On Wed, 2015-06-17 at 19:56 -0400, Dan Williams wrote:

Upon detection of a read-only backing device arrange for the btt to
device to be read only.  Implement a catch for the BLKROSET ioctl and
only allow a btt-instance to become read-write when the backing-device
becomes read-write.  Conversely, if a backing-device becomes read-only
arrange for its parent btt to be marked read-only.  Synchronize these
changes under the bus lock.

Signed-off-by: Dan Williams <redacted>
---
 drivers/nvdimm/blk.c      |    4 +++
 drivers/nvdimm/btt.c      |   34 ++++++++++++++++++++++++++--
 drivers/nvdimm/btt_devs.c |   42 ++++++++++++++++++++++++++++++++++
 drivers/nvdimm/bus.c      |   55 +++++++++++++++++++++++++++++++++++++++++++++
 drivers/nvdimm/nd-core.h  |   14 +++++++++++
 drivers/nvdimm/nd.h       |    4 +++
 drivers/nvdimm/pmem.c     |    4 +++
 7 files changed, 154 insertions(+), 3 deletions(-)

Reviewed-by: Vishal Verma <vishal.l.verma@intel.com>