From a500c2efbbb3a57f83e18382e927b18513aca4cd Mon Sep 17 00:00:00 2001 From: Andreas Gruenbacher Date: Thu, 27 Jan 2011 14:12:23 +0100 Subject: [PATCH] drbd: struct drbd_request: Introduce a new collision flag This flag is set when a processes puts itself to sleep to wait for a conflicting request to complete. Signed-off-by: Philipp Reisner Signed-off-by: Lars Ellenberg --- drivers/block/drbd/drbd_receiver.c | 7 +++-- drivers/block/drbd/drbd_req.c | 42 +++--------------------------- drivers/block/drbd/drbd_req.h | 7 +++++ 3 files changed, 15 insertions(+), 41 deletions(-) diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c index b4e1dab62dc1..d9f3f7fd9bb2 100644 --- a/drivers/block/drbd/drbd_receiver.c +++ b/drivers/block/drbd/drbd_receiver.c @@ -1815,6 +1815,7 @@ static int receive_Data(struct drbd_conf *mdev, enum drbd_packet cmd, first = 1; for (;;) { struct drbd_interval *i; + struct drbd_request *req2; int have_unacked = 0; int have_conflict = 0; prepare_to_wait(&mdev->misc_wait, &wait, @@ -1822,8 +1823,7 @@ static int receive_Data(struct drbd_conf *mdev, enum drbd_packet cmd, i = drbd_find_overlap(&mdev->write_requests, sector, size); if (i) { - struct drbd_request *req2 = - container_of(i, struct drbd_request, i); + req2 = container_of(i, struct drbd_request, i); /* only ALERT on first iteration, * we may be woken up early... */ @@ -1869,6 +1869,9 @@ static int receive_Data(struct drbd_conf *mdev, enum drbd_packet cmd, goto out_interrupted; } + /* Indicate to wake up mdev->misc_wait upon completion. */ + req2->rq_state |= RQ_COLLISION; + spin_unlock_irq(&mdev->tconn->req_lock); if (first) { first = 0; diff --git a/drivers/block/drbd/drbd_req.c b/drivers/block/drbd/drbd_req.c index 25fa87c95a10..8b4ba94538bd 100644 --- a/drivers/block/drbd/drbd_req.c +++ b/drivers/block/drbd/drbd_req.c @@ -176,45 +176,9 @@ static void _about_to_complete_local_write(struct drbd_conf *mdev, req->epoch == mdev->tconn->newest_tle->br_number) queue_barrier(mdev); - /* we need to do the conflict detection stuff, - * if the epoch_entries tree is non-empty and - * this request has completed on the network */ - if ((s & RQ_NET_DONE) && !RB_EMPTY_ROOT(&mdev->epoch_entries)) { - const sector_t sector = req->i.sector; - const int size = req->i.size; - struct drbd_interval *i; - - /* ASSERT: - * there must be no conflicting requests, since - * they must have been failed on the spot */ - - i = drbd_find_overlap(&mdev->write_requests, sector, size); - if (i) { - struct drbd_request *req2 = - container_of(i, struct drbd_request, i); - - dev_alert(DEV, "LOGIC BUG: completed: %p %llus +%u; " - "other: %p %llus +%u\n", - req, (unsigned long long)sector, size, - i, (unsigned long long)req2->i.sector, req2->i.size); - } - - /* maybe "wake" those conflicting epoch entries - * that wait for this request to finish. - * - * currently, there can be only _one_ such ee - * (well, or some more, which would be pending - * P_DISCARD_ACK not yet sent by the asender...), - * since we block the receiver thread upon the - * first conflict detection, which will wait on - * misc_wait. maybe we want to assert that? - * - * anyways, if we found one, - * we just have to do a wake_up. */ - i = drbd_find_overlap(&mdev->epoch_entries, sector, size); - if (i) - wake_up(&mdev->misc_wait); - } + /* Wake up any processes waiting for this request to complete. */ + if ((s & RQ_NET_DONE) && (s & RQ_COLLISION)) + wake_up(&mdev->misc_wait); } void complete_master_bio(struct drbd_conf *mdev, diff --git a/drivers/block/drbd/drbd_req.h b/drivers/block/drbd/drbd_req.h index 431e3f962c3a..7a7464a2b3a6 100644 --- a/drivers/block/drbd/drbd_req.h +++ b/drivers/block/drbd/drbd_req.h @@ -194,6 +194,12 @@ enum drbd_req_state_bits { /* Should call drbd_al_complete_io() for this request... */ __RQ_IN_ACT_LOG, + + /* + * Set when a processes puts itself to sleep to wait for this request + * to complete. + */ + __RQ_COLLISION, }; #define RQ_LOCAL_PENDING (1UL << __RQ_LOCAL_PENDING) @@ -214,6 +220,7 @@ enum drbd_req_state_bits { #define RQ_WRITE (1UL << __RQ_WRITE) #define RQ_IN_ACT_LOG (1UL << __RQ_IN_ACT_LOG) +#define RQ_COLLISION (1UL << __RQ_COLLISION) /* For waking up the frozen transfer log mod_req() has to return if the request should be counted in the epoch object*/ -- 2.34.1