| From foo@baz Thu Feb 1 13:45:42 CET 2018 |
| From: Josef Bacik <jbacik@fb.com> |
| Date: Wed, 15 Nov 2017 16:20:52 -0500 |
| Subject: btrfs: fix deadlock when writing out space cache |
| |
| From: Josef Bacik <jbacik@fb.com> |
| |
| |
| [ 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@fb.com> |
| Reviewed-by: Omar Sandoval <osandov@fb.com> |
| Reviewed-by: Liu Bo <bo.li.liu@oracle.com> |
| Reviewed-by: David Sterba <dsterba@suse.com> |
| [ add label and use existing unlocking code ] |
| Signed-off-by: David Sterba <dsterba@suse.com> |
| |
| Signed-off-by: Sasha Levin <alexander.levin@verizon.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| 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 |
| @@ -1264,7 +1264,7 @@ 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); |
| @@ -1358,6 +1358,7 @@ out_nospc_locked: |
| out_nospc: |
| cleanup_write_cache_enospc(inode, io_ctl, &cached_state); |
| |
| +out_unlock: |
| if (block_group && (block_group->flags & BTRFS_BLOCK_GROUP_DATA)) |
| up_write(&block_group->data_rwsem); |
| |
