Re: [scsi_debug] 20b58d1e6b: blktests.block.001.fail

[Douglas Gilbert <dgilbert@interlog.com>]

On 2021-03-23 9:26 a.m., kernel test robot wrote:
> 
> 
> Greeting,
> 
> FYI, we noticed the following commit (built with gcc-9):
> 
> commit: 20b58d1e6b9cda142cd142a0a2f94c0d04b0a5a0 ("[RFC] scsi_debug: add hosts initialization --> worker")
> url: https://github.com/0day-ci/linux/commits/Douglas-Gilbert/scsi_debug-add-hosts-initialization-worker/20210319-230817
> base: https://git.kernel.org/cgit/linux/kernel/git/jejb/scsi.git for-next
> 
> in testcase: blktests
> version: blktests-x86_64-a210761-1_20210124
> with following parameters:
> 
> 	disk: 1SSD
> 	test: block-group-00
> 	ucode: 0xe2
> 
> 
> 
> on test machine: 4 threads Intel(R) Core(TM) i5-6500 CPU @ 3.20GHz with 32G memory
> 
> caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace):

This RFC was proposed for Luis Chamberlain to consider for this report:
    https://bugzilla.kernel.org/show_bug.cgi?id=212337

Luis predicted that this change would trip up some blktests which is exactly 
what has happened here. The question here is whether it is reasonable (i.e.
a correct simulation of what real hardware does) to assume that as soon as
the loading of the scsi_debug is complete, that _all_ LUNs (devices) specified
in its parameters are ready for media access?

If yes then this RFC can be dropped or relegated to only occur when a driver
parameter is set to a non-default value.

If no then those blktest scripts need to be fixed to reflect that after a
HBA is loaded, all the targets and LUNs connected to it do _not_ immediately
become available.

Doug Gilbert


> If you fix the issue, kindly add following tag
> Reported-by: kernel test robot <oliver.sang@intel.com>
> 
> 2021-03-21 02:40:23 sed "s:^:block/:" /lkp/benchmarks/blktests/tests/block-group-00
> 2021-03-21 02:40:23 ./check block/001
> block/001 (stress device hotplugging)
> block/001 (stress device hotplugging)                        [failed]
>      runtime  ...  30.370s
>      --- tests/block/001.out	2021-01-24 06:04:08.000000000 +0000
>      +++ /lkp/benchmarks/blktests/results/nodev/block/001.out.bad	2021-03-21 02:40:53.652003261 +0000
>      @@ -1,4 +1,7 @@
>       Running block/001
>       Stressing sd
>      +ls: cannot access '/sys/class/scsi_device/4:0:0:0/device/block': No such file or directory
>      +ls: cannot access '/sys/class/scsi_device/5:0:0:0/device/block': No such file or directory
>       Stressing sr
>      +ls: cannot access '/sys/class/scsi_device/4:0:0:0/device/block': No such file or directory
>       Test complete
> 
> 
> 
> To reproduce:
> 
>          git clone https://github.com/intel/lkp-tests.git
>          cd lkp-tests
>          bin/lkp install                job.yaml  # job file is attached in this email
>          bin/lkp split-job --compatible job.yaml
>          bin/lkp run                    compatible-job.yaml
> 
> 
> 
> ---
> 0DAY/LKP+ Test Infrastructure                   Open Source Technology Center
> https://lists.01.org/hyperkitty/list/lkp@lists.01.org       Intel Corporation
> 
> Thanks,
> Oliver Sang
>