On Tue, 18 Jul 2023 at 03:04, Theodore Ts'o tytso@mit.edu wrote:
On Mon, Jul 17, 2023 at 08:04:54PM +0530, Ritesh Harjani wrote:
These can basically trigger in extremely low memory space and only when such ranges exist in the PA rbtree. Hence, I guess it is a little hard to tigger race.
Ritesh, thanks for looking into this!
Naresh, how easy is it for you to trigger the BUG when using LTP? I did two xfstests runs using "gce-xfstests -c ext2/default -g auto", one on the ext4 dev branch, and one on linux-next 20230717, and I wasn't able to trigger the BUG.
If you can trivially trigger it using LTP (perhaps with a low memory configuration in your test setup?), that would be useful to know.
In our setup it is not easy to reproduce with the same device and same build on x86_4 and arm64 juno-r2 connected with SSD drive and running LTP fs testing.
LTP fs_fill is triggering several ENOSPC before getting this reported kernel BUG at fs/ext4/mballoc.c:4369!
The reported issues are not noticed on latest Linux next tags.
- Naresh
Cheers,
- Ted