[CIFS] cifs: reconnect unresponsive servers
If the server isn't responding to echoes, we don't want to leave tasks
hung waiting for it to reply. At that point, we'll want to reconnect
so that soft mounts can return an error to userspace quickly.
If the client hasn't received a reply after a specified number of echo
intervals, assume that the transport is down and attempt to reconnect
the socket.
The number of echo_intervals to wait before attempting to reconnect is
tunable via a module parameter. Setting it to 0, means that the client
will never attempt to reconnect. The default is 5.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index f38ca08..f5d7b59 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -186,6 +186,7 @@
kfree(server->session_key.response);
server->session_key.response = NULL;
server->session_key.len = 0;
+ server->lstrp = jiffies;
mutex_unlock(&server->srv_mutex);
/* mark submitted MIDs for retry and issue callback */
@@ -420,7 +421,20 @@
smb_msg.msg_control = NULL;
smb_msg.msg_controllen = 0;
pdu_length = 4; /* enough to get RFC1001 header */
+
incomplete_rcv:
+ if (echo_retries > 0 &&
+ time_after(jiffies, server->lstrp +
+ (echo_retries * SMB_ECHO_INTERVAL))) {
+ cERROR(1, "Server %s has not responded in %d seconds. "
+ "Reconnecting...", server->hostname,
+ (echo_retries * SMB_ECHO_INTERVAL / HZ));
+ cifs_reconnect(server);
+ csocket = server->ssocket;
+ wake_up(&server->response_q);
+ continue;
+ }
+
length =
kernel_recvmsg(csocket, &smb_msg,
&iov, 1, pdu_length, 0 /* BB other flags? */);
@@ -581,6 +595,8 @@
}
mid_entry = NULL;
+ server->lstrp = jiffies;
+
spin_lock(&GlobalMid_Lock);
list_for_each_safe(tmp, tmp2, &server->pending_mid_q) {
mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
@@ -629,10 +645,6 @@
#ifdef CONFIG_CIFS_STATS2
mid_entry->when_received = jiffies;
#endif
- /* so we do not time out requests to server
- which is still responding (since server could
- be busy but not dead) */
- server->lstrp = jiffies;
break;
}
mid_entry = NULL;
@@ -1685,6 +1697,7 @@
volume_info->target_rfc1001_name, RFC1001_NAME_LEN_WITH_NULL);
tcp_ses->session_estab = false;
tcp_ses->sequence_number = 0;
+ tcp_ses->lstrp = jiffies;
INIT_LIST_HEAD(&tcp_ses->tcp_ses_list);
INIT_LIST_HEAD(&tcp_ses->smb_ses_list);
INIT_DELAYED_WORK(&tcp_ses->echo, cifs_echo_request);
