When mounting with "modefromsid" set mode bits (chmod) by
    adding ACE with special SID (S-1-5-88-3-<mode>) to the ACL.
    Subsequent patch will fix setting default mode on file
    create and mkdir.

    See See e.g.
        https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2008-R2-and-2008/hh509017(v=ws.10)

An example:

# touch /mnt-to-windows/newfile0754

# chmod 0754 /mnt-to-windows/newfile0754

# stat /mnt-to-windows/newfile0754
  File: /mnt-to-windows/newfile0754
  Size: 0          Blocks: 0          IO Block: 1048576 regular empty file
Device: 33h/51d Inode: 3659174697263184  Links: 1
Access: (0754/-rwxr-xr--)  Uid: (    0/    root)   Gid: (    0/    root)
Access: 2019-07-19 08:21:14.970287500 +0000
Modify: 2019-07-19 08:21:14.970287500 +0000
Change: 2019-07-19 08:21:25.665086200 +0000

(Notice the last ACE which has the mode bits embedded, 492 decimal is
0754 octal)

# getcifsacl /mnt-to-windows/newfile0754
REVISION:0x1
CONTROL:0x8004
OWNER:S-1-5-32-544
GROUP:S-1-5-21-3447553893-1265514152-1435875098-513
ACL:S-1-5-32-544:ALLOWED/0x0/FULL
ACL:S-1-5-21-3447553893-1265514152-1435875098-513:ALLOWED/0x0/0x1f01b9
ACL:S-1-1-0:ALLOWED/0x0/0x1f0199
ACL:S-1-5-88-3-492:DENIED/0x0/

-- 
Thanks,

Steve