mutex_unlock(&fs_info->chunk_mutex);
2254         if (ret) {
2255                 printk(KERN_WARNING "btrfs: failed to read the system "
2256                        "array on %s\n", sb->s_id);
2257                 goto fail_sb_buffer;
2258         }
2259
2260         blocksize = btrfs_level_size(tree_root,
2261                                      btrfs_super_chunk_root_level(disk_super));
2262         generation = btrfs_super_chunk_root_generation(disk_super);
2263
2264         __setup_root(nodesize, leafsize, sectorsize, stripesize,
2265                      chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
2266
2267         chunk_root->node = read_tree_block(chunk_root,
2268                                            btrfs_super_chunk_root(disk_super),
2269                                            blocksize, generation);
2270         BUG_ON(!chunk_root->node);
2271         if (!test_bit(EXTENT_BUFFER_UPTODATE, &chunk_root->node->bflags)) {
2272                 printk(KERN_WARNING "btrfs: failed to read chunk root on %s\n",
2273                        sb->s_id);
2274                 goto fail_tree_roots;
2275         }
2276         btrfs_set_root_node(&chunk_root->root_item, chunk_root->node);
2277         chunk_root->commit_root = btrfs_root_node(chunk_root);
2278
2279         read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
2280            (unsigned long)btrfs_header_chunk_tree_uuid(chunk_root->node),
2281            BTRFS_UUID_SIZE);
2282
2283         ret = btrfs_read_chunk_tree(chunk_root);
2284         if (ret) {
2285                 printk(KERN_WARNING "btrfs: failed to read chunk tree on %s\n",
2286                        sb->s_id);
2287                 goto fail_tree_roots;
2288         }
2289
2290         btrfs_close_extra_devices(fs_devices);
2291
2292 retry_root_backup:
2293         blocksize = btrfs_level_size(tree_root,
2294                                      btrfs_super_root_level(disk_super));
2295         generation = btrfs_super_generation(disk_super);
2296
2297         tree_root->node = read_tree_block(tree_root,
2298                                           btrfs_super_root(disk_super),
2299                                           blocksize, generation);
2300         if (!tree_root->node ||
2301             !test_bit(EXTENT_BUFFER_UPTODATE, &tree_root->node->bflags)) {
2302                 printk(KERN_WARNING "btrfs: failed to read tree root on %s\n",
2303                        sb->s_id);
2304
2305                 goto recovery_tree_root;
2306         }
2307
2308         btrfs_set_root_node(&tree_root->root_item, tree_root->node);
2309         tree_root->commit_root = btrfs_root_node(tree_root);
2310
2311         ret = find_and_setup_root(tree_root, fs_info,
2312                                   BTRFS_EXTENT_TREE_OBJECTID, extent_root);
2313         if (ret)
2314                 goto recovery_tree_root;
2315         extent_root->track_dirty = 1;
2316
2317         ret = find_and_setup_root(tree_root, fs_info,
2318                                   BTRFS_DEV_TREE_OBJECTID, dev_root);
2319         if (ret)
2320                 goto recovery_tree_root;
2321         dev_root->track_dirty = 1;
2322
2323         ret = find_and_setup_root(tree_root, fs_info,
2324                                   BTRFS_CSUM_TREE_OBJECTID, csum_root);
2325         if (ret)
2326                 goto recovery_tree_root;
2327
2328         csum_root->track_dirty = 1;
2329
2330         fs_info->generation = generation;
2331         fs_info->last_trans_committed = generation;
2332
2333         ret = btrfs_init_space_info(fs_info);
2334         if (ret) {
2335                 printk(KERN_ERR "Failed to initial space info: %d\n", ret);
2336                 goto fail_block_groups;
2337         }
2338
2339         ret = btrfs_read_block_groups(extent_root);
2340         if (ret) {
2341                 printk(KERN_ERR "Failed to read block groups: %d\n", ret);
2342                 goto fail_block_groups;
2343         }
2344
2345         fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
2346                                                "btrfs-cleaner");
2347         if (IS_ERR(fs_info->cleaner_kthread))
2348                 goto fail_block_groups;
2349
2350         fs_info->transaction_kthread = kthread_run(transaction_kthread,
2351                                                    tree_root,
2352                                                    "btrfs-transaction");
2353         if (IS_ERR(fs_info->transaction_kthread))
2354                 goto fail_cleaner;
2355
2356         if (!btrfs_test_opt(tree_root, SSD) &&
2357             !btrfs_test_opt(tree_root, NOSSD) &&
2358             !fs_info->fs_devices->rotating) {
2359                 printk(KERN_INFO "Btrfs detected SSD devices, enabling SSD "
2360                        "mode\n");
2361                 btrfs_set_opt(fs_info->mount_opt, SSD);
2362         }
2363
2364 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
2365         if (btrfs_test_opt(tree_root, CHECK_INTEGRITY)) {
2366                 ret = btrfsic_mount(tree_root, fs_devices,
2367                                     btrfs_test_opt(tree_root,
2368                                         CHECK_INTEGRITY_INCLUDING_EXTENT_DATA) ?
2369                                     1 : 0,
2370                                     fs_info->check_integrity_print_mask);
2371                 if (ret)
2372                         printk(KERN_WARNING "btrfs: failed to initialize"
2373                                " integrity check module %s\n", sb->s_id);
2374         }
2375 #endif
2376
2377         /* do not make disk changes in broken FS */
2378         if (btrfs_super_log_root(disk_super) != 0 &&
2379             !(fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR)) {
2380                 u64 bytenr = btrfs_super_log_root(disk_super);
2381
2382                 if (fs_devices->rw_devices == 0) {
2383                         printk(KERN_WARNING "Btrfs log replay required "
2384                                "on RO media\n");
2385                         err = -EIO;
2386                         goto fail_trans_kthread;
2387                 }
2388                 blocksize =
2389                      btrfs_level_size(tree_root,
2390                                       btrfs_super_log_root_level(disk_super));
2391
2392                 log_tree_root = kzalloc(sizeof(struct btrfs_root), GFP_NOFS);
2393                 if (!log_tree_root) {
2394                         err = -ENOMEM;
2395                         goto fail_trans_kthread;
2396                 }
2397
2398                 __setup_root(nodesize, leafsize, sectorsize, stripesize,
2399                              log_tree_root, fs_info, BTRFS_TREE_LOG_OBJECTID);
2400
2401                 log_tree_root->node = read_tree_block(tree_root, bytenr,
2402                                                       blocksize,
2403                                                       generation + 1);
2404                 ret = btrfs_recover_log_trees(log_tree_root);
2405                 BUG_ON(ret);
2406
2407                 if (sb->s_flags & MS_RDONLY) {
2408                         ret =  btrfs_commit_super(tree_root);
2409                         BUG_ON(ret);
2410                 }
2411         }
2412
2413         ret = btrfs_find_orphan_roots(tree_root);
2414         BUG_ON(ret);
2415
2416         if (!(sb->s_flags & MS_RDONLY)) {
2417                 ret = btrfs_cleanup_fs_roots(fs_info);
2418                 BUG_ON(ret);
2419
2420                 ret = btrfs_recover_relocation(tree_root);
2421                 if (ret < 0) {
2422                         printk(KERN_WARNING
2423                                "btrfs: failed to recover relocation\n");
2424                         err = -EINVAL;
2425                         goto fail_trans_kthread;
2426                 }
2427         }
2428
2429         location.objectid = BTRFS_FS_TREE_OBJECTID;
2430         location.type = BTRFS_ROOT_ITEM_KEY;
2431         location.offset = (u64)-1;
2432
2433         fs_info->fs_root = btrfs_read_fs_root_no_name(fs_info, &location);
2434         if (!fs_info->fs_root)
2435                 goto fail_trans_kthread;
2436         if (IS_ERR(fs_info->fs_root)) {
2437                 err = PTR_ERR(fs_info->fs_root);
2438                 goto fail_trans_kthread;
2439         }
2440
2441         if (!(sb->s_flags & MS_RDONLY)) {
2442                 down_read(&fs_info->cleanup_work_sem);
2443                 err = btrfs_orphan_cleanup(fs_info->fs_root);
2444                 if (!err)
2445                         err = btrfs_orphan_cleanup(fs_info->tree_root);
2446                 up_read(&fs_info->cleanup_work_sem);
2447
2448                 if (!err)
2449                         err = btrfs_recover_balance(fs_info->tree_root);
2450
2451                 if (err) {
2452                         close_ctree(tree_root);
2453                         return ERR_PTR(err);
2454                 }
2455         }
2456
2457         return tree_root;
2458
2459 fail_trans_kthread:
2460         kthread_stop(fs_info->transaction_kthread);
2461 fail_cleaner:
2462         kthread_stop(fs_info->cleaner_kthread);
2463
2464         /*
2465          * make sure we're done with the btree inode before we stop our
2466          * kthreads
2467          */
2468         filemap_write_and_wait(fs_info->btree_inode->i_mapping);
2469         invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
2470
2471 fail_block_groups:
2472         btrfs_free_block_groups(fs_info);
2473
2474 fail_tree_roots:
2475         free_root_pointers(fs_info, 1);
2476
2477 fail_sb_buffer:
2478         btrfs_stop_workers(&fs_info->generic_worker);
2479         btrfs_stop_workers(&fs_info->readahead_workers);
2480         btrfs_stop_workers(&fs_info->fixup_workers);
2481         btrfs_stop_workers(&fs_info->delalloc_workers);
2482         btrfs_stop_workers(&fs_info->workers);
2483         btrfs_stop_workers(&fs_info->endio_workers);
2484         btrfs_stop_workers(&fs_info->endio_meta_workers);
2485         btrfs_stop_workers(&fs_info->endio_meta_write_workers);
2486         btrfs_stop_workers(&fs_info->endio_write_workers);
2487         btrfs_stop_workers(&fs_info->endio_freespace_worker);
2488         btrfs_stop_workers(&fs_info->submit_workers);
2489         btrfs_stop_workers(&fs_info->delayed_workers);
2490         btrfs_stop_workers(&fs_info->caching_workers);
2491 fail_alloc:
2492 fail_iput:
2493         btrfs_mapping_tree_free(&fs_info->mapping_tree);
2494
2495         invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
2496         iput(fs_info->btree_inode);
2497 fail_bdi:
2498         bdi_destroy(&fs_info->bdi);
2499 fail_srcu:
2500         cleanup_srcu_struct(&fs_info->subvol_srcu);
2501 fail:
2502         btrfs_close_devices(fs_info->fs_devices);
2503         free_fs_info(fs_info);
2504         return ERR_PTR(err);
2505
2506 recovery_tree_root:
2507         if (!btrfs_test_opt(tree_root, RECOVERY))
2508                 goto fail_tree_roots;
2509
2510         free_root_pointers(fs_info, 0);
2511
2512         /* don't use the log in recovery mode, it won't be valid */
2513         btrfs_set_super_log_root(disk_super, 0);
2514
2515         /* we can't trust the free space cache either */
2516         btrfs_set_opt(fs_info->mount_opt, CLEAR_CACHE);
2517
2518         ret = next_root_backup(fs_info, fs_info->super_copy,
2519                                &num_backups_tried, &backup_index);
2520         if (ret == -1)
2521                 goto fail_block_groups;
2522         goto retry_root_backup;
2523 }
2524
2525 static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
2526 {
2527         char b[BDEVNAME_SIZE];
2528
2529         if (uptodate) {
2530                 set_buffer_uptodate(bh);
2531         } else {
2532                 printk_ratelimited(KERN_WARNING "lost page write due to "
2533                                         "I/O error on %s\n",
2534                                        bdevname(bh->b_bdev, b));
2535                 /* note, we dont' set_buffer_write_io_error because we have
2536                  * our own ways of dealing with the IO errors
2537                  */
2538                 clear_buffer_uptodate(bh);
2539         }
2540         unlock_buffer(bh);
2541         put_bh(bh);
2542 }
2543
2544 struct buffer_head *btrfs_read_dev_super(struct block_device *bdev)
2545 {
2546         struct buffer_head *bh;
2547         struct buffer_head *latest = NULL;
2548         struct btrfs_super_block *super;
2549         int i;
2550         u64 transid = 0;
2551         u64 bytenr;
2552
2553         /* we would like to check all the supers, but that would make
2554          * a btrfs mount succeed after a mkfs from a different FS.
2555          * So, we need to add a special mount option to scan for
2556          * later supers, using BTRFS_SUPER_MIRROR_MAX instead
2557          */
2558         for (i = 0; i < 1; i++) {
2559                 bytenr = btrfs_sb_offset(i);
2560                 if (bytenr + 4096 >= i_size_read(bdev->bd_inode))
2561                         break;
2562                 bh = __bread(bdev, bytenr / 4096, 4096);
2563                 if (!bh)
2564                         continue;
2565
2566                 super = (struct btrfs_super_block *)bh->b_data;
2567                 if (btrfs_super_bytenr(super) != bytenr ||
2568                     strncmp((char *)(&super->magic), BTRFS_MAGIC,
2569                             sizeof(super->magic))) {
2570                         brelse(bh);
2571                         continue;
2572                 }
2573
2574                 if (!latest || btrfs_super_generation(super) > transid) {
2575                         brelse(latest);
2576                         latest = bh;
2577                         transid = btrfs_super_generation(super);
2578                 } else {
2579                         brelse(bh);
2580                 }
2581         }
2582         return latest;
2583 }
2584
2585 /*
2586  * this should be called twice, once with wait == 0 and
2587  * once with wait == 1.  When wait == 0 is done, all the buffer heads
2588  * we write are pinned.
2589  *
2590  * They are released when wait == 1 is done.
2591  * max_mirrors must be the same for both runs, and it indicates how
2592  * many supers on this one device should be written.
2593  *
2594  * max_mirrors == 0 means to write them all.
2595  */
2596 static int write_dev_supers(struct btrfs_device *device,
2597                             struct btrfs_super_block *sb,
2598                             int do_barriers, int wait, int max_mirrors)
2599 {
2600         struct buffer_head *bh;
2601         int i;
2602         int ret;
2603         int errors = 0;
2604         u32 crc;
2605         u64 bytenr;
2606
2607         if (max_mirrors == 0)
2608                 max_mirrors = BTRFS_SUPER_MIRROR_MAX;
2609
2610         for (i = 0; i < max_mirrors; i++) {
2611                 bytenr = btrfs_sb_offset(i);
2612                 if (bytenr + BTRFS_SUPER_INFO_SIZE >= device->total_bytes)
2613                         break;
2614
2615                 if (wait) {
2616                         bh = __find_get_block(device->bdev, bytenr / 4096,
2617                                               BTRFS_SUPER_INFO_SIZE);
2618                         BUG_ON(!bh);
2619                         wait_on_buffer(bh);
2620                         if (!buffer_uptodate(bh))
2621                                 errors++;
2622
2623                         /* drop our reference */
2624                         brelse(bh);
2625
2626                         /* drop the reference from the wait == 0 run */
2627                         brelse(bh);
2628                         continue;
2629                 } else {
2630                         btrfs_set_super_bytenr(sb, bytenr);
2631
2632                         crc = ~(u32)0;
2633                         crc = btrfs_csum_data(NULL, (char *)sb +
2634                                               BTRFS_CSUM_SIZE, crc,
2635                                               BTRFS_SUPER_INFO_SIZE -
2636                                               BTRFS_CSUM_SIZE);
2637                         btrfs_csum_final(crc, sb->csum);
2638
2639                         /*
2640                          * one reference for us, and we leave it for the
2641                          * caller
2642                          */
2643                         bh = __getblk(device->bdev, bytenr / 4096,
2644                                       BTRFS_SUPER_INFO_SIZE);
2645                         memcpy(bh->b_data, sb, BTRFS_SUPER_INFO_SIZE);
2646
2647                         /* one reference for submit_bh */
2648                         get_bh(bh);
2649
2650                         set_buffer_uptodate(bh);
2651                         lock_buffer(bh);
2652                         bh->b_end_io = btrfs_end_buffer_write_sync;
2653                 }
2654
2655                 /*
2656                  * we fua the first super.  The others we allow
2657                  * to go down lazy.
2658                  */
2659                 ret = btrfsic_submit_bh(WRITE_FUA, bh);
2660                 if (ret)
2661                         errors++;
2662         }
2663         return errors < i ? 0 : -1;
2664 }
2665
2666 /*
2667  * endio for the write_dev_flush, this will wake anyone waiting
2668  * for the barrier when it is done
2669  */
2670 static void btrfs_end_empty_barrier(struct bio *bio, int err)
2671 {
2672         if (err) {
2673                 if (err == -EOPNOTSUPP)
2674                         set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
2675                 clear_bit(BIO_UPTODATE, &bio->bi_flags);
2676         }
2677         if (bio->bi_private)
2678                 complete(bio->bi_private);
2679         bio_put(bio);
2680 }
2681
2682 /*
2683  * trigger flushes for one the devices.  If you pass wait == 0, the flushes are
2684  * sent down.  With wait == 1, it waits for the previous flush.
2685  *
2686  * any device where the flush fails with eopnotsupp are flagged as not-barrier
2687  * capable
2688  */
2689 static int write_dev_flush(struct btrfs_device *device, int wait)
2690 {
2691         struct bio *bio;
2692         int ret = 0;
2693
2694         if (device->nobarriers)
2695                 return 0;
2696
2697         if (wait) {
2698                 bio = device->flush_bio;
2699                 if (!bio)
2700                         return 0;
2701
2702                 wait_for_completion(&device->flush_wait);
2703
2704                 if (bio_flagged(bio, BIO_EOPNOTSUPP)) {
2705                         printk("btrfs: disabling barriers on dev %s\n",
2706                                device->name);
2707                         device->nobarriers = 1;
2708                 }
2709                 if (!bio_flagged(bio, BIO_UPTODATE)) {
2710                         ret = -EIO;
2711                 }
2712
2713                 /* drop the reference from the wait == 0 run */
2714                 bio_put(bio);
2715                 device->flush_bio = NULL;
2716
2717                 return ret;
2718         }
2719
2720         /*
2721          * one reference for us, and we leave it for the
2722          * caller
2723          */
2724         device->flush_bio = NULL;;
2725         bio = bio_alloc(GFP_NOFS, 0);
2726         if (!bio)
2727                 return -ENOMEM;
2728
2729         bio->bi_end_io = btrfs_end_empty_barrier;
2730         bio->bi_bdev = device->bdev;
2731         init_completion(&device->flush_wait);
2732         bio->bi_private = &device->flush_wait;
2733         device->flush_bio = bio;
2734
2735         bio_get(bio);
2736         btrfsic_submit_bio(WRITE_FLUSH, bio);
2737
2738         return 0;
2739 }
2740
2741 /*
2742  * send an empty flush down to each device in parallel,
2743  * then wait for them
2744  */
2745 static int barrier_all_devices(struct btrfs_fs_info *info)
2746 {
2747         struct list_head *head;
2748         struct btrfs_device *dev;
2749         int errors = 0;
2750         int ret;
2751
2752         /* send down all the barriers */
2753         head = &info->fs_devices->devices;
2754         list_for_each_entry_rcu(dev, head, dev_list) {
2755                 if (!dev->bdev) {
2756                         errors++;
2757                         continue;
2758                 }
2759                 if (!dev->in_fs_metadata || !dev->writeable)
2760                         continue;
2761
2762                 ret = write_dev_flush(dev, 0);
2763                 if (ret)
2764                         errors++;
2765         }
2766
2767         /* wait for all the barriers */
2768         list_for_each_entry_rcu(dev, head, dev_list) {
2769                 if (!dev->bdev) {
2770                         errors++;
2771                         continue;
2772                 }
2773                 if (!dev->in_fs_metadata || !dev->writeable)
2774                         continue;
2775
2776                 ret = write_dev_flush(dev, 1);
2777                 if (ret)
2778                         errors++;
2779         }
2780         if (errors)
2781                 return -EIO;
2782         return 0;
2783 }
2784
2785 int write_all_supers(struct btrfs_root *root, int max_mirrors)
2786 {
2787         struct list_head *head;
2788         struct btrfs_device *dev;
2789         struct btrfs_super_block *sb;
2790         struct btrfs_dev_item *dev_item;
2791         int ret;
2792         int do_barriers;
2793         int max_errors;
2794         int total_errors = 0;
2795         u64 flags;
2796
2797         max_errors = btrfs_super_num_devices(root->fs_info->super_copy) - 1;
2798         do_barriers = !btrfs_test_opt(root, NOBARRIER);
2799         backup_super_roots(root->fs_info);
2800
2801         sb = root->fs_info->super_for_commit;
2802         dev_item = &sb->dev_item;
2803
2804         mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
2805         head = &root->fs_info->fs_devices->devices;
2806
2807         if (do_barriers)
2808                 barrier_all_devices(root->fs_info);
2809
2810         list_for_each_entry_rcu(dev, head, dev_list) {
2811                 if (!dev->bdev) {
2812                         total_errors++;
2813                         continue;
2814                 }
2815                 if (!dev->in_fs_metadata || !dev->writeable)
2816                         continue;
2817
2818                 btrfs_set_stack_device_generation(dev_item, 0);
2819                 btrfs_set_stack_device_type(dev_item, dev->type);
2820                 btrfs_set_stack_device_id(dev_item, dev->devid);
2821                 btrfs_set_stack_device_total_bytes(dev_item, dev->total_bytes);
2822                 btrfs_set_stack_device_bytes_used(dev_item, dev->bytes_used);
2823                 btrfs_set_stack_device_io_align(dev_item, dev->io_align);
2824                 btrfs_set_stack_device_io_width(dev_item, dev->io_width);
2825                 btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
2826                 memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
2827                 memcpy(dev_item->fsid, dev->fs_devices->fsid, BTRFS_UUID_SIZE);
2828
2829                 flags = btrfs_super_flags(sb);
2830                 btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
2831
2832                 ret = write_dev_supers(dev, sb, do_barriers, 0, max_mirrors);
2833                 if (ret)
2834                         total_errors++;
2835         }
2836         if (total_errors > max_errors) {
2837                 printk(KERN_ERR "btrfs: %d errors while writing supers\n",
2838                        total_errors);
2839                 BUG();
2840         }
2841
2842         total_errors = 0;
2843         list_for_each_entry_rcu(dev, head, dev_list) {
2844                 if (!dev->bdev)
2845                         continue;
2846                 if (!dev->in_fs_metadata || !dev->writeable)
2847                         continue;
2848
2849                 ret = write_dev_supers(dev, sb, do_barriers, 1, max_mirrors);
2850                 if (ret)
2851                         total_errors++;
2852         }
2853         mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2854         if (total_errors > max_errors) {
2855                 printk(KERN_ERR "btrfs: %d errors while writing supers\n",
2856                        total_errors);
2857                 BUG();
2858         }
2859         return 0;
2860 }
2861
2862 int write_ctree_super(struct btrfs_trans_handle *trans,
2863                       struct btrfs_root *root, int max_mirrors)
2864 {
2865         int ret;
2866
2867         ret = write_all_supers(root, max_mirrors);
2868         return ret;
2869 }
2870
2871 int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
2872 {
2873         spin_lock(&fs_info->fs_roots_radix_lock);
2874         radix_tree_delete(&fs_info->fs_roots_radix,
2875                           (unsigned long)root->root_key.objectid);
2876         spin_unlock(&fs_info->fs_roots_radix_lock);
2877
2878         if (btrfs_root_refs(&root->root_item) == 0)
2879                 synchronize_srcu(&fs_info->subvol_srcu);
2880
2881         __btrfs_remove_free_space_cache(root->free_ino_pinned);
2882         __btrfs_remove_free_space_cache(root->free_ino_ctl);
2883         free_fs_root(root);
2884         return 0;
2885 }
2886
2887 static void free_fs_root(struct btrfs_root *root)
2888 {
2889         iput(root->cache_inode);
2890         WARN_ON(!RB_EMPTY_ROOT(&root->inode_tree));
2891         if (root->anon_dev)
2892                 free_anon_bdev(root->anon_dev);
2893         free_extent_buffer(root->node);
2894         free_extent_buffer(root->commit_root);
2895         kfree(root->free_ino_ctl);
2896         kfree(root->free_ino_pinned);
2897         kfree(root->name);
2898         kfree(root);
2899 }
2900
2901 static int del_fs_roots(struct btrfs_fs_info *fs_info)
2902 {
2903         int ret;
2904         struct btrfs_root *gang[8];
2905         int i;
2906
2907         while (!list_empty(&fs_info->dead_roots)) {
2908                 gang[0] = list_entry(fs_info->dead_roots.next,
2909                                      struct btrfs_root, root_list);
2910                 list_del(&gang[0]->root_list);
2911
2912                 if (gang[0]->in_radix) {
2913                         btrfs_free_fs_root(fs_info, gang[0]);
2914                 } else {
2915                         free_extent_buffer(gang[0]->node);
2916                         free_extent_buffer(gang[0]->commit_root);
2917                         kfree(gang[0]);
2918                 }
2919         }
2920
2921         while (1) {
2922                 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2923                                              (void **)gang, 0,
2924                                              ARRAY_SIZE(gang));
2925                 if (!ret)
2926                         break;
2927                 for (i = 0; i < ret; i++)
2928                         btrfs_free_fs_root(fs_info, gang[i]);
2929         }
2930         return 0;
2931 }
2932
2933 int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
2934 {
2935         u64 root_objectid = 0;
2936         struct btrfs_root *gang[8];
2937         int i;
2938         int ret;
2939
2940         while (1) {
2941                 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2942                                              (void **)gang, root_objectid,
2943                                              ARRAY_SIZE(gang));
2944                 if (!ret)
2945                         break;
2946
2947                 root_objectid = gang[ret - 1]->root_key.objectid + 1;
2948                 for (i = 0; i < ret; i++) {
2949                         int err;
2950
2951                         root_objectid = gang[i]->root_key.objectid;
2952                         err = btrfs_orphan_cleanup(gang[i]);
2953                         if (err)
2954                                 return err;
2955                 }
2956                 root_objectid++;
2957         }
2958         return 0;
2959 }
2960
2961 int btrfs_commit_super(struct btrfs_root *root)
2962 {
2963         struct btrfs_trans_handle *trans;
2964         int ret;
2965
2966         mutex_lock(&root->fs_info->cleaner_mutex);
2967         btrfs_run_delayed_iputs(root);
2968         btrfs_clean_old_snapshots(root);
2969         mutex_unlock(&root->fs_info->cleaner_mutex);
2970
2971         /* wait until ongoing cleanup work done */
2972         down_write(&root->fs_info->cleanup_work_sem);
2973         up_write(&root->fs_info->cleanup_work_sem);
2974
2975         trans = btrfs_join_transaction(root);
2976         if (IS_ERR(trans))
2977                 return PTR_ERR(trans);
2978         ret = btrfs_commit_transaction(trans, root);
2979         BUG_ON(ret);
2980         /* run commit again to drop the original snapshot */
2981         trans = btrfs_join_transaction(root);
2982         if (IS_ERR(trans))
2983                 return PTR_ERR(trans);
2984         btrfs_commit_transaction(trans, root);
2985         ret = btrfs_write_and_wait_transaction(NULL, root);
2986         BUG_ON(ret);
2987
2988         ret = write_ctree_super(NULL, root, 0);
2989         return ret;
2990 }
2991
2992 int close_ctree(struct btrfs_root *root)
2993 {
2994         struct btrfs_fs_info *fs_info = root->fs_info;
2995         int ret;
2996
2997         fs_info->closing = 1;
2998         smp_mb();
2999
3000         /* pause restriper - we want to resume on mount */
3001         btrfs_pause_balance(root->fs_info);
3002
3003         btrfs_scrub_cancel(root);
3004
3005         /* wait for any defraggers to finish */
3006         wait_event(fs_info->transaction_wait,
3007                    (atomic_read(&fs_info->defrag_running) == 0));
3008
3009         /* clear out the rbtree of defraggable inodes */
3010         btrfs_run_defrag_inodes(root->fs_info);
3011
3012         /*
3013          * Here come 2 situations when btrfs is broken to flip readonly:
3014          *
3015          * 1. when btrfs flips readonly somewhere else before
3016          * btrfs_commit_super, sb->s_flags has MS_RDONLY flag,
3017          * and btrfs will skip to write sb directly to keep
3018          * ERROR state on disk.
3019          *
3020          * 2. when btrfs flips readonly just in btrfs_commit_super,
3021          * and in such case, btrfs cannot write sb via btrfs_commit_super,
3022          * and since fs_state has been set BTRFS_SUPER_FLAG_ERROR flag,
3023          * btrfs will cleanup all FS resources first and write sb then.
3024          */
3025         if (!(fs_info->sb->s_flags & MS_RDONLY)) {
3026                 ret = btrfs_commit_super(root);
3027                 if (ret)
3028                         printk(KERN_ERR "btrfs: commit super ret %d\n", ret);
3029         }
3030
3031         if (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) {
3032                 ret = btrfs_error_commit_super(root);
3033                 if (ret)
3034                         printk(KERN_ERR "btrfs: commit super ret %d\n", ret);
3035         }
3036
3037         btrfs_put_block_group_cache(fs_info);
3038
3039         kthread_stop(root->fs_info->transaction_kthread);
3040         kthread_stop(root->fs_info->cleaner_kthread);
3041
3042         fs_info->closing = 2;
3043         smp_mb();
3044
3045         if (fs_info->delalloc_bytes) {
3046                 printk(KERN_INFO "btrfs: at unmount delalloc count %llu\n",
3047                        (unsigned long long)fs_info->delalloc_bytes);
3048         }
3049         if (fs_info->total_ref_cache_size) {
3050                 printk(KERN_INFO "btrfs: at umount reference cache size %llu\n",
3051                        (unsigned long long)fs_info->total_ref_cache_size);
3052         }
3053
3054         free_extent_buffer(fs_info->extent_root->node);
3055         free_extent_buffer(fs_info->extent_root->commit_root);
3056         free_extent_buffer(fs_info->tree_root->node);
3057         free_extent_buffer(fs_info->tree_root->commit_root);
3058         free_extent_buffer(root->fs_info->chunk_root->node);
3059         free_extent_buffer(root->fs_info->chunk_root->commit_root);
3060         free_extent_buffer(root->fs_info->dev_root->node);
3061         free_extent_buffer(root->fs_info->dev_root->commit_root);
3062         free_extent_buffer(root->fs_info->csum_root->node);
3063         free_extent_buffer(root->fs_info->csum_root->commit_root);
3064
3065         btrfs_free_block_groups(root->fs_info);
3066
3067         del_fs_roots(fs_info);
3068
3069         iput(fs_info->btree_inode);
3070
3071         btrfs_stop_workers(&fs_info->generic_worker);
3072         btrfs_stop_workers(&fs_info->fixup_workers);
3073         btrfs_stop_workers(&fs_info->delalloc_workers);
3074         btrfs_stop_workers(&fs_info->workers);
3075         btrfs_stop_workers(&fs_info->endio_workers);
3076         btrfs_stop_workers(&fs_info->endio_meta_workers);
3077         btrfs_stop_workers(&fs_info->endio_meta_write_workers);
3078         btrfs_stop_workers(&fs_info->endio_write_workers);
3079         btrfs_stop_workers(&fs_info->endio_freespace_worker);
3080         btrfs_stop_workers(&fs_info->submit_workers);
3081         btrfs_stop_workers(&fs_info->delayed_workers);
3082         btrfs_stop_workers(&fs_info->caching_workers);
3083         btrfs_stop_workers(&fs_info->readahead_workers);
3084
3085 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
3086         if (btrfs_test_opt(root, CHECK_INTEGRITY))
3087                 btrfsic_unmount(root, fs_info->fs_devices);
3088 #endif
3089
3090         btrfs_close_devices(fs_info->fs_devices);
3091         btrfs_mapping_tree_free(&fs_info->mapping_tree);
3092
3093         bdi_destroy(&fs_info->bdi);
3094         cleanup_srcu_struct(&fs_info->subvol_srcu);
3095
3096         free_fs_info(fs_info);
3097
3098         return 0;
3099 }
3100
3101 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid)
3102 {
3103         int ret;
3104         struct inode *btree_inode = buf->first_page->mapping->host;
3105
3106         ret = extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree, buf,
3107                                      NULL);
3108         if (!ret)
3109                 return ret;
3110
3111         ret = verify_parent_transid(&BTRFS_I(btree_inode)->io_tree, buf,
3112                                     parent_transid);
3113         return !ret;
3114 }
3115
3116 int btrfs_set_buffer_uptodate(struct extent_buffer *buf)
3117 {
3118         struct inode *btree_inode = buf->first_page->mapping->host;
3119         return set_extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree,
3120                                           buf);
3121 }
3122
3123 void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
3124 {
3125         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
3126         u64 transid = btrfs_header_generation(buf);
3127         struct inode *btree_inode = root->fs_info->btree_inode;
3128         int was_dirty;
3129
3130         btrfs_assert_tree_locked(buf);
3131         if (transid != root->fs_info->generation) {
3132                 printk(KERN_CRIT "btrfs transid mismatch buffer %llu, "
3133                        "found %llu running %llu\n",
3134                         (unsigned long long)buf->start,
3135                         (unsigned long long)transid,
3136                         (unsigned long long)root->fs_info->generation);
3137                 WARN_ON(1);
3138         }
3139         was_dirty = set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
3140                                             buf);
3141         if (!was_dirty) {
3142                 spin_lock(&root->fs_info->delalloc_lock);
3143                 root->fs_info->dirty_metadata_bytes += buf->len;
3144                 spin_unlock(&root->fs_info->delalloc_lock);
3145         }
3146 }
3147
3148 void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
3149 {
3150         /*
3151          * looks as though older kernels can get into trouble with
3152          * this code, they end up stuck in balance_dirty_pages forever
3153          */
3154         u64 num_dirty;
3155         unsigned long thresh = 32 * 1024 * 1024;
3156
3157         if (current->flags & PF_MEMALLOC)
3158                 return;
3159
3160         btrfs_balance_delayed_items(root);
3161
3162         num_dirty = root->fs_info->dirty_metadata_bytes;
3163
3164         if (num_dirty > thresh) {
3165                 balance_dirty_pages_ratelimited_nr(
3166                                    root->fs_info->btree_inode->i_mapping, 1);
3167         }
3168         return;
3169 }
3170
3171 void __btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
3172 {
3173         /*
3174          * looks as though older kernels can get into trouble with
3175          * this code, they end up stuck in balance_dirty_pages forever
3176          */
3177         u64 num_dirty;
3178         unsigned long thresh = 32 * 1024 * 1024;
3179
3180         if (current->flags & PF_MEMALLOC)
3181                 return;
3182
3183         num_dirty = root->fs_info->dirty_metadata_bytes;
3184
3185         if (num_dirty > thresh) {
3186                 balance_dirty_pages_ratelimited_nr(
3187                                    root->fs_info->btree_inode->i_mapping, 1);
3188         }
3189         return;
3190 }
3191
3192 int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid)
3193 {
3194         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
3195         int ret;
3196         ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
3197         if (ret == 0)
3198                 set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
3199         return ret;
3200 }
3201
3202 static int btree_lock_page_hook(struct page *page, void *data,
3203                                 void (*flush_fn)(void *))
3204 {
3205         struct inode *inode = page->mapping->host;
3206         struct btrfs_root *root = BTRFS_I(inode)->root;
3207         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
3208         struct extent_buffer *eb;
3209         unsigned long len;
3210         u64 bytenr = page_offset(page);
3211
3212         if (page->private == EXTENT_PAGE_PRIVATE)
3213                 goto out;
3214
3215         len = page->private >> 2;
3216         eb = find_extent_buffer(io_tree, bytenr, len);
3217         if (!eb)
3218                 goto out;
3219
3220         if (!btrfs_try_tree_write_lock(eb)) {
3221                 flush_fn(data);
3222                 btrfs_tree_lock(eb);
3223         }
3224         btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
3225
3226         if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
3227                 spin_lock(&root->fs_info->delalloc_lock);
3228                 if (root->fs_info->dirty_metadata_bytes >= eb->len)
3229                         root->fs_info->dirty_metadata_bytes -= eb->len;
3230                 else
3231                         WARN_ON(1);
3232                 spin_unlock(&root->fs_info->delalloc_lock);
3233         }
3234
3235         btrfs_tree_unlock(eb);
3236         free_extent_buffer(eb);
3237 out:
3238         if (!trylock_page(page)) {
3239                 flush_fn(data);
3240                 lock_page(page);
3241         }
3242         return 0;
3243 }
3244
3245 static void btrfs_check_super_valid(struct btrfs_fs_info *fs_info,
3246                               int read_only)
3247 {
3248         if (read_only)
3249                 return;
3250
3251         if (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR)
3252                 printk(KERN_WARNING "warning: mount fs with errors, "
3253                        "running btrfsck is recommended\n");
3254 }
3255
3256 int btrfs_error_commit_super(struct btrfs_root *root)
3257 {
3258         int ret;
3259
3260         mutex_lock(&root->fs_info->cleaner_mutex);
3261         btrfs_run_delayed_iputs(root);
3262         mutex_unlock(&root->fs_info->cleaner_mutex);
3263
3264         down_write(&root->fs_info->cleanup_work_sem);
3265         up_write(&root->fs_info->cleanup_work_sem);
3266
3267         /* cleanup FS via transaction */
3268         btrfs_cleanup_transaction(root);
3269
3270         ret = write_ctree_super(NULL, root, 0);
3271
3272         return ret;
3273 }
3274
3275 static int btrfs_destroy_ordered_operations(struct btrfs_root *root)
3276 {
3277         struct btrfs_inode *btrfs_inode;
3278         struct list_head splice;
3279
3280         INIT_LIST_HEAD(&splice);
3281
3282         mutex_lock(&root->fs_info->ordered_operations_mutex);
3283         spin_lock(&root->fs_info->ordered_extent_lock);
3284
3285         list_splice_init(&root->fs_info->ordered_operations, &splice);
3286         while (!list_empty(&splice)) {
3287                 btrfs_inode = list_entry(splice.next, struct btrfs_inode,
3288                                          ordered_operations);
3289
3290                 list_del_init(&btrfs_inode->ordered_operations);
3291
3292                 btrfs_invalidate_inodes(btrfs_inode->root);
3293         }
3294
3295         spin_unlock(&root->fs_info->ordered_extent_lock);
3296         mutex_unlock(&root->fs_info->ordered_operations_mutex);
3297
3298         return 0;
3299 }
3300
3301 static int btrfs_destroy_ordered_extents(struct btrfs_root *root)
3302 {
3303         struct list_head splice;
3304         struct btrfs_ordered_extent *ordered;
3305         struct inode *inode;
3306
3307         INIT_LIST_HEAD(&splice);
3308
3309         spin_lock(&root->fs_info->ordered_extent_lock);
3310
3311         list_splice_init(&root->fs_info->ordered_extents, &splice);
3312         while (!list_empty(&splice)) {
3313                 ordered = list_entry(splice.next, struct btrfs_ordered_extent,
3314                                      root_extent_list);
3315
3316                 list_del_init(&ordered->root_extent_list);
3317                 atomic_inc(&ordered->refs);
3318
3319                 /* the inode may be getting freed (in sys_unlink path). */
3320                 inode = igrab(ordered->inode);
3321
3322                 spin_unlock(&root->fs_info->ordered_extent_lock);
3323                 if (inode)
3324                         iput(inode);
3325
3326                 atomic_set(&ordered->refs, 1);
3327                 btrfs_put_ordered_extent(ordered);
3328
3329                 spin_lock(&root->fs_info->ordered_extent_lock);
3330         }
3331
3332         spin_unlock(&root->fs_info->ordered_extent_lock);
3333
3334         return 0;
3335 }
3336
3337 static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
3338                                       struct btrfs_root *root)
3339 {
3340         struct rb_node *node;
3341         struct btrfs_delayed_ref_root *delayed_refs;
3342         struct btrfs_delayed_ref_node *ref;
3343         int ret = 0;
3344
3345         delayed_refs = &trans->delayed_refs;
3346
3347         spin_lock(&delayed_refs->lock);
3348         if (delayed_refs->num_entries == 0) {
3349                 spin_unlock(&delayed_refs->lock);
3350                 printk(KERN_INFO "delayed_refs has NO entry\n");
3351                 return ret;
3352         }
3353
3354         node = rb_first(&delayed_refs->root);
3355         while (node) {
3356                 ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
3357                 node = rb_next(node);
3358
3359                 ref->in_tree = 0;
3360                 rb_erase(&ref->rb_node, &delayed_refs->root);
3361                 delayed_refs->num_entries--;
3362
3363                 atomic_set(&ref->refs, 1);
3364                 if (btrfs_delayed_ref_is_head(ref)) {
3365                         struct btrfs_delayed_ref_head *head;
3366
3367                         head = btrfs_delayed_node_to_head(ref);
3368                         mutex_lock(&head->mutex);
3369                         kfree(head->extent_op);
3370                         delayed_refs->num_heads--;
3371                         if (list_empty(&head->cluster))
3372                               &nb