simplify gendisk and request_queue allocation for bio based drivers

[Christoph Hellwig <hch@lst.de>]

Hi all,

this series is the first part of cleaning up lifetimes and allocation of
the gendisk and request_queue structure.  It adds a new interface to
allocate the disk and queue together for bio based drivers, and a helper
for cleanup/free them when a driver is unloaded or a device is removed.

Together this removes the need to treat the gendisk and request_queue
as separate entities for bio based drivers.

Diffstat:
 arch/m68k/emu/nfblock.c             |   20 +---
 arch/xtensa/platforms/iss/simdisk.c |   29 +------
 block/blk-core.c                    |    1 
 block/blk.h                         |    6 -
 block/genhd.c                       |  149 +++++++++++++++++++-----------------
 block/partitions/core.c             |   19 ++--
 drivers/block/brd.c                 |   94 +++++++---------------
 drivers/block/drbd/drbd_main.c      |   23 +----
 drivers/block/n64cart.c             |    8 -
 drivers/block/null_blk/main.c       |   38 ++++-----
 drivers/block/pktcdvd.c             |   11 --
 drivers/block/ps3vram.c             |   31 +------
 drivers/block/rsxx/dev.c            |   39 +++------
 drivers/block/rsxx/rsxx_priv.h      |    1 
 drivers/block/zram/zram_drv.c       |   19 ----
 drivers/lightnvm/core.c             |   24 +----
 drivers/md/bcache/super.c           |   15 ---
 drivers/md/dm.c                     |   16 +--
 drivers/md/md.c                     |   25 ++----
 drivers/memstick/core/ms_block.c    |    1 
 drivers/nvdimm/blk.c                |   27 +-----
 drivers/nvdimm/btt.c                |   25 +-----
 drivers/nvdimm/btt.h                |    2 
 drivers/nvdimm/pmem.c               |   17 +---
 drivers/nvme/host/core.c            |    1 
 drivers/nvme/host/multipath.c       |   46 +++--------
 drivers/s390/block/dcssblk.c        |   26 +-----
 drivers/s390/block/xpram.c          |   26 ++----
 include/linux/blkdev.h              |    1 
 include/linux/genhd.h               |   23 +++++
 30 files changed, 297 insertions(+), 466 deletions(-)