[PATCH 4/5] mountmgr.sys: Add the ability to query filesystem attributes on a file handle.

[Erich E. Hoover]

On Wed, Mar 24, 2021 at 10:59 AM Alexandre Julliard <julliard at winehq.org> wrote:
>
> "Zebediah Figura (she/her)" <zfigura at codeweavers.com> writes:
>
> > On 3/18/21 11:54 AM, Erich E. Hoover wrote:
> >> @@ -2019,6 +2057,30 @@ NTSTATUS query_volume( void *buff, SIZE_T insize, SIZE_T outsize, IO_STATUS_BLOC
> >>      }
> >>      LeaveCriticalSection( &device_section );
> >>  +    if (!volume && input->info_class ==
> >> FileFsAttributeInformation)
> >> +    {
> >> +        enum fs_type fs_type = FS_UNKNOWN;
> >> +        HANDLE hProcess, handle;
> >> +        BOOL ret;
> >> +        int fd;
> >> +
> >> +        if (!(hProcess = OpenProcess( PROCESS_DUP_HANDLE, FALSE, input->process )))
> >> +            return status;
> >
> > This is right, but it looks wrong. I'd recommend returning early in
> > the if (volume) block, and explicitly returning STATUS_NO_SUCH_DEVICE
> > instead of initializing it at the top.
>
> Actually I don't think mountmgr has any business resolving client
> handles itself. There has to be a better way.

There are a couple other ways that I can see:
1) duplicate the handle on the calling end
2) call fstatfs() on the calling end and send the appropriate
"fallback" fs_type for the mountmgr to decode

Do either of these sound good to you?

Best,
Erich