Re: [LSF/MM TOPIC] : blktests: status, an expansion plan for the storage stack test framework

[Damien Le Moal <Damien.LeMoal@wdc.com>]

On 2019/02/06 19:32, Johannes Thumshirn wrote:
> On 06/02/2019 06:21, Chaitanya Kulkarni wrote:
>> Hi,
>>
>> Since discussion of the storage stack and device driver at the LSFMM 2017
>> (https://lwn.net/Articles/717699/),  Omar Sandoval introduced a new framework
>> "blktests" dedicated for Linux Kernel Block layer testing.
>> (https://lwn.net/Articles/722785/, https://github.com/osandov/blktests).
>>  
>> As Linux Kernel Block layer is central to the various file systems and underlying
>> low-level device drivers it is important to have a centralized testing framework and
>> make sure it grows with the latest block layer changed which are being added based
>> on the different device features from different device types
>> (e.g. NVMe devices with Zoned Namespace support).
>>
>> Since then blktests has grown and became go-to framework where we have integrated
>> different stand-alone test suites like SRP-tests, NVMFTESTS, NVMe Multipath tests,
>> zone block device tests, into one central framework, which has made an overall block layer
>> testing and development much easier than having to configure and execute different
>> test cases for each kernel release for different subsystems such as FS, NVMe,
>> Zone Block devices, etc). 
>>
>> Here is the list of the existing test categories:-
>>
>> ├── block                                           28 Tests
>> ├── loop                                             07 Tests
>> ├── meta                                            12 Tests
>> ├── nbd                                              02 Tests
>> ├── nvme                                           28 Tests
>> ├── nvmeof-mp                                  12 Tests
>> ├── scsi                                              06 Tests
>> ├── srp                                               13 Tests
>> └── zbd                                              05 Tests
>> ---------------------------------------------------------------- 
>>            9 Categories                            ~110 Tests
>>
>> This project has gathered much attention and storage stack community is actively
>> participating and adding new test cases with different categories to the framework. 
>>
>> For storage track, we would like to propose a session dedicated to blktests. It is a great
>> opportunity for the storage developers to gather and have a discussion about:-
>>
>> 1. Current status of the blktests framework.
>> 2. Any new/missing features that we want to add in the blktests.
>> 3. Any new kernel features that could be used to make testing easier?
>> E.g. Implementing new features in the null_blk.c in order to have device
>> independent complete test coverage. (e.g. adding discard command for null_blk or any
>> other specific REQ_OP). Discussion about having any new tracepoint events in the block layer.
>> 4. Any new test cases/categories which are lacking in the blktests framework.
> 
> One thing I'd love to see is more hardware/driver specific tests. I'm
> sure Broadcom, Marvell, Huawei and all the others out there do have test
> suites for their HBA drivers but not a single one of these tests is
> publicly available.
> 
> We're also lacking tests for things like ioprio, persistent reservation,
> bcache and so on.

+1 for ioprio discussion. I mentioned my interest in discussing this in my
invite request. Having it as a topic would be great. Since we are in the middle
of blktest improvements for zoned devices, I can try to put together a proposal
as a discussion base.

> 
> Adding support for collecting gcov information after running a test case
> would also be awesome (this is missing in xfstests as well).
> 
> So I think a session on blktests can help us get the gap closed.
> 
> Byte,
> 	Johannes
> 


-- 
Damien Le Moal
Western Digital Research