Re: 2.6.6-rc1-mm1

[Christoph Hellwig <hch@infradead.org>]

On Wed, Apr 21, 2004 at 08:31:38PM +0800, raven@themaw.net wrote:
> If it is decided to do this then would something like this be approiate 
> Andrew?
> 
> I have
> - renamed autofs4_may_umount to may_umount_tree and moved
>   it to namespace.c
> - removed the EXPORT_SYMBOL for vfsmount_lock
> - updated autofs4 to suit
> 
> It is not possible to merge the functionality of may_umount into this as, 
> it stands, as autofs v3 requires a slightly different semantic. That is if 
> there are submounts that are not busy then it should return -EBUSY but 
> may_umount_tree would return not busy.

What about adding a paramter 'ignore_busy_submounts' and use most of the
function in common for both autofs3 and autofs4?

> +	struct list_head *next;
> +	struct vfsmount *this_parent = mnt;
> +	int actual_refs;
> +	int minimum_refs;
> +
> +	spin_lock(&vfsmount_lock);
> +	actual_refs = atomic_read(&mnt->mnt_count);
> +	minimum_refs = 2;
> +repeat:
> +	next = this_parent->mnt_mounts.next;
> +resume:
> +	while (next != &this_parent->mnt_mounts) {
> +		struct vfsmount *p = list_entry(next, struct vfsmount, mnt_child);
> +
> +		next = next->next;

Any chance to use list_for_each_entry here?

> +		if ( !list_empty(&p->mnt_mounts) ) {

This wants a white-space fixup.