From 61c30c98ef17e5a330d7bb8494b78b3d6dffe9b8 Mon Sep 17 00:00:00 2001
From: Jan Kara <jack@suse.cz>
Date: Mon, 29 Jul 2019 13:57:49 +0200
Subject: [PATCH] dax: Fix missed wakeup in put_unlocked_entry()
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>
---
fs/dax.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/dax.c b/fs/dax.c
index a237141d87871..b64964ef44f62 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -266,7 +266,7 @@ static void wait_entry_unlocked(struct xa_state *xas, void *entry)
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);
}
--
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