Re: [PATCH 11/20] fuse: implement FUSE_INIT map_alignment field

[Miklos Szeredi]

On Wed, Mar 4, 2020 at 5:59 PM Vivek Goyal <vgoyal@xxxxxxxxxx> wrote:
>
> The device communicates FUSE_SETUPMAPPING/FUSE_REMOVMAPPING alignment
> constraints via the FUST_INIT map_alignment field.  Parse this field and
> ensure our DAX mappings meet the alignment constraints.
>
> We don't actually align anything differently since our mappings are
> already 2MB aligned.  Just check the value when the connection is
> established.  If it becomes necessary to honor arbitrary alignments in
> the future we'll have to adjust how mappings are sized.
>
> The upshot of this commit is that we can be confident that mappings will
> work even when emulating x86 on Power and similar combinations where the
> host page sizes are different.
>
> Signed-off-by: Stefan Hajnoczi <stefanha@xxxxxxxxxx>
> Signed-off-by: Vivek Goyal <vgoyal@xxxxxxxxxx>

Reviewed-by: Miklos Szeredi <mszeredi@xxxxxxxxxx>