Skip site navigation (1)Skip section navigation (2)
Date:      Fri, 8 Mar 2024 22:07:07 -0700
From:      Warner Losh <imp@bsdimp.com>
To:        Jamie Landeg-Jones <jamie@catflap.org>
Cc:        current@freebsd.org, Alexander@leidinger.net
Subject:   Re: Reason why "nocache" option is not displayed in "mount"?
Message-ID:  <CANCZdfq2Z30jgh6Wt9Set=fZ271qr42Thy73YOxF=bh04R6Bfg@mail.gmail.com>
In-Reply-To: <202403072005.427K58KX014923@donotpassgo.dyslexicfish.net>
References:  <09bb45dea82d96c11f34cc48dda540dc@Leidinger.net> <202403072005.427K58KX014923@donotpassgo.dyslexicfish.net>

next in thread | previous in thread | raw e-mail | index | archive | help
--000000000000661900061333488d
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

On Thu, Mar 7, 2024 at 1:05=E2=80=AFPM Jamie Landeg-Jones <jamie@catflap.or=
g> wrote:

> Alexander Leidinger <Alexander@Leidinger.net> wrote:
>
> > Hi,
> >
> > what is the reason why "nocache" is not displayed in the output of
> > "mount" for nullfs options?
>
> Good catch. I also notice that "hidden" is not shown either.
>
> I guess that as for some time, "nocache" was a "secret" option, no-one
> update "mount" to display it?
>

So a couple of things to know.

First, there's a list of known options. These are converted to a bitmask.
This is then decoded and reported by mount. The other strings are passed to
the filesystem directly. They decode it and do things, but they don't
export them (that I can find). I believe that's why they aren't reported
with 'mount'. There's a couple of other options in /etc/fstab that are
pseudo options too.

Warner

--000000000000661900061333488d
Content-Type: text/html; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

<div dir=3D"ltr"><div dir=3D"ltr"><br></div><br><div class=3D"gmail_quote">=
<div dir=3D"ltr" class=3D"gmail_attr">On Thu, Mar 7, 2024 at 1:05=E2=80=AFP=
M Jamie Landeg-Jones &lt;<a href=3D"mailto:jamie@catflap.org">jamie@catflap=
.org</a>&gt; wrote:<br></div><blockquote class=3D"gmail_quote" style=3D"mar=
gin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1=
ex">Alexander Leidinger &lt;Alexander@Leidinger.net&gt; wrote:<br>
<br>
&gt; Hi,<br>
&gt;<br>
&gt; what is the reason why &quot;nocache&quot; is not displayed in the out=
put of <br>
&gt; &quot;mount&quot; for nullfs options?<br>
<br>
Good catch. I also notice that &quot;hidden&quot; is not shown either.<br>
<br>
I guess that as for some time, &quot;nocache&quot; was a &quot;secret&quot;=
 option, no-one<br>
update &quot;mount&quot; to display it?<br></blockquote><div><br></div><div=
>So a couple of things to know.</div><div><br></div><div>First, there&#39;s=
 a list of known options. These are converted to a bitmask. This is then de=
coded and reported by mount. The other strings are passed to the filesystem=
 directly. They decode it and do things, but they don&#39;t export them (th=
at I can find). I believe that&#39;s why they aren&#39;t reported with &#39=
;mount&#39;. There&#39;s a couple of other options in /etc/fstab that are p=
seudo options too.</div><div><br></div><div>Warner</div></div></div>

--000000000000661900061333488d--



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?CANCZdfq2Z30jgh6Wt9Set=fZ271qr42Thy73YOxF=bh04R6Bfg>