From 81e5007269cc33ff6acf27051b1f3b5b986f878a Mon Sep 17 00:00:00 2001

From: Lennart Poettering <lennart@poettering.net>

Date: Wed, 24 Jul 2013 08:08:57 +0200

Subject: [PATCH] journal: immediately sync to disk as soon as we receieve an

 EMERG/ALERT/CRIT message

---

 TODO                          |  2 --

 man/journald.conf.xml         | 14 +++++++++++---

 src/journal/journald-server.c | 26 ++++++++++++++++----------

 src/journal/journald-server.h |  2 +-

 4 files changed, 28 insertions(+), 16 deletions(-)

diff --git a/TODO b/TODO

index ba8bb8e..279ea60 100644

--- a/TODO

+++ b/TODO

@@ -74,8 +74,6 @@ Features:

 * journald: optionally, log debug messages to /run but everything else to /var

-* journald: optionally, when messages with a high log priority are logged, sync() immediately.

-

 * systemctl list-unit-files should list generated files (and probably with a new state "generated" for them, or so)

 * do we really need both hasprefix() and startswith()?

diff --git a/man/journald.conf.xml b/man/journald.conf.xml

index 487e8d6..9219b3d 100644

--- a/man/journald.conf.xml

+++ b/man/journald.conf.xml

@@ -348,9 +348,17 @@

                         <varlistentry>

                                 <term><varname>SyncIntervalSec=</varname></term>

-                                <listitem><para>The timeout before synchronizing journal

-                                data to disk. After syncing, journal files have

-                                the OFFLINE state. Default timeout is 5 minutes.

+                                <listitem><para>The timeout before

+                                synchronizing journal files to

+                                disk. After syncing, journal files are

+                                placed in the OFFLINE state. Note that

+                                syncing is unconditionally done

+                                immediately after a log message of

+                                priority CRIT, ALERT or EMERG has been

+                                logged, this setting hence applies

+                                only to messages of the levels ERR,

+                                WARNING, NOTICE, INFO, DEBUG. The

+                                default timeout is 5 minutes.

                                 </para></listitem>

                         </varlistentry>

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

index c5c195a..f417059 100644

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

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

@@ -352,13 +352,12 @@ void server_rotate(Server *s) {

 }

 void server_sync(Server *s) {

+        static const struct itimerspec sync_timer_disable = {};

         JournalFile *f;

         void *k;

         Iterator i;

         int r;

-        static const struct itimerspec sync_timer_disable = {};

-

         if (s->system_journal) {

                 r = journal_file_set_offline(s->system_journal);

                 if (r < 0)

@@ -443,7 +442,7 @@ bool shall_try_append_again(JournalFile *f, int r) {

         return true;

 }

-static void write_to_journal(Server *s, uid_t uid, struct iovec *iovec, unsigned n) {

+static void write_to_journal(Server *s, uid_t uid, struct iovec *iovec, unsigned n, int priority) {

         JournalFile *f;

         bool vacuumed = false;

         int r;

@@ -469,7 +468,7 @@ static void write_to_journal(Server *s, uid_t uid, struct iovec *iovec, unsigned

         r = journal_file_append_entry(f, NULL, iovec, n, &s->seqnum, NULL, NULL);

         if (r >= 0) {

-                server_schedule_sync(s);

+                server_schedule_sync(s, priority);

                 return;

         }

@@ -499,7 +498,8 @@ static void write_to_journal(Server *s, uid_t uid, struct iovec *iovec, unsigned

                         size += iovec[i].iov_len;

                 log_error("Failed to write entry (%d items, %zu bytes) despite vacuuming, ignoring: %s", n, size, strerror(-r));

-        }

+        } else

+                server_schedule_sync(s, priority);

 }

 static void dispatch_message_real(

@@ -509,6 +509,7 @@ static void dispatch_message_real(

                 struct timeval *tv,

                 const char *label, size_t label_len,

                 const char *unit_id,

+                int priority,

                 pid_t object_pid) {

         char    pid[sizeof("_PID=") + DECIMAL_STR_MAX(pid_t)],

@@ -523,7 +524,6 @@ static void dispatch_message_real(

                 o_owner_uid[sizeof("OBJECT_SYSTEMD_OWNER_UID=") + DECIMAL_STR_MAX(uid_t)];

         uid_t object_uid;

         gid_t object_gid;

-

         char *x;

         sd_id128_t id;

         int r;

@@ -786,7 +786,7 @@ static void dispatch_message_real(

         else

                 journal_uid = 0;

-        write_to_journal(s, journal_uid, iovec, n);

+        write_to_journal(s, journal_uid, iovec, n, priority);

 }

 void server_driver_message(Server *s, sd_id128_t message_id, const char *format, ...) {

@@ -820,7 +820,7 @@ void server_driver_message(Server *s, sd_id128_t message_id, const char *format,

         ucred.uid = getuid();

         ucred.gid = getgid();

-        dispatch_message_real(s, iovec, n, ELEMENTSOF(iovec), &ucred, NULL, NULL, 0, NULL, 0);

+        dispatch_message_real(s, iovec, n, ELEMENTSOF(iovec), &ucred, NULL, NULL, 0, NULL, LOG_INFO, 0);

 }

 void server_dispatch_message(

@@ -886,7 +886,7 @@ void server_dispatch_message(

                                       "Suppressed %u messages from %s", rl - 1, path);

 finish:

-        dispatch_message_real(s, iovec, n, m, ucred, tv, label, label_len, unit_id, object_pid);

+        dispatch_message_real(s, iovec, n, m, ucred, tv, label, label_len, unit_id, priority, object_pid);

 }

@@ -1418,11 +1418,17 @@ static int server_open_sync_timer(Server *s) {

         return 0;

 }

-int server_schedule_sync(Server *s) {

+int server_schedule_sync(Server *s, int priority) {

         int r;

         assert(s);

+        if (priority <= LOG_CRIT) {

+                /* Immediately sync to disk when this is of priority CRIT, ALERT, EMERG */

+                server_sync(s);

+                return 0;

+        }

+

         if (s->sync_scheduled)

                 return 0;

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

index 9ff3300..e856ef2 100644

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

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

@@ -153,7 +153,7 @@ void server_done(Server *s);

 void server_sync(Server *s);

 void server_vacuum(Server *s);

 void server_rotate(Server *s);

-int server_schedule_sync(Server *s);

+int server_schedule_sync(Server *s, int priority);

 int server_flush_to_var(Server *s);

 int process_event(Server *s, struct epoll_event *ev);

 void server_maybe_append_tags(Server *s);