From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from userp2120.oracle.com ([156.151.31.85]:50634 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727478AbeGaBTJ (ORCPT ); Mon, 30 Jul 2018 21:19:09 -0400 Date: Mon, 30 Jul 2018 16:41:38 -0700 From: "Darrick J. Wong" Subject: Re: [PATCH 3/3] xfs: verify icount in superblock write Message-ID: <20180730234138.GS30972@magnolia> References: <153292860880.19274.14533449137039985963.stgit@magnolia> <153292862751.19274.16285578072920087708.stgit@magnolia> <091b2c87-d6d1-e8c5-7ee7-175095252fe8@sandeen.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <091b2c87-d6d1-e8c5-7ee7-175095252fe8@sandeen.net> Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: Eric Sandeen Cc: linux-xfs@vger.kernel.org, Bill O'Donnell On Mon, Jul 30, 2018 at 06:26:29PM -0500, Eric Sandeen wrote: > On 7/30/18 12:30 AM, Darrick J. Wong wrote: > > From: Darrick J. Wong > > > > Add a helper predicate to check the inode count for sanity, then use it > > in the superblock write verifier to inspect sb_icount. > > > > Signed-off-by: Darrick J. Wong > > Reviewed-by: Bill O'Donnell > > --- > > fs/xfs/libxfs/xfs_sb.c | 1 + > > fs/xfs/libxfs/xfs_types.c | 34 ++++++++++++++++++++++++++++++++++ > > fs/xfs/libxfs/xfs_types.h | 1 + > > 3 files changed, 36 insertions(+) > > > > > > diff --git a/fs/xfs/libxfs/xfs_sb.c b/fs/xfs/libxfs/xfs_sb.c > > index 64bc471d57e6..e5972121e82d 100644 > > --- a/fs/xfs/libxfs/xfs_sb.c > > +++ b/fs/xfs/libxfs/xfs_sb.c > > @@ -160,6 +160,7 @@ xfs_validate_sb_write( > > * cases. > > */ > > if (sbp->sb_fdblocks > sbp->sb_dblocks || > > + !xfs_verify_icount(mp, sbp->sb_icount) || > > sbp->sb_ifree > sbp->sb_icount) { > > xfs_warn(mp, "SB summary counter sanity check failed"); > > return -EFSCORRUPTED; > > diff --git a/fs/xfs/libxfs/xfs_types.c b/fs/xfs/libxfs/xfs_types.c > > index 2e2a243cef2e..57f4fd028898 100644 > > --- a/fs/xfs/libxfs/xfs_types.c > > +++ b/fs/xfs/libxfs/xfs_types.c > > @@ -171,3 +171,37 @@ xfs_verify_rtbno( > > { > > return rtbno < mp->m_sb.sb_rblocks; > > } > > + > > +/* Calculate the range of valid icount values. */ > > +static void > > +xfs_icount_range( > > + struct xfs_mount *mp, > > + unsigned long long *min, > > + unsigned long long *max) > > +{ > > + unsigned long long nr_inos = 0; > > + xfs_agnumber_t agno; > > + > > + /* root, rtbitmap, rtsum all live in the first chunk */ > > + *min = XFS_INODES_PER_CHUNK; > > + > > + for (agno = 0; agno < mp->m_sb.sb_agcount; agno++) { > > + xfs_agino_t first, last; > > + > > + xfs_agino_range(mp, agno, &first, &last); > > + nr_inos += last - first + 1; > > + } > > + *max = nr_inos; > > I still think this is more work than we need to do for a verifier, > TBH. > > In practice how far off is this from do_div(dblocks, inodes_per_block) ? > > Oh well. I guess computationally it's pretty cheap... > > > +} > > + > > +/* Sanity-checking of inode counts. */ > > +bool > > +xfs_verify_icount( > > + struct xfs_mount *mp, > > + unsigned long long icount) > > +{ > > + unsigned long long min, max; > > + > > + xfs_icount_range(mp, &min, &max); > > + return icount >= min && icount < max; > > Since you've calculated it down to the very last inode, why is > "= max" out of range? I think that's a bug, will fix. :/ --D > > +} > > diff --git a/fs/xfs/libxfs/xfs_types.h b/fs/xfs/libxfs/xfs_types.h > > index 4055d62f690c..b9e6c89284c3 100644 > > --- a/fs/xfs/libxfs/xfs_types.h > > +++ b/fs/xfs/libxfs/xfs_types.h > > @@ -165,5 +165,6 @@ bool xfs_verify_ino(struct xfs_mount *mp, xfs_ino_t ino); > > bool xfs_internal_inum(struct xfs_mount *mp, xfs_ino_t ino); > > bool xfs_verify_dir_ino(struct xfs_mount *mp, xfs_ino_t ino); > > bool xfs_verify_rtbno(struct xfs_mount *mp, xfs_rtblock_t rtbno); > > +bool xfs_verify_icount(struct xfs_mount *mp, unsigned long long icount); > > > > #endif /* __XFS_TYPES_H__ */ > > -- > To unsubscribe from this list: send the line "unsubscribe linux-xfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html