btrfs-progs: add blake2b support

Add definition, crypto wrappers and support to mkfs for blake2 for
checksumming. There are 2 aliases either blake2 or blake2b.

Signed-off-by: David Sterba <dsterba@suse.com>

cmds/inspect-dump-super.c

@@ -317,6 +317,7 @@ static bool is_valid_csum_type(u16 csum_type)
 	case BTRFS_CSUM_TYPE_CRC32:
 	case BTRFS_CSUM_TYPE_XXHASH:
 	case BTRFS_CSUM_TYPE_SHA256:
+	case BTRFS_CSUM_TYPE_BLAKE2:
 		return true;
 	default:
 		return false;

crypto/hash.c

@@ -2,6 +2,7 @@
 #include "crypto/crc32c.h"
 #include "crypto/xxhash.h"
 #include "crypto/sha.h"
+#include "crypto/blake2.h"
 
 int hash_crc32c(const u8* buf, size_t length, u8 *out)
 {
@@ -37,3 +38,14 @@ int hash_sha256(const u8 *buf, size_t len, u8 *out)
 
 	return 0;
 }
+
+int hash_blake2b(const u8 *buf, size_t len, u8 *out)
+{
+	blake2b_state S;
+
+	blake2b_init(&S, CRYPTO_HASH_SIZE_MAX);
+	blake2b_update(&S, buf, len);
+	blake2b_final(&S, out, CRYPTO_HASH_SIZE_MAX);
+
+	return 0;
+}

crypto/hash.h

@@ -8,5 +8,6 @@
 int hash_crc32c(const u8 *buf, size_t length, u8 *out);
 int hash_xxhash(const u8 *buf, size_t length, u8 *out);
 int hash_sha256(const u8 *buf, size_t length, u8 *out);
+int hash_blake2b(const u8 *buf, size_t length, u8 *out);
 
 #endif

ctree.c

@@ -45,6 +45,7 @@ static const struct btrfs_csum {
 	[BTRFS_CSUM_TYPE_CRC32]		= {  4, "crc32c" },
 	[BTRFS_CSUM_TYPE_XXHASH]	= {  8, "xxhash64" },
 	[BTRFS_CSUM_TYPE_SHA256]	= { 32, "sha256" },
+	[BTRFS_CSUM_TYPE_BLAKE2]	= { 32, "blake2" },
 };
 
 u16 btrfs_super_csum_size(const struct btrfs_super_block *sb)

ctree.h

@@ -169,6 +169,7 @@ enum btrfs_csum_type {
 	BTRFS_CSUM_TYPE_CRC32		= 0,
 	BTRFS_CSUM_TYPE_XXHASH		= 1,
 	BTRFS_CSUM_TYPE_SHA256		= 2,
+	BTRFS_CSUM_TYPE_BLAKE2		= 3,
 };
 
 #define BTRFS_EMPTY_DIR_SIZE 0

disk-io.c

@@ -150,6 +150,8 @@ int btrfs_csum_data(u16 csum_type, const u8 *data, u8 *out, size_t len)
 		return hash_xxhash(data, len, out);
 	case BTRFS_CSUM_TYPE_SHA256:
 		return hash_sha256(data, len, out);
+	case BTRFS_CSUM_TYPE_BLAKE2:
+		return hash_blake2b(data, len, out);
 	default:
 		fprintf(stderr, "ERROR: unknown csum type: %d\n", csum_type);
 		ASSERT(0);

mkfs/main.c

@@ -397,6 +397,9 @@ static enum btrfs_csum_type parse_csum_type(const char *s)
 		return BTRFS_CSUM_TYPE_XXHASH;
 	} else if (strcasecmp(s, "sha256") == 0) {
 		return BTRFS_CSUM_TYPE_SHA256;
+	} else if (strcasecmp(s, "blake2b") == 0 ||
+		   strcasecmp(s, "blake2") == 0) {
+		return BTRFS_CSUM_TYPE_BLAKE2;
 	} else {
 		error("unknown csum type %s", s);
 		exit(1);