From: Steve French <stfrench@microsoft.com>
Date: Tue, 9 May 2023 01:37:19 -0500
Subject: [PATCH] smb3: fix problem remounting a share after shutdown
References: bsc#1012628
Patch-mainline: 6.3.3
Git-commit: 716a3cf317456fa01d54398bb14ab354f50ed6a2

commit 716a3cf317456fa01d54398bb14ab354f50ed6a2 upstream.

xfstests generic/392 showed a problem where even after a
shutdown call was made on a mount, we would still attempt
to use the (now inaccessible) superblock if another mount
was attempted for the same share.

Reported-by: David Howells <dhowells@redhat.com>
Reviewed-by: David Howells <dhowells@redhat.com>
Cc: <stable@vger.kernel.org>
Fixes: 087f757b0129 ("cifs: add shutdown support")
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
 fs/cifs/connect.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 2c573062..59a10330 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -2705,6 +2705,13 @@ cifs_match_super(struct super_block *sb, void *data)
 
 	spin_lock(&cifs_tcp_ses_lock);
 	cifs_sb = CIFS_SB(sb);
+
+	/* We do not want to use a superblock that has been shutdown */
+	if (CIFS_MOUNT_SHUTDOWN & cifs_sb->mnt_cifs_flags) {
+		spin_unlock(&cifs_tcp_ses_lock);
+		return 0;
+	}
+
 	tlink = cifs_get_tlink(cifs_sb_master_tlink(cifs_sb));
 	if (tlink == NULL) {
 		/* can not match superblock if tlink were ever null */
-- 
2.35.3