Re: [libvirt PATCH v2 2/5] nodedev: Handle NULL command variable

In commit 68580a51, I removed the checks for NULL cmd variables because virCommandRun() already handles the case where it is called with a NULL cmd. Unfortunately, it handles this case by raising a generic error which is both unhelpful and overwrites our existing error message. So for example, when I attempt to create a mediated device with an invalid parent, I get the following output: virsh # nodedev-create mdev-test.xml error: Failed to create node device from mdev-test.xml error: internal error: invalid use of command API With this patch, I now get a useful error message again: virsh # nodedev-create mdev-test.xml error: Failed to create node device from mdev-test.xml error: internal error: unable to find parent device 'pci_0000_00_03_0' Signed-off-by: Jonathon Jongsma <jjongsma(a)redhat.com&gt; --- src/node_device/node_device_driver.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/src/node_device/node_device_driver.c b/src/node_device/node_device_driver.c index 0f13cb4849..43a8c1bf60 100644 --- a/src/node_device/node_device_driver.c +++ b/src/node_device/node_device_driver.c @@ -799,6 +799,10 @@ virMdevctlCreate(virNodeDeviceDef *def, char **uuid, char **errmsg) MDEVCTL_CMD_CREATE, uuid, errmsg); + + if (!cmd) + return -1; + /* an auto-generated uuid is returned via stdout if no uuid is specified in * the mdevctl args */ if (virCommandRun(cmd, &status) < 0 || status != 0) @@ -819,6 +823,9 @@ virMdevctlDefine(virNodeDeviceDef *def, char **uuid, char **errmsg) MDEVCTL_CMD_DEFINE, uuid, errmsg); + if (!cmd) + return -1; + /* an auto-generated uuid is returned via stdout if no uuid is specified in * the mdevctl args */ if (virCommandRun(cmd, &status) < 0 || status != 0) @@ -925,6 +932,9 @@ virMdevctlStop(virNodeDeviceDef *def, char **errmsg) cmd = nodeDeviceGetMdevctlCommand(def, MDEVCTL_CMD_STOP, NULL, errmsg); + if (!cmd) + return -1; + if (virCommandRun(cmd, &status) < 0 || status != 0) return -1; @@ -940,6 +950,9 @@ virMdevctlUndefine(virNodeDeviceDef *def, char **errmsg) cmd = nodeDeviceGetMdevctlCommand(def, MDEVCTL_CMD_UNDEFINE, NULL, errmsg); + if (!cmd) + return -1; + if (virCommandRun(cmd, &status) < 0 || status != 0) return -1; @@ -955,6 +968,9 @@ virMdevctlStart(virNodeDeviceDef *def, char **errmsg) cmd = nodeDeviceGetMdevctlCommand(def, MDEVCTL_CMD_START, NULL, errmsg); + if (!cmd) + return -1; + if (virCommandRun(cmd, &status) < 0 || status != 0) return -1;