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=-16.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 58D1AC12002 for ; Wed, 14 Jul 2021 22:44:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 33543613C2 for ; Wed, 14 Jul 2021 22:44:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230440AbhGNWrn (ORCPT ); Wed, 14 Jul 2021 18:47:43 -0400 Received: from mail.kernel.org ([198.145.29.99]:59078 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229983AbhGNWrn (ORCPT ); Wed, 14 Jul 2021 18:47:43 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id ED122613B2; Wed, 14 Jul 2021 22:44:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1626302691; bh=PL0xvptAUH+uAD6LIxRe7m4zpYdhsj5rlyIqikLfjLs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=cp0Vj8BjF2IWSijVZ0v9fDo2/pUgudxm5S93PnQcA5kAYAWGRUOQEfHDxnRtxM8qV NA9X822MqyFRoDnq533Coj9O3ugy84WUx6ELLn3C7y47K4uG1Go4oEaixI1gjJbKa8 XKCU/pgqPdx8mvv3VBcllPJYfzFmWqy67/iolijrBt7dmwMhLFh2wUcoQagdwDN4e2 +YwJDhH7ueTOl8FFPfdG6HPs/QxGCDcLMW1mwGBJhENNfegZ+YE4r0CTrxkJ2EkQB/ wDT7wsrH/vHkHnXWo+R7E3BErexDbumNk/F0xlwXtHzdmgssDjS/fnRwuq0tGovp5Z PPJvd0LK+nl2Q== Date: Wed, 14 Jul 2021 15:44:50 -0700 From: "Darrick J. Wong" To: Dave Chinner Cc: linux-xfs@vger.kernel.org Subject: Re: [PATCH 01/16] xfs: sb verifier doesn't handle uncached sb buffer Message-ID: <20210714224450.GT22402@magnolia> References: <20210714041912.2625692-1-david@fromorbit.com> <20210714041912.2625692-2-david@fromorbit.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210714041912.2625692-2-david@fromorbit.com> Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org On Wed, Jul 14, 2021 at 02:18:57PM +1000, Dave Chinner wrote: > From: Dave Chinner > > The verifier checks explicitly for bp->b_bn == XFS_SB_DADDR to match > the primary superblock buffer, but the primary superblock is an > uncached buffer and so bp->b_bn is always -1ULL. Hence this never > matches and the CRC error reporting is wholly dependent on the > mount superblock already being populated so CRC feature checks pass > and allow CRC errors to be reported. > > Fix this so that the primary superblock CRC error reporting is not > dependent on already having read the superblock into memory. > > Signed-off-by: Dave Chinner > --- > fs/xfs/libxfs/xfs_sb.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/fs/xfs/libxfs/xfs_sb.c b/fs/xfs/libxfs/xfs_sb.c > index 04f5386446db..4a4586bd2ba2 100644 > --- a/fs/xfs/libxfs/xfs_sb.c > +++ b/fs/xfs/libxfs/xfs_sb.c > @@ -636,7 +636,7 @@ xfs_sb_read_verify( > > if (!xfs_buf_verify_cksum(bp, XFS_SB_CRC_OFF)) { > /* Only fail bad secondaries on a known V5 filesystem */ > - if (bp->b_bn == XFS_SB_DADDR || > + if (bp->b_maps[0].bm_bn == XFS_SB_DADDR || I did not know that b_bn only applies to cached buffers. Would you mind ... I dunno, updating the comment in the struct xfs_buf declaration to make this clearer? /* * Block number of buffer, when this buffer is cached. For * uncached buffers, only the buffer map (i.e. b_maps[0].bm_bn) * contains the block number. */ xfs_daddr_t b_bn; With that changed, this looks reasonable to me. Reviewed-by: Darrick J. Wong --D > xfs_sb_version_hascrc(&mp->m_sb)) { > error = -EFSBADCRC; > goto out_error; > -- > 2.31.1 >