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>
23 #include <linux/ratelimit.h>
25 #include "free-space-cache.h"
26 #include "transaction.h"
28 #include "extent_io.h"
29 #include "inode-map.h"
31 #define BITS_PER_BITMAP (PAGE_CACHE_SIZE * 8)
32 #define MAX_CACHE_BYTES_PER_GIG (32 * 1024)
34 static int link_free_space(struct btrfs_free_space_ctl
*ctl
,
35 struct btrfs_free_space
*info
);
36 static void unlink_free_space(struct btrfs_free_space_ctl
*ctl
,
37 struct btrfs_free_space
*info
);
39 static struct inode
*__lookup_free_space_inode(struct btrfs_root
*root
,
40 struct btrfs_path
*path
,
44 struct btrfs_key location
;
45 struct btrfs_disk_key disk_key
;
46 struct btrfs_free_space_header
*header
;
47 struct extent_buffer
*leaf
;
48 struct inode
*inode
= NULL
;
51 key
.objectid
= BTRFS_FREE_SPACE_OBJECTID
;
55 ret
= btrfs_search_slot(NULL
, root
, &key
, path
, 0, 0);
59 btrfs_release_path(path
);
60 return ERR_PTR(-ENOENT
);
63 leaf
= path
->nodes
[0];
64 header
= btrfs_item_ptr(leaf
, path
->slots
[0],
65 struct btrfs_free_space_header
);
66 btrfs_free_space_key(leaf
, header
, &disk_key
);
67 btrfs_disk_key_to_cpu(&location
, &disk_key
);
68 btrfs_release_path(path
);
70 inode
= btrfs_iget(root
->fs_info
->sb
, &location
, root
, NULL
);
72 return ERR_PTR(-ENOENT
);
75 if (is_bad_inode(inode
)) {
77 return ERR_PTR(-ENOENT
);
80 mapping_set_gfp_mask(inode
->i_mapping
,
81 mapping_gfp_mask(inode
->i_mapping
) & ~__GFP_FS
);
86 struct inode
*lookup_free_space_inode(struct btrfs_root
*root
,
87 struct btrfs_block_group_cache
88 *block_group
, struct btrfs_path
*path
)
90 struct inode
*inode
= NULL
;
91 u32 flags
= BTRFS_INODE_NODATASUM
| BTRFS_INODE_NODATACOW
;
93 spin_lock(&block_group
->lock
);
94 if (block_group
->inode
)
95 inode
= igrab(block_group
->inode
);
96 spin_unlock(&block_group
->lock
);
100 inode
= __lookup_free_space_inode(root
, path
,
101 block_group
->key
.objectid
);
105 spin_lock(&block_group
->lock
);
106 if (!((BTRFS_I(inode
)->flags
& flags
) == flags
)) {
107 printk(KERN_INFO
"Old style space inode found, converting.\n");
108 BTRFS_I(inode
)->flags
|= BTRFS_INODE_NODATASUM
|
109 BTRFS_INODE_NODATACOW
;
110 block_group
->disk_cache_state
= BTRFS_DC_CLEAR
;
113 if (!block_group
->iref
) {
114 block_group
->inode
= igrab(inode
);
115 block_group
->iref
= 1;
117 spin_unlock(&block_group
->lock
);
122 int __create_free_space_inode(struct btrfs_root
*root
,
123 struct btrfs_trans_handle
*trans
,
124 struct btrfs_path
*path
, u64 ino
, u64 offset
)
126 struct btrfs_key key
;
127 struct btrfs_disk_key disk_key
;
128 struct btrfs_free_space_header
*header
;
129 struct btrfs_inode_item
*inode_item
;
130 struct extent_buffer
*leaf
;
131 u64 flags
= BTRFS_INODE_NOCOMPRESS
| BTRFS_INODE_PREALLOC
;
134 ret
= btrfs_insert_empty_inode(trans
, root
, path
, ino
);
138 /* We inline crc's for the free disk space cache */
139 if (ino
!= BTRFS_FREE_INO_OBJECTID
)
140 flags
|= BTRFS_INODE_NODATASUM
| BTRFS_INODE_NODATACOW
;
142 leaf
= path
->nodes
[0];
143 inode_item
= btrfs_item_ptr(leaf
, path
->slots
[0],
144 struct btrfs_inode_item
);
145 btrfs_item_key(leaf
, &disk_key
, path
->slots
[0]);
146 memset_extent_buffer(leaf
, 0, (unsigned long)inode_item
,
147 sizeof(*inode_item
));
148 btrfs_set_inode_generation(leaf
, inode_item
, trans
->transid
);
149 btrfs_set_inode_size(leaf
, inode_item
, 0);
150 btrfs_set_inode_nbytes(leaf
, inode_item
, 0);
151 btrfs_set_inode_uid(leaf
, inode_item
, 0);
152 btrfs_set_inode_gid(leaf
, inode_item
, 0);
153 btrfs_set_inode_mode(leaf
, inode_item
, S_IFREG
| 0600);
154 btrfs_set_inode_flags(leaf
, inode_item
, flags
);
155 btrfs_set_inode_nlink(leaf
, inode_item
, 1);
156 btrfs_set_inode_transid(leaf
, inode_item
, trans
->transid
);
157 btrfs_set_inode_block_group(leaf
, inode_item
, offset
);
158 btrfs_mark_buffer_dirty(leaf
);
159 btrfs_release_path(path
);
161 key
.objectid
= BTRFS_FREE_SPACE_OBJECTID
;
165 ret
= btrfs_insert_empty_item(trans
, root
, path
, &key
,
166 sizeof(struct btrfs_free_space_header
));
168 btrfs_release_path(path
);
171 leaf
= path
->nodes
[0];
172 header
= btrfs_item_ptr(leaf
, path
->slots
[0],
173 struct btrfs_free_space_header
);
174 memset_extent_buffer(leaf
, 0, (unsigned long)header
, sizeof(*header
));
175 btrfs_set_free_space_key(leaf
, header
, &disk_key
);
176 btrfs_mark_buffer_dirty(leaf
);
177 btrfs_release_path(path
);
182 int create_free_space_inode(struct btrfs_root
*root
,
183 struct btrfs_trans_handle
*trans
,
184 struct btrfs_block_group_cache
*block_group
,
185 struct btrfs_path
*path
)
190 ret
= btrfs_find_free_objectid(root
, &ino
);
194 return __create_free_space_inode(root
, trans
, path
, ino
,
195 block_group
->key
.objectid
);
198 int btrfs_truncate_free_space_cache(struct btrfs_root
*root
,
199 struct btrfs_trans_handle
*trans
,
200 struct btrfs_path
*path
,
203 struct btrfs_block_rsv
*rsv
;
208 rsv
= trans
->block_rsv
;
209 trans
->block_rsv
= &root
->fs_info
->global_block_rsv
;
211 /* 1 for slack space, 1 for updating the inode */
212 needed_bytes
= btrfs_calc_trunc_metadata_size(root
, 1) +
213 btrfs_calc_trans_metadata_size(root
, 1);
215 spin_lock(&trans
->block_rsv
->lock
);
216 if (trans
->block_rsv
->reserved
< needed_bytes
) {
217 spin_unlock(&trans
->block_rsv
->lock
);
218 trans
->block_rsv
= rsv
;
221 spin_unlock(&trans
->block_rsv
->lock
);
223 oldsize
= i_size_read(inode
);
224 btrfs_i_size_write(inode
, 0);
225 truncate_pagecache(inode
, oldsize
, 0);
228 * We don't need an orphan item because truncating the free space cache
229 * will never be split across transactions.
231 ret
= btrfs_truncate_inode_items(trans
, root
, inode
,
232 0, BTRFS_EXTENT_DATA_KEY
);
235 trans
->block_rsv
= rsv
;
236 btrfs_abort_transaction(trans
, root
, ret
);
240 ret
= btrfs_update_inode(trans
, root
, inode
);
242 btrfs_abort_transaction(trans
, root
, ret
);
243 trans
->block_rsv
= rsv
;
248 static int readahead_cache(struct inode
*inode
)
250 struct file_ra_state
*ra
;
251 unsigned long last_index
;
253 ra
= kzalloc(sizeof(*ra
), GFP_NOFS
);
257 file_ra_state_init(ra
, inode
->i_mapping
);
258 last_index
= (i_size_read(inode
) - 1) >> PAGE_CACHE_SHIFT
;
260 page_cache_sync_readahead(inode
->i_mapping
, ra
, NULL
, 0, last_index
);
271 struct btrfs_root
*root
;
275 unsigned check_crcs
:1;
278 static int io_ctl_init(struct io_ctl
*io_ctl
, struct inode
*inode
,
279 struct btrfs_root
*root
)
281 memset(io_ctl
, 0, sizeof(struct io_ctl
));
282 io_ctl
->num_pages
= (i_size_read(inode
) + PAGE_CACHE_SIZE
- 1) >>
284 io_ctl
->pages
= kzalloc(sizeof(struct page
*) * io_ctl
->num_pages
,
289 if (btrfs_ino(inode
) != BTRFS_FREE_INO_OBJECTID
)
290 io_ctl
->check_crcs
= 1;
294 static void io_ctl_free(struct io_ctl
*io_ctl
)
296 kfree(io_ctl
->pages
);
299 static void io_ctl_unmap_page(struct io_ctl
*io_ctl
)
302 kunmap(io_ctl
->page
);
308 static void io_ctl_map_page(struct io_ctl
*io_ctl
, int clear
)
310 BUG_ON(io_ctl
->index
>= io_ctl
->num_pages
);
311 io_ctl
->page
= io_ctl
->pages
[io_ctl
->index
++];
312 io_ctl
->cur
= kmap(io_ctl
->page
);
313 io_ctl
->orig
= io_ctl
->cur
;
314 io_ctl
->size
= PAGE_CACHE_SIZE
;
316 memset(io_ctl
->cur
, 0, PAGE_CACHE_SIZE
);
319 static void io_ctl_drop_pages(struct io_ctl
*io_ctl
)
323 io_ctl_unmap_page(io_ctl
);
325 for (i
= 0; i
< io_ctl
->num_pages
; i
++) {
326 if (io_ctl
->pages
[i
]) {
327 ClearPageChecked(io_ctl
->pages
[i
]);
328 unlock_page(io_ctl
->pages
[i
]);
329 page_cache_release(io_ctl
->pages
[i
]);
334 static int io_ctl_prepare_pages(struct io_ctl
*io_ctl
, struct inode
*inode
,
338 gfp_t mask
= btrfs_alloc_write_mask(inode
->i_mapping
);
341 for (i
= 0; i
< io_ctl
->num_pages
; i
++) {
342 page
= find_or_create_page(inode
->i_mapping
, i
, mask
);
344 io_ctl_drop_pages(io_ctl
);
347 io_ctl
->pages
[i
] = page
;
348 if (uptodate
&& !PageUptodate(page
)) {
349 btrfs_readpage(NULL
, page
);
351 if (!PageUptodate(page
)) {
352 printk(KERN_ERR
"btrfs: error reading free "
354 io_ctl_drop_pages(io_ctl
);
360 for (i
= 0; i
< io_ctl
->num_pages
; i
++) {
361 clear_page_dirty_for_io(io_ctl
->pages
[i
]);
362 set_page_extent_mapped(io_ctl
->pages
[i
]);
368 static void io_ctl_set_generation(struct io_ctl
*io_ctl
, u64 generation
)
372 io_ctl_map_page(io_ctl
, 1);
375 * Skip the csum areas. If we don't check crcs then we just have a
376 * 64bit chunk at the front of the first page.
378 if (io_ctl
->check_crcs
) {
379 io_ctl
->cur
+= (sizeof(u32
) * io_ctl
->num_pages
);
380 io_ctl
->size
-= sizeof(u64
) + (sizeof(u32
) * io_ctl
->num_pages
);
382 io_ctl
->cur
+= sizeof(u64
);
383 io_ctl
->size
-= sizeof(u64
) * 2;
387 *val
= cpu_to_le64(generation
);
388 io_ctl
->cur
+= sizeof(u64
);
391 static int io_ctl_check_generation(struct io_ctl
*io_ctl
, u64 generation
)
396 * Skip the crc area. If we don't check crcs then we just have a 64bit
397 * chunk at the front of the first page.
399 if (io_ctl
->check_crcs
) {
400 io_ctl
->cur
+= sizeof(u32
) * io_ctl
->num_pages
;
401 io_ctl
->size
-= sizeof(u64
) +
402 (sizeof(u32
) * io_ctl
->num_pages
);
404 io_ctl
->cur
+= sizeof(u64
);
405 io_ctl
->size
-= sizeof(u64
) * 2;
409 if (le64_to_cpu(*gen
) != generation
) {
410 printk_ratelimited(KERN_ERR
"btrfs: space cache generation "
411 "(%Lu) does not match inode (%Lu)\n", *gen
,
413 io_ctl_unmap_page(io_ctl
);
416 io_ctl
->cur
+= sizeof(u64
);
420 static void io_ctl_set_crc(struct io_ctl
*io_ctl
, int index
)
426 if (!io_ctl
->check_crcs
) {
427 io_ctl_unmap_page(io_ctl
);
432 offset
= sizeof(u32
) * io_ctl
->num_pages
;
434 crc
= btrfs_csum_data(io_ctl
->root
, io_ctl
->orig
+ offset
, crc
,
435 PAGE_CACHE_SIZE
- offset
);
436 btrfs_csum_final(crc
, (char *)&crc
);
437 io_ctl_unmap_page(io_ctl
);
438 tmp
= kmap(io_ctl
->pages
[0]);
441 kunmap(io_ctl
->pages
[0]);
444 static int io_ctl_check_crc(struct io_ctl
*io_ctl
, int index
)
450 if (!io_ctl
->check_crcs
) {
451 io_ctl_map_page(io_ctl
, 0);
456 offset
= sizeof(u32
) * io_ctl
->num_pages
;
458 tmp
= kmap(io_ctl
->pages
[0]);
461 kunmap(io_ctl
->pages
[0]);
463 io_ctl_map_page(io_ctl
, 0);
464 crc
= btrfs_csum_data(io_ctl
->root
, io_ctl
->orig
+ offset
, crc
,
465 PAGE_CACHE_SIZE
- offset
);
466 btrfs_csum_final(crc
, (char *)&crc
);
468 printk_ratelimited(KERN_ERR
"btrfs: csum mismatch on free "
470 io_ctl_unmap_page(io_ctl
);
477 static int io_ctl_add_entry(struct io_ctl
*io_ctl
, u64 offset
, u64 bytes
,
480 struct btrfs_free_space_entry
*entry
;
486 entry
->offset
= cpu_to_le64(offset
);
487 entry
->bytes
= cpu_to_le64(bytes
);
488 entry
->type
= (bitmap
) ? BTRFS_FREE_SPACE_BITMAP
:
489 BTRFS_FREE_SPACE_EXTENT
;
490 io_ctl
->cur
+= sizeof(struct btrfs_free_space_entry
);
491 io_ctl
->size
-= sizeof(struct btrfs_free_space_entry
);
493 if (io_ctl
->size
>= sizeof(struct btrfs_free_space_entry
))
496 io_ctl_set_crc(io_ctl
, io_ctl
->index
- 1);
498 /* No more pages to map */
499 if (io_ctl
->index
>= io_ctl
->num_pages
)
502 /* map the next page */
503 io_ctl_map_page(io_ctl
, 1);
507 static int io_ctl_add_bitmap(struct io_ctl
*io_ctl
, void *bitmap
)
513 * If we aren't at the start of the current page, unmap this one and
514 * map the next one if there is any left.
516 if (io_ctl
->cur
!= io_ctl
->orig
) {
517 io_ctl_set_crc(io_ctl
, io_ctl
->index
- 1);
518 if (io_ctl
->index
>= io_ctl
->num_pages
)
520 io_ctl_map_page(io_ctl
, 0);
523 memcpy(io_ctl
->cur
, bitmap
, PAGE_CACHE_SIZE
);
524 io_ctl_set_crc(io_ctl
, io_ctl
->index
- 1);
525 if (io_ctl
->index
< io_ctl
->num_pages
)
526 io_ctl_map_page(io_ctl
, 0);
530 static void io_ctl_zero_remaining_pages(struct io_ctl
*io_ctl
)
533 * If we're not on the boundary we know we've modified the page and we
534 * need to crc the page.
536 if (io_ctl
->cur
!= io_ctl
->orig
)
537 io_ctl_set_crc(io_ctl
, io_ctl
->index
- 1);
539 io_ctl_unmap_page(io_ctl
);
541 while (io_ctl
->index
< io_ctl
->num_pages
) {
542 io_ctl_map_page(io_ctl
, 1);
543 io_ctl_set_crc(io_ctl
, io_ctl
->index
- 1);
547 static int io_ctl_read_entry(struct io_ctl
*io_ctl
,
548 struct btrfs_free_space
*entry
, u8
*type
)
550 struct btrfs_free_space_entry
*e
;
554 ret
= io_ctl_check_crc(io_ctl
, io_ctl
->index
);
560 entry
->offset
= le64_to_cpu(e
->offset
);
561 entry
->bytes
= le64_to_cpu(e
->bytes
);
563 io_ctl
->cur
+= sizeof(struct btrfs_free_space_entry
);
564 io_ctl
->size
-= sizeof(struct btrfs_free_space_entry
);
566 if (io_ctl
->size
>= sizeof(struct btrfs_free_space_entry
))
569 io_ctl_unmap_page(io_ctl
);
574 static int io_ctl_read_bitmap(struct io_ctl
*io_ctl
,
575 struct btrfs_free_space
*entry
)
579 ret
= io_ctl_check_crc(io_ctl
, io_ctl
->index
);
583 memcpy(entry
->bitmap
, io_ctl
->cur
, PAGE_CACHE_SIZE
);
584 io_ctl_unmap_page(io_ctl
);
590 * Since we attach pinned extents after the fact we can have contiguous sections
591 * of free space that are split up in entries. This poses a problem with the
592 * tree logging stuff since it could have allocated across what appears to be 2
593 * entries since we would have merged the entries when adding the pinned extents
594 * back to the free space cache. So run through the space cache that we just
595 * loaded and merge contiguous entries. This will make the log replay stuff not
596 * blow up and it will make for nicer allocator behavior.
598 static void merge_space_tree(struct btrfs_free_space_ctl
*ctl
)
600 struct btrfs_free_space
*e
, *prev
= NULL
;
604 spin_lock(&ctl
->tree_lock
);
605 for (n
= rb_first(&ctl
->free_space_offset
); n
; n
= rb_next(n
)) {
606 e
= rb_entry(n
, struct btrfs_free_space
, offset_index
);
609 if (e
->bitmap
|| prev
->bitmap
)
611 if (prev
->offset
+ prev
->bytes
== e
->offset
) {
612 unlink_free_space(ctl
, prev
);
613 unlink_free_space(ctl
, e
);
614 prev
->bytes
+= e
->bytes
;
615 kmem_cache_free(btrfs_free_space_cachep
, e
);
616 link_free_space(ctl
, prev
);
618 spin_unlock(&ctl
->tree_lock
);
624 spin_unlock(&ctl
->tree_lock
);
627 int __load_free_space_cache(struct btrfs_root
*root
, struct inode
*inode
,
628 struct btrfs_free_space_ctl
*ctl
,
629 struct btrfs_path
*path
, u64 offset
)
631 struct btrfs_free_space_header
*header
;
632 struct extent_buffer
*leaf
;
633 struct io_ctl io_ctl
;
634 struct btrfs_key key
;
635 struct btrfs_free_space
*e
, *n
;
636 struct list_head bitmaps
;
643 INIT_LIST_HEAD(&bitmaps
);
645 /* Nothing in the space cache, goodbye */
646 if (!i_size_read(inode
))
649 key
.objectid
= BTRFS_FREE_SPACE_OBJECTID
;
653 ret
= btrfs_search_slot(NULL
, root
, &key
, path
, 0, 0);
657 btrfs_release_path(path
);
663 leaf
= path
->nodes
[0];
664 header
= btrfs_item_ptr(leaf
, path
->slots
[0],
665 struct btrfs_free_space_header
);
666 num_entries
= btrfs_free_space_entries(leaf
, header
);
667 num_bitmaps
= btrfs_free_space_bitmaps(leaf
, header
);
668 generation
= btrfs_free_space_generation(leaf
, header
);
669 btrfs_release_path(path
);
671 if (BTRFS_I(inode
)->generation
!= generation
) {
672 printk(KERN_ERR
"btrfs: free space inode generation (%llu) did"
673 " not match free space cache generation (%llu)\n",
674 (unsigned long long)BTRFS_I(inode
)->generation
,
675 (unsigned long long)generation
);
682 ret
= io_ctl_init(&io_ctl
, inode
, root
);
686 ret
= readahead_cache(inode
);
690 ret
= io_ctl_prepare_pages(&io_ctl
, inode
, 1);
694 ret
= io_ctl_check_crc(&io_ctl
, 0);
698 ret
= io_ctl_check_generation(&io_ctl
, generation
);
702 while (num_entries
) {
703 e
= kmem_cache_zalloc(btrfs_free_space_cachep
,
708 ret
= io_ctl_read_entry(&io_ctl
, e
, &type
);
710 kmem_cache_free(btrfs_free_space_cachep
, e
);
715 kmem_cache_free(btrfs_free_space_cachep
, e
);
719 if (type
== BTRFS_FREE_SPACE_EXTENT
) {
720 spin_lock(&ctl
->tree_lock
);
721 ret
= link_free_space(ctl
, e
);
722 spin_unlock(&ctl
->tree_lock
);
724 printk(KERN_ERR
"Duplicate entries in "
725 "free space cache, dumping\n");
726 kmem_cache_free(btrfs_free_space_cachep
, e
);
730 BUG_ON(!num_bitmaps
);
732 e
->bitmap
= kzalloc(PAGE_CACHE_SIZE
, GFP_NOFS
);
735 btrfs_free_space_cachep
, e
);
738 spin_lock(&ctl
->tree_lock
);
739 ret
= link_free_space(ctl
, e
);
740 ctl
->total_bitmaps
++;
741 ctl
->op
->recalc_thresholds(ctl
);
742 spin_unlock(&ctl
->tree_lock
);
744 printk(KERN_ERR
"Duplicate entries in "
745 "free space cache, dumping\n");
746 kmem_cache_free(btrfs_free_space_cachep
, e
);
749 list_add_tail(&e
->list
, &bitmaps
);
755 io_ctl_unmap_page(&io_ctl
);
758 * We add the bitmaps at the end of the entries in order that
759 * the bitmap entries are added to the cache.
761 list_for_each_entry_safe(e
, n
, &bitmaps
, list
) {
762 list_del_init(&e
->list
);
763 ret
= io_ctl_read_bitmap(&io_ctl
, e
);
768 io_ctl_drop_pages(&io_ctl
);
769 merge_space_tree(ctl
);
772 io_ctl_free(&io_ctl
);
775 io_ctl_drop_pages(&io_ctl
);
776 __btrfs_remove_free_space_cache(ctl
);
780 int load_free_space_cache(struct btrfs_fs_info
*fs_info
,
781 struct btrfs_block_group_cache
*block_group
)
783 struct btrfs_free_space_ctl
*ctl
= block_group
->free_space_ctl
;
784 struct btrfs_root
*root
= fs_info
->tree_root
;
786 struct btrfs_path
*path
;
789 u64 used
= btrfs_block_group_used(&block_group
->item
);
792 * If this block group has been marked to be cleared for one reason or
793 * another then we can't trust the on disk cache, so just return.
795 spin_lock(&block_group
->lock
);
796 if (block_group
->disk_cache_state
!= BTRFS_DC_WRITTEN
) {
797 spin_unlock(&block_group
->lock
);
800 spin_unlock(&block_group
->lock
);
802 path
= btrfs_alloc_path();
805 path
->search_commit_root
= 1;
806 path
->skip_locking
= 1;
808 inode
= lookup_free_space_inode(root
, block_group
, path
);
810 btrfs_free_path(path
);
814 /* We may have converted the inode and made the cache invalid. */
815 spin_lock(&block_group
->lock
);
816 if (block_group
->disk_cache_state
!= BTRFS_DC_WRITTEN
) {
817 spin_unlock(&block_group
->lock
);
818 btrfs_free_path(path
);
821 spin_unlock(&block_group
->lock
);
823 ret
= __load_free_space_cache(fs_info
->tree_root
, inode
, ctl
,
824 path
, block_group
->key
.objectid
);
825 btrfs_free_path(path
);
829 spin_lock(&ctl
->tree_lock
);
830 matched
= (ctl
->free_space
== (block_group
->key
.offset
- used
-
831 block_group
->bytes_super
));
832 spin_unlock(&ctl
->tree_lock
);
835 __btrfs_remove_free_space_cache(ctl
);
836 printk(KERN_ERR
"block group %llu has an wrong amount of free "
837 "space\n", block_group
->key
.objectid
);
842 /* This cache is bogus, make sure it gets cleared */
843 spin_lock(&block_group
->lock
);
844 block_group
->disk_cache_state
= BTRFS_DC_CLEAR
;
845 spin_unlock(&block_group
->lock
);
848 printk(KERN_ERR
"btrfs: failed to load free space cache "
849 "for block group %llu\n", block_group
->key
.objectid
);
857 * __btrfs_write_out_cache - write out cached info to an inode
858 * @root - the root the inode belongs to
859 * @ctl - the free space cache we are going to write out
860 * @block_group - the block_group for this cache if it belongs to a block_group
861 * @trans - the trans handle
862 * @path - the path to use
863 * @offset - the offset for the key we'll insert
865 * This function writes out a free space cache struct to disk for quick recovery
866 * on mount. This will return 0 if it was successfull in writing the cache out,
867 * and -1 if it was not.
869 int __btrfs_write_out_cache(struct btrfs_root
*root
, struct inode
*inode
,
870 struct btrfs_free_space_ctl
*ctl
,
871 struct btrfs_block_group_cache
*block_group
,
872 struct btrfs_trans_handle
*trans
,
873 struct btrfs_path
*path
, u64 offset
)
875 struct btrfs_free_space_header
*header
;
876 struct extent_buffer
*leaf
;
877 struct rb_node
*node
;
878 struct list_head
*pos
, *n
;
879 struct extent_state
*cached_state
= NULL
;
880 struct btrfs_free_cluster
*cluster
= NULL
;
881 struct extent_io_tree
*unpin
= NULL
;
882 struct io_ctl io_ctl
;
883 struct list_head bitmap_list
;
884 struct btrfs_key key
;
885 u64 start
, extent_start
, extent_end
, len
;
891 INIT_LIST_HEAD(&bitmap_list
);
893 if (!i_size_read(inode
))
896 ret
= io_ctl_init(&io_ctl
, inode
, root
);
900 /* Get the cluster for this block_group if it exists */
901 if (block_group
&& !list_empty(&block_group
->cluster_list
))
902 cluster
= list_entry(block_group
->cluster_list
.next
,
903 struct btrfs_free_cluster
,
906 /* Lock all pages first so we can lock the extent safely. */
907 io_ctl_prepare_pages(&io_ctl
, inode
, 0);
909 lock_extent_bits(&BTRFS_I(inode
)->io_tree
, 0, i_size_read(inode
) - 1,
912 node
= rb_first(&ctl
->free_space_offset
);
913 if (!node
&& cluster
) {
914 node
= rb_first(&cluster
->root
);
918 /* Make sure we can fit our crcs into the first page */
919 if (io_ctl
.check_crcs
&&
920 (io_ctl
.num_pages
* sizeof(u32
)) >= PAGE_CACHE_SIZE
) {
925 io_ctl_set_generation(&io_ctl
, trans
->transid
);
927 /* Write out the extent entries */
929 struct btrfs_free_space
*e
;
931 e
= rb_entry(node
, struct btrfs_free_space
, offset_index
);
934 ret
= io_ctl_add_entry(&io_ctl
, e
->offset
, e
->bytes
,
940 list_add_tail(&e
->list
, &bitmap_list
);
943 node
= rb_next(node
);
944 if (!node
&& cluster
) {
945 node
= rb_first(&cluster
->root
);
951 * We want to add any pinned extents to our free space cache
952 * so we don't leak the space
956 * We shouldn't have switched the pinned extents yet so this is the
959 unpin
= root
->fs_info
->pinned_extents
;
962 start
= block_group
->key
.objectid
;
964 while (block_group
&& (start
< block_group
->key
.objectid
+
965 block_group
->key
.offset
)) {
966 ret
= find_first_extent_bit(unpin
, start
,
967 &extent_start
, &extent_end
,
974 /* This pinned extent is out of our range */
975 if (extent_start
>= block_group
->key
.objectid
+
976 block_group
->key
.offset
)
979 extent_start
= max(extent_start
, start
);
980 extent_end
= min(block_group
->key
.objectid
+
981 block_group
->key
.offset
, extent_end
+ 1);
982 len
= extent_end
- extent_start
;
985 ret
= io_ctl_add_entry(&io_ctl
, extent_start
, len
, NULL
);
992 /* Write out the bitmaps */
993 list_for_each_safe(pos
, n
, &bitmap_list
) {
994 struct btrfs_free_space
*entry
=
995 list_entry(pos
, struct btrfs_free_space
, list
);
997 ret
= io_ctl_add_bitmap(&io_ctl
, entry
->bitmap
);
1000 list_del_init(&entry
->list
);
1003 /* Zero out the rest of the pages just to make sure */
1004 io_ctl_zero_remaining_pages(&io_ctl
);
1006 ret
= btrfs_dirty_pages(root
, inode
, io_ctl
.pages
, io_ctl
.num_pages
,
1007 0, i_size_read(inode
), &cached_state
);
1008 io_ctl_drop_pages(&io_ctl
);
1009 unlock_extent_cached(&BTRFS_I(inode
)->io_tree
, 0,
1010 i_size_read(inode
) - 1, &cached_state
, GFP_NOFS
);
1016 btrfs_wait_ordered_range(inode
, 0, (u64
)-1);
1018 key
.objectid
= BTRFS_FREE_SPACE_OBJECTID
;
1019 key
.offset
= offset
;
1022 ret
= btrfs_search_slot(trans
, root
, &key
, path
, 0, 1);
1024 clear_extent_bit(&BTRFS_I(inode
)->io_tree
, 0, inode
->i_size
- 1,
1025 EXTENT_DIRTY
| EXTENT_DELALLOC
, 0, 0, NULL
,
1029 leaf
= path
->nodes
[0];
1031 struct btrfs_key found_key
;
1032 BUG_ON(!path
->slots
[0]);
1034 btrfs_item_key_to_cpu(leaf
, &found_key
, path
->slots
[0]);
1035 if (found_key
.objectid
!= BTRFS_FREE_SPACE_OBJECTID
||
1036 found_key
.offset
!= offset
) {
1037 clear_extent_bit(&BTRFS_I(inode
)->io_tree
, 0,
1039 EXTENT_DIRTY
| EXTENT_DELALLOC
, 0, 0,
1041 btrfs_release_path(path
);
1046 BTRFS_I(inode
)->generation
= trans
->transid
;
1047 header
= btrfs_item_ptr(leaf
, path
->slots
[0],
1048 struct btrfs_free_space_header
);
1049 btrfs_set_free_space_entries(leaf
, header
, entries
);
1050 btrfs_set_free_space_bitmaps(leaf
, header
, bitmaps
);
1051 btrfs_set_free_space_generation(leaf
, header
, trans
->transid
);
1052 btrfs_mark_buffer_dirty(leaf
);
1053 btrfs_release_path(path
);
1057 io_ctl_free(&io_ctl
);
1059 invalidate_inode_pages2(inode
->i_mapping
);
1060 BTRFS_I(inode
)->generation
= 0;
1062 btrfs_update_inode(trans
, root
, inode
);
1066 list_for_each_safe(pos
, n
, &bitmap_list
) {
1067 struct btrfs_free_space
*entry
=
1068 list_entry(pos
, struct btrfs_free_space
, list
);
1069 list_del_init(&entry
->list
);
1071 io_ctl_drop_pages(&io_ctl
);
1072 unlock_extent_cached(&BTRFS_I(inode
)->io_tree
, 0,
1073 i_size_read(inode
) - 1, &cached_state
, GFP_NOFS
);
1077 int btrfs_write_out_cache(struct btrfs_root
*root
,
1078 struct btrfs_trans_handle
*trans
,
1079 struct btrfs_block_group_cache
*block_group
,
1080 struct btrfs_path
*path
)
1082 struct btrfs_free_space_ctl
*ctl
= block_group
->free_space_ctl
;
1083 struct inode
*inode
;
1086 root
= root
->fs_info
->tree_root
;
1088 spin_lock(&block_group
->lock
);
1089 if (block_group
->disk_cache_state
< BTRFS_DC_SETUP
) {
1090 spin_unlock(&block_group
->lock
);
1093 spin_unlock(&block_group
->lock
);
1095 inode
= lookup_free_space_inode(root
, block_group
, path
);
1099 ret
= __btrfs_write_out_cache(root
, inode
, ctl
, block_group
, trans
,
1100 path
, block_group
->key
.objectid
);
1102 spin_lock(&block_group
->lock
);
1103 block_group
->disk_cache_state
= BTRFS_DC_ERROR
;
1104 spin_unlock(&block_group
->lock
);
1107 printk(KERN_ERR
"btrfs: failed to write free space cache "
1108 "for block group %llu\n", block_group
->key
.objectid
);
1116 static inline unsigned long offset_to_bit(u64 bitmap_start
, u32 unit
,
1119 BUG_ON(offset
< bitmap_start
);
1120 offset
-= bitmap_start
;
1121 return (unsigned long)(div_u64(offset
, unit
));
1124 static inline unsigned long bytes_to_bits(u64 bytes
, u32 unit
)
1126 return (unsigned long)(div_u64(bytes
, unit
));
1129 static inline u64
offset_to_bitmap(struct btrfs_free_space_ctl
*ctl
,
1133 u64 bytes_per_bitmap
;
1135 bytes_per_bitmap
= BITS_PER_BITMAP
* ctl
->unit
;
1136 bitmap_start
= offset
- ctl
->start
;
1137 bitmap_start
= div64_u64(bitmap_start
, bytes_per_bitmap
);
1138 bitmap_start
*= bytes_per_bitmap
;
1139 bitmap_start
+= ctl
->start
;
1141 return bitmap_start
;
1144 static int tree_insert_offset(struct rb_root
*root
, u64 offset
,
1145 struct rb_node
*node
, int bitmap
)
1147 struct rb_node
**p
= &root
->rb_node
;
1148 struct rb_node
*parent
= NULL
;
1149 struct btrfs_free_space
*info
;
1153 info
= rb_entry(parent
, struct btrfs_free_space
, offset_index
);
1155 if (offset
< info
->offset
) {
1157 } else if (offset
> info
->offset
) {
1158 p
= &(*p
)->rb_right
;
1161 * we could have a bitmap entry and an extent entry
1162 * share the same offset. If this is the case, we want
1163 * the extent entry to always be found first if we do a
1164 * linear search through the tree, since we want to have
1165 * the quickest allocation time, and allocating from an
1166 * extent is faster than allocating from a bitmap. So
1167 * if we're inserting a bitmap and we find an entry at
1168 * this offset, we want to go right, or after this entry
1169 * logically. If we are inserting an extent and we've
1170 * found a bitmap, we want to go left, or before
1178 p
= &(*p
)->rb_right
;
1180 if (!info
->bitmap
) {
1189 rb_link_node(node
, parent
, p
);
1190 rb_insert_color(node
, root
);
1196 * searches the tree for the given offset.
1198 * fuzzy - If this is set, then we are trying to make an allocation, and we just
1199 * want a section that has at least bytes size and comes at or after the given
1202 static struct btrfs_free_space
*
1203 tree_search_offset(struct btrfs_free_space_ctl
*ctl
,
1204 u64 offset
, int bitmap_only
, int fuzzy
)
1206 struct rb_node
*n
= ctl
->free_space_offset
.rb_node
;
1207 struct btrfs_free_space
*entry
, *prev
= NULL
;
1209 /* find entry that is closest to the 'offset' */
1216 entry
= rb_entry(n
, struct btrfs_free_space
, offset_index
);
1219 if (offset
< entry
->offset
)
1221 else if (offset
> entry
->offset
)
1234 * bitmap entry and extent entry may share same offset,
1235 * in that case, bitmap entry comes after extent entry.
1240 entry
= rb_entry(n
, struct btrfs_free_space
, offset_index
);
1241 if (entry
->offset
!= offset
)
1244 WARN_ON(!entry
->bitmap
);
1247 if (entry
->bitmap
) {
1249 * if previous extent entry covers the offset,
1250 * we should return it instead of the bitmap entry
1252 n
= rb_prev(&entry
->offset_index
);
1254 prev
= rb_entry(n
, struct btrfs_free_space
,
1256 if (!prev
->bitmap
&&
1257 prev
->offset
+ prev
->bytes
> offset
)
1267 /* find last entry before the 'offset' */
1269 if (entry
->offset
> offset
) {
1270 n
= rb_prev(&entry
->offset_index
);
1272 entry
= rb_entry(n
, struct btrfs_free_space
,
1274 BUG_ON(entry
->offset
> offset
);
1283 if (entry
->bitmap
) {
1284 n
= rb_prev(&entry
->offset_index
);
1286 prev
= rb_entry(n
, struct btrfs_free_space
,
1288 if (!prev
->bitmap
&&
1289 prev
->offset
+ prev
->bytes
> offset
)
1292 if (entry
->offset
+ BITS_PER_BITMAP
* ctl
->unit
> offset
)
1294 } else if (entry
->offset
+ entry
->bytes
> offset
)
1301 if (entry
->bitmap
) {
1302 if (entry
->offset
+ BITS_PER_BITMAP
*
1306 if (entry
->offset
+ entry
->bytes
> offset
)
1310 n
= rb_next(&entry
->offset_index
);
1313 entry
= rb_entry(n
, struct btrfs_free_space
, offset_index
);
1319 __unlink_free_space(struct btrfs_free_space_ctl
*ctl
,
1320 struct btrfs_free_space
*info
)
1322 rb_erase(&info
->offset_index
, &ctl
->free_space_offset
);
1323 ctl
->free_extents
--;
1326 static void unlink_free_space(struct btrfs_free_space_ctl
*ctl
,
1327 struct btrfs_free_space
*info
)
1329 __unlink_free_space(ctl
, info
);
1330 ctl
->free_space
-= info
->bytes
;
1333 static int link_free_space(struct btrfs_free_space_ctl
*ctl
,
1334 struct btrfs_free_space
*info
)
1338 BUG_ON(!info
->bitmap
&& !info
->bytes
);
1339 ret
= tree_insert_offset(&ctl
->free_space_offset
, info
->offset
,
1340 &info
->offset_index
, (info
->bitmap
!= NULL
));
1344 ctl
->free_space
+= info
->bytes
;
1345 ctl
->free_extents
++;
1349 static void recalculate_thresholds(struct btrfs_free_space_ctl
*ctl
)
1351 struct btrfs_block_group_cache
*block_group
= ctl
->private;
1355 u64 size
= block_group
->key
.offset
;
1356 u64 bytes_per_bg
= BITS_PER_BITMAP
* ctl
->unit
;
1357 int max_bitmaps
= div64_u64(size
+ bytes_per_bg
- 1, bytes_per_bg
);
1359 BUG_ON(ctl
->total_bitmaps
> max_bitmaps
);
1362 * The goal is to keep the total amount of memory used per 1gb of space
1363 * at or below 32k, so we need to adjust how much memory we allow to be
1364 * used by extent based free space tracking
1366 if (size
< 1024 * 1024 * 1024)
1367 max_bytes
= MAX_CACHE_BYTES_PER_GIG
;
1369 max_bytes
= MAX_CACHE_BYTES_PER_GIG
*
1370 div64_u64(size
, 1024 * 1024 * 1024);
1373 * we want to account for 1 more bitmap than what we have so we can make
1374 * sure we don't go over our overall goal of MAX_CACHE_BYTES_PER_GIG as
1375 * we add more bitmaps.
1377 bitmap_bytes
= (ctl
->total_bitmaps
+ 1) * PAGE_CACHE_SIZE
;
1379 if (bitmap_bytes
>= max_bytes
) {
1380 ctl
->extents_thresh
= 0;
1385 * we want the extent entry threshold to always be at most 1/2 the maxw
1386 * bytes we can have, or whatever is less than that.
1388 extent_bytes
= max_bytes
- bitmap_bytes
;
1389 extent_bytes
= min_t(u64
, extent_bytes
, div64_u64(max_bytes
, 2));
1391 ctl
->extents_thresh
=
1392 div64_u64(extent_bytes
, (sizeof(struct btrfs_free_space
)));
1395 static inline void __bitmap_clear_bits(struct btrfs_free_space_ctl
*ctl
,
1396 struct btrfs_free_space
*info
,
1397 u64 offset
, u64 bytes
)
1399 unsigned long start
, count
;
1401 start
= offset_to_bit(info
->offset
, ctl
->unit
, offset
);
1402 count
= bytes_to_bits(bytes
, ctl
->unit
);
1403 BUG_ON(start
+ count
> BITS_PER_BITMAP
);
1405 bitmap_clear(info
->bitmap
, start
, count
);
1407 info
->bytes
-= bytes
;
1410 static void bitmap_clear_bits(struct btrfs_free_space_ctl
*ctl
,
1411 struct btrfs_free_space
*info
, u64 offset
,
1414 __bitmap_clear_bits(ctl
, info
, offset
, bytes
);
1415 ctl
->free_space
-= bytes
;
1418 static void bitmap_set_bits(struct btrfs_free_space_ctl
*ctl
,
1419 struct btrfs_free_space
*info
, u64 offset
,
1422 unsigned long start
, count
;
1424 start
= offset_to_bit(info
->offset
, ctl
->unit
, offset
);
1425 count
= bytes_to_bits(bytes
, ctl
->unit
);
1426 BUG_ON(start
+ count
> BITS_PER_BITMAP
);
1428 bitmap_set(info
->bitmap
, start
, count
);
1430 info
->bytes
+= bytes
;
1431 ctl
->free_space
+= bytes
;
1434 static int search_bitmap(struct btrfs_free_space_ctl
*ctl
,
1435 struct btrfs_free_space
*bitmap_info
, u64
*offset
,
1438 unsigned long found_bits
= 0;
1439 unsigned long bits
, i
;
1440 unsigned long next_zero
;
1442 i
= offset_to_bit(bitmap_info
->offset
, ctl
->unit
,
1443 max_t(u64
, *offset
, bitmap_info
->offset
));
1444 bits
= bytes_to_bits(*bytes
, ctl
->unit
);
1446 for_each_set_bit_from(i
, bitmap_info
->bitmap
, BITS_PER_BITMAP
) {
1447 next_zero
= find_next_zero_bit(bitmap_info
->bitmap
,
1448 BITS_PER_BITMAP
, i
);
1449 if ((next_zero
- i
) >= bits
) {
1450 found_bits
= next_zero
- i
;
1457 *offset
= (u64
)(i
* ctl
->unit
) + bitmap_info
->offset
;
1458 *bytes
= (u64
)(found_bits
) * ctl
->unit
;
1465 static struct btrfs_free_space
*
1466 find_free_space(struct btrfs_free_space_ctl
*ctl
, u64
*offset
, u64
*bytes
)
1468 struct btrfs_free_space
*entry
;
1469 struct rb_node
*node
;
1472 if (!ctl
->free_space_offset
.rb_node
)
1475 entry
= tree_search_offset(ctl
, offset_to_bitmap(ctl
, *offset
), 0, 1);
1479 for (node
= &entry
->offset_index
; node
; node
= rb_next(node
)) {
1480 entry
= rb_entry(node
, struct btrfs_free_space
, offset_index
);
1481 if (entry
->bytes
< *bytes
)
1484 if (entry
->bitmap
) {
1485 ret
= search_bitmap(ctl
, entry
, offset
, bytes
);
1491 *offset
= entry
->offset
;
1492 *bytes
= entry
->bytes
;
1499 static void add_new_bitmap(struct btrfs_free_space_ctl
*ctl
,
1500 struct btrfs_free_space
*info
, u64 offset
)
1502 info
->offset
= offset_to_bitmap(ctl
, offset
);
1504 INIT_LIST_HEAD(&info
->list
);
1505 link_free_space(ctl
, info
);
1506 ctl
->total_bitmaps
++;
1508 ctl
->op
->recalc_thresholds(ctl
);
1511 static void free_bitmap(struct btrfs_free_space_ctl
*ctl
,
1512 struct btrfs_free_space
*bitmap_info
)
1514 unlink_free_space(ctl
, bitmap_info
);
1515 kfree(bitmap_info
->bitmap
);
1516 kmem_cache_free(btrfs_free_space_cachep
, bitmap_info
);
1517 ctl
->total_bitmaps
--;
1518 ctl
->op
->recalc_thresholds(ctl
);
1521 static noinline
int remove_from_bitmap(struct btrfs_free_space_ctl
*ctl
,
1522 struct btrfs_free_space
*bitmap_info
,
1523 u64
*offset
, u64
*bytes
)
1526 u64 search_start
, search_bytes
;
1530 end
= bitmap_info
->offset
+ (u64
)(BITS_PER_BITMAP
* ctl
->unit
) - 1;
1533 * We need to search for bits in this bitmap. We could only cover some
1534 * of the extent in this bitmap thanks to how we add space, so we need
1535 * to search for as much as it as we can and clear that amount, and then
1536 * go searching for the next bit.
1538 search_start
= *offset
;
1539 search_bytes
= ctl
->unit
;
1540 search_bytes
= min(search_bytes
, end
- search_start
+ 1);
1541 ret
= search_bitmap(ctl
, bitmap_info
, &search_start
, &search_bytes
);
1542 BUG_ON(ret
< 0 || search_start
!= *offset
);
1544 /* We may have found more bits than what we need */
1545 search_bytes
= min(search_bytes
, *bytes
);
1547 /* Cannot clear past the end of the bitmap */
1548 search_bytes
= min(search_bytes
, end
- search_start
+ 1);
1550 bitmap_clear_bits(ctl
, bitmap_info
, search_start
, search_bytes
);
1551 *offset
+= search_bytes
;
1552 *bytes
-= search_bytes
;
1555 struct rb_node
*next
= rb_next(&bitmap_info
->offset_index
);
1556 if (!bitmap_info
->bytes
)
1557 free_bitmap(ctl
, bitmap_info
);
1560 * no entry after this bitmap, but we still have bytes to
1561 * remove, so something has gone wrong.
1566 bitmap_info
= rb_entry(next
, struct btrfs_free_space
,
1570 * if the next entry isn't a bitmap we need to return to let the
1571 * extent stuff do its work.
1573 if (!bitmap_info
->bitmap
)
1577 * Ok the next item is a bitmap, but it may not actually hold
1578 * the information for the rest of this free space stuff, so
1579 * look for it, and if we don't find it return so we can try
1580 * everything over again.
1582 search_start
= *offset
;
1583 search_bytes
= ctl
->unit
;
1584 ret
= search_bitmap(ctl
, bitmap_info
, &search_start
,
1586 if (ret
< 0 || search_start
!= *offset
)
1590 } else if (!bitmap_info
->bytes
)
1591 free_bitmap(ctl
, bitmap_info
);
1596 static u64
add_bytes_to_bitmap(struct btrfs_free_space_ctl
*ctl
,
1597 struct btrfs_free_space
*info
, u64 offset
,
1600 u64 bytes_to_set
= 0;
1603 end
= info
->offset
+ (u64
)(BITS_PER_BITMAP
* ctl
->unit
);
1605 bytes_to_set
= min(end
- offset
, bytes
);
1607 bitmap_set_bits(ctl
, info
, offset
, bytes_to_set
);
1609 return bytes_to_set
;
1613 static bool use_bitmap(struct btrfs_free_space_ctl
*ctl
,
1614 struct btrfs_free_space
*info
)
1616 struct btrfs_block_group_cache
*block_group
= ctl
->private;
1619 * If we are below the extents threshold then we can add this as an
1620 * extent, and don't have to deal with the bitmap
1622 if (ctl
->free_extents
< ctl
->extents_thresh
) {
1624 * If this block group has some small extents we don't want to
1625 * use up all of our free slots in the cache with them, we want
1626 * to reserve them to larger extents, however if we have plent
1627 * of cache left then go ahead an dadd them, no sense in adding
1628 * the overhead of a bitmap if we don't have to.
1630 if (info
->bytes
<= block_group
->sectorsize
* 4) {
1631 if (ctl
->free_extents
* 2 <= ctl
->extents_thresh
)
1639 * some block groups are so tiny they can't be enveloped by a bitmap, so
1640 * don't even bother to create a bitmap for this
1642 if (BITS_PER_BITMAP
* ctl
->unit
> block_group
->key
.offset
)
1648 static struct btrfs_free_space_op free_space_op
= {
1649 .recalc_thresholds
= recalculate_thresholds
,
1650 .use_bitmap
= use_bitmap
,
1653 static int insert_into_bitmap(struct btrfs_free_space_ctl
*ctl
,
1654 struct btrfs_free_space
*info
)
1656 struct btrfs_free_space
*bitmap_info
;
1657 struct btrfs_block_group_cache
*block_group
= NULL
;
1659 u64 bytes
, offset
, bytes_added
;
1662 bytes
= info
->bytes
;
1663 offset
= info
->offset
;
1665 if (!ctl
->op
->use_bitmap(ctl
, info
))
1668 if (ctl
->op
== &free_space_op
)
1669 block_group
= ctl
->private;
1672 * Since we link bitmaps right into the cluster we need to see if we
1673 * have a cluster here, and if so and it has our bitmap we need to add
1674 * the free space to that bitmap.
1676 if (block_group
&& !list_empty(&block_group
->cluster_list
)) {
1677 struct btrfs_free_cluster
*cluster
;
1678 struct rb_node
*node
;
1679 struct btrfs_free_space
*entry
;
1681 cluster
= list_entry(block_group
->cluster_list
.next
,
1682 struct btrfs_free_cluster
,
1684 spin_lock(&cluster
->lock
);
1685 node
= rb_first(&cluster
->root
);
1687 spin_unlock(&cluster
->lock
);
1688 goto no_cluster_bitmap
;
1691 entry
= rb_entry(node
, struct btrfs_free_space
, offset_index
);
1692 if (!entry
->bitmap
) {
1693 spin_unlock(&cluster
->lock
);
1694 goto no_cluster_bitmap
;
1697 if (entry
->offset
== offset_to_bitmap(ctl
, offset
)) {
1698 bytes_added
= add_bytes_to_bitmap(ctl
, entry
,
1700 bytes
-= bytes_added
;
1701 offset
+= bytes_added
;
1703 spin_unlock(&cluster
->lock
);
1711 bitmap_info
= tree_search_offset(ctl
, offset_to_bitmap(ctl
, offset
),
1718 bytes_added
= add_bytes_to_bitmap(ctl
, bitmap_info
, offset
, bytes
);
1719 bytes
-= bytes_added
;
1720 offset
+= bytes_added
;
1730 if (info
&& info
->bitmap
) {
1731 add_new_bitmap(ctl
, info
, offset
);
1736 spin_unlock(&ctl
->tree_lock
);
1738 /* no pre-allocated info, allocate a new one */
1740 info
= kmem_cache_zalloc(btrfs_free_space_cachep
,
1743 spin_lock(&ctl
->tree_lock
);
1749 /* allocate the bitmap */
1750 info
->bitmap
= kzalloc(PAGE_CACHE_SIZE
, GFP_NOFS
);
1751 spin_lock(&ctl
->tree_lock
);
1752 if (!info
->bitmap
) {
1762 kfree(info
->bitmap
);
1763 kmem_cache_free(btrfs_free_space_cachep
, info
);
1769 static bool try_merge_free_space(struct btrfs_free_space_ctl
*ctl
,
1770 struct btrfs_free_space
*info
, bool update_stat
)
1772 struct btrfs_free_space
*left_info
;
1773 struct btrfs_free_space
*right_info
;
1774 bool merged
= false;
1775 u64 offset
= info
->offset
;
1776 u64 bytes
= info
->bytes
;
1779 * first we want to see if there is free space adjacent to the range we
1780 * are adding, if there is remove that struct and add a new one to
1781 * cover the entire range
1783 right_info
= tree_search_offset(ctl
, offset
+ bytes
, 0, 0);
1784 if (right_info
&& rb_prev(&right_info
->offset_index
))
1785 left_info
= rb_entry(rb_prev(&right_info
->offset_index
),
1786 struct btrfs_free_space
, offset_index
);
1788 left_info
= tree_search_offset(ctl
, offset
- 1, 0, 0);
1790 if (right_info
&& !right_info
->bitmap
) {
1792 unlink_free_space(ctl
, right_info
);
1794 __unlink_free_space(ctl
, right_info
);
1795 info
->bytes
+= right_info
->bytes
;
1796 kmem_cache_free(btrfs_free_space_cachep
, right_info
);
1800 if (left_info
&& !left_info
->bitmap
&&
1801 left_info
->offset
+ left_info
->bytes
== offset
) {
1803 unlink_free_space(ctl
, left_info
);
1805 __unlink_free_space(ctl
, left_info
);
1806 info
->offset
= left_info
->offset
;
1807 info
->bytes
+= left_info
->bytes
;
1808 kmem_cache_free(btrfs_free_space_cachep
, left_info
);
1815 int __btrfs_add_free_space(struct btrfs_free_space_ctl
*ctl
,
1816 u64 offset
, u64 bytes
)
1818 struct btrfs_free_space
*info
;
1821 info
= kmem_cache_zalloc(btrfs_free_space_cachep
, GFP_NOFS
);
1825 info
->offset
= offset
;
1826 info
->bytes
= bytes
;
1828 spin_lock(&ctl
->tree_lock
);
1830 if (try_merge_free_space(ctl
, info
, true))
1834 * There was no extent directly to the left or right of this new
1835 * extent then we know we're going to have to allocate a new extent, so
1836 * before we do that see if we need to drop this into a bitmap
1838 ret
= insert_into_bitmap(ctl
, info
);
1846 ret
= link_free_space(ctl
, info
);
1848 kmem_cache_free(btrfs_free_space_cachep
, info
);
1850 spin_unlock(&ctl
->tree_lock
);
1853 printk(KERN_CRIT
"btrfs: unable to add free space :%d\n", ret
);
1854 BUG_ON(ret
== -EEXIST
);
1860 int btrfs_remove_free_space(struct btrfs_block_group_cache
*block_group
,
1861 u64 offset
, u64 bytes
)
1863 struct btrfs_free_space_ctl
*ctl
= block_group
->free_space_ctl
;
1864 struct btrfs_free_space
*info
;
1866 bool re_search
= false;
1868 spin_lock(&ctl
->tree_lock
);
1875 info
= tree_search_offset(ctl
, offset
, 0, 0);
1878 * oops didn't find an extent that matched the space we wanted
1879 * to remove, look for a bitmap instead
1881 info
= tree_search_offset(ctl
, offset_to_bitmap(ctl
, offset
),
1885 * If we found a partial bit of our free space in a
1886 * bitmap but then couldn't find the other part this may
1887 * be a problem, so WARN about it.
1895 if (!info
->bitmap
) {
1896 unlink_free_space(ctl
, info
);
1897 if (offset
== info
->offset
) {
1898 u64 to_free
= min(bytes
, info
->bytes
);
1900 info
->bytes
-= to_free
;
1901 info
->offset
+= to_free
;
1903 ret
= link_free_space(ctl
, info
);
1906 kmem_cache_free(btrfs_free_space_cachep
, info
);
1913 u64 old_end
= info
->bytes
+ info
->offset
;
1915 info
->bytes
= offset
- info
->offset
;
1916 ret
= link_free_space(ctl
, info
);
1921 /* Not enough bytes in this entry to satisfy us */
1922 if (old_end
< offset
+ bytes
) {
1923 bytes
-= old_end
- offset
;
1926 } else if (old_end
== offset
+ bytes
) {
1930 spin_unlock(&ctl
->tree_lock
);
1932 ret
= btrfs_add_free_space(block_group
, offset
+ bytes
,
1933 old_end
- (offset
+ bytes
));
1939 ret
= remove_from_bitmap(ctl
, info
, &offset
, &bytes
);
1940 if (ret
== -EAGAIN
) {
1944 BUG_ON(ret
); /* logic error */
1946 spin_unlock(&ctl
->tree_lock
);
1951 void btrfs_dump_free_space(struct btrfs_block_group_cache
*block_group
,
1954 struct btrfs_free_space_ctl
*ctl
= block_group
->free_space_ctl
;
1955 struct btrfs_free_space
*info
;
1959 for (n
= rb_first(&ctl
->free_space_offset
); n
; n
= rb_next(n
)) {
1960 info
= rb_entry(n
, struct btrfs_free_space
, offset_index
);
1961 if (info
->bytes
>= bytes
&& !block_group
->ro
)
1963 printk(KERN_CRIT
"entry offset %llu, bytes %llu, bitmap %s\n",
1964 (unsigned long long)info
->offset
,
1965 (unsigned long long)info
->bytes
,
1966 (info
->bitmap
) ? "yes" : "no");
1968 printk(KERN_INFO
"block group has cluster?: %s\n",
1969 list_empty(&block_group
->cluster_list
) ? "no" : "yes");
1970 printk(KERN_INFO
"%d blocks of free space at or bigger than bytes is"
1974 void btrfs_init_free_space_ctl(struct btrfs_block_group_cache
*block_group
)
1976 struct btrfs_free_space_ctl
*ctl
= block_group
->free_space_ctl
;
1978 spin_lock_init(&ctl
->tree_lock
);
1979 ctl
->unit
= block_group
->sectorsize
;
1980 ctl
->start
= block_group
->key
.objectid
;
1981 ctl
->private = block_group
;
1982 ctl
->op
= &free_space_op
;
1985 * we only want to have 32k of ram per block group for keeping
1986 * track of free space, and if we pass 1/2 of that we want to
1987 * start converting things over to using bitmaps
1989 ctl
->extents_thresh
= ((1024 * 32) / 2) /
1990 sizeof(struct btrfs_free_space
);
1994 * for a given cluster, put all of its extents back into the free
1995 * space cache. If the block group passed doesn't match the block group
1996 * pointed to by the cluster, someone else raced in and freed the
1997 * cluster already. In that case, we just return without changing anything
2000 __btrfs_return_cluster_to_free_space(
2001 struct btrfs_block_group_cache
*block_group
,
2002 struct btrfs_free_cluster
*cluster
)
2004 struct btrfs_free_space_ctl
*ctl
= block_group
->free_space_ctl
;
2005 struct btrfs_free_space
*entry
;
2006 struct rb_node
*node
;
2008 spin_lock(&cluster
->lock
);
2009 if (cluster
->block_group
!= block_group
)
2012 cluster
->block_group
= NULL
;
2013 cluster
->window_start
= 0;
2014 list_del_init(&cluster
->block_group_list
);
2016 node
= rb_first(&cluster
->root
);
2020 entry
= rb_entry(node
, struct btrfs_free_space
, offset_index
);
2021 node
= rb_next(&entry
->offset_index
);
2022 rb_erase(&entry
->offset_index
, &cluster
->root
);
2024 bitmap
= (entry
->bitmap
!= NULL
);
2026 try_merge_free_space(ctl
, entry
, false);
2027 tree_insert_offset(&ctl
->free_space_offset
,
2028 entry
->offset
, &entry
->offset_index
, bitmap
);
2030 cluster
->root
= RB_ROOT
;
2033 spin_unlock(&cluster
->lock
);
2034 btrfs_put_block_group(block_group
);
2038 void __btrfs_remove_free_space_cache_locked(struct btrfs_free_space_ctl
*ctl
)
2040 struct btrfs_free_space
*info
;
2041 struct rb_node
*node
;
2043 while ((node
= rb_last(&ctl
->free_space_offset
)) != NULL
) {
2044 info
= rb_entry(node
, struct btrfs_free_space
, offset_index
);
2045 if (!info
->bitmap
) {
2046 unlink_free_space(ctl
, info
);
2047 kmem_cache_free(btrfs_free_space_cachep
, info
);
2049 free_bitmap(ctl
, info
);
2051 if (need_resched()) {
2052 spin_unlock(&ctl
->tree_lock
);
2054 spin_lock(&ctl
->tree_lock
);
2059 void __btrfs_remove_free_space_cache(struct btrfs_free_space_ctl
*ctl
)
2061 spin_lock(&ctl
->tree_lock
);
2062 __btrfs_remove_free_space_cache_locked(ctl
);
2063 spin_unlock(&ctl
->tree_lock
);
2066 void btrfs_remove_free_space_cache(struct btrfs_block_group_cache
*block_group
)
2068 struct btrfs_free_space_ctl
*ctl
= block_group
->free_space_ctl
;
2069 struct btrfs_free_cluster
*cluster
;
2070 struct list_head
*head
;
2072 spin_lock(&ctl
->tree_lock
);
2073 while ((head
= block_group
->cluster_list
.next
) !=
2074 &block_group
->cluster_list
) {
2075 cluster
= list_entry(head
, struct btrfs_free_cluster
,
2078 WARN_ON(cluster
->block_group
!= block_group
);
2079 __btrfs_return_cluster_to_free_space(block_group
, cluster
);
2080 if (need_resched()) {
2081 spin_unlock(&ctl
->tree_lock
);
2083 spin_lock(&ctl
->tree_lock
);
2086 __btrfs_remove_free_space_cache_locked(ctl
);
2087 spin_unlock(&ctl
->tree_lock
);
2091 u64
btrfs_find_space_for_alloc(struct btrfs_block_group_cache
*block_group
,
2092 u64 offset
, u64 bytes
, u64 empty_size
)
2094 struct btrfs_free_space_ctl
*ctl
= block_group
->free_space_ctl
;
2095 struct btrfs_free_space
*entry
= NULL
;
2096 u64 bytes_search
= bytes
+ empty_size
;
2099 spin_lock(&ctl
->tree_lock
);
2100 entry
= find_free_space(ctl
, &offset
, &bytes_search
);
2105 if (entry
->bitmap
) {
2106 bitmap_clear_bits(ctl
, entry
, offset
, bytes
);
2108 free_bitmap(ctl
, entry
);
2110 unlink_free_space(ctl
, entry
);
2111 entry
->offset
+= bytes
;
2112 entry
->bytes
-= bytes
;
2114 kmem_cache_free(btrfs_free_space_cachep
, entry
);
2116 link_free_space(ctl
, entry
);
2120 spin_unlock(&ctl
->tree_lock
);
2126 * given a cluster, put all of its extents back into the free space
2127 * cache. If a block group is passed, this function will only free
2128 * a cluster that belongs to the passed block group.
2130 * Otherwise, it'll get a reference on the block group pointed to by the
2131 * cluster and remove the cluster from it.
2133 int btrfs_return_cluster_to_free_space(
2134 struct btrfs_block_group_cache
*block_group
,
2135 struct btrfs_free_cluster
*cluster
)
2137 struct btrfs_free_space_ctl
*ctl
;
2140 /* first, get a safe pointer to the block group */
2141 spin_lock(&cluster
->lock
);
2143 block_group
= cluster
->block_group
;
2145 spin_unlock(&cluster
->lock
);
2148 } else if (cluster
->block_group
!= block_group
) {
2149 /* someone else has already freed it don't redo their work */
2150 spin_unlock(&cluster
->lock
);
2153 atomic_inc(&block_group
->count
);
2154 spin_unlock(&cluster
->lock
);
2156 ctl
= block_group
->free_space_ctl
;
2158 /* now return any extents the cluster had on it */
2159 spin_lock(&ctl
->tree_lock
);
2160 ret
= __btrfs_return_cluster_to_free_space(block_group
, cluster
);
2161 spin_unlock(&ctl
->tree_lock
);
2163 /* finally drop our ref */
2164 btrfs_put_block_group(block_group
);
2168 static u64
btrfs_alloc_from_bitmap(struct btrfs_block_group_cache
*block_group
,
2169 struct btrfs_free_cluster
*cluster
,
2170 struct btrfs_free_space
*entry
,
2171 u64 bytes
, u64 min_start
)
2173 struct btrfs_free_space_ctl
*ctl
= block_group
->free_space_ctl
;
2175 u64 search_start
= cluster
->window_start
;
2176 u64 search_bytes
= bytes
;
2179 search_start
= min_start
;
2180 search_bytes
= bytes
;
2182 err
= search_bitmap(ctl
, entry
, &search_start
, &search_bytes
);
2187 __bitmap_clear_bits(ctl
, entry
, ret
, bytes
);
2193 * given a cluster, try to allocate 'bytes' from it, returns 0
2194 * if it couldn't find anything suitably large, or a logical disk offset
2195 * if things worked out
2197 u64
btrfs_alloc_from_cluster(struct btrfs_block_group_cache
*block_group
,
2198 struct btrfs_free_cluster
*cluster
, u64 bytes
,
2201 struct btrfs_free_space_ctl
*ctl
= block_group
->free_space_ctl
;
2202 struct btrfs_free_space
*entry
= NULL
;
2203 struct rb_node
*node
;
2206 spin_lock(&cluster
->lock
);
2207 if (bytes
> cluster
->max_size
)
2210 if (cluster
->block_group
!= block_group
)
2213 node
= rb_first(&cluster
->root
);
2217 entry
= rb_entry(node
, struct btrfs_free_space
, offset_index
);
2219 if (entry
->bytes
< bytes
||
2220 (!entry
->bitmap
&& entry
->offset
< min_start
)) {
2221 node
= rb_next(&entry
->offset_index
);
2224 entry
= rb_entry(node
, struct btrfs_free_space
,
2229 if (entry
->bitmap
) {
2230 ret
= btrfs_alloc_from_bitmap(block_group
,
2231 cluster
, entry
, bytes
,
2232 cluster
->window_start
);
2234 node
= rb_next(&entry
->offset_index
);
2237 entry
= rb_entry(node
, struct btrfs_free_space
,
2241 cluster
->window_start
+= bytes
;
2243 ret
= entry
->offset
;
2245 entry
->offset
+= bytes
;
2246 entry
->bytes
-= bytes
;
2249 if (entry
->bytes
== 0)
2250 rb_erase(&entry
->offset_index
, &cluster
->root
);
2254 spin_unlock(&cluster
->lock
);
2259 spin_lock(&ctl
->tree_lock
);
2261 ctl
->free_space
-= bytes
;
2262 if (entry
->bytes
== 0) {
2263 ctl
->free_extents
--;
2264 if (entry
->bitmap
) {
2265 kfree(entry
->bitmap
);
2266 ctl
->total_bitmaps
--;
2267 ctl
->op
->recalc_thresholds(ctl
);
2269 kmem_cache_free(btrfs_free_space_cachep
, entry
);
2272 spin_unlock(&ctl
->tree_lock
);
2277 static int btrfs_bitmap_cluster(struct btrfs_block_group_cache
*block_group
,
2278 struct btrfs_free_space
*entry
,
2279 struct btrfs_free_cluster
*cluster
,
2280 u64 offset
, u64 bytes
,
2281 u64 cont1_bytes
, u64 min_bytes
)
2283 struct btrfs_free_space_ctl
*ctl
= block_group
->free_space_ctl
;
2284 unsigned long next_zero
;
2286 unsigned long want_bits
;
2287 unsigned long min_bits
;
2288 unsigned long found_bits
;
2289 unsigned long start
= 0;
2290 unsigned long total_found
= 0;
2293 i
= offset_to_bit(entry
->offset
, ctl
->unit
,
2294 max_t(u64
, offset
, entry
->offset
));
2295 want_bits
= bytes_to_bits(bytes
, ctl
->unit
);
2296 min_bits
= bytes_to_bits(min_bytes
, ctl
->unit
);
2300 for_each_set_bit_from(i
, entry
->bitmap
, BITS_PER_BITMAP
) {
2301 next_zero
= find_next_zero_bit(entry
->bitmap
,
2302 BITS_PER_BITMAP
, i
);
2303 if (next_zero
- i
>= min_bits
) {
2304 found_bits
= next_zero
- i
;
2315 cluster
->max_size
= 0;
2318 total_found
+= found_bits
;
2320 if (cluster
->max_size
< found_bits
* ctl
->unit
)
2321 cluster
->max_size
= found_bits
* ctl
->unit
;
2323 if (total_found
< want_bits
|| cluster
->max_size
< cont1_bytes
) {
2328 cluster
->window_start
= start
* ctl
->unit
+ entry
->offset
;
2329 rb_erase(&entry
->offset_index
, &ctl
->free_space_offset
);
2330 ret
= tree_insert_offset(&cluster
->root
, entry
->offset
,
2331 &entry
->offset_index
, 1);
2332 BUG_ON(ret
); /* -EEXIST; Logic error */
2334 trace_btrfs_setup_cluster(block_group
, cluster
,
2335 total_found
* ctl
->unit
, 1);
2340 * This searches the block group for just extents to fill the cluster with.
2341 * Try to find a cluster with at least bytes total bytes, at least one
2342 * extent of cont1_bytes, and other clusters of at least min_bytes.
2345 setup_cluster_no_bitmap(struct btrfs_block_group_cache
*block_group
,
2346 struct btrfs_free_cluster
*cluster
,
2347 struct list_head
*bitmaps
, u64 offset
, u64 bytes
,
2348 u64 cont1_bytes
, u64 min_bytes
)
2350 struct btrfs_free_space_ctl
*ctl
= block_group
->free_space_ctl
;
2351 struct btrfs_free_space
*first
= NULL
;
2352 struct btrfs_free_space
*entry
= NULL
;
2353 struct btrfs_free_space
*last
;
2354 struct rb_node
*node
;
2360 entry
= tree_search_offset(ctl
, offset
, 0, 1);
2365 * We don't want bitmaps, so just move along until we find a normal
2368 while (entry
->bitmap
|| entry
->bytes
< min_bytes
) {
2369 if (entry
->bitmap
&& list_empty(&entry
->list
))
2370 list_add_tail(&entry
->list
, bitmaps
);
2371 node
= rb_next(&entry
->offset_index
);
2374 entry
= rb_entry(node
, struct btrfs_free_space
, offset_index
);
2377 window_start
= entry
->offset
;
2378 window_free
= entry
->bytes
;
2379 max_extent
= entry
->bytes
;
2383 for (node
= rb_next(&entry
->offset_index
); node
;
2384 node
= rb_next(&entry
->offset_index
)) {
2385 entry
= rb_entry(node
, struct btrfs_free_space
, offset_index
);
2387 if (entry
->bitmap
) {
2388 if (list_empty(&entry
->list
))
2389 list_add_tail(&entry
->list
, bitmaps
);
2393 if (entry
->bytes
< min_bytes
)
2397 window_free
+= entry
->bytes
;
2398 if (entry
->bytes
> max_extent
)
2399 max_extent
= entry
->bytes
;
2402 if (window_free
< bytes
|| max_extent
< cont1_bytes
)
2405 cluster
->window_start
= first
->offset
;
2407 node
= &first
->offset_index
;
2410 * now we've found our entries, pull them out of the free space
2411 * cache and put them into the cluster rbtree
2416 entry
= rb_entry(node
, struct btrfs_free_space
, offset_index
);
2417 node
= rb_next(&entry
->offset_index
);
2418 if (entry
->bitmap
|| entry
->bytes
< min_bytes
)
2421 rb_erase(&entry
->offset_index
, &ctl
->free_space_offset
);
2422 ret
= tree_insert_offset(&cluster
->root
, entry
->offset
,
2423 &entry
->offset_index
, 0);
2424 total_size
+= entry
->bytes
;
2425 BUG_ON(ret
); /* -EEXIST; Logic error */
2426 } while (node
&& entry
!= last
);
2428 cluster
->max_size
= max_extent
;
2429 trace_btrfs_setup_cluster(block_group
, cluster
, total_size
, 0);
2434 * This specifically looks for bitmaps that may work in the cluster, we assume
2435 * that we have already failed to find extents that will work.
2438 setup_cluster_bitmap(struct btrfs_block_group_cache
*block_group
,
2439 struct btrfs_free_cluster
*cluster
,
2440 struct list_head
*bitmaps
, u64 offset
, u64 bytes
,
2441 u64 cont1_bytes
, u64 min_bytes
)
2443 struct btrfs_free_space_ctl
*ctl
= block_group
->free_space_ctl
;
2444 struct btrfs_free_space
*entry
;
2446 u64 bitmap_offset
= offset_to_bitmap(ctl
, offset
);
2448 if (ctl
->total_bitmaps
== 0)
2452 * The bitmap that covers offset won't be in the list unless offset
2453 * is just its start offset.
2455 entry
= list_first_entry(bitmaps
, struct btrfs_free_space
, list
);
2456 if (entry
->offset
!= bitmap_offset
) {
2457 entry
= tree_search_offset(ctl
, bitmap_offset
, 1, 0);
2458 if (entry
&& list_empty(&entry
->list
))
2459 list_add(&entry
->list
, bitmaps
);
2462 list_for_each_entry(entry
, bitmaps
, list
) {
2463 if (entry
->bytes
< bytes
)
2465 ret
= btrfs_bitmap_cluster(block_group
, entry
, cluster
, offset
,
2466 bytes
, cont1_bytes
, min_bytes
);
2472 * The bitmaps list has all the bitmaps that record free space
2473 * starting after offset, so no more search is required.
2479 * here we try to find a cluster of blocks in a block group. The goal
2480 * is to find at least bytes+empty_size.
2481 * We might not find them all in one contiguous area.
2483 * returns zero and sets up cluster if things worked out, otherwise
2484 * it returns -enospc
2486 int btrfs_find_space_cluster(struct btrfs_trans_handle
*trans
,
2487 struct btrfs_root
*root
,
2488 struct btrfs_block_group_cache
*block_group
,
2489 struct btrfs_free_cluster
*cluster
,
2490 u64 offset
, u64 bytes
, u64 empty_size
)
2492 struct btrfs_free_space_ctl
*ctl
= block_group
->free_space_ctl
;
2493 struct btrfs_free_space
*entry
, *tmp
;
2500 * Choose the minimum extent size we'll require for this
2501 * cluster. For SSD_SPREAD, don't allow any fragmentation.
2502 * For metadata, allow allocates with smaller extents. For
2503 * data, keep it dense.
2505 if (btrfs_test_opt(root
, SSD_SPREAD
)) {
2506 cont1_bytes
= min_bytes
= bytes
+ empty_size
;
2507 } else if (block_group
->flags
& BTRFS_BLOCK_GROUP_METADATA
) {
2508 cont1_bytes
= bytes
;
2509 min_bytes
= block_group
->sectorsize
;
2511 cont1_bytes
= max(bytes
, (bytes
+ empty_size
) >> 2);
2512 min_bytes
= block_group
->sectorsize
;
2515 spin_lock(&ctl
->tree_lock
);
2518 * If we know we don't have enough space to make a cluster don't even
2519 * bother doing all the work to try and find one.
2521 if (ctl
->free_space
< bytes
) {
2522 spin_unlock(&ctl
->tree_lock
);
2526 spin_lock(&cluster
->lock
);
2528 /* someone already found a cluster, hooray */
2529 if (cluster
->block_group
) {
2534 trace_btrfs_find_cluster(block_group
, offset
, bytes
, empty_size
,
2537 INIT_LIST_HEAD(&bitmaps
);
2538 ret
= setup_cluster_no_bitmap(block_group
, cluster
, &bitmaps
, offset
,
2540 cont1_bytes
, min_bytes
);
2542 ret
= setup_cluster_bitmap(block_group
, cluster
, &bitmaps
,
2543 offset
, bytes
+ empty_size
,
2544 cont1_bytes
, min_bytes
);
2546 /* Clear our temporary list */
2547 list_for_each_entry_safe(entry
, tmp
, &bitmaps
, list
)
2548 list_del_init(&entry
->list
);
2551 atomic_inc(&block_group
->count
);
2552 list_add_tail(&cluster
->block_group_list
,
2553 &block_group
->cluster_list
);
2554 cluster
->block_group
= block_group
;
2556 trace_btrfs_failed_cluster_setup(block_group
);
2559 spin_unlock(&cluster
->lock
);
2560 spin_unlock(&ctl
->tree_lock
);
2566 * simple code to zero out a cluster
2568 void btrfs_init_free_cluster(struct btrfs_free_cluster
*cluster
)
2570 spin_lock_init(&cluster
->lock
);
2571 spin_lock_init(&cluster
->refill_lock
);
2572 cluster
->root
= RB_ROOT
;
2573 cluster
->max_size
= 0;
2574 INIT_LIST_HEAD(&cluster
->block_group_list
);
2575 cluster
->block_group
= NULL
;
2578 static int do_trimming(struct btrfs_block_group_cache
*block_group
,
2579 u64
*total_trimmed
, u64 start
, u64 bytes
,
2580 u64 reserved_start
, u64 reserved_bytes
)
2582 struct btrfs_space_info
*space_info
= block_group
->space_info
;
2583 struct btrfs_fs_info
*fs_info
= block_group
->fs_info
;
2588 spin_lock(&space_info
->lock
);
2589 spin_lock(&block_group
->lock
);
2590 if (!block_group
->ro
) {
2591 block_group
->reserved
+= reserved_bytes
;
2592 space_info
->bytes_reserved
+= reserved_bytes
;
2595 spin_unlock(&block_group
->lock
);
2596 spin_unlock(&space_info
->lock
);
2598 ret
= btrfs_error_discard_extent(fs_info
->extent_root
,
2599 start
, bytes
, &trimmed
);
2601 *total_trimmed
+= trimmed
;
2603 btrfs_add_free_space(block_group
, reserved_start
, reserved_bytes
);
2606 spin_lock(&space_info
->lock
);
2607 spin_lock(&block_group
->lock
);
2608 if (block_group
->ro
)
2609 space_info
->bytes_readonly
+= reserved_bytes
;
2610 block_group
->reserved
-= reserved_bytes
;
2611 space_info
->bytes_reserved
-= reserved_bytes
;
2612 spin_unlock(&space_info
->lock
);
2613 spin_unlock(&block_group
->lock
);
2619 static int trim_no_bitmap(struct btrfs_block_group_cache
*block_group
,
2620 u64
*total_trimmed
, u64 start
, u64 end
, u64 minlen
)
2622 struct btrfs_free_space_ctl
*ctl
= block_group
->free_space_ctl
;
2623 struct btrfs_free_space
*entry
;
2624 struct rb_node
*node
;
2630 while (start
< end
) {
2631 spin_lock(&ctl
->tree_lock
);
2633 if (ctl
->free_space
< minlen
) {
2634 spin_unlock(&ctl
->tree_lock
);
2638 entry
= tree_search_offset(ctl
, start
, 0, 1);
2640 spin_unlock(&ctl
->tree_lock
);
2645 while (entry
->bitmap
) {
2646 node
= rb_next(&entry
->offset_index
);
2648 spin_unlock(&ctl
->tree_lock
);
2651 entry
= rb_entry(node
, struct btrfs_free_space
,
2655 if (entry
->offset
>= end
) {
2656 spin_unlock(&ctl
->tree_lock
);
2660 extent_start
= entry
->offset
;
2661 extent_bytes
= entry
->bytes
;
2662 start
= max(start
, extent_start
);
2663 bytes
= min(extent_start
+ extent_bytes
, end
) - start
;
2664 if (bytes
< minlen
) {
2665 spin_unlock(&ctl
->tree_lock
);
2669 unlink_free_space(ctl
, entry
);
2670 kmem_cache_free(btrfs_free_space_cachep
, entry
);
2672 spin_unlock(&ctl
->tree_lock
);
2674 ret
= do_trimming(block_group
, total_trimmed
, start
, bytes
,
2675 extent_start
, extent_bytes
);
2681 if (fatal_signal_pending(current
)) {
2692 static int trim_bitmaps(struct btrfs_block_group_cache
*block_group
,
2693 u64
*total_trimmed
, u64 start
, u64 end
, u64 minlen
)
2695 struct btrfs_free_space_ctl
*ctl
= block_group
->free_space_ctl
;
2696 struct btrfs_free_space
*entry
;
2700 u64 offset
= offset_to_bitmap(ctl
, start
);
2702 while (offset
< end
) {
2703 bool next_bitmap
= false;
2705 spin_lock(&ctl
->tree_lock
);
2707 if (ctl
->free_space
< minlen
) {
2708 spin_unlock(&ctl
->tree_lock
);
2712 entry
= tree_search_offset(ctl
, offset
, 1, 0);
2714 spin_unlock(&ctl
->tree_lock
);
2720 ret2
= search_bitmap(ctl
, entry
, &start
, &bytes
);
2721 if (ret2
|| start
>= end
) {
2722 spin_unlock(&ctl
->tree_lock
);
2727 bytes
= min(bytes
, end
- start
);
2728 if (bytes
< minlen
) {
2729 spin_unlock(&ctl
->tree_lock
);
2733 bitmap_clear_bits(ctl
, entry
, start
, bytes
);
2734 if (entry
->bytes
== 0)
2735 free_bitmap(ctl
, entry
);
2737 spin_unlock(&ctl
->tree_lock
);
2739 ret
= do_trimming(block_group
, total_trimmed
, start
, bytes
,
2745 offset
+= BITS_PER_BITMAP
* ctl
->unit
;
2748 if (start
>= offset
+ BITS_PER_BITMAP
* ctl
->unit
)
2749 offset
+= BITS_PER_BITMAP
* ctl
->unit
;
2752 if (fatal_signal_pending(current
)) {
2763 int btrfs_trim_block_group(struct btrfs_block_group_cache
*block_group
,
2764 u64
*trimmed
, u64 start
, u64 end
, u64 minlen
)
2770 ret
= trim_no_bitmap(block_group
, trimmed
, start
, end
, minlen
);
2774 ret
= trim_bitmaps(block_group
, trimmed
, start
, end
, minlen
);
2780 * Find the left-most item in the cache tree, and then return the
2781 * smallest inode number in the item.
2783 * Note: the returned inode number may not be the smallest one in
2784 * the tree, if the left-most item is a bitmap.
2786 u64
btrfs_find_ino_for_alloc(struct btrfs_root
*fs_root
)
2788 struct btrfs_free_space_ctl
*ctl
= fs_root
->free_ino_ctl
;
2789 struct btrfs_free_space
*entry
= NULL
;
2792 spin_lock(&ctl
->tree_lock
);
2794 if (RB_EMPTY_ROOT(&ctl
->free_space_offset
))
2797 entry
= rb_entry(rb_first(&ctl
->free_space_offset
),
2798 struct btrfs_free_space
, offset_index
);
2800 if (!entry
->bitmap
) {
2801 ino
= entry
->offset
;
2803 unlink_free_space(ctl
, entry
);
2807 kmem_cache_free(btrfs_free_space_cachep
, entry
);
2809 link_free_space(ctl
, entry
);
2815 ret
= search_bitmap(ctl
, entry
, &offset
, &count
);
2816 /* Logic error; Should be empty if it can't find anything */
2820 bitmap_clear_bits(ctl
, entry
, offset
, 1);
2821 if (entry
->bytes
== 0)
2822 free_bitmap(ctl
, entry
);
2825 spin_unlock(&ctl
->tree_lock
);
2830 struct inode
*lookup_free_ino_inode(struct btrfs_root
*root
,
2831 struct btrfs_path
*path
)
2833 struct inode
*inode
= NULL
;
2835 spin_lock(&root
->cache_lock
);
2836 if (root
->cache_inode
)
2837 inode
= igrab(root
->cache_inode
);
2838 spin_unlock(&root
->cache_lock
);
2842 inode
= __lookup_free_space_inode(root
, path
, 0);
2846 spin_lock(&root
->cache_lock
);
2847 if (!btrfs_fs_closing(root
->fs_info
))
2848 root
->cache_inode
= igrab(inode
);
2849 spin_unlock(&root
->cache_lock
);
2854 int create_free_ino_inode(struct btrfs_root
*root
,
2855 struct btrfs_trans_handle
*trans
,
2856 struct btrfs_path
*path
)
2858 return __create_free_space_inode(root
, trans
, path
,
2859 BTRFS_FREE_INO_OBJECTID
, 0);
2862 int load_free_ino_cache(struct btrfs_fs_info
*fs_info
, struct btrfs_root
*root
)
2864 struct btrfs_free_space_ctl
*ctl
= root
->free_ino_ctl
;
2865 struct btrfs_path
*path
;
2866 struct inode
*inode
;
2868 u64 root_gen
= btrfs_root_generation(&root
->root_item
);
2870 if (!btrfs_test_opt(root
, INODE_MAP_CACHE
))
2874 * If we're unmounting then just return, since this does a search on the
2875 * normal root and not the commit root and we could deadlock.
2877 if (btrfs_fs_closing(fs_info
))
2880 path
= btrfs_alloc_path();
2884 inode
= lookup_free_ino_inode(root
, path
);
2888 if (root_gen
!= BTRFS_I(inode
)->generation
)
2891 ret
= __load_free_space_cache(root
, inode
, ctl
, path
, 0);
2894 printk(KERN_ERR
"btrfs: failed to load free ino cache for "
2895 "root %llu\n", root
->root_key
.objectid
);
2899 btrfs_free_path(path
);
2903 int btrfs_write_out_ino_cache(struct btrfs_root
*root
,
2904 struct btrfs_trans_handle
*trans
,
2905 struct btrfs_path
*path
)
2907 struct btrfs_free_space_ctl
*ctl
= root
->free_ino_ctl
;
2908 struct inode
*inode
;
2911 if (!btrfs_test_opt(root
, INODE_MAP_CACHE
))
2914 inode
= lookup_free_ino_inode(root
, path
);
2918 ret
= __btrfs_write_out_cache(root
, inode
, ctl
, NULL
, trans
, path
, 0);
2920 btrfs_delalloc_release_metadata(inode
, inode
->i_size
);
2922 printk(KERN_ERR
"btrfs: failed to write free ino cache "
2923 "for root %llu\n", root
->root_key
.objectid
);