chiark / gitweb /
f0f85ff05986642699a30c68f0683ce42c708ed9
[elogind.git] / udevsettle.c
1 /*
2  * udevsettle.c
3  *
4  * Copyright (C) 2006 Kay Sievers <kay@vrfy.org>
5  *
6  *      This program is free software; you can redistribute it and/or modify it
7  *      under the terms of the GNU General Public License as published by the
8  *      Free Software Foundation version 2 of the License.
9  * 
10  *      This program is distributed in the hope that it will be useful, but
11  *      WITHOUT ANY WARRANTY; without even the implied warranty of
12  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13  *      General Public License for more details.
14  * 
15  *      You should have received a copy of the GNU General Public License along
16  *      with this program; if not, write to the Free Software Foundation, Inc.,
17  *      675 Mass Ave, Cambridge, MA 02139, USA.
18  *
19  */
20
21 #include <stdlib.h>
22 #include <stddef.h>
23 #include <string.h>
24 #include <stdio.h>
25 #include <unistd.h>
26 #include <errno.h>
27 #include <dirent.h>
28 #include <fcntl.h>
29 #include <syslog.h>
30 #include <sys/stat.h>
31 #include <sys/types.h>
32
33 #include "udev.h"
34 #include "udevd.h"
35
36 #define LOOP_PER_SECOND                 20
37
38 static const char *udev_log_str;
39
40 #ifdef USE_LOG
41 void log_message(int priority, const char *format, ...)
42 {
43         va_list args;
44
45         if (priority > udev_log_priority)
46                 return;
47
48         va_start(args, format);
49         vsyslog(priority, format, args);
50         va_end(args);
51 }
52 #endif
53
54 int main(int argc, char *argv[], char *envp[])
55 {
56         char queuename[PATH_SIZE];
57         char filename[PATH_SIZE];
58         unsigned long long seq_kernel;
59         unsigned long long seq_udev;
60         char seqnum[32];
61         int fd;
62         ssize_t len;
63         int timeout = 30;
64         int loop;
65         int i;
66         int rc = 1;
67
68         logging_init("udevsettle");
69         udev_config_init();
70         dbg("version %s", UDEV_VERSION);
71
72         udev_log_str = getenv("UDEV_LOG");
73
74         for (i = 1 ; i < argc; i++) {
75                 char *arg = argv[i];
76
77                 if (strncmp(arg, "--timeout=", 10) == 0) {
78                         char *str = &arg[10];
79
80                         timeout = atoi(str);
81                         dbg("timeout=%i", timeout);
82                         if (timeout <= 0) {
83                                 fprintf(stderr, "Invalid timeout value.\n");
84                                 goto exit;
85                         }
86                 } else {
87                         fprintf(stderr, "Usage: udevsettle [--timeout=<seconds>]\n");
88                         goto exit;
89                 }
90         }
91
92         sysfs_init();
93         strlcpy(queuename, udev_root, sizeof(queuename));
94         strlcat(queuename, "/" EVENT_QUEUE_DIR, sizeof(queuename));
95
96         loop = timeout * LOOP_PER_SECOND;
97         while (loop--) {
98                 /* wait for events in queue to finish */
99                 while (loop--) {
100                         struct stat statbuf;
101
102                         if (stat(queuename, &statbuf) < 0) {
103                                 info("queue is empty");
104                                 break;
105                         }
106                         usleep(1000 * 1000 / LOOP_PER_SECOND);
107                 }
108                 if (loop <= 0) {
109                         info("timeout waiting for queue");
110                         goto exit;
111                 }
112
113                 /* read current kernel seqnum */
114                 strlcpy(filename, sysfs_path, sizeof(filename));
115                 strlcat(filename, "/kernel/uevent_seqnum", sizeof(filename));
116                 fd = open(filename, O_RDONLY);
117                 if (fd < 0)
118                         goto exit;
119                 len = read(fd, seqnum, sizeof(seqnum)-1);
120                 close(fd);
121                 if (len <= 0)
122                         goto exit;
123                 seqnum[len] = '\0';
124                 seq_kernel = strtoull(seqnum, NULL, 10);
125                 info("kernel seqnum = %llu", seq_kernel);
126
127                 /* read current udev seqnum */
128                 strlcpy(filename, udev_root, sizeof(filename));
129                 strlcat(filename, "/" EVENT_SEQNUM, sizeof(filename));
130                 fd = open(filename, O_RDONLY);
131                 if (fd < 0)
132                         goto exit;
133                 len = read(fd, seqnum, sizeof(seqnum)-1);
134                 close(fd);
135                 if (len <= 0)
136                         goto exit;
137                 seqnum[len] = '\0';
138                 seq_udev = strtoull(seqnum, NULL, 10);
139                 info("udev seqnum = %llu", seq_udev);
140
141                 /* make sure all kernel events have arrived in the queue */
142                 if (seq_udev >= seq_kernel) {
143                         info("queue is empty and no pending events left");
144                         rc = 0;
145                         goto exit;
146                 }
147                 usleep(1000 * 1000 / LOOP_PER_SECOND);
148                 info("queue is empty, but events still pending");
149         }
150
151 exit:
152         sysfs_cleanup();
153         logging_close();
154         return rc;
155 }