btrfs: return -EUCLEAN for delayed tree ref with a ref count not equals to 1

[ Upstream commit 1bf76df3fee56d6637718e267f7c34ed70d0c7dc ]

When running a delayed tree reference, if we find a ref count different
from 1, we return -EIO. This isn't an IO error, as it indicates either a
bug in the delayed refs code or a memory corruption, so change the error
code from -EIO to -EUCLEAN. Also tag the branch as 'unlikely' as this is
not expected to ever happen, and change the error message to print the
tree block's bytenr without the parenthesis (and there was a missing space
between the 'block' word and the opening parenthesis), for consistency as
that's the style we used everywhere else.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 08ff10a81cb90f6913599792d7d953363531aa35..2a7c9088fe1f8dd0645c5a06b3f72461b6784c34 100644 (file)
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -1663,12 +1663,12 @@ static int run_delayed_tree_ref(struct btrfs_trans_handle *trans,
                parent = ref->parent;
        ref_root = ref->root;
 
-       if (node->ref_mod != 1) {
+       if (unlikely(node->ref_mod != 1)) {
                btrfs_err(trans->fs_info,
-       "btree block(%llu) has %d references rather than 1: action %d ref_root %llu parent %llu",
+       "btree block %llu has %d references rather than 1: action %d ref_root %llu parent %llu",
                          node->bytenr, node->ref_mod, node->action, ref_root,
                          parent);
-               return -EIO;
+               return -EUCLEAN;
        }
        if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) {
                BUG_ON(!extent_op || !extent_op->update_flags);