PM: submit bio in a sane way in cases without bio_chain

Make bio submission in kernel/power/block_io.c to properly submit
bios also when bio_chain is not available. In that case, it's not
necessary to handle refcount with bio_get(), but it's saner to simply
call a predefined helper submit_bio_wait(). So call bio_get() only
when bio_chain is given.

Cc: Christoph Hellwig <>
Acked-by: Rafael J. Wysocki <>
Signed-off-by: Kent Overstreet <>
[dpark: add more description in commit message]
Signed-off-by: Dongsu Park <>
Signed-off-by: Ming Lin <>
1 file changed