2 * Copyright (C) 2008 Red Hat. All rights reserved.
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.
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.
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.
19 #include <linux/pagemap.h>
20 #include <linux/sched.h>
21 #include <linux/slab.h>
22 #include <linux/math64.h>
24 #include "free-space-cache.h"
25 #include "transaction.h"
28 #define BITS_PER_BITMAP (PAGE_CACHE_SIZE * 8)
29 #define MAX_CACHE_BYTES_PER_GIG (32 * 1024)
31 static void recalculate_thresholds(struct btrfs_block_group_cache
33 static int link_free_space(struct btrfs_block_group_cache *block_group,
34 struct btrfs_free_space *info);
36 struct inode *lookup_free_space_inode(struct btrfs_root *root,
37 struct btrfs_block_group_cache
38 *block_group, struct btrfs_path *path)
41 struct btrfs_key location;
42 struct btrfs_disk_key disk_key;
43 struct btrfs_free_space_header *header;
44 struct extent_buffer *leaf;
45 struct inode *inode = NULL;
48 spin_lock(&block_group->lock);
49 if (block_group->inode)
50 inode = igrab(block_group->inode);
51 spin_unlock(&block_group->lock);
55 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
56 key.offset = block_group->key.objectid;
59 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
63 btrfs_release_path(root, path);
64 return ERR_PTR(-ENOENT);
67 leaf = path->nodes[0];
68 header = btrfs_item_ptr(leaf, path->slots[0],
69 struct btrfs_free_space_header);
70 btrfs_free_space_key(leaf, header, &disk_key);
71 btrfs_disk_key_to_cpu(&location, &disk_key);
72 btrfs_release_path(root, path);
74 inode = btrfs_iget(root->fs_info->sb, &location, root, NULL);
76 return ERR_PTR(-ENOENT);
79 if (is_bad_inode(inode)) {
81 return ERR_PTR(-ENOENT);
84 spin_lock(&block_group->lock);
85 if (!root->fs_info->closing) {
86 block_group->inode = igrab(inode);
87 block_group->iref = 1;
89 spin_unlock(&block_group->lock);
94 int create_free_space_inode(struct btrfs_root *root,
95 struct btrfs_trans_handle *trans,
96 struct btrfs_block_group_cache *block_group,
97 struct btrfs_path *path)
100 struct btrfs_disk_key disk_key;
101 struct btrfs_free_space_header *header;
102 struct btrfs_inode_item *inode_item;
103 struct extent_buffer *leaf;
107 ret = btrfs_find_free_objectid(trans, root, 0, &objectid);
111 ret = btrfs_insert_empty_inode(trans, root, path, objectid);
115 leaf = path->nodes[0];
116 inode_item = btrfs_item_ptr(leaf, path->slots[0],
117 struct btrfs_inode_item);
118 btrfs_item_key(leaf, &disk_key, path->slots[0]);
119 memset_extent_buffer(leaf, 0, (unsigned long)inode_item,
120 sizeof(*inode_item));
121 btrfs_set_inode_generation(leaf, inode_item, trans->transid);
122 btrfs_set_inode_size(leaf, inode_item, 0);
123 btrfs_set_inode_nbytes(leaf, inode_item, 0);
124 btrfs_set_inode_uid(leaf, inode_item, 0);
125 btrfs_set_inode_gid(leaf, inode_item, 0);
126 btrfs_set_inode_mode(leaf, inode_item, S_IFREG | 0600);
127 btrfs_set_inode_flags(leaf, inode_item, BTRFS_INODE_NOCOMPRESS |
128 BTRFS_INODE_PREALLOC | BTRFS_INODE_NODATASUM);
129 btrfs_set_inode_nlink(leaf, inode_item, 1);
130 btrfs_set_inode_transid(leaf, inode_item, trans->transid);
131 btrfs_set_inode_block_group(leaf, inode_item,
132 block_group->key.objectid);
133 btrfs_mark_buffer_dirty(leaf);
134 btrfs_release_path(root, path);
136 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
137 key.offset = block_group->key.objectid;
140 ret = btrfs_insert_empty_item(trans, root, path, &key,
141 sizeof(struct btrfs_free_space_header));
143 btrfs_release_path(root, path);
146 leaf = path->nodes[0];
147 header = btrfs_item_ptr(leaf, path->slots[0],
148 struct btrfs_free_space_header);
149 memset_extent_buffer(leaf, 0, (unsigned long)header, sizeof(*header));
150 btrfs_set_free_space_key(leaf, header, &disk_key);
151 btrfs_mark_buffer_dirty(leaf);
152 btrfs_release_path(root, path);
157 int btrfs_truncate_free_space_cache(struct btrfs_root *root,
158 struct btrfs_trans_handle *trans,
159 struct btrfs_path *path,
165 trans->block_rsv = root->orphan_block_rsv;
166 ret = btrfs_block_rsv_check(trans, root,
167 root->orphan_block_rsv,
172 oldsize = i_size_read(inode);
173 btrfs_i_size_write(inode, 0);
174 truncate_pagecache(inode, oldsize, 0);
177 * We don't need an orphan item because truncating the free space cache
178 * will never be split across transactions.
180 ret = btrfs_truncate_inode_items(trans, root, inode,
181 0, BTRFS_EXTENT_DATA_KEY);
187 return btrfs_update_inode(trans, root, inode);
190 static int readahead_cache(struct inode *inode)
192 struct file_ra_state *ra;
193 unsigned long last_index;
195 ra = kzalloc(sizeof(*ra), GFP_NOFS);
199 file_ra_state_init(ra, inode->i_mapping);
200 last_index = (i_size_read(inode) - 1) >> PAGE_CACHE_SHIFT;
202 page_cache_sync_readahead(inode->i_mapping, ra, NULL, 0, last_index);
209 int load_free_space_cache(struct btrfs_fs_info *fs_info,
210 struct btrfs_block_group_cache *block_group)
212 struct btrfs_root *root = fs_info->tree_root;
214 struct btrfs_free_space_header *header;
215 struct extent_buffer *leaf;
217 struct btrfs_path *path;
218 u32 *checksums = NULL, *crc;
219 char *disk_crcs = NULL;
220 struct btrfs_key key;
221 struct list_head bitmaps;
225 u32 cur_crc = ~(u32)0;
227 unsigned long first_page_offset;
232 * If we're unmounting then just return, since this does a search on the
233 * normal root and not the commit root and we could deadlock.
236 if (fs_info->closing)
240 * If this block group has been marked to be cleared for one reason or
241 * another then we can't trust the on disk cache, so just return.
243 spin_lock(&block_group->lock);
244 if (block_group->disk_cache_state != BTRFS_DC_WRITTEN) {
245 spin_unlock(&block_group->lock);
248 spin_unlock(&block_group->lock);
250 INIT_LIST_HEAD(&bitmaps);
252 path = btrfs_alloc_path();
256 inode = lookup_free_space_inode(root, block_group, path);
258 btrfs_free_path(path);
262 /* Nothing in the space cache, goodbye */
263 if (!i_size_read(inode)) {
264 btrfs_free_path(path);
268 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
269 key.offset = block_group->key.objectid;
272 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
274 btrfs_free_path(path);
278 leaf = path->nodes[0];
279 header = btrfs_item_ptr(leaf, path->slots[0],
280 struct btrfs_free_space_header);
281 num_entries = btrfs_free_space_entries(leaf, header);
282 num_bitmaps = btrfs_free_space_bitmaps(leaf, header);
283 generation = btrfs_free_space_generation(leaf, header);
284 btrfs_free_path(path);
286 if (BTRFS_I(inode)->generation != generation) {
287 printk(KERN_ERR "btrfs: free space inode generation (%llu) did"
288 " not match free space cache generation (%llu) for "
289 "block group %llu\n",
290 (unsigned long long)BTRFS_I(inode)->generation,
291 (unsigned long long)generation,
292 (unsigned long long)block_group->key.objectid);
299 /* Setup everything for doing checksumming */
300 num_checksums = i_size_read(inode) / PAGE_CACHE_SIZE;
301 checksums = crc = kzalloc(sizeof(u32) * num_checksums, GFP_NOFS);
304 first_page_offset = (sizeof(u32) * num_checksums) + sizeof(u64);
305 disk_crcs = kzalloc(first_page_offset, GFP_NOFS);
309 ret = readahead_cache(inode);
316 struct btrfs_free_space_entry *entry;
317 struct btrfs_free_space *e;
319 unsigned long offset = 0;
320 unsigned long start_offset = 0;
323 if (!num_entries && !num_bitmaps)
327 start_offset = first_page_offset;
328 offset = start_offset;
331 page = grab_cache_page(inode->i_mapping, index);
337 if (!PageUptodate(page)) {
338 btrfs_readpage(NULL, page);
340 if (!PageUptodate(page)) {
342 page_cache_release(page);
343 printk(KERN_ERR "btrfs: error reading free "
344 "space cache: %llu\n",
346 block_group->key.objectid);
355 memcpy(disk_crcs, addr, first_page_offset);
356 gen = addr + (sizeof(u32) * num_checksums);
357 if (*gen != BTRFS_I(inode)->generation) {
358 printk(KERN_ERR "btrfs: space cache generation"
359 " (%llu) does not match inode (%llu) "
360 "for block group %llu\n",
361 (unsigned long long)*gen,
363 BTRFS_I(inode)->generation,
365 block_group->key.objectid);
368 page_cache_release(page);
371 crc = (u32 *)disk_crcs;
373 entry = addr + start_offset;
375 /* First lets check our crc before we do anything fun */
377 cur_crc = btrfs_csum_data(root, addr + start_offset, cur_crc,
378 PAGE_CACHE_SIZE - start_offset);
379 btrfs_csum_final(cur_crc, (char *)&cur_crc);
380 if (cur_crc != *crc) {
381 printk(KERN_ERR "btrfs: crc mismatch for page %lu in "
382 "block group %llu\n", index,
383 (unsigned long long)block_group->key.objectid);
386 page_cache_release(page);
396 e = kzalloc(sizeof(struct btrfs_free_space), GFP_NOFS);
400 page_cache_release(page);
404 e->offset = le64_to_cpu(entry->offset);
405 e->bytes = le64_to_cpu(entry->bytes);
410 page_cache_release(page);
414 if (entry->type == BTRFS_FREE_SPACE_EXTENT) {
415 spin_lock(&block_group->tree_lock);
416 ret = link_free_space(block_group, e);
417 spin_unlock(&block_group->tree_lock);
420 e->bitmap = kzalloc(PAGE_CACHE_SIZE, GFP_NOFS);
425 page_cache_release(page);
428 spin_lock(&block_group->tree_lock);
429 ret = link_free_space(block_group, e);
430 block_group->total_bitmaps++;
431 recalculate_thresholds(block_group);
432 spin_unlock(&block_group->tree_lock);
433 list_add_tail(&e->list, &bitmaps);
437 offset += sizeof(struct btrfs_free_space_entry);
438 if (offset + sizeof(struct btrfs_free_space_entry) >=
445 * We read an entry out of this page, we need to move on to the
454 * We add the bitmaps at the end of the entries in order that
455 * the bitmap entries are added to the cache.
457 e = list_entry(bitmaps.next, struct btrfs_free_space, list);
458 list_del_init(&e->list);
459 memcpy(e->bitmap, addr, PAGE_CACHE_SIZE);
464 page_cache_release(page);
476 /* This cache is bogus, make sure it gets cleared */
477 spin_lock(&block_group->lock);
478 block_group->disk_cache_state = BTRFS_DC_CLEAR;
479 spin_unlock(&block_group->lock);
480 btrfs_remove_free_space_cache(block_group);
484 int btrfs_write_out_cache(struct btrfs_root *root,
485 struct btrfs_trans_handle *trans,
486 struct btrfs_block_group_cache *block_group,
487 struct btrfs_path *path)
489 struct btrfs_free_space_header *header;
490 struct extent_buffer *leaf;
492 struct rb_node *node;
493 struct list_head *pos, *n;
495 struct extent_state *cached_state = NULL;
496 struct list_head bitmap_list;
497 struct btrfs_key key;
499 u32 *crc, *checksums;
500 pgoff_t index = 0, last_index = 0;
501 unsigned long first_page_offset;
507 root = root->fs_info->tree_root;
509 INIT_LIST_HEAD(&bitmap_list);
511 spin_lock(&block_group->lock);
512 if (block_group->disk_cache_state < BTRFS_DC_SETUP) {
513 spin_unlock(&block_group->lock);
516 spin_unlock(&block_group->lock);
518 inode = lookup_free_space_inode(root, block_group, path);
522 if (!i_size_read(inode)) {
527 last_index = (i_size_read(inode) - 1) >> PAGE_CACHE_SHIFT;
528 filemap_write_and_wait(inode->i_mapping);
529 btrfs_wait_ordered_range(inode, inode->i_size &
530 ~(root->sectorsize - 1), (u64)-1);
532 /* We need a checksum per page. */
533 num_checksums = i_size_read(inode) / PAGE_CACHE_SIZE;
534 crc = checksums = kzalloc(sizeof(u32) * num_checksums, GFP_NOFS);
540 /* Since the first page has all of our checksums and our generation we
541 * need to calculate the offset into the page that we can start writing
544 first_page_offset = (sizeof(u32) * num_checksums) + sizeof(u64);
546 node = rb_first(&block_group->free_space_offset);
551 * Lock all pages first so we can lock the extent safely.
553 * NOTE: Because we hold the ref the entire time we're going to write to
554 * the page find_get_page should never fail, so we don't do a check
555 * after find_get_page at this point. Just putting this here so people
556 * know and don't freak out.
558 while (index <= last_index) {
559 page = grab_cache_page(inode->i_mapping, index);
564 page = find_get_page(inode->i_mapping, i);
566 page_cache_release(page);
567 page_cache_release(page);
576 lock_extent_bits(&BTRFS_I(inode)->io_tree, 0, i_size_read(inode) - 1,
577 0, &cached_state, GFP_NOFS);
579 /* Write out the extent entries */
581 struct btrfs_free_space_entry *entry;
583 unsigned long offset = 0;
584 unsigned long start_offset = 0;
587 start_offset = first_page_offset;
588 offset = start_offset;
591 page = find_get_page(inode->i_mapping, index);
594 entry = addr + start_offset;
596 memset(addr, 0, PAGE_CACHE_SIZE);
598 struct btrfs_free_space *e;
600 e = rb_entry(node, struct btrfs_free_space, offset_index);
603 entry->offset = cpu_to_le64(e->offset);
604 entry->bytes = cpu_to_le64(e->bytes);
606 entry->type = BTRFS_FREE_SPACE_BITMAP;
607 list_add_tail(&e->list, &bitmap_list);
610 entry->type = BTRFS_FREE_SPACE_EXTENT;
612 node = rb_next(node);
615 offset += sizeof(struct btrfs_free_space_entry);
616 if (offset + sizeof(struct btrfs_free_space_entry) >=
622 *crc = btrfs_csum_data(root, addr + start_offset, *crc,
623 PAGE_CACHE_SIZE - start_offset);
626 btrfs_csum_final(*crc, (char *)crc);
629 bytes += PAGE_CACHE_SIZE;
631 ClearPageChecked(page);
632 set_page_extent_mapped(page);
633 SetPageUptodate(page);
634 set_page_dirty(page);
637 * We need to release our reference we got for grab_cache_page,
638 * except for the first page which will hold our checksums, we
643 page_cache_release(page);
646 page_cache_release(page);
651 /* Write out the bitmaps */
652 list_for_each_safe(pos, n, &bitmap_list) {
654 struct btrfs_free_space *entry =
655 list_entry(pos, struct btrfs_free_space, list);
657 page = find_get_page(inode->i_mapping, index);
660 memcpy(addr, entry->bitmap, PAGE_CACHE_SIZE);
662 *crc = btrfs_csum_data(root, addr, *crc, PAGE_CACHE_SIZE);
664 btrfs_csum_final(*crc, (char *)crc);
666 bytes += PAGE_CACHE_SIZE;
668 ClearPageChecked(page);
669 set_page_extent_mapped(page);
670 SetPageUptodate(page);
671 set_page_dirty(page);
673 page_cache_release(page);
674 page_cache_release(page);
675 list_del_init(&entry->list);
679 /* Zero out the rest of the pages just to make sure */
680 while (index <= last_index) {
683 page = find_get_page(inode->i_mapping, index);
686 memset(addr, 0, PAGE_CACHE_SIZE);
688 ClearPageChecked(page);
689 set_page_extent_mapped(page);
690 SetPageUptodate(page);
691 set_page_dirty(page);
693 page_cache_release(page);
694 page_cache_release(page);
695 bytes += PAGE_CACHE_SIZE;
699 btrfs_set_extent_delalloc(inode, 0, bytes - 1, &cached_state);
701 /* Write the checksums and trans id to the first page */
706 page = find_get_page(inode->i_mapping, 0);
709 memcpy(addr, checksums, sizeof(u32) * num_checksums);
710 gen = addr + (sizeof(u32) * num_checksums);
711 *gen = trans->transid;
713 ClearPageChecked(page);
714 set_page_extent_mapped(page);
715 SetPageUptodate(page);
716 set_page_dirty(page);
718 page_cache_release(page);
719 page_cache_release(page);
721 BTRFS_I(inode)->generation = trans->transid;
723 unlock_extent_cached(&BTRFS_I(inode)->io_tree, 0,
724 i_size_read(inode) - 1, &cached_state, GFP_NOFS);
726 filemap_write_and_wait(inode->i_mapping);
728 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
729 key.offset = block_group->key.objectid;
732 ret = btrfs_search_slot(trans, root, &key, path, 1, 1);
735 clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, bytes - 1,
736 EXTENT_DIRTY | EXTENT_DELALLOC |
737 EXTENT_DO_ACCOUNTING, 0, 0, NULL, GFP_NOFS);
740 leaf = path->nodes[0];
742 struct btrfs_key found_key;
743 BUG_ON(!path->slots[0]);
745 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
746 if (found_key.objectid != BTRFS_FREE_SPACE_OBJECTID ||
747 found_key.offset != block_group->key.objectid) {
749 clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, bytes - 1,
750 EXTENT_DIRTY | EXTENT_DELALLOC |
751 EXTENT_DO_ACCOUNTING, 0, 0, NULL,
753 btrfs_release_path(root, path);
757 header = btrfs_item_ptr(leaf, path->slots[0],
758 struct btrfs_free_space_header);
759 btrfs_set_free_space_entries(leaf, header, entries);
760 btrfs_set_free_space_bitmaps(leaf, header, bitmaps);
761 btrfs_set_free_space_generation(leaf, header, trans->transid);
762 btrfs_mark_buffer_dirty(leaf);
763 btrfs_release_path(root, path);
769 invalidate_inode_pages2_range(inode->i_mapping, 0, index);
770 spin_lock(&block_group->lock);
771 block_group->disk_cache_state = BTRFS_DC_ERROR;
772 spin_unlock(&block_group->lock);
773 BTRFS_I(inode)->generation = 0;
776 btrfs_update_inode(trans, root, inode);
781 static inline unsigned long offset_to_bit(u64 bitmap_start, u64 sectorsize,
784 BUG_ON(offset < bitmap_start);
785 offset -= bitmap_start;
786 return (unsigned long)(div64_u64(offset, sectorsize));
789 static inline unsigned long bytes_to_bits(u64 bytes, u64 sectorsize)
791 return (unsigned long)(div64_u64(bytes, sectorsize));
794 static inline u64 offset_to_bitmap(struct btrfs_block_group_cache *block_group,
798 u64 bytes_per_bitmap;
800 bytes_per_bitmap = BITS_PER_BITMAP * block_group->sectorsize;
801 bitmap_start = offset - block_group->key.objectid;
802 bitmap_start = div64_u64(bitmap_start, bytes_per_bitmap);
803 bitmap_start *= bytes_per_bitmap;
804 bitmap_start += block_group->key.objectid;
809 static int tree_insert_offset(struct rb_root *root, u64 offset,
810 struct rb_node *node, int bitmap)
812 struct rb_node **p = &root->rb_node;
813 struct rb_node *parent = NULL;
814 struct btrfs_free_space *info;
818 info = rb_entry(parent, struct btrfs_free_space, offset_index);
820 if (offset < info->offset) {
822 } else if (offset > info->offset) {
826 * we could have a bitmap entry and an extent entry
827 * share the same offset. If this is the case, we want
828 * the extent entry to always be found first if we do a
829 * linear search through the tree, since we want to have
830 * the quickest allocation time, and allocating from an
831 * extent is faster than allocating from a bitmap. So
832 * if we're inserting a bitmap and we find an entry at
833 * this offset, we want to go right, or after this entry
834 * logically. If we are inserting an extent and we've
835 * found a bitmap, we want to go left, or before
839 WARN_ON(info->bitmap);
842 WARN_ON(!info->bitmap);
848 rb_link_node(node, parent, p);
849 rb_insert_color(node, root);
855 * searches the tree for the given offset.
857 * fuzzy - If this is set, then we are trying to make an allocation, and we just
858 * want a section that has at least bytes size and comes at or after the given
861 static struct btrfs_free_space *
862 tree_search_offset(struct btrfs_block_group_cache *block_group,
863 u64 offset, int bitmap_only, int fuzzy)
865 struct rb_node *n = block_group->free_space_offset.rb_node;
866 struct btrfs_free_space *entry, *prev = NULL;
868 /* find entry that is closest to the 'offset' */
875 entry = rb_entry(n, struct btrfs_free_space, offset_index);
878 if (offset < entry->offset)
880 else if (offset > entry->offset)
893 * bitmap entry and extent entry may share same offset,
894 * in that case, bitmap entry comes after extent entry.
899 entry = rb_entry(n, struct btrfs_free_space, offset_index);
900 if (entry->offset != offset)
903 WARN_ON(!entry->bitmap);
908 * if previous extent entry covers the offset,
909 * we should return it instead of the bitmap entry
911 n = &entry->offset_index;
916 prev = rb_entry(n, struct btrfs_free_space,
919 if (prev->offset + prev->bytes > offset)
931 /* find last entry before the 'offset' */
933 if (entry->offset > offset) {
934 n = rb_prev(&entry->offset_index);
936 entry = rb_entry(n, struct btrfs_free_space,
938 BUG_ON(entry->offset > offset);
948 n = &entry->offset_index;
953 prev = rb_entry(n, struct btrfs_free_space,
956 if (prev->offset + prev->bytes > offset)
961 if (entry->offset + BITS_PER_BITMAP *
962 block_group->sectorsize > offset)
964 } else if (entry->offset + entry->bytes > offset)
972 if (entry->offset + BITS_PER_BITMAP *
973 block_group->sectorsize > offset)
976 if (entry->offset + entry->bytes > offset)
980 n = rb_next(&entry->offset_index);
983 entry = rb_entry(n, struct btrfs_free_space, offset_index);
988 static void unlink_free_space(struct btrfs_block_group_cache *block_group,
989 struct btrfs_free_space *info)
991 rb_erase(&info->offset_index, &block_group->free_space_offset);
992 block_group->free_extents--;
993 block_group->free_space -= info->bytes;
996 static int link_free_space(struct btrfs_block_group_cache *block_group,
997 struct btrfs_free_space *info)
1001 BUG_ON(!info->bitmap && !info->bytes);
1002 ret = tree_insert_offset(&block_group->free_space_offset, info->offset,
1003 &info->offset_index, (info->bitmap != NULL));
1007 block_group->free_space += info->bytes;
1008 block_group->free_extents++;
1012 static void recalculate_thresholds(struct btrfs_block_group_cache *block_group)
1019 * The goal is to keep the total amount of memory used per 1gb of space
1020 * at or below 32k, so we need to adjust how much memory we allow to be
1021 * used by extent based free space tracking
1023 max_bytes = MAX_CACHE_BYTES_PER_GIG *
1024 (div64_u64(block_group->key.offset, 1024 * 1024 * 1024));
1027 * we want to account for 1 more bitmap than what we have so we can make
1028 * sure we don't go over our overall goal of MAX_CACHE_BYTES_PER_GIG as
1029 * we add more bitmaps.
1031 bitmap_bytes = (block_group->total_bitmaps + 1) * PAGE_CACHE_SIZE;
1033 if (bitmap_bytes >= max_bytes) {
1034 block_group->extents_thresh = 0;
1039 * we want the extent entry threshold to always be at most 1/2 the maxw
1040 * bytes we can have, or whatever is less than that.
1042 extent_bytes = max_bytes - bitmap_bytes;
1043 extent_bytes = min_t(u64, extent_bytes, div64_u64(max_bytes, 2));
1045 block_group->extents_thresh =
1046 div64_u64(extent_bytes, (sizeof(struct btrfs_free_space)));
1049 static void bitmap_clear_bits(struct btrfs_block_group_cache *block_group,
1050 struct btrfs_free_space *info, u64 offset,
1053 unsigned long start, end;
1056 start = offset_to_bit(info->offset, block_group->sectorsize, offset);
1057 end = start + bytes_to_bits(bytes, block_group->sectorsize);
1058 BUG_ON(end > BITS_PER_BITMAP);
1060 for (i = start; i < end; i++)
1061 clear_bit(i, info->bitmap);
1063 info->bytes -= bytes;
1064 block_group->free_space -= bytes;
1067 static void bitmap_set_bits(struct btrfs_block_group_cache *block_group,
1068 struct btrfs_free_space *info, u64 offset,
1071 unsigned long start, end;
1074 start = offset_to_bit(info->offset, block_group->sectorsize, offset);
1075 end = start + bytes_to_bits(bytes, block_group->sectorsize);
1076 BUG_ON(end > BITS_PER_BITMAP);
1078 for (i = start; i < end; i++)
1079 set_bit(i, info->bitmap);
1081 info->bytes += bytes;
1082 block_group->free_space += bytes;
1085 static int search_bitmap(struct btrfs_block_group_cache *block_group,
1086 struct btrfs_free_space *bitmap_info, u64 *offset,
1089 unsigned long found_bits = 0;
1090 unsigned long bits, i;
1091 unsigned long next_zero;
1093 i = offset_to_bit(bitmap_info->offset, block_group->sectorsize,
1094 max_t(u64, *offset, bitmap_info->offset));
1095 bits = bytes_to_bits(*bytes, block_group->sectorsize);
1097 for (i = find_next_bit(bitmap_info->bitmap, BITS_PER_BITMAP, i);
1098 i < BITS_PER_BITMAP;
1099 i = find_next_bit(bitmap_info->bitmap, BITS_PER_BITMAP, i + 1)) {
1100 next_zero = find_next_zero_bit(bitmap_info->bitmap,
1101 BITS_PER_BITMAP, i);
1102 if ((next_zero - i) >= bits) {
1103 found_bits = next_zero - i;
1110 *offset = (u64)(i * block_group->sectorsize) +
1111 bitmap_info->offset;
1112 *bytes = (u64)(found_bits) * block_group->sectorsize;
1119 static struct btrfs_free_space *find_free_space(struct btrfs_block_group_cache
1120 *block_group, u64 *offset,
1121 u64 *bytes, int debug)
1123 struct btrfs_free_space *entry;
1124 struct rb_node *node;
1127 if (!block_group->free_space_offset.rb_node)
1130 entry = tree_search_offset(block_group,
1131 offset_to_bitmap(block_group, *offset),
1136 for (node = &entry->offset_index; node; node = rb_next(node)) {
1137 entry = rb_entry(node, struct btrfs_free_space, offset_index);
1138 if (entry->bytes < *bytes)
1141 if (entry->bitmap) {
1142 ret = search_bitmap(block_group, entry, offset, bytes);
1148 *offset = entry->offset;
1149 *bytes = entry->bytes;
1156 static void add_new_bitmap(struct btrfs_block_group_cache *block_group,
1157 struct btrfs_free_space *info, u64 offset)
1159 u64 bytes_per_bg = BITS_PER_BITMAP * block_group->sectorsize;
1160 int max_bitmaps = (int)div64_u64(block_group->key.offset +
1161 bytes_per_bg - 1, bytes_per_bg);
1162 BUG_ON(block_group->total_bitmaps >= max_bitmaps);
1164 info->offset = offset_to_bitmap(block_group, offset);
1166 link_free_space(block_group, info);
1167 block_group->total_bitmaps++;
1169 recalculate_thresholds(block_group);
1172 static noinline int remove_from_bitmap(struct btrfs_block_group_cache *block_group,
1173 struct btrfs_free_space *bitmap_info,
1174 u64 *offset, u64 *bytes)
1177 u64 search_start, search_bytes;
1181 end = bitmap_info->offset +
1182 (u64)(BITS_PER_BITMAP * block_group->sectorsize) - 1;
1185 * XXX - this can go away after a few releases.
1187 * since the only user of btrfs_remove_free_space is the tree logging
1188 * stuff, and the only way to test that is under crash conditions, we
1189 * want to have this debug stuff here just in case somethings not
1190 * working. Search the bitmap for the space we are trying to use to
1191 * make sure its actually there. If its not there then we need to stop
1192 * because something has gone wrong.
1194 search_start = *offset;
1195 search_bytes = *bytes;
1196 ret = search_bitmap(block_group, bitmap_info, &search_start,
1198 BUG_ON(ret < 0 || search_start != *offset);
1200 if (*offset > bitmap_info->offset && *offset + *bytes > end) {
1201 bitmap_clear_bits(block_group, bitmap_info, *offset,
1203 *bytes -= end - *offset + 1;
1205 } else if (*offset >= bitmap_info->offset && *offset + *bytes <= end) {
1206 bitmap_clear_bits(block_group, bitmap_info, *offset, *bytes);
1211 struct rb_node *next = rb_next(&bitmap_info->offset_index);
1212 if (!bitmap_info->bytes) {
1213 unlink_free_space(block_group, bitmap_info);
1214 kfree(bitmap_info->bitmap);
1216 block_group->total_bitmaps--;
1217 recalculate_thresholds(block_group);
1221 * no entry after this bitmap, but we still have bytes to
1222 * remove, so something has gone wrong.
1227 bitmap_info = rb_entry(next, struct btrfs_free_space,
1231 * if the next entry isn't a bitmap we need to return to let the
1232 * extent stuff do its work.
1234 if (!bitmap_info->bitmap)
1238 * Ok the next item is a bitmap, but it may not actually hold
1239 * the information for the rest of this free space stuff, so
1240 * look for it, and if we don't find it return so we can try
1241 * everything over again.
1243 search_start = *offset;
1244 search_bytes = *bytes;
1245 ret = search_bitmap(block_group, bitmap_info, &search_start,
1247 if (ret < 0 || search_start != *offset)
1251 } else if (!bitmap_info->bytes) {
1252 unlink_free_space(block_group, bitmap_info);
1253 kfree(bitmap_info->bitmap);
1255 block_group->total_bitmaps--;
1256 recalculate_thresholds(block_group);
1262 static int insert_into_bitmap(struct btrfs_block_group_cache *block_group,
1263 struct btrfs_free_space *info)
1265 struct btrfs_free_space *bitmap_info;
1267 u64 bytes, offset, end;
1271 * If we are below the extents threshold then we can add this as an
1272 * extent, and don't have to deal with the bitmap
1274 if (block_group->free_extents < block_group->extents_thresh &&
1275 info->bytes > block_group->sectorsize * 4)
1279 * some block groups are so tiny they can't be enveloped by a bitmap, so
1280 * don't even bother to create a bitmap for this
1282 if (BITS_PER_BITMAP * block_group->sectorsize >
1283 block_group->key.offset)
1286 bytes = info->bytes;
1287 offset = info->offset;
1290 bitmap_info = tree_search_offset(block_group,
1291 offset_to_bitmap(block_group, offset),
1298 end = bitmap_info->offset +
1299 (u64)(BITS_PER_BITMAP * block_group->sectorsize);
1301 if (offset >= bitmap_info->offset && offset + bytes > end) {
1302 bitmap_set_bits(block_group, bitmap_info, offset,
1304 bytes -= end - offset;
1307 } else if (offset >= bitmap_info->offset && offset + bytes <= end) {
1308 bitmap_set_bits(block_group, bitmap_info, offset, bytes);
1321 if (info && info->bitmap) {
1322 add_new_bitmap(block_group, info, offset);
1327 spin_unlock(&block_group->tree_lock);
1329 /* no pre-allocated info, allocate a new one */
1331 info = kzalloc(sizeof(struct btrfs_free_space),
1334 spin_lock(&block_group->tree_lock);
1340 /* allocate the bitmap */
1341 info->bitmap = kzalloc(PAGE_CACHE_SIZE, GFP_NOFS);
1342 spin_lock(&block_group->tree_lock);
1343 if (!info->bitmap) {
1353 kfree(info->bitmap);
1360 int btrfs_add_free_space(struct btrfs_block_group_cache *block_group,
1361 u64 offset, u64 bytes)
1363 struct btrfs_free_space *right_info = NULL;
1364 struct btrfs_free_space *left_info = NULL;
1365 struct btrfs_free_space *info = NULL;
1368 info = kzalloc(sizeof(struct btrfs_free_space), GFP_NOFS);
1372 info->offset = offset;
1373 info->bytes = bytes;
1375 spin_lock(&block_group->tree_lock);
1378 * first we want to see if there is free space adjacent to the range we
1379 * are adding, if there is remove that struct and add a new one to
1380 * cover the entire range
1382 right_info = tree_search_offset(block_group, offset + bytes, 0, 0);
1383 if (right_info && rb_prev(&right_info->offset_index))
1384 left_info = rb_entry(rb_prev(&right_info->offset_index),
1385 struct btrfs_free_space, offset_index);
1387 left_info = tree_search_offset(block_group, offset - 1, 0, 0);
1390 * If there was no extent directly to the left or right of this new
1391 * extent then we know we're going to have to allocate a new extent, so
1392 * before we do that see if we need to drop this into a bitmap
1394 if ((!left_info || left_info->bitmap) &&
1395 (!right_info || right_info->bitmap)) {
1396 ret = insert_into_bitmap(block_group, info);
1406 if (right_info && !right_info->bitmap) {
1407 unlink_free_space(block_group, right_info);
1408 info->bytes += right_info->bytes;
1412 if (left_info && !left_info->bitmap &&
1413 left_info->offset + left_info->bytes == offset) {
1414 unlink_free_space(block_group, left_info);
1415 info->offset = left_info->offset;
1416 info->bytes += left_info->bytes;
1420 ret = link_free_space(block_group, info);
1424 spin_unlock(&block_group->tree_lock);
1427 printk(KERN_CRIT "btrfs: unable to add free space :%d\n", ret);
1428 BUG_ON(ret == -EEXIST);
1434 int btrfs_remove_free_space(struct btrfs_block_group_cache *block_group,
1435 u64 offset, u64 bytes)
1437 struct btrfs_free_space *info;
1438 struct btrfs_free_space *next_info = NULL;
1441 spin_lock(&block_group->tree_lock);
1444 info = tree_search_offset(block_group, offset, 0, 0);
1447 * oops didn't find an extent that matched the space we wanted
1448 * to remove, look for a bitmap instead
1450 info = tree_search_offset(block_group,
1451 offset_to_bitmap(block_group, offset),
1459 if (info->bytes < bytes && rb_next(&info->offset_index)) {
1461 next_info = rb_entry(rb_next(&info->offset_index),
1462 struct btrfs_free_space,
1465 if (next_info->bitmap)
1466 end = next_info->offset + BITS_PER_BITMAP *
1467 block_group->sectorsize - 1;
1469 end = next_info->offset + next_info->bytes;
1471 if (next_info->bytes < bytes ||
1472 next_info->offset > offset || offset > end) {
1473 printk(KERN_CRIT "Found free space at %llu, size %llu,"
1474 " trying to use %llu\n",
1475 (unsigned long long)info->offset,
1476 (unsigned long long)info->bytes,
1477 (unsigned long long)bytes);
1486 if (info->bytes == bytes) {
1487 unlink_free_space(block_group, info);
1489 kfree(info->bitmap);
1490 block_group->total_bitmaps--;
1496 if (!info->bitmap && info->offset == offset) {
1497 unlink_free_space(block_group, info);
1498 info->offset += bytes;
1499 info->bytes -= bytes;
1500 link_free_space(block_group, info);
1504 if (!info->bitmap && info->offset <= offset &&
1505 info->offset + info->bytes >= offset + bytes) {
1506 u64 old_start = info->offset;
1508 * we're freeing space in the middle of the info,
1509 * this can happen during tree log replay
1511 * first unlink the old info and then
1512 * insert it again after the hole we're creating
1514 unlink_free_space(block_group, info);
1515 if (offset + bytes < info->offset + info->bytes) {
1516 u64 old_end = info->offset + info->bytes;
1518 info->offset = offset + bytes;
1519 info->bytes = old_end - info->offset;
1520 ret = link_free_space(block_group, info);
1525 /* the hole we're creating ends at the end
1526 * of the info struct, just free the info
1530 spin_unlock(&block_group->tree_lock);
1532 /* step two, insert a new info struct to cover
1533 * anything before the hole
1535 ret = btrfs_add_free_space(block_group, old_start,
1536 offset - old_start);
1541 ret = remove_from_bitmap(block_group, info, &offset, &bytes);
1546 spin_unlock(&block_group->tree_lock);
1551 void btrfs_dump_free_space(struct btrfs_block_group_cache *block_group,
1554 struct btrfs_free_space *info;
1558 for (n = rb_first(&block_group->free_space_offset); n; n = rb_next(n)) {
1559 info = rb_entry(n, struct btrfs_free_space, offset_index);
1560 if (info->bytes >= bytes)
1562 printk(KERN_CRIT "entry offset %llu, bytes %llu, bitmap %s\n",
1563 (unsigned long long)info->offset,
1564 (unsigned long long)info->bytes,
1565 (info->bitmap) ? "yes" : "no");
1567 printk(KERN_INFO "block group has cluster?: %s\n",
1568 list_empty(&block_group->cluster_list) ? "no" : "yes");
1569 printk(KERN_INFO "%d blocks of free space at or bigger than bytes is"
1573 u64 btrfs_block_group_free_space(struct btrfs_block_group_cache *block_group)
1575 struct btrfs_free_space *info;
1579 for (n = rb_first(&block_group->free_space_offset); n;
1581 info = rb_entry(n, struct btrfs_free_space, offset_index);
1589 * for a given cluster, put all of its extents back into the free
1590 * space cache. If the block group passed doesn't match the block group
1591 * pointed to by the cluster, someone else raced in and freed the
1592 * cluster already. In that case, we just return without changing anything
1595 __btrfs_return_cluster_to_free_space(
1596 struct btrfs_block_group_cache *block_group,
1597 struct btrfs_free_cluster *cluster)
1599 struct btrfs_free_space *entry;
1600 struct rb_node *node;
1603 spin_lock(&cluster->lock);
1604 if (cluster->block_group != block_group)
1607 bitmap = cluster->points_to_bitmap;
1608 cluster->block_group = NULL;
1609 cluster->window_start = 0;
1610 list_del_init(&cluster->block_group_list);
1611 cluster->points_to_bitmap = false;
1616 node = rb_first(&cluster->root);
1618 entry = rb_entry(node, struct btrfs_free_space, offset_index);
1619 node = rb_next(&entry->offset_index);
1620 rb_erase(&entry->offset_index, &cluster->root);
1621 BUG_ON(entry->bitmap);
1622 tree_insert_offset(&block_group->free_space_offset,
1623 entry->offset, &entry->offset_index, 0);
1625 cluster->root = RB_ROOT;
1628 spin_unlock(&cluster->lock);
1629 btrfs_put_block_group(block_group);
1633 void btrfs_remove_free_space_cache(struct btrfs_block_group_cache *block_group)
1635 struct btrfs_free_space *info;
1636 struct rb_node *node;
1637 struct btrfs_free_cluster *cluster;
1638 struct list_head *head;
1640 spin_lock(&block_group->tree_lock);
1641 while ((head = block_group->cluster_list.next) !=
1642 &block_group->cluster_list) {
1643 cluster = list_entry(head, struct btrfs_free_cluster,
1646 WARN_ON(cluster->block_group != block_group);
1647 __btrfs_return_cluster_to_free_space(block_group, cluster);
1648 if (need_resched()) {
1649 spin_unlock(&block_group->tree_lock);
1651 spin_lock(&block_group->tree_lock);
1655 while ((node = rb_last(&block_group->free_space_offset)) != NULL) {
1656 info = rb_entry(node, struct btrfs_free_space, offset_index);
1657 unlink_free_space(block_group, info);
1659 kfree(info->bitmap);
1661 if (need_resched()) {
1662 spin_unlock(&block_group->tree_lock);
1664 spin_lock(&block_group->tree_lock);
1668 spin_unlock(&block_group->tree_lock);
1671 u64 btrfs_find_space_for_alloc(struct btrfs_block_group_cache *block_group,
1672 u64 offset, u64 bytes, u64 empty_size)
1674 struct btrfs_free_space *entry = NULL;
1675 u64 bytes_search = bytes + empty_size;
1678 spin_lock(&block_group->tree_lock);
1679 entry = find_free_space(block_group, &offset, &bytes_search, 0);
1684 if (entry->bitmap) {
1685 bitmap_clear_bits(block_group, entry, offset, bytes);
1686 if (!entry->bytes) {
1687 unlink_free_space(block_group, entry);
1688 kfree(entry->bitmap);
1690 block_group->total_bitmaps--;
1691 recalculate_thresholds(block_group);
1694 unlink_free_space(block_group, entry);
1695 entry->offset += bytes;
1696 entry->bytes -= bytes;
1700 link_free_space(block_group, entry);
1704 spin_unlock(&block_group->tree_lock);
1710 * given a cluster, put all of its extents back into the free space
1711 * cache. If a block group is passed, this function will only free
1712 * a cluster that belongs to the passed block group.
1714 * Otherwise, it'll get a reference on the block group pointed to by the
1715 * cluster and remove the cluster from it.
1717 int btrfs_return_cluster_to_free_space(
1718 struct btrfs_block_group_cache *block_group,
1719 struct btrfs_free_cluster *cluster)
1723 /* first, get a safe pointer to the block group */
1724 spin_lock(&cluster->lock);
1726 block_group = cluster->block_group;
1728 spin_unlock(&cluster->lock);
1731 } else if (cluster->block_group != block_group) {
1732 /* someone else has already freed it don't redo their work */
1733 spin_unlock(&cluster->lock);
1736 atomic_inc(&block_group->count);
1737 spin_unlock(&cluster->lock);
1739 /* now return any extents the cluster had on it */
1740 spin_lock(&block_group->tree_lock);
1741 ret = __btrfs_return_cluster_to_free_space(block_group, cluster);
1742 spin_unlock(&block_group->tree_lock);
1744 /* finally drop our ref */
1745 btrfs_put_block_group(block_group);
1749 static u64 btrfs_alloc_from_bitmap(struct btrfs_block_group_cache *block_group,
1750 struct btrfs_free_cluster *cluster,
1751 u64 bytes, u64 min_start)
1753 struct btrfs_free_space *entry;
1755 u64 search_start = cluster->window_start;
1756 u64 search_bytes = bytes;
1759 spin_lock(&block_group->tree_lock);
1760 spin_lock(&cluster->lock);
1762 if (!cluster->points_to_bitmap)
1765 if (cluster->block_group != block_group)
1769 * search_start is the beginning of the bitmap, but at some point it may
1770 * be a good idea to point to the actual start of the free area in the
1771 * bitmap, so do the offset_to_bitmap trick anyway, and set bitmap_only
1772 * to 1 to make sure we get the bitmap entry
1774 entry = tree_search_offset(block_group,
1775 offset_to_bitmap(block_group, search_start),
1777 if (!entry || !entry->bitmap)
1780 search_start = min_start;
1781 search_bytes = bytes;
1783 err = search_bitmap(block_group, entry, &search_start,
1789 bitmap_clear_bits(block_group, entry, ret, bytes);
1791 spin_unlock(&cluster->lock);
1792 spin_unlock(&block_group->tree_lock);
1798 * given a cluster, try to allocate 'bytes' from it, returns 0
1799 * if it couldn't find anything suitably large, or a logical disk offset
1800 * if things worked out
1802 u64 btrfs_alloc_from_cluster(struct btrfs_block_group_cache *block_group,
1803 struct btrfs_free_cluster *cluster, u64 bytes,
1806 struct btrfs_free_space *entry = NULL;
1807 struct rb_node *node;
1810 if (cluster->points_to_bitmap)
1811 return btrfs_alloc_from_bitmap(block_group, cluster, bytes,
1814 spin_lock(&cluster->lock);
1815 if (bytes > cluster->max_size)
1818 if (cluster->block_group != block_group)
1821 node = rb_first(&cluster->root);
1825 entry = rb_entry(node, struct btrfs_free_space, offset_index);
1828 if (entry->bytes < bytes || entry->offset < min_start) {
1829 struct rb_node *node;
1831 node = rb_next(&entry->offset_index);
1834 entry = rb_entry(node, struct btrfs_free_space,
1838 ret = entry->offset;
1840 entry->offset += bytes;
1841 entry->bytes -= bytes;
1843 if (entry->bytes == 0) {
1844 rb_erase(&entry->offset_index, &cluster->root);
1850 spin_unlock(&cluster->lock);
1855 static int btrfs_bitmap_cluster(struct btrfs_block_group_cache *block_group,
1856 struct btrfs_free_space *entry,
1857 struct btrfs_free_cluster *cluster,
1858 u64 offset, u64 bytes, u64 min_bytes)
1860 unsigned long next_zero;
1862 unsigned long search_bits;
1863 unsigned long total_bits;
1864 unsigned long found_bits;
1865 unsigned long start = 0;
1866 unsigned long total_found = 0;
1869 i = offset_to_bit(entry->offset, block_group->sectorsize,
1870 max_t(u64, offset, entry->offset));
1871 search_bits = bytes_to_bits(min_bytes, block_group->sectorsize);
1872 total_bits = bytes_to_bits(bytes, block_group->sectorsize);
1876 for (i = find_next_bit(entry->bitmap, BITS_PER_BITMAP, i);
1877 i < BITS_PER_BITMAP;
1878 i = find_next_bit(entry->bitmap, BITS_PER_BITMAP, i + 1)) {
1879 next_zero = find_next_zero_bit(entry->bitmap,
1880 BITS_PER_BITMAP, i);
1881 if (next_zero - i >= search_bits) {
1882 found_bits = next_zero - i;
1896 total_found += found_bits;
1898 if (cluster->max_size < found_bits * block_group->sectorsize)
1899 cluster->max_size = found_bits * block_group->sectorsize;
1901 if (total_found < total_bits) {
1902 i = find_next_bit(entry->bitmap, BITS_PER_BITMAP, next_zero);
1903 if (i - start > total_bits * 2) {
1905 cluster->max_size = 0;
1911 cluster->window_start = start * block_group->sectorsize +
1913 cluster->points_to_bitmap = true;
1919 * here we try to find a cluster of blocks in a block group. The goal
1920 * is to find at least bytes free and up to empty_size + bytes free.
1921 * We might not find them all in one contiguous area.
1923 * returns zero and sets up cluster if things worked out, otherwise
1924 * it returns -enospc
1926 int btrfs_find_space_cluster(struct btrfs_trans_handle *trans,
1927 struct btrfs_root *root,
1928 struct btrfs_block_group_cache *block_group,
1929 struct btrfs_free_cluster *cluster,
1930 u64 offset, u64 bytes, u64 empty_size)
1932 struct btrfs_free_space *entry = NULL;
1933 struct rb_node *node;
1934 struct btrfs_free_space *next;
1935 struct btrfs_free_space *last = NULL;
1940 bool found_bitmap = false;
1943 /* for metadata, allow allocates with more holes */
1944 if (btrfs_test_opt(root, SSD_SPREAD)) {
1945 min_bytes = bytes + empty_size;
1946 } else if (block_group->flags & BTRFS_BLOCK_GROUP_METADATA) {
1948 * we want to do larger allocations when we are
1949 * flushing out the delayed refs, it helps prevent
1950 * making more work as we go along.
1952 if (trans->transaction->delayed_refs.flushing)
1953 min_bytes = max(bytes, (bytes + empty_size) >> 1);
1955 min_bytes = max(bytes, (bytes + empty_size) >> 4);
1957 min_bytes = max(bytes, (bytes + empty_size) >> 2);
1959 spin_lock(&block_group->tree_lock);
1960 spin_lock(&cluster->lock);
1962 /* someone already found a cluster, hooray */
1963 if (cluster->block_group) {
1968 entry = tree_search_offset(block_group, offset, found_bitmap, 1);
1975 * If found_bitmap is true, we exhausted our search for extent entries,
1976 * and we just want to search all of the bitmaps that we can find, and
1977 * ignore any extent entries we find.
1979 while (entry->bitmap || found_bitmap ||
1980 (!entry->bitmap && entry->bytes < min_bytes)) {
1981 struct rb_node *node = rb_next(&entry->offset_index);
1983 if (entry->bitmap && entry->bytes > bytes + empty_size) {
1984 ret = btrfs_bitmap_cluster(block_group, entry, cluster,
1985 offset, bytes + empty_size,
1995 entry = rb_entry(node, struct btrfs_free_space, offset_index);
1999 * We already searched all the extent entries from the passed in offset
2000 * to the end and didn't find enough space for the cluster, and we also
2001 * didn't find any bitmaps that met our criteria, just go ahead and exit
2008 cluster->points_to_bitmap = false;
2009 window_start = entry->offset;
2010 window_free = entry->bytes;
2012 max_extent = entry->bytes;
2015 /* out window is just right, lets fill it */
2016 if (window_free >= bytes + empty_size)
2019 node = rb_next(&last->offset_index);
2026 next = rb_entry(node, struct btrfs_free_space, offset_index);
2029 * we found a bitmap, so if this search doesn't result in a
2030 * cluster, we know to go and search again for the bitmaps and
2031 * start looking for space there
2035 offset = next->offset;
2036 found_bitmap = true;
2042 * we haven't filled the empty size and the window is
2043 * very large. reset and try again
2045 if (next->offset - (last->offset + last->bytes) > 128 * 1024 ||
2046 next->offset - window_start > (bytes + empty_size) * 2) {
2048 window_start = entry->offset;
2049 window_free = entry->bytes;
2051 max_extent = entry->bytes;
2054 window_free += next->bytes;
2055 if (entry->bytes > max_extent)
2056 max_extent = entry->bytes;
2060 cluster->window_start = entry->offset;
2063 * now we've found our entries, pull them out of the free space
2064 * cache and put them into the cluster rbtree
2066 * The cluster includes an rbtree, but only uses the offset index
2067 * of each free space cache entry.
2070 node = rb_next(&entry->offset_index);
2071 if (entry->bitmap && node) {
2072 entry = rb_entry(node, struct btrfs_free_space,
2075 } else if (entry->bitmap && !node) {
2079 rb_erase(&entry->offset_index, &block_group->free_space_offset);
2080 ret = tree_insert_offset(&cluster->root, entry->offset,
2081 &entry->offset_index, 0);
2084 if (!node || entry == last)
2087 entry = rb_entry(node, struct btrfs_free_space, offset_index);
2090 cluster->max_size = max_extent;
2093 atomic_inc(&block_group->count);
2094 list_add_tail(&cluster->block_group_list, &block_group->cluster_list);
2095 cluster->block_group = block_group;
2097 spin_unlock(&cluster->lock);
2098 spin_unlock(&block_group->tree_lock);
2104 * simple code to zero out a cluster
2106 void btrfs_init_free_cluster(struct btrfs_free_cluster *cluster)
2108 spin_lock_init(&cluster->lock);
2109 spin_lock_init(&cluster->refill_lock);
2110 cluster->root = RB_ROOT;
2111 cluster->max_size = 0;
2112 cluster->points_to_bitmap = false;
2113 INIT_LIST_HEAD(&cluster->block_group_list);
2114 cluster->block_group = NULL;