Re: [PATCH] scsi_debug: fix compare and write errors

[Christoph Hellwig <hch@infradead.org>]

Any chance to get a review for this one and Dougs other scsi_debug
patch?

On Wed, Nov 26, 2014 at 12:45:13PM -0500, Douglas Gilbert wrote:
> From: Douglas Gilbert <dgilbert@interlog.com>
> Date: Wed, 26 Nov 2014 12:33:48 -0500
> Subject: [PATCH] scsi_debug fix compare and write errors
> 
> Kernel build tools pointed out a memory leak so that has been
> fixed and its error paths strengthened with a goto. Testing
> showed compare and write was only working for lba=0; correcting
> the length of the LBA field fixed that.
> ---
>  drivers/scsi/scsi_debug.c | 31 ++++++++++++++++---------------
>  1 file changed, 16 insertions(+), 15 deletions(-)
> 
> Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>

> >From 699d7b799ebbc0e1b5bc905ccfd50dc77003a9e8 Mon Sep 17 00:00:00 2001
> From: Douglas Gilbert <dgilbert@interlog.com>
> Date: Wed, 26 Nov 2014 12:33:48 -0500
> Subject: [PATCH] scsi_debug fix compare and write errors
> 
> Kernel build tools pointed out a memory leak so that has been
> fixed and its error paths strengthened with a goto. Testing
> showed compare and write was only working for lba=0; correcting
> the length of the LBA field fixed that.
> ---
>  drivers/scsi/scsi_debug.c | 31 ++++++++++++++++---------------
>  1 file changed, 16 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
> index aa4b6b8..747c691 100644
> --- a/drivers/scsi/scsi_debug.c
> +++ b/drivers/scsi/scsi_debug.c
> @@ -3045,18 +3045,12 @@ resp_comp_write(struct scsi_cmnd *scp, struct sdebug_dev_info *devip)
>  	u8 num;
>  	unsigned long iflags;
>  	int ret;
> +	int retval = 0;
>  
> -	lba = get_unaligned_be32(cmd + 2);
> +	lba = get_unaligned_be64(cmd + 2);
>  	num = cmd[13];		/* 1 to a maximum of 255 logical blocks */
>  	if (0 == num)
>  		return 0;	/* degenerate case, not an error */
> -	dnum = 2 * num;
> -	arr = kzalloc(dnum * lb_size, GFP_ATOMIC);
> -	if (NULL == arr) {
> -		mk_sense_buffer(scp, ILLEGAL_REQUEST, INSUFF_RES_ASC,
> -				INSUFF_RES_ASCQ);
> -		return check_condition_result;
> -	}
>  	if (scsi_debug_dif == SD_DIF_TYPE2_PROTECTION &&
>  	    (cmd[1] & 0xe0)) {
>  		mk_sense_invalid_opcode(scp);
> @@ -3079,6 +3073,13 @@ resp_comp_write(struct scsi_cmnd *scp, struct sdebug_dev_info *devip)
>  		mk_sense_buffer(scp, ILLEGAL_REQUEST, INVALID_FIELD_IN_CDB, 0);
>  		return check_condition_result;
>  	}
> +	dnum = 2 * num;
> +	arr = kzalloc(dnum * lb_size, GFP_ATOMIC);
> +	if (NULL == arr) {
> +		mk_sense_buffer(scp, ILLEGAL_REQUEST, INSUFF_RES_ASC,
> +				INSUFF_RES_ASCQ);
> +		return check_condition_result;
> +	}
>  
>  	write_lock_irqsave(&atomic_rw, iflags);
>  
> @@ -3089,24 +3090,24 @@ resp_comp_write(struct scsi_cmnd *scp, struct sdebug_dev_info *devip)
>  	ret = do_device_access(scp, 0, dnum, true);
>  	fake_storep = fake_storep_hold;
>  	if (ret == -1) {
> -		write_unlock_irqrestore(&atomic_rw, iflags);
> -		kfree(arr);
> -		return DID_ERROR << 16;
> +		retval = DID_ERROR << 16;
> +		goto cleanup;
>  	} else if ((ret < (dnum * lb_size)) &&
>  		 (SCSI_DEBUG_OPT_NOISE & scsi_debug_opts))
>  		sdev_printk(KERN_INFO, scp->device, "%s: compare_write: cdb "
>  			    "indicated=%u, IO sent=%d bytes\n", my_name,
>  			    dnum * lb_size, ret);
>  	if (!comp_write_worker(lba, num, arr)) {
> -		write_unlock_irqrestore(&atomic_rw, iflags);
> -		kfree(arr);
>  		mk_sense_buffer(scp, MISCOMPARE, MISCOMPARE_VERIFY_ASC, 0);
> -		return check_condition_result;
> +		retval = check_condition_result;
> +		goto cleanup;
>  	}
>  	if (scsi_debug_lbp())
>  		map_region(lba, num);
> +cleanup:
>  	write_unlock_irqrestore(&atomic_rw, iflags);
> -	return 0;
> +	kfree(arr);
> +	return retval;
>  }
>  
>  struct unmap_block_desc {
> -- 
> 1.9.1
> 

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