Re: [PATCH 3/3] fs: unicode: Add utf8 module and a unicode layer
From: Gabriel Krisman Bertazi
Date: Mon Mar 15 2021 - 00:22:56 EST
Shreeya Patel <shreeya.patel@xxxxxxxxxxxxx> writes:
> On 14/03/21 7:19 am, Gabriel Krisman Bertazi wrote:
>> Shreeya Patel <shreeya.patel@xxxxxxxxxxxxx> writes:
>>
>>> utf8data.h_shipped has a large database table which is an auto-generated
>>> decodification trie for the unicode normalization functions.
>>> It is not necessary to carry this large table in the kernel hence make
>>> UTF-8 encoding loadable by converting it into a module.
>>> Also, modify the file called unicode-core which will act as a layer for
>>> unicode subsystem. It will load the UTF-8 module and access it's functions
>>> whenever any filesystem that needs unicode is mounted.
>>>
>>> Signed-off-by: Shreeya Patel <shreeya.patel@xxxxxxxxxxxxx>
>> Hi Shreeya,
> Hi Gabriel,
>>
>>> ---
>>> fs/unicode/Kconfig | 7 +-
>>> fs/unicode/Makefile | 5 +-
>>> fs/unicode/unicode-core.c | 201 ++++++-------------------------
>>> fs/unicode/utf8-core.c | 112 +++++++++++++++++
>>> fs/unicode/utf8mod.c | 246 ++++++++++++++++++++++++++++++++++++++
>>> include/linux/unicode.h | 20 ++++
>>> 6 files changed, 427 insertions(+), 164 deletions(-)
>>> create mode 100644 fs/unicode/utf8-core.c
>>> create mode 100644 fs/unicode/utf8mod.c
>>>
>>> diff --git a/fs/unicode/Kconfig b/fs/unicode/Kconfig
>>> index 2c27b9a5cd6c..33a27deef729 100644
>>> --- a/fs/unicode/Kconfig
>>> +++ b/fs/unicode/Kconfig
>>> @@ -8,7 +8,12 @@ config UNICODE
>>> Say Y here to enable UTF-8 NFD normalization and NFD+CF casefolding
>>> support.
>>> +config UNICODE_UTF8
>>> + tristate "UTF-8 module"
>>> + depends on UNICODE
>>> + default m
>>> +
>>> config UNICODE_NORMALIZATION_SELFTEST
>>> tristate "Test UTF-8 normalization support"
>>> - depends on UNICODE
>>> + depends on UNICODE_UTF8
>>> default n
>>> diff --git a/fs/unicode/Makefile b/fs/unicode/Makefile
>>> index fbf9a629ed0d..9dbb04194b32 100644
>>> --- a/fs/unicode/Makefile
>>> +++ b/fs/unicode/Makefile
>>> @@ -1,11 +1,14 @@
>>> # SPDX-License-Identifier: GPL-2.0
>>> obj-$(CONFIG_UNICODE) += unicode.o
>>> +obj-$(CONFIG_UNICODE_UTF8) += utf8.o
>>> obj-$(CONFIG_UNICODE_NORMALIZATION_SELFTEST) += utf8-selftest.o
>>> -unicode-y := utf8-norm.o unicode-core.o
>>> +unicode-y := unicode-core.o
>>> +utf8-y := utf8mod.o utf8-norm.o
>>> $(obj)/utf8-norm.o: $(obj)/utf8data.h
>>> +$(obj)/utf8mod.o: $(obj)/utf8-norm.o
>>> # In the normal build, the checked-in utf8data.h is just shipped.
>>> #
>>> diff --git a/fs/unicode/unicode-core.c b/fs/unicode/unicode-core.c
>>> index d5f09e022ac5..b832341f1e7b 100644
>>> --- a/fs/unicode/unicode-core.c
>>> +++ b/fs/unicode/unicode-core.c
>>> @@ -7,70 +7,29 @@
>>> #include <linux/errno.h>
>>> #include <linux/unicode.h>
>>> #include <linux/stringhash.h>
>>> +#include <linux/delay.h>
>>> -#include "utf8n.h"
>>> +struct unicode_ops *utf8_ops;
>>> +
>>> +static int unicode_load_module(void);
>> This is unnecessary
>>> int unicode_validate(const struct unicode_map *um, const struct
>>> qstr *str)
>>> {
>>> - const struct utf8data *data = utf8nfdi(um->version);
>>> -
>>> - if (utf8nlen(data, str->name, str->len) < 0)
>>> - return -1;
>>> - return 0;
>>> + return utf8_ops->validate(um, str);
>>> }
>>> EXPORT_SYMBOL(unicode_validate);
>>> int unicode_strncmp(const struct unicode_map *um,
>>> const struct qstr *s1, const struct qstr *s2)
>>> {
>>> - const struct utf8data *data = utf8nfdi(um->version);
>>> - struct utf8cursor cur1, cur2;
>>> - int c1, c2;
>>> -
>>> - if (utf8ncursor(&cur1, data, s1->name, s1->len) < 0)
>>> - return -EINVAL;
>>> -
>>> - if (utf8ncursor(&cur2, data, s2->name, s2->len) < 0)
>>> - return -EINVAL;
>>> -
>>> - do {
>>> - c1 = utf8byte(&cur1);
>>> - c2 = utf8byte(&cur2);
>>> -
>>> - if (c1 < 0 || c2 < 0)
>>> - return -EINVAL;
>>> - if (c1 != c2)
>>> - return 1;
>>> - } while (c1);
>>> -
>>> - return 0;
>>> + return utf8_ops->strncmp(um, s1, s2);
>>> }
>> I think these would go on a header file and inlined.
>>
>>> EXPORT_SYMBOL(unicode_strncmp);
>>> int unicode_strncasecmp(const struct unicode_map *um,
>>> const struct qstr *s1, const struct qstr *s2)
>>> {
>>> - const struct utf8data *data = utf8nfdicf(um->version);
>>> - struct utf8cursor cur1, cur2;
>>> - int c1, c2;
>>> -
>>> - if (utf8ncursor(&cur1, data, s1->name, s1->len) < 0)
>>> - return -EINVAL;
>>> -
>>> - if (utf8ncursor(&cur2, data, s2->name, s2->len) < 0)
>>> - return -EINVAL;
>>> -
>>> - do {
>>> - c1 = utf8byte(&cur1);
>>> - c2 = utf8byte(&cur2);
>>> -
>>> - if (c1 < 0 || c2 < 0)
>>> - return -EINVAL;
>>> - if (c1 != c2)
>>> - return 1;
>>> - } while (c1);
>>> -
>>> - return 0;
>>> + return utf8_ops->strncasecmp(um, s1, s2);
>>> }
>>> EXPORT_SYMBOL(unicode_strncasecmp);
>>> @@ -81,155 +40,73 @@ int unicode_strncasecmp_folded(const struct
>>> unicode_map *um,
>>> const struct qstr *cf,
>>> const struct qstr *s1)
>>> {
>>> - const struct utf8data *data = utf8nfdicf(um->version);
>>> - struct utf8cursor cur1;
>>> - int c1, c2;
>>> - int i = 0;
>>> -
>>> - if (utf8ncursor(&cur1, data, s1->name, s1->len) < 0)
>>> - return -EINVAL;
>>> -
>>> - do {
>>> - c1 = utf8byte(&cur1);
>>> - c2 = cf->name[i++];
>>> - if (c1 < 0)
>>> - return -EINVAL;
>>> - if (c1 != c2)
>>> - return 1;
>>> - } while (c1);
>>> -
>>> - return 0;
>>> + return utf8_ops->strncasecmp_folded(um, cf, s1);
>>> }
>>> EXPORT_SYMBOL(unicode_strncasecmp_folded);
>>> int unicode_casefold(const struct unicode_map *um, const struct
>>> qstr *str,
>>> unsigned char *dest, size_t dlen)
>>> {
>>> - const struct utf8data *data = utf8nfdicf(um->version);
>>> - struct utf8cursor cur;
>>> - size_t nlen = 0;
>>> -
>>> - if (utf8ncursor(&cur, data, str->name, str->len) < 0)
>>> - return -EINVAL;
>>> -
>>> - for (nlen = 0; nlen < dlen; nlen++) {
>>> - int c = utf8byte(&cur);
>>> -
>>> - dest[nlen] = c;
>>> - if (!c)
>>> - return nlen;
>>> - if (c == -1)
>>> - break;
>>> - }
>>> - return -EINVAL;
>>> + return utf8_ops->casefold(um, str, dest, dlen);
>>> }
>>> EXPORT_SYMBOL(unicode_casefold);
>>> int unicode_casefold_hash(const struct unicode_map *um, const
>>> void *salt,
>>> struct qstr *str)
>>> {
>>> - const struct utf8data *data = utf8nfdicf(um->version);
>>> - struct utf8cursor cur;
>>> - int c;
>>> - unsigned long hash = init_name_hash(salt);
>>> -
>>> - if (utf8ncursor(&cur, data, str->name, str->len) < 0)
>>> - return -EINVAL;
>>> -
>>> - while ((c = utf8byte(&cur))) {
>>> - if (c < 0)
>>> - return -EINVAL;
>>> - hash = partial_name_hash((unsigned char)c, hash);
>>> - }
>>> - str->hash = end_name_hash(hash);
>>> - return 0;
>>> + return utf8_ops->casefold_hash(um, salt, str);
>>> }
>>> EXPORT_SYMBOL(unicode_casefold_hash);
>>> int unicode_normalize(const struct unicode_map *um, const struct
>>> qstr *str,
>>> unsigned char *dest, size_t dlen)
>>> {
>>> - const struct utf8data *data = utf8nfdi(um->version);
>>> - struct utf8cursor cur;
>>> - ssize_t nlen = 0;
>>> + return utf8_ops->normalize(um, str, dest, dlen);
>>> +}
>>> +EXPORT_SYMBOL(unicode_normalize);
>>> - if (utf8ncursor(&cur, data, str->name, str->len) < 0)
>>> - return -EINVAL;
>>> +struct unicode_map *unicode_load(const char *version)
>>> +{
>>> + int ret = unicode_load_module();
>>> - for (nlen = 0; nlen < dlen; nlen++) {
>>> - int c = utf8byte(&cur);
>>> + if (ret)
>>> + return ERR_PTR(ret);
>>> - dest[nlen] = c;
>>> - if (!c)
>>> - return nlen;
>>> - if (c == -1)
>>> - break;
>>> - }
>>> - return -EINVAL;
>>> + else
>>> + return utf8_ops->load(version);
>>> }
>>> -EXPORT_SYMBOL(unicode_normalize);
>>> +EXPORT_SYMBOL(unicode_load);
>>> -static int unicode_parse_version(const char *version, unsigned int
>>> *maj,
>>> - unsigned int *min, unsigned int *rev)
>>> +void unicode_unload(struct unicode_map *um)
>>> {
>>> - substring_t args[3];
>>> - char version_string[12];
>>> - static const struct match_token token[] = {
>>> - {1, "%d.%d.%d"},
>>> - {0, NULL}
>>> - };
>>> + kfree(um);
>>> +}
>>> +EXPORT_SYMBOL(unicode_unload);
>>> - strncpy(version_string, version, sizeof(version_string));
>>> +static int unicode_load_module(void)
>>> +{
>>> + int ret = request_module("utf8");
>>> - if (match_token(version_string, token, args) != 1)
>>> - return -EINVAL;
>>> + msleep(100);
>> I think I misunderstood when you mentioned you did this msleep. It was
>> ok to debug the issue you were observing, but it is not a solution.
>> Setting an arbitrary amount of time will either waste time, or you can
>> still fail if things take longer than expected. There are mechanisms to
>> load and wait on a module. See how fs/nls/nls_base.c do exactly this.
>>
>>> - if (match_int(&args[0], maj) || match_int(&args[1], min) ||
>>> - match_int(&args[2], rev))
>>> - return -EINVAL;
>>> + if (ret) {
>>> + pr_err("Failed to load UTF-8 module\n");
>>> + return ret;
>>> + }
>>> return 0;
>>> }
>>> -struct unicode_map *unicode_load(const char *version)
>>> +void unicode_register(struct unicode_ops *ops)
>>> {
>>> - struct unicode_map *um = NULL;
>>> - int unicode_version;
>>> -
>>> - if (version) {
>>> - unsigned int maj, min, rev;
>>> -
>>> - if (unicode_parse_version(version, &maj, &min, &rev) < 0)
>>> - return ERR_PTR(-EINVAL);
>>> -
>>> - if (!utf8version_is_supported(maj, min, rev))
>>> - return ERR_PTR(-EINVAL);
>>> -
>>> - unicode_version = UNICODE_AGE(maj, min, rev);
>>> - } else {
>>> - unicode_version = utf8version_latest();
>>> - printk(KERN_WARNING"UTF-8 version not specified. "
>>> - "Assuming latest supported version (%d.%d.%d).",
>>> - (unicode_version >> 16) & 0xff,
>>> - (unicode_version >> 8) & 0xff,
>>> - (unicode_version & 0xff));
>>> - }
>>> -
>>> - um = kzalloc(sizeof(struct unicode_map), GFP_KERNEL);
>>> - if (!um)
>>> - return ERR_PTR(-ENOMEM);
>>> -
>>> - um->charset = "UTF-8";
>>> - um->version = unicode_version;
>>> -
>>> - return um;
>>> + utf8_ops = ops;
>>> }
>>> -EXPORT_SYMBOL(unicode_load);
>>> +EXPORT_SYMBOL(unicode_register);
>>> -void unicode_unload(struct unicode_map *um)
>>> +void unicode_unregister(void)
>>> {
>>> - kfree(um);
>>> + utf8_ops = NULL;
>>> }
>>> -EXPORT_SYMBOL(unicode_unload);
>>> +EXPORT_SYMBOL(unicode_unregister);
>>> MODULE_LICENSE("GPL v2");
>>> diff --git a/fs/unicode/utf8-core.c b/fs/unicode/utf8-core.c
>>> new file mode 100644
>>> index 000000000000..009faa68330c
>>> --- /dev/null
>>> +++ b/fs/unicode/utf8-core.c
>>> @@ -0,0 +1,112 @@
>>> +/* SPDX-License-Identifier: GPL-2.0 */
>>> +#include <linux/module.h>
>>> +#include <linux/kernel.h>
>>> +#include <linux/string.h>
>>> +#include <linux/slab.h>
>>> +#include <linux/parser.h>
>>> +#include <linux/errno.h>
>>> +#include <linux/unicode.h>
>>> +#include <linux/stringhash.h>
>>> +#include <linux/delay.h>
>>> +
>>> +struct unicode_ops *utf8_ops;
>>> +
>>> +static int unicode_load_module(void);
>>> +
>>> +int unicode_validate(const struct unicode_map *um, const struct qstr *str)
>>> +{
>>> + return utf8_ops->validate(um, str);
>>> +}
>>> +EXPORT_SYMBOL(unicode_validate);
>>> +
>>> +int unicode_strncmp(const struct unicode_map *um,
>>> + const struct qstr *s1, const struct qstr *s2)
>>> +{
>>> + return utf8_ops->strncmp(um, s1, s2);
>>> +}
>>> +EXPORT_SYMBOL(unicode_strncmp);
>> I'm confused now. Isn't this redefining unicode_strncmp ? It was
>> defined in unicode_core.c on the hunk above and now it is redefined on
>> utf8_core.c. There is something odd here.
> sorry, I think I messed up patches while using git send-email and that
> is why you might see
> two copies of the last patch. Let me resend the series and then it might
> make sense. One question
Hi Shreeya,
Yes, I noticed that too, but this comment just was about the patch I reviewed.
If I read the patch correctly, unicode_strncmp is defined in two places,
in file unicode_core.c and utf8_core.c, in this single patch?
> though, why would unicode_strncmp go into the header file?
Since unicode_strnmcp is now just a wrapper that calls the ->ops hook,
putting it in the header file will allow it to be inlined by the
compiler inside the caller function.
>>> +
>>> +int unicode_strncasecmp(const struct unicode_map *um,
>>> + const struct qstr *s1, const struct qstr *s2)
>>> +{
>>> + return utf8_ops->strncasecmp(um, s1, s2);
>>> +}
>>> +EXPORT_SYMBOL(unicode_strncasecmp);
>>> +
>>> +/* String cf is expected to be a valid UTF-8 casefolded
>>> + * string.
>>> + */
>>> +int unicode_strncasecmp_folded(const struct unicode_map *um,
>>> + const struct qstr *cf,
>>> + const struct qstr *s1)
>>> +{
>>> + return utf8_ops->strncasecmp_folded(um, cf, s1);
>>> +}
>>> +EXPORT_SYMBOL(unicode_strncasecmp_folded);
>>> +
>>> +int unicode_casefold(const struct unicode_map *um, const struct qstr *str,
>>> + unsigned char *dest, size_t dlen)
>>> +{
>>> + return utf8_ops->casefold(um, str, dest, dlen);
>>> +}
>>> +EXPORT_SYMBOL(unicode_casefold);
>>> +
>>> +int unicode_casefold_hash(const struct unicode_map *um, const void *salt,
>>> + struct qstr *str)
>>> +{
>>> + return utf8_ops->casefold_hash(um, salt, str);
>>> +}
>>> +EXPORT_SYMBOL(unicode_casefold_hash);
>>> +
>>> +int unicode_normalize(const struct unicode_map *um, const struct qstr *str,
>>> + unsigned char *dest, size_t dlen)
>>> +{
>>> + return utf8_ops->normalize(um, str, dest, dlen);
>>> +}
>>> +EXPORT_SYMBOL(unicode_normalize);
>>> +
>>> +struct unicode_map *unicode_load(const char *version)
>>> +{
>>> + int ret = unicode_load_module();
>>> +
>>> + if (ret)
>>> + return ERR_PTR(ret);
>>> +
>>> + else
>>> + return utf8_ops->load(version);
>>> +}
>>> +EXPORT_SYMBOL(unicode_load);
>>> +
>>> +void unicode_unload(struct unicode_map *um)
>>> +{
>>> + kfree(um);
>>> +}
>>> +EXPORT_SYMBOL(unicode_unload);
>>> +
>>> +void unicode_register(struct unicode_ops *ops)
>>> +{
>>> + utf8_ops = ops;
>>> +}
>>> +EXPORT_SYMBOL(unicode_register);
>>> +
>>> +void unicode_unregister(void)
>>> +{
>>> + utf8_ops = NULL;
>>> +}
>>> +EXPORT_SYMBOL(unicode_unregister);
>>> +
>>> +static int unicode_load_module(void)
>>> +{
>>> + int ret = request_module("utf8");
>>> +
>>> + msleep(100);
>>> +
>>> + if (ret) {
>>> + pr_err("Failed to load UTF-8 module\n");
>>> + return ret;
>>> + }
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +MODULE_LICENSE("GPL v2");
>>> diff --git a/fs/unicode/utf8mod.c b/fs/unicode/utf8mod.c
>>> new file mode 100644
>>> index 000000000000..8eaeeb27255c
>>> --- /dev/null
>>> +++ b/fs/unicode/utf8mod.c
>>> @@ -0,0 +1,246 @@
>>> +/* SPDX-License-Identifier: GPL-2.0 */
>>> +#include <linux/module.h>
>>> +#include <linux/kernel.h>
>>> +#include <linux/string.h>
>>> +#include <linux/slab.h>
>>> +#include <linux/parser.h>
>>> +#include <linux/errno.h>
>>> +#include <linux/unicode.h>
>>> +#include <linux/stringhash.h>
>>> +
>>> +#include "utf8n.h"
>>> +
>>> +static int utf8_validate(const struct unicode_map *um, const struct qstr *str)
>>> +{
>>> + const struct utf8data *data = utf8nfdi(um->version);
>>> +
>>> + if (utf8nlen(data, str->name, str->len) < 0)
>>> + return -1;
>>> + return 0;
>>> +}
>>> +
>>> +static int utf8_strncmp(const struct unicode_map *um,
>>> + const struct qstr *s1, const struct qstr *s2)
>>> +{
>>> + const struct utf8data *data = utf8nfdi(um->version);
>>> + struct utf8cursor cur1, cur2;
>>> + int c1, c2;
>>> +
>>> + if (utf8ncursor(&cur1, data, s1->name, s1->len) < 0)
>>> + return -EINVAL;
>>> +
>>> + if (utf8ncursor(&cur2, data, s2->name, s2->len) < 0)
>>> + return -EINVAL;
>>> +
>>> + do {
>>> + c1 = utf8byte(&cur1);
>>> + c2 = utf8byte(&cur2);
>>> +
>>> + if (c1 < 0 || c2 < 0)
>>> + return -EINVAL;
>>> + if (c1 != c2)
>>> + return 1;
>>> + } while (c1);
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int utf8_strncasecmp(const struct unicode_map *um,
>>> + const struct qstr *s1, const struct qstr *s2)
>>> +{
>>> + const struct utf8data *data = utf8nfdicf(um->version);
>>> + struct utf8cursor cur1, cur2;
>>> + int c1, c2;
>>> +
>>> + if (utf8ncursor(&cur1, data, s1->name, s1->len) < 0)
>>> + return -EINVAL;
>>> +
>>> + if (utf8ncursor(&cur2, data, s2->name, s2->len) < 0)
>>> + return -EINVAL;
>>> +
>>> + do {
>>> + c1 = utf8byte(&cur1);
>>> + c2 = utf8byte(&cur2);
>>> +
>>> + if (c1 < 0 || c2 < 0)
>>> + return -EINVAL;
>>> + if (c1 != c2)
>>> + return 1;
>>> + } while (c1);
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +/* String cf is expected to be a valid UTF-8 casefolded
>>> + * string.
>>> + */
>>> +static int utf8_strncasecmp_folded(const struct unicode_map *um,
>>> + const struct qstr *cf,
>>> + const struct qstr *s1)
>>> +{
>>> + const struct utf8data *data = utf8nfdicf(um->version);
>>> + struct utf8cursor cur1;
>>> + int c1, c2;
>>> + int i = 0;
>>> +
>>> + if (utf8ncursor(&cur1, data, s1->name, s1->len) < 0)
>>> + return -EINVAL;
>>> +
>>> + do {
>>> + c1 = utf8byte(&cur1);
>>> + c2 = cf->name[i++];
>>> + if (c1 < 0)
>>> + return -EINVAL;
>>> + if (c1 != c2)
>>> + return 1;
>>> + } while (c1);
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int utf8_casefold(const struct unicode_map *um, const struct qstr *str,
>>> + unsigned char *dest, size_t dlen)
>>> +{
>>> + const struct utf8data *data = utf8nfdicf(um->version);
>>> + struct utf8cursor cur;
>>> + size_t nlen = 0;
>>> +
>>> + if (utf8ncursor(&cur, data, str->name, str->len) < 0)
>>> + return -EINVAL;
>>> +
>>> + for (nlen = 0; nlen < dlen; nlen++) {
>>> + int c = utf8byte(&cur);
>>> +
>>> + dest[nlen] = c;
>>> + if (!c)
>>> + return nlen;
>>> + if (c == -1)
>>> + break;
>>> + }
>>> + return -EINVAL;
>>> +}
>>> +
>>> +static int utf8_casefold_hash(const struct unicode_map *um, const void *salt,
>>> + struct qstr *str)
>>> +{
>>> + const struct utf8data *data = utf8nfdicf(um->version);
>>> + struct utf8cursor cur;
>>> + int c;
>>> + unsigned long hash = init_name_hash(salt);
>>> +
>>> + if (utf8ncursor(&cur, data, str->name, str->len) < 0)
>>> + return -EINVAL;
>>> +
>>> + while ((c = utf8byte(&cur))) {
>>> + if (c < 0)
>>> + return -EINVAL;
>>> + hash = partial_name_hash((unsigned char)c, hash);
>>> + }
>>> + str->hash = end_name_hash(hash);
>>> + return 0;
>>> +}
>>> +
>>> +static int utf8_normalize(const struct unicode_map *um, const struct qstr *str,
>>> + unsigned char *dest, size_t dlen)
>>> +{
>>> + const struct utf8data *data = utf8nfdi(um->version);
>>> + struct utf8cursor cur;
>>> + ssize_t nlen = 0;
>>> +
>>> + if (utf8ncursor(&cur, data, str->name, str->len) < 0)
>>> + return -EINVAL;
>>> +
>>> + for (nlen = 0; nlen < dlen; nlen++) {
>>> + int c = utf8byte(&cur);
>>> +
>>> + dest[nlen] = c;
>>> + if (!c)
>>> + return nlen;
>>> + if (c == -1)
>>> + break;
>>> + }
>>> + return -EINVAL;
>>> +}
>>> +
>>> +static int utf8_parse_version(const char *version, unsigned int *maj,
>>> + unsigned int *min, unsigned int *rev)
>>> +{
>>> + substring_t args[3];
>>> + char version_string[12];
>>> + static const struct match_token token[] = {
>>> + {1, "%d.%d.%d"},
>>> + {0, NULL}
>>> + };
>>> +
>>> + strncpy(version_string, version, sizeof(version_string));
>>> +
>>> + if (match_token(version_string, 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;
>>> +}
>>> +
>>> +static struct unicode_map *utf8_load(const char *version)
>>> +{
>>> + struct unicode_map *um = NULL;
>>> + int unicode_version;
>>> +
>>> + if (version) {
>>> + unsigned int maj, min, rev;
>>> +
>>> + if (utf8_parse_version(version, &maj, &min, &rev) < 0)
>>> + return ERR_PTR(-EINVAL);
>>> +
>>> + if (!utf8version_is_supported(maj, min, rev))
>>> + return ERR_PTR(-EINVAL);
>>> +
>>> + unicode_version = UNICODE_AGE(maj, min, rev);
>>> + } else {
>>> + unicode_version = utf8version_latest();
>>> + printk(KERN_WARNING"UTF-8 version not specified. "
>>> + "Assuming latest supported version (%d.%d.%d).",
>>> + (unicode_version >> 16) & 0xff,
>>> + (unicode_version >> 8) & 0xff,
>>> + (unicode_version & 0xff));
>>> + }
>>> +
>>> + um = kzalloc(sizeof(struct unicode_map), GFP_KERNEL);
>>> + if (!um)
>>> + return ERR_PTR(-ENOMEM);
>>> +
>>> + um->charset = "UTF-8";
>>> + um->version = unicode_version;
>>> +
>>> + return um;
>>> +}
>>> +
>>> +static struct unicode_ops ops = {
>>> + .validate = utf8_validate,
>>> + .strncmp = utf8_strncmp,
>>> + .strncasecmp = utf8_strncasecmp,
>>> + .strncasecmp_folded = utf8_strncasecmp_folded,
>>> + .casefold = utf8_casefold,
>>> + .casefold_hash = utf8_casefold_hash,
>>> + .normalize = utf8_normalize,
>>> + .load = utf8_load,
>>> +};
>>> +
>>> +static int __init utf8_init(void)
>>> +{
>>> + unicode_register(&ops);
>>> + return 0;
>>> +}
>>> +
>>> +static void __exit utf8_exit(void)
>>> +{
>>> + unicode_unregister();
>>> +}
>>> +
>>> +module_init(utf8_init);
>>> +module_exit(utf8_exit);
>>> +
>>> +MODULE_LICENSE("GPL v2");
>>> diff --git a/include/linux/unicode.h b/include/linux/unicode.h
>>> index de23f9ee720b..b0d59069e438 100644
>>> --- a/include/linux/unicode.h
>>> +++ b/include/linux/unicode.h
>>> @@ -10,6 +10,23 @@ struct unicode_map {
>>> int version;
>>> };
>>> +struct unicode_ops {
>>> + int (*validate)(const struct unicode_map *um, const struct qstr *str);
>>> + int (*strncmp)(const struct unicode_map *um, const struct qstr *s1,
>>> + const struct qstr *s2);
>>> + int (*strncasecmp)(const struct unicode_map *um, const struct qstr *s1,
>>> + const struct qstr *s2);
>>> + int (*strncasecmp_folded)(const struct unicode_map *um, const struct qstr *cf,
>>> + const struct qstr *s1);
>>> + int (*normalize)(const struct unicode_map *um, const struct qstr *str,
>>> + unsigned char *dest, size_t dlen);
>>> + int (*casefold)(const struct unicode_map *um, const struct qstr *str,
>>> + unsigned char *dest, size_t dlen);
>>> + int (*casefold_hash)(const struct unicode_map *um, const void *salt,
>>> + struct qstr *str);
>>> + struct unicode_map* (*load)(const char *version);
>>> +};
>> Also, make sure you run checkpatch.pl on the patch series before
>> submitting.
> I ran checkpatch.pl over the patch, but it seems there were some
> previously existing warnings
> which are not introduced due to any change made in this patch series.
> I am not sure if I am supposed to resolve those warnings in this patch
> series.
>
>>> +
>>> int unicode_validate(const struct unicode_map *um, const struct qstr *str);
>>> int unicode_strncmp(const struct unicode_map *um,
>>> @@ -33,4 +50,7 @@ int unicode_casefold_hash(const struct unicode_map *um, const void *salt,
>>> struct unicode_map *unicode_load(const char *version);
>>> void unicode_unload(struct unicode_map *um);
>>> +void unicode_register(struct unicode_ops *ops);
>>> +void unicode_unregister(void);
>>> +
>>> #endif /* _LINUX_UNICODE_H */
>
--
Gabriel Krisman Bertazi