chiark / gitweb /
open-code pollfd setup
[elogind.git] / udev / udevd.c
index 9096f9505be922df85cd26ea2e2b518d8a95b46c..d227a71fd1f5bc742229275ecb576cc723bae5df 100644 (file)
@@ -27,7 +27,9 @@
 #include <fcntl.h>
 #include <time.h>
 #include <getopt.h>
+#include <dirent.h>
 #include <sys/select.h>
+#include <sys/poll.h>
 #include <sys/wait.h>
 #include <sys/stat.h>
 #include <sys/ioctl.h>
@@ -62,10 +64,10 @@ static struct udev_rules *rules;
 static struct udev_ctrl *udev_ctrl;
 static struct udev_monitor *kernel_monitor;
 static int inotify_fd = -1;
-static int signal_pipe[2] = {-1, -1};
 static volatile int sigchilds_waiting;
 static volatile int udev_exit;
 static volatile int reload_config;
+static volatile int signal_received;
 static int run_exec_q;
 static int stop_exec_q;
 static int max_childs;
@@ -193,8 +195,6 @@ static void event_fork(struct udev_event *event)
                udev_ctrl_unref(udev_ctrl);
                if (inotify_fd >= 0)
                        close(inotify_fd);
-               close(signal_pipe[READ_END]);
-               close(signal_pipe[WRITE_END]);
                logging_close();
                logging_init("udevd-event");
                setpriority(PRIO_PROCESS, 0, UDEV_PRIORITY);
@@ -430,7 +430,6 @@ static void event_queue_manager(struct udev *udev)
                        continue;
                }
 
-               /* do dendencies, start event */
                event_fork(loop_event);
                dbg(udev, "moved seq %llu to running list\n", udev_device_get_seqnum(loop_event->dev));
        }
@@ -520,8 +519,7 @@ static void asmlinkage sig_handler(int signum)
                        break;
        }
 
-       /* write to pipe, which will wakeup select() in our mainloop */
-       write(signal_pipe[WRITE_END], "", 1);
+       signal_received = 1;
 }
 
 static void udev_done(int pid, int exitstatus)
@@ -570,6 +568,38 @@ static void reap_sigchilds(void)
        }
 }
 
+static void cleanup_queue_dir(struct udev *udev)
+{
+       char dirname[UTIL_PATH_SIZE];
+       char filename[UTIL_PATH_SIZE];
+       DIR *dir;
+
+       util_strlcpy(filename, udev_get_dev_path(udev), sizeof(filename));
+       util_strlcat(filename, "/.udev/uevent_seqnum", sizeof(filename));
+       unlink(filename);
+
+       util_strlcpy(dirname, udev_get_dev_path(udev), sizeof(dirname));
+       util_strlcat(dirname, "/.udev/queue", sizeof(dirname));
+       dir = opendir(dirname);
+       if (dir != NULL) {
+               while (1) {
+                       struct dirent *dent;
+
+                       dent = readdir(dir);
+                       if (dent == NULL || dent->d_name[0] == '\0')
+                               break;
+                       if (dent->d_name[0] == '.')
+                               continue;
+                       util_strlcpy(filename, dirname, sizeof(filename));
+                       util_strlcat(filename, "/", sizeof(filename));
+                       util_strlcat(filename, dent->d_name, sizeof(filename));
+                       unlink(filename);
+               }
+               closedir(dir);
+               rmdir(dirname);
+       }
+}
+
 static void export_initial_seqnum(struct udev *udev)
 {
        char filename[UTIL_PATH_SIZE];
@@ -601,10 +631,8 @@ static void export_initial_seqnum(struct udev *udev)
 int main(int argc, char *argv[])
 {
        struct udev *udev;
-       int err;
        int fd;
        struct sigaction act;
-       fd_set readfds;
        const char *value;
        int daemonize = 0;
        static const struct option options[] = {
@@ -616,7 +644,6 @@ int main(int argc, char *argv[])
                {}
        };
        int rc = 1;
-       int maxfd;
 
        udev = udev_new();
        if (udev == NULL)
@@ -699,40 +726,13 @@ int main(int argc, char *argv[])
        }
        udev_monitor_set_receive_buffer_size(kernel_monitor, 128*1024*1024);
 
-       err = pipe(signal_pipe);
-       if (err < 0) {
-               err(udev, "error getting pipes: %m\n");
-               goto exit;
-       }
-
-       err = fcntl(signal_pipe[READ_END], F_GETFL, 0);
-       if (err < 0) {
-               err(udev, "error fcntl on read pipe: %m\n");
-               goto exit;
-       }
-       err = fcntl(signal_pipe[READ_END], F_SETFL, err | O_NONBLOCK);
-       if (err < 0) {
-               err(udev, "error fcntl on read pipe: %m\n");
-               goto exit;
-       }
-
-       err = fcntl(signal_pipe[WRITE_END], F_GETFL, 0);
-       if (err < 0) {
-               err(udev, "error fcntl on write pipe: %m\n");
-               goto exit;
-       }
-       err = fcntl(signal_pipe[WRITE_END], F_SETFL, err | O_NONBLOCK);
-       if (err < 0) {
-               err(udev, "error fcntl on write pipe: %m\n");
-               goto exit;
-       }
-
        rules = udev_rules_new(udev, 1);
        if (rules == NULL) {
                err(udev, "error reading rules\n");
                goto exit;
        }
        udev_list_init(&event_list);
+       cleanup_queue_dir(udev);
        export_initial_seqnum(udev);
 
        if (daemonize) {
@@ -790,9 +790,10 @@ int main(int argc, char *argv[])
                util_strlcat(path, "/class/mem/null", sizeof(path));
                if (lstat(path, &statbuf) == 0) {
                        if (S_ISDIR(statbuf.st_mode)) {
-                               const char *depr_str = "<6>udev: deprecated sysfs layout (kernel too old, "
-                                                       "or CONFIG_SYSFS_DEPRECATED) is unsupported, some "
-                                                       "udev features may fail\n";
+                               const char *depr_str =
+                                       "<6>udev: deprecated sysfs layout; update the kernel or "
+                                       "disable CONFIG_SYSFS_DEPRECATED; some udev features will "
+                                       "not work correctly\n";
 
                                write(fd, depr_str, strlen(depr_str));
                        }
@@ -804,7 +805,6 @@ int main(int argc, char *argv[])
        memset(&act, 0x00, sizeof(struct sigaction));
        act.sa_handler = (void (*)(int)) sig_handler;
        sigemptyset(&act.sa_mask);
-       act.sa_flags = SA_RESTART;
        sigaction(SIGINT, &act, NULL);
        sigaction(SIGTERM, &act, NULL);
        sigaction(SIGCHLD, &act, NULL);
@@ -831,7 +831,7 @@ int main(int argc, char *argv[])
                                          IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
                }
        } else if (errno == ENOSYS)
-               err(udev, "the kernel does not support inotify, udevd can't monitor rules file changes\n");
+               info(udev, "unable to use inotify, udevd will not monitor rule files changes\n");
        else
                err(udev, "inotify_init failed: %m\n");
 
@@ -851,32 +851,49 @@ int main(int argc, char *argv[])
                max_childs = strtoul(value, NULL, 10);
        info(udev, "initialize max_childs to %u\n", max_childs);
 
-       maxfd = udev_ctrl_get_fd(udev_ctrl);
-       maxfd = UDEV_MAX(maxfd, udev_monitor_get_fd(kernel_monitor));
-       maxfd = UDEV_MAX(maxfd, signal_pipe[READ_END]);
-       maxfd = UDEV_MAX(maxfd, inotify_fd);
        while (!udev_exit) {
+               sigset_t blocked_mask, orig_mask;
+               struct pollfd pfd[4];
+               struct pollfd *ctrl_poll, *monitor_poll, *inotify_poll = NULL;
+               int nfds = 0;
                int fdcount;
 
-               FD_ZERO(&readfds);
-               FD_SET(signal_pipe[READ_END], &readfds);
-               FD_SET(udev_ctrl_get_fd(udev_ctrl), &readfds);
-               FD_SET(udev_monitor_get_fd(kernel_monitor), &readfds);
-               if (inotify_fd >= 0)
-                       FD_SET(inotify_fd, &readfds);
-               fdcount = select(maxfd+1, &readfds, NULL, NULL, NULL);
+               sigfillset(&blocked_mask);
+               sigprocmask(SIG_SETMASK, &blocked_mask, &orig_mask);
+               if (signal_received) {
+                       sigprocmask(SIG_SETMASK, &orig_mask, NULL);
+                       goto handle_signals;
+               }
+
+               ctrl_poll = &pfd[nfds++];
+               ctrl_poll->fd = udev_ctrl_get_fd(udev_ctrl);
+               ctrl_poll->events = POLLIN;
+
+               monitor_poll = &pfd[nfds++];
+               monitor_poll->fd = udev_monitor_get_fd(kernel_monitor);
+               monitor_poll->events = POLLIN;
+
+               if (inotify_fd >= 0) {
+                       inotify_poll = &pfd[nfds++];
+                       inotify_poll->fd = inotify_fd;
+                       inotify_poll->events = POLLIN;
+               }
+
+               fdcount = ppoll(pfd, nfds, NULL, &orig_mask);
+               sigprocmask(SIG_SETMASK, &orig_mask, NULL);
                if (fdcount < 0) {
-                       if (errno != EINTR)
-                               err(udev, "error in select: %m\n");
+                       if (errno == EINTR)
+                               goto handle_signals;
+                       err(udev, "error in select: %m\n");
                        continue;
                }
 
                /* get control message */
-               if (FD_ISSET(udev_ctrl_get_fd(udev_ctrl), &readfds))
+               if (ctrl_poll->revents & POLLIN)
                        handle_ctrl_msg(udev_ctrl);
 
                /* get kernel uevent */
-               if (FD_ISSET(udev_monitor_get_fd(kernel_monitor), &readfds)) {
+               if (monitor_poll->revents & POLLIN) {
                        struct udev_device *dev;
 
                        dev = udev_monitor_receive_device(kernel_monitor);
@@ -891,15 +908,8 @@ int main(int argc, char *argv[])
                        }
                }
 
-               /* received a signal, clear our notification pipe */
-               if (FD_ISSET(signal_pipe[READ_END], &readfds)) {
-                       char buf[256];
-
-                       read(signal_pipe[READ_END], &buf, sizeof(buf));
-               }
-
                /* rules directory inotify watch */
-               if ((inotify_fd >= 0) && FD_ISSET(inotify_fd, &readfds)) {
+               if (inotify_poll && (inotify_poll->revents & POLLIN)) {
                        int nbytes;
 
                        /* discard all possible events, we can just reload the config */
@@ -918,6 +928,9 @@ int main(int argc, char *argv[])
                        }
                }
 
+handle_signals:
+               signal_received = 0;
+
                /* rules changed, set by inotify or a HUP signal */
                if (reload_config) {
                        struct udev_rules *rules_new;
@@ -941,21 +954,14 @@ int main(int argc, char *argv[])
                                event_queue_manager(udev);
                }
        }
+       cleanup_queue_dir(udev);
        rc = 0;
-
 exit:
        udev_rules_unref(rules);
-
-       if (signal_pipe[READ_END] >= 0)
-               close(signal_pipe[READ_END]);
-       if (signal_pipe[WRITE_END] >= 0)
-               close(signal_pipe[WRITE_END]);
-
        udev_ctrl_unref(udev_ctrl);
        if (inotify_fd >= 0)
                close(inotify_fd);
        udev_monitor_unref(kernel_monitor);
-
        udev_selinux_exit(udev);
        udev_unref(udev);
        logging_close();