Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

Pull ext4 updates from Ted Ts'o:
 "Add as a feature case-insensitive directories (the casefold feature)
  using Unicode 12.1.

  Also, the usual largish number of cleanups and bug fixes"

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (25 commits)
  ext4: export /sys/fs/ext4/feature/casefold if Unicode support is present
  ext4: fix ext4_show_options for file systems w/o journal
  unicode: refactor the rule for regenerating utf8data.h
  docs: ext4.rst: document case-insensitive directories
  ext4: Support case-insensitive file name lookups
  ext4: include charset encoding information in the superblock
  MAINTAINERS: add Unicode subsystem entry
  unicode: update unicode database unicode version 12.1.0
  unicode: introduce test module for normalized utf8 implementation
  unicode: implement higher level API for string handling
  unicode: reduce the size of utf8data[]
  unicode: introduce code for UTF-8 normalization
  unicode: introduce UTF-8 character database
  ext4: actually request zeroing of inode table after grow
  ext4: cond_resched in work-heavy group loops
  ext4: fix use-after-free race with debug_want_extra_isize
  ext4: avoid drop reference to iloc.bh twice
  ext4: ignore e_value_offs for xattrs with value-in-ea-inode
  ext4: protect journal inode's blocks using block_validity
  ext4: use BUG() instead of BUG_ON(1)
  ...

2 files changed, 32 insertions, 0 deletions

diff --git a/include/linux/fs.h b/include/linux/fs.h
index 0fa5b47509d5..f7fdfe93e25d 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1963,6 +1963,7 @@ struct super_operations {
 #define S_DAX		0	/* Make all the DAX code disappear */
 #endif
 #define S_ENCRYPTED	16384	/* Encrypted file (using fs/crypto/) */
+#define S_CASEFOLD	32768	/* Casefolded file */
 
 /*
  * Note that nosuid etc flags are inode-specific: setting some file-system
@@ -2003,6 +2004,7 @@ static inline bool sb_rdonly(const struct super_block *sb) { return sb->s_flags
 #define IS_NOSEC(inode)		((inode)->i_flags & S_NOSEC)
 #define IS_DAX(inode)		((inode)->i_flags & S_DAX)
 #define IS_ENCRYPTED(inode)	((inode)->i_flags & S_ENCRYPTED)
+#define IS_CASEFOLDED(inode)	((inode)->i_flags & S_CASEFOLD)
 
 #define IS_WHITEOUT(inode)	(S_ISCHR(inode->i_mode) && \
 				 (inode)->i_rdev == WHITEOUT_DEV)
diff --git a/include/linux/unicode.h b/include/linux/unicode.h
new file mode 100644
index 000000000000..aec2c6d800aa
--- /dev/null
+++ b/include/linux/unicode.h
@@ -0,0 +1,30 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_UNICODE_H
+#define _LINUX_UNICODE_H
+
+#include <linux/init.h>
+#include <linux/dcache.h>
+
+struct unicode_map {
+	const char *charset;
+	int version;
+};
+
+int utf8_validate(const struct unicode_map *um, const struct qstr *str);
+
+int utf8_strncmp(const struct unicode_map *um,
+		 const struct qstr *s1, const struct qstr *s2);
+
+int utf8_strncasecmp(const struct unicode_map *um,
+		 const struct qstr *s1, const struct qstr *s2);
+
+int utf8_normalize(const struct unicode_map *um, const struct qstr *str,
+		   unsigned char *dest, size_t dlen);
+
+int utf8_casefold(const struct unicode_map *um, const struct qstr *str,
+		  unsigned char *dest, size_t dlen);
+
+struct unicode_map *utf8_load(const char *version);
+void utf8_unload(struct unicode_map *um);
+
+#endif /* _LINUX_UNICODE_H */