diff options
| -rw-r--r-- | fs/btrfs/block-group.c | 21 |
1 files changed, 16 insertions, 5 deletions
diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c index cbea2bf25714..cbfcdd65e15e 100644 --- a/fs/btrfs/block-group.c +++ b/fs/btrfs/block-group.c @@ -1823,7 +1823,7 @@ void btrfs_reclaim_bgs_work(struct work_struct *work) list_sort(NULL, &fs_info->reclaim_bgs, reclaim_bgs_cmp); while (!list_empty(&fs_info->reclaim_bgs)) { u64 zone_unusable; - u64 reclaimed; + u64 used; int ret = 0; bg = list_first_entry(&fs_info->reclaim_bgs, @@ -1919,19 +1919,30 @@ void btrfs_reclaim_bgs_work(struct work_struct *work) if (ret < 0) goto next; + /* + * Grab the used bytes counter while holding the block group's + * spinlock to prevent races with tasks concurrently updating it + * due to extent allocation and deallocation (running + * btrfs_update_block_group()) - we have set the block group to + * RO but that only prevents extent reservation, allocation + * happens after reservation. + */ + spin_lock(&bg->lock); + used = bg->used; + spin_unlock(&bg->lock); + btrfs_info(fs_info, "reclaiming chunk %llu with %llu%% used %llu%% unusable", bg->start, - div64_u64(bg->used * 100, bg->length), + div64_u64(used * 100, bg->length), div64_u64(zone_unusable * 100, bg->length)); trace_btrfs_reclaim_block_group(bg); - reclaimed = bg->used; ret = btrfs_relocate_chunk(fs_info, bg->start); if (ret) { btrfs_dec_block_group_ro(bg); btrfs_err(fs_info, "error relocating chunk %llu", bg->start); - reclaimed = 0; + used = 0; spin_lock(&space_info->lock); space_info->reclaim_errors++; if (READ_ONCE(space_info->periodic_reclaim)) @@ -1940,7 +1951,7 @@ void btrfs_reclaim_bgs_work(struct work_struct *work) } spin_lock(&space_info->lock); space_info->reclaim_count++; - space_info->reclaim_bytes += reclaimed; + space_info->reclaim_bytes += used; spin_unlock(&space_info->lock); next: |