On Wed, Aug 01, 2018 at 03:49:45PM -0500, Eric Sandeen wrote:
> From: Jeff Mahoney <jeffm@xxxxxxxx>
>
> Commit 051b4e37f5e (mkfs: factor AG alignment) factored out the
> AG alignment code into a separate function. It got rid of
> redundant checks for dswidth != 0 since calc_stripe_factors was
> supposed to guarantee that if dsunit is non-zero dswidth will be
> as well. Unfortunately, there's hardware out there that reports its
> optimal i/o size as larger than the maximum i/o size, which the kernel
> treats as broken and zeros out the optimal i/o size.
>
> To resolve this we can check the topology before consuming it, and
> ignore the bad stripe geometry.
>
> [sandeen: remove guessing heuristic, just warn and ignore bad data.]
>
> Fixes: 051b4e37f5e (mkfs: factor AG alignment)
> Signed-off-by: Jeff Mahoney <jeffm@xxxxxxxx>
> Reviewed-by: Eric Sandeen <sandeen@xxxxxxxxxx>
> Signed-off-by: Eric Sandeen <sandeen@xxxxxxxxxxx>
> ---
>
> so, I rewrote this a bit. I'm not a fan of guessing what the kernel
> really must have meant, becaue next time the root cause may be differnt.
> In other cases we ignore bad geometry, I think we should in this case as
> well. This will also let me go forward with a factored-out geometry checker,
> and for user-specified badness we'll warn and exit, for kernel-provided
> badness we'll warn and ignore.
>
> diff --git a/mkfs/xfs_mkfs.c b/mkfs/xfs_mkfs.c
> index 1074886..2e53c1e 100644
> --- a/mkfs/xfs_mkfs.c
> +++ b/mkfs/xfs_mkfs.c
> @@ -2281,11 +2281,20 @@ _("data stripe width (%d) must be a multiple of the data stripe unit (%d)\n"),
>
> /* if no stripe config set, use the device default */
> if (!dsunit) {
> - dsunit = ft->dsunit;
> - dswidth = ft->dswidth;
> - use_dev = true;
> + /* Ignore nonsense from device. XXX add more validation */
> + if (ft->dsunit && ft->dswidth == 0) {
> + fprintf(stderr,
> +_("%s: Volume reports stripe unit of %d bytes and stripe width of 0, ignoring.\n"),
> + progname, BBTOB(ft->dsunit));
> + ft->dsunit = 0;
> + ft->dswidth = 0;
Not sure this is the right thing to do. If a stripe unit has been
given, then the device has an alignment requirement. If it hasn't
given an "optimal IO size", then shouldn't we just set ft->dswidth =
ft->dsunit to retain the alignment the device requested?
Cheers,
Dave.
--
Dave Chinner
david@xxxxxxxxxxxxx
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