b=19529

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.