cifs: add IOCTL for QUERY_INFO passthrough to userspace

This allows userspace tools to query the raw info levels for cifs files
and process the response in userspace.
In particular this is useful for many of those data where there is no
corresponding native data structure in linux.
For example querying the security descriptor for a file and extract the
SIDs.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
7 files changed