| Message ID | 20240902225511.757831-5-andrealmeid@igalia.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | tmpfs: Add case-insesitive support for tmpfs | expand |
On Mon, Sep 02, 2024 at 07:55:06PM -0300, André Almeida wrote: > 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. > > 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@igalia.com> Reviewed-by: Theodore Ts'o <tytso@mit.edu>
diff --git a/fs/unicode/utf8-core.c b/fs/unicode/utf8-core.c index 4966e175ed71..3e8afd637b28 100644 --- a/fs/unicode/utf8-core.c +++ b/fs/unicode/utf8-core.c @@ -240,3 +240,33 @@ bool utf8_check_strict_name(struct inode *dir, struct qstr *d_name) utf8_validate(dir->i_sb->s_encoding, d_name)); } EXPORT_SYMBOL(utf8_check_strict_name); + +/** + * utf8_parse_version - Parse a UTF-8 version number from a string + * + * @version: input string + * @maj: output major version number + * @min: output minor version number + * @rev: output minor revision number + * + * Returns 0 on success, negative code on error + */ +int utf8_parse_version(char *version, unsigned int *maj, + unsigned int *min, unsigned int *rev) +{ + substring_t args[3]; + 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 0; +} +EXPORT_SYMBOL(utf8_parse_version); diff --git a/include/linux/unicode.h b/include/linux/unicode.h index fb56fb5e686c..724db2cd709d 100644 --- a/include/linux/unicode.h +++ b/include/linux/unicode.h @@ -78,4 +78,7 @@ void utf8_unload(struct unicode_map *um); bool utf8_check_strict_name(struct inode *dir, struct qstr *d_name); +int utf8_parse_version(char *version, unsigned int *maj, unsigned int *min, + unsigned int *rev); + #endif /* _LINUX_UNICODE_H */
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. 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@igalia.com> --- fs/unicode/utf8-core.c | 30 ++++++++++++++++++++++++++++++ include/linux/unicode.h | 3 +++ 2 files changed, 33 insertions(+)