Re: [RFC PATCH] fstests: test fix for an agbno overflow in __xfs_getfsmap_datadev

[Dave Chinner <david@fromorbit.com>]

On Sun, Aug 27, 2023 at 08:56:46AM -0700, Darrick J. Wong wrote:
> On Sun, Aug 27, 2023 at 09:06:44PM +0800, Zorro Lang wrote:
> > On Tue, Aug 22, 2023 at 06:02:39PM -0700, Darrick J. Wong wrote:
> > > From: Darrick J. Wong <djwong@kernel.org>
> > > 
> > > Dave Chinner reported that xfs/273 fails if the AG size happens to be an
> > > exact power of two.  I traced this to an agbno integer overflow when the
> > > current GETFSMAP call is a continuation of a previous GETFSMAP call, and
> > > the last record returned was non-shareable space at the end of an AG.
> > > 
> > > This is the regression test for that bug.
> > > 
> > > Signed-off-by: Darrick J. Wong <djwong@kernel.org>
.....
> > > +echo "desired asize=$desired_agsize" >> $seqres.full
> > > +_scratch_mkfs -d "agsize=${desired_agsize}b" | _filter_mkfs 2> $tmp.mkfs >> $seqres.full
> > > +source $tmp.mkfs
> > > +
> > > +test "$desired_agsize" -eq "$agsize" || _notrun "wanted agsize=$desired_agsize, got $agsize"
> > > +
> > > +_scratch_mount
> > > +$XFS_IO_PROG -c 'fsmap -n 1024 -v' $SCRATCH_MNT >> $tmp.big
> > > +$XFS_IO_PROG -c 'fsmap -n 1 -v' $SCRATCH_MNT >> $tmp.small
> > 
> > This line reports:
> > 
> >   xfs_io: xfsctl(XFS_IOC_GETFSMAP) iflags=0x0 ["/mnt/xfstests/scratch"]: Invalid argument
> > 
> > when the test case fails. Is that normal?
> 
> Yes.  The attached bugfix should make that go away.

The kernel bug fix fixes the same problem with xfs/273; I haven't
tested this specific new regression test.

-Dave.
-- 
Dave Chinner
david@fromorbit.com