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 64784C282CE for ; Mon, 22 Apr 2019 19:50:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2A85621738 for ; Mon, 22 Apr 2019 19:50:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1555962627; bh=nCJH+M4OiG25caNM7scUkmrL7vcAYvQIldlSCZyxsvI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=wmoqJ8nTCJUO43P48WEXdYHun5zoEtmB0LpeSzTwfQiT6dcQ//RSaCCNV1lnmkVa2 rZNkBGtU40COufbZ1tUmzG1xF+3BPCgPQ7EXwWdiAG/V47a7n03LHsYcR1xWhXVoZj /uzuHYhdSIdXoyeXK6Q5fiClqWChX79DtHO7UOIo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731089AbfDVTu0 (ORCPT ); Mon, 22 Apr 2019 15:50:26 -0400 Received: from mail.kernel.org ([198.145.29.99]:54224 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731050AbfDVTuT (ORCPT ); Mon, 22 Apr 2019 15:50:19 -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 6972620643; Mon, 22 Apr 2019 19:50:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1555962618; bh=nCJH+M4OiG25caNM7scUkmrL7vcAYvQIldlSCZyxsvI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=y+9klNqvCS/04w0oDCS1BcdqUYSqRL23sL0odvbYwt9tWPD/z269e6b6RN52x2bMD KkJxR26ZbyHZvYRtUh45p+QXZ3VVcJS1496Rghyra8GCnrSCuIQtqXvPeLecf/oZX4 okx2PhJWisZJPnWL0VFQxqlv3794hFJvjxzH3AaM= 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 4.4 19/21] scsi: zfcp: reduce flood of fcrscn1 trace records on multi-element RSCN Date: Mon, 22 Apr 2019 15:49:39 -0400 Message-Id: <20190422194941.13433-19-sashal@kernel.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20190422194941.13433-1-sashal@kernel.org> References: <20190422194941.13433-1-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