kern/60024: zfs mount overrides zfs properties like "readonly"

["imuwoto%gmail.com@localhost via gnats" <gnats-admin%NetBSD.org@localhost>]

>Number:         60024
>Category:       kern
>Synopsis:       zfs mount overrides zfs properties like "readonly"
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sat Feb 21 10:10:00 +0000 2026
>Originator:     YAMAMOTO Takashi
>Release:        NetBSD 10.1
>Organization:
>Environment:
amd64
>Description:
see the following example, where readonly=on property is
somehow disabled by a re-mount.

uma# zfs set readonly=on y/tmp
uma# zfs get readonly y/tmp
NAME   PROPERTY  VALUE   SOURCE
y/tmp  readonly  on      local
uma# zfs umount y/tmp
uma# zfs get readonly y/tmp
NAME   PROPERTY  VALUE   SOURCE
y/tmp  readonly  on      local
uma# zfs mount y/tmp      
uma# zfs get readonly y/tmp
NAME   PROPERTY  VALUE   SOURCE
y/tmp  readonly  off     temporary
uma# 
>How-To-Repeat:

>Fix:
i'm testing this: https://github.com/yamt/netbsd-src/commit/1ba3ad1c41aa1a43de794d27ffaeb817ad58a3c1