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 51BD9C79F91 for ; Sun, 6 Sep 2026 03:13:14 +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-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=PtbPZNBFuNEaVdJiADg/XpC8nk45FV+Ig7tFOf+O/bM=; b=4NWWAj87mn6/VhPDUV2r0e9i2k 8Gft2Siaf1SUku3EobgLmP0LHDINQDleu+i1dyicF1PgJzHg67ZisllmGHdZ/1fzncX4I/xCxH+t/ C+X7b4MF6EJzI6pTbbfTx69lEskW8PsyjqhpYQFSPaUpob+4P3UjFV32zAfHTywReMi9gGwp/6ZkZ TL2J1wL8wIC6nyt9ODHXt1xsnuDFwsXoK+Zon65r7C2JTB/xFZUMoGrEjR7Yd5Xr4gRNAfjp+bg3g WrVFOYTlTyi1x/0ZeQCE06QQj5tJ8QagTUyyezcSMgspsrPeeUzarolvySP76tXOHz3RBgNav+CjQ qQUq3GHg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1x33JW-00000004avC-1x7O; Sun, 06 Sep 2026 03:13:02 +0000 Received: from dggsgout12.his.huawei.com ([45.249.212.56]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1x33JI-00000004aib-1oPz; Sun, 06 Sep 2026 03:12:50 +0000 Received: from mail.maildlp.com (unknown [172.19.163.170]) by dggsgout12.his.huawei.com (SkyGuard) with ESMTPS id 4hcwGK5XsjzKHMRW; Sun, 6 Sep 2026 11:11:37 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.112]) by mail.maildlp.com (Postfix) with ESMTP id AE05C4056B; Sun, 6 Sep 2026 11:12:35 +0800 (CST) Received: from huaweicloud.com (unknown [10.50.85.155]) by APP1 (Coremail) with UTF8SMTPSA id cCh0CgBnUAsW2pxqmzytAw--.18069S7; Sun, 06 Sep 2026 11:12:35 +0800 (CST) From: Zhou Minqiang To: linux@armlinux.org.uk, vz@mleia.com, piotr.wojtaszczyk@timesys.com, maddy@linux.ibm.com, dwmw2@infradead.org, richard@nod.at Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-mtd@lists.infradead.org, chengzhihao1@huawei.com, yangerkun@huawei.com, yi.zhang@huawei.com, zhouminqiang Subject: [PATCH v4 3/8] jffs2: replace per-superblock verify buffer with per-write buffer Date: Sun, 6 Sep 2026 11:03:39 +0800 Message-ID: <20260906030344.2448622-4-zhouminqiang2@huawei.com> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260906030344.2448622-1-zhouminqiang2@huawei.com> References: <20260906030344.2448622-1-zhouminqiang2@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CM-TRANSID: cCh0CgBnUAsW2pxqmzytAw--.18069S7 X-Coremail-Antispam: 1UD129KBjvJXoWxCr4UKry8KFyrGr45tr13Arb_yoWrtw45pF sayF13Ar48JryxWrs5tFn5Cw15KrW8Gr1Igr47C348Xa18tr1Iqa4rtFy8ZrWrArZ7Wr1S ka9Ikw1rXF1UX37anT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUmGb4IE77IF4wAFF20E14v26rWj6s0DM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28IrcIa0xkI8VA2jI8067AKxVWUWw A2048vs2IY020Ec7CjxVAFwI0_Xr0E3s1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0rcxS w2x7M28EF7xvwVC0I7IYx2IY67AKxVW8JVW5JwA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxV W8Jr0_Cr1UM28EF7xvwVC2z280aVAFwI0_Gr1j6F4UJwA2z4x0Y4vEx4A2jsIEc7CjxVAF wI0_Cr1j6rxdM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40Ex7 xfMcIj6xIIjxv20xvE14v26r106r15McIj6I8E87Iv67AKxVWUJVW8JwAm72CE4IkC6x0Y z7v_Jr0_Gr1lF7xvr2IYc2Ij64vIr41lFIxGxcIEc7CjxVA2Y2ka0xkIwI1lc7CjxVAaw2 AFwI0_Jw0_GFyl42xK82IYc2Ij64vIr41l42xK82IY64kExVAvwVAq07x20xyl4I8I3I0E 4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAqx4xG67AKxVWUJVWUGwC20s026x8GjcxK67AKxVWUGV WUWwC2zVAF1VAY17CE14v26r1q6r43MIIYrxkI7VAKI48JMIIF0xvE2Ix0cI8IcVAFwI0_ Gr0_Xr1lIxAIcVC0I7IYx2IY6xkF7I0E14v26F4j6r4UJwCI42IY6xAIw20EY4v20xvaj4 0_Jr0_JF4lIxAIcVC2z280aVAFwI0_Gr0_Cr1lIxAIcVC2z280aVCY1x0267AKxVW8JVW8 JrUvcSsGvfC2KfnxnUUI43ZEXa7IUbdMaUUUUUU== X-CM-SenderInfo: 52kr3z5lqtxttqj6x35dzhxuhorxvhhfrp/ X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260905_201248_841111_7E83806C X-CRM114-Status: GOOD ( 12.95 ) 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 From: zhouminqiang 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 ab247117ec77..7e52241de457 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