static void lxc_monitor_fifo_send(struct lxc_msg *msg, const char *lxcpath)
{
int fd,ret;
char fifo_path[PATH_MAX];
BUILD_BUG_ON(sizeof(*msg) > PIPE_BUF); /* write not guaranteed atomic */
ret = lxc_monitor_fifo_name(lxcpath, fifo_path, sizeof(fifo_path), 0);
if (ret < 0)
return;
process_lock();
fd = open(fifo_path, O_WRONLY);
process_unlock();
if (fd < 0) {
/* it is normal for this open to fail when there is no monitor
* running, so we don't log it
*/
return;
}
ret = write(fd, msg, sizeof(*msg));
if (ret != sizeof(*msg)) {
process_lock();
close(fd);
process_unlock();
SYSERROR("failed to write monitor fifo %s", fifo_path);
return;
}
process_lock();
close(fd);
process_unlock();
}
static int lxc_monitord_fifo_create(struct lxc_monitor *mon)
{
struct flock lk;
char fifo_path[PATH_MAX];
int ret;
ret = lxc_monitor_fifo_name(mon->lxcpath, fifo_path, sizeof(fifo_path), 1);
if (ret < 0)
return ret;
ret = mknod(fifo_path, S_IFIFO|S_IRUSR|S_IWUSR, 0);
if (ret < 0 && errno != EEXIST) {
INFO("failed to mknod monitor fifo %s %s", fifo_path, strerror(errno));
return -1;
}
mon->fifofd = open(fifo_path, O_RDWR);
if (mon->fifofd < 0) {
unlink(fifo_path);
ERROR("failed to open monitor fifo");
return -1;
}
lk.l_type = F_WRLCK;
lk.l_whence = SEEK_SET;
lk.l_start = 0;
lk.l_len = 0;
if (fcntl(mon->fifofd, F_SETLK, &lk) != 0) {
/* another lxc-monitord is already running, don't start up */
DEBUG("lxc-monitord already running on lxcpath %s", mon->lxcpath);
close(mon->fifofd);
return -1;
}
return 0;
}
static int lxc_monitord_fifo_delete(struct lxc_monitor *mon)
{
char fifo_path[PATH_MAX];
int ret;
ret = lxc_monitor_fifo_name(mon->lxcpath, fifo_path, sizeof(fifo_path), 0);
if (ret < 0)
return ret;
unlink(fifo_path);
return 0;
}
static int lxc_monitord_fifo_create(struct lxc_monitor *mon)
{
char fifo_path[PATH_MAX];
int ret;
ret = lxc_monitor_fifo_name(mon->lxcpath, fifo_path, sizeof(fifo_path), 1);
if (ret < 0)
return ret;
ret = mknod(fifo_path, S_IFIFO|S_IRUSR|S_IWUSR, 0);
if (ret < 0) {
INFO("monitor fifo %s exists, already running?", fifo_path);
return -1;
}
mon->fifofd = open(fifo_path, O_RDWR);
if (mon->fifofd < 0) {
unlink(fifo_path);
ERROR("failed to open monitor fifo");
return -1;
}
return 0;
}
static void lxc_monitor_fifo_send(struct lxc_msg *msg, const char *lxcpath)
{
int fd,ret;
char fifo_path[PATH_MAX];
BUILD_BUG_ON(sizeof(*msg) > PIPE_BUF); /* write not guaranteed atomic */
ret = lxc_monitor_fifo_name(lxcpath, fifo_path, sizeof(fifo_path), 0);
if (ret < 0)
return;
/* open the fifo nonblock in case the monitor is dead, we don't want
* the open to wait for a reader since it may never come.
*/
fd = open(fifo_path, O_WRONLY|O_NONBLOCK);
if (fd < 0) {
/* it is normal for this open to fail ENXIO when there is no
* monitor running, so we don't log it
*/
return;
}
if (fcntl(fd, F_SETFL, O_WRONLY) < 0) {
close(fd);
return;
}
ret = write(fd, msg, sizeof(*msg));
if (ret != sizeof(*msg)) {
close(fd);
SYSERROR("failed to write monitor fifo %s", fifo_path);
return;
}
close(fd);
}
