Re: [PATCH] scsi: scsi_debug: make timeout faults by set delay to maximum value

[John Garry <john.g.garry@oracle.com>]

On 05/11/2025 12:01, JiangJianJun wrote:

I got this patch 3x times...

> The injection of timeout faults is achieved by directly discarding the
> SCSI command.
> 
> However, after the timeout, the SCSI mid-layer cancels the SCSI command.
> At this point, if the command is checked during cancellation, 

What do you mean by "checked during cancellation"?

> it will result
> in a "not found" outcome, making it impossible to cancel the command properly.

I don't know what is meant by "cancel the command properly".

> 
> Therefore, the approach has been changed to avoid direct cancellation, and the
> delay is set to the maximum value(0x7FFFFFFF).
> 
> Signed-off-by: JiangJianJun <jiangjianjun3@huawei.com>
> ---
>   drivers/scsi/scsi_debug.c | 7 +++++--
>   1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
> index 353cb60e1abe..7d86a6f10130 100644
> --- a/drivers/scsi/scsi_debug.c
> +++ b/drivers/scsi/scsi_debug.c
> @@ -9249,6 +9249,7 @@ static int scsi_debug_queuecommand(struct Scsi_Host *shost,
>   	bool inject_now;
>   	int ret = 0;
>   	struct sdebug_err_inject err;
> +	bool timeout = false;
>   
>   	scsi_set_resid(scp, 0);
>   	if (sdebug_statistics) {
> @@ -9291,7 +9292,7 @@ static int scsi_debug_queuecommand(struct Scsi_Host *shost,
>   
>   	if (sdebug_timeout_cmd(scp)) {
>   		scmd_printk(KERN_INFO, scp, "timeout command 0x%x\n", opcode);
> -		return 0;
> +		timeout = true;
>   	}
>   
>   	ret = sdebug_fail_queue_cmd(scp);
> @@ -9398,7 +9399,9 @@ static int scsi_debug_queuecommand(struct Scsi_Host *shost,
>   		pfp = r_pfp;    /* if leaf function ptr NULL, try the root's */
>   
>   fini:
> -	if (F_DELAY_OVERR & flags)	/* cmds like INQUIRY respond asap */
> +	if (unlikely(timeout)) /* inject timeout */
> +		return schedule_resp(scp, devip, errsts, pfp, 0x7FFFFFFF, 0x7FFFFFFF);
> +	else if (F_DELAY_OVERR & flags)	/* cmds like INQUIRY respond asap */
>   		return schedule_resp(scp, devip, errsts, pfp, 0, 0);
>   	else if ((flags & F_LONG_DELAY) && (sdebug_jdelay > 0 ||
>   					    sdebug_ndelay > 10000)) {