NetBSD/libexec/lfs_cleanerd/cleansrv.c

223 lines
5.6 KiB
C

/* $NetBSD: cleansrv.c,v 1.3 2008/04/28 20:23:04 martin Exp $ */
/*-
* Copyright (c) 2005 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Konrad E. Schroder <perseant@hhhh.org>.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/
#ifdef USE_CLIENT_SERVER
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <sys/syslog.h>
#include <sys/param.h>
#include <sys/mount.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <ufs/ufs/inode.h>
#include <ufs/lfs/lfs.h>
#include "bufcache.h"
#include "vnode.h"
#include "lfs.h"
#include "fdfs.h"
#include "cleaner.h"
#define LFS_CLEANERD_SOCKDIR "/tmp/.lfs_cleanerd"
#define LFS_CLEANERD_SOCKFILE LFS_CLEANERD_SOCKDIR "/socket"
int control_socket = -1;
extern int nfss;
extern struct clfs **fsp;
struct lfs_cleanerd_cmd {
int cmd;
int len;
char data[PATH_MAX];
};
void
check_control_socket(void)
{
int c, r;
struct lfs_cleanerd_cmd cmd;
struct clfs **nfsp;
if (control_socket < 0)
return;
while(1) {
ioctl(control_socket, FIONREAD, &c);
if (c <= 0)
return;
read(control_socket, (char *)&cmd, sizeof(cmd));
switch(cmd.cmd) {
case 'C': /* Add filesystem for cleaning */
++nfss;
nfsp = (struct clfs **)realloc(fsp,
nfss * sizeof(*fsp));
if (nfsp == NULL) {
--nfss;
break;
}
fsp = nfsp;
fsp[nfss - 1] = (struct clfs *)malloc(sizeof(**fsp));
if (fsp[nfss - 1] == NULL) {
syslog(LOG_ERR, "%s: couldn't alloc memory: %m"
cmd.data);
--nfsp;
break;
}
if ((r = init_fs(fsp[nfss - 1], cmd.data)) < 0) {
syslog(LOG_ERR, "%s: couldn't init: "
"error code %d", cmd.data, r);
handle_error(fsp, nfss - 1);
}
break;
default:
syslog(LOG_NOTICE, "unknown message type %d", cmd.cmd);
break;
}
}
}
static int
send_fss_to_master(int argc, char **argv)
{
struct sockaddr_un sun;
struct lfs_cleanerd_cmd cmd;
int i, r, s;
strcpy(sun.sun_path, LFS_CLEANERD_SOCKFILE);
sun.sun_family = AF_LOCAL;
sun.sun_len = sizeof(sa_family_t) + 1 + strlen(sun.sun_path);
s = socket(PF_LOCAL, SOCK_DGRAM, 0);
if (s < 0) {
syslog(LOG_DEBUG, "open failed: %m");
return -1;
}
cmd.cmd = 'C';
for (i = 0; i < argc; i++) {
strncpy(cmd.data, argv[i], PATH_MAX);
cmd.len = 2 * sizeof(int) + strlen(cmd.data) + 1;
r = sendto(s, &cmd, sizeof(cmd), 0, (struct sockaddr *)&sun,
sizeof(sun));
if (r < 0) {
syslog(LOG_DEBUG, "sendto failed: %m");
return -1;
}
}
return 0;
}
static void
sig_donothing(int sig)
{
/* Do nothing */
dlog("caught sigio");
}
static void
cleanup_socket(void)
{
if (control_socket >= 0) {
close(control_socket);
unlink(LFS_CLEANERD_SOCKFILE);
rmdir(LFS_CLEANERD_SOCKDIR);
}
}
void
try_to_become_master(int argc, char **argv)
{
struct sockaddr_un sun;
int fd;
int pid;
int flags;
char scratch[80];
if (mkdir(LFS_CLEANERD_SOCKDIR, 0700) < 0) {
if (errno != EEXIST)
return;
pid = 0;
fd = open("/var/run/lfs_cleanerd.pid", O_RDONLY);
if (fd >= 0) {
read(fd, scratch, 80);
scratch[79] = '\0';
pid = atoi(scratch);
if (kill(pid, 0) == 0) {
send_fss_to_master(argc, argv);
exit(0);
}
close(fd);
}
/*
* Master is no longer present even though directory
* exists. Remove the socket and proceed. There is
* a race condition here which could result in more than
* one master daemon. That would not be a catastrophe.
*/
if (unlink(LFS_CLEANERD_SOCKFILE) != 0)
return;
}
/*
* Create the socket and bind it in the namespace
*/
control_socket = socket(PF_LOCAL, SOCK_DGRAM, 0);
strcpy(sun.sun_path, LFS_CLEANERD_SOCKFILE);
sun.sun_family = AF_LOCAL;
sun.sun_len = sizeof(sa_family_t) + 1 + strlen(sun.sun_path);
bind(control_socket, (struct sockaddr *)&sun, sizeof(sun));
/* Clean up when we leave */
atexit(cleanup_socket);
/*
* Wake us when there is i/o on this socket. We don't need
* to actually do anything when we get the signal, but we
* have to install a signal handler so LFCNSEGWAIT will be
* interrupted when data comes in on the socket.
*/
fcntl(control_socket, F_SETOWN, getpid());
flags = fcntl(control_socket, F_GETFL, NULL);
flags |= O_ASYNC;
fcntl(control_socket, F_SETFL, flags);
signal(SIGIO, sig_donothing);
/* And finally record our pid */
pidfile("lfs_cleanerd");
}
#endif /* USE_CLIENT_SERVER */