[dm-devel] [PATCH v2] dm: gracefully fail any request beyond the end of the device

[Jun'ichi Nomura]

On 09/22/12 00:47, Mike Snitzer wrote:
> @@ -1651,19 +1654,31 @@ static void dm_request_fn(struct request
>  		if (!rq)
>  			goto delay_and_out;
>  
> +		clone = rq->special;
> +
>  		/* always use block 0 to find the target for flushes for now */
>  		pos = 0;
>  		if (!(rq->cmd_flags & REQ_FLUSH))
>  			pos = blk_rq_pos(rq);
>  
>  		ti = dm_table_find_target(map, pos);
> -		BUG_ON(!dm_target_is_valid(ti));
> +		if (!dm_target_is_valid(ti)) {
> +			/*
> +			 * Must perform setup, that dm_done() requires,
> +			 * before calling dm_kill_unmapped_request
> +			 */
> +			DMERR_LIMIT("request attempted access beyond the end of device");
> +			blk_start_request(rq);
> +			atomic_inc(&md->pending[rq_data_dir(clone)]);
> +			dm_get(md);
> +			dm_kill_unmapped_request(clone, -EIO);
> +			goto out;

This "goto out" should be "continue" so that request_fn
process next requests in the queue.

Also I think introducing a function dm_start_request()
will make this part of code a little bit easier for reading.
An edited patch is attached.

-- 
Jun'ichi Nomura, NEC Corporation

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