[PATCH] nodedev: fix error when no defined mdev exist

[Boris Fiuczynski]

On 7/9/21 3:39 PM, Boris Fiuczynski wrote:
> Commit e9b534905f4 introduced an error when parsing an empty list
> returned from mdevctl.
> 
> This occurs e.g. if nodedev-undefine is used to undefine the last
> defined mdev which cuases the following error messages
> 
>   libvirtd[33143]: internal error: Unexpected format for mdevctl response
>   libvirtd[33143]: internal error: failed to query mdevs from mdevctl:
>   libvirtd[33143]: mdevctl failed to updated mediated devices
> 
> Signed-off-by: Boris Fiuczynski <fiuczy at linux.ibm.com>
> ---
>   src/node_device/node_device_driver.c          | 68 ++++++++++---------
>   .../mdevctl-list-empty.json                   |  1 +
>   .../mdevctl-list-empty.out.xml                |  0
>   tests/nodedevmdevctltest.c                    |  1 +
>   4 files changed, 37 insertions(+), 33 deletions(-)
>   create mode 100644 tests/nodedevmdevctldata/mdevctl-list-empty.json
>   create mode 100644 tests/nodedevmdevctldata/mdevctl-list-empty.out.xml
> 
> diff --git a/src/node_device/node_device_driver.c b/src/node_device/node_device_driver.c
> index b4dd57e5f4..31525f2312 100644
> --- a/src/node_device/node_device_driver.c
> +++ b/src/node_device/node_device_driver.c
> @@ -1123,51 +1123,53 @@ nodeDeviceParseMdevctlJSON(const char *jsonstring,
>       /* mdevctl list --dumpjson produces an output that is an array that
>        * contains only a single object which contains a property for each parent
>        * device */
> -    if (virJSONValueArraySize(json_devicelist) != 1) {
> -        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
> -                       _("Unexpected format for mdevctl response"));
> -        goto error;
> -    }
> -
> -    obj = virJSONValueArrayGet(json_devicelist, 0);
> -
> -    if (!virJSONValueIsObject(obj)) {
> -        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
> -                       _("device list is not an object"));
> -        goto error;
> -    }
> -
> -    n = virJSONValueObjectKeysNumber(obj);
> -    for (i = 0; i < n; i++) {
> -        const char *parent;
> -        virJSONValue *child_array;
> -        int nchildren;
> +    if (virJSONValueArraySize(json_devicelist) > 0) {

This seems now to break nodedev-create which created transient devices 
since the related objects now also vanish.

> +        if (virJSONValueArraySize(json_devicelist) != 1) {
> +            virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
> +                           _("Unexpected format for mdevctl response"));
> +            goto error;
> +        }
>   
> -        /* The key of each object property is the name of a parent device
> -         * which maps to an array of child devices */
> -        parent = virJSONValueObjectGetKey(obj, i);
> -        child_array = virJSONValueObjectGetValue(obj, i);
> +        obj = virJSONValueArrayGet(json_devicelist, 0);
>   
> -        if (!virJSONValueIsArray(child_array)) {
> +        if (!virJSONValueIsObject(obj)) {
>               virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
> -                           _("Parent device's JSON object data is not an array"));
> +                           _("device list is not an object"));
>               goto error;
>           }
>   
> -        nchildren = virJSONValueArraySize(child_array);
> +        n = virJSONValueObjectKeysNumber(obj);
> +        for (i = 0; i < n; i++) {
> +            const char *parent;
> +            virJSONValue *child_array;
> +            int nchildren;
>   
> -        for (j = 0; j < nchildren; j++) {
> -            g_autoptr(virNodeDeviceDef) child = NULL;
> -            virJSONValue *child_obj = virJSONValueArrayGet(child_array, j);
> +            /* The key of each object property is the name of a parent device
> +             * which maps to an array of child devices */
> +            parent = virJSONValueObjectGetKey(obj, i);
> +            child_array = virJSONValueObjectGetValue(obj, i);
>   
> -            if (!(child = nodeDeviceParseMdevctlChildDevice(parent, child_obj))) {
> +            if (!virJSONValueIsArray(child_array)) {
>                   virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
> -                               _("Unable to parse child device"));
> +                               _("Parent device's JSON object data is not an array"));
>                   goto error;
>               }
>   
> -            if (VIR_APPEND_ELEMENT(outdevs, noutdevs, child) < 0)
> -                goto error;
> +            nchildren = virJSONValueArraySize(child_array);
> +
> +            for (j = 0; j < nchildren; j++) {
> +                g_autoptr(virNodeDeviceDef) child = NULL;
> +                virJSONValue *child_obj = virJSONValueArrayGet(child_array, j);
> +
> +                if (!(child = nodeDeviceParseMdevctlChildDevice(parent, child_obj))) {
> +                    virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
> +                                   _("Unable to parse child device"));
> +                    goto error;
> +                }
> +
> +                if (VIR_APPEND_ELEMENT(outdevs, noutdevs, child) < 0)
> +                    goto error;
> +            }
>           }
>       }
>   
> diff --git a/tests/nodedevmdevctldata/mdevctl-list-empty.json b/tests/nodedevmdevctldata/mdevctl-list-empty.json
> new file mode 100644
> index 0000000000..fe51488c70
> --- /dev/null
> +++ b/tests/nodedevmdevctldata/mdevctl-list-empty.json
> @@ -0,0 +1 @@
> +[]
> diff --git a/tests/nodedevmdevctldata/mdevctl-list-empty.out.xml b/tests/nodedevmdevctldata/mdevctl-list-empty.out.xml
> new file mode 100644
> index 0000000000..e69de29bb2
> diff --git a/tests/nodedevmdevctltest.c b/tests/nodedevmdevctltest.c
> index 8ba1d2da70..e246de4d87 100644
> --- a/tests/nodedevmdevctltest.c
> +++ b/tests/nodedevmdevctltest.c
> @@ -360,6 +360,7 @@ mymain(void)
>   
>       DO_TEST_LIST_DEFINED();
>   
> +    DO_TEST_PARSE_JSON("mdevctl-list-empty");
>       DO_TEST_PARSE_JSON("mdevctl-list-multiple");
>   
>       DO_TEST_DEFINE("mdev_d069d019_36ea_4111_8f0a_8c9a70e21366");
> 


-- 
Mit freundlichen Grüßen/Kind regards
    Boris Fiuczynski

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