From a0e2a8e5376bd67fae67e3107b474d2b70d6271c 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 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 --- 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 cdc9f4015ec36..4426d1c73e50f 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); -- 2.39.5