Commit ec302645 authored by Sage Weil's avatar Sage Weil
Browse files

ceph: use connection mutex to protect read and write stages 



Use a single mutex (previously out_mutex) to protect both read and write
activity from concurrent ceph_con_* calls.  Drop the mutex when doing
callbacks to avoid nested locking (the callback may need to call something
like ceph_con_close).

Signed-off-by: default avatarSage Weil <sage@newdream.net>
parent 529cfcc4

fs/ceph/messenger.c

+31 −18
Original line number Diff line number Diff line
@@ -316,7 +316,6 @@ static void reset_connection(struct ceph_connection *con) 
{

	/* reset connection, out_queue, msg_ and connect_seq */

	/* discard existing out_queue and msg_seq */

	mutex_lock(&con->out_mutex);

	ceph_msg_remove_list(&con->out_queue);

	ceph_msg_remove_list(&con->out_sent);
@@ -332,7 +331,6 @@ static void reset_connection(struct ceph_connection *con) 
		con->out_msg = NULL;

	}

	con->in_seq = 0;

	mutex_unlock(&con->out_mutex);

}



/*
@@ -343,7 +341,9 @@ void ceph_con_close(struct ceph_connection *con) 
	dout("con_close %p peer %s\n", con, pr_addr(&con->peer_addr.in_addr));

	set_bit(CLOSED, &con->state);  /* in case there's queued work */

	clear_bit(STANDBY, &con->state);  /* avoid connect_seq bump */

	mutex_lock(&con->mutex);

	reset_connection(con);

	mutex_unlock(&con->mutex);

	queue_con(con);

}
@@ -392,7 +392,7 @@ void ceph_con_init(struct ceph_messenger *msgr, struct ceph_connection *con) 
	memset(con, 0, sizeof(*con));

	atomic_set(&con->nref, 1);

	con->msgr = msgr;

	mutex_init(&con->out_mutex);

	mutex_init(&con->mutex);

	INIT_LIST_HEAD(&con->out_queue);

	INIT_LIST_HEAD(&con->out_sent);

	INIT_DELAYED_WORK(&con->work, con_work);
@@ -571,11 +571,13 @@ static void prepare_connect_authorizer(struct ceph_connection *con) 
	int auth_len = 0;

	int auth_protocol = 0;



	mutex_unlock(&con->mutex);

	if (con->ops->get_authorizer)

		con->ops->get_authorizer(con, &auth_buf, &auth_len,

					 &auth_protocol, &con->auth_reply_buf,

					 &con->auth_reply_buf_len,

					 con->auth_retry);

	mutex_lock(&con->mutex);



	con->out_connect.authorizer_protocol = cpu_to_le32(auth_protocol);

	con->out_connect.authorizer_len = cpu_to_le32(auth_len);
@@ -1094,10 +1096,13 @@ static int process_connect(struct ceph_connection *con) 
		       le32_to_cpu(con->out_connect.protocol_version),

		       le32_to_cpu(con->in_reply.protocol_version));

		con->error_msg = "protocol version mismatch";

		if (con->ops->bad_proto)

			con->ops->bad_proto(con);

		reset_connection(con);

		set_bit(CLOSED, &con->state);  /* in case there's queued work */



		mutex_unlock(&con->mutex);

		if (con->ops->bad_proto)

			con->ops->bad_proto(con);

		mutex_lock(&con->mutex);

		return -1;



	case CEPH_MSGR_TAG_BADAUTHORIZER:
@@ -1133,9 +1138,11 @@ static int process_connect(struct ceph_connection *con) 
		prepare_read_connect(con);



		/* Tell ceph about it. */

		mutex_unlock(&con->mutex);

		pr_info("reset on %s%lld\n", ENTITY_NAME(con->peer_name));

		if (con->ops->peer_reset)

			con->ops->peer_reset(con);

		mutex_lock(&con->mutex);

		break;



	case CEPH_MSGR_TAG_RETRY_SESSION:
@@ -1221,7 +1228,6 @@ static void process_ack(struct ceph_connection *con) 
	u64 ack = le64_to_cpu(con->in_temp_ack);

	u64 seq;



	mutex_lock(&con->out_mutex);

	while (!list_empty(&con->out_sent)) {

		m = list_first_entry(&con->out_sent, struct ceph_msg,

				     list_head);
@@ -1232,7 +1238,6 @@ static void process_ack(struct ceph_connection *con) 
		     le16_to_cpu(m->hdr.type), m);

		ceph_msg_remove(m);

	}

	mutex_unlock(&con->out_mutex);

	prepare_read_tag(con);

}
@@ -1366,8 +1371,10 @@ static int read_partial_message(struct ceph_connection *con) 
		/* find pages for data payload */

		want = calc_pages_for(data_off & ~PAGE_MASK, data_len);

		ret = -1;

		mutex_unlock(&con->mutex);

		if (con->ops->prepare_pages)

			ret = con->ops->prepare_pages(con, m, want);

		mutex_lock(&con->mutex);

		if (ret < 0) {

			dout("%p prepare_pages failed, skipping payload\n", m);

			con->in_base_pos = -data_len - sizeof(m->footer);
@@ -1454,9 +1461,8 @@ static void process_message(struct ceph_connection *con) 
	if (con->peer_name.type == 0)

		con->peer_name = msg->hdr.src.name;



	mutex_lock(&con->out_mutex);

	con->in_seq++;

	mutex_unlock(&con->out_mutex);

	mutex_unlock(&con->mutex);



	dout("===== %p %llu from %s%lld %d=%s len %d+%d (%u %u %u) =====\n",

	     msg, le64_to_cpu(msg->hdr.seq),
@@ -1467,6 +1473,8 @@ static void process_message(struct ceph_connection *con) 
	     le32_to_cpu(msg->hdr.data_len),

	     con->in_front_crc, con->in_middle_crc, con->in_data_crc);

	con->ops->dispatch(con, msg);



	mutex_lock(&con->mutex);

	prepare_read_tag(con);

}
@@ -1483,7 +1491,7 @@ static int try_write(struct ceph_connection *con) 
	dout("try_write start %p state %lu nref %d\n", con, con->state,

	     atomic_read(&con->nref));



	mutex_lock(&con->out_mutex);

	mutex_lock(&con->mutex);

more:

	dout("try_write out_kvec_bytes %d\n", con->out_kvec_bytes);
@@ -1576,7 +1584,7 @@ static int try_write(struct ceph_connection *con) 
done:

	ret = 0;

out:

	mutex_unlock(&con->out_mutex);

	mutex_unlock(&con->mutex);

	dout("try_write done on %p\n", con);

	return ret;

}
@@ -1600,6 +1608,8 @@ static int try_read(struct ceph_connection *con) 
	dout("try_read start on %p\n", con);

	msgr = con->msgr;



	mutex_lock(&con->mutex);



more:

	dout("try_read tag %d in_base_pos %d\n", (int)con->in_tag,

	     con->in_base_pos);
@@ -1693,6 +1703,7 @@ static int try_read(struct ceph_connection *con) 
done:

	ret = 0;

out:

	mutex_unlock(&con->mutex);

	dout("try_read done on %p\n", con);

	return ret;
@@ -1818,6 +1829,8 @@ static void ceph_fault(struct ceph_connection *con) 


	clear_bit(BUSY, &con->state);  /* to avoid an improbable race */



	mutex_lock(&con->mutex);



	con_close_socket(con);



	if (con->in_msg) {
@@ -1827,24 +1840,24 @@ static void ceph_fault(struct ceph_connection *con) 


	/* If there are no messages in the queue, place the connection

	 * in a STANDBY state (i.e., don't try to reconnect just yet). */

	mutex_lock(&con->out_mutex);

	if (list_empty(&con->out_queue) && !con->out_keepalive_pending) {

		dout("fault setting STANDBY\n");

		set_bit(STANDBY, &con->state);

		mutex_unlock(&con->out_mutex);

		mutex_unlock(&con->mutex);

		goto out;

	}



	/* Requeue anything that hasn't been acked, and retry after a

	 * delay. */

	list_splice_init(&con->out_sent, &con->out_queue);

	mutex_unlock(&con->out_mutex);



	if (con->delay == 0)

		con->delay = BASE_DELAY_INTERVAL;

	else if (con->delay < MAX_DELAY_INTERVAL)

		con->delay *= 2;



	mutex_unlock(&con->mutex);



	/* explicitly schedule work to try to reconnect again later. */

	dout("fault queueing %p delay %lu\n", con, con->delay);

	con->ops->get(con);
@@ -1920,7 +1933,7 @@ void ceph_con_send(struct ceph_connection *con, struct ceph_msg *msg) 
	msg->hdr.dst_erank = con->peer_addr.erank;



	/* queue */

	mutex_lock(&con->out_mutex);

	mutex_lock(&con->mutex);

	BUG_ON(!list_empty(&msg->list_head));

	list_add_tail(&msg->list_head, &con->out_queue);

	dout("----- %p to %s%lld %d=%s len %d+%d+%d -----\n", msg,
@@ -1929,7 +1942,7 @@ void ceph_con_send(struct ceph_connection *con, struct ceph_msg *msg) 
	     le32_to_cpu(msg->hdr.front_len),

	     le32_to_cpu(msg->hdr.middle_len),

	     le32_to_cpu(msg->hdr.data_len));

	mutex_unlock(&con->out_mutex);

	mutex_unlock(&con->mutex);



	/* if there wasn't anything waiting to send before, queue

	 * new work */
@@ -1942,7 +1955,7 @@ void ceph_con_send(struct ceph_connection *con, struct ceph_msg *msg) 
 */

void ceph_con_revoke(struct ceph_connection *con, struct ceph_msg *msg)

{

	mutex_lock(&con->out_mutex);

	mutex_lock(&con->mutex);

	if (!list_empty(&msg->list_head)) {

		dout("con_revoke %p msg %p\n", con, msg);

		list_del_init(&msg->list_head);
@@ -1959,7 +1972,7 @@ void ceph_con_revoke(struct ceph_connection *con, struct ceph_msg *msg) 
	} else {

		dout("con_revoke %p msg %p - not queued (sent?)\n", con, msg);

	}

	mutex_unlock(&con->out_mutex);

	mutex_unlock(&con->mutex);

}



/*

fs/ceph/messenger.h

+2 −1
Original line number Diff line number Diff line
@@ -155,8 +155,9 @@ struct ceph_connection { 
	void *auth_reply_buf;   /* where to put the authorizer reply */

	int auth_reply_buf_len;



	struct mutex mutex;



	/* out queue */

	struct mutex out_mutex;

	struct list_head out_queue;

	struct list_head out_sent;   /* sending or sent but unacked */

	u64 out_seq;		     /* last message queued for send */