Fix syslogger to not fail when log_rotation_age exceeds 2^31 milliseconds.

We need to avoid calling WaitLatch with timeouts exceeding INT_MAX.
Fortunately a simple clamp will do the trick, since no harm is done if
the wait times out before it's really time to rotate the log file.
Per bug #7670 (probably bug #7545 is the same thing, too).

In passing, fix bogus definition of log_rotation_age's maximum value in
guc.c --- it was numerically right, but only because MINS_PER_HOUR and
SECS_PER_MINUTE have the same value.

Back-patch to 9.2.  Before that, syslogger wasn't using WaitLatch.

diff --git a/src/backend/postmaster/syslogger.c b/src/backend/postmaster/syslogger.c
index cccec743b0d28922964acd5b597ed74548588856..bb36633ee52e645838353dc020c874881bec90eb 100644 (file)
--- a/src/backend/postmaster/syslogger.c
+++ b/src/backend/postmaster/syslogger.c
@@ -24,6 +24,7 @@
 #include "postgres.h"
 
 #include <fcntl.h>
+#include <limits.h>
 #include <signal.h>
 #include <time.h>
 #include <unistd.h>
@@ -416,11 +417,23 @@ SysLoggerMain(int argc, char *argv[])
         * above is still close enough.  Note we can't make this calculation
         * until after calling logfile_rotate(), since it will advance
         * next_rotation_time.
+        *
+        * Also note that we need to beware of overflow in calculation of the
+        * timeout: with large settings of Log_RotationAge, next_rotation_time
+        * could be more than INT_MAX msec in the future.  In that case we'll
+        * wait no more than INT_MAX msec, and try again.
         */
        if (Log_RotationAge > 0 && !rotation_disabled)
        {
-           if (now < next_rotation_time)
-               cur_timeout = (next_rotation_time - now) * 1000L;       /* msec */
+           pg_time_t   delay;
+
+           delay = next_rotation_time - now;
+           if (delay > 0)
+           {
+               if (delay > INT_MAX / 1000)
+                   delay = INT_MAX / 1000;
+               cur_timeout = delay * 1000L;    /* msec */
+           }
            else
                cur_timeout = 0;
            cur_flags = WL_TIMEOUT;

diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index 745e7be68e493b4a7ff623733e14ebfdfa6ce213..54461c830fe7306057e5fa8ecea88e1d4e53c901 100644 (file)
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -2147,7 +2147,7 @@ static struct config_int ConfigureNamesInt[] =
            GUC_UNIT_MIN
        },
        &Log_RotationAge,
-       HOURS_PER_DAY * MINS_PER_HOUR, 0, INT_MAX / MINS_PER_HOUR,
+       HOURS_PER_DAY * MINS_PER_HOUR, 0, INT_MAX / SECS_PER_MINUTE,
        NULL, NULL, NULL
    },