[Ocfs2-tools-devel] [PATCH 4/5] ocfs2-tools: add xattr_uuid_hash in libocfs2

[Coly Li]

Tiger Yang Wrote:
> this function use to calculate uuid hash, this hash value will be
> used as random seed to calculate xattr hash.
> 
> Signed-off-by: Tiger Yang <tiger.yang at oracle.com>
> ---
>  include/ocfs2/ocfs2.h |    2 ++
>  libocfs2/Makefile     |    3 ++-
>  libocfs2/xattr.c      |   34 ++++++++++++++++++++++++++++++++++
>  3 files changed, 38 insertions(+), 1 deletions(-)
>  create mode 100644 libocfs2/xattr.c
> 
> diff --git a/include/ocfs2/ocfs2.h b/include/ocfs2/ocfs2.h
> index 68ba4f5..4aa24f5 100644
> --- a/include/ocfs2/ocfs2.h
> +++ b/include/ocfs2/ocfs2.h
> @@ -1040,4 +1040,6 @@ errcode_t ocfs2_block_iterate_inode(ocfs2_filesys *fs,
>  						void *priv_data),
>  				    void *priv_data);
>  
> +uint32_t xattr_uuid_hash(unsigned char *uuid);
> +
>  #endif  /* _FILESYS_H */
> diff --git a/libocfs2/Makefile b/libocfs2/Makefile
> index 446c8b4..569d2af 100644
> --- a/libocfs2/Makefile
> +++ b/libocfs2/Makefile
> @@ -72,7 +72,8 @@ CFILES = 		\
>  	lockid.c	\
>  	backup_super.c	\
>  	feature_string.c\
> -	image.c
> +	image.c		\
> +	xattr.c
>  
>  HFILES =		\
>  	bitmap.h	\
> diff --git a/libocfs2/xattr.c b/libocfs2/xattr.c
> new file mode 100644
> index 0000000..287ce0e
> --- /dev/null
> +++ b/libocfs2/xattr.c
> @@ -0,0 +1,34 @@
> +/* -*- mode: c; c-basic-offset: 8; -*-
> + * vim: noexpandtab sw=8 ts=8 sts=0:
> + *
> + * xattr.c
> + *
> + * Copyright (C) 2004, 2008 Oracle.  All rights reserved.
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public
> + * License version 2 as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> + * General Public License for more details.
> + */
> +#include <string.h>
> +#include <inttypes.h>
> +
> +#include "ocfs2/byteorder.h"
> +#include "ocfs2/ocfs2.h"
> +
> +uint32_t xattr_uuid_hash(unsigned char *uuid)
> +{
> +	uint32_t i, hash = 0;
> +
> +	for (i = 0; i < OCFS2_VOL_UUID_LEN; i++) {
> +		hash = (hash << OCFS2_HASH_SHIFT) ^
> +			(hash >> (8*sizeof(hash) - OCFS2_HASH_SHIFT)) ^
> +			*uuid++;
Maybe *(uuid ++) is more clear ?

> +	}
> +	return hash;
> +}
> +

-- 
Coly Li
SuSE PRC Labs