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=-5.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_2 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 89117C43331 for ; Mon, 30 Mar 2020 13:52:45 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 5BC3F206CC for ; Mon, 30 Mar 2020 13:52:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="ZEMkBdaJ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5BC3F206CC Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=bootlin.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-mtd-bounces+linux-mtd=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=jf2+upx1VrU6eIoeecR/7ZGSSfMh8PeE1fFUirLjl4Y=; b=ZEMkBdaJrpxJn7 5ZO2QuqRYJK8pkYJdkvJD5d49OTlgAIr3bt1kdCweqJJMysleTvJTrc4YCdas0H3a1g7+sKMjvQgu 2A/ShGZM0WqwPp9yCetD8ODmT3lynZo5+p366gFBsviiNjllscqfKZ7SfqGZSjrsBkkBOArVfw+4o Jfs506zln1QZPQN2hOSkXuJXau7vM2li1Z/qMgu+ilEDCamuVh+L1Xv9Z6iv287Zn7REqklaPOnLR VYwYtjtTeLqd9oz7jld3k+BbAfRLx3HLLNmIaR+LW50f0J4/9mvZx64J9y3vvxsOVbGNcCQZdK/CL WF6HkE5vYnjtAKy6yfJQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jIuq8-0004NW-3X; Mon, 30 Mar 2020 13:52:32 +0000 Received: from relay7-d.mail.gandi.net ([217.70.183.200]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jIuq4-0004Mp-QH for linux-mtd@lists.infradead.org; Mon, 30 Mar 2020 13:52:30 +0000 X-Originating-IP: 91.224.148.103 Received: from xps13 (unknown [91.224.148.103]) (Authenticated sender: miquel.raynal@bootlin.com) by relay7-d.mail.gandi.net (Postfix) with ESMTPSA id C14F520009; Mon, 30 Mar 2020 13:52:24 +0000 (UTC) Date: Mon, 30 Mar 2020 15:52:22 +0200 From: Miquel Raynal To: Xiaoming Ni Subject: Re: [PATCH v3] mtd:fix cache_state to avoid writing to bad blocks repeatedly Message-ID: <20200330155222.20359293@xps13> In-Reply-To: <1585575925-84017-1-git-send-email-nixiaoming@huawei.com> References: <1585575925-84017-1-git-send-email-nixiaoming@huawei.com> Organization: Bootlin X-Mailer: Claws Mail 3.17.4 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200330_065228_987964_D3D8B269 X-CRM114-Status: GOOD ( 10.44 ) X-BeenThere: linux-mtd@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: wangle6@huawei.com, vigneshr@ti.com, richard@nod.at, houtao1@huawei.com, linux-kernel@vger.kernel.org, linux-mtd@lists.infradead.org, zhangweimin12@huawei.com, gregkh@linuxfoundation.org, stable@kernel.org, yebin10@huawei.com Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-mtd" Errors-To: linux-mtd-bounces+linux-mtd=archiver.kernel.org@lists.infradead.org Hi Xiaoming, Xiaoming Ni wrote on Mon, 30 Mar 2020 21:45:25 +0800: > The function call process is as follows: > mtd_blktrans_work() > while (1) > do_blktrans_request() > mtdblock_writesect() > do_cached_write() > write_cached_data() /*if cache_state is STATE_DIRTY*/ > erase_write() > > write_cached_data() returns failure without modifying cache_state > and cache_offset. So when do_cached_write() is called again, > write_cached_data() will be called again to perform erase_write() > on the same cache_offset. > > But if this cache_offset points to a bad block, erase_write() will > always return -EIO. Writing to this mtdblk is equivalent to losing > the current data, and repeatedly writing to the bad block. > > Repeatedly writing a bad block has no real benefits, > but brings some negative effects: > 1 Lost subsequent data > 2 Loss of flash device life > 3 erase_write() bad blocks are very time-consuming. For example: > the function do_erase_oneblock() in chips/cfi_cmdset_0020.c or > chips/cfi_cmdset_0002.c may take more than 20 seconds to return > > Therefore, when erase_write() returns -EIO in write_cached_data(), > clear cache_state to avoid writing to bad blocks repeatedly. > > Signed-off-by: Xiaoming Ni > Reviewed-by: Miquel Raynal > Cc: stable@vger.kernel.org Still missing: * Fixes: tag * Wrong title prefix ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/