1 files changed, 16 insertions, 0 deletions
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 013d0abcd46b..5baad9bebc62 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -5758,6 +5758,22 @@ static int btrfs_log_inode_parent(struct btrfs_trans_handle *trans,
 			goto end_trans;
 	}
 
+	/*
+	 * If a new hard link was added to the inode in the current transaction
+	 * and its link count is now greater than 1, we need to fallback to a
+	 * transaction commit, otherwise we can end up not logging all its new
+	 * parents for all the hard links. Here just from the dentry used to
+	 * fsync, we can not visit the ancestor inodes for all the other hard
+	 * links to figure out if any is new, so we fallback to a transaction
+	 * commit (instead of adding a lot of complexity of scanning a btree,
+	 * since this scenario is not a common use case).
+	 */
+	if (inode->vfs_inode.i_nlink > 1 &&
+	    inode->last_link_trans > last_committed) {
+		ret = -EMLINK;
+		goto end_trans;
+	}
+
 	while (1) {
 		if (!parent || d_really_is_negative(parent) || sb != parent->d_sb)
 			break;