[SRU][N:linux-azure][PATCH v2 6/8] cifs: do not disable interface polling on failure

[Vinicius Peixoto]

From: Shyam Prasad N <sprasad at microsoft.com>

BugLink: https://bugs.launchpad.net/bugs/2118807

When a server has multichannel enabled, we keep polling the server
for interfaces periodically. However, when this query fails, we
disable the polling. This can be problematic as it takes away the
chance for the server to start advertizing again.

This change reschedules the delayed work, even if the current call
failed. That way, multichannel sessions can recover.

Signed-off-by: Shyam Prasad N <sprasad at microsoft.com>
Cc: stable at vger.kernel.org
Signed-off-by: Steve French <stfrench at microsoft.com>
(cherry picked from commit 42ca547b13a20e7cbb04fbdf8d5f089ac4bb35b7)
Signed-off-by: Vinicius Peixoto <vinicius.peixoto at canonical.com>
---
 fs/smb/client/connect.c | 6 +-----
 fs/smb/client/smb2pdu.c | 9 +++++----
 2 files changed, 6 insertions(+), 9 deletions(-)

diff --git a/fs/smb/client/connect.c b/fs/smb/client/connect.c
index a1787fc08a21..1ce60fc11a96 100644
--- a/fs/smb/client/connect.c
+++ b/fs/smb/client/connect.c
@@ -135,13 +135,9 @@ static void smb2_query_server_interfaces(struct work_struct *work)
 	rc = server->ops->query_server_interfaces(xid, tcon, false);
 	free_xid(xid);
 
-	if (rc) {
-		if (rc == -EOPNOTSUPP)
-			return;
-
+	if (rc)
 		cifs_dbg(FYI, "%s: failed to query server interfaces: %d\n",
 				__func__, rc);
-	}
 
 	queue_delayed_work(cifsiod_wq, &tcon->query_interfaces,
 			   (SMB_INTERFACE_POLL_INTERVAL * HZ));
diff --git a/fs/smb/client/smb2pdu.c b/fs/smb/client/smb2pdu.c
index 9891329387f3..69b6351f77c8 100644
--- a/fs/smb/client/smb2pdu.c
+++ b/fs/smb/client/smb2pdu.c
@@ -437,6 +437,10 @@ smb2_reconnect(__le16 smb2_command, struct cifs_tcon *tcon,
 		free_xid(xid);
 		ses->flags &= ~CIFS_SES_FLAGS_PENDING_QUERY_INTERFACES;
 
+		/* regardless of rc value, setup polling */
+		queue_delayed_work(cifsiod_wq, &tcon->query_interfaces,
+				   (SMB_INTERFACE_POLL_INTERVAL * HZ));
+
 		mutex_unlock(&ses->session_mutex);
 
 		if (rc == -EOPNOTSUPP && ses->chan_count > 1) {
@@ -457,11 +461,8 @@ smb2_reconnect(__le16 smb2_command, struct cifs_tcon *tcon,
 		if (ses->chan_max > ses->chan_count &&
 		    ses->iface_count &&
 		    !SERVER_IS_CHAN(server)) {
-			if (ses->chan_count == 1) {
+			if (ses->chan_count == 1)
 				cifs_server_dbg(VFS, "supports multichannel now\n");
-				queue_delayed_work(cifsiod_wq, &tcon->query_interfaces,
-						 (SMB_INTERFACE_POLL_INTERVAL * HZ));
-			}
 
 			cifs_try_adding_channels(ses);
 		}
-- 
2.45.2