fs: btrfs: Add more checksum algorithms

This mostly crossports crypto/hash.[ch] from btrfs-progs.

The differences are:
- No blake2 support
  No blake2 related library in U-Boot yet.

- Use uboot xxhash/sha256 directly
  No need to implement the code as U-Boot has already provided the
  interface.

This adds the support for the following csums:
- SHA256
- XXHASH

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Marek Behún <marek.behun@nic.cz>

fs/btrfs/Makefile

@@ -3,4 +3,4 @@
 # 2017 Marek Behun, CZ.NIC, marek.behun@nic.cz
 
 obj-y := btrfs.o chunk-map.o compression.o ctree.o dev.o dir-item.o \
-	extent-io.o hash.o inode.o root.o subvolume.o super.o
+	extent-io.o inode.o root.o subvolume.o super.o crypto/hash.o disk-io.o

fs/btrfs/btrfs.c

@@ -5,11 +5,12 @@
  * 2017 Marek Behun, CZ.NIC, marek.behun@nic.cz
  */
 
-#include "btrfs.h"
 #include <config.h>
 #include <malloc.h>
 #include <uuid.h>
 #include <linux/time.h>
+#include "btrfs.h"
+#include "crypto/hash.h"
 
 struct btrfs_info btrfs_info;
 

fs/btrfs/btrfs.h

@@ -23,17 +23,6 @@ struct btrfs_info {
 
 extern struct btrfs_info btrfs_info;
 
-/* hash.c */
-void btrfs_hash_init(void);
-u32 btrfs_crc32c(u32, const void *, size_t);
-u32 btrfs_csum_data(char *, u32, size_t);
-void btrfs_csum_final(u32, void *);
-
-static inline u64 btrfs_name_hash(const char *name, int len)
-{
-	return btrfs_crc32c((u32) ~1, name, len);
-}
-
 /* dev.c */
 extern struct blk_desc *btrfs_blk_desc;
 extern struct disk_partition *btrfs_part_info;

fs/btrfs/crypto/hash.c

@@ -0,0 +1,55 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+#include <linux/xxhash.h>
+#include <linux/unaligned/access_ok.h>
+#include <linux/types.h>
+#include <u-boot/sha256.h>
+#include <u-boot/crc.h>
+
+static u32 btrfs_crc32c_table[256];
+
+void btrfs_hash_init(void)
+{
+	static int inited = 0;
+
+	if (!inited) {
+		crc32c_init(btrfs_crc32c_table, 0x82F63B78);
+		inited = 1;
+	}
+}
+
+int hash_sha256(const u8 *buf, size_t length, u8 *out)
+{
+	sha256_context ctx;
+
+	sha256_starts(&ctx);
+	sha256_update(&ctx, buf, length);
+	sha256_finish(&ctx, out);
+
+	return 0;
+}
+
+int hash_xxhash(const u8 *buf, size_t length, u8 *out)
+{
+	u64 hash;
+
+	hash = xxh64(buf, length, 0);
+	put_unaligned_le64(hash, out);
+
+	return 0;
+}
+
+int hash_crc32c(const u8 *buf, size_t length, u8 *out)
+{
+	u32 crc;
+
+	crc = crc32c_cal((u32)~0, (char *)buf, length, btrfs_crc32c_table);
+	put_unaligned_le32(~crc, out);
+
+	return 0;
+}
+
+u32 crc32c(u32 seed, const void * data, size_t len)
+{
+	return crc32c_cal(seed, data, len, btrfs_crc32c_table);
+}

fs/btrfs/crypto/hash.h

@@ -0,0 +1,17 @@
+#ifndef CRYPTO_HASH_H
+#define CRYPTO_HASH_H
+
+#include <linux/types.h>
+
+#define CRYPTO_HASH_SIZE_MAX	32
+
+void btrfs_hash_init(void);
+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);
+
+u32 crc32c(u32 seed, const void * data, size_t len);
+
+/* Blake2B is not yet supported due to lack of library */
+
+#endif

fs/btrfs/dir-item.c

@@ -6,6 +6,7 @@
  */
 
 #include "btrfs.h"
+#include "disk-io.h"
 
 static int verify_dir_item(struct btrfs_dir_item *item, u32 start, u32 total)
 {

fs/btrfs/disk-io.c

@@ -0,0 +1,22 @@
+// SPDX-License-Identifier: GPL-2.0+
+#include <common.h>
+#include <fs_internal.h>
+#include "disk-io.h"
+#include "crypto/hash.h"
+
+int btrfs_csum_data(u16 csum_type, const u8 *data, u8 *out, size_t len)
+{
+	memset(out, 0, BTRFS_CSUM_SIZE);
+
+	switch (csum_type) {
+	case BTRFS_CSUM_TYPE_CRC32:
+		return hash_crc32c(data, len, out);
+	case BTRFS_CSUM_TYPE_XXHASH:
+		return hash_xxhash(data, len, out);
+	case BTRFS_CSUM_TYPE_SHA256:
+		return hash_sha256(data, len, out);
+	default:
+		printf("Unknown csum type %d\n", csum_type);
+		return -EINVAL;
+	}
+}

fs/btrfs/disk-io.h

@@ -0,0 +1,20 @@
+// SPDX-License-Identifier: GPL-2.0+
+#ifndef __BTRFS_DISK_IO_H__
+#define __BTRFS_DISK_IO_H__
+
+#include "crypto/hash.h"
+#include "ctree.h"
+#include "disk-io.h"
+
+static inline u64 btrfs_name_hash(const char *name, int len)
+{
+	u32 crc;
+
+	crc = crc32c((u32)~1, (unsigned char *)name, len);
+
+	return (u64)crc;
+}
+
+int btrfs_csum_data(u16 csum_type, const u8 *data, u8 *out, size_t len);
+
+#endif

fs/btrfs/hash.c

@@ -1,38 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0+
-/*
- * BTRFS filesystem implementation for U-Boot
- *
- * 2017 Marek Behun, CZ.NIC, marek.behun@nic.cz
- */
-
-#include "btrfs.h"
-#include <u-boot/crc.h>
-#include <asm/unaligned.h>
-
-static u32 btrfs_crc32c_table[256];
-
-void btrfs_hash_init(void)
-{
-	static int inited = 0;
-
-	if (!inited) {
-		crc32c_init(btrfs_crc32c_table, 0x82F63B78);
-		inited = 1;
-	}
-}
-
-u32 btrfs_crc32c(u32 crc, const void *data, size_t length)
-{
-	return crc32c_cal(crc, (const char *) data, length,
-			  btrfs_crc32c_table);
-}
-
-u32 btrfs_csum_data(char *data, u32 seed, size_t len)
-{
-	return btrfs_crc32c(seed, data, len);
-}
-
-void btrfs_csum_final(u32 crc, void *result)
-{
-	put_unaligned(cpu_to_le32(~crc), (u32 *)result);
-}

fs/btrfs/super.c

@@ -11,6 +11,7 @@
 #include <part.h>
 #include <linux/compat.h>
 #include "btrfs.h"
+#include "disk-io.h"
 
 #define BTRFS_SUPER_FLAG_SUPP	(BTRFS_HEADER_FLAG_WRITTEN	\
 				 | BTRFS_HEADER_FLAG_RELOC	\
@@ -61,19 +62,19 @@ static int btrfs_check_super_csum(char *raw_disk_sb)
 		(struct btrfs_super_block *) raw_disk_sb;
 	u16 csum_type = le16_to_cpu(disk_sb->csum_type);
 
-	if (csum_type == BTRFS_CSUM_TYPE_CRC32) {
-		u32 crc = ~(u32) 0;
-		const int csum_size = sizeof(crc);
-		char result[csum_size];
+	if (csum_type == BTRFS_CSUM_TYPE_CRC32 ||
+	    csum_type == BTRFS_CSUM_TYPE_SHA256 ||
+	    csum_type == BTRFS_CSUM_TYPE_XXHASH) {
+		u8 result[BTRFS_CSUM_SIZE];
 
-		crc = btrfs_csum_data(raw_disk_sb + BTRFS_CSUM_SIZE, crc,
-				      BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
-		btrfs_csum_final(crc, result);
+		btrfs_csum_data(csum_type, (u8 *)raw_disk_sb + BTRFS_CSUM_SIZE,
+			result, BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
 
-		if (memcmp(raw_disk_sb, result, csum_size))
-			return -1;
-	} else {
-		return -1;
+		if (memcmp(raw_disk_sb, result, BTRFS_CSUM_SIZE))
+			return -EIO;
+	} else if (csum_type == BTRFS_CSUM_TYPE_BLAKE2) {
+		printf("Blake2 csum type is not supported yet\n");
+		return -ENOTSUPP;
 	}
 
 	return 0;