[libvirt] [PATCH v3 4/4] storage: Disallow usage of the HBA for a fc_host backing

John Ferlan posted 4 patches 7 years, 9 months ago
[libvirt] [PATCH v3 4/4] storage: Disallow usage of the HBA for a fc_host backing
Posted by John Ferlan 7 years, 9 months ago
Disallow providing the wwnn/wwpn of the HBA in the adapter XML:

  <adapter type='fc_host' [parent='scsi_hostN'] wwnn='HBA_wwnn'
    wwpn='HBA_wwpn'/>

This should be considered a configuration error since a vHBA
would not be created. In order to use the HBA as the backing the
following XML should be used:

  <adapter type='scsi_host' name='scsi_hostN'/>

This also alters the caller such that the @parent_name param
into checkParent can be NULL so as to confirm that at least
the provided wwnn/wwpn found a vHBA instead of an HBA.

Signed-off-by: John Ferlan <jferlan@redhat.com>
---
 docs/formatstorage.html.in         | 27 +++++++++++++----------
 src/storage/storage_backend_scsi.c | 45 ++++++++++++++++++++++++++++----------
 2 files changed, 49 insertions(+), 23 deletions(-)

diff --git a/docs/formatstorage.html.in b/docs/formatstorage.html.in
index 4946ddf..27578e8 100644
--- a/docs/formatstorage.html.in
+++ b/docs/formatstorage.html.in
@@ -207,18 +207,21 @@
         </dl>
         <dl>
           <dt><code>wwnn</code> and <code>wwpn</code></dt>
-          <dd>The "World Wide Node Name" (<code>wwnn</code>) and "World Wide
-            Port Name" (<code>wwpn</code>) are used by the "fc_host" adapter
-            to uniquely identify the device in the Fibre Channel storage fabric
-            (the device can be either a HBA or vHBA). Both wwnn and wwpn should
-            be specified. Use the command 'virsh nodedev-dumpxml' to determine
-            how to set the values for the wwnn/wwpn of a (v)HBA. The wwnn and
-            wwpn have very specific numerical format requirements based on the
-            hypervisor being used, thus care should be taken if you decide to
-            generate your own to follow the standards; otherwise, the pool
-            will fail to start with an opaque error message indicating failure
-            to write to the vport_create file during vport create/delete due
-            to "No such file or directory".
+          <dd>The required "World Wide Node Name" (<code>wwnn</code>) and
+            "World Wide Port Name" (<code>wwpn</code>) are used by the
+            "fc_host" adapter to uniquely identify the vHBA device in the
+            Fibre Channel storage fabric. If the vHBA device already exists
+            as a Node Device, then libvirt will use it; otherwise, the vHBA
+            will be created using the provided values. It is considered a
+            configuration error use the values from the HBA as those would
+            be for a "scsi_host" <code>type</code> pool instead. The
+            <code>wwnn</code> and <code>wwpn</code> have very specific
+            format requirements based on the hypervisor being used, thus
+            care should be taken if you decide to generate your own to
+            follow the standards; otherwise, the pool will fail to start
+            with an opaque error message indicating failure to write to
+            the vport_create file during vport create/delete due to
+            "No such file or directory".
             <span class="since">Since 1.0.4</span>
           </dd>
         </dl>
diff --git a/src/storage/storage_backend_scsi.c b/src/storage/storage_backend_scsi.c
index af12889..c802738 100644
--- a/src/storage/storage_backend_scsi.c
+++ b/src/storage/storage_backend_scsi.c
@@ -231,22 +231,47 @@ checkParent(virConnectPtr conn,
     if (!conn)
         return true;
 
-    if (virSCSIHostGetNumber(parent_name, &host_num) < 0) {
-        virReportError(VIR_ERR_XML_ERROR,
-                       _("parent '%s' is not properly formatted"),
-                       parent_name);
+    /* If there's a parent_name, then make sure it's valid */
+    if (parent_name) {
+        if (virSCSIHostGetNumber(parent_name, &host_num) < 0) {
+            virReportError(VIR_ERR_XML_ERROR,
+                           _("parent '%s' is not properly formatted"),
+                           parent_name);
+            goto cleanup;
+        }
+
+        if (!virVHBAPathExists(NULL, host_num)) {
+            virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+                           _("parent '%s' is not an fc_host for the wwnn/wwpn"),
+                           parent_name);
+            goto cleanup;
+        }
+    }
+
+    if (virAsprintf(&scsi_host_name, "scsi_%s", name) < 0)
+        goto cleanup;
+
+    if (virSCSIHostGetNumber(scsi_host_name, &host_num) < 0) {
+        virReportError(VIR_ERR_INTERNAL_ERROR,
+                       _("host name '%s' is not properly formatted"),
+                       name);
         goto cleanup;
     }
 
-    if (!virVHBAPathExists(NULL, host_num)) {
+    /* If scsi_host_name is vport capable, then it's an HBA. This is
+     * a configuration error as the wwnn/wwpn should only be for a vHBA */
+    if (virVHBAIsVportCapable(NULL, host_num)) {
         virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
-                       _("parent '%s' is not an fc_host for the wwnn/wwpn"),
-                       parent_name);
+                       _("the wwnn/wwpn for '%s' are assigned to an HBA"),
+                       scsi_host_name);
         goto cleanup;
     }
 
-    if (virAsprintf(&scsi_host_name, "scsi_%s", name) < 0)
+    /* No parent name, then no need to get/compare against vhba_parent */
+    if (!parent_name) {
+        retval = true;
         goto cleanup;
+    }
 
     if (!(vhba_parent = virNodeDeviceGetParentName(conn, scsi_host_name)))
         goto cleanup;
@@ -288,9 +313,7 @@ createVport(virConnectPtr conn,
      * this pool and we don't have to create the vHBA
      */
     if ((name = virVHBAGetHostByWWN(NULL, fchost->wwnn, fchost->wwpn))) {
-        /* If a parent was provided, let's make sure the 'name' we've
-         * retrieved has the same parent. If not this will cause failure. */
-        if (!fchost->parent || checkParent(conn, name, fchost->parent))
+        if (checkParent(conn, name, fchost->parent))
             ret = 0;
 
         goto cleanup;
-- 
2.9.4

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Re: [libvirt] [PATCH v3 4/4] storage: Disallow usage of the HBA for a fc_host backing
Posted by Erik Skultety 7 years, 9 months ago
On Thu, Jul 20, 2017 at 03:48:49PM -0400, John Ferlan wrote:
> Disallow providing the wwnn/wwpn of the HBA in the adapter XML:
>
>   <adapter type='fc_host' [parent='scsi_hostN'] wwnn='HBA_wwnn'
>     wwpn='HBA_wwpn'/>
>
> This should be considered a configuration error since a vHBA
> would not be created. In order to use the HBA as the backing the
> following XML should be used:
>
>   <adapter type='scsi_host' name='scsi_hostN'/>
>
> This also alters the caller such that the @parent_name param
> into checkParent can be NULL so as to confirm that at least
> the provided wwnn/wwpn found a vHBA instead of an HBA.
>
> Signed-off-by: John Ferlan <jferlan@redhat.com>
> ---
>  docs/formatstorage.html.in         | 27 +++++++++++++----------
>  src/storage/storage_backend_scsi.c | 45 ++++++++++++++++++++++++++++----------
>  2 files changed, 49 insertions(+), 23 deletions(-)
>
> diff --git a/docs/formatstorage.html.in b/docs/formatstorage.html.in
> index 4946ddf..27578e8 100644
> --- a/docs/formatstorage.html.in
> +++ b/docs/formatstorage.html.in
> @@ -207,18 +207,21 @@
>          </dl>
>          <dl>
>            <dt><code>wwnn</code> and <code>wwpn</code></dt>
> -          <dd>The "World Wide Node Name" (<code>wwnn</code>) and "World Wide
> -            Port Name" (<code>wwpn</code>) are used by the "fc_host" adapter
> -            to uniquely identify the device in the Fibre Channel storage fabric
> -            (the device can be either a HBA or vHBA). Both wwnn and wwpn should
> -            be specified. Use the command 'virsh nodedev-dumpxml' to determine
> -            how to set the values for the wwnn/wwpn of a (v)HBA. The wwnn and
> -            wwpn have very specific numerical format requirements based on the
> -            hypervisor being used, thus care should be taken if you decide to
> -            generate your own to follow the standards; otherwise, the pool
> -            will fail to start with an opaque error message indicating failure
> -            to write to the vport_create file during vport create/delete due
> -            to "No such file or directory".
> +          <dd>The required "World Wide Node Name" (<code>wwnn</code>) and
> +            "World Wide Port Name" (<code>wwpn</code>) are used by the
> +            "fc_host" adapter to uniquely identify the vHBA device in the
> +            Fibre Channel storage fabric. If the vHBA device already exists
> +            as a Node Device, then libvirt will use it; otherwise, the vHBA
> +            will be created using the provided values. It is considered a
> +            configuration error use the values from the HBA as those would
> +            be for a "scsi_host" <code>type</code> pool instead. The
> +            <code>wwnn</code> and <code>wwpn</code> have very specific
> +            format requirements based on the hypervisor being used, thus
> +            care should be taken if you decide to generate your own to
> +            follow the standards; otherwise, the pool will fail to start
> +            with an opaque error message indicating failure to write to
> +            the vport_create file during vport create/delete due to
> +            "No such file or directory".
>              <span class="since">Since 1.0.4</span>
>            </dd>
>          </dl>
> diff --git a/src/storage/storage_backend_scsi.c b/src/storage/storage_backend_scsi.c
> index af12889..c802738 100644
> --- a/src/storage/storage_backend_scsi.c
> +++ b/src/storage/storage_backend_scsi.c
> @@ -231,22 +231,47 @@ checkParent(virConnectPtr conn,
>      if (!conn)
>          return true;
>
> -    if (virSCSIHostGetNumber(parent_name, &host_num) < 0) {
> -        virReportError(VIR_ERR_XML_ERROR,
> -                       _("parent '%s' is not properly formatted"),
> -                       parent_name);
> +    /* If there's a parent_name, then make sure it's valid */
> +    if (parent_name) {
> +        if (virSCSIHostGetNumber(parent_name, &host_num) < 0) {
> +            virReportError(VIR_ERR_XML_ERROR,
> +                           _("parent '%s' is not properly formatted"),
> +                           parent_name);
> +            goto cleanup;
> +        }
> +
> +        if (!virVHBAPathExists(NULL, host_num)) {
> +            virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
> +                           _("parent '%s' is not an fc_host for the wwnn/wwpn"),
> +                           parent_name);
> +            goto cleanup;
> +        }
> +    }

^Here you're handling the device's parent - it's existence

> +
> +    if (virAsprintf(&scsi_host_name, "scsi_%s", name) < 0)
> +        goto cleanup;
> +
> +    if (virSCSIHostGetNumber(scsi_host_name, &host_num) < 0) {
> +        virReportError(VIR_ERR_INTERNAL_ERROR,
> +                       _("host name '%s' is not properly formatted"),
> +                       name);
>          goto cleanup;
>      }
>
> -    if (!virVHBAPathExists(NULL, host_num)) {
> +    /* If scsi_host_name is vport capable, then it's an HBA. This is
> +     * a configuration error as the wwnn/wwpn should only be for a vHBA */
> +    if (virVHBAIsVportCapable(NULL, host_num)) {
>          virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
> -                       _("parent '%s' is not an fc_host for the wwnn/wwpn"),
> -                       parent_name);
> +                       _("the wwnn/wwpn for '%s' are assigned to an HBA"),
> +                       scsi_host_name);
>          goto cleanup;
>      }

^Here you're handling the device itself.

>
> -    if (virAsprintf(&scsi_host_name, "scsi_%s", name) < 0)
> +    /* No parent name, then no need to get/compare against vhba_parent */
> +    if (!parent_name) {
> +        retval = true;
>          goto cleanup;
> +    }
>

And ^here you're again handling the device's parent - it's !existence and
perform some further parent device validation in the already existing hunk
below. Would it make more sense to first verify the device whether it's a vHBA,
if not then throw an error and then, if @parent_name wasn't supplied, return
successfully otherwise do both the parent existence check and validation, both
in a large "else" block. The checks make sense and work as described, I just
find it more understandable - the logic would be IMHO more continuous, as
opposed "scattered" (is that even the right term for this? But I think you get
the picture...)

if (scsi_host_name is vport capable)
    # it's an HBA
    error
    return failure

if (!parent_name)
    # no parent to validate
    return success
else
    if (parent doesn't exist)
        error - not an fc_host
        return failure

    if (provided_parent != actual_parent)
        error - invalid parent
        return failure

return success

Erik.

>      if (!(vhba_parent = virNodeDeviceGetParentName(conn, scsi_host_name)))
>          goto cleanup;
> @@ -288,9 +313,7 @@ createVport(virConnectPtr conn,
>       * this pool and we don't have to create the vHBA
>       */
>      if ((name = virVHBAGetHostByWWN(NULL, fchost->wwnn, fchost->wwpn))) {
> -        /* If a parent was provided, let's make sure the 'name' we've
> -         * retrieved has the same parent. If not this will cause failure. */
> -        if (!fchost->parent || checkParent(conn, name, fchost->parent))
> +        if (checkParent(conn, name, fchost->parent))
>              ret = 0;
>
>          goto cleanup;
> --
> 2.9.4
>
> --
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> libvir-list@redhat.com
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Re: [libvirt] [PATCH v3 4/4] storage: Disallow usage of the HBA for a fc_host backing
Posted by John Ferlan 7 years, 9 months ago

On 07/24/2017 11:00 AM, Erik Skultety wrote:
> On Thu, Jul 20, 2017 at 03:48:49PM -0400, John Ferlan wrote:
>> Disallow providing the wwnn/wwpn of the HBA in the adapter XML:
>>
>>   <adapter type='fc_host' [parent='scsi_hostN'] wwnn='HBA_wwnn'
>>     wwpn='HBA_wwpn'/>
>>
>> This should be considered a configuration error since a vHBA
>> would not be created. In order to use the HBA as the backing the
>> following XML should be used:
>>
>>   <adapter type='scsi_host' name='scsi_hostN'/>
>>
>> This also alters the caller such that the @parent_name param
>> into checkParent can be NULL so as to confirm that at least
>> the provided wwnn/wwpn found a vHBA instead of an HBA.
>>
>> Signed-off-by: John Ferlan <jferlan@redhat.com>
>> ---
>>  docs/formatstorage.html.in         | 27 +++++++++++++----------
>>  src/storage/storage_backend_scsi.c | 45 ++++++++++++++++++++++++++++----------
>>  2 files changed, 49 insertions(+), 23 deletions(-)
>>
>> diff --git a/docs/formatstorage.html.in b/docs/formatstorage.html.in
>> index 4946ddf..27578e8 100644
>> --- a/docs/formatstorage.html.in
>> +++ b/docs/formatstorage.html.in
>> @@ -207,18 +207,21 @@
>>          </dl>
>>          <dl>
>>            <dt><code>wwnn</code> and <code>wwpn</code></dt>
>> -          <dd>The "World Wide Node Name" (<code>wwnn</code>) and "World Wide
>> -            Port Name" (<code>wwpn</code>) are used by the "fc_host" adapter
>> -            to uniquely identify the device in the Fibre Channel storage fabric
>> -            (the device can be either a HBA or vHBA). Both wwnn and wwpn should
>> -            be specified. Use the command 'virsh nodedev-dumpxml' to determine
>> -            how to set the values for the wwnn/wwpn of a (v)HBA. The wwnn and
>> -            wwpn have very specific numerical format requirements based on the
>> -            hypervisor being used, thus care should be taken if you decide to
>> -            generate your own to follow the standards; otherwise, the pool
>> -            will fail to start with an opaque error message indicating failure
>> -            to write to the vport_create file during vport create/delete due
>> -            to "No such file or directory".
>> +          <dd>The required "World Wide Node Name" (<code>wwnn</code>) and
>> +            "World Wide Port Name" (<code>wwpn</code>) are used by the
>> +            "fc_host" adapter to uniquely identify the vHBA device in the
>> +            Fibre Channel storage fabric. If the vHBA device already exists
>> +            as a Node Device, then libvirt will use it; otherwise, the vHBA
>> +            will be created using the provided values. It is considered a
>> +            configuration error use the values from the HBA as those would
>> +            be for a "scsi_host" <code>type</code> pool instead. The
>> +            <code>wwnn</code> and <code>wwpn</code> have very specific
>> +            format requirements based on the hypervisor being used, thus
>> +            care should be taken if you decide to generate your own to
>> +            follow the standards; otherwise, the pool will fail to start
>> +            with an opaque error message indicating failure to write to
>> +            the vport_create file during vport create/delete due to
>> +            "No such file or directory".
>>              <span class="since">Since 1.0.4</span>
>>            </dd>
>>          </dl>
>> diff --git a/src/storage/storage_backend_scsi.c b/src/storage/storage_backend_scsi.c
>> index af12889..c802738 100644
>> --- a/src/storage/storage_backend_scsi.c
>> +++ b/src/storage/storage_backend_scsi.c
>> @@ -231,22 +231,47 @@ checkParent(virConnectPtr conn,
>>      if (!conn)
>>          return true;
>>
>> -    if (virSCSIHostGetNumber(parent_name, &host_num) < 0) {
>> -        virReportError(VIR_ERR_XML_ERROR,
>> -                       _("parent '%s' is not properly formatted"),
>> -                       parent_name);
>> +    /* If there's a parent_name, then make sure it's valid */
>> +    if (parent_name) {
>> +        if (virSCSIHostGetNumber(parent_name, &host_num) < 0) {
>> +            virReportError(VIR_ERR_XML_ERROR,
>> +                           _("parent '%s' is not properly formatted"),
>> +                           parent_name);
>> +            goto cleanup;
>> +        }
>> +
>> +        if (!virVHBAPathExists(NULL, host_num)) {
>> +            virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
>> +                           _("parent '%s' is not an fc_host for the wwnn/wwpn"),
>> +                           parent_name);
>> +            goto cleanup;
>> +        }
>> +    }
> 
> ^Here you're handling the device's parent - it's existence
> 
>> +
>> +    if (virAsprintf(&scsi_host_name, "scsi_%s", name) < 0)
>> +        goto cleanup;
>> +
>> +    if (virSCSIHostGetNumber(scsi_host_name, &host_num) < 0) {
>> +        virReportError(VIR_ERR_INTERNAL_ERROR,
>> +                       _("host name '%s' is not properly formatted"),
>> +                       name);
>>          goto cleanup;
>>      }
>>
>> -    if (!virVHBAPathExists(NULL, host_num)) {
>> +    /* If scsi_host_name is vport capable, then it's an HBA. This is
>> +     * a configuration error as the wwnn/wwpn should only be for a vHBA */
>> +    if (virVHBAIsVportCapable(NULL, host_num)) {
>>          virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
>> -                       _("parent '%s' is not an fc_host for the wwnn/wwpn"),
>> -                       parent_name);
>> +                       _("the wwnn/wwpn for '%s' are assigned to an HBA"),
>> +                       scsi_host_name);
>>          goto cleanup;
>>      }
> 
> ^Here you're handling the device itself.
> 
>>
>> -    if (virAsprintf(&scsi_host_name, "scsi_%s", name) < 0)
>> +    /* No parent name, then no need to get/compare against vhba_parent */
>> +    if (!parent_name) {
>> +        retval = true;
>>          goto cleanup;
>> +    }
>>
> 
> And ^here you're again handling the device's parent - it's !existence and
> perform some further parent device validation in the already existing hunk
> below. Would it make more sense to first verify the device whether it's a vHBA,
> if not then throw an error and then, if @parent_name wasn't supplied, return
> successfully otherwise do both the parent existence check and validation, both
> in a large "else" block. The checks make sense and work as described, I just
> find it more understandable - the logic would be IMHO more continuous, as
> opposed "scattered" (is that even the right term for this? But I think you get
> the picture...)

True - I was also trying to keep diffs to a minimum while also trying to
preserve both sets of error checking while considering patch 3 ordering.

Patch 3 adds the parent_name check above "scsi_host/vhba_parent" because
I didn't want to stick the logic between the virAsprintf and
GetParentName call and it felt awkward to needlessly get vhba_parent
without first checking if @parent_name was going to fail.

But you're right I can do better on this and stop making checkParent be
the slave to too many masters.  I'll push the first 3 and repost
something a bit different that I think will be more palatable.

Thanks -

John

FWIW: I did originally have the logic swapped like shown below, but the
patch 4 diffs got really ugly...

> 
> if (scsi_host_name is vport capable)
>     # it's an HBA
>     error
>     return failure
> 
> if (!parent_name)
>     # no parent to validate
>     return success
> else
>     if (parent doesn't exist)
>         error - not an fc_host
>         return failure
> 
>     if (provided_parent != actual_parent)
>         error - invalid parent
>         return failure
> 
> return success
> 
> Erik.
> 
>>      if (!(vhba_parent = virNodeDeviceGetParentName(conn, scsi_host_name)))
>>          goto cleanup;
>> @@ -288,9 +313,7 @@ createVport(virConnectPtr conn,
>>       * this pool and we don't have to create the vHBA
>>       */
>>      if ((name = virVHBAGetHostByWWN(NULL, fchost->wwnn, fchost->wwpn))) {
>> -        /* If a parent was provided, let's make sure the 'name' we've
>> -         * retrieved has the same parent. If not this will cause failure. */
>> -        if (!fchost->parent || checkParent(conn, name, fchost->parent))
>> +        if (checkParent(conn, name, fchost->parent))
>>              ret = 0;
>>
>>          goto cleanup;
>> --
>> 2.9.4
>>
>> --
>> libvir-list mailing list
>> libvir-list@redhat.com
>> https://www.redhat.com/mailman/listinfo/libvir-list

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