Pass an unit number to bcache_strategy, so it can flush the cache when necessary. Pass an absolute block number too, instead of receiving a relative one in realstrategy(), as bcache_strategy() requires this.
Pass an unit number to bcache_strategy, so it can flush the cache when
necessary. Pass an absolute block number too, instead of receiving a
relative one in realstrategy(), as bcache_strategy() requires this.

The fix is sligthly different from the one in the PR.

PR:		17098
Submitted by:	John Hood <jhood@sitaranetworks.com>

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase