diff --git a/fs/ext4/dir.c b/fs/ext4/dir.c
index ab1bc1c43063..5118723a5d9a 100644
--- a/fs/ext4/dir.c
+++ b/fs/ext4/dir.c
@@ -682,7 +682,10 @@ static int ext4_d_hash(const struct dentry *dentry, struct qstr *str)
 	if (!norm)
 		return -ENOMEM;
 
-	len = utf8_normalize(um, str, norm, PATH_MAX);
+	if (!IS_CASEFOLDED(dentry->d_inode))
+		len = utf8_normalize(um, str, norm, PATH_MAX);
+	else
+		len = utf8_casefold(um, str, norm, PATH_MAX);
 
 	if (len < 0) {
 		if (ext4_has_strict_mode(sbi))
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 18035350b28f..21ad8d71008c 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -399,10 +399,11 @@ struct flex_groups {
 #define EXT4_EOFBLOCKS_FL		0x00400000 /* Blocks allocated beyond EOF */
 #define EXT4_INLINE_DATA_FL		0x10000000 /* Inode has inline data. */
 #define EXT4_PROJINHERIT_FL		0x20000000 /* Create with parents projid */
+#define EXT4_CASEFOLD_FL		0x40000000 /* Casefolded file */
 #define EXT4_RESERVED_FL		0x80000000 /* reserved for ext4 lib */
 
-#define EXT4_FL_USER_VISIBLE		0x304BDFFF /* User visible flags */
-#define EXT4_FL_USER_MODIFIABLE		0x204BC0FF /* User modifiable flags */
+#define EXT4_FL_USER_VISIBLE		0x704BDFFF /* User visible flags */
+#define EXT4_FL_USER_MODIFIABLE		0x604BC0FF /* User modifiable flags */
 
 /* Flags we can manipulate with through EXT4_IOC_FSSETXATTR */
 #define EXT4_FL_XFLAG_VISIBLE		(EXT4_SYNC_FL | \
@@ -417,10 +418,10 @@ struct flex_groups {
 			   EXT4_SYNC_FL | EXT4_NODUMP_FL | EXT4_NOATIME_FL |\
 			   EXT4_NOCOMPR_FL | EXT4_JOURNAL_DATA_FL |\
 			   EXT4_NOTAIL_FL | EXT4_DIRSYNC_FL |\
-			   EXT4_PROJINHERIT_FL)
+			   EXT4_PROJINHERIT_FL | EXT4_CASEFOLD_FL)
 
 /* Flags that are appropriate for regular files (all but dir-specific ones). */
-#define EXT4_REG_FLMASK (~(EXT4_DIRSYNC_FL | EXT4_TOPDIR_FL))
+#define EXT4_REG_FLMASK (~(EXT4_DIRSYNC_FL | EXT4_TOPDIR_FL | EXT4_CASEFOLD_FL))
 
 /* Flags that are appropriate for non-directories/regular files. */
 #define EXT4_OTHER_FLMASK (EXT4_NODUMP_FL | EXT4_NOATIME_FL)
diff --git a/fs/ext4/hash.c b/fs/ext4/hash.c
index 5a33c72efc56..f1a30e1353f6 100644
--- a/fs/ext4/hash.c
+++ b/fs/ext4/hash.c
@@ -285,7 +285,10 @@ int ext4fs_dirhash(const struct inode *dir, const char *name, int len,
 		if (!buff)
 			return -1;
 
-		dlen = utf8_normalize(um, &qstr, buff, PATH_MAX);
+		if (!IS_CASEFOLDED(dir))
+			dlen = utf8_normalize(um, &qstr, buff, PATH_MAX);
+		else
+			dlen = utf8_casefold(um, &qstr, buff, PATH_MAX);
 
 		if (dlen < 0) {
 			kfree(buff);
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index b54b261ded36..9a990f5557b5 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -4738,9 +4738,11 @@ void ext4_set_inode_flags(struct inode *inode)
 		new_fl |= S_DAX;
 	if (flags & EXT4_ENCRYPT_FL)
 		new_fl |= S_ENCRYPTED;
+	if (flags & EXT4_CASEFOLD_FL)
+		new_fl |= S_CASEFOLD;
 	inode_set_flags(inode, new_fl,
 			S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC|S_DAX|
-			S_ENCRYPTED);
+			S_ENCRYPTED|S_CASEFOLD);
 }
 
 static blkcnt_t ext4_inode_blocks(struct ext4_inode *raw_inode,
diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
index 3c4f8bb59f8a..d61312d9236d 100644
--- a/fs/ext4/ioctl.c
+++ b/fs/ext4/ioctl.c
@@ -278,6 +278,7 @@ static int ext4_ioctl_setflags(struct inode *inode,
 	struct ext4_iloc iloc;
 	unsigned int oldflags, mask, i;
 	unsigned int jflag;
+	struct super_block *sb = inode->i_sb;
 
 	/* Is it quota file? Do not allow user to mess with it */
 	if (ext4_is_quota_file(inode))
@@ -322,6 +323,23 @@ static int ext4_ioctl_setflags(struct inode *inode,
 			goto flags_out;
 	}
 
+	if ((flags ^ oldflags) & EXT4_CASEFOLD_FL) {
+		if (!ext4_has_feature_fname_encoding(sb)) {
+			err = -EOPNOTSUPP;
+			goto flags_out;
+		}
+
+		if (!S_ISDIR(inode->i_mode)) {
+			err = -ENOTDIR;
+			goto flags_out;
+		}
+
+		if (!ext4_empty_dir(inode)) {
+			err = -ENOTEMPTY;
+			goto flags_out;
+		}
+	}
+
 	handle = ext4_journal_start(inode, EXT4_HT_INODE, 1);
 	if (IS_ERR(handle)) {
 		err = PTR_ERR(handle);
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 0caaa210be8c..173f45321162 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -1261,7 +1261,11 @@ int ext4_encoding_cmp(const struct inode *parent, const struct qstr *name,
 	const struct unicode_map *um = sbi->s_encoding;
 	int ret;
 
-	ret = utf8_strncmp(um, name, entry);
+	if (!IS_CASEFOLDED(parent))
+		ret = utf8_strncmp(um, name, entry);
+	else
+		ret = utf8_strncasecmp(um, name, entry);
+
 	if (ret < 0) {
 		/* Handle invalid character sequence as either an error
 		 * or as an opaque byte sequence.
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 8b42df09b04c..6261090e605b 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1953,6 +1953,7 @@ struct super_operations {
 #define S_DAX		0	/* Make all the DAX code disappear */
 #endif
 #define S_ENCRYPTED	16384	/* Encrypted file (using fs/crypto/) */
+#define S_CASEFOLD	32768	/* Casefolded file */
 
 /*
  * Note that nosuid etc flags are inode-specific: setting some file-system
@@ -1993,6 +1994,7 @@ static inline bool sb_rdonly(const struct super_block *sb) { return sb->s_flags
 #define IS_NOSEC(inode)		((inode)->i_flags & S_NOSEC)
 #define IS_DAX(inode)		((inode)->i_flags & S_DAX)
 #define IS_ENCRYPTED(inode)	((inode)->i_flags & S_ENCRYPTED)
+#define IS_CASEFOLDED(inode)	((inode)->i_flags & S_CASEFOLD)
 
 #define IS_WHITEOUT(inode)	(S_ISCHR(inode->i_mode) && \
 				 (inode)->i_rdev == WHITEOUT_DEV)
