From: Lucas Amaral <lucaaamaral@gmail.com> Previously, users had to manually specify a TCP port when starting a pull-mode backup with an NBD server. A TODO comment in qemuBackupPrepare() noted this limitation and pointed toward using virPortAllocator, as done for migration, VNC, and SPICE ports. When a pull-mode backup is started without specifying a TCP port, a port is now acquired automatically from the configured range via virPortAllocatorAcquire(). The port is released when the backup ends or if startup fails. Signed-off-by: Lucas Amaral <lucaaamaral@gmail.com> Signed-off-by: Peter Krempa <pkrempa@redhat.com> Reviewed-by: Peter Krempa <pkrempa@redhat.com> --- docs/formatbackup.rst | 3 ++- src/qemu/qemu_backup.c | 30 ++++++++++++++++++++---------- src/qemu/qemu_domain.h | 1 + 3 files changed, 23 insertions(+), 11 deletions(-) diff --git a/docs/formatbackup.rst b/docs/formatbackup.rst index df6392e3bd..24857eaf72 100644 --- a/docs/formatbackup.rst +++ b/docs/formatbackup.rst @@ -42,7 +42,8 @@ were supplied). The following child elements and attributes are supported: ```protocol`` element of a disk <formatdomain.html#hard-drives-floppy-disks-cdroms>`__ attached via NBD in the domain (such as transport, socket, name, port, or tls), necessary to set up an NBD server that exposes the content of each disk at - the time the backup is started. + the time the backup is started. For TCP transport, if ``port`` is omitted, a + port is allocated automatically from the range configured in ``/etc/libvirt/qemu.conf``. In addition to the above the NBD server used for backups allows using ``transport='fd' fdgroup='NAME'`` where ``NAME`` is the name used with diff --git a/src/qemu/qemu_backup.c b/src/qemu/qemu_backup.c index d380dd3a63..ddab4be34b 100644 --- a/src/qemu/qemu_backup.c +++ b/src/qemu/qemu_backup.c @@ -32,6 +32,7 @@ #include "storage_source.h" #include "storage_source_conf.h" #include "virerror.h" +#include "virportallocator.h" #include "virlog.h" #include "virbuffer.h" #include "backup_conf.h" @@ -58,7 +59,8 @@ qemuDomainGetBackup(virDomainObj *vm) static int -qemuBackupPrepare(virDomainBackupDef *def) +qemuBackupPrepare(qemuDomainObjPrivate *priv, + virDomainBackupDef *def) { if (def->type == VIR_DOMAIN_BACKUP_TYPE_PULL) { @@ -71,15 +73,12 @@ qemuBackupPrepare(virDomainBackupDef *def) switch (def->server->transport) { case VIR_STORAGE_NET_HOST_TRANS_TCP: - /* TODO: Update qemu.conf to provide a port range, - * probably starting at 10809, for obtaining automatic - * port via virPortAllocatorAcquire, as well as store - * somewhere if we need to call virPortAllocatorRelease - * during BackupEnd. Until then, user must provide port */ if (!def->server->port) { - virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s", - _("<domainbackup> must specify TCP port for now")); - return -1; + if (virPortAllocatorAcquire(priv->driver->backupPorts, + &priv->backupNBDPort) < 0) + return -1; + + def->server->port = priv->backupNBDPort; } break; @@ -838,7 +837,7 @@ qemuBackupBegin(virDomainObj *vm, goto endjob; } - if (qemuBackupPrepare(def) < 0) + if (qemuBackupPrepare(priv, def) < 0) goto endjob; if (qemuBackupBeginPrepareTLS(vm, cfg, def, &tlsProps, &tlsSecretProps) < 0) @@ -969,6 +968,11 @@ qemuBackupBegin(virDomainObj *vm, qemuDomainObjExitMonitor(vm); } + if (ret < 0 && priv->backupNBDPort) { + virPortAllocatorRelease(priv->backupNBDPort); + priv->backupNBDPort = 0; + } + if (ret < 0 && !job_started && priv->backup) def = g_steal_pointer(&priv->backup); @@ -1026,6 +1030,12 @@ qemuBackupNotifyBlockjobEndStopNBD(virDomainObj *vm, qemuDomainObjExitMonitor(vm); backup->nbdStopped = true; + + if (priv->backupNBDPort) { + virPortAllocatorRelease(priv->backupNBDPort); + priv->backupNBDPort = 0; + backup->server->port = 0; + } } diff --git a/src/qemu/qemu_domain.h b/src/qemu/qemu_domain.h index f797542a87..b321a64e96 100644 --- a/src/qemu/qemu_domain.h +++ b/src/qemu/qemu_domain.h @@ -147,6 +147,7 @@ struct _qemuDomainObjPrivate { char *origname; int nbdPort; /* Port used for migration with NBD */ unsigned short migrationPort; + unsigned short backupNBDPort; int preMigrationState; unsigned long long preMigrationMemlock; /* Original RLIMIT_MEMLOCK in case it was changed for the current -- 2.53.0