cifs: cifs_pick_channel should try selecting active channels

[ Upstream commit fc43a8a ]

cifs_pick_channel today just selects a channel based
on the policy of least loaded channel. However, it
does not take into account if the channel needs
reconnect. As a result, we can have failures in send
that can be completely avoided.

This change doesn't make a channel a candidate for
this selection if it needs reconnect.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

fs/smb/client/transport.c

@@ -1026,6 +1026,9 @@ struct TCP_Server_Info *cifs_pick_channel(struct cifs_ses *ses)
 		if (!server || server->terminate)
 			continue;
 
+		if (CIFS_CHAN_NEEDS_RECONNECT(ses, i))
+			continue;
+
 		/*
 		 * strictly speaking, we should pick up req_lock to read
 		 * server->in_flight. But it shouldn't matter much here if we