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From: Miklos Szeredi <miklos@szeredi.hu>
To: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Subject: Re: [RFC PATCH] vfs: make rename_lock per-sb
Date: Wed, 11 Dec 2019 12:33:43 +0100	[thread overview]
Message-ID: <CAJfpegsy520VMOp_J5Ncr+zuWMw=dL_4VAaZ6ETBKpV14vwLyw@mail.gmail.com> (raw)
In-Reply-To: <20191208055411.GT4203@ZenIV.linux.org.uk>

On Sun, Dec 8, 2019 at 6:54 AM Al Viro <viro@zeniv.linux.org.uk> wrote:
>
> On Thu, Nov 28, 2019 at 04:48:58PM +0100, Miklos Szeredi wrote:
>
> > Turning rename_lock into a per-sb lock mitigates the above issues.
>
> ... and completely fucks d_lookup(), since false negative can be
> caused by rename of *ANYTHING* you've encountered while walking
> a hash chain.

Drat.

Could we use the bitlock in the hash chain head for verification of a
negative?  Seems like much finer grained than having to rely on a
global seqlock for hash integrity.

Thanks,
Miklos

      reply	other threads:[~2019-12-11 11:33 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-11-28 15:48 [RFC PATCH] vfs: make rename_lock per-sb Miklos Szeredi
2019-12-08  5:54 ` Al Viro
2019-12-11 11:33   ` Miklos Szeredi [this message]

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