linux-kernel - Re: [PATCH v3 05/12] man/man2/fspick.2: document "new" mount API

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Message-ID: <2025-08-22.1755869779-quirky-demur-grunts-mace-Hoxz0h@cyphar.com>
Date: Fri, 22 Aug 2025 23:40:18 +1000
From: Aleksa Sarai <cyphar@...har.com>
To: Askar Safin <safinaskar@...omail.com>
Cc: Alejandro Colomar <alx@...nel.org>, 
	"Michael T. Kerrisk" <mtk.manpages@...il.com>, Alexander Viro <viro@...iv.linux.org.uk>, 
	Jan Kara <jack@...e.cz>, "G. Branden Robinson" <g.branden.robinson@...il.com>, 
	linux-man <linux-man@...r.kernel.org>, linux-api <linux-api@...r.kernel.org>, 
	linux-fsdevel <linux-fsdevel@...r.kernel.org>, linux-kernel <linux-kernel@...r.kernel.org>, 
	David Howells <dhowells@...hat.com>, Christian Brauner <brauner@...nel.org>
Subject: Re: [PATCH v3 05/12] man/man2/fspick.2: document "new" mount API

On 2025-08-22, Askar Safin <safinaskar@...omail.com> wrote:
>  ---- On Sat, 09 Aug 2025 00:39:49 +0400  Aleksa Sarai <cyphar@...har.com> wrote --- 
>  > +The above procedure is functionally equivalent to
>  > +the following mount operation using
>  > +.BR mount (2):
> 
> This is not true.
> 
> fspick adds options to superblock. It doesn't remove existing ones.

fspick "copies the existing parameters" would be more accurate. I can
reword this, but it's an example and I don't think it makes sense to add
a large amount of clarifying text for each example.

The comparisons to mount(2) are meant to be indicative, but if you I can
also just remove them (David's versions didn't include them).

> mount(MS_REMOUNT) replaces options. I. e. mount(2) call provided in
> example will unset all other options.
> 
> In the end of this message you will find C code, which proves this.

Yes, I am already keenly aware of this behaviour.

-- 
Aleksa Sarai
Senior Software Engineer (Containers)
SUSE Linux GmbH
https://www.cyphar.com/

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