Unverified Commit 142fa60f authored by André Almeida's avatar André Almeida Committed by Christian Brauner
Browse files

unicode: Recreate utf8_parse_version() 



All filesystems that currently support UTF-8 casefold can fetch the
UTF-8 version from the filesystem metadata stored on disk. They can get
the data stored and directly match it to a integer, so they can skip the
string parsing step, which motivated the removal of this function in the
first place.

However, for tmpfs, the only way to tell the kernel which UTF-8 version
we are about to use is via mount options, using a string. Re-introduce
utf8_parse_version() to be used by tmpfs.

This version differs from the original by skipping the intermediate step
of copying the version string to an auxiliary string before calling
match_token(). This versions calls match_token() in the argument string.
The paramenters are simpler now as well.

utf8_parse_version() was created by 9d53690f ("unicode: implement
higher level API for string handling") and later removed by 49bd03cc
("unicode: pass a UNICODE_AGE() tripple to utf8_load").

Signed-off-by: default avatarAndré Almeida <andrealmeid@igalia.com>
Link: https://lore.kernel.org/r/20241021-tonyk-tmpfs-v8-4-f443d5814194@igalia.com


Reviewed-by: default avatarTheodore Ts'o <tytso@mit.edu>
Reviewed-by: default avatarGabriel Krisman Bertazi <krisman@suse.de>
Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent 04dad6c6

fs/unicode/utf8-core.c

+26 −0
Original line number Diff line number Diff line
@@ -214,3 +214,29 @@ void utf8_unload(struct unicode_map *um) 
}

EXPORT_SYMBOL(utf8_unload);



/**

 * utf8_parse_version - Parse a UTF-8 version number from a string

 *

 * @version: input string

 *

 * Returns the parsed version on success, negative code on error

 */

int utf8_parse_version(char *version)

{

	substring_t args[3];

	unsigned int maj, min, rev;

	static const struct match_token token[] = {

		{1, "%d.%d.%d"},

		{0, NULL}

	};



	if (match_token(version, token, args) != 1)

		return -EINVAL;



	if (match_int(&args[0], &maj) || match_int(&args[1], &min) ||

	    match_int(&args[2], &rev))

		return -EINVAL;



	return UNICODE_AGE(maj, min, rev);

}

EXPORT_SYMBOL(utf8_parse_version);

include/linux/unicode.h

+2 −0
Original line number Diff line number Diff line
@@ -78,4 +78,6 @@ int utf8_casefold_hash(const struct unicode_map *um, const void *salt, 
struct unicode_map *utf8_load(unsigned int version);

void utf8_unload(struct unicode_map *um);



int utf8_parse_version(char *version);



#endif /* _LINUX_UNICODE_H */