Re: [PATCH 3/7] megaraid_sas : Do not process IOCTLs and SCSI commands during driver removal

[Tomas Henzl <thenzl@redhat.com>]

On 11/10/2014 01:21 PM, Sumit.Saxena@avagotech.com wrote:
> Do not process any SCSI and IOCTL command further(return them with appropriate return values to callers),
> while driver removal is in progress/PCI shutdown is invoked. 
>
> Signed-off-by: Sumit Saxena <sumit.saxena@avagotech.com>
> Signed-off-by: Kashyap Desai <kashyap.desai@avagotech.com>
> ---
>  drivers/scsi/megaraid/megaraid_sas_base.c |   20 ++++++++++++++++----
>  1 files changed, 16 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/scsi/megaraid/megaraid_sas_base.c b/drivers/scsi/megaraid/megaraid_sas_base.c
> index f6a69a3..7754eeb 100644
> --- a/drivers/scsi/megaraid/megaraid_sas_base.c
> +++ b/drivers/scsi/megaraid/megaraid_sas_base.c
> @@ -1572,6 +1572,12 @@ megasas_queue_command(struct Scsi_Host *shost, struct scsi_cmnd *scmd)
>  	instance = (struct megasas_instance *)
>  	    scmd->device->host->hostdata;
>  
> +	if (instance->unload == 1) {
> +		scmd->result = DID_NO_CONNECT << 16;
> +		scmd->scsi_done(scmd);
> +		return 0;
> +	}
> +
>  	if (instance->issuepend_done == 0)
>  		return SCSI_MLQUEUE_HOST_BUSY;
>  
> @@ -4957,10 +4963,6 @@ static int megasas_io_attach(struct megasas_instance *instance)
>  		return -ENODEV;
>  	}
>  
> -	/*
> -	 * Trigger SCSI to scan our drives
> -	 */
> -	scsi_scan_host(host);
>  	return 0;
>  }
>  
> @@ -5288,6 +5290,10 @@ retry_irq_register:
>  		goto fail_io_attach;
>  
>  	instance->unload = 0;
> +	/*
> +	 * Trigger SCSI to scan our drives
> +	 */
> +	scsi_scan_host(host);
>  
>  	/*
>  	 * Initiate AEN (Asynchronous Event Notification)
> @@ -6051,6 +6057,12 @@ megasas_mgmt_fw_ioctl(struct megasas_instance *instance,
>  	megasas_issue_blocked_cmd(instance, cmd, 0);
>  	cmd->sync_cmd = 0;

I've expected that you'll not send the command to the card,
you first issue blocked command and after that test unload state.
Shouldn't it be reversed?

>  
> +	if (instance->unload == 1) {
> +		dev_info(&instance->pdev->dev, "we are doing unload so no need"
> +			"to submit data to application. This may be force exit"
> +			"from driver\n");

I'm not a native speaker, so I'll not comment on the wording, but you should add
a space at the line breaks.
+		dev_info(&instance->pdev->dev, "we are doing unload so no need "
+			"to submit data to application. This may be force exit "
+			"from driver\n");

> +		goto out;
> +	}
>  	/*
>  	 * copy out the kernel buffers to user buffers
>  	 */

Aren't there other ioctl paths too - for example 
megasas_mgmt_ioctl_aen - isn't a block needed there too?