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/*-
* Copyright (c) 1997, Duke University
* All rights reserved.
*
* Author:
* Andrew Gallatin <gallatin@cs.duke.edu>
*
* 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.
* 3. The name of Duke University may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY DUKE UNIVERSITY ``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 DUKE UNIVERSITY 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 PROFITSOR 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.
*
* $FreeBSD$
*/
/*
* This is a set of routines for enabling and disabling copy on write
* protection for data written into sockets.
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/proc.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/mbuf.h>
#include <sys/socketvar.h>
#include <sys/uio.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/pmap.h>
#include <vm/vm_map.h>
#include <vm/vm_page.h>
#include <vm/vm_object.h>
#if 0
#include <vm/vm_pager.h>
#include <vm/vm_kern.h>
#include <vm/vm_extern.h>
#include <vm/vm_zone.h>
#include <vm/swap_pager.h>
#endif
struct netsend_cow_stats {
int attempted;
int fail_not_mapped;
int fail_wired;
int fail_not_anon;
int fail_pmap_cow;
int fail_pg_error;
int fail_kva;
int free_post_exit;
int success;
int iodone;
int freed;
};
static struct netsend_cow_stats socow_stats = {0,0,0,0,0,0,0,0,0,0,0};
extern struct sf_buf *sf_bufs;
extern vm_offset_t sf_base;
#define dtosf(x) (&sf_bufs[((uintptr_t)(x) - (uintptr_t)sf_base) >> PAGE_SHIFT])
static void socow_iodone(void *addr, void *args);
static void
socow_iodone(void *addr, void *args)
{
int s;
struct sf_buf *sf;
vm_offset_t paddr;
vm_page_t pp;
sf = dtosf(addr);
paddr = vtophys((vm_offset_t)addr);
pp = PHYS_TO_VM_PAGE(paddr);
s = splvm();
/* remove COW mapping */
vm_page_lock_queues();
vm_page_cowclear(pp);
vm_page_unlock_queues();
vm_object_deallocate(pp->object);
splx(s);
/* note that sf_buf_free() unwires the page for us*/
sf_buf_free(addr, NULL);
socow_stats.iodone++;
}
int
socow_setup(struct mbuf *m0, struct uio *uio)
{
struct sf_buf *sf;
vm_page_t pp;
vm_offset_t pa;
struct iovec *iov;
struct vmspace *vmspace;
struct vm_map *map;
vm_offset_t uva;
int s;
vmspace = curproc->p_vmspace;;
map = &vmspace->vm_map;
uva = (vm_offset_t) uio->uio_iov->iov_base;
s = splvm();
/*
* verify page is mapped & not already wired for i/o
*/
socow_stats.attempted++;
pa=pmap_extract(map->pmap, uva);
if(!pa) {
socow_stats.fail_not_mapped++;
splx(s);
return(0);
}
pp = PHYS_TO_VM_PAGE(pa);
sf = sf_buf_alloc();
sf->m = pp;
pmap_qenter(sf->kva, &pp, 1);
/*
* set up COW
*/
vm_page_lock_queues();
vm_page_cowsetup(pp);
/*
* wire the page for I/O
*/
vm_page_wire(pp);
vm_page_unlock_queues();
/*
* prevent the process from exiting on us.
*/
vm_object_reference(pp->object);
/*
* attach to mbuf
*/
m0->m_data = (caddr_t)sf->kva;
m0->m_len = PAGE_SIZE;
MEXTADD(m0, sf->kva, PAGE_SIZE, socow_iodone, NULL, 0, EXT_SFBUF);
socow_stats.success++;
iov = uio->uio_iov;
iov->iov_base = (char *)iov->iov_base + PAGE_SIZE;
iov->iov_len -= PAGE_SIZE;
uio->uio_resid -= PAGE_SIZE;
uio->uio_offset += PAGE_SIZE;
if (iov->iov_len == 0) {
uio->uio_iov++;
uio->uio_iovcnt--;
}
splx(s);
return(1);
}
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