From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934112AbbIVSKS (ORCPT ); Tue, 22 Sep 2015 14:10:18 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:42868 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933425AbbIVRx4 (ORCPT ); Tue, 22 Sep 2015 13:53:56 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: "Martin K. Petersen" , James Bottomley , Kamal Mostafa Subject: [PATCH 3.19.y-ckt 061/102] sd: Fix maximum I/O size for BLOCK_PC requests Date: Tue, 22 Sep 2015 10:51:57 -0700 Message-Id: <1442944358-1248-62-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1442944358-1248-1-git-send-email-kamal@canonical.com> References: <1442944358-1248-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.19 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.19.8-ckt7 -stable review patch. If anyone has any objections, please let me know. ------------------ From: "Martin K. Petersen" commit 4f258a46346c03fa0bbb6199ffaf4e1f9f599660 upstream. Commit bcdb247c6b6a ("sd: Limit transfer length") clamped the maximum size of an I/O request to the MAXIMUM TRANSFER LENGTH field in the BLOCK LIMITS VPD. This had the unfortunate effect of also limiting the maximum size of non-filesystem requests sent to the device through sg/bsg. Avoid using blk_queue_max_hw_sectors() and set the max_sectors queue limit directly. Also update the comment in blk_limits_max_hw_sectors() to clarify that max_hw_sectors defines the limit for the I/O controller only. Signed-off-by: Martin K. Petersen Reported-by: Brian King Tested-by: Brian King Signed-off-by: James Bottomley Signed-off-by: Kamal Mostafa --- block/blk-settings.c | 4 ++-- drivers/scsi/sd.c | 6 +++--- 2 files changed, 5 insertions(+), 5 deletions(-) diff --git a/block/blk-settings.c b/block/blk-settings.c index 12600bf..e0057d0 100644 --- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -241,8 +241,8 @@ EXPORT_SYMBOL(blk_queue_bounce_limit); * Description: * Enables a low level driver to set a hard upper limit, * max_hw_sectors, on the size of requests. max_hw_sectors is set by - * the device driver based upon the combined capabilities of I/O - * controller and storage device. + * the device driver based upon the capabilities of the I/O + * controller. * * max_sectors is a soft limit imposed by the block layer for * filesystem type requests. This value can be overridden on a diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index 7f71d7d..c80e1fe 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -2794,9 +2794,9 @@ static int sd_revalidate_disk(struct gendisk *disk) max_xfer = sdkp->max_xfer_blocks; max_xfer <<= ilog2(sdp->sector_size) - 9; - max_xfer = min_not_zero(queue_max_hw_sectors(sdkp->disk->queue), - max_xfer); - blk_queue_max_hw_sectors(sdkp->disk->queue, max_xfer); + sdkp->disk->queue->limits.max_sectors = + min_not_zero(queue_max_hw_sectors(sdkp->disk->queue), max_xfer); + set_capacity(disk, sdkp->capacity); sd_config_write_same(sdkp); kfree(buffer); -- 1.9.1