Branch HEAD

 Branch HEAD
 b=19529
 i=andrew.perepechko
 i=adilger
Description: Avoid deadlock for local client writes
Details    : Use new OBD_BRW_MEMALLOC flag to notify OST about writes in the
             memory freeing context. This allows OST threads to set the
             PF_MEMALLOC flag on task structures in order to allocate memory
             from reserved pools and complete IO.
             Use GFP_HIGHUSER for OST allocations for non-local client writes,
             so that the OST threads generate memory pressure and allow
             inactive pages to be reclaimed