[PATCH 5.17 289/343] cifs: force new session setup and tcon for dfs

From: Greg Kroah-Hartman
Date: Tue Apr 12 2022 - 05:11:11 EST


From: Paulo Alcantara <pc@xxxxxx>

commit fb39d30e227233498c8debe6a9fe3e7cf575c85f upstream.

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@xxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Reviewed-by: Enzo Matsumiya <ematsumiya@xxxxxxx>
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/cifs/connect.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)

--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -453,9 +453,7 @@ static int reconnect_target_unlocked(str
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_I
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_Inf
}
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)