Re: [PATCH] fs/dcache.c: re-add cond_resched() in shrink_dcache_parent()

From: Linus Torvalds
Date: Sat Apr 14 2018 - 17:47:35 EST


On Sat, Apr 14, 2018 at 1:58 PM, Al Viro <viro@xxxxxxxxxxxxxxxxxx> wrote:
>
> That breaks d_invalidate(), unfortunately. Look at the termination
> conditions in the loop there...

Ugh. I was going to say "but that doesn't even use select_collect()",
but yeah, detach_and_collect() calls it.

It would be easy enough to just change the

if (!list_empty(&data.select.dispose))

there to

if (!list_empty(&data.select.found))

too.

In fact, it probably *should* do that, exactly to get the whole
"cond_resched()" call in that whole call chain too. Because as-is, it
looks like it has the same issue as shrink_dcache_parent() does..

But yeah, the fact that I didn't notice that makes me a bit nervous.
But now I triple-checked, there are no other indirect callers.

Linus