[PATCH v2] cifs: force new session setup and tcon for dfs

From: Paulo Alcantara <pc@cjr.nz>
To: linux-cifs@vger.kernel.org, smfrench@gmail.com
Cc: Paulo Alcantara <pc@cjr.nz>
Subject: [PATCH v2] cifs: force new session setup and tcon for dfs
Date: Fri,  1 Apr 2022 13:51:34 -0300	[thread overview]
Message-ID: <20220401165134.25471-1-pc@cjr.nz> (raw)
In-Reply-To: <20220331180151.5301-2-pc@cjr.nz>

Do not reuse existing sessions and tcons in DFS failover as it might
connect to different servers and shares.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
---
 fs/cifs/connect.c | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 3ca06bd88b6e..54155eb4faac 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -453,9 +453,7 @@ static int reconnect_target_unlocked(struct TCP_Server_Info *server, struct dfs_
 	return rc;
 }
 
-static int
-reconnect_dfs_server(struct TCP_Server_Info *server,
-		     bool mark_smb_session)
+static int reconnect_dfs_server(struct TCP_Server_Info *server)
 {
 	int rc = 0;
 	const char *refpath = server->current_fullpath + 1;
@@ -479,7 +477,12 @@ reconnect_dfs_server(struct TCP_Server_Info *server,
 	if (!cifs_tcp_ses_needs_reconnect(server, num_targets))
 		return 0;
 
-	cifs_mark_tcp_ses_conns_for_reconnect(server, mark_smb_session);
+	/*
+	 * Unconditionally mark all sessions & tcons for reconnect as we might be connecting to a
+	 * different server or share during failover.  It could be improved by adding some logic to
+	 * only do that in case it connects to a different server or share, though.
+	 */
+	cifs_mark_tcp_ses_conns_for_reconnect(server, true);
 
 	cifs_abort_connection(server);
 
@@ -537,7 +540,7 @@ int cifs_reconnect(struct TCP_Server_Info *server, bool mark_smb_session)
 	}
 	spin_unlock(&cifs_tcp_ses_lock);
 
-	return reconnect_dfs_server(server, mark_smb_session);
+	return reconnect_dfs_server(server);
 }
 #else
 int cifs_reconnect(struct TCP_Server_Info *server, bool mark_smb_session)
-- 
2.35.1

