mirror_zfs/include/sys/bitmap.h
Pawel Jakub Dawidek 67a1b03791
Implementation of block cloning for ZFS
Block Cloning allows to manually clone a file (or a subset of its
blocks) into another (or the same) file by just creating additional
references to the data blocks without copying the data itself.
Those references are kept in the Block Reference Tables (BRTs).

The whole design of block cloning is documented in module/zfs/brt.c.

Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Christian Schwarz <christian.schwarz@nutanix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Rich Ercolani <rincebrain@gmail.com>
Signed-off-by: Pawel Jakub Dawidek <pawel@dawidek.net>
Closes #13392
2023-03-10 11:59:53 -08:00

94 lines
2.5 KiB
C

/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2006 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/* All Rights Reserved */
#ifndef _SYS_BITMAP_H
#define _SYS_BITMAP_H
#ifdef __cplusplus
extern "C" {
#endif
/*
* Operations on bitmaps of arbitrary size
* A bitmap is a vector of 1 or more ulong_t's.
* The user of the package is responsible for range checks and keeping
* track of sizes.
*/
#ifdef _LP64
#define BT_ULSHIFT 6 /* log base 2 of BT_NBIPUL, to extract word index */
#define BT_ULSHIFT32 5 /* log base 2 of BT_NBIPUL, to extract word index */
#else
#define BT_ULSHIFT 5 /* log base 2 of BT_NBIPUL, to extract word index */
#endif
#define BT_NBIPUL (1 << BT_ULSHIFT) /* n bits per ulong_t */
#define BT_ULMASK (BT_NBIPUL - 1) /* to extract bit index */
/*
* bitmap is a ulong_t *, bitindex an index_t
*
* The macros BT_WIM and BT_BIW internal; there is no need
* for users of this package to use them.
*/
/*
* word in map
*/
#define BT_WIM(bitmap, bitindex) \
((bitmap)[(bitindex) >> BT_ULSHIFT])
/*
* bit in word
*/
#define BT_BIW(bitindex) \
(1UL << ((bitindex) & BT_ULMASK))
/*
* These are public macros
*
* BT_BITOUL == n bits to n ulong_t's
*/
#define BT_BITOUL(nbits) \
(((nbits) + BT_NBIPUL - 1l) / BT_NBIPUL)
#define BT_SIZEOFMAP(nbits) \
(BT_BITOUL(nbits) * sizeof (ulong_t))
#define BT_TEST(bitmap, bitindex) \
((BT_WIM((bitmap), (bitindex)) & BT_BIW(bitindex)) ? 1 : 0)
#define BT_SET(bitmap, bitindex) \
{ BT_WIM((bitmap), (bitindex)) |= BT_BIW(bitindex); }
#define BT_CLEAR(bitmap, bitindex) \
{ BT_WIM((bitmap), (bitindex)) &= ~BT_BIW(bitindex); }
#ifdef __cplusplus
}
#endif
#endif /* _SYS_BITMAP_H */