4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Josef Bacik <jbacik@xxxxxx> [ Upstream commit b77000ed558daa3bef0899d29bf171b8c9b5e6a8 ] If we fail to prepare our pages for whatever reason (out of memory in our case) we need to make sure to drop the block_group->data_rwsem, otherwise hilarity ensues. Signed-off-by: Josef Bacik <jbacik@xxxxxx> Reviewed-by: Omar Sandoval <osandov@xxxxxx> Reviewed-by: Liu Bo <bo.li.liu@xxxxxxxxxx> Reviewed-by: David Sterba <dsterba@xxxxxxxx> [ add label and use existing unlocking code ] Signed-off-by: David Sterba <dsterba@xxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/btrfs/free-space-cache.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/fs/btrfs/free-space-cache.c +++ b/fs/btrfs/free-space-cache.c @@ -1253,7 +1253,7 @@ static int __btrfs_write_out_cache(struc /* Lock all pages first so we can lock the extent safely. */ ret = io_ctl_prepare_pages(io_ctl, inode, 0); if (ret) - goto out; + goto out_unlock; lock_extent_bits(&BTRFS_I(inode)->io_tree, 0, i_size_read(inode) - 1, &cached_state); @@ -1346,6 +1346,7 @@ out_nospc_locked: out_nospc: cleanup_write_cache_enospc(inode, io_ctl, &cached_state, &bitmap_list); +out_unlock: if (block_group && (block_group->flags & BTRFS_BLOCK_GROUP_DATA)) up_write(&block_group->data_rwsem);