From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-20.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1AF15C48BE5 for ; Thu, 17 Jun 2021 23:26:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F0AC2610A5 for ; Thu, 17 Jun 2021 23:26:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233027AbhFQX2e (ORCPT ); Thu, 17 Jun 2021 19:28:34 -0400 Received: from mail.klausen.dk ([157.90.24.29]:53242 "EHLO mail.klausen.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233003AbhFQX2d (ORCPT ); Thu, 17 Jun 2021 19:28:33 -0400 X-Greylist: delayed 4444 seconds by postgrey-1.27 at vger.kernel.org; Thu, 17 Jun 2021 19:28:33 EDT Subject: Re: [PATCH] loop: Fix missing discard support when using LOOP_CONFIGURE DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=klausen.dk; s=dkim; t=1623972380; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Vbn0+3h5DgI8ES1Iq5xmrf83w+go5eMbfDrACNi+IXI=; b=EEWCeGBCComITFZI0wjYvj4fzKKJPD21r1GbCyHZzX/yBTQlPh1EBQxjkJ0QQfWNsvaXT1 CbpEfu0vIK5DQu4oEsdBjAjh6sg6ZJDUyO+MTwZYninaAZs3QWWzJlj06ZZRx3xkQzZiLj zIFOPvDFu1p6qyRCsJGd0jImD71exHg= To: Ming Lei Cc: linux-block@vger.kernel.org, stable@vger.kernel.org, Jens Axboe , Martijn Coenen , open list References: <20210617221158.7045-1-kristian@klausen.dk> From: Kristian Klausen Message-ID: <8445d1b6-0118-37d4-c927-3b7e6ff480ea@klausen.dk> Date: Fri, 18 Jun 2021 01:26:19 +0200 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 18.06.2021 01.03, Ming Lei wrote: > On Fri, Jun 18, 2021 at 12:11:57AM +0200, Kristian Klausen wrote: > > Commit log? I will try to come up with a commit message. AFAIU the missing call to loop_config_discard() causes the block device to report "no discard support" (best-case) or stale/incorrect discard support (ex: if the loop device was configured with LOOP_SET_STATUS(64) and later LOOP_CONFIGURE). > >> Cc: # 5.8.x- >> Fixes: 3448914e8cc5 ("loop: Add LOOP_CONFIGURE ioctl") >> Signed-off-by: Kristian Klausen >> --- >> Tested like so (without the patch): >> losetup 2.37<= uses LOOP_CONFIGURE instead of LOOP_SET_STATUS64[1] >> >> # fallocate -l100M disk.img >> # rmmod loop >> # losetup --version >> losetup from util-linux 2.36.2 >> # losetup --find --show disk.img >> /dev/loop0 >> # grep '' /sys/devices/virtual/block/loop0/queue/*discard* >> /sys/devices/virtual/block/loop0/queue/discard_granularity:4096 >> /sys/devices/virtual/block/loop0/queue/discard_max_bytes:4294966784 >> /sys/devices/virtual/block/loop0/queue/discard_max_hw_bytes:4294966784 >> /sys/devices/virtual/block/loop0/queue/discard_zeroes_data:0 >> /sys/devices/virtual/block/loop0/queue/max_discard_segments:1 >> # losetup -d /dev/loop0 >> # [update util-linux] >> # losetup --version >> losetup from util-linux 2.37 >> # rmmod loop >> # losetup --find --show disk.img >> /dev/loop0 >> # grep '' /sys/devices/virtual/block/loop0/queue/*discard* >> /sys/devices/virtual/block/loop0/queue/discard_granularity:0 >> /sys/devices/virtual/block/loop0/queue/discard_max_bytes:0 >> /sys/devices/virtual/block/loop0/queue/discard_max_hw_bytes:0 >> /sys/devices/virtual/block/loop0/queue/discard_zeroes_data:0 >> /sys/devices/virtual/block/loop0/queue/max_discard_segments:1 >> >> >> With the patch applied: >> >> # losetup --version >> losetup from util-linux 2.37 >> # rmmod loop >> # losetup --find --show disk.img >> /dev/loop0 >> # grep '' /sys/devices/virtual/block/loop0/queue/*discard* >> /sys/devices/virtual/block/loop0/queue/discard_granularity:4096 >> /sys/devices/virtual/block/loop0/queue/discard_max_bytes:4294966784 >> /sys/devices/virtual/block/loop0/queue/discard_max_hw_bytes:4294966784 >> /sys/devices/virtual/block/loop0/queue/discard_zeroes_data:0 >> /sys/devices/virtual/block/loop0/queue/max_discard_segments:1 >> >> [1] https://github.com/karelzak/util-linux/pull/1152 >> >> drivers/block/loop.c | 2 ++ >> 1 file changed, 2 insertions(+) >> >> diff --git a/drivers/block/loop.c b/drivers/block/loop.c >> index 76e12f3482a9..ec957f6d8a49 100644 >> --- a/drivers/block/loop.c >> +++ b/drivers/block/loop.c >> @@ -1168,6 +1168,8 @@ static int loop_configure(struct loop_device *lo, fmode_t mode, >> if (partscan) >> lo->lo_disk->flags &= ~GENHD_FL_NO_PART_SCAN; >> >> + loop_config_discard(lo); >> + > It could be better to move loop_config_discard() around > loop_update_rotational/loop_update_dio(), then we setup everything > before updating loop as Lo_bound. I will move it before loop_update_rotational(). > > Otherwise, this patch looks fine. > > > Thanks, > Ming >