On Wed, Jul 13, 2022 at 08:17:22PM -0500, Eric Sandeen wrote:
> On 7/12/22 8:09 PM, Darrick J. Wong wrote:
> > From: Darrick J. Wong <djwong@xxxxxxxxxx>
> >
> > xfs/042 trips over an impossible fs geometry when nrext64 is enabled.
> > The minimum log size calculation comes out to 4287 blocks, but the mkfs
> > parameters specify an AG size of 4096 blocks. This eventually causes
> > mkfs to complain that the autoselected log size doesn't meet the minimum
> > size, but we could be a little more explicit in pointing out that the
> > two size constraints make for an impossible geometry.
> >
> > Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx>
> > ---
> > mkfs/xfs_mkfs.c | 7 +++++++
> > 1 file changed, 7 insertions(+)
> >
> >
> > diff --git a/mkfs/xfs_mkfs.c b/mkfs/xfs_mkfs.c
> > index db322b3a..61ac1a4a 100644
> > --- a/mkfs/xfs_mkfs.c
> > +++ b/mkfs/xfs_mkfs.c
> > @@ -3401,6 +3401,13 @@ _("external log device size %lld blocks too small, must be at least %lld blocks\
> > * an AG.
> > */
> > max_logblocks = libxfs_alloc_ag_max_usable(mp) - 1;
> > + if (max_logblocks < min_logblocks) {
> > + fprintf(stderr,
> > +_("max log size %d smaller than min log size %d\n"),
>
> And when the user sees this, they will know that they should ___________ ?
I dunno, ask for creating a bigger filesystem?
It's better than "log size 4083 blocks too small, minimum size is 4287
blocks", which hides the part where we autoselected 4083 blocks because
that's max_logblocks.
/me would suggest pulling in the no tiny fs patch, which will at least
fail the cases where the user wants tiny AGs but the featureset wants a
big log with "your fs is too small".
I haven't gotten around to playing with raid stripe size variations yet
though, so I don't know if this problem will come back with (say) a 301M
filesystem and a giant RAID stripe.
--D
> > + max_logblocks,
> > + min_logblocks);
> > + usage();
> > + }
> >
> > /* internal log - if no size specified, calculate automatically */
> > if (!cfg->logblocks) {
> >
