Re: [RFC PATCH] fs: use a sequence counter instead of file_lock in fd_install

From: Eric Dumazet <eric.dumazet@gmail.com>
To: Mateusz Guzik <mguzik@redhat.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>,
	Andrew Morton <akpm@linux-foundation.org>,
	"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
	Yann Droneaud <ydroneaud@opteya.com>,
	Konstantin Khlebnikov <khlebnikov@yandex-team.ru>,
	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [RFC PATCH] fs: use a sequence counter instead of file_lock in fd_install
Date: Mon, 20 Apr 2015 09:48:25 -0700	[thread overview]
Message-ID: <1429548505.7346.263.camel@edumazet-glaptop2.roam.corp.google.com> (raw)
In-Reply-To: <1429548382.7346.261.camel@edumazet-glaptop2.roam.corp.google.com>

On Mon, 2015-04-20 at 09:46 -0700, Eric Dumazet wrote:

> 
> Hey, that's because I really meant (during the week end)

old = xchg(&fdt->fd[fd], file);
if (unlikely(old && old != file))
	filp_close(old, files);

That's going to be hard.

If you thought this problem was trivial, it probably means you missed
something.