3 files changed, 56 insertions, 3 deletions
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 3e53ba079f17..eae7ce884030 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -46,6 +46,7 @@
 #include <linux/maple_tree.h>
 #include <linux/rw_hint.h>
 #include <linux/file_ref.h>
+#include <linux/unicode.h>
 
 #include <asm/byteorder.h>
 #include <uapi/linux/fs.h>
@@ -3479,6 +3480,54 @@ extern int generic_ci_match(const struct inode *parent,
 			    const struct qstr *folded_name,
 			    const u8 *de_name, u32 de_name_len);
 
+#if IS_ENABLED(CONFIG_UNICODE)
+int generic_ci_d_hash(const struct dentry *dentry, struct qstr *str);
+int generic_ci_d_compare(const struct dentry *dentry, unsigned int len,
+			 const char *str, const struct qstr *name);
+
+/**
+ * generic_ci_validate_strict_name - Check if a given name is suitable
+ * for a directory
+ *
+ * This functions checks if the proposed filename is valid for the
+ * parent directory. That means that only valid UTF-8 filenames will be
+ * accepted for casefold directories from filesystems created with the
+ * strict encoding flag.  That also means that any name will be
+ * accepted for directories that doesn't have casefold enabled, or
+ * aren't being strict with the encoding.
+ *
+ * @dir: inode of the directory where the new file will be created
+ * @name: name of the new file
+ *
+ * Return:
+ * * True: if the filename is suitable for this directory. It can be
+ *   true if a given name is not suitable for a strict encoding
+ *   directory, but the directory being used isn't strict
+ * * False if the filename isn't suitable for this directory. This only
+ *   happens when a directory is casefolded and the filesystem is strict
+ *   about its encoding.
+ */
+static inline bool generic_ci_validate_strict_name(struct inode *dir, struct qstr *name)
+{
+	if (!IS_CASEFOLDED(dir) || !sb_has_strict_encoding(dir->i_sb))
+		return true;
+
+	/*
+	 * A casefold dir must have a encoding set, unless the filesystem
+	 * is corrupted
+	 */
+	if (WARN_ON_ONCE(!dir->i_sb->s_encoding))
+		return true;
+
+	return !utf8_validate(dir->i_sb->s_encoding, name);
+}
+#else
+static inline bool generic_ci_validate_strict_name(struct inode *dir, struct qstr *name)
+{
+	return true;
+}
+#endif
+
 static inline bool sb_has_encoding(const struct super_block *sb)
 {
 #if IS_ENABLED(CONFIG_UNICODE)
diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h
index 515a9a6a3c6f..018da28c01e7 100644
--- a/include/linux/shmem_fs.h
+++ b/include/linux/shmem_fs.h
@@ -42,10 +42,10 @@ struct shmem_inode_info {
 	struct inode		vfs_inode;
 };
 
-#define SHMEM_FL_USER_VISIBLE		FS_FL_USER_VISIBLE
+#define SHMEM_FL_USER_VISIBLE		(FS_FL_USER_VISIBLE | FS_CASEFOLD_FL)
 #define SHMEM_FL_USER_MODIFIABLE \
-	(FS_IMMUTABLE_FL | FS_APPEND_FL | FS_NODUMP_FL | FS_NOATIME_FL)
-#define SHMEM_FL_INHERITED		(FS_NODUMP_FL | FS_NOATIME_FL)
+	(FS_IMMUTABLE_FL | FS_APPEND_FL | FS_NODUMP_FL | FS_NOATIME_FL | FS_CASEFOLD_FL)
+#define SHMEM_FL_INHERITED		(FS_NODUMP_FL | FS_NOATIME_FL | FS_CASEFOLD_FL)
 
 struct shmem_quota_limits {
 	qsize_t usrquota_bhardlimit; /* Default user quota block hard limit */
diff --git a/include/linux/unicode.h b/include/linux/unicode.h
index 4d39e6e11a95..5e6b212a2aed 100644
--- a/include/linux/unicode.h
+++ b/include/linux/unicode.h
@@ -16,6 +16,8 @@ struct utf8data_table;
 	 ((unsigned int)(MIN) << UNICODE_MIN_SHIFT) |	\
 	 ((unsigned int)(REV)))
 
+#define UTF8_LATEST        UNICODE_AGE(12, 1, 0)
+
 static inline u8 unicode_major(unsigned int age)
 {
 	return (age >> UNICODE_MAJ_SHIFT) & 0xff;
@@ -76,4 +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 */