RDS: Fix locking in send on m_rs_lock

Do not nest m_rs_lock under c_lock

Disable interrupts in {rdma,atomic}_send_complete

Signed-off-by: Andy Grover <andy.grover@oracle.com>

1 files changed, 8 insertions, 7 deletions

diff --git a/net/rds/send.c b/net/rds/send.c
index aee58f931b69..725fb0419797 100644
--- a/net/rds/send.c
+++ b/net/rds/send.c
@@ -415,8 +415,9 @@ void rds_rdma_send_complete(struct rds_message *rm, int status)
         struct rds_sock *rs = NULL;
         struct rds_rdma_op *ro;
         struct rds_notifier *notifier;
+        unsigned long flags;
 
-        spin_lock(&rm->m_rs_lock);
+        spin_lock_irqsave(&rm->m_rs_lock, flags);
 
         ro = rm->m_rdma_op;
         if (test_bit(RDS_MSG_ON_SOCK, &rm->m_flags) &&
@@ -433,7 +434,7 @@ void rds_rdma_send_complete(struct rds_message *rm, int status)
                 ro->r_notifier = NULL;
         }
 
-        spin_unlock(&rm->m_rs_lock);
+        spin_unlock_irqrestore(&rm->m_rs_lock, flags);
 
         if (rs) {
                 rds_wake_sk_sleep(rs);
@@ -647,8 +648,8 @@ void rds_send_drop_to(struct rds_sock *rs, struct sockaddr_in *dest)
         list_for_each_entry(rm, &list, m_sock_item) {
 
                 conn = rm->m_inc.i_conn;
-                spin_lock_irqsave(&conn->c_lock, flags);
 
+                spin_lock_irqsave(&conn->c_lock, flags);
                 /*
                  * Maybe someone else beat us to removing rm from the conn.
                  * If we race with their flag update we'll get the lock and
@@ -658,23 +659,23 @@ void rds_send_drop_to(struct rds_sock *rs, struct sockaddr_in *dest)
                         spin_unlock_irqrestore(&conn->c_lock, flags);
                         continue;
                 }
+                list_del_init(&rm->m_conn_item);
+                spin_unlock_irqrestore(&conn->c_lock, flags);
 
                 /*
                  * Couldn't grab m_rs_lock in top loop (lock ordering),
                  * but we can now.
                  */
-                spin_lock(&rm->m_rs_lock);
+                spin_lock_irqsave(&rm->m_rs_lock, flags);
 
                 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(&rm->m_rs_lock);
+                spin_unlock_irqrestore(&rm->m_rs_lock, flags);
 
-                list_del_init(&rm->m_conn_item);
                 rds_message_put(rm);
-                spin_unlock_irqrestore(&conn->c_lock, flags);
         }
 
         rds_wake_sk_sleep(rs);