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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Tue, 26 Mar 2019 13:37:34 -0000 Received: from d06av22.portsmouth.uk.ibm.com (d06av22.portsmouth.uk.ibm.com [9.149.105.58]) by b06cxnps4074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x2QDbX3d39977060 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 26 Mar 2019 13:37:33 GMT Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 2BC634C04E; Tue, 26 Mar 2019 13:37:33 +0000 (GMT) Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id CA4104C050; Tue, 26 Mar 2019 13:37:32 +0000 (GMT) Received: from tuxmaker.boeblingen.de.ibm.com (unknown [9.152.85.9]) by d06av22.portsmouth.uk.ibm.com (Postfix) with ESMTPS; Tue, 26 Mar 2019 13:37:32 +0000 (GMT) From: Steffen Maier To: "James E . J . Bottomley" , "Martin K . Petersen" Cc: linux-scsi@vger.kernel.org, linux-s390@vger.kernel.org, Benjamin Block , Martin Schwidefsky , Heiko Carstens , Steffen Maier Subject: [PATCH 3/3] zfcp: reduce flood of fcrscn1 trace records on multi-element RSCN Date: Tue, 26 Mar 2019 14:37:00 +0100 X-Mailer: git-send-email 2.16.4 In-Reply-To: <20190326133700.88655-1-maier@linux.ibm.com> References: <20190326133700.88655-1-maier@linux.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 19032613-0020-0000-0000-00000327BFE5 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19032613-0021-0000-0000-00002179FCB3 Message-Id: <20190326133700.88655-4-maier@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-03-26_10:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=794 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1903260096 Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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 --- 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 db00b5e3abbe..33eddb02ee30 100644 --- a/drivers/s390/scsi/zfcp_fc.c +++ b/drivers/s390/scsi/zfcp_fc.c @@ -239,10 +239,6 @@ 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); } @@ -250,6 +246,7 @@ 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; @@ -263,6 +260,22 @@ static void zfcp_fc_incoming_rscn(struct zfcp_fsf_req *fsf_req) no_entries = be16_to_cpu(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++;