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=-1.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,T_DKIMWL_WL_MED autolearn=ham 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 E4714C46464 for ; Tue, 14 Aug 2018 16:24:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7D2AE214C2 for ; Tue, 14 Aug 2018 16:24:54 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=kernel-dk.20150623.gappssmtp.com header.i=@kernel-dk.20150623.gappssmtp.com header.b="J0ebdlDo" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7D2AE214C2 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.dk Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732900AbeHNTMm (ORCPT ); Tue, 14 Aug 2018 15:12:42 -0400 Received: from mail-ua1-f68.google.com ([209.85.222.68]:34680 "EHLO mail-ua1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728978AbeHNTMm (ORCPT ); Tue, 14 Aug 2018 15:12:42 -0400 Received: by mail-ua1-f68.google.com with SMTP id r15-v6so13787698uao.1 for ; Tue, 14 Aug 2018 09:24:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=iRuenKUIWBuqHAcjNk19T2wq2U3TLJLVakenm0TqYXo=; b=J0ebdlDopMPDQuCRFuXEoEx+wqi368xrYWvzbIlxuNzD9wgQvOEvx5LDk865JRQswd mDNj/y1t2K5o2srUh2guKlFKhrRL4k8D5wlX8/4INCSsMY4Kw7dTDV6BFe+O6FPLIagy 7AJs8cgM9hIpjFOKRfYarLpfN1sfmcmTdECsedl8LKqRCZHxi9kz/OxYmjH+2RNiD6It HqmFq3B4unCBQ0E1UXvx9PJv46+i1UQYCL2RwZrO7yAUsgNAyNPkIxcGG2Gp6DiSFhYq dzy8vjXzvFjWarWjD6cC/XvFOXpQM+hzb9fswKh7ITuq5887AX4ug+4Xaae4UUFp/ljQ eSBQ== 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=iRuenKUIWBuqHAcjNk19T2wq2U3TLJLVakenm0TqYXo=; b=HyO7L1BlFMRDTvdiNF9cm8ooAIY51TawmMZOHdjfBVXpxtdowozuFJUxIDxRzja24x 6xjREUGNysAeoZb5zQcvtFQMdwBXd6UNwh0H3+IE5IZTLzq8R4xE8Q0KkWOuEBR+AXYf jJ36VQ8eLPBzdXTFTDBGdu6EE9m3Cj6ml6YfeU2vIG31UZ7FVOpAM6efrXhIqrgHV7wW uYEifceAaLtHa/+55AoKhz5mzbdSan5/zcGk7TkbJd/ogpjF8nwiAHjddDxSGJ9i9LUz 93p0vGQ+oxN1QhqhhzuIOqhpSw7ivz7SQiIXhI8KYv5wOB3DI77OaW1bhOnt6I8zmU3J +5Iw== X-Gm-Message-State: AOUpUlF5Gl0SD8Y3lpx4ot0waAiCnxwEOeKsy6sZO1SILBbR6108hOfm jdRKjYIkZERRss1EfMQqfZ6unUGLQHs= X-Google-Smtp-Source: AA+uWPzDj/J0drWmVMkApnaTusGJLvqBNkmSRPBjJiZVuZl3HTb2A9CQmwNAwwo2K906BT2AFRefZw== X-Received: by 2002:ab0:6a6:: with SMTP id g35-v6mr14865927uag.16.1534263890230; Tue, 14 Aug 2018 09:24:50 -0700 (PDT) Received: from [192.168.1.56] ([216.160.245.98]) by smtp.gmail.com with ESMTPSA id h8-v6sm3135619uao.25.2018.08.14.09.24.48 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 14 Aug 2018 09:24:49 -0700 (PDT) Subject: Re: Warning when using eMMC and partprobe: generic_make_request: Trying to write to read-only block-device To: Linus Torvalds , Ilya Dryomov Cc: stefan@agner.ch, Sagi Grimberg , linux-arm-kernel , Linux Kernel Mailing List References: <7f57199f45df7212fdbba0bd1e78142a@agner.ch> From: Jens Axboe Message-ID: <22fff85b-63e5-3cfe-0e72-255044e53bab@kernel.dk> Date: Tue, 14 Aug 2018 10:24:47 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 8/14/18 10:22 AM, Linus Torvalds wrote: > On Tue, Aug 14, 2018 at 8:24 AM Ilya Dryomov wrote: >> >> Looks like it's coming from that fsync(): >> >> sys_fsync >> do_fsync >> vfs_fsync_range >> blkdev_fsync >> blkdev_issue_flush >> >> I think we need to teach blkdev_issue_flush() to bail out if the bdev >> is read-only, similar to blkdev_issue_discard(), _write_zeroes(), etc. >> The question is which error code to use. blkdev_fsync() already skips >> over EOPNOTSUPP, so it is a (no-so-good) option. Other blkdev_issue_ >> functions return EPERM. > > Oh, just make issue_flush() return EROFS for a read-only device. > > Or maybe we should even just consider the flush to be a read operation? > > But I guess the error code gets percolated all the way to user space? > The safest option might just be to return 0. We probably just want to special case a flush for this check. In other situations, like resource allocation and issue, we'd want to consider it a write. -- Jens Axboe