Re: [PATCH v6] btrfs-progs: add xxhash64 to mkfs

[Qu Wenruo <quwenruo.btrfs@gmx.com>]

On 2019/9/26 下午6:11, Johannes Thumshirn wrote:
> Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
> ---

Not related to the patchset itself, but it would be pretty nice if we
check the sysfs interface to guess if we can mount the fs.

And if not supported, a warning (at stdout) will not hurt.

Thanks,
Qu

>
> Changes since v5:
> - add xxhash64 to hash table
>
>  Makefile                  |  3 ++-
>  cmds/inspect-dump-super.c |  1 +
>  crypto/hash.c             | 16 ++++++++++++++++
>  crypto/hash.h             | 10 ++++++++++
>  ctree.c                   |  1 +
>  ctree.h                   |  3 ++-
>  disk-io.c                 |  3 +++
>  mkfs/main.c               |  3 +++
>  8 files changed, 38 insertions(+), 2 deletions(-)
>  create mode 100644 crypto/hash.c
>  create mode 100644 crypto/hash.h
>
> diff --git a/Makefile b/Makefile
> index 370e0c37ff65..45530749e2b9 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -151,7 +151,8 @@ cmds_objects = cmds/subvolume.o cmds/filesystem.o cmds/device.o cmds/scrub.o \
>  	       mkfs/common.o check/mode-common.o check/mode-lowmem.o
>  libbtrfs_objects = send-stream.o send-utils.o kernel-lib/rbtree.o btrfs-list.o \
>  		   kernel-lib/crc32c.o common/messages.o \
> -		   uuid-tree.o utils-lib.o common/rbtree-utils.o
> +		   uuid-tree.o utils-lib.o common/rbtree-utils.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 bf380ad2b56a..73e986ed8ee8 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 000000000000..8c428cba11f0
> --- /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 000000000000..45c1ef17bc57
> --- /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 a52ccfe19f94..139ffd613da5 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 f70271dc658e..144c89eb4a36 100644
> --- a/ctree.h
> +++ b/ctree.h
> @@ -166,7 +166,8 @@ struct btrfs_free_space_ctl;
>
>  /* csum types */
>  enum btrfs_csum_type {
> -	BTRFS_CSUM_TYPE_CRC32   = 0,
> +	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 72c672919cf9..59e297e2039c 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 f52e8b61a460..a6deddc47c69 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);
>