Re: install/56890: sysinst should ignore default labeleveninDISKLABEL_NO_ONDISK_VERIFY case

[Izumi Tsutsui <tsutsui%ceres.dti.ne.jp@localhost>]

The following reply was made to PR install/56890; it has been noted by GNATS.

From: Izumi Tsutsui <tsutsui%ceres.dti.ne.jp@localhost>
To: martin%duskware.de@localhost
Cc: gnats-bugs%netbsd.org@localhost, tsutsui%ceres.dti.ne.jp@localhost
Subject: Re: install/56890: sysinst should ignore default labeleveninDISKLABEL_NO_ONDISK_VERIFY
	 case
Date: Fri, 24 Jun 2022 01:39:26 +0900

 > > Note several ports (including x68k) support both a BSD disklabel
 > > and port specific native OS derived label, so a check by disklabel -r
 > > might still be worth to try even in DISKLABEL_NO_ONDISK_VERIFY case.
 > 
 > Doesn't the kernel deal with both cases then? What would the additional
 > "disklabel -r" return code buy us?
 
 I'm not sure what's your point, but
 
 - disklabel(8) -r doesn't use ioctl(2) but just try to read BSD disklabel
   at LABELSECTOR directly via opendisk(3)
    https://nxr.netbsd.org/xref/src/sbin/disklabel/main.c?r=1.57#1208
 
 - x68k readdisklabel(9) via DIOCGDINFO checks BSD disklabel at LABELSECTOR
   first and if not found then checks Human68k partition
    https://nxr.netbsd.org/xref/src/sys/arch/x68k/x68k/disksubr.c?r=1.36#63
 
 So the former could return success (and could also fail) on x68k and
 we don't have to bother to check the latter ("looks like the default")
 if the former is valid.
 
 ---
 Izumi Tsutsui