SVCRDMA: Add xprt refs to fix close/unmount crash
SVCRDMA: Add xprt refs to fix close/unmount crash

RDMA connection shutdown on an SMP machine can cause a kernel crash due
to the transport close path racing with the I/O tasklet.

Additional transport references were added as follows:
- A reference when on the DTO Q to avoid having the transport
  deleted while queued for I/O.
- A reference while there is a QP able to generate events.
- A reference until the DISCONNECTED event is received on the CM ID

Signed-off-by: Tom Tucker <96835dd8bfa718bd6447ccc87af89ae1675daeca@opengridcomputing.com>
Signed-off-by: J. Bruce Fields <51738506c1b2ccb0761f23bdc612c93babf738ea@citi.umich.edu>
Signed-off-by: Linus Torvalds <69652caca27c8b940640ad396ab71f93cacec34f@linux-foundation.org>

KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs