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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 75901C3815B for ; Mon, 20 Apr 2020 13:22:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5DC982070B for ; Mon, 20 Apr 2020 13:22:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726723AbgDTNWQ (ORCPT ); Mon, 20 Apr 2020 09:22:16 -0400 Received: from mail-pf1-f194.google.com ([209.85.210.194]:34944 "EHLO mail-pf1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726049AbgDTNWQ (ORCPT ); Mon, 20 Apr 2020 09:22:16 -0400 Received: by mail-pf1-f194.google.com with SMTP id r14so4935852pfg.2; Mon, 20 Apr 2020 06:22:16 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=/fj0h2mvNbIHyUZqMnIDvXRJPwVGn8bQL5X9tlS0mAQ=; b=IqGy//5bTtxci2XD/6Dx7/Azk8EeeLPeM5Xeu3Ij6NONSpeZWR+bDhxWbW00M6Dfyn JswNDUlaGeTrumQ/KBM1CHSCZeOwEj8m/E+MNFPZwv4guutWSg35FcRe43K6P8tM9QZM tNgFqx4Fa0uDJ9Ic8ZAFs40dTMX5GYoSQrIKBHeX5NQlEo8uzzeHBHNtcigU+4xBenlo sTI3qX+FQ7ic26Ec4l77IPEJV9IItgGO76qHSoncViBNrz3Q8L5Z46xjrSYLt/6QsfaX MiSYLi50mShf8cYN0VewLiQCA/cJNKogbc4FsW932GlBOWPjeKDvQH18VGiVfKP6gLy7 DgvQ== X-Gm-Message-State: AGi0PuajACcyW1nz54cnt2vaBn9beVTO8Fwwpdsg47EItNygF5rtW2Yz 4yS/jSzSiR1G/UqtvrfE91Q= X-Google-Smtp-Source: APiQypKc8DZ+iGhnJz49xipKnTbgAUEKLEIk5iShNar5T6096pSGHpVeLspz/QgDTCgvwoagnRVdWw== X-Received: by 2002:aa7:850f:: with SMTP id v15mr16282159pfn.204.1587388935780; Mon, 20 Apr 2020 06:22:15 -0700 (PDT) Received: from [100.124.9.192] ([104.129.199.10]) by smtp.gmail.com with ESMTPSA id j7sm1231550pjy.9.2020.04.20.06.22.13 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 20 Apr 2020 06:22:14 -0700 (PDT) Subject: Re: [PATCH 1/4] loop: Refactor size calculation. To: Martijn Coenen , axboe@kernel.dk, hch@lst.de, ming.lei@redhat.com Cc: narayan@google.com, zezeozue@google.com, kernel-team@android.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, maco@google.com, Chaitanya.Kulkarni@wdc.com, Jaegeuk Kim References: <20200420080409.111693-1-maco@android.com> <20200420080409.111693-2-maco@android.com> From: Bart Van Assche Message-ID: Date: Mon, 20 Apr 2020 06:22:12 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.6.0 MIME-Version: 1.0 In-Reply-To: <20200420080409.111693-2-maco@android.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 4/20/20 1:04 AM, Martijn Coenen wrote: > +/** > + * loop_set_size - sets device size and notifies userspace > + * @lo: struct loop_device to set the size for > + * @size: new size of the loop device > + * > + * Callers must validate that the size passed into this function fits into > + * a sector_t. > + */ > +static void loop_set_size(struct loop_device *lo, loff_t size) > +{ > + struct block_device *bdev = lo->lo_device; > + > + set_capacity(lo->lo_disk, size); > + bd_set_size(bdev, size << 9); > + /* let user-space know about the new size */ > + kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, KOBJ_CHANGE); > +} How about using the SECTOR_SHIFT constant instead of "9"? I think the following has been added recently in include/linux/blkdev.h: #define SECTOR_SHIFT 9 > @@ -1295,6 +1321,15 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info) > /* I/O need to be drained during transfer transition */ > blk_mq_freeze_queue(lo->lo_queue); > > + if (size_changed && lo->lo_device->bd_inode->i_mapping->nrpages) { > + /* kill_bdev should have truncated all the pages */ > + err = -EAGAIN; > + pr_warn("%s: loop%d (%s) has still dirty pages (nrpages=%lu)\n", > + __func__, lo->lo_number, lo->lo_file_name, > + lo->lo_device->bd_inode->i_mapping->nrpages); > + goto out_unfreeze; > + } > + > err = loop_release_xfer(lo); > if (err) > goto out_unfreeze; Please Cc Jaegeuk for any changes in this code (see also https://lore.kernel.org/linux-block/20190518005304.GA19446@jaegeuk-macbookpro.roam.corp.google.com/). Please also change the "kill_bdev should have truncated all the pages" comment into something like "return -EAGAIN if any pages have been dirtied after kill_bdev() returned". Thanks, Bart.