Re: [PATCH V4 2/4] scsi: storvsc: Properly support Fibre Channel devices

From: Hannes Reinecke
Date: Mon Dec 28 2015 - 07:02:22 EST


On 12/23/2015 10:15 PM, K. Y. Srinivasan wrote:
For FC devices managed by this driver, atttach the appropriate transport
template. This will allow us to create the appropriate sysfs files for
these devices. With this we can publish the wwn for both the port and the node.

Signed-off-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx>
Reviewed-by: Long Li <longli@xxxxxxxxxxxxx>
Tested-by: Alex Ng <alexng@xxxxxxxxxxxxx>
---
V2: Fixed error paths - Dan Carpenter <dan.carpenter@xxxxxxxxxx>
V3: Fixed build issues reported by kbuild test robot <lkp@xxxxxxxxx>
V4: Handle configuration of SCSI_FC_ATTRS correctly (both module and built in)

drivers/scsi/storvsc_drv.c | 181 ++++++++++++++++++++++++++++++++-----------
1 files changed, 134 insertions(+), 47 deletions(-)

diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
index 00bb4bd..cfbb289 100644
--- a/drivers/scsi/storvsc_drv.c
+++ b/drivers/scsi/storvsc_drv.c
@@ -41,6 +41,7 @@
#include <scsi/scsi_eh.h>
#include <scsi/scsi_devinfo.h>
#include <scsi/scsi_dbg.h>
+#include <scsi/scsi_transport_fc.h>

/*
* All wire protocol details (storage protocol between the guest and the host)
@@ -397,6 +398,9 @@ static int storvsc_timeout = 180;

static int msft_blist_flags = BLIST_TRY_VPD_PAGES;

+#if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
+static struct scsi_transport_template *fc_transport_template;
+#endif

static void storvsc_on_channel_callback(void *context);

@@ -456,6 +460,11 @@ struct storvsc_device {
/* Used for vsc/vsp channel reset process */
struct storvsc_cmd_request init_request;
struct storvsc_cmd_request reset_request;
+ /*
+ * Currently active port and node names for FC devices.
+ */
+ u64 node_name;
+ u64 port_name;
};

struct hv_host_device {
@@ -695,7 +704,26 @@ static void handle_multichannel_storage(struct hv_device *device, int max_chns)
vmbus_are_subchannels_present(device->channel);
}

-static int storvsc_channel_init(struct hv_device *device)
+static void cache_wwn(struct storvsc_device *stor_device,
+ struct vstor_packet *vstor_packet)
+{
+ /*
+ * Cache the currently active port and node ww names.
+ */
+ if (vstor_packet->wwn_packet.primary_active) {
+ stor_device->node_name =
+ wwn_to_u64(vstor_packet->wwn_packet.primary_node_wwn);
+ stor_device->port_name =
+ wwn_to_u64(vstor_packet->wwn_packet.primary_port_wwn);
+ } else {
+ stor_device->node_name =
+ wwn_to_u64(vstor_packet->wwn_packet.secondary_node_wwn);
+ stor_device->port_name =
+ wwn_to_u64(vstor_packet->wwn_packet.secondary_port_wwn);
+ }
+}
+
+static int storvsc_channel_init(struct hv_device *device, bool is_fc)
{
struct storvsc_device *stor_device;
struct storvsc_cmd_request *request;
@@ -727,19 +755,15 @@ static int storvsc_channel_init(struct hv_device *device)
VM_PKT_DATA_INBAND,
VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
if (ret != 0)
- goto cleanup;
+ return ret;

t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
- if (t == 0) {
- ret = -ETIMEDOUT;
- goto cleanup;
- }
+ if (t == 0)
+ return -ETIMEDOUT;

if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
- vstor_packet->status != 0) {
- ret = -EINVAL;
- goto cleanup;
- }
+ vstor_packet->status != 0)
+ return -EINVAL;


for (i = 0; i < ARRAY_SIZE(vmstor_protocols); i++) {
@@ -764,18 +788,14 @@ static int storvsc_channel_init(struct hv_device *device)
VM_PKT_DATA_INBAND,
VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
if (ret != 0)
- goto cleanup;
+ return ret;

t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
- if (t == 0) {
- ret = -ETIMEDOUT;
- goto cleanup;
- }
+ if (t == 0)
+ return -ETIMEDOUT;

- if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO) {
- ret = -EINVAL;
- goto cleanup;
- }
+ if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO)
+ return -EINVAL;

if (vstor_packet->status == 0) {
vmstor_proto_version =
@@ -791,10 +811,8 @@ static int storvsc_channel_init(struct hv_device *device)
}
}

- if (vstor_packet->status != 0) {
- ret = -EINVAL;
- goto cleanup;
- }
+ if (vstor_packet->status != 0)
+ return -EINVAL;


memset(vstor_packet, 0, sizeof(struct vstor_packet));
@@ -809,19 +827,15 @@ static int storvsc_channel_init(struct hv_device *device)
VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);

if (ret != 0)
- goto cleanup;
+ return ret;

t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
- if (t == 0) {
- ret = -ETIMEDOUT;
- goto cleanup;
- }
+ if (t == 0)
+ return -ETIMEDOUT;

if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
- vstor_packet->status != 0) {
- ret = -EINVAL;
- goto cleanup;
- }
+ vstor_packet->status != 0)
+ return -EINVAL;

/*
* Check to see if multi-channel support is there.
@@ -837,6 +851,38 @@ static int storvsc_channel_init(struct hv_device *device)
stor_device->max_transfer_bytes =
vstor_packet->storage_channel_properties.max_transfer_bytes;

+ if (!is_fc)
+ goto done;
+
+ memset(vstor_packet, 0, sizeof(struct vstor_packet));
+ vstor_packet->operation = VSTOR_OPERATION_FCHBA_DATA;
+ vstor_packet->flags = REQUEST_COMPLETION_FLAG;
+
+ ret = vmbus_sendpacket(device->channel, vstor_packet,
+ (sizeof(struct vstor_packet) -
+ vmscsi_size_delta),
+ (unsigned long)request,
+ VM_PKT_DATA_INBAND,
+ VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
+
+ if (ret != 0)
+ return ret;
+
+ t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
+ if (t == 0)
+ return -ETIMEDOUT;
+
+ if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
+ vstor_packet->status != 0)
+ return -EINVAL;
+
+ /*
+ * Cache the currently active port and node ww names.
+ */
+ cache_wwn(stor_device, vstor_packet);
+
+done:
+
memset(vstor_packet, 0, sizeof(struct vstor_packet));
vstor_packet->operation = VSTOR_OPERATION_END_INITIALIZATION;
vstor_packet->flags = REQUEST_COMPLETION_FLAG;
@@ -849,25 +895,19 @@ static int storvsc_channel_init(struct hv_device *device)
VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);

if (ret != 0)
- goto cleanup;
+ return ret;

t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
- if (t == 0) {
- ret = -ETIMEDOUT;
- goto cleanup;
- }
+ if (t == 0)
+ return -ETIMEDOUT;

if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
- vstor_packet->status != 0) {
- ret = -EINVAL;
- goto cleanup;
- }
+ vstor_packet->status != 0)
+ return -EINVAL;

if (process_sub_channels)
handle_multichannel_storage(device, max_chns);

-
-cleanup:
return ret;
}

@@ -1076,6 +1116,14 @@ static void storvsc_on_receive(struct hv_device *device,
schedule_work(&work->work);
break;

+ case VSTOR_OPERATION_FCHBA_DATA:
+ stor_device = get_in_stor_device(device);
+ cache_wwn(stor_device, vstor_packet);
+#if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
+ fc_host_node_name(stor_device->host) = stor_device->node_name;
+ fc_host_port_name(stor_device->host) = stor_device->port_name;
+#endif
+ break;
default:
break;
}
@@ -1131,7 +1179,8 @@ static void storvsc_on_channel_callback(void *context)
return;
}

-static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size)
+static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size,
+ bool is_fc)
{
struct vmstorage_channel_properties props;
int ret;
@@ -1148,7 +1197,7 @@ static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size)
if (ret != 0)
return ret;

- ret = storvsc_channel_init(device);
+ ret = storvsc_channel_init(device, is_fc);

return ret;
}
@@ -1573,6 +1622,7 @@ static int storvsc_probe(struct hv_device *device,
struct Scsi_Host *host;
struct hv_host_device *host_dev;
bool dev_is_ide = ((dev_id->driver_data == IDE_GUID) ? true : false);
+ bool is_fc = ((dev_id->driver_data == SFC_GUID) ? true : false);
int target = 0;
struct storvsc_device *stor_device;
int max_luns_per_target;
@@ -1630,7 +1680,7 @@ static int storvsc_probe(struct hv_device *device,
hv_set_drvdata(device, stor_device);

stor_device->port_number = host->host_no;
- ret = storvsc_connect_to_vsp(device, storvsc_ringbuffer_size);
+ ret = storvsc_connect_to_vsp(device, storvsc_ringbuffer_size, is_fc);
if (ret)
goto err_out1;

@@ -1642,6 +1692,9 @@ static int storvsc_probe(struct hv_device *device,
host->max_lun = STORVSC_FC_MAX_LUNS_PER_TARGET;
host->max_id = STORVSC_FC_MAX_TARGETS;
host->max_channel = STORVSC_FC_MAX_CHANNELS - 1;
+#if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
+ host->transportt = fc_transport_template;
+#endif
break;

case SCSI_GUID:
@@ -1681,6 +1734,12 @@ static int storvsc_probe(struct hv_device *device,
goto err_out2;
}
}
+#if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
+ if (host->transportt == fc_transport_template) {
+ fc_host_node_name(host) = stor_device->node_name;
+ fc_host_port_name(host) = stor_device->port_name;
+ }
+#endif
return 0;

err_out2:
@@ -1706,6 +1765,10 @@ static int storvsc_remove(struct hv_device *dev)
struct storvsc_device *stor_device = hv_get_drvdata(dev);
struct Scsi_Host *host = stor_device->host;

+#if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
+ if (host->transportt == fc_transport_template)
+ fc_remove_host(host);
+#endif
scsi_remove_host(host);
storvsc_dev_remove(dev);
scsi_host_put(host);
@@ -1720,8 +1783,16 @@ static struct hv_driver storvsc_drv = {
.remove = storvsc_remove,
};

+#if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
+static struct fc_function_template fc_transport_functions = {
+ .show_host_node_name = 1,
+ .show_host_port_name = 1,
+};
+#endif
+
static int __init storvsc_drv_init(void)
{
+ int ret;

/*
* Divide the ring buffer data size (which is 1 page less
@@ -1736,12 +1807,28 @@ static int __init storvsc_drv_init(void)
vmscsi_size_delta,
sizeof(u64)));

- return vmbus_driver_register(&storvsc_drv);
+#if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
+ fc_transport_template = fc_attach_transport(&fc_transport_functions);
+ if (!fc_transport_template)
+ return -ENODEV;
+#endif
+
+ ret = vmbus_driver_register(&storvsc_drv);
+
+#if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
+ if (ret)
+ fc_release_transport(fc_transport_template);
+#endif
+
+ return ret;
}

static void __exit storvsc_drv_exit(void)
{
vmbus_driver_unregister(&storvsc_drv);
+#if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
+ fc_release_transport(fc_transport_template);
+#endif
}

MODULE_LICENSE("GPL");

My original question still stands: Where is the point if supporting FC devices if CONFIG_SCSI_FC_ATTRS is disabled?
I would rather disable FC support completely if that option is deselected; otherwise you'll end up with a strange cross-breed which presents FC LUNs but no attributes.

Cheers,

Hannes
--
Dr. Hannes Reinecke zSeries & Storage
hare@xxxxxxx +49 911 74053 688
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: J. Hawn, J. Guild, F. Imendörffer, HRB 16746 (AG Nürnberg)
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