From: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
To: Dmitry Popov <dp@highloadlab.com>, netdev@vger.kernel.org
Subject: Re: [PATCH 5/5] tcp: ipv4 listen state scaled
Date: Wed, 27 Oct 2010 19:04:34 +0400 [thread overview]
Message-ID: <20101027150434.GA13121@ms2.inr.ac.ru> (raw)
In-Reply-To: <AANLkTikRsOevLBHn0xb0S_YvfPMWpAdw373bxQUc+xbV@mail.gmail.com>
Hello!
It looks like there is at least one hole here.
You take lock, check syn table and drop lock in tcp_v4_hnd_req().
Then you immediately enter tcp_v4_conn_request() and grab lock again.
Oops, in the tiny hole while lock was dropped the request can be already
created (even funnier, the whole socket can be already created and even accepted).
So, if you drop lock, you have to restart the whole tcp_v4_rcv_listen()
(which seems to be impossible without additional tricks)
Alexey
next prev parent reply other threads:[~2010-10-27 15:04 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-10-27 13:32 [PATCH 5/5] tcp: ipv4 listen state scaled Dmitry Popov
2010-10-27 15:04 ` Alexey Kuznetsov [this message]
2010-10-27 16:44 ` Dmitry Popov
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