PR/60024 CVS commit: src/external/cddl/osnet/sys/kern

["YAMAMOTO Takashi" <yamt%netbsd.org@localhost>]

The following reply was made to PR kern/60024; it has been noted by GNATS.

From: "YAMAMOTO Takashi" <yamt%netbsd.org@localhost>
To: gnats-bugs%gnats.NetBSD.org@localhost
Cc: 
Subject: PR/60024 CVS commit: src/external/cddl/osnet/sys/kern
Date: Sun, 1 Mar 2026 13:52:29 +0000

 Module Name:	src
 Committed By:	yamt
 Date:		Sun Mar  1 13:52:29 UTC 2026
 
 Modified Files:
 	src/external/cddl/osnet/sys/kern: vfs.c
 
 Log Message:
 solaris vfs_optionisset: treat 0 as unspecified
 
 this allows users to leave it default.
 
 before this change, when a user runs "zfs mount -a",
 it was processed as "mount them read-write, overriding readonly property".
 i don't think it's what the user usually intends.
 
 looking at the illumos code, it seems that mount options there are
 basically tri-state. that is, "ro", "rw", and unspecified.
 as NetBSD only has a single bit, MNT_RDONLY or !MNT_RDONLY, this commit
 maps !MNT_RDONLY to unspecified, which i believe more often matches
 the user's intention. it also seems like what illumos does for the legacy
 MS_RDONLY bit if i read their code correctly. that is, if MS_RDONLY is set,
 it sets MNTOPT_RO. on the other hand, a lack of MS_RDONLY doesn't imply
 MNTOPT_RW.
 
 references:
 "Temporary Mount Point Properties" section of zfs(8)
 
 PR/60024
 https://gnats.netbsd.org/60024
 
 
 To generate a diff of this commit:
 cvs rdiff -u -r1.9 -r1.10 src/external/cddl/osnet/sys/kern/vfs.c
 
 Please note that diffs are not public domain; they are subject to the
 copyright notices on the relevant files.