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=-3.9 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,URIBL_BLOCKED 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 4F09EC2D0EE for ; Tue, 31 Mar 2020 10:42:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 26A5E208E0 for ; Tue, 31 Mar 2020 10:42:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585651334; bh=qXYGan3lC779UiSGNbkx/irqz1ZRbNY3U4gPt+oVvNs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=ZuGAtib6IE4aGdFPcw62IZhE5ff0AGE+Gy0u4Ok5X9aHb/AL7VIlIjcCTn3cPtkz1 3ZN4VIL4s3+La3mq3F8n8OMTvoIMRbOj0WlDGeN8tMF2R6XUqDrhZ2mTxNJiKiiU1T FgYXS7mcbZ+nHEjggIB6slKBy5AH0dpvAArk2hvs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730168AbgCaKmM (ORCPT ); Tue, 31 Mar 2020 06:42:12 -0400 Received: from mail.kernel.org ([198.145.29.99]:41422 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730358AbgCaKmK (ORCPT ); Tue, 31 Mar 2020 06:42:10 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 5B671208E0; Tue, 31 Mar 2020 10:42:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585651329; bh=qXYGan3lC779UiSGNbkx/irqz1ZRbNY3U4gPt+oVvNs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=hsPfFunQ02BmTHKKFtir9ut35F9P9YjKaPlHLZW9hFH9J/xnm+jUJq5Mgs8bZQLtM WUSwDyTNB+Re535zwl1y9zC6ChhQW98qrQhHuxvSQ0SQ3U/v7f0kqXtA4HBZRlHKXy sWIj8NjtWv48J2xvfQtItUUZjY0dfuLRM03uOYz0= Date: Tue, 31 Mar 2020 12:05:26 +0200 From: Greg KH To: Xiaoming Ni Cc: miquel.raynal@bootlin.com, richard@nod.at, vigneshr@ti.com, linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org, wangle6@huawei.com, zhangweimin12@huawei.com, yebin10@huawei.com, houtao1@huawei.com Subject: Re: [PATCH v4] mtd: clear cache_state to avoid writing to bad blocks repeatedly Message-ID: <20200331100526.GC1204199@kroah.com> References: <1585618319-119741-1-git-send-email-nixiaoming@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1585618319-119741-1-git-send-email-nixiaoming@huawei.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Mar 31, 2020 at 09:31:59AM +0800, Xiaoming Ni wrote: > 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 > --- > drivers/mtd/mtdblock.c | 11 +++++++---- > 1 file changed, 7 insertions(+), 4 deletions(-) $ ./scripts/get_maintainer.pl --file drivers/mtd/mtdblock.c Miquel Raynal (maintainer:MEMORY TECHNOLOGY DEVICES (MTD)) Richard Weinberger (maintainer:MEMORY TECHNOLOGY DEVICES (MTD)) Vignesh Raghavendra (maintainer:MEMORY TECHNOLOGY DEVICES (MTD)) linux-mtd@lists.infradead.org (open list:MEMORY TECHNOLOGY DEVICES (MTD)) linux-kernel@vger.kernel.org (open list) No where on there is my name/email, so why am I getting these? confused, greg k-h