Commit 83c38e3e authored by Kent Overstreet's avatar Kent Overstreet
Browse files

bcachefs: check inode backpointer in bch2_lookup() 



Signed-off-by: default avatarKent Overstreet <kent.overstreet@linux.dev>
parent 4da1713a

fs/bcachefs/fs.c

+18 −6
Original line number Diff line number Diff line
@@ -400,6 +400,7 @@ static struct bch_inode_info *bch2_lookup_trans(struct btree_trans *trans, 
	struct bch_fs *c = trans->c;

	struct btree_iter dirent_iter = {};

	subvol_inum inum = {};

	struct printbuf buf = PRINTBUF;



	struct bkey_s_c k = bch2_hash_lookup(trans, &dirent_iter, bch2_dirent_hash_desc,

					     dir_hash_info, dir, name, 0);
@@ -426,20 +427,31 @@ static struct bch_inode_info *bch2_lookup_trans(struct btree_trans *trans, 
	ret =   bch2_subvolume_get(trans, inum.subvol, true, 0, &subvol) ?:

		bch2_inode_find_by_inum_nowarn_trans(trans, inum, &inode_u) ?:

		PTR_ERR_OR_ZERO(inode = bch2_new_inode(trans));

	if (bch2_err_matches(ret, ENOENT)) {

		struct printbuf buf = PRINTBUF;



		bch2_bkey_val_to_text(&buf, c, k);

		bch_err(c, "%s points to missing inode", buf.buf);

		printbuf_exit(&buf);

	}

	bch2_fs_inconsistent_on(bch2_err_matches(ret, ENOENT),

				c, "dirent to missing inode:\n  %s",

				(bch2_bkey_val_to_text(&buf, c, k), buf.buf));

	if (ret)

		goto err;



	/* regular files may have hardlinks: */

	if (bch2_fs_inconsistent_on(bch2_inode_should_have_bp(&inode_u) &&

				    !bkey_eq(k.k->p, POS(inode_u.bi_dir, inode_u.bi_dir_offset)),

				    c,

				    "dirent points to inode that does not point back:\n  %s",

				    (bch2_bkey_val_to_text(&buf, c, k),

				     prt_printf(&buf, "\n  "),

				     bch2_inode_unpacked_to_text(&buf, &inode_u),

				     buf.buf))) {

		ret = -ENOENT;

		goto err;

	}



	bch2_vfs_inode_init(trans, inum, inode, &inode_u, &subvol);

	inode = bch2_inode_insert(c, inode);

out:

	bch2_trans_iter_exit(trans, &dirent_iter);

	printbuf_exit(&buf);

	return inode;

err:

	inode = ERR_PTR(ret);