Re: [libvirt PATCH v4 18/31] qemu: include nbdkit state in private xml

Add xml to the private data for a disk source to represent the nbdkit process so that the state can be re-created if the libvirt daemon is restarted. Format: <nbdkit> <pidfile>/path/to/nbdkit.pid</pidfile> <socketfile>/path/to/nbdkit.socket</socketfile> </nbdkit> Signed-off-by: Jonathon Jongsma <jjongsma(a)redhat.com&gt; --- src/qemu/qemu_domain.c | 48 ++++++++++++++ src/qemu/qemu_nbdkit.c | 77 +++++++++++++++++++++++ src/qemu/qemu_nbdkit.h | 8 +++ src/qemu/qemu_process.c | 11 ++++ tests/qemustatusxml2xmldata/modern-in.xml | 4 ++ 5 files changed, 148 insertions(+) diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c index 0e3eaf49f8..28d4bddf14 100644 --- a/src/qemu/qemu_domain.c +++ b/src/qemu/qemu_domain.c @@ -1911,6 +1911,29 @@ qemuStorageSourcePrivateDataAssignSecinfo(qemuDomainSecretInfo **secinfo, } +static int +qemuStorageSourcePrivateDataParseNbdkit(xmlNodePtr node, + xmlXPathContextPtr ctxt, + virStorageSource *src) +{ + g_autofree char *pidfile = NULL; + g_autofree char *socketfile = NULL; + VIR_XPATH_NODE_AUTORESTORE(ctxt); + + ctxt->node = node; + + if (!(pidfile = virXPathString("string(./pidfile)", ctxt))) + return -1;

+ + if (!(socketfile = virXPathString("string(./socketfile)", ctxt))) + return -1; + + qemuNbdkitReconnectStorageSource(src, pidfile, socketfile); + + return 0; +}

diff --git a/src/qemu/qemu_nbdkit.c b/src/qemu/qemu_nbdkit.c index 00ca945904..2b26e9bc08 100644 --- a/src/qemu/qemu_nbdkit.c +++ b/src/qemu/qemu_nbdkit.c @@ -627,6 +627,83 @@ qemuNbdkitProcessNew(virStorageSource *source,

+static int +qemuNbdkitStorageSourceManageProcessOne(virStorageSource *source) +{ + qemuDomainStorageSourcePrivate *srcpriv = QEMU_DOMAIN_STORAGE_SOURCE_PRIVATE(source); + qemuNbdkitProcess *proc; + + if (!srcpriv) + return 0; + + proc = srcpriv->nbdkitProcess; + + if (proc) { + if (proc->pid <= 0) { + if (virPidFileReadPath(proc->pidfile, &proc->pid) < 0) + return -1; + } + + if (virProcessKill(proc->pid, 0) < 0) { + virReportError(VIR_ERR_INTERNAL_ERROR, + _("nbdkit process %i is not alive"), proc->pid); + return -1;

+ } + } + + return 0; +} + +/** + * qemuNbdkitStorageSourceManageProcess: + * @source: a storage source + * @vm: the vm that owns this storage source + * + * This function re-enables monitoring of any nbdkit processes associated with the backing chain of + * @source. It is intended to be called after libvirt restarts and has loaded its current state from + * disk and is attempting to re-connect to active domains. + */ +int +qemuNbdkitStorageSourceManageProcess(virStorageSource *source) +{ + virStorageSource *backing; + for (backing = source->backingStore; backing != NULL; backing = backing->backingStore) {

+ if (qemuNbdkitStorageSourceManageProcessOne(backing) < 0) + return -1; + } + + return qemuNbdkitStorageSourceManageProcessOne(source);

+}

diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c index 6d1751b5d7..7ec31ef6ac 100644 --- a/src/qemu/qemu_process.c +++ b/src/qemu/qemu_process.c @@ -9047,6 +9047,17 @@ qemuProcessReconnect(void *opaque) } } + for (i = 0; i < obj->def->ndisks; i++) { + virDomainDiskDef *disk = obj->def->disks[i]; + if (qemuNbdkitStorageSourceManageProcess(disk->src) < 0) + goto error;

+ } + + if (obj->def->os.loader && obj->def->os.loader->nvram) { + if (qemuNbdkitStorageSourceManageProcess(obj->def->os.loader->nvram) < 0) + goto error; + } +