new file mode 100644
@@ -0,0 +1,13 @@
+What: /sys/fs/unicode/latest
+Date: April 2020
+Contact: Gabriel Krisman Bertazi <krisman@collabora.com>
+Description:
+ The latest version of the Unicode Standard supported by
+ this kernel
+
+What: /sys/fs/unicode/encodings
+Date: April 2020
+Contact: Gabriel Krisman Bertazi <krisman@collabora.com>
+Description:
+ List of encodings and corresponding versions supported
+ by this kernel
@@ -6,6 +6,7 @@
#include <linux/parser.h>
#include <linux/errno.h>
#include <linux/unicode.h>
+#include <linux/fs.h>
#include "utf8n.h"
@@ -212,4 +213,67 @@ void utf8_unload(struct unicode_map *um)
}
EXPORT_SYMBOL(utf8_unload);
+static ssize_t latest_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ int l = utf8version_latest();
+
+ return snprintf(buf, PAGE_SIZE, "UTF-8 %d.%d.%d\n", UNICODE_AGE_MAJ(l),
+ UNICODE_AGE_MIN(l), UNICODE_AGE_REV(l));
+
+}
+static ssize_t encodings_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ int n;
+
+ n = snprintf(buf, PAGE_SIZE, "UTF-8:");
+ n += utf8version_list(buf + n, PAGE_SIZE - n);
+ n += snprintf(buf+n, PAGE_SIZE-n, "\n");
+
+ return n;
+}
+
+#define UCD_ATTR(x) \
+ static struct kobj_attribute x ## _attr = __ATTR_RO(x)
+
+UCD_ATTR(latest);
+UCD_ATTR(encodings);
+
+static struct attribute *ucd_attrs[] = {
+ &latest_attr.attr,
+ &encodings_attr.attr,
+ NULL,
+};
+static const struct attribute_group ucd_attr_group = {
+ .attrs = ucd_attrs,
+};
+static struct kobject *ucd_root;
+
+int __init ucd_init(void)
+{
+ int ret;
+
+ ucd_root = kobject_create_and_add("unicode", fs_kobj);
+ if (!ucd_root)
+ return -ENOMEM;
+
+ ret = sysfs_create_group(ucd_root, &ucd_attr_group);
+ if (ret) {
+ kobject_put(ucd_root);
+ ucd_root = NULL;
+ return ret;
+ }
+
+ return 0;
+}
+
+void __exit ucd_exit(void)
+{
+ kobject_put(ucd_root);
+}
+
+module_init(ucd_init);
+module_exit(ucd_exit)
+
MODULE_LICENSE("GPL v2");
@@ -35,6 +35,24 @@ int utf8version_latest(void)
}
EXPORT_SYMBOL(utf8version_latest);
+int utf8version_list(char *buf, int len)
+{
+ int i = ARRAY_SIZE(utf8agetab) - 1;
+ int ret = 0;
+
+ /*
+ * Print most relevant (latest) first. No filesystem uses
+ * unicode <= 12.0.0, so don't expose them to userspace.
+ */
+ for (; utf8agetab[i] >= UNICODE_AGE(12, 0, 0); i--) {
+ ret += snprintf(buf+ret, len-ret, " %d.%d.%d",
+ UNICODE_AGE_MAJ(utf8agetab[i]),
+ UNICODE_AGE_MIN(utf8agetab[i]),
+ UNICODE_AGE_REV(utf8agetab[i]));
+ }
+ return ret;
+}
+
/*
* UTF-8 valid ranges.
*
@@ -21,9 +21,14 @@
((unsigned int)(MIN) << UNICODE_MIN_SHIFT) | \
((unsigned int)(REV)))
+#define UNICODE_AGE_MAJ(x) ((x) >> UNICODE_MAJ_SHIFT & 0xff)
+#define UNICODE_AGE_MIN(x) ((x) >> UNICODE_MIN_SHIFT & 0xff)
+#define UNICODE_AGE_REV(x) ((x) & 0xff)
+
/* Highest unicode version supported by the data tables. */
extern int utf8version_is_supported(u8 maj, u8 min, u8 rev);
extern int utf8version_latest(void);
+extern int utf8version_list(char *buf, int len);
/*
* Look for the correct const struct utf8data for a unicode version.
A filesystem configuration utility has no way to detect which filename encodings are supported by the running kernel. This means, for instance, mkfs has no way to tell if the generated filesystem will be mountable in the current kernel or not. Also, users have no easy way to know if they can update the encoding in their filesystems and still have something functional in the end. This exposes details of the encodings available in the unicode subsystem, to fill that gap. Cc: Theodore Ts'o <tytso@mit.edu> Cc: Jaegeuk Kim <jaegeuk@kernel.org> Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com> --- Documentation/ABI/testing/sysfs-fs-unicode | 13 +++++ fs/unicode/utf8-core.c | 64 ++++++++++++++++++++++ fs/unicode/utf8-norm.c | 18 ++++++ fs/unicode/utf8n.h | 5 ++ 4 files changed, 100 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-fs-unicode