From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 91EABC10F11 for ; Mon, 22 Apr 2019 19:49:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6006E2175B for ; Mon, 22 Apr 2019 19:49:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1555962591; bh=nCJH+M4OiG25caNM7scUkmrL7vcAYvQIldlSCZyxsvI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=FEFWv3ei9j2flHK4O7ZBrBE0YJL81rPj6NXeRXiaItyOAPAWDbReVCyHkk05C1AzI UlzAN4Enw7UecG0rRsu8K67xclZv4+2cuARR3eBTelxdU+ovbGzGiHEW5kpNMXZ8lW 1whbY5KYprVNwAQZzS5PHuTYjTWP2CATbz58mXyw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730941AbfDVTtt (ORCPT ); Mon, 22 Apr 2019 15:49:49 -0400 Received: from mail.kernel.org ([198.145.29.99]:53446 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730884AbfDVTtg (ORCPT ); Mon, 22 Apr 2019 15:49:36 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D68A42175B; Mon, 22 Apr 2019 19:49:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1555962575; bh=nCJH+M4OiG25caNM7scUkmrL7vcAYvQIldlSCZyxsvI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=T3TfdjFS63oynWM2eNtQGMWpSwH6y5PRNfX5ZG52Jhu/cstUycWYojTm8uVg9IFgg aCiGnLhK+5TgZZRGnmVvUeLs387+tfi8XT1DMecXvDuTvS7dqGmncvnuFGWwk78kjV WciOw8Jv1TtuPXyTkiCwy7QydBxHN9TDMh+D809o= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Steffen Maier , "Martin K . Petersen" , Sasha Levin , linux-s390@vger.kernel.org Subject: [PATCH AUTOSEL 4.9 25/29] scsi: zfcp: reduce flood of fcrscn1 trace records on multi-element RSCN Date: Mon, 22 Apr 2019 15:48:44 -0400 Message-Id: <20190422194848.13049-25-sashal@kernel.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20190422194848.13049-1-sashal@kernel.org> References: <20190422194848.13049-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Steffen Maier [ Upstream commit c8206579175c34a2546de8a74262456278a7795a ] If an incoming ELS of type RSCN contains more than one element, zfcp suboptimally causes repeated erp trigger NOP trace records for each previously failed port. These could be ports that went away. It loops over each RSCN element, and for each of those in an inner loop over all zfcp_ports. The trigger to recover failed ports should be just the reception of some RSCN, no matter how many elements it has. So we can loop over failed ports separately, and only then loop over each RSCN element to handle the non-failed ports. The call chain was: zfcp_fc_incoming_rscn for (i = 1; i < no_entries; i++) _zfcp_fc_incoming_rscn list_for_each_entry(port, &adapter->port_list, list) if (masked port->d_id match) zfcp_fc_test_link if (!port->d_id) zfcp_erp_port_reopen "fcrscn1" <=== In order the reduce the "flooding" of the REC trace area in such cases, we factor out handling the failed ports to be outside of the entries loop: zfcp_fc_incoming_rscn if (no_entries > 1) <=== list_for_each_entry(port, &adapter->port_list, list) <=== if (!port->d_id) zfcp_erp_port_reopen "fcrscn1" <=== for (i = 1; i < no_entries; i++) _zfcp_fc_incoming_rscn list_for_each_entry(port, &adapter->port_list, list) if (masked port->d_id match) zfcp_fc_test_link Abbreviated example trace records before this code change: Tag : fcrscn1 WWPN : 0x500507630310d327 ERP want : 0x02 ERP need : 0x02 Tag : fcrscn1 WWPN : 0x500507630310d327 ERP want : 0x02 ERP need : 0x00 NOP => superfluous trace record The last trace entry repeats if there are more than 2 RSCN elements. Signed-off-by: Steffen Maier Reviewed-by: Benjamin Block Reviewed-by: Jens Remus Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin (Microsoft) --- drivers/s390/scsi/zfcp_fc.c | 21 +++++++++++++++++---- 1 file changed, 17 insertions(+), 4 deletions(-) diff --git a/drivers/s390/scsi/zfcp_fc.c b/drivers/s390/scsi/zfcp_fc.c index 237688af179b..f7630cf581cd 100644 --- a/drivers/s390/scsi/zfcp_fc.c +++ b/drivers/s390/scsi/zfcp_fc.c @@ -238,10 +238,6 @@ static void _zfcp_fc_incoming_rscn(struct zfcp_fsf_req *fsf_req, u32 range, list_for_each_entry(port, &adapter->port_list, list) { if ((port->d_id & range) == (ntoh24(page->rscn_fid) & range)) zfcp_fc_test_link(port); - if (!port->d_id) - zfcp_erp_port_reopen(port, - ZFCP_STATUS_COMMON_ERP_FAILED, - "fcrscn1"); } read_unlock_irqrestore(&adapter->port_list_lock, flags); } @@ -249,6 +245,7 @@ static void _zfcp_fc_incoming_rscn(struct zfcp_fsf_req *fsf_req, u32 range, static void zfcp_fc_incoming_rscn(struct zfcp_fsf_req *fsf_req) { struct fsf_status_read_buffer *status_buffer = (void *)fsf_req->data; + struct zfcp_adapter *adapter = fsf_req->adapter; struct fc_els_rscn *head; struct fc_els_rscn_page *page; u16 i; @@ -261,6 +258,22 @@ static void zfcp_fc_incoming_rscn(struct zfcp_fsf_req *fsf_req) /* see FC-FS */ no_entries = head->rscn_plen / sizeof(struct fc_els_rscn_page); + if (no_entries > 1) { + /* handle failed ports */ + unsigned long flags; + struct zfcp_port *port; + + read_lock_irqsave(&adapter->port_list_lock, flags); + list_for_each_entry(port, &adapter->port_list, list) { + if (port->d_id) + continue; + zfcp_erp_port_reopen(port, + ZFCP_STATUS_COMMON_ERP_FAILED, + "fcrscn1"); + } + read_unlock_irqrestore(&adapter->port_list_lock, flags); + } + for (i = 1; i < no_entries; i++) { /* skip head and start with 1st element */ page++; -- 2.19.1