This command allows to change the backing file name recorded in the metadata of a qcow (or other) image. The capability also notifies that the "block-stream" and "block-commit" commands understand the "backing-file" attribute. --- src/qemu/qemu_capabilities.c | 2 ++ src/qemu/qemu_capabilities.h | 1 + 2 files changed, 3 insertions(+) diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c index d5f2ef3..0baff2f 100644 --- a/src/qemu/qemu_capabilities.c +++ b/src/qemu/qemu_capabilities.c @@ -257,6 +257,7 @@ VIR_ENUM_IMPL(virQEMUCaps, QEMU_CAPS_LAST, "host-pci-multidomain", "msg-timestamp", "active-commit", + "change-backing-file", ); @@ -1416,6 +1417,7 @@ struct virQEMUCapsStringFlags virQEMUCapsCommands[] = { { "blockdev-snapshot-sync", QEMU_CAPS_DISK_SNAPSHOT }, { "add-fd", QEMU_CAPS_ADD_FD }, { "nbd-server-start", QEMU_CAPS_NBD_SERVER }, + { "change-backing-file", QEMU_CAPS_CHANGE_BACKING_FILE }, }; struct virQEMUCapsStringFlags virQEMUCapsEvents[] = { diff --git a/src/qemu/qemu_capabilities.h b/src/qemu/qemu_capabilities.h index 3dae302..89dcc6f 100644 --- a/src/qemu/qemu_capabilities.h +++ b/src/qemu/qemu_capabilities.h @@ -207,6 +207,7 @@ typedef enum { QEMU_CAPS_HOST_PCI_MULTIDOMAIN = 166, /* support domain > 0 in host pci address */ QEMU_CAPS_MSG_TIMESTAMP = 167, /* -msg timestamp */ QEMU_CAPS_ACTIVE_COMMIT = 168, /* block-commit works without 'top' */ + QEMU_CAPS_CHANGE_BACKING_FILE = 169, /* change name of backing file in metadata */ QEMU_CAPS_LAST, /* this must always be the last item */ } virQEMUCapsFlags; -- 1.9.3

To allow changing the name that is recorded in the top of the current image chain used in a block pull/rebase operation, we need to specify the backing name to qemu. This is done via the "backing-file" attribute to the block-stream commad. --- src/qemu/qemu_driver.c | 8 ++++---- src/qemu/qemu_migration.c | 6 +++--- src/qemu/qemu_monitor.c | 12 +++++++----- src/qemu/qemu_monitor.h | 3 ++- src/qemu/qemu_monitor_json.c | 15 +++++++++++++++ src/qemu/qemu_monitor_json.h | 1 + 6 files changed, 32 insertions(+), 13 deletions(-) diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index 9f9fdea..ba1bfe2 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -14894,7 +14894,7 @@ qemuDomainBlockPivot(virConnectPtr conn, /* Probe the status, if needed. */ if (!disk->mirroring) { qemuDomainObjEnterMonitor(driver, vm); - rc = qemuMonitorBlockJob(priv->mon, device, NULL, 0, &info, + rc = qemuMonitorBlockJob(priv->mon, device, NULL, NULL, 0, &info, BLOCK_JOB_INFO, true); qemuDomainObjExitMonitor(driver, vm); if (rc < 0) @@ -15112,7 +15112,7 @@ qemuDomainBlockJobImpl(virDomainObjPtr vm, qemuDomainObjEnterMonitor(driver, vm); ret = qemuMonitorBlockJob(priv->mon, device, baseIndex ? baseSource->path : base, - bandwidth, info, mode, async); + NULL, bandwidth, info, mode, async); qemuDomainObjExitMonitor(driver, vm); if (ret < 0) goto endjob; @@ -15158,8 +15158,8 @@ qemuDomainBlockJobImpl(virDomainObjPtr vm, virDomainBlockJobInfo dummy; qemuDomainObjEnterMonitor(driver, vm); - ret = qemuMonitorBlockJob(priv->mon, device, NULL, 0, &dummy, - BLOCK_JOB_INFO, async); + ret = qemuMonitorBlockJob(priv->mon, device, NULL, NULL, 0, + &dummy, BLOCK_JOB_INFO, async); qemuDomainObjExitMonitor(driver, vm); if (ret <= 0) diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c index 7684aec..addae1d 100644 --- a/src/qemu/qemu_migration.c +++ b/src/qemu/qemu_migration.c @@ -1308,7 +1308,7 @@ qemuMigrationDriveMirror(virQEMUDriverPtr driver, _("canceled by client")); goto error; } - mon_ret = qemuMonitorBlockJob(priv->mon, diskAlias, NULL, 0, + mon_ret = qemuMonitorBlockJob(priv->mon, diskAlias, NULL, NULL, 0, &info, BLOCK_JOB_INFO, true); qemuDomainObjExitMonitor(driver, vm); @@ -1360,7 +1360,7 @@ qemuMigrationDriveMirror(virQEMUDriverPtr driver, continue; if (qemuDomainObjEnterMonitorAsync(driver, vm, QEMU_ASYNC_JOB_MIGRATION_OUT) == 0) { - if (qemuMonitorBlockJob(priv->mon, diskAlias, NULL, 0, + if (qemuMonitorBlockJob(priv->mon, diskAlias, NULL, NULL, 0, NULL, BLOCK_JOB_ABORT, true) < 0) { VIR_WARN("Unable to cancel block-job on '%s'", diskAlias); } @@ -1426,7 +1426,7 @@ qemuMigrationCancelDriveMirror(qemuMigrationCookiePtr mig, QEMU_ASYNC_JOB_MIGRATION_OUT) < 0) goto cleanup; - if (qemuMonitorBlockJob(priv->mon, diskAlias, NULL, 0, + if (qemuMonitorBlockJob(priv->mon, diskAlias, NULL, NULL, 0, NULL, BLOCK_JOB_ABORT, true) < 0) VIR_WARN("Unable to stop block job on %s", diskAlias); qemuDomainObjExitMonitor(driver, vm); diff --git a/src/qemu/qemu_monitor.c b/src/qemu/qemu_monitor.c index 3bc06e5..4693870 100644 --- a/src/qemu/qemu_monitor.c +++ b/src/qemu/qemu_monitor.c @@ -3365,6 +3365,7 @@ int qemuMonitorScreendump(qemuMonitorPtr mon, int qemuMonitorBlockJob(qemuMonitorPtr mon, const char *device, const char *base, + const char *backingName, unsigned long bandwidth, virDomainBlockJobInfoPtr info, qemuMonitorBlockJobCmd mode, @@ -3373,9 +3374,10 @@ int qemuMonitorBlockJob(qemuMonitorPtr mon, int ret = -1; unsigned long long speed; - VIR_DEBUG("mon=%p, device=%s, base=%s, bandwidth=%luM, info=%p, mode=%o, " - "modern=%d", mon, device, NULLSTR(base), bandwidth, info, mode, - modern); + VIR_DEBUG("mon=%p, device=%s, base=%s, backingName=%s, bandwidth=%luM, " + "info=%p, mode=%o, modern=%d", + mon, device, NULLSTR(base), NULLSTR(backingName), + bandwidth, info, mode, modern); /* Convert bandwidth MiB to bytes - unfortunately the JSON QMP protocol is * limited to LLONG_MAX also for unsigned values */ @@ -3389,8 +3391,8 @@ int qemuMonitorBlockJob(qemuMonitorPtr mon, speed <<= 20; if (mon->json) - ret = qemuMonitorJSONBlockJob(mon, device, base, speed, info, mode, - modern); + ret = qemuMonitorJSONBlockJob(mon, device, base, backingName, + speed, info, mode, modern); else virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s", _("block jobs require JSON monitor")); diff --git a/src/qemu/qemu_monitor.h b/src/qemu/qemu_monitor.h index 4652ea5..8a23267 100644 --- a/src/qemu/qemu_monitor.h +++ b/src/qemu/qemu_monitor.h @@ -692,7 +692,8 @@ typedef enum { int qemuMonitorBlockJob(qemuMonitorPtr mon, const char *device, - const char *back, + const char *base, + const char *backingName, unsigned long bandwidth, virDomainBlockJobInfoPtr info, qemuMonitorBlockJobCmd mode, diff --git a/src/qemu/qemu_monitor_json.c b/src/qemu/qemu_monitor_json.c index 719be66..3dbce44 100644 --- a/src/qemu/qemu_monitor_json.c +++ b/src/qemu/qemu_monitor_json.c @@ -3789,6 +3789,7 @@ int qemuMonitorJSONBlockJob(qemuMonitorPtr mon, const char *device, const char *base, + const char *backingName, unsigned long long speed, virDomainBlockJobInfoPtr info, qemuMonitorBlockJobCmd mode, @@ -3804,6 +3805,19 @@ qemuMonitorJSONBlockJob(qemuMonitorPtr mon, _("only modern block pull supports base: %s"), base); return -1; } + + if (backingName && mode != BLOCK_JOB_PULL) { + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", + _("backing name is supported only for block pull")); + return -1; + } + + if (backingName && !base) { + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", + _("backing name requires a base image")); + return -1; + } + if (speed && mode == BLOCK_JOB_PULL && !modern) { virReportError(VIR_ERR_INTERNAL_ERROR, _("only modern block pull supports speed: %llu"), @@ -3838,6 +3852,7 @@ qemuMonitorJSONBlockJob(qemuMonitorPtr mon, "s:device", device, "P:speed", speed, "S:base", base, + "S:backing-file", backingName, NULL); break; } diff --git a/src/qemu/qemu_monitor_json.h b/src/qemu/qemu_monitor_json.h index 652a4b6..385211c 100644 --- a/src/qemu/qemu_monitor_json.h +++ b/src/qemu/qemu_monitor_json.h @@ -283,6 +283,7 @@ int qemuMonitorJSONScreendump(qemuMonitorPtr mon, int qemuMonitorJSONBlockJob(qemuMonitorPtr mon, const char *device, const char *base, + const char *backingName, unsigned long long speed, virDomainBlockJobInfoPtr info, qemuMonitorBlockJobCmd mode, -- 1.9.3

Introduce flag for the block rebase API to allow the rebase operation to leave the chain relatively addressed. Also adds a virsh switch to enable this behavior. --- include/libvirt/libvirt.h.in | 3 +++ src/libvirt.c | 3 +++ tools/virsh-domain.c | 12 ++++++++++-- tools/virsh.pod | 4 ++++ 4 files changed, 20 insertions(+), 2 deletions(-) diff --git a/include/libvirt/libvirt.h.in b/include/libvirt/libvirt.h.in index d6a4a0f..d438251 100644 --- a/include/libvirt/libvirt.h.in +++ b/include/libvirt/libvirt.h.in @@ -2580,6 +2580,9 @@ typedef enum { file for a copy */ VIR_DOMAIN_BLOCK_REBASE_COPY_RAW = 1 << 2, /* Make destination file raw */ VIR_DOMAIN_BLOCK_REBASE_COPY = 1 << 3, /* Start a copy job */ + VIR_DOMAIN_BLOCK_REBASE_RELATIVE = 1 << 4, /* Keep backing chain + referenced using relative + names */ } virDomainBlockRebaseFlags; int virDomainBlockRebase(virDomainPtr dom, const char *disk, diff --git a/src/libvirt.c b/src/libvirt.c index 5c19ec9..307de2a 100644 --- a/src/libvirt.c +++ b/src/libvirt.c @@ -19721,6 +19721,9 @@ virDomainBlockPull(virDomainPtr dom, const char *disk, * exists. If the job is aborted, a new one can be started later to * resume from the same point. * + * If @flags contains VIR_DOMAIN_BLOCK_REBASE_RELATIVE, the name recorded + * into the active disk as the location for @base will be kept relative. + * * When @flags includes VIR_DOMAIN_BLOCK_REBASE_COPY, this starts a copy, * where @base must be the name of a new file to copy the chain to. By * default, the copy will pull the entire source chain into the destination diff --git a/tools/virsh-domain.c b/tools/virsh-domain.c index b825a05..8275755 100644 --- a/tools/virsh-domain.c +++ b/tools/virsh-domain.c @@ -1479,10 +1479,14 @@ blockJobImpl(vshControl *ctl, const vshCmd *cmd, case VSH_CMD_BLOCK_JOB_PULL: if (vshCommandOptStringReq(ctl, cmd, "base", &base) < 0) goto cleanup; - if (base) - ret = virDomainBlockRebase(dom, path, base, bandwidth, 0); + if (vshCommandOptBool(cmd, "keep-relative")) + flags |= VIR_DOMAIN_BLOCK_REBASE_RELATIVE; + + if (base || flags) + ret = virDomainBlockRebase(dom, path, base, bandwidth, flags); else ret = virDomainBlockPull(dom, path, bandwidth, 0); + break; case VSH_CMD_BLOCK_JOB_COMMIT: if (vshCommandOptStringReq(ctl, cmd, "base", &base) < 0 || @@ -2118,6 +2122,10 @@ static const vshCmdOptDef opts_block_pull[] = { .type = VSH_OT_BOOL, .help = N_("with --wait, don't wait for cancel to finish") }, + {.name = "keep-relative", + .type = VSH_OT_BOOL, + .help = N_("keep the backing chain relatively referenced") + }, {.name = NULL} }; diff --git a/tools/virsh.pod b/tools/virsh.pod index 1fe359c..949cf57 100644 --- a/tools/virsh.pod +++ b/tools/virsh.pod @@ -876,6 +876,7 @@ I<bandwidth> specifies copying bandwidth limit in MiB/s. =item B<blockpull> I<domain> I<path> [I<bandwidth>] [I<base>] [I<--wait> [I<--verbose>] [I<--timeout> B<seconds>] [I<--async>]] +[I<--keep-relative>] Populate a disk from its backing image chain. By default, this command flattens the entire chain; but if I<base> is specified, containing the @@ -895,6 +896,9 @@ is triggered, I<--async> will return control to the user as fast as possible, otherwise the command may continue to block a little while longer until the job is done cleaning up. +Using the I<--keep-relative> flag will keep the backing chain names +relative. + I<path> specifies fully-qualified path of the disk; it corresponds to a unique target name (<target dev='name'/>) or source file (<source file='name'/>) for one of the disk devices attached to I<domain> (see -- 1.9.3

Now that we are able to select images from the backing chain via indexed access we should also convert possible network sources to qemu-compatible strings before passing them to qemu. --- src/qemu/qemu_driver.c | 45 +++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 41 insertions(+), 4 deletions(-) diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index c142646..dd7ea88 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -15042,6 +15042,8 @@ qemuDomainBlockJobImpl(virDomainObjPtr vm, virDomainDiskDefPtr disk; virStorageSourcePtr baseSource = NULL; unsigned int baseIndex = 0; + char *basePath = NULL; + char *backingPath = NULL; if (!virDomainObjIsActive(vm)) { virReportError(VIR_ERR_OPERATION_INVALID, "%s", @@ -15049,6 +15051,13 @@ qemuDomainBlockJobImpl(virDomainObjPtr vm, goto cleanup; } + if (flags & VIR_DOMAIN_BLOCK_REBASE_RELATIVE && !base) { + virReportError(VIR_ERR_INVALID_ARG, "%s", + _("flag VIR_DOMAIN_BLOCK_REBASE_RELATIVE is valid only " + " with non-null base ")); + goto cleanup; + } + priv = vm->privateData; if (virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_BLOCKJOB_ASYNC)) { async = true; @@ -15109,10 +15118,35 @@ qemuDomainBlockJobImpl(virDomainObjPtr vm, base, baseIndex, NULL)))) goto endjob; + if (baseSource) { + if (qemuGetDriveSourceString(baseSource, NULL, &basePath) < 0) + goto endjob; + + if (flags & VIR_DOMAIN_BLOCK_REBASE_RELATIVE) { + if (!virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_CHANGE_BACKING_FILE)) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s", + _("this QEMU binary doesn't support relative " + "block pull/rebase")); + goto endjob; + } + + if (virStorageFileGetRelativeBackingPath(disk->src->backingStore, + baseSource, + &backingPath) < 0) + goto endjob; + + + if (!backingPath) { + virReportError(VIR_ERR_OPERATION_INVALID, "%s", + _("can't keep relative backing relationship")); + goto endjob; + } + } + } + qemuDomainObjEnterMonitor(driver, vm); - ret = qemuMonitorBlockJob(priv->mon, device, - baseIndex ? baseSource->path : base, - NULL, bandwidth, info, mode, async); + ret = qemuMonitorBlockJob(priv->mon, device, basePath, backingPath, + bandwidth, info, mode, async); qemuDomainObjExitMonitor(driver, vm); if (ret < 0) goto endjob; @@ -15188,6 +15222,8 @@ qemuDomainBlockJobImpl(virDomainObjPtr vm, } cleanup: + VIR_FREE(basePath); + VIR_FREE(backingPath); VIR_FREE(device); if (vm) virObjectUnlock(vm); @@ -15434,7 +15470,8 @@ qemuDomainBlockRebase(virDomainPtr dom, const char *path, const char *base, virCheckFlags(VIR_DOMAIN_BLOCK_REBASE_SHALLOW | VIR_DOMAIN_BLOCK_REBASE_REUSE_EXT | VIR_DOMAIN_BLOCK_REBASE_COPY | - VIR_DOMAIN_BLOCK_REBASE_COPY_RAW, -1); + VIR_DOMAIN_BLOCK_REBASE_COPY_RAW | + VIR_DOMAIN_BLOCK_REBASE_RELATIVE, -1); if (!(vm = qemuDomObjFromDomain(dom))) return -1; -- 1.9.3