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

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

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.