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=-8.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 47EEDC7CFDC for ; Fri, 13 Dec 2019 20:39:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7B8EA247E5 for ; Fri, 13 Dec 2019 20:39:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="B2eYy5YP" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728485AbfLMRpf (ORCPT ); Fri, 13 Dec 2019 12:45:35 -0500 Received: from us-smtp-2.mimecast.com ([207.211.31.81]:58266 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728012AbfLMRpf (ORCPT ); Fri, 13 Dec 2019 12:45:35 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1576259133; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=YlnU8fYcIUYj/+C3C8/AIKtjj0JFSB5QA7qT3Q7CYrA=; b=B2eYy5YP9N29A83MzRc8lMlizVRBkMQxQSlvPs+rrllxx5/elT+qAIOLfWe/jLWZuvRIWq mleeRauH77b0gNgNuZWVD9WXWPecw9nTI28Gs4uxsNHw0LJdSZ7YubY3ShSTFex8h60UN2 MgpX/oc0D2lzgUoP9FKVwJvOi6n6ofA= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-223-BmBa7jtsMsCfmnJgQV305A-1; Fri, 13 Dec 2019 12:45:29 -0500 X-MC-Unique: BmBa7jtsMsCfmnJgQV305A-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id E8EB1911E8; Fri, 13 Dec 2019 17:45:27 +0000 (UTC) Received: from bfoster (dhcp-41-2.bos.redhat.com [10.18.41.2]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 643F019C4F; Fri, 13 Dec 2019 17:45:27 +0000 (UTC) Date: Fri, 13 Dec 2019 12:45:26 -0500 From: Brian Foster To: "Darrick J. Wong" Cc: xfs , Alex Lyakas , Dave Chinner Subject: Re: [PATCH v2] xfs: don't commit sunit/swidth updates to disk if that would cause repair failures Message-ID: <20191213174526.GH43376@bfoster> References: <20191213161349.GH99875@magnolia> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191213161349.GH99875@magnolia> User-Agent: Mutt/1.12.1 (2019-06-15) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Sender: linux-xfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org On Fri, Dec 13, 2019 at 08:13:49AM -0800, Darrick J. Wong wrote: > From: Darrick J. Wong > > Alex Lyakas reported[1] that mounting an xfs filesystem with new sunit > and swidth values could cause xfs_repair to fail loudly. The problem > here is that repair calculates the where mkfs should have allocated the > root inode, based on the superblock geometry. The allocation decisions > depend on sunit, which means that we really can't go updating sunit if > it would lead to a subsequent repair failure on an otherwise correct > filesystem. > > Port from xfs_repair some code that computes the location of the root > inode and teach mount to skip the ondisk update if it would cause > problems for repair. Along the way we'll update the documentation, > provide a function for computing the minimum AGFL size instead of > open-coding it, and cut down some indenting in the mount code. > > Note that we allow the mount to proceed (and new allocations will > reflect this new geometry) because we've never screened this kind of > thing before. We'll have to wait for a new future incompat feature to > enforce correct behavior, alas. > > Note that the geometry reporting always uses the superblock values, not > the incore ones, so that is what xfs_info and xfs_growfs will report. > > [1] https://lore.kernel.org/linux-xfs/20191125130744.GA44777@bfoster/T/#m00f9594b511e076e2fcdd489d78bc30216d72a7d > > Reported-by: Alex Lyakas > Signed-off-by: Darrick J. Wong > --- > v2: refactor the agfl length calculations, clarify the fsgeometry ioctl > behavior, fix a bunch of the comments and make it clearer how we compute > the rootino location > --- > fs/xfs/libxfs/xfs_alloc.c | 18 ++++++--- > fs/xfs/libxfs/xfs_ialloc.c | 70 ++++++++++++++++++++++++++++++++++ > fs/xfs/libxfs/xfs_ialloc.h | 1 > fs/xfs/xfs_mount.c | 90 ++++++++++++++++++++++++++++++-------------- > fs/xfs/xfs_trace.h | 21 ++++++++++ > 5 files changed, 166 insertions(+), 34 deletions(-) > ... > diff --git a/fs/xfs/libxfs/xfs_ialloc.h b/fs/xfs/libxfs/xfs_ialloc.h > index 323592d563d5..72b3468b97b1 100644 > --- a/fs/xfs/libxfs/xfs_ialloc.h > +++ b/fs/xfs/libxfs/xfs_ialloc.h ... > @@ -398,28 +431,26 @@ xfs_update_alignment(xfs_mount_t *mp) > } > } > > - /* > - * Update superblock with new values > - * and log changes > - */ > - if (xfs_sb_version_hasdalign(sbp)) { > - if (sbp->sb_unit != mp->m_dalign) { > - sbp->sb_unit = mp->m_dalign; > - mp->m_update_sb = true; > - } > - if (sbp->sb_width != mp->m_swidth) { > - sbp->sb_width = mp->m_swidth; > - mp->m_update_sb = true; > - } > - } else { > + /* Update superblock with new values and log changes. */ > + if (!xfs_sb_version_hasdalign(sbp)) { > xfs_warn(mp, > "cannot change alignment: superblock does not support data alignment"); > return -EINVAL; > } > + > + if (sbp->sb_unit == mp->m_dalign && > + sbp->sb_width == mp->m_swidth) > + return 0; > + > + xfs_check_new_dalign(mp, mp->m_dalign); > + > + sbp->sb_unit = mp->m_dalign; > + sbp->sb_width = mp->m_swidth; > + mp->m_update_sb = true; Isn't this supposed to conditionally update the superblock based on the rootino calculation? Brian > } else if ((mp->m_flags & XFS_MOUNT_NOALIGN) != XFS_MOUNT_NOALIGN && > xfs_sb_version_hasdalign(&mp->m_sb)) { > - mp->m_dalign = sbp->sb_unit; > - mp->m_swidth = sbp->sb_width; > + mp->m_dalign = sbp->sb_unit; > + mp->m_swidth = sbp->sb_width; > } > > return 0; > @@ -647,16 +678,6 @@ xfs_mountfs( > mp->m_update_sb = true; > } > > - /* > - * Check if sb_agblocks is aligned at stripe boundary > - * If sb_agblocks is NOT aligned turn off m_dalign since > - * allocator alignment is within an ag, therefore ag has > - * to be aligned at stripe boundary. > - */ > - error = xfs_update_alignment(mp); > - if (error) > - goto out; > - > xfs_alloc_compute_maxlevels(mp); > xfs_bmap_compute_maxlevels(mp, XFS_DATA_FORK); > xfs_bmap_compute_maxlevels(mp, XFS_ATTR_FORK); > @@ -664,6 +685,17 @@ xfs_mountfs( > xfs_rmapbt_compute_maxlevels(mp); > xfs_refcountbt_compute_maxlevels(mp); > > + /* > + * Check if sb_agblocks is aligned at stripe boundary. If sb_agblocks > + * is NOT aligned turn off m_dalign since allocator alignment is within > + * an ag, therefore ag has to be aligned at stripe boundary. Note that > + * we must compute the free space and rmap btree geometry before doing > + * this. > + */ > + error = xfs_update_alignment(mp); > + if (error) > + goto out; > + > /* enable fail_at_unmount as default */ > mp->m_fail_unmount = true; > > diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h > index c13bb3655e48..a86be7f807ee 100644 > --- a/fs/xfs/xfs_trace.h > +++ b/fs/xfs/xfs_trace.h > @@ -3573,6 +3573,27 @@ DEFINE_KMEM_EVENT(kmem_alloc_large); > DEFINE_KMEM_EVENT(kmem_realloc); > DEFINE_KMEM_EVENT(kmem_zone_alloc); > > +TRACE_EVENT(xfs_check_new_dalign, > + TP_PROTO(struct xfs_mount *mp, int new_dalign, xfs_ino_t calc_rootino), > + TP_ARGS(mp, new_dalign, calc_rootino), > + TP_STRUCT__entry( > + __field(dev_t, dev) > + __field(int, new_dalign) > + __field(xfs_ino_t, sb_rootino) > + __field(xfs_ino_t, calc_rootino) > + ), > + TP_fast_assign( > + __entry->dev = mp->m_super->s_dev; > + __entry->new_dalign = new_dalign; > + __entry->sb_rootino = mp->m_sb.sb_rootino; > + __entry->calc_rootino = calc_rootino; > + ), > + TP_printk("dev %d:%d new_dalign %d sb_rootino %llu calc_rootino %llu", > + MAJOR(__entry->dev), MINOR(__entry->dev), > + __entry->new_dalign, __entry->sb_rootino, > + __entry->calc_rootino) > +) > + > #endif /* _TRACE_XFS_H */ > > #undef TRACE_INCLUDE_PATH >