Document mounting options for casefold support in tmpfs.
Reviewed-by: Gabriel Krisman Bertazi <krisman@xxxxxxx>
Reviewed-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
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 56a26c843dbe964086503dda9b4e8066a1242d72..d677e0428c3f68148a3761bb232bbed5b9a41f76 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 the +F attribute in an
+empty directory. Nevertheless, new directories will inherit the attribute. The
+mountpoint itself cannot be made case-insensitive.
+
+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
--
2.47.0
