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 btrfs_info(root->fs_info,
108 "Old style space inode found, converting.");
109 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM |
110 BTRFS_INODE_NODATACOW;
111 block_group->disk_cache_state = BTRFS_DC_CLEAR;
114 if (!block_group->iref) {
115 block_group->inode = igrab(inode);
116 block_group->iref = 1;
118 spin_unlock(&block_group->lock);
123 static int __create_free_space_inode(struct btrfs_root *root,
124 struct btrfs_trans_handle *trans,
125 struct btrfs_path *path,
128 struct btrfs_key key;
129 struct btrfs_disk_key disk_key;
130 struct btrfs_free_space_header *header;
131 struct btrfs_inode_item *inode_item;
132 struct extent_buffer *leaf;
133 u64 flags = BTRFS_INODE_NOCOMPRESS | BTRFS_INODE_PREALLOC;
136 ret = btrfs_insert_empty_inode(trans, root, path, ino);
140 /* We inline crc's for the free disk space cache */
141 if (ino != BTRFS_FREE_INO_OBJECTID)
142 flags |= BTRFS_INODE_NODATASUM | BTRFS_INODE_NODATACOW;
144 leaf = path->nodes[0];
145 inode_item = btrfs_item_ptr(leaf, path->slots[0],
146 struct btrfs_inode_item);
147 btrfs_item_key(leaf, &disk_key, path->slots[0]);
148 memset_extent_buffer(leaf, 0, (unsigned long)inode_item,
149 sizeof(*inode_item));
150 btrfs_set_inode_generation(leaf, inode_item, trans->transid);
151 btrfs_set_inode_size(leaf, inode_item, 0);
152 btrfs_set_inode_nbytes(leaf, inode_item, 0);
153 btrfs_set_inode_uid(leaf, inode_item, 0);
154 btrfs_set_inode_gid(leaf, inode_item, 0);
155 btrfs_set_inode_mode(leaf, inode_item, S_IFREG | 0600);
156 btrfs_set_inode_flags(leaf, inode_item, flags);
157 btrfs_set_inode_nlink(leaf, inode_item, 1);
158 btrfs_set_inode_transid(leaf, inode_item, trans->transid);
159 btrfs_set_inode_block_group(leaf, inode_item, offset);
160 btrfs_mark_buffer_dirty(leaf);
161 btrfs_release_path(path);
163 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
167 ret = btrfs_insert_empty_item(trans, root, path, &key,
168 sizeof(struct btrfs_free_space_header));
170 btrfs_release_path(path);
173 leaf = path->nodes[0];
174 header = btrfs_item_ptr(leaf, path->slots[0],
175 struct btrfs_free_space_header);
176 memset_extent_buffer(leaf, 0, (unsigned long)header, sizeof(*header));
177 btrfs_set_free_space_key(leaf, header, &disk_key);
178 btrfs_mark_buffer_dirty(leaf);
179 btrfs_release_path(path);
184 int create_free_space_inode(struct btrfs_root *root,
185 struct btrfs_trans_handle *trans,
186 struct btrfs_block_group_cache *block_group,
187 struct btrfs_path *path)
192 ret = btrfs_find_free_objectid(root, &ino);
196 return __create_free_space_inode(root, trans, path, ino,
197 block_group->key.objectid);
200 int btrfs_check_trunc_cache_free_space(struct btrfs_root *root,
201 struct btrfs_block_rsv *rsv)
206 /* 1 for slack space, 1 for updating the inode */
207 needed_bytes = btrfs_calc_trunc_metadata_size(root, 1) +
208 btrfs_calc_trans_metadata_size(root, 1);
210 spin_lock(&rsv->lock);
211 if (rsv->reserved < needed_bytes)
215 spin_unlock(&rsv->lock);
219 int btrfs_truncate_free_space_cache(struct btrfs_root *root,
220 struct btrfs_trans_handle *trans,
225 btrfs_i_size_write(inode, 0);
226 truncate_pagecache(inode, 0);
229 * We don't need an orphan item because truncating the free space cache
230 * will never be split across transactions.
232 ret = btrfs_truncate_inode_items(trans, root, inode,
233 0, BTRFS_EXTENT_DATA_KEY);
235 btrfs_abort_transaction(trans, root, ret);
239 ret = btrfs_update_inode(trans, root, inode);
241 btrfs_abort_transaction(trans, root, ret);
246 static int readahead_cache(struct inode *inode)
248 struct file_ra_state *ra;
249 unsigned long last_index;
251 ra = kzalloc(sizeof(*ra), GFP_NOFS);
255 file_ra_state_init(ra, inode->i_mapping);
256 last_index = (i_size_read(inode) - 1) >> PAGE_CACHE_SHIFT;
258 page_cache_sync_readahead(inode->i_mapping, ra, NULL, 0, last_index);
269 struct btrfs_root *root;
273 unsigned check_crcs:1;
276 static int io_ctl_init(struct io_ctl *io_ctl, struct inode *inode,
277 struct btrfs_root *root, int write)
282 num_pages = DIV_ROUND_UP(i_size_read(inode), PAGE_CACHE_SIZE);
284 if (btrfs_ino(inode) != BTRFS_FREE_INO_OBJECTID)
287 /* Make sure we can fit our crcs into the first page */
288 if (write && check_crcs &&
289 (num_pages * sizeof(u32)) >= PAGE_CACHE_SIZE)
292 memset(io_ctl, 0, sizeof(struct io_ctl));
294 io_ctl->pages = kzalloc(sizeof(struct page *) * num_pages, GFP_NOFS);
298 io_ctl->num_pages = num_pages;
300 io_ctl->check_crcs = check_crcs;
305 static void io_ctl_free(struct io_ctl *io_ctl)
307 kfree(io_ctl->pages);
310 static void io_ctl_unmap_page(struct io_ctl *io_ctl)
313 kunmap(io_ctl->page);
319 static void io_ctl_map_page(struct io_ctl *io_ctl, int clear)
321 ASSERT(io_ctl->index < io_ctl->num_pages);
322 io_ctl->page = io_ctl->pages[io_ctl->index++];
323 io_ctl->cur = kmap(io_ctl->page);
324 io_ctl->orig = io_ctl->cur;
325 io_ctl->size = PAGE_CACHE_SIZE;
327 memset(io_ctl->cur, 0, PAGE_CACHE_SIZE);
330 static void io_ctl_drop_pages(struct io_ctl *io_ctl)
334 io_ctl_unmap_page(io_ctl);
336 for (i = 0; i < io_ctl->num_pages; i++) {
337 if (io_ctl->pages[i]) {
338 ClearPageChecked(io_ctl->pages[i]);
339 unlock_page(io_ctl->pages[i]);
340 page_cache_release(io_ctl->pages[i]);
345 static int io_ctl_prepare_pages(struct io_ctl *io_ctl, struct inode *inode,
349 gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
352 for (i = 0; i < io_ctl->num_pages; i++) {
353 page = find_or_create_page(inode->i_mapping, i, mask);
355 io_ctl_drop_pages(io_ctl);
358 io_ctl->pages[i] = page;
359 if (uptodate && !PageUptodate(page)) {
360 btrfs_readpage(NULL, page);
362 if (!PageUptodate(page)) {
363 btrfs_err(BTRFS_I(inode)->root->fs_info,
364 "error reading free space cache");
365 io_ctl_drop_pages(io_ctl);
371 for (i = 0; i < io_ctl->num_pages; i++) {
372 clear_page_dirty_for_io(io_ctl->pages[i]);
373 set_page_extent_mapped(io_ctl->pages[i]);
379 static void io_ctl_set_generation(struct io_ctl *io_ctl, u64 generation)
383 io_ctl_map_page(io_ctl, 1);
386 * Skip the csum areas. If we don't check crcs then we just have a
387 * 64bit chunk at the front of the first page.
389 if (io_ctl->check_crcs) {
390 io_ctl->cur += (sizeof(u32) * io_ctl->num_pages);
391 io_ctl->size -= sizeof(u64) + (sizeof(u32) * io_ctl->num_pages);
393 io_ctl->cur += sizeof(u64);
394 io_ctl->size -= sizeof(u64) * 2;
398 *val = cpu_to_le64(generation);
399 io_ctl->cur += sizeof(u64);
402 static int io_ctl_check_generation(struct io_ctl *io_ctl, u64 generation)
407 * Skip the crc area. If we don't check crcs then we just have a 64bit
408 * chunk at the front of the first page.
410 if (io_ctl->check_crcs) {
411 io_ctl->cur += sizeof(u32) * io_ctl->num_pages;
412 io_ctl->size -= sizeof(u64) +
413 (sizeof(u32) * io_ctl->num_pages);
415 io_ctl->cur += sizeof(u64);
416 io_ctl->size -= sizeof(u64) * 2;
420 if (le64_to_cpu(*gen) != generation) {
421 printk_ratelimited(KERN_ERR "BTRFS: space cache generation "
422 "(%Lu) does not match inode (%Lu)\n", *gen,
424 io_ctl_unmap_page(io_ctl);
427 io_ctl->cur += sizeof(u64);
431 static void io_ctl_set_crc(struct io_ctl *io_ctl, int index)
437 if (!io_ctl->check_crcs) {
438 io_ctl_unmap_page(io_ctl);
443 offset = sizeof(u32) * io_ctl->num_pages;
445 crc = btrfs_csum_data(io_ctl->orig + offset, crc,
446 PAGE_CACHE_SIZE - offset);
447 btrfs_csum_final(crc, (char *)&crc);
448 io_ctl_unmap_page(io_ctl);
449 tmp = kmap(io_ctl->pages[0]);
452 kunmap(io_ctl->pages[0]);
455 static int io_ctl_check_crc(struct io_ctl *io_ctl, int index)
461 if (!io_ctl->check_crcs) {
462 io_ctl_map_page(io_ctl, 0);
467 offset = sizeof(u32) * io_ctl->num_pages;
469 tmp = kmap(io_ctl->pages[0]);
472 kunmap(io_ctl->pages[0]);
474 io_ctl_map_page(io_ctl, 0);
475 crc = btrfs_csum_data(io_ctl->orig + offset, crc,
476 PAGE_CACHE_SIZE - offset);
477 btrfs_csum_final(crc, (char *)&crc);
479 printk_ratelimited(KERN_ERR "BTRFS: csum mismatch on free "
481 io_ctl_unmap_page(io_ctl);
488 static int io_ctl_add_entry(struct io_ctl *io_ctl, u64 offset, u64 bytes,
491 struct btrfs_free_space_entry *entry;
497 entry->offset = cpu_to_le64(offset);
498 entry->bytes = cpu_to_le64(bytes);
499 entry->type = (bitmap) ? BTRFS_FREE_SPACE_BITMAP :
500 BTRFS_FREE_SPACE_EXTENT;
501 io_ctl->cur += sizeof(struct btrfs_free_space_entry);
502 io_ctl->size -= sizeof(struct btrfs_free_space_entry);
504 if (io_ctl->size >= sizeof(struct btrfs_free_space_entry))
507 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
509 /* No more pages to map */
510 if (io_ctl->index >= io_ctl->num_pages)
513 /* map the next page */
514 io_ctl_map_page(io_ctl, 1);
518 static int io_ctl_add_bitmap(struct io_ctl *io_ctl, void *bitmap)
524 * If we aren't at the start of the current page, unmap this one and
525 * map the next one if there is any left.
527 if (io_ctl->cur != io_ctl->orig) {
528 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
529 if (io_ctl->index >= io_ctl->num_pages)
531 io_ctl_map_page(io_ctl, 0);
534 memcpy(io_ctl->cur, bitmap, PAGE_CACHE_SIZE);
535 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
536 if (io_ctl->index < io_ctl->num_pages)
537 io_ctl_map_page(io_ctl, 0);
541 static void io_ctl_zero_remaining_pages(struct io_ctl *io_ctl)
544 * If we're not on the boundary we know we've modified the page and we
545 * need to crc the page.
547 if (io_ctl->cur != io_ctl->orig)
548 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
550 io_ctl_unmap_page(io_ctl);
552 while (io_ctl->index < io_ctl->num_pages) {
553 io_ctl_map_page(io_ctl, 1);
554 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
558 static int io_ctl_read_entry(struct io_ctl *io_ctl,
559 struct btrfs_free_space *entry, u8 *type)
561 struct btrfs_free_space_entry *e;
565 ret = io_ctl_check_crc(io_ctl, io_ctl->index);
571 entry->offset = le64_to_cpu(e->offset);
572 entry->bytes = le64_to_cpu(e->bytes);
574 io_ctl->cur += sizeof(struct btrfs_free_space_entry);
575 io_ctl->size -= sizeof(struct btrfs_free_space_entry);
577 if (io_ctl->size >= sizeof(struct btrfs_free_space_entry))
580 io_ctl_unmap_page(io_ctl);
585 static int io_ctl_read_bitmap(struct io_ctl *io_ctl,
586 struct btrfs_free_space *entry)
590 ret = io_ctl_check_crc(io_ctl, io_ctl->index);
594 memcpy(entry->bitmap, io_ctl->cur, PAGE_CACHE_SIZE);
595 io_ctl_unmap_page(io_ctl);
601 * Since we attach pinned extents after the fact we can have contiguous sections
602 * of free space that are split up in entries. This poses a problem with the
603 * tree logging stuff since it could have allocated across what appears to be 2
604 * entries since we would have merged the entries when adding the pinned extents
605 * back to the free space cache. So run through the space cache that we just
606 * loaded and merge contiguous entries. This will make the log replay stuff not
607 * blow up and it will make for nicer allocator behavior.
609 static void merge_space_tree(struct btrfs_free_space_ctl *ctl)
611 struct btrfs_free_space *e, *prev = NULL;
615 spin_lock(&ctl->tree_lock);
616 for (n = rb_first(&ctl->free_space_offset); n; n = rb_next(n)) {
617 e = rb_entry(n, struct btrfs_free_space, offset_index);
620 if (e->bitmap || prev->bitmap)
622 if (prev->offset + prev->bytes == e->offset) {
623 unlink_free_space(ctl, prev);
624 unlink_free_space(ctl, e);
625 prev->bytes += e->bytes;
626 kmem_cache_free(btrfs_free_space_cachep, e);
627 link_free_space(ctl, prev);
629 spin_unlock(&ctl->tree_lock);
635 spin_unlock(&ctl->tree_lock);
638 static int __load_free_space_cache(struct btrfs_root *root, struct inode *inode,
639 struct btrfs_free_space_ctl *ctl,
640 struct btrfs_path *path, u64 offset)
642 struct btrfs_free_space_header *header;
643 struct extent_buffer *leaf;
644 struct io_ctl io_ctl;
645 struct btrfs_key key;
646 struct btrfs_free_space *e, *n;
647 struct list_head bitmaps;
654 INIT_LIST_HEAD(&bitmaps);
656 /* Nothing in the space cache, goodbye */
657 if (!i_size_read(inode))
660 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
664 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
668 btrfs_release_path(path);
674 leaf = path->nodes[0];
675 header = btrfs_item_ptr(leaf, path->slots[0],
676 struct btrfs_free_space_header);
677 num_entries = btrfs_free_space_entries(leaf, header);
678 num_bitmaps = btrfs_free_space_bitmaps(leaf, header);
679 generation = btrfs_free_space_generation(leaf, header);
680 btrfs_release_path(path);
682 if (!BTRFS_I(inode)->generation) {
683 btrfs_info(root->fs_info,
684 "The free space cache file (%llu) is invalid. skip it\n",
689 if (BTRFS_I(inode)->generation != generation) {
690 btrfs_err(root->fs_info,
691 "free space inode generation (%llu) "
692 "did not match free space cache generation (%llu)",
693 BTRFS_I(inode)->generation, generation);
700 ret = io_ctl_init(&io_ctl, inode, root, 0);
704 ret = readahead_cache(inode);
708 ret = io_ctl_prepare_pages(&io_ctl, inode, 1);
712 ret = io_ctl_check_crc(&io_ctl, 0);
716 ret = io_ctl_check_generation(&io_ctl, generation);
720 while (num_entries) {
721 e = kmem_cache_zalloc(btrfs_free_space_cachep,
726 ret = io_ctl_read_entry(&io_ctl, e, &type);
728 kmem_cache_free(btrfs_free_space_cachep, e);
733 kmem_cache_free(btrfs_free_space_cachep, e);
737 if (type == BTRFS_FREE_SPACE_EXTENT) {
738 spin_lock(&ctl->tree_lock);
739 ret = link_free_space(ctl, e);
740 spin_unlock(&ctl->tree_lock);
742 btrfs_err(root->fs_info,
743 "Duplicate entries in free space cache, dumping");
744 kmem_cache_free(btrfs_free_space_cachep, e);
750 e->bitmap = kzalloc(PAGE_CACHE_SIZE, GFP_NOFS);
753 btrfs_free_space_cachep, e);
756 spin_lock(&ctl->tree_lock);
757 ret = link_free_space(ctl, e);
758 ctl->total_bitmaps++;
759 ctl->op->recalc_thresholds(ctl);
760 spin_unlock(&ctl->tree_lock);
762 btrfs_err(root->fs_info,
763 "Duplicate entries in free space cache, dumping");
764 kmem_cache_free(btrfs_free_space_cachep, e);
767 list_add_tail(&e->list, &bitmaps);
773 io_ctl_unmap_page(&io_ctl);
776 * We add the bitmaps at the end of the entries in order that
777 * the bitmap entries are added to the cache.
779 list_for_each_entry_safe(e, n, &bitmaps, list) {
780 list_del_init(&e->list);
781 ret = io_ctl_read_bitmap(&io_ctl, e);
786 io_ctl_drop_pages(&io_ctl);
787 merge_space_tree(ctl);
790 io_ctl_free(&io_ctl);
793 io_ctl_drop_pages(&io_ctl);
794 __btrfs_remove_free_space_cache(ctl);
798 int load_free_space_cache(struct btrfs_fs_info *fs_info,
799 struct btrfs_block_group_cache *block_group)
801 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
802 struct btrfs_root *root = fs_info->tree_root;
804 struct btrfs_path *path;
807 u64 used = btrfs_block_group_used(&block_group->item);
810 * If this block group has been marked to be cleared for one reason or
811 * another then we can't trust the on disk cache, so just return.
813 spin_lock(&block_group->lock);
814 if (block_group->disk_cache_state != BTRFS_DC_WRITTEN) {
815 spin_unlock(&block_group->lock);
818 spin_unlock(&block_group->lock);
820 path = btrfs_alloc_path();
823 path->search_commit_root = 1;
824 path->skip_locking = 1;
826 inode = lookup_free_space_inode(root, block_group, path);
828 btrfs_free_path(path);
832 /* We may have converted the inode and made the cache invalid. */
833 spin_lock(&block_group->lock);
834 if (block_group->disk_cache_state != BTRFS_DC_WRITTEN) {
835 spin_unlock(&block_group->lock);
836 btrfs_free_path(path);
839 spin_unlock(&block_group->lock);
841 ret = __load_free_space_cache(fs_info->tree_root, inode, ctl,
842 path, block_group->key.objectid);
843 btrfs_free_path(path);
847 spin_lock(&ctl->tree_lock);
848 matched = (ctl->free_space == (block_group->key.offset - used -
849 block_group->bytes_super));
850 spin_unlock(&ctl->tree_lock);
853 __btrfs_remove_free_space_cache(ctl);
854 btrfs_warn(fs_info, "block group %llu has wrong amount of free space",
855 block_group->key.objectid);
860 /* This cache is bogus, make sure it gets cleared */
861 spin_lock(&block_group->lock);
862 block_group->disk_cache_state = BTRFS_DC_CLEAR;
863 spin_unlock(&block_group->lock);
866 btrfs_warn(fs_info, "failed to load free space cache for block group %llu, rebuild it now",
867 block_group->key.objectid);
874 static noinline_for_stack
875 int write_cache_extent_entries(struct io_ctl *io_ctl,
876 struct btrfs_free_space_ctl *ctl,
877 struct btrfs_block_group_cache *block_group,
878 int *entries, int *bitmaps,
879 struct list_head *bitmap_list)
882 struct btrfs_free_cluster *cluster = NULL;
883 struct rb_node *node = rb_first(&ctl->free_space_offset);
885 /* Get the cluster for this block_group if it exists */
886 if (block_group && !list_empty(&block_group->cluster_list)) {
887 cluster = list_entry(block_group->cluster_list.next,
888 struct btrfs_free_cluster,
892 if (!node && cluster) {
893 node = rb_first(&cluster->root);
897 /* Write out the extent entries */
899 struct btrfs_free_space *e;
901 e = rb_entry(node, struct btrfs_free_space, offset_index);
904 ret = io_ctl_add_entry(io_ctl, e->offset, e->bytes,
910 list_add_tail(&e->list, bitmap_list);
913 node = rb_next(node);
914 if (!node && cluster) {
915 node = rb_first(&cluster->root);
924 static noinline_for_stack int
925 update_cache_item(struct btrfs_trans_handle *trans,
926 struct btrfs_root *root,
928 struct btrfs_path *path, u64 offset,
929 int entries, int bitmaps)
931 struct btrfs_key key;
932 struct btrfs_free_space_header *header;
933 struct extent_buffer *leaf;
936 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
940 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
942 clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, inode->i_size - 1,
943 EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0, NULL,
947 leaf = path->nodes[0];
949 struct btrfs_key found_key;
950 ASSERT(path->slots[0]);
952 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
953 if (found_key.objectid != BTRFS_FREE_SPACE_OBJECTID ||
954 found_key.offset != offset) {
955 clear_extent_bit(&BTRFS_I(inode)->io_tree, 0,
957 EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0,
959 btrfs_release_path(path);
964 BTRFS_I(inode)->generation = trans->transid;
965 header = btrfs_item_ptr(leaf, path->slots[0],
966 struct btrfs_free_space_header);
967 btrfs_set_free_space_entries(leaf, header, entries);
968 btrfs_set_free_space_bitmaps(leaf, header, bitmaps);
969 btrfs_set_free_space_generation(leaf, header, trans->transid);
970 btrfs_mark_buffer_dirty(leaf);
971 btrfs_release_path(path);
979 static noinline_for_stack int
980 write_pinned_extent_entries(struct btrfs_root *root,
981 struct btrfs_block_group_cache *block_group,
982 struct io_ctl *io_ctl,
985 u64 start, extent_start, extent_end, len;
986 struct extent_io_tree *unpin = NULL;
993 * We want to add any pinned extents to our free space cache
994 * so we don't leak the space
996 * We shouldn't have switched the pinned extents yet so this is the
999 unpin = root->fs_info->pinned_extents;
1001 start = block_group->key.objectid;
1003 while (start < block_group->key.objectid + block_group->key.offset) {
1004 ret = find_first_extent_bit(unpin, start,
1005 &extent_start, &extent_end,
1006 EXTENT_DIRTY, NULL);
1010 /* This pinned extent is out of our range */
1011 if (extent_start >= block_group->key.objectid +
1012 block_group->key.offset)
1015 extent_start = max(extent_start, start);
1016 extent_end = min(block_group->key.objectid +
1017 block_group->key.offset, extent_end + 1);
1018 len = extent_end - extent_start;
1021 ret = io_ctl_add_entry(io_ctl, extent_start, len, NULL);
1031 static noinline_for_stack int
1032 write_bitmap_entries(struct io_ctl *io_ctl, struct list_head *bitmap_list)
1034 struct list_head *pos, *n;
1037 /* Write out the bitmaps */
1038 list_for_each_safe(pos, n, bitmap_list) {
1039 struct btrfs_free_space *entry =
1040 list_entry(pos, struct btrfs_free_space, list);
1042 ret = io_ctl_add_bitmap(io_ctl, entry->bitmap);
1045 list_del_init(&entry->list);
1051 static int flush_dirty_cache(struct inode *inode)
1055 ret = btrfs_wait_ordered_range(inode, 0, (u64)-1);
1057 clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, inode->i_size - 1,
1058 EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0, NULL,
1064 static void noinline_for_stack
1065 cleanup_write_cache_enospc(struct inode *inode,
1066 struct io_ctl *io_ctl,
1067 struct extent_state **cached_state,
1068 struct list_head *bitmap_list)
1070 struct list_head *pos, *n;
1072 list_for_each_safe(pos, n, bitmap_list) {
1073 struct btrfs_free_space *entry =
1074 list_entry(pos, struct btrfs_free_space, list);
1075 list_del_init(&entry->list);
1077 io_ctl_drop_pages(io_ctl);
1078 unlock_extent_cached(&BTRFS_I(inode)->io_tree, 0,
1079 i_size_read(inode) - 1, cached_state,
1084 * __btrfs_write_out_cache - write out cached info to an inode
1085 * @root - the root the inode belongs to
1086 * @ctl - the free space cache we are going to write out
1087 * @block_group - the block_group for this cache if it belongs to a block_group
1088 * @trans - the trans handle
1089 * @path - the path to use
1090 * @offset - the offset for the key we'll insert
1092 * This function writes out a free space cache struct to disk for quick recovery
1093 * on mount. This will return 0 if it was successfull in writing the cache out,
1094 * and -1 if it was not.
1096 static int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode,
1097 struct btrfs_free_space_ctl *ctl,
1098 struct btrfs_block_group_cache *block_group,
1099 struct btrfs_trans_handle *trans,
1100 struct btrfs_path *path, u64 offset)
1102 struct extent_state *cached_state = NULL;
1103 struct io_ctl io_ctl;
1104 LIST_HEAD(bitmap_list);
1109 if (!i_size_read(inode))
1112 ret = io_ctl_init(&io_ctl, inode, root, 1);
1116 if (block_group && (block_group->flags & BTRFS_BLOCK_GROUP_DATA)) {
1117 down_write(&block_group->data_rwsem);
1118 spin_lock(&block_group->lock);
1119 if (block_group->delalloc_bytes) {
1120 block_group->disk_cache_state = BTRFS_DC_WRITTEN;
1121 spin_unlock(&block_group->lock);
1122 up_write(&block_group->data_rwsem);
1123 BTRFS_I(inode)->generation = 0;
1127 spin_unlock(&block_group->lock);
1130 /* Lock all pages first so we can lock the extent safely. */
1131 io_ctl_prepare_pages(&io_ctl, inode, 0);
1133 lock_extent_bits(&BTRFS_I(inode)->io_tree, 0, i_size_read(inode) - 1,
1136 io_ctl_set_generation(&io_ctl, trans->transid);
1138 /* Write out the extent entries in the free space cache */
1139 ret = write_cache_extent_entries(&io_ctl, ctl,
1140 block_group, &entries, &bitmaps,
1146 * Some spaces that are freed in the current transaction are pinned,
1147 * they will be added into free space cache after the transaction is
1148 * committed, we shouldn't lose them.
1150 ret = write_pinned_extent_entries(root, block_group, &io_ctl, &entries);
1154 /* At last, we write out all the bitmaps. */
1155 ret = write_bitmap_entries(&io_ctl, &bitmap_list);
1159 /* Zero out the rest of the pages just to make sure */
1160 io_ctl_zero_remaining_pages(&io_ctl);
1162 /* Everything is written out, now we dirty the pages in the file. */
1163 ret = btrfs_dirty_pages(root, inode, io_ctl.pages, io_ctl.num_pages,
1164 0, i_size_read(inode), &cached_state);
1168 if (block_group && (block_group->flags & BTRFS_BLOCK_GROUP_DATA))
1169 up_write(&block_group->data_rwsem);
1171 * Release the pages and unlock the extent, we will flush
1174 io_ctl_drop_pages(&io_ctl);
1176 unlock_extent_cached(&BTRFS_I(inode)->io_tree, 0,
1177 i_size_read(inode) - 1, &cached_state, GFP_NOFS);
1179 /* Flush the dirty pages in the cache file. */
1180 ret = flush_dirty_cache(inode);
1184 /* Update the cache item to tell everyone this cache file is valid. */
1185 ret = update_cache_item(trans, root, inode, path, offset,
1188 io_ctl_free(&io_ctl);
1190 invalidate_inode_pages2(inode->i_mapping);
1191 BTRFS_I(inode)->generation = 0;
1193 btrfs_update_inode(trans, root, inode);
1197 cleanup_write_cache_enospc(inode, &io_ctl, &cached_state, &bitmap_list);
1199 if (block_group && (block_group->flags & BTRFS_BLOCK_GROUP_DATA))
1200 up_write(&block_group->data_rwsem);
1205 int btrfs_write_out_cache(struct btrfs_root *root,
1206 struct btrfs_trans_handle *trans,
1207 struct btrfs_block_group_cache *block_group,
1208 struct btrfs_path *path)
1210 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
1211 struct inode *inode;
1214 root = root->fs_info->tree_root;
1216 spin_lock(&block_group->lock);
1217 if (block_group->disk_cache_state < BTRFS_DC_SETUP) {
1218 spin_unlock(&block_group->lock);
1222 if (block_group->delalloc_bytes) {
1223 block_group->disk_cache_state = BTRFS_DC_WRITTEN;
1224 spin_unlock(&block_group->lock);
1227 spin_unlock(&block_group->lock);
1229 inode = lookup_free_space_inode(root, block_group, path);
1233 ret = __btrfs_write_out_cache(root, inode, ctl, block_group, trans,
1234 path, block_group->key.objectid);
1236 spin_lock(&block_group->lock);
1237 block_group->disk_cache_state = BTRFS_DC_ERROR;
1238 spin_unlock(&block_group->lock);
1241 btrfs_err(root->fs_info,
1242 "failed to write free space cache for block group %llu",
1243 block_group->key.objectid);
1251 static inline unsigned long offset_to_bit(u64 bitmap_start, u32 unit,
1254 ASSERT(offset >= bitmap_start);
1255 offset -= bitmap_start;
1256 return (unsigned long)(div_u64(offset, unit));
1259 static inline unsigned long bytes_to_bits(u64 bytes, u32 unit)
1261 return (unsigned long)(div_u64(bytes, unit));
1264 static inline u64 offset_to_bitmap(struct btrfs_free_space_ctl *ctl,
1268 u64 bytes_per_bitmap;
1270 bytes_per_bitmap = BITS_PER_BITMAP * ctl->unit;
1271 bitmap_start = offset - ctl->start;
1272 bitmap_start = div64_u64(bitmap_start, bytes_per_bitmap);
1273 bitmap_start *= bytes_per_bitmap;
1274 bitmap_start += ctl->start;
1276 return bitmap_start;
1279 static int tree_insert_offset(struct rb_root *root, u64 offset,
1280 struct rb_node *node, int bitmap)
1282 struct rb_node **p = &root->rb_node;
1283 struct rb_node *parent = NULL;
1284 struct btrfs_free_space *info;
1288 info = rb_entry(parent, struct btrfs_free_space, offset_index);
1290 if (offset < info->offset) {
1292 } else if (offset > info->offset) {
1293 p = &(*p)->rb_right;
1296 * we could have a bitmap entry and an extent entry
1297 * share the same offset. If this is the case, we want
1298 * the extent entry to always be found first if we do a
1299 * linear search through the tree, since we want to have
1300 * the quickest allocation time, and allocating from an
1301 * extent is faster than allocating from a bitmap. So
1302 * if we're inserting a bitmap and we find an entry at
1303 * this offset, we want to go right, or after this entry
1304 * logically. If we are inserting an extent and we've
1305 * found a bitmap, we want to go left, or before
1313 p = &(*p)->rb_right;
1315 if (!info->bitmap) {
1324 rb_link_node(node, parent, p);
1325 rb_insert_color(node, root);
1331 * searches the tree for the given offset.
1333 * fuzzy - If this is set, then we are trying to make an allocation, and we just
1334 * want a section that has at least bytes size and comes at or after the given
1337 static struct btrfs_free_space *
1338 tree_search_offset(struct btrfs_free_space_ctl *ctl,
1339 u64 offset, int bitmap_only, int fuzzy)
1341 struct rb_node *n = ctl->free_space_offset.rb_node;
1342 struct btrfs_free_space *entry, *prev = NULL;
1344 /* find entry that is closest to the 'offset' */
1351 entry = rb_entry(n, struct btrfs_free_space, offset_index);
1354 if (offset < entry->offset)
1356 else if (offset > entry->offset)
1369 * bitmap entry and extent entry may share same offset,
1370 * in that case, bitmap entry comes after extent entry.
1375 entry = rb_entry(n, struct btrfs_free_space, offset_index);
1376 if (entry->offset != offset)
1379 WARN_ON(!entry->bitmap);
1382 if (entry->bitmap) {
1384 * if previous extent entry covers the offset,
1385 * we should return it instead of the bitmap entry
1387 n = rb_prev(&entry->offset_index);
1389 prev = rb_entry(n, struct btrfs_free_space,
1391 if (!prev->bitmap &&
1392 prev->offset + prev->bytes > offset)
1402 /* find last entry before the 'offset' */
1404 if (entry->offset > offset) {
1405 n = rb_prev(&entry->offset_index);
1407 entry = rb_entry(n, struct btrfs_free_space,
1409 ASSERT(entry->offset <= offset);
1418 if (entry->bitmap) {
1419 n = rb_prev(&entry->offset_index);
1421 prev = rb_entry(n, struct btrfs_free_space,
1423 if (!prev->bitmap &&
1424 prev->offset + prev->bytes > offset)
1427 if (entry->offset + BITS_PER_BITMAP * ctl->unit > offset)
1429 } else if (entry->offset + entry->bytes > offset)
1436 if (entry->bitmap) {
1437 if (entry->offset + BITS_PER_BITMAP *
1441 if (entry->offset + entry->bytes > offset)
1445 n = rb_next(&entry->offset_index);
1448 entry = rb_entry(n, struct btrfs_free_space, offset_index);
1454 __unlink_free_space(struct btrfs_free_space_ctl *ctl,
1455 struct btrfs_free_space *info)
1457 rb_erase(&info->offset_index, &ctl->free_space_offset);
1458 ctl->free_extents--;
1461 static void unlink_free_space(struct btrfs_free_space_ctl *ctl,
1462 struct btrfs_free_space *info)
1464 __unlink_free_space(ctl, info);
1465 ctl->free_space -= info->bytes;
1468 static int link_free_space(struct btrfs_free_space_ctl *ctl,
1469 struct btrfs_free_space *info)
1473 ASSERT(info->bytes || info->bitmap);
1474 ret = tree_insert_offset(&ctl->free_space_offset, info->offset,
1475 &info->offset_index, (info->bitmap != NULL));
1479 ctl->free_space += info->bytes;
1480 ctl->free_extents++;
1484 static void recalculate_thresholds(struct btrfs_free_space_ctl *ctl)
1486 struct btrfs_block_group_cache *block_group = ctl->private;
1490 u64 size = block_group->key.offset;
1491 u64 bytes_per_bg = BITS_PER_BITMAP * ctl->unit;
1492 int max_bitmaps = div64_u64(size + bytes_per_bg - 1, bytes_per_bg);
1494 max_bitmaps = max(max_bitmaps, 1);
1496 ASSERT(ctl->total_bitmaps <= max_bitmaps);
1499 * The goal is to keep the total amount of memory used per 1gb of space
1500 * at or below 32k, so we need to adjust how much memory we allow to be
1501 * used by extent based free space tracking
1503 if (size < 1024 * 1024 * 1024)
1504 max_bytes = MAX_CACHE_BYTES_PER_GIG;
1506 max_bytes = MAX_CACHE_BYTES_PER_GIG *
1507 div64_u64(size, 1024 * 1024 * 1024);
1510 * we want to account for 1 more bitmap than what we have so we can make
1511 * sure we don't go over our overall goal of MAX_CACHE_BYTES_PER_GIG as
1512 * we add more bitmaps.
1514 bitmap_bytes = (ctl->total_bitmaps + 1) * PAGE_CACHE_SIZE;
1516 if (bitmap_bytes >= max_bytes) {
1517 ctl->extents_thresh = 0;
1522 * we want the extent entry threshold to always be at most 1/2 the maxw
1523 * bytes we can have, or whatever is less than that.
1525 extent_bytes = max_bytes - bitmap_bytes;
1526 extent_bytes = min_t(u64, extent_bytes, div64_u64(max_bytes, 2));
1528 ctl->extents_thresh =
1529 div64_u64(extent_bytes, (sizeof(struct btrfs_free_space)));
1532 static inline void __bitmap_clear_bits(struct btrfs_free_space_ctl *ctl,
1533 struct btrfs_free_space *info,
1534 u64 offset, u64 bytes)
1536 unsigned long start, count;
1538 start = offset_to_bit(info->offset, ctl->unit, offset);
1539 count = bytes_to_bits(bytes, ctl->unit);
1540 ASSERT(start + count <= BITS_PER_BITMAP);
1542 bitmap_clear(info->bitmap, start, count);
1544 info->bytes -= bytes;
1547 static void bitmap_clear_bits(struct btrfs_free_space_ctl *ctl,
1548 struct btrfs_free_space *info, u64 offset,
1551 __bitmap_clear_bits(ctl, info, offset, bytes);
1552 ctl->free_space -= bytes;
1555 static void bitmap_set_bits(struct btrfs_free_space_ctl *ctl,
1556 struct btrfs_free_space *info, u64 offset,
1559 unsigned long start, count;
1561 start = offset_to_bit(info->offset, ctl->unit, offset);
1562 count = bytes_to_bits(bytes, ctl->unit);
1563 ASSERT(start + count <= BITS_PER_BITMAP);
1565 bitmap_set(info->bitmap, start, count);
1567 info->bytes += bytes;
1568 ctl->free_space += bytes;
1572 * If we can not find suitable extent, we will use bytes to record
1573 * the size of the max extent.
1575 static int search_bitmap(struct btrfs_free_space_ctl *ctl,
1576 struct btrfs_free_space *bitmap_info, u64 *offset,
1579 unsigned long found_bits = 0;
1580 unsigned long max_bits = 0;
1581 unsigned long bits, i;
1582 unsigned long next_zero;
1583 unsigned long extent_bits;
1585 i = offset_to_bit(bitmap_info->offset, ctl->unit,
1586 max_t(u64, *offset, bitmap_info->offset));
1587 bits = bytes_to_bits(*bytes, ctl->unit);
1589 for_each_set_bit_from(i, bitmap_info->bitmap, BITS_PER_BITMAP) {
1590 next_zero = find_next_zero_bit(bitmap_info->bitmap,
1591 BITS_PER_BITMAP, i);
1592 extent_bits = next_zero - i;
1593 if (extent_bits >= bits) {
1594 found_bits = extent_bits;
1596 } else if (extent_bits > max_bits) {
1597 max_bits = extent_bits;
1603 *offset = (u64)(i * ctl->unit) + bitmap_info->offset;
1604 *bytes = (u64)(found_bits) * ctl->unit;
1608 *bytes = (u64)(max_bits) * ctl->unit;
1612 /* Cache the size of the max extent in bytes */
1613 static struct btrfs_free_space *
1614 find_free_space(struct btrfs_free_space_ctl *ctl, u64 *offset, u64 *bytes,
1615 unsigned long align, u64 *max_extent_size)
1617 struct btrfs_free_space *entry;
1618 struct rb_node *node;
1623 if (!ctl->free_space_offset.rb_node)
1626 entry = tree_search_offset(ctl, offset_to_bitmap(ctl, *offset), 0, 1);
1630 for (node = &entry->offset_index; node; node = rb_next(node)) {
1631 entry = rb_entry(node, struct btrfs_free_space, offset_index);
1632 if (entry->bytes < *bytes) {
1633 if (entry->bytes > *max_extent_size)
1634 *max_extent_size = entry->bytes;
1638 /* make sure the space returned is big enough
1639 * to match our requested alignment
1641 if (*bytes >= align) {
1642 tmp = entry->offset - ctl->start + align - 1;
1644 tmp = tmp * align + ctl->start;
1645 align_off = tmp - entry->offset;
1648 tmp = entry->offset;
1651 if (entry->bytes < *bytes + align_off) {
1652 if (entry->bytes > *max_extent_size)
1653 *max_extent_size = entry->bytes;
1657 if (entry->bitmap) {
1660 ret = search_bitmap(ctl, entry, &tmp, &size);
1665 } else if (size > *max_extent_size) {
1666 *max_extent_size = size;
1672 *bytes = entry->bytes - align_off;
1679 static void add_new_bitmap(struct btrfs_free_space_ctl *ctl,
1680 struct btrfs_free_space *info, u64 offset)
1682 info->offset = offset_to_bitmap(ctl, offset);
1684 INIT_LIST_HEAD(&info->list);
1685 link_free_space(ctl, info);
1686 ctl->total_bitmaps++;
1688 ctl->op->recalc_thresholds(ctl);
1691 static void free_bitmap(struct btrfs_free_space_ctl *ctl,
1692 struct btrfs_free_space *bitmap_info)
1694 unlink_free_space(ctl, bitmap_info);
1695 kfree(bitmap_info->bitmap);
1696 kmem_cache_free(btrfs_free_space_cachep, bitmap_info);
1697 ctl->total_bitmaps--;
1698 ctl->op->recalc_thresholds(ctl);
1701 static noinline int remove_from_bitmap(struct btrfs_free_space_ctl *ctl,
1702 struct btrfs_free_space *bitmap_info,
1703 u64 *offset, u64 *bytes)
1706 u64 search_start, search_bytes;
1710 end = bitmap_info->offset + (u64)(BITS_PER_BITMAP * ctl->unit) - 1;
1713 * We need to search for bits in this bitmap. We could only cover some
1714 * of the extent in this bitmap thanks to how we add space, so we need
1715 * to search for as much as it as we can and clear that amount, and then
1716 * go searching for the next bit.
1718 search_start = *offset;
1719 search_bytes = ctl->unit;
1720 search_bytes = min(search_bytes, end - search_start + 1);
1721 ret = search_bitmap(ctl, bitmap_info, &search_start, &search_bytes);
1722 if (ret < 0 || search_start != *offset)
1725 /* We may have found more bits than what we need */
1726 search_bytes = min(search_bytes, *bytes);
1728 /* Cannot clear past the end of the bitmap */
1729 search_bytes = min(search_bytes, end - search_start + 1);
1731 bitmap_clear_bits(ctl, bitmap_info, search_start, search_bytes);
1732 *offset += search_bytes;
1733 *bytes -= search_bytes;
1736 struct rb_node *next = rb_next(&bitmap_info->offset_index);
1737 if (!bitmap_info->bytes)
1738 free_bitmap(ctl, bitmap_info);
1741 * no entry after this bitmap, but we still have bytes to
1742 * remove, so something has gone wrong.
1747 bitmap_info = rb_entry(next, struct btrfs_free_space,
1751 * if the next entry isn't a bitmap we need to return to let the
1752 * extent stuff do its work.
1754 if (!bitmap_info->bitmap)
1758 * Ok the next item is a bitmap, but it may not actually hold
1759 * the information for the rest of this free space stuff, so
1760 * look for it, and if we don't find it return so we can try
1761 * everything over again.
1763 search_start = *offset;
1764 search_bytes = ctl->unit;
1765 ret = search_bitmap(ctl, bitmap_info, &search_start,
1767 if (ret < 0 || search_start != *offset)
1771 } else if (!bitmap_info->bytes)
1772 free_bitmap(ctl, bitmap_info);
1777 static u64 add_bytes_to_bitmap(struct btrfs_free_space_ctl *ctl,
1778 struct btrfs_free_space *info, u64 offset,
1781 u64 bytes_to_set = 0;
1784 end = info->offset + (u64)(BITS_PER_BITMAP * ctl->unit);
1786 bytes_to_set = min(end - offset, bytes);
1788 bitmap_set_bits(ctl, info, offset, bytes_to_set);
1790 return bytes_to_set;
1794 static bool use_bitmap(struct btrfs_free_space_ctl *ctl,
1795 struct btrfs_free_space *info)
1797 struct btrfs_block_group_cache *block_group = ctl->private;
1800 * If we are below the extents threshold then we can add this as an
1801 * extent, and don't have to deal with the bitmap
1803 if (ctl->free_extents < ctl->extents_thresh) {
1805 * If this block group has some small extents we don't want to
1806 * use up all of our free slots in the cache with them, we want
1807 * to reserve them to larger extents, however if we have plent
1808 * of cache left then go ahead an dadd them, no sense in adding
1809 * the overhead of a bitmap if we don't have to.
1811 if (info->bytes <= block_group->sectorsize * 4) {
1812 if (ctl->free_extents * 2 <= ctl->extents_thresh)
1820 * The original block groups from mkfs can be really small, like 8
1821 * megabytes, so don't bother with a bitmap for those entries. However
1822 * some block groups can be smaller than what a bitmap would cover but
1823 * are still large enough that they could overflow the 32k memory limit,
1824 * so allow those block groups to still be allowed to have a bitmap
1827 if (((BITS_PER_BITMAP * ctl->unit) >> 1) > block_group->key.offset)
1833 static struct btrfs_free_space_op free_space_op = {
1834 .recalc_thresholds = recalculate_thresholds,
1835 .use_bitmap = use_bitmap,
1838 static int insert_into_bitmap(struct btrfs_free_space_ctl *ctl,
1839 struct btrfs_free_space *info)
1841 struct btrfs_free_space *bitmap_info;
1842 struct btrfs_block_group_cache *block_group = NULL;
1844 u64 bytes, offset, bytes_added;
1847 bytes = info->bytes;
1848 offset = info->offset;
1850 if (!ctl->op->use_bitmap(ctl, info))
1853 if (ctl->op == &free_space_op)
1854 block_group = ctl->private;
1857 * Since we link bitmaps right into the cluster we need to see if we
1858 * have a cluster here, and if so and it has our bitmap we need to add
1859 * the free space to that bitmap.
1861 if (block_group && !list_empty(&block_group->cluster_list)) {
1862 struct btrfs_free_cluster *cluster;
1863 struct rb_node *node;
1864 struct btrfs_free_space *entry;
1866 cluster = list_entry(block_group->cluster_list.next,
1867 struct btrfs_free_cluster,
1869 spin_lock(&cluster->lock);
1870 node = rb_first(&cluster->root);
1872 spin_unlock(&cluster->lock);
1873 goto no_cluster_bitmap;
1876 entry = rb_entry(node, struct btrfs_free_space, offset_index);
1877 if (!entry->bitmap) {
1878 spin_unlock(&cluster->lock);
1879 goto no_cluster_bitmap;
1882 if (entry->offset == offset_to_bitmap(ctl, offset)) {
1883 bytes_added = add_bytes_to_bitmap(ctl, entry,
1885 bytes -= bytes_added;
1886 offset += bytes_added;
1888 spin_unlock(&cluster->lock);
1896 bitmap_info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
1903 bytes_added = add_bytes_to_bitmap(ctl, bitmap_info, offset, bytes);
1904 bytes -= bytes_added;
1905 offset += bytes_added;
1915 if (info && info->bitmap) {
1916 add_new_bitmap(ctl, info, offset);
1921 spin_unlock(&ctl->tree_lock);
1923 /* no pre-allocated info, allocate a new one */
1925 info = kmem_cache_zalloc(btrfs_free_space_cachep,
1928 spin_lock(&ctl->tree_lock);
1934 /* allocate the bitmap */
1935 info->bitmap = kzalloc(PAGE_CACHE_SIZE, GFP_NOFS);
1936 spin_lock(&ctl->tree_lock);
1937 if (!info->bitmap) {
1947 kfree(info->bitmap);
1948 kmem_cache_free(btrfs_free_space_cachep, info);
1954 static bool try_merge_free_space(struct btrfs_free_space_ctl *ctl,
1955 struct btrfs_free_space *info, bool update_stat)
1957 struct btrfs_free_space *left_info;
1958 struct btrfs_free_space *right_info;
1959 bool merged = false;
1960 u64 offset = info->offset;
1961 u64 bytes = info->bytes;
1964 * first we want to see if there is free space adjacent to the range we
1965 * are adding, if there is remove that struct and add a new one to
1966 * cover the entire range
1968 right_info = tree_search_offset(ctl, offset + bytes, 0, 0);
1969 if (right_info && rb_prev(&right_info->offset_index))
1970 left_info = rb_entry(rb_prev(&right_info->offset_index),
1971 struct btrfs_free_space, offset_index);
1973 left_info = tree_search_offset(ctl, offset - 1, 0, 0);
1975 if (right_info && !right_info->bitmap) {
1977 unlink_free_space(ctl, right_info);
1979 __unlink_free_space(ctl, right_info);
1980 info->bytes += right_info->bytes;
1981 kmem_cache_free(btrfs_free_space_cachep, right_info);
1985 if (left_info && !left_info->bitmap &&
1986 left_info->offset + left_info->bytes == offset) {
1988 unlink_free_space(ctl, left_info);
1990 __unlink_free_space(ctl, left_info);
1991 info->offset = left_info->offset;
1992 info->bytes += left_info->bytes;
1993 kmem_cache_free(btrfs_free_space_cachep, left_info);
2000 static bool steal_from_bitmap_to_end(struct btrfs_free_space_ctl *ctl,
2001 struct btrfs_free_space *info,
2004 struct btrfs_free_space *bitmap;
2007 const u64 end = info->offset + info->bytes;
2008 const u64 bitmap_offset = offset_to_bitmap(ctl, end);
2011 bitmap = tree_search_offset(ctl, bitmap_offset, 1, 0);
2015 i = offset_to_bit(bitmap->offset, ctl->unit, end);
2016 j = find_next_zero_bit(bitmap->bitmap, BITS_PER_BITMAP, i);
2019 bytes = (j - i) * ctl->unit;
2020 info->bytes += bytes;
2023 bitmap_clear_bits(ctl, bitmap, end, bytes);
2025 __bitmap_clear_bits(ctl, bitmap, end, bytes);
2028 free_bitmap(ctl, bitmap);
2033 static bool steal_from_bitmap_to_front(struct btrfs_free_space_ctl *ctl,
2034 struct btrfs_free_space *info,
2037 struct btrfs_free_space *bitmap;
2041 unsigned long prev_j;
2044 bitmap_offset = offset_to_bitmap(ctl, info->offset);
2045 /* If we're on a boundary, try the previous logical bitmap. */
2046 if (bitmap_offset == info->offset) {
2047 if (info->offset == 0)
2049 bitmap_offset = offset_to_bitmap(ctl, info->offset - 1);
2052 bitmap = tree_search_offset(ctl, bitmap_offset, 1, 0);
2056 i = offset_to_bit(bitmap->offset, ctl->unit, info->offset) - 1;
2058 prev_j = (unsigned long)-1;
2059 for_each_clear_bit_from(j, bitmap->bitmap, BITS_PER_BITMAP) {
2067 if (prev_j == (unsigned long)-1)
2068 bytes = (i + 1) * ctl->unit;
2070 bytes = (i - prev_j) * ctl->unit;
2072 info->offset -= bytes;
2073 info->bytes += bytes;
2076 bitmap_clear_bits(ctl, bitmap, info->offset, bytes);
2078 __bitmap_clear_bits(ctl, bitmap, info->offset, bytes);
2081 free_bitmap(ctl, bitmap);
2087 * We prefer always to allocate from extent entries, both for clustered and
2088 * non-clustered allocation requests. So when attempting to add a new extent
2089 * entry, try to see if there's adjacent free space in bitmap entries, and if
2090 * there is, migrate that space from the bitmaps to the extent.
2091 * Like this we get better chances of satisfying space allocation requests
2092 * because we attempt to satisfy them based on a single cache entry, and never
2093 * on 2 or more entries - even if the entries represent a contiguous free space
2094 * region (e.g. 1 extent entry + 1 bitmap entry starting where the extent entry
2097 static void steal_from_bitmap(struct btrfs_free_space_ctl *ctl,
2098 struct btrfs_free_space *info,
2102 * Only work with disconnected entries, as we can change their offset,
2103 * and must be extent entries.
2105 ASSERT(!info->bitmap);
2106 ASSERT(RB_EMPTY_NODE(&info->offset_index));
2108 if (ctl->total_bitmaps > 0) {
2110 bool stole_front = false;
2112 stole_end = steal_from_bitmap_to_end(ctl, info, update_stat);
2113 if (ctl->total_bitmaps > 0)
2114 stole_front = steal_from_bitmap_to_front(ctl, info,
2117 if (stole_end || stole_front)
2118 try_merge_free_space(ctl, info, update_stat);
2122 int __btrfs_add_free_space(struct btrfs_free_space_ctl *ctl,
2123 u64 offset, u64 bytes)
2125 struct btrfs_free_space *info;
2128 info = kmem_cache_zalloc(btrfs_free_space_cachep, GFP_NOFS);
2132 info->offset = offset;
2133 info->bytes = bytes;
2134 RB_CLEAR_NODE(&info->offset_index);
2136 spin_lock(&ctl->tree_lock);
2138 if (try_merge_free_space(ctl, info, true))
2142 * There was no extent directly to the left or right of this new
2143 * extent then we know we're going to have to allocate a new extent, so
2144 * before we do that see if we need to drop this into a bitmap
2146 ret = insert_into_bitmap(ctl, info);
2155 * Only steal free space from adjacent bitmaps if we're sure we're not
2156 * going to add the new free space to existing bitmap entries - because
2157 * that would mean unnecessary work that would be reverted. Therefore
2158 * attempt to steal space from bitmaps if we're adding an extent entry.
2160 steal_from_bitmap(ctl, info, true);
2162 ret = link_free_space(ctl, info);
2164 kmem_cache_free(btrfs_free_space_cachep, info);
2166 spin_unlock(&ctl->tree_lock);
2169 printk(KERN_CRIT "BTRFS: unable to add free space :%d\n", ret);
2170 ASSERT(ret != -EEXIST);
2176 int btrfs_remove_free_space(struct btrfs_block_group_cache *block_group,
2177 u64 offset, u64 bytes)
2179 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2180 struct btrfs_free_space *info;
2182 bool re_search = false;
2184 spin_lock(&ctl->tree_lock);
2191 info = tree_search_offset(ctl, offset, 0, 0);
2194 * oops didn't find an extent that matched the space we wanted
2195 * to remove, look for a bitmap instead
2197 info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
2201 * If we found a partial bit of our free space in a
2202 * bitmap but then couldn't find the other part this may
2203 * be a problem, so WARN about it.
2211 if (!info->bitmap) {
2212 unlink_free_space(ctl, info);
2213 if (offset == info->offset) {
2214 u64 to_free = min(bytes, info->bytes);
2216 info->bytes -= to_free;
2217 info->offset += to_free;
2219 ret = link_free_space(ctl, info);
2222 kmem_cache_free(btrfs_free_space_cachep, info);
2229 u64 old_end = info->bytes + info->offset;
2231 info->bytes = offset - info->offset;
2232 ret = link_free_space(ctl, info);
2237 /* Not enough bytes in this entry to satisfy us */
2238 if (old_end < offset + bytes) {
2239 bytes -= old_end - offset;
2242 } else if (old_end == offset + bytes) {
2246 spin_unlock(&ctl->tree_lock);
2248 ret = btrfs_add_free_space(block_group, offset + bytes,
2249 old_end - (offset + bytes));
2255 ret = remove_from_bitmap(ctl, info, &offset, &bytes);
2256 if (ret == -EAGAIN) {
2261 spin_unlock(&ctl->tree_lock);
2266 void btrfs_dump_free_space(struct btrfs_block_group_cache *block_group,
2269 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2270 struct btrfs_free_space *info;
2274 for (n = rb_first(&ctl->free_space_offset); n; n = rb_next(n)) {
2275 info = rb_entry(n, struct btrfs_free_space, offset_index);
2276 if (info->bytes >= bytes && !block_group->ro)
2278 btrfs_crit(block_group->fs_info,
2279 "entry offset %llu, bytes %llu, bitmap %s",
2280 info->offset, info->bytes,
2281 (info->bitmap) ? "yes" : "no");
2283 btrfs_info(block_group->fs_info, "block group has cluster?: %s",
2284 list_empty(&block_group->cluster_list) ? "no" : "yes");
2285 btrfs_info(block_group->fs_info,
2286 "%d blocks of free space at or bigger than bytes is", count);
2289 void btrfs_init_free_space_ctl(struct btrfs_block_group_cache *block_group)
2291 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2293 spin_lock_init(&ctl->tree_lock);
2294 ctl->unit = block_group->sectorsize;
2295 ctl->start = block_group->key.objectid;
2296 ctl->private = block_group;
2297 ctl->op = &free_space_op;
2300 * we only want to have 32k of ram per block group for keeping
2301 * track of free space, and if we pass 1/2 of that we want to
2302 * start converting things over to using bitmaps
2304 ctl->extents_thresh = ((1024 * 32) / 2) /
2305 sizeof(struct btrfs_free_space);
2309 * for a given cluster, put all of its extents back into the free
2310 * space cache. If the block group passed doesn't match the block group
2311 * pointed to by the cluster, someone else raced in and freed the
2312 * cluster already. In that case, we just return without changing anything
2315 __btrfs_return_cluster_to_free_space(
2316 struct btrfs_block_group_cache *block_group,
2317 struct btrfs_free_cluster *cluster)
2319 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2320 struct btrfs_free_space *entry;
2321 struct rb_node *node;
2323 spin_lock(&cluster->lock);
2324 if (cluster->block_group != block_group)
2327 cluster->block_group = NULL;
2328 cluster->window_start = 0;
2329 list_del_init(&cluster->block_group_list);
2331 node = rb_first(&cluster->root);
2335 entry = rb_entry(node, struct btrfs_free_space, offset_index);
2336 node = rb_next(&entry->offset_index);
2337 rb_erase(&entry->offset_index, &cluster->root);
2338 RB_CLEAR_NODE(&entry->offset_index);
2340 bitmap = (entry->bitmap != NULL);
2342 try_merge_free_space(ctl, entry, false);
2343 steal_from_bitmap(ctl, entry, false);
2345 tree_insert_offset(&ctl->free_space_offset,
2346 entry->offset, &entry->offset_index, bitmap);
2348 cluster->root = RB_ROOT;
2351 spin_unlock(&cluster->lock);
2352 btrfs_put_block_group(block_group);
2356 static void __btrfs_remove_free_space_cache_locked(
2357 struct btrfs_free_space_ctl *ctl)
2359 struct btrfs_free_space *info;
2360 struct rb_node *node;
2362 while ((node = rb_last(&ctl->free_space_offset)) != NULL) {
2363 info = rb_entry(node, struct btrfs_free_space, offset_index);
2364 if (!info->bitmap) {
2365 unlink_free_space(ctl, info);
2366 kmem_cache_free(btrfs_free_space_cachep, info);
2368 free_bitmap(ctl, info);
2370 if (need_resched()) {
2371 spin_unlock(&ctl->tree_lock);
2373 spin_lock(&ctl->tree_lock);
2378 void __btrfs_remove_free_space_cache(struct btrfs_free_space_ctl *ctl)
2380 spin_lock(&ctl->tree_lock);
2381 __btrfs_remove_free_space_cache_locked(ctl);
2382 spin_unlock(&ctl->tree_lock);
2385 void btrfs_remove_free_space_cache(struct btrfs_block_group_cache *block_group)
2387 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2388 struct btrfs_free_cluster *cluster;
2389 struct list_head *head;
2391 spin_lock(&ctl->tree_lock);
2392 while ((head = block_group->cluster_list.next) !=
2393 &block_group->cluster_list) {
2394 cluster = list_entry(head, struct btrfs_free_cluster,
2397 WARN_ON(cluster->block_group != block_group);
2398 __btrfs_return_cluster_to_free_space(block_group, cluster);
2399 if (need_resched()) {
2400 spin_unlock(&ctl->tree_lock);
2402 spin_lock(&ctl->tree_lock);
2405 __btrfs_remove_free_space_cache_locked(ctl);
2406 spin_unlock(&ctl->tree_lock);
2410 u64 btrfs_find_space_for_alloc(struct btrfs_block_group_cache *block_group,
2411 u64 offset, u64 bytes, u64 empty_size,
2412 u64 *max_extent_size)
2414 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2415 struct btrfs_free_space *entry = NULL;
2416 u64 bytes_search = bytes + empty_size;
2419 u64 align_gap_len = 0;
2421 spin_lock(&ctl->tree_lock);
2422 entry = find_free_space(ctl, &offset, &bytes_search,
2423 block_group->full_stripe_len, max_extent_size);
2428 if (entry->bitmap) {
2429 bitmap_clear_bits(ctl, entry, offset, bytes);
2431 free_bitmap(ctl, entry);
2433 unlink_free_space(ctl, entry);
2434 align_gap_len = offset - entry->offset;
2435 align_gap = entry->offset;
2437 entry->offset = offset + bytes;
2438 WARN_ON(entry->bytes < bytes + align_gap_len);
2440 entry->bytes -= bytes + align_gap_len;
2442 kmem_cache_free(btrfs_free_space_cachep, entry);
2444 link_free_space(ctl, entry);
2447 spin_unlock(&ctl->tree_lock);
2450 __btrfs_add_free_space(ctl, align_gap, align_gap_len);
2455 * given a cluster, put all of its extents back into the free space
2456 * cache. If a block group is passed, this function will only free
2457 * a cluster that belongs to the passed block group.
2459 * Otherwise, it'll get a reference on the block group pointed to by the
2460 * cluster and remove the cluster from it.
2462 int btrfs_return_cluster_to_free_space(
2463 struct btrfs_block_group_cache *block_group,
2464 struct btrfs_free_cluster *cluster)
2466 struct btrfs_free_space_ctl *ctl;
2469 /* first, get a safe pointer to the block group */
2470 spin_lock(&cluster->lock);
2472 block_group = cluster->block_group;
2474 spin_unlock(&cluster->lock);
2477 } else if (cluster->block_group != block_group) {
2478 /* someone else has already freed it don't redo their work */
2479 spin_unlock(&cluster->lock);
2482 atomic_inc(&block_group->count);
2483 spin_unlock(&cluster->lock);
2485 ctl = block_group->free_space_ctl;
2487 /* now return any extents the cluster had on it */
2488 spin_lock(&ctl->tree_lock);
2489 ret = __btrfs_return_cluster_to_free_space(block_group, cluster);
2490 spin_unlock(&ctl->tree_lock);
2492 /* finally drop our ref */
2493 btrfs_put_block_group(block_group);
2497 static u64 btrfs_alloc_from_bitmap(struct btrfs_block_group_cache *block_group,
2498 struct btrfs_free_cluster *cluster,
2499 struct btrfs_free_space *entry,
2500 u64 bytes, u64 min_start,
2501 u64 *max_extent_size)
2503 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2505 u64 search_start = cluster->window_start;
2506 u64 search_bytes = bytes;
2509 search_start = min_start;
2510 search_bytes = bytes;
2512 err = search_bitmap(ctl, entry, &search_start, &search_bytes);
2514 if (search_bytes > *max_extent_size)
2515 *max_extent_size = search_bytes;
2520 __bitmap_clear_bits(ctl, entry, ret, bytes);
2526 * given a cluster, try to allocate 'bytes' from it, returns 0
2527 * if it couldn't find anything suitably large, or a logical disk offset
2528 * if things worked out
2530 u64 btrfs_alloc_from_cluster(struct btrfs_block_group_cache *block_group,
2531 struct btrfs_free_cluster *cluster, u64 bytes,
2532 u64 min_start, u64 *max_extent_size)
2534 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2535 struct btrfs_free_space *entry = NULL;
2536 struct rb_node *node;
2539 spin_lock(&cluster->lock);
2540 if (bytes > cluster->max_size)
2543 if (cluster->block_group != block_group)
2546 node = rb_first(&cluster->root);
2550 entry = rb_entry(node, struct btrfs_free_space, offset_index);
2552 if (entry->bytes < bytes && entry->bytes > *max_extent_size)
2553 *max_extent_size = entry->bytes;
2555 if (entry->bytes < bytes ||
2556 (!entry->bitmap && entry->offset < min_start)) {
2557 node = rb_next(&entry->offset_index);
2560 entry = rb_entry(node, struct btrfs_free_space,
2565 if (entry->bitmap) {
2566 ret = btrfs_alloc_from_bitmap(block_group,
2567 cluster, entry, bytes,
2568 cluster->window_start,
2571 node = rb_next(&entry->offset_index);
2574 entry = rb_entry(node, struct btrfs_free_space,
2578 cluster->window_start += bytes;
2580 ret = entry->offset;
2582 entry->offset += bytes;
2583 entry->bytes -= bytes;
2586 if (entry->bytes == 0)
2587 rb_erase(&entry->offset_index, &cluster->root);
2591 spin_unlock(&cluster->lock);
2596 spin_lock(&ctl->tree_lock);
2598 ctl->free_space -= bytes;
2599 if (entry->bytes == 0) {
2600 ctl->free_extents--;
2601 if (entry->bitmap) {
2602 kfree(entry->bitmap);
2603 ctl->total_bitmaps--;
2604 ctl->op->recalc_thresholds(ctl);
2606 kmem_cache_free(btrfs_free_space_cachep, entry);
2609 spin_unlock(&ctl->tree_lock);
2614 static int btrfs_bitmap_cluster(struct btrfs_block_group_cache *block_group,
2615 struct btrfs_free_space *entry,
2616 struct btrfs_free_cluster *cluster,
2617 u64 offset, u64 bytes,
2618 u64 cont1_bytes, u64 min_bytes)
2620 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2621 unsigned long next_zero;
2623 unsigned long want_bits;
2624 unsigned long min_bits;
2625 unsigned long found_bits;
2626 unsigned long start = 0;
2627 unsigned long total_found = 0;
2630 i = offset_to_bit(entry->offset, ctl->unit,
2631 max_t(u64, offset, entry->offset));
2632 want_bits = bytes_to_bits(bytes, ctl->unit);
2633 min_bits = bytes_to_bits(min_bytes, ctl->unit);
2637 for_each_set_bit_from(i, entry->bitmap, BITS_PER_BITMAP) {
2638 next_zero = find_next_zero_bit(entry->bitmap,
2639 BITS_PER_BITMAP, i);
2640 if (next_zero - i >= min_bits) {
2641 found_bits = next_zero - i;
2652 cluster->max_size = 0;
2655 total_found += found_bits;
2657 if (cluster->max_size < found_bits * ctl->unit)
2658 cluster->max_size = found_bits * ctl->unit;
2660 if (total_found < want_bits || cluster->max_size < cont1_bytes) {
2665 cluster->window_start = start * ctl->unit + entry->offset;
2666 rb_erase(&entry->offset_index, &ctl->free_space_offset);
2667 ret = tree_insert_offset(&cluster->root, entry->offset,
2668 &entry->offset_index, 1);
2669 ASSERT(!ret); /* -EEXIST; Logic error */
2671 trace_btrfs_setup_cluster(block_group, cluster,
2672 total_found * ctl->unit, 1);
2677 * This searches the block group for just extents to fill the cluster with.
2678 * Try to find a cluster with at least bytes total bytes, at least one
2679 * extent of cont1_bytes, and other clusters of at least min_bytes.
2682 setup_cluster_no_bitmap(struct btrfs_block_group_cache *block_group,
2683 struct btrfs_free_cluster *cluster,
2684 struct list_head *bitmaps, u64 offset, u64 bytes,
2685 u64 cont1_bytes, u64 min_bytes)
2687 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2688 struct btrfs_free_space *first = NULL;
2689 struct btrfs_free_space *entry = NULL;
2690 struct btrfs_free_space *last;
2691 struct rb_node *node;
2696 entry = tree_search_offset(ctl, offset, 0, 1);
2701 * We don't want bitmaps, so just move along until we find a normal
2704 while (entry->bitmap || entry->bytes < min_bytes) {
2705 if (entry->bitmap && list_empty(&entry->list))
2706 list_add_tail(&entry->list, bitmaps);
2707 node = rb_next(&entry->offset_index);
2710 entry = rb_entry(node, struct btrfs_free_space, offset_index);
2713 window_free = entry->bytes;
2714 max_extent = entry->bytes;
2718 for (node = rb_next(&entry->offset_index); node;
2719 node = rb_next(&entry->offset_index)) {
2720 entry = rb_entry(node, struct btrfs_free_space, offset_index);
2722 if (entry->bitmap) {
2723 if (list_empty(&entry->list))
2724 list_add_tail(&entry->list, bitmaps);
2728 if (entry->bytes < min_bytes)
2732 window_free += entry->bytes;
2733 if (entry->bytes > max_extent)
2734 max_extent = entry->bytes;
2737 if (window_free < bytes || max_extent < cont1_bytes)
2740 cluster->window_start = first->offset;
2742 node = &first->offset_index;
2745 * now we've found our entries, pull them out of the free space
2746 * cache and put them into the cluster rbtree
2751 entry = rb_entry(node, struct btrfs_free_space, offset_index);
2752 node = rb_next(&entry->offset_index);
2753 if (entry->bitmap || entry->bytes < min_bytes)
2756 rb_erase(&entry->offset_index, &ctl->free_space_offset);
2757 ret = tree_insert_offset(&cluster->root, entry->offset,
2758 &entry->offset_index, 0);
2759 total_size += entry->bytes;
2760 ASSERT(!ret); /* -EEXIST; Logic error */
2761 } while (node && entry != last);
2763 cluster->max_size = max_extent;
2764 trace_btrfs_setup_cluster(block_group, cluster, total_size, 0);
2769 * This specifically looks for bitmaps that may work in the cluster, we assume
2770 * that we have already failed to find extents that will work.
2773 setup_cluster_bitmap(struct btrfs_block_group_cache *block_group,
2774 struct btrfs_free_cluster *cluster,
2775 struct list_head *bitmaps, u64 offset, u64 bytes,
2776 u64 cont1_bytes, u64 min_bytes)
2778 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2779 struct btrfs_free_space *entry;
2781 u64 bitmap_offset = offset_to_bitmap(ctl, offset);
2783 if (ctl->total_bitmaps == 0)
2787 * The bitmap that covers offset won't be in the list unless offset
2788 * is just its start offset.
2790 entry = list_first_entry(bitmaps, struct btrfs_free_space, list);
2791 if (entry->offset != bitmap_offset) {
2792 entry = tree_search_offset(ctl, bitmap_offset, 1, 0);
2793 if (entry && list_empty(&entry->list))
2794 list_add(&entry->list, bitmaps);
2797 list_for_each_entry(entry, bitmaps, list) {
2798 if (entry->bytes < bytes)
2800 ret = btrfs_bitmap_cluster(block_group, entry, cluster, offset,
2801 bytes, cont1_bytes, min_bytes);
2807 * The bitmaps list has all the bitmaps that record free space
2808 * starting after offset, so no more search is required.
2814 * here we try to find a cluster of blocks in a block group. The goal
2815 * is to find at least bytes+empty_size.
2816 * We might not find them all in one contiguous area.
2818 * returns zero and sets up cluster if things worked out, otherwise
2819 * it returns -enospc
2821 int btrfs_find_space_cluster(struct btrfs_root *root,
2822 struct btrfs_block_group_cache *block_group,
2823 struct btrfs_free_cluster *cluster,
2824 u64 offset, u64 bytes, u64 empty_size)
2826 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2827 struct btrfs_free_space *entry, *tmp;
2834 * Choose the minimum extent size we'll require for this
2835 * cluster. For SSD_SPREAD, don't allow any fragmentation.
2836 * For metadata, allow allocates with smaller extents. For
2837 * data, keep it dense.
2839 if (btrfs_test_opt(root, SSD_SPREAD)) {
2840 cont1_bytes = min_bytes = bytes + empty_size;
2841 } else if (block_group->flags & BTRFS_BLOCK_GROUP_METADATA) {
2842 cont1_bytes = bytes;
2843 min_bytes = block_group->sectorsize;
2845 cont1_bytes = max(bytes, (bytes + empty_size) >> 2);
2846 min_bytes = block_group->sectorsize;
2849 spin_lock(&ctl->tree_lock);
2852 * If we know we don't have enough space to make a cluster don't even
2853 * bother doing all the work to try and find one.
2855 if (ctl->free_space < bytes) {
2856 spin_unlock(&ctl->tree_lock);
2860 spin_lock(&cluster->lock);
2862 /* someone already found a cluster, hooray */
2863 if (cluster->block_group) {
2868 trace_btrfs_find_cluster(block_group, offset, bytes, empty_size,
2871 INIT_LIST_HEAD(&bitmaps);
2872 ret = setup_cluster_no_bitmap(block_group, cluster, &bitmaps, offset,
2874 cont1_bytes, min_bytes);
2876 ret = setup_cluster_bitmap(block_group, cluster, &bitmaps,
2877 offset, bytes + empty_size,
2878 cont1_bytes, min_bytes);
2880 /* Clear our temporary list */
2881 list_for_each_entry_safe(entry, tmp, &bitmaps, list)
2882 list_del_init(&entry->list);
2885 atomic_inc(&block_group->count);
2886 list_add_tail(&cluster->block_group_list,
2887 &block_group->cluster_list);
2888 cluster->block_group = block_group;
2890 trace_btrfs_failed_cluster_setup(block_group);
2893 spin_unlock(&cluster->lock);
2894 spin_unlock(&ctl->tree_lock);
2900 * simple code to zero out a cluster
2902 void btrfs_init_free_cluster(struct btrfs_free_cluster *cluster)
2904 spin_lock_init(&cluster->lock);
2905 spin_lock_init(&cluster->refill_lock);
2906 cluster->root = RB_ROOT;
2907 cluster->max_size = 0;
2908 INIT_LIST_HEAD(&cluster->block_group_list);
2909 cluster->block_group = NULL;
2912 static int do_trimming(struct btrfs_block_group_cache *block_group,
2913 u64 *total_trimmed, u64 start, u64 bytes,
2914 u64 reserved_start, u64 reserved_bytes)
2916 struct btrfs_space_info *space_info = block_group->space_info;
2917 struct btrfs_fs_info *fs_info = block_group->fs_info;
2922 spin_lock(&space_info->lock);
2923 spin_lock(&block_group->lock);
2924 if (!block_group->ro) {
2925 block_group->reserved += reserved_bytes;
2926 space_info->bytes_reserved += reserved_bytes;
2929 spin_unlock(&block_group->lock);
2930 spin_unlock(&space_info->lock);
2932 ret = btrfs_error_discard_extent(fs_info->extent_root,
2933 start, bytes, &trimmed);
2935 *total_trimmed += trimmed;
2937 btrfs_add_free_space(block_group, reserved_start, reserved_bytes);
2940 spin_lock(&space_info->lock);
2941 spin_lock(&block_group->lock);
2942 if (block_group->ro)
2943 space_info->bytes_readonly += reserved_bytes;
2944 block_group->reserved -= reserved_bytes;
2945 space_info->bytes_reserved -= reserved_bytes;
2946 spin_unlock(&space_info->lock);
2947 spin_unlock(&block_group->lock);
2953 static int trim_no_bitmap(struct btrfs_block_group_cache *block_group,
2954 u64 *total_trimmed, u64 start, u64 end, u64 minlen)
2956 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2957 struct btrfs_free_space *entry;
2958 struct rb_node *node;
2964 while (start < end) {
2965 spin_lock(&ctl->tree_lock);
2967 if (ctl->free_space < minlen) {
2968 spin_unlock(&ctl->tree_lock);
2972 entry = tree_search_offset(ctl, start, 0, 1);
2974 spin_unlock(&ctl->tree_lock);
2979 while (entry->bitmap) {
2980 node = rb_next(&entry->offset_index);
2982 spin_unlock(&ctl->tree_lock);
2985 entry = rb_entry(node, struct btrfs_free_space,
2989 if (entry->offset >= end) {
2990 spin_unlock(&ctl->tree_lock);
2994 extent_start = entry->offset;
2995 extent_bytes = entry->bytes;
2996 start = max(start, extent_start);
2997 bytes = min(extent_start + extent_bytes, end) - start;
2998 if (bytes < minlen) {
2999 spin_unlock(&ctl->tree_lock);
3003 unlink_free_space(ctl, entry);
3004 kmem_cache_free(btrfs_free_space_cachep, entry);
3006 spin_unlock(&ctl->tree_lock);
3008 ret = do_trimming(block_group, total_trimmed, start, bytes,
3009 extent_start, extent_bytes);
3015 if (fatal_signal_pending(current)) {
3026 static int trim_bitmaps(struct btrfs_block_group_cache *block_group,
3027 u64 *total_trimmed, u64 start, u64 end, u64 minlen)
3029 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3030 struct btrfs_free_space *entry;
3034 u64 offset = offset_to_bitmap(ctl, start);
3036 while (offset < end) {
3037 bool next_bitmap = false;
3039 spin_lock(&ctl->tree_lock);
3041 if (ctl->free_space < minlen) {
3042 spin_unlock(&ctl->tree_lock);
3046 entry = tree_search_offset(ctl, offset, 1, 0);
3048 spin_unlock(&ctl->tree_lock);
3054 ret2 = search_bitmap(ctl, entry, &start, &bytes);
3055 if (ret2 || start >= end) {
3056 spin_unlock(&ctl->tree_lock);
3061 bytes = min(bytes, end - start);
3062 if (bytes < minlen) {
3063 spin_unlock(&ctl->tree_lock);
3067 bitmap_clear_bits(ctl, entry, start, bytes);
3068 if (entry->bytes == 0)
3069 free_bitmap(ctl, entry);
3071 spin_unlock(&ctl->tree_lock);
3073 ret = do_trimming(block_group, total_trimmed, start, bytes,
3079 offset += BITS_PER_BITMAP * ctl->unit;
3082 if (start >= offset + BITS_PER_BITMAP * ctl->unit)
3083 offset += BITS_PER_BITMAP * ctl->unit;
3086 if (fatal_signal_pending(current)) {
3097 int btrfs_trim_block_group(struct btrfs_block_group_cache *block_group,
3098 u64 *trimmed, u64 start, u64 end, u64 minlen)
3104 ret = trim_no_bitmap(block_group, trimmed, start, end, minlen);
3108 ret = trim_bitmaps(block_group, trimmed, start, end, minlen);
3114 * Find the left-most item in the cache tree, and then return the
3115 * smallest inode number in the item.
3117 * Note: the returned inode number may not be the smallest one in
3118 * the tree, if the left-most item is a bitmap.
3120 u64 btrfs_find_ino_for_alloc(struct btrfs_root *fs_root)
3122 struct btrfs_free_space_ctl *ctl = fs_root->free_ino_ctl;
3123 struct btrfs_free_space *entry = NULL;
3126 spin_lock(&ctl->tree_lock);
3128 if (RB_EMPTY_ROOT(&ctl->free_space_offset))
3131 entry = rb_entry(rb_first(&ctl->free_space_offset),
3132 struct btrfs_free_space, offset_index);
3134 if (!entry->bitmap) {
3135 ino = entry->offset;
3137 unlink_free_space(ctl, entry);
3141 kmem_cache_free(btrfs_free_space_cachep, entry);
3143 link_free_space(ctl, entry);
3149 ret = search_bitmap(ctl, entry, &offset, &count);
3150 /* Logic error; Should be empty if it can't find anything */
3154 bitmap_clear_bits(ctl, entry, offset, 1);
3155 if (entry->bytes == 0)
3156 free_bitmap(ctl, entry);
3159 spin_unlock(&ctl->tree_lock);
3164 struct inode *lookup_free_ino_inode(struct btrfs_root *root,
3165 struct btrfs_path *path)
3167 struct inode *inode = NULL;
3169 spin_lock(&root->ino_cache_lock);
3170 if (root->ino_cache_inode)
3171 inode = igrab(root->ino_cache_inode);
3172 spin_unlock(&root->ino_cache_lock);
3176 inode = __lookup_free_space_inode(root, path, 0);
3180 spin_lock(&root->ino_cache_lock);
3181 if (!btrfs_fs_closing(root->fs_info))
3182 root->ino_cache_inode = igrab(inode);
3183 spin_unlock(&root->ino_cache_lock);
3188 int create_free_ino_inode(struct btrfs_root *root,
3189 struct btrfs_trans_handle *trans,
3190 struct btrfs_path *path)
3192 return __create_free_space_inode(root, trans, path,
3193 BTRFS_FREE_INO_OBJECTID, 0);
3196 int load_free_ino_cache(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
3198 struct btrfs_free_space_ctl *ctl = root->free_ino_ctl;
3199 struct btrfs_path *path;
3200 struct inode *inode;
3202 u64 root_gen = btrfs_root_generation(&root->root_item);
3204 if (!btrfs_test_opt(root, INODE_MAP_CACHE))
3208 * If we're unmounting then just return, since this does a search on the
3209 * normal root and not the commit root and we could deadlock.
3211 if (btrfs_fs_closing(fs_info))
3214 path = btrfs_alloc_path();
3218 inode = lookup_free_ino_inode(root, path);
3222 if (root_gen != BTRFS_I(inode)->generation)
3225 ret = __load_free_space_cache(root, inode, ctl, path, 0);
3229 "failed to load free ino cache for root %llu",
3230 root->root_key.objectid);
3234 btrfs_free_path(path);
3238 int btrfs_write_out_ino_cache(struct btrfs_root *root,
3239 struct btrfs_trans_handle *trans,
3240 struct btrfs_path *path,
3241 struct inode *inode)
3243 struct btrfs_free_space_ctl *ctl = root->free_ino_ctl;
3246 if (!btrfs_test_opt(root, INODE_MAP_CACHE))
3249 ret = __btrfs_write_out_cache(root, inode, ctl, NULL, trans, path, 0);
3251 btrfs_delalloc_release_metadata(inode, inode->i_size);
3253 btrfs_err(root->fs_info,
3254 "failed to write free ino cache for root %llu",
3255 root->root_key.objectid);
3262 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
3264 * Use this if you need to make a bitmap or extent entry specifically, it
3265 * doesn't do any of the merging that add_free_space does, this acts a lot like
3266 * how the free space cache loading stuff works, so you can get really weird
3269 int test_add_free_space_entry(struct btrfs_block_group_cache *cache,
3270 u64 offset, u64 bytes, bool bitmap)
3272 struct btrfs_free_space_ctl *ctl = cache->free_space_ctl;
3273 struct btrfs_free_space *info = NULL, *bitmap_info;
3280 info = kmem_cache_zalloc(btrfs_free_space_cachep, GFP_NOFS);
3286 spin_lock(&ctl->tree_lock);
3287 info->offset = offset;
3288 info->bytes = bytes;
3289 ret = link_free_space(ctl, info);
3290 spin_unlock(&ctl->tree_lock);
3292 kmem_cache_free(btrfs_free_space_cachep, info);
3297 map = kzalloc(PAGE_CACHE_SIZE, GFP_NOFS);
3299 kmem_cache_free(btrfs_free_space_cachep, info);
3304 spin_lock(&ctl->tree_lock);
3305 bitmap_info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
3310 add_new_bitmap(ctl, info, offset);
3315 bytes_added = add_bytes_to_bitmap(ctl, bitmap_info, offset, bytes);
3316 bytes -= bytes_added;
3317 offset += bytes_added;
3318 spin_unlock(&ctl->tree_lock);
3324 kmem_cache_free(btrfs_free_space_cachep, info);
3331 * Checks to see if the given range is in the free space cache. This is really
3332 * just used to check the absence of space, so if there is free space in the
3333 * range at all we will return 1.
3335 int test_check_exists(struct btrfs_block_group_cache *cache,
3336 u64 offset, u64 bytes)
3338 struct btrfs_free_space_ctl *ctl = cache->free_space_ctl;
3339 struct btrfs_free_space *info;
3342 spin_lock(&ctl->tree_lock);
3343 info = tree_search_offset(ctl, offset, 0, 0);
3345 info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
3353 u64 bit_off, bit_bytes;
3355 struct btrfs_free_space *tmp;
3358 bit_bytes = ctl->unit;
3359 ret = search_bitmap(ctl, info, &bit_off, &bit_bytes);
3361 if (bit_off == offset) {
3364 } else if (bit_off > offset &&
3365 offset + bytes > bit_off) {
3371 n = rb_prev(&info->offset_index);
3373 tmp = rb_entry(n, struct btrfs_free_space,
3375 if (tmp->offset + tmp->bytes < offset)
3377 if (offset + bytes < tmp->offset) {
3378 n = rb_prev(&info->offset_index);
3385 n = rb_next(&info->offset_index);
3387 tmp = rb_entry(n, struct btrfs_free_space,
3389 if (offset + bytes < tmp->offset)
3391 if (tmp->offset + tmp->bytes < offset) {
3392 n = rb_next(&info->offset_index);
3403 if (info->offset == offset) {
3408 if (offset > info->offset && offset < info->offset + info->bytes)
3411 spin_unlock(&ctl->tree_lock);
3414 #endif /* CONFIG_BTRFS_FS_RUN_SANITY_TESTS */