From: Jan Kara jack@suse.cz
commit 61c30c98ef17e5a330d7bb8494b78b3d6dffe9b8 upstream.
The condition checking whether put_unlocked_entry() needs to wake up following waiter got broken by commit 23c84eb78375 ("dax: Fix missed wakeup with PMD faults"). We need to wake the waiter whenever the passed entry is valid (i.e., non-NULL and not special conflict entry). This could lead to processes never being woken up when waiting for entry lock. Fix the condition.
Cc: stable@vger.kernel.org Link: http://lore.kernel.org/r/20190729120228.GC17833@quack2.suse.cz Fixes: 23c84eb78375 ("dax: Fix missed wakeup with PMD faults") Signed-off-by: Jan Kara jack@suse.cz Signed-off-by: Dan Williams dan.j.williams@intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- fs/dax.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/fs/dax.c +++ b/fs/dax.c @@ -267,7 +267,7 @@ static void wait_entry_unlocked(struct x static void put_unlocked_entry(struct xa_state *xas, void *entry) { /* If we were the only waiter woken, wake the next one */ - if (entry && dax_is_conflict(entry)) + if (entry && !dax_is_conflict(entry)) dax_wake_entry(xas, entry, false); }