Btrfs: use RB_ROOT to intialize rb_trees instead of setting rb_node to NULL

btrfs inialize rb trees in quite a number of places by settin rb_node =
NULL;  The problem with this is that 17d9ddc72fb8bba0d4f678 in the
linux-next tree adds a new field to that struct which needs to be NULL for
the new rbtree library code to work properly.  This patch uses RB_ROOT as
the intializer so all of the relevant fields will be NULL'd.  Without the
patch I get a panic.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

8 files changed, 12 insertions, 12 deletions

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 2b59201b955c..0427183e3e05 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -901,7 +901,7 @@ static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
         root->highest_objectid = 0;
         root->name = NULL;
         root->in_sysfs = 0;
-        root->inode_tree.rb_node = NULL;
+        root->inode_tree = RB_ROOT;
 
         INIT_LIST_HEAD(&root->dirty_list);
         INIT_LIST_HEAD(&root->orphan_list);
@@ -1673,7 +1673,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
         insert_inode_hash(fs_info->btree_inode);
 
         spin_lock_init(&fs_info->block_group_cache_lock);
-        fs_info->block_group_cache_tree.rb_node = NULL;
+        fs_info->block_group_cache_tree = RB_ROOT;
 
         extent_io_tree_init(&fs_info->freed_extents[0],
                              fs_info->btree_inode->i_mapping, GFP_NOFS);
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index b177ed319612..7073cbb1b2d4 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -104,8 +104,8 @@ void extent_io_exit(void)
 void extent_io_tree_init(struct extent_io_tree *tree,
                           struct address_space *mapping, gfp_t mask)
 {
-        tree->state.rb_node = NULL;
-        tree->buffer.rb_node = NULL;
+        tree->state = RB_ROOT;
+        tree->buffer = RB_ROOT;
         tree->ops = NULL;
         tree->dirty_bytes = 0;
         spin_lock_init(&tree->lock);
diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index 5a4f73b79b75..5a01f35507dd 100644
--- a/fs/btrfs/extent_map.c
+++ b/fs/btrfs/extent_map.c
@@ -35,7 +35,7 @@ void extent_map_exit(void)
  */
 void extent_map_tree_init(struct extent_map_tree *tree, gfp_t mask)
 {
-        tree->map.rb_node = NULL;
+        tree->map = RB_ROOT;
         rwlock_init(&tree->lock);
 }
 
diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index cb2849f03251..dd831ed31eea 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -870,7 +870,7 @@ __btrfs_return_cluster_to_free_space(
                 tree_insert_offset(&block_group->free_space_offset,
                                    entry->offset, &entry->offset_index, 0);
         }
-        cluster->root.rb_node = NULL;
+        cluster->root = RB_ROOT;
 
 out:
         spin_unlock(&cluster->lock);
@@ -1355,7 +1355,7 @@ void btrfs_init_free_cluster(struct btrfs_free_cluster *cluster)
 {
         spin_lock_init(&cluster->lock);
         spin_lock_init(&cluster->refill_lock);
-        cluster->root.rb_node = NULL;
+        cluster->root = RB_ROOT;
         cluster->max_size = 0;
         cluster->points_to_bitmap = false;
         INIT_LIST_HEAD(&cluster->block_group_list);
diff --git a/fs/btrfs/ordered-data.h b/fs/btrfs/ordered-data.h
index 1fe1282ef47c..9116c6d0c5a9 100644
--- a/fs/btrfs/ordered-data.h
+++ b/fs/btrfs/ordered-data.h
@@ -129,7 +129,7 @@ static inline void
 btrfs_ordered_inode_tree_init(struct btrfs_ordered_inode_tree *t)
 {
         mutex_init(&t->mutex);
-        t->tree.rb_node = NULL;
+        t->tree = RB_ROOT;
         t->last = NULL;
 }
 
diff --git a/fs/btrfs/ref-cache.h b/fs/btrfs/ref-cache.h
index bc283ad2db73..e2a55cb2072b 100644
--- a/fs/btrfs/ref-cache.h
+++ b/fs/btrfs/ref-cache.h
@@ -52,7 +52,7 @@ static inline size_t btrfs_leaf_ref_size(int nr_extents)
 
 static inline void btrfs_leaf_ref_tree_init(struct btrfs_leaf_ref_tree *tree)
 {
-        tree->root.rb_node = NULL;
+        tree->root = RB_ROOT;
         INIT_LIST_HEAD(&tree->list);
         spin_lock_init(&tree->lock);
 }
diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index ab7ab5318745..0109e5606bad 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -170,14 +170,14 @@ struct async_merge {
 
 static void mapping_tree_init(struct mapping_tree *tree)
 {
-        tree->rb_root.rb_node = NULL;
+        tree->rb_root = RB_ROOT;
         spin_lock_init(&tree->lock);
 }
 
 static void backref_cache_init(struct backref_cache *cache)
 {
         int i;
-        cache->rb_root.rb_node = NULL;
+        cache->rb_root = RB_ROOT;
         for (i = 0; i < BTRFS_MAX_LEVEL; i++)
                 INIT_LIST_HEAD(&cache->pending[i]);
         spin_lock_init(&cache->lock);
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index b2acc79f1b34..2a36e236a492 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -69,7 +69,7 @@ static noinline int join_transaction(struct btrfs_root *root)
                 cur_trans->commit_done = 0;
                 cur_trans->start_time = get_seconds();
 
-                cur_trans->delayed_refs.root.rb_node = NULL;
+                cur_trans->delayed_refs.root = RB_ROOT;
                 cur_trans->delayed_refs.num_entries = 0;
                 cur_trans->delayed_refs.num_heads_ready = 0;
                 cur_trans->delayed_refs.num_heads = 0;