Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758013AbZIRT3R (ORCPT ); Fri, 18 Sep 2009 15:29:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757485AbZIRT3N (ORCPT ); Fri, 18 Sep 2009 15:29:13 -0400 Received: from rcsinet12.oracle.com ([148.87.113.124]:43959 "EHLO rgminet12.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757095AbZIRT3M (ORCPT ); Fri, 18 Sep 2009 15:29:12 -0400 To: device-mapper development Cc: Jens Axboe , Mike Snitzer , "Martin K. Petersen" , Alasdair G Kergon , linux-kernel@vger.kernel.org Subject: Re: [dm-devel] [PATCH 1/3] block: Add blk_queue_copy_limits() From: "Martin K. Petersen" Organization: Oracle References: <4AB3B43D.9000802@ce.jp.nec.com> Date: Fri, 18 Sep 2009 15:28:56 -0400 In-Reply-To: <4AB3B43D.9000802@ce.jp.nec.com> (Jun'ichi Nomura's message of "Sat, 19 Sep 2009 01:24:29 +0900") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Source-IP: abhmt001.oracle.com [141.146.116.10] X-Auth-Type: Internal IP X-CT-RefId: str=0001.0A090204.4AB3DF7C.0038:SCFSTAT5015188,ss=1,fgs=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1897 Lines: 49 >>>>> "Jun'ichi" == Jun'ichi Nomura writes: + if (q->limits.max_sectors == 0 || q->limits.max_hw_sectors == 0) + blk_queue_max_sectors(q, SAFE_MAX_SECTORS); I'm really not keen on perpetuating SAFE_MAX_SECTORS for something that was written in this millennium. I'd much rather we just do this, then: block: Set max_sectors correctly for stacking devices The topology changes unintentionally caused SAFE_MAX_SECTORS to be set for stacking devices. Set the default limit to BLK_DEF_MAX_SECTORS and provide SAFE_MAX_SECTORS in blk_queue_make_request() for legacy hw drivers that depend on the old behavior. Signed-off-by: Martin K. Petersen --- diff --git a/block/blk-settings.c b/block/blk-settings.c index 83413ff..cd9b730 100644 --- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -111,7 +111,7 @@ void blk_set_default_limits(struct queue_limits *lim) lim->max_hw_segments = MAX_HW_SEGMENTS; lim->seg_boundary_mask = BLK_SEG_BOUNDARY_MASK; lim->max_segment_size = MAX_SEGMENT_SIZE; - lim->max_sectors = lim->max_hw_sectors = SAFE_MAX_SECTORS; + lim->max_sectors = lim->max_hw_sectors = BLK_DEF_MAX_SECTORS; lim->logical_block_size = lim->physical_block_size = lim->io_min = 512; lim->bounce_pfn = (unsigned long)(BLK_BOUNCE_ANY >> PAGE_SHIFT); lim->alignment_offset = 0; @@ -164,6 +164,7 @@ void blk_queue_make_request(struct request_queue *q, make_request_fn *mfn) q->unplug_timer.data = (unsigned long)q; blk_set_default_limits(&q->limits); + blk_queue_max_sectors(q, SAFE_MAX_SECTORS); /* * If the caller didn't supply a lock, fall back to our embedded -- 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/