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Commit a1897fdd authored by Liu Bo's avatar Liu Bo Committed by Josef Bacik
Browse files

Btrfs: record first logical byte in memory



This'd save us a rbtree search which may become expensive in large filesystem.

Signed-off-by: default avatarLiu Bo <bo.li.liu@oracle.com>
Signed-off-by: default avatarJosef Bacik <jbacik@fusionio.com>
parent 39f9d028
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+1 −0
Original line number Diff line number Diff line
@@ -1250,6 +1250,7 @@ struct btrfs_fs_info {

	/* block group cache stuff */
	spinlock_t block_group_cache_lock;
	u64 first_logical_byte;
	struct rb_root block_group_cache_tree;

	/* keep track of unallocated space */
+1 −0
Original line number Diff line number Diff line
@@ -2130,6 +2130,7 @@ int open_ctree(struct super_block *sb,

	spin_lock_init(&fs_info->block_group_cache_lock);
	fs_info->block_group_cache_tree = RB_ROOT;
	fs_info->first_logical_byte = (u64)-1;

	extent_io_tree_init(&fs_info->freed_extents[0],
			     fs_info->btree_inode->i_mapping);
+18 −1
Original line number Diff line number Diff line
@@ -161,6 +161,10 @@ static int btrfs_add_block_group_cache(struct btrfs_fs_info *info,
	rb_link_node(&block_group->cache_node, parent, p);
	rb_insert_color(&block_group->cache_node,
			&info->block_group_cache_tree);

	if (info->first_logical_byte > block_group->key.objectid)
		info->first_logical_byte = block_group->key.objectid;

	spin_unlock(&info->block_group_cache_lock);

	return 0;
@@ -202,8 +206,11 @@ block_group_cache_tree_search(struct btrfs_fs_info *info, u64 bytenr,
			break;
		}
	}
	if (ret)
	if (ret) {
		btrfs_get_block_group(ret);
		if (bytenr == 0 && info->first_logical_byte > ret->key.objectid)
			info->first_logical_byte = ret->key.objectid;
	}
	spin_unlock(&info->block_group_cache_lock);

	return ret;
@@ -4848,6 +4855,13 @@ static u64 first_logical_byte(struct btrfs_root *root, u64 search_start)
	struct btrfs_block_group_cache *cache;
	u64 bytenr;

	spin_lock(&root->fs_info->block_group_cache_lock);
	bytenr = root->fs_info->first_logical_byte;
	spin_unlock(&root->fs_info->block_group_cache_lock);

	if (bytenr < (u64)-1)
		return bytenr;

	cache = btrfs_lookup_first_block_group(root->fs_info, search_start);
	if (!cache)
		return 0;
@@ -8059,6 +8073,9 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
	spin_lock(&root->fs_info->block_group_cache_lock);
	rb_erase(&block_group->cache_node,
		 &root->fs_info->block_group_cache_tree);

	if (root->fs_info->first_logical_byte == block_group->key.objectid)
		root->fs_info->first_logical_byte = (u64)-1;
	spin_unlock(&root->fs_info->block_group_cache_lock);

	down_write(&block_group->space_info->groups_sem);