Messages in this thread | | | Date | Wed, 01 Apr 2009 22:28:02 +0900 | From | Tejun Heo <> | Subject | Re: [PATCH 8/8] blk-map: reimplement blk_rq_map_user() using blk_rq_map_user_iov() |
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FUJITA Tomonori wrote: > Sounds a good idea. But I need to review that. > > But 7/8 and 8/8 patches are not bug fixes at all (as I wrote, your > descriptions about checking is untrue). It can't be for 2.6.30. So put > them to the next patchset.
Yeah, it should.
>>>> reason blk_rq_map_user() had multiple bio chaining was to work around >>>> BIO_MAX_SIZE. blk_rq_map_user_iov() doesn't support multiple bio >>>> chaining, so sans blk_rq_append_bio() or playing with rq/bio internals >>>> directly, there's no way to use or even know about multiple bios. >>> Yes, only non iovec interface of SG_IO supports large data >>> transfer. Users have been lived with that. >> This patch doesn't remove any feature. You don't lose anything. What >> used to be done with multiple bios is now done with single bio. The >> implementation is simpler and shorter. Using or not using multiple >> bios doesn't (and shouldn't) make any difference to blk_map_*() users. > > Hmm, with your change, blk_rq_map_user can't handle larger than > BIO_MAX_SIZE, right?
Yes, it can. The previous bio_kmalloc() thing was for this.
Thanks.
-- tejun
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