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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 120D3C61DD9 for ; Sat, 29 Aug 2026 06:25:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type: Content-Transfer-Encoding:MIME-Version:References:In-Reply-To:Message-ID:Date :Subject:CC:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=S1yrFP4Pe6B/KX4VlbIF1fox942sBDwMlaUs6T4ODEg=; b=cBRxcJpJyrmdmo26omIUAxalYc F4Nl1psBb87VMaWfT1nbLJyTHXfuhcTofym+kz46XROi6bB2ZUwvQaB/pVKRoFaoxBfMz2N3w9KZB SvrJwwoDHTF9RAtf9xc2JLUC50oziHpyH8B3lThKnlGXR4yIP3loG4wy0Bq3o9n88uyEQSgAF5FUV yawcXZpg/W+BqZ1sQzIH2rGoRBm+RaLcq9wx7kzjXwXdU+tXx8IFgQgLIV6AfPodHrdHhyRiGI9J4 V5JKPEwCxw47AqDRzYtQaL9K+cLXahaUa74G3n8Kw5YR7H/uxde0mKcXGvbxj1V9eopbIKuY9mhNU l+spuI/w==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1x0CVb-00000006mR5-3aMO; Sat, 29 Aug 2026 06:25:43 +0000 Received: from canpmsgout05.his.huawei.com ([113.46.200.220]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1x0CVY-00000006mPi-3g6U; Sat, 29 Aug 2026 06:25:43 +0000 dkim-signature: v=1; a=rsa-sha256; d=huawei.com; s=dkim; c=relaxed/relaxed; q=dns/txt; h=From; bh=S1yrFP4Pe6B/KX4VlbIF1fox942sBDwMlaUs6T4ODEg=; b=kGw3GOQA7j/ll6HjJ7opjr9yugQSx0srBbftBV0nHJqV0lNwEOmiK55GOyWVY9oQbti8dmf7Y fC4xbX4RXHos2KXMZCje/FHwjDuB0cBw1kirsBique2cBcbiJQ2mXWYVhME5LToy5ot11FKhUtz sEGnHGsHsyS5KN6nFTFNgsI= Received: from mail.maildlp.com (unknown [172.19.162.140]) by canpmsgout05.his.huawei.com (SkyGuard) with ESMTPS id 4hX4jv5tR9z12LDl; Sat, 29 Aug 2026 14:15:15 +0800 (CST) Received: from dggpemr100018.china.huawei.com (unknown [7.185.36.64]) by mail.maildlp.com (Postfix) with ESMTPS id 4728820333; Sat, 29 Aug 2026 14:25:31 +0800 (CST) Received: from huawei.com (10.50.85.155) by dggpemr100018.china.huawei.com (7.185.36.64) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.36; Sat, 29 Aug 2026 14:25:30 +0800 From: zhouminqiang To: , , , , , CC: , , , , , , Subject: [PATCH v2 2/7] jffs2: replace per-superblock verify buffer with per-write buffer Date: Sat, 29 Aug 2026 14:16:52 +0800 Message-ID: <20260829061658.306854-3-zhouminqiang2@huawei.com> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260829061658.306854-1-zhouminqiang2@huawei.com> References: <20260829061658.306854-1-zhouminqiang2@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-Originating-IP: [10.50.85.155] X-ClientProxiedBy: kwepems100001.china.huawei.com (7.221.188.238) To dggpemr100018.china.huawei.com (7.185.36.64) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260828_232541_624121_8A339681 X-CRM114-Status: GOOD ( 13.86 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Subsequent patches will extend write verification to additional write paths that may execute concurrently. A shared per-superblock buffer would require a coarse lock to serialize all verification, hurting concurrency. To avoid this contention, remove the wbuf_verify field from jffs2_sb_info, along with the scattered kmalloc/kfree of wbuf_verify in jffs2_nand_flash_setup, jffs2_dataflash_setup, jffs2_nor_wbuf_flash_setup and their corresponding cleanup functions. Instead, allocate a temporary buffer inside jffs2_verify_write(), giving each invocation its own buffer and eliminating the shared state. Signed-off-by: zhouminqiang --- fs/jffs2/jffs2_fs_sb.h | 3 --- fs/jffs2/wbuf.c | 61 ++++++++++++++++-------------------------- 2 files changed, 23 insertions(+), 41 deletions(-) diff --git a/fs/jffs2/jffs2_fs_sb.h b/fs/jffs2/jffs2_fs_sb.h index 5a7091746f68..8a75870d3fc8 100644 --- a/fs/jffs2/jffs2_fs_sb.h +++ b/fs/jffs2/jffs2_fs_sb.h @@ -124,9 +124,6 @@ struct jffs2_sb_info { uint32_t wbuf_pagesize; /* 0 for NOR and other flashes with no wbuf */ -#ifdef CONFIG_JFFS2_FS_WBUF_VERIFY - unsigned char *wbuf_verify; /* read-back buffer for verification */ -#endif #ifdef CONFIG_JFFS2_FS_WRITEBUFFER unsigned char *wbuf; /* Write-behind buffer for NAND flash */ uint32_t wbuf_ofs; diff --git a/fs/jffs2/wbuf.c b/fs/jffs2/wbuf.c index 61e3dbd4cd7b..f10be57c5543 100644 --- a/fs/jffs2/wbuf.c +++ b/fs/jffs2/wbuf.c @@ -233,19 +233,31 @@ static int jffs2_verify_write(struct jffs2_sb_info *c, unsigned char *buf, int ret; size_t retlen; char *eccstr; + void *verify_buf; + + verify_buf = kmalloc(c->wbuf_pagesize, GFP_NOFS); + if (!verify_buf) { + pr_warn("%s(): verify buffer allocation failed, skipping verification\n", + __func__); + return 0; + } + + ret = mtd_read(c->mtd, ofs, c->wbuf_pagesize, &retlen, verify_buf); - ret = mtd_read(c->mtd, ofs, c->wbuf_pagesize, &retlen, c->wbuf_verify); if (ret && ret != -EUCLEAN && ret != -EBADMSG) { pr_warn("%s(): Read back of page at %08x failed: %d\n", __func__, c->wbuf_ofs, ret); - return ret; + goto out_free; } else if (retlen != c->wbuf_pagesize) { pr_warn("%s(): Read back of page at %08x gave short read: %zd not %d\n", __func__, ofs, retlen, c->wbuf_pagesize); - return -EIO; + ret = -EIO; + goto out_free; + } + if (!memcmp(buf, verify_buf, c->wbuf_pagesize)) { + ret = 0; + goto out_free; } - if (!memcmp(buf, c->wbuf_verify, c->wbuf_pagesize)) - return 0; if (ret == -EUCLEAN) eccstr = "corrected"; @@ -261,9 +273,14 @@ static int jffs2_verify_write(struct jffs2_sb_info *c, unsigned char *buf, pr_warn("Read back:\n"); print_hex_dump(KERN_WARNING, "", DUMP_PREFIX_OFFSET, 16, 1, - c->wbuf_verify, c->wbuf_pagesize, 0); + verify_buf, c->wbuf_pagesize, 0); + kfree(verify_buf); return -EIO; + +out_free: + kfree(verify_buf); + return ret; } #else #define jffs2_verify_write(c,b,o) (0) @@ -1217,22 +1234,11 @@ int jffs2_nand_flash_setup(struct jffs2_sb_info *c) return -ENOMEM; } -#ifdef CONFIG_JFFS2_FS_WBUF_VERIFY - c->wbuf_verify = kmalloc(c->wbuf_pagesize, GFP_KERNEL); - if (!c->wbuf_verify) { - kfree(c->oobbuf); - kfree(c->wbuf); - return -ENOMEM; - } -#endif return 0; } void jffs2_nand_flash_cleanup(struct jffs2_sb_info *c) { -#ifdef CONFIG_JFFS2_FS_WBUF_VERIFY - kfree(c->wbuf_verify); -#endif kfree(c->wbuf); kfree(c->oobbuf); } @@ -1272,14 +1278,6 @@ int jffs2_dataflash_setup(struct jffs2_sb_info *c) { if (!c->wbuf) return -ENOMEM; -#ifdef CONFIG_JFFS2_FS_WBUF_VERIFY - c->wbuf_verify = kmalloc(c->wbuf_pagesize, GFP_KERNEL); - if (!c->wbuf_verify) { - kfree(c->wbuf); - return -ENOMEM; - } -#endif - pr_info("write-buffering enabled buffer (%d) erasesize (%d)\n", c->wbuf_pagesize, c->sector_size); @@ -1287,9 +1285,6 @@ int jffs2_dataflash_setup(struct jffs2_sb_info *c) { } void jffs2_dataflash_cleanup(struct jffs2_sb_info *c) { -#ifdef CONFIG_JFFS2_FS_WBUF_VERIFY - kfree(c->wbuf_verify); -#endif kfree(c->wbuf); } @@ -1309,20 +1304,10 @@ int jffs2_nor_wbuf_flash_setup(struct jffs2_sb_info *c) { if (!c->wbuf) return -ENOMEM; -#ifdef CONFIG_JFFS2_FS_WBUF_VERIFY - c->wbuf_verify = kmalloc(c->wbuf_pagesize, GFP_KERNEL); - if (!c->wbuf_verify) { - kfree(c->wbuf); - return -ENOMEM; - } -#endif return 0; } void jffs2_nor_wbuf_flash_cleanup(struct jffs2_sb_info *c) { -#ifdef CONFIG_JFFS2_FS_WBUF_VERIFY - kfree(c->wbuf_verify); -#endif kfree(c->wbuf); } -- 2.52.0