[PATCH 3.18 092/150] drbd: Fix state change in case of connection timeout

Greg Kroah-Hartman
2015-01-14T07:31:03Z

From: Philipp Reisner <philipp.reisner@linbit.com>

commit 9581f97a687724ea41cf2e145dda4751161198c1 upstream.

A connection timeout affects all volumes of a resource!
Under the following conditions:

A resource with multiple volumes
AND
ko-count >=1
AND
a write request triggers the timeout (ko-count * timeout)

DRBD's internal state gets confused. That in turn may
lead to very miss leading follow up failures. E.g.
"BUG: scheduling while atomic"

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/block/drbd/drbd_req.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/block/drbd/drbd_req.c
+++ b/drivers/block/drbd/drbd_req.c
@@ -1629,7 +1629,7 @@ void request_timer_fn(unsigned long data
time_after(now, req_peer->pre_send_jif + ent) &&
!time_in_range(now, connection->last_reconnect_jif, connection->last_reconnect_jif + ent)) {
drbd_warn(device, "Remote failed to finish a request within ko-count * timeout\n");
- _drbd_set_state(_NS(device, conn, C_TIMEOUT), CS_VERBOSE | CS_HARD, NULL);
+ _conn_request_state(connection, NS(conn, C_TIMEOUT), CS_VERBOSE | CS_HARD);
}
if (dt && oldest_submit_jif != now &&
time_after(now, oldest_submit_jif + dt) &&