smbd as a daemon

[Alexander Bokovoy]

On Wed, Mar 26, 2014 at 2:03 PM, Alexander Bokovoy <ab at samba.org> wrote:
> On Wed, Mar 26, 2014 at 9:47 AM, Andreas Schneider <asn at samba.org> wrote:
>> On Tuesday 25 March 2014 21:52:34 Alexander Bokovoy wrote:
>>> On Tue, Mar 25, 2014 at 9:38 PM, Jeremy Allison <jra at samba.org> wrote:
>>> > On Tue, Mar 25, 2014 at 09:28:34PM +0200, Alexander Bokovoy wrote:
>>> >> > Ok, attached patch compiles for me and links libsystem-daemon
>>> >> > properly. I'm going to run some package tests tomorrow.
>>> >>
>>> >> Updated patch -- I forgot one define for non-systemd case and also
>>> >> added changes to systemd services.
>>> >
>>> > Few comments inline.
>>> >
>>> >>   Become a daemon, discarding the controlling terminal.
>>> >>
>>> >>  ************************************************************************
>>> >>  ****/>>
>>> >> -_PUBLIC_ void become_daemon(bool do_fork, bool no_process_group, bool
>>> >> log_stdout) +_PUBLIC_ void become_daemon(bool do_fork, bool
>>> >> no_process_group, bool log_stdout, bool wait_for_child_init)>
>>> > What is the extra parameter 'bool wait_for_child_init' for ?
>>> > In the calling code you're always passing it as 'true' so
>>> > what does it achieve ?
>>>
>>> I somehow thought I saw more become_daemon() uses. Looked again, I
>>> don't see any more.
>>> This should explain why I added it.
>>>
>>> >> -             become_daemon(Fork, no_process_group, log_stdout);
>>> >> +             become_daemon(Fork, no_process_group, log_stdout, True);
>>> >
>>> > Bah. We don't use 'True' anymore. If you do end up
>>> > keeping the parameter please use 'true/false' in all
>>> > new code.
>>>
>>> Yes, changed it several times and missed here.
>>>
>>> > Otherwise looks ok to me.
>>>
>>> Updated patch attached, removed changes to become_daemon() prototype.
>>
>> The manpage states:
>>
>> A daemon could send the following shortly before exiting, on failure
>>
>> sd_notifyf(0, "STATUS=Failed to start up: %s\n"
>>               "ERRNO=%i",
>>               strerror(errno),
>>               errno);
>>
>>
>> So I would like to see
>>
>> static void exit_smbd(const char *msg, int error)
>> {
>> #ifdef HAVE_SYSTEMD
>>         if (msg == NULL) {
>>                 msg = strerror(error);
>>         }
>>
>>         sd_notifyf(0, "STATUS=smbd failed to start: %s\n"
>>                       "ERRNO=%i",
>>                       msg,
>>                       errno);
>> #endif
>>         DEBUG(0, "STATUS=smbd failed to start: %s\n", msg);
>>         exit(1);
>> }
>>
>>
>> and then call this function if init fails in main().
>
> Ok, I've now have a version that works. The only issue I see is when
> systemd stops the service, it unconditionally removes pid file and
> then our pid removal code complaints that pid file is not there.
Addtionally, here is what happens on error. If I remove
/var/lib/samba, smbd startup fails due to missing secrets.tdb and we
see that in the status:
[root at masteripa lib]# mv samba samba.l
[root at masteripa lib]# systemctl start smb
Job for smb.service failed. See 'systemctl status smb.service' and
'journalctl -xn' for details.
[root at masteripa lib]# systemctl status smb
smb.service - Samba SMB Daemon
   Loaded: loaded (/usr/lib/systemd/system/smb.service; disabled)
   Active: failed (Result: exit-code) since Ср 2014-03-26 14:38:16 EET; 4s ago
  Process: 11723 ExecStart=/usr/sbin/smbd $SMBDOPTIONS (code=exited,
status=1/FAILURE)
 Main PID: 11723 (code=exited, status=1/FAILURE)
   Status: "daemon failed to start: smbd can not open secrets.tdb"

мар 26 14:38:16 masteripa.ipa.weald.vda.li smbd[11722]: [2014/03/26
14:38:16.676499,  0] ../source3/smbd/server.c:1278(main)
мар 26 14:38:16 masteripa.ipa.weald.vda.li smbd[11722]: standard input
is not a socket, assuming -D option
мар 26 14:38:16 masteripa.ipa.weald.vda.li systemd[1]: smb.service:
Supervising process 11723 which is not our child. We'll most likely
not notice when it exits.
мар 26 14:38:16 masteripa.ipa.weald.vda.li smbd[11723]: [2014/03/26
14:38:16.684517,  0] ../source3/passdb/secrets.c:85(secrets_init_path)
мар 26 14:38:16 masteripa.ipa.weald.vda.li smbd[11723]: Failed to open
/var/lib/samba/private/secrets.tdb
мар 26 14:38:16 masteripa.ipa.weald.vda.li smbd[11723]: [2014/03/26
14:38:16.685992,  0] ../lib/util/become_daemon.c:121(exit_daemon)
мар 26 14:38:16 masteripa.ipa.weald.vda.li smbd[11723]: STATUS=daemon
failed to start: smbd can not open secrets.tdb, error code 13
мар 26 14:38:16 masteripa.ipa.weald.vda.li systemd[1]: smb.service:
main process exited, code=exited, status=1/FAILURE
мар 26 14:38:16 masteripa.ipa.weald.vda.li systemd[1]: Failed to start
Samba SMB Daemon.
мар 26 14:38:16 masteripa.ipa.weald.vda.li systemd[1]: Unit
smb.service entered failed state.

-- 
/ Alexander Bokovoy