linux-kernel - Re: [PATCH v3 9/9] docs: tmpfs: Add casefold options

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <87v7z9op90.fsf@mailhost.krisman.be>
Date: Thu, 05 Sep 2024 15:48:59 -0400
From: Gabriel Krisman Bertazi <gabriel@...sman.be>
To: André Almeida <andrealmeid@...lia.com>
Cc: Hugh Dickins <hughd@...gle.com>,  Andrew Morton
 <akpm@...ux-foundation.org>,  Alexander Viro <viro@...iv.linux.org.uk>,
  Christian Brauner <brauner@...nel.org>,  Jan Kara <jack@...e.cz>,
  krisman@...nel.org,  linux-mm@...ck.org,  linux-kernel@...r.kernel.org,
  linux-fsdevel@...r.kernel.org,  kernel-dev@...lia.com,  Daniel Rosenberg
 <drosen@...gle.com>,  smcv@...labora.com,  Christoph Hellwig <hch@....de>,
  Theodore Ts'o <tytso@....edu>
Subject: Re: [PATCH v3 9/9] docs: tmpfs: Add casefold options

André Almeida <andrealmeid@...lia.com> writes:

> Document mounting options for casefold support in tmpfs.
>
> Signed-off-by: André Almeida <andrealmeid@...lia.com>
> ---
>  Documentation/filesystems/tmpfs.rst | 23 +++++++++++++++++++++++
>  1 file changed, 23 insertions(+)
>
> diff --git a/Documentation/filesystems/tmpfs.rst b/Documentation/filesystems/tmpfs.rst
> index 56a26c843dbe..636afd3eaf48 100644
> --- a/Documentation/filesystems/tmpfs.rst
> +++ b/Documentation/filesystems/tmpfs.rst
> @@ -241,6 +241,27 @@ So 'mount -t tmpfs -o size=10G,nr_inodes=10k,mode=700 tmpfs /mytmpfs'
>  will give you tmpfs instance on /mytmpfs which can allocate 10GB
>  RAM/SWAP in 10240 inodes and it is only accessible by root.
>  
> +tmpfs has the following mounting options for case-insensitive lookups
> support:

lookups->lookup

> +
> +================= ==============================================================
> +casefold          Enable casefold support at this mount point using the given
> +                  argument as the encoding standard. Currently only UTF-8
> +                  encodings are supported. If no argument is used, it will load
> +                  the latest UTF-8 encoding available.
> +strict_encoding   Enable strict encoding at this mount point (disabled by
> +                  default). In this mode, the filesystem refuses to create file
> +                  and directory with names containing invalid UTF-8 characters.
> +================= ==============================================================
> +
> +Note that this option doesn't enable casefold by default; 

I think this is fine as is. but if we need a new iteration, could you
perhaps rephrase this to something like:

This option doesn't render the entire filesystem case-insensitive.
One needs to still set the casefold flag per directory, by flipping +F
attribute in an empty directory. Nevertheless, new directories will
inherit the attribute.  The mountpoint itself will cannot be made
case-insensitive.

> +
> +Example::
> +
> +    $ mount -t tmpfs -o casefold=utf8-12.1.0,strict_enconding fs_name /mytmpfs

strict_encoding

> +    $ mount -t tmpfs -o casefold fs_name /mytmpfs
> +
>  
>  :Author:
>     Christoph Rohland <cr@....com>, 1.12.01
> @@ -250,3 +271,5 @@ RAM/SWAP in 10240 inodes and it is only accessible by root.
>     KOSAKI Motohiro, 16 Mar 2010
>  :Updated:
>     Chris Down, 13 July 2020
> +:Updated:
> +   André Almeida, 23 Aug 2024

-- 
Gabriel Krisman Bertazi