From 7e0e4e0958ef794ee868838249880d5c521ff761 Mon Sep 17 00:00:00 2001 From: Steffen Maier Date: Thu, 12 Mar 2020 18:44:59 +0100 Subject: scsi: zfcp: fix fc_host attributes that should be unknown on local link down When we get an unsolicited notification on local link went down, zfcp_fsf_status_read_link_down() calls zfcp_fsf_link_down_info_eval(). This only blocks rports, and sets ZFCP_STATUS_ADAPTER_LINK_UNPLUGGED and ZFCP_STATUS_COMMON_ERP_FAILED. Only the fc_host port_state changes to "Linkdown", because zfcp_scsi_get_host_port_state() is an active callback and uses the adapter status. Other fc_host attributes model, port_id, port_type, speed, fabric_name (and zfcp device attributes card_version, peer_wwpn, peer_wwnn, peer_d_id) which depend on a local link, continued to show their last known "good" value. Only if something triggered an exchange config data, some values were updated to their unknown equivalent via case FSF_EXCHANGE_CONFIG_DATA_INCOMPLETE due to local link down. Triggers for exchange config data are adapter recovery, or reading any of the following zfcp-specific scsi host sysfs attributes "requests", "megabytes", or "seconds_active" in /sys/devices/css*/*.*.*/*.*.*/host*/scsi_host/host*/. The other fc_host attributes active_fc4s and permanent_port_name continued to show their last known "good" value. Only if something triggered an exchange port data, some values changed. Active_fc4s became all zeros as unknown equivalent during link down. Permanent_port_name does not depend on a local link. But for non-NPIV FCP devices, permanent_port_name erroneously became whatever value fc_host port_name had at that point in time (see previous paragraph). Triggers for exchange port data are the zfcp-specific scsi host sysfs attribute "utilization", or [{reset,get}_fc_host_stats] write anything into "reset_statistics" or read any of the other attributes under /sys/devices/css*/*.*.*/*.*.*/host*/fc_host/host*/statistics/. (cf. v4.9 commit bd77befa5bcf ("zfcp: fix fc_host port_type with NPIV")) This is particularly confusing when using "lszfcp -b -Ha" or dbginfo.sh which read fc_host attributes and also scsi_host attributes. After link down, the first invocation produces (abbreviated): Class = "fc_host" active_fc4s = "0x00 0x00 0x01 0x00 ..." ... fabric_name = "0x10000027f8e04c49" ... permanent_port_name = "0xc05076e4588059c1" port_id = "0x244800" port_state = "Linkdown" port_type = "NPort (fabric via point-to-point)" ... speed = "16 Gbit" Class = "scsi_host" ... megabytes = "0 0" ... requests = "0 0 0" seconds_active = "37" ... utilization = "0 0 0" The second and next invocations produce (abbreviated): Class = "fc_host" active_fc4s = "0x00 0x00 0x00 0x00 ..." ... fabric_name = "0x0" ... permanent_port_name = "0x0" port_id = "0x000000" port_state = "Linkdown" port_type = "Unknown" ... speed = "unknown" Class = "scsi_host" ... megabytes = "0 0" ... requests = "0 0 0" seconds_active = "38" ... utilization = "0 0 0" Factor out the resetting of local link dependent fc_host attributes from zfcp_fsf_exchange_config_data_handler() case FSF_EXCHANGE_CONFIG_DATA_INCOMPLETE into a new helper function zfcp_fsf_fc_host_link_down(). All code places that detect local link down (SRB, FSF_PROT_LINK_DOWN, xconf data/port incomplete) call zfcp_fsf_link_down_info_eval(). Call the new helper from there. This works because zfcp_fsf_link_down_info_eval() and thus the helper is called before zfcp_fsf_exchange_{config,port}_evaluate(). Port_name and node_name are always valid, so never reset them. Get the permanent_port_name from exchange port data unconditionally as it always has a valid known good value, even during link down. Note: Rather than hardcode in zfcp_fsf_exchange_config_evaluate(), fc_host supported_classes could theoretically get its value from fsf_qtcb_bottom_port.class_of_service in zfcp_fsf_exchange_port_evaluate(). When the link comes back, we get a different notification, perform adapter recovery, and this triggers an implicit exchange config data followed by exchange port data filling in the link dependent fc_host attributes with known good values again. Link: https://lore.kernel.org/r/20200312174505.51294-5-maier@linux.ibm.com Reviewed-by: Jens Remus Reviewed-by: Benjamin Block Signed-off-by: Steffen Maier Signed-off-by: Martin K. Petersen --- drivers/s390/scsi/zfcp_fsf.c | 39 +++++++++++++++++++++------------------ 1 file changed, 21 insertions(+), 18 deletions(-) (limited to 'drivers/s390/scsi') diff --git a/drivers/s390/scsi/zfcp_fsf.c b/drivers/s390/scsi/zfcp_fsf.c index 31ecbc160482..1fa94277d287 100644 --- a/drivers/s390/scsi/zfcp_fsf.c +++ b/drivers/s390/scsi/zfcp_fsf.c @@ -120,6 +120,23 @@ static void zfcp_fsf_status_read_port_closed(struct zfcp_fsf_req *req) read_unlock_irqrestore(&adapter->port_list_lock, flags); } +static void zfcp_fsf_fc_host_link_down(struct zfcp_adapter *adapter) +{ + struct Scsi_Host *shost = adapter->scsi_host; + + fc_host_port_id(shost) = 0; + fc_host_fabric_name(shost) = 0; + fc_host_speed(shost) = FC_PORTSPEED_UNKNOWN; + fc_host_port_type(shost) = FC_PORTTYPE_UNKNOWN; + adapter->hydra_version = 0; + snprintf(fc_host_model(shost), FC_SYMBOLIC_NAME_SIZE, "0x%04x", 0); + memset(fc_host_active_fc4s(shost), 0, FC_FC4_LIST_SIZE); + + adapter->peer_wwpn = 0; + adapter->peer_wwnn = 0; + adapter->peer_d_id = 0; +} + static void zfcp_fsf_link_down_info_eval(struct zfcp_fsf_req *req, struct fsf_link_down_info *link_down) { @@ -132,6 +149,8 @@ static void zfcp_fsf_link_down_info_eval(struct zfcp_fsf_req *req, zfcp_scsi_schedule_rports_block(adapter); + zfcp_fsf_fc_host_link_down(adapter); + if (!link_down) goto out; @@ -512,9 +531,6 @@ static int zfcp_fsf_exchange_config_evaluate(struct zfcp_fsf_req *req) adapter->stat_read_buf_num = max(bottom->status_read_buf_num, (u16)FSF_STATUS_READS_RECOM); - if (fc_host_permanent_port_name(shost) == -1) - fc_host_permanent_port_name(shost) = fc_host_port_name(shost); - zfcp_scsi_set_prot(adapter); /* no error return above here, otherwise must fix call chains */ @@ -608,16 +624,6 @@ static void zfcp_fsf_exchange_config_data_handler(struct zfcp_fsf_req *req) zfcp_diag_update_xdata(diag_hdr, bottom, true); req->status |= ZFCP_STATUS_FSFREQ_XDATAINCOMPLETE; - fc_host_node_name(shost) = 0; - fc_host_port_name(shost) = 0; - fc_host_port_id(shost) = 0; - fc_host_fabric_name(shost) = 0; - fc_host_speed(shost) = FC_PORTSPEED_UNKNOWN; - fc_host_port_type(shost) = FC_PORTTYPE_UNKNOWN; - adapter->hydra_version = 0; - snprintf(fc_host_model(shost), FC_SYMBOLIC_NAME_SIZE, "0x%04x", - 0); - /* avoids adapter shutdown to be able to recognize * events such as LINK UP */ atomic_or(ZFCP_STATUS_ADAPTER_XCONFIG_OK, @@ -667,10 +673,7 @@ static void zfcp_fsf_exchange_port_evaluate(struct zfcp_fsf_req *req) if (req->data) memcpy(req->data, bottom, sizeof(*bottom)); - if (adapter->connection_features & FSF_FEATURE_NPIV_MODE) { - fc_host_permanent_port_name(shost) = bottom->wwpn; - } else - fc_host_permanent_port_name(shost) = fc_host_port_name(shost); + fc_host_permanent_port_name(shost) = bottom->wwpn; fc_host_maxframe_size(shost) = bottom->maximum_frame_size; fc_host_supported_speeds(shost) = zfcp_fsf_convert_portspeed(bottom->supported_speed); @@ -704,9 +707,9 @@ static void zfcp_fsf_exchange_port_data_handler(struct zfcp_fsf_req *req) zfcp_diag_update_xdata(diag_hdr, bottom, true); req->status |= ZFCP_STATUS_FSFREQ_XDATAINCOMPLETE; - zfcp_fsf_exchange_port_evaluate(req); zfcp_fsf_link_down_info_eval(req, &qtcb->header.fsf_status_qual.link_down_info); + zfcp_fsf_exchange_port_evaluate(req); break; } } -- cgit v1.2.3