udevadm-settle.c revision 17fcfb5972977b6a3aedca6ad2aa8d1fbfbc761d
/*
* Copyright (C) 2006-2008 Kay Sievers <kay@vrfy.org>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <stdlib.h>
#include <stddef.h>
#include <string.h>
#include <stdio.h>
#include <unistd.h>
#include <errno.h>
#include <dirent.h>
#include <fcntl.h>
#include <syslog.h>
#include <getopt.h>
#include <sys/stat.h>
#include <sys/types.h>
#include "udev.h"
#define DEFAULT_TIMEOUT 180
#define LOOP_PER_SECOND 20
static void print_queue(struct udev *udev, const char *dir)
{
LIST_HEAD(files);
struct name_entry *item;
if (add_matching_files(udev, &files, dir, NULL) < 0)
return;
printf("\n\nAfter the udevadm settle timeout, the events queue contains:\n\n");
list_for_each_entry(item, &files, node) {
char target[UTIL_NAME_SIZE];
size_t len;
const char *filename = strrchr(item->name, '/');
if (filename == NULL)
continue;
filename++;
if (*filename == '\0')
continue;
len = readlink(item->name, target, sizeof(target));
if (len < 0)
continue;
target[len] = '\0';
printf("%s: %s\n", filename, target);
}
printf("\n\n");
}
int udevadm_settle(struct udev *udev, int argc, char *argv[])
{
char queuename[UTIL_PATH_SIZE];
char filename[UTIL_PATH_SIZE];
unsigned long long seq_kernel;
unsigned long long seq_udev;
char seqnum[32];
int fd;
ssize_t len;
int timeout = DEFAULT_TIMEOUT;
int loop;
static const struct option options[] = {
{ "timeout", 1, NULL, 't' },
{ "help", 0, NULL, 'h' },
{}
};
int option;
int rc = 1;
int seconds;
dbg(udev, "version %s\n", VERSION);
while (1) {
option = getopt_long(argc, argv, "t:h", options, NULL);
if (option == -1)
break;
switch (option) {
case 't':
seconds = atoi(optarg);
if (seconds > 0)
timeout = seconds;
else
fprintf(stderr, "invalid timeout value\n");
dbg(udev, "timeout=%i\n", timeout);
break;
case 'h':
printf("Usage: udevadm settle [--help] [--timeout=<seconds>]\n\n");
goto exit;
}
}
util_strlcpy(queuename, udev_get_dev_path(udev), sizeof(queuename));
util_strlcat(queuename, "/.udev/queue", sizeof(queuename));
loop = timeout * LOOP_PER_SECOND;
while (loop--) {
/* wait for events in queue to finish */
while (loop--) {
struct stat statbuf;
if (stat(queuename, &statbuf) < 0) {
info(udev, "queue is empty\n");
break;
}
usleep(1000 * 1000 / LOOP_PER_SECOND);
}
if (loop <= 0) {
info(udev, "timeout waiting for queue\n");
print_queue(udev, queuename);
goto exit;
}
/* read current udev seqnum */
util_strlcpy(filename, udev_get_dev_path(udev), sizeof(filename));
util_strlcat(filename, "/.udev/uevent_seqnum", sizeof(filename));
fd = open(filename, O_RDONLY);
if (fd < 0)
goto exit;
len = read(fd, seqnum, sizeof(seqnum)-1);
close(fd);
if (len <= 0)
goto exit;
seqnum[len] = '\0';
seq_udev = strtoull(seqnum, NULL, 10);
info(udev, "udev seqnum = %llu\n", seq_udev);
/* read current kernel seqnum */
util_strlcpy(filename, udev_get_sys_path(udev), sizeof(filename));
util_strlcat(filename, "/kernel/uevent_seqnum", sizeof(filename));
fd = open(filename, O_RDONLY);
if (fd < 0)
goto exit;
len = read(fd, seqnum, sizeof(seqnum)-1);
close(fd);
if (len <= 0)
goto exit;
seqnum[len] = '\0';
seq_kernel = strtoull(seqnum, NULL, 10);
info(udev, "kernel seqnum = %llu\n", seq_kernel);
/* make sure all kernel events have arrived in the queue */
if (seq_udev >= seq_kernel) {
info(udev, "queue is empty and no pending events left\n");
rc = 0;
goto exit;
}
usleep(1000 * 1000 / LOOP_PER_SECOND);
info(udev, "queue is empty, but events still pending\n");
}
exit:
return rc;
}