On 05/12/2009 02:25 PM, Jens Axboe wrote: > On Thu, May 07 2009, Boaz Harrosh wrote: >> Osd library needs to submit pre-allocated bios, form several sources. >> osdblk exofs and pNFS-layout driver all have prepared bios for IO submission. >> On top of that the osd library needs to append additional segments to the >> IO memory, for get/set attributes and more. >> >> All these are done today by use of a temporary hack - blk_rq_append_bio. >> This is bad on few accounts. >> 1. blk_rq_append_bio was not meant to be exported and is very specific to its users. >> 2. blk_rq_append_bio does not support chained bios. >> 3. blk_rq_append_bio does not bounce the bio and therefore current osd implementation >> has a bug. >> >> The proposed solution adds two new fixtures to the block layer, and a corresponding >> fixing patch to osd. These are: >> >> [PATCH 1/4] allow blk_rq_map_kern to append to requests >> [PATCH 2/4] libosd: Use new blk_rq_map_kern >> >> This is originally a James patch and it's used, to let blk_rq_map_kern append it's buffer >> to existing bio, and there for is able to be called multiple times in a loop, to append >> multiple segments. This API can also be useful for scsi/block targets that have segment >> information in some other memory structure (like scatterlist) and wants to set it into >> a request. Until such time that they have a proper support for mapping scatterlists directly. >> (Since above called on long lists might not be good for performance) >> >> Here in osd it makes tons of sense, and should be considered for inclusion. >> (The patches are based on linus-tip but should patch on block tree) >> >> [RFC 3/4] New blk_make_request(), takes bio, returns a request >> [RFC 4/4] libosd: Use of new blk_make_request >> >> Here I propose a new block API, that will support proper delegation of a bio >> to a full request. Please read inside the patch descriptions for details. >> After this patch both osd and block layer will have the proper support for osdblk >> driver as well as future needs. >> These patches also eliminate the last use of blk_rq_append_bio which can be now un-exported. >> >> These two patches conflic with Tejun's branch and are based on linus-tip. Upon positive review >> I will serialize them with Tejun and submit them properly. But first they must be agreed upon. >> Jens, I specially need your opinion on this? > > Looks sane to me. Can you resubmit against 'for-2.6.31' of the block git > repo? > Thanks Jens. I have done the rebase and ran some tests, however I was unable to test these patches as is, because there are some inter tree fallouts. Jens, James, Stephan, I please need your help The situation is like that. - Both block/for-next and scsi/master are based on an old osd upstream-point (v2.6.30-rc3--ce8a7424) - Linus tip has important OSD patches that went in via scsi-rc-fixes which changed Wire format - If I try and merge block/for-next ontop of plain linus/master I get a merge conflict - If I try merge scsi/master block/for-next I get build errors / conflicts So there is no sane tree point that I can test on. It would be nice if both Jens block/for-next and scsi-misc/master could be rebased on Linus rc5++ and resolve these conflicts. (And scsi-misc conflicts with Tejun's cleanups be put in a second stage tree) Should I send the patches as is half tested? Or wait for things to settle after I tested them with all changes included? I have cut a new osd/linux-next branch which is based, not on linus, but on v2.6.30-rc3--ce8a7424 the base point for block/for-next and scsi-misc/master. So in next it should all come together well, and I will try to clone tomorrow's next and test on top of that. Please Advise on what I should do? Thanks in advance 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
