This bug is missing log files that will aid in diagnosing the problem.
While running an Ubuntu kernel (not a mainline or third-party kernel)
please enter the following command in a terminal window:
apport-collect 1834693
and then change the status of the bug to 'Confirmed'.
If, due to the nature of the issue you have encountered, you are unable
to run this command, please add a comment stating that fact and change
the bug status to 'Confirmed'.
This change has been made by an automated script, maintained by the
Ubuntu Kernel Team.
** Changed in: linux (Ubuntu)
Status: New => Incomplete
--
You received this bug notification because you are a member of Kernel
Packages, which is subscribed to linux in Ubuntu.
https://bugs.launchpad.net/bugs/1834693
Title:
Simultaneous creation and teardown of separate loops causes udev
softlock
Status in linux package in Ubuntu:
Incomplete
Bug description:
What I expected to happen: Loops can be successfully created and removed from
multiple different threads without any adverse effects
What happened instead: Udev processes ended up in D state, which soft locked
the system (unable to reboot without resorting to "echo b >
/proc/sysrq-trigger", various other commands [losetup -a, mount -l] would hang)
The use case that this was originally reproduced on required frequent
setup and teardown of loops in order to persist and access various
snapshots of backup files. Through various methods of analysis, we
were able to create a script that recreates the bad behavior
relatively quickly (see attachment testudevLoopOnly.php).
We captured some stack traces from a locked up system, and found that
many of the calls were originating from loop.c. Investigating that
file (specifically lo_setup and lo_release functions) showed that the
4.4 usage of mutexes is different from earlier versions of the kernel
package (4.4.0.142.148), which doesn't exhibit this same behavior.
It's also different from the 4.15 version of the kernel package, which
also does not exhibit the same (incorrect) behavior.
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1834693/+subscriptions
--
Mailing list: https://launchpad.net/~kernel-packages
Post to : kernel-packages@lists.launchpad.net
Unsubscribe : https://launchpad.net/~kernel-packages
More help : https://help.launchpad.net/ListHelp
