> -----Original Message----- > From: KY Srinivasan > Sent: Sunday, March 20, 2016 11:59 AM > To: 'James Bottomley' <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx>; Martin > K. Petersen <martin.petersen@xxxxxxxxxx> > Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx>; gregkh@xxxxxxxxxxxxxxxxxxx; > linux-kernel@xxxxxxxxxxxxxxx; devel@xxxxxxxxxxxxxxxxxxxxxx; > ohering@xxxxxxxx; jbottomley@xxxxxxxxxxxxx; linux-scsi@xxxxxxxxxxxxxxx; > apw@xxxxxxxxxxxxx; vkuznets@xxxxxxxxxx; jasowang@xxxxxxxxxx; > hare@xxxxxxx > Subject: RE: [PATCH 1/1] scsi: storvsc: Support manual scan of FC hosts on > Hyper-V > > > > > -----Original Message----- > > From: James Bottomley > [mailto:James.Bottomley@xxxxxxxxxxxxxxxxxxxxx] > > Sent: Friday, March 18, 2016 3:41 PM > > To: KY Srinivasan <kys@xxxxxxxxxxxxx>; Martin K. Petersen > > <martin.petersen@xxxxxxxxxx> > > Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx>; gregkh@xxxxxxxxxxxxxxxxxxx; > > linux-kernel@xxxxxxxxxxxxxxx; devel@xxxxxxxxxxxxxxxxxxxxxx; > > ohering@xxxxxxxx; jbottomley@xxxxxxxxxxxxx; linux-scsi@xxxxxxxxxxxxxxx; > > apw@xxxxxxxxxxxxx; vkuznets@xxxxxxxxxx; jasowang@xxxxxxxxxx; > > hare@xxxxxxx > > 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? > > Yes; thank you very much James. Looking at the patch though, it may be an > overkill considering how much of the code is duplicated. The current fc > transport > class does give us the flexibility to control the attributes we want to surface > (fc_function_template). In any case I will test this code and get back to you > soon. Today I got a chance to test this patch. Looks like all the state is not getting properly set in this new transport class. I am hitting this NULL pointer reference fault in get_device_parent(). Looks like the device class is not properly setup for this transport class. class_dir_create_and_add() is not called for this class and so the glue_dirs is NULL. I fixed the issue: 1) You will need to call the transport_class_register() for this new transport class in fc_transport_init() 2) We cannot use fc_host as the name in this new class since the standard fc transport already Uses that name. I changed the name to get this to work. This will create a new directory under /sys/class. So my original goal of being compatible with existing scripts that expect to find the information under /sys/class/fc_host will not be met. Regards, K. Y > > Regards, > > K. Y > > > > > > From 7af7c428e7e04ddcc87fda12d6571e3dff8ae024 Mon Sep 17 00:00:00 > > 2001 > > From: James Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx> > > 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 <jejb@xxxxxxxxxxxxxxxxxx> > > --- > > 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 ��.n��������+%������w��{.n�����{������ܨ}���Ơz�j:+v�����w����ޙ��&�)ߡ�a����z�ޗ���ݢj��w�f
