</varlistentry>
<varlistentry>
+ <term><option>--sync</option></term>
+
+ <listitem><para>Ask the journal daemon to write all yet
+ unwritten journal data to the backing file system and
+ synchronize all journals. This call does not return until the
+ operation is complete. This command guarantees that any log
+ messages written before its invocation are safely stored on
+ disk at the time it returns.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
<term><option>--flush</option></term>
<listitem><para>Asks the journal daemon to flush any log data
stored in <filename>/run/log/journal</filename> into
- <filename>/var/log/journal</filename>, if persistent storage is
- enabled. This call does not return until the operation is
- complete.</para></listitem>
+ <filename>/var/log/journal</filename>, if persistent storage
+ is enabled. This call does not return until the operation is
+ complete. Note that this call is idempotent: the data is only
+ flushed from <filename>/run/log/journal</filename> into
+ <filename>/var/log/journal</filename> once during system
+ runtime, and this command exits cleanly without executing any
+ operation if this has already has happened. This command
+ effectively guarantees that all data is flushed to
+ <filename>/var/log/journal</filename> at the time it
+ returns.</para></listitem>
</varlistentry>
<varlistentry>
this is enabled). This must be used after
<filename>/var/</filename> is mounted, as otherwise log data
from <filename>/run</filename> is never flushed to
- <filename>/var</filename> regardless of the
- configuration.</para></listitem>
+ <filename>/var</filename> regardless of the configuration. The
+ <command>journalctl --flush</command> command uses this signal
+ to request flushing of the journal files, and then waits for
+ the operation to complete. See
+ <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>
+ for details.</para></listitem>
</varlistentry>
<varlistentry>
<term>SIGUSR2</term>
<listitem><para>Request immediate rotation of the journal
- files.</para></listitem>
+ files. The <command>journalctl --rotate</command> command uses
+ this signal to request journal file
+ rotation.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term>SIGRTMIN+1</term>
+
+ <listitem><para>Request that all unwritten log data is written
+ to disk. The <command>journalctl --sync</command> command uses
+ this signal to trigger journal synchronization, and then waits
+ for the operation to complete.</para></listitem>
</varlistentry>
</variablelist>
</refsect1>
<citerefentry><refentrytitle>systemd-coredump</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
<citerefentry project='die-net'><refentrytitle>setfacl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
<citerefentry><refentrytitle>sd_journal_print</refentrytitle><manvolnum>4</manvolnum></citerefentry>,
- <command>pydoc systemd.journal</command>.
+ <command>pydoc systemd.journal</command>
</para>
</refsect1>
ACTION_FLUSH,
ACTION_ROTATE,
ACTION_VACUUM,
+ ACTION_SYNC,
} arg_action = ACTION_SHOW;
typedef struct BootId {
printf("%s [OPTIONS...] [MATCHES...]\n\n"
"Query the journal.\n\n"
- "Flags:\n"
+ "Options:\n"
" --system Show the system journal\n"
" --user Show the user journal for the current user\n"
" -M --machine=CONTAINER Operate on local container\n"
" -m --merge Show entries from all available journals\n"
" -D --directory=PATH Show journal files from directory\n"
" --file=PATH Show journal file\n"
- " --root=ROOT Operate on catalog files underneath the root ROOT\n"
+ " --root=ROOT Operate on catalog files below a root directory\n"
#ifdef HAVE_GCRYPT
" --interval=TIME Time interval for changing the FSS sealing key\n"
" --verify-key=KEY Specify FSS verification key\n"
" -h --help Show this help text\n"
" --version Show package version\n"
" -F --field=FIELD List all values that a specified field takes\n"
- " --new-id128 Generate a new 128-bit ID\n"
" --disk-usage Show total disk usage of all journal files\n"
" --vacuum-size=BYTES Reduce disk usage below specified size\n"
" --vacuum-files=INT Leave only the specified number of journal files\n"
" --vacuum-time=TIME Remove journal files older than specified time\n"
+ " --verify Verify journal file consistency\n"
+ " --sync Synchronize unwritten journal messages to disk\n"
" --flush Flush all journal data from /run into /var\n"
" --rotate Request immediate rotation of the journal files\n"
" --header Show journal header information\n"
" --list-catalog Show all message IDs in the catalog\n"
" --dump-catalog Show entries in the message catalog\n"
" --update-catalog Update the message catalog database\n"
+ " --new-id128 Generate a new 128-bit ID\n"
#ifdef HAVE_GCRYPT
" --setup-keys Generate a new FSS key pair\n"
- " --verify Verify journal file consistency\n"
#endif
, program_invocation_short_name);
}
ARG_UPDATE_CATALOG,
ARG_FORCE,
ARG_UTC,
+ ARG_SYNC,
ARG_FLUSH,
ARG_ROTATE,
ARG_VACUUM_SIZE,
{ "machine", required_argument, NULL, 'M' },
{ "utc", no_argument, NULL, ARG_UTC },
{ "flush", no_argument, NULL, ARG_FLUSH },
+ { "sync", no_argument, NULL, ARG_SYNC },
{ "rotate", no_argument, NULL, ARG_ROTATE },
{ "vacuum-size", required_argument, NULL, ARG_VACUUM_SIZE },
{ "vacuum-files", required_argument, NULL, ARG_VACUUM_FILES },
arg_action = ACTION_ROTATE;
break;
+ case ARG_SYNC:
+ arg_action = ACTION_SYNC;
+ break;
+
case '?':
return -EINVAL;
&error,
NULL,
"ssi", "systemd-journald.service", "main", SIGUSR1);
- if (r < 0) {
- log_error("Failed to kill journal service: %s", bus_error_message(&error, r));
- return r;
- }
+ if (r < 0)
+ return log_error_errno(r, "Failed to kill journal service: %s", bus_error_message(&error, r));
mkdir_p("/run/systemd/journal", 0755);
return 0;
}
+static int sync_journal(void) {
+ _cleanup_bus_flush_close_unref_ sd_bus *bus = NULL;
+ _cleanup_close_ int watch_fd = -1;
+ usec_t start;
+ int r;
+
+ start = now(CLOCK_REALTIME);
+
+ /* Let's watch /run/systemd/sync until it's mtime is above
+ * the time we started the sync. Let's enqueue SIGRTMIN+1 to
+ * start the sync. */
+
+ for (;;) {
+ struct stat st;
+
+ /* See if a sync happened by now. */
+ if (stat("/run/systemd/journal/synced", &st) < 0) {
+ if (errno != ENOENT)
+ return log_error_errno(errno, "Failed to stat /run/systemd/journal/synced: %m");
+ } else {
+ if (timespec_load(&st.st_mtim) >= start)
+ return 0;
+ }
+
+ /* Let's ask for a sync, but only once. */
+ if (!bus) {
+ _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
+
+ r = bus_connect_system_systemd(&bus);
+ if (r < 0)
+ return log_error_errno(r, "Failed to get D-Bus connection: %m");
+
+ r = sd_bus_call_method(
+ bus,
+ "org.freedesktop.systemd1",
+ "/org/freedesktop/systemd1",
+ "org.freedesktop.systemd1.Manager",
+ "KillUnit",
+ &error,
+ NULL,
+ "ssi", "systemd-journald.service", "main", SIGRTMIN+1);
+ if (r < 0)
+ return log_error_errno(r, "Failed to kill journal service: %s", bus_error_message(&error, r));
+
+ continue;
+ }
+
+ /* Let's install the inotify watch, if we didn't do that yet. */
+ if (watch_fd < 0) {
+
+ mkdir_p("/run/systemd/journal", 0755);
+
+ watch_fd = inotify_init1(IN_NONBLOCK|IN_CLOEXEC);
+ if (watch_fd < 0)
+ return log_error_errno(errno, "Failed to create inotify watch: %m");
+
+ r = inotify_add_watch(watch_fd, "/run/systemd/journal", IN_CREATE|IN_ATTRIB|IN_DONT_FOLLOW|IN_ONLYDIR);
+ if (r < 0)
+ return log_error_errno(errno, "Failed to watch journal directory: %m");
+
+ /* Recheck the flag file immediately, so that we don't miss any event since the last check. */
+ continue;
+ }
+
+ /* OK, all preparatory steps done, let's wait until
+ * inotify reports an event. */
+
+ r = fd_wait_for_event(watch_fd, POLLIN, USEC_INFINITY);
+ if (r < 0)
+ return log_error_errno(r, "Failed to wait for event: %m");
+
+ r = flush_fd(watch_fd);
+ if (r < 0)
+ return log_error_errno(r, "Failed to flush inotify events: %m");
+ }
+
+ return 0;
+}
+
int main(int argc, char *argv[]) {
int r;
_cleanup_journal_close_ sd_journal *j = NULL;
goto finish;
}
+ if (arg_action == ACTION_SYNC) {
+ r = sync_journal();
+ goto finish;
+ }
+
if (arg_action == ACTION_ROTATE) {
r = rotate();
goto finish;
assert(s);
- log_info("Received request to flush runtime journal from PID %"PRIu32, si->ssi_pid);
+ log_info("Received request to flush runtime journal from PID " PID_FMT, si->ssi_pid);
server_flush_to_var(s);
server_sync(s);
assert(s);
- log_info("Received request to rotate journal from PID %"PRIu32, si->ssi_pid);
+ log_info("Received request to rotate journal from PID " PID_FMT, si->ssi_pid);
server_rotate(s);
server_vacuum(s, true, true);
return 0;
}
+static int dispatch_sigrtmin1(sd_event_source *es, const struct signalfd_siginfo *si, void *userdata) {
+ Server *s = userdata;
+
+ assert(s);
+
+ log_debug("Received request to sync from PID " PID_FMT, si->ssi_pid);
+
+ server_sync(s);
+
+ /* Let clients know when the most recent sync happened. */
+ (void) touch("/run/systemd/journal/synced");
+
+ return 0;
+}
+
static int setup_signals(Server *s) {
int r;
assert(s);
- assert(sigprocmask_many(SIG_SETMASK, NULL, SIGINT, SIGTERM, SIGUSR1, SIGUSR2, -1) >= 0);
+ assert(sigprocmask_many(SIG_SETMASK, NULL, SIGINT, SIGTERM, SIGUSR1, SIGUSR2, SIGRTMIN+1, -1) >= 0);
r = sd_event_add_signal(s->event, &s->sigusr1_event_source, SIGUSR1, dispatch_sigusr1, s);
if (r < 0)
if (r < 0)
return r;
+ /* SIGRTMIN+1 causes an immediate sync. We process this very
+ * late, so that everything else queued at this point is
+ * really written to disk. Clients can watch
+ * /run/systemd/journal/synced with inotify until its mtime
+ * changes to see when a sync happened. */
+ r = sd_event_add_signal(s->event, &s->sigrtmin1_event_source, SIGRTMIN+1, dispatch_sigrtmin1, s);
+ if (r < 0)
+ return r;
+
+ r = sd_event_source_set_priority(s->sigrtmin1_event_source, SD_EVENT_PRIORITY_NORMAL+15);
+ if (r < 0)
+ return r;
+
return 0;
}
sd_event_source_unref(s->sigusr2_event_source);
sd_event_source_unref(s->sigterm_event_source);
sd_event_source_unref(s->sigint_event_source);
+ sd_event_source_unref(s->sigrtmin1_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);
projects / platform / upstream / systemd.git / commitdiff