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=-9.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 92614C38A2A for ; Fri, 8 May 2020 06:40:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 63B3B20870 for ; Fri, 8 May 2020 06:40:29 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="ARzHXfMt" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727956AbgEHGk1 (ORCPT ); Fri, 8 May 2020 02:40:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59510 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1727086AbgEHGkV (ORCPT ); Fri, 8 May 2020 02:40:21 -0400 Received: from mail-pj1-x1043.google.com (mail-pj1-x1043.google.com [IPv6:2607:f8b0:4864:20::1043]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2A517C05BD0B for ; Thu, 7 May 2020 23:40:21 -0700 (PDT) Received: by mail-pj1-x1043.google.com with SMTP id t40so3799935pjb.3 for ; Thu, 07 May 2020 23:40:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=cqKLrad562FQwghELBGLStRGtw4lwT2qr64qzOycGEI=; b=ARzHXfMtCypZrxvF85mfdVA/KP8ufpi4gPXaLVOYgNUIU61qwjqLN7fQ5sAMsfOrvh mjdyxFyWjrCuP7yH1sI47OqQ0SXQTCs5R1wxNReQuEZklKLVNgdfzlza+QMwwEhDOKC9 SASqIO1879iv+QvLzBVO4qYr07B7P7U5q1pkQ= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=cqKLrad562FQwghELBGLStRGtw4lwT2qr64qzOycGEI=; b=X673MaKTMK8ad/F/cJcVCsrit0xgdO3KNvsr5agaaDHuZQ5E8Ivi1GCbSeurlEZBQT wv5+VChfGuq356dQ5ZBXlTPXVIhJKx1US1sbHRwnFtyTnbZ0eYWpLP+4Ihl7hqyfQ/zg 7c1TBpJv7KVehINP2Gcec3VEcSlFy3svzfv5STBs3PuXNAwDPATedgUbNdEabCE0POq0 xZ2QZ9LJYpBu1ffzV71pEeKMcvJuaPXFsPG8dZCA6RdXWhhe/tPsvZzZKBGn6oD92MZ2 W4SOig0GJ1J6c1r6SR/mt/DK8YPg1mhl4AlYnXMBvwrV7umyAPbAkh3xxkCTrywii5ye WPRQ== X-Gm-Message-State: AGi0PubqI7S6MRxXlvsbxhUCa5EILFLFb/ZY4kZDZUB+DGWOpHEFd/ay 7sfO76uEbIpjL9mmiIR/SDbPHQ== X-Google-Smtp-Source: APiQypLiORqo7LA6/jRy+SiU1pTTL3uX0VuwjBVR/lnJgE/kkJAZVbD3aWdNHul8G866o7w6pioCJg== X-Received: by 2002:a17:90a:d17:: with SMTP id t23mr4455269pja.77.1588920020669; Thu, 07 May 2020 23:40:20 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id h14sm1490829pjc.46.2020.05.07.23.40.15 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 07 May 2020 23:40:16 -0700 (PDT) From: Kees Cook To: WeiXiong Liao Cc: Kees Cook , Anton Vorontsov , Colin Cross , Tony Luck , Petr Mladek , Sergey Senozhatsky , Steven Rostedt , linux-doc@vger.kernel.org, linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH v4 09/12] pstore/zone: Provide way to skip "broken" zone for MTD devices Date: Thu, 7 May 2020 23:40:01 -0700 Message-Id: <20200508064004.57898-10-keescook@chromium.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200508064004.57898-1-keescook@chromium.org> References: <20200508064004.57898-1-keescook@chromium.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: WeiXiong Liao One requirement to support MTD devices in pstore/zone is having a way to declare certain regions as broken. Add this support to pstore/zone. The MTD driver should return -ENOMSG when encountering a bad region, which tells pstore/zone to skip and try the next one. Signed-off-by: WeiXiong Liao Link: https://lore.kernel.org/r/1585126506-18635-9-git-send-email-liaoweixiong@allwinnertech.com Signed-off-by: Kees Cook --- fs/pstore/blk.c | 10 ++++-- fs/pstore/zone.c | 65 ++++++++++++++++++++++++++++++------- include/linux/pstore_blk.h | 3 +- include/linux/pstore_zone.h | 12 ++++--- 4 files changed, 71 insertions(+), 19 deletions(-) diff --git a/fs/pstore/blk.c b/fs/pstore/blk.c index 5db811b7018d..e33e58afd4cb 100644 --- a/fs/pstore/blk.c +++ b/fs/pstore/blk.c @@ -101,9 +101,12 @@ static struct bdev_info { * means error. * @write: The same as @read, but the following error number: * -EBUSY means try to write again later. + * -ENOMSG means to try next zone. * @panic_write:The write operation only used for panic case. It's optional - * if you do not care panic log. The parameters and return value - * are the same as @read. + * if you do not care panic log. The parameters are relative + * value to storage. + * On success, the number of bytes should be returned, others + * excluding -ENOMSG mean error. -ENOMSG means to try next zone. */ struct psblk_device { unsigned long total_size; @@ -315,6 +318,9 @@ static ssize_t psblk_blk_panic_write(const char *buf, size_t size, /* size and off must align to SECTOR_SIZE for block device */ ret = blkdev_panic_write(buf, off >> SECTOR_SHIFT, size >> SECTOR_SHIFT); + /* try next zone */ + if (ret == -ENOMSG) + return ret; return ret ? -EIO : size; } diff --git a/fs/pstore/zone.c b/fs/pstore/zone.c index 36d78c63bd20..43d44d016039 100644 --- a/fs/pstore/zone.c +++ b/fs/pstore/zone.c @@ -247,6 +247,9 @@ static int psz_zone_write(struct pstore_zone *zone, return 0; dirty: + /* no need to mark dirty if going to try next zone */ + if (wcnt == -ENOMSG) + return -ENOMSG; atomic_set(&zone->dirty, true); /* flush dirty zones nicely */ if (wcnt == -EBUSY && !is_on_panic()) @@ -382,7 +385,11 @@ static int psz_recover_oops_meta(struct psz_context *cxt) return -EINVAL; rcnt = info->read((char *)buf, len, zone->off); - if (rcnt != len) { + if (rcnt == -ENOMSG) { + pr_debug("%s with id %lu may be broken, skip\n", + zone->name, i); + continue; + } else if (rcnt != len) { pr_err("read %s with id %lu failed\n", zone->name, i); return (int)rcnt < 0 ? (int)rcnt : -EIO; } @@ -717,24 +724,58 @@ static void psz_write_kmsg_hdr(struct pstore_zone *zone, hdr->counter = 0; } +/* + * In case zone is broken, which may occur to MTD device, we try each zones, + * start at cxt->oops_write_cnt. + */ static inline int notrace psz_oops_write_record(struct psz_context *cxt, struct pstore_record *record) { + int ret = -EBUSY; size_t size, hlen; struct pstore_zone *zone; - unsigned int zonenum; + unsigned int i; - zonenum = cxt->oops_write_cnt; - zone = cxt->opszs[zonenum]; - if (unlikely(!zone)) - return -ENOSPC; - cxt->oops_write_cnt = (zonenum + 1) % cxt->oops_max_cnt; + for (i = 0; i < cxt->oops_max_cnt; i++) { + unsigned int zonenum, len; + + zonenum = (cxt->oops_write_cnt + i) % cxt->oops_max_cnt; + zone = cxt->opszs[zonenum]; + if (unlikely(!zone)) + return -ENOSPC; - pr_debug("write %s to zone id %d\n", zone->name, zonenum); - psz_write_kmsg_hdr(zone, record); - hlen = sizeof(struct psz_oops_header); - size = min_t(size_t, record->size, zone->buffer_size - hlen); - return psz_zone_write(zone, FLUSH_ALL, record->buf, size, hlen); + /* avoid destorying old data, allocate a new one */ + len = zone->buffer_size + sizeof(*zone->buffer); + zone->oldbuf = zone->buffer; + zone->buffer = kzalloc(len, GFP_KERNEL); + if (!zone->buffer) { + zone->buffer = zone->oldbuf; + return -ENOMEM; + } + zone->buffer->sig = zone->oldbuf->sig; + + pr_debug("write %s to zone id %d\n", zone->name, zonenum); + psz_write_kmsg_hdr(zone, record); + hlen = sizeof(struct psz_oops_header); + size = min_t(size_t, record->size, zone->buffer_size - hlen); + ret = psz_zone_write(zone, FLUSH_ALL, record->buf, size, hlen); + if (likely(!ret || ret != -ENOMSG)) { + cxt->oops_write_cnt = zonenum + 1; + cxt->oops_write_cnt %= cxt->oops_max_cnt; + /* no need to try next zone, free last zone buffer */ + kfree(zone->oldbuf); + zone->oldbuf = NULL; + return ret; + } + + pr_debug("zone %u may be broken, try next dmesg zone\n", + zonenum); + kfree(zone->buffer); + zone->buffer = zone->oldbuf; + zone->oldbuf = NULL; + } + + return -EBUSY; } static int notrace psz_oops_write(struct psz_context *cxt, diff --git a/include/linux/pstore_blk.h b/include/linux/pstore_blk.h index d8f609e60288..828b0763d477 100644 --- a/include/linux/pstore_blk.h +++ b/include/linux/pstore_blk.h @@ -14,7 +14,8 @@ * @start_sect: start sector to block device * @sects: sectors count on buf * - * Return: On success, zero should be returned. Others mean error. + * Return: On success, zero should be returned. Others excluding -ENOMSG + * mean error. -ENOMSG means to try next zone. * * Panic write to block device must be aligned to SECTOR_SIZE. */ diff --git a/include/linux/pstore_zone.h b/include/linux/pstore_zone.h index 94f441b8b616..ddb3dfea4ea6 100644 --- a/include/linux/pstore_zone.h +++ b/include/linux/pstore_zone.h @@ -23,11 +23,15 @@ typedef ssize_t (*psz_write_op)(const char *, size_t, loff_t); * @read: The general read operation. Both of the function parameters * @size and @offset are relative value to storage. * On success, the number of bytes should be returned, others - * means error. - * @write: The same as @read, but -EBUSY means try to write again later. + * mean error. + * @write: The same as @read, but the following error number: + * -EBUSY means try to write again later. + * -ENOMSG means to try next zone. * @panic_write:The write operation only used for panic case. It's optional - * if you do not care panic log. The parameters and return value - * are the same as @read. + * if you do not care panic log. The parameters are relative + * value to storage. + * On success, the number of bytes should be returned, others + * excluding -ENOMSG mean error. -ENOMSG means to try next zone. */ struct pstore_zone_info { struct module *owner; -- 2.20.1 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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 B140EC38A2A for ; Fri, 8 May 2020 06:42:45 +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 73D8620735 for ; Fri, 8 May 2020 06:42:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="P5KtOv6w"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="ARzHXfMt" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 73D8620735 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=chromium.org 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:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=cWuRyf4V59oyyibU3KYs8jxXxdUWux6I0CXUazpLRhI=; b=P5KtOv6wAW4/aa A5ElUivGFGCpGwzRcOKti7bUfXQV2lPIHYC7+gawuD2MKOSvJyAFk/M/kpox2UEeg/G+dq//lZFW+ WV3vsLDVHgy5YXc2atV+f2M41yWzMZtBt7lHznr7IiQg+s88jQ6ywfn5siisR2z5lbH4MCMqgLhOr Dp8K2rByn3rteMv2tLLL+cqAukoBu8rIEUtDSIwh7xwVeSpzsBKJewHvV6gsJb6FbbWcSnOaxaKXK iw2O2Zvd5KvLN2fyHKqb58/dTOA1s4EnsAwPdrK1AAXXnCeLP+fPryBx/cQUVfauHCJF18cvpzzze oL33So9AggIpqRbMmYWg==; 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 1jWwiT-0001ld-AM; Fri, 08 May 2020 06:42:37 +0000 Received: from mail-pl1-x644.google.com ([2607:f8b0:4864:20::644]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jWwgH-0008Hc-Gz for linux-mtd@lists.infradead.org; Fri, 08 May 2020 06:40:25 +0000 Received: by mail-pl1-x644.google.com with SMTP id t7so313014plr.0 for ; Thu, 07 May 2020 23:40:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=cqKLrad562FQwghELBGLStRGtw4lwT2qr64qzOycGEI=; b=ARzHXfMtCypZrxvF85mfdVA/KP8ufpi4gPXaLVOYgNUIU61qwjqLN7fQ5sAMsfOrvh mjdyxFyWjrCuP7yH1sI47OqQ0SXQTCs5R1wxNReQuEZklKLVNgdfzlza+QMwwEhDOKC9 SASqIO1879iv+QvLzBVO4qYr07B7P7U5q1pkQ= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=cqKLrad562FQwghELBGLStRGtw4lwT2qr64qzOycGEI=; b=FmZf4JZbCl1SsMV7dPJRmxksUypW/xy3WIOHFcpG98TV4IGkNxkOWwAGWOrbSskrCJ xPngP/i1gB9zFvda9fgjQPSWmxTRLajf2omFPYzCwiEwZn2426JKybXiXU+2sW5QMXc3 teFezZ+Rx7JSMLSkwqggwOrYBh3aoBUO3RTO6Iz+UwVNnLHPFtLuebilLnJFzGfekuiE auLZoh3r2RfshIxXA9h18HVUk2Q60vXaJQ/jT0qnEwYMw46KWlLYvhiKk7X9DUgry2u8 VvdHQ3m3smT8Ji66gRzQf3kStncgZ+Z3SHzwS0lfU/O38C5BSzMRbKO8Wg8o0NFg9C7n H9CA== X-Gm-Message-State: AGi0Pubt9dqEyCn3cT4gVuMASDJa+Zokpa5IFLF/8c2RQJ1UONYQEN3z peAuEvKA10toCcdZxqY3UFsCtwb61G0= X-Google-Smtp-Source: APiQypLiORqo7LA6/jRy+SiU1pTTL3uX0VuwjBVR/lnJgE/kkJAZVbD3aWdNHul8G866o7w6pioCJg== X-Received: by 2002:a17:90a:d17:: with SMTP id t23mr4455269pja.77.1588920020669; Thu, 07 May 2020 23:40:20 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id h14sm1490829pjc.46.2020.05.07.23.40.15 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 07 May 2020 23:40:16 -0700 (PDT) From: Kees Cook To: WeiXiong Liao Subject: [PATCH v4 09/12] pstore/zone: Provide way to skip "broken" zone for MTD devices Date: Thu, 7 May 2020 23:40:01 -0700 Message-Id: <20200508064004.57898-10-keescook@chromium.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200508064004.57898-1-keescook@chromium.org> References: <20200508064004.57898-1-keescook@chromium.org> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200507_234021_567184_F9BFCF39 X-CRM114-Status: GOOD ( 18.74 ) 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: Petr Mladek , Tony Luck , Kees Cook , linux-doc@vger.kernel.org, Anton Vorontsov , linux-kernel@vger.kernel.org, Steven Rostedt , Sergey Senozhatsky , linux-mtd@lists.infradead.org, Colin Cross 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 From: WeiXiong Liao One requirement to support MTD devices in pstore/zone is having a way to declare certain regions as broken. Add this support to pstore/zone. The MTD driver should return -ENOMSG when encountering a bad region, which tells pstore/zone to skip and try the next one. Signed-off-by: WeiXiong Liao Link: https://lore.kernel.org/r/1585126506-18635-9-git-send-email-liaoweixiong@allwinnertech.com Signed-off-by: Kees Cook --- fs/pstore/blk.c | 10 ++++-- fs/pstore/zone.c | 65 ++++++++++++++++++++++++++++++------- include/linux/pstore_blk.h | 3 +- include/linux/pstore_zone.h | 12 ++++--- 4 files changed, 71 insertions(+), 19 deletions(-) diff --git a/fs/pstore/blk.c b/fs/pstore/blk.c index 5db811b7018d..e33e58afd4cb 100644 --- a/fs/pstore/blk.c +++ b/fs/pstore/blk.c @@ -101,9 +101,12 @@ static struct bdev_info { * means error. * @write: The same as @read, but the following error number: * -EBUSY means try to write again later. + * -ENOMSG means to try next zone. * @panic_write:The write operation only used for panic case. It's optional - * if you do not care panic log. The parameters and return value - * are the same as @read. + * if you do not care panic log. The parameters are relative + * value to storage. + * On success, the number of bytes should be returned, others + * excluding -ENOMSG mean error. -ENOMSG means to try next zone. */ struct psblk_device { unsigned long total_size; @@ -315,6 +318,9 @@ static ssize_t psblk_blk_panic_write(const char *buf, size_t size, /* size and off must align to SECTOR_SIZE for block device */ ret = blkdev_panic_write(buf, off >> SECTOR_SHIFT, size >> SECTOR_SHIFT); + /* try next zone */ + if (ret == -ENOMSG) + return ret; return ret ? -EIO : size; } diff --git a/fs/pstore/zone.c b/fs/pstore/zone.c index 36d78c63bd20..43d44d016039 100644 --- a/fs/pstore/zone.c +++ b/fs/pstore/zone.c @@ -247,6 +247,9 @@ static int psz_zone_write(struct pstore_zone *zone, return 0; dirty: + /* no need to mark dirty if going to try next zone */ + if (wcnt == -ENOMSG) + return -ENOMSG; atomic_set(&zone->dirty, true); /* flush dirty zones nicely */ if (wcnt == -EBUSY && !is_on_panic()) @@ -382,7 +385,11 @@ static int psz_recover_oops_meta(struct psz_context *cxt) return -EINVAL; rcnt = info->read((char *)buf, len, zone->off); - if (rcnt != len) { + if (rcnt == -ENOMSG) { + pr_debug("%s with id %lu may be broken, skip\n", + zone->name, i); + continue; + } else if (rcnt != len) { pr_err("read %s with id %lu failed\n", zone->name, i); return (int)rcnt < 0 ? (int)rcnt : -EIO; } @@ -717,24 +724,58 @@ static void psz_write_kmsg_hdr(struct pstore_zone *zone, hdr->counter = 0; } +/* + * In case zone is broken, which may occur to MTD device, we try each zones, + * start at cxt->oops_write_cnt. + */ static inline int notrace psz_oops_write_record(struct psz_context *cxt, struct pstore_record *record) { + int ret = -EBUSY; size_t size, hlen; struct pstore_zone *zone; - unsigned int zonenum; + unsigned int i; - zonenum = cxt->oops_write_cnt; - zone = cxt->opszs[zonenum]; - if (unlikely(!zone)) - return -ENOSPC; - cxt->oops_write_cnt = (zonenum + 1) % cxt->oops_max_cnt; + for (i = 0; i < cxt->oops_max_cnt; i++) { + unsigned int zonenum, len; + + zonenum = (cxt->oops_write_cnt + i) % cxt->oops_max_cnt; + zone = cxt->opszs[zonenum]; + if (unlikely(!zone)) + return -ENOSPC; - pr_debug("write %s to zone id %d\n", zone->name, zonenum); - psz_write_kmsg_hdr(zone, record); - hlen = sizeof(struct psz_oops_header); - size = min_t(size_t, record->size, zone->buffer_size - hlen); - return psz_zone_write(zone, FLUSH_ALL, record->buf, size, hlen); + /* avoid destorying old data, allocate a new one */ + len = zone->buffer_size + sizeof(*zone->buffer); + zone->oldbuf = zone->buffer; + zone->buffer = kzalloc(len, GFP_KERNEL); + if (!zone->buffer) { + zone->buffer = zone->oldbuf; + return -ENOMEM; + } + zone->buffer->sig = zone->oldbuf->sig; + + pr_debug("write %s to zone id %d\n", zone->name, zonenum); + psz_write_kmsg_hdr(zone, record); + hlen = sizeof(struct psz_oops_header); + size = min_t(size_t, record->size, zone->buffer_size - hlen); + ret = psz_zone_write(zone, FLUSH_ALL, record->buf, size, hlen); + if (likely(!ret || ret != -ENOMSG)) { + cxt->oops_write_cnt = zonenum + 1; + cxt->oops_write_cnt %= cxt->oops_max_cnt; + /* no need to try next zone, free last zone buffer */ + kfree(zone->oldbuf); + zone->oldbuf = NULL; + return ret; + } + + pr_debug("zone %u may be broken, try next dmesg zone\n", + zonenum); + kfree(zone->buffer); + zone->buffer = zone->oldbuf; + zone->oldbuf = NULL; + } + + return -EBUSY; } static int notrace psz_oops_write(struct psz_context *cxt, diff --git a/include/linux/pstore_blk.h b/include/linux/pstore_blk.h index d8f609e60288..828b0763d477 100644 --- a/include/linux/pstore_blk.h +++ b/include/linux/pstore_blk.h @@ -14,7 +14,8 @@ * @start_sect: start sector to block device * @sects: sectors count on buf * - * Return: On success, zero should be returned. Others mean error. + * Return: On success, zero should be returned. Others excluding -ENOMSG + * mean error. -ENOMSG means to try next zone. * * Panic write to block device must be aligned to SECTOR_SIZE. */ diff --git a/include/linux/pstore_zone.h b/include/linux/pstore_zone.h index 94f441b8b616..ddb3dfea4ea6 100644 --- a/include/linux/pstore_zone.h +++ b/include/linux/pstore_zone.h @@ -23,11 +23,15 @@ typedef ssize_t (*psz_write_op)(const char *, size_t, loff_t); * @read: The general read operation. Both of the function parameters * @size and @offset are relative value to storage. * On success, the number of bytes should be returned, others - * means error. - * @write: The same as @read, but -EBUSY means try to write again later. + * mean error. + * @write: The same as @read, but the following error number: + * -EBUSY means try to write again later. + * -ENOMSG means to try next zone. * @panic_write:The write operation only used for panic case. It's optional - * if you do not care panic log. The parameters and return value - * are the same as @read. + * if you do not care panic log. The parameters are relative + * value to storage. + * On success, the number of bytes should be returned, others + * excluding -ENOMSG mean error. -ENOMSG means to try next zone. */ struct pstore_zone_info { struct module *owner; -- 2.20.1 ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/