[PATCH e2fsprogs v4 0/9] Support encoding awareness and casefold

[PATCH e2fsprogs v4 0/9] Support encoding awareness and casefold

[Gabriel Krisman Bertazi]

Hey,

This version introduces the changes you requested on your review of my
v3.  It doesn't implement the fsck trick I suggested because that is not
trivial and it can go in a different series (it won't matter until we
have another unicode version to update to).

e2fsprogs:
  https://gitlab.collabora.com/krisman/e2fsprogs -b encoding-feature-merge_v4
linux:
  https://gitlab.collabora.com/krisman/e2fsprogs -b ext4-ci-directory_v3
xfstests
  https://gitlab.collabora.com/krisman/xfstests -b encoding_v4

Please, let me know your thoughts.


----
Original cover letter message:


These are the modifications to e2fsprogs in order to support encoding
awareness and case folding.  This patch series is divided in 3 parts:

Patch 1 & 2 work on reserving superblock fields.  Patch 1 is actually
unrelated, just updating the super_block to resynchronize with the
kernel.  Patch 2 reserves the feature bit and superblock fields for this
feature.

Patch 3 through 5 implements the changes the changes to mke2fs and
chattr/lsattr to enable the encoding feature at mkfs time and flipping
the casefold flag on demand for specific directories.

Patch 6 through 9 is where things get a bit ugly.  fsck needs to become
encoding aware, in order to calculate directory hashes correctly and
verify/fix inconsistencies.  This requires a tiny bit of plumbing to
pass the encoding information up to the point where we calculate the
hash, as well as implementing a simple nls-like interface in e2fsprogs
to do normalization/casefolding.  You'll see that in this series I've
actually dropped the utf8 part because that patch is huge and I'd rather
discuss it separately.  I did it in a hacky way now, where we import the
utf8n code from linux.  I thought about using libunistring but it
doesn't seem to support versioning and we risk being incompatible with
the kernel hashes.  I think we could follow the kernel approach and make
ucd files available in e2fsprogs and generate the data at
compilation. What do you think?

If you want to see a full utf8 capable version of this series, please
clone from:

  ...

If you don't object to patch 1 & 2, can we get them merged before the
rest of the series is ready, so I can reserve the bits in the super
block for this feature (patch 2) and avoid more rebasing on my side?


Gabriel Krisman Bertazi (9):
  libe2p: Helpers for configuring the encoding superblock fields
  mke2fs: Configure encoding during superblock initialization
  chattr/lsattr: Support casefold attribute
  lib/ext2fs: Implement NLS support
  lib/ext2fs: Support encoding when calculating dx hashes
  debugfs/htree: Support encoding when printing the file hash
  tune2fs: Prevent enabling encryption flag on encoding-aware fs
  ext2fs: nls: Support UTF-8 11.0 with NFKD normalization
  ext4.5: Add fname_encoding feature to ext4 man page

 debugfs/Makefile.in        |    1 +
 debugfs/htree.c            |   30 +-
 e2fsck/Makefile.in         |    7 +-
 e2fsck/dx_dirinfo.c        |    4 +-
 e2fsck/e2fsck.h            |    4 +-
 e2fsck/pass1.c             |    3 +-
 e2fsck/pass2.c             |   11 +-
 e2fsck/rehash.c            |   20 +-
 e2fsck/unix.c              |   10 +
 lib/e2p/Makefile.in        |    8 +-
 lib/e2p/e2p.h              |    4 +
 lib/e2p/encoding.c         |  104 +
 lib/e2p/feature.c          |    2 +-
 lib/e2p/pf.c               |    1 +
 lib/ext2fs/Makefile.in     |   16 +-
 lib/ext2fs/dirhash.c       |   55 +
 lib/ext2fs/ext2_fs.h       |   12 +-
 lib/ext2fs/ext2fs.h        |    8 +
 lib/ext2fs/initialize.c    |    4 +
 lib/ext2fs/nls.h           |   72 +
 lib/ext2fs/nls_ascii.c     |   68 +
 lib/ext2fs/nls_utf8-norm.c |  793 +++++
 lib/ext2fs/nls_utf8.c      |   95 +
 lib/ext2fs/utf8data.h      | 6079 ++++++++++++++++++++++++++++++++++++
 lib/ext2fs/utf8n.h         |  120 +
 misc/chattr.1.in           |    8 +-
 misc/chattr.c              |    3 +-
 misc/ext4.5.in             |   10 +
 misc/mke2fs.8.in           |   25 +
 misc/mke2fs.c              |   81 +
 misc/mke2fs.conf.5.in      |    4 +
 misc/mke2fs.conf.in        |    3 +
 misc/tune2fs.c             |    6 +
 33 files changed, 7636 insertions(+), 35 deletions(-)
 create mode 100644 lib/e2p/encoding.c
 create mode 100644 lib/ext2fs/nls.h
 create mode 100644 lib/ext2fs/nls_ascii.c
 create mode 100644 lib/ext2fs/nls_utf8-norm.c
 create mode 100644 lib/ext2fs/nls_utf8.c
 create mode 100644 lib/ext2fs/utf8data.h
 create mode 100644 lib/ext2fs/utf8n.h

-- 
2.20.0.rc1

[PATCH v4 1/9] libe2p: Helpers for configuring the encoding superblock fields

[Gabriel Krisman Bertazi]

From: Gabriel Krisman Bertazi <krisman@collabora.co.uk>

Implement helper functions to convert the encoding name and specific
parameters requested by the user on the command line into the format
that is written to disk.

Changes since v3:
  - Don't require version at mkfs time

Changes since v2:
  - Rename defines to add EXT4_ prefix
  - Use unicode X.Y versioning scheme

Changes since v1:
  - Drop struct ext4_encoding_map name.
  - remove question mark in comment.
  - Reword 0x0 -> NULL
  - Prevent out of bound array access if requested invalid encoding

Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.co.uk>
---
 lib/e2p/Makefile.in  |   8 +++-
 lib/e2p/e2p.h        |   4 ++
 lib/e2p/encoding.c   | 104 +++++++++++++++++++++++++++++++++++++++++++
 lib/ext2fs/ext2_fs.h |   7 +++
 4 files changed, 121 insertions(+), 2 deletions(-)
 create mode 100644 lib/e2p/encoding.c

diff --git a/lib/e2p/Makefile.in b/lib/e2p/Makefile.in
index 2b0aa1915130..68d534cdaf11 100644
--- a/lib/e2p/Makefile.in
+++ b/lib/e2p/Makefile.in
@@ -19,7 +19,8 @@ all::	e2p.pc
 OBJS=		feature.o fgetflags.o fsetflags.o fgetversion.o fsetversion.o \
 		getflags.o getversion.o hashstr.o iod.o ls.o ljs.o mntopts.o \
 		parse_num.o pe.o pf.o ps.o setflags.o setversion.o uuid.o \
-		ostype.o percent.o crypto_mode.o fgetproject.o fsetproject.o
+		ostype.o percent.o crypto_mode.o fgetproject.o fsetproject.o \
+		encoding.o
 
 SRCS=		$(srcdir)/feature.c $(srcdir)/fgetflags.c \
 		$(srcdir)/fsetflags.c $(srcdir)/fgetversion.c \
@@ -29,7 +30,7 @@ SRCS=		$(srcdir)/feature.c $(srcdir)/fgetflags.c \
 		$(srcdir)/pe.c $(srcdir)/pf.c $(srcdir)/ps.c \
 		$(srcdir)/setflags.c $(srcdir)/setversion.c $(srcdir)/uuid.c \
 		$(srcdir)/ostype.c $(srcdir)/percent.c $(srcdir)/crypto_mode.c \
-		$(srcdir)/fgetproject.c $(srcdir)/fsetproject.c
+		$(srcdir)/fgetproject.c $(srcdir)/fsetproject.c $(srcdir)/encoding.c
 HFILES= e2p.h
 
 LIBRARY= libe2p
@@ -147,6 +148,9 @@ getversion.o: $(srcdir)/getversion.c $(top_builddir)/lib/config.h \
 hashstr.o: $(srcdir)/hashstr.c $(top_builddir)/lib/config.h \
  $(top_builddir)/lib/dirpaths.h $(srcdir)/e2p.h \
  $(top_srcdir)/lib/ext2fs/ext2_fs.h $(top_builddir)/lib/ext2fs/ext2_types.h
+encoding.o: $(srcdir)/encoding.c $(top_builddir)/lib/config.h \
+ $(top_builddir)/lib/dirpaths.h $(srcdir)/e2p.h \
+ $(top_srcdir)/lib/ext2fs/ext2_fs.h $(top_builddir)/lib/ext2fs/ext2_types.h
 iod.o: $(srcdir)/iod.c $(top_builddir)/lib/config.h \
  $(top_builddir)/lib/dirpaths.h $(srcdir)/e2p.h \
  $(top_srcdir)/lib/ext2fs/ext2_fs.h $(top_builddir)/lib/ext2fs/ext2_types.h
diff --git a/lib/e2p/e2p.h b/lib/e2p/e2p.h
index d70b59a5d358..cc2dbf39bfeb 100644
--- a/lib/e2p/e2p.h
+++ b/lib/e2p/e2p.h
@@ -80,3 +80,7 @@ unsigned int e2p_percent(int percent, unsigned int base);
 
 const char *e2p_encmode2string(int num);
 int e2p_string2encmode(char *string);
+
+int e2p_str2encoding(const char *string);
+int e2p_get_encoding_flags(int encoding);
+int e2p_str2encoding_flags(int encoding, char *param, __u16 *flags);
diff --git a/lib/e2p/encoding.c b/lib/e2p/encoding.c
new file mode 100644
index 000000000000..88433310a1dd
--- /dev/null
+++ b/lib/e2p/encoding.c
@@ -0,0 +1,104 @@
+/*
+ * encoding.c --- convert between encoding magic numbers and strings
+ *
+ * Copyright (C) 2018  Collabora Ltd.
+ *
+ * %Begin-Header%
+ * This file may be redistributed under the terms of the GNU Library
+ * General Public License, version 2.
+ * %End-Header%
+ */
+
+#include "config.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <ctype.h>
+#include <errno.h>
+#include <stdio.h>
+
+#include "e2p.h"
+
+#define ARRAY_SIZE(array)			\
+        (sizeof(array) / sizeof(array[0]))
+
+static const struct {
+	char *name;
+	__u16 encoding_magic;
+	__u16 default_flags;
+
+} ext4_encoding_map[] = {
+	{
+		.encoding_magic = EXT4_ENC_ASCII,
+		.name = "ascii",
+		.default_flags = 0
+	},
+	{
+		.encoding_magic = EXT4_ENC_UTF8_11_0,
+		.name = "utf8",
+		.default_flags = (EXT4_UTF8_NORMALIZATION_TYPE_NFKD |
+				  EXT4_UTF8_CASEFOLD_TYPE_NFKDCF)
+	},
+};
+
+static const struct enc_flags {
+	__u16 flag;
+	char *param;
+} encoding_flags[] = {
+	{ EXT4_ENC_STRICT_MODE_FL, "strict" },
+};
+
+/* Return a positive number < 0xff indicating the encoding magic number
+ * or a negative value indicating error. */
+int e2p_str2encoding(const char *string)
+{
+	int i;
+
+	for (i = 0 ; i < ARRAY_SIZE(ext4_encoding_map); i++)
+		if (!strcmp(string, ext4_encoding_map[i].name))
+			return ext4_encoding_map[i].encoding_magic;
+
+	return -EINVAL;
+}
+
+int e2p_get_encoding_flags(int encoding)
+{
+	int i;
+
+	for (i = 0 ; i < ARRAY_SIZE(ext4_encoding_map); i++)
+		if (ext4_encoding_map[i].encoding_magic == encoding)
+			return ext4_encoding_map[encoding].default_flags;
+
+	return 0;
+}
+
+int e2p_str2encoding_flags(int encoding, char *param, __u16 *flags)
+{
+	char *f = strtok(param, "-");
+	const struct enc_flags *fl;
+	int i, neg = 0;
+
+	while (f) {
+		neg = 0;
+		if (!strncmp("no", f, 2)) {
+			neg = 1;
+			f += 2;
+		}
+
+		for (i = 0; i < ARRAY_SIZE(encoding_flags); i++) {
+			fl = &encoding_flags[i];
+			if (!strcmp(fl->param, f)) {
+				if (neg)
+					*flags &= ~fl->flag;
+				else
+					*flags |= fl->flag;
+
+				goto next_flag;
+			}
+		}
+		return -EINVAL;
+	next_flag:
+		f = strtok(NULL, "-");
+	}
+	return 0;
+}
diff --git a/lib/ext2fs/ext2_fs.h b/lib/ext2fs/ext2_fs.h
index f1c405b76339..c7d62b8d40b2 100644
--- a/lib/ext2fs/ext2_fs.h
+++ b/lib/ext2fs/ext2_fs.h
@@ -1127,4 +1127,11 @@ struct mmp_struct {
  */
 #define EXT4_INLINE_DATA_DOTDOT_SIZE	(4)
 
+#define EXT4_ENC_ASCII		0
+#define EXT4_ENC_UTF8_11_0	1
+
+#define EXT4_ENC_STRICT_MODE_FL			(1 << 0) /* Reject invalid sequences */
+#define EXT4_UTF8_NORMALIZATION_TYPE_NFKD	(1 << 1)
+#define EXT4_UTF8_CASEFOLD_TYPE_NFKDCF		(1 << 4)
+
 #endif	/* _LINUX_EXT2_FS_H */
-- 
2.20.0.rc1

[PATCH v4 2/9] mke2fs: Configure encoding during superblock initialization

[Gabriel Krisman Bertazi]

From: Gabriel Krisman Bertazi <krisman@collabora.co.uk>

This patch implements two new extended options to mkefs, allowing the
user to specify an encoding for file name operations and encoding flags
during filesystem creation.  We provide default flags for each encoding,
which the user can overwrite by passing -E fname_encoding-flags to mkfs.

If the user doesn't specify an encoding, the default value from
options.fname_encoding in mke2fs.conf.in file will be used.

Changes since v2:
  - Rename feature encoding -> fname_encoding
  - Add default encoding option to mke2fs.conf.in
  - Fix behavior on -O fname_encoding
  - Prevent use of encrypt and encoding simultaneously

Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
---
 lib/e2p/feature.c       |  2 +-
 lib/ext2fs/initialize.c |  4 ++
 misc/mke2fs.8.in        | 25 +++++++++++++
 misc/mke2fs.c           | 81 +++++++++++++++++++++++++++++++++++++++++
 misc/mke2fs.conf.5.in   |  4 ++
 misc/mke2fs.conf.in     |  3 ++
 6 files changed, 118 insertions(+), 1 deletion(-)

diff --git a/lib/e2p/feature.c b/lib/e2p/feature.c
index 294a56a40b52..ded87f5611dc 100644
--- a/lib/e2p/feature.c
+++ b/lib/e2p/feature.c
@@ -110,7 +110,7 @@ static struct feature feature_list[] = {
 	{       E2P_FEATURE_INCOMPAT, EXT4_FEATURE_INCOMPAT_ENCRYPT,
 			"encrypt"},
 	{       E2P_FEATURE_INCOMPAT, EXT4_FEATURE_INCOMPAT_FNAME_ENCODING,
-			"encoding"},
+			"fname_encoding"},
 	{	0, 0, 0 },
 };
 
diff --git a/lib/ext2fs/initialize.c b/lib/ext2fs/initialize.c
index 8c9e97fee831..30b1ae033340 100644
--- a/lib/ext2fs/initialize.c
+++ b/lib/ext2fs/initialize.c
@@ -186,6 +186,10 @@ errcode_t ext2fs_initialize(const char *name, int flags,
 	set_field(s_flags, 0);
 	assign_field(s_backup_bgs[0]);
 	assign_field(s_backup_bgs[1]);
+
+	assign_field(s_encoding);
+	assign_field(s_encoding_flags);
+
 	if (super->s_feature_incompat & ~EXT2_LIB_FEATURE_INCOMPAT_SUPP) {
 		retval = EXT2_ET_UNSUPP_FEATURE;
 		goto cleanup;
diff --git a/misc/mke2fs.8.in b/misc/mke2fs.8.in
index 603e37e54a78..4a2aa8fd9672 100644
--- a/misc/mke2fs.8.in
+++ b/misc/mke2fs.8.in
@@ -280,6 +280,31 @@ option is still accepted for backwards compatibility, but is deprecated.
 The following extended options are supported:
 .RS 1.2i
 .TP
+.BI fname_encoding= encoding-name
+Enable the
+.I fname_encoding
+feature in the super block and set
+.I encoding-name
+as the encoding to be used.  If
+.I encoding-name
+is not specified, the encoding defined in
+.BR mke2fs.conf (5)
+is used.
+.TP
+.BI fname_encoding_flags= encoding-flags
+Define parameters for file name character encoding operations.  If a
+flag is not changed using this parameter, its default value is used.
+.I encoding-flags
+should be a comma-separated lists of flags to be enabled.  To disable a
+flag, add it to the list with the prefix "no".
+
+The only flag that can be set right now is
+.I strict
+which means that invalid strings should be rejected by the file system.
+In the default configuration, the
+.I strict
+flag is disabled.
+.TP
 .BI mmp_update_interval= interval
 Adjust the initial MMP update interval to
 .I interval
diff --git a/misc/mke2fs.c b/misc/mke2fs.c
index f05003fc30b9..41f2532bc84f 100644
--- a/misc/mke2fs.c
+++ b/misc/mke2fs.c
@@ -790,6 +790,8 @@ static void parse_extended_opts(struct ext2_super_block *param,
 	int	len;
 	int	r_usage = 0;
 	int	ret;
+	int	encoding = -1;
+	char 	*encoding_flags = NULL;
 
 	len = strlen(opts);
 	buf = malloc(len+1);
@@ -1056,6 +1058,31 @@ static void parse_extended_opts(struct ext2_super_block *param,
 			}
 		} else if (!strcmp(token, "android_sparse")) {
 			android_sparse_file = 1;
+		} else if (!strcmp(token, "fname_encoding")) {
+			if (!arg) {
+				profile_get_string(profile, "options",
+						   "fname_encoding", 0, 0,
+						   &arg);
+				if (!arg) {
+					r_usage++;
+					continue;
+				}
+			}
+
+			encoding = e2p_str2encoding(arg);
+			if (encoding < 0) {
+				fprintf(stderr, _("Invalid encoding: %s"), arg);
+				r_usage++;
+				continue;
+			}
+			param->s_encoding = encoding;
+			ext2fs_set_feature_fname_encoding(param);
+		} else if (!strcmp(token, "fname_encoding_flags")) {
+			if (!arg) {
+				r_usage++;
+				continue;
+			}
+			encoding_flags = arg;
 		} else {
 			r_usage++;
 			badopt = token;
@@ -1080,6 +1107,8 @@ static void parse_extended_opts(struct ext2_super_block *param,
 			"\ttest_fs\n"
 			"\tdiscard\n"
 			"\tnodiscard\n"
+			"\tfname_encoding=<encoding>\n"
+			"\tfname_encoding_flags=<flags>\n"
 			"\tquotatype=<quota type(s) to be enabled>\n\n"),
 			badopt ? badopt : "");
 		free(buf);
@@ -1091,6 +1120,25 @@ static void parse_extended_opts(struct ext2_super_block *param,
 				  "multiple of stride %u.\n\n"),
 			param->s_raid_stripe_width, param->s_raid_stride);
 
+	if (ext2fs_has_feature_fname_encoding(param)) {
+		param->s_encoding_flags =
+			e2p_get_encoding_flags(param->s_encoding);
+
+		if (encoding_flags &&
+		    e2p_str2encoding_flags(param->s_encoding, encoding_flags,
+					   &param->s_encoding_flags)) {
+			fprintf(stderr, _("error: Invalid encoding flag: %s\n"),
+				encoding_flags);
+			free(buf);
+			exit(1);
+		}
+	} else if (encoding_flags) {
+		fprintf(stderr, _("error: An encoding must be explicitely "
+				  "specified when passing encoding-flags\n"));
+		free(buf);
+		exit(1);
+	}
+
 	free(buf);
 }
 
@@ -1112,6 +1160,7 @@ static __u32 ok_features[3] = {
 		EXT4_FEATURE_INCOMPAT_64BIT|
 		EXT4_FEATURE_INCOMPAT_INLINE_DATA|
 		EXT4_FEATURE_INCOMPAT_ENCRYPT |
+		EXT4_FEATURE_INCOMPAT_FNAME_ENCODING |
 		EXT4_FEATURE_INCOMPAT_CSUM_SEED |
 		EXT4_FEATURE_INCOMPAT_LARGEDIR,
 	/* R/O compat */
@@ -1518,6 +1567,8 @@ static void PRS(int argc, char *argv[])
 	int		use_bsize;
 	char		*newpath;
 	int		pathlen = sizeof(PATH_SET) + 1;
+	char		*encoding_name = NULL;
+	int		encoding;
 
 	if (oldpath)
 		pathlen += strlen(oldpath);
@@ -2026,6 +2077,7 @@ profile_error:
 		ext2fs_clear_feature_huge_file(&fs_param);
 		ext2fs_clear_feature_metadata_csum(&fs_param);
 		ext2fs_clear_feature_ea_inode(&fs_param);
+		ext2fs_clear_feature_fname_encoding(&fs_param);
 	}
 	edit_feature(fs_features ? fs_features : tmp,
 		     &fs_param.s_feature_compat);
@@ -2341,6 +2393,26 @@ profile_error:
 	if (packed_meta_blocks)
 		journal_location = 0;
 
+	if (ext2fs_has_feature_fname_encoding(&fs_param)) {
+		profile_get_string(profile, "options", "fname_encoding",
+				   0, 0, &encoding_name);
+		if (!encoding_name) {
+			com_err(program_name, 0, "%s",
+				_("Filename encoding type must be specified\n"
+				  "Use -E fname_encoding=<name> instead"));
+			exit(1);
+		}
+		encoding = e2p_str2encoding(encoding_name);
+		if (encoding < 0) {
+			com_err(program_name, 0, "%s",
+				_("Unknown default filename encoding\n"
+				  "Use -E fname_encoding=<name> instead"));
+			exit(1);
+		}
+		fs_param.s_encoding = encoding;
+		fs_param.s_encoding_flags = e2p_get_encoding_flags(encoding);
+	}
+
 	/* Get options from profile */
 	for (cpp = fs_types; *cpp; cpp++) {
 		tmp = NULL;
@@ -2385,6 +2457,15 @@ profile_error:
 		}
 	}
 
+	if (ext2fs_has_feature_fname_encoding(&fs_param) &&
+	    ext2fs_has_feature_encrypt(&fs_param)) {
+		com_err(program_name, 0, "%s",
+			_("The encrypt and encoding features are not "
+			  "compatible.\nThey can not be both enabled "
+			  "simultaneously.\n"));
+		      exit (1);
+	}
+
 	/* Don't allow user to set both metadata_csum and uninit_bg bits. */
 	if (ext2fs_has_feature_metadata_csum(&fs_param) &&
 	    ext2fs_has_feature_gdt_csum(&fs_param))
diff --git a/misc/mke2fs.conf.5.in b/misc/mke2fs.conf.5.in
index c086b4113b50..ab93c7761a16 100644
--- a/misc/mke2fs.conf.5.in
+++ b/misc/mke2fs.conf.5.in
@@ -97,6 +97,10 @@ The following relations are defined in the
 .I [options]
 stanza.
 .TP
+.I fname_encoding
+This relation defines the file name encoding to be used by mke2fs, in
+case the user doesn't specify an encoding in the command line.
+.TP
 .I proceed_delay
 If this relation is set to a positive integer, then mke2fs will
 wait
diff --git a/misc/mke2fs.conf.in b/misc/mke2fs.conf.in
index 01e35cf83150..10819f18c332 100644
--- a/misc/mke2fs.conf.in
+++ b/misc/mke2fs.conf.in
@@ -45,3 +45,6 @@
 	     blocksize = 4096
 	     inode_size = 128
 	}
+
+[options]
+fname_encoding = utf8
-- 
2.20.0.rc1

[PATCH v4 3/9] chattr/lsattr: Support casefold attribute

[Gabriel Krisman Bertazi]

From: Gabriel Krisman Bertazi <krisman@collabora.co.uk>

This flag can be set on directories to request insensitive file name
lookups.

I used the letter 'F', referring to "caseFold" for lack of a better
option.

Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.co.uk>
---
 lib/e2p/pf.c         | 1 +
 lib/ext2fs/ext2_fs.h | 5 +++--
 misc/chattr.1.in     | 8 +++++++-
 misc/chattr.c        | 3 ++-
 4 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/lib/e2p/pf.c b/lib/e2p/pf.c
index 884f1671edae..0c6998c4b766 100644
--- a/lib/e2p/pf.c
+++ b/lib/e2p/pf.c
@@ -44,6 +44,7 @@ static struct flags_name flags_array[] = {
 	{ EXT2_TOPDIR_FL, "T", "Top_of_Directory_Hierarchies" },
 	{ EXT4_EXTENTS_FL, "e", "Extents" },
 	{ FS_NOCOW_FL, "C", "No_COW" },
+	{ EXT4_CASEFOLD_FL, "F", "Casefold" },
 	{ EXT4_INLINE_DATA_FL, "N", "Inline_Data" },
 	{ EXT4_PROJINHERIT_FL, "P", "Project_Hierarchy" },
 	{ EXT4_VERITY_FL, "V", "Verity" },
diff --git a/lib/ext2fs/ext2_fs.h b/lib/ext2fs/ext2_fs.h
index c7d62b8d40b2..19bd94da008a 100644
--- a/lib/ext2fs/ext2_fs.h
+++ b/lib/ext2fs/ext2_fs.h
@@ -339,10 +339,11 @@ struct ext2_dx_tail {
 #define EXT4_SNAPFILE_SHRUNK_FL		0x08000000  /* Snapshot shrink has completed */
 #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 EXT2_RESERVED_FL		0x80000000 /* reserved for ext2 lib */
 
-#define EXT2_FL_USER_VISIBLE		0x204BDFFF /* User visible flags */
-#define EXT2_FL_USER_MODIFIABLE		0x204B80FF /* User modifiable flags */
+#define EXT2_FL_USER_VISIBLE		0x604BDFFF /* User visible flags */
+#define EXT2_FL_USER_MODIFIABLE		0x604B80FF /* User modifiable flags */
 
 /*
  * ioctl commands
diff --git a/misc/chattr.1.in b/misc/chattr.1.in
index 028ae9e7ca4c..5949d096687b 100644
--- a/misc/chattr.1.in
+++ b/misc/chattr.1.in
@@ -29,7 +29,7 @@ The operator '+' causes the selected attributes to be added to the
 existing attributes of the files; '-' causes them to be removed; and '='
 causes them to be the only attributes that the files have.
 .PP
-The letters 'aAcCdDeijPsStTu' select the new attributes for the files:
+The letters 'aAcCdDeFijPsStTu' select the new attributes for the files:
 append only (a),
 no atime updates (A),
 compressed (c),
@@ -37,6 +37,7 @@ no copy on write (C),
 no dump (d),
 synchronous directory updates (D),
 extent format (e),
+case-insensitive directory lookups (F),
 immutable (i),
 data journalling (j),
 project hierarchy (P),
@@ -119,6 +120,11 @@ set or reset using
 although it can be displayed by
 .BR lsattr (1).
 .PP
+A directory with the 'F' attribute set indicates that all the path
+lookups inside that directory are made in a case-insensitive fashion.
+This attribute can only be changed in empty directories on file systems
+with the fname_encoding feature enabled.
+.PP
 A file with the 'i' attribute cannot be modified: it cannot be deleted or
 renamed, no link can be created to this file, most of the file's
 metadata can not be modified, and the file can not be opened in write mode.
diff --git a/misc/chattr.c b/misc/chattr.c
index a5b401a741b7..a5d60170bdb6 100644
--- a/misc/chattr.c
+++ b/misc/chattr.c
@@ -86,7 +86,7 @@ static unsigned long sf;
 static void usage(void)
 {
 	fprintf(stderr,
-		_("Usage: %s [-pRVf] [-+=aAcCdDeijPsStTu] [-v version] files...\n"),
+		_("Usage: %s [-pRVf] [-+=aAcCdDeijPsStTuF] [-v version] files...\n"),
 		program_name);
 	exit(1);
 }
@@ -112,6 +112,7 @@ static const struct flags_char flags_array[] = {
 	{ EXT2_NOTAIL_FL, 't' },
 	{ EXT2_TOPDIR_FL, 'T' },
 	{ FS_NOCOW_FL, 'C' },
+	{ EXT4_CASEFOLD_FL, 'F' },
 	{ 0, 0 }
 };
 
-- 
2.20.0.rc1

[PATCH v4 4/9] lib/ext2fs: Implement NLS support

[Gabriel Krisman Bertazi]

From: Gabriel Krisman Bertazi <krisman@collabora.co.uk>

Basic NLS support is required in e2fsprogs because of fsck, which
needsto calculate dx hashes for encoding aware filesystems.  this patch
implements this infrastructure as well as ascii support.

We don't need to do all the dance of versioning as we do in the kernel,
because we know before-hand which encodings and versions we
support (those we know how to store in the sb), so it is simpler just to
create static tables.

Changes since v3:
  - Prevent buffer overflow during normalization/casefold.
  - Signal invalid sequences and let caller handle it.

Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.co.uk>
---
 lib/ext2fs/Makefile.in | 10 ++++--
 lib/ext2fs/nls.h       | 70 ++++++++++++++++++++++++++++++++++++++++++
 lib/ext2fs/nls_ascii.c | 68 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 146 insertions(+), 2 deletions(-)
 create mode 100644 lib/ext2fs/nls.h
 create mode 100644 lib/ext2fs/nls_ascii.c

diff --git a/lib/ext2fs/Makefile.in b/lib/ext2fs/Makefile.in
index 4a197cdf4e4a..a2f07403c9ae 100644
--- a/lib/ext2fs/Makefile.in
+++ b/lib/ext2fs/Makefile.in
@@ -20,6 +20,9 @@ COMPILE_ET=	_ET_DIR_OVERRIDE=$(srcdir)/../et ../et/compile_et
 @TEST_IO_CMT@TEST_IO_LIB_OBJS = test_io.o
 @IMAGER_CMT@E2IMAGE_LIB_OBJS = imager.o
 
+NLS_OBJS=nls_ascii.o
+NLS_SRCS=nls_ascii.c
+
 DEBUG_OBJS= debug_cmds.o extent_cmds.o tst_cmds.o debugfs.o util.o \
 	ncheck.o icheck.o ls.o lsdel.o dump.o set_fields.o logdump.o \
 	htree.o unused.o e2freefrag.o filefrag.o extent_inode.o zap.o \
@@ -130,7 +133,8 @@ OBJS= $(DEBUGFS_LIB_OBJS) $(RESIZE_LIB_OBJS) $(E2IMAGE_LIB_OBJS) \
 	unlink.o \
 	valid_blk.o \
 	version.o \
-	rbtree.o
+	rbtree.o \
+	$(NLS_OBJS)
 
 SRCS= ext2_err.c \
 	$(srcdir)/alloc.c \
@@ -222,7 +226,8 @@ SRCS= ext2_err.c \
 	$(srcdir)/write_bb_file.c \
 	$(srcdir)/rbtree.c \
 	$(srcdir)/tst_libext2fs.c \
-	$(DEBUG_SRCS)
+	$(DEBUG_SRCS) \
+	$(NLS_SRCS)
 
 HFILES= bitops.h ext2fs.h ext2_io.h ext2_fs.h ext2_ext_attr.h ext3_extents.h \
 	tdb.h qcow2.h hashmap.h
@@ -1412,3 +1417,4 @@ do_journal.o: $(top_srcdir)/debugfs/do_journal.c $(top_builddir)/lib/config.h \
  $(top_srcdir)/lib/support/quotaio_tree.h $(srcdir)/kernel-jbd.h \
  $(srcdir)/jfs_compat.h $(srcdir)/kernel-list.h \
  $(top_srcdir)/debugfs/journal.h $(srcdir)/../../e2fsck/jfs_user.h
+$(NLS_OBJS): $(srcdir)/nls.h
diff --git a/lib/ext2fs/nls.h b/lib/ext2fs/nls.h
new file mode 100644
index 000000000000..adfd92300688
--- /dev/null
+++ b/lib/ext2fs/nls.h
@@ -0,0 +1,70 @@
+/*
+ * nls.h - Header for encoding support functions
+ *
+ * Copyright (C) 2017 Collabora Ltd.
+ *
+ *
+ * This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or (at
+ *  your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef EXT2FS_NLS_H
+#define EXT2FS_NLS_H
+
+#include <unistd.h>
+#include <string.h>
+#include <stdio.h>
+
+#include "ext2_fs.h"
+
+struct nls_table;
+
+#define ARRAY_SIZE(array)			\
+        (sizeof(array) / sizeof(array[0]))
+
+struct nls_ops {
+	int (*normalize)(const struct nls_table *charset,
+			 const unsigned char *str, size_t len,
+			 unsigned char *dest, size_t dlen);
+
+	int (*casefold)(const struct nls_table *charset,
+			const unsigned char *str, size_t len,
+			unsigned char *dest, size_t dlen);
+};
+
+struct nls_table {
+	int version;
+	const struct nls_ops *ops;
+};
+
+extern const struct nls_table nls_ascii;
+
+static const struct {
+	int encoding_magic;
+	const struct nls_table *tbl;
+} nls_map[] = {
+	{ EXT4_ENC_ASCII, &nls_ascii },
+};
+
+static const struct nls_table *nls_load_table(int encoding)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(nls_map); i++) {
+		if (encoding == nls_map[i].encoding_magic)
+			return nls_map[i].tbl;
+	}
+	return NULL;
+}
+
+#endif
diff --git a/lib/ext2fs/nls_ascii.c b/lib/ext2fs/nls_ascii.c
new file mode 100644
index 000000000000..5d513df404c1
--- /dev/null
+++ b/lib/ext2fs/nls_ascii.c
@@ -0,0 +1,68 @@
+#include "nls.h"
+
+#include <errno.h>
+#include <string.h>
+
+
+static unsigned char charset_tolower(const struct nls_table *table,
+				     unsigned int c)
+{
+	if (c >= 'A' && c <= 'Z')
+		return (c | 0x20);
+	return c;
+}
+
+static unsigned char charset_toupper(const struct nls_table *table,
+				     unsigned int c)
+{
+	if (c >= 'a' && c <= 'z')
+		return (c & ~0x20);
+	return c;
+}
+
+static int ascii_casefold(const struct nls_table *table,
+			  const unsigned char *str, size_t len,
+			  unsigned char *dest, size_t dlen)
+{
+	int i;
+
+	if (dlen < len)
+		return -ENAMETOOLONG;
+
+	for (i = 0; i < len; i++) {
+		if (str[i] & 0x80)
+			return -EINVAL;
+
+		dest[i] = charset_toupper(table, str[i]);
+	}
+
+	return len;
+}
+
+static int ascii_normalize(const struct nls_table *table,
+			   const unsigned char *str, size_t len,
+			   unsigned char *dest, size_t dlen)
+{
+	int i;
+
+	if (dlen < len)
+		return -ENAMETOOLONG;
+
+	for (i = 0; i < len; i++) {
+		if (str[i] & 0x80)
+			return -EINVAL;
+
+		dest[i] = str[i];
+	}
+
+	return len;
+}
+
+const static struct nls_ops ascii_ops = {
+	.casefold = ascii_casefold,
+	.normalize = ascii_normalize,
+};
+
+const struct nls_table nls_ascii = {
+	.ops = &ascii_ops,
+};
-- 
2.20.0.rc1

[PATCH v4 5/9] lib/ext2fs: Support encoding when calculating dx hashes

[Gabriel Krisman Bertazi]

From: Gabriel Krisman Bertazi <krisman@collabora.co.uk>

fsck must be aware of the superblock encoding and the casefold directory
setting, such that it is able to correctly calculate the dentry hashes.

Changes since v3:
  - Handle case where filename is too large

Changes since V2:
  - Don't modify dirhash symbol

Changes since V1:
  - Abort if encoding is invalid.

Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.co.uk>
---
 e2fsck/Makefile.in     |  7 +++---
 e2fsck/dx_dirinfo.c    |  4 ++-
 e2fsck/e2fsck.h        |  4 ++-
 e2fsck/pass1.c         |  3 ++-
 e2fsck/pass2.c         | 11 ++++++---
 e2fsck/rehash.c        | 20 +++++++++------
 e2fsck/unix.c          | 10 ++++++++
 lib/ext2fs/Makefile.in |  3 ++-
 lib/ext2fs/dirhash.c   | 55 ++++++++++++++++++++++++++++++++++++++++++
 lib/ext2fs/ext2fs.h    |  8 ++++++
 10 files changed, 107 insertions(+), 18 deletions(-)

diff --git a/e2fsck/Makefile.in b/e2fsck/Makefile.in
index 676ab7ddcc1d..9799274fa74e 100644
--- a/e2fsck/Makefile.in
+++ b/e2fsck/Makefile.in
@@ -293,7 +293,8 @@ pass1.o: $(srcdir)/pass1.c $(top_builddir)/lib/config.h \
  $(top_srcdir)/lib/ext2fs/bitops.h $(top_srcdir)/lib/support/profile.h \
  $(top_builddir)/lib/support/prof_err.h $(top_srcdir)/lib/support/quotaio.h \
  $(top_srcdir)/lib/support/dqblk_v2.h \
- $(top_srcdir)/lib/support/quotaio_tree.h $(srcdir)/problem.h
+ $(top_srcdir)/lib/support/quotaio_tree.h $(srcdir)/problem.h \
+ $(top_srcdir)/lib/ext2fs/nls.h
 pass1b.o: $(srcdir)/pass1b.c $(top_builddir)/lib/config.h \
  $(top_builddir)/lib/dirpaths.h $(top_srcdir)/lib/et/com_err.h \
  $(srcdir)/e2fsck.h $(top_srcdir)/lib/ext2fs/ext2_fs.h \
@@ -317,7 +318,7 @@ pass2.o: $(srcdir)/pass2.c $(top_builddir)/lib/config.h \
  $(top_builddir)/lib/support/prof_err.h $(top_srcdir)/lib/support/quotaio.h \
  $(top_srcdir)/lib/support/dqblk_v2.h \
  $(top_srcdir)/lib/support/quotaio_tree.h $(srcdir)/problem.h \
- $(top_srcdir)/lib/support/dict.h
+ $(top_srcdir)/lib/support/dict.h $(top_srcdir)/lib/ext2fs/nls.h
 pass3.o: $(srcdir)/pass3.c $(top_builddir)/lib/config.h \
  $(top_builddir)/lib/dirpaths.h $(srcdir)/e2fsck.h \
  $(top_srcdir)/lib/ext2fs/ext2_fs.h $(top_builddir)/lib/ext2fs/ext2_types.h \
@@ -416,7 +417,7 @@ unix.o: $(srcdir)/unix.c $(top_builddir)/lib/config.h \
  $(top_srcdir)/lib/et/com_err.h $(top_srcdir)/lib/support/plausible.h \
  $(srcdir)/e2fsck.h $(top_srcdir)/lib/ext2fs/ext2fs.h \
  $(top_srcdir)/lib/ext2fs/ext3_extents.h $(top_srcdir)/lib/ext2fs/ext2_io.h \
- $(top_builddir)/lib/ext2fs/ext2_err.h \
+ $(top_builddir)/lib/ext2fs/ext2_err.h  $(top_srcdir)/lib/ext2fs/nls.h \
  $(top_srcdir)/lib/ext2fs/ext2_ext_attr.h $(top_srcdir)/lib/ext2fs/hashmap.h \
  $(top_srcdir)/lib/ext2fs/bitops.h $(top_srcdir)/lib/support/profile.h \
  $(top_builddir)/lib/support/prof_err.h $(top_srcdir)/lib/support/quotaio.h \
diff --git a/e2fsck/dx_dirinfo.c b/e2fsck/dx_dirinfo.c
index c7b605685339..c0b0e9a41235 100644
--- a/e2fsck/dx_dirinfo.c
+++ b/e2fsck/dx_dirinfo.c
@@ -13,7 +13,8 @@
  * entry.  During pass1, the passed-in parent is 0; it will get filled
  * in during pass2.
  */
-void e2fsck_add_dx_dir(e2fsck_t ctx, ext2_ino_t ino, int num_blocks)
+void e2fsck_add_dx_dir(e2fsck_t ctx, ext2_ino_t ino, struct ext2_inode *inode,
+		       int num_blocks)
 {
 	struct dx_dir_info *dir;
 	int		i, j;
@@ -72,6 +73,7 @@ void e2fsck_add_dx_dir(e2fsck_t ctx, ext2_ino_t ino, int num_blocks)
 	dir->ino = ino;
 	dir->numblocks = num_blocks;
 	dir->hashversion = 0;
+	dir->casefolded_hash = inode->i_flags & EXT4_CASEFOLD_FL;
 	dir->dx_block = e2fsck_allocate_memory(ctx, num_blocks
 				       * sizeof (struct dx_dirblock_info),
 				       "dx_block info array");
diff --git a/e2fsck/e2fsck.h b/e2fsck/e2fsck.h
index cd5cba2f6031..1c7a67cba1ce 100644
--- a/e2fsck/e2fsck.h
+++ b/e2fsck/e2fsck.h
@@ -109,6 +109,7 @@ struct dx_dir_info {
 	int			hashversion;
 	short			depth;		/* depth of tree */
 	struct dx_dirblock_info	*dx_block; 	/* Array of size numblocks */
+	int			casefolded_hash;
 };
 
 #define DX_DIRBLOCK_ROOT	1
@@ -471,7 +472,8 @@ extern int e2fsck_dir_info_get_dotdot(e2fsck_t ctx, ext2_ino_t ino,
 				      ext2_ino_t *dotdot);
 
 /* dx_dirinfo.c */
-extern void e2fsck_add_dx_dir(e2fsck_t ctx, ext2_ino_t ino, int num_blocks);
+extern void e2fsck_add_dx_dir(e2fsck_t ctx, ext2_ino_t ino,
+			      struct ext2_inode *inode, int num_blocks);
 extern struct dx_dir_info *e2fsck_get_dx_dir_info(e2fsck_t ctx, ext2_ino_t ino);
 extern void e2fsck_free_dx_dir_info(e2fsck_t ctx);
 extern int e2fsck_get_num_dx_dirinfo(e2fsck_t ctx);
diff --git a/e2fsck/pass1.c b/e2fsck/pass1.c
index 8abf0c33a1d3..16ebec18db6f 100644
--- a/e2fsck/pass1.c
+++ b/e2fsck/pass1.c
@@ -48,6 +48,7 @@
 
 #include "e2fsck.h"
 #include <ext2fs/ext2_ext_attr.h>
+#include <e2p/e2p.h>
 
 #include "problem.h"
 
@@ -3381,7 +3382,7 @@ static void check_blocks(e2fsck_t ctx, struct problem_context *pctx,
 			inode->i_flags &= ~EXT2_INDEX_FL;
 			dirty_inode++;
 		} else {
-			e2fsck_add_dx_dir(ctx, ino, pb.last_block+1);
+			e2fsck_add_dx_dir(ctx, ino, inode, pb.last_block+1);
 		}
 	}
 
diff --git a/e2fsck/pass2.c b/e2fsck/pass2.c
index b92eec1e149f..a7d9c47dbe8e 100644
--- a/e2fsck/pass2.c
+++ b/e2fsck/pass2.c
@@ -933,6 +933,7 @@ static int check_dir_block(ext2_filsys fs,
 	int	filetype = 0;
 	int	encrypted = 0;
 	size_t	max_block_size;
+	int	hash_flags = 0;
 
 	cd = (struct check_dir_struct *) priv_data;
 	ibuf = buf = cd->buf;
@@ -1426,9 +1427,13 @@ skip_checksum:
 			dir_modified++;
 
 		if (dx_db) {
-			ext2fs_dirhash(dx_dir->hashversion, dirent->name,
-				       ext2fs_dirent_name_len(dirent),
-				       fs->super->s_hash_seed, &hash, 0);
+			if (dx_dir->casefolded_hash)
+				hash_flags = EXT4_CASEFOLD_FL;
+
+			ext2fs_dirhash2(dx_dir->hashversion, dirent->name,
+					ext2fs_dirent_name_len(dirent),
+					fs->encoding, hash_flags,
+					fs->super->s_hash_seed, &hash, 0);
 			if (hash < dx_db->min_hash)
 				dx_db->min_hash = hash;
 			if (hash > dx_db->max_hash)
diff --git a/e2fsck/rehash.c b/e2fsck/rehash.c
index 7c4ab0836482..a5fc1be1a210 100644
--- a/e2fsck/rehash.c
+++ b/e2fsck/rehash.c
@@ -113,7 +113,7 @@ static int fill_dir_block(ext2_filsys fs,
 	struct ext2_dir_entry 	*dirent;
 	char			*dir;
 	unsigned int		offset, dir_offset, rec_len, name_len;
-	int			hash_alg;
+	int			hash_alg, hash_flags;
 
 	if (blockcnt < 0)
 		return 0;
@@ -139,6 +139,7 @@ static int fill_dir_block(ext2_filsys fs,
 		if (fd->err)
 			return BLOCK_ABORT;
 	}
+	hash_flags = fd->inode->i_flags & EXT4_CASEFOLD_FL;
 	hash_alg = fs->super->s_def_hash_version;
 	if ((hash_alg <= EXT2_HASH_TEA) &&
 	    (fs->super->s_flags & EXT2_FLAGS_UNSIGNED_HASH))
@@ -184,10 +185,11 @@ static int fill_dir_block(ext2_filsys fs,
 		if (fd->compress)
 			ent->hash = ent->minor_hash = 0;
 		else {
-			fd->err = ext2fs_dirhash(hash_alg, dirent->name,
-						 name_len,
-						 fs->super->s_hash_seed,
-						 &ent->hash, &ent->minor_hash);
+			fd->err = ext2fs_dirhash2(hash_alg,
+						  dirent->name, name_len,
+						  fs->encoding, hash_flags,
+						  fs->super->s_hash_seed,
+						  &ent->hash, &ent->minor_hash);
 			if (fd->err)
 				return BLOCK_ABORT;
 		}
@@ -371,6 +373,7 @@ static int duplicate_search_and_fix(e2fsck_t ctx, ext2_filsys fs,
 	char			new_name[256];
 	unsigned int		new_len;
 	int			hash_alg;
+	int hash_flags = fd->inode->i_flags & EXT4_CASEFOLD_FL;
 
 	clear_problem_context(&pctx);
 	pctx.ino = ino;
@@ -415,9 +418,10 @@ static int duplicate_search_and_fix(e2fsck_t ctx, ext2_filsys fs,
 		if (fix_problem(ctx, PR_2_NON_UNIQUE_FILE, &pctx)) {
 			memcpy(ent->dir->name, new_name, new_len);
 			ext2fs_dirent_set_name_len(ent->dir, new_len);
-			ext2fs_dirhash(hash_alg, new_name, new_len,
-				       fs->super->s_hash_seed,
-				       &ent->hash, &ent->minor_hash);
+			ext2fs_dirhash2(hash_alg, new_name, new_len,
+					fs->encoding, hash_flags,
+					fs->super->s_hash_seed,
+					&ent->hash, &ent->minor_hash);
 			fixed++;
 		}
 	}
diff --git a/e2fsck/unix.c b/e2fsck/unix.c
index 2df22b17146f..5b3552ece6b1 100644
--- a/e2fsck/unix.c
+++ b/e2fsck/unix.c
@@ -55,6 +55,7 @@ extern int optind;
 #include "problem.h"
 #include "jfs_user.h"
 #include "../version.h"
+#include <ext2fs/nls.h>
 
 /* Command line options */
 static int cflag;		/* check disk */
@@ -1784,6 +1785,15 @@ print_unsupp_features:
 		goto get_newer;
 	}
 
+	if (ext2fs_has_feature_fname_encoding(sb)) {
+		fs->encoding = nls_load_table(sb->s_encoding);
+		if (!fs->encoding) {
+			log_err(ctx, _("%s has unsupported encoding: %0x\n"),
+				ctx->filesystem_name, sb->s_encoding);
+			goto get_newer;
+		}
+	}
+
 	/*
 	 * If the user specified a specific superblock, presumably the
 	 * master superblock has been trashed.  So we mark the
diff --git a/lib/ext2fs/Makefile.in b/lib/ext2fs/Makefile.in
index a2f07403c9ae..b756bbdf35a5 100644
--- a/lib/ext2fs/Makefile.in
+++ b/lib/ext2fs/Makefile.in
@@ -779,7 +779,8 @@ dirhash.o: $(srcdir)/dirhash.c $(top_builddir)/lib/config.h \
  $(top_builddir)/lib/ext2fs/ext2_types.h $(srcdir)/ext2fs.h \
  $(srcdir)/ext2_fs.h $(srcdir)/ext3_extents.h $(top_srcdir)/lib/et/com_err.h \
  $(srcdir)/ext2_io.h $(top_builddir)/lib/ext2fs/ext2_err.h \
- $(srcdir)/ext2_ext_attr.h $(srcdir)/hashmap.h $(srcdir)/bitops.h
+ $(srcdir)/ext2_ext_attr.h $(srcdir)/hashmap.h $(srcdir)/bitops.h \
+ $(srcdir)/nls.h
 dir_iterate.o: $(srcdir)/dir_iterate.c $(top_builddir)/lib/config.h \
  $(top_builddir)/lib/dirpaths.h $(srcdir)/ext2_fs.h \
  $(top_builddir)/lib/ext2fs/ext2_types.h $(srcdir)/ext2fsP.h \
diff --git a/lib/ext2fs/dirhash.c b/lib/ext2fs/dirhash.c
index 4ba3f35c091f..0caf5d4ed6e7 100644
--- a/lib/ext2fs/dirhash.c
+++ b/lib/ext2fs/dirhash.c
@@ -14,9 +14,11 @@
 #include "config.h"
 #include <stdio.h>
 #include <string.h>
+#include <limits.h>
 
 #include "ext2_fs.h"
 #include "ext2fs.h"
+#include "nls.h"
 
 /*
  * Keyed 32-bit hash function using TEA in a Davis-Meyer function
@@ -184,6 +186,11 @@ static void str2hashbuf(const char *msg, int len, __u32 *buf, int num,
  * A particular hash version specifies whether or not the seed is
  * represented, and whether or not the returned hash is 32 bits or 64
  * bits.  32 bit hashes will return 0 for the minor hash.
+ *
+ * This function doesn't do any normalization or casefolding of the
+ * input string.  To take charset encoding into account, use
+ * ext2fs_dirhash2.
+ *
  */
 errcode_t ext2fs_dirhash(int version, const char *name, int len,
 			 const __u32 *seed,
@@ -257,3 +264,51 @@ errcode_t ext2fs_dirhash(int version, const char *name, int len,
 		*ret_minor_hash = minor_hash;
 	return 0;
 }
+
+/*
+ * Returns the hash of a filename considering normalization and
+ * casefolding.  This is a wrapper around ext2fs_dirhash with string
+ * encoding support based on the nls_table and the flags. Check
+ * ext2fs_dirhash for documentation on the input and output parameters.
+ */
+errcode_t ext2fs_dirhash2(int version, const char *name, int len,
+			  const struct nls_table *charset, int hash_flags,
+			  const __u32 *seed,
+			  ext2_dirhash_t *ret_hash,
+			  ext2_dirhash_t *ret_minor_hash)
+{
+	errcode_t r;
+	int dlen;
+	unsigned char *buff;
+
+	if (len && charset) {
+		buff = calloc(sizeof (char), PATH_MAX);
+		if (!buff)
+			return -ENOMEM;
+
+		if (hash_flags & EXT4_CASEFOLD_FL)
+			dlen = charset->ops->casefold(charset, name, len, buff,
+						  PATH_MAX);
+		else
+			dlen = charset->ops->normalize(charset, name, len, buff,
+						  PATH_MAX);
+
+		if (dlen < 0) {
+			free(buff);
+			if (dlen == -EINVAL)
+				goto opaque_seq;
+
+			return dlen;
+		}
+
+		r = ext2fs_dirhash(version, buff, dlen, seed, ret_hash,
+				   ret_minor_hash);
+
+		free(buff);
+		return r;
+	}
+
+opaque_seq:
+	return ext2fs_dirhash(version, name, len, seed, ret_hash,
+			      ret_minor_hash);
+}
diff --git a/lib/ext2fs/ext2fs.h b/lib/ext2fs/ext2fs.h
index 64c5b8758a40..f7760e579508 100644
--- a/lib/ext2fs/ext2fs.h
+++ b/lib/ext2fs/ext2fs.h
@@ -307,6 +307,8 @@ struct struct_ext2_filsys {
 
 	/* hashmap for SHA of data blocks */
 	struct ext2fs_hashmap* block_sha_map;
+
+	const struct nls_table *encoding;
 };
 
 #if EXT2_FLAT_INCLUDES
@@ -1174,6 +1176,12 @@ extern errcode_t ext2fs_dirhash(int version, const char *name, int len,
 				ext2_dirhash_t *ret_hash,
 				ext2_dirhash_t *ret_minor_hash);
 
+extern errcode_t ext2fs_dirhash2(int version, const char *name, int len,
+				 const struct nls_table *charset,
+				 int hash_flags,
+				 const __u32 *seed,
+				 ext2_dirhash_t *ret_hash,
+				 ext2_dirhash_t *ret_minor_hash);
 
 /* dir_iterate.c */
 extern errcode_t ext2fs_get_rec_len(ext2_filsys fs,
-- 
2.20.0.rc1

[PATCH v4 6/9] debugfs/htree: Support encoding when printing the file hash

[Gabriel Krisman Bertazi]

From: Gabriel Krisman Bertazi <krisman@collabora.co.uk>

Implement two parameters -e and -c, to specify encoding and casefold
when printing the hash of a given file.

Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.co.uk>
---
 debugfs/Makefile.in    |  1 +
 debugfs/htree.c        | 30 +++++++++++++++++++++++-------
 lib/ext2fs/Makefile.in |  2 +-
 3 files changed, 25 insertions(+), 8 deletions(-)

diff --git a/debugfs/Makefile.in b/debugfs/Makefile.in
index bb4d1947b33b..bc59f5f97513 100644
--- a/debugfs/Makefile.in
+++ b/debugfs/Makefile.in
@@ -287,6 +287,7 @@ htree.o: $(srcdir)/htree.c $(top_builddir)/lib/config.h \
  $(top_srcdir)/lib/ext2fs/ext2_io.h $(top_builddir)/lib/ext2fs/ext2_err.h \
  $(top_srcdir)/lib/ext2fs/ext2_ext_attr.h $(top_srcdir)/lib/ext2fs/hashmap.h \
  $(top_srcdir)/lib/ext2fs/bitops.h $(srcdir)/../misc/create_inode.h \
+ $(top_srcdir)/lib/ext2fs/nls.h \
  $(top_srcdir)/lib/e2p/e2p.h $(top_srcdir)/lib/support/quotaio.h \
  $(top_srcdir)/lib/support/dqblk_v2.h \
  $(top_srcdir)/lib/support/quotaio_tree.h
diff --git a/debugfs/htree.c b/debugfs/htree.c
index 0c6a3852393e..1cdb3c6a5bb7 100644
--- a/debugfs/htree.c
+++ b/debugfs/htree.c
@@ -27,6 +27,8 @@ extern char *optarg;
 #include "uuid/uuid.h"
 #include "e2p/e2p.h"
 
+#include "ext2fs/nls.h"
+
 static FILE *pager;
 
 static void htree_dump_leaf_node(ext2_filsys fs, ext2_ino_t ino,
@@ -44,6 +46,7 @@ static void htree_dump_leaf_node(ext2_filsys fs, ext2_ino_t ino,
 	ext2_dirhash_t 	hash, minor_hash;
 	unsigned int	rec_len;
 	int		hash_alg;
+	int		hash_flags = inode->i_flags & EXT4_CASEFOLD_FL;
 	int		csum_size = 0;
 
 	if (ext2fs_has_feature_metadata_csum(fs->super))
@@ -89,9 +92,10 @@ static void htree_dump_leaf_node(ext2_filsys fs, ext2_ino_t ino,
 		}
 		strncpy(name, dirent->name, thislen);
 		name[thislen] = '\0';
-		errcode = ext2fs_dirhash(hash_alg, name,
-					 thislen, fs->super->s_hash_seed,
-					 &hash, &minor_hash);
+		errcode = ext2fs_dirhash2(hash_alg, name, thislen,
+					  fs->encoding, hash_flags,
+					  fs->super->s_hash_seed,
+					  &hash, &minor_hash);
 		if (errcode)
 			com_err("htree_dump_leaf_node", errcode,
 				"while calculating hash");
@@ -306,11 +310,12 @@ errout:
 void do_dx_hash(int argc, char *argv[], int sci_idx EXT2FS_ATTR((unused)),
 		void *infop EXT2FS_ATTR((unused)))
 {
-	ext2_dirhash_t hash, minor_hash;
+	ext2_dirhash_t hash, minor_hash, hash_flags;
 	errcode_t	err;
 	int		c;
 	int		hash_version = 0;
 	__u32		hash_seed[4];
+	const struct nls_table *encoding;
 
 	hash_seed[0] = hash_seed[1] = hash_seed[2] = hash_seed[3] = 0;
 
@@ -329,6 +334,15 @@ void do_dx_hash(int argc, char *argv[], int sci_idx EXT2FS_ATTR((unused)),
 				return;
 			}
 			break;
+		case 'c':
+			hash_flags = EXT4_CASEFOLD_FL;
+			break;
+		case 'e':
+			encoding = nls_load_table(e2p_str2encoding(optarg));
+			if (!encoding)
+				fprintf(stderr, "Invalid encoding: %s\n",
+					optarg);
+				return;
 		default:
 			goto print_usage;
 		}
@@ -336,11 +350,13 @@ void do_dx_hash(int argc, char *argv[], int sci_idx EXT2FS_ATTR((unused)),
 	if (optind != argc-1) {
 	print_usage:
 		com_err(argv[0], 0, "usage: dx_hash [-h hash_alg] "
-			"[-s hash_seed] filename");
+			"[-s hash_seed] [-c] [-e encoding] filename");
 		return;
 	}
-	err = ext2fs_dirhash(hash_version, argv[optind], strlen(argv[optind]),
-			     hash_seed, &hash, &minor_hash);
+	err = ext2fs_dirhash2(hash_version, argv[optind],
+			      strlen(argv[optind]), encoding, hash_flags,
+			      hash_seed, &hash, &minor_hash);
+
 	if (err) {
 		com_err(argv[0], err, "while calculating hash");
 		return;
diff --git a/lib/ext2fs/Makefile.in b/lib/ext2fs/Makefile.in
index b756bbdf35a5..78c54d1a09de 100644
--- a/lib/ext2fs/Makefile.in
+++ b/lib/ext2fs/Makefile.in
@@ -1299,7 +1299,7 @@ htree.o: $(top_srcdir)/debugfs/htree.c $(top_builddir)/lib/config.h \
  $(srcdir)/hashmap.h $(srcdir)/bitops.h \
  $(top_srcdir)/debugfs/../misc/create_inode.h $(top_srcdir)/lib/e2p/e2p.h \
  $(top_srcdir)/lib/support/quotaio.h $(top_srcdir)/lib/support/dqblk_v2.h \
- $(top_srcdir)/lib/support/quotaio_tree.h
+ $(top_srcdir)/lib/support/quotaio_tree.h $(srcdir)/nls.h
 unused.o: $(top_srcdir)/debugfs/unused.c $(top_builddir)/lib/config.h \
  $(top_builddir)/lib/dirpaths.h $(top_srcdir)/debugfs/debugfs.h \
  $(top_srcdir)/lib/ss/ss.h $(top_builddir)/lib/ss/ss_err.h \
-- 
2.20.0.rc1

[PATCH v4 7/9] tune2fs: Prevent enabling encryption flag on encoding-aware fs

[Gabriel Krisman Bertazi]

From: Gabriel Krisman Bertazi <krisman@collabora.co.uk>

The kernel will refuse to mount filesystems with the encryption and
encoding features enabled at the same time.  The encoding feature can
only be set at mount time, so we can just prevent encryption from being
set at a later time by tune2fs.

Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.co.uk>
---
 misc/tune2fs.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/misc/tune2fs.c b/misc/tune2fs.c
index a680b461cc86..4c92bee30b38 100644
--- a/misc/tune2fs.c
+++ b/misc/tune2fs.c
@@ -1459,6 +1459,12 @@ mmp_error:
 	}
 
 	if (FEATURE_ON(E2P_FEATURE_INCOMPAT, EXT4_FEATURE_INCOMPAT_ENCRYPT)) {
+		if (ext2fs_has_feature_fname_encoding(sb)) {
+			fputs(_("Cannot enable encrypt feature on filesystems "
+				"with the encoding feature enabled.\n"),
+			      stderr);
+			return 1;
+		}
 		fs->super->s_encrypt_algos[0] =
 			EXT4_ENCRYPTION_MODE_AES_256_XTS;
 		fs->super->s_encrypt_algos[1] =
-- 
2.20.0.rc1

[PATCH v4 9/9] ext4.5: Add fname_encoding feature to ext4 man page

[Gabriel Krisman Bertazi]

Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
---
 misc/ext4.5.in | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/misc/ext4.5.in b/misc/ext4.5.in
index 8f4c4f51ea85..d65598428a35 100644
--- a/misc/ext4.5.in
+++ b/misc/ext4.5.in
@@ -151,6 +151,16 @@ can be specified using the
 .B \-G
 option.
 .TP
+.B fname_encoding
+.br
+This ext4 feature provides file system level character encoding support
+for files and directories name.  This feature is name-preserving on the
+disk, but it allows applications to lookup for a file in the file system
+using any encoding equivalent version of the file name.
+
+This feature is required to perform in-kernel case-insensitive file
+name lookups.
+.TP
 .B has_journal
 .br
 Create a journal to ensure filesystem consistency even across unclean
-- 
2.20.0.rc1

Re: [PATCH e2fsprogs v4 0/9] Support encoding awareness and casefold

[Theodore Y. Ts'o]

Hi Gabriel,

Thanks for all of your work on it so far.  There's still some work
that we need to do, but I think this is good enough for merge what we
have, so I've pulled this into the e2fsprogs master and next branches.
There were a few commit description adjustments, and in one place I
replaced a call to calloc() with a fixed-size buffer to just using a
on-stack buffer.

The main thing I noticed is that nothing is initializing fs->encoding.
We need to do that in ext2fs_open() and ext2fs_initialize().  We also
need to add some test cases --- if we did, we would have noticed the
missing initialization of fs->encoding.

I do want to include of the script which generates utf8data.h in
e2fsprogs sources; we'll need to it in sync with the kernel sources,
and so long as it stays in sync, we can always double check that
version of utf8data.h in e2fsprogs matches the version the one in the
kernel.  But for reasons of GPL compliance, we should keep a copy of
the script which creates the generated .h file.

Again, thanks for the work so far!

					- Ted

Re: [PATCH e2fsprogs v4 0/9] Support encoding awareness and casefold

[Gabriel Krisman Bertazi]

"Theodore Y. Ts'o" <tytso@mit.edu> writes:

> Hi Gabriel,
>
> Thanks for all of your work on it so far.  There's still some work
> that we need to do, but I think this is good enough for merge what we
> have, so I've pulled this into the e2fsprogs master and next branches.
> There were a few commit description adjustments, and in one place I
> replaced a call to calloc() with a fixed-size buffer to just using a
> on-stack buffer.

Hi Ted,

Thank you for helping me get this done and for amending the remaining
edges.

> The main thing I noticed is that nothing is initializing fs->encoding.
> We need to do that in ext2fs_open() and ext2fs_initialize().  We also
> need to add some test cases --- if we did, we would have noticed the
> missing initialization of fs->encoding.

I didn't want to load the table in those functions because I didn't want
to fail there if the nls_table wasn't found.  If the user has some new
unsupported encoding, e2fsprogs could provide some functionality, even
if it can't deal with the file tree itself.  Failing during open seemed
too harsh.

Do you think the patch below is better?  It tries to load the table
early, but only aborts the execution for fsck.  I'm not sure it is a
valid interface.

> I do want to include of the script which generates utf8data.h in
> e2fsprogs sources; we'll need to it in sync with the kernel sources,
> and so long as it stays in sync, we can always double check that
> version of utf8data.h in e2fsprogs matches the version the one in the
> kernel.  But for reasons of GPL compliance, we should keep a copy of
> the script which creates the generated .h file.

I can send another patch for this right away.  Should we also include
the ucd files into e2fsprogs tree?

Thanks,

-- >8 --
Subject: [PATCH] ext2fs: Always attempt to load nls table when loading the
 filesystem

fs->encoding is exposed by the library, so we need to at least try to
load it when populating ext2_filsys.  Nevertheless, failing to do so
shouldn't be a fatal error, unless the user really needs that
information.  Thus, we ignore this failure during open/initialization
and let the user who needs it validate that field before trying to use
it.

Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
---
 e2fsck/unix.c           | 12 ++++--------
 lib/ext2fs/initialize.c |  4 ++++
 lib/ext2fs/openfs.c     |  4 ++++
 3 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/e2fsck/unix.c b/e2fsck/unix.c
index 5b3552ece6b1..7c24f2e31e4f 100644
--- a/e2fsck/unix.c
+++ b/e2fsck/unix.c
@@ -55,7 +55,6 @@ extern int optind;
 #include "problem.h"
 #include "jfs_user.h"
 #include "../version.h"
-#include <ext2fs/nls.h>
 
 /* Command line options */
 static int cflag;		/* check disk */
@@ -1785,13 +1784,10 @@ print_unsupp_features:
 		goto get_newer;
 	}
 
-	if (ext2fs_has_feature_fname_encoding(sb)) {
-		fs->encoding = nls_load_table(sb->s_encoding);
-		if (!fs->encoding) {
-			log_err(ctx, _("%s has unsupported encoding: %0x\n"),
-				ctx->filesystem_name, sb->s_encoding);
-			goto get_newer;
-		}
+	if (ext2fs_has_feature_fname_encoding(sb) && !fs->encoding) {
+		log_err(ctx, _("%s has unsupported encoding: %0x\n"),
+			ctx->filesystem_name, sb->s_encoding);
+		goto get_newer;
 	}
 
 	/*
diff --git a/lib/ext2fs/initialize.c b/lib/ext2fs/initialize.c
index 30b1ae033340..2d470a070bcc 100644
--- a/lib/ext2fs/initialize.c
+++ b/lib/ext2fs/initialize.c
@@ -27,6 +27,7 @@
 
 #include "ext2_fs.h"
 #include "ext2fs.h"
+#include "nls.h"
 
 #ifndef O_BINARY
 #define O_BINARY 0
@@ -190,6 +191,9 @@ errcode_t ext2fs_initialize(const char *name, int flags,
 	assign_field(s_encoding);
 	assign_field(s_encoding_flags);
 
+	if (ext2fs_has_feature_fname_encoding(param))
+		fs->encoding = nls_load_table(param->s_encoding);
+
 	if (super->s_feature_incompat & ~EXT2_LIB_FEATURE_INCOMPAT_SUPP) {
 		retval = EXT2_ET_UNSUPP_FEATURE;
 		goto cleanup;
diff --git a/lib/ext2fs/openfs.c b/lib/ext2fs/openfs.c
index 85d73e2a429b..9ee6cd07f7f3 100644
--- a/lib/ext2fs/openfs.c
+++ b/lib/ext2fs/openfs.c
@@ -32,6 +32,7 @@
 
 #include "ext2fs.h"
 #include "e2image.h"
+#include "nls.h"
 
 blk64_t ext2fs_descriptor_block_loc2(ext2_filsys fs, blk64_t group_block,
 				     dgrp_t i)
@@ -502,6 +503,9 @@ errcode_t ext2fs_open2(const char *name, const char *io_options,
 		ext2fs_set_feature_shared_blocks(fs->super);
 	}
 
+	if (ext2fs_has_feature_fname_encoding(fs->super))
+		fs->encoding = nls_load_table(fs->super->s_encoding);
+
 	fs->flags &= ~EXT2_FLAG_NOFREE_ON_ERROR;
 	*ret_fs = fs;
 
-- 
2.20.0.rc2

Re: [PATCH e2fsprogs v4 0/9] Support encoding awareness and casefold

[Theodore Y. Ts'o]

On Mon, Dec 03, 2018 at 04:00:12PM -0500, Gabriel Krisman Bertazi wrote:
> I didn't want to load the table in those functions because I didn't want
> to fail there if the nls_table wasn't found.  If the user has some new
> unsupported encoding, e2fsprogs could provide some functionality, even
> if it can't deal with the file tree itself.  Failing during open seemed
> too harsh.

Unfortunately, I think the only thing we can do is to fail at open or
mount if the encoding is unknown.  The problem is that we can't
correctly handle case-folded directories which have htree enabled.
The problem is that we might have encoding-oblivious applications,
such as fuse2fs (for example) where if they use the high-level
libext2fs interfaces, they don't *need* to be encoding aware.

But if we don't fail the open, then what do we do if the library
routine to calculate a directory hash is called?  Most applications
(or callers in libext2fs for that matter) won't gracefully handle an
error there.

It's one thing if we only support Unicode version N, and the file
system is Unicode version N+1.  So long as the user isn't trying to
use the new scripts, things are mostly OK.

But what if the alternate encoding is something completely different?
Say, EBCDIC, or UTF-EBCDIC[1]?  :-) There really is nothing we can do
sanely but to fail the mount.

This also effectively means that new encodings are effectively
incompatible features, but I think that's OK.

						- Ted
						

[1] Which really is a thing[2].  Oh, the horror....
[2] https://www.unicode.org/reports/tr16/

Re: [PATCH e2fsprogs v4 0/9] Support encoding awareness and casefold

[Andreas Dilger]

[-- Attachment #1: Type: text/plain, Size: 2251 bytes --]

On Dec 8, 2018, at 10:45 AM, Theodore Y. Ts'o <tytso@mit.edu> wrote:
> 
> On Mon, Dec 03, 2018 at 04:00:12PM -0500, Gabriel Krisman Bertazi wrote:
>> I didn't want to load the table in those functions because I didn't want
>> to fail there if the nls_table wasn't found.  If the user has some new
>> unsupported encoding, e2fsprogs could provide some functionality, even
>> if it can't deal with the file tree itself.  Failing during open seemed
>> too harsh.
> 
> Unfortunately, I think the only thing we can do is to fail at open or
> mount if the encoding is unknown.  The problem is that we can't
> correctly handle case-folded directories which have htree enabled.
> The problem is that we might have encoding-oblivious applications,
> such as fuse2fs (for example) where if they use the high-level
> libext2fs interfaces, they don't *need* to be encoding aware.
> 
> But if we don't fail the open, then what do we do if the library
> routine to calculate a directory hash is called?  Most applications
> (or callers in libext2fs for that matter) won't gracefully handle an
> error there.
> 
> It's one thing if we only support Unicode version N, and the file
> system is Unicode version N+1.  So long as the user isn't trying to
> use the new scripts, things are mostly OK.
> 
> But what if the alternate encoding is something completely different?
> Say, EBCDIC, or UTF-EBCDIC[1]?  :-) There really is nothing we can do
> sanely but to fail the mount.
> 
> This also effectively means that new encodings are effectively
> incompatible features, but I think that's OK.

Doesn't this meant that if opening a filesystem with an unknown encoding
fails, that any kind of corruption to the encoding type would cause
problems, and opening the filesystem to _remove_ the encoding would also
fail?

I think that it makes more sense to allow the filesystem to be opened
in this case, and only fail operations that need the specific encoding
(e.g. "e2fsck -fD" that needs to know the hashing).  It shouldn't hurt
tune2fs, debugfs, resize2fs, etc. that probably do not need to know the
encoding.  At worst, they could revert the htree directory to a flat
directory if they need to insert an entry and don't understand how to
hash it.

Cheers, Andreas






[-- Attachment #2: Message signed with OpenPGP --]
[-- Type: application/pgp-signature, Size: 873 bytes --]

Re: [PATCH v4 4/9] lib/ext2fs: Implement NLS support

[Eric Biggers]

On Fri, Nov 30, 2018 at 07:39:05PM -0500, Gabriel Krisman Bertazi wrote:
> From: Gabriel Krisman Bertazi <krisman@collabora.co.uk>
> 
> Basic NLS support is required in e2fsprogs because of fsck, which
> needsto calculate dx hashes for encoding aware filesystems.  this patch
> implements this infrastructure as well as ascii support.
> 
> We don't need to do all the dance of versioning as we do in the kernel,
> because we know before-hand which encodings and versions we
> support (those we know how to store in the sb), so it is simpler just to
> create static tables.
> 
> Changes since v3:
>   - Prevent buffer overflow during normalization/casefold.
>   - Signal invalid sequences and let caller handle it.
> 
[...]
> diff --git a/lib/ext2fs/nls_ascii.c b/lib/ext2fs/nls_ascii.c
> new file mode 100644
> index 000000000000..5d513df404c1
> --- /dev/null
> +++ b/lib/ext2fs/nls_ascii.c
> @@ -0,0 +1,68 @@
> +#include "nls.h"
> +
> +#include <errno.h>
> +#include <string.h>
> +
> +
> +static unsigned char charset_tolower(const struct nls_table *table,
> +				     unsigned int c)
> +{
> +	if (c >= 'A' && c <= 'Z')
> +		return (c | 0x20);
> +	return c;
> +}

Is charset_tolower() supposed to be used for something?  It's never called.

- Eric