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

From: Douglas Gilbert
Date: Tue May 02 2023 - 19:52:20 EST


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@xxxxxxxxxxxx>


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