| From | Greg Kroah-Hartman <> | Subject | [PATCH 5.2 081/131] dax: Fix missed wakeup in put_unlocked_entry() | Date | Mon, 5 Aug 2019 15:02:48 +0200 |
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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); }
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