[PATCH v2 2/2] f2fs: Advertise encrypted casefolding in sysfs

[Daniel Rosenberg <drosen@google.com>]

Older kernels don't support encryption with casefolding. This adds
the sysfs entry encrypted_casefold to show support for those combined
features. Support for this feature was originally added by
commit 7ad08a58bf67 ("f2fs: Handle casefolding with Encryption")

Fixes: 7ad08a58bf67 ("f2fs: Handle casefolding with Encryption")
Cc: stable@vger.kernel.org # v5.11+
Signed-off-by: Daniel Rosenberg <drosen@google.com>
---
 fs/f2fs/sysfs.c | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
index 09e3f258eb52..6604291a3cdf 100644
--- a/fs/f2fs/sysfs.c
+++ b/fs/f2fs/sysfs.c
@@ -161,6 +161,9 @@ static ssize_t features_show(struct f2fs_attr *a,
 	if (f2fs_sb_has_compression(sbi))
 		len += scnprintf(buf + len, PAGE_SIZE - len, "%s%s",
 				len ? ", " : "", "compression");
+	if (f2fs_sb_has_casefold(sbi) && f2fs_sb_has_encrypt(sbi))
+		len += scnprintf(buf + len, PAGE_SIZE - len, "%s%s",
+				len ? ", " : "", "encrypted_casefold");
 	len += scnprintf(buf + len, PAGE_SIZE - len, "%s%s",
 				len ? ", " : "", "pin_file");
 	len += scnprintf(buf + len, PAGE_SIZE - len, "\n");
@@ -579,6 +582,7 @@ enum feat_id {
 	FEAT_CASEFOLD,
 	FEAT_COMPRESSION,
 	FEAT_TEST_DUMMY_ENCRYPTION_V2,
+	FEAT_ENCRYPTED_CASEFOLD,
 };
 
 static ssize_t f2fs_feature_show(struct f2fs_attr *a,
@@ -600,6 +604,7 @@ static ssize_t f2fs_feature_show(struct f2fs_attr *a,
 	case FEAT_CASEFOLD:
 	case FEAT_COMPRESSION:
 	case FEAT_TEST_DUMMY_ENCRYPTION_V2:
+	case FEAT_ENCRYPTED_CASEFOLD:
 		return sprintf(buf, "supported\n");
 	}
 	return 0;
@@ -704,7 +709,10 @@ F2FS_GENERAL_RO_ATTR(avg_vblocks);
 #ifdef CONFIG_FS_ENCRYPTION
 F2FS_FEATURE_RO_ATTR(encryption, FEAT_CRYPTO);
 F2FS_FEATURE_RO_ATTR(test_dummy_encryption_v2, FEAT_TEST_DUMMY_ENCRYPTION_V2);
-#endif
+#ifdef CONFIG_UNICODE
+F2FS_FEATURE_RO_ATTR(encrypted_casefold, FEAT_ENCRYPTED_CASEFOLD);
+#endif /* CONFIG_UNICODE */
+#endif /* CONFIG_FS_ENCRYPTION */
 #ifdef CONFIG_BLK_DEV_ZONED
 F2FS_FEATURE_RO_ATTR(block_zoned, FEAT_BLKZONED);
 #endif
@@ -815,7 +823,10 @@ static struct attribute *f2fs_feat_attrs[] = {
 #ifdef CONFIG_FS_ENCRYPTION
 	ATTR_LIST(encryption),
 	ATTR_LIST(test_dummy_encryption_v2),
-#endif
+#ifdef CONFIG_UNICODE
+	ATTR_LIST(encrypted_casefold),
+#endif /* CONFIG_UNICODE */
+#endif /* CONFIG_FS_ENCRYPTION */
 #ifdef CONFIG_BLK_DEV_ZONED
 	ATTR_LIST(block_zoned),
 #endif
-- 
2.32.0.rc0.204.g9fa02ecfa5-goog