Messages in this thread |  | | From | Ming Lei <> | Date | Sun, 30 Oct 2016 06:20:09 +0800 | Subject | Re: [PATCH 23/60] block: introduce flag QUEUE_FLAG_NO_MP |
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On Sat, Oct 29, 2016 at 11:29 PM, Christoph Hellwig <hch@infradead.org> wrote: > On Sat, Oct 29, 2016 at 04:08:22PM +0800, Ming Lei wrote: >> MD(especially raid1 and raid10) is a bit difficult to support >> multipage bvec, so introduce this flag for not enabling multipage >> bvec, then MD can still accept singlepage bvec only, and once >> direct access to bvec table in MD and other fs/drivers are cleanuped, >> the flag can be removed. BTRFS has the similar issue too. > > There is really no good reason for that. The RAID1 and 10 code really > just needs some love to use the bio cloning infrastructure, bio > iterators and generally recent bio apis. btrfs just needs a tiny little > bit of help and I'll send patches soon.
That is very nice of you to do this cleanup, cool!
I guess it still need a bit time, and hope that won't be the block for the whole patchset, :-)
[linux-2.6-next]$git grep -n -E "bi_io_vec|bi_vcnt" ./fs/btrfs/ | wc -l 45
[linux-2.6-next]$git grep -n -E "bi_io_vec|bi_vcnt" ./drivers/md/ | grep raid | wc -l 54
> > Having two different code path is just asking for trouble in the long > run.
Definitely, that flag is introduced just as a short-term solution.
Thanks, Ming Lei
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