Received-SPF: softfail (google.com: domain of transitioning linux-kernel-owner@vger.kernel.org does not designate 23.128.96.19 as permitted sender) client-ip=23.128.96.19;
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Enzo Matsumiya <ematsumiya@suse.de>,
        Shyam Prasad N <sprasad@microsoft.com>,
        "Paulo Alcantara (SUSE)" <pc@cjr.nz>,
        Steve French <stfrench@microsoft.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.17 229/343] cifs: fix potential race with cifsd thread
Date:   Tue, 12 Apr 2022 08:30:47 +0200
Message-Id: <20220412062957.947491639@linuxfoundation.org>
In-Reply-To: <20220412062951.095765152@linuxfoundation.org>
References: <20220412062951.095765152@linuxfoundation.org>
User-Agent: quilt/0.66
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Precedence: bulk

From: Paulo Alcantara <pc@cjr.nz>

[ Upstream commit 687127c81ad32c8900a3fedbc7ed8f686ca95855 ]

To avoid racing with demultiplex thread while it is handling data on
socket, use cifs_signal_cifsd_for_reconnect() helper for marking
current server to reconnect and let the demultiplex thread handle the
rest.

Fixes: dca65818c80c ("cifs: use a different reconnect helper for non-cifsd threads")
Reviewed-by: Enzo Matsumiya <ematsumiya@suse.de>
Reviewed-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/cifs/connect.c | 2 +-
 fs/cifs/netmisc.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index d6f8ccc7bfe2..0270b412f801 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -4465,7 +4465,7 @@ static int tree_connect_dfs_target(const unsigned int xid, struct cifs_tcon *tco
 	 */
 	if (rc && server->current_fullpath != server->origin_fullpath) {
 		server->current_fullpath = server->origin_fullpath;
-		cifs_reconnect(tcon->ses->server, true);
+		cifs_signal_cifsd_for_reconnect(server, true);
 	}
 
 	dfs_cache_free_tgts(tl);
diff --git a/fs/cifs/netmisc.c b/fs/cifs/netmisc.c
index ebe236b9d9f5..235aa1b395eb 100644
--- a/fs/cifs/netmisc.c
+++ b/fs/cifs/netmisc.c
@@ -896,7 +896,7 @@ map_and_check_smb_error(struct mid_q_entry *mid, bool logErr)
 		if (class == ERRSRV && code == ERRbaduid) {
 			cifs_dbg(FYI, "Server returned 0x%x, reconnecting session...\n",
 				code);
-			cifs_reconnect(mid->server, false);
+			cifs_signal_cifsd_for_reconnect(mid->server, false);
 		}
 	}
 
-- 
2.35.1