Hi,
I've hit a regression in the 5.13-rc4 kernel with loop mounting. When
running the stress-ng loop stress test with multiple CPUs (e.g. 8) with
multiple stressors I get softlock hangs with the following commit:
commit c76f48eb5c084b1e15c931ae8cc1826cd771d70d (refs/bisect/bad)
Author: Christoph Hellwig <hch@xxxxxx>
Date: Tue Apr 6 08:22:56 2021 +0200
block: take bd_mutex around delete_partitions in del_gendisk
How to reproduce (run on a multi-threaded machine):
git clone git://kernel.ubuntu.com/cking/stress-ng
cd stress-ng
make clean
make
sudo ./stress-ng --loop 8 -t 60 -v
Without the commit the stress test will complete. With the commit the
stressors will softlock up after a couple of minutes or so.
The stress-ng stressor does force some races as it does rapid loopback
exercising.
Colin
