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freebsd-dev/sys/vm/vm_pager.h
Gleb Smirnoff 90effb2341 Merge from projects/sendfile: 
o Provide a new VOP_GETPAGES_ASYNC(), which works like VOP_GETPAGES(), but
  doesn't sleep. It returns immediately, and will execute the I/O done handler
  function that must be supplied as argument.
o Provide VOP_GETPAGES_ASYNC() for the FFS, which uses vnode_pager.
o Extend pagertab to support pgo_getpages_async method, and implement this
  method for vnode_pager.

Reviewed by:	kib
Tested by:	pho
Sponsored by:	Netflix
Sponsored by:	Nginx, Inc.
2014-11-23 12:01:52 +00:00

229 lines
7.4 KiB
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/*-
* Copyright (c) 1990 University of Utah.
* Copyright (c) 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* the Systems Programming Group of the University of Utah Computer
* Science Department.
*
* 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.
* 4. 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 REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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.
*
* @(#)vm_pager.h 8.4 (Berkeley) 1/12/94
* $FreeBSD$
*/
/*
* Pager routine interface definition.
*/
#ifndef _VM_PAGER_
#define _VM_PAGER_
#include <sys/queue.h>
TAILQ_HEAD(pagerlst, vm_object);
typedef void pgo_init_t(void);
typedef vm_object_t pgo_alloc_t(void *, vm_ooffset_t, vm_prot_t, vm_ooffset_t,
struct ucred *);
typedef void pgo_dealloc_t(vm_object_t);
typedef int pgo_getpages_t(vm_object_t, vm_page_t *, int, int);
typedef void pgo_getpages_iodone_t(void *, vm_page_t *, int, int);
typedef int pgo_getpages_async_t(vm_object_t, vm_page_t *, int, int,
pgo_getpages_iodone_t, void *);
typedef void pgo_putpages_t(vm_object_t, vm_page_t *, int, int, int *);
typedef boolean_t pgo_haspage_t(vm_object_t, vm_pindex_t, int *, int *);
typedef void pgo_pageunswapped_t(vm_page_t);
struct pagerops {
pgo_init_t *pgo_init; /* Initialize pager. */
pgo_alloc_t *pgo_alloc; /* Allocate pager. */
pgo_dealloc_t *pgo_dealloc; /* Disassociate. */
pgo_getpages_t *pgo_getpages; /* Get (read) page. */
pgo_getpages_async_t *pgo_getpages_async; /* Get page asyncly. */
pgo_putpages_t *pgo_putpages; /* Put (write) page. */
pgo_haspage_t *pgo_haspage; /* Query page. */
pgo_pageunswapped_t *pgo_pageunswapped;
};
extern struct pagerops defaultpagerops;
extern struct pagerops swappagerops;
extern struct pagerops vnodepagerops;
extern struct pagerops devicepagerops;
extern struct pagerops physpagerops;
extern struct pagerops sgpagerops;
extern struct pagerops mgtdevicepagerops;
/*
* get/put return values
* OK operation was successful
* BAD specified data was out of the accepted range
* FAIL specified data was in range, but doesn't exist
* PEND operations was initiated but not completed
* ERROR error while accessing data that is in range and exists
* AGAIN temporary resource shortage prevented operation from happening
*/
#define VM_PAGER_OK 0
#define VM_PAGER_BAD 1
#define VM_PAGER_FAIL 2
#define VM_PAGER_PEND 3
#define VM_PAGER_ERROR 4
#define VM_PAGER_AGAIN 5
#define VM_PAGER_PUT_SYNC 0x0001
#define VM_PAGER_PUT_INVAL 0x0002
#define VM_PAGER_CLUSTER_OK 0x0008
#ifdef _KERNEL
extern struct pagerops *pagertab[];
extern struct mtx_padalign pbuf_mtx;
vm_object_t vm_pager_allocate(objtype_t, void *, vm_ooffset_t, vm_prot_t,
vm_ooffset_t, struct ucred *);
void vm_pager_bufferinit(void);
void vm_pager_deallocate(vm_object_t);
static __inline int vm_pager_get_pages(vm_object_t, vm_page_t *, int, int);
static inline int vm_pager_get_pages_async(vm_object_t, vm_page_t *, int,
int, pgo_getpages_iodone_t, void *);
static __inline boolean_t vm_pager_has_page(vm_object_t, vm_pindex_t, int *, int *);
void vm_pager_init(void);
vm_object_t vm_pager_object_lookup(struct pagerlst *, void *);
void vm_pager_free_nonreq(vm_object_t object, vm_page_t ma[], int reqpage,
int npages);
/*
* vm_page_get_pages:
*
* Retrieve pages from the VM system in order to map them into an object
* ( or into VM space somewhere ). If the pagein was successful, we
* must fully validate it.
*/
static __inline int
vm_pager_get_pages(
vm_object_t object,
vm_page_t *m,
int count,
int reqpage
) {
int r;
VM_OBJECT_ASSERT_WLOCKED(object);
r = (*pagertab[object->type]->pgo_getpages)(object, m, count, reqpage);
if (r == VM_PAGER_OK && m[reqpage]->valid != VM_PAGE_BITS_ALL) {
vm_page_zero_invalid(m[reqpage], TRUE);
}
return (r);
}
static inline int
vm_pager_get_pages_async(vm_object_t object, vm_page_t *m, int count,
int reqpage, pgo_getpages_iodone_t iodone, void *arg)
{
VM_OBJECT_ASSERT_WLOCKED(object);
return ((*pagertab[object->type]->pgo_getpages_async)(object, m,
count, reqpage, iodone, arg));
}
static __inline void
vm_pager_put_pages(
vm_object_t object,
vm_page_t *m,
int count,
int flags,
int *rtvals
) {
VM_OBJECT_ASSERT_WLOCKED(object);
(*pagertab[object->type]->pgo_putpages)
(object, m, count, flags, rtvals);
}
/*
* vm_pager_haspage
*
* Check to see if an object's pager has the requested page. The
* object's pager will also set before and after to give the caller
* some idea of the number of pages before and after the requested
* page can be I/O'd efficiently.
*
* The object must be locked.
*/
static __inline boolean_t
vm_pager_has_page(
vm_object_t object,
vm_pindex_t offset,
int *before,
int *after
) {
boolean_t ret;
VM_OBJECT_ASSERT_WLOCKED(object);
ret = (*pagertab[object->type]->pgo_haspage)
(object, offset, before, after);
return (ret);
}
/*
* vm_pager_page_unswapped
*
* Destroy swap associated with the page.
*
* The object containing the page must be locked.
* This function may not block.
*
* XXX: A much better name would be "vm_pager_page_dirtied()"
* XXX: It is not obvious if this could be profitably used by any
* XXX: pagers besides the swap_pager or if it should even be a
* XXX: generic pager_op in the first place.
*/
static __inline void
vm_pager_page_unswapped(vm_page_t m)
{
VM_OBJECT_ASSERT_LOCKED(m->object);
if (pagertab[m->object->type]->pgo_pageunswapped)
(*pagertab[m->object->type]->pgo_pageunswapped)(m);
}
struct cdev_pager_ops {
int (*cdev_pg_fault)(vm_object_t vm_obj, vm_ooffset_t offset,
int prot, vm_page_t *mres);
int (*cdev_pg_ctor)(void *handle, vm_ooffset_t size, vm_prot_t prot,
vm_ooffset_t foff, struct ucred *cred, u_short *color);
void (*cdev_pg_dtor)(void *handle);
};
vm_object_t cdev_pager_allocate(void *handle, enum obj_type tp,
struct cdev_pager_ops *ops, vm_ooffset_t size, vm_prot_t prot,
vm_ooffset_t foff, struct ucred *cred);
vm_object_t cdev_pager_lookup(void *handle);
void cdev_pager_free_page(vm_object_t object, vm_page_t m);
#endif /* _KERNEL */
#endif /* _VM_PAGER_ */
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