[libvirt] [PATCH v3 3/4] qemu_migration: Send disk sizes to the other side
Michal Privoznik
mprivozn at redhat.com
Tue Dec 2 16:13:42 UTC 2014
Up 'til now, users need to precreate non-shared storage on migration
themselves. This is not very friendly requirement and we should do
something about it. In this patch, the migration cookie is extended,
so that <nbd/> section does not only contain NBD port, but info on
disks being migrated. This patch sends a list of pairs of:
<disk target; disk size>
to the destination. The actual storage allocation is left for next
commit.
Signed-off-by: Michal Privoznik <mprivozn at redhat.com>
---
src/qemu/qemu_migration.c | 160 ++++++++++++++++++++++++++++++++++++++++------
1 file changed, 140 insertions(+), 20 deletions(-)
diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c
index f19e68c..36b7e43 100644
--- a/src/qemu/qemu_migration.c
+++ b/src/qemu/qemu_migration.c
@@ -141,6 +141,12 @@ typedef struct _qemuMigrationCookieNBD qemuMigrationCookieNBD;
typedef qemuMigrationCookieNBD *qemuMigrationCookieNBDPtr;
struct _qemuMigrationCookieNBD {
int port; /* on which port does NBD server listen for incoming data */
+
+ size_t ndisks; /* Number of items in @disk array */
+ struct {
+ char *target; /* Disk target */
+ unsigned long long capacity; /* And its capacity */
+ } *disks;
};
typedef struct _qemuMigrationCookie qemuMigrationCookie;
@@ -206,6 +212,18 @@ qemuMigrationCookieNetworkFree(qemuMigrationCookieNetworkPtr network)
}
+static void qemuMigrationCookieNBDFree(qemuMigrationCookieNBDPtr nbd)
+{
+ if (!nbd)
+ return;
+
+ while (nbd->ndisks)
+ VIR_FREE(nbd->disks[--nbd->ndisks].target);
+ VIR_FREE(nbd->disks);
+ VIR_FREE(nbd);
+}
+
+
static void qemuMigrationCookieFree(qemuMigrationCookiePtr mig)
{
if (!mig)
@@ -213,13 +231,13 @@ static void qemuMigrationCookieFree(qemuMigrationCookiePtr mig)
qemuMigrationCookieGraphicsFree(mig->graphics);
qemuMigrationCookieNetworkFree(mig->network);
+ qemuMigrationCookieNBDFree(mig->nbd);
VIR_FREE(mig->localHostname);
VIR_FREE(mig->remoteHostname);
VIR_FREE(mig->name);
VIR_FREE(mig->lockState);
VIR_FREE(mig->lockDriver);
- VIR_FREE(mig->nbd);
VIR_FREE(mig->jobInfo);
VIR_FREE(mig);
}
@@ -525,20 +543,64 @@ qemuMigrationCookieAddNetwork(qemuMigrationCookiePtr mig,
static int
qemuMigrationCookieAddNBD(qemuMigrationCookiePtr mig,
- virQEMUDriverPtr driver ATTRIBUTE_UNUSED,
+ virQEMUDriverPtr driver,
virDomainObjPtr vm)
{
qemuDomainObjPrivatePtr priv = vm->privateData;
+ virHashTablePtr stats = NULL;
+ size_t i;
+ int ret = -1;
/* It is not a bug if there already is a NBD data */
if (!mig->nbd &&
VIR_ALLOC(mig->nbd) < 0)
return -1;
+ if (vm->def->ndisks &&
+ VIR_ALLOC_N(mig->nbd->disks, vm->def->ndisks) < 0)
+ return -1;
+ mig->nbd->ndisks = 0;
+
+ for (i = 0; i < vm->def->ndisks; i++) {
+ virDomainDiskDefPtr disk = vm->def->disks[i];
+ qemuBlockStats *entry;
+
+ if (!stats) {
+ if (!(stats = virHashCreate(10, virHashValueFree)))
+ goto cleanup;
+
+ qemuDomainObjEnterMonitor(driver, vm);
+ if (qemuMonitorBlockStatsUpdateCapacity(priv->mon, stats) < 0) {
+ qemuDomainObjExitMonitor(driver, vm);
+ goto cleanup;
+ }
+ qemuDomainObjExitMonitor(driver, vm);
+
+ if (!virDomainObjIsActive(vm)) {
+ virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+ _("domain exited meanwhile"));
+ goto cleanup;
+ }
+ }
+
+ if (!disk->info.alias ||
+ !(entry = virHashLookup(stats, disk->info.alias)))
+ continue;
+
+ if (VIR_STRDUP(mig->nbd->disks[mig->nbd->ndisks].target,
+ disk->dst) < 0)
+ goto cleanup;
+ mig->nbd->disks[mig->nbd->ndisks].capacity = entry->capacity;
+ mig->nbd->ndisks++;
+ }
+
mig->nbd->port = priv->nbdPort;
mig->flags |= QEMU_MIGRATION_COOKIE_NBD;
- return 0;
+ ret = 0;
+ cleanup:
+ virHashFree(stats);
+ return ret;
}
@@ -763,7 +825,20 @@ qemuMigrationCookieXMLFormat(virQEMUDriverPtr driver,
virBufferAddLit(buf, "<nbd");
if (mig->nbd->port)
virBufferAsprintf(buf, " port='%d'", mig->nbd->port);
- virBufferAddLit(buf, "/>\n");
+ if (mig->nbd->ndisks) {
+ virBufferAddLit(buf, ">\n");
+ virBufferAdjustIndent(buf, 2);
+ for (i = 0; i < mig->nbd->ndisks; i++) {
+ virBufferEscapeString(buf, "<disk target='%s'",
+ mig->nbd->disks[i].target);
+ virBufferAsprintf(buf, " capacity='%llu'/>\n",
+ mig->nbd->disks[i].capacity);
+ }
+ virBufferAdjustIndent(buf, -2);
+ virBufferAddLit(buf, "</nbd>\n");
+ } else {
+ virBufferAddLit(buf, "/>\n");
+ }
}
if (mig->flags & QEMU_MIGRATION_COOKIE_STATS && mig->jobInfo)
@@ -891,6 +966,64 @@ qemuMigrationCookieNetworkXMLParse(xmlXPathContextPtr ctxt)
}
+static qemuMigrationCookieNBDPtr
+qemuMigrationCookieNBDXMLParse(xmlXPathContextPtr ctxt)
+{
+ qemuMigrationCookieNBDPtr ret = NULL;
+ char *port = NULL, *capacity = NULL;
+ size_t i;
+ int n;
+ xmlNodePtr *disks = NULL;
+ xmlNodePtr save_ctxt = ctxt->node;
+
+ if (VIR_ALLOC(ret) < 0)
+ goto error;
+
+ port = virXPathString("string(./nbd/@port)", ctxt);
+ if (port && virStrToLong_i(port, NULL, 10, &ret->port) < 0) {
+ virReportError(VIR_ERR_INTERNAL_ERROR,
+ _("Malformed nbd port '%s'"),
+ port);
+ goto error;
+ }
+
+ /* Now check if source sent a list of disks to prealloc. We might be
+ * talking to an older server, so it's not an error if the list is
+ * missing. */
+ if ((n = virXPathNodeSet("./nbd/disk", ctxt, &disks)) > 0) {
+ if (VIR_ALLOC_N(ret->disks, n) < 0)
+ goto error;
+ ret->ndisks = n;
+
+ for (i = 0; i < n; i++) {
+ ctxt->node = disks[i];
+ VIR_FREE(capacity);
+
+ ret->disks[i].target = virXPathString("string(./@target)", ctxt);
+ capacity = virXPathString("string(./@capacity)", ctxt);
+ if (virStrToLong_ull(capacity, NULL, 10,
+ &ret->disks[i].capacity) < 0) {
+ virReportError(VIR_ERR_INTERNAL_ERROR,
+ _("Malformed disk capacity: '%s'"),
+ capacity);
+ goto error;
+ }
+ }
+ }
+
+ cleanup:
+ VIR_FREE(port);
+ VIR_FREE(capacity);
+ VIR_FREE(disks);
+ ctxt->node = save_ctxt;
+ return ret;
+ error:
+ qemuMigrationCookieNBDFree(ret);
+ ret = NULL;
+ goto cleanup;
+}
+
+
static qemuDomainJobInfoPtr
qemuMigrationCookieStatisticsXMLParse(xmlXPathContextPtr ctxt)
{
@@ -1123,22 +1256,9 @@ qemuMigrationCookieXMLParse(qemuMigrationCookiePtr mig,
goto error;
if (flags & QEMU_MIGRATION_COOKIE_NBD &&
- virXPathBoolean("boolean(./nbd)", ctxt)) {
- char *port;
-
- if (VIR_ALLOC(mig->nbd) < 0)
- goto error;
-
- port = virXPathString("string(./nbd/@port)", ctxt);
- if (port && virStrToLong_i(port, NULL, 10, &mig->nbd->port) < 0) {
- virReportError(VIR_ERR_INTERNAL_ERROR,
- _("Malformed nbd port '%s'"),
- port);
- VIR_FREE(port);
- goto error;
- }
- VIR_FREE(port);
- }
+ virXPathBoolean("boolean(./nbd)", ctxt) &&
+ (!(mig->nbd = qemuMigrationCookieNBDXMLParse(ctxt))))
+ goto error;
if (flags & QEMU_MIGRATION_COOKIE_STATS &&
virXPathBoolean("boolean(./statistics)", ctxt) &&
--
2.0.4
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