From f52afc93cd018fe6910133a05d44671192d1aeb0 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Thu, 27 Sep 2018 13:23:32 +0200 Subject: [PATCH] dax: Fix deadlock in dax_lock_mapping_entry() When dax_lock_mapping_entry() has to sleep to obtain entry lock, it will fail to unlock mapping->i_pages spinlock and thus immediately deadlock against itself when retrying to grab the entry lock again. Fix the problem by unlocking mapping->i_pages before retrying. Fixes: c2a7d2a11552 ("filesystem-dax: Introduce dax_lock_mapping_entry()") Reported-by: Barret Rhoden Signed-off-by: Jan Kara Signed-off-by: Dan Williams --- fs/dax.c | 1 + 1 file changed, 1 insertion(+) diff --git a/fs/dax.c b/fs/dax.c index f32d712..e4ef8af 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -447,6 +447,7 @@ bool dax_lock_mapping_entry(struct page *page) xa_unlock_irq(&mapping->i_pages); break; } else if (IS_ERR(entry)) { + xa_unlock_irq(&mapping->i_pages); WARN_ON_ONCE(PTR_ERR(entry) != -EAGAIN); continue; } -- 2.7.4