cifs: allow chmod to set mode bits using special sid

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)

Signed-off-by: Steve French <stfrench@microsoft.com>

fs/cifs/inode.c

@@ -2489,7 +2489,8 @@ cifs_setattr_nounix(struct dentry *direntry, struct iattr *attrs)
 	if (attrs->ia_valid & ATTR_GID)
 		gid = attrs->ia_gid;
 
-	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL) {
+	if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL) ||
+	    (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MODE_FROM_SID)) {
 		if (uid_valid(uid) || gid_valid(gid)) {
 			rc = id_mode_to_cifs_acl(inode, full_path, NO_CHANGE_64,
 							uid, gid);
@@ -2510,7 +2511,8 @@ cifs_setattr_nounix(struct dentry *direntry, struct iattr *attrs)
 	if (attrs->ia_valid & ATTR_MODE) {
 		mode = attrs->ia_mode;
 		rc = 0;
-		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL) {
+		if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL) ||
+		    (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MODE_FROM_SID)) {
 			rc = id_mode_to_cifs_acl(inode, full_path, mode,
 						INVALID_UID, INVALID_GID);
 			if (rc) {