f2fs: Show casefolding support only when supported

stable inclusion
from stable-5.10.53
commit a62177b35730650c54339c3eb581a1c84f7387da
bugzilla: 175574 https://gitee.com/openeuler/kernel/issues/I4DTUX

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=a62177b35730650c54339c3eb581a1c84f7387da

--------------------------------

commit 39307f8e upstream.

The casefolding feature is only supported when CONFIG_UNICODE is set.
This modifies the feature list f2fs presents under sysfs accordingly.

Fixes: 5aba5430 ("f2fs: include charset encoding information in the superblock")
Cc: stable@vger.kernel.org # v5.4+
Signed-off-by: NDaniel Rosenberg <drosen@google.com>
Reviewed-by: NEric Biggers <ebiggers@google.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: NEric Biggers <ebiggers@google.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Acked-by: NWeilong Chen <chenweilong@huawei.com>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

fs/f2fs/sysfs.c

@@ -612,7 +612,9 @@ F2FS_FEATURE_RO_ATTR(lost_found, FEAT_LOST_FOUND);
 F2FS_FEATURE_RO_ATTR(verity, FEAT_VERITY);
 #endif
 F2FS_FEATURE_RO_ATTR(sb_checksum, FEAT_SB_CHECKSUM);
+#ifdef CONFIG_UNICODE
 F2FS_FEATURE_RO_ATTR(casefold, FEAT_CASEFOLD);
+#endif
 #ifdef CONFIG_F2FS_FS_COMPRESSION
 F2FS_FEATURE_RO_ATTR(compression, FEAT_COMPRESSION);
 #endif
@@ -700,7 +702,9 @@ static struct attribute *f2fs_feat_attrs[] = {
 	ATTR_LIST(verity),
 #endif
 	ATTR_LIST(sb_checksum),
+#ifdef CONFIG_UNICODE
 	ATTR_LIST(casefold),
+#endif
 #ifdef CONFIG_F2FS_FS_COMPRESSION
 	ATTR_LIST(compression),
 #endif