Merge tag 'pull-mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull vfs mount updates from Al Viro:

 - mount hash conflicts rudiments are gone now - we do not allow
     multiple mounts with the same parent/mountpoint to be hashed at the
     same time.

 - 'struct mount' changes:
      - mnt_umounting is gone
      - mnt_slave_list/mnt_slave is an hlist now
      - overmounts are kept track of by explicit pointer in mount
      - a bunch of flags moved out of mnt_flags to a new field, with
        only namespace_sem for protection
      - mnt_expiry is protected by mount_lock now (instead of
        namespace_sem)
      - MNT_LOCKED is used only for mounts that need to remain attached
        to their parents to prevent mountpoint exposure - no more
        overloading it for absolute roots
      - all mnt_list uses are transient now - it's used only to
        represent temporary sets during umount_tree()

 - mount refcounting change: children no longer pin parents for any
   mounts, whether they'd passed through umount_tree() or not

 - 'struct mountpoint' changes:
      - refcount is no more; what matters is ->m_list emptiness
      - instead of temporary bumping the refcount, we insert a new
        object (pinned_mountpoint) into ->m_list
      - new calling conventions for lock_mount() and friends

 - do_move_mount()/attach_recursive_mnt() seriously cleaned up

 - globals in fs/pnode.c are gone

 - propagate_mnt(), change_mnt_propagation() and propagate_umount()
   cleaned up (in the last case - pretty much completely rewritten).

 - freeing of emptied mnt_namespace is done in namespace_unlock(). For
   one thing, there are subtle ordering requirements there; for another
   it simplifies cleanups.

 - assorted cleanups

 - restore the machinery for long-term mounts from accumulated bitrot.

   This is going to get a followup come next cycle, when the change of
   vfs_fs_parse_string() calling conventions goes into -next

* tag 'pull-mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (48 commits)
  statmount_mnt_basic(): simplify the logics for group id
  invent_group_ids(): zero ->mnt_group_id always implies !IS_MNT_SHARED()
  get rid of CL_SHARE_TO_SLAVE
  take freeing of emptied mnt_namespace to namespace_unlock()
  copy_tree(): don't link the mounts via mnt_list
  change_mnt_propagation(): move ->mnt_master assignment into MS_SLAVE case
  mnt_slave_list/mnt_slave: turn into hlist_head/hlist_node
  turn do_make_slave() into transfer_propagation()
  do_make_slave(): choose new master sanely
  change_mnt_propagation(): do_make_slave() is a no-op unless IS_MNT_SHARED()
  change_mnt_propagation() cleanups, step 1
  propagate_mnt(): fix comment and convert to kernel-doc, while we are at it
  propagate_mnt(): get rid of last_dest
  fs/pnode.c: get rid of globals
  propagate_one(): fold into the sole caller
  propagate_one(): separate the "what should be the master for this copy" part
  propagate_one(): separate the "do we need secondary here?" logics
  propagate_mnt(): handle all peer groups in the same loop
  propagate_one(): get rid of dest_master
  mount: separate the flags accessed only under namespace_sem
  ...

1 files changed, 3 insertions, 15 deletions

diff --git a/include/linux/mount.h b/include/linux/mount.h
index 1a508beba446..5f9c053b0897 100644
--- a/include/linux/mount.h
+++ b/include/linux/mount.h
@@ -35,9 +35,6 @@ enum mount_flags {
 	MNT_SHRINKABLE	= 0x100,
 	MNT_WRITE_HOLD	= 0x200,
 
-	MNT_SHARED	= 0x1000, /* if the vfsmount is a shared mount */
-	MNT_UNBINDABLE	= 0x2000, /* if the vfsmount is a unbindable mount */
-
 	MNT_INTERNAL	= 0x4000,
 
 	MNT_LOCK_ATIME		= 0x040000,
@@ -48,25 +45,15 @@ enum mount_flags {
 	MNT_LOCKED		= 0x800000,
 	MNT_DOOMED		= 0x1000000,
 	MNT_SYNC_UMOUNT		= 0x2000000,
-	MNT_MARKED		= 0x4000000,
 	MNT_UMOUNT		= 0x8000000,
 
-	/*
-	 * MNT_SHARED_MASK is the set of flags that should be cleared when a
-	 * mount becomes shared.  Currently, this is only the flag that says a
-	 * mount cannot be bind mounted, since this is how we create a mount
-	 * that shares events with another mount.  If you add a new MNT_*
-	 * flag, consider how it interacts with shared mounts.
-	 */
-	MNT_SHARED_MASK	= MNT_UNBINDABLE,
 	MNT_USER_SETTABLE_MASK  = MNT_NOSUID | MNT_NODEV | MNT_NOEXEC
 				  | MNT_NOATIME | MNT_NODIRATIME | MNT_RELATIME
 				  | MNT_READONLY | MNT_NOSYMFOLLOW,
 	MNT_ATIME_MASK = MNT_NOATIME | MNT_NODIRATIME | MNT_RELATIME,
 
-	MNT_INTERNAL_FLAGS = MNT_SHARED | MNT_WRITE_HOLD | MNT_INTERNAL |
-			     MNT_DOOMED | MNT_SYNC_UMOUNT | MNT_MARKED |
-			     MNT_LOCKED,
+	MNT_INTERNAL_FLAGS = MNT_WRITE_HOLD | MNT_INTERNAL | MNT_DOOMED |
+			     MNT_SYNC_UMOUNT | MNT_LOCKED
 };
 
 struct vfsmount {
@@ -98,6 +85,7 @@ int mnt_get_write_access(struct vfsmount *mnt);
 void mnt_put_write_access(struct vfsmount *mnt);
 
 extern struct vfsmount *fc_mount(struct fs_context *fc);
+extern struct vfsmount *fc_mount_longterm(struct fs_context *fc);
 extern struct vfsmount *vfs_create_mount(struct fs_context *fc);
 extern struct vfsmount *vfs_kern_mount(struct file_system_type *type,
 				      int flags, const char *name,