commit 6acddc5e911bb3a4a007448371ed7317c85669da
author Jörn Engel <joern@logfs.org> Thu Apr 12 17:33:58 2012 -0400
committer James Bottomley <JBottomley@Parallels.com> Thu May 17 10:08:54 2012 +0100
tree ef5ac2ea141645723d2e898f83ed4414dc36f4bc
parent ebaf466be5afa6c6dca29005374de4534e0e6b33

[SCSI] sg: prevent unwoken sleep

srp->done is protected by sfp->rq_list_lock everywhere, except for this
one case.  Result can be that the wake-up happens before the cacheline
with the changed srp->done has arrived, so the waiter can go back to
sleep and never be woken up again.

The wait_event_interruptible() means that anyone trying to debug this
unlikely race will likely notice everything working fine again, as the
next signal will unwedge things.  Evil.

Signed-off-by: Joern Engel <joern@logfs.org>
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>