static int del_pending_extents(struct btrfs_trans_handle *trans, struct
                               btrfs_root *extent_root);
 
+static int find_search_start(struct btrfs_root *root, int data)
+{
+       struct btrfs_block_group_cache *cache[8];
+       struct btrfs_fs_info *info = root->fs_info;
+       u64 used;
+       u64 last;
+       int i;
+       int ret;
+
+       cache[0] = info->block_group_cache;
+       if (!cache[0])
+               goto find_new;
+       used = btrfs_block_group_used(&cache[0]->item);
+       if (used < (cache[0]->key.offset * 3 / 2))
+               return 0;
+find_new:
+       last = 0;
+       while(1) {
+               ret = radix_tree_gang_lookup_tag(&info->block_group_radix,
+                                                (void **)cache,
+                                                last, ARRAY_SIZE(cache),
+                                                BTRFS_BLOCK_GROUP_DIRTY);
+               if (!ret)
+                       break;
+               for (i = 0; i < ret; i++) {
+                       used = btrfs_block_group_used(&cache[i]->item);
+                       if (used < (cache[i]->key.offset * 3 / 2)) {
+                               info->block_group_cache = cache[i];
+                               cache[i]->last_alloc = cache[i]->first_free;
+                               return 0;
+                       }
+                       last = cache[i]->key.objectid +
+                               cache[i]->key.offset - 1;
+               }
+       }
+       last = 0;
+       while(1) {
+               ret = radix_tree_gang_lookup(&info->block_group_radix,
+                                                (void **)cache,
+                                                last, ARRAY_SIZE(cache));
+               if (!ret)
+                       break;
+               for (i = 0; i < ret; i++) {
+                       used = btrfs_block_group_used(&cache[i]->item);
+                       if (used < (cache[i]->key.offset * 3 / 2)) {
+                               info->block_group_cache = cache[i];
+                               cache[i]->last_alloc = cache[i]->first_free;
+                               return 0;
+                       }
+                       last = cache[i]->key.objectid +
+                               cache[i]->key.offset - 1;
+               }
+       }
+       info->block_group_cache = NULL;
+       return 0;
+}
+
 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
                                struct btrfs_root *root,
                                u64 blocknr, u64 num_blocks)
        while(total) {
                ret = radix_tree_gang_lookup(&info->block_group_radix,
                                             (void **)&cache, blocknr, 1);
-               if (!ret)
+               if (!ret) {
+                       printk(KERN_CRIT "blocknr %Lu lookup failed\n",
+                              blocknr);
                        return -1;
+               }
                block_in_group = blocknr - cache->key.objectid;
                WARN_ON(block_in_group > cache->key.offset);
                radix_tree_tag_set(&info->block_group_radix,
                num = min(total, cache->key.offset - block_in_group);
                total -= num;
                blocknr += num;
-               if (alloc)
+               if (alloc) {
                        old_val += num;
-               else
+                       if (blocknr > cache->last_alloc)
+                               cache->last_alloc = blocknr;
+               } else {
                        old_val -= num;
+                       if (blocknr < cache->first_free)
+                               cache->first_free = blocknr;
+               }
                btrfs_set_block_group_used(&cache->item, old_val);
        }
        return 0;
                        clear_radix_bit(pinned_radix, gang[i]);
                }
        }
-       if (root->fs_info->last_insert.objectid > first)
-               root->fs_info->last_insert.objectid = first;
-       root->fs_info->last_insert.offset = 0;
+       root->fs_info->block_group_cache = NULL;
        return 0;
 }
 
                num_blocks = 1;
                total_needed = min(level + 2, BTRFS_MAX_LEVEL) * 3;
        }
-       if (info->last_insert.objectid > search_start)
-               search_start = info->last_insert.objectid;
+       find_search_start(root, 0);
+       if (info->block_group_cache &&
+           info->block_group_cache->last_alloc > search_start)
+               search_start = info->block_group_cache->last_alloc;
 
 check_failed:
        btrfs_init_path(path);
                      total_found < total_needed) {
                        nr = total_needed - total_found - 1;
                        BUG_ON(nr < 0);
-                       root->fs_info->extent_tree_prealloc[nr] =
-                               test_block;
+                       info->extent_tree_prealloc[nr] = test_block;
                        total_found++;
                        test_block++;
                }
                        search_start = test_block;
                        goto check_failed;
                }
-               root->fs_info->extent_tree_prealloc_nr = total_found;
+               info->extent_tree_prealloc_nr = total_found;
+       }
+       ret = radix_tree_gang_lookup(&info->block_group_radix,
+                                    (void **)&info->block_group_cache,
+                                    ins->objectid, 1);
+       if (ret) {
+               info->block_group_cache->last_alloc = ins->objectid;
        }
-       root->fs_info->last_insert.objectid = ins->objectid;
        ins->offset = num_blocks;
        btrfs_free_path(path);
        return 0;
                                    struct btrfs_block_group_item);
                memcpy(&cache->item, bi, sizeof(*bi));
                memcpy(&cache->key, &found_key, sizeof(found_key));
+               cache->last_alloc = 0;
+               cache->first_free = 0;
                key.objectid = found_key.objectid + found_key.offset;
                btrfs_release_path(root, path);
                ret = radix_tree_insert(&root->fs_info->block_group_radix,