From patchwork Fri Sep 18 16:24:29 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Junichi Nomura X-Patchwork-Id: 48565 Received: from hormel.redhat.com (hormel1.redhat.com [209.132.177.33]) by demeter.kernel.org (8.14.2/8.14.2) with ESMTP id n8IGkthZ016227 for ; Fri, 18 Sep 2009 16:46:55 GMT Received: from listman.util.phx.redhat.com (listman.util.phx.redhat.com [10.8.4.110]) by hormel.redhat.com (Postfix) with ESMTP id DDA3E61A699; Fri, 18 Sep 2009 12:46:54 -0400 (EDT) Received: from int-mx01.intmail.prod.int.phx2.redhat.com (nat-pool.util.phx.redhat.com [10.8.5.200]) by listman.util.phx.redhat.com (8.13.1/8.13.1) with ESMTP id n8IGkrNx003593 for ; Fri, 18 Sep 2009 12:46:53 -0400 Received: from mx1.redhat.com (ext-mx10.extmail.prod.ext.phx2.redhat.com [10.5.110.14]) by int-mx01.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id n8IGkrIZ029077; Fri, 18 Sep 2009 12:46:53 -0400 Received: from tyo202.gate.nec.co.jp (TYO202.gate.nec.co.jp [202.32.8.206]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id n8IGkgZn024220; Fri, 18 Sep 2009 12:46:43 -0400 Received: from mailgate3.nec.co.jp ([10.7.69.197]) by tyo202.gate.nec.co.jp (8.13.8/8.13.4) with ESMTP id n8IGkaxl007247; Sat, 19 Sep 2009 01:46:36 +0900 (JST) Received: (from root@localhost) by mailgate3.nec.co.jp (8.11.7/3.7W-MAILGATE-NEC) id n8IGkai09881; Sat, 19 Sep 2009 01:46:36 +0900 (JST) Received: from mail02.kamome.nec.co.jp (mail02.kamome.nec.co.jp [10.25.43.5]) by mailsv.nec.co.jp (8.13.8/8.13.4) with ESMTP id n8IGkZx6023889; Sat, 19 Sep 2009 01:46:35 +0900 (JST) Received: from monta.jp.nec.com ([10.26.220.14] [10.26.220.14]) by mail03.kamome.nec.co.jp with ESMTP id BT-MMP-2080513; Sat, 19 Sep 2009 01:24:37 +0900 Received: from [10.66.61.195] ([10.66.61.195] [10.66.61.195]) by mail.jp.nec.com with ESMTP; Sat, 19 Sep 2009 01:24:35 +0900 Message-ID: <4AB3B43D.9000802@ce.jp.nec.com> Date: Sat, 19 Sep 2009 01:24:29 +0900 From: "Jun'ichi Nomura" User-Agent: Thunderbird 2.0.0.19 (Windows/20081209) MIME-Version: 1.0 To: Jens Axboe , Mike Snitzer , "Martin K. Petersen" , Alasdair G Kergon X-RedHat-Spam-Score: 0 () X-Scanned-By: MIMEDefang 2.67 on 10.5.11.11 X-Scanned-By: MIMEDefang 2.67 on 10.5.110.14 X-loop: dm-devel@redhat.com Cc: device-mapper development , linux-kernel@vger.kernel.org Subject: [dm-devel] [PATCH 1/3] block: Add blk_queue_copy_limits() X-BeenThere: dm-devel@redhat.com X-Mailman-Version: 2.1.5 Precedence: junk Reply-To: device-mapper development List-Id: device-mapper development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com This patch is a preparation for the last patch in this patchset which changes blk_set_default_limits() to set 0 to max_sectors. dm uses blk_stack_limits() to merge limits of underlying devices and copy the end result to the queue. But if there's no underlying device (like 'zero' target), max_sectors/max_hw_sectors are left unchanged from the default 0 and just copying it to the queue causes problems. Provide blk_queue_copy_limits() to get a safe copy with invalid values fixed-up. Signed-off-by: Kiyoshi Ueda Signed-off-by: Jun'ichi Nomura Cc: David Strand Cc: Mike Snitzer Cc: Alasdair G Kergon Cc: Martin K. Petersen Cc: Jens Axboe --- block/blk-settings.c | 28 ++++++++++++++++++++++++++++ include/linux/blkdev.h | 1 + 2 files changed, 29 insertions(+) extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev, -- dm-devel mailing list dm-devel@redhat.com https://www.redhat.com/mailman/listinfo/dm-devel Index: linux-2.6.31.work/block/blk-settings.c =================================================================== --- linux-2.6.31.work.orig/block/blk-settings.c +++ linux-2.6.31.work/block/blk-settings.c @@ -122,6 +122,34 @@ void blk_set_default_limits(struct queue EXPORT_SYMBOL(blk_set_default_limits); /** + * blk_queue_copy_limits - copy limits to queue + * @q: the request queue whose limits as a copy destination + * @lim: the queue_limits structure as a copy source + * + * Description: + * Copies a queue_limit struct contents to @q with fix-ups to + * invalid values. + */ +void blk_queue_copy_limits(struct request_queue *q, struct queue_limits *lim) +{ + q->limits = *lim; + + /* + * blk_set_default_limits() sets 0 to max_sectors/max_hw_sectors + * so that blk_stack_limits() appropriately propagate the values + * of lower-stack by min_not_zero(). + * However, if the default value 0 is unchanged (e.g. the stacking + * device is virtual and has no underlying device), it results + * in unusable device. + * Check if max_sectors/max_hw_sectors have non-zero values, + * and set SAFE_MAX_SECTORS if they do. + */ + if (q->limits.max_sectors == 0 || q->limits.max_hw_sectors == 0) + blk_queue_max_sectors(q, SAFE_MAX_SECTORS); +} +EXPORT_SYMBOL(blk_queue_copy_limits); + +/** * blk_queue_make_request - define an alternate make_request function for a device * @q: the request queue for the device to be affected * @mfn: the alternate make_request function Index: linux-2.6.31.work/include/linux/blkdev.h =================================================================== --- linux-2.6.31.work.orig/include/linux/blkdev.h +++ linux-2.6.31.work/include/linux/blkdev.h @@ -917,6 +917,7 @@ extern void blk_limits_io_min(struct que extern void blk_queue_io_min(struct request_queue *q, unsigned int min); extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt); extern void blk_set_default_limits(struct queue_limits *lim); +extern void blk_queue_copy_limits(struct request_queue *q, struct queue_limits *lim); extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, sector_t offset);