From 928066e61940e3c19f85d543d15c55fcae20208f Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Wed, 15 Nov 2017 16:20:52 -0500 Subject: [PATCH] btrfs: fix deadlock when writing out space cache [ 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 Reviewed-by: Omar Sandoval Reviewed-by: Liu Bo Reviewed-by: David Sterba [ add label and use existing unlocking code ] Signed-off-by: David Sterba Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- fs/btrfs/free-space-cache.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c index cdc9f40..4426d1c 100644 --- a/fs/btrfs/free-space-cache.c +++ b/fs/btrfs/free-space-cache.c @@ -1264,7 +1264,7 @@ static int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode, /* 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); -- 2.7.4