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 9d53690f0d4 ("unicode: implement higher level API for string handling") and later removed by 49bd03cc7e9 ("unicode: pass a UNICODE_AGE() tripple to utf8_load"). Signed-off-by: André Almeida <andrealmeid@xxxxxxxxxx> Reviewed-by: Theodore Ts'o <tytso@xxxxxxx> Reviewed-by: Gabriel Krisman Bertazi <krisman@xxxxxxx> --- Changes from v3: - Return version on the return value, instead of returning version at function args. --- fs/unicode/utf8-core.c | 26 ++++++++++++++++++++++++++ include/linux/unicode.h | 2 ++ 2 files changed, 28 insertions(+) diff --git a/fs/unicode/utf8-core.c b/fs/unicode/utf8-core.c index 8395066341a437d0c20d6ab49b0a022eac7eec5c..7f7cb14e01ce8aa87d14dffdd767f63a90cf11f7 100644 --- a/fs/unicode/utf8-core.c +++ b/fs/unicode/utf8-core.c @@ -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); diff --git a/include/linux/unicode.h b/include/linux/unicode.h index 0c0ab04e84ee80227f9390ad0498f21a7ab7d34b..5e6b212a2aedab7ebf4363083339f4c5e9b82f8f 100644 --- a/include/linux/unicode.h +++ b/include/linux/unicode.h @@ -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 */ -- 2.47.0