blob: fa4be7e276b4e4978504fa0976717ac5b64e0917 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
|
/*
* Copyright (c) 1998 Matthew Dillon. Terms of use and redistribution in all
* forms are covered by the BSD copyright in the file "/usr/src/COPYRIGHT".
*
* Implements bitmap resource lists.
*
* Usage:
* blist = blist_create(blocks)
* (void) blist_destroy(blist)
* blkno = blist_alloc(blist, count)
* (void) blist_free(blist, blkno, count)
* (void) blist_resize(&blist, count, freeextra)
*
*
* 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 (2^31) 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 u_int32_t u_daddr_t; /* unsigned disk address */
static __inline int
LOG2(u_daddr_t v)
{
int i = -1;
if (!v)
return(0);
while (v) {
i++;
v >>= 1;
}
return (i);
}
/*
* blmeta and bl_bitmap_t MUST be a power of 2 in size.
*/
typedef struct blmeta {
union {
daddr_t bmu_avail; /* space available under us */
u_daddr_t bmu_bitmap; /* bitmap if we are a leaf */
} u;
daddr_t bm_bighint; /* biggest contiguous block hint*/
} blmeta_t;
typedef struct blist {
daddr_t bl_blocks; /* area of coverage */
daddr_t bl_radix; /* coverage radix */
daddr_t bl_skip; /* starting skip */
daddr_t bl_free; /* number of free blocks */
blmeta_t *bl_root; /* root of radix tree */
daddr_t bl_rootblks; /* daddr_t blks allocated for tree */
} *blist_t;
#define BLIST_META_RADIX 16
#define BLIST_META_RADIX_SHIFT LOG2(BLIST_META_RADIX)
#define BLIST_BMAP_RADIX (sizeof(u_daddr_t)*8)
#define BLIST_BMAP_RADIX_SHIFT LOG2(BLIST_BMAP_RADIX)
#define BLIST_MAX_ALLOC BLIST_BMAP_RADIX
extern blist_t blist_create(daddr_t blocks);
extern void blist_destroy(blist_t blist);
extern daddr_t blist_alloc(blist_t blist, daddr_t count);
extern void blist_free(blist_t blist, daddr_t blkno, daddr_t count);
extern void blist_print(blist_t blist);
extern void blist_resize(blist_t *pblist, daddr_t count, int freenew);
#endif /* _SYS_BLIST_H_ */
|
