Re: [libvirt] [PATCH v2 3/5] qemu: Track domain quiesced status

Adds an quiesced flag into qemuDomainObjPrivate that tracks whether guest filesystems of the domain is quiesced of 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 to avoid confusing the tracking of quiesced status. --- src/qemu/qemu_domain.h | 2 ++ src/qemu/qemu_driver.c | 41 +++++++++++++++++++++++++++++++---------- 2 files changed, 33 insertions(+), 10 deletions(-) diff --git a/src/qemu/qemu_domain.h b/src/qemu/qemu_domain.h index 0bed50b..8a79a00 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 9aad2dc..8109e46 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -12040,6 +12040,8 @@ cleanup: } +/* Return -1 if request is not sent to agent due to misconfig, -2 on agent + * failure, and number of frozen filesystems on success. */ static int qemuDomainSnapshotFSFreeze(virDomainObjPtr vm) { qemuDomainObjPrivatePtr priv = vm->privateData; @@ -12056,14 +12058,24 @@ qemuDomainSnapshotFSFreeze(virDomainObjPtr vm) { _("QEMU guest agent is not configured")); 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; + + return freezed < 0 ? -2 : freezed; } +/* Return -1 if request is not sent to agent due to misconfig, -2 on agent + * failure, and number of thawed filesystems on success. */ static int qemuDomainSnapshotFSThaw(virDomainObjPtr vm, bool report) { @@ -12084,6 +12096,11 @@ qemuDomainSnapshotFSThaw(virDomainObjPtr vm, bool report) _("QEMU guest agent is not configured")); return -1; } + if (!priv->quiesced && report) { + virReportError(VIR_ERR_OPERATION_INVALID, "%s", + _("domain is not quiesced")); + return -1; + } qemuDomainObjEnterAgent(vm); if (!report) @@ -12093,8 +12110,11 @@ qemuDomainSnapshotFSThaw(virDomainObjPtr vm, bool report) virSetError(err); qemuDomainObjExitAgent(vm); + if (thawed >= 0) + priv->quiesced = false; + virFreeError(err); - return thawed; + return thawed < 0 ? -2 : thawed; }

/* The domain is expected to be locked and inactive. */ @@ -13069,17 +13089,18 @@ 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 the 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(vm); + if (freeze < 0) { + /* the helper reported the error */ + if (freeze != -1) + thaw = -1; /* the command is sent but agent failed */ goto endjob; - } else { - thaw = 1; } + thaw = 1; }