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authorSowmini Varadhan <sowmini.varadhan@oracle.com>2017-07-17 02:43:46 +0300
committerDavid S. Miller <davem@davemloft.net>2017-07-17 05:07:35 +0300
commitaed20a53a7d91e45c6a8cb8920c77aaaa88f76ee (patch)
tree78bdb7167413d66c08f14ec1056cffd85fa0bc7d /net/rds/connection.c
parentce3dbe29749e3a3ef25540b394a68215e3113462 (diff)
downloadlinux-aed20a53a7d91e45c6a8cb8920c77aaaa88f76ee.tar.xz
rds: cancel send/recv work before queuing connection shutdown
We could end up executing rds_conn_shutdown before the rds_recv_worker thread, then rds_conn_shutdown -> rds_tcp_conn_shutdown can do a sock_release and set sock->sk to null, which may interleave in bad ways with rds_recv_worker, e.g., it could result in: "BUG: unable to handle kernel NULL pointer dereference at 0000000000000078" [ffff881769f6fd70] release_sock at ffffffff815f337b [ffff881769f6fd90] rds_tcp_recv at ffffffffa043c888 [rds_tcp] [ffff881769f6fdb0] rds_recv_worker at ffffffffa04a4810 [rds] [ffff881769f6fde0] process_one_work at ffffffff810a14c1 [ffff881769f6fe40] worker_thread at ffffffff810a1940 [ffff881769f6fec0] kthread at ffffffff810a6b1e Also, do not enqueue any new shutdown workq items when the connection is shutting down (this may happen for rds-tcp in softirq mode, if a FIN or CLOSE is received while the modules is in the middle of an unload) Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/rds/connection.c')
-rw-r--r--net/rds/connection.c16
1 files changed, 10 insertions, 6 deletions
diff --git a/net/rds/connection.c b/net/rds/connection.c
index 50a3789ac23e..005bca68aa94 100644
--- a/net/rds/connection.c
+++ b/net/rds/connection.c
@@ -374,13 +374,13 @@ static void rds_conn_path_destroy(struct rds_conn_path *cp)
if (!cp->cp_transport_data)
return;
- rds_conn_path_drop(cp);
- flush_work(&cp->cp_down_w);
-
/* make sure lingering queued work won't try to ref the conn */
cancel_delayed_work_sync(&cp->cp_send_w);
cancel_delayed_work_sync(&cp->cp_recv_w);
+ rds_conn_path_drop(cp, true);
+ flush_work(&cp->cp_down_w);
+
/* tear down queued messages */
list_for_each_entry_safe(rm, rtmp,
&cp->cp_send_queue,
@@ -664,9 +664,13 @@ void rds_conn_exit(void)
/*
* Force a disconnect
*/
-void rds_conn_path_drop(struct rds_conn_path *cp)
+void rds_conn_path_drop(struct rds_conn_path *cp, bool destroy)
{
atomic_set(&cp->cp_state, RDS_CONN_ERROR);
+
+ if (!destroy && cp->cp_conn->c_destroy_in_prog)
+ return;
+
queue_work(rds_wq, &cp->cp_down_w);
}
EXPORT_SYMBOL_GPL(rds_conn_path_drop);
@@ -674,7 +678,7 @@ EXPORT_SYMBOL_GPL(rds_conn_path_drop);
void rds_conn_drop(struct rds_connection *conn)
{
WARN_ON(conn->c_trans->t_mp_capable);
- rds_conn_path_drop(&conn->c_path[0]);
+ rds_conn_path_drop(&conn->c_path[0], false);
}
EXPORT_SYMBOL_GPL(rds_conn_drop);
@@ -706,5 +710,5 @@ __rds_conn_path_error(struct rds_conn_path *cp, const char *fmt, ...)
vprintk(fmt, ap);
va_end(ap);
- rds_conn_path_drop(cp);
+ rds_conn_path_drop(cp, false);
}