tree d6510d4f326674e96bdf70c4f07472f492537db8
parent 0475bd6c65976c390e3805a1e5f10fc30ca8def2
author Christoph Hellwig <hch@lst.de> 1586850144 +0200
committer Jens Axboe <axboe@kernel.dk> 1587574055 -0600

block: move dma drain handling to scsi

Don't burden the common block code with with specifics of the libata DMA
draining mechanism.  Instead move most of the code to the scsi midlayer.

That also means the nr_phys_segments adjustments in the blk-mq fast path
can go away entirely, given that SCSI never looks at nr_phys_segments
after mapping the request to a scatterlist.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>