From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from canpmsgout10.his.huawei.com (canpmsgout10.his.huawei.com [113.46.200.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0BF0B414DD3 for ; Thu, 20 Aug 2026 10:57:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=113.46.200.225 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787223428; cv=none; b=ZNRH3xDZV8VRG1SUgdfgnBU1mftAifIYv4J41UFQFzqwl3Z/msBr+M2W6YkvAlonQ6PJJlSW5zFGd05q/ZN5LVmkDuXEKDSnToH1aDIyilPnXb4NP4f7kn2jgvtqngVVnzuGkAvFrRUMdz3bOFSzvSNMa+zQtSuOBfMzvHoUX30= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787223428; c=relaxed/simple; bh=LdiBfwokbgp0kmpUdpQ0ABPigU7aFMaB8G0KE4qGnSs=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=Z6gkkBvQ9TfFJj0MP37cMtL8410LmSSzvgSp2UWvqo2LyZi/sGhggp4G/XSf2DllTPqaZykj3H5QbGk6Cm2n8tziTUD1y6nz0PSJpnne8WuiFRQR7LdoLiyeAH9GtunFLTYHEBitK24Rw1v4Zhn+4VkQSt+BjG6RhNCk+K+qT1Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; dkim=pass (1024-bit key) header.d=huawei.com header.i=@huawei.com header.b=XgLrhPFO; arc=none smtp.client-ip=113.46.200.225 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=huawei.com header.i=@huawei.com header.b="XgLrhPFO" dkim-signature: v=1; a=rsa-sha256; d=huawei.com; s=dkim; c=relaxed/relaxed; q=dns/txt; h=From; bh=quF9NbDt4UT4axTaHFsmKw/ynG1LA3xITgMxyw7ruVA=; b=XgLrhPFOqBO51eUXgJ2ZLYpR5MUCQHvTRv5ZV/N/JfHQrMP4M4HuhTd/mMpb89J5qwdxo5qfu CfGyN4d5XHND6gkPA+6Gy0vENi5FKeD4vnBYk+nff0WAU4cyAE6ngqnJR00/CKZ2BG1TuwUbR7d e+7thHf81upk5wfVFsCoIsU= Received: from mail.maildlp.com (unknown [172.19.163.127]) by canpmsgout10.his.huawei.com (SkyGuard) with ESMTPS id 4hQg8l5PCkz1K96b; Thu, 20 Aug 2026 18:46:15 +0800 (CST) Received: from dggpemr100018.china.huawei.com (unknown [7.185.36.64]) by mail.maildlp.com (Postfix) with ESMTPS id D27AB40572; Thu, 20 Aug 2026 18:56:57 +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; Thu, 20 Aug 2026 18:56:57 +0800 From: zhouminqiang To: , CC: , , , , Subject: [PATCH 1/6] jffs2: replace per-superblock verify buffer with per-write buffer Date: Thu, 20 Aug 2026 18:49:57 +0800 Message-ID: <20260820105003.2525647-2-zhouminqiang2@huawei.com> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260820105003.2525647-1-zhouminqiang2@huawei.com> References: <20260820105003.2525647-1-zhouminqiang2@huawei.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-ClientProxiedBy: kwepems200002.china.huawei.com (7.221.188.68) To dggpemr100018.china.huawei.com (7.185.36.64) 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 3b7803c75d58..7e4608b43a4e 100644 --- a/fs/jffs2/wbuf.c +++ b/fs/jffs2/wbuf.c @@ -15,6 +15,7 @@ #include #include +#include #include #include #include @@ -233,19 +234,30 @@ static int jffs2_verify_write(struct jffs2_sb_info *c, unsigned char *buf, int ret; size_t retlen; char *eccstr; + void *verify_buf; - ret = mtd_read(c->mtd, ofs, c->wbuf_pagesize, &retlen, c->wbuf_verify); + verify_buf = __vmalloc(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); 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); + vfree(verify_buf); return -EIO; + +out_free: + vfree(verify_buf); + return ret; } #else #define jffs2_verify_write(c,b,o) (0) @@ -1214,22 +1231,11 @@ 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); } @@ -1269,14 +1275,6 @@ 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); @@ -1284,9 +1282,6 @@ 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); } @@ -1306,20 +1301,10 @@ 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