Discard handling splits large request into several steps.
However the actual size of request map for discard was
determined based on original request size, not step request
size, resulting in waste of memory and allocations > 4K.
Signed-off-by: Adam Rutkowski <adam.j.rutkowski@intel.com>
512K is the maximum request size for which request map
fits into one page (4K) regardless of cacheline size.
Signed-off-by: Adam Rutkowski <adam.j.rutkowski@intel.com>
There is one RW lock per hash bucket. Write lock is required
to map cacheline, read lock is sufficient for traversing.
Hash bucket locks are always acquired under global metadata
read lock. This assures mutual exclusion with eviction and
management paths, where global metadata write lock is held.
Signed-off-by: Adam Rutkowski <adam.j.rutkowski@intel.com>
ocf_request has always been first class citizen in OCF,
so lets place it along with another essential objects.
Signed-off-by: Robert Baldyga <robert.baldyga@intel.com>
