md/raid1: submit IO from originating thread instead of md thread.

[uclinux-h8/linux.git] / drivers / md / raid1.c

diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 36a8fc0..9f01870 100644 (file)
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -870,6 +870,44 @@ do_sync_io:
        pr_debug("%dB behind alloc failed, doing sync I/O\n", bio->bi_size);
 }
 
+struct raid1_plug_cb {
+       struct blk_plug_cb      cb;
+       struct bio_list         pending;
+       int                     pending_cnt;
+};
+
+static void raid1_unplug(struct blk_plug_cb *cb, bool from_schedule)
+{
+       struct raid1_plug_cb *plug = container_of(cb, struct raid1_plug_cb,
+                                                 cb);
+       struct mddev *mddev = plug->cb.data;
+       struct r1conf *conf = mddev->private;
+       struct bio *bio;
+
+       if (from_schedule) {
+               spin_lock_irq(&conf->device_lock);
+               bio_list_merge(&conf->pending_bio_list, &plug->pending);
+               conf->pending_count += plug->pending_cnt;
+               spin_unlock_irq(&conf->device_lock);
+               md_wakeup_thread(mddev->thread);
+               kfree(plug);
+               return;
+       }
+
+       /* we aren't scheduling, so we can do the write-out directly. */
+       bio = bio_list_get(&plug->pending);
+       bitmap_unplug(mddev->bitmap);
+       wake_up(&conf->wait_barrier);
+
+       while (bio) { /* submit pending writes */
+               struct bio *next = bio->bi_next;
+               bio->bi_next = NULL;
+               generic_make_request(bio);
+               bio = next;
+       }
+       kfree(plug);
+}
+
 static void make_request(struct mddev *mddev, struct bio * bio)
 {
        struct r1conf *conf = mddev->private;
@@ -883,6 +921,8 @@ static void make_request(struct mddev *mddev, struct bio * bio)
        const unsigned long do_sync = (bio->bi_rw & REQ_SYNC);
        const unsigned long do_flush_fua = (bio->bi_rw & (REQ_FLUSH | REQ_FUA));
        struct md_rdev *blocked_rdev;
+       struct blk_plug_cb *cb;
+       struct raid1_plug_cb *plug = NULL;
        int first_clone;
        int sectors_handled;
        int max_sectors;
@@ -1185,11 +1225,22 @@ read_again:
                mbio->bi_private = r1_bio;
 
                atomic_inc(&r1_bio->remaining);
+
+               cb = blk_check_plugged(raid1_unplug, mddev, sizeof(*plug));
+               if (cb)
+                       plug = container_of(cb, struct raid1_plug_cb, cb);
+               else
+                       plug = NULL;
                spin_lock_irqsave(&conf->device_lock, flags);
-               bio_list_add(&conf->pending_bio_list, mbio);
-               conf->pending_count++;
+               if (plug) {
+                       bio_list_add(&plug->pending, mbio);
+                       plug->pending_cnt++;
+               } else {
+                       bio_list_add(&conf->pending_bio_list, mbio);
+                       conf->pending_count++;
+               }
                spin_unlock_irqrestore(&conf->device_lock, flags);
-               if (!mddev_check_plugged(mddev))
+               if (!plug)
                        md_wakeup_thread(mddev->thread);
        }
        /* Mustn't call r1_bio_write_done before this next test,