Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760876Ab2FGRM0 (ORCPT ); Thu, 7 Jun 2012 13:12:26 -0400 Received: from mexforward.lss.emc.com ([128.222.32.20]:48857 "EHLO mexforward.lss.emc.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754204Ab2FGRMZ (ORCPT ); Thu, 7 Jun 2012 13:12:25 -0400 From: Tao Guo To: linux-kernel@vger.kernel.org Cc: Tao Guo , Tao Guo , Neil Brown , Jens Axboe , Shaohua Li , Subject: [PATCH V2] umem: fix up unplugging Date: Thu, 7 Jun 2012 13:07:15 -0400 Message-Id: <1339088835-2614-1-git-send-email-glorioustao@gmail.com> X-Mailer: git-send-email 1.7.7.6 X-EMM-MHVC: 1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2307 Lines: 82 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: Shaohua Li Cc: --- 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 aa27120..9a72277 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; -- 1.7.7.6 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/