The next pile of mount massage; it will grow - there will be further modifications, as well as fixes and documentation, but this is the subset I've got in more or less settled form right now. Review and testing would be very welcome. This series (-rc1-based) sits in git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs.git #work.mount individual patches in followups. Rough overview: Part 1: trivial cleanups and helpers: 1) copy_tree(): don't set ->mnt_mountpoint on the root of copy Ancient bogosity, fortunately harmless, but confusing. 2) constify mnt_has_parent() 3) pnode: lift peers() into pnode.h 4) new predicate: mount_is_ancestor() Incidentally, I wonder if the "early bail out on move of anon into the same anon" was not due to (now eliminated) corner case in loop detection... Christian? 5) constify is_local_mountpoint() 6) new predicate: anon_ns_root(mount) 7) dissolve_on_fput(): use anon_ns_root() 8) don't set MNT_LOCKED on parentless mounts Simplify the rules for MNT_LOCKED 9) clone_mnt(): simplify the propagation-related logics ... making it somewhat easier to verify correctness wrt propagation graph invariants. 10) do_umount(): simplify the "is it still mounted" checks it needs to check that mount is ours and it has gradually grown an equivalent of such check, but it's badly obfuscated. Part 2: (somewhat of a side story) restore the machinery for long-term mounts from accumulated bitrot. 11) sanitize handling of long-term internal mounts Part 3: propagate_umount() rewrite (posted last cycle) 12) Rewrite of propagate_umount() Part 4: untangling do_move_mount()/attach_recursive_mnt(). This is one area that will definitely grow - reliable avoidance of having multiple mounts with the same parent/mountpoint pair will go in there. 13) attach_mnt(): expand in attach_recursive_mnt(), then lose the flag argument 14) do_move_mount(): take dropping the old mountpoint into attach_recursive_mnt() 15) get rid of mnt_set_mountpoint_beneath() 16) make commit_tree() usable in same-namespace move case 17) attach_recursive_mnt(): unify the mnt_change_mountpoint() logics 18) attach_recursive_mnt(): pass destination mount in all cases 19) attach_recursive_mnt(): get rid of flags entirely 20) do_move_mount(): get rid of 'attached' flag Part 5: change locking for expiry lists. 21) attach_recursive_mnt(): remove from expiry list on move 22) take ->mnt_expire handling under mount_lock [read_seqlock_excl] Part 6: struct mountpoint massage. 23) pivot_root(): reorder tree surgeries, collapse unhash_mnt() and put_mountpoint() 24) combine __put_mountpoint() with unhash_mnt() 25) get rid of mountpoint->m_count Part 7: regularize mount refcounting a bit 26) don't have mounts pin their parents
