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=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 6AB41C3A5A2 for ; Wed, 4 Sep 2019 02:12:40 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (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 ECCEC21897 for ; Wed, 4 Sep 2019 02:12:39 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org ECCEC21897 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linux-erofs-bounces+linux-erofs=archiver.kernel.org@lists.ozlabs.org Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 46NS5L1PtVzDqnF for ; Wed, 4 Sep 2019 12:12:38 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=huawei.com (client-ip=45.249.212.191; helo=huawei.com; envelope-from=gaoxiang25@huawei.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=huawei.com Received: from huawei.com (szxga05-in.huawei.com [45.249.212.191]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 46NS3B3qprzDql2 for ; Wed, 4 Sep 2019 12:10:43 +1000 (AEST) Received: from DGGEMS411-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id BCE90E5B70EC5FF3B70F; Wed, 4 Sep 2019 10:10:40 +0800 (CST) Received: from architecture4.huawei.com (10.140.130.215) by smtp.huawei.com (10.3.19.211) with Microsoft SMTP Server (TLS) id 14.3.439.0; Wed, 4 Sep 2019 10:10:31 +0800 From: Gao Xiang To: Chao Yu , Greg Kroah-Hartman , Christoph Hellwig , Subject: [PATCH v2 23/25] erofs: use read_mapping_page instead of sb_bread Date: Wed, 4 Sep 2019 10:09:10 +0800 Message-ID: <20190904020912.63925-24-gaoxiang25@huawei.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190904020912.63925-1-gaoxiang25@huawei.com> References: <20190901055130.30572-1-hsiangkao@aol.com> <20190904020912.63925-1-gaoxiang25@huawei.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.140.130.215] X-CFilter-Loop: Reflected X-BeenThere: linux-erofs@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Development of Linux EROFS file system List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-fsdevel@vger.kernel.org, Miao Xie , linux-erofs@lists.ozlabs.org Errors-To: linux-erofs-bounces+linux-erofs=archiver.kernel.org@lists.ozlabs.org Sender: "Linux-erofs" As Christoph said [1], "This seems to be your only direct use of buffer heads, which while not deprecated are a bit of an ugly step child. So if you can easily avoid creating a buffer_head dependency in a new filesystem I think you should avoid it. " [1] https://lore.kernel.org/r/20190902125109.GA9826@infradead.org/ Reported-by: Christoph Hellwig Signed-off-by: Gao Xiang --- fs/erofs/super.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/fs/erofs/super.c b/fs/erofs/super.c index 1d9880195ef0..caf9a95173b0 100644 --- a/fs/erofs/super.c +++ b/fs/erofs/super.c @@ -98,20 +98,22 @@ static bool check_layout_compatibility(struct super_block *sb, static int erofs_read_superblock(struct super_block *sb) { struct erofs_sb_info *sbi; - struct buffer_head *bh; + struct page *page; struct erofs_super_block *dsb; unsigned int blkszbits; + void *data; int ret; - bh = sb_bread(sb, 0); - - if (!bh) { + page = read_mapping_page(sb->s_bdev->bd_inode->i_mapping, 0, NULL); + if (!page) { erofs_err(sb, "cannot read erofs superblock"); return -EIO; } sbi = EROFS_SB(sb); - dsb = (struct erofs_super_block *)(bh->b_data + EROFS_SUPER_OFFSET); + + data = kmap_atomic(page); + dsb = (struct erofs_super_block *)(data + EROFS_SUPER_OFFSET); ret = -EINVAL; if (le32_to_cpu(dsb->magic) != EROFS_SUPER_MAGIC_V1) { @@ -153,7 +155,8 @@ static int erofs_read_superblock(struct super_block *sb) } ret = 0; out: - brelse(bh); + kunmap_atomic(data); + put_page(page); return ret; } -- 2.17.1