Re: dcache shrink list corruption?

[Al Viro <viro@ZenIV.linux.org.uk>]

On Fri, May 02, 2014 at 02:18:43PM -0700, Linus Torvalds wrote:
> On Fri, May 2, 2014 at 2:08 PM, Miklos Szeredi <miklos@szeredi.hu> wrote:
> > There's more of the "delete from shrink list not owned by us" in select parent.
> > Proposed patch appended.
> 
> Ahh. Clearly this needs more work before I pull.

*nod*

Besides, I want to put Miklos' "don't bother with RCU in shrink_dentry_list()"
in there as soon as select_collect() has been dealt with.  I don't think
that the currently posted patch for select_collect() is right, though -
see my reply to parent posting.  Basically, I think we should treat "it's
on the shrink list already" as "increment data->found and keep going".  IOW,
	if (on shrink list) {
		data->found++;
	} else {
		if (on lru list)
			d_lru_del
		if (refcount is zero) {
			d_shrink_add
			data->found++;
		}
	}
	if (data->found)
		ret = need_resched() ? D_WALK_QUIT : D_WALK_NORETRY;