On Wed, 2009-05-13 at 17:36 +0300, Boaz Harrosh wrote: > 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 So just pull them into Linus head and build on that ... as long as you explain what the base was, I can rebase scsi-misc (or run a post merge tree) to cope. It needs rebasing anyway to redo the mvsas patches. > > - 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 This is the problem of the renames ... I think we need a block postmerge tree to fix this up, but that probably needs sorting out first. > > 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 ? What you really want is on the combination of the necessary trees. If it's only block, then sure ... if it's block and SCSI, that's postmerge territory. James -- 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
