[Dovecot] Dovecot-2.1.14 - pop3 processes always hangs forever - another follow-up

[Timo Sirainen]

On Fri, 2013-02-15 at 17:32 +0100, Axel Luttgens wrote:

>  a pop connection hangs forever after the pass command
> 
> 	$ telnet 127.0.0.1 110
> 	Trying 127.0.0.1...
> 	Connected to localhost.
> 	Escape character is '^]'.
> 	+OK Dovecot ready.
> 	user user2
> 	+OK
> 	pass pass2
> 
> and the log shows (here, when the user connects for the first time)
> 
> 	dovecot[2997]: pop3-login: Login: user=<user2>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, mpid=3113, secured, session=<GTOlMjfV3gB/AAAB>
> 	dovecot[2997]: pop3(user2): Debug: Effective uid=100003, gid=100003, home=/_Data/Mailstores/100003
> 	dovecot[2997]: pop3(user2): Debug: Home dir not found: /_Data/Mailstores/100003
> 	dovecot[2997]: pop3(user2): Debug: fs: root=/_Data/Mailstores/100003/mboxes, index=, control=, inbox=/_Data/Mailstores/100003/mboxes/inbox, alt=
> 	dovecot[2997]: pop3(user2): Debug: Namespace : /_Data/Mailstores/100003/mboxes doesn't exist yet, using default permissions
> 	dovecot[2997]: pop3(user2): Debug: Namespace : Using permissions from /_Data/Mailstores/100003/mboxes: mode=0700 gid=-1
> 	dovecot[2997]: pop3(user2): Debug: Namespace : /_Data/Mailstores/100003/mboxes/inbox doesn't exist yet, using default permissions
> 	dovecot[2997]: pop3(user2): Debug: Namespace : Using permissions from /_Data/Mailstores/100003/mboxes: mode=0700 gid=-1
> 	dovecot[2997]: pop3(user2): Debug: Namespace : /_Data/Mailstores/100003/mboxes/inbox doesn't exist yet, using default permissions
> 	dovecot[2997]: pop3(user2): Debug: Namespace : Using permissions from /_Data/Mailstores/100003/mboxes: mode=0700 gid=-1
> 
> With exactly the same config, imap connections are fully functional.
> 
> Does someone have an explanation?

a) dtruss the pop3 process to see which syscall hangs. Maybe this works:

service pop3 {
  executable = /usr/bin/dtruss /usr/local/libexec/dovecot/pop3
}

It logs to Dovecot's error log.

b) get gdb backtrace:

gdb -p <pid of pop3 process>
bt full