block: add support for write hints in a bio
authorJens Axboe <axboe@kernel.dk>
Tue, 27 Jun 2017 15:22:02 +0000 (09:22 -0600)
committerJens Axboe <axboe@kernel.dk>
Tue, 27 Jun 2017 18:05:27 +0000 (12:05 -0600)
commitcb6934f8ea1a595902ca37e250e0917d4dd7b2a7
tree4280f328f9b632f6940a613e852f264918619e55
parentc75b1d9421f80f4143e389d2d50ddfc8a28c8c35
block: add support for write hints in a bio

No functional changes in this patch, we just use up some holes
in the bio and request structures to define a write hint that
we psas down the stack.

Ensure that we don't merge requests that have different life time
hints assigned to them, and that we inherit the write hint when
cloning a bio.

Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
block/bio.c
block/blk-core.c
block/blk-merge.c
include/linux/blk_types.h
include/linux/blkdev.h