Pull block fixes from Jens Axboe:
"A few fixes/changes that should go into this release:
- null_blk zoned fixes (Damien)
- blkdev_close() sync improvement (Douglas)
- Fix regression in blk-iocost that impacted (at least) systemtap
(Waiman)
- Comment fix, header removal (Zhiqiang, Jianpeng)"
* tag 'block-5.7-2020-04-24' of git://git.kernel.dk/linux-block:
null_blk: Cleanup zoned device initialization
null_blk: Fix zoned command handling
block: remove unused header
blk-iocost: Fix error on iocost_ioc_vrate_adj
bdev: Reduce time holding bd_mutex in sync in blkdev_close()
buffer: remove useless comment and WB_REASON_FREE_MORE_MEM, reason.