Btrfs: Do more extensive readahead during tree searches (2cc58cf2) · Commits · e / devices / android_kernel_fairphone_FP5

fs/btrfs/ctree.c

+49 −13

Original line number	Diff line number	Diff line
		@@ -43,8 +43,10 @@ struct btrfs_path *btrfs_alloc_path(void)
		{
		struct btrfs_path *path;
		path = kmem_cache_alloc(btrfs_path_cachep, GFP_NOFS);
		if (path)
		if (path) {
		btrfs_init_path(path);
		path->reada = 1;
		}
		return path;
		}

		@@ -159,6 +161,34 @@ static int close_blocks(u64 blocknr, u64 other)
		return 0;
		}

		static int should_defrag_leaf(struct buffer_head *bh)
		{
		struct btrfs_leaf *leaf = btrfs_buffer_leaf(bh);
		struct btrfs_disk_key *key;
		u32 nritems;

		if (buffer_defrag(bh))
		return 1;

		nritems = btrfs_header_nritems(&leaf->header);
		if (nritems == 0)
		return 0;

		key = &leaf->items[0].key;
		if (btrfs_disk_key_type(key) == BTRFS_DIR_ITEM_KEY)
		return 1;

		key = &leaf->items[nritems-1].key;
		if (btrfs_disk_key_type(key) == BTRFS_DIR_ITEM_KEY)
		return 1;
		if (nritems > 4) {
		key = &leaf->items[nritems/2].key;
		if (btrfs_disk_key_type(key) == BTRFS_DIR_ITEM_KEY)
		return 1;
		}
		return 0;
		}

		int btrfs_realloc_node(struct btrfs_trans_handle *trans,
		struct btrfs_root root, struct buffer_head parent,
		int cache_only, u64 *last_ret)
		@@ -217,7 +247,9 @@ int btrfs_realloc_node(struct btrfs_trans_handle *trans,

		cur_bh = btrfs_find_tree_block(root, blocknr);
		if (!cur_bh \|\| !buffer_uptodate(cur_bh) \|\|
		buffer_locked(cur_bh) \|\| !buffer_defrag(cur_bh)) {
		buffer_locked(cur_bh) \|\|
		(parent_level != 1 && !buffer_defrag(cur_bh)) \|\|
		(parent_level == 1 && !should_defrag_leaf(cur_bh))) {
		if (cache_only) {
		brelse(cur_bh);
		continue;
		@@ -297,6 +329,7 @@ static int check_node(struct btrfs_root root, struct btrfs_path path,
		parent = btrfs_buffer_node(path->nodes[level + 1]);

		slot = path->slots[level];
		BUG_ON(!buffer_uptodate(path->nodes[level]));
		BUG_ON(nritems == 0);
		if (parent) {
		struct btrfs_disk_key *parent_key;
		@@ -511,9 +544,6 @@ static int balance_level(struct btrfs_trans_handle *trans, struct btrfs_root
		err_on_enospc = 1;

		left_buf = read_node_slot(root, parent_buf, pslot - 1);
		right_buf = read_node_slot(root, parent_buf, pslot + 1);

		/* first, try to make some room in the middle buffer */
		if (left_buf) {
		wret = btrfs_cow_block(trans, root, left_buf,
		parent_buf, pslot - 1, &left_buf);
		@@ -521,6 +551,19 @@ static int balance_level(struct btrfs_trans_handle *trans, struct btrfs_root
		ret = wret;
		goto enospc;
		}
		}
		right_buf = read_node_slot(root, parent_buf, pslot + 1);
		if (right_buf) {
		wret = btrfs_cow_block(trans, root, right_buf,
		parent_buf, pslot + 1, &right_buf);
		if (wret) {
		ret = wret;
		goto enospc;
		}
		}

		/* first, try to make some room in the middle buffer */
		if (left_buf) {
		left = btrfs_buffer_node(left_buf);
		orig_slot += btrfs_header_nritems(&left->header);
		wret = push_node_left(trans, root, left_buf, mid_buf);
		@@ -534,13 +577,6 @@ static int balance_level(struct btrfs_trans_handle *trans, struct btrfs_root
		* then try to empty the right most buffer into the middle
		*/
		if (right_buf) {
		wret = btrfs_cow_block(trans, root, right_buf,
		parent_buf, pslot + 1, &right_buf);
		if (wret) {
		ret = wret;
		goto enospc;
		}

		right = btrfs_buffer_node(right_buf);
		wret = push_node_left(trans, root, mid_buf, right_buf);
		if (wret < 0 && wret != -ENOSPC)
		@@ -817,7 +853,7 @@ static void reada_for_search(struct btrfs_root root, struct btrfs_path path,
		for (i = 0; i < ret; i++) {
		blocknr = gang[i];
		clear_radix_bit(&found, blocknr);
		if (nread > 32)
		if (path->reada == 1 && nread > 16)
		continue;
		if (close_blocks(cluster_start, blocknr)) {
		readahead_tree_block(root, blocknr);

fs/btrfs/extent-tree.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -52,7 +52,7 @@ static int cache_block_group(struct btrfs_root *root,
		path = btrfs_alloc_path();
		if (!path)
		return -ENOMEM;
		path->reada = 1;
		path->reada = 2;
		key.objectid = block_group->key.objectid;
		key.flags = 0;
		key.offset = 0;
		@@ -1015,7 +1015,7 @@ static int find_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
		ins->objectid = search_start;
		ins->offset = 0;
		start_found = 0;
		path->reada = 1;
		path->reada = 2;

		ret = btrfs_search_slot(trans, root, ins, path, 0, 0);
		if (ret < 0)

fs/btrfs/inode.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -827,7 +827,7 @@ static int btrfs_readdir(struct file filp, void dirent, filldir_t filldir)
		btrfs_set_key_type(&key, key_type);
		key.offset = filp->f_pos;
		path = btrfs_alloc_path();
		path->reada = 1;
		path->reada = 2;
		ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
		if (ret < 0)
		goto err;