1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 2008 Red Hat. All rights reserved.
6 #include <linux/pagemap.h>
7 #include <linux/sched.h>
8 #include <linux/sched/signal.h>
9 #include <linux/slab.h>
10 #include <linux/math64.h>
11 #include <linux/ratelimit.h>
12 #include <linux/error-injection.h>
13 #include <linux/sched/mm.h>
15 #include "free-space-cache.h"
16 #include "transaction.h"
18 #include "extent_io.h"
19 #include "inode-map.h"
21 #include "space-info.h"
22 #include "delalloc-space.h"
23 #include "block-group.h"
26 #define BITS_PER_BITMAP (PAGE_SIZE * 8UL)
27 #define MAX_CACHE_BYTES_PER_GIG SZ_64K
28 #define FORCE_EXTENT_THRESHOLD SZ_1M
30 struct btrfs_trim_range {
33 struct list_head list;
36 static int count_bitmap_extents(struct btrfs_free_space_ctl *ctl,
37 struct btrfs_free_space *bitmap_info);
38 static int link_free_space(struct btrfs_free_space_ctl *ctl,
39 struct btrfs_free_space *info);
40 static void unlink_free_space(struct btrfs_free_space_ctl *ctl,
41 struct btrfs_free_space *info);
42 static int btrfs_wait_cache_io_root(struct btrfs_root *root,
43 struct btrfs_trans_handle *trans,
44 struct btrfs_io_ctl *io_ctl,
45 struct btrfs_path *path);
47 static struct inode *__lookup_free_space_inode(struct btrfs_root *root,
48 struct btrfs_path *path,
51 struct btrfs_fs_info *fs_info = root->fs_info;
53 struct btrfs_key location;
54 struct btrfs_disk_key disk_key;
55 struct btrfs_free_space_header *header;
56 struct extent_buffer *leaf;
57 struct inode *inode = NULL;
61 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
65 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
69 btrfs_release_path(path);
70 return ERR_PTR(-ENOENT);
73 leaf = path->nodes[0];
74 header = btrfs_item_ptr(leaf, path->slots[0],
75 struct btrfs_free_space_header);
76 btrfs_free_space_key(leaf, header, &disk_key);
77 btrfs_disk_key_to_cpu(&location, &disk_key);
78 btrfs_release_path(path);
81 * We are often under a trans handle at this point, so we need to make
82 * sure NOFS is set to keep us from deadlocking.
84 nofs_flag = memalloc_nofs_save();
85 inode = btrfs_iget_path(fs_info->sb, location.objectid, root, path);
86 btrfs_release_path(path);
87 memalloc_nofs_restore(nofs_flag);
91 mapping_set_gfp_mask(inode->i_mapping,
92 mapping_gfp_constraint(inode->i_mapping,
93 ~(__GFP_FS | __GFP_HIGHMEM)));
98 struct inode *lookup_free_space_inode(struct btrfs_block_group *block_group,
99 struct btrfs_path *path)
101 struct btrfs_fs_info *fs_info = block_group->fs_info;
102 struct inode *inode = NULL;
103 u32 flags = BTRFS_INODE_NODATASUM | BTRFS_INODE_NODATACOW;
105 spin_lock(&block_group->lock);
106 if (block_group->inode)
107 inode = igrab(block_group->inode);
108 spin_unlock(&block_group->lock);
112 inode = __lookup_free_space_inode(fs_info->tree_root, path,
117 spin_lock(&block_group->lock);
118 if (!((BTRFS_I(inode)->flags & flags) == flags)) {
119 btrfs_info(fs_info, "Old style space inode found, converting.");
120 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM |
121 BTRFS_INODE_NODATACOW;
122 block_group->disk_cache_state = BTRFS_DC_CLEAR;
125 if (!block_group->iref) {
126 block_group->inode = igrab(inode);
127 block_group->iref = 1;
129 spin_unlock(&block_group->lock);
134 static int __create_free_space_inode(struct btrfs_root *root,
135 struct btrfs_trans_handle *trans,
136 struct btrfs_path *path,
139 struct btrfs_key key;
140 struct btrfs_disk_key disk_key;
141 struct btrfs_free_space_header *header;
142 struct btrfs_inode_item *inode_item;
143 struct extent_buffer *leaf;
144 u64 flags = BTRFS_INODE_NOCOMPRESS | BTRFS_INODE_PREALLOC;
147 ret = btrfs_insert_empty_inode(trans, root, path, ino);
151 /* We inline crc's for the free disk space cache */
152 if (ino != BTRFS_FREE_INO_OBJECTID)
153 flags |= BTRFS_INODE_NODATASUM | BTRFS_INODE_NODATACOW;
155 leaf = path->nodes[0];
156 inode_item = btrfs_item_ptr(leaf, path->slots[0],
157 struct btrfs_inode_item);
158 btrfs_item_key(leaf, &disk_key, path->slots[0]);
159 memzero_extent_buffer(leaf, (unsigned long)inode_item,
160 sizeof(*inode_item));
161 btrfs_set_inode_generation(leaf, inode_item, trans->transid);
162 btrfs_set_inode_size(leaf, inode_item, 0);
163 btrfs_set_inode_nbytes(leaf, inode_item, 0);
164 btrfs_set_inode_uid(leaf, inode_item, 0);
165 btrfs_set_inode_gid(leaf, inode_item, 0);
166 btrfs_set_inode_mode(leaf, inode_item, S_IFREG | 0600);
167 btrfs_set_inode_flags(leaf, inode_item, flags);
168 btrfs_set_inode_nlink(leaf, inode_item, 1);
169 btrfs_set_inode_transid(leaf, inode_item, trans->transid);
170 btrfs_set_inode_block_group(leaf, inode_item, offset);
171 btrfs_mark_buffer_dirty(leaf);
172 btrfs_release_path(path);
174 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
177 ret = btrfs_insert_empty_item(trans, root, path, &key,
178 sizeof(struct btrfs_free_space_header));
180 btrfs_release_path(path);
184 leaf = path->nodes[0];
185 header = btrfs_item_ptr(leaf, path->slots[0],
186 struct btrfs_free_space_header);
187 memzero_extent_buffer(leaf, (unsigned long)header, sizeof(*header));
188 btrfs_set_free_space_key(leaf, header, &disk_key);
189 btrfs_mark_buffer_dirty(leaf);
190 btrfs_release_path(path);
195 int create_free_space_inode(struct btrfs_trans_handle *trans,
196 struct btrfs_block_group *block_group,
197 struct btrfs_path *path)
202 ret = btrfs_find_free_objectid(trans->fs_info->tree_root, &ino);
206 return __create_free_space_inode(trans->fs_info->tree_root, trans, path,
207 ino, block_group->start);
210 int btrfs_check_trunc_cache_free_space(struct btrfs_fs_info *fs_info,
211 struct btrfs_block_rsv *rsv)
216 /* 1 for slack space, 1 for updating the inode */
217 needed_bytes = btrfs_calc_insert_metadata_size(fs_info, 1) +
218 btrfs_calc_metadata_size(fs_info, 1);
220 spin_lock(&rsv->lock);
221 if (rsv->reserved < needed_bytes)
225 spin_unlock(&rsv->lock);
229 int btrfs_truncate_free_space_cache(struct btrfs_trans_handle *trans,
230 struct btrfs_block_group *block_group,
233 struct btrfs_root *root = BTRFS_I(inode)->root;
238 struct btrfs_path *path = btrfs_alloc_path();
245 mutex_lock(&trans->transaction->cache_write_mutex);
246 if (!list_empty(&block_group->io_list)) {
247 list_del_init(&block_group->io_list);
249 btrfs_wait_cache_io(trans, block_group, path);
250 btrfs_put_block_group(block_group);
254 * now that we've truncated the cache away, its no longer
257 spin_lock(&block_group->lock);
258 block_group->disk_cache_state = BTRFS_DC_CLEAR;
259 spin_unlock(&block_group->lock);
260 btrfs_free_path(path);
263 btrfs_i_size_write(BTRFS_I(inode), 0);
264 truncate_pagecache(inode, 0);
267 * We skip the throttling logic for free space cache inodes, so we don't
268 * need to check for -EAGAIN.
270 ret = btrfs_truncate_inode_items(trans, root, inode,
271 0, BTRFS_EXTENT_DATA_KEY);
275 ret = btrfs_update_inode(trans, root, inode);
279 mutex_unlock(&trans->transaction->cache_write_mutex);
281 btrfs_abort_transaction(trans, ret);
286 static void readahead_cache(struct inode *inode)
288 struct file_ra_state *ra;
289 unsigned long last_index;
291 ra = kzalloc(sizeof(*ra), GFP_NOFS);
295 file_ra_state_init(ra, inode->i_mapping);
296 last_index = (i_size_read(inode) - 1) >> PAGE_SHIFT;
298 page_cache_sync_readahead(inode->i_mapping, ra, NULL, 0, last_index);
303 static int io_ctl_init(struct btrfs_io_ctl *io_ctl, struct inode *inode,
309 num_pages = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE);
311 if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FREE_INO_OBJECTID)
314 /* Make sure we can fit our crcs and generation into the first page */
315 if (write && check_crcs &&
316 (num_pages * sizeof(u32) + sizeof(u64)) > PAGE_SIZE)
319 memset(io_ctl, 0, sizeof(struct btrfs_io_ctl));
321 io_ctl->pages = kcalloc(num_pages, sizeof(struct page *), GFP_NOFS);
325 io_ctl->num_pages = num_pages;
326 io_ctl->fs_info = btrfs_sb(inode->i_sb);
327 io_ctl->check_crcs = check_crcs;
328 io_ctl->inode = inode;
332 ALLOW_ERROR_INJECTION(io_ctl_init, ERRNO);
334 static void io_ctl_free(struct btrfs_io_ctl *io_ctl)
336 kfree(io_ctl->pages);
337 io_ctl->pages = NULL;
340 static void io_ctl_unmap_page(struct btrfs_io_ctl *io_ctl)
348 static void io_ctl_map_page(struct btrfs_io_ctl *io_ctl, int clear)
350 ASSERT(io_ctl->index < io_ctl->num_pages);
351 io_ctl->page = io_ctl->pages[io_ctl->index++];
352 io_ctl->cur = page_address(io_ctl->page);
353 io_ctl->orig = io_ctl->cur;
354 io_ctl->size = PAGE_SIZE;
356 clear_page(io_ctl->cur);
359 static void io_ctl_drop_pages(struct btrfs_io_ctl *io_ctl)
363 io_ctl_unmap_page(io_ctl);
365 for (i = 0; i < io_ctl->num_pages; i++) {
366 if (io_ctl->pages[i]) {
367 ClearPageChecked(io_ctl->pages[i]);
368 unlock_page(io_ctl->pages[i]);
369 put_page(io_ctl->pages[i]);
374 static int io_ctl_prepare_pages(struct btrfs_io_ctl *io_ctl, bool uptodate)
377 struct inode *inode = io_ctl->inode;
378 gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
381 for (i = 0; i < io_ctl->num_pages; i++) {
382 page = find_or_create_page(inode->i_mapping, i, mask);
384 io_ctl_drop_pages(io_ctl);
387 io_ctl->pages[i] = page;
388 if (uptodate && !PageUptodate(page)) {
389 btrfs_readpage(NULL, page);
391 if (page->mapping != inode->i_mapping) {
392 btrfs_err(BTRFS_I(inode)->root->fs_info,
393 "free space cache page truncated");
394 io_ctl_drop_pages(io_ctl);
397 if (!PageUptodate(page)) {
398 btrfs_err(BTRFS_I(inode)->root->fs_info,
399 "error reading free space cache");
400 io_ctl_drop_pages(io_ctl);
406 for (i = 0; i < io_ctl->num_pages; i++) {
407 clear_page_dirty_for_io(io_ctl->pages[i]);
408 set_page_extent_mapped(io_ctl->pages[i]);
414 static void io_ctl_set_generation(struct btrfs_io_ctl *io_ctl, u64 generation)
418 io_ctl_map_page(io_ctl, 1);
421 * Skip the csum areas. If we don't check crcs then we just have a
422 * 64bit chunk at the front of the first page.
424 if (io_ctl->check_crcs) {
425 io_ctl->cur += (sizeof(u32) * io_ctl->num_pages);
426 io_ctl->size -= sizeof(u64) + (sizeof(u32) * io_ctl->num_pages);
428 io_ctl->cur += sizeof(u64);
429 io_ctl->size -= sizeof(u64) * 2;
433 *val = cpu_to_le64(generation);
434 io_ctl->cur += sizeof(u64);
437 static int io_ctl_check_generation(struct btrfs_io_ctl *io_ctl, u64 generation)
442 * Skip the crc area. If we don't check crcs then we just have a 64bit
443 * chunk at the front of the first page.
445 if (io_ctl->check_crcs) {
446 io_ctl->cur += sizeof(u32) * io_ctl->num_pages;
447 io_ctl->size -= sizeof(u64) +
448 (sizeof(u32) * io_ctl->num_pages);
450 io_ctl->cur += sizeof(u64);
451 io_ctl->size -= sizeof(u64) * 2;
455 if (le64_to_cpu(*gen) != generation) {
456 btrfs_err_rl(io_ctl->fs_info,
457 "space cache generation (%llu) does not match inode (%llu)",
459 io_ctl_unmap_page(io_ctl);
462 io_ctl->cur += sizeof(u64);
466 static void io_ctl_set_crc(struct btrfs_io_ctl *io_ctl, int index)
472 if (!io_ctl->check_crcs) {
473 io_ctl_unmap_page(io_ctl);
478 offset = sizeof(u32) * io_ctl->num_pages;
480 crc = btrfs_crc32c(crc, io_ctl->orig + offset, PAGE_SIZE - offset);
481 btrfs_crc32c_final(crc, (u8 *)&crc);
482 io_ctl_unmap_page(io_ctl);
483 tmp = page_address(io_ctl->pages[0]);
488 static int io_ctl_check_crc(struct btrfs_io_ctl *io_ctl, int index)
494 if (!io_ctl->check_crcs) {
495 io_ctl_map_page(io_ctl, 0);
500 offset = sizeof(u32) * io_ctl->num_pages;
502 tmp = page_address(io_ctl->pages[0]);
506 io_ctl_map_page(io_ctl, 0);
507 crc = btrfs_crc32c(crc, io_ctl->orig + offset, PAGE_SIZE - offset);
508 btrfs_crc32c_final(crc, (u8 *)&crc);
510 btrfs_err_rl(io_ctl->fs_info,
511 "csum mismatch on free space cache");
512 io_ctl_unmap_page(io_ctl);
519 static int io_ctl_add_entry(struct btrfs_io_ctl *io_ctl, u64 offset, u64 bytes,
522 struct btrfs_free_space_entry *entry;
528 entry->offset = cpu_to_le64(offset);
529 entry->bytes = cpu_to_le64(bytes);
530 entry->type = (bitmap) ? BTRFS_FREE_SPACE_BITMAP :
531 BTRFS_FREE_SPACE_EXTENT;
532 io_ctl->cur += sizeof(struct btrfs_free_space_entry);
533 io_ctl->size -= sizeof(struct btrfs_free_space_entry);
535 if (io_ctl->size >= sizeof(struct btrfs_free_space_entry))
538 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
540 /* No more pages to map */
541 if (io_ctl->index >= io_ctl->num_pages)
544 /* map the next page */
545 io_ctl_map_page(io_ctl, 1);
549 static int io_ctl_add_bitmap(struct btrfs_io_ctl *io_ctl, void *bitmap)
555 * If we aren't at the start of the current page, unmap this one and
556 * map the next one if there is any left.
558 if (io_ctl->cur != io_ctl->orig) {
559 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
560 if (io_ctl->index >= io_ctl->num_pages)
562 io_ctl_map_page(io_ctl, 0);
565 copy_page(io_ctl->cur, bitmap);
566 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
567 if (io_ctl->index < io_ctl->num_pages)
568 io_ctl_map_page(io_ctl, 0);
572 static void io_ctl_zero_remaining_pages(struct btrfs_io_ctl *io_ctl)
575 * If we're not on the boundary we know we've modified the page and we
576 * need to crc the page.
578 if (io_ctl->cur != io_ctl->orig)
579 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
581 io_ctl_unmap_page(io_ctl);
583 while (io_ctl->index < io_ctl->num_pages) {
584 io_ctl_map_page(io_ctl, 1);
585 io_ctl_set_crc(io_ctl, io_ctl->index - 1);
589 static int io_ctl_read_entry(struct btrfs_io_ctl *io_ctl,
590 struct btrfs_free_space *entry, u8 *type)
592 struct btrfs_free_space_entry *e;
596 ret = io_ctl_check_crc(io_ctl, io_ctl->index);
602 entry->offset = le64_to_cpu(e->offset);
603 entry->bytes = le64_to_cpu(e->bytes);
605 io_ctl->cur += sizeof(struct btrfs_free_space_entry);
606 io_ctl->size -= sizeof(struct btrfs_free_space_entry);
608 if (io_ctl->size >= sizeof(struct btrfs_free_space_entry))
611 io_ctl_unmap_page(io_ctl);
616 static int io_ctl_read_bitmap(struct btrfs_io_ctl *io_ctl,
617 struct btrfs_free_space *entry)
621 ret = io_ctl_check_crc(io_ctl, io_ctl->index);
625 copy_page(entry->bitmap, io_ctl->cur);
626 io_ctl_unmap_page(io_ctl);
632 * Since we attach pinned extents after the fact we can have contiguous sections
633 * of free space that are split up in entries. This poses a problem with the
634 * tree logging stuff since it could have allocated across what appears to be 2
635 * entries since we would have merged the entries when adding the pinned extents
636 * back to the free space cache. So run through the space cache that we just
637 * loaded and merge contiguous entries. This will make the log replay stuff not
638 * blow up and it will make for nicer allocator behavior.
640 static void merge_space_tree(struct btrfs_free_space_ctl *ctl)
642 struct btrfs_free_space *e, *prev = NULL;
646 spin_lock(&ctl->tree_lock);
647 for (n = rb_first(&ctl->free_space_offset); n; n = rb_next(n)) {
648 e = rb_entry(n, struct btrfs_free_space, offset_index);
651 if (e->bitmap || prev->bitmap)
653 if (prev->offset + prev->bytes == e->offset) {
654 unlink_free_space(ctl, prev);
655 unlink_free_space(ctl, e);
656 prev->bytes += e->bytes;
657 kmem_cache_free(btrfs_free_space_cachep, e);
658 link_free_space(ctl, prev);
660 spin_unlock(&ctl->tree_lock);
666 spin_unlock(&ctl->tree_lock);
669 static int __load_free_space_cache(struct btrfs_root *root, struct inode *inode,
670 struct btrfs_free_space_ctl *ctl,
671 struct btrfs_path *path, u64 offset)
673 struct btrfs_fs_info *fs_info = root->fs_info;
674 struct btrfs_free_space_header *header;
675 struct extent_buffer *leaf;
676 struct btrfs_io_ctl io_ctl;
677 struct btrfs_key key;
678 struct btrfs_free_space *e, *n;
686 /* Nothing in the space cache, goodbye */
687 if (!i_size_read(inode))
690 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
694 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
698 btrfs_release_path(path);
704 leaf = path->nodes[0];
705 header = btrfs_item_ptr(leaf, path->slots[0],
706 struct btrfs_free_space_header);
707 num_entries = btrfs_free_space_entries(leaf, header);
708 num_bitmaps = btrfs_free_space_bitmaps(leaf, header);
709 generation = btrfs_free_space_generation(leaf, header);
710 btrfs_release_path(path);
712 if (!BTRFS_I(inode)->generation) {
714 "the free space cache file (%llu) is invalid, skip it",
719 if (BTRFS_I(inode)->generation != generation) {
721 "free space inode generation (%llu) did not match free space cache generation (%llu)",
722 BTRFS_I(inode)->generation, generation);
729 ret = io_ctl_init(&io_ctl, inode, 0);
733 readahead_cache(inode);
735 ret = io_ctl_prepare_pages(&io_ctl, true);
739 ret = io_ctl_check_crc(&io_ctl, 0);
743 ret = io_ctl_check_generation(&io_ctl, generation);
747 while (num_entries) {
748 e = kmem_cache_zalloc(btrfs_free_space_cachep,
753 ret = io_ctl_read_entry(&io_ctl, e, &type);
755 kmem_cache_free(btrfs_free_space_cachep, e);
760 * Sync discard ensures that the free space cache is always
761 * trimmed. So when reading this in, the state should reflect
762 * that. We also do this for async as a stop gap for lack of
765 if (btrfs_test_opt(fs_info, DISCARD_SYNC) ||
766 btrfs_test_opt(fs_info, DISCARD_ASYNC))
767 e->trim_state = BTRFS_TRIM_STATE_TRIMMED;
770 kmem_cache_free(btrfs_free_space_cachep, e);
774 if (type == BTRFS_FREE_SPACE_EXTENT) {
775 spin_lock(&ctl->tree_lock);
776 ret = link_free_space(ctl, e);
777 spin_unlock(&ctl->tree_lock);
780 "Duplicate entries in free space cache, dumping");
781 kmem_cache_free(btrfs_free_space_cachep, e);
787 e->bitmap = kmem_cache_zalloc(
788 btrfs_free_space_bitmap_cachep, GFP_NOFS);
791 btrfs_free_space_cachep, e);
794 spin_lock(&ctl->tree_lock);
795 ret = link_free_space(ctl, e);
796 ctl->total_bitmaps++;
797 ctl->op->recalc_thresholds(ctl);
798 spin_unlock(&ctl->tree_lock);
801 "Duplicate entries in free space cache, dumping");
802 kmem_cache_free(btrfs_free_space_cachep, e);
805 list_add_tail(&e->list, &bitmaps);
811 io_ctl_unmap_page(&io_ctl);
814 * We add the bitmaps at the end of the entries in order that
815 * the bitmap entries are added to the cache.
817 list_for_each_entry_safe(e, n, &bitmaps, list) {
818 list_del_init(&e->list);
819 ret = io_ctl_read_bitmap(&io_ctl, e);
822 e->bitmap_extents = count_bitmap_extents(ctl, e);
823 if (!btrfs_free_space_trimmed(e)) {
824 ctl->discardable_extents[BTRFS_STAT_CURR] +=
826 ctl->discardable_bytes[BTRFS_STAT_CURR] += e->bytes;
830 io_ctl_drop_pages(&io_ctl);
831 merge_space_tree(ctl);
834 btrfs_discard_update_discardable(ctl->private, ctl);
835 io_ctl_free(&io_ctl);
838 io_ctl_drop_pages(&io_ctl);
839 __btrfs_remove_free_space_cache(ctl);
843 int load_free_space_cache(struct btrfs_block_group *block_group)
845 struct btrfs_fs_info *fs_info = block_group->fs_info;
846 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
848 struct btrfs_path *path;
851 u64 used = block_group->used;
854 * If this block group has been marked to be cleared for one reason or
855 * another then we can't trust the on disk cache, so just return.
857 spin_lock(&block_group->lock);
858 if (block_group->disk_cache_state != BTRFS_DC_WRITTEN) {
859 spin_unlock(&block_group->lock);
862 spin_unlock(&block_group->lock);
864 path = btrfs_alloc_path();
867 path->search_commit_root = 1;
868 path->skip_locking = 1;
871 * We must pass a path with search_commit_root set to btrfs_iget in
872 * order to avoid a deadlock when allocating extents for the tree root.
874 * When we are COWing an extent buffer from the tree root, when looking
875 * for a free extent, at extent-tree.c:find_free_extent(), we can find
876 * block group without its free space cache loaded. When we find one
877 * we must load its space cache which requires reading its free space
878 * cache's inode item from the root tree. If this inode item is located
879 * in the same leaf that we started COWing before, then we end up in
880 * deadlock on the extent buffer (trying to read lock it when we
881 * previously write locked it).
883 * It's safe to read the inode item using the commit root because
884 * block groups, once loaded, stay in memory forever (until they are
885 * removed) as well as their space caches once loaded. New block groups
886 * once created get their ->cached field set to BTRFS_CACHE_FINISHED so
887 * we will never try to read their inode item while the fs is mounted.
889 inode = lookup_free_space_inode(block_group, path);
891 btrfs_free_path(path);
895 /* We may have converted the inode and made the cache invalid. */
896 spin_lock(&block_group->lock);
897 if (block_group->disk_cache_state != BTRFS_DC_WRITTEN) {
898 spin_unlock(&block_group->lock);
899 btrfs_free_path(path);
902 spin_unlock(&block_group->lock);
904 ret = __load_free_space_cache(fs_info->tree_root, inode, ctl,
905 path, block_group->start);
906 btrfs_free_path(path);
910 spin_lock(&ctl->tree_lock);
911 matched = (ctl->free_space == (block_group->length - used -
912 block_group->bytes_super));
913 spin_unlock(&ctl->tree_lock);
916 __btrfs_remove_free_space_cache(ctl);
918 "block group %llu has wrong amount of free space",
924 /* This cache is bogus, make sure it gets cleared */
925 spin_lock(&block_group->lock);
926 block_group->disk_cache_state = BTRFS_DC_CLEAR;
927 spin_unlock(&block_group->lock);
931 "failed to load free space cache for block group %llu, rebuilding it now",
939 static noinline_for_stack
940 int write_cache_extent_entries(struct btrfs_io_ctl *io_ctl,
941 struct btrfs_free_space_ctl *ctl,
942 struct btrfs_block_group *block_group,
943 int *entries, int *bitmaps,
944 struct list_head *bitmap_list)
947 struct btrfs_free_cluster *cluster = NULL;
948 struct btrfs_free_cluster *cluster_locked = NULL;
949 struct rb_node *node = rb_first(&ctl->free_space_offset);
950 struct btrfs_trim_range *trim_entry;
952 /* Get the cluster for this block_group if it exists */
953 if (block_group && !list_empty(&block_group->cluster_list)) {
954 cluster = list_entry(block_group->cluster_list.next,
955 struct btrfs_free_cluster,
959 if (!node && cluster) {
960 cluster_locked = cluster;
961 spin_lock(&cluster_locked->lock);
962 node = rb_first(&cluster->root);
966 /* Write out the extent entries */
968 struct btrfs_free_space *e;
970 e = rb_entry(node, struct btrfs_free_space, offset_index);
973 ret = io_ctl_add_entry(io_ctl, e->offset, e->bytes,
979 list_add_tail(&e->list, bitmap_list);
982 node = rb_next(node);
983 if (!node && cluster) {
984 node = rb_first(&cluster->root);
985 cluster_locked = cluster;
986 spin_lock(&cluster_locked->lock);
990 if (cluster_locked) {
991 spin_unlock(&cluster_locked->lock);
992 cluster_locked = NULL;
996 * Make sure we don't miss any range that was removed from our rbtree
997 * because trimming is running. Otherwise after a umount+mount (or crash
998 * after committing the transaction) we would leak free space and get
999 * an inconsistent free space cache report from fsck.
1001 list_for_each_entry(trim_entry, &ctl->trimming_ranges, list) {
1002 ret = io_ctl_add_entry(io_ctl, trim_entry->start,
1003 trim_entry->bytes, NULL);
1012 spin_unlock(&cluster_locked->lock);
1016 static noinline_for_stack int
1017 update_cache_item(struct btrfs_trans_handle *trans,
1018 struct btrfs_root *root,
1019 struct inode *inode,
1020 struct btrfs_path *path, u64 offset,
1021 int entries, int bitmaps)
1023 struct btrfs_key key;
1024 struct btrfs_free_space_header *header;
1025 struct extent_buffer *leaf;
1028 key.objectid = BTRFS_FREE_SPACE_OBJECTID;
1029 key.offset = offset;
1032 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1034 clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, inode->i_size - 1,
1035 EXTENT_DELALLOC, 0, 0, NULL);
1038 leaf = path->nodes[0];
1040 struct btrfs_key found_key;
1041 ASSERT(path->slots[0]);
1043 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1044 if (found_key.objectid != BTRFS_FREE_SPACE_OBJECTID ||
1045 found_key.offset != offset) {
1046 clear_extent_bit(&BTRFS_I(inode)->io_tree, 0,
1047 inode->i_size - 1, EXTENT_DELALLOC, 0,
1049 btrfs_release_path(path);
1054 BTRFS_I(inode)->generation = trans->transid;
1055 header = btrfs_item_ptr(leaf, path->slots[0],
1056 struct btrfs_free_space_header);
1057 btrfs_set_free_space_entries(leaf, header, entries);
1058 btrfs_set_free_space_bitmaps(leaf, header, bitmaps);
1059 btrfs_set_free_space_generation(leaf, header, trans->transid);
1060 btrfs_mark_buffer_dirty(leaf);
1061 btrfs_release_path(path);
1069 static noinline_for_stack int write_pinned_extent_entries(
1070 struct btrfs_trans_handle *trans,
1071 struct btrfs_block_group *block_group,
1072 struct btrfs_io_ctl *io_ctl,
1075 u64 start, extent_start, extent_end, len;
1076 struct extent_io_tree *unpin = NULL;
1083 * We want to add any pinned extents to our free space cache
1084 * so we don't leak the space
1086 * We shouldn't have switched the pinned extents yet so this is the
1089 unpin = &trans->transaction->pinned_extents;
1091 start = block_group->start;
1093 while (start < block_group->start + block_group->length) {
1094 ret = find_first_extent_bit(unpin, start,
1095 &extent_start, &extent_end,
1096 EXTENT_DIRTY, NULL);
1100 /* This pinned extent is out of our range */
1101 if (extent_start >= block_group->start + block_group->length)
1104 extent_start = max(extent_start, start);
1105 extent_end = min(block_group->start + block_group->length,
1107 len = extent_end - extent_start;
1110 ret = io_ctl_add_entry(io_ctl, extent_start, len, NULL);
1120 static noinline_for_stack int
1121 write_bitmap_entries(struct btrfs_io_ctl *io_ctl, struct list_head *bitmap_list)
1123 struct btrfs_free_space *entry, *next;
1126 /* Write out the bitmaps */
1127 list_for_each_entry_safe(entry, next, bitmap_list, list) {
1128 ret = io_ctl_add_bitmap(io_ctl, entry->bitmap);
1131 list_del_init(&entry->list);
1137 static int flush_dirty_cache(struct inode *inode)
1141 ret = btrfs_wait_ordered_range(inode, 0, (u64)-1);
1143 clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, inode->i_size - 1,
1144 EXTENT_DELALLOC, 0, 0, NULL);
1149 static void noinline_for_stack
1150 cleanup_bitmap_list(struct list_head *bitmap_list)
1152 struct btrfs_free_space *entry, *next;
1154 list_for_each_entry_safe(entry, next, bitmap_list, list)
1155 list_del_init(&entry->list);
1158 static void noinline_for_stack
1159 cleanup_write_cache_enospc(struct inode *inode,
1160 struct btrfs_io_ctl *io_ctl,
1161 struct extent_state **cached_state)
1163 io_ctl_drop_pages(io_ctl);
1164 unlock_extent_cached(&BTRFS_I(inode)->io_tree, 0,
1165 i_size_read(inode) - 1, cached_state);
1168 static int __btrfs_wait_cache_io(struct btrfs_root *root,
1169 struct btrfs_trans_handle *trans,
1170 struct btrfs_block_group *block_group,
1171 struct btrfs_io_ctl *io_ctl,
1172 struct btrfs_path *path, u64 offset)
1175 struct inode *inode = io_ctl->inode;
1180 /* Flush the dirty pages in the cache file. */
1181 ret = flush_dirty_cache(inode);
1185 /* Update the cache item to tell everyone this cache file is valid. */
1186 ret = update_cache_item(trans, root, inode, path, offset,
1187 io_ctl->entries, io_ctl->bitmaps);
1189 io_ctl_free(io_ctl);
1191 invalidate_inode_pages2(inode->i_mapping);
1192 BTRFS_I(inode)->generation = 0;
1194 btrfs_debug(root->fs_info,
1195 "failed to write free space cache for block group %llu error %d",
1196 block_group->start, ret);
1198 btrfs_update_inode(trans, root, inode);
1201 /* the dirty list is protected by the dirty_bgs_lock */
1202 spin_lock(&trans->transaction->dirty_bgs_lock);
1204 /* the disk_cache_state is protected by the block group lock */
1205 spin_lock(&block_group->lock);
1208 * only mark this as written if we didn't get put back on
1209 * the dirty list while waiting for IO. Otherwise our
1210 * cache state won't be right, and we won't get written again
1212 if (!ret && list_empty(&block_group->dirty_list))
1213 block_group->disk_cache_state = BTRFS_DC_WRITTEN;
1215 block_group->disk_cache_state = BTRFS_DC_ERROR;
1217 spin_unlock(&block_group->lock);
1218 spin_unlock(&trans->transaction->dirty_bgs_lock);
1219 io_ctl->inode = NULL;
1227 static int btrfs_wait_cache_io_root(struct btrfs_root *root,
1228 struct btrfs_trans_handle *trans,
1229 struct btrfs_io_ctl *io_ctl,
1230 struct btrfs_path *path)
1232 return __btrfs_wait_cache_io(root, trans, NULL, io_ctl, path, 0);
1235 int btrfs_wait_cache_io(struct btrfs_trans_handle *trans,
1236 struct btrfs_block_group *block_group,
1237 struct btrfs_path *path)
1239 return __btrfs_wait_cache_io(block_group->fs_info->tree_root, trans,
1240 block_group, &block_group->io_ctl,
1241 path, block_group->start);
1245 * __btrfs_write_out_cache - write out cached info to an inode
1246 * @root - the root the inode belongs to
1247 * @ctl - the free space cache we are going to write out
1248 * @block_group - the block_group for this cache if it belongs to a block_group
1249 * @trans - the trans handle
1251 * This function writes out a free space cache struct to disk for quick recovery
1252 * on mount. This will return 0 if it was successful in writing the cache out,
1253 * or an errno if it was not.
1255 static int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode,
1256 struct btrfs_free_space_ctl *ctl,
1257 struct btrfs_block_group *block_group,
1258 struct btrfs_io_ctl *io_ctl,
1259 struct btrfs_trans_handle *trans)
1261 struct extent_state *cached_state = NULL;
1262 LIST_HEAD(bitmap_list);
1268 if (!i_size_read(inode))
1271 WARN_ON(io_ctl->pages);
1272 ret = io_ctl_init(io_ctl, inode, 1);
1276 if (block_group && (block_group->flags & BTRFS_BLOCK_GROUP_DATA)) {
1277 down_write(&block_group->data_rwsem);
1278 spin_lock(&block_group->lock);
1279 if (block_group->delalloc_bytes) {
1280 block_group->disk_cache_state = BTRFS_DC_WRITTEN;
1281 spin_unlock(&block_group->lock);
1282 up_write(&block_group->data_rwsem);
1283 BTRFS_I(inode)->generation = 0;
1288 spin_unlock(&block_group->lock);
1291 /* Lock all pages first so we can lock the extent safely. */
1292 ret = io_ctl_prepare_pages(io_ctl, false);
1296 lock_extent_bits(&BTRFS_I(inode)->io_tree, 0, i_size_read(inode) - 1,
1299 io_ctl_set_generation(io_ctl, trans->transid);
1301 mutex_lock(&ctl->cache_writeout_mutex);
1302 /* Write out the extent entries in the free space cache */
1303 spin_lock(&ctl->tree_lock);
1304 ret = write_cache_extent_entries(io_ctl, ctl,
1305 block_group, &entries, &bitmaps,
1308 goto out_nospc_locked;
1311 * Some spaces that are freed in the current transaction are pinned,
1312 * they will be added into free space cache after the transaction is
1313 * committed, we shouldn't lose them.
1315 * If this changes while we are working we'll get added back to
1316 * the dirty list and redo it. No locking needed
1318 ret = write_pinned_extent_entries(trans, block_group, io_ctl, &entries);
1320 goto out_nospc_locked;
1323 * At last, we write out all the bitmaps and keep cache_writeout_mutex
1324 * locked while doing it because a concurrent trim can be manipulating
1325 * or freeing the bitmap.
1327 ret = write_bitmap_entries(io_ctl, &bitmap_list);
1328 spin_unlock(&ctl->tree_lock);
1329 mutex_unlock(&ctl->cache_writeout_mutex);
1333 /* Zero out the rest of the pages just to make sure */
1334 io_ctl_zero_remaining_pages(io_ctl);
1336 /* Everything is written out, now we dirty the pages in the file. */
1337 ret = btrfs_dirty_pages(BTRFS_I(inode), io_ctl->pages,
1338 io_ctl->num_pages, 0, i_size_read(inode),
1343 if (block_group && (block_group->flags & BTRFS_BLOCK_GROUP_DATA))
1344 up_write(&block_group->data_rwsem);
1346 * Release the pages and unlock the extent, we will flush
1349 io_ctl_drop_pages(io_ctl);
1351 unlock_extent_cached(&BTRFS_I(inode)->io_tree, 0,
1352 i_size_read(inode) - 1, &cached_state);
1355 * at this point the pages are under IO and we're happy,
1356 * The caller is responsible for waiting on them and updating the
1357 * the cache and the inode
1359 io_ctl->entries = entries;
1360 io_ctl->bitmaps = bitmaps;
1362 ret = btrfs_fdatawrite_range(inode, 0, (u64)-1);
1369 cleanup_bitmap_list(&bitmap_list);
1370 spin_unlock(&ctl->tree_lock);
1371 mutex_unlock(&ctl->cache_writeout_mutex);
1374 cleanup_write_cache_enospc(inode, io_ctl, &cached_state);
1377 if (block_group && (block_group->flags & BTRFS_BLOCK_GROUP_DATA))
1378 up_write(&block_group->data_rwsem);
1381 io_ctl->inode = NULL;
1382 io_ctl_free(io_ctl);
1384 invalidate_inode_pages2(inode->i_mapping);
1385 BTRFS_I(inode)->generation = 0;
1387 btrfs_update_inode(trans, root, inode);
1393 int btrfs_write_out_cache(struct btrfs_trans_handle *trans,
1394 struct btrfs_block_group *block_group,
1395 struct btrfs_path *path)
1397 struct btrfs_fs_info *fs_info = trans->fs_info;
1398 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
1399 struct inode *inode;
1402 spin_lock(&block_group->lock);
1403 if (block_group->disk_cache_state < BTRFS_DC_SETUP) {
1404 spin_unlock(&block_group->lock);
1407 spin_unlock(&block_group->lock);
1409 inode = lookup_free_space_inode(block_group, path);
1413 ret = __btrfs_write_out_cache(fs_info->tree_root, inode, ctl,
1414 block_group, &block_group->io_ctl, trans);
1416 btrfs_debug(fs_info,
1417 "failed to write free space cache for block group %llu error %d",
1418 block_group->start, ret);
1419 spin_lock(&block_group->lock);
1420 block_group->disk_cache_state = BTRFS_DC_ERROR;
1421 spin_unlock(&block_group->lock);
1423 block_group->io_ctl.inode = NULL;
1428 * if ret == 0 the caller is expected to call btrfs_wait_cache_io
1429 * to wait for IO and put the inode
1435 static inline unsigned long offset_to_bit(u64 bitmap_start, u32 unit,
1438 ASSERT(offset >= bitmap_start);
1439 offset -= bitmap_start;
1440 return (unsigned long)(div_u64(offset, unit));
1443 static inline unsigned long bytes_to_bits(u64 bytes, u32 unit)
1445 return (unsigned long)(div_u64(bytes, unit));
1448 static inline u64 offset_to_bitmap(struct btrfs_free_space_ctl *ctl,
1452 u64 bytes_per_bitmap;
1454 bytes_per_bitmap = BITS_PER_BITMAP * ctl->unit;
1455 bitmap_start = offset - ctl->start;
1456 bitmap_start = div64_u64(bitmap_start, bytes_per_bitmap);
1457 bitmap_start *= bytes_per_bitmap;
1458 bitmap_start += ctl->start;
1460 return bitmap_start;
1463 static int tree_insert_offset(struct rb_root *root, u64 offset,
1464 struct rb_node *node, int bitmap)
1466 struct rb_node **p = &root->rb_node;
1467 struct rb_node *parent = NULL;
1468 struct btrfs_free_space *info;
1472 info = rb_entry(parent, struct btrfs_free_space, offset_index);
1474 if (offset < info->offset) {
1476 } else if (offset > info->offset) {
1477 p = &(*p)->rb_right;
1480 * we could have a bitmap entry and an extent entry
1481 * share the same offset. If this is the case, we want
1482 * the extent entry to always be found first if we do a
1483 * linear search through the tree, since we want to have
1484 * the quickest allocation time, and allocating from an
1485 * extent is faster than allocating from a bitmap. So
1486 * if we're inserting a bitmap and we find an entry at
1487 * this offset, we want to go right, or after this entry
1488 * logically. If we are inserting an extent and we've
1489 * found a bitmap, we want to go left, or before
1497 p = &(*p)->rb_right;
1499 if (!info->bitmap) {
1508 rb_link_node(node, parent, p);
1509 rb_insert_color(node, root);
1515 * searches the tree for the given offset.
1517 * fuzzy - If this is set, then we are trying to make an allocation, and we just
1518 * want a section that has at least bytes size and comes at or after the given
1521 static struct btrfs_free_space *
1522 tree_search_offset(struct btrfs_free_space_ctl *ctl,
1523 u64 offset, int bitmap_only, int fuzzy)
1525 struct rb_node *n = ctl->free_space_offset.rb_node;
1526 struct btrfs_free_space *entry, *prev = NULL;
1528 /* find entry that is closest to the 'offset' */
1535 entry = rb_entry(n, struct btrfs_free_space, offset_index);
1538 if (offset < entry->offset)
1540 else if (offset > entry->offset)
1553 * bitmap entry and extent entry may share same offset,
1554 * in that case, bitmap entry comes after extent entry.
1559 entry = rb_entry(n, struct btrfs_free_space, offset_index);
1560 if (entry->offset != offset)
1563 WARN_ON(!entry->bitmap);
1566 if (entry->bitmap) {
1568 * if previous extent entry covers the offset,
1569 * we should return it instead of the bitmap entry
1571 n = rb_prev(&entry->offset_index);
1573 prev = rb_entry(n, struct btrfs_free_space,
1575 if (!prev->bitmap &&
1576 prev->offset + prev->bytes > offset)
1586 /* find last entry before the 'offset' */
1588 if (entry->offset > offset) {
1589 n = rb_prev(&entry->offset_index);
1591 entry = rb_entry(n, struct btrfs_free_space,
1593 ASSERT(entry->offset <= offset);
1602 if (entry->bitmap) {
1603 n = rb_prev(&entry->offset_index);
1605 prev = rb_entry(n, struct btrfs_free_space,
1607 if (!prev->bitmap &&
1608 prev->offset + prev->bytes > offset)
1611 if (entry->offset + BITS_PER_BITMAP * ctl->unit > offset)
1613 } else if (entry->offset + entry->bytes > offset)
1620 if (entry->bitmap) {
1621 if (entry->offset + BITS_PER_BITMAP *
1625 if (entry->offset + entry->bytes > offset)
1629 n = rb_next(&entry->offset_index);
1632 entry = rb_entry(n, struct btrfs_free_space, offset_index);
1638 __unlink_free_space(struct btrfs_free_space_ctl *ctl,
1639 struct btrfs_free_space *info)
1641 rb_erase(&info->offset_index, &ctl->free_space_offset);
1642 ctl->free_extents--;
1644 if (!info->bitmap && !btrfs_free_space_trimmed(info)) {
1645 ctl->discardable_extents[BTRFS_STAT_CURR]--;
1646 ctl->discardable_bytes[BTRFS_STAT_CURR] -= info->bytes;
1650 static void unlink_free_space(struct btrfs_free_space_ctl *ctl,
1651 struct btrfs_free_space *info)
1653 __unlink_free_space(ctl, info);
1654 ctl->free_space -= info->bytes;
1657 static int link_free_space(struct btrfs_free_space_ctl *ctl,
1658 struct btrfs_free_space *info)
1662 ASSERT(info->bytes || info->bitmap);
1663 ret = tree_insert_offset(&ctl->free_space_offset, info->offset,
1664 &info->offset_index, (info->bitmap != NULL));
1668 if (!info->bitmap && !btrfs_free_space_trimmed(info)) {
1669 ctl->discardable_extents[BTRFS_STAT_CURR]++;
1670 ctl->discardable_bytes[BTRFS_STAT_CURR] += info->bytes;
1673 ctl->free_space += info->bytes;
1674 ctl->free_extents++;
1678 static void recalculate_thresholds(struct btrfs_free_space_ctl *ctl)
1680 struct btrfs_block_group *block_group = ctl->private;
1684 u64 size = block_group->length;
1685 u64 bytes_per_bg = BITS_PER_BITMAP * ctl->unit;
1686 u64 max_bitmaps = div64_u64(size + bytes_per_bg - 1, bytes_per_bg);
1688 max_bitmaps = max_t(u64, max_bitmaps, 1);
1690 ASSERT(ctl->total_bitmaps <= max_bitmaps);
1693 * We are trying to keep the total amount of memory used per 1GiB of
1694 * space to be MAX_CACHE_BYTES_PER_GIG. However, with a reclamation
1695 * mechanism of pulling extents >= FORCE_EXTENT_THRESHOLD out of
1696 * bitmaps, we may end up using more memory than this.
1699 max_bytes = MAX_CACHE_BYTES_PER_GIG;
1701 max_bytes = MAX_CACHE_BYTES_PER_GIG * div_u64(size, SZ_1G);
1703 bitmap_bytes = ctl->total_bitmaps * ctl->unit;
1706 * we want the extent entry threshold to always be at most 1/2 the max
1707 * bytes we can have, or whatever is less than that.
1709 extent_bytes = max_bytes - bitmap_bytes;
1710 extent_bytes = min_t(u64, extent_bytes, max_bytes >> 1);
1712 ctl->extents_thresh =
1713 div_u64(extent_bytes, sizeof(struct btrfs_free_space));
1716 static inline void __bitmap_clear_bits(struct btrfs_free_space_ctl *ctl,
1717 struct btrfs_free_space *info,
1718 u64 offset, u64 bytes)
1720 unsigned long start, count, end;
1721 int extent_delta = -1;
1723 start = offset_to_bit(info->offset, ctl->unit, offset);
1724 count = bytes_to_bits(bytes, ctl->unit);
1725 end = start + count;
1726 ASSERT(end <= BITS_PER_BITMAP);
1728 bitmap_clear(info->bitmap, start, count);
1730 info->bytes -= bytes;
1731 if (info->max_extent_size > ctl->unit)
1732 info->max_extent_size = 0;
1734 if (start && test_bit(start - 1, info->bitmap))
1737 if (end < BITS_PER_BITMAP && test_bit(end, info->bitmap))
1740 info->bitmap_extents += extent_delta;
1741 if (!btrfs_free_space_trimmed(info)) {
1742 ctl->discardable_extents[BTRFS_STAT_CURR] += extent_delta;
1743 ctl->discardable_bytes[BTRFS_STAT_CURR] -= bytes;
1747 static void bitmap_clear_bits(struct btrfs_free_space_ctl *ctl,
1748 struct btrfs_free_space *info, u64 offset,
1751 __bitmap_clear_bits(ctl, info, offset, bytes);
1752 ctl->free_space -= bytes;
1755 static void bitmap_set_bits(struct btrfs_free_space_ctl *ctl,
1756 struct btrfs_free_space *info, u64 offset,
1759 unsigned long start, count, end;
1760 int extent_delta = 1;
1762 start = offset_to_bit(info->offset, ctl->unit, offset);
1763 count = bytes_to_bits(bytes, ctl->unit);
1764 end = start + count;
1765 ASSERT(end <= BITS_PER_BITMAP);
1767 bitmap_set(info->bitmap, start, count);
1769 info->bytes += bytes;
1770 ctl->free_space += bytes;
1772 if (start && test_bit(start - 1, info->bitmap))
1775 if (end < BITS_PER_BITMAP && test_bit(end, info->bitmap))
1778 info->bitmap_extents += extent_delta;
1779 if (!btrfs_free_space_trimmed(info)) {
1780 ctl->discardable_extents[BTRFS_STAT_CURR] += extent_delta;
1781 ctl->discardable_bytes[BTRFS_STAT_CURR] += bytes;
1786 * If we can not find suitable extent, we will use bytes to record
1787 * the size of the max extent.
1789 static int search_bitmap(struct btrfs_free_space_ctl *ctl,
1790 struct btrfs_free_space *bitmap_info, u64 *offset,
1791 u64 *bytes, bool for_alloc)
1793 unsigned long found_bits = 0;
1794 unsigned long max_bits = 0;
1795 unsigned long bits, i;
1796 unsigned long next_zero;
1797 unsigned long extent_bits;
1800 * Skip searching the bitmap if we don't have a contiguous section that
1801 * is large enough for this allocation.
1804 bitmap_info->max_extent_size &&
1805 bitmap_info->max_extent_size < *bytes) {
1806 *bytes = bitmap_info->max_extent_size;
1810 i = offset_to_bit(bitmap_info->offset, ctl->unit,
1811 max_t(u64, *offset, bitmap_info->offset));
1812 bits = bytes_to_bits(*bytes, ctl->unit);
1814 for_each_set_bit_from(i, bitmap_info->bitmap, BITS_PER_BITMAP) {
1815 if (for_alloc && bits == 1) {
1819 next_zero = find_next_zero_bit(bitmap_info->bitmap,
1820 BITS_PER_BITMAP, i);
1821 extent_bits = next_zero - i;
1822 if (extent_bits >= bits) {
1823 found_bits = extent_bits;
1825 } else if (extent_bits > max_bits) {
1826 max_bits = extent_bits;
1832 *offset = (u64)(i * ctl->unit) + bitmap_info->offset;
1833 *bytes = (u64)(found_bits) * ctl->unit;
1837 *bytes = (u64)(max_bits) * ctl->unit;
1838 bitmap_info->max_extent_size = *bytes;
1842 static inline u64 get_max_extent_size(struct btrfs_free_space *entry)
1845 return entry->max_extent_size;
1846 return entry->bytes;
1849 /* Cache the size of the max extent in bytes */
1850 static struct btrfs_free_space *
1851 find_free_space(struct btrfs_free_space_ctl *ctl, u64 *offset, u64 *bytes,
1852 unsigned long align, u64 *max_extent_size)
1854 struct btrfs_free_space *entry;
1855 struct rb_node *node;
1860 if (!ctl->free_space_offset.rb_node)
1863 entry = tree_search_offset(ctl, offset_to_bitmap(ctl, *offset), 0, 1);
1867 for (node = &entry->offset_index; node; node = rb_next(node)) {
1868 entry = rb_entry(node, struct btrfs_free_space, offset_index);
1869 if (entry->bytes < *bytes) {
1870 *max_extent_size = max(get_max_extent_size(entry),
1875 /* make sure the space returned is big enough
1876 * to match our requested alignment
1878 if (*bytes >= align) {
1879 tmp = entry->offset - ctl->start + align - 1;
1880 tmp = div64_u64(tmp, align);
1881 tmp = tmp * align + ctl->start;
1882 align_off = tmp - entry->offset;
1885 tmp = entry->offset;
1888 if (entry->bytes < *bytes + align_off) {
1889 *max_extent_size = max(get_max_extent_size(entry),
1894 if (entry->bitmap) {
1897 ret = search_bitmap(ctl, entry, &tmp, &size, true);
1904 max(get_max_extent_size(entry),
1911 *bytes = entry->bytes - align_off;
1918 static int count_bitmap_extents(struct btrfs_free_space_ctl *ctl,
1919 struct btrfs_free_space *bitmap_info)
1921 struct btrfs_block_group *block_group = ctl->private;
1922 u64 bytes = bitmap_info->bytes;
1923 unsigned int rs, re;
1926 if (!block_group || !bytes)
1929 bitmap_for_each_set_region(bitmap_info->bitmap, rs, re, 0,
1931 bytes -= (rs - re) * ctl->unit;
1941 static void add_new_bitmap(struct btrfs_free_space_ctl *ctl,
1942 struct btrfs_free_space *info, u64 offset)
1944 info->offset = offset_to_bitmap(ctl, offset);
1946 info->bitmap_extents = 0;
1947 INIT_LIST_HEAD(&info->list);
1948 link_free_space(ctl, info);
1949 ctl->total_bitmaps++;
1951 ctl->op->recalc_thresholds(ctl);
1954 static void free_bitmap(struct btrfs_free_space_ctl *ctl,
1955 struct btrfs_free_space *bitmap_info)
1958 * Normally when this is called, the bitmap is completely empty. However,
1959 * if we are blowing up the free space cache for one reason or another
1960 * via __btrfs_remove_free_space_cache(), then it may not be freed and
1961 * we may leave stats on the table.
1963 if (bitmap_info->bytes && !btrfs_free_space_trimmed(bitmap_info)) {
1964 ctl->discardable_extents[BTRFS_STAT_CURR] -=
1965 bitmap_info->bitmap_extents;
1966 ctl->discardable_bytes[BTRFS_STAT_CURR] -= bitmap_info->bytes;
1969 unlink_free_space(ctl, bitmap_info);
1970 kmem_cache_free(btrfs_free_space_bitmap_cachep, bitmap_info->bitmap);
1971 kmem_cache_free(btrfs_free_space_cachep, bitmap_info);
1972 ctl->total_bitmaps--;
1973 ctl->op->recalc_thresholds(ctl);
1976 static noinline int remove_from_bitmap(struct btrfs_free_space_ctl *ctl,
1977 struct btrfs_free_space *bitmap_info,
1978 u64 *offset, u64 *bytes)
1981 u64 search_start, search_bytes;
1985 end = bitmap_info->offset + (u64)(BITS_PER_BITMAP * ctl->unit) - 1;
1988 * We need to search for bits in this bitmap. We could only cover some
1989 * of the extent in this bitmap thanks to how we add space, so we need
1990 * to search for as much as it as we can and clear that amount, and then
1991 * go searching for the next bit.
1993 search_start = *offset;
1994 search_bytes = ctl->unit;
1995 search_bytes = min(search_bytes, end - search_start + 1);
1996 ret = search_bitmap(ctl, bitmap_info, &search_start, &search_bytes,
1998 if (ret < 0 || search_start != *offset)
2001 /* We may have found more bits than what we need */
2002 search_bytes = min(search_bytes, *bytes);
2004 /* Cannot clear past the end of the bitmap */
2005 search_bytes = min(search_bytes, end - search_start + 1);
2007 bitmap_clear_bits(ctl, bitmap_info, search_start, search_bytes);
2008 *offset += search_bytes;
2009 *bytes -= search_bytes;
2012 struct rb_node *next = rb_next(&bitmap_info->offset_index);
2013 if (!bitmap_info->bytes)
2014 free_bitmap(ctl, bitmap_info);
2017 * no entry after this bitmap, but we still have bytes to
2018 * remove, so something has gone wrong.
2023 bitmap_info = rb_entry(next, struct btrfs_free_space,
2027 * if the next entry isn't a bitmap we need to return to let the
2028 * extent stuff do its work.
2030 if (!bitmap_info->bitmap)
2034 * Ok the next item is a bitmap, but it may not actually hold
2035 * the information for the rest of this free space stuff, so
2036 * look for it, and if we don't find it return so we can try
2037 * everything over again.
2039 search_start = *offset;
2040 search_bytes = ctl->unit;
2041 ret = search_bitmap(ctl, bitmap_info, &search_start,
2042 &search_bytes, false);
2043 if (ret < 0 || search_start != *offset)
2047 } else if (!bitmap_info->bytes)
2048 free_bitmap(ctl, bitmap_info);
2053 static u64 add_bytes_to_bitmap(struct btrfs_free_space_ctl *ctl,
2054 struct btrfs_free_space *info, u64 offset,
2055 u64 bytes, enum btrfs_trim_state trim_state)
2057 u64 bytes_to_set = 0;
2061 * This is a tradeoff to make bitmap trim state minimal. We mark the
2062 * whole bitmap untrimmed if at any point we add untrimmed regions.
2064 if (trim_state == BTRFS_TRIM_STATE_UNTRIMMED) {
2065 if (btrfs_free_space_trimmed(info)) {
2066 ctl->discardable_extents[BTRFS_STAT_CURR] +=
2067 info->bitmap_extents;
2068 ctl->discardable_bytes[BTRFS_STAT_CURR] += info->bytes;
2070 info->trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
2073 end = info->offset + (u64)(BITS_PER_BITMAP * ctl->unit);
2075 bytes_to_set = min(end - offset, bytes);
2077 bitmap_set_bits(ctl, info, offset, bytes_to_set);
2080 * We set some bytes, we have no idea what the max extent size is
2083 info->max_extent_size = 0;
2085 return bytes_to_set;
2089 static bool use_bitmap(struct btrfs_free_space_ctl *ctl,
2090 struct btrfs_free_space *info)
2092 struct btrfs_block_group *block_group = ctl->private;
2093 struct btrfs_fs_info *fs_info = block_group->fs_info;
2094 bool forced = false;
2096 #ifdef CONFIG_BTRFS_DEBUG
2097 if (btrfs_should_fragment_free_space(block_group))
2101 /* This is a way to reclaim large regions from the bitmaps. */
2102 if (!forced && info->bytes >= FORCE_EXTENT_THRESHOLD)
2106 * If we are below the extents threshold then we can add this as an
2107 * extent, and don't have to deal with the bitmap
2109 if (!forced && ctl->free_extents < ctl->extents_thresh) {
2111 * If this block group has some small extents we don't want to
2112 * use up all of our free slots in the cache with them, we want
2113 * to reserve them to larger extents, however if we have plenty
2114 * of cache left then go ahead an dadd them, no sense in adding
2115 * the overhead of a bitmap if we don't have to.
2117 if (info->bytes <= fs_info->sectorsize * 8) {
2118 if (ctl->free_extents * 3 <= ctl->extents_thresh)
2126 * The original block groups from mkfs can be really small, like 8
2127 * megabytes, so don't bother with a bitmap for those entries. However
2128 * some block groups can be smaller than what a bitmap would cover but
2129 * are still large enough that they could overflow the 32k memory limit,
2130 * so allow those block groups to still be allowed to have a bitmap
2133 if (((BITS_PER_BITMAP * ctl->unit) >> 1) > block_group->length)
2139 static const struct btrfs_free_space_op free_space_op = {
2140 .recalc_thresholds = recalculate_thresholds,
2141 .use_bitmap = use_bitmap,
2144 static int insert_into_bitmap(struct btrfs_free_space_ctl *ctl,
2145 struct btrfs_free_space *info)
2147 struct btrfs_free_space *bitmap_info;
2148 struct btrfs_block_group *block_group = NULL;
2150 u64 bytes, offset, bytes_added;
2151 enum btrfs_trim_state trim_state;
2154 bytes = info->bytes;
2155 offset = info->offset;
2156 trim_state = info->trim_state;
2158 if (!ctl->op->use_bitmap(ctl, info))
2161 if (ctl->op == &free_space_op)
2162 block_group = ctl->private;
2165 * Since we link bitmaps right into the cluster we need to see if we
2166 * have a cluster here, and if so and it has our bitmap we need to add
2167 * the free space to that bitmap.
2169 if (block_group && !list_empty(&block_group->cluster_list)) {
2170 struct btrfs_free_cluster *cluster;
2171 struct rb_node *node;
2172 struct btrfs_free_space *entry;
2174 cluster = list_entry(block_group->cluster_list.next,
2175 struct btrfs_free_cluster,
2177 spin_lock(&cluster->lock);
2178 node = rb_first(&cluster->root);
2180 spin_unlock(&cluster->lock);
2181 goto no_cluster_bitmap;
2184 entry = rb_entry(node, struct btrfs_free_space, offset_index);
2185 if (!entry->bitmap) {
2186 spin_unlock(&cluster->lock);
2187 goto no_cluster_bitmap;
2190 if (entry->offset == offset_to_bitmap(ctl, offset)) {
2191 bytes_added = add_bytes_to_bitmap(ctl, entry, offset,
2193 bytes -= bytes_added;
2194 offset += bytes_added;
2196 spin_unlock(&cluster->lock);
2204 bitmap_info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
2211 bytes_added = add_bytes_to_bitmap(ctl, bitmap_info, offset, bytes,
2213 bytes -= bytes_added;
2214 offset += bytes_added;
2224 if (info && info->bitmap) {
2225 add_new_bitmap(ctl, info, offset);
2230 spin_unlock(&ctl->tree_lock);
2232 /* no pre-allocated info, allocate a new one */
2234 info = kmem_cache_zalloc(btrfs_free_space_cachep,
2237 spin_lock(&ctl->tree_lock);
2243 /* allocate the bitmap */
2244 info->bitmap = kmem_cache_zalloc(btrfs_free_space_bitmap_cachep,
2246 info->trim_state = BTRFS_TRIM_STATE_TRIMMED;
2247 spin_lock(&ctl->tree_lock);
2248 if (!info->bitmap) {
2258 kmem_cache_free(btrfs_free_space_bitmap_cachep,
2260 kmem_cache_free(btrfs_free_space_cachep, info);
2267 * Free space merging rules:
2268 * 1) Merge trimmed areas together
2269 * 2) Let untrimmed areas coalesce with trimmed areas
2270 * 3) Always pull neighboring regions from bitmaps
2272 * The above rules are for when we merge free space based on btrfs_trim_state.
2273 * Rules 2 and 3 are subtle because they are suboptimal, but are done for the
2274 * same reason: to promote larger extent regions which makes life easier for
2275 * find_free_extent(). Rule 2 enables coalescing based on the common path
2276 * being returning free space from btrfs_finish_extent_commit(). So when free
2277 * space is trimmed, it will prevent aggregating trimmed new region and
2278 * untrimmed regions in the rb_tree. Rule 3 is purely to obtain larger extents
2279 * and provide find_free_extent() with the largest extents possible hoping for
2282 static bool try_merge_free_space(struct btrfs_free_space_ctl *ctl,
2283 struct btrfs_free_space *info, bool update_stat)
2285 struct btrfs_free_space *left_info;
2286 struct btrfs_free_space *right_info;
2287 bool merged = false;
2288 u64 offset = info->offset;
2289 u64 bytes = info->bytes;
2290 const bool is_trimmed = btrfs_free_space_trimmed(info);
2293 * first we want to see if there is free space adjacent to the range we
2294 * are adding, if there is remove that struct and add a new one to
2295 * cover the entire range
2297 right_info = tree_search_offset(ctl, offset + bytes, 0, 0);
2298 if (right_info && rb_prev(&right_info->offset_index))
2299 left_info = rb_entry(rb_prev(&right_info->offset_index),
2300 struct btrfs_free_space, offset_index);
2302 left_info = tree_search_offset(ctl, offset - 1, 0, 0);
2304 /* See try_merge_free_space() comment. */
2305 if (right_info && !right_info->bitmap &&
2306 (!is_trimmed || btrfs_free_space_trimmed(right_info))) {
2308 unlink_free_space(ctl, right_info);
2310 __unlink_free_space(ctl, right_info);
2311 info->bytes += right_info->bytes;
2312 kmem_cache_free(btrfs_free_space_cachep, right_info);
2316 /* See try_merge_free_space() comment. */
2317 if (left_info && !left_info->bitmap &&
2318 left_info->offset + left_info->bytes == offset &&
2319 (!is_trimmed || btrfs_free_space_trimmed(left_info))) {
2321 unlink_free_space(ctl, left_info);
2323 __unlink_free_space(ctl, left_info);
2324 info->offset = left_info->offset;
2325 info->bytes += left_info->bytes;
2326 kmem_cache_free(btrfs_free_space_cachep, left_info);
2333 static bool steal_from_bitmap_to_end(struct btrfs_free_space_ctl *ctl,
2334 struct btrfs_free_space *info,
2337 struct btrfs_free_space *bitmap;
2340 const u64 end = info->offset + info->bytes;
2341 const u64 bitmap_offset = offset_to_bitmap(ctl, end);
2344 bitmap = tree_search_offset(ctl, bitmap_offset, 1, 0);
2348 i = offset_to_bit(bitmap->offset, ctl->unit, end);
2349 j = find_next_zero_bit(bitmap->bitmap, BITS_PER_BITMAP, i);
2352 bytes = (j - i) * ctl->unit;
2353 info->bytes += bytes;
2355 /* See try_merge_free_space() comment. */
2356 if (!btrfs_free_space_trimmed(bitmap))
2357 info->trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
2360 bitmap_clear_bits(ctl, bitmap, end, bytes);
2362 __bitmap_clear_bits(ctl, bitmap, end, bytes);
2365 free_bitmap(ctl, bitmap);
2370 static bool steal_from_bitmap_to_front(struct btrfs_free_space_ctl *ctl,
2371 struct btrfs_free_space *info,
2374 struct btrfs_free_space *bitmap;
2378 unsigned long prev_j;
2381 bitmap_offset = offset_to_bitmap(ctl, info->offset);
2382 /* If we're on a boundary, try the previous logical bitmap. */
2383 if (bitmap_offset == info->offset) {
2384 if (info->offset == 0)
2386 bitmap_offset = offset_to_bitmap(ctl, info->offset - 1);
2389 bitmap = tree_search_offset(ctl, bitmap_offset, 1, 0);
2393 i = offset_to_bit(bitmap->offset, ctl->unit, info->offset) - 1;
2395 prev_j = (unsigned long)-1;
2396 for_each_clear_bit_from(j, bitmap->bitmap, BITS_PER_BITMAP) {
2404 if (prev_j == (unsigned long)-1)
2405 bytes = (i + 1) * ctl->unit;
2407 bytes = (i - prev_j) * ctl->unit;
2409 info->offset -= bytes;
2410 info->bytes += bytes;
2412 /* See try_merge_free_space() comment. */
2413 if (!btrfs_free_space_trimmed(bitmap))
2414 info->trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
2417 bitmap_clear_bits(ctl, bitmap, info->offset, bytes);
2419 __bitmap_clear_bits(ctl, bitmap, info->offset, bytes);
2422 free_bitmap(ctl, bitmap);
2428 * We prefer always to allocate from extent entries, both for clustered and
2429 * non-clustered allocation requests. So when attempting to add a new extent
2430 * entry, try to see if there's adjacent free space in bitmap entries, and if
2431 * there is, migrate that space from the bitmaps to the extent.
2432 * Like this we get better chances of satisfying space allocation requests
2433 * because we attempt to satisfy them based on a single cache entry, and never
2434 * on 2 or more entries - even if the entries represent a contiguous free space
2435 * region (e.g. 1 extent entry + 1 bitmap entry starting where the extent entry
2438 static void steal_from_bitmap(struct btrfs_free_space_ctl *ctl,
2439 struct btrfs_free_space *info,
2443 * Only work with disconnected entries, as we can change their offset,
2444 * and must be extent entries.
2446 ASSERT(!info->bitmap);
2447 ASSERT(RB_EMPTY_NODE(&info->offset_index));
2449 if (ctl->total_bitmaps > 0) {
2451 bool stole_front = false;
2453 stole_end = steal_from_bitmap_to_end(ctl, info, update_stat);
2454 if (ctl->total_bitmaps > 0)
2455 stole_front = steal_from_bitmap_to_front(ctl, info,
2458 if (stole_end || stole_front)
2459 try_merge_free_space(ctl, info, update_stat);
2463 int __btrfs_add_free_space(struct btrfs_fs_info *fs_info,
2464 struct btrfs_free_space_ctl *ctl,
2465 u64 offset, u64 bytes,
2466 enum btrfs_trim_state trim_state)
2468 struct btrfs_block_group *block_group = ctl->private;
2469 struct btrfs_free_space *info;
2471 u64 filter_bytes = bytes;
2473 info = kmem_cache_zalloc(btrfs_free_space_cachep, GFP_NOFS);
2477 info->offset = offset;
2478 info->bytes = bytes;
2479 info->trim_state = trim_state;
2480 RB_CLEAR_NODE(&info->offset_index);
2482 spin_lock(&ctl->tree_lock);
2484 if (try_merge_free_space(ctl, info, true))
2488 * There was no extent directly to the left or right of this new
2489 * extent then we know we're going to have to allocate a new extent, so
2490 * before we do that see if we need to drop this into a bitmap
2492 ret = insert_into_bitmap(ctl, info);
2501 * Only steal free space from adjacent bitmaps if we're sure we're not
2502 * going to add the new free space to existing bitmap entries - because
2503 * that would mean unnecessary work that would be reverted. Therefore
2504 * attempt to steal space from bitmaps if we're adding an extent entry.
2506 steal_from_bitmap(ctl, info, true);
2508 filter_bytes = max(filter_bytes, info->bytes);
2510 ret = link_free_space(ctl, info);
2512 kmem_cache_free(btrfs_free_space_cachep, info);
2514 btrfs_discard_update_discardable(block_group, ctl);
2515 spin_unlock(&ctl->tree_lock);
2518 btrfs_crit(fs_info, "unable to add free space :%d", ret);
2519 ASSERT(ret != -EEXIST);
2522 if (trim_state != BTRFS_TRIM_STATE_TRIMMED) {
2523 btrfs_discard_check_filter(block_group, filter_bytes);
2524 btrfs_discard_queue_work(&fs_info->discard_ctl, block_group);
2530 int btrfs_add_free_space(struct btrfs_block_group *block_group,
2531 u64 bytenr, u64 size)
2533 enum btrfs_trim_state trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
2535 if (btrfs_test_opt(block_group->fs_info, DISCARD_SYNC))
2536 trim_state = BTRFS_TRIM_STATE_TRIMMED;
2538 return __btrfs_add_free_space(block_group->fs_info,
2539 block_group->free_space_ctl,
2540 bytenr, size, trim_state);
2544 * This is a subtle distinction because when adding free space back in general,
2545 * we want it to be added as untrimmed for async. But in the case where we add
2546 * it on loading of a block group, we want to consider it trimmed.
2548 int btrfs_add_free_space_async_trimmed(struct btrfs_block_group *block_group,
2549 u64 bytenr, u64 size)
2551 enum btrfs_trim_state trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
2553 if (btrfs_test_opt(block_group->fs_info, DISCARD_SYNC) ||
2554 btrfs_test_opt(block_group->fs_info, DISCARD_ASYNC))
2555 trim_state = BTRFS_TRIM_STATE_TRIMMED;
2557 return __btrfs_add_free_space(block_group->fs_info,
2558 block_group->free_space_ctl,
2559 bytenr, size, trim_state);
2562 int btrfs_remove_free_space(struct btrfs_block_group *block_group,
2563 u64 offset, u64 bytes)
2565 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2566 struct btrfs_free_space *info;
2568 bool re_search = false;
2570 spin_lock(&ctl->tree_lock);
2577 info = tree_search_offset(ctl, offset, 0, 0);
2580 * oops didn't find an extent that matched the space we wanted
2581 * to remove, look for a bitmap instead
2583 info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
2587 * If we found a partial bit of our free space in a
2588 * bitmap but then couldn't find the other part this may
2589 * be a problem, so WARN about it.
2597 if (!info->bitmap) {
2598 unlink_free_space(ctl, info);
2599 if (offset == info->offset) {
2600 u64 to_free = min(bytes, info->bytes);
2602 info->bytes -= to_free;
2603 info->offset += to_free;
2605 ret = link_free_space(ctl, info);
2608 kmem_cache_free(btrfs_free_space_cachep, info);
2615 u64 old_end = info->bytes + info->offset;
2617 info->bytes = offset - info->offset;
2618 ret = link_free_space(ctl, info);
2623 /* Not enough bytes in this entry to satisfy us */
2624 if (old_end < offset + bytes) {
2625 bytes -= old_end - offset;
2628 } else if (old_end == offset + bytes) {
2632 spin_unlock(&ctl->tree_lock);
2634 ret = __btrfs_add_free_space(block_group->fs_info, ctl,
2636 old_end - (offset + bytes),
2643 ret = remove_from_bitmap(ctl, info, &offset, &bytes);
2644 if (ret == -EAGAIN) {
2649 btrfs_discard_update_discardable(block_group, ctl);
2650 spin_unlock(&ctl->tree_lock);
2655 void btrfs_dump_free_space(struct btrfs_block_group *block_group,
2658 struct btrfs_fs_info *fs_info = block_group->fs_info;
2659 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2660 struct btrfs_free_space *info;
2664 spin_lock(&ctl->tree_lock);
2665 for (n = rb_first(&ctl->free_space_offset); n; n = rb_next(n)) {
2666 info = rb_entry(n, struct btrfs_free_space, offset_index);
2667 if (info->bytes >= bytes && !block_group->ro)
2669 btrfs_crit(fs_info, "entry offset %llu, bytes %llu, bitmap %s",
2670 info->offset, info->bytes,
2671 (info->bitmap) ? "yes" : "no");
2673 spin_unlock(&ctl->tree_lock);
2674 btrfs_info(fs_info, "block group has cluster?: %s",
2675 list_empty(&block_group->cluster_list) ? "no" : "yes");
2677 "%d blocks of free space at or bigger than bytes is", count);
2680 void btrfs_init_free_space_ctl(struct btrfs_block_group *block_group)
2682 struct btrfs_fs_info *fs_info = block_group->fs_info;
2683 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2685 spin_lock_init(&ctl->tree_lock);
2686 ctl->unit = fs_info->sectorsize;
2687 ctl->start = block_group->start;
2688 ctl->private = block_group;
2689 ctl->op = &free_space_op;
2690 INIT_LIST_HEAD(&ctl->trimming_ranges);
2691 mutex_init(&ctl->cache_writeout_mutex);
2694 * we only want to have 32k of ram per block group for keeping
2695 * track of free space, and if we pass 1/2 of that we want to
2696 * start converting things over to using bitmaps
2698 ctl->extents_thresh = (SZ_32K / 2) / sizeof(struct btrfs_free_space);
2702 * for a given cluster, put all of its extents back into the free
2703 * space cache. If the block group passed doesn't match the block group
2704 * pointed to by the cluster, someone else raced in and freed the
2705 * cluster already. In that case, we just return without changing anything
2707 static void __btrfs_return_cluster_to_free_space(
2708 struct btrfs_block_group *block_group,
2709 struct btrfs_free_cluster *cluster)
2711 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2712 struct btrfs_free_space *entry;
2713 struct rb_node *node;
2715 spin_lock(&cluster->lock);
2716 if (cluster->block_group != block_group)
2719 cluster->block_group = NULL;
2720 cluster->window_start = 0;
2721 list_del_init(&cluster->block_group_list);
2723 node = rb_first(&cluster->root);
2727 entry = rb_entry(node, struct btrfs_free_space, offset_index);
2728 node = rb_next(&entry->offset_index);
2729 rb_erase(&entry->offset_index, &cluster->root);
2730 RB_CLEAR_NODE(&entry->offset_index);
2732 bitmap = (entry->bitmap != NULL);
2734 /* Merging treats extents as if they were new */
2735 if (!btrfs_free_space_trimmed(entry)) {
2736 ctl->discardable_extents[BTRFS_STAT_CURR]--;
2737 ctl->discardable_bytes[BTRFS_STAT_CURR] -=
2741 try_merge_free_space(ctl, entry, false);
2742 steal_from_bitmap(ctl, entry, false);
2744 /* As we insert directly, update these statistics */
2745 if (!btrfs_free_space_trimmed(entry)) {
2746 ctl->discardable_extents[BTRFS_STAT_CURR]++;
2747 ctl->discardable_bytes[BTRFS_STAT_CURR] +=
2751 tree_insert_offset(&ctl->free_space_offset,
2752 entry->offset, &entry->offset_index, bitmap);
2754 cluster->root = RB_ROOT;
2757 spin_unlock(&cluster->lock);
2758 btrfs_put_block_group(block_group);
2761 static void __btrfs_remove_free_space_cache_locked(
2762 struct btrfs_free_space_ctl *ctl)
2764 struct btrfs_free_space *info;
2765 struct rb_node *node;
2767 while ((node = rb_last(&ctl->free_space_offset)) != NULL) {
2768 info = rb_entry(node, struct btrfs_free_space, offset_index);
2769 if (!info->bitmap) {
2770 unlink_free_space(ctl, info);
2771 kmem_cache_free(btrfs_free_space_cachep, info);
2773 free_bitmap(ctl, info);
2776 cond_resched_lock(&ctl->tree_lock);
2780 void __btrfs_remove_free_space_cache(struct btrfs_free_space_ctl *ctl)
2782 spin_lock(&ctl->tree_lock);
2783 __btrfs_remove_free_space_cache_locked(ctl);
2785 btrfs_discard_update_discardable(ctl->private, ctl);
2786 spin_unlock(&ctl->tree_lock);
2789 void btrfs_remove_free_space_cache(struct btrfs_block_group *block_group)
2791 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2792 struct btrfs_free_cluster *cluster;
2793 struct list_head *head;
2795 spin_lock(&ctl->tree_lock);
2796 while ((head = block_group->cluster_list.next) !=
2797 &block_group->cluster_list) {
2798 cluster = list_entry(head, struct btrfs_free_cluster,
2801 WARN_ON(cluster->block_group != block_group);
2802 __btrfs_return_cluster_to_free_space(block_group, cluster);
2804 cond_resched_lock(&ctl->tree_lock);
2806 __btrfs_remove_free_space_cache_locked(ctl);
2807 btrfs_discard_update_discardable(block_group, ctl);
2808 spin_unlock(&ctl->tree_lock);
2813 * btrfs_is_free_space_trimmed - see if everything is trimmed
2814 * @block_group: block_group of interest
2816 * Walk @block_group's free space rb_tree to determine if everything is trimmed.
2818 bool btrfs_is_free_space_trimmed(struct btrfs_block_group *block_group)
2820 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2821 struct btrfs_free_space *info;
2822 struct rb_node *node;
2825 spin_lock(&ctl->tree_lock);
2826 node = rb_first(&ctl->free_space_offset);
2829 info = rb_entry(node, struct btrfs_free_space, offset_index);
2831 if (!btrfs_free_space_trimmed(info)) {
2836 node = rb_next(node);
2839 spin_unlock(&ctl->tree_lock);
2843 u64 btrfs_find_space_for_alloc(struct btrfs_block_group *block_group,
2844 u64 offset, u64 bytes, u64 empty_size,
2845 u64 *max_extent_size)
2847 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2848 struct btrfs_discard_ctl *discard_ctl =
2849 &block_group->fs_info->discard_ctl;
2850 struct btrfs_free_space *entry = NULL;
2851 u64 bytes_search = bytes + empty_size;
2854 u64 align_gap_len = 0;
2855 enum btrfs_trim_state align_gap_trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
2857 spin_lock(&ctl->tree_lock);
2858 entry = find_free_space(ctl, &offset, &bytes_search,
2859 block_group->full_stripe_len, max_extent_size);
2864 if (entry->bitmap) {
2865 bitmap_clear_bits(ctl, entry, offset, bytes);
2867 if (!btrfs_free_space_trimmed(entry))
2868 atomic64_add(bytes, &discard_ctl->discard_bytes_saved);
2871 free_bitmap(ctl, entry);
2873 unlink_free_space(ctl, entry);
2874 align_gap_len = offset - entry->offset;
2875 align_gap = entry->offset;
2876 align_gap_trim_state = entry->trim_state;
2878 if (!btrfs_free_space_trimmed(entry))
2879 atomic64_add(bytes, &discard_ctl->discard_bytes_saved);
2881 entry->offset = offset + bytes;
2882 WARN_ON(entry->bytes < bytes + align_gap_len);
2884 entry->bytes -= bytes + align_gap_len;
2886 kmem_cache_free(btrfs_free_space_cachep, entry);
2888 link_free_space(ctl, entry);
2891 btrfs_discard_update_discardable(block_group, ctl);
2892 spin_unlock(&ctl->tree_lock);
2895 __btrfs_add_free_space(block_group->fs_info, ctl,
2896 align_gap, align_gap_len,
2897 align_gap_trim_state);
2902 * given a cluster, put all of its extents back into the free space
2903 * cache. If a block group is passed, this function will only free
2904 * a cluster that belongs to the passed block group.
2906 * Otherwise, it'll get a reference on the block group pointed to by the
2907 * cluster and remove the cluster from it.
2909 void btrfs_return_cluster_to_free_space(
2910 struct btrfs_block_group *block_group,
2911 struct btrfs_free_cluster *cluster)
2913 struct btrfs_free_space_ctl *ctl;
2915 /* first, get a safe pointer to the block group */
2916 spin_lock(&cluster->lock);
2918 block_group = cluster->block_group;
2920 spin_unlock(&cluster->lock);
2923 } else if (cluster->block_group != block_group) {
2924 /* someone else has already freed it don't redo their work */
2925 spin_unlock(&cluster->lock);
2928 btrfs_get_block_group(block_group);
2929 spin_unlock(&cluster->lock);
2931 ctl = block_group->free_space_ctl;
2933 /* now return any extents the cluster had on it */
2934 spin_lock(&ctl->tree_lock);
2935 __btrfs_return_cluster_to_free_space(block_group, cluster);
2936 spin_unlock(&ctl->tree_lock);
2938 btrfs_discard_queue_work(&block_group->fs_info->discard_ctl, block_group);
2940 /* finally drop our ref */
2941 btrfs_put_block_group(block_group);
2944 static u64 btrfs_alloc_from_bitmap(struct btrfs_block_group *block_group,
2945 struct btrfs_free_cluster *cluster,
2946 struct btrfs_free_space *entry,
2947 u64 bytes, u64 min_start,
2948 u64 *max_extent_size)
2950 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2952 u64 search_start = cluster->window_start;
2953 u64 search_bytes = bytes;
2956 search_start = min_start;
2957 search_bytes = bytes;
2959 err = search_bitmap(ctl, entry, &search_start, &search_bytes, true);
2961 *max_extent_size = max(get_max_extent_size(entry),
2967 __bitmap_clear_bits(ctl, entry, ret, bytes);
2973 * given a cluster, try to allocate 'bytes' from it, returns 0
2974 * if it couldn't find anything suitably large, or a logical disk offset
2975 * if things worked out
2977 u64 btrfs_alloc_from_cluster(struct btrfs_block_group *block_group,
2978 struct btrfs_free_cluster *cluster, u64 bytes,
2979 u64 min_start, u64 *max_extent_size)
2981 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
2982 struct btrfs_discard_ctl *discard_ctl =
2983 &block_group->fs_info->discard_ctl;
2984 struct btrfs_free_space *entry = NULL;
2985 struct rb_node *node;
2988 spin_lock(&cluster->lock);
2989 if (bytes > cluster->max_size)
2992 if (cluster->block_group != block_group)
2995 node = rb_first(&cluster->root);
2999 entry = rb_entry(node, struct btrfs_free_space, offset_index);
3001 if (entry->bytes < bytes)
3002 *max_extent_size = max(get_max_extent_size(entry),
3005 if (entry->bytes < bytes ||
3006 (!entry->bitmap && entry->offset < min_start)) {
3007 node = rb_next(&entry->offset_index);
3010 entry = rb_entry(node, struct btrfs_free_space,
3015 if (entry->bitmap) {
3016 ret = btrfs_alloc_from_bitmap(block_group,
3017 cluster, entry, bytes,
3018 cluster->window_start,
3021 node = rb_next(&entry->offset_index);
3024 entry = rb_entry(node, struct btrfs_free_space,
3028 cluster->window_start += bytes;
3030 ret = entry->offset;
3032 entry->offset += bytes;
3033 entry->bytes -= bytes;
3036 if (entry->bytes == 0)
3037 rb_erase(&entry->offset_index, &cluster->root);
3041 spin_unlock(&cluster->lock);
3046 spin_lock(&ctl->tree_lock);
3048 if (!btrfs_free_space_trimmed(entry))
3049 atomic64_add(bytes, &discard_ctl->discard_bytes_saved);
3051 ctl->free_space -= bytes;
3052 if (!entry->bitmap && !btrfs_free_space_trimmed(entry))
3053 ctl->discardable_bytes[BTRFS_STAT_CURR] -= bytes;
3054 if (entry->bytes == 0) {
3055 ctl->free_extents--;
3056 if (entry->bitmap) {
3057 kmem_cache_free(btrfs_free_space_bitmap_cachep,
3059 ctl->total_bitmaps--;
3060 ctl->op->recalc_thresholds(ctl);
3061 } else if (!btrfs_free_space_trimmed(entry)) {
3062 ctl->discardable_extents[BTRFS_STAT_CURR]--;
3064 kmem_cache_free(btrfs_free_space_cachep, entry);
3067 spin_unlock(&ctl->tree_lock);
3072 static int btrfs_bitmap_cluster(struct btrfs_block_group *block_group,
3073 struct btrfs_free_space *entry,
3074 struct btrfs_free_cluster *cluster,
3075 u64 offset, u64 bytes,
3076 u64 cont1_bytes, u64 min_bytes)
3078 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3079 unsigned long next_zero;
3081 unsigned long want_bits;
3082 unsigned long min_bits;
3083 unsigned long found_bits;
3084 unsigned long max_bits = 0;
3085 unsigned long start = 0;
3086 unsigned long total_found = 0;
3089 i = offset_to_bit(entry->offset, ctl->unit,
3090 max_t(u64, offset, entry->offset));
3091 want_bits = bytes_to_bits(bytes, ctl->unit);
3092 min_bits = bytes_to_bits(min_bytes, ctl->unit);
3095 * Don't bother looking for a cluster in this bitmap if it's heavily
3098 if (entry->max_extent_size &&
3099 entry->max_extent_size < cont1_bytes)
3103 for_each_set_bit_from(i, entry->bitmap, BITS_PER_BITMAP) {
3104 next_zero = find_next_zero_bit(entry->bitmap,
3105 BITS_PER_BITMAP, i);
3106 if (next_zero - i >= min_bits) {
3107 found_bits = next_zero - i;
3108 if (found_bits > max_bits)
3109 max_bits = found_bits;
3112 if (next_zero - i > max_bits)
3113 max_bits = next_zero - i;
3118 entry->max_extent_size = (u64)max_bits * ctl->unit;
3124 cluster->max_size = 0;
3127 total_found += found_bits;
3129 if (cluster->max_size < found_bits * ctl->unit)
3130 cluster->max_size = found_bits * ctl->unit;
3132 if (total_found < want_bits || cluster->max_size < cont1_bytes) {
3137 cluster->window_start = start * ctl->unit + entry->offset;
3138 rb_erase(&entry->offset_index, &ctl->free_space_offset);
3139 ret = tree_insert_offset(&cluster->root, entry->offset,
3140 &entry->offset_index, 1);
3141 ASSERT(!ret); /* -EEXIST; Logic error */
3143 trace_btrfs_setup_cluster(block_group, cluster,
3144 total_found * ctl->unit, 1);
3149 * This searches the block group for just extents to fill the cluster with.
3150 * Try to find a cluster with at least bytes total bytes, at least one
3151 * extent of cont1_bytes, and other clusters of at least min_bytes.
3154 setup_cluster_no_bitmap(struct btrfs_block_group *block_group,
3155 struct btrfs_free_cluster *cluster,
3156 struct list_head *bitmaps, u64 offset, u64 bytes,
3157 u64 cont1_bytes, u64 min_bytes)
3159 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3160 struct btrfs_free_space *first = NULL;
3161 struct btrfs_free_space *entry = NULL;
3162 struct btrfs_free_space *last;
3163 struct rb_node *node;
3168 entry = tree_search_offset(ctl, offset, 0, 1);
3173 * We don't want bitmaps, so just move along until we find a normal
3176 while (entry->bitmap || entry->bytes < min_bytes) {
3177 if (entry->bitmap && list_empty(&entry->list))
3178 list_add_tail(&entry->list, bitmaps);
3179 node = rb_next(&entry->offset_index);
3182 entry = rb_entry(node, struct btrfs_free_space, offset_index);
3185 window_free = entry->bytes;
3186 max_extent = entry->bytes;
3190 for (node = rb_next(&entry->offset_index); node;
3191 node = rb_next(&entry->offset_index)) {
3192 entry = rb_entry(node, struct btrfs_free_space, offset_index);
3194 if (entry->bitmap) {
3195 if (list_empty(&entry->list))
3196 list_add_tail(&entry->list, bitmaps);
3200 if (entry->bytes < min_bytes)
3204 window_free += entry->bytes;
3205 if (entry->bytes > max_extent)
3206 max_extent = entry->bytes;
3209 if (window_free < bytes || max_extent < cont1_bytes)
3212 cluster->window_start = first->offset;
3214 node = &first->offset_index;
3217 * now we've found our entries, pull them out of the free space
3218 * cache and put them into the cluster rbtree
3223 entry = rb_entry(node, struct btrfs_free_space, offset_index);
3224 node = rb_next(&entry->offset_index);
3225 if (entry->bitmap || entry->bytes < min_bytes)
3228 rb_erase(&entry->offset_index, &ctl->free_space_offset);
3229 ret = tree_insert_offset(&cluster->root, entry->offset,
3230 &entry->offset_index, 0);
3231 total_size += entry->bytes;
3232 ASSERT(!ret); /* -EEXIST; Logic error */
3233 } while (node && entry != last);
3235 cluster->max_size = max_extent;
3236 trace_btrfs_setup_cluster(block_group, cluster, total_size, 0);
3241 * This specifically looks for bitmaps that may work in the cluster, we assume
3242 * that we have already failed to find extents that will work.
3245 setup_cluster_bitmap(struct btrfs_block_group *block_group,
3246 struct btrfs_free_cluster *cluster,
3247 struct list_head *bitmaps, u64 offset, u64 bytes,
3248 u64 cont1_bytes, u64 min_bytes)
3250 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3251 struct btrfs_free_space *entry = NULL;
3253 u64 bitmap_offset = offset_to_bitmap(ctl, offset);
3255 if (ctl->total_bitmaps == 0)
3259 * The bitmap that covers offset won't be in the list unless offset
3260 * is just its start offset.
3262 if (!list_empty(bitmaps))
3263 entry = list_first_entry(bitmaps, struct btrfs_free_space, list);
3265 if (!entry || entry->offset != bitmap_offset) {
3266 entry = tree_search_offset(ctl, bitmap_offset, 1, 0);
3267 if (entry && list_empty(&entry->list))
3268 list_add(&entry->list, bitmaps);
3271 list_for_each_entry(entry, bitmaps, list) {
3272 if (entry->bytes < bytes)
3274 ret = btrfs_bitmap_cluster(block_group, entry, cluster, offset,
3275 bytes, cont1_bytes, min_bytes);
3281 * The bitmaps list has all the bitmaps that record free space
3282 * starting after offset, so no more search is required.
3288 * here we try to find a cluster of blocks in a block group. The goal
3289 * is to find at least bytes+empty_size.
3290 * We might not find them all in one contiguous area.
3292 * returns zero and sets up cluster if things worked out, otherwise
3293 * it returns -enospc
3295 int btrfs_find_space_cluster(struct btrfs_block_group *block_group,
3296 struct btrfs_free_cluster *cluster,
3297 u64 offset, u64 bytes, u64 empty_size)
3299 struct btrfs_fs_info *fs_info = block_group->fs_info;
3300 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3301 struct btrfs_free_space *entry, *tmp;
3308 * Choose the minimum extent size we'll require for this
3309 * cluster. For SSD_SPREAD, don't allow any fragmentation.
3310 * For metadata, allow allocates with smaller extents. For
3311 * data, keep it dense.
3313 if (btrfs_test_opt(fs_info, SSD_SPREAD)) {
3314 cont1_bytes = min_bytes = bytes + empty_size;
3315 } else if (block_group->flags & BTRFS_BLOCK_GROUP_METADATA) {
3316 cont1_bytes = bytes;
3317 min_bytes = fs_info->sectorsize;
3319 cont1_bytes = max(bytes, (bytes + empty_size) >> 2);
3320 min_bytes = fs_info->sectorsize;
3323 spin_lock(&ctl->tree_lock);
3326 * If we know we don't have enough space to make a cluster don't even
3327 * bother doing all the work to try and find one.
3329 if (ctl->free_space < bytes) {
3330 spin_unlock(&ctl->tree_lock);
3334 spin_lock(&cluster->lock);
3336 /* someone already found a cluster, hooray */
3337 if (cluster->block_group) {
3342 trace_btrfs_find_cluster(block_group, offset, bytes, empty_size,
3345 ret = setup_cluster_no_bitmap(block_group, cluster, &bitmaps, offset,
3347 cont1_bytes, min_bytes);
3349 ret = setup_cluster_bitmap(block_group, cluster, &bitmaps,
3350 offset, bytes + empty_size,
3351 cont1_bytes, min_bytes);
3353 /* Clear our temporary list */
3354 list_for_each_entry_safe(entry, tmp, &bitmaps, list)
3355 list_del_init(&entry->list);
3358 btrfs_get_block_group(block_group);
3359 list_add_tail(&cluster->block_group_list,
3360 &block_group->cluster_list);
3361 cluster->block_group = block_group;
3363 trace_btrfs_failed_cluster_setup(block_group);
3366 spin_unlock(&cluster->lock);
3367 spin_unlock(&ctl->tree_lock);
3373 * simple code to zero out a cluster
3375 void btrfs_init_free_cluster(struct btrfs_free_cluster *cluster)
3377 spin_lock_init(&cluster->lock);
3378 spin_lock_init(&cluster->refill_lock);
3379 cluster->root = RB_ROOT;
3380 cluster->max_size = 0;
3381 cluster->fragmented = false;
3382 INIT_LIST_HEAD(&cluster->block_group_list);
3383 cluster->block_group = NULL;
3386 static int do_trimming(struct btrfs_block_group *block_group,
3387 u64 *total_trimmed, u64 start, u64 bytes,
3388 u64 reserved_start, u64 reserved_bytes,
3389 enum btrfs_trim_state reserved_trim_state,
3390 struct btrfs_trim_range *trim_entry)
3392 struct btrfs_space_info *space_info = block_group->space_info;
3393 struct btrfs_fs_info *fs_info = block_group->fs_info;
3394 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3397 const u64 end = start + bytes;
3398 const u64 reserved_end = reserved_start + reserved_bytes;
3399 enum btrfs_trim_state trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
3402 spin_lock(&space_info->lock);
3403 spin_lock(&block_group->lock);
3404 if (!block_group->ro) {
3405 block_group->reserved += reserved_bytes;
3406 space_info->bytes_reserved += reserved_bytes;
3409 spin_unlock(&block_group->lock);
3410 spin_unlock(&space_info->lock);
3412 ret = btrfs_discard_extent(fs_info, start, bytes, &trimmed);
3414 *total_trimmed += trimmed;
3415 trim_state = BTRFS_TRIM_STATE_TRIMMED;
3418 mutex_lock(&ctl->cache_writeout_mutex);
3419 if (reserved_start < start)
3420 __btrfs_add_free_space(fs_info, ctl, reserved_start,
3421 start - reserved_start,
3422 reserved_trim_state);
3423 if (start + bytes < reserved_start + reserved_bytes)
3424 __btrfs_add_free_space(fs_info, ctl, end, reserved_end - end,
3425 reserved_trim_state);
3426 __btrfs_add_free_space(fs_info, ctl, start, bytes, trim_state);
3427 list_del(&trim_entry->list);
3428 mutex_unlock(&ctl->cache_writeout_mutex);
3431 spin_lock(&space_info->lock);
3432 spin_lock(&block_group->lock);
3433 if (block_group->ro)
3434 space_info->bytes_readonly += reserved_bytes;
3435 block_group->reserved -= reserved_bytes;
3436 space_info->bytes_reserved -= reserved_bytes;
3437 spin_unlock(&block_group->lock);
3438 spin_unlock(&space_info->lock);
3445 * If @async is set, then we will trim 1 region and return.
3447 static int trim_no_bitmap(struct btrfs_block_group *block_group,
3448 u64 *total_trimmed, u64 start, u64 end, u64 minlen,
3451 struct btrfs_discard_ctl *discard_ctl =
3452 &block_group->fs_info->discard_ctl;
3453 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3454 struct btrfs_free_space *entry;
3455 struct rb_node *node;
3459 enum btrfs_trim_state extent_trim_state;
3461 const u64 max_discard_size = READ_ONCE(discard_ctl->max_discard_size);
3463 while (start < end) {
3464 struct btrfs_trim_range trim_entry;
3466 mutex_lock(&ctl->cache_writeout_mutex);
3467 spin_lock(&ctl->tree_lock);
3469 if (ctl->free_space < minlen)
3472 entry = tree_search_offset(ctl, start, 0, 1);
3476 /* Skip bitmaps and if async, already trimmed entries */
3477 while (entry->bitmap ||
3478 (async && btrfs_free_space_trimmed(entry))) {
3479 node = rb_next(&entry->offset_index);
3482 entry = rb_entry(node, struct btrfs_free_space,
3486 if (entry->offset >= end)
3489 extent_start = entry->offset;
3490 extent_bytes = entry->bytes;
3491 extent_trim_state = entry->trim_state;
3493 start = entry->offset;
3494 bytes = entry->bytes;
3495 if (bytes < minlen) {
3496 spin_unlock(&ctl->tree_lock);
3497 mutex_unlock(&ctl->cache_writeout_mutex);
3500 unlink_free_space(ctl, entry);
3502 * Let bytes = BTRFS_MAX_DISCARD_SIZE + X.
3503 * If X < BTRFS_ASYNC_DISCARD_MIN_FILTER, we won't trim
3504 * X when we come back around. So trim it now.
3506 if (max_discard_size &&
3507 bytes >= (max_discard_size +
3508 BTRFS_ASYNC_DISCARD_MIN_FILTER)) {
3509 bytes = max_discard_size;
3510 extent_bytes = max_discard_size;
3511 entry->offset += max_discard_size;
3512 entry->bytes -= max_discard_size;
3513 link_free_space(ctl, entry);
3515 kmem_cache_free(btrfs_free_space_cachep, entry);
3518 start = max(start, extent_start);
3519 bytes = min(extent_start + extent_bytes, end) - start;
3520 if (bytes < minlen) {
3521 spin_unlock(&ctl->tree_lock);
3522 mutex_unlock(&ctl->cache_writeout_mutex);
3526 unlink_free_space(ctl, entry);
3527 kmem_cache_free(btrfs_free_space_cachep, entry);
3530 spin_unlock(&ctl->tree_lock);
3531 trim_entry.start = extent_start;
3532 trim_entry.bytes = extent_bytes;
3533 list_add_tail(&trim_entry.list, &ctl->trimming_ranges);
3534 mutex_unlock(&ctl->cache_writeout_mutex);
3536 ret = do_trimming(block_group, total_trimmed, start, bytes,
3537 extent_start, extent_bytes, extent_trim_state,
3540 block_group->discard_cursor = start + bytes;
3545 block_group->discard_cursor = start;
3546 if (async && *total_trimmed)
3549 if (fatal_signal_pending(current)) {
3560 block_group->discard_cursor = btrfs_block_group_end(block_group);
3561 spin_unlock(&ctl->tree_lock);
3562 mutex_unlock(&ctl->cache_writeout_mutex);
3568 * If we break out of trimming a bitmap prematurely, we should reset the
3569 * trimming bit. In a rather contrieved case, it's possible to race here so
3570 * reset the state to BTRFS_TRIM_STATE_UNTRIMMED.
3572 * start = start of bitmap
3573 * end = near end of bitmap
3575 * Thread 1: Thread 2:
3576 * trim_bitmaps(start)
3578 * end_trimming_bitmap()
3579 * reset_trimming_bitmap()
3581 static void reset_trimming_bitmap(struct btrfs_free_space_ctl *ctl, u64 offset)
3583 struct btrfs_free_space *entry;
3585 spin_lock(&ctl->tree_lock);
3586 entry = tree_search_offset(ctl, offset, 1, 0);
3588 if (btrfs_free_space_trimmed(entry)) {
3589 ctl->discardable_extents[BTRFS_STAT_CURR] +=
3590 entry->bitmap_extents;
3591 ctl->discardable_bytes[BTRFS_STAT_CURR] += entry->bytes;
3593 entry->trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
3596 spin_unlock(&ctl->tree_lock);
3599 static void end_trimming_bitmap(struct btrfs_free_space_ctl *ctl,
3600 struct btrfs_free_space *entry)
3602 if (btrfs_free_space_trimming_bitmap(entry)) {
3603 entry->trim_state = BTRFS_TRIM_STATE_TRIMMED;
3604 ctl->discardable_extents[BTRFS_STAT_CURR] -=
3605 entry->bitmap_extents;
3606 ctl->discardable_bytes[BTRFS_STAT_CURR] -= entry->bytes;
3611 * If @async is set, then we will trim 1 region and return.
3613 static int trim_bitmaps(struct btrfs_block_group *block_group,
3614 u64 *total_trimmed, u64 start, u64 end, u64 minlen,
3615 u64 maxlen, bool async)
3617 struct btrfs_discard_ctl *discard_ctl =
3618 &block_group->fs_info->discard_ctl;
3619 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3620 struct btrfs_free_space *entry;
3624 u64 offset = offset_to_bitmap(ctl, start);
3625 const u64 max_discard_size = READ_ONCE(discard_ctl->max_discard_size);
3627 while (offset < end) {
3628 bool next_bitmap = false;
3629 struct btrfs_trim_range trim_entry;
3631 mutex_lock(&ctl->cache_writeout_mutex);
3632 spin_lock(&ctl->tree_lock);
3634 if (ctl->free_space < minlen) {
3635 block_group->discard_cursor =
3636 btrfs_block_group_end(block_group);
3637 spin_unlock(&ctl->tree_lock);
3638 mutex_unlock(&ctl->cache_writeout_mutex);
3642 entry = tree_search_offset(ctl, offset, 1, 0);
3644 * Bitmaps are marked trimmed lossily now to prevent constant
3645 * discarding of the same bitmap (the reason why we are bound
3646 * by the filters). So, retrim the block group bitmaps when we
3647 * are preparing to punt to the unused_bgs list. This uses
3648 * @minlen to determine if we are in BTRFS_DISCARD_INDEX_UNUSED
3649 * which is the only discard index which sets minlen to 0.
3651 if (!entry || (async && minlen && start == offset &&
3652 btrfs_free_space_trimmed(entry))) {
3653 spin_unlock(&ctl->tree_lock);
3654 mutex_unlock(&ctl->cache_writeout_mutex);
3660 * Async discard bitmap trimming begins at by setting the start
3661 * to be key.objectid and the offset_to_bitmap() aligns to the
3662 * start of the bitmap. This lets us know we are fully
3663 * scanning the bitmap rather than only some portion of it.
3665 if (start == offset)
3666 entry->trim_state = BTRFS_TRIM_STATE_TRIMMING;
3669 ret2 = search_bitmap(ctl, entry, &start, &bytes, false);
3670 if (ret2 || start >= end) {
3672 * We lossily consider a bitmap trimmed if we only skip
3673 * over regions <= BTRFS_ASYNC_DISCARD_MIN_FILTER.
3675 if (ret2 && minlen <= BTRFS_ASYNC_DISCARD_MIN_FILTER)
3676 end_trimming_bitmap(ctl, entry);
3678 entry->trim_state = BTRFS_TRIM_STATE_UNTRIMMED;
3679 spin_unlock(&ctl->tree_lock);
3680 mutex_unlock(&ctl->cache_writeout_mutex);
3686 * We already trimmed a region, but are using the locking above
3687 * to reset the trim_state.
3689 if (async && *total_trimmed) {
3690 spin_unlock(&ctl->tree_lock);
3691 mutex_unlock(&ctl->cache_writeout_mutex);
3695 bytes = min(bytes, end - start);
3696 if (bytes < minlen || (async && maxlen && bytes > maxlen)) {
3697 spin_unlock(&ctl->tree_lock);
3698 mutex_unlock(&ctl->cache_writeout_mutex);
3703 * Let bytes = BTRFS_MAX_DISCARD_SIZE + X.
3704 * If X < @minlen, we won't trim X when we come back around.
3705 * So trim it now. We differ here from trimming extents as we
3706 * don't keep individual state per bit.
3710 bytes > (max_discard_size + minlen))
3711 bytes = max_discard_size;
3713 bitmap_clear_bits(ctl, entry, start, bytes);
3714 if (entry->bytes == 0)
3715 free_bitmap(ctl, entry);
3717 spin_unlock(&ctl->tree_lock);
3718 trim_entry.start = start;
3719 trim_entry.bytes = bytes;
3720 list_add_tail(&trim_entry.list, &ctl->trimming_ranges);
3721 mutex_unlock(&ctl->cache_writeout_mutex);
3723 ret = do_trimming(block_group, total_trimmed, start, bytes,
3724 start, bytes, 0, &trim_entry);
3726 reset_trimming_bitmap(ctl, offset);
3727 block_group->discard_cursor =
3728 btrfs_block_group_end(block_group);
3733 offset += BITS_PER_BITMAP * ctl->unit;
3738 block_group->discard_cursor = start;
3740 if (fatal_signal_pending(current)) {
3741 if (start != offset)
3742 reset_trimming_bitmap(ctl, offset);
3751 block_group->discard_cursor = end;
3757 int btrfs_trim_block_group(struct btrfs_block_group *block_group,
3758 u64 *trimmed, u64 start, u64 end, u64 minlen)
3760 struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
3766 spin_lock(&block_group->lock);
3767 if (block_group->removed) {
3768 spin_unlock(&block_group->lock);
3771 btrfs_freeze_block_group(block_group);
3772 spin_unlock(&block_group->lock);
3774 ret = trim_no_bitmap(block_group, trimmed, start, end, minlen, false);
3778 ret = trim_bitmaps(block_group, trimmed, start, end, minlen, 0, false);
3779 div64_u64_rem(end, BITS_PER_BITMAP * ctl->unit, &rem);
3780 /* If we ended in the middle of a bitmap, reset the trimming flag */
3782 reset_trimming_bitmap(ctl, offset_to_bitmap(ctl, end));
3784 btrfs_unfreeze_block_group(block_group);
3788 int btrfs_trim_block_group_extents(struct btrfs_block_group *block_group,
3789 u64 *trimmed, u64 start, u64 end, u64 minlen,
3796 spin_lock(&block_group->lock);
3797 if (block_group->removed) {
3798 spin_unlock(&block_group->lock);
3801 btrfs_freeze_block_group(block_group);
3802 spin_unlock(&block_group->lock);
3804 ret = trim_no_bitmap(block_group, trimmed, start, end, minlen, async);
3805 btrfs_unfreeze_block_group(block_group);
3810 int btrfs_trim_block_group_bitmaps(struct btrfs_block_group *block_group,
3811 u64 *trimmed, u64 start, u64 end, u64 minlen,
3812 u64 maxlen, bool async)
3818 spin_lock(&block_group->lock);
3819 if (block_group->removed) {
3820 spin_unlock(&block_group->lock);
3823 btrfs_freeze_block_group(block_group);
3824 spin_unlock(&block_group->lock);
3826 ret = trim_bitmaps(block_group, trimmed, start, end, minlen, maxlen,
3829 btrfs_unfreeze_block_group(block_group);
3835 * Find the left-most item in the cache tree, and then return the
3836 * smallest inode number in the item.
3838 * Note: the returned inode number may not be the smallest one in
3839 * the tree, if the left-most item is a bitmap.
3841 u64 btrfs_find_ino_for_alloc(struct btrfs_root *fs_root)
3843 struct btrfs_free_space_ctl *ctl = fs_root->free_ino_ctl;
3844 struct btrfs_free_space *entry = NULL;
3847 spin_lock(&ctl->tree_lock);
3849 if (RB_EMPTY_ROOT(&ctl->free_space_offset))
3852 entry = rb_entry(rb_first(&ctl->free_space_offset),
3853 struct btrfs_free_space, offset_index);
3855 if (!entry->bitmap) {
3856 ino = entry->offset;
3858 unlink_free_space(ctl, entry);
3862 kmem_cache_free(btrfs_free_space_cachep, entry);
3864 link_free_space(ctl, entry);
3870 ret = search_bitmap(ctl, entry, &offset, &count, true);
3871 /* Logic error; Should be empty if it can't find anything */
3875 bitmap_clear_bits(ctl, entry, offset, 1);
3876 if (entry->bytes == 0)
3877 free_bitmap(ctl, entry);
3880 spin_unlock(&ctl->tree_lock);
3885 struct inode *lookup_free_ino_inode(struct btrfs_root *root,
3886 struct btrfs_path *path)
3888 struct inode *inode = NULL;
3890 spin_lock(&root->ino_cache_lock);
3891 if (root->ino_cache_inode)
3892 inode = igrab(root->ino_cache_inode);
3893 spin_unlock(&root->ino_cache_lock);
3897 inode = __lookup_free_space_inode(root, path, 0);
3901 spin_lock(&root->ino_cache_lock);
3902 if (!btrfs_fs_closing(root->fs_info))
3903 root->ino_cache_inode = igrab(inode);
3904 spin_unlock(&root->ino_cache_lock);
3909 int create_free_ino_inode(struct btrfs_root *root,
3910 struct btrfs_trans_handle *trans,
3911 struct btrfs_path *path)
3913 return __create_free_space_inode(root, trans, path,
3914 BTRFS_FREE_INO_OBJECTID, 0);
3917 int load_free_ino_cache(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
3919 struct btrfs_free_space_ctl *ctl = root->free_ino_ctl;
3920 struct btrfs_path *path;
3921 struct inode *inode;
3923 u64 root_gen = btrfs_root_generation(&root->root_item);
3925 if (!btrfs_test_opt(fs_info, INODE_MAP_CACHE))
3929 * If we're unmounting then just return, since this does a search on the
3930 * normal root and not the commit root and we could deadlock.
3932 if (btrfs_fs_closing(fs_info))
3935 path = btrfs_alloc_path();
3939 inode = lookup_free_ino_inode(root, path);
3943 if (root_gen != BTRFS_I(inode)->generation)
3946 ret = __load_free_space_cache(root, inode, ctl, path, 0);
3950 "failed to load free ino cache for root %llu",
3951 root->root_key.objectid);
3955 btrfs_free_path(path);
3959 int btrfs_write_out_ino_cache(struct btrfs_root *root,
3960 struct btrfs_trans_handle *trans,
3961 struct btrfs_path *path,
3962 struct inode *inode)
3964 struct btrfs_fs_info *fs_info = root->fs_info;
3965 struct btrfs_free_space_ctl *ctl = root->free_ino_ctl;
3967 struct btrfs_io_ctl io_ctl;
3968 bool release_metadata = true;
3970 if (!btrfs_test_opt(fs_info, INODE_MAP_CACHE))
3973 memset(&io_ctl, 0, sizeof(io_ctl));
3974 ret = __btrfs_write_out_cache(root, inode, ctl, NULL, &io_ctl, trans);
3977 * At this point writepages() didn't error out, so our metadata
3978 * reservation is released when the writeback finishes, at
3979 * inode.c:btrfs_finish_ordered_io(), regardless of it finishing
3980 * with or without an error.
3982 release_metadata = false;
3983 ret = btrfs_wait_cache_io_root(root, trans, &io_ctl, path);
3987 if (release_metadata)
3988 btrfs_delalloc_release_metadata(BTRFS_I(inode),
3989 inode->i_size, true);
3990 btrfs_debug(fs_info,
3991 "failed to write free ino cache for root %llu error %d",
3992 root->root_key.objectid, ret);
3998 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
4000 * Use this if you need to make a bitmap or extent entry specifically, it
4001 * doesn't do any of the merging that add_free_space does, this acts a lot like
4002 * how the free space cache loading stuff works, so you can get really weird
4005 int test_add_free_space_entry(struct btrfs_block_group *cache,
4006 u64 offset, u64 bytes, bool bitmap)
4008 struct btrfs_free_space_ctl *ctl = cache->free_space_ctl;
4009 struct btrfs_free_space *info = NULL, *bitmap_info;
4011 enum btrfs_trim_state trim_state = BTRFS_TRIM_STATE_TRIMMED;
4017 info = kmem_cache_zalloc(btrfs_free_space_cachep, GFP_NOFS);
4023 spin_lock(&ctl->tree_lock);
4024 info->offset = offset;
4025 info->bytes = bytes;
4026 info->max_extent_size = 0;
4027 ret = link_free_space(ctl, info);
4028 spin_unlock(&ctl->tree_lock);
4030 kmem_cache_free(btrfs_free_space_cachep, info);
4035 map = kmem_cache_zalloc(btrfs_free_space_bitmap_cachep, GFP_NOFS);
4037 kmem_cache_free(btrfs_free_space_cachep, info);
4042 spin_lock(&ctl->tree_lock);
4043 bitmap_info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
4048 add_new_bitmap(ctl, info, offset);
4053 bytes_added = add_bytes_to_bitmap(ctl, bitmap_info, offset, bytes,
4056 bytes -= bytes_added;
4057 offset += bytes_added;
4058 spin_unlock(&ctl->tree_lock);
4064 kmem_cache_free(btrfs_free_space_cachep, info);
4066 kmem_cache_free(btrfs_free_space_bitmap_cachep, map);
4071 * Checks to see if the given range is in the free space cache. This is really
4072 * just used to check the absence of space, so if there is free space in the
4073 * range at all we will return 1.
4075 int test_check_exists(struct btrfs_block_group *cache,
4076 u64 offset, u64 bytes)
4078 struct btrfs_free_space_ctl *ctl = cache->free_space_ctl;
4079 struct btrfs_free_space *info;
4082 spin_lock(&ctl->tree_lock);
4083 info = tree_search_offset(ctl, offset, 0, 0);
4085 info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
4093 u64 bit_off, bit_bytes;
4095 struct btrfs_free_space *tmp;
4098 bit_bytes = ctl->unit;
4099 ret = search_bitmap(ctl, info, &bit_off, &bit_bytes, false);
4101 if (bit_off == offset) {
4104 } else if (bit_off > offset &&
4105 offset + bytes > bit_off) {
4111 n = rb_prev(&info->offset_index);
4113 tmp = rb_entry(n, struct btrfs_free_space,
4115 if (tmp->offset + tmp->bytes < offset)
4117 if (offset + bytes < tmp->offset) {
4118 n = rb_prev(&tmp->offset_index);
4125 n = rb_next(&info->offset_index);
4127 tmp = rb_entry(n, struct btrfs_free_space,
4129 if (offset + bytes < tmp->offset)
4131 if (tmp->offset + tmp->bytes < offset) {
4132 n = rb_next(&tmp->offset_index);
4143 if (info->offset == offset) {
4148 if (offset > info->offset && offset < info->offset + info->bytes)
4151 spin_unlock(&ctl->tree_lock);
4154 #endif /* CONFIG_BTRFS_FS_RUN_SANITY_TESTS */