[PATCH, RFC 12/30] parport: fix interruptible_sleep_on race

[Arnd Bergmann]

The interruptible_sleep_on function is can still lead to the
deadlock mentioned in the comment above the caller, and we want
to remove it soon, so replace it now with the race-free
wait_event_interruptible.

Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxx>
---
 drivers/parport/share.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/parport/share.c b/drivers/parport/share.c
index 6a83ee1..3fa6624 100644
--- a/drivers/parport/share.c
+++ b/drivers/parport/share.c
@@ -905,7 +905,8 @@ int parport_claim_or_block(struct pardevice *dev)
 		/* If dev->waiting is clear now, an interrupt
 		   gave us the port and we would deadlock if we slept.  */
 		if (dev->waiting) {
-			interruptible_sleep_on (&dev->wait_q);
+			wait_event_interruptible(dev->wait_q,
+						 !dev->waiting);
 			if (signal_pending (current)) {
 				return -EINTR;
 			}
-- 
1.8.3.2

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