From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752744AbbAMPp6 (ORCPT ); Tue, 13 Jan 2015 10:45:58 -0500 Received: from mail-pa0-f42.google.com ([209.85.220.42]:40121 "EHLO mail-pa0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752298AbbAMPpy (ORCPT ); Tue, 13 Jan 2015 10:45:54 -0500 From: Ming Lei To: linux-kernel@vger.kernel.org, Dave Kleikamp Cc: Jens Axboe , Zach Brown , Christoph Hellwig , Maxim Patlasov , Andrew Morton , Alexander Viro , Benjamin LaHaise , Ming Lei Subject: [PATCH v2 3/4] block: loop: introduce 'use_aio' sysfs file Date: Tue, 13 Jan 2015 23:44:47 +0800 Message-Id: <1421163888-21452-4-git-send-email-ming.lei@canonical.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1421163888-21452-1-git-send-email-ming.lei@canonical.com> References: <1421163888-21452-1-git-send-email-ming.lei@canonical.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org So that users can control if kernel aio is used to submit I/O. Signed-off-by: Ming Lei --- drivers/block/loop.c | 33 +++++++++++++++++++++++++++++++++ drivers/block/loop.h | 1 + 2 files changed, 34 insertions(+) diff --git a/drivers/block/loop.c b/drivers/block/loop.c index d1f168b..47af456 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -659,6 +659,38 @@ static ssize_t loop_attr_partscan_show(struct loop_device *lo, char *buf) return sprintf(buf, "%s\n", partscan ? "1" : "0"); } +static ssize_t loop_attr_do_show_use_aio(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct gendisk *disk = dev_to_disk(dev); + struct loop_device *lo = disk->private_data; + + return sprintf(buf, "%s\n", lo->use_aio ? "1" : "0"); +} + +ssize_t loop_attr_do_store_use_aio(struct device *dev, + struct device_attribute *attr, const char *buf, + size_t count) +{ + struct gendisk *disk = dev_to_disk(dev); + struct loop_device *lo = disk->private_data; + int err; + unsigned long v; + + err = kstrtoul(buf, 10, &v); + if (err < 0) + return err; + if (v) + lo->use_aio = true; + else + lo->use_aio = false; + return count; +} + +static struct device_attribute loop_attr_use_aio = + __ATTR(use_aio, S_IRUGO | S_IWUSR, loop_attr_do_show_use_aio, + loop_attr_do_store_use_aio); + LOOP_ATTR_RO(backing_file); LOOP_ATTR_RO(offset); LOOP_ATTR_RO(sizelimit); @@ -671,6 +703,7 @@ static struct attribute *loop_attrs[] = { &loop_attr_sizelimit.attr, &loop_attr_autoclear.attr, &loop_attr_partscan.attr, + &loop_attr_use_aio.attr, NULL, }; diff --git a/drivers/block/loop.h b/drivers/block/loop.h index 301c27f..15049e9 100644 --- a/drivers/block/loop.h +++ b/drivers/block/loop.h @@ -57,6 +57,7 @@ struct loop_device { struct list_head write_cmd_head; struct work_struct write_work; bool write_started; + bool use_aio; int lo_state; struct mutex lo_ctl_mutex; -- 1.7.9.5