Re: [PATCH v4 10/10] docs: tmpfs: Add casefold options

From: Gabriel Krisman Bertazi
Date: Thu Sep 12 2024 - 15:08:42 EST


André Almeida <andrealmeid@xxxxxxxxxx> writes:

> Document mounting options for casefold support in tmpfs.
>
> Signed-off-by: André Almeida <andrealmeid@xxxxxxxxxx>
> ---
> Changes from v3:
> - Rewrote note about "this doesn't enable casefold by default" (Krisman)
> ---
> Documentation/filesystems/tmpfs.rst | 24 ++++++++++++++++++++++++
> 1 file changed, 24 insertions(+)
>
> diff --git a/Documentation/filesystems/tmpfs.rst b/Documentation/filesystems/tmpfs.rst
> index 56a26c843dbe..f72fcc0baef3 100644
> --- a/Documentation/filesystems/tmpfs.rst
> +++ b/Documentation/filesystems/tmpfs.rst
> @@ -241,6 +241,28 @@ 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 lookup support:
> +
> +================= ==============================================================
> +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.
> +================= ==============================================================
> +
> +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.

s/will//

Other than that:

Reviewed-by: Gabriel Krisman Bertazi <krisman@xxxxxxx>

> +
> +Example::
> +
> + $ mount -t tmpfs -o casefold=utf8-12.1.0,strict_encoding fs_name /mytmpfs
> + $ mount -t tmpfs -o casefold fs_name /mytmpfs
> +
>
> :Author:
> Christoph Rohland <cr@xxxxxxx>, 1.12.01
> @@ -250,3 +272,5 @@ 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