Btrfs: Further reduce the concurrency penalty of defrag and drop_snapshot (409eb95d) · Commits · 戴 / test

fs/btrfs/extent-tree.c

+6 −7

Original line number	Diff line number	Diff line
		@@ -1312,7 +1312,10 @@ static void reada_walk_down(struct btrfs_root *root,
		BUG_ON(ret);
		if (refs != 1)
		continue;
		mutex_unlock(&root->fs_info->fs_mutex);
		ret = readahead_tree_block(root, blocknr);
		cond_resched();
		mutex_lock(&root->fs_info->fs_mutex);
		if (ret)
		break;
		}
		@@ -1445,7 +1448,6 @@ int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root
		struct btrfs_path *path;
		int i;
		int orig_level;
		int num_walks = 0;
		struct btrfs_root_item *root_item = &root->root_item;

		path = btrfs_alloc_path();
		@@ -1486,13 +1488,10 @@ int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root
		break;
		if (wret < 0)
		ret = wret;
		num_walks++;
		if (num_walks > 2) {
		ret = -EAGAIN;
		get_bh(root->node);
		break;
		}
		}
		for (i = 0; i <= orig_level; i++) {
		if (path->nodes[i]) {
		btrfs_block_release(root, path->nodes[i]);

+3 −0

Original line number	Diff line number	Diff line
		@@ -364,6 +364,9 @@ int btrfs_defrag_dirty_roots(struct btrfs_fs_info *info)
		break;
		}
		root->defrag_running = 0;
		radix_tree_tag_clear(&info->fs_roots_radix,
		(unsigned long)root->root_key.objectid,
		BTRFS_ROOT_DEFRAG_TAG);
		}
		}
		btrfs_end_transaction(trans, tree_root);

+2 −5

Original line number	Diff line number	Diff line
		@@ -148,7 +148,6 @@ int btrfs_defrag_leaves(struct btrfs_trans_handle *trans,
		int level;
		int orig_level;
		int i;
		int num_runs = 0;

		if (root->ref_cows == 0) {
		goto out;
		@@ -200,11 +199,9 @@ int btrfs_defrag_leaves(struct btrfs_trans_handle *trans,
		break;
		if (wret < 0)
		ret = wret;
		if (num_runs++ > 8) {
		ret = -EAGAIN;
		break;
		}
		}
		for (i = 0; i <= orig_level; i++) {
		if (path->nodes[i]) {
		btrfs_block_release(root, path->nodes[i]);