On 05/13/2009 05:28 PM, Boaz Harrosh wrote: > 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. > This will not work I have one patch [3/4] New blk_make_request(), takes bio, returns a request which will conflict with block/for-next if I rebase it on v2.6.30-rc3--ce8a7424. Should I cut osd/linux-next on top of block/for-next ? > 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 -- 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
