mythburn.py crash

[t.brackertz@…]

Burn a DVD using mytharchive:

In the very end of the process the script tries to eject the burned DVD. If this is impossible it crashes with the following backtrace:

Failed to eject the disc!
chmod: Beim Setzen der Zugriffsrechte für „/mythpuffer/mytharchive/“: Die Operation ist nicht erlaubt
chmod: Beim Setzen der Zugriffsrechte für „/mythpuffer/mytharchive/logs“: Die Operation ist nicht erlaubt
chmod: Beim Setzen der Zugriffsrechte für „/mythpuffer/mytharchive/logs/mythburn.log“: Die Operation ist nicht erlaubt
chmod: Beim Setzen der Zugriffsrechte für „/mythpuffer/mytharchive/config“: Die Operation ist nicht erlaubt
chmod: Beim Setzen der Zugriffsrechte für „/mythpuffer/mytharchive/config/mydata.xml“: Die Operation ist nicht erlaubt
chmod: Beim Setzen der Zugriffsrechte für „/mythpuffer/mytharchive/work“: Die Operation ist nicht erlaubt
------------------------------------------------------------
Traceback (most recent call last):
  File "/usr/share/mythtv/mytharchive/scripts/mythburn.py", line 5182, in main
    processJob(job)
  File "/usr/share/mythtv/mytharchive/scripts/mythburn.py", line 4980, in processJob
    BurnDVDISO(title)
  File "/usr/share/mythtv/mytharchive/scripts/mythburn.py", line 2335, in BurnDVDISO
    tray(CDROM.CDROMEJECT)
  File "/usr/share/mythtv/mytharchive/scripts/mythburn.py", line 2266, in tray
    os.close(f)
UnboundLocalError: local variable 'f' referenced before assignment
------------------------------------------------------------

The produced DVD is fine. But the script leaves back a .lock-file which prevents the user from burning another DVD.

Path attached.

[t.brackertz@…]

Path against current git (2012-4-1): mythtv/mythplugins/mytharchive/mythburn/scripts/mythburn.py

[business.weston@…]

I'm seeing this issue in .25.

[Mike Kutner <videoguy1080@…>]

I confirmed that the patch fixes the crash in 26.1. Thank you! On my system (Mythbuntu 12.04.1) there are two subsequent issues:

• the script calls 'pumount' which is not installed

​https://bugs.launchpad.net/mythbuntu/+bug/1069823

• in any case the disc does not eject - likely because the script should call 'eject'

I recommend incorporating this patch into mythtv.

[t.brackertz@…]

In earlyer versions of the script the programm eject was used. Now

            r = ioctl(f,action, 0)

should eject the drive. The aim to change this was to avoid an additional dependency, get a clearer code and better error handling. This doesn't always work but eject didn't always work, either. So it was no regression.

I think we have to figure out, if using the scsi-eject command or some unlock-command has to be tried in addition.

[Mike Kutner <videoguy1080@…>]

Ah - yes - you are absolutely correct. Your attached patch fixes the original issue and should be accepted.

I verified that my failure to eject is the same as http://code.mythtv.org/trac/ticket/4022. The root cause is that /lib/udev/rules.d/60-cdrom_id.rules locks the CD/DVD drive. I am not a python expert, but this change to mythburn.py fixes the failure to eject:

@@ -2254,6 +2254,8 @@ def BurnDVDISO(title):
         waitForDrive()
         res = False
         f = os.open(dvddrivepath, os.O_RDONLY | os.O_NONBLOCK)
+        if (action == CDROM.CDROMEJECT):
+            ioctl(f, CDROM.CDROM_LOCKDOOR, 0)
         try:
             ioctl(f,action, 0)
             res = True

I am not sure how this works for the case that the CD/DVD drive is not locked. Do you think that I should move this to a separate issue?

[t.brackertz@…]

improved path

[t.brackertz@…]

mythburn.py.patch_2​ doesn't only fix the crash issue but gives a more robust eject-mechanism in addition. "eject" is used as fallback if installed.

Fixes http://code.mythtv.org/trac/ticket/4022 too

[Mike Kutner <videoguy1080@…>]

I confirmed that mythburn.py.patch_2 fixes both the original issue and 4022 - thank you very much.