[PATCH] udevd - cleanup and better timeout handling
Here is the next revision for udevd:
o Small cleanups all over the place.
o Swich to the usual linked list format "list.h".
o Better timeout handling.
We store a timestamp in in every queued event, so we don't wait longer
than the timeout specified, if the hole in the list is not shrinking.
o ignore udevd target if klibc is used
This commit is contained in:
kay.sievers@vrfy.org
Greg KH
parent
eea34a0e99
commit
a695feaeff
8
Makefile
8
Makefile
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@ -151,6 +151,7 @@ ifeq ($(strip $(USE_KLIBC)),true)
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-I$(LINUX_INCLUDE_DIR)
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LIB_OBJS =
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LDFLAGS = --static --nostdlib -nostartfiles -nodefaultlibs
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UDEVD =
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else
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WARNINGS += -Wshadow -Wstrict-prototypes -Wmissing-prototypes -Wmissing-declarations
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CRT0 =
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@ -158,11 +159,12 @@ else
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CFLAGS += $(WARNINGS) -I$(GCCINCDIR)
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LIB_OBJS = -lc
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LDFLAGS =
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UDEVD = $(DAEMON) $(SENDER)
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endif
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CFLAGS += -I$(PWD)/libsysfs
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all: $(ROOT) $(DAEMON) $(SENDER)
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all: $(ROOT) $(UDEVD)
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@extras="$(EXTRAS)" ; for target in $$extras ; do \
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echo $$target ; \
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$(MAKE) prefix=$(prefix) LD="$(LD)" SYSFS="$(SYSFS)" \
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@ -236,11 +238,11 @@ $(ROOT): $(OBJS) udev.h namedev.h udev_version.h udev_dbus.h udevdb.h klibc_fixu
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$(LD) $(LDFLAGS) -o $(ROOT) $(CRT0) $(OBJS) $(LIB_OBJS) $(ARCH_LIB_OBJS)
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$(STRIPCMD) $(ROOT)
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$(DAEMON): $(ROOT) udevd.h udevd.o
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$(DAEMON): udevd.h udevd.o udevd.o logging.o
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$(LD) $(LDFLAGS) -o $(DAEMON) $(CRT0) udevd.o logging.o $(LIB_OBJS) $(ARCH_LIB_OBJS)
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$(STRIPCMD) $(ROOT)
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$(SENDER): $(ROOT) udevd.h udevsend.o
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$(SENDER): udevd.h udevsend.o udevd.o logging.o
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$(LD) $(LDFLAGS) -o $(SENDER) $(CRT0) udevsend.o logging.o $(LIB_OBJS) $(ARCH_LIB_OBJS)
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$(STRIPCMD) $(ROOT)
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227
udevd.c
227
udevd.c
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@ -22,6 +22,7 @@
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*
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*/
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#include <stddef.h>
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#include <sys/types.h>
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#include <sys/ipc.h>
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#include <sys/wait.h>
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@ -32,29 +33,38 @@
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <time.h>
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#include <fcntl.h>
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#include "list.h"
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#include "udev.h"
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#include "udevd.h"
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#include "logging.h"
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#define BUFFER_SIZE 1024
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#define EVENT_TIMEOUT_SECONDS 10
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#define DAEMON_TIMEOUT_SECONDS 30
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static int expect_seqnum = 0;
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static struct hotplug_msg *head = NULL;
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static int lock_file = -1;
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static char *lock_filename = ".udevd_lock";
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LIST_HEAD(msg_list);
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static void sig_alarmhandler(int signum)
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static void sig_handler(int signum)
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{
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dbg("caught signal %d", signum);
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switch (signum) {
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case SIGALRM:
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dbg("event timeout reached");
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break;
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case SIGINT:
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case SIGTERM:
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case SIGKILL:
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if (lock_file >= 0) {
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close(lock_file);
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unlink(lock_filename);
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}
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exit(20 + signum);
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break;
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default:
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dbg("unhandled signal");
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}
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@ -62,41 +72,32 @@ static void sig_alarmhandler(int signum)
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static void dump_queue(void)
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{
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struct hotplug_msg *p;
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p = head;
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struct hotplug_msg *msg;
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dbg("next expected sequence is %d", expect_seqnum);
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while(p != NULL) {
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dbg("sequence %d in queue", p->seqnum);
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p = p->next;
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}
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list_for_each_entry(msg, &msg_list, list)
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dbg("sequence %d in queue", msg->seqnum);
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}
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static void dump_msg(struct hotplug_msg *pmsg)
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static void dump_msg(struct hotplug_msg *msg)
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{
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dbg("sequence %d, '%s', '%s', '%s'",
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pmsg->seqnum, pmsg->action, pmsg->devpath, pmsg->subsystem);
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msg->seqnum, msg->action, msg->devpath, msg->subsystem);
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}
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static int dispatch_msg(struct hotplug_msg *pmsg)
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static int dispatch_msg(struct hotplug_msg *msg)
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{
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pid_t pid;
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char *argv[3];
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extern char **environ;
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dump_msg(pmsg);
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dump_msg(msg);
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setenv("ACTION", pmsg->action, 1);
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setenv("DEVPATH", pmsg->devpath, 1);
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argv[0] = DEFAULT_UDEV_EXEC;
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argv[1] = pmsg->subsystem;
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argv[2] = NULL;
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setenv("ACTION", msg->action, 1);
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setenv("DEVPATH", msg->devpath, 1);
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pid = fork();
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switch (pid) {
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case 0:
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/* child */
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execve(argv[0], argv, environ);
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execl(UDEV_EXEC, "udev", msg->subsystem, NULL);
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dbg("exec of child failed");
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exit(1);
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break;
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@ -104,108 +105,119 @@ static int dispatch_msg(struct hotplug_msg *pmsg)
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dbg("fork of child failed");
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return -1;
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default:
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wait(0);
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wait(NULL);
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}
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return 0;
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}
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static void set_timer(int seconds)
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static void set_timeout(int seconds)
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{
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signal(SIGALRM, sig_alarmhandler);
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alarm(seconds);
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dbg("set timeout in %d seconds", seconds);
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}
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static void check_queue(void)
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{
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struct hotplug_msg *p;
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p = head;
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struct hotplug_msg *msg;
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struct hotplug_msg *tmp_msg;
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time_t msg_age;
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dump_queue();
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while(head != NULL && head->seqnum == expect_seqnum) {
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dispatch_msg(head);
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recheck:
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/* dispatch events until one is missing */
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list_for_each_entry_safe(msg, tmp_msg, &msg_list, list) {
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if (msg->seqnum != expect_seqnum)
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break;
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dispatch_msg(msg);
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expect_seqnum++;
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p = head;
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head = head->next;
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free(p);
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list_del_init(&msg->list);
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free(msg);
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}
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if (head != NULL)
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set_timer(EVENT_TIMEOUT_SECONDS);
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else
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set_timer(DAEMON_TIMEOUT_SECONDS);
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/* recalculate timeout */
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if (list_empty(&msg_list) == 0) {
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msg_age = time(NULL) - msg->queue_time;
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if (msg_age > EVENT_TIMEOUT_SECONDS-1) {
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info("event %d, age %li seconds, skip event %d-%d",
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msg->seqnum, msg_age, expect_seqnum, msg->seqnum-1);
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expect_seqnum = msg->seqnum;
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goto recheck;
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}
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set_timeout(EVENT_TIMEOUT_SECONDS - msg_age);
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return;
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}
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/* queue is empty */
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set_timeout(UDEVD_TIMEOUT_SECONDS);
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}
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static void add_queue(struct hotplug_msg *pmsg)
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static int queue_msg(struct hotplug_msg *msg)
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{
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struct hotplug_msg *pnewmsg;
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struct hotplug_msg *p;
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struct hotplug_msg *p1;
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struct hotplug_msg *new_msg;
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struct hotplug_msg *tmp_msg;
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p = head;
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p1 = NULL;
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pnewmsg = malloc(sizeof(struct hotplug_msg));
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*pnewmsg = *pmsg;
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pnewmsg->next = NULL;
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while(p != NULL && pmsg->seqnum > p->seqnum) {
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p1 = p;
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p = p->next;
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new_msg = malloc(sizeof(*new_msg));
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if (new_msg == NULL) {
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dbg("error malloc");
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return -ENOMEM;
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}
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pnewmsg->next = p;
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if (p1 == NULL) {
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head = pnewmsg;
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} else {
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p1->next = pnewmsg;
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}
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dump_queue();
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memcpy(new_msg, msg, sizeof(*new_msg));
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/* store timestamp of queuing */
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new_msg->queue_time = time(NULL);
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/* sort message by sequence number into list*/
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list_for_each_entry(tmp_msg, &msg_list, list)
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if (tmp_msg->seqnum > new_msg->seqnum)
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break;
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list_add_tail(&new_msg->list, &tmp_msg->list);
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return 0;
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}
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static int lock_file = -1;
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static char *lock_filename = ".udevd_lock";
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static int process_queue(void)
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static void work(void)
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{
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struct hotplug_msg *msg;
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int msgid;
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key_t key;
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struct hotplug_msg *pmsg;
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char buf[BUFFER_SIZE];
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int ret;
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key = ftok(DEFAULT_UDEVD_EXEC, IPC_KEY_ID);
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pmsg = (struct hotplug_msg *) buf;
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key = ftok(UDEVD_EXEC, IPC_KEY_ID);
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msg = (struct hotplug_msg *) buf;
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msgid = msgget(key, IPC_CREAT);
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if (msgid == -1) {
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dbg("open message queue error");
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return -1;
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exit(1);
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}
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while (1) {
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ret = msgrcv(msgid, (struct msgbuf *) buf, BUFFER_SIZE-4, HOTPLUGMSGTYPE, 0);
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if (ret != -1) {
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dbg("current sequence %d, expected sequence %d", pmsg->seqnum, expect_seqnum);
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/* init expected sequence with value from first call */
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/* init the expected sequence with value from first call */
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if (expect_seqnum == 0) {
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expect_seqnum = pmsg->seqnum;
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expect_seqnum = msg->seqnum;
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dbg("init next expected sequence number to %d", expect_seqnum);
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}
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if (pmsg->seqnum > expect_seqnum) {
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add_queue(pmsg);
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set_timer(EVENT_TIMEOUT_SECONDS);
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} else {
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if (pmsg->seqnum == expect_seqnum) {
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dispatch_msg(pmsg);
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expect_seqnum++;
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check_queue();
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} else {
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dbg("timeout event for unexpected sequence number %d", pmsg->seqnum);
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}
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dbg("current sequence %d, expected sequence %d", msg->seqnum, expect_seqnum);
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if (msg->seqnum == expect_seqnum) {
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/* execute expected event */
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dispatch_msg(msg);
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expect_seqnum++;
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check_queue();
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dump_queue();
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continue;
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}
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if (msg->seqnum > expect_seqnum) {
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/* something missing, queue event*/
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queue_msg(msg);
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check_queue();
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dump_queue();
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continue;
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}
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dbg("too late for event with sequence %d, even skipped ", msg->seqnum);
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} else {
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if (errno == EINTR) {
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if (head != NULL) {
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/* event timeout, skip all missing, proceed with next queued event */
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info("timeout reached, skip events %d - %d", expect_seqnum, head->seqnum-1);
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expect_seqnum = head->seqnum;
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} else {
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/* timeout */
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if (list_empty(&msg_list)) {
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info("we have nothing to do, so daemon exits...");
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if (lock_file >= 0) {
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close(lock_file);
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@ -214,31 +226,12 @@ static int process_queue(void)
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exit(0);
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}
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check_queue();
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} else {
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dbg("ipc message receive error '%s'", strerror(errno));
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dump_queue();
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continue;
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}
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dbg("ipc message receive error '%s'", strerror(errno));
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}
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}
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return 0;
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}
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static void sig_handler(int signum)
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{
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dbg("caught signal %d", signum);
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switch (signum) {
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case SIGINT:
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case SIGTERM:
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case SIGKILL:
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if (lock_file >= 0) {
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close(lock_file);
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unlink(lock_filename);
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}
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exit(20 + signum);
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break;
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default:
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dbg("unhandled signal");
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}
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}
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static int one_and_only(void)
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@ -249,18 +242,18 @@ static int one_and_only(void)
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/* see if we can open */
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if (lock_file < 0)
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return -EINVAL;
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return -1;
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/* see if we can lock */
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if (lockf(lock_file, F_TLOCK, 0) < 0) {
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close(lock_file);
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unlink(lock_filename);
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return -EINVAL;
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return -1;
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}
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snprintf(string, sizeof(string), "%d\n", getpid());
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write(lock_file, string, strlen(string));
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return 0;
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}
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@ -274,11 +267,11 @@ int main(int argc, char *argv[])
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signal(SIGINT, sig_handler);
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signal(SIGTERM, sig_handler);
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signal(SIGKILL, sig_handler);
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signal(SIGALRM, sig_handler);
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/* we exit if we have nothing to do, next event will start us again */
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set_timer(DAEMON_TIMEOUT_SECONDS);
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set_timeout(UDEVD_TIMEOUT_SECONDS);
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/* main loop */
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process_queue();
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return 0;
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work();
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exit(0);
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}
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15
udevd.h
15
udevd.h
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@ -21,17 +21,22 @@
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*
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*/
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#define DEFAULT_UDEV_EXEC "./udev"
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#define DEFAULT_UDEVD_EXEC "./udevd"
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#include "list.h"
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#define IPC_KEY_ID 0
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#define HOTPLUGMSGTYPE 44
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#define UDEV_EXEC "./udev"
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#define UDEVD_EXEC "./udevd"
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#define UDEVD_TIMEOUT_SECONDS 60
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#define EVENT_TIMEOUT_SECONDS 5
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#define IPC_KEY_ID 0
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#define HOTPLUGMSGTYPE 44
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struct hotplug_msg {
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long mtype;
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struct hotplug_msg *next;
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struct list_head list;
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int seqnum;
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time_t queue_time;
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char action[8];
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char devpath[128];
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char subsystem[16];
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10
udevsend.c
10
udevsend.c
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@ -64,6 +64,7 @@ static inline char *get_seqnum(void)
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static int build_hotplugmsg(struct hotplug_msg *msg, char *action,
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char *devpath, char *subsystem, int seqnum)
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{
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memset(msg, 0x00, sizeof(msg));
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msg->mtype = HOTPLUGMSGTYPE;
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msg->seqnum = seqnum;
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strncpy(msg->action, action, 8);
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@ -85,7 +86,8 @@ static int start_daemon(void)
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switch (child_pid) {
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case 0:
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/* daemon */
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execl(DEFAULT_UDEVD_EXEC, NULL);
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setsid();
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execl(UDEVD_EXEC, "udevd", NULL);
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dbg("exec of daemon failed");
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exit(1);
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case -1:
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@ -99,7 +101,7 @@ static int start_daemon(void)
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dbg("fork of helper failed");
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return -1;
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default:
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wait(0);
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wait(NULL);
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}
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return 0;
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}
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@ -147,7 +149,7 @@ int main(int argc, char* argv[])
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seq = atoi(seqnum);
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/* create ipc message queue or get id of our existing one */
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key = ftok(DEFAULT_UDEVD_EXEC, IPC_KEY_ID);
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key = ftok(UDEVD_EXEC, IPC_KEY_ID);
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size = build_hotplugmsg(&message, action, devpath, subsystem, seq);
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msgid = msgget(key, IPC_CREAT);
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if (msgid == -1) {
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@ -165,7 +167,7 @@ int main(int argc, char* argv[])
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/* get state of ipc queue */
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tspec.tv_sec = 0;
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tspec.tv_nsec = 10000000; /* 10 millisec */
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loop = 20;
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loop = 30;
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while (loop--) {
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retval = msgctl(msgid, IPC_STAT, &msg_queue);
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if (retval == -1) {
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