cifs: translate network errors on send to -ECONNABORTED

[ Upstream commit a68106a ]

When the network stack returns various errors, we today bubble
up the error to the user (in case of soft mounts).

This change translates all network errors except -EINTR and
-EAGAIN to -ECONNABORTED. A similar approach is taken when
we receive network errors when reading from the socket.

The change also forces the cifsd thread to reconnect during
it's next activity.

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

@@ -400,10 +400,17 @@ __smb_send_rqst(struct TCP_Server_Info *server, int num_rqst,
 						  server->conn_id, server->hostname);
 	}
 smbd_done:
-	if (rc < 0 && rc != -EINTR)
+	/*
+	 * there's hardly any use for the layers above to know the
+	 * actual error code here. All they should do at this point is
+	 * to retry the connection and hope it goes away.
+	 */
+	if (rc < 0 && rc != -EINTR && rc != -EAGAIN) {
 		cifs_server_dbg(VFS, "Error %d sending data on socket to server\n",
 			 rc);
-	else if (rc > 0)
+		rc = -ECONNABORTED;
+		cifs_signal_cifsd_for_reconnect(server, false);
+	} else if (rc > 0)
 		rc = 0;
 out:
 	cifs_in_send_dec(server);