Hi,

the first message about lack of permissions is common and should be
harmless. The failure happens possibly with the attempt to get 16 MiB
of memory via call mmap(2). But it is not obvious why this only succeeds
if you are superuser.
So this might too be a red herring and the actual reason for wodim to
abort is something that is not reported.

The last messages about "HUP" probably say that wodim closed the pipes
by which it was connected to Brasero. Not necessarily the reason but
rather a consequence of the problem.

------------------------------------------------------------------------

The reason for the mmap error message is probably

  addr = mmap(0, mmap_sizeparm(size),
                        PROT_READ|PROT_WRITE, MAP_SHARED, f, 0);

where "f" points to /dev/zero.
(https://sources.debian.org/src/cdrkit/9:1.1.11-3/wodim/fifo.c/#L272)

The man page of mmap says about the error EAGAIN ("Resource temporarily
unavailable"):
  EAGAIN The  file  has  been  locked, or too much memory has been locked
         (see setrlimit(2)).

man 2 setrlimit points to prlimit(1). But running it shows no mmap specific
limiting parameter other than "MEMLOCK", which would only matter if flag
"MAP_LOCKED" was used with the mmap() call.

What do you get from this command:

  cat /proc/sys/kernel/shmmax

(Mine says 18446744073692774399. I.e. no real limit.)

What permission do you see with

  ls -ld /dev/shm

------------------------------------------------------------------------

As a workaround for non-superusers you could switch in Brasero from
the wodim plugin to the libburn plugin. It is supposed to use a slightly
different mmap() call when allocating its fifo buffer.


Have a nice day :)

Thomas

-- 
You received this bug notification because you are a member of Desktop
Packages, which is subscribed to brasero in Ubuntu.
https://bugs.launchpad.net/bugs/1764096

Title:
  Brasero can't burn DVD because of permissions issue

Status in brasero package in Ubuntu:
  New

Bug description:
  When trying to burn a data project with Brasero it exits with "unknown
  error". In the log file it says the following:

  BraseroWodim stderr: wodim: Operation not permitted. Warning: Cannot raise 
RLIMIT_MEMLOCK limits.
  BraseroWodim called brasero_job_get_flags
  BraseroWodim stderr: wodim: Resource temporarily unavailable. Cannot get mmap 
for 16781312 Bytes on /dev/zero.
  BraseroWodim called brasero_job_get_flags
  BraseroWodim stdout: TOC Type: 1 = CD-ROM
  BraseroWodim stderr: HUP
  BraseroWodim stdout: HUP
  BraseroWodim process finished with status 11
  BraseroWodim called brasero_job_error
  BraseroWodim finished with an error
  BraseroWodim asked to stop because of an error
        error           = 0
        message = "no message"
  BraseroWodim stopping
  Session error : unknown (brasero_burn_record brasero-burn.c:2859)

  Current user is a member of the cdrom group.

  As a workaround I set setuid bit on /usr/bin/wodim, after that Brasero
  was able to burn the DVD.

  sudo chmod +s $(which wodim)

  As far as I remember DVD burning used to work on Ubuntu 17.10.

  ProblemType: Bug
  DistroRelease: Ubuntu 18.04
  Package: brasero 3.12.1-4ubuntu2
  ProcVersionSignature: Ubuntu 4.15.0-15.16-generic 4.15.15
  Uname: Linux 4.15.0-15-generic x86_64
  NonfreeKernelModules: nvidia_modeset nvidia
  ApportVersion: 2.20.9-0ubuntu4
  Architecture: amd64
  CurrentDesktop: GNOME
  Date: Sun Apr 15 16:23:20 2018
  InstallationDate: Installed on 2018-03-17 (28 days ago)
  InstallationMedia: Ubuntu 18.04 LTS "Bionic Beaver" - Alpha amd64 (20180316)
  SourcePackage: brasero
  UpgradeStatus: No upgrade log present (probably fresh install)

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/brasero/+bug/1764096/+subscriptions

-- 
Mailing list: https://launchpad.net/~desktop-packages
Post to     : desktop-packages@lists.launchpad.net
Unsubscribe : https://launchpad.net/~desktop-packages
More help   : https://help.launchpad.net/ListHelp

Reply via email to