From 803cc77a3acc3821f2f34c5d07338c108305f019 Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Thu, 14 Sep 2023 21:55:29 -0400
Subject: [PATCH] ceph_wait_on_conflict_unlink(): grab reference before
 dropping ->d_lock

[ Upstream commit dc32464a5fe4946fe1a4d8f8e29961dc411933c5 ]

Use of dget() after we'd dropped ->d_lock is too late - dentry might
be gone by that point.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/ceph/mds_client.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index f6a7fd47efd7..82874be94524 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -709,8 +709,8 @@ int ceph_wait_on_conflict_unlink(struct dentry *dentry)
 		if (!d_same_name(udentry, pdentry, &dname))
 			goto next;
 
+		found = dget_dlock(udentry);
 		spin_unlock(&udentry->d_lock);
-		found = dget(udentry);
 		break;
 next:
 		spin_unlock(&udentry->d_lock);