These will freeze and thaw filesystems within guest. The APIs take @flags arguments which are currently not used, for future extensions. Signed-off-by: Tomoki Sekiyama <tomoki.sekiyama(a)hds.com&gt; --- include/libvirt/libvirt.h.in | 6 ++++ src/driver.h | 10 ++++++ src/libvirt.c | 70 ++++++++++++++++++++++++++++++++++++++++++ src/libvirt_public.syms | 2 + 4 files changed, 88 insertions(+) diff --git a/include/libvirt/libvirt.h.in b/include/libvirt/libvirt.h.in index 91e3e3b..afe92c6 100644 --- a/include/libvirt/libvirt.h.in +++ b/include/libvirt/libvirt.h.in @@ -5277,6 +5277,12 @@ int virDomainFSTrim(virDomainPtr dom, unsigned long long minimum, unsigned int flags); +int virDomainFSFreeze(virDomainPtr dom, + unsigned int flags); + +int virDomainFSThaw(virDomainPtr dom, + unsigned int flags); + /** * virSchedParameterType: * diff --git a/src/driver.h b/src/driver.h index e66fc7a..50258e2 100644 --- a/src/driver.h +++ b/src/driver.h @@ -1149,6 +1149,14 @@ typedef int unsigned int flags, int cancelled); +typedef int +(*virDrvDomainFSFreeze)(virDomainPtr dom, + unsigned int flags); + +typedef int +(*virDrvDomainFSThaw)(virDomainPtr dom, + unsigned int flags); + typedef struct _virDriver virDriver; typedef virDriver *virDriverPtr; @@ -1363,6 +1371,8 @@ struct _virDriver { virDrvDomainMigrateFinish3Params domainMigrateFinish3Params; virDrvDomainMigrateConfirm3Params domainMigrateConfirm3Params; virDrvConnectGetCPUModelNames connectGetCPUModelNames; + virDrvDomainFSFreeze domainFSFreeze; + virDrvDomainFSThaw domainFSThaw; }; diff --git a/src/libvirt.c b/src/libvirt.c index 4454829..48b9902 100644 --- a/src/libvirt.c +++ b/src/libvirt.c @@ -20658,3 +20658,73 @@ virDomainFSTrim(virDomainPtr dom, virDispatchError(dom->conn); return -1; } + +/** + * virDomainFSFreeze: + * @dom: a domain object + * @flags: extra flags, not used yet, so callers should always pass 0 + * + * Freeze filesystems within the guest (hence guest agent may be + * required depending on hypervisor used). + * + * Returns 0 on success, -1 otherwise. + */ +int +virDomainFSFreeze(virDomainPtr dom, + unsigned int flags) +{ + VIR_DOMAIN_DEBUG(dom, "flags=%x", flags); + + virResetLastError(); + + virCheckDomainReturn(dom, -1); + virCheckReadOnlyGoto(dom->conn->flags, error); + + if (dom->conn->driver->domainFSFreeze) { + int ret = dom->conn->driver->domainFSFreeze(dom, flags); + if (ret < 0) + goto error; + return ret; + } + + virReportUnsupportedError(); + + error: + virDispatchError(dom->conn); + return -1; +} + +/** + * virDomainFSThaw: + * @dom: a domain object + * @flags: extra flags, not used yet, so callers should always pass 0 + * + * Thaw the frozen filesystems within the guest (hence guest agent + * may be required depending on hypervisor used). + * + * Returns 0 on success, -1 otherwise. + */ +int +virDomainFSThaw(virDomainPtr dom, + unsigned int flags) +{ + VIR_DOMAIN_DEBUG(dom, "flags=%x", flags); + + virResetLastError(); + + virCheckDomainReturn(dom, -1); + virCheckReadOnlyGoto(dom->conn->flags, error); + + if (dom->conn->driver->domainFSThaw) { + int ret = dom->conn->driver->domainFSThaw(dom, flags); + if (ret < 0) + goto error; + return ret; + } + + virReportUnsupportedError(); + + error: + virDispatchError(dom->conn); + return -1; +} diff --git a/src/libvirt_public.syms b/src/libvirt_public.syms index 9ab0c92..42793c9 100644 --- a/src/libvirt_public.syms +++ b/src/libvirt_public.syms @@ -648,6 +648,8 @@ LIBVIRT_1.2.1 { LIBVIRT_1.2.3 { global: virDomainCoreDumpWithFormat; + virDomainFSFreeze; + virDomainFSThaw; } LIBVIRT_1.2.1;

Adds an quiesced flag into qemuDomainObjPrivate that tracks whether guest filesystems of the domain is quiesced or not. It also modify error code from qemuDomainSnapshotFSFreeze and qemuDomainSnapshotFSThaw, so that a caller can know whether the command is actually sent to the guest agent. If the error is caused before sending a freeze command, a counterpart thaw command shouldn't be sent either, not to thaw the guest unexpectedly by error handling code. Signed-off-by: Tomoki Sekiyama <tomoki.sekiyama(a)hds.com&gt; --- src/qemu/qemu_domain.c | 5 ++++ src/qemu/qemu_domain.h | 2 + src/qemu/qemu_driver.c | 66 +++++++++++++++++++++++++++++++++++++++--------- 3 files changed, 60 insertions(+), 13 deletions(-) diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c index 36cb2c6..52aa09d 100644 --- a/src/qemu/qemu_domain.c +++ b/src/qemu/qemu_domain.c @@ -357,6 +357,9 @@ qemuDomainObjPrivateXMLFormat(virBufferPtr buf, void *data) virBufferAddLit(buf, "</devices>\n"); } + if (priv->quiesced) + virBufferAddLit(buf, "<quiesced/>\n"); + return 0; } @@ -518,6 +521,8 @@ qemuDomainObjPrivateXMLParse(xmlXPathContextPtr ctxt, void *data) } VIR_FREE(nodes); + priv->quiesced = virXPathBoolean("boolean(./quiesced)", ctxt) == 1; + return 0; error: diff --git a/src/qemu/qemu_domain.h b/src/qemu/qemu_domain.h index b2830c4..5fb1665 100644 --- a/src/qemu/qemu_domain.h +++ b/src/qemu/qemu_domain.h @@ -176,6 +176,8 @@ struct _qemuDomainObjPrivate { char **qemuDevices; /* NULL-terminated list of devices aliases known to QEMU */ bool hookRun; /* true if there was a hook run over this domain */ + + bool quiesced; /* true if the domain filesystems are quiesced */ }; typedef enum { diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index b032441..7fd8b6d 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -12100,32 +12100,61 @@ qemuDomainPrepareDiskChainElement(virQEMUDriverPtr driver, } +/* Return -1 if request is not sent to agent due to misconfig, -2 if request + * is sent but failed, and number of frozen filesystems on success. */ static int -qemuDomainSnapshotFSFreeze(virDomainObjPtr vm) +qemuDomainSnapshotFSFreeze(virQEMUDriverPtr driver, virDomainObjPtr vm) { qemuDomainObjPrivatePtr priv = vm->privateData; + virQEMUDriverConfigPtr cfg; int freezed; if (!qemuDomainAgentAvailable(priv, true)) return -1; + if (priv->quiesced) { + virReportError(VIR_ERR_OPERATION_INVALID, "%s", + _("domain is already quiesced")); + return -1; + } + qemuDomainObjEnterAgent(vm); freezed = qemuAgentFSFreeze(priv->agent); qemuDomainObjExitAgent(vm); - return freezed; + if (freezed >= 0) + priv->quiesced = true; + + cfg = virQEMUDriverGetConfig(driver); + if (virDomainSaveStatus(driver->xmlopt, cfg->stateDir, vm) < 0) { + virObjectUnref(cfg); + return -2; + } + virObjectUnref(cfg); + + return freezed < 0 ? -2 : freezed; } +/* Return -1 if request is not sent to agent due to misconfig, -2 if request + * is send but failed, and number of thawed filesystems on success. */ static int -qemuDomainSnapshotFSThaw(virDomainObjPtr vm, bool report) +qemuDomainSnapshotFSThaw(virQEMUDriverPtr driver, + virDomainObjPtr vm, bool report) { qemuDomainObjPrivatePtr priv = vm->privateData; + virQEMUDriverConfigPtr cfg; int thawed; virErrorPtr err = NULL; if (!qemuDomainAgentAvailable(priv, report)) return -1; + if (!priv->quiesced && report) { + virReportError(VIR_ERR_OPERATION_INVALID, "%s", + _("domain is not quiesced")); + return -1; + } + qemuDomainObjEnterAgent(vm); if (!report) err = virSaveLastError(); @@ -12134,8 +12163,18 @@ qemuDomainSnapshotFSThaw(virDomainObjPtr vm, bool report) virSetError(err); qemuDomainObjExitAgent(vm); + if (thawed >= 0) + priv->quiesced = false; + + cfg = virQEMUDriverGetConfig(driver); + if (virDomainSaveStatus(driver->xmlopt, cfg->stateDir, vm) < 0) { + virObjectUnref(cfg); + return -2; + } + virObjectUnref(cfg); + virFreeError(err); - return thawed; + return thawed < 0 ? -2 : thawed; } /* The domain is expected to be locked and inactive. */ @@ -13114,17 +13153,18 @@ qemuDomainSnapshotCreateActiveExternal(virConnectPtr conn, goto cleanup; /* If quiesce was requested, then issue a freeze command, and a - * counterpart thaw command, no matter what. The command will - * fail if the guest is paused or the guest agent is not - * running. */ + * counterpart thaw command when it is actually sent to agent. + * The command will fail if the guest is paused or the guest agent + * is not running, or is already quiesced. */ if (flags & VIR_DOMAIN_SNAPSHOT_CREATE_QUIESCE) { - if (qemuDomainSnapshotFSFreeze(vm) < 0) { - /* helper reported the error */ - thaw = -1; + int freeze = qemuDomainSnapshotFSFreeze(driver, vm); + if (freeze < 0) { + /* the helper reported the error */ + if (freeze == -2) + thaw = -1; /* the command is sent but agent failed */ goto endjob; - } else { - thaw = 1; } + thaw = 1; } /* We need to track what state the guest is in, since taking the @@ -13265,7 +13305,7 @@ qemuDomainSnapshotCreateActiveExternal(virConnectPtr conn, goto cleanup; } if (vm && thaw != 0 && - qemuDomainSnapshotFSThaw(vm, thaw > 0) < 0) { + qemuDomainSnapshotFSThaw(driver, vm, thaw > 0) < 0) { /* helper reported the error, if it was needed */ if (thaw > 0) ret = -1;

These are exposed under domfsfreeze command and domfsthaw command. Signed-off-by: Tomoki Sekiyama <tomoki.sekiyama(a)hds.com&gt; --- tools/virsh-domain.c | 92 ++++++++++++++++++++++++++++++++++++++++++++++++++ tools/virsh.pod | 15 ++++++++ 2 files changed, 107 insertions(+) diff --git a/tools/virsh-domain.c b/tools/virsh-domain.c index d9aa4fa..b0cf68d 100644 --- a/tools/virsh-domain.c +++ b/tools/virsh-domain.c @@ -11391,6 +11391,86 @@ cmdDomFSTrim(vshControl *ctl, const vshCmd *cmd) return ret; } +static const vshCmdInfo info_domfsfreeze[] = { + {.name = "help", + .data = N_("Freeze domain's mounted filesystems.") + }, + {.name = "desc", + .data = N_("Freeze domain's mounted filesystems.") + }, + {.name = NULL} +}; + +static const vshCmdOptDef opts_domfsfreeze[] = { + {.name = "domain", + .type = VSH_OT_DATA, + .flags = VSH_OFLAG_REQ, + .help = N_("domain name, id or uuid") + }, + {.name = NULL} +}; +static bool +cmdDomFSFreeze(vshControl *ctl, const vshCmd *cmd) +{ + virDomainPtr dom = NULL; + bool ret = false; + unsigned int flags = 0; + + if (!(dom = vshCommandOptDomain(ctl, cmd, NULL))) + return ret; + + if (virDomainFSFreeze(dom, flags) < 0) { + vshError(ctl, _("Unable to freeze filesystems")); + goto cleanup; + } + + ret = true; + + cleanup: + virDomainFree(dom); + return ret; +} + +static const vshCmdInfo info_domfsthaw[] = { + {.name = "help", + .data = N_("Thaw domain's mounted filesystems.") + }, + {.name = "desc", + .data = N_("Thaw domain's mounted filesystems.") + }, + {.name = NULL} +}; + +static const vshCmdOptDef opts_domfsthaw[] = { + {.name = "domain", + .type = VSH_OT_DATA, + .flags = VSH_OFLAG_REQ, + .help = N_("domain name, id or uuid") + }, + {.name = NULL} +}; +static bool +cmdDomFSThaw(vshControl *ctl, const vshCmd *cmd) +{ + virDomainPtr dom = NULL; + bool ret = false; + unsigned int flags = 0; + + if (!(dom = vshCommandOptDomain(ctl, cmd, NULL))) + return ret; + + if (virDomainFSThaw(dom, flags) < 0) { + vshError(ctl, _("Unable to thaw filesystems")); + goto cleanup; + } + + ret = true; + + cleanup: + virDomainFree(dom); + return ret; +} + const vshCmdDef domManagementCmds[] = { {.name = "attach-device", .handler = cmdAttachDevice, @@ -11538,6 +11618,18 @@ const vshCmdDef domManagementCmds[] = { .info = info_domdisplay, .flags = 0 }, + {.name = "domfsfreeze", + .handler = cmdDomFSFreeze, + .opts = opts_domfsfreeze, + .info = info_domfsfreeze, + .flags = 0 + }, + {.name = "domfsthaw", + .handler = cmdDomFSThaw, + .opts = opts_domfsthaw, + .info = info_domfsthaw, + .flags = 0 + }, {.name = "domfstrim", .handler = cmdDomFSTrim, .opts = opts_domfstrim, diff --git a/tools/virsh.pod b/tools/virsh.pod index 20352cb..3f41f77 100644 --- a/tools/virsh.pod +++ b/tools/virsh.pod @@ -941,6 +941,21 @@ Output a URI which can be used to connect to the graphical display of the domain via VNC, SPICE or RDP. If I<--include-password> is specified, the SPICE channel password will be included in the URI. +=item B<domfsfreeze> I<domain> + +Freeze all mounted filesystems within a running domain to prepare for +consistent snapshots. + +Note that B<snapshot-create> command has a I<--quiesce> option to freeze +and thaw the filesystems automatically to keep snapshots consistent. +B<domfsfreeze> command is only needed when a user wants to utilize the +native snapshot features of storage devices not supported by libvirt yet. + +=item B<domfsthaw> I<domain> + +Thaw all mounted filesystems within a running domain, which are frozen +by domfsfreeze command. + =item B<domfstrim> I<domain> [I<--minimum> B<bytes>] [I<--mountpoint mountPoint>]