minix/servers/vm/vfs.c

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#define _SYSTEM 1
#define VERBOSE 0
#include <minix/callnr.h>
#include <minix/com.h>
#include <minix/config.h>
#include <minix/const.h>
#include <minix/ds.h>
#include <minix/endpoint.h>
#include <minix/keymap.h>
#include <minix/minlib.h>
#include <minix/type.h>
#include <minix/ipc.h>
#include <minix/sysutil.h>
#include <minix/syslib.h>
#include <minix/safecopies.h>
#include <errno.h>
#include <string.h>
#include <env.h>
#include <stdio.h>
#include "glo.h"
#include "proto.h"
#include "util.h"
/*===========================================================================*
* register_callback *
*===========================================================================*/
PRIVATE void register_callback(struct vmproc *for_who, callback_t callback,
int callback_type)
{
if(for_who->vm_callback) {
vm_panic("register_callback: callback already registered",
for_who->vm_callback_type);
}
for_who->vm_callback = callback;
for_who->vm_callback_type = callback_type;
return;
}
/*===========================================================================*
* vfs_open *
*===========================================================================*/
PUBLIC int vfs_open(struct vmproc *for_who, callback_t callback,
cp_grant_id_t filename_gid, int filename_len, int flags, int mode)
{
static message m;
int r;
register_callback(for_who, callback, VM_VFS_REPLY_OPEN);
m.m_type = VM_VFS_OPEN;
m.VMVO_NAME_GRANT = filename_gid;
m.VMVO_NAME_LENGTH = filename_len;
m.VMVO_FLAGS = flags;
m.VMVO_MODE = mode;
m.VMVO_ENDPOINT = for_who->vm_endpoint;
if((r=asynsend(VFS_PROC_NR, &m)) != OK) {
vm_panic("vfs_open: asynsend failed", r);
}
return r;
}
/*===========================================================================*
* vfs_close *
*===========================================================================*/
PUBLIC int vfs_close(struct vmproc *for_who, callback_t callback, int fd)
{
static message m;
int r;
register_callback(for_who, callback, VM_VFS_REPLY_CLOSE);
m.m_type = VM_VFS_CLOSE;
m.VMVC_ENDPOINT = for_who->vm_endpoint;
m.VMVC_FD = fd;
if((r=asynsend(VFS_PROC_NR, &m)) != OK) {
vm_panic("vfs_close: asynsend failed", r);
}
return r;
}
/*===========================================================================*
* do_vfs_reply *
*===========================================================================*/
PUBLIC int do_vfs_reply(message *m)
{
/* Reply to a request has been received from vfs. Handle it. First verify
* and look up which process, identified by endpoint, this is about.
* Then call the callback function that was registered when the request
* was done. Return result to vfs.
*/
endpoint_t ep;
struct vmproc *vmp;
int procno;
callback_t cb;
ep = m->VMV_ENDPOINT;
if(vm_isokendpt(ep, &procno) != OK) {
printf("VM:do_vfs_reply: reply %d about invalid endpoint %d\n",
m->m_type, ep);
vm_panic("do_vfs_reply: invalid endpoint from vfs", NO_NUM);
}
vmp = &vmproc[procno];
if(!vmp->vm_callback) {
printf("VM:do_vfs_reply: reply %d: endpoint %d not waiting\n",
m->m_type, ep);
vm_panic("do_vfs_reply: invalid endpoint from vfs", NO_NUM);
}
if(vmp->vm_callback_type != m->m_type) {
printf("VM:do_vfs_reply: reply %d unexpected for endpoint %d\n"
" (expecting %d)\n", m->m_type, ep, vmp->vm_callback_type);
vm_panic("do_vfs_reply: invalid reply from vfs", NO_NUM);
}
if(vmp->vm_flags & VMF_EXITING) {
/* This is not fatal or impossible, but the callback
* function has to realize it shouldn't do any PM or
* VFS calls for this process.
*/
printf("VM:do_vfs_reply: reply %d for EXITING endpoint %d\n",
m->m_type, ep);
}
/* All desired callback state has been used, so save and reset
* the callback. This allows the callback to register another
* one.
*/
cb = vmp->vm_callback;
vmp->vm_callback = NULL;
cb(vmp, m);
return SUSPEND;
}