Btrfs: send, don't BUG_ON() when an empty symlink is found

[firefly-linux-kernel-4.4.55.git] / fs / btrfs / send.c

diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c
index 355a458cba1abe29efb3410a6ae93261052ba1e9..63a6152be04b4f4265b25e253eadb1d4d91b8969 100644 (file)
--- a/fs/btrfs/send.c
+++ b/fs/btrfs/send.c
@@ -1469,7 +1469,21 @@ static int read_symlink(struct btrfs_root *root,
        ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
        if (ret < 0)
                goto out;
-       BUG_ON(ret);
+       if (ret) {
+               /*
+                * An empty symlink inode. Can happen in rare error paths when
+                * creating a symlink (transaction committed before the inode
+                * eviction handler removed the symlink inode items and a crash
+                * happened in between or the subvol was snapshoted in between).
+                * Print an informative message to dmesg/syslog so that the user
+                * can delete the symlink.
+                */
+               btrfs_err(root->fs_info,
+                         "Found empty symlink inode %llu at root %llu",
+                         ino, root->root_key.objectid);
+               ret = -EIO;
+               goto out;
+       }
 
        ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
                        struct btrfs_file_extent_item);