1/*
2 * Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28/*
29 * Mach Operating System
30 * Copyright (c) 1987 Carnegie-Mellon University
31 * All rights reserved. The CMU software License Agreement specifies
32 * the terms and conditions for use and redistribution.
33 */
34
35#ifndef _VNODE_PAGER_
36#define _VNODE_PAGER_ 1
37
38#include <mach/kern_return.h>
39#include <sys/types.h>
40#include <kern/queue.h>
41
42#ifdef KERNEL
43#include <mach/boolean.h>
44#include <mach/memory_object_types.h>
45#include <mach/vm_types.h>
46#include <vm/vm_protos.h>
47#include <vm/vm_pager.h>
48
49/*
50 * Vstructs are the internal (to us) description of a unit of backing store.
51 * The are the link between memory objects and the backing store they represent.
52 * For the vnode pager, backing store comes in two flavors: normal files and
53 * swap files.
54 *
55 * For objects that page to and from normal files (e.g. objects that represent
56 * program text segments), we maintain some simple parameters that allow us to
57 * access the file's contents directly through the vnode interface.
58 *
59 * Data for objects without associated vnodes is maintained in the swap files.
60 * Each object that uses one of these as backing store has a vstruct indicating
61 * the swap file of preference (vs_pf) and a mapping between contiguous object
62 * offsets and swap file offsets (vs_pmap). Each entry in this mapping specifies
63 * the pager file to use, and the offset of the page in that pager file. These
64 * mapping entries are of type pfMapEntry.
65 */
66
67/*
68 * Pager file structure. One per swap file.
69 */
70typedef struct pager_file {
71 queue_chain_t pf_chain; /* link to other paging files */
72 struct vnode *pf_vp; /* vnode of paging file */
73 u_int pf_count; /* Number of vstruct using this file */
74 u_char *pf_bmap; /* Map of used blocks */
75 long pf_npgs; /* Size of file in pages */
76 long pf_pfree; /* Number of unused pages */
77 long pf_lowat; /* Low water page */
78 long pf_hipage; /* Highest page allocated */
79 long pf_hint; /* Lowest page unallocated */
80 char *pf_name; /* Filename of this file */
81 boolean_t pf_prefer;
82 int pf_index; /* index into the pager_file array */
83 void * pf_lock; /* Lock for alloc and dealloc */
84} *pager_file_t;
85
86#define PAGER_FILE_NULL (pager_file_t) 0
87
88#define MAXPAGERFILES 16
89
90#define MAX_BACKING_STORE 100
91
92struct bs_map {
93 struct vnode *vp;
94 void *bs;
95};
96extern struct bs_map bs_port_table[];
97
98
99
100/*
101 * Pager file data structures.
102 */
103#define INDEX_NULL 0
104typedef struct {
105 unsigned int index:8; /* paging file this block is in */
106 unsigned int offset:24; /* page number where block resides */
107} pf_entry;
108
109typedef enum {
110 IS_INODE, /* Local disk */
111 IS_RNODE /* NFS */
112 } vpager_fstype;
113
114/*
115 * Basic vnode pager structure. One per object, backing-store pair.
116 */
117typedef struct vstruct {
118 boolean_t is_device; /* Must be first - see vm_pager.h */
119 pager_file_t vs_pf; /* Pager file this uses */
120 pf_entry **vs_pmap; /* Map of pages into paging file */
121 unsigned int
122 /* boolean_t */ vs_swapfile:1; /* vnode is a swapfile */
123 short vs_count; /* use count */
124 int vs_size; /* size of this chunk in pages*/
125 struct vnode *vs_vp; /* vnode to page to */
126} *vnode_pager_t;
127
128#define VNODE_PAGER_NULL ((vnode_pager_t) 0)
129
130#endif /* KERNEL */
131
132#endif /* _VNODE_PAGER_ */
133