Commit 9dd4658d authored by Sage Weil's avatar Sage Weil
Browse files

ceph: close messenger race 



Simplify messenger locking, and close race between ceph_con_close() setting
the CLOSED bit and con_work() checking the bit, then taking the mutex.

Signed-off-by: default avatarSage Weil <sage@newdream.net>
parent 4f48280e

fs/ceph/messenger.c

+7 −7
Original line number Diff line number Diff line
@@ -1546,7 +1546,6 @@ 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->mutex);

more:

	dout("try_write out_kvec_bytes %d\n", con->out_kvec_bytes);
@@ -1639,7 +1638,6 @@ static int try_write(struct ceph_connection *con) 
done:

	ret = 0;

out:

	mutex_unlock(&con->mutex);

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

	return ret;

}
@@ -1651,7 +1649,6 @@ static int try_write(struct ceph_connection *con) 
 */

static int try_read(struct ceph_connection *con)

{

	struct ceph_messenger *msgr;

	int ret = -1;



	if (!con->sock)
@@ -1661,9 +1658,6 @@ static int try_read(struct ceph_connection *con) 
		return 0;



	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,
@@ -1758,7 +1752,6 @@ 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;
@@ -1830,6 +1823,8 @@ static void con_work(struct work_struct *work) 
	dout("con_work %p start, clearing QUEUED\n", con);

	clear_bit(QUEUED, &con->state);



	mutex_lock(&con->mutex);



	if (test_bit(CLOSED, &con->state)) { /* e.g. if we are replaced */

		dout("con_work CLOSED\n");

		con_close_socket(con);
@@ -1844,11 +1839,16 @@ static void con_work(struct work_struct *work) 
	if (test_and_clear_bit(SOCK_CLOSED, &con->state) ||

	    try_read(con) < 0 ||

	    try_write(con) < 0) {

		mutex_unlock(&con->mutex);

		backoff = 1;

		ceph_fault(con);     /* error/fault path */

		goto done_unlocked;

	}



done:

	mutex_unlock(&con->mutex);



done_unlocked:

	clear_bit(BUSY, &con->state);

	dout("con->state=%lu\n", con->state);

	if (test_bit(QUEUED, &con->state)) {