Re: [Patch] VFS : mount lock scalability for files systems without mount point (WAS vfsmount lock issues on very large ppc64 box)

[Christoph Hellwig <hch@infradead.org>]

I think you actually want this done in kern_mount_data, as both
ipc and proc want long-term references as well.  I also suspect with
additional creep of container awareness more internal mounts will switch
to kern_mount_data.  Al, what do you think about simply passing the
private data argument to kern_mount and kill kern_mount_data?  It's not
like the additional argument is going to cause us any pain.


> +struct vfsmount *kern_mount(struct file_system_type *type)
> +{
> +	struct vfsmount *mnt;
> +
> +	mnt = kern_mount_data(type, NULL);
> +	if (!IS_ERR(mnt)) {
> +		/* it is a longterm mount, don't release mnt until */
> +		/* we unmount before file sys is unregistered */

Please use normal kernel comment style, e.g.

	/*
	 * This is a longterm mount, don't release mnt until we umount
	 * it just before unregister_filesystem().
	 */
	
Adding proper kerneldoc comments for the kern_mount/umount function that
explain things in more detail would also be nice.