zs_create_pool() currently takes a gfp flags argument
that is used when growing the memory pool. However
it is not used in allocating the metadata for the pool
itself. That is currently hardcoded to GFP_KERNEL.
zswap calls zs_create_pool() at swapon time which is done
in atomic context, resulting in a "might sleep" warning.
This patch changes the meaning of the flags argument in
zs_create_pool() to mean the flags for the metadata allocation,
and adds a flags argument to zs_malloc that will be used for
memory pool growth if required.
Signed-off-by: Seth Jennings <sjenning@xxxxxxxxxxxxxxxxxx>