Comment 27 for bug 1907262

Hi Thimo,

I have been doing quite a bit of regression testing, and so far everything is
looking good. The performance of the block discard is there, and I haven't
come across any data corruption.

I have also spent some time running through the testcase you created for this
bug, and I have the results of those tests below.

For each of the 5.11, 5.8, 5.4 and 4.15 kernels, the problem does not reproduce,
as the values of /sys/block/md0/md/mismatch_cnt are always 0, and mounting each
disk in singular and performing a full deep fsck shows no data corruption.

Test results for each kernel are below:

5.11.0-16-generic #17+TEST1896578v20210503b1-Ubuntu
https://paste.ubuntu.com/p/Dp3sR9mNdY/

5.8.0-50-generic #56+TEST1896578v20210504b1-Ubuntu
https://paste.ubuntu.com/p/tXmtmd5Jys/

5.4.0-72-generic #80+TEST1896578v20210504b1-Ubuntu
https://paste.ubuntu.com/p/VzX2mXcKbF/

4.15.0-142-generic #146+TEST1896578v20210504b1-Ubuntu
https://paste.ubuntu.com/p/HpMcX3N9fD/

I'm going to look into some longer running test cases as well, so far I have
been focusing on short term (less than six hour) test cases.

Otherwise, I have submitted the patches to the Ubuntu kernel mailing list for
SRU. Now, these patches will still be subject to review by senior members of the
kernel team, and their approval is required before they get applied to the
official Ubuntu kernels. I will let you know if they get approval or not.

In the meantime, please test the test kernels, and if you find any issues at
all with the test kernels, please let me know.

Thanks,
Matthew