Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932961Ab2KZRGj (ORCPT ); Mon, 26 Nov 2012 12:06:39 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:47514 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932794Ab2KZRGe (ORCPT ); Mon, 26 Nov 2012 12:06:34 -0500 From: Herton Ronaldo Krzesinski To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Alex Elder , Herton Ronaldo Krzesinski Subject: [PATCH 108/270] libceph: don't touch con state in con_close_socket() Date: Mon, 26 Nov 2012 14:56:38 -0200 Message-Id: <1353949160-26803-109-git-send-email-herton.krzesinski@canonical.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1353949160-26803-1-git-send-email-herton.krzesinski@canonical.com> References: <1353949160-26803-1-git-send-email-herton.krzesinski@canonical.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2184 Lines: 61 3.5.7u1 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Alex Elder commit 456ea46865787283088b23a8a7f69244513b95f0 upstream. In con_close_socket(), a connection's SOCK_CLOSED flag gets set and then cleared while its shutdown method is called and its reference gets dropped. Previously, that flag got set only if it had not already been set, so setting it in con_close_socket() might have prevented additional processing being done on a socket being shut down. We no longer set SOCK_CLOSED in the socket event routine conditionally, so setting that bit here no longer provides whatever benefit it might have provided before. A race condition could still leave the SOCK_CLOSED bit set even after we've issued the call to con_close_socket(), so we still clear that bit after shutting the socket down. Add a comment explaining the reason for this. Signed-off-by: Alex Elder Reviewed-by: Sage Weil Signed-off-by: Herton Ronaldo Krzesinski --- net/ceph/messenger.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c index cd1aaa8..dfff350 100644 --- a/net/ceph/messenger.c +++ b/net/ceph/messenger.c @@ -392,10 +392,16 @@ static int con_close_socket(struct ceph_connection *con) dout("con_close_socket on %p sock %p\n", con, con->sock); if (!con->sock) return 0; - set_bit(SOCK_CLOSED, &con->flags); rc = con->sock->ops->shutdown(con->sock, SHUT_RDWR); sock_release(con->sock); con->sock = NULL; + + /* + * Forcibly clear the SOCK_CLOSE flag. It gets set + * independent of the connection mutex, and we could have + * received a socket close event before we had the chance to + * shut the socket down. + */ clear_bit(SOCK_CLOSED, &con->flags); con_sock_state_closed(con); return rc; -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/