From d623b650637f54780f4afa794d4e0dd88168b405 Mon Sep 17 00:00:00 2001 From: Tao Guo Date: Thu, 3 May 2012 15:43:11 +1000 Subject: [PATCH] umem: fix up unplugging Fix a regression introduced by 7eaceaccab5f40 ("block: remove per-queue plugging"). In that patch, Jens removed the whole mm_unplug_device() function, which used to be the trigger to make umem start to work. We need to implement unplugging to make umem start to work, or I/O will never be triggered. Signed-off-by: Tao Guo Cc: Neil Brown Cc: Jens Axboe Cc: Signed-off-by: Andrew Morton --- drivers/block/umem.c | 33 ++++++++++++++++++++++++++++++++- 1 file changed, 32 insertions(+), 1 deletion(-) diff --git a/drivers/block/umem.c b/drivers/block/umem.c index aa2712060bfb..c3bf98e4b88c 100644 --- a/drivers/block/umem.c +++ b/drivers/block/umem.c @@ -111,7 +111,8 @@ struct cardinfo { int current_idx; sector_t current_sector; - struct request_queue *queue; + struct request_queue *queue; + struct blk_plug_cb plug_cb; struct mm_page { dma_addr_t page_dma; @@ -513,6 +514,33 @@ static void process_page(unsigned long data) } } +static void mm_unplug(struct blk_plug_cb *cb) +{ + struct cardinfo *card = container_of(cb, struct cardinfo, plug_cb); + + spin_lock_irq(&card->lock); + activate(card); + spin_unlock_irq(&card->lock); +} + +int mm_check_plugged(struct cardinfo *card) +{ + struct blk_plug *plug = current->plug; + struct cardinfo *c; + + if (!plug) + return 0; + + list_for_each_entry(c, &plug->cb_list, plug_cb.list) { + if (c == card) + return 1; + } + + /* set up unplug callback */ + list_add(&card->plug_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 +551,8 @@ 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; @@ -884,6 +914,7 @@ static int __devinit mm_pci_probe(struct pci_dev *dev, blk_queue_make_request(card->queue, mm_make_request); card->queue->queue_lock = &card->lock; card->queue->queuedata = card; + card->plug_cb.callback = mm_unplug; tasklet_init(&card->tasklet, process_page, (unsigned long)card); -- 2.39.5