84110e7e0b
v_writecount. Keep the amount of the virtual address space used by the mappings in the new vm_object un_pager.vnp.writemappings counter. The vnode v_writecount is incremented when writemappings gets non-zero value, and decremented when writemappings is returned to zero. Writeable shared vnode-backed mappings are accounted for in vm_mmap(), and vm_map_insert() is instructed to set MAP_ENTRY_VN_WRITECNT flag on the created map entry. During deferred map entry deallocation, vm_map_process_deferred() checks for MAP_ENTRY_VN_WRITECOUNT and decrements writemappings for the vm object. Now, the writeable mount cannot be demoted to read-only while writeable shared mappings of the vnodes from the mount point exist. Also, execve(2) fails for such files with ETXTBUSY, as it should be. Noted by: tegge Reviewed by: tegge (long time ago, early version), alc Tested by: pho MFC after: 3 weeks
57 lines
2.4 KiB
C
57 lines
2.4 KiB
C
/*-
|
|
* 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.
|
|
*
|
|
* @(#)vnode_pager.h 8.1 (Berkeley) 6/11/93
|
|
* $FreeBSD$
|
|
*/
|
|
|
|
#ifndef _VNODE_PAGER_
|
|
#define _VNODE_PAGER_ 1
|
|
|
|
#ifdef _KERNEL
|
|
|
|
int vnode_pager_generic_getpages(struct vnode *vp, vm_page_t *m,
|
|
int count, int reqpage);
|
|
int vnode_pager_generic_putpages(struct vnode *vp, vm_page_t *m,
|
|
int count, boolean_t sync,
|
|
int *rtvals);
|
|
|
|
void vnode_pager_release_writecount(vm_object_t object, vm_offset_t start,
|
|
vm_offset_t end);
|
|
void vnode_pager_undirty_pages(vm_page_t *ma, int *rtvals, int written);
|
|
void vnode_pager_update_writecount(vm_object_t object, vm_offset_t start,
|
|
vm_offset_t end);
|
|
|
|
#endif /* _KERNEL */
|
|
#endif /* _VNODE_PAGER_ */
|