blk: centralize non-request unplug handling.

Both md and umem has similar code for getting notified on an
blk_finish_plug event.
Centralize this code in block/ and allow each driver to
provide its distinctive difference.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 6 insertions, 29 deletions

diff --git a/drivers/block/umem.c b/drivers/block/umem.c
index 9a72277a31df..6ef3489568e3 100644
--- a/drivers/block/umem.c
+++ b/drivers/block/umem.c
@@ -513,42 +513,19 @@ static void process_page(unsigned long data)
         }
 }
 
-struct mm_plug_cb {
-        struct blk_plug_cb cb;
-        struct cardinfo *card;
-};
-
 static void mm_unplug(struct blk_plug_cb *cb)
 {
-        struct mm_plug_cb *mmcb = container_of(cb, struct mm_plug_cb, cb);
+        struct cardinfo *card = cb->data;
 
-        spin_lock_irq(&mmcb->card->lock);
-        activate(mmcb->card);
-        spin_unlock_irq(&mmcb->card->lock);
-        kfree(mmcb);
+        spin_lock_irq(&card->lock);
+        activate(card);
+        spin_unlock_irq(&card->lock);
+        kfree(cb);
 }
 
 static int mm_check_plugged(struct cardinfo *card)
 {
-        struct blk_plug *plug = current->plug;
-        struct mm_plug_cb *mmcb;
-
-        if (!plug)
-                return 0;
-
-        list_for_each_entry(mmcb, &plug->cb_list, cb.list) {
-                if (mmcb->cb.callback == mm_unplug && mmcb->card == card)
-                        return 1;
-        }
-        /* Not currently on the callback list */
-        mmcb = kmalloc(sizeof(*mmcb), GFP_ATOMIC);
-        if (!mmcb)
-                return 0;
-
-        mmcb->card = card;
-        mmcb->cb.callback = mm_unplug;
-        list_add(&mmcb->cb.list, &plug->cb_list);
-        return 1;
+        return !!blk_check_plugged(mm_unplug, card, sizeof(struct blk_plug_cb));
 }
 
 static void mm_make_request(struct request_queue *q, struct bio *bio)