On Mon, Nov 5, 2018 at 7:57 PM Amir Goldstein <amir73il@xxxxxxxxx> wrote:
>
> On Sat, Nov 3, 2018 at 7:15 PM Amir Goldstein <amir73il@xxxxxxxxx> wrote:
> >
> > From: Brian Foster <bfoster@xxxxxxxxxx>
> >
> > The truncate transaction does not ever modify the inode btree, but
> > includes an associated log reservation. Update
> > xfs_calc_itruncate_reservation() to remove the reservation
> > associated with inobt updates.
> >
> > [Amir: This commit was merged for kernel v4.16 and a twin commit was
> > merged for xfsprogs v4.16. As a result, a small xfs filesystem
> > formatted with features -m rmapbt=1,reflink=1 using mkfs.xfs
> > version >= v4.16 cannot be mounted with kernel < v4.16.
> >
> > For example, xfstests generic/17{1,2,3} format a small fs and
> > when trying to mount it, they fail with an assert on this very
> > demonic line:
> >
> > XFS (vdc): Log size 3075 blocks too small, minimum size is 3717 blocks
> > XFS (vdc): AAIEEE! Log failed size checks. Abort!
> > XFS: Assertion failed: 0, file: src/linux/fs/xfs/xfs_log.c, line: 666
> >
> > The simple solution for stable kernels is to apply this patch,
> > because mkfs.xfs v4.16 is already in the wild, so we have to
> > assume that xfs filesystems with a "too small" log exist.
> > Regardless, xfsprogs maintainers should also consider reverting
> > the twin patch to stop creating those filesystems for the sake
> > of users with unpatched kernels.]
> >
> > Signed-off-by: Brian Foster <bfoster@xxxxxxxxxx>
> > Reviewed-by: Dave Chinner <dchinner@xxxxxxxxxx>
> > Reviewed-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
> > Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
> > Cc: <stable@xxxxxxxxxxxxxxx> # v4.9+
> > Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx>
> > ---
> >
> > Darrick/Dave,
> >
> > It took me a while to figure out what was going on with my test systems
> > when small test partitions (10G) stopped working with older kernels.
> >
> > Please bless this change for stable and consider the remedie for mkfs.xfs
> > I verified that patch cleanly applies to stable kernels 4.14.y and 4.9.y
> > and that I can mount a filsystem created with new mkfs.xfs.
> >
> > I am now running quick tests on stable 4.14.y with configs 4k, 1k,
> > reflink,reflink+overlay to verify no regressions from this patch.
> >
>
> FYI no regressions detected.
>
> Thoughts?
>
Maybe you'd want to chalk it up to reflink/rmapbt being Experimental
before kernel 4.16? so the change in "minimum log size" is an on-disk format
change prior to removing the Experimental label??
Thanks,
Amir.
