diff options
| -rw-r--r-- | drivers/block/umem.c | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/drivers/block/umem.c b/drivers/block/umem.c index aa2712060bfb..9a72277a31df 100644 --- a/drivers/block/umem.c +++ b/drivers/block/umem.c @@ -513,6 +513,44 @@ 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); + + spin_lock_irq(&mmcb->card->lock); + activate(mmcb->card); + spin_unlock_irq(&mmcb->card->lock); + kfree(mmcb); +} + +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; +} + static void mm_make_request(struct request_queue *q, struct bio *bio) { struct cardinfo *card = q->queuedata; @@ -523,6 +561,8 @@ static void mm_make_request(struct request_queue *q, struct bio *bio) *card->biotail = bio; bio->bi_next = NULL; card->biotail = &bio->bi_next; + if (bio->bi_rw & REQ_SYNC || !mm_check_plugged(card)) + activate(card); spin_unlock_irq(&card->lock); return; |