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Date: Wed, 30 Apr 2014 17:03:45 +0100
From: Al Viro <viro@ZenIV.linux.org.uk>
To: Miklos Szeredi <miklos@szeredi.hu>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
        Dave Chinner <david@fromorbit.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        linux-fsdevel <linux-fsdevel@vger.kernel.org>
Subject: Re: dcache shrink list corruption?
Message-ID: <20140430160345.GP18016@ZenIV.linux.org.uk>
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On Wed, Apr 30, 2014 at 05:49:58PM +0200, Miklos Szeredi wrote:
> > FWIW, the first two are really straightforward expanding the function
> > into its only callsite.  The last needs more splitup.  Not sure if the
> > following is good enough, but it ought to be at least somewhat cleaner.
> > Combined change is identical to the original, so it doesn't invalidate
> > the testing so far...
> 
> Hmm, patches look okay, but I'm wondering if we really need the morgue list and
> the waiting.  Why not just skip dentries that are presently being handled by
> dentry_kill()?

Who will be freeing them?  If we do that from dentry_kill(), we are back to
needing them removed from shrink list by something called by dput().  And
if we do that from shrink_dentry_list(), we'd damn better wait for
dentry_iput() et.al. to finish.