Re: [BUG] btrfs potential failure on 32 core LTP test (fallocate05)

From: Josef Bacik
Date: Tue Jun 29 2021 - 13:20:49 EST


On 6/29/21 1:00 PM, Krzysztof Kozlowski wrote:
Dear BTRFS folks,

I am hitting a potential regression of btrfs, visible only with
fallocate05 test from LTP (Linux Test Project) only on 32+ core Azure
instances (x86_64).

Tested:
v5.8 (Ubuntu with our stable patches): PASS
v5.11 (Ubuntu with our stable patches): FAIL
v5.13 mainline: FAIL

PASS means test passes on all instances
FAIL means test passes on other instance types (e.g. 4 or 16 core) but
fails on 32 and 64 core instances (did not test higher),
e.g.: Standard_F32s_v2, Standard_F64s_v2, Standard_D32s_v3,
Standard_E32s_v3

Reproduction steps:
git clone https://github.com/linux-test-project/ltp.git
cd ltp
./build.sh && make install -j8
cd ../ltp-install
sudo ./runltp -f syscalls -s fallocate05


This thing keeps trying to test ext2, how do I make it only test btrfs? Thanks,

Josef