Btrfs: Create larger bios for btree blocks
[linux-2.6] / 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/crc32c.h>
22 #include <linux/scatterlist.h>
23 #include <linux/swap.h>
24 #include <linux/radix-tree.h>
25 #include <linux/writeback.h>
26 #include <linux/buffer_head.h> // for block_sync_page
27 #include "ctree.h"
28 #include "disk-io.h"
29 #include "transaction.h"
30 #include "btrfs_inode.h"
31 #include "print-tree.h"
32
33 #if 0
34 static int check_tree_block(struct btrfs_root *root, struct extent_buffer *buf)
35 {
36         if (extent_buffer_blocknr(buf) != btrfs_header_blocknr(buf)) {
37                 printk(KERN_CRIT "buf blocknr(buf) is %llu, header is %llu\n",
38                        (unsigned long long)extent_buffer_blocknr(buf),
39                        (unsigned long long)btrfs_header_blocknr(buf));
40                 return 1;
41         }
42         return 0;
43 }
44 #endif
45
46 static struct extent_io_ops btree_extent_io_ops;
47
48 struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
49                                             u64 bytenr, u32 blocksize)
50 {
51         struct inode *btree_inode = root->fs_info->btree_inode;
52         struct extent_buffer *eb;
53         eb = find_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
54                                 bytenr, blocksize, GFP_NOFS);
55         return eb;
56 }
57
58 struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
59                                                  u64 bytenr, u32 blocksize)
60 {
61         struct inode *btree_inode = root->fs_info->btree_inode;
62         struct extent_buffer *eb;
63
64         eb = alloc_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
65                                  bytenr, blocksize, NULL, GFP_NOFS);
66         return eb;
67 }
68
69 struct extent_map *btree_get_extent(struct inode *inode, struct page *page,
70                                     size_t page_offset, u64 start, u64 len,
71                                     int create)
72 {
73         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
74         struct extent_map *em;
75         int ret;
76
77 again:
78         spin_lock(&em_tree->lock);
79         em = lookup_extent_mapping(em_tree, start, len);
80         spin_unlock(&em_tree->lock);
81         if (em) {
82                 goto out;
83         }
84         em = alloc_extent_map(GFP_NOFS);
85         if (!em) {
86                 em = ERR_PTR(-ENOMEM);
87                 goto out;
88         }
89         em->start = 0;
90         em->len = i_size_read(inode);
91         em->block_start = 0;
92         em->bdev = inode->i_sb->s_bdev;
93
94         spin_lock(&em_tree->lock);
95         ret = add_extent_mapping(em_tree, em);
96         spin_unlock(&em_tree->lock);
97
98         if (ret == -EEXIST) {
99                 free_extent_map(em);
100                 em = NULL;
101                 goto again;
102         } else if (ret) {
103                 em = ERR_PTR(ret);
104         }
105 out:
106         return em;
107 }
108
109 u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len)
110 {
111         return crc32c(seed, data, len);
112 }
113
114 void btrfs_csum_final(u32 crc, char *result)
115 {
116         *(__le32 *)result = ~cpu_to_le32(crc);
117 }
118
119 static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
120                            int verify)
121 {
122         char result[BTRFS_CRC32_SIZE];
123         unsigned long len;
124         unsigned long cur_len;
125         unsigned long offset = BTRFS_CSUM_SIZE;
126         char *map_token = NULL;
127         char *kaddr;
128         unsigned long map_start;
129         unsigned long map_len;
130         int err;
131         u32 crc = ~(u32)0;
132
133         len = buf->len - offset;
134         while(len > 0) {
135                 err = map_private_extent_buffer(buf, offset, 32,
136                                         &map_token, &kaddr,
137                                         &map_start, &map_len, KM_USER0);
138                 if (err) {
139                         printk("failed to map extent buffer! %lu\n",
140                                offset);
141                         return 1;
142                 }
143                 cur_len = min(len, map_len - (offset - map_start));
144                 crc = btrfs_csum_data(root, kaddr + offset - map_start,
145                                       crc, cur_len);
146                 len -= cur_len;
147                 offset += cur_len;
148                 unmap_extent_buffer(buf, map_token, KM_USER0);
149         }
150         btrfs_csum_final(crc, result);
151
152         if (verify) {
153                 int from_this_trans = 0;
154
155                 if (root->fs_info->running_transaction &&
156                     btrfs_header_generation(buf) ==
157                     root->fs_info->running_transaction->transid)
158                         from_this_trans = 1;
159
160                 /* FIXME, this is not good */
161                 if (from_this_trans == 0 &&
162                     memcmp_extent_buffer(buf, result, 0, BTRFS_CRC32_SIZE)) {
163                         u32 val;
164                         u32 found = 0;
165                         memcpy(&found, result, BTRFS_CRC32_SIZE);
166
167                         read_extent_buffer(buf, &val, 0, BTRFS_CRC32_SIZE);
168                         printk("btrfs: %s checksum verify failed on %llu "
169                                "wanted %X found %X from_this_trans %d\n",
170                                root->fs_info->sb->s_id,
171                                buf->start, val, found, from_this_trans);
172                         return 1;
173                 }
174         } else {
175                 write_extent_buffer(buf, result, 0, BTRFS_CRC32_SIZE);
176         }
177         return 0;
178 }
179
180
181 int csum_dirty_buffer(struct btrfs_root *root, struct page *page)
182 {
183         struct extent_io_tree *tree;
184         u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
185         u64 found_start;
186         int found_level;
187         unsigned long len;
188         struct extent_buffer *eb;
189         tree = &BTRFS_I(page->mapping->host)->io_tree;
190
191         if (page->private == EXTENT_PAGE_PRIVATE)
192                 goto out;
193         if (!page->private)
194                 goto out;
195         len = page->private >> 2;
196         if (len == 0) {
197                 WARN_ON(1);
198         }
199         eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
200         read_extent_buffer_pages(tree, eb, start + PAGE_CACHE_SIZE, 1,
201                                  btree_get_extent);
202         btrfs_clear_buffer_defrag(eb);
203         found_start = btrfs_header_bytenr(eb);
204         if (found_start != start) {
205                 printk("warning: eb start incorrect %Lu buffer %Lu len %lu\n",
206                        start, found_start, len);
207                 WARN_ON(1);
208                 goto err;
209         }
210         if (eb->first_page != page) {
211                 printk("bad first page %lu %lu\n", eb->first_page->index,
212                        page->index);
213                 WARN_ON(1);
214                 goto err;
215         }
216         if (!PageUptodate(page)) {
217                 printk("csum not up to date page %lu\n", page->index);
218                 WARN_ON(1);
219                 goto err;
220         }
221         found_level = btrfs_header_level(eb);
222         csum_tree_block(root, eb, 0);
223 err:
224         free_extent_buffer(eb);
225 out:
226         return 0;
227 }
228
229 static int btree_writepage_io_hook(struct page *page, u64 start, u64 end)
230 {
231         struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
232
233         csum_dirty_buffer(root, page);
234         return 0;
235 }
236
237 static int btree_writepage(struct page *page, struct writeback_control *wbc)
238 {
239         struct extent_io_tree *tree;
240         tree = &BTRFS_I(page->mapping->host)->io_tree;
241         return extent_write_full_page(tree, page, btree_get_extent, wbc);
242 }
243
244 static int btree_writepages(struct address_space *mapping,
245                             struct writeback_control *wbc)
246 {
247         struct extent_io_tree *tree;
248         tree = &BTRFS_I(mapping->host)->io_tree;
249         if (wbc->sync_mode == WB_SYNC_NONE) {
250                 u64 num_dirty;
251                 u64 start = 0;
252                 unsigned long thresh = 96 * 1024 * 1024;
253
254                 if (wbc->for_kupdate)
255                         return 0;
256
257                 if (current_is_pdflush()) {
258                         thresh = 96 * 1024 * 1024;
259                 } else {
260                         thresh = 8 * 1024 * 1024;
261                 }
262                 num_dirty = count_range_bits(tree, &start, (u64)-1,
263                                              thresh, EXTENT_DIRTY);
264                 if (num_dirty < thresh) {
265                         return 0;
266                 }
267         }
268         return extent_writepages(tree, mapping, btree_get_extent, wbc);
269 }
270
271 int btree_readpage(struct file *file, struct page *page)
272 {
273         struct extent_io_tree *tree;
274         tree = &BTRFS_I(page->mapping->host)->io_tree;
275         return extent_read_full_page(tree, page, btree_get_extent);
276 }
277
278 static int btree_releasepage(struct page *page, gfp_t gfp_flags)
279 {
280         struct extent_io_tree *tree;
281         struct extent_map_tree *map;
282         int ret;
283
284         tree = &BTRFS_I(page->mapping->host)->io_tree;
285         map = &BTRFS_I(page->mapping->host)->extent_tree;
286         ret = try_release_extent_mapping(map, tree, page, gfp_flags);
287         if (ret == 1) {
288                 ClearPagePrivate(page);
289                 set_page_private(page, 0);
290                 page_cache_release(page);
291         }
292         return ret;
293 }
294
295 static void btree_invalidatepage(struct page *page, unsigned long offset)
296 {
297         struct extent_io_tree *tree;
298         tree = &BTRFS_I(page->mapping->host)->io_tree;
299         extent_invalidatepage(tree, page, offset);
300         btree_releasepage(page, GFP_NOFS);
301 }
302
303 #if 0
304 static int btree_writepage(struct page *page, struct writeback_control *wbc)
305 {
306         struct buffer_head *bh;
307         struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
308         struct buffer_head *head;
309         if (!page_has_buffers(page)) {
310                 create_empty_buffers(page, root->fs_info->sb->s_blocksize,
311                                         (1 << BH_Dirty)|(1 << BH_Uptodate));
312         }
313         head = page_buffers(page);
314         bh = head;
315         do {
316                 if (buffer_dirty(bh))
317                         csum_tree_block(root, bh, 0);
318                 bh = bh->b_this_page;
319         } while (bh != head);
320         return block_write_full_page(page, btree_get_block, wbc);
321 }
322 #endif
323
324 static struct address_space_operations btree_aops = {
325         .readpage       = btree_readpage,
326         .writepage      = btree_writepage,
327         .writepages     = btree_writepages,
328         .releasepage    = btree_releasepage,
329         .invalidatepage = btree_invalidatepage,
330         .sync_page      = block_sync_page,
331 };
332
333 int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize)
334 {
335         struct extent_buffer *buf = NULL;
336         struct inode *btree_inode = root->fs_info->btree_inode;
337         int ret = 0;
338
339         buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
340         if (!buf)
341                 return 0;
342         read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
343                                  buf, 0, 0, btree_get_extent);
344         free_extent_buffer(buf);
345         return ret;
346 }
347
348 struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
349                                       u32 blocksize)
350 {
351         struct extent_buffer *buf = NULL;
352         struct inode *btree_inode = root->fs_info->btree_inode;
353         struct extent_io_tree *io_tree;
354         u64 end;
355         int ret;
356
357         io_tree = &BTRFS_I(btree_inode)->io_tree;
358
359         buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
360         if (!buf)
361                 return NULL;
362         read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree, buf, 0, 1,
363                                  btree_get_extent);
364
365         if (buf->flags & EXTENT_CSUM)
366                 return buf;
367
368         end = buf->start + PAGE_CACHE_SIZE - 1;
369         if (test_range_bit(io_tree, buf->start, end, EXTENT_CSUM, 1)) {
370                 buf->flags |= EXTENT_CSUM;
371                 return buf;
372         }
373
374         lock_extent(io_tree, buf->start, end, GFP_NOFS);
375
376         if (test_range_bit(io_tree, buf->start, end, EXTENT_CSUM, 1)) {
377                 buf->flags |= EXTENT_CSUM;
378                 goto out_unlock;
379         }
380
381         ret = csum_tree_block(root, buf, 1);
382         set_extent_bits(io_tree, buf->start, end, EXTENT_CSUM, GFP_NOFS);
383         buf->flags |= EXTENT_CSUM;
384
385 out_unlock:
386         unlock_extent(io_tree, buf->start, end, GFP_NOFS);
387         return buf;
388 }
389
390 int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
391                      struct extent_buffer *buf)
392 {
393         struct inode *btree_inode = root->fs_info->btree_inode;
394         if (btrfs_header_generation(buf) ==
395             root->fs_info->running_transaction->transid)
396                 clear_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
397                                           buf);
398         return 0;
399 }
400
401 int wait_on_tree_block_writeback(struct btrfs_root *root,
402                                  struct extent_buffer *buf)
403 {
404         struct inode *btree_inode = root->fs_info->btree_inode;
405         wait_on_extent_buffer_writeback(&BTRFS_I(btree_inode)->io_tree,
406                                         buf);
407         return 0;
408 }
409
410 static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
411                         u32 stripesize, struct btrfs_root *root,
412                         struct btrfs_fs_info *fs_info,
413                         u64 objectid)
414 {
415         root->node = NULL;
416         root->inode = NULL;
417         root->commit_root = NULL;
418         root->sectorsize = sectorsize;
419         root->nodesize = nodesize;
420         root->leafsize = leafsize;
421         root->stripesize = stripesize;
422         root->ref_cows = 0;
423         root->fs_info = fs_info;
424         root->objectid = objectid;
425         root->last_trans = 0;
426         root->highest_inode = 0;
427         root->last_inode_alloc = 0;
428         root->name = NULL;
429         root->in_sysfs = 0;
430         memset(&root->root_key, 0, sizeof(root->root_key));
431         memset(&root->root_item, 0, sizeof(root->root_item));
432         memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
433         memset(&root->root_kobj, 0, sizeof(root->root_kobj));
434         init_completion(&root->kobj_unregister);
435         root->defrag_running = 0;
436         root->defrag_level = 0;
437         root->root_key.objectid = objectid;
438         return 0;
439 }
440
441 static int find_and_setup_root(struct btrfs_root *tree_root,
442                                struct btrfs_fs_info *fs_info,
443                                u64 objectid,
444                                struct btrfs_root *root)
445 {
446         int ret;
447         u32 blocksize;
448
449         __setup_root(tree_root->nodesize, tree_root->leafsize,
450                      tree_root->sectorsize, tree_root->stripesize,
451                      root, fs_info, objectid);
452         ret = btrfs_find_last_root(tree_root, objectid,
453                                    &root->root_item, &root->root_key);
454         BUG_ON(ret);
455
456         blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
457         root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
458                                      blocksize);
459         BUG_ON(!root->node);
460         return 0;
461 }
462
463 struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_fs_info *fs_info,
464                                                struct btrfs_key *location)
465 {
466         struct btrfs_root *root;
467         struct btrfs_root *tree_root = fs_info->tree_root;
468         struct btrfs_path *path;
469         struct extent_buffer *l;
470         u64 highest_inode;
471         u32 blocksize;
472         int ret = 0;
473
474         root = kzalloc(sizeof(*root), GFP_NOFS);
475         if (!root)
476                 return ERR_PTR(-ENOMEM);
477         if (location->offset == (u64)-1) {
478                 ret = find_and_setup_root(tree_root, fs_info,
479                                           location->objectid, root);
480                 if (ret) {
481                         kfree(root);
482                         return ERR_PTR(ret);
483                 }
484                 goto insert;
485         }
486
487         __setup_root(tree_root->nodesize, tree_root->leafsize,
488                      tree_root->sectorsize, tree_root->stripesize,
489                      root, fs_info, location->objectid);
490
491         path = btrfs_alloc_path();
492         BUG_ON(!path);
493         ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
494         if (ret != 0) {
495                 if (ret > 0)
496                         ret = -ENOENT;
497                 goto out;
498         }
499         l = path->nodes[0];
500         read_extent_buffer(l, &root->root_item,
501                btrfs_item_ptr_offset(l, path->slots[0]),
502                sizeof(root->root_item));
503         memcpy(&root->root_key, location, sizeof(*location));
504         ret = 0;
505 out:
506         btrfs_release_path(root, path);
507         btrfs_free_path(path);
508         if (ret) {
509                 kfree(root);
510                 return ERR_PTR(ret);
511         }
512         blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
513         root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
514                                      blocksize);
515         BUG_ON(!root->node);
516 insert:
517         root->ref_cows = 1;
518         ret = btrfs_find_highest_inode(root, &highest_inode);
519         if (ret == 0) {
520                 root->highest_inode = highest_inode;
521                 root->last_inode_alloc = highest_inode;
522         }
523         return root;
524 }
525
526 struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
527                                         u64 root_objectid)
528 {
529         struct btrfs_root *root;
530
531         if (root_objectid == BTRFS_ROOT_TREE_OBJECTID)
532                 return fs_info->tree_root;
533         if (root_objectid == BTRFS_EXTENT_TREE_OBJECTID)
534                 return fs_info->extent_root;
535
536         root = radix_tree_lookup(&fs_info->fs_roots_radix,
537                                  (unsigned long)root_objectid);
538         return root;
539 }
540
541 struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
542                                               struct btrfs_key *location)
543 {
544         struct btrfs_root *root;
545         int ret;
546
547         if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
548                 return fs_info->tree_root;
549         if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
550                 return fs_info->extent_root;
551
552         root = radix_tree_lookup(&fs_info->fs_roots_radix,
553                                  (unsigned long)location->objectid);
554         if (root)
555                 return root;
556
557         root = btrfs_read_fs_root_no_radix(fs_info, location);
558         if (IS_ERR(root))
559                 return root;
560         ret = radix_tree_insert(&fs_info->fs_roots_radix,
561                                 (unsigned long)root->root_key.objectid,
562                                 root);
563         if (ret) {
564                 free_extent_buffer(root->node);
565                 kfree(root);
566                 return ERR_PTR(ret);
567         }
568         ret = btrfs_find_dead_roots(fs_info->tree_root,
569                                     root->root_key.objectid, root);
570         BUG_ON(ret);
571
572         return root;
573 }
574
575 struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
576                                       struct btrfs_key *location,
577                                       const char *name, int namelen)
578 {
579         struct btrfs_root *root;
580         int ret;
581
582         root = btrfs_read_fs_root_no_name(fs_info, location);
583         if (!root)
584                 return NULL;
585
586         if (root->in_sysfs)
587                 return root;
588
589         ret = btrfs_set_root_name(root, name, namelen);
590         if (ret) {
591                 free_extent_buffer(root->node);
592                 kfree(root);
593                 return ERR_PTR(ret);
594         }
595
596         ret = btrfs_sysfs_add_root(root);
597         if (ret) {
598                 free_extent_buffer(root->node);
599                 kfree(root->name);
600                 kfree(root);
601                 return ERR_PTR(ret);
602         }
603         root->in_sysfs = 1;
604         return root;
605 }
606 #if 0
607 static int add_hasher(struct btrfs_fs_info *info, char *type) {
608         struct btrfs_hasher *hasher;
609
610         hasher = kmalloc(sizeof(*hasher), GFP_NOFS);
611         if (!hasher)
612                 return -ENOMEM;
613         hasher->hash_tfm = crypto_alloc_hash(type, 0, CRYPTO_ALG_ASYNC);
614         if (!hasher->hash_tfm) {
615                 kfree(hasher);
616                 return -EINVAL;
617         }
618         spin_lock(&info->hash_lock);
619         list_add(&hasher->list, &info->hashers);
620         spin_unlock(&info->hash_lock);
621         return 0;
622 }
623 #endif
624 struct btrfs_root *open_ctree(struct super_block *sb)
625 {
626         u32 sectorsize;
627         u32 nodesize;
628         u32 leafsize;
629         u32 blocksize;
630         u32 stripesize;
631         struct btrfs_root *extent_root = kmalloc(sizeof(struct btrfs_root),
632                                                  GFP_NOFS);
633         struct btrfs_root *tree_root = kmalloc(sizeof(struct btrfs_root),
634                                                GFP_NOFS);
635         struct btrfs_fs_info *fs_info = kmalloc(sizeof(*fs_info),
636                                                 GFP_NOFS);
637         int ret;
638         int err = -EIO;
639         struct btrfs_super_block *disk_super;
640
641         if (!extent_root || !tree_root || !fs_info) {
642                 err = -ENOMEM;
643                 goto fail;
644         }
645         INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_NOFS);
646         INIT_LIST_HEAD(&fs_info->trans_list);
647         INIT_LIST_HEAD(&fs_info->dead_roots);
648         INIT_LIST_HEAD(&fs_info->hashers);
649         spin_lock_init(&fs_info->hash_lock);
650         spin_lock_init(&fs_info->delalloc_lock);
651         spin_lock_init(&fs_info->new_trans_lock);
652
653         memset(&fs_info->super_kobj, 0, sizeof(fs_info->super_kobj));
654         init_completion(&fs_info->kobj_unregister);
655         sb_set_blocksize(sb, 4096);
656         fs_info->running_transaction = NULL;
657         fs_info->last_trans_committed = 0;
658         fs_info->tree_root = tree_root;
659         fs_info->extent_root = extent_root;
660         fs_info->sb = sb;
661         fs_info->throttles = 0;
662         fs_info->mount_opt = 0;
663         fs_info->max_extent = (u64)-1;
664         fs_info->max_inline = 8192 * 1024;
665         fs_info->delalloc_bytes = 0;
666         fs_info->btree_inode = new_inode(sb);
667         fs_info->btree_inode->i_ino = 1;
668         fs_info->btree_inode->i_nlink = 1;
669         fs_info->btree_inode->i_size = sb->s_bdev->bd_inode->i_size;
670         fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
671         extent_io_tree_init(&BTRFS_I(fs_info->btree_inode)->io_tree,
672                              fs_info->btree_inode->i_mapping,
673                              GFP_NOFS);
674         extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree,
675                              GFP_NOFS);
676
677         BTRFS_I(fs_info->btree_inode)->io_tree.ops = &btree_extent_io_ops;
678
679         extent_io_tree_init(&fs_info->free_space_cache,
680                              fs_info->btree_inode->i_mapping, GFP_NOFS);
681         extent_io_tree_init(&fs_info->block_group_cache,
682                              fs_info->btree_inode->i_mapping, GFP_NOFS);
683         extent_io_tree_init(&fs_info->pinned_extents,
684                              fs_info->btree_inode->i_mapping, GFP_NOFS);
685         extent_io_tree_init(&fs_info->pending_del,
686                              fs_info->btree_inode->i_mapping, GFP_NOFS);
687         extent_io_tree_init(&fs_info->extent_ins,
688                              fs_info->btree_inode->i_mapping, GFP_NOFS);
689         fs_info->do_barriers = 1;
690         fs_info->closing = 0;
691         fs_info->total_pinned = 0;
692         fs_info->last_alloc = 0;
693         fs_info->last_data_alloc = 0;
694
695 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
696         INIT_WORK(&fs_info->trans_work, btrfs_transaction_cleaner, fs_info);
697 #else
698         INIT_DELAYED_WORK(&fs_info->trans_work, btrfs_transaction_cleaner);
699 #endif
700         BTRFS_I(fs_info->btree_inode)->root = tree_root;
701         memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
702                sizeof(struct btrfs_key));
703         insert_inode_hash(fs_info->btree_inode);
704         mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
705
706         mutex_init(&fs_info->trans_mutex);
707         mutex_init(&fs_info->fs_mutex);
708
709 #if 0
710         ret = add_hasher(fs_info, "crc32c");
711         if (ret) {
712                 printk("btrfs: failed hash setup, modprobe cryptomgr?\n");
713                 err = -ENOMEM;
714                 goto fail_iput;
715         }
716 #endif
717         __setup_root(512, 512, 512, 512, tree_root,
718                      fs_info, BTRFS_ROOT_TREE_OBJECTID);
719
720         fs_info->sb_buffer = read_tree_block(tree_root,
721                                              BTRFS_SUPER_INFO_OFFSET,
722                                              512);
723
724         if (!fs_info->sb_buffer)
725                 goto fail_iput;
726
727         read_extent_buffer(fs_info->sb_buffer, &fs_info->super_copy, 0,
728                            sizeof(fs_info->super_copy));
729
730         read_extent_buffer(fs_info->sb_buffer, fs_info->fsid,
731                            (unsigned long)btrfs_super_fsid(fs_info->sb_buffer),
732                            BTRFS_FSID_SIZE);
733         disk_super = &fs_info->super_copy;
734         if (!btrfs_super_root(disk_super))
735                 goto fail_sb_buffer;
736
737         nodesize = btrfs_super_nodesize(disk_super);
738         leafsize = btrfs_super_leafsize(disk_super);
739         sectorsize = btrfs_super_sectorsize(disk_super);
740         stripesize = btrfs_super_stripesize(disk_super);
741         tree_root->nodesize = nodesize;
742         tree_root->leafsize = leafsize;
743         tree_root->sectorsize = sectorsize;
744         tree_root->stripesize = stripesize;
745         sb_set_blocksize(sb, sectorsize);
746
747         i_size_write(fs_info->btree_inode,
748                      btrfs_super_total_bytes(disk_super));
749
750         if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
751                     sizeof(disk_super->magic))) {
752                 printk("btrfs: valid FS not found on %s\n", sb->s_id);
753                 goto fail_sb_buffer;
754         }
755
756         blocksize = btrfs_level_size(tree_root,
757                                      btrfs_super_root_level(disk_super));
758
759         tree_root->node = read_tree_block(tree_root,
760                                           btrfs_super_root(disk_super),
761                                           blocksize);
762         if (!tree_root->node)
763                 goto fail_sb_buffer;
764
765         mutex_lock(&fs_info->fs_mutex);
766
767         ret = find_and_setup_root(tree_root, fs_info,
768                                   BTRFS_EXTENT_TREE_OBJECTID, extent_root);
769         if (ret) {
770                 mutex_unlock(&fs_info->fs_mutex);
771                 goto fail_tree_root;
772         }
773
774         btrfs_read_block_groups(extent_root);
775
776         fs_info->generation = btrfs_super_generation(disk_super) + 1;
777         mutex_unlock(&fs_info->fs_mutex);
778         return tree_root;
779
780 fail_tree_root:
781         free_extent_buffer(tree_root->node);
782 fail_sb_buffer:
783         free_extent_buffer(fs_info->sb_buffer);
784 fail_iput:
785         iput(fs_info->btree_inode);
786 fail:
787         kfree(extent_root);
788         kfree(tree_root);
789         kfree(fs_info);
790         return ERR_PTR(err);
791 }
792
793 int write_ctree_super(struct btrfs_trans_handle *trans, struct btrfs_root
794                       *root)
795 {
796         int ret;
797         struct extent_buffer *super = root->fs_info->sb_buffer;
798         struct inode *btree_inode = root->fs_info->btree_inode;
799         struct super_block *sb = root->fs_info->sb;
800
801         if (!btrfs_test_opt(root, NOBARRIER))
802                 blkdev_issue_flush(sb->s_bdev, NULL);
803         set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree, super);
804         ret = sync_page_range_nolock(btree_inode, btree_inode->i_mapping,
805                                      super->start, super->len);
806         if (!btrfs_test_opt(root, NOBARRIER))
807                 blkdev_issue_flush(sb->s_bdev, NULL);
808         return ret;
809 }
810
811 int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
812 {
813         radix_tree_delete(&fs_info->fs_roots_radix,
814                           (unsigned long)root->root_key.objectid);
815         if (root->in_sysfs)
816                 btrfs_sysfs_del_root(root);
817         if (root->inode)
818                 iput(root->inode);
819         if (root->node)
820                 free_extent_buffer(root->node);
821         if (root->commit_root)
822                 free_extent_buffer(root->commit_root);
823         if (root->name)
824                 kfree(root->name);
825         kfree(root);
826         return 0;
827 }
828
829 static int del_fs_roots(struct btrfs_fs_info *fs_info)
830 {
831         int ret;
832         struct btrfs_root *gang[8];
833         int i;
834
835         while(1) {
836                 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
837                                              (void **)gang, 0,
838                                              ARRAY_SIZE(gang));
839                 if (!ret)
840                         break;
841                 for (i = 0; i < ret; i++)
842                         btrfs_free_fs_root(fs_info, gang[i]);
843         }
844         return 0;
845 }
846
847 int close_ctree(struct btrfs_root *root)
848 {
849         int ret;
850         struct btrfs_trans_handle *trans;
851         struct btrfs_fs_info *fs_info = root->fs_info;
852
853         fs_info->closing = 1;
854         btrfs_transaction_flush_work(root);
855         mutex_lock(&fs_info->fs_mutex);
856         btrfs_defrag_dirty_roots(root->fs_info);
857         trans = btrfs_start_transaction(root, 1);
858         ret = btrfs_commit_transaction(trans, root);
859         /* run commit again to  drop the original snapshot */
860         trans = btrfs_start_transaction(root, 1);
861         btrfs_commit_transaction(trans, root);
862         ret = btrfs_write_and_wait_transaction(NULL, root);
863         BUG_ON(ret);
864         write_ctree_super(NULL, root);
865         mutex_unlock(&fs_info->fs_mutex);
866
867         if (fs_info->delalloc_bytes) {
868                 printk("btrfs: at unmount delalloc count %Lu\n",
869                        fs_info->delalloc_bytes);
870         }
871         if (fs_info->extent_root->node)
872                 free_extent_buffer(fs_info->extent_root->node);
873
874         if (fs_info->tree_root->node)
875                 free_extent_buffer(fs_info->tree_root->node);
876
877         free_extent_buffer(fs_info->sb_buffer);
878
879         btrfs_free_block_groups(root->fs_info);
880         del_fs_roots(fs_info);
881
882         filemap_write_and_wait(fs_info->btree_inode->i_mapping);
883
884         extent_io_tree_empty_lru(&fs_info->free_space_cache);
885         extent_io_tree_empty_lru(&fs_info->block_group_cache);
886         extent_io_tree_empty_lru(&fs_info->pinned_extents);
887         extent_io_tree_empty_lru(&fs_info->pending_del);
888         extent_io_tree_empty_lru(&fs_info->extent_ins);
889         extent_io_tree_empty_lru(&BTRFS_I(fs_info->btree_inode)->io_tree);
890
891         truncate_inode_pages(fs_info->btree_inode->i_mapping, 0);
892
893         iput(fs_info->btree_inode);
894 #if 0
895         while(!list_empty(&fs_info->hashers)) {
896                 struct btrfs_hasher *hasher;
897                 hasher = list_entry(fs_info->hashers.next, struct btrfs_hasher,
898                                     hashers);
899                 list_del(&hasher->hashers);
900                 crypto_free_hash(&fs_info->hash_tfm);
901                 kfree(hasher);
902         }
903 #endif
904         kfree(fs_info->extent_root);
905         kfree(fs_info->tree_root);
906         return 0;
907 }
908
909 int btrfs_buffer_uptodate(struct extent_buffer *buf)
910 {
911         struct inode *btree_inode = buf->first_page->mapping->host;
912         return extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree, buf);
913 }
914
915 int btrfs_set_buffer_uptodate(struct extent_buffer *buf)
916 {
917         struct inode *btree_inode = buf->first_page->mapping->host;
918         return set_extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree,
919                                           buf);
920 }
921
922 void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
923 {
924         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
925         u64 transid = btrfs_header_generation(buf);
926         struct inode *btree_inode = root->fs_info->btree_inode;
927
928         if (transid != root->fs_info->generation) {
929                 printk(KERN_CRIT "transid mismatch buffer %llu, found %Lu running %Lu\n",
930                         (unsigned long long)buf->start,
931                         transid, root->fs_info->generation);
932                 WARN_ON(1);
933         }
934         set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree, buf);
935 }
936
937 void btrfs_throttle(struct btrfs_root *root)
938 {
939         struct backing_dev_info *bdi;
940
941         bdi = root->fs_info->sb->s_bdev->bd_inode->i_mapping->backing_dev_info;
942         if (root->fs_info->throttles && bdi_write_congested(bdi)) {
943 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,18)
944                 congestion_wait(WRITE, HZ/20);
945 #else
946                 blk_congestion_wait(WRITE, HZ/20);
947 #endif
948         }
949 }
950
951 void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
952 {
953         balance_dirty_pages_ratelimited_nr(
954                         root->fs_info->btree_inode->i_mapping, 1);
955 }
956
957 void btrfs_set_buffer_defrag(struct extent_buffer *buf)
958 {
959         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
960         struct inode *btree_inode = root->fs_info->btree_inode;
961         set_extent_bits(&BTRFS_I(btree_inode)->io_tree, buf->start,
962                         buf->start + buf->len - 1, EXTENT_DEFRAG, GFP_NOFS);
963 }
964
965 void btrfs_set_buffer_defrag_done(struct extent_buffer *buf)
966 {
967         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
968         struct inode *btree_inode = root->fs_info->btree_inode;
969         set_extent_bits(&BTRFS_I(btree_inode)->io_tree, buf->start,
970                         buf->start + buf->len - 1, EXTENT_DEFRAG_DONE,
971                         GFP_NOFS);
972 }
973
974 int btrfs_buffer_defrag(struct extent_buffer *buf)
975 {
976         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
977         struct inode *btree_inode = root->fs_info->btree_inode;
978         return test_range_bit(&BTRFS_I(btree_inode)->io_tree,
979                      buf->start, buf->start + buf->len - 1, EXTENT_DEFRAG, 0);
980 }
981
982 int btrfs_buffer_defrag_done(struct extent_buffer *buf)
983 {
984         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
985         struct inode *btree_inode = root->fs_info->btree_inode;
986         return test_range_bit(&BTRFS_I(btree_inode)->io_tree,
987                      buf->start, buf->start + buf->len - 1,
988                      EXTENT_DEFRAG_DONE, 0);
989 }
990
991 int btrfs_clear_buffer_defrag_done(struct extent_buffer *buf)
992 {
993         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
994         struct inode *btree_inode = root->fs_info->btree_inode;
995         return clear_extent_bits(&BTRFS_I(btree_inode)->io_tree,
996                      buf->start, buf->start + buf->len - 1,
997                      EXTENT_DEFRAG_DONE, GFP_NOFS);
998 }
999
1000 int btrfs_clear_buffer_defrag(struct extent_buffer *buf)
1001 {
1002         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
1003         struct inode *btree_inode = root->fs_info->btree_inode;
1004         return clear_extent_bits(&BTRFS_I(btree_inode)->io_tree,
1005                      buf->start, buf->start + buf->len - 1,
1006                      EXTENT_DEFRAG, GFP_NOFS);
1007 }
1008
1009 int btrfs_read_buffer(struct extent_buffer *buf)
1010 {
1011         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
1012         struct inode *btree_inode = root->fs_info->btree_inode;
1013         return read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
1014                                         buf, 0, 1, btree_get_extent);
1015 }
1016
1017 static struct extent_io_ops btree_extent_io_ops = {
1018         .writepage_io_hook = btree_writepage_io_hook,
1019 };