From: Lars Ellenberg Date: Tue, 24 Jan 2012 15:58:11 +0000 (+0100) Subject: drbd: introduce completion_ref and kref to struct drbd_request X-Git-Tag: v3.8-rc1~78^2~18^2~62 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=b406777e6496de346e8ee12fa64e1fe0adc02a78;p=profile%2Fivi%2Fkernel-adaptation-intel-automotive.git drbd: introduce completion_ref and kref to struct drbd_request cherry-picked and adapted from drbd 9 devel branch completion_ref will count pending events necessary for completion. kref is for destruction. This only introduces these new members of struct drbd_request, a followup patch will make actual use of them. Signed-off-by: Philipp Reisner Signed-off-by: Lars Ellenberg --- diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h index 8536fab..52ad1bf 100644 --- a/drivers/block/drbd/drbd_int.h +++ b/drivers/block/drbd/drbd_int.h @@ -577,6 +577,11 @@ struct drbd_request { struct bio *master_bio; /* master bio pointer */ unsigned long rq_state; /* see comments above _req_mod() */ unsigned long start_time; + + /* once it hits 0, we may complete the master_bio */ + atomic_t completion_ref; + /* once it hits 0, we may destroy this drbd_request object */ + struct kref kref; }; struct drbd_epoch { diff --git a/drivers/block/drbd/drbd_req.c b/drivers/block/drbd/drbd_req.c index 6bac415..ae894af 100644 --- a/drivers/block/drbd/drbd_req.c +++ b/drivers/block/drbd/drbd_req.c @@ -85,17 +85,15 @@ static struct drbd_request *drbd_req_new(struct drbd_conf *mdev, INIT_LIST_HEAD(&req->tl_requests); INIT_LIST_HEAD(&req->w.list); + atomic_set(&req->completion_ref, 1); + kref_init(&req->kref); return req; } -static void drbd_req_free(struct drbd_request *req) -{ - mempool_free(req, drbd_request_mempool); -} - -/* rw is bio_data_dir(), only READ or WRITE */ -static void _req_is_done(struct drbd_conf *mdev, struct drbd_request *req, const int rw) +static void drbd_req_destroy(struct kref *kref) { + struct drbd_request *req = container_of(kref, struct drbd_request, kref); + struct drbd_conf *mdev = req->w.mdev; const unsigned long s = req->rq_state; /* remove it from the transfer log. @@ -109,7 +107,7 @@ static void _req_is_done(struct drbd_conf *mdev, struct drbd_request *req, const /* if it was a write, we may have to set the corresponding * bit(s) out-of-sync first. If it had a local part, we need to * release the reference to the activity log. */ - if (rw == WRITE) { + if (s & RQ_WRITE) { /* Set out-of-sync unless both OK flags are set * (local only or remote failed). * Other places where we set out-of-sync: @@ -146,7 +144,7 @@ static void _req_is_done(struct drbd_conf *mdev, struct drbd_request *req, const if (s & RQ_POSTPONED) drbd_restart_request(req); else - drbd_req_free(req); + mempool_free(req, drbd_request_mempool); } static void wake_all_senders(struct drbd_tconn *tconn) { @@ -196,12 +194,10 @@ static void req_may_be_done(struct drbd_request *req) { const unsigned long s = req->rq_state; - struct drbd_conf *mdev = req->w.mdev; - int rw = req->rq_state & RQ_WRITE ? WRITE : READ; /* req->master_bio still present means: Not yet completed. * - * Unless this is RQ_POSTPONED, which will cause _req_is_done() to + * Unless this is RQ_POSTPONED, which will cause drbd_req_destroy() to * queue it on the retry workqueue instead of destroying it. */ if (req->master_bio && !(s & RQ_POSTPONED)) @@ -216,7 +212,7 @@ void req_may_be_done(struct drbd_request *req) /* this is disconnected (local only) operation, * or protocol A, B, or C P_BARRIER_ACK, * or killed from the transfer log due to connection loss. */ - _req_is_done(mdev, req, rw); + kref_put(&req->kref, drbd_req_destroy); } /* else: network part and not DONE yet. that is * protocol A, B, or C, barrier ack still pending... */ @@ -250,6 +246,15 @@ void req_may_be_completed(struct drbd_request *req, struct bio_and_error *m) if (s & RQ_NET_PENDING) return; + /* FIXME + * instead of all the RQ_FLAGS, actually use the completion_ref + * to decide if this is ready to be completed. */ + if (req->master_bio) { + int complete = atomic_dec_and_test(&req->completion_ref); + D_ASSERT(complete != 0); + } else + D_ASSERT(atomic_read(&req->completion_ref) == 0); + if (req->master_bio) { int rw = bio_rw(req->master_bio); @@ -1113,7 +1118,7 @@ struct drbd_request *find_oldest_request(struct drbd_tconn *tconn) * and find the oldest not yet completed request */ struct drbd_request *r; list_for_each_entry(r, &tconn->transfer_log, tl_requests) { - if (r->rq_state & (RQ_NET_PENDING|RQ_LOCAL_PENDING)) + if (atomic_read(&r->completion_ref)) return r; } return NULL;