Btrfs: Change the remaining radix trees used by extent-tree.c to extent_map trees
[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
32 #if 0
33 static int check_tree_block(struct btrfs_root *root, struct extent_buffer *buf)
34 {
35         if (extent_buffer_blocknr(buf) != btrfs_header_blocknr(buf)) {
36                 printk(KERN_CRIT "buf blocknr(buf) is %llu, header is %llu\n",
37                        (unsigned long long)extent_buffer_blocknr(buf),
38                        (unsigned long long)btrfs_header_blocknr(buf));
39                 return 1;
40         }
41         return 0;
42 }
43 #endif
44
45 struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
46                                             u64 blocknr)
47 {
48         struct inode *btree_inode = root->fs_info->btree_inode;
49         struct extent_buffer *eb;
50         eb = find_extent_buffer(&BTRFS_I(btree_inode)->extent_tree,
51                                    blocknr * root->sectorsize,
52                                    root->sectorsize, GFP_NOFS);
53         if (eb)
54                 eb->alloc_addr = (unsigned long)__builtin_return_address(0);
55         return eb;
56 }
57
58 struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
59                                                  u64 blocknr)
60 {
61         struct inode *btree_inode = root->fs_info->btree_inode;
62         struct extent_buffer *eb;
63         eb = alloc_extent_buffer(&BTRFS_I(btree_inode)->extent_tree,
64                                    blocknr * root->sectorsize,
65                                    root->sectorsize, GFP_NOFS);
66         eb->alloc_addr = (unsigned long)__builtin_return_address(0);
67         return eb;
68 }
69
70 struct extent_map *btree_get_extent(struct inode *inode, struct page *page,
71                                     size_t page_offset, u64 start, u64 end,
72                                     int create)
73 {
74         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
75         struct extent_map *em;
76         int ret;
77
78 again:
79         em = lookup_extent_mapping(em_tree, start, end);
80         if (em) {
81                 goto out;
82         }
83         em = alloc_extent_map(GFP_NOFS);
84         if (!em) {
85                 em = ERR_PTR(-ENOMEM);
86                 goto out;
87         }
88         em->start = 0;
89         em->end = (i_size_read(inode) & ~((u64)PAGE_CACHE_SIZE -1)) - 1;
90         em->block_start = 0;
91         em->block_end = em->end;
92         em->bdev = inode->i_sb->s_bdev;
93         ret = add_extent_mapping(em_tree, em);
94         if (ret == -EEXIST) {
95                 free_extent_map(em);
96                 em = NULL;
97                 goto again;
98         } else if (ret) {
99                 em = ERR_PTR(ret);
100         }
101 out:
102         return em;
103 }
104
105 static int btree_writepage(struct page *page, struct writeback_control *wbc)
106 {
107         struct extent_map_tree *tree;
108         tree = &BTRFS_I(page->mapping->host)->extent_tree;
109         return extent_write_full_page(tree, page, btree_get_extent, wbc);
110 }
111 int btree_readpage(struct file *file, struct page *page)
112 {
113         struct extent_map_tree *tree;
114         tree = &BTRFS_I(page->mapping->host)->extent_tree;
115         return extent_read_full_page(tree, page, btree_get_extent);
116 }
117
118 static int btree_releasepage(struct page *page, gfp_t unused_gfp_flags)
119 {
120         struct extent_map_tree *tree;
121         int ret;
122
123         BUG_ON(page->private != 1);
124         tree = &BTRFS_I(page->mapping->host)->extent_tree;
125         ret = try_release_extent_mapping(tree, page);
126         if (ret == 1) {
127                 ClearPagePrivate(page);
128                 set_page_private(page, 0);
129                 page_cache_release(page);
130         }
131         return ret;
132 }
133
134 static void btree_invalidatepage(struct page *page, unsigned long offset)
135 {
136         struct extent_map_tree *tree;
137         tree = &BTRFS_I(page->mapping->host)->extent_tree;
138         extent_invalidatepage(tree, page, offset);
139         btree_releasepage(page, GFP_NOFS);
140 }
141
142 int btrfs_csum_data(struct btrfs_root * root, char *data, size_t len,
143                     char *result)
144 {
145         return 0;
146 #if 0
147         u32 crc;
148         crc = crc32c(0, data, len);
149         memcpy(result, &crc, BTRFS_CRC32_SIZE);
150         return 0;
151 #endif
152 }
153
154 #if 0
155 static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
156                            int verify)
157 {
158         return 0;
159         char result[BTRFS_CRC32_SIZE];
160         int ret;
161         struct btrfs_node *node;
162
163         ret = btrfs_csum_data(root, bh->b_data + BTRFS_CSUM_SIZE,
164                               bh->b_size - BTRFS_CSUM_SIZE, result);
165         if (ret)
166                 return ret;
167         if (verify) {
168                 if (memcmp(bh->b_data, result, BTRFS_CRC32_SIZE)) {
169                         printk("btrfs: %s checksum verify failed on %llu\n",
170                                root->fs_info->sb->s_id,
171                                (unsigned long long)bh_blocknr(bh));
172                         return 1;
173                 }
174         } else {
175                 node = btrfs_buffer_node(bh);
176                 memcpy(node->header.csum, result, BTRFS_CRC32_SIZE);
177         }
178         return 0;
179 }
180 #endif
181
182 #if 0
183 static int btree_writepage(struct page *page, struct writeback_control *wbc)
184 {
185         struct buffer_head *bh;
186         struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
187         struct buffer_head *head;
188         if (!page_has_buffers(page)) {
189                 create_empty_buffers(page, root->fs_info->sb->s_blocksize,
190                                         (1 << BH_Dirty)|(1 << BH_Uptodate));
191         }
192         head = page_buffers(page);
193         bh = head;
194         do {
195                 if (buffer_dirty(bh))
196                         csum_tree_block(root, bh, 0);
197                 bh = bh->b_this_page;
198         } while (bh != head);
199         return block_write_full_page(page, btree_get_block, wbc);
200 }
201 #endif
202
203 static struct address_space_operations btree_aops = {
204         .readpage       = btree_readpage,
205         .writepage      = btree_writepage,
206         .releasepage    = btree_releasepage,
207         .invalidatepage = btree_invalidatepage,
208         .sync_page      = block_sync_page,
209 };
210
211 int readahead_tree_block(struct btrfs_root *root, u64 blocknr)
212 {
213         struct extent_buffer *buf = NULL;
214         struct inode *btree_inode = root->fs_info->btree_inode;
215         int ret = 0;
216
217         buf = btrfs_find_create_tree_block(root, blocknr);
218         if (!buf)
219                 return 0;
220         read_extent_buffer_pages(&BTRFS_I(btree_inode)->extent_tree,
221                                  buf, 0);
222         free_extent_buffer(buf);
223         return ret;
224 }
225
226 struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 blocknr)
227 {
228         struct extent_buffer *buf = NULL;
229         struct inode *btree_inode = root->fs_info->btree_inode;
230
231         buf = btrfs_find_create_tree_block(root, blocknr);
232         if (!buf)
233                 return NULL;
234         read_extent_buffer_pages(&BTRFS_I(btree_inode)->extent_tree,
235                                  buf, 1);
236         buf->alloc_addr = (unsigned long)__builtin_return_address(0);
237         return buf;
238 }
239
240 int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
241                      struct extent_buffer *buf)
242 {
243         struct inode *btree_inode = root->fs_info->btree_inode;
244         clear_extent_buffer_dirty(&BTRFS_I(btree_inode)->extent_tree, buf);
245         return 0;
246 }
247
248 int wait_on_tree_block_writeback(struct btrfs_root *root,
249                                  struct extent_buffer *buf)
250 {
251         struct inode *btree_inode = root->fs_info->btree_inode;
252         wait_on_extent_buffer_writeback(&BTRFS_I(btree_inode)->extent_tree,
253                                         buf);
254         return 0;
255 }
256
257 int set_tree_block_dirty(struct btrfs_root *root, struct extent_buffer *buf)
258 {
259         struct inode *btree_inode = root->fs_info->btree_inode;
260         set_extent_buffer_dirty(&BTRFS_I(btree_inode)->extent_tree, buf);
261         return 0;
262 }
263
264 static int __setup_root(int blocksize,
265                         struct btrfs_root *root,
266                         struct btrfs_fs_info *fs_info,
267                         u64 objectid)
268 {
269         root->node = NULL;
270         root->inode = NULL;
271         root->commit_root = NULL;
272         root->sectorsize = blocksize;
273         root->nodesize = blocksize;
274         root->leafsize = blocksize;
275         root->ref_cows = 0;
276         root->fs_info = fs_info;
277         root->objectid = objectid;
278         root->last_trans = 0;
279         root->highest_inode = 0;
280         root->last_inode_alloc = 0;
281         root->name = NULL;
282         memset(&root->root_key, 0, sizeof(root->root_key));
283         memset(&root->root_item, 0, sizeof(root->root_item));
284         memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
285         memset(&root->root_kobj, 0, sizeof(root->root_kobj));
286         init_completion(&root->kobj_unregister);
287         init_rwsem(&root->snap_sem);
288         root->defrag_running = 0;
289         root->defrag_level = 0;
290         root->root_key.objectid = objectid;
291         return 0;
292 }
293
294 static int find_and_setup_root(int blocksize,
295                                struct btrfs_root *tree_root,
296                                struct btrfs_fs_info *fs_info,
297                                u64 objectid,
298                                struct btrfs_root *root)
299 {
300         int ret;
301
302         __setup_root(blocksize, root, fs_info, objectid);
303         ret = btrfs_find_last_root(tree_root, objectid,
304                                    &root->root_item, &root->root_key);
305         BUG_ON(ret);
306
307         root->node = read_tree_block(root,
308                                      btrfs_root_blocknr(&root->root_item));
309         BUG_ON(!root->node);
310         return 0;
311 }
312
313 struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_fs_info *fs_info,
314                                                struct btrfs_key *location)
315 {
316         struct btrfs_root *root;
317         struct btrfs_root *tree_root = fs_info->tree_root;
318         struct btrfs_path *path;
319         struct extent_buffer *l;
320         u64 highest_inode;
321         int ret = 0;
322
323         root = kzalloc(sizeof(*root), GFP_NOFS);
324         if (!root)
325                 return ERR_PTR(-ENOMEM);
326         if (location->offset == (u64)-1) {
327                 ret = find_and_setup_root(fs_info->sb->s_blocksize,
328                                           fs_info->tree_root, fs_info,
329                                           location->objectid, root);
330                 if (ret) {
331                         kfree(root);
332                         return ERR_PTR(ret);
333                 }
334                 goto insert;
335         }
336
337         __setup_root(fs_info->sb->s_blocksize, root, fs_info,
338                      location->objectid);
339
340         path = btrfs_alloc_path();
341         BUG_ON(!path);
342         ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
343         if (ret != 0) {
344                 if (ret > 0)
345                         ret = -ENOENT;
346                 goto out;
347         }
348         l = path->nodes[0];
349         read_extent_buffer(l, &root->root_item,
350                btrfs_item_ptr_offset(l, path->slots[0]),
351                sizeof(root->root_item));
352         ret = 0;
353 out:
354         btrfs_release_path(root, path);
355         btrfs_free_path(path);
356         if (ret) {
357                 kfree(root);
358                 return ERR_PTR(ret);
359         }
360         root->node = read_tree_block(root,
361                                      btrfs_root_blocknr(&root->root_item));
362         BUG_ON(!root->node);
363 insert:
364         root->ref_cows = 1;
365         ret = btrfs_find_highest_inode(root, &highest_inode);
366         if (ret == 0) {
367                 root->highest_inode = highest_inode;
368                 root->last_inode_alloc = highest_inode;
369         }
370         return root;
371 }
372
373 struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
374                                       struct btrfs_key *location,
375                                       const char *name, int namelen)
376 {
377         struct btrfs_root *root;
378         int ret;
379
380         root = radix_tree_lookup(&fs_info->fs_roots_radix,
381                                  (unsigned long)location->objectid);
382         if (root)
383                 return root;
384
385         root = btrfs_read_fs_root_no_radix(fs_info, location);
386         if (IS_ERR(root))
387                 return root;
388         ret = radix_tree_insert(&fs_info->fs_roots_radix,
389                                 (unsigned long)root->root_key.objectid,
390                                 root);
391         if (ret) {
392                 free_extent_buffer(root->node);
393                 kfree(root);
394                 return ERR_PTR(ret);
395         }
396
397         ret = btrfs_set_root_name(root, name, namelen);
398         if (ret) {
399                 free_extent_buffer(root->node);
400                 kfree(root);
401                 return ERR_PTR(ret);
402         }
403
404         ret = btrfs_sysfs_add_root(root);
405         if (ret) {
406                 free_extent_buffer(root->node);
407                 kfree(root->name);
408                 kfree(root);
409                 return ERR_PTR(ret);
410         }
411
412         ret = btrfs_find_dead_roots(fs_info->tree_root,
413                                     root->root_key.objectid, root);
414         BUG_ON(ret);
415
416         return root;
417 }
418
419 struct btrfs_root *open_ctree(struct super_block *sb)
420 {
421         struct btrfs_root *extent_root = kmalloc(sizeof(struct btrfs_root),
422                                                  GFP_NOFS);
423         struct btrfs_root *tree_root = kmalloc(sizeof(struct btrfs_root),
424                                                GFP_NOFS);
425         struct btrfs_fs_info *fs_info = kmalloc(sizeof(*fs_info),
426                                                 GFP_NOFS);
427         int ret;
428         int err = -EIO;
429         struct btrfs_super_block *disk_super;
430
431         if (!extent_root || !tree_root || !fs_info) {
432                 err = -ENOMEM;
433                 goto fail;
434         }
435         INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_NOFS);
436         INIT_LIST_HEAD(&fs_info->trans_list);
437         INIT_LIST_HEAD(&fs_info->dead_roots);
438         memset(&fs_info->super_kobj, 0, sizeof(fs_info->super_kobj));
439         init_completion(&fs_info->kobj_unregister);
440         sb_set_blocksize(sb, 4096);
441         fs_info->running_transaction = NULL;
442         fs_info->last_trans_committed = 0;
443         fs_info->tree_root = tree_root;
444         fs_info->extent_root = extent_root;
445         fs_info->sb = sb;
446         fs_info->btree_inode = new_inode(sb);
447         fs_info->btree_inode->i_ino = 1;
448         fs_info->btree_inode->i_nlink = 1;
449         fs_info->btree_inode->i_size = sb->s_bdev->bd_inode->i_size;
450         fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
451         extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree,
452                              fs_info->btree_inode->i_mapping,
453                              GFP_NOFS);
454         extent_map_tree_init(&fs_info->free_space_cache,
455                              fs_info->btree_inode->i_mapping, GFP_NOFS);
456         extent_map_tree_init(&fs_info->block_group_cache,
457                              fs_info->btree_inode->i_mapping, GFP_NOFS);
458         extent_map_tree_init(&fs_info->pinned_extents,
459                              fs_info->btree_inode->i_mapping, GFP_NOFS);
460         extent_map_tree_init(&fs_info->pending_del,
461                              fs_info->btree_inode->i_mapping, GFP_NOFS);
462         extent_map_tree_init(&fs_info->extent_ins,
463                              fs_info->btree_inode->i_mapping, GFP_NOFS);
464         fs_info->do_barriers = 1;
465         fs_info->closing = 0;
466
467         INIT_DELAYED_WORK(&fs_info->trans_work, btrfs_transaction_cleaner);
468         BTRFS_I(fs_info->btree_inode)->root = tree_root;
469         memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
470                sizeof(struct btrfs_key));
471         insert_inode_hash(fs_info->btree_inode);
472         mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
473
474         mutex_init(&fs_info->trans_mutex);
475         mutex_init(&fs_info->fs_mutex);
476
477         __setup_root(sb->s_blocksize, tree_root,
478                      fs_info, BTRFS_ROOT_TREE_OBJECTID);
479
480         fs_info->sb_buffer = read_tree_block(tree_root,
481                                              BTRFS_SUPER_INFO_OFFSET /
482                                              sb->s_blocksize);
483
484         if (!fs_info->sb_buffer)
485                 goto fail_iput;
486
487         read_extent_buffer(fs_info->sb_buffer, &fs_info->super_copy, 0,
488                            sizeof(fs_info->super_copy));
489
490         read_extent_buffer(fs_info->sb_buffer, fs_info->fsid,
491                            (unsigned long)btrfs_super_fsid(fs_info->sb_buffer),
492                            BTRFS_FSID_SIZE);
493         disk_super = &fs_info->super_copy;
494         if (!btrfs_super_root(disk_super))
495                 goto fail_sb_buffer;
496
497         i_size_write(fs_info->btree_inode,
498                      btrfs_super_total_blocks(disk_super) <<
499                      fs_info->btree_inode->i_blkbits);
500
501
502         if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
503                     sizeof(disk_super->magic))) {
504                 printk("btrfs: valid FS not found on %s\n", sb->s_id);
505                 goto fail_sb_buffer;
506         }
507         tree_root->node = read_tree_block(tree_root,
508                                           btrfs_super_root(disk_super));
509         if (!tree_root->node)
510                 goto fail_sb_buffer;
511
512         mutex_lock(&fs_info->fs_mutex);
513         ret = find_and_setup_root(sb->s_blocksize, tree_root, fs_info,
514                                   BTRFS_EXTENT_TREE_OBJECTID, extent_root);
515         if (ret) {
516                 mutex_unlock(&fs_info->fs_mutex);
517                 goto fail_tree_root;
518         }
519
520         btrfs_read_block_groups(extent_root);
521
522         fs_info->generation = btrfs_super_generation(disk_super) + 1;
523         mutex_unlock(&fs_info->fs_mutex);
524         return tree_root;
525
526 fail_tree_root:
527         free_extent_buffer(tree_root->node);
528 fail_sb_buffer:
529         free_extent_buffer(fs_info->sb_buffer);
530 fail_iput:
531         iput(fs_info->btree_inode);
532 fail:
533         kfree(extent_root);
534         kfree(tree_root);
535         kfree(fs_info);
536         return ERR_PTR(err);
537 }
538
539 int write_ctree_super(struct btrfs_trans_handle *trans, struct btrfs_root
540                       *root)
541 {
542         int ret;
543         struct extent_buffer *super = root->fs_info->sb_buffer;
544         struct inode *btree_inode = root->fs_info->btree_inode;
545
546         set_extent_buffer_dirty(&BTRFS_I(btree_inode)->extent_tree, super);
547         ret = sync_page_range_nolock(btree_inode, btree_inode->i_mapping,
548                                      super->start, super->len);
549         return ret;
550 }
551
552 int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
553 {
554         radix_tree_delete(&fs_info->fs_roots_radix,
555                           (unsigned long)root->root_key.objectid);
556         btrfs_sysfs_del_root(root);
557         if (root->inode)
558                 iput(root->inode);
559         if (root->node)
560                 free_extent_buffer(root->node);
561         if (root->commit_root)
562                 free_extent_buffer(root->commit_root);
563         if (root->name)
564                 kfree(root->name);
565         kfree(root);
566         return 0;
567 }
568
569 static int del_fs_roots(struct btrfs_fs_info *fs_info)
570 {
571         int ret;
572         struct btrfs_root *gang[8];
573         int i;
574
575         while(1) {
576                 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
577                                              (void **)gang, 0,
578                                              ARRAY_SIZE(gang));
579                 if (!ret)
580                         break;
581                 for (i = 0; i < ret; i++)
582                         btrfs_free_fs_root(fs_info, gang[i]);
583         }
584         return 0;
585 }
586
587 int close_ctree(struct btrfs_root *root)
588 {
589         int ret;
590         struct btrfs_trans_handle *trans;
591         struct btrfs_fs_info *fs_info = root->fs_info;
592
593         fs_info->closing = 1;
594         btrfs_transaction_flush_work(root);
595         mutex_lock(&fs_info->fs_mutex);
596         btrfs_defrag_dirty_roots(root->fs_info);
597         trans = btrfs_start_transaction(root, 1);
598         ret = btrfs_commit_transaction(trans, root);
599         /* run commit again to  drop the original snapshot */
600         trans = btrfs_start_transaction(root, 1);
601         btrfs_commit_transaction(trans, root);
602         ret = btrfs_write_and_wait_transaction(NULL, root);
603         BUG_ON(ret);
604         write_ctree_super(NULL, root);
605         mutex_unlock(&fs_info->fs_mutex);
606
607         if (fs_info->extent_root->node)
608                 free_extent_buffer(fs_info->extent_root->node);
609
610         if (fs_info->tree_root->node)
611                 free_extent_buffer(fs_info->tree_root->node);
612
613         free_extent_buffer(fs_info->sb_buffer);
614         truncate_inode_pages(fs_info->btree_inode->i_mapping, 0);
615         iput(fs_info->btree_inode);
616
617         btrfs_free_block_groups(root->fs_info);
618         del_fs_roots(fs_info);
619         kfree(fs_info->extent_root);
620         kfree(fs_info->tree_root);
621         return 0;
622 }
623
624 int btrfs_buffer_uptodate(struct extent_buffer *buf)
625 {
626         struct inode *btree_inode = buf->first_page->mapping->host;
627         return extent_buffer_uptodate(&BTRFS_I(btree_inode)->extent_tree, buf);
628 }
629
630 int btrfs_set_buffer_uptodate(struct extent_buffer *buf)
631 {
632         struct inode *btree_inode = buf->first_page->mapping->host;
633         return set_extent_buffer_uptodate(&BTRFS_I(btree_inode)->extent_tree,
634                                           buf);
635 }
636
637 void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
638 {
639         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
640         u64 transid = btrfs_header_generation(buf);
641         struct inode *btree_inode = root->fs_info->btree_inode;
642
643         if (transid != root->fs_info->generation) {
644                 printk(KERN_CRIT "transid mismatch buffer %llu, found %Lu running %Lu\n",
645                         (unsigned long long)extent_buffer_blocknr(buf),
646                         transid, root->fs_info->generation);
647                 WARN_ON(1);
648         }
649         set_extent_buffer_dirty(&BTRFS_I(btree_inode)->extent_tree, buf);
650 }
651
652 void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
653 {
654         balance_dirty_pages_ratelimited_nr(
655                         root->fs_info->btree_inode->i_mapping, nr);
656 }