btrfs: Go readonly on bad extent refs in update_ref_for_cow()
update_ref_for_cow() will BUG_ON() after it's call to
btrfs_lookup_extent_info() if no existing references are found. Since refs
are computed directly from disk, this should be treated as a corruption
instead of a logic error.
Signed-off-by: Mark Fasheh <mfasheh@suse.de>
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index e2e43c0..3b767d2 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -333,7 +333,11 @@
buf->len, &refs, &flags);
if (ret)
return ret;
- BUG_ON(refs == 0);
+ if (refs == 0) {
+ ret = -EROFS;
+ btrfs_std_error(root->fs_info, ret);
+ return ret;
+ }
} else {
refs = 1;
if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID ||
