From: Benjamin Block <bblock@linux.ibm.com>
Date: Fri, 25 Oct 2019 18:12:43 +0200
Subject: scsi: zfcp: signal incomplete or error for sync exchange config/port
data
Patch-mainline: v5.5-rc1
Git-commit: 92953c6e0aa77d4febcca6dd691e8192910c8a28
References: bsc#1158050
Adds a new FSF-Request status flag (ZFCP_STATUS_FSFREQ_XDATAINCOMPLETE)
that signal that the data received using Exchange Config Data or Exchange
Port Data was incomplete. This new flags is set in the respective handlers
during the response path.
With this patch, only the synchronous FSF-functions for each command got
support for the new flag, otherwise it is transparent.
Together with this new flag and already existing status flags the
synchronous FSF-functions are extended to now detect whether the received
data is complete, incomplete or completely invalid (this includes cases
where a command ran into a timeout). This is now signaled back to the
caller, where previously only failures on the request path would result in
a bad return-code.
For complete data the return-code remains 0. For incomplete data a new
return-code -EAGAIN is added to the function-interface. For completely
invalid data the already existing return-code -EIO is reused - formerly
this was used to signal failures on the request path.
Existing callers of the FSF-functions are adjusted so that they behave as
before for return-code 0 and -EAGAIN, to not change the user-interface. As
-EIO existed all along, it was already exposed to the user - and needed
handling - and will now also be exposed in this new special case.
Link: https://lore.kernel.org/r/e14f0702fa2b00a4d1f37c7981a13f2dd1ea2c83.1572018130.git.bblock@linux.ibm.com
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Martin Wilck <mwilck@suse.com>
---
drivers/s390/scsi/zfcp_def.h | 1
drivers/s390/scsi/zfcp_fsf.c | 46 ++++++++++++++++++++++++++++++++++++-----
drivers/s390/scsi/zfcp_scsi.c | 4 +--
drivers/s390/scsi/zfcp_sysfs.c | 4 +--
4 files changed, 46 insertions(+), 9 deletions(-)
--- a/drivers/s390/scsi/zfcp_def.h
+++ b/drivers/s390/scsi/zfcp_def.h
@@ -86,6 +86,7 @@
#define ZFCP_STATUS_FSFREQ_ABORTNOTNEEDED 0x00000080
#define ZFCP_STATUS_FSFREQ_TMFUNCFAILED 0x00000200
#define ZFCP_STATUS_FSFREQ_DISMISSED 0x00001000
+#define ZFCP_STATUS_FSFREQ_XDATAINCOMPLETE 0x00020000
/************************* STRUCTURE DEFINITIONS *****************************/
--- a/drivers/s390/scsi/zfcp_fsf.c
+++ b/drivers/s390/scsi/zfcp_fsf.c
@@ -585,6 +585,8 @@ static void zfcp_fsf_exchange_config_dat
&adapter->status);
break;
case FSF_EXCHANGE_CONFIG_DATA_INCOMPLETE:
+ req->status |= ZFCP_STATUS_FSFREQ_XDATAINCOMPLETE;
+
fc_host_node_name(shost) = 0;
fc_host_port_name(shost) = 0;
fc_host_port_id(shost) = 0;
@@ -663,6 +665,8 @@ static void zfcp_fsf_exchange_port_data_
zfcp_fsf_exchange_port_evaluate(req);
break;
case FSF_EXCHANGE_CONFIG_DATA_INCOMPLETE:
+ 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);
@@ -1278,6 +1282,19 @@ out:
return retval;
}
+
+/**
+ * zfcp_fsf_exchange_config_data_sync() - Request information about FCP channel.
+ * @qdio: pointer to the QDIO-Queue to use for sending the command.
+ * @data: pointer to the QTCB-Bottom for storing the result of the command,
+ * might be %NULL.
+ *
+ * Returns:
+ * * 0 - Exchange Config Data was successful, @data is complete
+ * * -EIO - Exchange Config Data was not successful, @data is invalid
+ * * -EAGAIN - @data contains incomplete data
+ * * -ENOMEM - Some memory allocation failed along the way
+ */
int zfcp_fsf_exchange_config_data_sync(struct zfcp_qdio *qdio,
struct fsf_qtcb_bottom_config *data)
{
@@ -1309,9 +1326,16 @@ int zfcp_fsf_exchange_config_data_sync(s
zfcp_fsf_start_timer(req, ZFCP_FSF_REQUEST_TIMEOUT);
retval = zfcp_fsf_req_send(req);
spin_unlock_irq(&qdio->req_q_lock);
+
if (!retval) {
/* NOTE: ONLY TOUCH SYNC req AGAIN ON req->completion. */
wait_for_completion(&req->completion);
+
+ if (req->status &
+ (ZFCP_STATUS_FSFREQ_ERROR | ZFCP_STATUS_FSFREQ_DISMISSED))
+ retval = -EIO;
+ else if (req->status & ZFCP_STATUS_FSFREQ_XDATAINCOMPLETE)
+ retval = -EAGAIN;
}
zfcp_fsf_req_free(req);
@@ -1369,10 +1393,17 @@ out:
}
/**
- * zfcp_fsf_exchange_port_data_sync - request information about local port
- * @qdio: pointer to struct zfcp_qdio
- * @data: pointer to struct fsf_qtcb_bottom_port
- * Returns: 0 on success, error otherwise
+ * zfcp_fsf_exchange_port_data_sync() - Request information about local port.
+ * @qdio: pointer to the QDIO-Queue to use for sending the command.
+ * @data: pointer to the QTCB-Bottom for storing the result of the command,
+ * might be %NULL.
+ *
+ * Returns:
+ * * 0 - Exchange Port Data was successful, @data is complete
+ * * -EIO - Exchange Port Data was not successful, @data is invalid
+ * * -EAGAIN - @data contains incomplete data
+ * * -ENOMEM - Some memory allocation failed along the way
+ * * -EOPNOTSUPP - This operation is not supported
*/
int zfcp_fsf_exchange_port_data_sync(struct zfcp_qdio *qdio,
struct fsf_qtcb_bottom_port *data)
@@ -1408,10 +1439,15 @@ int zfcp_fsf_exchange_port_data_sync(str
if (!retval) {
/* NOTE: ONLY TOUCH SYNC req AGAIN ON req->completion. */
wait_for_completion(&req->completion);
+
+ if (req->status &
+ (ZFCP_STATUS_FSFREQ_ERROR | ZFCP_STATUS_FSFREQ_DISMISSED))
+ retval = -EIO;
+ else if (req->status & ZFCP_STATUS_FSFREQ_XDATAINCOMPLETE)
+ retval = -EAGAIN;
}
zfcp_fsf_req_free(req);
-
return retval;
out_unlock:
--- a/drivers/s390/scsi/zfcp_scsi.c
+++ b/drivers/s390/scsi/zfcp_scsi.c
@@ -605,7 +605,7 @@ zfcp_scsi_get_fc_host_stats(struct Scsi_
return NULL;
ret = zfcp_fsf_exchange_port_data_sync(adapter->qdio, data);
- if (ret) {
+ if (ret != 0 && ret != -EAGAIN) {
kfree(data);
return NULL;
}
@@ -634,7 +634,7 @@ static void zfcp_scsi_reset_fc_host_stat
return;
ret = zfcp_fsf_exchange_port_data_sync(adapter->qdio, data);
- if (ret)
+ if (ret != 0 && ret != -EAGAIN)
kfree(data);
else {
adapter->stats_reset = jiffies/HZ;
--- a/drivers/s390/scsi/zfcp_sysfs.c
+++ b/drivers/s390/scsi/zfcp_sysfs.c
@@ -577,7 +577,7 @@ static ssize_t zfcp_sysfs_adapter_util_s
return -ENOMEM;
retval = zfcp_fsf_exchange_port_data_sync(adapter->qdio, qtcb_port);
- if (!retval)
+ if (retval == 0 || retval == -EAGAIN)
retval = sprintf(buf, "%u %u %u\n", qtcb_port->cp_util,
qtcb_port->cb_util, qtcb_port->a_util);
kfree(qtcb_port);
@@ -603,7 +603,7 @@ static int zfcp_sysfs_adapter_ex_config(
return -ENOMEM;
retval = zfcp_fsf_exchange_config_data_sync(adapter->qdio, qtcb_config);
- if (!retval)
+ if (retval == 0 || retval == -EAGAIN)
*stat_inf = qtcb_config->stat_info;
kfree(qtcb_config);