[PATCH] f2fs-tools: Casefolded Encryption support

[PATCH] f2fs-tools: Casefolded Encryption support

[Daniel Rosenberg]

This adds support for casefolded and encrypted directories.
Fsck cannot check the hashes of such directories because it would
require access to the encryption key to generate the siphash

Signed-off-by: Daniel Rosenberg <drosen@google.com>
---
 fsck/fsck.c        | 4 ++++
 fsck/mount.c       | 6 ------
 mkfs/f2fs_format.c | 4 ----
 3 files changed, 4 insertions(+), 10 deletions(-)

diff --git a/fsck/fsck.c b/fsck/fsck.c
index 2ae3bd5..ebbdf44 100644
--- a/fsck/fsck.c
+++ b/fsck/fsck.c
@@ -1290,6 +1290,10 @@ static int f2fs_check_hash_code(int encoding, int casefolded,
 			struct f2fs_dir_entry *dentry,
 			const unsigned char *name, u32 len, int enc_name)
 {
+	/* Casefolded Encrypted names require a key to compute siphash */
+	if (enc_name && casefolded)
+		return 0;
+
 	f2fs_hash_t hash_code = f2fs_dentry_hash(encoding, casefolded, name, len);
 	/* fix hash_code made by old buggy code */
 	if (dentry->hash_code != hash_code) {
diff --git a/fsck/mount.c b/fsck/mount.c
index 4814dfe..3286899 100644
--- a/fsck/mount.c
+++ b/fsck/mount.c
@@ -2965,12 +2965,6 @@ static int tune_sb_features(struct f2fs_sb_info *sbi)
 	int sb_changed = 0;
 	struct f2fs_super_block *sb = F2FS_RAW_SUPER(sbi);
 
-	if (c.feature & cpu_to_le32(F2FS_FEATURE_ENCRYPT) &&
-		c.feature & cpu_to_le32(F2FS_FEATURE_CASEFOLD)) {
-		ERR_MSG("ERROR: Cannot set both encrypt and casefold. Skipping.\n");
-		return -1;
-	}
-
 	if (!(sb->feature & cpu_to_le32(F2FS_FEATURE_ENCRYPT)) &&
 			c.feature & cpu_to_le32(F2FS_FEATURE_ENCRYPT)) {
 		sb->feature |= cpu_to_le32(F2FS_FEATURE_ENCRYPT);
diff --git a/mkfs/f2fs_format.c b/mkfs/f2fs_format.c
index 9402619..0bfe963 100644
--- a/mkfs/f2fs_format.c
+++ b/mkfs/f2fs_format.c
@@ -517,10 +517,6 @@ static int f2fs_prepare_super_block(void)
 	memcpy(sb->init_version, c.version, VERSION_LEN);
 
 	if (c.feature & cpu_to_le32(F2FS_FEATURE_CASEFOLD)) {
-		if (c.feature & cpu_to_le32(F2FS_FEATURE_ENCRYPT)) {
-			MSG(0, "\tError: Casefolding and encryption are not compatible\n");
-			return -1;
-		}
 		set_sb(s_encoding, c.s_encoding);
 		set_sb(s_encoding_flags, c.s_encoding_flags);
 	}
-- 
2.24.0.393.g34dc348eaf-goog