A data access method in a file system comprises receiving a data access request including an identifier of a to-be-accessed node, obtaining access permission for the to-be-accessed node based on the identifier of the to-be-accessed node, wherein when a permission version number of the to-be-accessed node is not the latest in permission version numbers of all nodes indicated by path information of the to-be-accessed node in a file system, the access permission for the to-be-accessed node inherits a permission record corresponding to a parent node that is of the to-be-accessed node and that has a latest permission version number, and performing authentication based on the access permission for the to-be-accessed node, and accessing data of the to-be-accessed node after the authentication succeeds.