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
= kmem_cache_zalloc(btrfs_free_space_cachep
,
401 page_cache_release(page
);
405 e
->offset
= le64_to_cpu(entry
->offset
);
406 e
->bytes
= le64_to_cpu(entry
->bytes
);
409 kmem_cache_free(btrfs_free_space_cachep
, e
);
411 page_cache_release(page
);
415 if (entry
->type
== BTRFS_FREE_SPACE_EXTENT
) {
416 spin_lock(&block_group
->tree_lock
);
417 ret
= link_free_space(block_group
, e
);
418 spin_unlock(&block_group
->tree_lock
);
421 e
->bitmap
= kzalloc(PAGE_CACHE_SIZE
, GFP_NOFS
);
425 btrfs_free_space_cachep
, e
);
427 page_cache_release(page
);
430 spin_lock(&block_group
->tree_lock
);
431 ret
= link_free_space(block_group
, e
);
432 block_group
->total_bitmaps
++;
433 recalculate_thresholds(block_group
);
434 spin_unlock(&block_group
->tree_lock
);
435 list_add_tail(&e
->list
, &bitmaps
);
439 offset
+= sizeof(struct btrfs_free_space_entry
);
440 if (offset
+ sizeof(struct btrfs_free_space_entry
) >=
447 * We read an entry out of this page, we need to move on to the
456 * We add the bitmaps at the end of the entries in order that
457 * the bitmap entries are added to the cache.
459 e
= list_entry(bitmaps
.next
, struct btrfs_free_space
, list
);
460 list_del_init(&e
->list
);
461 memcpy(e
->bitmap
, addr
, PAGE_CACHE_SIZE
);
466 page_cache_release(page
);
478 /* This cache is bogus, make sure it gets cleared */
479 spin_lock(&block_group
->lock
);
480 block_group
->disk_cache_state
= BTRFS_DC_CLEAR
;
481 spin_unlock(&block_group
->lock
);
482 btrfs_remove_free_space_cache(block_group
);
486 int btrfs_write_out_cache(struct btrfs_root
*root
,
487 struct btrfs_trans_handle
*trans
,
488 struct btrfs_block_group_cache
*block_group
,
489 struct btrfs_path
*path
)
491 struct btrfs_free_space_header
*header
;
492 struct extent_buffer
*leaf
;
494 struct rb_node
*node
;
495 struct list_head
*pos
, *n
;
497 struct extent_state
*cached_state
= NULL
;
498 struct list_head bitmap_list
;
499 struct btrfs_key key
;
501 u32
*crc
, *checksums
;
502 pgoff_t index
= 0, last_index
= 0;
503 unsigned long first_page_offset
;
509 root
= root
->fs_info
->tree_root
;
511 INIT_LIST_HEAD(&bitmap_list
);
513 spin_lock(&block_group
->lock
);
514 if (block_group
->disk_cache_state
< BTRFS_DC_SETUP
) {
515 spin_unlock(&block_group
->lock
);
518 spin_unlock(&block_group
->lock
);
520 inode
= lookup_free_space_inode(root
, block_group
, path
);
524 if (!i_size_read(inode
)) {
529 node
= rb_first(&block_group
->free_space_offset
);
535 last_index
= (i_size_read(inode
) - 1) >> PAGE_CACHE_SHIFT
;
536 filemap_write_and_wait(inode
->i_mapping
);
537 btrfs_wait_ordered_range(inode
, inode
->i_size
&
538 ~(root
->sectorsize
- 1), (u64
)-1);
540 /* We need a checksum per page. */
541 num_checksums
= i_size_read(inode
) / PAGE_CACHE_SIZE
;
542 crc
= checksums
= kzalloc(sizeof(u32
) * num_checksums
, GFP_NOFS
);
548 /* Since the first page has all of our checksums and our generation we
549 * need to calculate the offset into the page that we can start writing
552 first_page_offset
= (sizeof(u32
) * num_checksums
) + sizeof(u64
);
555 * Lock all pages first so we can lock the extent safely.
557 * NOTE: Because we hold the ref the entire time we're going to write to
558 * the page find_get_page should never fail, so we don't do a check
559 * after find_get_page at this point. Just putting this here so people
560 * know and don't freak out.
562 while (index
<= last_index
) {
563 page
= grab_cache_page(inode
->i_mapping
, index
);
568 page
= find_get_page(inode
->i_mapping
, i
);
570 page_cache_release(page
);
571 page_cache_release(page
);
580 lock_extent_bits(&BTRFS_I(inode
)->io_tree
, 0, i_size_read(inode
) - 1,
581 0, &cached_state
, GFP_NOFS
);
583 /* Write out the extent entries */
585 struct btrfs_free_space_entry
*entry
;
587 unsigned long offset
= 0;
588 unsigned long start_offset
= 0;
591 start_offset
= first_page_offset
;
592 offset
= start_offset
;
595 page
= find_get_page(inode
->i_mapping
, index
);
598 entry
= addr
+ start_offset
;
600 memset(addr
, 0, PAGE_CACHE_SIZE
);
602 struct btrfs_free_space
*e
;
604 e
= rb_entry(node
, struct btrfs_free_space
, offset_index
);
607 entry
->offset
= cpu_to_le64(e
->offset
);
608 entry
->bytes
= cpu_to_le64(e
->bytes
);
610 entry
->type
= BTRFS_FREE_SPACE_BITMAP
;
611 list_add_tail(&e
->list
, &bitmap_list
);
614 entry
->type
= BTRFS_FREE_SPACE_EXTENT
;
616 node
= rb_next(node
);
619 offset
+= sizeof(struct btrfs_free_space_entry
);
620 if (offset
+ sizeof(struct btrfs_free_space_entry
) >=
626 *crc
= btrfs_csum_data(root
, addr
+ start_offset
, *crc
,
627 PAGE_CACHE_SIZE
- start_offset
);
630 btrfs_csum_final(*crc
, (char *)crc
);
633 bytes
+= PAGE_CACHE_SIZE
;
635 ClearPageChecked(page
);
636 set_page_extent_mapped(page
);
637 SetPageUptodate(page
);
638 set_page_dirty(page
);
641 * We need to release our reference we got for grab_cache_page,
642 * except for the first page which will hold our checksums, we
647 page_cache_release(page
);
650 page_cache_release(page
);
655 /* Write out the bitmaps */
656 list_for_each_safe(pos
, n
, &bitmap_list
) {
658 struct btrfs_free_space
*entry
=
659 list_entry(pos
, struct btrfs_free_space
, list
);
661 page
= find_get_page(inode
->i_mapping
, index
);
664 memcpy(addr
, entry
->bitmap
, PAGE_CACHE_SIZE
);
666 *crc
= btrfs_csum_data(root
, addr
, *crc
, PAGE_CACHE_SIZE
);
668 btrfs_csum_final(*crc
, (char *)crc
);
670 bytes
+= PAGE_CACHE_SIZE
;
672 ClearPageChecked(page
);
673 set_page_extent_mapped(page
);
674 SetPageUptodate(page
);
675 set_page_dirty(page
);
677 page_cache_release(page
);
678 page_cache_release(page
);
679 list_del_init(&entry
->list
);
683 /* Zero out the rest of the pages just to make sure */
684 while (index
<= last_index
) {
687 page
= find_get_page(inode
->i_mapping
, index
);
690 memset(addr
, 0, PAGE_CACHE_SIZE
);
692 ClearPageChecked(page
);
693 set_page_extent_mapped(page
);
694 SetPageUptodate(page
);
695 set_page_dirty(page
);
697 page_cache_release(page
);
698 page_cache_release(page
);
699 bytes
+= PAGE_CACHE_SIZE
;
703 btrfs_set_extent_delalloc(inode
, 0, bytes
- 1, &cached_state
);
705 /* Write the checksums and trans id to the first page */
710 page
= find_get_page(inode
->i_mapping
, 0);
713 memcpy(addr
, checksums
, sizeof(u32
) * num_checksums
);
714 gen
= addr
+ (sizeof(u32
) * num_checksums
);
715 *gen
= trans
->transid
;
717 ClearPageChecked(page
);
718 set_page_extent_mapped(page
);
719 SetPageUptodate(page
);
720 set_page_dirty(page
);
722 page_cache_release(page
);
723 page_cache_release(page
);
725 BTRFS_I(inode
)->generation
= trans
->transid
;
727 unlock_extent_cached(&BTRFS_I(inode
)->io_tree
, 0,
728 i_size_read(inode
) - 1, &cached_state
, GFP_NOFS
);
730 filemap_write_and_wait(inode
->i_mapping
);
732 key
.objectid
= BTRFS_FREE_SPACE_OBJECTID
;
733 key
.offset
= block_group
->key
.objectid
;
736 ret
= btrfs_search_slot(trans
, root
, &key
, path
, 1, 1);
739 clear_extent_bit(&BTRFS_I(inode
)->io_tree
, 0, bytes
- 1,
740 EXTENT_DIRTY
| EXTENT_DELALLOC
|
741 EXTENT_DO_ACCOUNTING
, 0, 0, NULL
, GFP_NOFS
);
744 leaf
= path
->nodes
[0];
746 struct btrfs_key found_key
;
747 BUG_ON(!path
->slots
[0]);
749 btrfs_item_key_to_cpu(leaf
, &found_key
, path
->slots
[0]);
750 if (found_key
.objectid
!= BTRFS_FREE_SPACE_OBJECTID
||
751 found_key
.offset
!= block_group
->key
.objectid
) {
753 clear_extent_bit(&BTRFS_I(inode
)->io_tree
, 0, bytes
- 1,
754 EXTENT_DIRTY
| EXTENT_DELALLOC
|
755 EXTENT_DO_ACCOUNTING
, 0, 0, NULL
,
757 btrfs_release_path(root
, path
);
761 header
= btrfs_item_ptr(leaf
, path
->slots
[0],
762 struct btrfs_free_space_header
);
763 btrfs_set_free_space_entries(leaf
, header
, entries
);
764 btrfs_set_free_space_bitmaps(leaf
, header
, bitmaps
);
765 btrfs_set_free_space_generation(leaf
, header
, trans
->transid
);
766 btrfs_mark_buffer_dirty(leaf
);
767 btrfs_release_path(root
, path
);
773 invalidate_inode_pages2_range(inode
->i_mapping
, 0, index
);
774 spin_lock(&block_group
->lock
);
775 block_group
->disk_cache_state
= BTRFS_DC_ERROR
;
776 spin_unlock(&block_group
->lock
);
777 BTRFS_I(inode
)->generation
= 0;
780 btrfs_update_inode(trans
, root
, inode
);
785 static inline unsigned long offset_to_bit(u64 bitmap_start
, u64 sectorsize
,
788 BUG_ON(offset
< bitmap_start
);
789 offset
-= bitmap_start
;
790 return (unsigned long)(div64_u64(offset
, sectorsize
));
793 static inline unsigned long bytes_to_bits(u64 bytes
, u64 sectorsize
)
795 return (unsigned long)(div64_u64(bytes
, sectorsize
));
798 static inline u64
offset_to_bitmap(struct btrfs_block_group_cache
*block_group
,
802 u64 bytes_per_bitmap
;
804 bytes_per_bitmap
= BITS_PER_BITMAP
* block_group
->sectorsize
;
805 bitmap_start
= offset
- block_group
->key
.objectid
;
806 bitmap_start
= div64_u64(bitmap_start
, bytes_per_bitmap
);
807 bitmap_start
*= bytes_per_bitmap
;
808 bitmap_start
+= block_group
->key
.objectid
;
813 static int tree_insert_offset(struct rb_root
*root
, u64 offset
,
814 struct rb_node
*node
, int bitmap
)
816 struct rb_node
**p
= &root
->rb_node
;
817 struct rb_node
*parent
= NULL
;
818 struct btrfs_free_space
*info
;
822 info
= rb_entry(parent
, struct btrfs_free_space
, offset_index
);
824 if (offset
< info
->offset
) {
826 } else if (offset
> info
->offset
) {
830 * we could have a bitmap entry and an extent entry
831 * share the same offset. If this is the case, we want
832 * the extent entry to always be found first if we do a
833 * linear search through the tree, since we want to have
834 * the quickest allocation time, and allocating from an
835 * extent is faster than allocating from a bitmap. So
836 * if we're inserting a bitmap and we find an entry at
837 * this offset, we want to go right, or after this entry
838 * logically. If we are inserting an extent and we've
839 * found a bitmap, we want to go left, or before
843 WARN_ON(info
->bitmap
);
846 WARN_ON(!info
->bitmap
);
852 rb_link_node(node
, parent
, p
);
853 rb_insert_color(node
, root
);
859 * searches the tree for the given offset.
861 * fuzzy - If this is set, then we are trying to make an allocation, and we just
862 * want a section that has at least bytes size and comes at or after the given
865 static struct btrfs_free_space
*
866 tree_search_offset(struct btrfs_block_group_cache
*block_group
,
867 u64 offset
, int bitmap_only
, int fuzzy
)
869 struct rb_node
*n
= block_group
->free_space_offset
.rb_node
;
870 struct btrfs_free_space
*entry
, *prev
= NULL
;
872 /* find entry that is closest to the 'offset' */
879 entry
= rb_entry(n
, struct btrfs_free_space
, offset_index
);
882 if (offset
< entry
->offset
)
884 else if (offset
> entry
->offset
)
897 * bitmap entry and extent entry may share same offset,
898 * in that case, bitmap entry comes after extent entry.
903 entry
= rb_entry(n
, struct btrfs_free_space
, offset_index
);
904 if (entry
->offset
!= offset
)
907 WARN_ON(!entry
->bitmap
);
912 * if previous extent entry covers the offset,
913 * we should return it instead of the bitmap entry
915 n
= &entry
->offset_index
;
920 prev
= rb_entry(n
, struct btrfs_free_space
,
923 if (prev
->offset
+ prev
->bytes
> offset
)
935 /* find last entry before the 'offset' */
937 if (entry
->offset
> offset
) {
938 n
= rb_prev(&entry
->offset_index
);
940 entry
= rb_entry(n
, struct btrfs_free_space
,
942 BUG_ON(entry
->offset
> offset
);
952 n
= &entry
->offset_index
;
957 prev
= rb_entry(n
, struct btrfs_free_space
,
960 if (prev
->offset
+ prev
->bytes
> offset
)
965 if (entry
->offset
+ BITS_PER_BITMAP
*
966 block_group
->sectorsize
> offset
)
968 } else if (entry
->offset
+ entry
->bytes
> offset
)
976 if (entry
->offset
+ BITS_PER_BITMAP
*
977 block_group
->sectorsize
> offset
)
980 if (entry
->offset
+ entry
->bytes
> offset
)
984 n
= rb_next(&entry
->offset_index
);
987 entry
= rb_entry(n
, struct btrfs_free_space
, offset_index
);
993 __unlink_free_space(struct btrfs_block_group_cache
*block_group
,
994 struct btrfs_free_space
*info
)
996 rb_erase(&info
->offset_index
, &block_group
->free_space_offset
);
997 block_group
->free_extents
--;
1000 static void unlink_free_space(struct btrfs_block_group_cache
*block_group
,
1001 struct btrfs_free_space
*info
)
1003 __unlink_free_space(block_group
, info
);
1004 block_group
->free_space
-= info
->bytes
;
1007 static int link_free_space(struct btrfs_block_group_cache
*block_group
,
1008 struct btrfs_free_space
*info
)
1012 BUG_ON(!info
->bitmap
&& !info
->bytes
);
1013 ret
= tree_insert_offset(&block_group
->free_space_offset
, info
->offset
,
1014 &info
->offset_index
, (info
->bitmap
!= NULL
));
1018 block_group
->free_space
+= info
->bytes
;
1019 block_group
->free_extents
++;
1023 static void recalculate_thresholds(struct btrfs_block_group_cache
*block_group
)
1028 u64 size
= block_group
->key
.offset
;
1031 * The goal is to keep the total amount of memory used per 1gb of space
1032 * at or below 32k, so we need to adjust how much memory we allow to be
1033 * used by extent based free space tracking
1035 if (size
< 1024 * 1024 * 1024)
1036 max_bytes
= MAX_CACHE_BYTES_PER_GIG
;
1038 max_bytes
= MAX_CACHE_BYTES_PER_GIG
*
1039 div64_u64(size
, 1024 * 1024 * 1024);
1042 * we want to account for 1 more bitmap than what we have so we can make
1043 * sure we don't go over our overall goal of MAX_CACHE_BYTES_PER_GIG as
1044 * we add more bitmaps.
1046 bitmap_bytes
= (block_group
->total_bitmaps
+ 1) * PAGE_CACHE_SIZE
;
1048 if (bitmap_bytes
>= max_bytes
) {
1049 block_group
->extents_thresh
= 0;
1054 * we want the extent entry threshold to always be at most 1/2 the maxw
1055 * bytes we can have, or whatever is less than that.
1057 extent_bytes
= max_bytes
- bitmap_bytes
;
1058 extent_bytes
= min_t(u64
, extent_bytes
, div64_u64(max_bytes
, 2));
1060 block_group
->extents_thresh
=
1061 div64_u64(extent_bytes
, (sizeof(struct btrfs_free_space
)));
1064 static void bitmap_clear_bits(struct btrfs_block_group_cache
*block_group
,
1065 struct btrfs_free_space
*info
, u64 offset
,
1068 unsigned long start
, end
;
1071 start
= offset_to_bit(info
->offset
, block_group
->sectorsize
, offset
);
1072 end
= start
+ bytes_to_bits(bytes
, block_group
->sectorsize
);
1073 BUG_ON(end
> BITS_PER_BITMAP
);
1075 for (i
= start
; i
< end
; i
++)
1076 clear_bit(i
, info
->bitmap
);
1078 info
->bytes
-= bytes
;
1079 block_group
->free_space
-= bytes
;
1082 static void bitmap_set_bits(struct btrfs_block_group_cache
*block_group
,
1083 struct btrfs_free_space
*info
, u64 offset
,
1086 unsigned long start
, end
;
1089 start
= offset_to_bit(info
->offset
, block_group
->sectorsize
, offset
);
1090 end
= start
+ bytes_to_bits(bytes
, block_group
->sectorsize
);
1091 BUG_ON(end
> BITS_PER_BITMAP
);
1093 for (i
= start
; i
< end
; i
++)
1094 set_bit(i
, info
->bitmap
);
1096 info
->bytes
+= bytes
;
1097 block_group
->free_space
+= bytes
;
1100 static int search_bitmap(struct btrfs_block_group_cache
*block_group
,
1101 struct btrfs_free_space
*bitmap_info
, u64
*offset
,
1104 unsigned long found_bits
= 0;
1105 unsigned long bits
, i
;
1106 unsigned long next_zero
;
1108 i
= offset_to_bit(bitmap_info
->offset
, block_group
->sectorsize
,
1109 max_t(u64
, *offset
, bitmap_info
->offset
));
1110 bits
= bytes_to_bits(*bytes
, block_group
->sectorsize
);
1112 for (i
= find_next_bit(bitmap_info
->bitmap
, BITS_PER_BITMAP
, i
);
1113 i
< BITS_PER_BITMAP
;
1114 i
= find_next_bit(bitmap_info
->bitmap
, BITS_PER_BITMAP
, i
+ 1)) {
1115 next_zero
= find_next_zero_bit(bitmap_info
->bitmap
,
1116 BITS_PER_BITMAP
, i
);
1117 if ((next_zero
- i
) >= bits
) {
1118 found_bits
= next_zero
- i
;
1125 *offset
= (u64
)(i
* block_group
->sectorsize
) +
1126 bitmap_info
->offset
;
1127 *bytes
= (u64
)(found_bits
) * block_group
->sectorsize
;
1134 static struct btrfs_free_space
*find_free_space(struct btrfs_block_group_cache
1135 *block_group
, u64
*offset
,
1136 u64
*bytes
, int debug
)
1138 struct btrfs_free_space
*entry
;
1139 struct rb_node
*node
;
1142 if (!block_group
->free_space_offset
.rb_node
)
1145 entry
= tree_search_offset(block_group
,
1146 offset_to_bitmap(block_group
, *offset
),
1151 for (node
= &entry
->offset_index
; node
; node
= rb_next(node
)) {
1152 entry
= rb_entry(node
, struct btrfs_free_space
, offset_index
);
1153 if (entry
->bytes
< *bytes
)
1156 if (entry
->bitmap
) {
1157 ret
= search_bitmap(block_group
, entry
, offset
, bytes
);
1163 *offset
= entry
->offset
;
1164 *bytes
= entry
->bytes
;
1171 static void add_new_bitmap(struct btrfs_block_group_cache
*block_group
,
1172 struct btrfs_free_space
*info
, u64 offset
)
1174 u64 bytes_per_bg
= BITS_PER_BITMAP
* block_group
->sectorsize
;
1175 int max_bitmaps
= (int)div64_u64(block_group
->key
.offset
+
1176 bytes_per_bg
- 1, bytes_per_bg
);
1177 BUG_ON(block_group
->total_bitmaps
>= max_bitmaps
);
1179 info
->offset
= offset_to_bitmap(block_group
, offset
);
1181 link_free_space(block_group
, info
);
1182 block_group
->total_bitmaps
++;
1184 recalculate_thresholds(block_group
);
1187 static void free_bitmap(struct btrfs_block_group_cache
*block_group
,
1188 struct btrfs_free_space
*bitmap_info
)
1190 unlink_free_space(block_group
, bitmap_info
);
1191 kfree(bitmap_info
->bitmap
);
1192 kmem_cache_free(btrfs_free_space_cachep
, bitmap_info
);
1193 block_group
->total_bitmaps
--;
1194 recalculate_thresholds(block_group
);
1197 static noinline
int remove_from_bitmap(struct btrfs_block_group_cache
*block_group
,
1198 struct btrfs_free_space
*bitmap_info
,
1199 u64
*offset
, u64
*bytes
)
1202 u64 search_start
, search_bytes
;
1206 end
= bitmap_info
->offset
+
1207 (u64
)(BITS_PER_BITMAP
* block_group
->sectorsize
) - 1;
1210 * XXX - this can go away after a few releases.
1212 * since the only user of btrfs_remove_free_space is the tree logging
1213 * stuff, and the only way to test that is under crash conditions, we
1214 * want to have this debug stuff here just in case somethings not
1215 * working. Search the bitmap for the space we are trying to use to
1216 * make sure its actually there. If its not there then we need to stop
1217 * because something has gone wrong.
1219 search_start
= *offset
;
1220 search_bytes
= *bytes
;
1221 search_bytes
= min(search_bytes
, end
- search_start
+ 1);
1222 ret
= search_bitmap(block_group
, bitmap_info
, &search_start
,
1224 BUG_ON(ret
< 0 || search_start
!= *offset
);
1226 if (*offset
> bitmap_info
->offset
&& *offset
+ *bytes
> end
) {
1227 bitmap_clear_bits(block_group
, bitmap_info
, *offset
,
1229 *bytes
-= end
- *offset
+ 1;
1231 } else if (*offset
>= bitmap_info
->offset
&& *offset
+ *bytes
<= end
) {
1232 bitmap_clear_bits(block_group
, bitmap_info
, *offset
, *bytes
);
1237 struct rb_node
*next
= rb_next(&bitmap_info
->offset_index
);
1238 if (!bitmap_info
->bytes
)
1239 free_bitmap(block_group
, bitmap_info
);
1242 * no entry after this bitmap, but we still have bytes to
1243 * remove, so something has gone wrong.
1248 bitmap_info
= rb_entry(next
, struct btrfs_free_space
,
1252 * if the next entry isn't a bitmap we need to return to let the
1253 * extent stuff do its work.
1255 if (!bitmap_info
->bitmap
)
1259 * Ok the next item is a bitmap, but it may not actually hold
1260 * the information for the rest of this free space stuff, so
1261 * look for it, and if we don't find it return so we can try
1262 * everything over again.
1264 search_start
= *offset
;
1265 search_bytes
= *bytes
;
1266 ret
= search_bitmap(block_group
, bitmap_info
, &search_start
,
1268 if (ret
< 0 || search_start
!= *offset
)
1272 } else if (!bitmap_info
->bytes
)
1273 free_bitmap(block_group
, bitmap_info
);
1278 static int insert_into_bitmap(struct btrfs_block_group_cache
*block_group
,
1279 struct btrfs_free_space
*info
)
1281 struct btrfs_free_space
*bitmap_info
;
1283 u64 bytes
, offset
, end
;
1287 * If we are below the extents threshold then we can add this as an
1288 * extent, and don't have to deal with the bitmap
1290 if (block_group
->free_extents
< block_group
->extents_thresh
) {
1292 * If this block group has some small extents we don't want to
1293 * use up all of our free slots in the cache with them, we want
1294 * to reserve them to larger extents, however if we have plent
1295 * of cache left then go ahead an dadd them, no sense in adding
1296 * the overhead of a bitmap if we don't have to.
1298 if (info
->bytes
<= block_group
->sectorsize
* 4) {
1299 if (block_group
->free_extents
* 2 <=
1300 block_group
->extents_thresh
)
1308 * some block groups are so tiny they can't be enveloped by a bitmap, so
1309 * don't even bother to create a bitmap for this
1311 if (BITS_PER_BITMAP
* block_group
->sectorsize
>
1312 block_group
->key
.offset
)
1315 bytes
= info
->bytes
;
1316 offset
= info
->offset
;
1319 bitmap_info
= tree_search_offset(block_group
,
1320 offset_to_bitmap(block_group
, offset
),
1327 end
= bitmap_info
->offset
+
1328 (u64
)(BITS_PER_BITMAP
* block_group
->sectorsize
);
1330 if (offset
>= bitmap_info
->offset
&& offset
+ bytes
> end
) {
1331 bitmap_set_bits(block_group
, bitmap_info
, offset
,
1333 bytes
-= end
- offset
;
1336 } else if (offset
>= bitmap_info
->offset
&& offset
+ bytes
<= end
) {
1337 bitmap_set_bits(block_group
, bitmap_info
, offset
, bytes
);
1350 if (info
&& info
->bitmap
) {
1351 add_new_bitmap(block_group
, info
, offset
);
1356 spin_unlock(&block_group
->tree_lock
);
1358 /* no pre-allocated info, allocate a new one */
1360 info
= kmem_cache_zalloc(btrfs_free_space_cachep
,
1363 spin_lock(&block_group
->tree_lock
);
1369 /* allocate the bitmap */
1370 info
->bitmap
= kzalloc(PAGE_CACHE_SIZE
, GFP_NOFS
);
1371 spin_lock(&block_group
->tree_lock
);
1372 if (!info
->bitmap
) {
1382 kfree(info
->bitmap
);
1383 kmem_cache_free(btrfs_free_space_cachep
, info
);
1389 bool try_merge_free_space(struct btrfs_block_group_cache
*block_group
,
1390 struct btrfs_free_space
*info
, bool update_stat
)
1392 struct btrfs_free_space
*left_info
;
1393 struct btrfs_free_space
*right_info
;
1394 bool merged
= false;
1395 u64 offset
= info
->offset
;
1396 u64 bytes
= info
->bytes
;
1399 * first we want to see if there is free space adjacent to the range we
1400 * are adding, if there is remove that struct and add a new one to
1401 * cover the entire range
1403 right_info
= tree_search_offset(block_group
, offset
+ bytes
, 0, 0);
1404 if (right_info
&& rb_prev(&right_info
->offset_index
))
1405 left_info
= rb_entry(rb_prev(&right_info
->offset_index
),
1406 struct btrfs_free_space
, offset_index
);
1408 left_info
= tree_search_offset(block_group
, offset
- 1, 0, 0);
1410 if (right_info
&& !right_info
->bitmap
) {
1412 unlink_free_space(block_group
, right_info
);
1414 __unlink_free_space(block_group
, right_info
);
1415 info
->bytes
+= right_info
->bytes
;
1416 kmem_cache_free(btrfs_free_space_cachep
, right_info
);
1420 if (left_info
&& !left_info
->bitmap
&&
1421 left_info
->offset
+ left_info
->bytes
== offset
) {
1423 unlink_free_space(block_group
, left_info
);
1425 __unlink_free_space(block_group
, left_info
);
1426 info
->offset
= left_info
->offset
;
1427 info
->bytes
+= left_info
->bytes
;
1428 kmem_cache_free(btrfs_free_space_cachep
, left_info
);
1435 int btrfs_add_free_space(struct btrfs_block_group_cache
*block_group
,
1436 u64 offset
, u64 bytes
)
1438 struct btrfs_free_space
*info
;
1441 info
= kmem_cache_zalloc(btrfs_free_space_cachep
, GFP_NOFS
);
1445 info
->offset
= offset
;
1446 info
->bytes
= bytes
;
1448 spin_lock(&block_group
->tree_lock
);
1450 if (try_merge_free_space(block_group
, info
, true))
1454 * There was no extent directly to the left or right of this new
1455 * extent then we know we're going to have to allocate a new extent, so
1456 * before we do that see if we need to drop this into a bitmap
1458 ret
= insert_into_bitmap(block_group
, info
);
1466 ret
= link_free_space(block_group
, info
);
1468 kmem_cache_free(btrfs_free_space_cachep
, info
);
1470 spin_unlock(&block_group
->tree_lock
);
1473 printk(KERN_CRIT
"btrfs: unable to add free space :%d\n", ret
);
1474 BUG_ON(ret
== -EEXIST
);
1480 int btrfs_remove_free_space(struct btrfs_block_group_cache
*block_group
,
1481 u64 offset
, u64 bytes
)
1483 struct btrfs_free_space
*info
;
1484 struct btrfs_free_space
*next_info
= NULL
;
1487 spin_lock(&block_group
->tree_lock
);
1490 info
= tree_search_offset(block_group
, offset
, 0, 0);
1493 * oops didn't find an extent that matched the space we wanted
1494 * to remove, look for a bitmap instead
1496 info
= tree_search_offset(block_group
,
1497 offset_to_bitmap(block_group
, offset
),
1505 if (info
->bytes
< bytes
&& rb_next(&info
->offset_index
)) {
1507 next_info
= rb_entry(rb_next(&info
->offset_index
),
1508 struct btrfs_free_space
,
1511 if (next_info
->bitmap
)
1512 end
= next_info
->offset
+ BITS_PER_BITMAP
*
1513 block_group
->sectorsize
- 1;
1515 end
= next_info
->offset
+ next_info
->bytes
;
1517 if (next_info
->bytes
< bytes
||
1518 next_info
->offset
> offset
|| offset
> end
) {
1519 printk(KERN_CRIT
"Found free space at %llu, size %llu,"
1520 " trying to use %llu\n",
1521 (unsigned long long)info
->offset
,
1522 (unsigned long long)info
->bytes
,
1523 (unsigned long long)bytes
);
1532 if (info
->bytes
== bytes
) {
1533 unlink_free_space(block_group
, info
);
1535 kfree(info
->bitmap
);
1536 block_group
->total_bitmaps
--;
1538 kmem_cache_free(btrfs_free_space_cachep
, info
);
1542 if (!info
->bitmap
&& info
->offset
== offset
) {
1543 unlink_free_space(block_group
, info
);
1544 info
->offset
+= bytes
;
1545 info
->bytes
-= bytes
;
1546 link_free_space(block_group
, info
);
1550 if (!info
->bitmap
&& info
->offset
<= offset
&&
1551 info
->offset
+ info
->bytes
>= offset
+ bytes
) {
1552 u64 old_start
= info
->offset
;
1554 * we're freeing space in the middle of the info,
1555 * this can happen during tree log replay
1557 * first unlink the old info and then
1558 * insert it again after the hole we're creating
1560 unlink_free_space(block_group
, info
);
1561 if (offset
+ bytes
< info
->offset
+ info
->bytes
) {
1562 u64 old_end
= info
->offset
+ info
->bytes
;
1564 info
->offset
= offset
+ bytes
;
1565 info
->bytes
= old_end
- info
->offset
;
1566 ret
= link_free_space(block_group
, info
);
1571 /* the hole we're creating ends at the end
1572 * of the info struct, just free the info
1574 kmem_cache_free(btrfs_free_space_cachep
, info
);
1576 spin_unlock(&block_group
->tree_lock
);
1578 /* step two, insert a new info struct to cover
1579 * anything before the hole
1581 ret
= btrfs_add_free_space(block_group
, old_start
,
1582 offset
- old_start
);
1587 ret
= remove_from_bitmap(block_group
, info
, &offset
, &bytes
);
1592 spin_unlock(&block_group
->tree_lock
);
1597 void btrfs_dump_free_space(struct btrfs_block_group_cache
*block_group
,
1600 struct btrfs_free_space
*info
;
1604 for (n
= rb_first(&block_group
->free_space_offset
); n
; n
= rb_next(n
)) {
1605 info
= rb_entry(n
, struct btrfs_free_space
, offset_index
);
1606 if (info
->bytes
>= bytes
)
1608 printk(KERN_CRIT
"entry offset %llu, bytes %llu, bitmap %s\n",
1609 (unsigned long long)info
->offset
,
1610 (unsigned long long)info
->bytes
,
1611 (info
->bitmap
) ? "yes" : "no");
1613 printk(KERN_INFO
"block group has cluster?: %s\n",
1614 list_empty(&block_group
->cluster_list
) ? "no" : "yes");
1615 printk(KERN_INFO
"%d blocks of free space at or bigger than bytes is"
1619 u64
btrfs_block_group_free_space(struct btrfs_block_group_cache
*block_group
)
1621 struct btrfs_free_space
*info
;
1625 for (n
= rb_first(&block_group
->free_space_offset
); n
;
1627 info
= rb_entry(n
, struct btrfs_free_space
, offset_index
);
1635 * for a given cluster, put all of its extents back into the free
1636 * space cache. If the block group passed doesn't match the block group
1637 * pointed to by the cluster, someone else raced in and freed the
1638 * cluster already. In that case, we just return without changing anything
1641 __btrfs_return_cluster_to_free_space(
1642 struct btrfs_block_group_cache
*block_group
,
1643 struct btrfs_free_cluster
*cluster
)
1645 struct btrfs_free_space
*entry
;
1646 struct rb_node
*node
;
1648 spin_lock(&cluster
->lock
);
1649 if (cluster
->block_group
!= block_group
)
1652 cluster
->block_group
= NULL
;
1653 cluster
->window_start
= 0;
1654 list_del_init(&cluster
->block_group_list
);
1656 node
= rb_first(&cluster
->root
);
1660 entry
= rb_entry(node
, struct btrfs_free_space
, offset_index
);
1661 node
= rb_next(&entry
->offset_index
);
1662 rb_erase(&entry
->offset_index
, &cluster
->root
);
1664 bitmap
= (entry
->bitmap
!= NULL
);
1666 try_merge_free_space(block_group
, entry
, false);
1667 tree_insert_offset(&block_group
->free_space_offset
,
1668 entry
->offset
, &entry
->offset_index
, bitmap
);
1670 cluster
->root
= RB_ROOT
;
1673 spin_unlock(&cluster
->lock
);
1674 btrfs_put_block_group(block_group
);
1678 void btrfs_remove_free_space_cache(struct btrfs_block_group_cache
*block_group
)
1680 struct btrfs_free_space
*info
;
1681 struct rb_node
*node
;
1682 struct btrfs_free_cluster
*cluster
;
1683 struct list_head
*head
;
1685 spin_lock(&block_group
->tree_lock
);
1686 while ((head
= block_group
->cluster_list
.next
) !=
1687 &block_group
->cluster_list
) {
1688 cluster
= list_entry(head
, struct btrfs_free_cluster
,
1691 WARN_ON(cluster
->block_group
!= block_group
);
1692 __btrfs_return_cluster_to_free_space(block_group
, cluster
);
1693 if (need_resched()) {
1694 spin_unlock(&block_group
->tree_lock
);
1696 spin_lock(&block_group
->tree_lock
);
1700 while ((node
= rb_last(&block_group
->free_space_offset
)) != NULL
) {
1701 info
= rb_entry(node
, struct btrfs_free_space
, offset_index
);
1702 unlink_free_space(block_group
, info
);
1704 kfree(info
->bitmap
);
1705 kmem_cache_free(btrfs_free_space_cachep
, info
);
1706 if (need_resched()) {
1707 spin_unlock(&block_group
->tree_lock
);
1709 spin_lock(&block_group
->tree_lock
);
1713 spin_unlock(&block_group
->tree_lock
);
1716 u64
btrfs_find_space_for_alloc(struct btrfs_block_group_cache
*block_group
,
1717 u64 offset
, u64 bytes
, u64 empty_size
)
1719 struct btrfs_free_space
*entry
= NULL
;
1720 u64 bytes_search
= bytes
+ empty_size
;
1723 spin_lock(&block_group
->tree_lock
);
1724 entry
= find_free_space(block_group
, &offset
, &bytes_search
, 0);
1729 if (entry
->bitmap
) {
1730 bitmap_clear_bits(block_group
, entry
, offset
, bytes
);
1732 free_bitmap(block_group
, entry
);
1734 unlink_free_space(block_group
, entry
);
1735 entry
->offset
+= bytes
;
1736 entry
->bytes
-= bytes
;
1738 kmem_cache_free(btrfs_free_space_cachep
, entry
);
1740 link_free_space(block_group
, entry
);
1744 spin_unlock(&block_group
->tree_lock
);
1750 * given a cluster, put all of its extents back into the free space
1751 * cache. If a block group is passed, this function will only free
1752 * a cluster that belongs to the passed block group.
1754 * Otherwise, it'll get a reference on the block group pointed to by the
1755 * cluster and remove the cluster from it.
1757 int btrfs_return_cluster_to_free_space(
1758 struct btrfs_block_group_cache
*block_group
,
1759 struct btrfs_free_cluster
*cluster
)
1763 /* first, get a safe pointer to the block group */
1764 spin_lock(&cluster
->lock
);
1766 block_group
= cluster
->block_group
;
1768 spin_unlock(&cluster
->lock
);
1771 } else if (cluster
->block_group
!= block_group
) {
1772 /* someone else has already freed it don't redo their work */
1773 spin_unlock(&cluster
->lock
);
1776 atomic_inc(&block_group
->count
);
1777 spin_unlock(&cluster
->lock
);
1779 /* now return any extents the cluster had on it */
1780 spin_lock(&block_group
->tree_lock
);
1781 ret
= __btrfs_return_cluster_to_free_space(block_group
, cluster
);
1782 spin_unlock(&block_group
->tree_lock
);
1784 /* finally drop our ref */
1785 btrfs_put_block_group(block_group
);
1789 static u64
btrfs_alloc_from_bitmap(struct btrfs_block_group_cache
*block_group
,
1790 struct btrfs_free_cluster
*cluster
,
1791 struct btrfs_free_space
*entry
,
1792 u64 bytes
, u64 min_start
)
1795 u64 search_start
= cluster
->window_start
;
1796 u64 search_bytes
= bytes
;
1799 search_start
= min_start
;
1800 search_bytes
= bytes
;
1802 err
= search_bitmap(block_group
, entry
, &search_start
,
1808 bitmap_clear_bits(block_group
, entry
, ret
, bytes
);
1814 * given a cluster, try to allocate 'bytes' from it, returns 0
1815 * if it couldn't find anything suitably large, or a logical disk offset
1816 * if things worked out
1818 u64
btrfs_alloc_from_cluster(struct btrfs_block_group_cache
*block_group
,
1819 struct btrfs_free_cluster
*cluster
, u64 bytes
,
1822 struct btrfs_free_space
*entry
= NULL
;
1823 struct rb_node
*node
;
1826 spin_lock(&cluster
->lock
);
1827 if (bytes
> cluster
->max_size
)
1830 if (cluster
->block_group
!= block_group
)
1833 node
= rb_first(&cluster
->root
);
1837 entry
= rb_entry(node
, struct btrfs_free_space
, offset_index
);
1839 if (entry
->bytes
< bytes
||
1840 (!entry
->bitmap
&& entry
->offset
< min_start
)) {
1841 struct rb_node
*node
;
1843 node
= rb_next(&entry
->offset_index
);
1846 entry
= rb_entry(node
, struct btrfs_free_space
,
1851 if (entry
->bitmap
) {
1852 ret
= btrfs_alloc_from_bitmap(block_group
,
1853 cluster
, entry
, bytes
,
1856 struct rb_node
*node
;
1857 node
= rb_next(&entry
->offset_index
);
1860 entry
= rb_entry(node
, struct btrfs_free_space
,
1866 ret
= entry
->offset
;
1868 entry
->offset
+= bytes
;
1869 entry
->bytes
-= bytes
;
1872 if (entry
->bytes
== 0)
1873 rb_erase(&entry
->offset_index
, &cluster
->root
);
1877 spin_unlock(&cluster
->lock
);
1882 spin_lock(&block_group
->tree_lock
);
1884 block_group
->free_space
-= bytes
;
1885 if (entry
->bytes
== 0) {
1886 block_group
->free_extents
--;
1887 if (entry
->bitmap
) {
1888 kfree(entry
->bitmap
);
1889 block_group
->total_bitmaps
--;
1890 recalculate_thresholds(block_group
);
1892 kmem_cache_free(btrfs_free_space_cachep
, entry
);
1895 spin_unlock(&block_group
->tree_lock
);
1900 static int btrfs_bitmap_cluster(struct btrfs_block_group_cache
*block_group
,
1901 struct btrfs_free_space
*entry
,
1902 struct btrfs_free_cluster
*cluster
,
1903 u64 offset
, u64 bytes
, u64 min_bytes
)
1905 unsigned long next_zero
;
1907 unsigned long search_bits
;
1908 unsigned long total_bits
;
1909 unsigned long found_bits
;
1910 unsigned long start
= 0;
1911 unsigned long total_found
= 0;
1915 i
= offset_to_bit(entry
->offset
, block_group
->sectorsize
,
1916 max_t(u64
, offset
, entry
->offset
));
1917 search_bits
= bytes_to_bits(bytes
, block_group
->sectorsize
);
1918 total_bits
= bytes_to_bits(min_bytes
, block_group
->sectorsize
);
1922 for (i
= find_next_bit(entry
->bitmap
, BITS_PER_BITMAP
, i
);
1923 i
< BITS_PER_BITMAP
;
1924 i
= find_next_bit(entry
->bitmap
, BITS_PER_BITMAP
, i
+ 1)) {
1925 next_zero
= find_next_zero_bit(entry
->bitmap
,
1926 BITS_PER_BITMAP
, i
);
1927 if (next_zero
- i
>= search_bits
) {
1928 found_bits
= next_zero
- i
;
1942 total_found
+= found_bits
;
1944 if (cluster
->max_size
< found_bits
* block_group
->sectorsize
)
1945 cluster
->max_size
= found_bits
* block_group
->sectorsize
;
1947 if (total_found
< total_bits
) {
1948 i
= find_next_bit(entry
->bitmap
, BITS_PER_BITMAP
, next_zero
);
1949 if (i
- start
> total_bits
* 2) {
1951 cluster
->max_size
= 0;
1957 cluster
->window_start
= start
* block_group
->sectorsize
+
1959 rb_erase(&entry
->offset_index
, &block_group
->free_space_offset
);
1960 ret
= tree_insert_offset(&cluster
->root
, entry
->offset
,
1961 &entry
->offset_index
, 1);
1968 * This searches the block group for just extents to fill the cluster with.
1970 static int setup_cluster_no_bitmap(struct btrfs_block_group_cache
*block_group
,
1971 struct btrfs_free_cluster
*cluster
,
1972 u64 offset
, u64 bytes
, u64 min_bytes
)
1974 struct btrfs_free_space
*first
= NULL
;
1975 struct btrfs_free_space
*entry
= NULL
;
1976 struct btrfs_free_space
*prev
= NULL
;
1977 struct btrfs_free_space
*last
;
1978 struct rb_node
*node
;
1982 u64 max_gap
= 128 * 1024;
1984 entry
= tree_search_offset(block_group
, offset
, 0, 1);
1989 * We don't want bitmaps, so just move along until we find a normal
1992 while (entry
->bitmap
) {
1993 node
= rb_next(&entry
->offset_index
);
1996 entry
= rb_entry(node
, struct btrfs_free_space
, offset_index
);
1999 window_start
= entry
->offset
;
2000 window_free
= entry
->bytes
;
2001 max_extent
= entry
->bytes
;
2006 while (window_free
<= min_bytes
) {
2007 node
= rb_next(&entry
->offset_index
);
2010 entry
= rb_entry(node
, struct btrfs_free_space
, offset_index
);
2015 * we haven't filled the empty size and the window is
2016 * very large. reset and try again
2018 if (entry
->offset
- (prev
->offset
+ prev
->bytes
) > max_gap
||
2019 entry
->offset
- window_start
> (min_bytes
* 2)) {
2021 window_start
= entry
->offset
;
2022 window_free
= entry
->bytes
;
2024 max_extent
= entry
->bytes
;
2027 window_free
+= entry
->bytes
;
2028 if (entry
->bytes
> max_extent
)
2029 max_extent
= entry
->bytes
;
2034 cluster
->window_start
= first
->offset
;
2036 node
= &first
->offset_index
;
2039 * now we've found our entries, pull them out of the free space
2040 * cache and put them into the cluster rbtree
2045 entry
= rb_entry(node
, struct btrfs_free_space
, offset_index
);
2046 node
= rb_next(&entry
->offset_index
);
2050 rb_erase(&entry
->offset_index
, &block_group
->free_space_offset
);
2051 ret
= tree_insert_offset(&cluster
->root
, entry
->offset
,
2052 &entry
->offset_index
, 0);
2054 } while (node
&& entry
!= last
);
2056 cluster
->max_size
= max_extent
;
2062 * This specifically looks for bitmaps that may work in the cluster, we assume
2063 * that we have already failed to find extents that will work.
2065 static int setup_cluster_bitmap(struct btrfs_block_group_cache
*block_group
,
2066 struct btrfs_free_cluster
*cluster
,
2067 u64 offset
, u64 bytes
, u64 min_bytes
)
2069 struct btrfs_free_space
*entry
;
2070 struct rb_node
*node
;
2073 if (block_group
->total_bitmaps
== 0)
2076 entry
= tree_search_offset(block_group
,
2077 offset_to_bitmap(block_group
, offset
),
2082 node
= &entry
->offset_index
;
2084 entry
= rb_entry(node
, struct btrfs_free_space
, offset_index
);
2085 node
= rb_next(&entry
->offset_index
);
2088 if (entry
->bytes
< min_bytes
)
2090 ret
= btrfs_bitmap_cluster(block_group
, entry
, cluster
, offset
,
2092 } while (ret
&& node
);
2098 * here we try to find a cluster of blocks in a block group. The goal
2099 * is to find at least bytes free and up to empty_size + bytes free.
2100 * We might not find them all in one contiguous area.
2102 * returns zero and sets up cluster if things worked out, otherwise
2103 * it returns -enospc
2105 int btrfs_find_space_cluster(struct btrfs_trans_handle
*trans
,
2106 struct btrfs_root
*root
,
2107 struct btrfs_block_group_cache
*block_group
,
2108 struct btrfs_free_cluster
*cluster
,
2109 u64 offset
, u64 bytes
, u64 empty_size
)
2114 /* for metadata, allow allocates with more holes */
2115 if (btrfs_test_opt(root
, SSD_SPREAD
)) {
2116 min_bytes
= bytes
+ empty_size
;
2117 } else if (block_group
->flags
& BTRFS_BLOCK_GROUP_METADATA
) {
2119 * we want to do larger allocations when we are
2120 * flushing out the delayed refs, it helps prevent
2121 * making more work as we go along.
2123 if (trans
->transaction
->delayed_refs
.flushing
)
2124 min_bytes
= max(bytes
, (bytes
+ empty_size
) >> 1);
2126 min_bytes
= max(bytes
, (bytes
+ empty_size
) >> 4);
2128 min_bytes
= max(bytes
, (bytes
+ empty_size
) >> 2);
2130 spin_lock(&block_group
->tree_lock
);
2133 * If we know we don't have enough space to make a cluster don't even
2134 * bother doing all the work to try and find one.
2136 if (block_group
->free_space
< min_bytes
) {
2137 spin_unlock(&block_group
->tree_lock
);
2141 spin_lock(&cluster
->lock
);
2143 /* someone already found a cluster, hooray */
2144 if (cluster
->block_group
) {
2149 ret
= setup_cluster_no_bitmap(block_group
, cluster
, offset
, bytes
,
2152 ret
= setup_cluster_bitmap(block_group
, cluster
, offset
,
2156 atomic_inc(&block_group
->count
);
2157 list_add_tail(&cluster
->block_group_list
,
2158 &block_group
->cluster_list
);
2159 cluster
->block_group
= block_group
;
2162 spin_unlock(&cluster
->lock
);
2163 spin_unlock(&block_group
->tree_lock
);
2169 * simple code to zero out a cluster
2171 void btrfs_init_free_cluster(struct btrfs_free_cluster
*cluster
)
2173 spin_lock_init(&cluster
->lock
);
2174 spin_lock_init(&cluster
->refill_lock
);
2175 cluster
->root
= RB_ROOT
;
2176 cluster
->max_size
= 0;
2177 INIT_LIST_HEAD(&cluster
->block_group_list
);
2178 cluster
->block_group
= NULL
;
2181 int btrfs_trim_block_group(struct btrfs_block_group_cache
*block_group
,
2182 u64
*trimmed
, u64 start
, u64 end
, u64 minlen
)
2184 struct btrfs_free_space
*entry
= NULL
;
2185 struct btrfs_fs_info
*fs_info
= block_group
->fs_info
;
2187 u64 actually_trimmed
;
2192 while (start
< end
) {
2193 spin_lock(&block_group
->tree_lock
);
2195 if (block_group
->free_space
< minlen
) {
2196 spin_unlock(&block_group
->tree_lock
);
2200 entry
= tree_search_offset(block_group
, start
, 0, 1);
2202 entry
= tree_search_offset(block_group
,
2203 offset_to_bitmap(block_group
,
2207 if (!entry
|| entry
->offset
>= end
) {
2208 spin_unlock(&block_group
->tree_lock
);
2212 if (entry
->bitmap
) {
2213 ret
= search_bitmap(block_group
, entry
, &start
, &bytes
);
2216 spin_unlock(&block_group
->tree_lock
);
2219 bytes
= min(bytes
, end
- start
);
2220 bitmap_clear_bits(block_group
, entry
,
2222 if (entry
->bytes
== 0)
2223 free_bitmap(block_group
, entry
);
2225 start
= entry
->offset
+ BITS_PER_BITMAP
*
2226 block_group
->sectorsize
;
2227 spin_unlock(&block_group
->tree_lock
);
2232 start
= entry
->offset
;
2233 bytes
= min(entry
->bytes
, end
- start
);
2234 unlink_free_space(block_group
, entry
);
2238 spin_unlock(&block_group
->tree_lock
);
2240 if (bytes
>= minlen
) {
2242 update_ret
= btrfs_update_reserved_bytes(block_group
,
2245 ret
= btrfs_error_discard_extent(fs_info
->extent_root
,
2250 btrfs_add_free_space(block_group
,
2253 btrfs_update_reserved_bytes(block_group
,
2258 *trimmed
+= actually_trimmed
;
2263 if (fatal_signal_pending(current
)) {