Re: [PATCH v2 0/6] scsi:scsi_debug: Add error injection for single device

From: Douglas Gilbert <dgilbert@interlog.com>
To: Wenchao Hao <haowenchao2@huawei.com>,
	"James E . J . Bottomley" <jejb@linux.ibm.com>,
	"Martin K . Petersen" <martin.petersen@oracle.com>,
	linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: linfeilong@huawei.com, louhongxiang@huawei.com
Subject: Re: [PATCH v2 0/6] scsi:scsi_debug: Add error injection for single device
Date: Tue, 2 May 2023 19:52:10 -0400	[thread overview]
Message-ID: <585941de-3e17-d5aa-311b-17773c6fbf1f@interlog.com> (raw)
In-Reply-To: <20230428013320.347050-1-haowenchao2@huawei.com>

On 2023-04-27 21:33, Wenchao Hao wrote:
> The original error injection mechanism was based on scsi_host which
> could not inject fault for a single SCSI device.
> 
> This patchset provides the ability to inject errors for a single
> SCSI device. Now we supports inject timeout errors, queuecommand
> errors, and hostbyte, driverbyte, statusbyte, and sense data for
> specific SCSI Command.
> 
> The first two patch add an debugfs interface to add and inquiry single
> device's error injection info; the third patch defined how to remove
> an injection which has been added. The following 3 patches use the
> injection info and generate the related error type.
> 
> V2:
>    - Using debugfs rather than sysfs attribute interface to manage error
> 
> Wenchao Hao (6):
>    scsi:scsi_debug: create scsi_debug directory in the debugfs filesystem
>    scsi:scsi_debug: Add interface to manage single device's error inject
>    scsi:scsi_debug: Define grammar to remove added error injection
>    scsi:scsi_debug: timeout command if the error is injected
>    scsi:scsi_debug: Return failed value if the error is injected
>    scsi:scsi_debug: set command's result and sense data if the error is
>      injected
> 
>   drivers/scsi/scsi_debug.c | 318 ++++++++++++++++++++++++++++++++++++++
>   1 file changed, 318 insertions(+)

Been playing around with this patchset and it seems to work as expected. Took me
a while to work my way through interface description at the beginning of
   [PATCH v2 2/6] scsi:scsi_debug: Add interface to manage single device's error 
inject

so I cut and paste it into my scsi_debug.html page and did some work on it, see:
    https://doug-gilbert.github.io/scsi_debug.html

There is a new chapter titled: Per device error injection
Kept the ASCII art so it could be ported back to [PATCH v2 2/6]'s description
if Wenchao is agreeable.

So for the whole series:
   Acked-by: Douglas Gilbert <dgilbert@interlog.com>

One suggestion for later work: perhaps the Command opcode field could be
expanded to: x8[,x16] so optionally a Service Action (in hex) could be
given (e.g. '9e,10' for the READ CAPACITY (16) command).

Doug Gilbert