From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:45972 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753150AbeBUNNN (ORCPT ); Wed, 21 Feb 2018 08:13:13 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Mike Christie , Florian Westphal , Nicholas Bellinger Subject: [PATCH 4.15 133/163] iscsi-target: make sure to wake up sleeping login worker Date: Wed, 21 Feb 2018 13:49:22 +0100 Message-Id: <20180221124537.534820304@linuxfoundation.org> In-Reply-To: <20180221124529.931834518@linuxfoundation.org> References: <20180221124529.931834518@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Florian Westphal commit 1c130ae00b769a2e2df41bad3d6051ee8234b636 upstream. Mike Christie reports: Starting in 4.14 iscsi logins will fail around 50% of the time. Problem appears to be that iscsi_target_sk_data_ready() callback may return without doing anything in case it finds the login work queue is still blocked in sock_recvmsg(). Nicholas Bellinger says: It would indicate users providing their own ->sk_data_ready() callback must be responsible for waking up a kthread context blocked on sock_recvmsg(..., MSG_WAITALL), when a second ->sk_data_ready() is received before the first sock_recvmsg(..., MSG_WAITALL) completes. So, do this and invoke the original data_ready() callback -- in case of tcp sockets this takes care of waking the thread. Disclaimer: I do not understand why this problem did not show up before tcp prequeue removal. (Drop WARN_ON usage - nab) Reported-by: Mike Christie Bisected-by: Mike Christie Tested-by: Mike Christie Diagnosed-by: Nicholas Bellinger Fixes: e7942d0633c4 ("tcp: remove prequeue support") Signed-off-by: Florian Westphal Cc: stable@vger.kernel.org # 4.14+ Signed-off-by: Nicholas Bellinger Signed-off-by: Greg Kroah-Hartman --- drivers/target/iscsi/iscsi_target_nego.c | 3 +++ 1 file changed, 3 insertions(+) --- a/drivers/target/iscsi/iscsi_target_nego.c +++ b/drivers/target/iscsi/iscsi_target_nego.c @@ -432,6 +432,9 @@ static void iscsi_target_sk_data_ready(s if (test_and_set_bit(LOGIN_FLAGS_READ_ACTIVE, &conn->login_flags)) { write_unlock_bh(&sk->sk_callback_lock); pr_debug("Got LOGIN_FLAGS_READ_ACTIVE=1, conn: %p >>>>\n", conn); + if (iscsi_target_sk_data_ready == conn->orig_data_ready) + return; + conn->orig_data_ready(sk); return; }