We can properly track the job type when starting the job so that we
don't have to infer it later.

This patch also adds an enum of block job types specific to qemu
(qemuBlockjobType) which mirrors the public block job types
(virDomainBlockJobType) but allows for other types to be added later
which will not be public.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Block jobs can also happen on objects which are not a disk at a given
point (e.g. the frontend was not hotplugged yet) and thus will be
eventually kept separately. Add a reference back to the disk for
blockjobs which do correspond to a disk.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

If the job wasn't started, we don't need to end the synchronous job. Add
a note and drop the unnecessary calls.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Rather than directly modifying fields in the qemuBlockJobDataPtr
structure add a bunch of fields which allow to do the transitions.

This will help later when adding more complexity to the job handling.

APIs introduced in this patch are:

qemuBlockJobDiskNew - prepare for starting a new blockjob on a disk
qemuBlockJobDiskGetJob - get the block job data structure for a disk

For individual job state manipulation the following APIs are added:
qemuBlockJobStarted - Sets the job as started with qemu. Until that
                      the job can be cancelled without asking qemu.

qemuBlockJobStartupFinalize - finalize job startup. If the job was
                              started in qemu already, just releases
                              reference to the job object. Otherwise
                              clears everything as if the job was never
                              started.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

The field is used to note the state the job has transitioned to while
handling the blockjob state change event. Rename the field so that it's
obvious that this is the new state and not the general state of the
blockjob.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Reference counting will simplify semantics of the lifecycle of the
object.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

qemuBlockJobEventProcessLegacy was getting too big. Remove handling of
completed jobs in a separate function.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

This will handle blockjob finalizing for the old approach so rename it
accordingly.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Struct qemuDomainDiskPrivate was holding multiple variables connected to
a disk block job. Consolidate them into a new struct qemuBlockJobData.

This will also allow simpler extensions to the block job mechanisms.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

The blockjob module uses 'qemuDomainAsyncJob' in it's public headers.
As I plan adding a new structure containing job data which will need to
be included in "qemu_domain.h" it's necessary to break the circular
dependency.

Convert 'qemuDomainAsyncJob' type to 'int' as it's an enum.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

All the public APIs of the qemu_blockjob module operate on a 'disk'.
Since I'll be adding APIs which operate on a job later let's rename the
existing ones.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

The function is now only called locally. Some code movement was
necessary to avoid forward declarations.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

The event reports the disk path to identify the disk which makes sense
only for local disks. Additionally network backed disks like NBD don't
need to have a path so the callback would return NULL.

Report VIR_DOMAIN_EVENT_ID_BLOCK_JOB only for non-empty local disks.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Put the emitting of VIR_DOMAIN_EVENT_ID_BLOCK_JOB and
VIR_DOMAIN_EVENT_ID_BLOCK_JOB_2 into a separate function.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

In some cases backing chain needs to be cleared prior to re-detection.
Move this step out of qemuDomainDetermineDiskChain as only certain
places need it and the function itself is able to skip to the end of the
chain to perform detection.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

And replace all calls with virObjectEventStateQueue such that:

    qemuDomainEventQueue(driver, event);

becomes:

    virObjectEventStateQueue(driver->domainEventState, event);

And remove NULL checking from all callers.
Signed-off-by: NAnya Harter <aharter@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>
Signed-off-by: NJán Tomko <jtomko@redhat.com>

The pointer to the qemu driver is already included in domain object's
private data, so does not need to be passed as yet another parameter
when the domain object is already passed.

Also removes parameter 'driver' from functions which had it just because of
qemuBlockJobUpdate.
Signed-off-by: NRoland Schulz <schullzroll@gmail.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>
Signed-off-by: NJán Tomko <jtomko@redhat.com>

Since we are re-detecting the backing chain after pivoting to the active
block commit target (or block copy target) the disk index needs to be
reset to 0. This is necessary since we move a member of the backing
chain to disk->src but clear indexes only starting from
disk->src->backingStore. The freshly detected images have indexes
starting from 1, but since we've pivoted into an image which was
previously a backing store it would have a non-0 index.
The lookup function would then return the top of the chain for queries
like 'vda[1]' instead of the first backing store.

This problem will not be present once we keep the disk indexes stable.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1519745

Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

This patch pass event error up to the place where we can
use it. Error is passed only for sync blockjob event mode
as we can't use the error in async mode. In async mode we
just pass the event details to the client thru event API
but current blockjob event API can not carry extra parameter.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

For VMs with persistent config the config may change upon successful
completion of a job. Save it always if a persistent VM finishes a
blockjob. This will simplify further additions.

The status XML would be saved only for the copy job (in case of success)
or on failure even for other jobs. As the status contains the backing
chain data, which change after success we should always save it on
block job completion.

Becase it can be called during migration out (namely on cancelling
blockjobs).
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

Detect the node names when setting block threshold and when reconnecting
or when they are cleared when a block job finishes. This operation will
become a no-op once we fully support node names.

Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

For the blockjobs, where libvirt is able to track the state internally
we can fix locking of images we can remove the appropriate locks.

Also when doing a pivoting operation we should not acquire the lock on
any of those images since both are actually locked already.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1302168

The virDomainObjFormat and virDomainSaveStatus methods
both call into virDomainDefFormat, so should be providing
a non-NULL virCapsPtr instance.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

virDomainSaveConfig calls virDomainDefFormat which was setting the caps
to NULL, thus keeping the old behaviour (i.e. not looking at
netprefix). This patch adds the virCapsPtr to the function and allows
the configuration to be saved and skipping interface names that were
registered with virCapabilitiesSetNetPrefix().
Signed-off-by: NJoao Martins <joao.m.martins@oracle.com>

Every single call to qemuDomainEventQueue() uses the following pattern:

    if (event)
        qemuDomainEventQueue(driver, event);

Let's move the check for valid event to qemuDomainEventQueue and
simplify all callers.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

This patch reverts commit 76c61cdc.

VIR_DOMAIN_DISK_MIRROR_STATE_ABORT says we asked for a block job to be
aborted rather than saying it was aborted. Let's just use
VIR_DOMAIN_DISK_MIRROR_STATE_NONE consistently whenever a block job
finishes since no caller depends on VIR_DOMAIN_DISK_MIRROR_STATE_ABORT
(anymore) to check whether a block job failed or it was cancelled.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

By switching block jobs to use domain conditions, we can drop some
pretty complicated code in NBD storage migration.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

The wrapper is useful for calling qemuBlockJobEventProcess with the
event details stored in disk's privateData, which is the most likely
usage of qemuBlockJobEventProcess.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

Most virDomainDiskIndexByName callers do not care about the index; what
they really want is a disk def pointer.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

qemuBlockJobSyncBegin and qemuBlockJobSyncEnd delimit a region of code
where block job events are processed "synchronously".
qemuBlockJobSyncWait and qemuBlockJobSyncWaitWithTimeout wait for an
event generated by a block job.

The Wait* functions may be called multiple times while the synchronous
block job is active. Any pending block job event will be processed by
only when Wait* or End is called.  disk->blockJobStatus is reset by
these functions, so if it is needed a pointer to a
virConnectDomainEventBlockJobStatus variable should be passed as the
last argument. It is safe to pass NULL if you do not care about the
block job status.

All functions assume the VM object is locked. The Wait* functions will
unlock the object for as long as they are waiting. They will return -1
and report an error if the domain exits before an event is received.

Typical use is as follows:

  virQEMUDriverPtr driver;
  virDomainObjPtr vm; /* locked */
  virDomainDiskDefPtr disk;
  virConnectDomainEventBlockJobStatus status;

  qemuBlockJobSyncBegin(disk);

  ... start block job ...

  if (qemuBlockJobSyncWait(driver, vm, disk, &status) < 0) {
      /* domain died while waiting for event */
      ret = -1;
      goto error;
  }

  ... possibly start other block jobs
      or wait for further events ...

  qemuBlockJobSyncEnd(driver, vm, disk, NULL);

To perform other tasks periodically while waiting for an event:

  virQEMUDriverPtr driver;
  virDomainObjPtr vm; /* locked */
  virDomainDiskDefPtr disk;
  virConnectDomainEventBlockJobStatus status;
  unsigned long long timeout = 500 * 1000ull; /* milliseconds */

  qemuBlockJobSyncBegin(disk);

  ... start block job ...

  do {
      ... do other task ...

      if (qemuBlockJobSyncWaitWithTimeout(driver, vm, disk,
                                          timeout, &status) < 0) {
          /* domain died while waiting for event */
          ret = -1;
          goto error;
      }
  } while (status == -1);

  qemuBlockJobSyncEnd(driver, vm, disk, NULL);
Signed-off-by: NMichael Chapman <mike@very.puzzling.org>

We will want to use synchronous block jobs from qemu_migration as well,
so split this function out into a new source file.
Signed-off-by: NMichael Chapman <mike@very.puzzling.org>