1 files changed, 56 insertions, 14 deletions

diff --git a/drivers/block/drbd/drbd_req.c b/drivers/block/drbd/drbd_req.c
index 43bc1d064bc7..b923d41678e1 100644
--- a/drivers/block/drbd/drbd_req.c
+++ b/drivers/block/drbd/drbd_req.c
@@ -1164,32 +1164,74 @@ void __drbd_make_request(struct drbd_conf *mdev, struct bio *bio, unsigned long
         drbd_send_and_submit(mdev, req);
 }
 
-void __drbd_make_request_from_worker(struct drbd_conf *mdev, struct drbd_request *req)
+static void submit_fast_path(struct drbd_conf *mdev, struct list_head *incoming)
 {
-        const int rw = bio_rw(req->master_bio);
+        struct drbd_request *req, *tmp;
+        list_for_each_entry_safe(req, tmp, incoming, tl_requests) {
+                const int rw = bio_data_dir(req->master_bio);
 
-        if (rw == WRITE && req->private_bio && req->i.size
-        && !test_bit(AL_SUSPENDED, &mdev->flags)) {
-                drbd_al_begin_io(mdev, &req->i, false);
-                req->rq_state |= RQ_IN_ACT_LOG;
+                if (rw == WRITE /* rw != WRITE should not even end up here! */
+                && req->private_bio && req->i.size
+                && !test_bit(AL_SUSPENDED, &mdev->flags)) {
+                        if (!drbd_al_begin_io_fastpath(mdev, &req->i))
+                                continue;
+
+                        req->rq_state |= RQ_IN_ACT_LOG;
+                }
+
+                list_del_init(&req->tl_requests);
+                drbd_send_and_submit(mdev, req);
         }
-        drbd_send_and_submit(mdev, req);
 }
 
+static bool prepare_al_transaction_nonblock(struct drbd_conf *mdev,
+                                            struct list_head *incoming,
+                                            struct list_head *pending)
+{
+        struct drbd_request *req, *tmp;
+        int wake = 0;
+        int err;
+
+        spin_lock_irq(&mdev->al_lock);
+        list_for_each_entry_safe(req, tmp, incoming, tl_requests) {
+                err = drbd_al_begin_io_nonblock(mdev, &req->i);
+                if (err == -EBUSY)
+                        wake = 1;
+                if (err)
+                        continue;
+                req->rq_state |= RQ_IN_ACT_LOG;
+                list_move_tail(&req->tl_requests, pending);
+        }
+        spin_unlock_irq(&mdev->al_lock);
+        if (wake)
+                wake_up(&mdev->al_wait);
+
+        return !list_empty(pending);
+}
 
 void do_submit(struct work_struct *ws)
 {
         struct drbd_conf *mdev = container_of(ws, struct drbd_conf, submit.worker);
-        LIST_HEAD(writes);
+        LIST_HEAD(incoming);
+        LIST_HEAD(pending);
         struct drbd_request *req, *tmp;
 
-        spin_lock(&mdev->submit.lock);
-        list_splice_init(&mdev->submit.writes, &writes);
-        spin_unlock(&mdev->submit.lock);
+        for (;;) {
+                spin_lock(&mdev->submit.lock);
+                list_splice_tail_init(&mdev->submit.writes, &incoming);
+                spin_unlock(&mdev->submit.lock);
 
-        list_for_each_entry_safe(req, tmp, &writes, tl_requests) {
-                list_del_init(&req->tl_requests);
-                __drbd_make_request_from_worker(mdev, req);
+                submit_fast_path(mdev, &incoming);
+                if (list_empty(&incoming))
+                        break;
+
+                wait_event(mdev->al_wait, prepare_al_transaction_nonblock(mdev, &incoming, &pending));
+                drbd_al_begin_io_commit(mdev, false);
+
+                list_for_each_entry_safe(req, tmp, &pending, tl_requests) {
+                        list_del_init(&req->tl_requests);
+                        drbd_send_and_submit(mdev, req);
+                }
         }
 }