diff mbox series

[RFC,13/20] hfsplus: Do not use broken utf8 NLS table for iocharset=utf8 mount option

Message ID 20210808162453.1653-14-pali@kernel.org (mailing list archive)
State New, archived
Headers show
Series fs: Remove usage of broken nls_utf8 and drop it | expand

Commit Message

Pali Rohár Aug. 8, 2021, 4:24 p.m. UTC 
NLS table for utf8 is broken and cannot be fixed.

So instead of broken utf8 nls functions char2uni() and uni2char() use
functions utf8_to_utf32() and utf32_to_utf8() which implements correct
encoding and decoding between Unicode code points and UTF-8 sequence.

Note that this fs driver does not support full Unicode range, specially
UTF-16 surrogate pairs are unsupported. This patch does not change this
limitation and support for UTF-16 surrogate pairs stay unimplemented.

When iochatset=utf8 is used then set sbi->nls to NULL and use it for
distinguish between the fact if NLS table or native UTF-8 functions should
be used.

Signed-off-by: Pali Rohár <pali@kernel.org>
---
 fs/hfsplus/dir.c            |  6 ++++--
 fs/hfsplus/options.c        | 32 ++++++++++++++++++--------------
 fs/hfsplus/super.c          |  7 +------
 fs/hfsplus/unicode.c        | 31 ++++++++++++++++++++++++++++---
 fs/hfsplus/xattr.c          | 14 +++++++++-----
 fs/hfsplus/xattr_security.c |  3 ++-
 6 files changed, 62 insertions(+), 31 deletions(-)

Comments

Viacheslav Dubeyko Aug. 9, 2021, 5:42 p.m. UTC | #1 
> On Aug 8, 2021, at 9:24 AM, Pali Rohár <pali@kernel.org> wrote:
> 
> NLS table for utf8 is broken and cannot be fixed.
> 
> So instead of broken utf8 nls functions char2uni() and uni2char() use
> functions utf8_to_utf32() and utf32_to_utf8() which implements correct
> encoding and decoding between Unicode code points and UTF-8 sequence.
> 
> Note that this fs driver does not support full Unicode range, specially
> UTF-16 surrogate pairs are unsupported. This patch does not change this
> limitation and support for UTF-16 surrogate pairs stay unimplemented.
> 
> When iochatset=utf8 is used then set sbi->nls to NULL and use it for
> distinguish between the fact if NLS table or native UTF-8 functions should
> be used.
> 
> Signed-off-by: Pali Rohár <pali@kernel.org>
> ---
> fs/hfsplus/dir.c            |  6 ++++--
> fs/hfsplus/options.c        | 32 ++++++++++++++++++--------------
> fs/hfsplus/super.c          |  7 +------
> fs/hfsplus/unicode.c        | 31 ++++++++++++++++++++++++++++---
> fs/hfsplus/xattr.c          | 14 +++++++++-----
> fs/hfsplus/xattr_security.c |  3 ++-
> 6 files changed, 62 insertions(+), 31 deletions(-)
> 
> diff --git a/fs/hfsplus/dir.c b/fs/hfsplus/dir.c
> index 84714bbccc12..2caf0cd82221 100644
> --- a/fs/hfsplus/dir.c
> +++ b/fs/hfsplus/dir.c
> @@ -144,7 +144,8 @@ static int hfsplus_readdir(struct file *file, struct dir_context *ctx)
> 	err = hfs_find_init(HFSPLUS_SB(sb)->cat_tree, &fd);
> 	if (err)
> 		return err;
> -	strbuf = kmalloc(NLS_MAX_CHARSET_SIZE * HFSPLUS_MAX_STRLEN + 1, GFP_KERNEL);
> +	strbuf = kmalloc((HFSPLUS_SB(sb)->nls ? NLS_MAX_CHARSET_SIZE : 4) *
> +			HFSPLUS_MAX_STRLEN + 1, GFP_KERNEL);

Maybe, introduce some variable that will contain the length calculation?

> 	if (!strbuf) {
> 		err = -ENOMEM;
> 		goto out;
> @@ -203,7 +204,8 @@ static int hfsplus_readdir(struct file *file, struct dir_context *ctx)
> 		hfs_bnode_read(fd.bnode, &entry, fd.entryoffset,
> 			fd.entrylength);
> 		type = be16_to_cpu(entry.type);
> -		len = NLS_MAX_CHARSET_SIZE * HFSPLUS_MAX_STRLEN;
> +		len = (HFSPLUS_SB(sb)->nls ? NLS_MAX_CHARSET_SIZE : 4) *
> +		      HFSPLUS_MAX_STRLEN;
> 		err = hfsplus_uni2asc(sb, &fd.key->cat.name, strbuf, &len);
> 		if (err)
> 			goto out;
> diff --git a/fs/hfsplus/options.c b/fs/hfsplus/options.c
> index a975548f6b91..16c08cb5c4f8 100644
> --- a/fs/hfsplus/options.c
> +++ b/fs/hfsplus/options.c
> @@ -104,6 +104,9 @@ int hfsplus_parse_options(char *input, struct hfsplus_sb_info *sbi)
> 	char *p;
> 	substring_t args[MAX_OPT_ARGS];
> 	int tmp, token;
> +	int have_iocharset;
> +
> +	have_iocharset = 0;

What’s about boolean type and to use true/false?

> 
> 	if (!input)
> 		goto done;
> @@ -171,20 +174,24 @@ int hfsplus_parse_options(char *input, struct hfsplus_sb_info *sbi)
> 			pr_warn("option nls= is deprecated, use iocharset=\n");
> 			/* fallthrough */
> 		case opt_iocharset:
> -			if (sbi->nls) {
> +			if (have_iocharset) {
> 				pr_err("unable to change nls mapping\n");
> 				return 0;
> 			}
> 			p = match_strdup(&args[0]);
> -			if (p)
> -				sbi->nls = load_nls(p);
> -			if (!sbi->nls) {
> -				pr_err("unable to load nls mapping \"%s\"\n",
> -				       p);
> -				kfree(p);
> +			if (!p)
> 				return 0;
> +			if (strcmp(p, "utf8") != 0) {
> +				sbi->nls = load_nls(p);
> +				if (!sbi->nls) {
> +					pr_err("unable to load nls mapping "
> +						"\"%s\"\n", p);
> +					kfree(p);
> +					return 0;
> +				}
> 			}
> 			kfree(p);
> +			have_iocharset = 1;

Ditto. What’s about true here?

> 			break;
> 		case opt_decompose:
> 			clear_bit(HFSPLUS_SB_NODECOMPOSE, &sbi->flags);
> @@ -207,13 +214,10 @@ int hfsplus_parse_options(char *input, struct hfsplus_sb_info *sbi)
> 	}
> 
> done:
> -	if (!sbi->nls) {
> -		/* try utf8 first, as this is the old default behaviour */
> -		sbi->nls = load_nls("utf8");
> -		if (!sbi->nls)
> -			sbi->nls = load_nls_default();
> -		if (!sbi->nls)
> -			return 0;
> +	if (!have_iocharset) {
> +		/* use utf8, as this is the old default behaviour */
> +		pr_debug("using native UTF-8 without nls\n");
> +		/* no sbi->nls means that native UTF-8 code is used */
> 	}
> 
> 	return 1;
> diff --git a/fs/hfsplus/super.c b/fs/hfsplus/super.c
> index b9e3db3f855f..985662451bfc 100644
> --- a/fs/hfsplus/super.c
> +++ b/fs/hfsplus/super.c
> @@ -403,11 +403,7 @@ static int hfsplus_fill_super(struct super_block *sb, void *data, int silent)
> 
> 	/* temporarily use utf8 to correctly find the hidden dir below */
> 	nls = sbi->nls;
> -	sbi->nls = load_nls("utf8");
> -	if (!sbi->nls) {
> -		pr_err("unable to load nls for utf8\n");
> -		goto out_unload_nls;
> -	}
> +	sbi->nls = NULL;
> 
> 	/* Grab the volume header */
> 	if (hfsplus_read_wrapper(sb)) {
> @@ -585,7 +581,6 @@ static int hfsplus_fill_super(struct super_block *sb, void *data, int silent)
> 		}
> 	}
> 
> -	unload_nls(sbi->nls);
> 	sbi->nls = nls;
> 	return 0;
> 
> diff --git a/fs/hfsplus/unicode.c b/fs/hfsplus/unicode.c
> index 73342c925a4b..1d8c31c5126f 100644
> --- a/fs/hfsplus/unicode.c
> +++ b/fs/hfsplus/unicode.c
> @@ -190,7 +190,12 @@ int hfsplus_uni2asc(struct super_block *sb,
> 				c0 = ':';
> 				break;
> 			}
> -			res = nls->uni2char(c0, op, len);
> +			if (nls)
> +				res = nls->uni2char(c0, op, len);
> +			else (len > 0)
> +				res = utf32_to_utf8(c0, op, len);
> +			else
> +				res = -ENAMETOOLONG;
> 			if (res < 0) {
> 				if (res == -ENAMETOOLONG)
> 					goto out;
> @@ -233,7 +238,12 @@ int hfsplus_uni2asc(struct super_block *sb,
> 			cc = c0;
> 		}
> done:
> -		res = nls->uni2char(cc, op, len);
> +		if (nls)
> +			res = nls->uni2char(cc, op, len);
> +		else (len > 0)
> +			res = utf32_to_utf8(cc, op, len);
> +		else
> +			res = -ENAMETOOLONG;
> 		if (res < 0) {
> 			if (res == -ENAMETOOLONG)
> 				goto out;
> @@ -256,7 +266,22 @@ int hfsplus_uni2asc(struct super_block *sb,
> static inline int asc2unichar(struct super_block *sb, const char *astr, int len,
> 			      wchar_t *uc)
> {
> -	int size = HFSPLUS_SB(sb)->nls->char2uni(astr, len, uc);
> +	struct nls_table *nls = HFSPLUS_SB(sb)->nls;
> +	unicode_t u;
> +	int size;
> +
> +	if (nls)
> +		size = nls->char2uni(astr, len, uc);
> +	else {
> +		size = utf8_to_utf32(astr, len, &u);
> +		if (size >= 0) {
> +			/* TODO: Add support for UTF-16 surrogate pairs */

Have you forgot to delete this string? Or do you plan to implement this?

> +			if (u <= MAX_WCHAR_T)
> +				*uc = u;
> +			else
> +				size = -EINVAL;
> +		}
> +	}
> 	if (size <= 0) {
> 		*uc = '?';
> 		size = 1;
> diff --git a/fs/hfsplus/xattr.c b/fs/hfsplus/xattr.c
> index e2855ceefd39..9b2653f08a5f 100644
> --- a/fs/hfsplus/xattr.c
> +++ b/fs/hfsplus/xattr.c
> @@ -425,7 +425,8 @@ int hfsplus_setxattr(struct inode *inode, const char *name,
> 	char *xattr_name;
> 	int res;
> 
> -	xattr_name = kmalloc(NLS_MAX_CHARSET_SIZE * HFSPLUS_ATTR_MAX_STRLEN + 1,
> +	xattr_name = kmalloc((HFSPLUS_SB(sb)->nls ? NLS_MAX_CHARSET_SIZE : 4) *
> +			     HFSPLUS_ATTR_MAX_STRLEN + 1,
> 		GFP_KERNEL);

What’s about to introduce a variable for length calculation?

> 	if (!xattr_name)
> 		return -ENOMEM;
> @@ -579,7 +580,8 @@ ssize_t hfsplus_getxattr(struct inode *inode, const char *name,
> 	int res;
> 	char *xattr_name;
> 
> -	xattr_name = kmalloc(NLS_MAX_CHARSET_SIZE * HFSPLUS_ATTR_MAX_STRLEN + 1,
> +	xattr_name = kmalloc((HFSPLUS_SB(sb)->nls ? NLS_MAX_CHARSET_SIZE : 4) *
> +			     HFSPLUS_ATTR_MAX_STRLEN + 1,
> 			     GFP_KERNEL);

Ditto. What’s about to introduce a variable for length calculation?

> 	if (!xattr_name)
> 		return -ENOMEM;
> @@ -699,8 +701,9 @@ ssize_t hfsplus_listxattr(struct dentry *dentry, char *buffer, size_t size)
> 		return err;
> 	}
> 
> -	strbuf = kmalloc(NLS_MAX_CHARSET_SIZE * HFSPLUS_ATTR_MAX_STRLEN +
> -			XATTR_MAC_OSX_PREFIX_LEN + 1, GFP_KERNEL);
> +	strbuf = kmalloc((HFSPLUS_SB(sb)->nls ? NLS_MAX_CHARSET_SIZE : 4) *
> +			HFSPLUS_ATTR_MAX_STRLEN + XATTR_MAC_OSX_PREFIX_LEN + 1,
> +			GFP_KERNEL);

Ditto. What’s about to introduce a variable for length calculation?

> 	if (!strbuf) {
> 		res = -ENOMEM;
> 		goto out;
> @@ -732,7 +735,8 @@ ssize_t hfsplus_listxattr(struct dentry *dentry, char *buffer, size_t size)
> 		if (be32_to_cpu(attr_key.cnid) != inode->i_ino)
> 			goto end_listxattr;
> 
> -		xattr_name_len = NLS_MAX_CHARSET_SIZE * HFSPLUS_ATTR_MAX_STRLEN;
> +		xattr_name_len = (HFSPLUS_SB(sb)->nls ? NLS_MAX_CHARSET_SIZE : 4)
> +				* HFSPLUS_ATTR_MAX_STRLEN;
> 		if (hfsplus_uni2asc(inode->i_sb,
> 			(const struct hfsplus_unistr *)&fd.key->attr.key_name,
> 					strbuf, &xattr_name_len)) {
> diff --git a/fs/hfsplus/xattr_security.c b/fs/hfsplus/xattr_security.c
> index c1c7a16cbf21..438ebcd1359b 100644
> --- a/fs/hfsplus/xattr_security.c
> +++ b/fs/hfsplus/xattr_security.c
> @@ -41,7 +41,8 @@ static int hfsplus_initxattrs(struct inode *inode,
> 	char *xattr_name;
> 	int err = 0;
> 
> -	xattr_name = kmalloc(NLS_MAX_CHARSET_SIZE * HFSPLUS_ATTR_MAX_STRLEN + 1,
> +	xattr_name = kmalloc((HFSPLUS_SB(sb)->nls ? NLS_MAX_CHARSET_SIZE : 4) *
> +			     HFSPLUS_ATTR_MAX_STRLEN + 1,
> 		GFP_KERNEL);

Ditto. What’s about to introduce a variable for length calculation?

Thanks,
Slava.

> 	if (!xattr_name)
> 		return -ENOMEM;
> -- 
> 2.20.1
>
Pali Rohár Sept. 25, 2022, 12:12 p.m. UTC | #2 
Hello!

On Monday 09 August 2021 10:42:02 Viacheslav Dubeyko wrote:
> > On Aug 8, 2021, at 9:24 AM, Pali Rohár <pali@kernel.org> wrote:
> > 
> > NLS table for utf8 is broken and cannot be fixed.
> > 
> > So instead of broken utf8 nls functions char2uni() and uni2char() use
> > functions utf8_to_utf32() and utf32_to_utf8() which implements correct
> > encoding and decoding between Unicode code points and UTF-8 sequence.
> > 
> > Note that this fs driver does not support full Unicode range, specially
> > UTF-16 surrogate pairs are unsupported. This patch does not change this
> > limitation and support for UTF-16 surrogate pairs stay unimplemented.
> > 
> > When iochatset=utf8 is used then set sbi->nls to NULL and use it for
> > distinguish between the fact if NLS table or native UTF-8 functions should
> > be used.
> > 
> > Signed-off-by: Pali Rohár <pali@kernel.org>
> > ---
> > fs/hfsplus/dir.c            |  6 ++++--
> > fs/hfsplus/options.c        | 32 ++++++++++++++++++--------------
> > fs/hfsplus/super.c          |  7 +------
> > fs/hfsplus/unicode.c        | 31 ++++++++++++++++++++++++++++---
> > fs/hfsplus/xattr.c          | 14 +++++++++-----
> > fs/hfsplus/xattr_security.c |  3 ++-
> > 6 files changed, 62 insertions(+), 31 deletions(-)
> > 
> > diff --git a/fs/hfsplus/dir.c b/fs/hfsplus/dir.c
> > index 84714bbccc12..2caf0cd82221 100644
> > --- a/fs/hfsplus/dir.c
> > +++ b/fs/hfsplus/dir.c
> > @@ -144,7 +144,8 @@ static int hfsplus_readdir(struct file *file, struct dir_context *ctx)
> > 	err = hfs_find_init(HFSPLUS_SB(sb)->cat_tree, &fd);
> > 	if (err)
> > 		return err;
> > -	strbuf = kmalloc(NLS_MAX_CHARSET_SIZE * HFSPLUS_MAX_STRLEN + 1, GFP_KERNEL);
> > +	strbuf = kmalloc((HFSPLUS_SB(sb)->nls ? NLS_MAX_CHARSET_SIZE : 4) *
> > +			HFSPLUS_MAX_STRLEN + 1, GFP_KERNEL);
> 
> Maybe, introduce some variable that will contain the length calculation?

Ok! I can introduce variable with calculated length into all places.

> > 	if (!strbuf) {
> > 		err = -ENOMEM;
> > 		goto out;
> > @@ -203,7 +204,8 @@ static int hfsplus_readdir(struct file *file, struct dir_context *ctx)
> > 		hfs_bnode_read(fd.bnode, &entry, fd.entryoffset,
> > 			fd.entrylength);
> > 		type = be16_to_cpu(entry.type);
> > -		len = NLS_MAX_CHARSET_SIZE * HFSPLUS_MAX_STRLEN;
> > +		len = (HFSPLUS_SB(sb)->nls ? NLS_MAX_CHARSET_SIZE : 4) *
> > +		      HFSPLUS_MAX_STRLEN;
> > 		err = hfsplus_uni2asc(sb, &fd.key->cat.name, strbuf, &len);
> > 		if (err)
> > 			goto out;
> > diff --git a/fs/hfsplus/options.c b/fs/hfsplus/options.c
> > index a975548f6b91..16c08cb5c4f8 100644
> > --- a/fs/hfsplus/options.c
> > +++ b/fs/hfsplus/options.c
> > @@ -104,6 +104,9 @@ int hfsplus_parse_options(char *input, struct hfsplus_sb_info *sbi)
> > 	char *p;
> > 	substring_t args[MAX_OPT_ARGS];
> > 	int tmp, token;
> > +	int have_iocharset;
> > +
> > +	have_iocharset = 0;
> 
> What’s about boolean type and to use true/false?

Ok. I can change type to "bool" and use "true"/"false" values.

> > 
> > 	if (!input)
> > 		goto done;
> > @@ -171,20 +174,24 @@ int hfsplus_parse_options(char *input, struct hfsplus_sb_info *sbi)
> > 			pr_warn("option nls= is deprecated, use iocharset=\n");
> > 			/* fallthrough */
> > 		case opt_iocharset:
> > -			if (sbi->nls) {
> > +			if (have_iocharset) {
> > 				pr_err("unable to change nls mapping\n");
> > 				return 0;
> > 			}
> > 			p = match_strdup(&args[0]);
> > -			if (p)
> > -				sbi->nls = load_nls(p);
> > -			if (!sbi->nls) {
> > -				pr_err("unable to load nls mapping \"%s\"\n",
> > -				       p);
> > -				kfree(p);
> > +			if (!p)
> > 				return 0;
> > +			if (strcmp(p, "utf8") != 0) {
> > +				sbi->nls = load_nls(p);
> > +				if (!sbi->nls) {
> > +					pr_err("unable to load nls mapping "
> > +						"\"%s\"\n", p);
> > +					kfree(p);
> > +					return 0;
> > +				}
> > 			}
> > 			kfree(p);
> > +			have_iocharset = 1;
> 
> Ditto. What’s about true here?
> 
> > 			break;
> > 		case opt_decompose:
> > 			clear_bit(HFSPLUS_SB_NODECOMPOSE, &sbi->flags);
...
> > @@ -256,7 +266,22 @@ int hfsplus_uni2asc(struct super_block *sb,
> > static inline int asc2unichar(struct super_block *sb, const char *astr, int len,
> > 			      wchar_t *uc)
> > {
> > -	int size = HFSPLUS_SB(sb)->nls->char2uni(astr, len, uc);
> > +	struct nls_table *nls = HFSPLUS_SB(sb)->nls;
> > +	unicode_t u;
> > +	int size;
> > +
> > +	if (nls)
> > +		size = nls->char2uni(astr, len, uc);
> > +	else {
> > +		size = utf8_to_utf32(astr, len, &u);
> > +		if (size >= 0) {
> > +			/* TODO: Add support for UTF-16 surrogate pairs */
> 
> Have you forgot to delete this string? Or do you plan to implement this?

No. I have not forgot. In current version there is missing support for
UTF-16 surrogate pairs and this my patch still does not implement it.

So this is kind a issue / bug in the driver and at least it should be
documented. So reader of this code would know it and maybe somebody in
future will implement it.

> > +			if (u <= MAX_WCHAR_T)
> > +				*uc = u;
> > +			else
> > +				size = -EINVAL;
> > +		}
> > +	}
diff mbox series

Patch

diff --git a/fs/hfsplus/dir.c b/fs/hfsplus/dir.c
index 84714bbccc12..2caf0cd82221 100644
--- a/fs/hfsplus/dir.c
+++ b/fs/hfsplus/dir.c
@@ -144,7 +144,8 @@  static int hfsplus_readdir(struct file *file, struct dir_context *ctx)
 	err = hfs_find_init(HFSPLUS_SB(sb)->cat_tree, &fd);
 	if (err)
 		return err;
-	strbuf = kmalloc(NLS_MAX_CHARSET_SIZE * HFSPLUS_MAX_STRLEN + 1, GFP_KERNEL);
+	strbuf = kmalloc((HFSPLUS_SB(sb)->nls ? NLS_MAX_CHARSET_SIZE : 4) *
+			HFSPLUS_MAX_STRLEN + 1, GFP_KERNEL);
 	if (!strbuf) {
 		err = -ENOMEM;
 		goto out;
@@ -203,7 +204,8 @@  static int hfsplus_readdir(struct file *file, struct dir_context *ctx)
 		hfs_bnode_read(fd.bnode, &entry, fd.entryoffset,
 			fd.entrylength);
 		type = be16_to_cpu(entry.type);
-		len = NLS_MAX_CHARSET_SIZE * HFSPLUS_MAX_STRLEN;
+		len = (HFSPLUS_SB(sb)->nls ? NLS_MAX_CHARSET_SIZE : 4) *
+		      HFSPLUS_MAX_STRLEN;
 		err = hfsplus_uni2asc(sb, &fd.key->cat.name, strbuf, &len);
 		if (err)
 			goto out;
diff --git a/fs/hfsplus/options.c b/fs/hfsplus/options.c
index a975548f6b91..16c08cb5c4f8 100644
--- a/fs/hfsplus/options.c
+++ b/fs/hfsplus/options.c
@@ -104,6 +104,9 @@  int hfsplus_parse_options(char *input, struct hfsplus_sb_info *sbi)
 	char *p;
 	substring_t args[MAX_OPT_ARGS];
 	int tmp, token;
+	int have_iocharset;
+
+	have_iocharset = 0;
 
 	if (!input)
 		goto done;
@@ -171,20 +174,24 @@  int hfsplus_parse_options(char *input, struct hfsplus_sb_info *sbi)
 			pr_warn("option nls= is deprecated, use iocharset=\n");
 			/* fallthrough */
 		case opt_iocharset:
-			if (sbi->nls) {
+			if (have_iocharset) {
 				pr_err("unable to change nls mapping\n");
 				return 0;
 			}
 			p = match_strdup(&args[0]);
-			if (p)
-				sbi->nls = load_nls(p);
-			if (!sbi->nls) {
-				pr_err("unable to load nls mapping \"%s\"\n",
-				       p);
-				kfree(p);
+			if (!p)
 				return 0;
+			if (strcmp(p, "utf8") != 0) {
+				sbi->nls = load_nls(p);
+				if (!sbi->nls) {
+					pr_err("unable to load nls mapping "
+						"\"%s\"\n", p);
+					kfree(p);
+					return 0;
+				}
 			}
 			kfree(p);
+			have_iocharset = 1;
 			break;
 		case opt_decompose:
 			clear_bit(HFSPLUS_SB_NODECOMPOSE, &sbi->flags);
@@ -207,13 +214,10 @@  int hfsplus_parse_options(char *input, struct hfsplus_sb_info *sbi)
 	}
 
 done:
-	if (!sbi->nls) {
-		/* try utf8 first, as this is the old default behaviour */
-		sbi->nls = load_nls("utf8");
-		if (!sbi->nls)
-			sbi->nls = load_nls_default();
-		if (!sbi->nls)
-			return 0;
+	if (!have_iocharset) {
+		/* use utf8, as this is the old default behaviour */
+		pr_debug("using native UTF-8 without nls\n");
+		/* no sbi->nls means that native UTF-8 code is used */
 	}
 
 	return 1;
diff --git a/fs/hfsplus/super.c b/fs/hfsplus/super.c
index b9e3db3f855f..985662451bfc 100644
--- a/fs/hfsplus/super.c
+++ b/fs/hfsplus/super.c
@@ -403,11 +403,7 @@  static int hfsplus_fill_super(struct super_block *sb, void *data, int silent)
 
 	/* temporarily use utf8 to correctly find the hidden dir below */
 	nls = sbi->nls;
-	sbi->nls = load_nls("utf8");
-	if (!sbi->nls) {
-		pr_err("unable to load nls for utf8\n");
-		goto out_unload_nls;
-	}
+	sbi->nls = NULL;
 
 	/* Grab the volume header */
 	if (hfsplus_read_wrapper(sb)) {
@@ -585,7 +581,6 @@  static int hfsplus_fill_super(struct super_block *sb, void *data, int silent)
 		}
 	}
 
-	unload_nls(sbi->nls);
 	sbi->nls = nls;
 	return 0;
 
diff --git a/fs/hfsplus/unicode.c b/fs/hfsplus/unicode.c
index 73342c925a4b..1d8c31c5126f 100644
--- a/fs/hfsplus/unicode.c
+++ b/fs/hfsplus/unicode.c
@@ -190,7 +190,12 @@  int hfsplus_uni2asc(struct super_block *sb,
 				c0 = ':';
 				break;
 			}
-			res = nls->uni2char(c0, op, len);
+			if (nls)
+				res = nls->uni2char(c0, op, len);
+			else (len > 0)
+				res = utf32_to_utf8(c0, op, len);
+			else
+				res = -ENAMETOOLONG;
 			if (res < 0) {
 				if (res == -ENAMETOOLONG)
 					goto out;
@@ -233,7 +238,12 @@  int hfsplus_uni2asc(struct super_block *sb,
 			cc = c0;
 		}
 done:
-		res = nls->uni2char(cc, op, len);
+		if (nls)
+			res = nls->uni2char(cc, op, len);
+		else (len > 0)
+			res = utf32_to_utf8(cc, op, len);
+		else
+			res = -ENAMETOOLONG;
 		if (res < 0) {
 			if (res == -ENAMETOOLONG)
 				goto out;
@@ -256,7 +266,22 @@  int hfsplus_uni2asc(struct super_block *sb,
 static inline int asc2unichar(struct super_block *sb, const char *astr, int len,
 			      wchar_t *uc)
 {
-	int size = HFSPLUS_SB(sb)->nls->char2uni(astr, len, uc);
+	struct nls_table *nls = HFSPLUS_SB(sb)->nls;
+	unicode_t u;
+	int size;
+
+	if (nls)
+		size = nls->char2uni(astr, len, uc);
+	else {
+		size = utf8_to_utf32(astr, len, &u);
+		if (size >= 0) {
+			/* TODO: Add support for UTF-16 surrogate pairs */
+			if (u <= MAX_WCHAR_T)
+				*uc = u;
+			else
+				size = -EINVAL;
+		}
+	}
 	if (size <= 0) {
 		*uc = '?';
 		size = 1;
diff --git a/fs/hfsplus/xattr.c b/fs/hfsplus/xattr.c
index e2855ceefd39..9b2653f08a5f 100644
--- a/fs/hfsplus/xattr.c
+++ b/fs/hfsplus/xattr.c
@@ -425,7 +425,8 @@  int hfsplus_setxattr(struct inode *inode, const char *name,
 	char *xattr_name;
 	int res;
 
-	xattr_name = kmalloc(NLS_MAX_CHARSET_SIZE * HFSPLUS_ATTR_MAX_STRLEN + 1,
+	xattr_name = kmalloc((HFSPLUS_SB(sb)->nls ? NLS_MAX_CHARSET_SIZE : 4) *
+			     HFSPLUS_ATTR_MAX_STRLEN + 1,
 		GFP_KERNEL);
 	if (!xattr_name)
 		return -ENOMEM;
@@ -579,7 +580,8 @@  ssize_t hfsplus_getxattr(struct inode *inode, const char *name,
 	int res;
 	char *xattr_name;
 
-	xattr_name = kmalloc(NLS_MAX_CHARSET_SIZE * HFSPLUS_ATTR_MAX_STRLEN + 1,
+	xattr_name = kmalloc((HFSPLUS_SB(sb)->nls ? NLS_MAX_CHARSET_SIZE : 4) *
+			     HFSPLUS_ATTR_MAX_STRLEN + 1,
 			     GFP_KERNEL);
 	if (!xattr_name)
 		return -ENOMEM;
@@ -699,8 +701,9 @@  ssize_t hfsplus_listxattr(struct dentry *dentry, char *buffer, size_t size)
 		return err;
 	}
 
-	strbuf = kmalloc(NLS_MAX_CHARSET_SIZE * HFSPLUS_ATTR_MAX_STRLEN +
-			XATTR_MAC_OSX_PREFIX_LEN + 1, GFP_KERNEL);
+	strbuf = kmalloc((HFSPLUS_SB(sb)->nls ? NLS_MAX_CHARSET_SIZE : 4) *
+			HFSPLUS_ATTR_MAX_STRLEN + XATTR_MAC_OSX_PREFIX_LEN + 1,
+			GFP_KERNEL);
 	if (!strbuf) {
 		res = -ENOMEM;
 		goto out;
@@ -732,7 +735,8 @@  ssize_t hfsplus_listxattr(struct dentry *dentry, char *buffer, size_t size)
 		if (be32_to_cpu(attr_key.cnid) != inode->i_ino)
 			goto end_listxattr;
 
-		xattr_name_len = NLS_MAX_CHARSET_SIZE * HFSPLUS_ATTR_MAX_STRLEN;
+		xattr_name_len = (HFSPLUS_SB(sb)->nls ? NLS_MAX_CHARSET_SIZE : 4)
+				* HFSPLUS_ATTR_MAX_STRLEN;
 		if (hfsplus_uni2asc(inode->i_sb,
 			(const struct hfsplus_unistr *)&fd.key->attr.key_name,
 					strbuf, &xattr_name_len)) {
diff --git a/fs/hfsplus/xattr_security.c b/fs/hfsplus/xattr_security.c
index c1c7a16cbf21..438ebcd1359b 100644
--- a/fs/hfsplus/xattr_security.c
+++ b/fs/hfsplus/xattr_security.c
@@ -41,7 +41,8 @@  static int hfsplus_initxattrs(struct inode *inode,
 	char *xattr_name;
 	int err = 0;
 
-	xattr_name = kmalloc(NLS_MAX_CHARSET_SIZE * HFSPLUS_ATTR_MAX_STRLEN + 1,
+	xattr_name = kmalloc((HFSPLUS_SB(sb)->nls ? NLS_MAX_CHARSET_SIZE : 4) *
+			     HFSPLUS_ATTR_MAX_STRLEN + 1,
 		GFP_KERNEL);
 	if (!xattr_name)
 		return -ENOMEM;