zio.h

xen 3.2.2 源码

/*
 *  GRUB  --  GRand Unified Bootloader
 *  Copyright (C) 1999,2000,2001,2002,2003,2004  Free Software Foundation, Inc.
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  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.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */
/*
 * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#ifndef _ZIO_H
#define	_ZIO_H

#define	ZBT_MAGIC	0x210da7ab10c7a11ULL	/* zio data bloc tail */

typedef struct zio_block_tail {
	uint64_t	zbt_magic;	/* for validation, endianness	*/
	zio_cksum_t	zbt_cksum;	/* 256-bit checksum		*/
} zio_block_tail_t;

/*
 * Gang block headers are self-checksumming and contain an array
 * of block pointers.
 */
#define	SPA_GANGBLOCKSIZE	SPA_MINBLOCKSIZE
#define	SPA_GBH_NBLKPTRS	((SPA_GANGBLOCKSIZE - \
	sizeof (zio_block_tail_t)) / sizeof (blkptr_t))
#define	SPA_GBH_FILLER		((SPA_GANGBLOCKSIZE - \
	sizeof (zio_block_tail_t) - \
	(SPA_GBH_NBLKPTRS * sizeof (blkptr_t))) /\
	sizeof (uint64_t))

#define	ZIO_GET_IOSIZE(zio)	\
	(BP_IS_GANG((zio)->io_bp) ? \
	SPA_GANGBLOCKSIZE : BP_GET_PSIZE((zio)->io_bp))

typedef struct zio_gbh {
	blkptr_t		zg_blkptr[SPA_GBH_NBLKPTRS];
	uint64_t		zg_filler[SPA_GBH_FILLER];
	zio_block_tail_t	zg_tail;
} zio_gbh_phys_t;

enum zio_checksum {
	ZIO_CHECKSUM_INHERIT = 0,
	ZIO_CHECKSUM_ON,
	ZIO_CHECKSUM_OFF,
	ZIO_CHECKSUM_LABEL,
	ZIO_CHECKSUM_GANG_HEADER,
	ZIO_CHECKSUM_ZILOG,
	ZIO_CHECKSUM_FLETCHER_2,
	ZIO_CHECKSUM_FLETCHER_4,
	ZIO_CHECKSUM_SHA256,
	ZIO_CHECKSUM_FUNCTIONS
};

#define	ZIO_CHECKSUM_ON_VALUE	ZIO_CHECKSUM_FLETCHER_2
#define	ZIO_CHECKSUM_DEFAULT	ZIO_CHECKSUM_ON

enum zio_compress {
	ZIO_COMPRESS_INHERIT = 0,
	ZIO_COMPRESS_ON,
	ZIO_COMPRESS_OFF,
	ZIO_COMPRESS_LZJB,
	ZIO_COMPRESS_EMPTY,
	ZIO_COMPRESS_FUNCTIONS
};

#endif	/* _ZIO_H */