From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda3.sgi.com [192.48.176.15]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id o2BMfEss194491 for ; Thu, 11 Mar 2010 16:41:14 -0600 Received: from mail.internode.on.net (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id 3A3111D2DEB9 for ; Thu, 11 Mar 2010 14:42:46 -0800 (PST) Received: from mail.internode.on.net (bld-mail16.adl2.internode.on.net [150.101.137.101]) by cuda.sgi.com with ESMTP id MOj1wJpAPD49VnLt for ; Thu, 11 Mar 2010 14:42:45 -0800 (PST) From: Dave Chinner Subject: [PATCH 16/19] xfs: don't hold onto reserved blocks on remount,ro Date: Fri, 12 Mar 2010 09:42:14 +1100 Message-Id: <1268347337-7160-17-git-send-email-david@fromorbit.com> In-Reply-To: <1268347337-7160-1-git-send-email-david@fromorbit.com> References: <1268347337-7160-1-git-send-email-david@fromorbit.com> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: stable@kernel.org Cc: xfs@oss.sgi.com >>From cbe132a8bdcff0f9afd9060948fb50597c7400b8 Date: Tue, 26 Jan 2010 15:08:49 +1100 If we hold onto reserved blocks when doing a remount,ro we end up writing the blocks used count to disk that includes the reserved blocks. Reserved blocks are not actually used, so this results in the values in the superblock being incorrect. Hence if we run xfs_check or xfs_repair -n while the filesystem is mounted remount,ro we end up with an inconsistent filesystem being reported. Also, running xfs_copy on the remount,ro filesystem will result in an inconsistent image being generated. To fix this, unreserve the blocks when doing the remount,ro, and reserved them again on remount,rw. This way a remount,ro filesystem will appear consistent on disk to all utilities. Signed-off-by: Dave Chinner Reviewed-by: Christoph Hellwig --- fs/xfs/linux-2.6/xfs_super.c | 28 ++++++++++++++++++++++++++++ fs/xfs/xfs_mount.h | 1 + 2 files changed, 29 insertions(+), 0 deletions(-) diff --git a/fs/xfs/linux-2.6/xfs_super.c b/fs/xfs/linux-2.6/xfs_super.c index ea7a59a..aae1249 100644 --- a/fs/xfs/linux-2.6/xfs_super.c +++ b/fs/xfs/linux-2.6/xfs_super.c @@ -1323,6 +1323,8 @@ xfs_fs_remount( /* ro -> rw */ if ((mp->m_flags & XFS_MOUNT_RDONLY) && !(*flags & MS_RDONLY)) { + __uint64_t resblks; + mp->m_flags &= ~XFS_MOUNT_RDONLY; if (mp->m_flags & XFS_MOUNT_BARRIER) xfs_mountfs_check_barriers(mp); @@ -1340,11 +1342,37 @@ xfs_fs_remount( } mp->m_update_flags = 0; } + + /* + * Fill out the reserve pool if it is empty. Use the stashed + * value if it is non-zero, otherwise go with the default. + */ + if (mp->m_resblks_save) { + resblks = mp->m_resblks_save; + mp->m_resblks_save = 0; + } else { + resblks = mp->m_sb.sb_dblocks; + do_div(resblks, 20); + resblks = min_t(__uint64_t, resblks, 1024); + } + xfs_reserve_blocks(mp, &resblks, NULL); } /* rw -> ro */ if (!(mp->m_flags & XFS_MOUNT_RDONLY) && (*flags & MS_RDONLY)) { + /* + * After we have synced the data but before we sync the + * metadata, we need to free up the reserve block pool so that + * the used block count in the superblock on disk is correct at + * the end of the remount. Stash the current reserve pool size + * so that if we get remounted rw, we can return it to the same + * size. + */ + __uint64_t resblks = 0; + xfs_quiesce_data(mp); + mp->m_resblks_save = mp->m_resblks; + xfs_reserve_blocks(mp, &resblks, NULL); xfs_quiesce_attr(mp); mp->m_flags |= XFS_MOUNT_RDONLY; } diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h index a6c023b..1e6094f 100644 --- a/fs/xfs/xfs_mount.h +++ b/fs/xfs/xfs_mount.h @@ -209,6 +209,7 @@ typedef struct xfs_mount { __uint64_t m_maxioffset; /* maximum inode offset */ __uint64_t m_resblks; /* total reserved blocks */ __uint64_t m_resblks_avail;/* available reserved blocks */ + __uint64_t m_resblks_save; /* reserved blks @ remount,ro */ int m_dalign; /* stripe unit */ int m_swidth; /* stripe width */ int m_sinoalign; /* stripe unit inode alignment */ -- 1.6.5 _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs