BACKPORT: ext4: Only advertise encrypted_casefold when encryption and unicode are enabled

[ Upstream commit e71f99f2dfb45f4e7203a0732e85f71ef1d04dab ]

Encrypted casefolding is only supported when both encryption and
casefolding are both enabled in the config.

Fixes: 471fbbea7ff7 ("ext4: handle casefolding with encryption")
Cc: stable@vger.kernel.org # 5.13+
Signed-off-by: Daniel Rosenberg <drosen@google.com>
Link: https://lore.kernel.org/r/20210603094849.314342-1-drosen@google.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Change-Id: I4655b3aab60006ea03fb3454a0a833634546373b

fs/ext4/sysfs.c

@@ -250,7 +250,9 @@ EXT4_ATTR_FEATURE(casefold);
 EXT4_ATTR_FEATURE(verity);
 #endif
 EXT4_ATTR_FEATURE(metadata_csum_seed);
+#if defined(CONFIG_UNICODE) && defined(CONFIG_FS_ENCRYPTION)
 EXT4_ATTR_FEATURE(encrypted_casefold);
+#endif
 
 static struct attribute *ext4_feat_attrs[] = {
 	ATTR_LIST(lazy_itable_init),
@@ -267,7 +269,9 @@ static struct attribute *ext4_feat_attrs[] = {
 	ATTR_LIST(verity),
 #endif
 	ATTR_LIST(metadata_csum_seed),
+#if defined(CONFIG_UNICODE) && defined(CONFIG_FS_ENCRYPTION)
 	ATTR_LIST(encrypted_casefold),
+#endif
 	NULL,
 };
 ATTRIBUTE_GROUPS(ext4_feat);