James Bottomley wrote: > On Thu, 2009-04-30 at 16:47 +0300, Boaz Harrosh wrote: >>> @@ -966,7 +965,7 @@ static int scsi_init_sgtable(struct request >> *req, struct scsi_data_buffer *sdb, >>> BUG_ON(count > sdb->table.nents); >>> sdb->table.nents = count; >>> if (blk_pc_request(req)) >>> - sdb->length = req->data_len; >>> + sdb->length = blk_rq_bytes(req); >>> else >>> sdb->length = blk_rq_sectors(req) << 9; >> Is this true. I thought they must be the same now. I was actually >> anticipating this if() removed. > > Me too ... there's one of these in scsi_lib.c as well. Not until the next patch. It's probably safe for scsi to make the switch here but I wanted to do the transition in two logical steps - 1. make all users use accessors in the defined manner without affecting anything else 2. knowing #1 is true for all low level drivers, unify implementation inside block layer. I had a following patch which tried to do sweep conversion of all llds (which is guaranteed to be safe after #2 has happened) but it looked like more trouble than worth and seems like best left to each subsystem, so please go ahead and clean up subsystems on top of this patchset. :-) > The difference comes because filesystem requests are always in sectors, > but BLOCK_PC requests are always in bytes .... we should be able to wrap > the accessors so they do the correct conversions. After this series is applied, blk_rq_bytes() >> 9 == blk_rq_sectors() is guaranteed (note that blk_rq_sectors() << 9 might not equal blk_rq_bytes() if the data transfer length isn't multiple of 512), so the above if can be removed. I just didn't want to make the conversion (probably safe for scsi) before the actual unification. Thanks. -- tejun -- 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
