Commit 550a8002 authored by Tina Yang's avatar Tina Yang Committed by David S. Miller
Browse files

RDS: Fix locking in rds_send_drop_to() 



It seems rds_send_drop_to() called
__rds_rdma_send_complete(rs, rm, RDS_RDMA_CANCELED)
with only rds_sock lock, but not rds_message lock. It raced with
other threads that is attempting to modify the rds_message as well,
such as from within rds_rdma_send_complete().

Signed-off-by: default avatarTina Yang <tina.yang@oracle.com>
Signed-off-by: default avatarAndy Grover <andy.grover@oracle.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 97069788

net/rds/send.c

+7 −6
Original line number Diff line number Diff line
@@ -632,9 +632,6 @@ void rds_send_drop_to(struct rds_sock *rs, struct sockaddr_in *dest) 
		list_move(&rm->m_sock_item, &list);

		rds_send_sndbuf_remove(rs, rm);

		clear_bit(RDS_MSG_ON_SOCK, &rm->m_flags);



		/* If this is a RDMA operation, notify the app. */

		__rds_rdma_send_complete(rs, rm, RDS_RDMA_CANCELED);

	}



	/* order flag updates with the rs lock */
@@ -643,9 +640,6 @@ void rds_send_drop_to(struct rds_sock *rs, struct sockaddr_in *dest) 


	spin_unlock_irqrestore(&rs->rs_lock, flags);



	if (wake)

		rds_wake_sk_sleep(rs);



	conn = NULL;



	/* now remove the messages from the conn list as needed */
@@ -653,6 +647,10 @@ void rds_send_drop_to(struct rds_sock *rs, struct sockaddr_in *dest) 
		/* We do this here rather than in the loop above, so that

		 * we don't have to nest m_rs_lock under rs->rs_lock */

		spin_lock_irqsave(&rm->m_rs_lock, flags2);

		/* If this is a RDMA operation, notify the app. */

		spin_lock(&rs->rs_lock);

		__rds_rdma_send_complete(rs, rm, RDS_RDMA_CANCELED);

		spin_unlock(&rs->rs_lock);

		rm->m_rs = NULL;

		spin_unlock_irqrestore(&rm->m_rs_lock, flags2);
@@ -681,6 +679,9 @@ void rds_send_drop_to(struct rds_sock *rs, struct sockaddr_in *dest) 
	if (conn)

		spin_unlock_irqrestore(&conn->c_lock, flags);



	if (wake)

		rds_wake_sk_sleep(rs);



	while (!list_empty(&list)) {

		rm = list_entry(list.next, struct rds_message, m_sock_item);

		list_del_init(&rm->m_sock_item);

CRA Git | Maintained and supported by SUSTech CRA and CCSE