RDS: Fix send locking issue
Fix a deadlock between rds_rdma_send_complete() and
rds_send_remove_from_sock() when rds socket lock and
rds message lock are acquired out-of-order.
Signed-off-by: Tina Yang <Tina.Yang@oracle.com>
Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/rds/send.c b/net/rds/send.c
index ad2e469..1a2ef24 100644
--- a/net/rds/send.c
+++ b/net/rds/send.c
@@ -533,14 +533,13 @@
if (rs != rm->m_rs) {
if (rs) {
- spin_unlock(&rs->rs_lock);
rds_wake_sk_sleep(rs);
sock_put(rds_rs_to_sk(rs));
}
rs = rm->m_rs;
- spin_lock(&rs->rs_lock);
sock_hold(rds_rs_to_sk(rs));
}
+ spin_lock(&rs->rs_lock);
if (test_and_clear_bit(RDS_MSG_ON_SOCK, &rm->m_flags)) {
struct rds_rdma_op *ro = rm->m_rdma_op;
@@ -560,6 +559,7 @@
rds_message_put(rm);
rm->m_rs = NULL;
}
+ spin_unlock(&rs->rs_lock);
unlock_and_drop:
spin_unlock(&rm->m_rs_lock);
@@ -567,7 +567,6 @@
}
if (rs) {
- spin_unlock(&rs->rs_lock);
rds_wake_sk_sleep(rs);
sock_put(rds_rs_to_sk(rs));
}