[PATCH 2/3] btrfs: relocation: Specify essential members for alloc_backref_node()

[Qu Wenruo <wqu@suse.com>]

Bytenr and level are essential parameters for backref_node, thus it
makes sense to initial them at alloc time.

Signed-off-by: Qu Wenruo <wqu@suse.com>
---
 fs/btrfs/relocation.c | 25 ++++++++++++-------------
 1 file changed, 12 insertions(+), 13 deletions(-)

diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index 660f4884fed4..f072d075a202 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -274,10 +274,12 @@ static void backref_cache_cleanup(struct backref_cache *cache)
 	ASSERT(!cache->nr_edges);
 }
 
-static struct backref_node *alloc_backref_node(struct backref_cache *cache)
+static struct backref_node *alloc_backref_node(struct backref_cache *cache,
+						u64 bytenr, int level)
 {
 	struct backref_node *node;
 
+	ASSERT(level >= 0 && level < BTRFS_MAX_LEVEL);
 	node = kzalloc(sizeof(*node), GFP_NOFS);
 	if (node) {
 		INIT_LIST_HEAD(&node->list);
@@ -285,6 +287,9 @@ static struct backref_node *alloc_backref_node(struct backref_cache *cache)
 		INIT_LIST_HEAD(&node->lower);
 		RB_CLEAR_NODE(&node->rb_node);
 		cache->nr_nodes++;
+
+		node->level = level;
+		node->bytenr = bytenr;
 	}
 	return node;
 }
@@ -701,13 +706,12 @@ static int handle_one_tree_backref(struct reloc_control *rc,
 		rb_node = tree_search(&cache->rb_root, ref_key->offset);
 		if (!rb_node) {
 			/* Parent node not yet cached */
-			upper = alloc_backref_node(cache);
+			upper = alloc_backref_node(cache, ref_key->offset,
+						   cur->level + 1);
 			if (!upper) {
 				free_backref_edge(cache, edge);
 				return -ENOMEM;
 			}
-			upper->bytenr = ref_key->offset;
-			upper->level = cur->level + 1;
 
 			/*
 			 *  backrefs for the upper level block isn't
@@ -788,15 +792,14 @@ static int handle_one_tree_backref(struct reloc_control *rc,
 		eb = path->nodes[level];
 		rb_node = tree_search(&cache->rb_root, eb->start);
 		if (!rb_node) {
-			upper = alloc_backref_node(cache);
+			upper = alloc_backref_node(cache, eb->start,
+						   lower->level + 1);
 			if (!upper) {
 				free_backref_edge(cache, edge);
 				ret = -ENOMEM;
 				goto out;
 			}
-			upper->bytenr = eb->start;
 			upper->owner = btrfs_header_owner(eb);
-			upper->level = lower->level + 1;
 			if (!test_bit(BTRFS_ROOT_REF_COWS,
 				      &root->state))
 				upper->cowonly = 1;
@@ -888,14 +891,12 @@ struct backref_node *build_backref_tree(struct reloc_control *rc,
 	}
 	path->reada = READA_FORWARD;
 
-	node = alloc_backref_node(cache);
+	node = alloc_backref_node(cache, bytenr, level);
 	if (!node) {
 		err = -ENOMEM;
 		goto out;
 	}
 
-	node->bytenr = bytenr;
-	node->level = level;
 	node->lowest = 1;
 	cur = node;
 again:
@@ -1206,12 +1207,10 @@ static int clone_backref_node(struct btrfs_trans_handle *trans,
 	if (!node)
 		return 0;
 
-	new_node = alloc_backref_node(cache);
+	new_node = alloc_backref_node(cache, dest->node->start, node->level);
 	if (!new_node)
 		return -ENOMEM;
 
-	new_node->bytenr = dest->node->start;
-	new_node->level = node->level;
 	new_node->lowest = node->lowest;
 	new_node->checked = 1;
 	new_node->root = dest;
-- 
2.25.1