diff options
authorLars Ellenberg <>2015-05-18 14:08:46 +0200
committerJens Axboe <>2015-11-25 09:22:03 -0700
commitf85d9f2d02cdcd1b79e00fccd667b37b251ba3ac (patch)
parent706447861bb210cf2fb6a58bc1d29a6636175987 (diff)
drbd: fix "endless" transfer log walk in protocol A
Don't remember a DRBD request as ack_pending, if it is not. In protocol A, we usually clear RQ_NET_PENDING at the same time we set RQ_NET_SENT, so when deciding to remember it as ack_pending, mod_rq_state needs to look at the current request state, not at the previous state before the current modification was applied. This should prevent advance_conn_req_ack_pending() from walking the full transfer log just to find NULL in protocol A, which would cause serious performance degradation with many "in-flight" requests, e.g. when working via DRBD-proxy, or with a huge bandwidth-delay product. Signed-off-by: Philipp Reisner <> Signed-off-by: Lars Ellenberg <> Signed-off-by: Jens Axboe <>
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/block/drbd/drbd_req.c b/drivers/block/drbd/drbd_req.c
index 7907fb562388..2255dcfebd2b 100644
--- a/drivers/block/drbd/drbd_req.c
+++ b/drivers/block/drbd/drbd_req.c
@@ -458,7 +458,7 @@ static void mod_rq_state(struct drbd_request *req, struct bio_and_error *m,
atomic_add(req->i.size >> 9, &device->ap_in_flight);
set_if_null_req_not_net_done(peer_device, req);
- if (s & RQ_NET_PENDING)
+ if (req->rq_state & RQ_NET_PENDING)
set_if_null_req_ack_pending(peer_device, req);