linux-kernel - [PATCH] smb: client: fix first failure in negotiation after server reboot

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Message-ID: <a4435153-eb55-4160-9b46-aa937cffa575@huawei.com>
Date: Fri, 13 Jun 2025 18:44:20 +0800
From: "zhangjian (CG)" <zhangjian496@...wei.com>
To: <stfrench@...rosoft.com>, <smfrench@...il.com>, <longli@...rosoft.com>,
	<wangzhaolong1@...wei.com>, <metze@...ba.org>, <dhowells@...hat.com>,
	<pc@...guebit.org>
CC: <linux-kernel@...r.kernel.org>, <linux-cifs@...r.kernel.org>
Subject: [PATCH] smb: client: fix first failure in negotiation after server
 reboot

After fabc4ed200f9, server_unresponsive add a condition to check whether 
client need to reconnect depending on server->lstrp. When client failed 
to reconnect in 180s, client will abort connection and update server->lstrp 
for the last time. In the following scene, server->lstrp is too 
old, which may cause failure for the first negotiation.

client                                                 | server
-------------------------------------------------------+------------------
mount to cifs server                                   |
ls                                                     |
                                                       | reboot
    stuck for 180s and return EHOSTDOWN                |
    abort connection and update server->lstrp          |
                                                       | sleep 21s
                                                       | service smb restart
ls                                                     |
    smb_negotiate                                      |
        server_unresponsive cause reconnect [in cifsd] |
        ( tcpStatus == CifsInNegotiate &&              |
	            jiffies > server->lstrp + 20s )        |
        cifs_sync_mid_result return EAGAIN             |
    smb_negotiate return EHOSTDOWN                     |
ls failed                                              |

The condition (tcpStatus == CifsInNegotiate && jiffies > server->lstrp + 20s)
expect client stay in CifsInNegotiate state for more than 20s. So we update 
server->lstrp before last switching into CifsInNegotiate state to avoid 
this failure.

Fixes: fabc4ed200f9 ("smb: client: fix hang in wait_for_response() for 
negproto")
Signed-off-by: zhangjian <zhangjian496@...wei.com>
---
 fs/smb/client/connect.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/smb/client/connect.c b/fs/smb/client/connect.c
index 28bc33496..f9aef60f1 100644
--- a/fs/smb/client/connect.c
+++ b/fs/smb/client/connect.c
@@ -4193,6 +4193,7 @@ cifs_negotiate_protocol(const unsigned int xid, struct cifs_ses *ses,
 		return 0;
 	}
 
+	server->lstrp = jiffies;
 	server->tcpStatus = CifsInNegotiate;
 	spin_unlock(&server->srv_lock);
 
-- 
2.33.0