From: Jan Kara Date: Mon, 29 Jul 2019 11:57:49 +0000 (+0200) Subject: dax: Fix missed wakeup in put_unlocked_entry() X-Git-Tag: v5.2.7~58 X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=349cd3dcbf9b73fcebe9206db124078188d1b9f5;p=users%2Fdwmw2%2Flinux.git dax: Fix missed wakeup in put_unlocked_entry() 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: 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 Signed-off-by: Dan Williams Signed-off-by: Greg Kroah-Hartman --- diff --git a/fs/dax.c b/fs/dax.c index 01ca13c80bb44..7d0e99982d48a 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -267,7 +267,7 @@ 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); }