| | 1 | /* |
| | 2 | * Copyright (c) 2000 Apple Computer, Inc. All rights reserved. |
| | 3 | * |
| | 4 | * @APPLE_LICENSE_HEADER_START@ |
| | 5 | * |
| | 6 | * Copyright (c) 1999-2003 Apple Computer, Inc. All Rights Reserved. |
| | 7 | * |
| | 8 | * This file contains Original Code and/or Modifications of Original Code |
| | 9 | * as defined in and that are subject to the Apple Public Source License |
| | 10 | * Version 2.0 (the 'License'). You may not use this file except in |
| | 11 | * compliance with the License. Please obtain a copy of the License at |
| | 12 | * http://www.opensource.apple.com/apsl/ and read it before using this |
| | 13 | * file. |
| | 14 | * |
| | 15 | * The Original Code and all software distributed under the License are |
| | 16 | * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER |
| | 17 | * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, |
| | 18 | * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, |
| | 19 | * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. |
| | 20 | * Please see the License for the specific language governing rights and |
| | 21 | * limitations under the License. |
| | 22 | * |
| | 23 | * @APPLE_LICENSE_HEADER_END@ |
| | 24 | */ |
| | 25 | /* |
| | 26 | * Mach Operating System |
| | 27 | * Copyright (c) 1987 Carnegie-Mellon University |
| | 28 | * All rights reserved. The CMU software License Agreement specifies |
| | 29 | * the terms and conditions for use and redistribution. |
| | 30 | */ |
| | 31 | |
| | 32 | #ifndef _VNODE_PAGER_ |
| | 33 | #define _VNODE_PAGER_ 1 |
| | 34 | |
| | 35 | #include <mach/kern_return.h> |
| | 36 | #include <sys/types.h> |
| | 37 | #include <kern/queue.h> |
| | 38 | |
| | 39 | #ifdef KERNEL |
| | 40 | |
| | 41 | #include <mach/boolean.h> |
| | 42 | #include <vm/vm_pager.h> |
| | 43 | |
| | 44 | vm_pager_t vnode_pager_setup(); |
| | 45 | boolean_t vnode_has_page(); |
| | 46 | boolean_t vnode_pager_active(); |
| | 47 | |
| | 48 | /* |
| | 49 | * Vstructs are the internal (to us) description of a unit of backing store. |
| | 50 | * The are the link between memory objects and the backing store they represent. |
| | 51 | * For the vnode pager, backing store comes in two flavors: normal files and |
| | 52 | * swap files. |
| | 53 | * |
| | 54 | * For objects that page to and from normal files (e.g. objects that represent |
| | 55 | * program text segments), we maintain some simple parameters that allow us to |
| | 56 | * access the file's contents directly through the vnode interface. |
| | 57 | * |
| | 58 | * Data for objects without associated vnodes is maintained in the swap files. |
| | 59 | * Each object that uses one of these as backing store has a vstruct indicating |
| | 60 | * the swap file of preference (vs_pf) and a mapping between contiguous object |
| | 61 | * offsets and swap file offsets (vs_pmap). Each entry in this mapping specifies |
| | 62 | * the pager file to use, and the offset of the page in that pager file. These |
| | 63 | * mapping entries are of type pfMapEntry. |
| | 64 | */ |
| | 65 | |
| | 66 | /* |
| | 67 | * Pager file structure. One per swap file. |
| | 68 | */ |
| | 69 | typedef struct pager_file { |
| | 70 | queue_chain_t pf_chain; /* link to other paging files */ |
| | 71 | struct vnode *pf_vp; /* vnode of paging file */ |
| | 72 | u_int pf_count; /* Number of vstruct using this file */ |
| | 73 | u_char *pf_bmap; /* Map of used blocks */ |
| | 74 | long pf_npgs; /* Size of file in pages */ |
| | 75 | long pf_pfree; /* Number of unused pages */ |
| | 76 | long pf_lowat; /* Low water page */ |
| | 77 | long pf_hipage; /* Highest page allocated */ |
| | 78 | long pf_hint; /* Lowest page unallocated */ |
| | 79 | char *pf_name; /* Filename of this file */ |
| | 80 | boolean_t pf_prefer; |
| | 81 | int pf_index; /* index into the pager_file array */ |
| | 82 | void * pf_lock; /* Lock for alloc and dealloc */ |
| | 83 | } *pager_file_t; |
| | 84 | |
| | 85 | #define PAGER_FILE_NULL (pager_file_t) 0 |
| | 86 | |
| | 87 | #define MAXPAGERFILES 16 |
| | 88 | |
| | 89 | #define MAX_BACKING_STORE 100 |
| | 90 | |
| | 91 | struct bs_map { |
| | 92 | struct vnode *vp; |
| | 93 | void *bs; |
| | 94 | }; |
| | 95 | |
| | 96 | |
| | 97 | |
| | 98 | /* |
| | 99 | * Pager file data structures. |
| | 100 | */ |
| | 101 | #define INDEX_NULL 0 |
| | 102 | typedef struct { |
| | 103 | unsigned int index:8; /* paging file this block is in */ |
| | 104 | unsigned int offset:24; /* page number where block resides */ |
| | 105 | } pf_entry; |
| | 106 | |
| | 107 | typedef enum { |
| | 108 | IS_INODE, /* Local disk */ |
| | 109 | IS_RNODE /* NFS */ |
| | 110 | } vpager_fstype; |
| | 111 | |
| | 112 | /* |
| | 113 | * Basic vnode pager structure. One per object, backing-store pair. |
| | 114 | */ |
| | 115 | typedef struct vstruct { |
| | 116 | boolean_t is_device; /* Must be first - see vm_pager.h */ |
| | 117 | pager_file_t vs_pf; /* Pager file this uses */ |
| | 118 | pf_entry **vs_pmap; /* Map of pages into paging file */ |
| | 119 | unsigned int |
| | 120 | /* boolean_t */ vs_swapfile:1; /* vnode is a swapfile */ |
| | 121 | short vs_count; /* use count */ |
| | 122 | int vs_size; /* size of this chunk in pages*/ |
| | 123 | struct vnode *vs_vp; /* vnode to page to */ |
| | 124 | } *vnode_pager_t; |
| | 125 | |
| | 126 | #define VNODE_PAGER_NULL ((vnode_pager_t) 0) |
| | 127 | |
| | 128 | |
| | 129 | |
| | 130 | pager_return_t pager_vnode_pagein(); |
| | 131 | pager_return_t pager_vnode_pageout(); |
| | 132 | pager_return_t vnode_pagein(); |
| | 133 | pager_return_t vnode_pageout(); |
| | 134 | |
| | 135 | #endif /* KERNEL */ |
| | 136 | |
| | 137 | #endif /* _VNODE_PAGER_ */ |
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