From 52f93e5ee700c24cf82db18bf8a78bf9666191c3 Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Thu, 14 Jan 2021 14:02:44 -0500 Subject: [PATCH] btrfs: do not warn if we can't find the reloc root when looking up backref commit f78743fbdae1bb31bc9c9233c3590a5048782381 upstream. The backref code is looking for a reloc_root that corresponds to the given fs root. However any number of things could have gone wrong while initializing that reloc_root, like ENOMEM while trying to allocate the root itself, or EIO while trying to write the root item. This would result in no corresponding reloc_root being in the reloc root cache, and thus would return NULL when we do the find_reloc_root() call. Because of this we do not want to WARN_ON(). This presumably was meant to catch developer errors, cases where we messed up adding the reloc root. However we can easily hit this case with error injection, and thus should not do a WARN_ON(). CC: stable@vger.kernel.org # 5.10+ Reported-by: Zygo Blaxell Signed-off-by: Josef Bacik Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Greg Kroah-Hartman --- fs/btrfs/backref.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c index 7b56a5769d7225..6e447bdaf9ec8b 100644 --- a/fs/btrfs/backref.c +++ b/fs/btrfs/backref.c @@ -2624,7 +2624,7 @@ static int handle_direct_tree_backref(struct btrfs_backref_cache *cache, /* Only reloc backref cache cares about a specific root */ if (cache->is_reloc) { root = find_reloc_root(cache->fs_info, cur->bytenr); - if (WARN_ON(!root)) + if (!root) return -ENOENT; cur->root = root; } else {