linux-kernel - Re: Hang/soft lockup in d_invalidate with simultaneous calls

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Message-ID: <20170615105058.GK31671@ZenIV.linux.org.uk>
Date:   Thu, 15 Jun 2017 11:50:58 +0100
From:   Al Viro <viro@...IV.linux.org.uk>
To:     Khazhismel Kumykov <khazhy@...gle.com>
Cc:     linux-kernel@...r.kernel.org, linux-fsdevel@...r.kernel.org,
        Miklos Szeredi <mszeredi@...hat.com>
Subject: Re: Hang/soft lockup in d_invalidate with simultaneous calls

On Mon, Jun 12, 2017 at 04:00:45PM -0700, Khazhismel Kumykov wrote:
> On Fri, Jun 2, 2017 at 11:47 PM, Khazhismel Kumykov <khazhy@...gle.com> wrote:
> > On Fri, Jun 2, 2017 at 11:20 PM, Al Viro <viro@...iv.linux.org.uk> wrote:
> >> The thing is, unlike shrink_dcache_parent() we *can* bugger off as
> >> soon as we'd found no victims, nothing mounted and dentry itself
> >> is unhashed.  We can't do anything in select_collect() (we would've
> >> broken shrink_dcache_parent() that way), but we can do unhashing
> >> in check_and_drop() in "really nothing to do" case and we can return
> >> from d_invalidate() after that.  So how about this:
> > That does the trick.
> 
> I'm not entirely familiar the process here, is the above change
> committed somewhere, should I propose a patch?

Sorry, got distracted by other stuff; I'll push that today.