From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Snitzer Subject: [PATCH v2 10/12] block: update request stacking methods to support discards Date: Sat, 24 Jul 2010 12:09:26 -0400 Message-ID: <1279987768-13275-11-git-send-email-snitzer@redhat.com> References: <1279987768-13275-1-git-send-email-snitzer@redhat.com> Reply-To: device-mapper development Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1279987768-13275-1-git-send-email-snitzer@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com To: dm-devel@redhat.com Cc: Jens Axboe , Christoph Hellwig , Kiyoshi Ueda List-Id: dm-devel.ids Propagate REQ_DISCARD in cmd_flags when cloning a discard request. Skip blk_rq_check_limits's existing checks for discard requests because discard limits will have already been checked in blkdev_issue_discard. Signed-off-by: Mike Snitzer Cc: Jens Axboe Cc: Christoph Hellwig Cc: Kiyoshi Ueda --- block/blk-core.c | 5 +++++ 1 file changed, 5 insertions(+) Index: linux-2.6-block/block/blk-core.c =================================================================== --- linux-2.6-block.orig/block/blk-core.c +++ linux-2.6-block/block/blk-core.c @@ -1644,6 +1644,9 @@ EXPORT_SYMBOL(submit_bio); */ int blk_rq_check_limits(struct request_queue *q, struct request *rq) { + if (rq->cmd_flags & REQ_DISCARD) + return 0; + if (blk_rq_sectors(rq) > queue_max_sectors(q) || blk_rq_bytes(rq) > queue_max_hw_sectors(q) << 9) { printk(KERN_ERR "%s: over max size limit.\n", __func__); @@ -2492,6 +2495,8 @@ static void __blk_rq_prep_clone(struct r { dst->cpu = src->cpu; dst->cmd_flags = (rq_data_dir(src) | REQ_NOMERGE); + if (src->cmd_flags & REQ_DISCARD) + dst->cmd_flags |= REQ_DISCARD; dst->cmd_type = src->cmd_type; dst->__sector = blk_rq_pos(src); dst->__data_len = blk_rq_bytes(src);