RDS: Fix m_rs_lock deadlock

rs_send_drop_to() is called during socket close. If it takes
m_rs_lock without disabling interrupts, then
rds_send_remove_from_sock() can run from the rx completion
handler and thus deadlock.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 3 deletions

diff --git a/net/rds/send.c b/net/rds/send.c
index 1b37364656f0..104fe033203d 100644
--- a/net/rds/send.c
+++ b/net/rds/send.c
@@ -615,7 +615,7 @@ void rds_send_drop_to(struct rds_sock *rs, struct sockaddr_in *dest)
 {
         struct rds_message *rm, *tmp;
         struct rds_connection *conn;
-        unsigned long flags;
+        unsigned long flags, flags2;
         LIST_HEAD(list);
         int wake = 0;
 
@@ -651,9 +651,9 @@ void rds_send_drop_to(struct rds_sock *rs, struct sockaddr_in *dest)
         list_for_each_entry(rm, &list, m_sock_item) {
                 /* 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(&rm->m_rs_lock);
+                spin_lock_irqsave(&rm->m_rs_lock, flags2);
                 rm->m_rs = NULL;
-                spin_unlock(&rm->m_rs_lock);
+                spin_unlock_irqrestore(&rm->m_rs_lock, flags2);
 
                 /*
                  * If we see this flag cleared then we're *sure* that someone