> -----Original Message-----
> From: James Bottomley [mailto:james.bottom...@hansenpartnership.com]
> Sent: Friday, March 18, 2016 3:41 PM
> To: KY Srinivasan <k...@microsoft.com>; Martin K. Petersen
> <martin.peter...@oracle.com>
> Cc: Christoph Hellwig <h...@infradead.org>; gre...@linuxfoundation.org;
> linux-ker...@vger.kernel.org; de...@linuxdriverproject.org;
> oher...@suse.com; jbottom...@parallels.com; linux-s...@vger.kernel.org;
> a...@canonical.com; vkuzn...@redhat.com; jasow...@redhat.com;
> h...@suse.de
> Subject: Re: [PATCH 1/1] scsi: storvsc: Support manual scan of FC hosts on
> Hyper-V
>
> On Thu, 2016-03-17 at 00:01 +0000, KY Srinivasan wrote:
> > The only attributes I would be interested are:
> > 1) node name
> > 2) port name
> >
> > Ideally, if this can show under /sys/class/fc_host/hostx/port_name
> > and node_name,
> > it will be ideal since all user scripts can work.
>
> OK, like this?
>
> From 7af7c428e7e04ddcc87fda12d6571e3dff8ae024 Mon Sep 17 00:00:00
> 2001
> From: James Bottomley <james.bottom...@hansenpartnership.com>
> Date: Fri, 18 Mar 2016 15:35:45 -0700
> Subject: scsi_transport_fc: introduce lightweight class for virtualization
> systems
>
> The FC transport class is very heavily tilted towards helping things
> which operate a fabric (as it should be). However, there seems to be
> a need for a lightweight version for use in virtual systems that
> simply want to show pass through FC information without making any use
> of the heavyweight functions. This is an attempt to give them what
> they want: the lightweight class has no vports or rports and only two
> host attributes. Essentially, it's designed for the HV storvsc
> driver, but if other virtualizataion systems have similar problems, we
> can add more attributes.
>
> Signed-off-by: James Bottomley <j...@linux.vnet.ibm.com>
> ---
> drivers/scsi/scsi_transport_fc.c | 94
> ++++++++++++++++++++++++++++++++++++++++
> include/scsi/scsi_transport_fc.h | 3 ++
> 2 files changed, 97 insertions(+)
>
> diff --git a/drivers/scsi/scsi_transport_fc.c
> b/drivers/scsi/scsi_transport_fc.c
> index 8a88226..a9fcb4d 100644
> --- a/drivers/scsi/scsi_transport_fc.c
> +++ b/drivers/scsi/scsi_transport_fc.c
> @@ -351,6 +351,27 @@ struct fc_internal {
>
> #define to_fc_internal(tmpl) container_of(tmpl, struct fc_internal, t)
>
> +#define FC_LW_HOST_NUM_ATTRS 2
> +struct fc_lw_internal {
> + struct scsi_transport_template t;
> + struct fc_function_template *f;
> +
> + /*
> + * For attributes : each object has :
> + * An array of the actual attributes structures
> + * An array of null-terminated pointers to the attribute
> + * structures - used for mid-layer interaction.
> + *
> + * The attribute containers for the starget and host are are
> + * part of the midlayer. As the remote port is specific to the
> + * fc transport, we must provide the attribute container.
> + */
> + struct device_attribute
> private_host_attrs[FC_LW_HOST_NUM_ATTRS];
> + struct device_attribute *host_attrs[FC_LW_HOST_NUM_ATTRS + 1];
> +};
> +
> +#define to_fc_lw_internal(tmpl) container_of(tmpl, struct
> fc_lw_internal, t)
> +
> static int fc_target_setup(struct transport_container *tc, struct device
> *dev,
> struct device *cdev)
> {
> @@ -472,6 +493,12 @@ static int fc_host_remove(struct transport_container
> *tc, struct device *dev,
> return 0;
> }
>
> +static DECLARE_TRANSPORT_CLASS(fc_lw_host_class,
> + "fc_host",
> + NULL,
> + NULL,
> + NULL);
> +
> static DECLARE_TRANSPORT_CLASS(fc_host_class,
> "fc_host",
> fc_host_setup,
> @@ -1968,6 +1995,25 @@ static int fc_host_match(struct
> attribute_container *cont,
> return &i->t.host_attrs.ac == cont;
> }
>
> +static int fc_lw_host_match(struct attribute_container *cont,
> + struct device *dev)
> +{
> + struct Scsi_Host *shost;
> + struct fc_lw_internal *i;
> +
> + if (!scsi_is_host_device(dev))
> + return 0;
> +
> + shost = dev_to_shost(dev);
> + if (!shost->transportt || shost->transportt->host_attrs.ac.class
> + != &fc_lw_host_class.class)
> + return 0;
> +
> + i = to_fc_lw_internal(shost->transportt);
> +
> + return &i->t.host_attrs.ac == cont;
> +}
> +
> static int fc_target_match(struct attribute_container *cont,
> struct device *dev)
> {
> @@ -2171,6 +2217,54 @@ static int fc_it_nexus_response(struct Scsi_Host
> *shost, u64 nexus, int result)
> return i->f->it_nexus_response(shost, nexus, result);
> }
>
> +/**
> + * fc_attach_lw_transport - light weight attach function
> + * @ft: function template for optional attributes
> + *
> + * This attach function is to be used only for virtual FC emulators
> + * which do not have a physical fabric underneath them and thus only
> + * need a few attributes and no helper functions
> + */
> +struct scsi_transport_template *
> +fc_lw_attach_transport(struct fc_function_template *ft)
> +{
> + int count;
> + struct fc_lw_internal *i = kzalloc(sizeof(struct fc_lw_internal),
> + GFP_KERNEL);
> +
> + if (unlikely(!i))
> + return NULL;
> +
> + i->t.host_attrs.ac.attrs = &i->host_attrs[0];
> + i->t.host_attrs.ac.class = &fc_lw_host_class.class;
> + i->t.host_attrs.ac.match = fc_lw_host_match;
> + i->t.host_size = sizeof(struct fc_host_attrs);
> + transport_container_register(&i->t.host_attrs);
> +
> + i->f = ft;
> +
> + count = 0;
> + SETUP_HOST_ATTRIBUTE_RD(node_name);
> + SETUP_HOST_ATTRIBUTE_RD(port_name);
> +
> + BUG_ON(count > FC_HOST_NUM_ATTRS);
> +
> + i->host_attrs[count] = NULL;
> +
> + return &i->t;
> +}
> +EXPORT_SYMBOL(fc_lw_attach_transport);
> +
> +void fc_lw_release_transport(struct scsi_transport_template *t)
> +{
> + struct fc_lw_internal *i = to_fc_lw_internal(t);
> +
> + transport_container_unregister(&i->t.host_attrs);
> +
> + kfree(i);
> +}
> +EXPORT_SYMBOL(fc_lw_release_transport);
> +
> struct scsi_transport_template *
> fc_attach_transport(struct fc_function_template *ft)
> {
> diff --git a/include/scsi/scsi_transport_fc.h
> b/include/scsi/scsi_transport_fc.h
> index 784bc2c..b0a9a64 100644
> --- a/include/scsi/scsi_transport_fc.h
> +++ b/include/scsi/scsi_transport_fc.h
> @@ -835,6 +835,9 @@ fc_vport_set_state(struct fc_vport *vport, enum
> fc_vport_state new_state)
> vport->vport_state = new_state;
> }
>
> +struct scsi_transport_template *fc_lw_attach_transport(
> + struct fc_function_template *);
> +void fc_lw_release_transport(struct scsi_transport_template *);
> struct scsi_transport_template *fc_attach_transport(
> struct fc_function_template *);
> void fc_release_transport(struct scsi_transport_template *);
> --
> 2.6.2
James,
It was great talking to you this afternoon. Is this what you had in mind:
drivers/scsi/scsi_transport_fc.c | 133 ++++++++++++++++++++++++++++++++++++--
include/scsi/scsi_transport_fc.h | 3 +
2 files changed, 130 insertions(+), 6 deletions(-)
diff --git a/drivers/scsi/scsi_transport_fc.c b/drivers/scsi/scsi_transport_fc.c
index 24eaaf6..b8cadd2 100644
--- a/drivers/scsi/scsi_transport_fc.c
+++ b/drivers/scsi/scsi_transport_fc.c
@@ -351,6 +351,27 @@ struct fc_internal {
#define to_fc_internal(tmpl) container_of(tmpl, struct fc_internal, t)
+#define FC_LW_HOST_NUM_ATTRS 2
+struct fc_lw_internal {
+ struct scsi_transport_template t;
+ struct fc_function_template *f;
+
+ /*
+ * For attributes : each object has :
+ * An array of the actual attributes structures
+ * An array of null-terminated pointers to the attribute
+ * structures - used for mid-layer interaction.
+ *
+ * The attribute containers for the starget and host are are
+ * part of the midlayer. As the remote port is specific to the
+ * fc transport, we must provide the attribute container.
+ */
+ struct device_attribute private_host_attrs[FC_LW_HOST_NUM_ATTRS];
+ struct device_attribute *host_attrs[FC_LW_HOST_NUM_ATTRS + 1];
+};
+
+#define to_fc_lw_internal(tmpl) container_of(tmpl, struct
fc_lw_internal, t)
+
static int fc_target_setup(struct transport_container *tc, struct device *dev,
struct device *cdev)
{
@@ -472,6 +493,12 @@ static int fc_host_remove(struct transport_container *tc,
struct device *dev,
return 0;
}
+static DECLARE_TRANSPORT_CLASS(fc_lw_host_class,
+ "fc_host",
+ NULL,
+ NULL,
+ NULL);
+
static DECLARE_TRANSPORT_CLASS(fc_host_class,
"fc_host",
fc_host_setup,
@@ -654,11 +681,20 @@ send_vendor_fail:
EXPORT_SYMBOL(fc_host_post_vendor_event);
+static bool transport_inited;
+static bool lw_transport_inited;
-static __init int fc_transport_init(void)
+static int fc_transport_init(bool lw_transport)
{
int error;
+ bool inited = cmpxchg(&transport_inited, transport_inited, true);
+ /*
+ * If transport has already been inited, just return.
+ */
+ if (inited)
+ return 0;
+
atomic_set(&fc_event_seq, 0);
error = transport_class_register(&fc_host_class);
@@ -670,9 +706,15 @@ static __init int fc_transport_init(void)
error = transport_class_register(&fc_rport_class);
if (error)
goto unreg_vport_class;
- error = transport_class_register(&fc_transport_class);
+ if (lw_transport)
+ error = transport_class_register(&fc_lw_host_class);
+ else
+ error = transport_class_register(&fc_transport_class);
if (error)
goto unreg_rport_class;
+
+ if (lw_transport)
+ lw_transport_inited = true;
return 0;
unreg_rport_class:
@@ -686,8 +728,12 @@ unreg_host_class:
static void __exit fc_transport_exit(void)
{
- transport_class_unregister(&fc_transport_class);
+ if (lw_transport_inited)
+ transport_class_unregister(&fc_lw_host_class);
+ else
+ transport_class_unregister(&fc_transport_class);
transport_class_unregister(&fc_rport_class);
+ if (lw_transport_inited)
transport_class_unregister(&fc_host_class);
transport_class_unregister(&fc_vport_class);
}
@@ -1968,6 +2014,25 @@ static int fc_host_match(struct attribute_container
*cont,
return &i->t.host_attrs.ac == cont;
}
+static int fc_lw_host_match(struct attribute_container *cont,
+ struct device *dev)
+{
+ struct Scsi_Host *shost;
+ struct fc_lw_internal *i;
+
+ if (!scsi_is_host_device(dev))
+ return 0;
+
+ shost = dev_to_shost(dev);
+ if (!shost->transportt || shost->transportt->host_attrs.ac.class
+ != &fc_lw_host_class.class)
+ return 0;
+
+ i = to_fc_lw_internal(shost->transportt);
+
+ return &i->t.host_attrs.ac == cont;
+}
+
static int fc_target_match(struct attribute_container *cont,
struct device *dev)
{
@@ -2171,13 +2236,70 @@ static int fc_it_nexus_response(struct Scsi_Host
*shost, u64 nexus, int result)
return i->f->it_nexus_response(shost, nexus, result);
}
+/**
+ * fc_attach_lw_transport - light weight attach function
+ * @ft: function template for optional attributes
+ *
+ * This attach function is to be used only for virtual FC emulators
+ * which do not have a physical fabric underneath them and thus only
+ * need a few attributes and no helper functions
+ */
+struct scsi_transport_template *
+fc_lw_attach_transport(struct fc_function_template *ft)
+{
+ int count;
+ struct fc_lw_internal *i;
+
+ if (fc_transport_init(true))
+ return NULL;
+
+ i = kzalloc(sizeof(struct fc_lw_internal),
+ GFP_KERNEL);
+
+ if (unlikely(!i))
+ return NULL;
+
+ i->t.host_attrs.ac.attrs = &i->host_attrs[0];
+ i->t.host_attrs.ac.class = &fc_lw_host_class.class;
+ i->t.host_attrs.ac.match = fc_lw_host_match;
+ i->t.host_size = sizeof(struct fc_host_attrs);
+ transport_container_register(&i->t.host_attrs);
+
+ i->f = ft;
+
+ count = 0;
+ SETUP_HOST_ATTRIBUTE_RD(node_name);
+ SETUP_HOST_ATTRIBUTE_RD(port_name);
+
+ BUG_ON(count > FC_HOST_NUM_ATTRS);
+
+ i->host_attrs[count] = NULL;
+
+ return &i->t;
+}
+EXPORT_SYMBOL(fc_lw_attach_transport);
+
+void fc_lw_release_transport(struct scsi_transport_template *t)
+{
+ struct fc_lw_internal *i = to_fc_lw_internal(t);
+
+ transport_container_unregister(&i->t.host_attrs);
+
+ kfree(i);
+}
+EXPORT_SYMBOL(fc_lw_release_transport);
+
struct scsi_transport_template *
fc_attach_transport(struct fc_function_template *ft)
{
int count;
- struct fc_internal *i = kzalloc(sizeof(struct fc_internal),
- GFP_KERNEL);
+ struct fc_internal *i;
+
+ if (fc_transport_init(false))
+ return NULL;
+ i = kzalloc(sizeof(struct fc_internal),
+ GFP_KERNEL);
if (unlikely(!i))
return NULL;
@@ -4148,5 +4270,4 @@ MODULE_AUTHOR("James Smart");
MODULE_DESCRIPTION("FC Transport Attributes");
MODULE_LICENSE("GPL");
-module_init(fc_transport_init);
module_exit(fc_transport_exit);
diff --git a/include/scsi/scsi_transport_fc.h b/include/scsi/scsi_transport_fc.h
index 784bc2c..b0a9a64 100644
--- a/include/scsi/scsi_transport_fc.h
+++ b/include/scsi/scsi_transport_fc.h
@@ -835,6 +835,9 @@ fc_vport_set_state(struct fc_vport *vport, enum
fc_vport_state new_state)
vport->vport_state = new_state;
}
+struct scsi_transport_template *fc_lw_attach_transport(
+ struct fc_function_template *);
+void fc_lw_release_transport(struct scsi_transport_template *);
struct scsi_transport_template *fc_attach_transport(
struct fc_function_template *);
void fc_release_transport(struct scsi_transport_template *);
--
1.7.4.1
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