From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay3.corp.sgi.com [198.149.34.15]) by oss.sgi.com (Postfix) with ESMTP id 93D4C7F58 for ; Thu, 24 Jul 2014 17:46:33 -0500 (CDT) Received: from cuda.sgi.com (cuda1.sgi.com [192.48.157.11]) by relay3.corp.sgi.com (Postfix) with ESMTP id 2DDE4AC005 for ; Thu, 24 Jul 2014 15:46:32 -0700 (PDT) Received: from ipmail05.adl6.internode.on.net (ipmail05.adl6.internode.on.net [150.101.137.143]) by cuda.sgi.com with ESMTP id G3145LhP74Go5AT5 for ; Thu, 24 Jul 2014 15:46:30 -0700 (PDT) Date: Fri, 25 Jul 2014 08:46:28 +1000 From: Dave Chinner Subject: Re: [PATCH 10/18] xfs: set sparse inodes feature bit when a sparse chunk is allocated Message-ID: <20140724224628.GS20518@dastard> References: <1406211788-63206-1-git-send-email-bfoster@redhat.com> <1406211788-63206-11-git-send-email-bfoster@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1406211788-63206-11-git-send-email-bfoster@redhat.com> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com To: Brian Foster Cc: xfs@oss.sgi.com On Thu, Jul 24, 2014 at 10:23:00AM -0400, Brian Foster wrote: > The sparse chunk inode record format is backwards compatible with old > format inobt records as long as full chunks are allocated. The holemask > field uses higher order bytes of the freecount. While sparse chunks can > be enabled on previously unsupported fs, older kernel drivers cannot > parse sparse inode records. > > Set the feature incompatible bit once a sparse inode chunk is allocated > to prevent older XFS drivers from tripping over the new format. > > Signed-off-by: Brian Foster > --- > fs/xfs/libxfs/xfs_ialloc.c | 33 +++++++++++++++++++++++++++++++++ > 1 file changed, 33 insertions(+) > > diff --git a/fs/xfs/libxfs/xfs_ialloc.c b/fs/xfs/libxfs/xfs_ialloc.c > index 4226b1b..4dd45c2 100644 > --- a/fs/xfs/libxfs/xfs_ialloc.c > +++ b/fs/xfs/libxfs/xfs_ialloc.c > @@ -407,6 +407,27 @@ error: > return error; > } > > +STATIC void > +xfs_sbversion_add_spinodes( > + struct xfs_trans *tp, > + struct xfs_mount *mp) > +{ > + if (xfs_sb_has_incompat_log_feature(&mp->m_sb, > + XFS_SB_FEAT_INCOMPAT_SPINODES)) wrong function. xfs_sb_has_incompat_feature(). > + return; > + > + spin_lock(&mp->m_sb_lock); > + if (xfs_sb_has_incompat_log_feature(&mp->m_sb, > + XFS_SB_FEAT_INCOMPAT_SPINODES)) { > + spin_unlock(&mp->m_sb_lock); > + return; > + } > + > + mp->m_sb.sb_features_incompat |= XFS_SB_FEAT_INCOMPAT_SPINODES; > + spin_unlock(&mp->m_sb_lock); > + xfs_mod_sb(tp, XFS_SB_FEATURES_INCOMPAT); > +} > + > /* > * Allocate new inodes in the allocation group specified by agbp. > * Return 0 for success, else error code. > @@ -631,6 +652,18 @@ xfs_ialloc_ag_alloc( > if (error) > return error; > } > + > + /* > + * Set an incompat feature bit as old drivers can't parse sparse > + * records. Pre-sparse inode chunk drivers will include the > + * holemask in the higher order freecount bits, resulting in a > + * bogus value. > + * > + * XXX: when is this bit removed? > + */ > + if (xfs_inobt_issparse(&rec)) > + xfs_sbversion_add_spinodes(tp, args.mp); I'd like to avoid this dynamic feature bit adding if possible. Do we really need it? Cheers, Dave. -- Dave Chinner david@fromorbit.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs