Linux kernel 6.3 changed a bunch of APIs to use the dedicated idmap
type for mounts (struct mnt_idmap), we need to detect these changes
and make zfs work with the new APIs.
NOTE: This backport only includes the configure checks to detect
the 6.3 idmap API changes. It does not include support for idmap.
When provided the idmap variable is ignored in most case in the
same way the user_ns argument was ignored. This change is solely
to provide compatibility with the new interfaces.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Youzhong Yang <yyang@mathworks.com>
Closes#14682