From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:33448 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755128AbdK1KsQ (ORCPT ); Tue, 28 Nov 2017 05:48:16 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Mike Christie , Hannes Reinecke , "Bryant G. Ly" , Michael Cyr , Potnuri Bharat Teja , Sagi Grimberg , Nicholas Bellinger Subject: [PATCH 4.14 117/193] target: Fix quiese during transport_write_pending_qf endless loop Date: Tue, 28 Nov 2017 11:26:04 +0100 Message-Id: <20171128100618.715471685@linuxfoundation.org> In-Reply-To: <20171128100613.638270407@linuxfoundation.org> References: <20171128100613.638270407@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Nicholas Bellinger commit 9574a497df2bbc0a676b609ce0dd24d237cee3a6 upstream. This patch fixes a potential end-less loop during QUEUE_FULL, where cmd->se_tfo->write_pending() callback fails repeatedly but __transport_wait_for_tasks() has already been invoked to quiese the outstanding se_cmd descriptor. To address this bug, this patch adds a CMD_T_STOP|CMD_T_ABORTED check within transport_write_pending_qf() and invokes the existing se_cmd->t_transport_stop_comp to signal quiese completion back to __transport_wait_for_tasks(). Cc: Mike Christie Cc: Hannes Reinecke Cc: Bryant G. Ly Cc: Michael Cyr Cc: Potnuri Bharat Teja Cc: Sagi Grimberg Signed-off-by: Nicholas Bellinger Signed-off-by: Greg Kroah-Hartman --- drivers/target/target_core_transport.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) --- a/drivers/target/target_core_transport.c +++ b/drivers/target/target_core_transport.c @@ -2575,7 +2575,20 @@ EXPORT_SYMBOL(transport_generic_new_cmd) static void transport_write_pending_qf(struct se_cmd *cmd) { + unsigned long flags; int ret; + bool stop; + + spin_lock_irqsave(&cmd->t_state_lock, flags); + stop = (cmd->transport_state & (CMD_T_STOP | CMD_T_ABORTED)); + spin_unlock_irqrestore(&cmd->t_state_lock, flags); + + if (stop) { + pr_debug("%s:%d CMD_T_STOP|CMD_T_ABORTED for ITT: 0x%08llx\n", + __func__, __LINE__, cmd->tag); + complete_all(&cmd->t_transport_stop_comp); + return; + } ret = cmd->se_tfo->write_pending(cmd); if (ret) {