From 652a44f9a9948a023fd7b26f72044fea0b13c25d Mon Sep 17 00:00:00 2001

From: Lennart Poettering <lennart@poettering.net>

Date: Tue, 3 Nov 2015 12:28:19 +0100

Subject: [PATCH] journal: restore watchdog support

(cherry picked from commit 119e9655dc36f18ed74f9a256d5c693b5aeb43ab)

Conflicts:

	src/journal/journald-server.h

	units/systemd-journald.service.in

Related: #1511565

---

 src/journal/journald-server.c     | 62 ++++++++++++++++++++++++++++---

 src/journal/journald-server.h     | 13 ++++---

 units/systemd-journald.service.in |  1 +

 3 files changed, 66 insertions(+), 10 deletions(-)

diff --git a/src/journal/journald-server.c b/src/journal/journald-server.c

index a810829b24..6e7568b60b 100644

--- a/src/journal/journald-server.c

+++ b/src/journal/journald-server.c

@@ -1572,10 +1572,10 @@ static int dispatch_notify_event(sd_event_source *es, int fd, uint32_t revents,

         }

         /* The $NOTIFY_SOCKET is writable again, now send exactly one

-         * message on it. Either it's the initial READY=1 event or an

-         * stdout stream event. If there's nothing to write anymore,

-         * turn our event source off. The next time there's something

-         * to send it will be turned on again. */

+         * message on it. Either it's the wtachdog event, the initial

+         * READY=1 event or an stdout stream event. If there's nothing

+         * to write anymore, turn our event source off. The next time

+         * there's something to send it will be turned on again. */

         if (!s->sent_notify_ready) {

                 static const char p[] =

@@ -1594,12 +1594,30 @@ static int dispatch_notify_event(sd_event_source *es, int fd, uint32_t revents,

                 s->sent_notify_ready = true;

                 log_debug("Sent READY=1 notification.");

+        } else if (s->send_watchdog) {

+

+                static const char p[] =

+                        "WATCHDOG=1";

+

+                ssize_t l;

+

+                l = send(s->notify_fd, p, strlen(p), MSG_DONTWAIT);

+                if (l < 0) {

+                        if (errno == EAGAIN)

+                                return 0;

+

+                        return log_error_errno(errno, "Failed to send WATCHDOG=1 notification message: %m");

+                }

+

+                s->send_watchdog = false;

+                log_debug("Sent WATCHDOG=1 notification.");

+

         } else if (s->stdout_streams_notify_queue)

                 /* Dispatch one stream notification event */

                 stdout_stream_send_notify(s->stdout_streams_notify_queue);

         /* Leave us enabled if there's still more to to do. */

-        if (s->stdout_streams_notify_queue)

+        if (s->send_watchdog || s->stdout_streams_notify_queue)

                 return 0;

         /* There was nothing to do anymore, let's turn ourselves off. */

@@ -1610,6 +1628,29 @@ static int dispatch_notify_event(sd_event_source *es, int fd, uint32_t revents,

         return 0;

 }

+static int dispatch_watchdog(sd_event_source *es, uint64_t usec, void *userdata) {

+        Server *s = userdata;

+        int r;

+

+        assert(s);

+

+        s->send_watchdog = true;

+

+        r = sd_event_source_set_enabled(s->notify_event_source, SD_EVENT_ON);

+        if (r < 0)

+                log_warning_errno(r, "Failed to turn on notify event source: %m");

+

+        r = sd_event_source_set_time(s->watchdog_event_source, usec + s->watchdog_usec / 2);

+        if (r < 0)

+                return log_error_errno(r, "Failed to restart watchdog event source: %m");

+

+        r = sd_event_source_set_enabled(s->watchdog_event_source, SD_EVENT_ON);

+        if (r < 0)

+                return log_error_errno(r, "Failed to enable watchdog event source: %m");

+

+        return 0;

+}

+

 static int server_connect_notify(Server *s) {

         union sockaddr_union sa = {

                 .un.sun_family = AF_UNIX,

@@ -1672,6 +1713,14 @@ static int server_connect_notify(Server *s) {

         if (r < 0)

                 return log_error_errno(r, "Failed to watch notification socket: %m");

+        if (sd_watchdog_enabled(false, &s->watchdog_usec) > 0) {

+                s->send_watchdog = true;

+

+                r = sd_event_add_time(s->event, &s->watchdog_event_source, CLOCK_MONOTONIC, now(CLOCK_MONOTONIC) + s->watchdog_usec/2, s->watchdog_usec*3/4, dispatch_watchdog, s);

+                if (r < 0)

+                        return log_error_errno(r, "Failed to add watchdog time event: %m");

+        }

+

         /* This should fire pretty soon, which we'll use to send the

          * READY=1 event. */

@@ -1689,6 +1738,8 @@ int server_init(Server *s) {

         s->compress = true;

         s->seal = true;

+        s->watchdog_usec = USEC_INFINITY;

+

         s->sync_interval_usec = DEFAULT_SYNC_INTERVAL_USEC;

         s->sync_scheduled = false;

@@ -1893,6 +1944,7 @@ void server_done(Server *s) {

         sd_event_source_unref(s->sigint_event_source);

         sd_event_source_unref(s->hostname_event_source);

         sd_event_source_unref(s->notify_event_source);

+        sd_event_source_unref(s->watchdog_event_source);

         sd_event_unref(s->event);

         safe_close(s->syslog_fd);

diff --git a/src/journal/journald-server.h b/src/journal/journald-server.h

index e59ff35e22..f046fde834 100644

--- a/src/journal/journald-server.h

+++ b/src/journal/journald-server.h

@@ -78,6 +78,7 @@ struct Server {

         sd_event_source *sigint_event_source;

         sd_event_source *hostname_event_source;

         sd_event_source *notify_event_source;

+        sd_event_source *watchdog_event_source;

         JournalFile *runtime_journal;

         JournalFile *system_journal;

@@ -133,14 +134,14 @@ struct Server {

         MMapCache *mmap;

-        bool dev_kmsg_readable;

+        struct udev *udev;

         uint64_t *kernel_seqnum;

+        bool dev_kmsg_readable:1;

-        struct udev *udev;

-

-        bool sent_notify_ready;

-        bool sync_scheduled;

+        bool send_watchdog:1;

+        bool sent_notify_ready:1;

+        bool sync_scheduled:1;

         char machine_id_field[sizeof("_MACHINE_ID=") + 32];

         char boot_id_field[sizeof("_BOOT_ID=") + 32];

@@ -149,6 +150,8 @@ struct Server {

         /* Cached cgroup root, so that we don't have to query that all the time */

         char *cgroup_root;

+        usec_t watchdog_usec;

+

         size_t line_max;

 };

diff --git a/units/systemd-journald.service.in b/units/systemd-journald.service.in

index c94c0bfba1..0d1ea61fe8 100644

--- a/units/systemd-journald.service.in

+++ b/units/systemd-journald.service.in

@@ -22,6 +22,7 @@ RestartSec=0

 StandardOutput=null

 FileDescriptorStoreMax=4224

 CapabilityBoundingSet=CAP_SYS_ADMIN CAP_DAC_OVERRIDE CAP_SYS_PTRACE CAP_SYSLOG CAP_AUDIT_CONTROL CAP_AUDIT_READ CAP_CHOWN CAP_DAC_READ_SEARCH CAP_FOWNER CAP_SETUID CAP_SETGID CAP_MAC_OVERRIDE

+WatchdogSec=3min

 # Increase the default a bit in order to allow many simultaneous

 # services being run since we keep one fd open per service. Also, when