1 files changed, 53 insertions, 4 deletions

diff --git a/fs/btrfs/uuid-tree.c b/fs/btrfs/uuid-tree.c
index 76b84f2397b1..76671a6bcb61 100644
--- a/fs/btrfs/uuid-tree.c
+++ b/fs/btrfs/uuid-tree.c
@@ -246,9 +246,53 @@ out:
 	return ret;
 }
 
-int btrfs_uuid_tree_iterate(struct btrfs_fs_info *fs_info,
-			    int (*check_func)(struct btrfs_fs_info *, u8 *, u8,
-					      u64))
+/*
+ * Check if there's an matching subvolume for given UUID
+ *
+ * Return:
+ * 0	check succeeded, the entry is not outdated
+ * > 0	if the check failed, the caller should remove the entry
+ * < 0	if an error occurred
+ */
+static int btrfs_check_uuid_tree_entry(struct btrfs_fs_info *fs_info,
+				       u8 *uuid, u8 type, u64 subvolid)
+{
+	struct btrfs_key key;
+	int ret = 0;
+	struct btrfs_root *subvol_root;
+
+	if (type != BTRFS_UUID_KEY_SUBVOL &&
+	    type != BTRFS_UUID_KEY_RECEIVED_SUBVOL)
+		goto out;
+
+	key.objectid = subvolid;
+	key.type = BTRFS_ROOT_ITEM_KEY;
+	key.offset = (u64)-1;
+	subvol_root = btrfs_get_fs_root(fs_info, &key, true);
+	if (IS_ERR(subvol_root)) {
+		ret = PTR_ERR(subvol_root);
+		if (ret == -ENOENT)
+			ret = 1;
+		goto out;
+	}
+
+	switch (type) {
+	case BTRFS_UUID_KEY_SUBVOL:
+		if (memcmp(uuid, subvol_root->root_item.uuid, BTRFS_UUID_SIZE))
+			ret = 1;
+		break;
+	case BTRFS_UUID_KEY_RECEIVED_SUBVOL:
+		if (memcmp(uuid, subvol_root->root_item.received_uuid,
+			   BTRFS_UUID_SIZE))
+			ret = 1;
+		break;
+	}
+	btrfs_put_root(subvol_root);
+out:
+	return ret;
+}
+
+int btrfs_uuid_tree_iterate(struct btrfs_fs_info *fs_info)
 {
 	struct btrfs_root *root = fs_info->uuid_root;
 	struct btrfs_key key;
@@ -278,6 +322,10 @@ again_search_slot:
 	}
 
 	while (1) {
+		if (btrfs_fs_closing(fs_info)) {
+			ret = -EINTR;
+			goto out;
+		}
 		cond_resched();
 		leaf = path->nodes[0];
 		slot = path->slots[0];
@@ -305,7 +353,8 @@ again_search_slot:
 			read_extent_buffer(leaf, &subid_le, offset,
 					   sizeof(subid_le));
 			subid_cpu = le64_to_cpu(subid_le);
-			ret = check_func(fs_info, uuid, key.type, subid_cpu);
+			ret = btrfs_check_uuid_tree_entry(fs_info, uuid,
+							  key.type, subid_cpu);
 			if (ret < 0)
 				goto out;
 			if (ret > 0) {