Re: [PATCH] 53c700: fix BUG on untagged commands

[Helge Deller <deller@gmx.de>]

On 14.06.2016 17:05, Christoph Hellwig wrote:
> Looks fine:
> 
> Acked-by: Christoph Hellwig <hch@lst.de>
> 
> But it should really go together with something like this:
> 
> ---
> From e54d1462ae244db3189a8b69018bc5f3e3d3b468 Mon Sep 17 00:00:00 2001
> From: Christoph Hellwig <hch@lst.de>
> Date: Tue, 14 Jun 2016 17:04:10 +0200
> Subject: scsi: move current_cmnd into the 53c700 driver
> 
> The 53c700 driver is the only user of the current_cmnd field in
> struct scsi_device, so let's move it into the driver private data.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Patch is OK.

Tested-by: Helge Deller <deller@gmx.de>

Even if this is not a real fix, I still would suggest to add
Cc: stable@vger.kernel.org	# 4.4+
as well to get both patches backported at the same time.

Helge

> ---
>  drivers/scsi/53c700.c      | 8 +++++---
>  drivers/scsi/53c700.h      | 1 +
>  include/scsi/scsi_device.h | 1 -
>  3 files changed, 6 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/scsi/53c700.c b/drivers/scsi/53c700.c
> index 3ddc85e..de53b23 100644
> --- a/drivers/scsi/53c700.c
> +++ b/drivers/scsi/53c700.c
> @@ -1120,9 +1120,9 @@ process_script_interrupt(__u32 dsps, __u32 dsp, struct scsi_cmnd *SCp,
>  				"reselection is tag %d, slot %p(%d)\n",
>  				hostdata->msgin[2], slot, slot->tag);
>  		} else {
> -			struct scsi_cmnd *SCp;
> +			struct NCR_700_Device_Parameters *p = SDp->hostdata;
> +			struct scsi_cmnd *SCp = p->current_cmnd;
>  
> -			SCp = SDp->current_cmnd;
>  			if(unlikely(SCp == NULL)) {
>  				sdev_printk(KERN_ERR, SDp,
>  					"no saved request for untagged cmd\n");
> @@ -1825,9 +1825,11 @@ NCR_700_queuecommand_lck(struct scsi_cmnd *SCp, void (*done)(struct scsi_cmnd *)
>  		CDEBUG(KERN_DEBUG, SCp, "sending out tag %d, slot %p\n",
>  		       slot->tag, slot);
>  	} else {
> +		struct NCR_700_Device_Parameters *p = SCp->device->hostdata;
> +
>  		slot->tag = SCSI_NO_TAG;
>  		/* save current command for reselection */
> -		SCp->device->current_cmnd = SCp;
> +		p->current_cmnd = SCp;
>  	}
>  	/* sanity check: some of the commands generated by the mid-layer
>  	 * have an eccentric idea of their sc_data_direction */
> diff --git a/drivers/scsi/53c700.h b/drivers/scsi/53c700.h
> index e06bdfe..83b157e 100644
> --- a/drivers/scsi/53c700.h
> +++ b/drivers/scsi/53c700.h
> @@ -82,6 +82,7 @@ struct NCR_700_Device_Parameters {
>  	 * cmnd[1], this could be in static storage */
>  	unsigned char cmnd[MAX_COMMAND_SIZE];
>  	__u8	depth;
> +	struct scsi_cmnd *current_cmnd;	/* currently active command */
>  };
>  
>  
> diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
> index a6c346d..8a95631 100644
> --- a/include/scsi/scsi_device.h
> +++ b/include/scsi/scsi_device.h
> @@ -94,7 +94,6 @@ struct scsi_device {
>  	spinlock_t list_lock;
>  	struct list_head cmd_list;	/* queue of in use SCSI Command structures */
>  	struct list_head starved_entry;
> -	struct scsi_cmnd *current_cmnd;	/* currently active command */
>  	unsigned short queue_depth;	/* How deep of a queue we want */
>  	unsigned short max_queue_depth;	/* max queue depth */
>  	unsigned short last_queue_full_depth; /* These two are used by */
>