Re: [libvirt PATCH v2 08/16] qemu: Add qemuNbdkitProcess

An object for storing information about a nbdkit process that is serving a specific virStorageSource. At the moment, this information is just stored in the private data of virStorageSource and not used at all. Future commits will use this data to actually start a nbdkit process. Signed-off-by: Jonathon Jongsma <jjongsma(a)redhat.com&gt; --- src/qemu/qemu_conf.c | 22 ++++++++++++ src/qemu/qemu_conf.h | 3 ++ src/qemu/qemu_domain.c | 29 +++++++++++++++ src/qemu/qemu_domain.h | 4 +++ src/qemu/qemu_nbdkit.c | 82 ++++++++++++++++++++++++++++++++++++++++++ src/qemu/qemu_nbdkit.h | 24 +++++++++++++ 6 files changed, 164 insertions(+) diff --git a/src/qemu/qemu_conf.c b/src/qemu/qemu_conf.c index 3b75cdeb95..b5f451a8f9 100644 --- a/src/qemu/qemu_conf.c +++ b/src/qemu/qemu_conf.c @@ -1571,3 +1571,25 @@ qemuGetMemoryBackingPath(virQEMUDriver *driver, *memPath = g_strdup_printf("%s/%s", domainPath, alias); return 0; } + +/* + * qemuGetNbdkitCaps: + * @driver: the qemu driver + * + * Gets the capabilities for Nbdkit for the specified driver. These can be used + * to determine whether a particular disk source can be served by nbdkit or + * not. + * + * Returns: a reference to qemuNbdkitCaps or NULL + */ +qemuNbdkitCaps* +qemuGetNbdkitCaps(virQEMUDriver *driver) +{ + if (!driver->nbdkitBinary) + driver->nbdkitBinary = virFindFileInPath("nbdkit"); + + if (driver->nbdkitBinary) + return virFileCacheLookup(driver->nbdkitCapsCache, driver->nbdkitBinary); + + return NULL; +} diff --git a/src/qemu/qemu_conf.h b/src/qemu/qemu_conf.h index 414bcfb8a2..91212d6608 100644 --- a/src/qemu/qemu_conf.h +++ b/src/qemu/qemu_conf.h @@ -309,6 +309,7 @@ struct _virQEMUDriver { virHashAtomic *migrationErrors; virFileCache *nbdkitCapsCache; + char *nbdkitBinary; }; virQEMUDriverConfig *virQEMUDriverConfigNew(bool privileged, @@ -362,3 +363,5 @@ int qemuGetMemoryBackingPath(virQEMUDriver *driver, const virDomainDef *def, const char *alias, char **memPath); + +qemuNbdkitCaps* qemuGetNbdkitCaps(virQEMUDriver *driver); diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c index fe3ce023a4..5b3b2d3e9c 100644 --- a/src/qemu/qemu_domain.c +++ b/src/qemu/qemu_domain.c @@ -819,6 +819,7 @@ qemuDomainStorageSourcePrivateDispose(void *obj) g_clear_pointer(&priv->encinfo, qemuDomainSecretInfoFree); g_clear_pointer(&priv->httpcookie, qemuDomainSecretInfoFree); g_clear_pointer(&priv->tlsKeySecret, qemuDomainSecretInfoFree); + g_clear_pointer(&priv->nbdkitProcess, qemuNbdkitProcessFree);

} @@ -10013,6 +10014,32 @@ qemuDomainPrepareStorageSourceNFS(virStorageSource *src) } +/* qemuPrepareStorageSourceNbdkit: + * @src: source for a disk + * + * If src is an network source that is managed by nbdkit, prepare data so that + * nbdkit can be launched before the domain is started + * + * Returns true if nbdkit will be used for this source, + */ +static bool +qemuDomainPrepareStorageSourceNbdkit(virStorageSource *src,

+ virQEMUDriverConfig *cfg, + const char *alias, + qemuDomainObjPrivate *priv) +{ + g_autoptr(qemuNbdkitCaps) nbdkit = qemuGetNbdkitCaps(priv->driver); + if (!nbdkit) + return false; + + if (virStorageSourceGetActualType(src) != VIR_STORAGE_TYPE_NETWORK) + return false;

+ + return qemuNbdkitInitStorageSource(nbdkit, src, priv->libDir, + alias, cfg->user, cfg->group); +} + + /* qemuProcessPrepareStorageSourceTLS: * @source: source for a disk * @cfg: driver configuration @@ -10787,6 +10814,8 @@ qemuDomainPrepareStorageSourceBlockdevNodename(virDomainDiskDef *disk, if (qemuDomainPrepareStorageSourceNFS(src) < 0) return -1; + qemuDomainPrepareStorageSourceNbdkit(src, cfg, src->nodestorage, priv);

+ return 0; } diff --git a/src/qemu/qemu_domain.h b/src/qemu/qemu_domain.h index 592ee9805b..563b0aa925 100644 --- a/src/qemu/qemu_domain.h +++ b/src/qemu/qemu_domain.h @@ -33,6 +33,7 @@ #include "qemu_conf.h" #include "qemu_capabilities.h" #include "qemu_migration_params.h" +#include "qemu_nbdkit.h" #include "qemu_slirp.h" #include "qemu_fd.h" #include "virchrdev.h" @@ -293,6 +294,9 @@ struct _qemuDomainStorageSourcePrivate { /* key for decrypting TLS certificate */ qemuDomainSecretInfo *tlsKeySecret; + + /* an nbdkit process for serving network storage sources */ + qemuNbdkitProcess *nbdkitProcess; }; virObject *qemuDomainStorageSourcePrivateNew(void); diff --git a/src/qemu/qemu_nbdkit.c b/src/qemu/qemu_nbdkit.c index fc83f80f1f..4df8957196 100644 --- a/src/qemu/qemu_nbdkit.c +++ b/src/qemu/qemu_nbdkit.c @@ -579,3 +579,85 @@ qemuNbdkitCapsCacheNew(const char *cachedir) g_autofree char *dir = g_build_filename(cachedir, "nbdkitcapabilities", NULL); return virFileCacheNew(dir, "xml", &nbdkitCapsCacheHandlers); } + + +static qemuNbdkitProcess * +qemuNbdkitProcessNew(qemuNbdkitCaps *caps, + virStorageSource *source, + char *statedir, + const char *alias, + uid_t user, + gid_t group) +{ + qemuNbdkitProcess *proc = g_new0(qemuNbdkitProcess, 1); + g_autofree char *pidfile = g_strdup_printf("nbdkit-%s.pid", alias); + g_autofree char *socketfile = g_strdup_printf("nbdkit-%s.socket", alias); + + proc->caps = g_object_ref(caps); + /* weak reference -- source owns this object, so it will always outlive us */ + proc->source = source; + proc->user = user; + proc->group = group; + proc->pidfile = g_build_filename(statedir, pidfile, NULL); + proc->socketfile = g_build_filename(statedir, socketfile, NULL); + + return proc; +} + + +bool +qemuNbdkitInitStorageSource(qemuNbdkitCaps *caps, + virStorageSource *source, + char *statedir, + const char *alias, + uid_t user, + gid_t group) +{ + qemuDomainStorageSourcePrivate *srcPriv = qemuDomainStorageSourcePrivateFetch(source); + + if (srcPriv->nbdkitProcess) + return false; + + switch (source->protocol) { + case VIR_STORAGE_NET_PROTOCOL_HTTP: + case VIR_STORAGE_NET_PROTOCOL_HTTPS: + case VIR_STORAGE_NET_PROTOCOL_FTP: + case VIR_STORAGE_NET_PROTOCOL_FTPS: + case VIR_STORAGE_NET_PROTOCOL_TFTP: + if (!virBitmapIsBitSet(caps->flags, QEMU_NBDKIT_CAPS_PLUGIN_CURL)) + return false; + break; + case VIR_STORAGE_NET_PROTOCOL_SSH: + if (!virBitmapIsBitSet(caps->flags, QEMU_NBDKIT_CAPS_PLUGIN_SSH)) + return false; + break; + case VIR_STORAGE_NET_PROTOCOL_NONE: + case VIR_STORAGE_NET_PROTOCOL_NBD: + case VIR_STORAGE_NET_PROTOCOL_RBD: + case VIR_STORAGE_NET_PROTOCOL_SHEEPDOG: + case VIR_STORAGE_NET_PROTOCOL_GLUSTER: + case VIR_STORAGE_NET_PROTOCOL_ISCSI: + case VIR_STORAGE_NET_PROTOCOL_VXHS: + case VIR_STORAGE_NET_PROTOCOL_NFS: + case VIR_STORAGE_NET_PROTOCOL_LAST: + return false; + } + srcPriv->nbdkitProcess = qemuNbdkitProcessNew(caps, source, statedir, alias, user, group); + + return true; +} + + +void +qemuNbdkitProcessFree(qemuNbdkitProcess *proc) +{ + if (virProcessKillPainfully(proc->pid, true) < 0) + VIR_WARN("Unable to kill nbdkit process");

+ + unlink(proc->pidfile); + g_clear_pointer(&proc->pidfile, g_free); + unlink(proc->socketfile); + g_clear_pointer(&proc->socketfile, g_free); + g_clear_object(&proc->caps); + g_free(proc); +}