@@ -58,7 +58,7 @@ void rds_message_addref(struct rds_message *rm)
*/
static void rds_message_purge(struct rds_message *rm)
{
- unsigned long i;
+ unsigned long i, flags;
if (unlikely(test_bit(RDS_MSG_PAGEVEC, &rm->m_flags)))
return;
@@ -69,6 +69,12 @@ static void rds_message_purge(struct rds_message *rm)
__free_page(sg_page(&rm->data.op_sg[i]));
}
rm->data.op_nents = 0;
+ spin_lock_irqsave(&rm->m_rs_lock, flags);
+ if (rm->m_rs) {
+ sock_put(rds_rs_to_sk(rm->m_rs));
+ rm->m_rs = NULL;
+ }
+ spin_unlock_irqrestore(&rm->m_rs_lock, flags);
if (rm->rdma.op_active)
rds_rdma_free_op(&rm->rdma);
@@ -649,7 +649,6 @@ static void rds_send_remove_from_sock(struct list_head *messages, int status)
rm->rdma.op_notifier = NULL;
}
was_on_sock = 1;
- rm->m_rs = NULL;
}
spin_unlock(&rs->rs_lock);
@@ -756,9 +755,6 @@ void rds_send_drop_to(struct rds_sock *rs, struct sockaddr_in *dest)
*/
if (!test_and_clear_bit(RDS_MSG_ON_CONN, &rm->m_flags)) {
spin_unlock_irqrestore(&cp->cp_lock, flags);
- spin_lock_irqsave(&rm->m_rs_lock, flags);
- rm->m_rs = NULL;
- spin_unlock_irqrestore(&rm->m_rs_lock, flags);
continue;
}
list_del_init(&rm->m_conn_item);
@@ -774,7 +770,6 @@ void rds_send_drop_to(struct rds_sock *rs, struct sockaddr_in *dest)
__rds_send_complete(rs, rm, RDS_RDMA_CANCELED);
spin_unlock(&rs->rs_lock);
- rm->m_rs = NULL;
spin_unlock_irqrestore(&rm->m_rs_lock, flags);
rds_message_put(rm);
@@ -798,7 +793,6 @@ void rds_send_drop_to(struct rds_sock *rs, struct sockaddr_in *dest)
__rds_send_complete(rs, rm, RDS_RDMA_CANCELED);
spin_unlock(&rs->rs_lock);
- rm->m_rs = NULL;
spin_unlock_irqrestore(&rm->m_rs_lock, flags);
rds_message_put(rm);
@@ -849,6 +843,7 @@ static int rds_send_queue_rm(struct rds_sock *rs, struct rds_connection *conn,
list_add_tail(&rm->m_sock_item, &rs->rs_send_queue);
set_bit(RDS_MSG_ON_SOCK, &rm->m_flags);
rds_message_addref(rm);
+ sock_hold(rds_rs_to_sk(rs));
rm->m_rs = rs;
/* The code ordering is a little weird, but we're
The existing model holds a reference from the rds_sock to the rds_message, but the rds_message does not itself hold a sock_put() on the rds_sock. Instead the m_rs field in the rds_message is assigned when the message is queued on the sock, and nulled when the message is dequeued from the sock. We want to be able to notify userspace when the rds_message is actually freed (from rds_message_purge(), after the refcounts to the rds_message go to 0). These notifications will signal that it is safe for uspace to free/reuse any pages that may have been pinned down for zerocopy, and are sent up on the PF_RDS socket. In order to be able to send the notifications on the rds_sock, we need to retain the m_rs assignment in the rds_message with the necessary refcount book-keeping. Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> --- net/rds/message.c | 8 +++++++- net/rds/send.c | 7 +------ 2 files changed, 8 insertions(+), 7 deletions(-)