tree 031f07f853e18e2fe09b054a3a8e432424362e60
parent 67e6682f18b3bf812a994ae027ff87174a297ae8
author Nick Piggin <npiggin@suse.de> 1196110690 -0600
committer Dave Kleikamp <shaggy@linux.vnet.ibm.com> 1199387504 -0600

JFS is missing a memory barrier

JFS is missing a memory barrier needed to close the critical section before
clearing the lock bit. Use lock bitops for this.

unlock_page() has a second barrier after clearing the lock, which is
required because it checks whether the waitqueue is active without locks.
Such a barrier is not required here because the waitqueue spinlock is
always taken (something to think about if performance is an issue).

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>