[linux-pm] [Bug 12713] Hang on resume from hibernation, apparently as result of 213d9417fec

[Roland Dreier]

 > I haven't read the code in depth, but taking running numbers and doing
 > bitwise "or"
 > on them looks a bit strange to me.
 > So here BIO_RW_SYNC is (3 | 4) = 7, that is the same as BIO_RW_FAILFAST_DEV.
 > So for example bio_failfast_dev and bio_sync are the same.

Yes, this is clearly wrong.  The fix seems to be to delete the
definition of BIO_RW_SYNC, and everywhere that breaks, replace

	1 << BIO_RW_SYNC

with

	(1 << BIO_RW_SYNCIO) | (1 << BIO_RW_UNPLUG)

 - R.