On Fri, 9 Jul 2021 15:39:47 +0200
Boris Fiuczynski <fiuczy@xxxxxxxxxxxxx> 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@xxxxxxxxxxxxx>
> ---
> 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) {
> + 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");
Thanks for catching this. I'd prefer to simplify this patch by
returning early if there are no elements in the array. That reduces the
diff to about 5 total lines changed, including the new test:
diff --git a/src/node_device/node_device_driver.c
b/src/node_device/node_device_driver.c index b4dd57e5f4..f63a65e26a
100644 --- a/src/node_device/node_device_driver.c
+++ b/src/node_device/node_device_driver.c
@@ -1120,6 +1120,9 @@ nodeDeviceParseMdevctlJSON(const char *jsonstring,
goto error;
}
+ if (virJSONValueArraySize(json_devicelist) == 0)
+ return 0;
+
/* mdevctl list --dumpjson produces an output that is an array that
* contains only a single object which contains a property for
each parent
* device */
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");
