sys/vm/vm_pager.h

   1 /*
   2  * Copyright (c) 1990 University of Utah.
   3  * Copyright (c) 1991, 1993
   4  *      The Regents of the University of California.  All rights reserved.
   5  *
   6  * This code is derived from software contributed to Berkeley by
   7  * the Systems Programming Group of the University of Utah Computer
   8  * Science Department.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 3. All advertising materials mentioning features or use of this software
  19  *    must display the following acknowledgement:
  20  *      This product includes software developed by the University of
  21  *      California, Berkeley and its contributors.
  22  * 4. Neither the name of the University nor the names of its contributors
  23  *    may be used to endorse or promote products derived from this software
  24  *    without specific prior written permission.
  25  *
  26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  36  * SUCH DAMAGE.
  37  *
  38  *      @(#)vm_pager.h  8.4 (Berkeley) 1/12/94
  39  * $FreeBSD: src/sys/vm/vm_pager.h,v 1.24.2.2 2002/12/31 09:34:51 dillon Exp $
  40  * $DragonFly: src/sys/vm/vm_pager.h,v 1.9 2006/12/28 21:24:02 dillon Exp $
  41  */
  42
  43 /*
  44  * Pager routine interface definition.
  45  */
  46
  47 #ifndef _VM_VM_PAGER_H_
  48 #define _VM_VM_PAGER_H_
  49
  50 #ifndef _SYS_QUEUE_H_
  51 #include <sys/queue.h>
  52 #endif
  53 #ifndef _VM_VM_PAGE_H_
  54 #include <vm/vm_page.h>
  55 #endif
  56 #ifndef _VM_VM_OBJECT_H_
  57 #include <vm/vm_object.h>
  58 #endif
  59
  60 struct buf;
  61 struct bio;
  62
  63 struct pagerops {
  64         void (*pgo_dealloc) (vm_object_t);
  65         int (*pgo_getpage) (vm_object_t, vm_page_t *, int);
  66         void (*pgo_putpages) (vm_object_t, vm_page_t *, int, int, int *);
  67         boolean_t (*pgo_haspage) (vm_object_t, vm_pindex_t);
  68 };
  69
  70 /*
  71  * get/put return values
  72  * OK    operation was successful
  73  * BAD   specified data was out of the accepted range
  74  * FAIL  specified data was in range, but doesn't exist
  75  * PEND  operations was initiated but not completed
  76  * ERROR error while accessing data that is in range and exists
  77  * AGAIN temporary resource shortage prevented operation from happening
  78  */
  79 #define VM_PAGER_OK     0
  80 #define VM_PAGER_BAD    1
  81 #define VM_PAGER_FAIL   2
  82 #define VM_PAGER_PEND   3
  83 #define VM_PAGER_ERROR  4
  84 #define VM_PAGER_AGAIN  5
  85
  86 #define VM_PAGER_PUT_SYNC               0x0001
  87 #define VM_PAGER_PUT_INVAL              0x0002
  88 #define VM_PAGER_IGNORE_CLEANCHK        0x0004
  89 #define VM_PAGER_CLUSTER_OK             0x0008
  90
  91 #ifdef _KERNEL
  92
  93 #ifdef MALLOC_DECLARE
  94 MALLOC_DECLARE(M_VMPGDATA);
  95 #endif
  96
  97 struct vnode;
  98
  99 extern struct vm_map pager_map;
 100 extern int pager_map_size;
 101 extern struct pagerops *pagertab[];
 102
 103 vm_object_t default_pager_alloc(void *, off_t, vm_prot_t, off_t);
 104 vm_object_t dev_pager_alloc(void *, off_t, vm_prot_t, off_t);
 105 vm_object_t phys_pager_alloc(void *, off_t, vm_prot_t, off_t);
 106 vm_object_t swap_pager_alloc(void *, off_t, vm_prot_t, off_t);
 107 vm_object_t vnode_pager_alloc (void *, off_t, vm_prot_t, off_t);
 108 vm_object_t vnode_pager_reference (struct vnode *);
 109
 110 void vm_pager_bufferinit (void);
 111 void vm_pager_deallocate (vm_object_t);
 112 static __inline int vm_pager_get_page (vm_object_t, vm_page_t *, int);
 113 static __inline boolean_t vm_pager_has_page (vm_object_t, vm_pindex_t);
 114 void vm_pager_sync (void);
 115 struct buf *getchainbuf(struct buf *bp, struct vnode *vp, int flags);
 116 void flushchainbuf(struct buf *nbp);
 117 void waitchainbuf(struct buf *bp, int count, int done);
 118 void autochaindone(struct buf *bp);
 119 void swap_pager_strategy(vm_object_t object, struct bio *bio);
 120 void swap_pager_unswapped (vm_page_t m);
 121
 122 /*
 123  * vm_page_get_pages:
 124  *
 125  * Retrieve the contents of the page from the object pager.  Note that the
 126  * object pager might replace the page.
 127  *
 128  * If the pagein was successful, we must fully validate it so it can be
 129  * memory mapped.
 130  */
 131
 132 static __inline int
 133 vm_pager_get_page(vm_object_t object, vm_page_t *m, int seqaccess)
 134 {
 135         int r;
 136
 137         r = (*pagertab[object->type]->pgo_getpage)(object, m, seqaccess);
 138         if (r == VM_PAGER_OK && (*m)->valid != VM_PAGE_BITS_ALL) {
 139                 vm_page_zero_invalid(*m, TRUE);
 140         }
 141         return(r);
 142 }
 143
 144 static __inline void
 145 vm_pager_put_pages(
 146         vm_object_t object,
 147         vm_page_t *m,
 148         int count,
 149         int flags,
 150         int *rtvals
 151 ) {
 152         (*pagertab[object->type]->pgo_putpages)
 153             (object, m, count, flags, rtvals);
 154 }
 155
 156 /*
 157  *      vm_pager_haspage
 158  *
 159  *      Check to see if an object's pager has the requested page.  The
 160  *      object's pager will also set before and after to give the caller
 161  *      some idea of the number of pages before and after the requested
 162  *      page can be I/O'd efficiently.
 163  *
 164  *      This routine does not have to be called at any particular spl.
 165  */
 166
 167 static __inline boolean_t
 168 vm_pager_has_page(vm_object_t object, vm_pindex_t offset)
 169 {
 170         return ((*pagertab[object->type]->pgo_haspage)(object, offset));
 171 }
 172
 173 #endif
 174
 175 #endif                          /* _VM_VM_PAGER_H_ */