ext4: add casefold flag to EXT4_INODE_* flags

No one currently needs EXT4_INODE_CASEFOLD, but add it to keep the
EXT4_INODE_* definitions in sync with the EXT4_*_FL definitions.

Also make it clearer that the casefold flag is only for directories.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20200510215252.87833-1-ebiggers@kernel.orgSigned-off-by: Theodore Ts'o <tytso@mit.edu>

fs/ext4/ext4.h

@@ -425,7 +425,7 @@ struct flex_groups {
 /* 0x00400000 was formerly EXT4_EOFBLOCKS_FL */
 #define EXT4_INLINE_DATA_FL		0x10000000 /* Inode has inline data. */
 #define EXT4_PROJINHERIT_FL		0x20000000 /* Create with parents projid */
-#define EXT4_CASEFOLD_FL		0x40000000 /* Casefolded file */
+#define EXT4_CASEFOLD_FL		0x40000000 /* Casefolded directory */
 #define EXT4_RESERVED_FL		0x80000000 /* reserved for ext4 lib */
 
 #define EXT4_FL_USER_VISIBLE		0x705BDFFF /* User visible flags */
@@ -498,6 +498,7 @@ enum {
 /* 22 was formerly EXT4_INODE_EOFBLOCKS */
 	EXT4_INODE_INLINE_DATA	= 28,	/* Data in inode. */
 	EXT4_INODE_PROJINHERIT	= 29,	/* Create with parents projid */
+	EXT4_INODE_CASEFOLD	= 30,	/* Casefolded directory */
 	EXT4_INODE_RESERVED	= 31,	/* reserved for ext4 lib */
 };
 
@@ -543,6 +544,7 @@ static inline void ext4_check_flag_values(void)
 	CHECK_FLAG_VALUE(EA_INODE);
 	CHECK_FLAG_VALUE(INLINE_DATA);
 	CHECK_FLAG_VALUE(PROJINHERIT);
+	CHECK_FLAG_VALUE(CASEFOLD);
 	CHECK_FLAG_VALUE(RESERVED);
 }