From: Josef Bacik josef@toxicpanda.com
commit 1314ca78b2c35d3e7d0f097268a2ee6dc0d369ef upstream.
If you try to force a chunk allocation, but you race with another chunk allocation, you will end up waiting on the chunk allocation that just occurred and then allocate another chunk. If you have many threads all doing this at once you can way over-allocate chunks.
Fix this by resetting force to NO_FORCE, that way if we think we need to allocate we can, otherwise we don't force another chunk allocation if one is already happening.
Reviewed-by: Filipe Manana fdmanana@suse.com CC: stable@vger.kernel.org # 5.4+ Signed-off-by: Josef Bacik josef@toxicpanda.com Signed-off-by: David Sterba dsterba@suse.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/btrfs/block-group.c | 1 + 1 file changed, 1 insertion(+)
--- a/fs/btrfs/block-group.c +++ b/fs/btrfs/block-group.c @@ -2938,6 +2938,7 @@ int btrfs_chunk_alloc(struct btrfs_trans * attempt. */ wait_for_alloc = true; + force = CHUNK_ALLOC_NO_FORCE; spin_unlock(&space_info->lock); mutex_lock(&fs_info->chunk_mutex); mutex_unlock(&fs_info->chunk_mutex);