block: add QUEUE_FLAG_DAX for devices to advertise their DAX support
authorToshi Kani <toshi.kani@hpe.com>
Thu, 23 Jun 2016 21:05:50 +0000 (17:05 -0400)
committerJens Axboe <axboe@fb.com>
Thu, 21 Jul 2016 03:01:01 +0000 (21:01 -0600)
commit163d4baaebe39c0e56d9c08597eab7b3ae0bf334
treea2874ed41e21f5163e45e6fbb177d94b13cb38ff
parentdf5c82a8dcca1a5f23fefebae973d2dd0bf5aa11
block: add QUEUE_FLAG_DAX for devices to advertise their DAX support

Currently, presence of direct_access() in block_device_operations
indicates support of DAX on its block device.  Because
block_device_operations is instantiated with 'const', this DAX
capablity may not be enabled conditinally.

In preparation for supporting DAX to device-mapper devices, add
QUEUE_FLAG_DAX to request_queue flags to advertise their DAX
support.  This will allow to set the DAX capability based on how
mapped device is composed.

Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: <linux-s390@vger.kernel.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
drivers/block/brd.c
drivers/nvdimm/pmem.c
drivers/s390/block/dcssblk.c
fs/block_dev.c
include/linux/blkdev.h