From mboxrd@z Thu Jan 1 00:00:00 1970 From: michaelc@cs.wisc.edu Subject: [PATCH 1/1] block: don't overwrite max_sectors if user has set it Date: Fri, 10 Apr 2015 02:08:40 -0500 Message-ID: <1428649720-14316-1-git-send-email-michaelc@cs.wisc.edu> Return-path: Received: from sabe.cs.wisc.edu ([128.105.6.20]:45366 "EHLO sabe.cs.wisc.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752182AbbDJHI6 (ORCPT ); Fri, 10 Apr 2015 03:08:58 -0400 Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: linux-scsi@vger.kernel.org, axboe@fb.com Cc: Mike Christie From: Mike Christie If the user has set max_sectors in sysfs, but the disk is revalidated due to it being removable or having write protections and it being opened, or dm/md claiming it, or something like a scsi rescan, etc, then we are overwriting the user specified max_sectors value. This patch only has us set the max_sectors if the new max_hw_sectors is smaller or if the user has not changed max_sectors. Signed-off-by: Mike Christie --- block/blk-settings.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/block/blk-settings.c b/block/blk-settings.c index 12600bf..d6c7b0c 100644 --- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -248,6 +248,10 @@ EXPORT_SYMBOL(blk_queue_bounce_limit); * filesystem type requests. This value can be overridden on a * per-device basis in /sys/block//queue/max_sectors_kb. * The soft limit can not exceed max_hw_sectors. + * + * If this is called as a result of a revalidation then we will only + * override the user specified max_sectors if the new max_hw_sectors is + * smaller. **/ void blk_limits_max_hw_sectors(struct queue_limits *limits, unsigned int max_hw_sectors) { @@ -257,7 +261,11 @@ void blk_limits_max_hw_sectors(struct queue_limits *limits, unsigned int max_hw_ __func__, max_hw_sectors); } - limits->max_sectors = limits->max_hw_sectors = max_hw_sectors; + if (limits->max_sectors == limits->max_hw_sectors || + max_hw_sectors < limits->max_sectors) + limits->max_sectors = limits->max_hw_sectors = max_hw_sectors; + else + limits->max_hw_sectors = max_hw_sectors; } EXPORT_SYMBOL(blk_limits_max_hw_sectors); -- 1.8.3.1