Re: [PATCH v3 1/2] fs: add the ability for statmount() to report the fs_subtype

[Miklos Szeredi]

On Mon, 11 Nov 2024 at 12:28, Jeff Layton <jlayton@xxxxxxxxxx> wrote:

> As far as I can tell, the existing cases in statmount_string() either
> always emit a string or an error code. If a string isn't emitted, then
> the two EOVERFLOW cases and the EAGAIN case can't happen, so I don't
> think this will result in any change in behavior for the existing code.

Both mnt_point and mnt_opts can be empty.

> The idea for statmount() was to add a statx() like interface. This is
> exactly how statx() works, so I don't think it ought to be any sort of
> surprise to anyone.

Maybe, but silently changing the interface is not okay.  At least make
it a separate patch.

> That said, if we did want to add a way to detect what flags are
> actually supported, we could just add a new STATMOUNT_SUPPORTED_FLAGS
> flag and add a field that holds a returned mask with all of the bits
> set that the kernel supports.

Yeah, that makes sense.

Thanks,
Miklos