From f070ece2e98f28c349af78f15ac487e23ada3ee1 Mon Sep 17 00:00:00 2001
From: Johannes Thumshirn <jthumshirn@suse.de>
Date: Wed, 25 Sep 2019 15:37:26 +0200
Subject: [PATCH] btrfs-progs: add xxhash64 to mkfs

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: David Sterba <dsterba@suse.com>
---
 Makefile                  |  3 ++-
 cmds/inspect-dump-super.c |  1 +
 crypto/hash.c             | 16 ++++++++++++++++
 crypto/hash.h             | 10 ++++++++++
 ctree.c                   |  1 +
 ctree.h                   |  1 +
 disk-io.c                 |  3 +++
 mkfs/main.c               |  3 +++
 8 files changed, 37 insertions(+), 1 deletion(-)
 create mode 100644 crypto/hash.c
 create mode 100644 crypto/hash.h

diff --git a/Makefile b/Makefile
index d9c38df7..cca0fbcb 100644
--- a/Makefile
+++ b/Makefile
@@ -156,7 +156,8 @@ libbtrfs_objects = send-stream.o send-utils.o kernel-lib/rbtree.o btrfs-list.o \
 		   free-space-tree.o repair.o inode-item.o file-item.o \
 		   kernel-lib/raid56.o kernel-lib/tables.o \
 		   common/device-scan.o common/path-utils.o \
-		   common/utils.o libbtrfsutil/subvolume.o libbtrfsutil/stubs.o
+		   common/utils.o libbtrfsutil/subvolume.o libbtrfsutil/stubs.o \
+		   crypto/hash.o crypto/xxhash.o
 libbtrfs_headers = send-stream.h send-utils.h send.h kernel-lib/rbtree.h btrfs-list.h \
 	       kernel-lib/crc32c.h kernel-lib/list.h kerncompat.h \
 	       kernel-lib/radix-tree.h kernel-lib/sizes.h kernel-lib/raid56.h \
diff --git a/cmds/inspect-dump-super.c b/cmds/inspect-dump-super.c
index bf380ad2..73e986ed 100644
--- a/cmds/inspect-dump-super.c
+++ b/cmds/inspect-dump-super.c
@@ -315,6 +315,7 @@ static bool is_valid_csum_type(u16 csum_type)
 {
 	switch (csum_type) {
 	case BTRFS_CSUM_TYPE_CRC32:
+	case BTRFS_CSUM_TYPE_XXHASH:
 		return true;
 	default:
 		return false;
diff --git a/crypto/hash.c b/crypto/hash.c
new file mode 100644
index 00000000..8c428cba
--- /dev/null
+++ b/crypto/hash.c
@@ -0,0 +1,16 @@
+#include "crypto/hash.h"
+#include "crypto/xxhash.h"
+
+int hash_xxhash(const u8 *buf, size_t length, u8 *out)
+{
+	XXH64_hash_t hash;
+
+	hash = XXH64(buf, length, 0);
+	/*
+	 * NOTE: we're not taking the canonical form here but the plain hash to
+	 * be compatible with the kernel implementation!
+	 */
+	memcpy(out, &hash, 8);
+
+	return 0;
+}
diff --git a/crypto/hash.h b/crypto/hash.h
new file mode 100644
index 00000000..45c1ef17
--- /dev/null
+++ b/crypto/hash.h
@@ -0,0 +1,10 @@
+#ifndef CRYPTO_HASH_H
+#define CRYPTO_HASH_H
+
+#include "../kerncompat.h"
+
+#define CRYPTO_HASH_SIZE_MAX	32
+
+int hash_xxhash(const u8 *buf, size_t length, u8 *out);
+
+#endif
diff --git a/ctree.c b/ctree.c
index 46d16513..006cfad3 100644
--- a/ctree.c
+++ b/ctree.c
@@ -43,6 +43,7 @@ static struct btrfs_csum {
 	const char *name;
 } btrfs_csums[] = {
 	[BTRFS_CSUM_TYPE_CRC32]		= {  4, "crc32c" },
+	[BTRFS_CSUM_TYPE_XXHASH]	= {  8, "xxhash64" },
 };
 
 u16 btrfs_super_csum_size(const struct btrfs_super_block *sb)
diff --git a/ctree.h b/ctree.h
index b2745e1e..5c3a66fb 100644
--- a/ctree.h
+++ b/ctree.h
@@ -167,6 +167,7 @@ struct btrfs_free_space_ctl;
 /* csum types */
 enum btrfs_csum_type {
 	BTRFS_CSUM_TYPE_CRC32		= 0,
+	BTRFS_CSUM_TYPE_XXHASH		= 1,
 };
 
 #define BTRFS_EMPTY_DIR_SIZE 0
diff --git a/disk-io.c b/disk-io.c
index c3e85c0e..b40c7225 100644
--- a/disk-io.c
+++ b/disk-io.c
@@ -34,6 +34,7 @@
 #include "print-tree.h"
 #include "common/rbtree-utils.h"
 #include "common/device-scan.h"
+#include "crypto/hash.h"
 
 /* specified errno for check_tree_block */
 #define BTRFS_BAD_BYTENR		(-1)
@@ -149,6 +150,8 @@ int btrfs_csum_data(u16 csum_type, const u8 *data, u8 *out, size_t len)
 		crc = crc32c(crc, data, len);
 		put_unaligned_le32(~crc, out);
 		return 0;
+	case BTRFS_CSUM_TYPE_XXHASH:
+		return hash_xxhash(data, len, out);
 	default:
 		fprintf(stderr, "ERROR: unknown csum type: %d\n", csum_type);
 		ASSERT(0);
diff --git a/mkfs/main.c b/mkfs/main.c
index f52e8b61..a6deddc4 100644
--- a/mkfs/main.c
+++ b/mkfs/main.c
@@ -392,6 +392,9 @@ static enum btrfs_csum_type parse_csum_type(const char *s)
 {
 	if (strcasecmp(s, "crc32c") == 0) {
 		return BTRFS_CSUM_TYPE_CRC32;
+	} else if (strcasecmp(s, "xxhash64") == 0 ||
+		   strcasecmp(s, "xxhash") == 0) {
+		return BTRFS_CSUM_TYPE_XXHASH;
 	} else {
 		error("unknown csum type %s", s);
 		exit(1);