zram: write incompressible pages to backing device

This patch enables write IO to transfer data to backing device.  For
that, it implements write_to_bdev function which creates new bio and
chaining with parent bio to make the parent bio asynchrnous.

For rw_page which don't have parent bio, it submit owned bio and handle
IO completion by zram_page_end_io.

Also, this patch defines new flag ZRAM_WB to mark written page for later
read IO.

[[email protected]: fix typo in comment]
  Link: http://lkml.kernel.org/r/[email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Minchan Kim <[email protected]>
Signed-off-by: Yisheng Xie <[email protected]>
Cc: Juneho Choi <[email protected]>
Cc: Sergey Senozhatsky <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions