PATCH: bogus Berkeley DB warnings (was: smtpd crashes)

[Wietse Venema]

Ralf Hildebrandt:
[ Charset UTF-8 unsupported, converting... ]
> * Wietse Venema <wie...@porcupine.org>:
> > >Jan  1 20:19:41 mail-ausfall postfix/verify[26329]: fatal: close database 
> > >/var/lib/postfix/verify.db: No such file or directory
> > 
> > Does not reproduce on Ubuntu 9.10-server with the default Berkeley DB 4.7.
> > 
> > Can you check if this warning (and the warning for postscreen) goes
> > away when automatic cache cleanup is turned off?
> > 
> > address_verify_cache_cleanup_interval = 0
> > postscreen_cache_cleanup_interval = 0
> 
> It never occured BEFORE the automatic cache cleanup was introduced.

New errors, bogus or not, happen after a program is changed so that
it executes code paths that it did not execute before.

I am going to take a very pragmatic decision. Having established
that this is a bogus error, I am going to log it as a non-error.

If someone can figure out how to reliably reproduce this, I am
mildly interested.

        Wietse

*** ./dict_db.c-        Thu Jan  4 09:06:07 2007
--- ./dict_db.c Sat Jan  2 16:28:08 2010
***************
*** 535,542 ****
  #endif
      if (DICT_DB_SYNC(dict_db->db, 0) < 0)
        msg_fatal("flush database %s: %m", dict_db->dict.name);
      if (DICT_DB_CLOSE(dict_db->db) < 0)
!       msg_fatal("close database %s: %m", dict_db->dict.name);
      if (dict_db->key_buf)
        vstring_free(dict_db->key_buf);
      if (dict_db->val_buf)
--- 535,553 ----
  #endif
      if (DICT_DB_SYNC(dict_db->db, 0) < 0)
        msg_fatal("flush database %s: %m", dict_db->dict.name);
+ 
+     /*
+      * With some Berkeley DB implementations, close fails with a bogus ENOENT
+      * error, while it reports no errors with put+sync, no errors with
+      * del+sync, and no errors with the sync operation just before this
+      * comment. This happens in programs that never fork and that never share
+      * the database with other processes. The bogus close error has been
+      * reported for programs that use the first/next iterator. Instead of
+      * making Postfix look bad because it reports errors that other programs
+      * ignore, I'm going to report the bogus error as a non-error.
+      */
      if (DICT_DB_CLOSE(dict_db->db) < 0)
!       msg_info("close database %s: %m", dict_db->dict.name);
      if (dict_db->key_buf)
        vstring_free(dict_db->key_buf);
      if (dict_db->val_buf)