[PATCH] writeback: use rb_entry()

[Geliang Tang]

To make the code clearer, use rb_entry() instead of container_of() to
deal with rbtree.

Signed-off-by: Geliang Tang <geliangt...@gmail.com>
---
 mm/backing-dev.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index 3bfed5ab..ffb77a1 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -410,8 +410,8 @@ wb_congested_get_create(struct backing_dev_info *bdi, int 
blkcg_id, gfp_t gfp)
 
        while (*node != NULL) {
                parent = *node;
-               congested = container_of(parent, struct bdi_writeback_congested,
-                                        rb_node);
+               congested = rb_entry(parent, struct bdi_writeback_congested,
+                                    rb_node);
                if (congested->blkcg_id < blkcg_id)
                        node = &parent->rb_left;
                else if (congested->blkcg_id > blkcg_id)
-- 
2.9.3