[PATCH] xen/blkback: use rb_entry()

[Geliang Tang <geliangtang@gmail.com>]

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

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
---
 drivers/block/xen-blkback/blkback.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c
index 726c32e..7e59fae 100644
--- a/drivers/block/xen-blkback/blkback.c
+++ b/drivers/block/xen-blkback/blkback.c
@@ -191,10 +191,10 @@ static void make_response(struct xen_blkif_ring *ring, u64 id,
 			  unsigned short op, int st);
 
 #define foreach_grant_safe(pos, n, rbtree, node) \
-	for ((pos) = container_of(rb_first((rbtree)), typeof(*(pos)), node), \
+	for ((pos) = rb_entry(rb_first((rbtree)), typeof(*(pos)), node), \
 	     (n) = (&(pos)->node != NULL) ? rb_next(&(pos)->node) : NULL; \
 	     &(pos)->node != NULL; \
-	     (pos) = container_of(n, typeof(*(pos)), node), \
+	     (pos) = rb_entry(n, typeof(*(pos)), node), \
 	     (n) = (&(pos)->node != NULL) ? rb_next(&(pos)->node) : NULL)
 
 
@@ -223,7 +223,7 @@ static int add_persistent_gnt(struct xen_blkif_ring *ring,
 	/* Figure out where to put new node */
 	new = &ring->persistent_gnts.rb_node;
 	while (*new) {
-		this = container_of(*new, struct persistent_gnt, node);
+		this = rb_entry(*new, struct persistent_gnt, node);
 
 		parent = *new;
 		if (persistent_gnt->gnt < this->gnt)
@@ -254,7 +254,7 @@ static struct persistent_gnt *get_persistent_gnt(struct xen_blkif_ring *ring,
 
 	node = ring->persistent_gnts.rb_node;
 	while (node) {
-		data = container_of(node, struct persistent_gnt, node);
+		data = rb_entry(node, struct persistent_gnt, node);
 
 		if (gref < data->gnt)
 			node = node->rb_left;
-- 
2.9.3