From 70f17b6bd18dfe33f40db7573baa663b866be6ba Mon Sep 17 00:00:00 2001 From: Lars Ellenberg Date: Mon, 3 Sep 2012 14:08:35 +0200 Subject: [PATCH] drbd: differentiate early and later "postponing" of requests We use the RQ_POSTPONED flag to mark a request for several reasons. It may be a conflicting request in a dual-primary setup, where conflict detection and resolution on the peer decided that this request needs to be re-submitted, it needs to re-enter drbd_make_request() to fix the data divergence caused by these conflicting, partially overlapping, quasi-simultaneous requests. In this case we need to mark the corresponding area as out-of-sync, before we call drbd_al_complete_io(). We also use the RQ_POSTPONED flag to just "push back" a request, before even processing it, if IO is suspended for some reason. In this case, as this request was neither submitted nor sent yet, we must not touch the bitmap. Signed-off-by: Philipp Reisner Signed-off-by: Lars Ellenberg --- drivers/block/drbd/drbd_req.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/block/drbd/drbd_req.c b/drivers/block/drbd/drbd_req.c index d1d17fcd9232..e307890e6afe 100644 --- a/drivers/block/drbd/drbd_req.c +++ b/drivers/block/drbd/drbd_req.c @@ -123,7 +123,14 @@ void drbd_req_destroy(struct kref *kref) * (local only or remote failed). * Other places where we set out-of-sync: * READ with local io-error */ - if (!(s & RQ_POSTPONED)) { + + /* There is a special case: + * we may notice late that IO was suspended, + * and postpone, or schedule for retry, a write, + * before it even was submitted or sent. + * In that case we do not want to touch the bitmap at all. + */ + if ((s & (RQ_POSTPONED|RQ_LOCAL_MASK|RQ_NET_MASK)) != RQ_POSTPONED) { if (!(s & RQ_NET_OK) || !(s & RQ_LOCAL_OK)) drbd_set_out_of_sync(mdev, req->i.sector, req->i.size); -- 2.39.5