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

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>

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index f356f08b55cb8e4646e105791454afc98c2cb840..4282bdb5a9f1adf06118d62e202bee42cbac0466 100644 (file)
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -1699,12 +1699,12 @@ 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);