On 04/23/2018 09:14 AM, Michal Privoznik wrote:
If qemu-pr-helper is compiled with multipath support the first thing it does is open /dev/mapper/control. Since we're going to be running it inside qemu namespace we need to create it there. Unfortunately, we don't know if it was compiled with or without multipath so we have to create it anyway.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com> --- src/qemu/qemu_domain.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+)
diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c index 53827d5396..5ccdeb8e3a 100644 --- a/src/qemu/qemu_domain.c +++ b/src/qemu/qemu_domain.c @@ -109,6 +109,7 @@ VIR_ENUM_IMPL(qemuDomainNamespace, QEMU_DOMAIN_NS_LAST, #define PROC_MOUNTS "/proc/mounts" #define DEVPREFIX "/dev/" #define DEV_VFIO "/dev/vfio/vfio" +#define DEVICE_MAPPER_CONTROL_PATH "/dev/mapper/control"
struct _qemuDomainLogContext { @@ -10207,6 +10208,11 @@ qemuDomainSetupDisk(virQEMUDriverConfigPtr cfg ATTRIBUTE_UNUSED, goto cleanup; }
+ /* qemu-pr-helper might require access to /dev/mapper/control. */ + if (virStoragePRDefIsEnabled(disk->src->pr) && + qemuDomainCreateDevice(DEVICE_MAPPER_CONTROL_PATH, data, true) < 0) + goto cleanup; +
This is from SetupAllDisks via qemuDomainBuildNamespace... Does it or could it matter that more than one disk would be doing this? Thus having multiple entries? Was too lazy to check.
ret = 0; cleanup: VIR_FREE(dst); @@ -11218,6 +11224,7 @@ qemuDomainNamespaceSetupDisk(virDomainObjPtr vm, virStorageSourcePtr next; const char **paths = NULL; size_t npaths = 0; + char *dmPath = NULL; int ret = -1;
if (!qemuDomainNamespaceEnabled(vm, QEMU_DOMAIN_NS_MOUNT)) @@ -11234,11 +11241,18 @@ qemuDomainNamespaceSetupDisk(virDomainObjPtr vm, goto cleanup; }
+ /* qemu-pr-helper might require access to /dev/mapper/control. */ + if (virStoragePRDefIsEnabled(src->pr) && + (VIR_STRDUP(dmPath, DEVICE_MAPPER_CONTROL_PATH) < 0 || + VIR_APPEND_ELEMENT_COPY(paths, npaths, dmPath) < 0)) + goto cleanup; +
... similarly when we add/hotplug a disk we could be repeating that path. If the duplication is OK or handled in some way that wasn't obvious, Reviewed-by: John Ferlan <jferlan@redhat.com> If you need to adjust the logic to handle this specially, then obviously I'd ask to wait for that OK. I wonder if the @prDaemonRunning logic added later on would suffice? John
if (qemuDomainNamespaceMknodPaths(vm, paths, npaths) < 0) goto cleanup;
ret = 0; cleanup: + VIR_FREE(dmPath); VIR_FREE(paths); return ret; }