On Thu, Feb 28 2008, Tejun Heo wrote: > rq->raw_data_len introduced for block layer padding and draining > (commit 6b00769fe1502b4ad97bb327ef7ac971b208bfb5) broke residual byte > count handling. Block drivers modify rq->data_len to notify residual > byte count to the block layer which blindly reported unmodified > rq->raw_data_len to userland. > > To keep block drivers dealing only with rq->data_len, this should be > handled inside block layer. However, how much extra buffer was > appened is lost after rq->data_len is modified. > > This patch replaces rq->raw_data_len with rq->extra_len and add > blk_rq_raw_data_len() helper to calculate raw data size from > rq->data_len and rq->extra_len. The helper returns correct raw > residual byte count when called on a rq whose data_len is modified to > carry residual byte count. > > This problem was reported and diagnosed by Mike Galbraith. Tejun, this patch isn't much cleaner at all. It really shows the pain of these two seperate, yet related, variables. -- Jens Axboe -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
