procd: skip respawn in case device disappeared

[project/procd.git] / watchdog.c

diff --git a/watchdog.c b/watchdog.c
index 592ae7e74f771472ef7a670f8badbac1084d4ed5..9d770b4470a946ec37cc65d5769445ecd544997b 100644 (file)
--- a/watchdog.c
+++ b/watchdog.c
@@ -30,13 +30,15 @@
 
 static struct uloop_timeout wdt_timeout;
 static int wdt_fd = -1;
+static int wdt_drv_timeout = 30;
 static int wdt_frequency = 5;
+static bool wdt_magicclose = false;
 
 void watchdog_ping(void)
 {
        DEBUG(4, "Ping\n");
        if (wdt_fd >= 0 && write(wdt_fd, "X", 1) < 0)
-               ERROR("WDT failed to write: %s\n", strerror(errno));
+               ERROR("WDT failed to write: %m\n");
 }
 
 static void watchdog_timeout_cb(struct uloop_timeout *t)
@@ -45,12 +47,75 @@ static void watchdog_timeout_cb(struct uloop_timeout *t)
        uloop_timeout_set(t, wdt_frequency * 1000);
 }
 
+static int watchdog_open(bool cloexec)
+{
+       char *env = getenv("WDTFD");
+
+       if (wdt_fd >= 0)
+               return wdt_fd;
+
+       if (env) {
+               DEBUG(2, "Watchdog handover: fd=%s\n", env);
+               wdt_fd = atoi(env);
+               unsetenv("WDTFD");
+       } else {
+               wdt_fd = open(WDT_PATH, O_WRONLY);
+       }
+
+       if (wdt_fd < 0)
+               return wdt_fd;
+
+       if (cloexec)
+               fcntl(wdt_fd, F_SETFD, fcntl(wdt_fd, F_GETFD) | FD_CLOEXEC);
+
+       return wdt_fd;
+}
+
+static void watchdog_close(void)
+{
+       if (wdt_fd < 0)
+               return;
+
+       if (write(wdt_fd, "V", 1) < 0)
+               ERROR("WDT failed to write release: %m\n");
+
+       if (close(wdt_fd) == -1)
+               ERROR("WDT failed to close watchdog: %m\n");
+
+       wdt_fd = -1;
+}
+
+static int watchdog_set_drv_timeout(void)
+{
+       if (wdt_fd < 0)
+               return -1;
+
+       return ioctl(wdt_fd, WDIOC_SETTIMEOUT, &wdt_drv_timeout);
+}
+
+void watchdog_set_magicclose(bool val)
+{
+       wdt_magicclose = val;
+}
+
+bool watchdog_get_magicclose(void)
+{
+       return wdt_magicclose;
+}
+
 void watchdog_set_stopped(bool val)
 {
-       if (val)
+       if (val) {
                uloop_timeout_cancel(&wdt_timeout);
-       else
+
+               if (wdt_magicclose)
+                       watchdog_close();
+       }
+       else {
+               watchdog_open(true);
+               watchdog_set_drv_timeout();
                watchdog_timeout_cb(&wdt_timeout);
+       }
 }
 
 bool watchdog_get_stopped(void)
@@ -60,23 +125,19 @@ bool watchdog_get_stopped(void)
 
 int watchdog_timeout(int timeout)
 {
-       if (wdt_fd < 0)
-               return 0;
-
        if (timeout) {
                DEBUG(4, "Set watchdog timeout: %ds\n", timeout);
-               ioctl(wdt_fd, WDIOC_SETTIMEOUT, &timeout);
+               wdt_drv_timeout = timeout;
+
+               if (wdt_fd >= 0)
+                       watchdog_set_drv_timeout();
        }
-       ioctl(wdt_fd, WDIOC_GETTIMEOUT, &timeout);
 
-       return timeout;
+       return wdt_drv_timeout;
 }
 
 int watchdog_frequency(int frequency)
 {
-       if (wdt_fd < 0)
-               return 0;
-
        if (frequency) {
                DEBUG(4, "Set watchdog frequency: %ds\n", frequency);
                wdt_frequency = frequency;
@@ -87,10 +148,11 @@ int watchdog_frequency(int frequency)
 
 char* watchdog_fd(void)
 {
-       static char fd_buf[3];
+       static char fd_buf[12];
 
        if (wdt_fd < 0)
                return NULL;
+
        snprintf(fd_buf, sizeof(fd_buf), "%d", wdt_fd);
 
        return fd_buf;
@@ -98,38 +160,28 @@ char* watchdog_fd(void)
 
 void watchdog_init(int preinit)
 {
-       char *env = getenv("WDTFD");
-
-       if (wdt_fd >= 0)
-               return;
-
        wdt_timeout.cb = watchdog_timeout_cb;
-       if (env) {
-               DEBUG(2, "Watchdog handover: fd=%s\n", env);
-               wdt_fd = atoi(env);
-               unsetenv("WDTFD");
-       } else {
-               wdt_fd = open("/dev/watchdog", O_WRONLY);
-       }
 
-       if (wdt_fd < 0)
+       if (watchdog_open(!preinit) < 0)
                return;
 
-       if (!preinit)
-               fcntl(wdt_fd, F_SETFD, fcntl(wdt_fd, F_GETFD) | FD_CLOEXEC);
-
        LOG("- watchdog -\n");
-       watchdog_timeout(30);
+       watchdog_set_drv_timeout();
        watchdog_timeout_cb(&wdt_timeout);
 
        DEBUG(4, "Opened watchdog with timeout %ds\n", watchdog_timeout(0));
 }
 
 
-void watchdog_no_cloexec(void)
+void watchdog_set_cloexec(bool val)
 {
        if (wdt_fd < 0)
                return;
 
-       fcntl(wdt_fd, F_SETFD, fcntl(wdt_fd, F_GETFD) & ~FD_CLOEXEC);
+       int flags = fcntl(wdt_fd, F_GETFD);
+       if (val)
+               flags |= FD_CLOEXEC;
+       else
+               flags &= ~FD_CLOEXEC;
+       fcntl(wdt_fd, F_SETFD,  flags);
 }