[PATCH v2] dm bio prison: 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 <geliangtang@xxxxxxxxx>
Acked-by: Coly Li <colyli@xxxxxxx>
---
Changes in v2:
 - Apply to dm-bio-prison-v1.c and dm-bio-prison-v2.c
---
 drivers/md/dm-bio-prison-v1.c | 2 +-
 drivers/md/dm-bio-prison-v2.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/md/dm-bio-prison-v1.c b/drivers/md/dm-bio-prison-v1.c
index ae7da2c..f8d221b 100644
--- a/drivers/md/dm-bio-prison-v1.c
+++ b/drivers/md/dm-bio-prison-v1.c
@@ -116,7 +116,7 @@ static int __bio_detain(struct dm_bio_prison *prison,
 
 	while (*new) {
 		struct dm_bio_prison_cell *cell =
-			container_of(*new, struct dm_bio_prison_cell, node);
+			rb_entry(*new, struct dm_bio_prison_cell, node);
 
 		r = cmp_keys(key, &cell->key);
 
diff --git a/drivers/md/dm-bio-prison-v2.c b/drivers/md/dm-bio-prison-v2.c
index c9b11f7..8ce3a1a 100644
--- a/drivers/md/dm-bio-prison-v2.c
+++ b/drivers/md/dm-bio-prison-v2.c
@@ -120,7 +120,7 @@ static bool __find_or_insert(struct dm_bio_prison_v2 *prison,
 
 	while (*new) {
 		struct dm_bio_prison_cell_v2 *cell =
-			container_of(*new, struct dm_bio_prison_cell_v2, node);
+			rb_entry(*new, struct dm_bio_prison_cell_v2, node);
 
 		r = cmp_keys(key, &cell->key);
 
-- 
2.9.3