Brasero can't burn DVD because of permissions issue
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
brasero (Ubuntu) |
Invalid
|
Undecided
|
Unassigned |
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_
BraseroWodim stderr: wodim: Resource temporarily unavailable. Cannot get mmap for 16781312 Bytes on /dev/zero.
BraseroWodim called brasero_
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_
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
ProcVersionSign
Uname: Linux 4.15.0-15-generic x86_64
NonfreeKernelMo
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)
Changed in brasero (Ubuntu): | |
status: | New → Invalid |
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. /sources. debian. org/src/ cdrkit/ 9:1.1.11- 3/wodim/ fifo.c/ #L272)
(https:/
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 184467440736927 74399. 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