Re: hba load error and silent mode - Mailing list pgsql-hackers

Magnus Hagander <magnus@hagander.net> writes:
> On Mon, Aug 24, 2009 at 20:51, Andrew Dunstan<andrew@dunslane.net> wrote:
>> We didn't check HBA validity at startup time before, did we? I would not be
>> surprised to get more complaints now.

Good point.

> We checked some of it, but we check it a whole lot more now.
> +1 for backpatching at least the move of the load_hba call.

OK, in that case I think it's reasonable to backpatch into 8.4.
Attached is my work-in-progress changes to pmdaemonize --- I think
the code is good now, but I need to go say something in the docs.
I haven't moved the load_hba call yet.

            regards, tom lane

Index: postmaster.c
===================================================================
RCS file: /cvsroot/pgsql/src/backend/postmaster/postmaster.c,v
retrieving revision 1.589
diff -c -r1.589 postmaster.c
*** postmaster.c    24 Aug 2009 18:09:37 -0000    1.589
--- postmaster.c    24 Aug 2009 19:22:28 -0000
***************
*** 191,197 ****

  /* still more option variables */
  bool        EnableSSL = false;
! bool        SilentMode = false; /* silent mode (-S) */

  int            PreAuthDelay = 0;
  int            AuthenticationTimeout = 60;
--- 191,197 ----

  /* still more option variables */
  bool        EnableSSL = false;
! bool        SilentMode = false; /* silent_mode */

  int            PreAuthDelay = 0;
  int            AuthenticationTimeout = 60;
***************
*** 744,750 ****
      }

      /*
!      * Fork away from controlling terminal, if -S specified.
       *
       * Must do this before we grab any interlock files, else the interlocks
       * will show the wrong PID.
--- 744,750 ----
      }

      /*
!      * Fork away from controlling terminal, if silent_mode specified.
       *
       * Must do this before we grab any interlock files, else the interlocks
       * will show the wrong PID.
***************
*** 1204,1218 ****


  /*
!  * Fork away from the controlling terminal (-S option)
   */
  static void
  pmdaemonize(void)
  {
  #ifndef WIN32
!     int            i;
      pid_t        pid;

      pid = fork_process();
      if (pid == (pid_t) -1)
      {
--- 1204,1249 ----


  /*
!  * Fork away from the controlling terminal (silent_mode option)
!  *
!  * Since this requires disconnecting from stdin/stdout/stderr (in case they're
!  * linked to the terminal), we re-point stdin to /dev/null and stdout/stderr
!  * to "postmaster.log" in the data directory, where we're already chdir'd.
   */
  static void
  pmdaemonize(void)
  {
  #ifndef WIN32
!     const char *pmlogname = "postmaster.log";
!     int            dvnull;
!     int            pmlog;
      pid_t        pid;
+     int            res;

+     /*
+      * Make sure we can open the files we're going to redirect to.  If this
+      * fails, we want to complain before disconnecting.  Mention the full path
+      * of the logfile in the error message, even though we address it by
+      * relative path.
+      */
+     dvnull = open(DEVNULL, O_RDONLY, 0);
+     if (dvnull < 0)
+     {
+         write_stderr("%s: could not open file \"%s\": %s\n",
+                      progname, DEVNULL, strerror(errno));
+         ExitPostmaster(1);
+     }
+     pmlog = open(pmlogname, O_CREAT | O_WRONLY | O_APPEND, 0600);
+     if (pmlog < 0)
+     {
+         write_stderr("%s: could not open log file \"%s/%s\": %s\n",
+                      progname, DataDir, pmlogname, strerror(errno));
+         ExitPostmaster(1);
+     }
+
+     /*
+      * Okay to fork.
+      */
      pid = fork_process();
      if (pid == (pid_t) -1)
      {
***************
*** 1231,1238 ****
      MyStartTime = time(NULL);

      /*
!      * GH: If there's no setsid(), we hopefully don't need silent mode. Until
!      * there's a better solution.
       */
  #ifdef HAVE_SETSID
      if (setsid() < 0)
--- 1262,1269 ----
      MyStartTime = time(NULL);

      /*
!      * Some systems use setsid() to dissociate from the TTY's process group,
!      * while on others it depends on stdin/stdout/stderr.  Do both if possible.
       */
  #ifdef HAVE_SETSID
      if (setsid() < 0)
***************
*** 1242,1255 ****
          ExitPostmaster(1);
      }
  #endif
!     i = open(DEVNULL, O_RDWR, 0);
!     dup2(i, 0);
!     dup2(i, 1);
!     dup2(i, 2);
!     close(i);
  #else                            /* WIN32 */
      /* not supported */
!     elog(FATAL, "SilentMode not supported under WIN32");
  #endif   /* WIN32 */
  }

--- 1273,1298 ----
          ExitPostmaster(1);
      }
  #endif
!
!     /*
!      * Reassociate stdin/stdout/stderr.  fork_process() cleared any pending
!      * output, so this should be safe.  The only plausible error is EINTR,
!      * which just means we should retry.
!      */
!     do {
!         res = dup2(dvnull, 0);
!     } while (res < 0 && errno == EINTR);
!     close(dvnull);
!     do {
!         res = dup2(pmlog, 1);
!     } while (res < 0 && errno == EINTR);
!     do {
!         res = dup2(pmlog, 2);
!     } while (res < 0 && errno == EINTR);
!     close(pmlog);
  #else                            /* WIN32 */
      /* not supported */
!     elog(FATAL, "silent_mode is not supported under Windows");
  #endif   /* WIN32 */
  }