Commit a464adeb authored Sep 16, 2005 by Zach Brown Committed by Linus Torvalds Sep 17, 2005

[PATCH] Add smp_mb__after_clear_bit() to unlock_kiocb()



Add smp_mb__after_clear_bit() to unlock_kiocb()

AIO's use of wait_on_bit_lock()/wake_up_bit() forgot to add a barrier
between clearing its lock bit and calling wake_up_bit() so wake_up_bit()'s
unlocked waitqueue_active() can race.  This puts AIO's use in line with the
others and the comment above wake_up_bit().

Signed-off-by: Zach Brown <zach.brown@oracle.com>
Acked-by: Benjamin LaHaise <bcrl@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

parent 8ac2120d

fs/aio.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -562,6 +562,7 @@ static inline void lock_kiocb(struct kiocb *iocb)
		static inline void unlock_kiocb(struct kiocb *iocb)
		{
		kiocbClearLocked(iocb);
		smp_mb__after_clear_bit();
		wake_up_bit(&iocb->ki_flags, KIF_LOCKED);
		}

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