On Wed, 2011-09-14 at 20:17 +0300, Boaz Harrosh wrote: > On 9/14/2011 12:19 AM, Christoph Hellwig wrote: > > On Mon, Sep 12, 2011 at 08:04:46PM +0200, Jens Axboe wrote: > >>> I really hate naming things different from the method they are > >>> implementing. I've tried to figure out what the point of the > >>> old blk_make_request is - why would we not go through > >>> generic_make_request for this? > >>> > >>> Boaz, any idea? > >> > >> I tend to agree, we could rename the existing blk_make_request(). It > >> could be blk_make_request_from_bio() or something like that, since > >> that's what it does. > > > > It should at very least be renamed. But I still can't figure out what > > it is for exactly. > > > > There are three users: > > > > (1) virtio_blk::virtblk_get_id(): > > This looks like it really should just use blk_rq_map_kern. > > (2) osd_initiator::_make_request(): > > This one looks like it should just use the same scheme as > > sg_io(), as it's doing the same thing. > > Good god what sg_io? That broken pointr+length from user-mode that sg.c > and bsg.c are using? no can do it's not user-mode pointers, and it's not > pointer+length it's pages pointers of a bio. The only other structure > that could carry the same information is struct sg, but we work very > hard to get rid of this contraption. (scsi_execute_async or something > that it was) > > blk_make_request() was made to be the parallel of __make_request, to be > used from filesystem level users. But with two differences. > 1. Mainly support for none-FS BLOCK_PC requests > 2. Also support chained bios. (was added later) > > > (3) target_core_pscsi::__pscsi_map_SG(): > > Same as (2). > > > > There is no better suitable structure in current Kernel to carry a list > of pages, with optional offset and length, then bio struct. Given a bio > at hand. how do you make a block request out of it? (If it's not an > FS_PC type IO?) > > As I remember target_core had their own pages-linked-list structure, and > how do you make a request out of that? again best at hand is bio. > FYI, for v3.1-rc code, target core has been converted to use native struct scatterlist for everything, and the legacy struct se_mem that existed before the advent of modern >= .24 SGL linking, et al. has been completely removed. --nab -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
