On 12/02/14 17:13, Michal Privoznik wrote:
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@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
@@ -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);
Note here that the existence of the @target element is not checked in case the cookie XML contains <nbd><disk .. entries. In 4/4 you use the field unconditionally which could lead to a crash with a specially crafted migration cookie. I think a check and a quick error message wouldn't hurt here.
+ capacity = virXPathString("string(./@capacity)", ctxt); + if (virStrToLong_ull(capacity, NULL, 10,
if (!capacity ||
+ &ret->disks[i].capacity) < 0) { + virReportError(VIR_ERR_INTERNAL_ERROR, + _("Malformed disk capacity: '%s'"), + capacity);
NULLSTR(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) {
ACK with NULL-hardening added. Peter