On 04/20/2009 11:36 PM, Nicholas A. Bellinger wrote: > On Sun, 2009-04-19 at 13:56 +0300, Boaz Harrosh wrote: >> Are you aware that scsi_execute_async() has gone in 2.6.30-rc1? >> >> I'm not sure what would be the best alternative for you. I would say >> a bio, but it is still being debated. Your current options are: >> >> 1. bio_alloc then loop () bio_add_pc_page, and finally blk_rq_append_bio >> (Which block people don't like) >> 2. sglist => page-pointers-array translation and blk_rq_map_user with >> struct rq_map_data mode. (not possible with all kind of sglists) >> 2. sglist => iovec translation and blk_rq_map_user_iov() >> (Very very ugly mapping of pages to virtual pointers) >> >> I have a similar situation with my OSD code. >> > > Hey, > > Thanks for the pointers on this.. Yeah, I knew it was going away soon, > but needed it for some legacy drivers..:-) > > Anyways, I will drop this patch for scsi_execute_async() when I branch > for v2.6.30-rcX and look and updating target_core_mod/pSCSI to one of > the listed methods to get up and running. From the looks of it however > we might want something slightly better than blk_rq_map_user() for the > kernel space pages attached to struct scatterlist and page_links.. > > Just FYI, the target_core_mod struct scatterlist memory will be in > struct list_head with struct page for allocated se_cmd_t (received CDB), > so it will be pretty easy from the target_core_mod+subsystem plugin side > side to put something that along the lines of list => > page-pointers-array translation and blk_rq_map_user() into a new > function.. Be ware that page-pointers-array mean that only first/last page can be incomplete and all middle pages must be full PAGE_SIZE. As I recall this might not be the case for network sglists. > > lio-core-2.6.git/drivers/target/target_core_transport.c is using > include/linux/scatterlist.h macros when interacting with struct > scatterlist allocated for each subsystem plugin (from the linked list > struct page memory) I will have a look and see what would need to be > down to allow all kinds of sglists with something new.. > right, in the general sglist model, only linked-bios will fit one-to-one. You should look into something like Tejun's RFCed blk_rq_map_kern_sgl() (Which was not yet accepted) > Thanks for your comments! > > --nab > > We'll see what comes up Boaz -- 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
