During swapoff the frontswap_map was NULL-ified before calling
frontswap_invalidate_area(). However the frontswap_invalidate_area()
exits early if frontswap_map is NULL. Invalidate was never called during
swapoff.

This patch moves frontswap_map_set() in swapoff just after calling
frontswap_invalidate_area() so outside of locks
(swap_lock and swap_info_struct->lock). This shouldn't be a problem as
during swapon the frontswap_map_set() is called also outside of any
locks.

Signed-off-by: Krzysztof Kozlowski <k.kozlow...@samsung.com>
---
 mm/swapfile.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/swapfile.c b/mm/swapfile.c
index 3963fc2..3a4896b 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -1922,10 +1922,10 @@ SYSCALL_DEFINE1(swapoff, const char __user *, 
specialfile)
        p->cluster_info = NULL;
        p->flags = 0;
        frontswap_map = frontswap_map_get(p);
-       frontswap_map_set(p, NULL);
        spin_unlock(&p->lock);
        spin_unlock(&swap_lock);
        frontswap_invalidate_area(type);
+       frontswap_map_set(p, NULL);
        mutex_unlock(&swapon_mutex);
        free_percpu(p->percpu_cluster);
        p->percpu_cluster = NULL;
-- 
1.7.9.5

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to