[PATCH v2 6/7] Btrfs: remove BUG_ON in __add_tree_block

[Liu Bo <bo.li.liu@oracle.com>]

The BUG_ON() can be triggered when the caller is processing an invalid
extent inline ref, e.g.

a shared data ref is offered instead of a extent data ref, such that
it tries to find a non-exist tree block and then btrfs_search_slot
returns 1 for no such item.

This replaces the BUG_ON() with a WARN() followed by calling
btrfs_print_leaf() to show more details about what's going on and
returning -EINVAL to upper callers.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
---
 fs/btrfs/relocation.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index 4806e78..cc6150e 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -32,6 +32,7 @@
 #include "free-space-cache.h"
 #include "inode-map.h"
 #include "qgroup.h"
+#include "print-tree.h"
 
 /*
  * backref_node, mapping_node and tree_block start with this
@@ -3485,7 +3486,15 @@ static int __add_tree_block(struct reloc_control *rc,
 			goto again;
 		}
 	}
-	BUG_ON(ret);
+	if (ret) {
+		ASSERT(ret == 1);
+		btrfs_print_leaf(rc->extent_root->fs_info, path->nodes[0]);
+		WARN(1,
+	     "tree block extent item (%llu) is not found in extent tree\n",
+		     bytenr);
+		ret = -EINVAL;
+		goto out;
+	}
 
 	ret = add_tree_block(rc, &key, path, blocks);
 out:
-- 
2.9.4