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

On Fri, 9 Jul 2021 15:39:47 +0200 Boris Fiuczynski <fiuczy(a)linux.ibm.com&gt; 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(a)linux.ibm.com&gt; > --- > 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");