btrfs-progs: check: repair inode orphan item in lowmem mode

Introduce repair_inode_orphan_item_lowmem() to add an orphan
item if the inode refs and nlink are both zero.

repair_inode_orphan_item_lowmem() is just a wrapper function
that calls btrfs_add_orphan_item().

Signed-off-by: Su Yue <suy.fnst@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/cmds-check.c b/cmds-check.c
index 5828ba0..ad0344d 100644 (file)
--- a/cmds-check.c
+++ b/cmds-check.c
@@ -5078,6 +5078,48 @@ out:
 }
 
 /*
+ * Wrapper function for btrfs_add_orphan_item().
+ *
+ * Returns 0     on success.
+ * Returns != 0  on error.
+ */
+static int repair_inode_orphan_item_lowmem(struct btrfs_root *root,
+                                          struct btrfs_path *path, u64 ino)
+{
+       struct btrfs_trans_handle *trans;
+       struct btrfs_key research_key;
+       int ret;
+       int err = 0;
+
+       btrfs_item_key_to_cpu(path->nodes[0], &research_key, path->slots[0]);
+
+       trans = btrfs_start_transaction(root, 1);
+       if (IS_ERR(trans)) {
+               ret = PTR_ERR(trans);
+               err |= ret;
+               goto out;
+       }
+
+       btrfs_release_path(path);
+       ret = btrfs_add_orphan_item(trans, root, path, ino);
+       err |= ret;
+       btrfs_commit_transaction(trans, root);
+out:
+       if (ret)
+               error("failed to add inode %llu as orphan item root %llu",
+                     ino, root->root_key.objectid);
+       else
+               printf("Added inode %llu as orphan item root %llu\n",
+                      ino, root->root_key.objectid);
+
+       btrfs_release_path(path);
+       ret = btrfs_search_slot(NULL, root, &research_key, path, 0, 0);
+       err |= ret;
+
+       return err;
+}
+
+/*
  * Check INODE_ITEM and related ITEMs (the same inode number)
  * 1. check link count
  * 2. check inode ref/extref
@@ -5228,7 +5270,14 @@ out:
                        error("root %llu INODE[%llu] nlink(%llu) not equal to inode_refs(%llu)",
                              root->objectid, inode_id, nlink, refs);
                } else if (!nlink) {
-                       err |= ORPHAN_ITEM;
+                       if (repair)
+                               ret = repair_inode_orphan_item_lowmem(root,
+                                                             path, inode_id);
+                       if (!repair || ret) {
+                               err |= ORPHAN_ITEM;
+                               error("root %llu INODE[%llu] is orphan item",
+                                     root->objectid, inode_id);
+                       }
                }
 
                if (!nbytes && !no_holes && extent_end < isize) {