Unverified Commit 0e152beb authored by André Almeida's avatar André Almeida Committed by Christian Brauner
Browse files

libfs: Create the helper function generic_ci_validate_strict_name() 



Create a helper function for filesystems do the checks required for
casefold directories and strict encoding.

Suggested-by: default avatarGabriel Krisman Bertazi <krisman@suse.de>
Reviewed-by: default avatarGabriel Krisman Bertazi <gabriel@krisman.be>
Signed-off-by: default avatarAndré Almeida <andrealmeid@igalia.com>
Link: https://lore.kernel.org/r/20241021-tonyk-tmpfs-v8-1-f443d5814194@igalia.com


Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent 42f7652d

include/linux/fs.h

+45 −0
Original line number Diff line number Diff line
@@ -45,6 +45,7 @@ 
#include <linux/slab.h>

#include <linux/maple_tree.h>

#include <linux/rw_hint.h>

#include <linux/unicode.h>



#include <asm/byteorder.h>

#include <uapi/linux/fs.h>
@@ -3456,6 +3457,50 @@ extern int generic_ci_match(const struct inode *parent, 
			    const struct qstr *folded_name,

			    const u8 *de_name, u32 de_name_len);



#if IS_ENABLED(CONFIG_UNICODE)

/**

 * generic_ci_validate_strict_name - Check if a given name is suitable

 * for a directory

 *

 * This functions checks if the proposed filename is valid for the

 * parent directory. That means that only valid UTF-8 filenames will be

 * accepted for casefold directories from filesystems created with the

 * strict encoding flag.  That also means that any name will be

 * accepted for directories that doesn't have casefold enabled, or

 * aren't being strict with the encoding.

 *

 * @dir: inode of the directory where the new file will be created

 * @name: name of the new file

 *

 * Return:

 * * True if the filename is suitable for this directory. It can be

 * true if a given name is not suitable for a strict encoding

 * directory, but the directory being used isn't strict

 * * False if the filename isn't suitable for this directory. This only

 * happens when a directory is casefolded and the filesystem is strict

 * about its encoding.

 */

static inline bool generic_ci_validate_strict_name(struct inode *dir, struct qstr *name)

{

	if (!IS_CASEFOLDED(dir) || !sb_has_strict_encoding(dir->i_sb))

		return true;



	/*

	 * A casefold dir must have a encoding set, unless the filesystem

	 * is corrupted

	 */

	if (WARN_ON_ONCE(!dir->i_sb->s_encoding))

		return true;



	return !utf8_validate(dir->i_sb->s_encoding, name);

}

#else

static inline bool generic_ci_validate_strict_name(struct inode *dir, struct qstr *name)

{

	return true;

}

#endif



static inline bool sb_has_encoding(const struct super_block *sb)

{

#if IS_ENABLED(CONFIG_UNICODE)