diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs b/Documentation/ABI/testing/sysfs-fs-f2fs
index dca326e0ee3e1..7ab2b1b5e255f 100644
--- a/Documentation/ABI/testing/sysfs-fs-f2fs
+++ b/Documentation/ABI/testing/sysfs-fs-f2fs
@@ -251,3 +251,10 @@ Description:
 		If checkpoint=disable, it displays the number of blocks that are unusable.
                 If checkpoint=enable it displays the enumber of blocks that would be unusable
                 if checkpoint=disable were to be set.
+
+What:		/sys/fs/f2fs/<disk>/encoding
+Date		July 2019
+Contact:	"Daniel Rosenberg" <drosen@google.com>
+Description:
+		Displays name and version of the encoding set for the filesystem.
+                If no encoding is set, displays (none)
diff --git a/Documentation/filesystems/f2fs.txt b/Documentation/filesystems/f2fs.txt
index 496fa28b24925..5fa38ab373cab 100644
--- a/Documentation/filesystems/f2fs.txt
+++ b/Documentation/filesystems/f2fs.txt
@@ -413,6 +413,9 @@ Files in /sys/fs/f2fs/<devname>
                               that would be unusable if checkpoint=disable were
                               to be set.
 
+encoding 	              This shows the encoding used for casefolding.
+                              If casefolding is not enabled, returns (none)
+
 ================================================================================
 USAGE
 ================================================================================
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 17382da7f0bd9..c6c7904572d0d 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -153,6 +153,7 @@ struct f2fs_mount_info {
 #define F2FS_FEATURE_LOST_FOUND		0x0200
 #define F2FS_FEATURE_VERITY		0x0400	/* reserved */
 #define F2FS_FEATURE_SB_CHKSUM		0x0800
+#define F2FS_FEATURE_CASEFOLD		0x1000
 
 #define __F2FS_HAS_FEATURE(raw_super, mask)				\
 	((raw_super->feature & cpu_to_le32(mask)) != 0)
@@ -1169,6 +1170,10 @@ struct f2fs_sb_info {
 	int valid_super_block;			/* valid super block no */
 	unsigned long s_flag;				/* flags for sbi */
 	struct mutex writepages;		/* mutex for writepages() */
+#ifdef CONFIG_UNICODE
+	struct unicode_map *s_encoding;
+	__u16 s_encoding_flags;
+#endif
 
 #ifdef CONFIG_BLK_DEV_ZONED
 	unsigned int blocks_per_blkz;		/* F2FS blocks per zone */
@@ -3562,6 +3567,7 @@ F2FS_FEATURE_FUNCS(quota_ino, QUOTA_INO);
 F2FS_FEATURE_FUNCS(inode_crtime, INODE_CRTIME);
 F2FS_FEATURE_FUNCS(lost_found, LOST_FOUND);
 F2FS_FEATURE_FUNCS(sb_chksum, SB_CHKSUM);
+F2FS_FEATURE_FUNCS(casefold, CASEFOLD);
 
 #ifdef CONFIG_BLK_DEV_ZONED
 static inline bool f2fs_blkz_is_seq(struct f2fs_sb_info *sbi, int devi,
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 6de6cda440315..068db78a1e03e 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -23,6 +23,7 @@
 #include <linux/f2fs_fs.h>
 #include <linux/sysfs.h>
 #include <linux/quota.h>
+#include <linux/unicode.h>
 
 #include "f2fs.h"
 #include "node.h"
@@ -222,6 +223,36 @@ void f2fs_printk(struct f2fs_sb_info *sbi, const char *fmt, ...)
 	va_end(args);
 }
 
+#ifdef CONFIG_UNICODE
+static const struct f2fs_sb_encodings {
+	__u16 magic;
+	char *name;
+	char *version;
+} f2fs_sb_encoding_map[] = {
+	{F2FS_ENC_UTF8_12_1, "utf8", "12.1.0"},
+};
+
+static int f2fs_sb_read_encoding(const struct f2fs_super_block *sb,
+				 const struct f2fs_sb_encodings **encoding,
+				 __u16 *flags)
+{
+	__u16 magic = le16_to_cpu(sb->s_encoding);
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(f2fs_sb_encoding_map); i++)
+		if (magic == f2fs_sb_encoding_map[i].magic)
+			break;
+
+	if (i >= ARRAY_SIZE(f2fs_sb_encoding_map))
+		return -EINVAL;
+
+	*encoding = &f2fs_sb_encoding_map[i];
+	*flags = le16_to_cpu(sb->s_encoding_flags);
+
+	return 0;
+}
+#endif
+
 static inline void limit_reserve_root(struct f2fs_sb_info *sbi)
 {
 	block_t limit = min((sbi->user_block_count << 1) / 1000,
@@ -798,6 +829,13 @@ static int parse_options(struct super_block *sb, char *options)
 		return -EINVAL;
 	}
 #endif
+#ifndef CONFIG_UNICODE
+	if (f2fs_sb_has_casefold(sbi)) {
+		f2fs_err(sbi,
+			"Filesystem with casefold feature cannot be mounted without CONFIG_UNICODE");
+		return -EINVAL;
+	}
+#endif
 
 	if (F2FS_IO_SIZE_BITS(sbi) && !test_opt(sbi, LFS)) {
 		f2fs_err(sbi, "Should set mode=lfs with %uKB-sized IO",
@@ -1089,6 +1127,9 @@ static void f2fs_put_super(struct super_block *sb)
 	destroy_percpu_info(sbi);
 	for (i = 0; i < NR_PAGE_TYPE; i++)
 		kvfree(sbi->write_io[i]);
+#ifdef CONFIG_UNICODE
+	utf8_unload(sbi->s_encoding);
+#endif
 	kvfree(sbi);
 }
 
@@ -3031,6 +3072,52 @@ static int f2fs_scan_devices(struct f2fs_sb_info *sbi)
 	return 0;
 }
 
+static int f2fs_setup_casefold(struct f2fs_sb_info *sbi)
+{
+#ifdef CONFIG_UNICODE
+	if (f2fs_sb_has_casefold(sbi) && !sbi->s_encoding) {
+		const struct f2fs_sb_encodings *encoding_info;
+		struct unicode_map *encoding;
+		__u16 encoding_flags;
+
+		if (f2fs_sb_has_encrypt(sbi)) {
+			f2fs_err(sbi,
+				"Can't mount with encoding and encryption");
+			return -EINVAL;
+		}
+
+		if (f2fs_sb_read_encoding(sbi->raw_super, &encoding_info,
+					  &encoding_flags)) {
+			f2fs_err(sbi,
+				 "Encoding requested by superblock is unknown");
+			return -EINVAL;
+		}
+
+		encoding = utf8_load(encoding_info->version);
+		if (IS_ERR(encoding)) {
+			f2fs_err(sbi,
+				 "can't mount with superblock charset: %s-%s "
+				 "not supported by the kernel. flags: 0x%x.",
+				 encoding_info->name, encoding_info->version,
+				 encoding_flags);
+			return PTR_ERR(encoding);
+		}
+		f2fs_info(sbi, "Using encoding defined by superblock: "
+			 "%s-%s with flags 0x%hx", encoding_info->name,
+			 encoding_info->version?:"\b", encoding_flags);
+
+		sbi->s_encoding = encoding;
+		sbi->s_encoding_flags = encoding_flags;
+	}
+#else
+	if (f2fs_sb_has_casefold(sbi)) {
+		f2fs_err(sbi, "Filesystem with casefold feature cannot be mounted without CONFIG_UNICODE");
+		return -EINVAL;
+	}
+#endif
+	return 0;
+}
+
 static void f2fs_tuning_parameters(struct f2fs_sb_info *sbi)
 {
 	struct f2fs_sm_info *sm_i = SM_I(sbi);
@@ -3127,6 +3214,10 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
 				le32_to_cpu(raw_super->log_blocksize);
 	sb->s_max_links = F2FS_LINK_MAX;
 
+	err = f2fs_setup_casefold(sbi);
+	if (err)
+		goto free_options;
+
 #ifdef CONFIG_QUOTA
 	sb->dq_op = &f2fs_quota_operations;
 	sb->s_qcop = &f2fs_quotactl_ops;
@@ -3477,6 +3568,10 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
 free_bio_info:
 	for (i = 0; i < NR_PAGE_TYPE; i++)
 		kvfree(sbi->write_io[i]);
+
+#ifdef CONFIG_UNICODE
+	utf8_unload(sbi->s_encoding);
+#endif
 free_options:
 #ifdef CONFIG_QUOTA
 	for (i = 0; i < MAXQUOTAS; i++)
diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
index 3aeacd0aacfd2..f9fcca695db9f 100644
--- a/fs/f2fs/sysfs.c
+++ b/fs/f2fs/sysfs.c
@@ -10,6 +10,7 @@
 #include <linux/proc_fs.h>
 #include <linux/f2fs_fs.h>
 #include <linux/seq_file.h>
+#include <linux/unicode.h>
 
 #include "f2fs.h"
 #include "segment.h"
@@ -81,6 +82,19 @@ static ssize_t unusable_show(struct f2fs_attr *a,
 		(unsigned long long)unusable);
 }
 
+static ssize_t encoding_show(struct f2fs_attr *a,
+		struct f2fs_sb_info *sbi, char *buf)
+{
+#ifdef CONFIG_UNICODE
+	if (f2fs_sb_has_casefold(sbi))
+		return snprintf(buf, PAGE_SIZE, "%s (%d.%d.%d)\n",
+			sbi->s_encoding->charset,
+			(sbi->s_encoding->version >> 16) & 0xff,
+			(sbi->s_encoding->version >> 8) & 0xff,
+			sbi->s_encoding->version & 0xff);
+#endif
+	return snprintf(buf, PAGE_SIZE, "(none)");
+}
 
 static ssize_t lifetime_write_kbytes_show(struct f2fs_attr *a,
 		struct f2fs_sb_info *sbi, char *buf)
@@ -134,6 +148,9 @@ static ssize_t features_show(struct f2fs_attr *a,
 	if (f2fs_sb_has_sb_chksum(sbi))
 		len += snprintf(buf + len, PAGE_SIZE - len, "%s%s",
 				len ? ", " : "", "sb_checksum");
+	if (f2fs_sb_has_casefold(sbi))
+		len += snprintf(buf + len, PAGE_SIZE - len, "%s%s",
+				len ? ", " : "", "casefold");
 	len += snprintf(buf + len, PAGE_SIZE - len, "\n");
 	return len;
 }
@@ -365,6 +382,7 @@ enum feat_id {
 	FEAT_INODE_CRTIME,
 	FEAT_LOST_FOUND,
 	FEAT_SB_CHECKSUM,
+	FEAT_CASEFOLD,
 };
 
 static ssize_t f2fs_feature_show(struct f2fs_attr *a,
@@ -382,6 +400,7 @@ static ssize_t f2fs_feature_show(struct f2fs_attr *a,
 	case FEAT_INODE_CRTIME:
 	case FEAT_LOST_FOUND:
 	case FEAT_SB_CHECKSUM:
+	case FEAT_CASEFOLD:
 		return snprintf(buf, PAGE_SIZE, "supported\n");
 	}
 	return 0;
@@ -455,6 +474,7 @@ F2FS_GENERAL_RO_ATTR(lifetime_write_kbytes);
 F2FS_GENERAL_RO_ATTR(features);
 F2FS_GENERAL_RO_ATTR(current_reserved_blocks);
 F2FS_GENERAL_RO_ATTR(unusable);
+F2FS_GENERAL_RO_ATTR(encoding);
 
 #ifdef CONFIG_FS_ENCRYPTION
 F2FS_FEATURE_RO_ATTR(encryption, FEAT_CRYPTO);
@@ -471,6 +491,7 @@ F2FS_FEATURE_RO_ATTR(quota_ino, FEAT_QUOTA_INO);
 F2FS_FEATURE_RO_ATTR(inode_crtime, FEAT_INODE_CRTIME);
 F2FS_FEATURE_RO_ATTR(lost_found, FEAT_LOST_FOUND);
 F2FS_FEATURE_RO_ATTR(sb_checksum, FEAT_SB_CHECKSUM);
+F2FS_FEATURE_RO_ATTR(casefold, FEAT_CASEFOLD);
 
 #define ATTR_LIST(name) (&f2fs_attr_##name.attr)
 static struct attribute *f2fs_attrs[] = {
@@ -515,6 +536,7 @@ static struct attribute *f2fs_attrs[] = {
 	ATTR_LIST(features),
 	ATTR_LIST(reserved_blocks),
 	ATTR_LIST(current_reserved_blocks),
+	ATTR_LIST(encoding),
 	NULL,
 };
 ATTRIBUTE_GROUPS(f2fs);
@@ -535,6 +557,7 @@ static struct attribute *f2fs_feat_attrs[] = {
 	ATTR_LIST(inode_crtime),
 	ATTR_LIST(lost_found),
 	ATTR_LIST(sb_checksum),
+	ATTR_LIST(casefold),
 	NULL,
 };
 ATTRIBUTE_GROUPS(f2fs_feat);
diff --git a/include/linux/f2fs_fs.h b/include/linux/f2fs_fs.h
index 65559900d4d76..b7c9c7f721339 100644
--- a/include/linux/f2fs_fs.h
+++ b/include/linux/f2fs_fs.h
@@ -36,6 +36,11 @@
 
 #define F2FS_MAX_QUOTAS		3
 
+#define F2FS_ENC_UTF8_12_1	1
+#define F2FS_ENC_STRICT_MODE_FL	(1 << 0)
+#define f2fs_has_strict_mode(sbi) \
+	(sbi->s_encoding_flags & F2FS_ENC_STRICT_MODE_FL)
+
 #define F2FS_IO_SIZE(sbi)	(1 << F2FS_OPTION(sbi).write_io_size_bits) /* Blocks */
 #define F2FS_IO_SIZE_KB(sbi)	(1 << (F2FS_OPTION(sbi).write_io_size_bits + 2)) /* KB */
 #define F2FS_IO_SIZE_BYTES(sbi)	(1 << (F2FS_OPTION(sbi).write_io_size_bits + 12)) /* B */
@@ -109,7 +114,9 @@ struct f2fs_super_block {
 	struct f2fs_device devs[MAX_DEVICES];	/* device list */
 	__le32 qf_ino[F2FS_MAX_QUOTAS];	/* quota inode numbers */
 	__u8 hot_ext_count;		/* # of hot file extension */
-	__u8 reserved[310];		/* valid reserved region */
+	__le16  s_encoding;		/* Filename charset encoding */
+	__le16  s_encoding_flags;	/* Filename charset encoding flags */
+	__u8 reserved[306];		/* valid reserved region */
 	__le32 crc;			/* checksum of superblock */
 } __packed;
 
