From: Shyam Prasad N <sprasad@microsoft.com>
Date: Wed, 6 Jul 2022 14:29:12 +0000
Subject: [PATCH] cifs: remove unnecessary locking of chan_lock while freeing
 session
Git-commit: 2883f4b5a0e1ac9472c7e3ae9bbdb4ea5a2117c6
References: bsc#1193629
Patch-mainline: v5.19-rc7

In cifs_put_smb_ses, when we're freeing the last ref count to
the session, we need to free up each channel. At this point,
it is unnecessary to take chan_lock, since we have the last
reference to the ses.

Picking up this lock also introduced a deadlock because it calls
cifs_put_tcp_ses, which locks cifs_tcp_ses_lock.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Acked-by: Enzo Matsumiya <ematsumiya@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
Acked-by: Paulo Alcantara <palcantara@suse.de>
---
 fs/cifs/connect.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index fa29c9aae24b..386bb523c69e 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -1918,7 +1918,6 @@ void cifs_put_smb_ses(struct cifs_ses *ses)
 	list_del_init(&ses->smb_ses_list);
 	spin_unlock(&cifs_tcp_ses_lock);
 
-	spin_lock(&ses->chan_lock);
 	chan_count = ses->chan_count;
 
 	/* close any extra channels */
@@ -1934,7 +1933,6 @@ void cifs_put_smb_ses(struct cifs_ses *ses)
 			ses->chans[i].server = NULL;
 		}
 	}
-	spin_unlock(&ses->chan_lock);
 
 	sesInfoFree(ses);
 	cifs_put_tcp_session(server, 0);
-- 
2.37.3