On Friday 08 May 2009 04:54:16 Tejun Heo wrote: > Till now block layer allowed two separate modes of request execution. > A request is always acquired from the request queue via > elv_next_request(). After that, drivers are free to either dequeue it > or process it without dequeueing. Dequeue allows elv_next_request() > to return the next request so that multiple requests can be in flight. > > Executing requests without dequeueing has its merits mostly in > allowing drivers for simpler devices which can't do sg to deal with > segments only without considering request boundary. However, the > benefit this brings is dubious and declining while the cost of the API > ambiguity is increasing. Segment based drivers are usually for very > old or limited devices and as converting to dequeueing model isn't > difficult, it doesn't justify the API overhead it puts on block layer > and its more modern users. > > Previous patches converted all block low level drivers to dequeueing > model. This patch completes the API transition by... > > * renaming elv_next_request() to blk_peek_request() > > * renaming blkdev_dequeue_request() to blk_start_request() > > * adding blk_fetch_request() which is combination of peek and start > > * disallowing completion of queued (not started) requests > > * applying new API to all LLDs > > Renamings are for consistency and to break out of tree code so that > it's apparent that out of tree drivers need updating. > > [ Impact: block request issue API cleanup, no functional change ] > > Signed-off-by: Tejun Heo <tj@xxxxxxxxxx> Acked-by: Bartlomiej Zolnierkiewicz <bzolnier@xxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
