X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=udevd.c;h=91033b068844a42965d48d46db91dc2c6b2558da;hp=a8328bbb81a60d2a093089d6490ddb8f7e58577b;hb=821d0ec803a72841f173739f5b713fe847edab75;hpb=1e26698933e89c11dc6806d8bd37fd4386814239

diff --git a/udevd.c b/udevd.c
index a8328bbb8..91033b068 100644
--- a/udevd.c
+++ b/udevd.c
@@ -1,7 +1,7 @@
 /*
  * udevd.c - hotplug event serializer
  *
- * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
+ * Copyright (C) 2004-2005 Kay Sievers <kay.sievers@vrfy.org>
  * Copyright (C) 2004 Chris Friesen <chris_friesen@sympatico.ca>
  *
  *
@@ -21,22 +21,26 @@
  */
 
 #include <stddef.h>
-#include <sys/wait.h>
 #include <signal.h>
 #include <unistd.h>
 #include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <ctype.h>
+#include <dirent.h>
+#include <fcntl.h>
+#include <sys/select.h>
+#include <sys/wait.h>
 #include <sys/time.h>
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <sys/un.h>
-#include <fcntl.h>
 #include <sys/sysinfo.h>
 #include <sys/stat.h>
 
 #include "list.h"
+#include "udev_libc_wrapper.h"
 #include "udev.h"
 #include "udev_version.h"
 #include "udev_utils.h"
@@ -45,6 +49,7 @@
 
 /* global variables*/
 static int udevsendsock;
+static pid_t sid;
 
 static int pipefds[2];
 static long startup_time;
@@ -64,34 +69,33 @@ static void user_sighandler(void);
 static void reap_sigchilds(void);
 char *udev_bin;
 
-#ifdef LOG
-void log_message (int level, const char *format, ...)
+#ifdef USE_LOG
+void log_message (int priority, const char *format, ...)
 {
-	va_list	args;
+	va_list args;
+
+	if (priority > udev_log_priority)
+		return;
 
 	va_start(args, format);
-	vsyslog(level, format, args);
+	vsyslog(priority, format, args);
 	va_end(args);
 }
 #endif
 
-#define msg_dump(msg) \
-	dbg("msg_dump: sequence %llu, '%s', '%s', '%s'", \
-	msg->seqnum, msg->action, msg->devpath, msg->subsystem);
-
 static void msg_dump_queue(void)
 {
 #ifdef DEBUG
 	struct hotplug_msg *msg;
 
-	list_for_each_entry(msg, &msg_list, list)
+	list_for_each_entry(msg, &msg_list, node)
 		dbg("sequence %llu in queue", msg->seqnum);
 #endif
 }
 
 static void run_queue_delete(struct hotplug_msg *msg)
 {
-	list_del(&msg->list);
+	list_del(&msg->node);
 	free(msg);
 }
 
@@ -103,18 +107,26 @@ static void msg_queue_insert(struct hotplug_msg *msg)
 
 	if (msg->seqnum == 0) {
 		dbg("no SEQNUM, move straight to the exec queue");
-		list_add(&msg->list, &exec_list);
+		list_add(&msg->node, &exec_list);
+		run_exec_q = 1;
+		return;
+	}
+
+	/* don't delay messages with timeout set */
+	if (msg->timeout) {
+		dbg("move seq %llu with timeout %u to exec queue", msg->seqnum, msg->timeout);
+		list_add(&msg->node, &exec_list);
 		run_exec_q = 1;
 		return;
 	}
 
 	/* sort message by sequence number into list */
-	list_for_each_entry_reverse(loop_msg, &msg_list, list) {
+	list_for_each_entry_reverse(loop_msg, &msg_list, node) {
 		if (loop_msg->seqnum < msg->seqnum)
 			break;
 
 		if (loop_msg->seqnum == msg->seqnum) {
-			dbg("ignoring duplicate message seq %llu", msg->seqnum);
+			info("ignoring duplicate message seq %llu", msg->seqnum);
 			return;
 		}
 	}
@@ -123,7 +135,7 @@ static void msg_queue_insert(struct hotplug_msg *msg)
 	sysinfo(&info);
 	msg->queue_time = info.uptime;
 
-	list_add(&msg->list, &loop_msg->list);
+	list_add(&msg->node, &loop_msg->node);
 	dbg("queued message seq %llu", msg->seqnum);
 
 	/* run msg queue manager */
@@ -133,7 +145,7 @@ static void msg_queue_insert(struct hotplug_msg *msg)
 }
 
 /* forks event and removes event from run queue when finished */
-static void udev_run(struct hotplug_msg *msg)
+static void execute_udev(struct hotplug_msg *msg)
 {
 	char *const argv[] = { "udev", msg->subsystem, NULL };
 	pid_t pid;
@@ -144,16 +156,15 @@ static void udev_run(struct hotplug_msg *msg)
 		/* child */
 		close(udevsendsock);
 		logging_close();
+
+		setpriority(PRIO_PROCESS, 0, UDEV_PRIORITY);
 		execve(udev_bin, argv, msg->envp);
-		dbg("exec of child failed");
+		err("exec of child failed");
 		_exit(1);
 		break;
 	case -1:
-		dbg("fork of child failed");
+		err("fork of child failed");
 		run_queue_delete(msg);
-		/* note: we never managed to run, so we had no impact on 
-		 * running_with_devpath(), so don't bother setting run_exec_q
-		 */
 		break;
 	default:
 		/* get SIGCHLD in main loop */
@@ -162,11 +173,105 @@ static void udev_run(struct hotplug_msg *msg)
 	}
 }
 
+static int running_processes(void)
+{
+	int f;
+	static char buf[4096];
+	int len;
+	int running;
+	const char *pos;
+
+	f = open("/proc/stat", O_RDONLY);
+	if (f == -1)
+		return -1;
+
+	len = read(f, buf, sizeof(buf));
+	close(f);
+
+	if (len <= 0)
+		return -1;
+	else
+		buf[len] = '\0';
+
+	pos = strstr(buf, "procs_running ");
+	if (pos == NULL)
+		return -1;
+
+	if (sscanf(pos, "procs_running %u", &running) != 1)
+		return -1;
+
+	return running;
+}
+
+/* return the number of process es in our session, count only until limit */
+static int running_processes_in_session(pid_t session, int limit)
+{
+	DIR *dir;
+	struct dirent *dent;
+	int running = 0;
+
+	dir = opendir("/proc");
+	if (!dir)
+		return -1;
+
+	/* read process info from /proc */
+	for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
+		int f;
+		char procdir[64];
+		char line[256];
+		const char *pos;
+		char state;
+		pid_t ppid, pgrp, sess;
+		int len;
+
+		if (!isdigit(dent->d_name[0]))
+			continue;
+
+		snprintf(procdir, sizeof(procdir), "/proc/%s/stat", dent->d_name);
+		procdir[sizeof(procdir)-1] = '\0';
+
+		f = open(procdir, O_RDONLY);
+		if (f == -1)
+			continue;
+
+		len = read(f, line, sizeof(line));
+		close(f);
+
+		if (len <= 0)
+			continue;
+		else
+			line[len] = '\0';
+
+		/* skip ugly program name */
+		pos = strrchr(line, ')') + 2;
+		if (pos == NULL)
+			continue;
+
+		if (sscanf(pos, "%c %d %d %d ", &state, &ppid, &pgrp, &sess) != 4)
+			continue;
+
+		/* count only processes in our session */
+		if (sess != session)
+			continue;
+
+		/* count only running, no sleeping processes */
+		if (state != 'R')
+			continue;
+
+		running++;
+		if (limit > 0 && running >= limit)
+			break;
+	}
+	closedir(dir);
+
+	return running;
+}
+
 static int compare_devpath(const char *running, const char *waiting)
 {
 	int i;
 
-	for (i = 0; i < DEVPATH_SIZE; i++) {
+	for (i = 0; i < PATH_SIZE; i++) {
 		/* identical device event found */
 		if (running[i] == '\0' && waiting[i] == '\0')
 			return 1;
@@ -195,7 +300,11 @@ static struct hotplug_msg *running_with_devpath(struct hotplug_msg *msg)
 	if (msg->devpath == NULL)
 		return NULL;
 
-	list_for_each_entry(loop_msg, &running_list, list) {
+	/* skip any events with a timeout set */
+	if (msg->timeout)
+		return NULL;
+
+	list_for_each_entry(loop_msg, &running_list, node) {
 		if (loop_msg->devpath == NULL)
 			continue;
 
@@ -218,13 +327,30 @@ static void exec_queue_manager(void)
 	struct hotplug_msg *loop_msg;
 	struct hotplug_msg *tmp_msg;
 	struct hotplug_msg *msg;
+	int running;
+
+	running = running_processes();
+	dbg("%d processes runnning on system", running);
+	if (running < 0)
+		running = THROTTLE_MAX_RUNNING_CHILDS;
+
+	list_for_each_entry_safe(loop_msg, tmp_msg, &exec_list, node) {
+		/* check running processes in our session and possibly throttle */
+		if (running >= THROTTLE_MAX_RUNNING_CHILDS) {
+			running = running_processes_in_session(sid, THROTTLE_MAX_RUNNING_CHILDS+10);
+			dbg("%d processes running in session", running);
+			if (running >= THROTTLE_MAX_RUNNING_CHILDS) {
+				dbg("delay seq %llu, cause too many processes already running", loop_msg->seqnum);
+				return;
+			}
+		}
 
-	list_for_each_entry_safe(loop_msg, tmp_msg, &exec_list, list) {
 		msg = running_with_devpath(loop_msg);
 		if (!msg) {
 			/* move event to run list */
-			list_move_tail(&loop_msg->list, &running_list);
-			udev_run(loop_msg);
+			list_move_tail(&loop_msg->node, &running_list);
+			execute_udev(loop_msg);
+			running++;
 			dbg("moved seq %llu to running list", loop_msg->seqnum);
 		} else {
 			dbg("delay seq %llu (%s), cause seq %llu (%s) is still running",
@@ -235,7 +361,7 @@ static void exec_queue_manager(void)
 
 static void msg_move_exec(struct hotplug_msg *msg)
 {
-	list_move_tail(&msg->list, &exec_list);
+	list_move_tail(&msg->node, &exec_list);
 	run_exec_q = 1;
 	expected_seqnum = msg->seqnum+1;
 	dbg("moved seq %llu to exec, next expected is %llu",
@@ -254,7 +380,7 @@ static void msg_queue_manager(void)
 
 	dbg("msg queue manager, next expected is %llu", expected_seqnum);
 recheck:
-	list_for_each_entry_safe(loop_msg, tmp_msg, &msg_list, list) {
+	list_for_each_entry_safe(loop_msg, tmp_msg, &msg_list, node) {
 		/* move event with expected sequence to the exec list */
 		if (loop_msg->seqnum == expected_seqnum) {
 			msg_move_exec(loop_msg);
@@ -325,17 +451,17 @@ static struct hotplug_msg *get_udevsend_msg(void)
 	cred = (struct ucred *) CMSG_DATA(cmsg);
 
 	if (cmsg == NULL || cmsg->cmsg_type != SCM_CREDENTIALS) {
-		dbg("no sender credentials received, message ignored");
+		info("no sender credentials received, message ignored");
 		return NULL;
 	}
 
 	if (cred->uid != 0) {
-		dbg("sender uid=%i, message ignored", cred->uid);
+		info("sender uid=%i, message ignored", cred->uid);
 		return NULL;
 	}
 
 	if (strncmp(usend_msg.magic, UDEV_MAGIC, sizeof(UDEV_MAGIC)) != 0 ) {
-		dbg("message magic '%s' doesn't match, ignore it", usend_msg.magic);
+		info("message magic '%s' doesn't match, ignore it", usend_msg.magic);
 		return NULL;
 	}
 
@@ -375,6 +501,9 @@ static struct hotplug_msg *get_udevsend_msg(void)
 
 		if (strncmp(key, "PHYSDEVPATH=", 12) == 0)
 			msg->physdevpath = &key[12];
+
+		if (strncmp(key, "TIMEOUT=", 8) == 0)
+			msg->timeout = strtoull(&key[8], NULL, 10);
 	}
 	msg->envp[i++] = "UDEVD_EVENT=1";
 	msg->envp[i] = NULL;
@@ -419,7 +548,7 @@ static void udev_done(int pid)
 	/* find msg associated with pid and delete it */
 	struct hotplug_msg *msg;
 
-	list_for_each_entry(msg, &running_list, list) {
+	list_for_each_entry(msg, &running_list, node) {
 		if (msg->pid == pid) {
 			dbg("<== exec seq %llu came back", msg->seqnum);
 			run_queue_delete(msg);
@@ -475,14 +604,14 @@ static int init_udevsend_socket(void)
 
 	udevsendsock = socket(AF_LOCAL, SOCK_DGRAM, 0);
 	if (udevsendsock == -1) {
-		dbg("error getting socket, %s", strerror(errno));
+		err("error getting socket, %s", strerror(errno));
 		return -1;
 	}
 
 	/* the bind takes care of ensuring only one copy running */
 	retval = bind(udevsendsock, (struct sockaddr *) &saddr, addrlen);
 	if (retval < 0) {
-		dbg("bind failed, %s", strerror(errno));
+		err("bind failed, %s", strerror(errno));
 		close(udevsendsock);
 		return -1;
 	}
@@ -504,10 +633,11 @@ int main(int argc, char *argv[], char *envp[])
 	const char *udevd_expected_seqnum;
 
 	logging_init("udevd");
+	udev_init_config();
 	dbg("version %s", UDEV_VERSION);
 
 	if (getuid() != 0) {
-		dbg("need to be root, exit");
+		err("need to be root, exit");
 		goto exit;
 	}
 
@@ -521,7 +651,7 @@ int main(int argc, char *argv[], char *envp[])
 			dbg("damonized fork running");
 			break;
 		case -1:
-			dbg("fork of daemon failed");
+			err("fork of daemon failed");
 			goto exit;
 		default:
 			logging_close();
@@ -529,10 +659,17 @@ int main(int argc, char *argv[], char *envp[])
 		}
 	}
 
+	/* become session leader */
+	sid = setsid();
+	dbg("our session is %d", sid);
+
 	/* make sure we don't lock any path */
 	chdir("/");
 	umask(umask(077) | 022);
 
+	/*set a reasonable scheduling priority for the daemon */
+	setpriority(PRIO_PROCESS, 0, UDEVD_PRIORITY);
+
 	/* Set fds to dev/null */
 	fd = open( "/dev/null", O_RDWR );
 	if (fd >= 0)  {
@@ -542,38 +679,36 @@ int main(int argc, char *argv[], char *envp[])
 		if (fd > 2)
 			close(fd);
 	} else
-		dbg("error opening /dev/null %s", strerror(errno));
-
-	/* become session leader */
-	setsid();
+		err("error opening /dev/null %s", strerror(errno));
 
 	/* setup signal handler pipe */
 	retval = pipe(pipefds);
 	if (retval < 0) {
-		dbg("error getting pipes: %s", strerror(errno));
+		err("error getting pipes: %s", strerror(errno));
 		goto exit;
 	}
 
 	retval = fcntl(pipefds[0], F_SETFL, O_NONBLOCK);
 	if (retval < 0) {
-		dbg("error fcntl on read pipe: %s", strerror(errno));
+		err("error fcntl on read pipe: %s", strerror(errno));
 		goto exit;
 	}
 	retval = fcntl(pipefds[0], F_SETFD, FD_CLOEXEC);
 	if (retval < 0)
-		dbg("error fcntl on read pipe: %s", strerror(errno));
+		err("error fcntl on read pipe: %s", strerror(errno));
 
 	retval = fcntl(pipefds[1], F_SETFL, O_NONBLOCK);
 	if (retval < 0) {
-		dbg("error fcntl on write pipe: %s", strerror(errno));
+		err("error fcntl on write pipe: %s", strerror(errno));
 		goto exit;
 	}
 	retval = fcntl(pipefds[1], F_SETFD, FD_CLOEXEC);
 	if (retval < 0)
-		dbg("error fcntl on write pipe: %s", strerror(errno));
+		err("error fcntl on write pipe: %s", strerror(errno));
 
 	/* set signal handlers */
-	act.sa_handler = (void (*) (int))sig_handler;
+	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);
@@ -593,18 +728,18 @@ int main(int argc, char *argv[], char *envp[])
 	/* possible override of udev binary, used for testing */
 	udev_bin = getenv("UDEV_BIN");
 	if (udev_bin != NULL)
-		dbg("udev binary is set to '%s'", udev_bin);
+		info("udev binary is set to '%s'", udev_bin);
 	else
 		udev_bin = UDEV_BIN;
 
-	/* possible set of expected_seqnum number */
+	/* possible init of expected_seqnum value */
 	udevd_expected_seqnum = getenv("UDEVD_EXPECTED_SEQNUM");
 	if (udevd_expected_seqnum != NULL) {
 		expected_seqnum = strtoull(udevd_expected_seqnum, NULL, 10);
-		dbg("initialize expected_seqnum to %llu", expected_seqnum);
+		info("initialize expected_seqnum to %llu", expected_seqnum);
 	}
 
-	/* get current time to provide shorter startup timeout */
+	/* get current time to provide shorter timeout on startup */
 	sysinfo(&info);
 	startup_time = info.uptime;