Btrfs: tree mod log's old roots could still be part of the tree (834328a8) · Commits · 戴 / test

fs/btrfs/ctree.c

+21 −4

Original line number	Diff line number	Diff line
		@@ -1239,6 +1239,7 @@ get_old_root(struct btrfs_root *root, u64 time_seq)
		struct tree_mod_root *old_root = NULL;
		u64 old_generation = 0;
		u64 logical;
		u32 blocksize;

		eb = btrfs_read_lock_root_node(root);
		tm = __tree_mod_log_oldest_root(root->fs_info, root, time_seq);
		@@ -1254,12 +1255,28 @@ get_old_root(struct btrfs_root *root, u64 time_seq)
		}

		tm = tree_mod_log_search(root->fs_info, logical, time_seq);
		if (old_root)
		if (old_root && tm && tm->op != MOD_LOG_KEY_REMOVE_WHILE_FREEING) {
		btrfs_tree_read_unlock(root->node);
		free_extent_buffer(root->node);
		blocksize = btrfs_level_size(root, old_root->level);
		eb = read_tree_block(root, logical, blocksize, 0);
		if (!eb) {
		pr_warn("btrfs: failed to read tree block %llu from get_old_root\n",
		logical);
		WARN_ON(1);
		} else {
		eb = btrfs_clone_extent_buffer(eb);
		}
		} else if (old_root) {
		btrfs_tree_read_unlock(root->node);
		free_extent_buffer(root->node);
		eb = alloc_dummy_extent_buffer(logical, root->nodesize);
		else
		} else {
		eb = btrfs_clone_extent_buffer(root->node);
		btrfs_tree_read_unlock(root->node);
		free_extent_buffer(root->node);
		}

		if (!eb)
		return NULL;
		btrfs_tree_read_lock(eb);