Btrfs: Insert extent record and the first backref in a single balance

Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 29 insertions, 11 deletions

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index fa54ea590078..0fc8dfd58da9 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -1664,12 +1664,13 @@ int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
         u64 root_used;
         u64 search_start = 0;
         u64 new_hint;
+        u32 sizes[2];
         struct btrfs_fs_info *info = root->fs_info;
         struct btrfs_root *extent_root = info->extent_root;
-        struct btrfs_extent_item extent_item;
+        struct btrfs_extent_item *extent_item;
+        struct btrfs_extent_ref *ref;
         struct btrfs_path *path;
-
-        btrfs_set_stack_extent_refs(&extent_item, 1);
+        struct btrfs_key keys[2];
 
         new_hint = max(hint_byte, root->fs_info->alloc_start);
         if (new_hint < btrfs_super_total_bytes(&info->super_copy))
@@ -1707,20 +1708,37 @@ int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
         WARN_ON(trans->alloc_exclude_nr);
         trans->alloc_exclude_start = ins->objectid;
         trans->alloc_exclude_nr = ins->offset;
-        ret = btrfs_insert_item(trans, extent_root, ins, &extent_item,
-                                sizeof(extent_item));
 
-        trans->alloc_exclude_start = 0;
-        trans->alloc_exclude_nr = 0;
-        BUG_ON(ret);
+        memcpy(&keys[0], ins, sizeof(*ins));
+        keys[1].offset = hash_extent_ref(root_objectid, ref_generation,
+                                         owner, owner_offset);
+        keys[1].objectid = ins->objectid;
+        keys[1].type = BTRFS_EXTENT_REF_KEY;
+        sizes[0] = sizeof(*extent_item);
+        sizes[1] = sizeof(*ref);
 
         path = btrfs_alloc_path();
         BUG_ON(!path);
-        ret = btrfs_insert_extent_backref(trans, extent_root, path,
-                                          ins->objectid, root_objectid,
-                                          ref_generation, owner, owner_offset);
+
+        ret = btrfs_insert_empty_items(trans, extent_root, path, keys,
+                                       sizes, 2);
 
         BUG_ON(ret);
+        extent_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
+                                     struct btrfs_extent_item);
+        btrfs_set_extent_refs(path->nodes[0], extent_item, 1);
+        ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
+                             struct btrfs_extent_ref);
+
+        btrfs_set_ref_root(path->nodes[0], ref, root_objectid);
+        btrfs_set_ref_generation(path->nodes[0], ref, ref_generation);
+        btrfs_set_ref_objectid(path->nodes[0], ref, owner);
+        btrfs_set_ref_offset(path->nodes[0], ref, owner_offset);
+
+        btrfs_mark_buffer_dirty(path->nodes[0]);
+
+        trans->alloc_exclude_start = 0;
+        trans->alloc_exclude_nr = 0;
         btrfs_free_path(path);
         finish_current_insert(trans, extent_root);
         pending_ret = del_pending_extents(trans, extent_root);