Re: linux-next: manual merge of the akpm tree with Linus' tree

From: Linus Torvalds
Date: Fri Sep 13 2013 - 16:25:53 EST


On Fri, Sep 13, 2013 at 4:00 PM, Al Viro <viro@xxxxxxxxxxxxxxxxxx> wrote:
\>
> It is right - for one thing, we are holding the lock on that LRU list,
> so list_lru_del() would deadlock right there. For another, the same
> list_lru_walk (OK, list_lru_walk_node()) will do ->nr_items decrement
> when we return LRU_REMOVED to it, so we don't want to do it twice.
> Plain list_del_init() is correct here.

Yes. And I found the opposite bug in one place: when we are collecting
dentries by walking the parents etc, we do *not* hold the global RCU
lock, so we cannot use the "d_lru_shrink_list()" thing after all. It's
correct as far as the internal logic of fs/dcache.c goes, but it
violates the global LRU list rules. So I replaced that with a
dentry_lru_del() followed by a d_shrink_add() instead.

Updated patch attached.

Linus

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