FAILED: patch "[PATCH] btrfs: abort in rename_exchange if we fail to insert the" failed to apply to 4.14-stable tree

The patch below does not apply to the 4.14-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From dc09ef3562726cd520c8338c1640872a60187af5 Mon Sep 17 00:00:00 2001
From: Josef Bacik <[email protected]>
Date: Wed, 19 May 2021 14:04:21 -0400
Subject: [PATCH] btrfs: abort in rename_exchange if we fail to insert the
second ref

Error injection stress uncovered a problem where we'd leave a dangling inode ref if we failed during a rename_exchange. This happens because we insert the inode ref for one side of the rename, and then for the other side. If this second inode ref insert fails we'll leave the first one dangling and leave a corrupt file system behind. Fix this by aborting if we did the insert for the first inode ref.

index e7de0c08b981..f5d32d85247a 100644
@@ -9101,6 +9101,7 @@ static int btrfs_rename_exchange(struct inode *old_dir,
 	int ret2;
 	bool root_log_pinned = false;
 	bool dest_log_pinned = false;
+	bool need_abort = false;
 
 	/* we only allow rename subvolume link between subvolumes */
 	if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)

@@ -9160,6 +9161,7 @@ static int btrfs_rename_exchange(struct inode *old_dir,
 					     old_idx);
 		if (ret)
 			goto out_fail;
+		need_abort = true;
 	}
 
 	/* And now for the dest. */

@@ -9175,8 +9177,11 @@ static int btrfs_rename_exchange(struct inode *old_dir,
 					     new_ino,
 					     btrfs_ino(BTRFS_I(old_dir)),
 					     new_idx);
-		if (ret)
+		if (ret) {
+			if (need_abort)
+				btrfs_abort_transaction(trans, ret);
 			goto out_fail;
+		}
 	}
 
 	/* Update inode version and ctime/mtime. */