From 779b3fe4c0e9dea19ae3ddef0b5fd1a663b63ee6 Mon Sep 17 00:00:00 2001 From: Lars Ellenberg Date: Tue, 19 Mar 2013 18:16:54 +0100 Subject: drbd: queue writes on submitter thread, unless they pass the activity log fastpath Signed-off-by: Philipp Reisner Signed-off-by: Lars Ellenberg Signed-off-by: Jens Axboe --- drivers/block/drbd/drbd_req.c | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-) (limited to 'drivers/block/drbd') diff --git a/drivers/block/drbd/drbd_req.c b/drivers/block/drbd/drbd_req.c index 4af709e0aae5..43bc1d064bc7 100644 --- a/drivers/block/drbd/drbd_req.c +++ b/drivers/block/drbd/drbd_req.c @@ -1020,6 +1020,14 @@ drbd_submit_req_private_bio(struct drbd_request *req) bio_endio(bio, -EIO); } +static void drbd_queue_write(struct drbd_conf *mdev, struct drbd_request *req) +{ + spin_lock(&mdev->submit.lock); + list_add_tail(&req->tl_requests, &mdev->submit.writes); + spin_unlock(&mdev->submit.lock); + queue_work(mdev->submit.wq, &mdev->submit.worker); +} + /* returns the new drbd_request pointer, if the caller is expected to * drbd_send_and_submit() it (to save latency), or NULL if we queued the * request on the submitter thread. @@ -1048,17 +1056,13 @@ drbd_request_prepare(struct drbd_conf *mdev, struct bio *bio, unsigned long star req->private_bio = NULL; } - /* For WRITES going to the local disk, grab a reference on the target - * extent. This waits for any resync activity in the corresponding - * resync extent to finish, and, if necessary, pulls in the target - * extent into the activity log, which involves further disk io because - * of transactional on-disk meta data updates. - * Empty flushes don't need to go into the activity log, they can only - * flush data for pending writes which are already in there. */ if (rw == WRITE && req->private_bio && req->i.size && !test_bit(AL_SUSPENDED, &mdev->flags)) { + if (!drbd_al_begin_io_fastpath(mdev, &req->i)) { + drbd_queue_write(mdev, req); + return NULL; + } req->rq_state |= RQ_IN_ACT_LOG; - drbd_al_begin_io(mdev, &req->i, true); } return req; -- cgit v1.2.3-59-g8ed1b