Commit 24213fa4 authored by Josef Bacik's avatar Josef Bacik Committed by David Sterba
Browse files

btrfs: do proper error handling in merge_reloc_roots 



We have a BUG_ON() if we get an error back from btrfs_get_fs_root().
This honestly should never fail, as at this point we have a solid
coordination of fs root to reloc root, and these roots will all be in
memory.  But in the name of killing BUG_ON()'s remove these and handle
the error condition properly, ASSERT()'ing for developers.

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 8717cf44

fs/btrfs/relocation.c

+23 −2
Original line number Diff line number Diff line
@@ -1969,8 +1969,29 @@ void merge_reloc_roots(struct reloc_control *rc) 
		root = btrfs_get_fs_root(fs_info, reloc_root->root_key.offset,

					 false);

		if (btrfs_root_refs(&reloc_root->root_item) > 0) {

			BUG_ON(IS_ERR(root));

			BUG_ON(root->reloc_root != reloc_root);

			if (IS_ERR(root)) {

				/*

				 * For recovery we read the fs roots on mount,

				 * and if we didn't find the root then we marked

				 * the reloc root as a garbage root.  For normal

				 * relocation obviously the root should exist in

				 * memory.  However there's no reason we can't

				 * handle the error properly here just in case.

				 */

				ASSERT(0);

				ret = PTR_ERR(root);

				goto out;

			}

			if (root->reloc_root != reloc_root) {

				/*

				 * This is actually impossible without something

				 * going really wrong (like weird race condition

				 * or cosmic rays).

				 */

				ASSERT(0);

				ret = -EINVAL;

				goto out;

			}

			ret = merge_reloc_root(rc, root);

			btrfs_put_root(root);

			if (ret) {