rds: don't let RDS shutdown a connection while senders are present
This is the first in a long line of patches that tries to fix races
between RDS connection shutdown and RDS traffic.
Here we are maintaining a count of active senders to make sure
the connection doesn't go away while they are using it.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/net/rds/connection.c b/net/rds/connection.c
index 7e4e9df..9c249f3 100644
--- a/net/rds/connection.c
+++ b/net/rds/connection.c
@@ -148,6 +148,7 @@
spin_lock_init(&conn->c_send_lock);
atomic_set(&conn->c_send_generation, 1);
+ atomic_set(&conn->c_senders, 0);
INIT_LIST_HEAD(&conn->c_send_queue);
INIT_LIST_HEAD(&conn->c_retrans);
@@ -276,6 +277,12 @@
spin_lock_irq(&conn->c_send_lock);
spin_unlock_irq(&conn->c_send_lock);
+ while(atomic_read(&conn->c_senders)) {
+ schedule_timeout(1);
+ spin_lock_irq(&conn->c_send_lock);
+ spin_unlock_irq(&conn->c_send_lock);
+ }
+
conn->c_trans->conn_shutdown(conn);
rds_conn_reset(conn);