cifs: improve checking of DFS links over STATUS_OBJECT_NAME_INVALID
Do not map STATUS_OBJECT_NAME_INVALID to -EREMOTE under non-DFS
shares, or 'nodfs' mounts or CONFIG_CIFS_DFS_UPCALL=n builds.
Otherwise, in the slow path, get a referral to figure out whether it
is an actual DFS link.
This could be simply reproduced under a non-DFS share by running the
following
$ mount.cifs //srv/share /mnt -o ...
$ cat /mnt/$(printf '\U110000')
cat: '/mnt/'$'\364\220\200\200': Object is remote
Fixes:
c877ce47e137 ("cifs: reduce roundtrips on create/qinfo requests")
CC: stable@vger.kernel.org # 6.2
Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>