sb
generic_shutdown_super does all fs-independent work on superblock shutdown. Typical ->kill_sb should pick all fs-specific objects that need destruction out of superblock, call generic_shutdown_super and release aforementioned objects. Note: dentries and inodes _are_ taken care of and do not need specific handling.
Upon calling this function, the filesystem may no longer alter or rearrange the set of dentries belonging to this super_block, nor may it change the attachments of dentries to inodes.