Btrfs: Add a helper that finds previous extent item (d548ee51) · Commits · e / devices / android_kernel_teracube_emerald

fs/btrfs/extent-tree.c

+36 −44

Original line number	Diff line number	Diff line
		@@ -33,6 +33,28 @@ static int finish_current_insert(struct btrfs_trans_handle *trans, struct
		btrfs_root *extent_root);
		static int del_pending_extents(struct btrfs_trans_handle *trans, struct
		btrfs_root *extent_root);
		static int find_previous_extent(struct btrfs_root *root,
		struct btrfs_path *path)
		{
		struct btrfs_key found_key;
		struct extent_buffer *leaf;
		int ret;

		while(1) {
		if (path->slots[0] == 0) {
		ret = btrfs_prev_leaf(root, path);
		if (ret != 0)
		return ret;
		} else {
		path->slots[0]--;
		}
		leaf = path->nodes[0];
		btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
		if (found_key.type == BTRFS_EXTENT_ITEM_KEY)
		return 0;
		}
		return 1;
		}

		static int cache_block_group(struct btrfs_root *root,
		struct btrfs_block_group_cache *block_group)
		@@ -65,16 +87,19 @@ static int cache_block_group(struct btrfs_root *root,
		first_free = block_group->key.objectid;
		key.objectid = block_group->key.objectid;
		key.offset = 0;

		btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
		ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);

		if (ret < 0)
		return ret;

		if (ret && path->slots[0] > 0)
		path->slots[0]--;

		ret = find_previous_extent(root, path);
		if (ret < 0)
		return ret;
		if (ret == 0) {
		leaf = path->nodes[0];
		btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
		if (key.objectid + key.offset > first_free)
		first_free = key.objectid + key.offset;
		}
		while(1) {
		leaf = path->nodes[0];
		slot = path->slots[0];
		@@ -88,15 +113,10 @@ static int cache_block_group(struct btrfs_root *root,
		break;
		}
		}

		btrfs_item_key_to_cpu(leaf, &key, slot);
		if (key.objectid < block_group->key.objectid) {
		if (btrfs_key_type(&key) != BTRFS_EXTENT_REF_KEY &&
		key.objectid + key.offset > first_free)
		first_free = key.objectid + key.offset;
		goto next;
		}

		if (key.objectid >= block_group->key.objectid +
		block_group->key.offset) {
		break;
		@@ -162,11 +182,9 @@ struct btrfs_block_group_cache *btrfs_lookup_block_group(struct
		return block_group;
		return NULL;
		}

		static u64 noinline find_search_start(struct btrfs_root *root,
		struct btrfs_block_group_cache **cache_ret,
		u64 search_start, int num,
		int data, int full_scan)
		u64 search_start, int num, int data)
		{
		int ret;
		struct btrfs_block_group_cache cache = cache_ret;
		@@ -771,9 +789,7 @@ u32 btrfs_count_snapshots_in_path(struct btrfs_root *root,
		out:
		btrfs_free_path(path);
		return total_count;

		}

		int btrfs_inc_root_ref(struct btrfs_trans_handle *trans,
		struct btrfs_root *root, u64 owner_objectid)
		{
		@@ -1422,7 +1438,7 @@ static int noinline find_free_extent(struct btrfs_trans_handle *trans,
		orig_search_start);
		}
		search_start = find_search_start(root, &block_group, search_start,
		total_needed, data, full_scan);
		total_needed, data);
		search_start = stripe_align(root, search_start);
		cached_start = search_start;
		btrfs_init_path(path);
		@@ -1434,35 +1450,11 @@ static int noinline find_free_extent(struct btrfs_trans_handle *trans,
		ret = btrfs_search_slot(trans, root, ins, path, 0, 0);
		if (ret < 0)
		goto error;

		if (path->slots[0] > 0) {
		path->slots[0]--;
		}

		l = path->nodes[0];
		btrfs_item_key_to_cpu(l, &key, path->slots[0]);

		/*
		* walk backwards to find the first extent item key
		*/
		while(btrfs_key_type(&key) != BTRFS_EXTENT_ITEM_KEY) {
		if (path->slots[0] == 0) {
		ret = btrfs_prev_leaf(root, path);
		if (ret != 0) {
		ret = btrfs_search_slot(trans, root, ins,
		path, 0, 0);
		ret = find_previous_extent(root, path);
		if (ret < 0)
		goto error;
		if (path->slots[0] > 0)
		path->slots[0]--;
		break;
		}
		} else {
		path->slots[0]--;
		}
		l = path->nodes[0];
		btrfs_item_key_to_cpu(l, &key, path->slots[0]);
		}
		while (1) {
		l = path->nodes[0];
		slot = path->slots[0];