/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 1998 Matthew Dillon. All Rights Reserved.
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
* OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
* GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/*
* Implements bitmap resource lists.
*
* Usage:
* blist = blist_create(blocks, flags)
* (void) blist_destroy(blist)
* blkno = blist_alloc(blist, &count, maxcount)
* (void) blist_free(blist, blkno, count)
* nblks = blist_fill(blist, blkno, count)
* (void) blist_resize(&blist, count, freeextra, flags)
*
*
* Notes:
* on creation, the entire list is marked reserved. You should
* first blist_free() the sections you want to make available
* for allocation before doing general blist_alloc()/free()
* ops.
*
* SWAPBLK_NONE is returned on failure. This module is typically
* capable of managing up to (2^63) blocks per blist, though
* the memory utilization would be insane if you actually did
* that. Managing something like 512MB worth of 4K blocks
* eats around 32 KBytes of memory.
*
* $FreeBSD$
*/
#ifndef _SYS_BLIST_H_
#define _SYS_BLIST_H_
typedef uint64_t u_daddr_t; /* unsigned disk address */
/*
* note: currently use SWAPBLK_NONE as an absolute value rather then
* a flag bit.
*/
#define SWAPBLK_MASK ((daddr_t)((u_daddr_t)-1 >> 1)) /* mask */
#define SWAPBLK_NONE ((daddr_t)((u_daddr_t)SWAPBLK_MASK + 1))/* flag */
/*
* Both blmeta and bm_bitmap MUST be a power of 2 in size.
*/
typedef struct blmeta {
u_daddr_t bm_bitmap; /* marking unfilled block sets */
daddr_t bm_bighint; /* biggest contiguous block hint*/
} blmeta_t;
typedef struct blist {
daddr_t bl_blocks; /* area of coverage */
daddr_t bl_avail; /* # available blocks */
u_daddr_t bl_radix; /* coverage radix */
daddr_t bl_cursor; /* next-fit search starts at */
blmeta_t bl_root[1]; /* root of radix tree */
} *blist_t;
#define BLIST_RADIX (sizeof(u_daddr_t) * 8)
#define BLIST_MAX_ALLOC BLIST_RADIX
struct sbuf;
daddr_t blist_alloc(blist_t blist, int *count, int maxcount);
daddr_t blist_avail(blist_t blist);
blist_t blist_create(daddr_t blocks, int flags);
void blist_destroy(blist_t blist);
daddr_t blist_fill(blist_t bl, daddr_t blkno, daddr_t count);
void blist_free(blist_t blist, daddr_t blkno, daddr_t count);
void blist_print(blist_t blist);
void blist_resize(blist_t *pblist, daddr_t count, int freenew, int flags);
void blist_stats(blist_t blist, struct sbuf *s);
#endif /* _SYS_BLIST_H_ */
