RDS: Rewrite connection cleanup, fixing oops on rmmod
This fixes a bug where a connection was unexpectedly
not on *any* list while being destroyed. It also
cleans up some code duplication and regularizes some
function names.
* Grab appropriate lock in conn_free() and explain in comment
* Ensure via locking that a conn is never not on either
a dev's list or the nodev list
* Add rds_xx_remove_conn() to match rds_xx_add_conn()
* Make rds_xx_add_conn() return void
* Rename remove_{,nodev_}conns() to
destroy_{,nodev_}conns() and unify their implementation
in a helper function
* Document lock ordering as nodev conn_lock before
dev_conn_lock
Reported-by: Yosef Etigin <yosefe@voltaire.com>
Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/rds/ib_rdma.c b/net/rds/ib_rdma.c
index 69a6289..81033af 100644
--- a/net/rds/ib_rdma.c
+++ b/net/rds/ib_rdma.c
@@ -139,7 +139,7 @@
return rds_ib_add_ipaddr(rds_ibdev, ipaddr);
}
-int rds_ib_add_conn(struct rds_ib_device *rds_ibdev, struct rds_connection *conn)
+void rds_ib_add_conn(struct rds_ib_device *rds_ibdev, struct rds_connection *conn)
{
struct rds_ib_connection *ic = conn->c_transport_data;
@@ -148,45 +148,44 @@
BUG_ON(list_empty(&ib_nodev_conns));
BUG_ON(list_empty(&ic->ib_node));
list_del(&ic->ib_node);
- spin_unlock_irq(&ib_nodev_conns_lock);
spin_lock_irq(&rds_ibdev->spinlock);
list_add_tail(&ic->ib_node, &rds_ibdev->conn_list);
spin_unlock_irq(&rds_ibdev->spinlock);
-
- ic->rds_ibdev = rds_ibdev;
-
- return 0;
-}
-
-void rds_ib_remove_nodev_conns(void)
-{
- struct rds_ib_connection *ic, *_ic;
- LIST_HEAD(tmp_list);
-
- /* avoid calling conn_destroy with irqs off */
- spin_lock_irq(&ib_nodev_conns_lock);
- list_splice(&ib_nodev_conns, &tmp_list);
- INIT_LIST_HEAD(&ib_nodev_conns);
spin_unlock_irq(&ib_nodev_conns_lock);
- list_for_each_entry_safe(ic, _ic, &tmp_list, ib_node) {
- if (ic->conn->c_passive)
- rds_conn_destroy(ic->conn->c_passive);
- rds_conn_destroy(ic->conn);
- }
+ ic->rds_ibdev = rds_ibdev;
}
-void rds_ib_remove_conns(struct rds_ib_device *rds_ibdev)
+void rds_ib_remove_conn(struct rds_ib_device *rds_ibdev, struct rds_connection *conn)
+{
+ struct rds_ib_connection *ic = conn->c_transport_data;
+
+ /* place conn on nodev_conns_list */
+ spin_lock(&ib_nodev_conns_lock);
+
+ spin_lock_irq(&rds_ibdev->spinlock);
+ BUG_ON(list_empty(&ic->ib_node));
+ list_del(&ic->ib_node);
+ spin_unlock_irq(&rds_ibdev->spinlock);
+
+ list_add_tail(&ic->ib_node, &ib_nodev_conns);
+
+ spin_unlock(&ib_nodev_conns_lock);
+
+ ic->rds_ibdev = NULL;
+}
+
+void __rds_ib_destroy_conns(struct list_head *list, spinlock_t *list_lock)
{
struct rds_ib_connection *ic, *_ic;
LIST_HEAD(tmp_list);
/* avoid calling conn_destroy with irqs off */
- spin_lock_irq(&rds_ibdev->spinlock);
- list_splice(&rds_ibdev->conn_list, &tmp_list);
- INIT_LIST_HEAD(&rds_ibdev->conn_list);
- spin_unlock_irq(&rds_ibdev->spinlock);
+ spin_lock_irq(list_lock);
+ list_splice(list, &tmp_list);
+ INIT_LIST_HEAD(list);
+ spin_unlock_irq(list_lock);
list_for_each_entry_safe(ic, _ic, &tmp_list, ib_node) {
if (ic->conn->c_passive)