On Tue, Feb 11 2014, Christoph Hellwig wrote: > Hi Jens, > > seems like with the SCSI work I introduced the first > BLK_MQ_RQ_QUEUE_ERROR error return in the tree, and immediately ran into > the first pitfall. The code as-is expects rq->errors set to an error > value, which otherwise is an internal field used by the block layer and > some drivers, but not part of the communication protocol between the > two. > > We can either make it part of the protocol for blk-mq, which would > require documenting and praying driver writers get it right, or > alternatively we could map BLK_MQ_RQ_QUEUE_ERROR to -EIO and if > nessecary introduce other return values if we need to return other > errors. The third option would be to remove BLK_MQ_RQ_QUEUE_ERROR > entirely and require drivers to call blk_mq_end_io themselves from > ->queue_rq, mirroring the ->queuecommand error handling. I'm undecided > between options 2 and 3, but I'd rather avoid the current pitfall.
Lets go for option #2. I agree that we should not make this a new depedency, it's a lot more robust to just have it be -EIO and add other error returns as needed. -- Jens Axboe -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
