Commit 8717cf44 authored by Josef Bacik's avatar Josef Bacik Committed by David Sterba
Browse files

btrfs: handle extent corruption with select_one_root properly 



In corruption cases we could have paths from a block up to no root at
all, and thus we'll BUG_ON(!root) in select_one_root.  Handle this by
adding an ASSERT() for developers, and returning an error for normal
users.

Signed-off-by: default avatarJosef Bacik <josef@toxicpanda.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent e0b085b0

fs/btrfs/relocation.c

+16 −3
Original line number Diff line number Diff line
@@ -2218,7 +2218,13 @@ struct btrfs_root *select_one_root(struct btrfs_backref_node *node) 
		cond_resched();

		next = walk_up_backref(next, edges, &index);

		root = next->root;

		BUG_ON(!root);



		/*

		 * This can occur if we have incomplete extent refs leading all

		 * the way up a particular path, in this case return -EUCLEAN.

		 */

		if (!root)

			return ERR_PTR(-EUCLEAN);



		/* No other choice for non-shareable tree */

		if (!test_bit(BTRFS_ROOT_SHAREABLE, &root->state))
@@ -2608,8 +2614,15 @@ static int relocate_tree_block(struct btrfs_trans_handle *trans, 


	BUG_ON(node->processed);

	root = select_one_root(node);

	if (root == ERR_PTR(-ENOENT)) {

	if (IS_ERR(root)) {

		ret = PTR_ERR(root);



		/* See explanation in select_one_root for the -EUCLEAN case. */

		ASSERT(ret == -ENOENT);

		if (ret == -ENOENT) {

			ret = 0;

			update_processed_blocks(rc, node);

		}

		goto out;

	}