[Dovecot] Problem in mbox-sync.c

[Hal Pomeranz]

We've just cut over to a new mail server running Dovecot 1.0.5.  
The underlying OS is RHEL 5.  User mailboxes are stored in Unix mbox
format on a local ext3 file system.  The MTA on the system is the
default RedHat version of Sendmail 8.13.8 with procmail for local
delivery.  We're using a combination of dotlock and fcntl style locking.
The output of "dovecot -n" for this system appears below my signature.

Periodically we see errors like the following in our logs:

Oct 21 19:36:01 postoffice1 dovecot: POP3(someuser): file mbox-sync.c: line 1433 (mbox_sync_handle_eof_updates): assertion failed: (file_size >= sync_ctx->expunged_space + trailer_size)
Oct 21 19:36:01 postoffice1 dovecot: POP3(someuser): Raw backtrace: pop3 [0x809eda1] -> pop3 [0x809ecbc] -> pop3(mbox_sync+0x1088) [0x806c4e8] -> pop3(mbox_storage_sync_init+0x3e) [0x806cb6e] -> pop3(client_create+0x1a4) [0x80552a4] -> pop3(main+0x556) [0x8057236] -> /lib/libc.so.6(__libc_start_main+0xdc) [0x304dec] -> pop3 [0x8054a11]
Oct 21 19:36:01 postoffice1 dovecot: child 24409 (pop3) killed with signal 6

Note that while the above log is for a POP3 user, we also see similar 
behavior when some users access mail folders via IMAP as well.

The real problem with this behavior is that sometimes, but not in all
cases, the process will leave behind a dotlock when it exits.  If the
abandoned dotlock is on the user's inbox, then procmail won't deliver
new mail to the user until the lock is cleared.  This is a big problem.

Anybody seen this behavior before and/or know what's causing it?  Can
anybody suggest ideas for further debugging this issue?  We'd appreciate
any help that you all can provide.  Thanks!

-- 
Hal Pomeranz, Founder/CEO      Deer Run Associates      hal at deer-run.com
    Network Connectivity and Security, Systems Management, Training
--

# /hpsw/mail/dovecot/sbin/dovecot -n
# 1.0.5: /hpsw/mail/dovecot/etc/dovecot.conf
syslog_facility: local3
protocols: imap imaps pop3 pop3s
ssl_cert_file: /hpsw/mail/configs/dovecot/pki/certs/dovecot.pem
ssl_key_file: /hpsw/mail/configs/dovecot/pki/private/dovecot.pem
disable_plaintext_auth: no
login_dir: /hpsw/mail/dovecot/var/run/dovecot/login
login_executable(default): /hpsw/mail/dovecot/libexec/dovecot/imap-login
login_executable(imap): /hpsw/mail/dovecot/libexec/dovecot/imap-login
login_executable(pop3): /hpsw/mail/dovecot/libexec/dovecot/pop3-login
mail_location: mbox:/hpsw/mail/users/%u/dovecot:INBOX=/hpsw/mail/users/%u/MBOX
mbox_read_locks: dotlock fcntl
mail_executable(default): /hpsw/mail/dovecot/libexec/dovecot/imap
mail_executable(imap): /hpsw/mail/dovecot/libexec/dovecot/imap
mail_executable(pop3): /hpsw/mail/dovecot/libexec/dovecot/pop3
mail_plugin_dir(default): /hpsw/mail/dovecot/lib/dovecot/imap
mail_plugin_dir(imap): /hpsw/mail/dovecot/lib/dovecot/imap
mail_plugin_dir(pop3): /hpsw/mail/dovecot/lib/dovecot/pop3
pop3_uidl_format(default):
pop3_uidl_format(imap):
pop3_uidl_format(pop3): %08Xu%08Xv
auth default:
  passdb:
    driver: pam
  userdb:
    driver: passwd