Add a validator which checks that a bitmap spanning multiple backing
chain members doesn't look broken. The current rules are that no
intermediate birmaps are missing (unfortunately it's hard to know
whether the topmost or bottommost bitmap is missing) and none of the
components is inconsistent.

We can obviously improve it over time.

The validator is also tested against the existing bitmap data we have
for the backup merging test as well as some of the existing broken
bitmap synthetic test cases.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Use the glib allocation function that never returns NULL and remove the
now dead-code checks from all callers.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Create a wrapper for qemuBlockGetNamedNodeData named
qemuBlockGetNamedNodeData. The purpose of the wrapper is to integrate
the monitor handling functionality and in the future possible
qemuCaps-based flags.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

libvirt treats 'luks' images as raw+encryption. The logic in
qemuBlockStorageSourceCreateFormat skipped the creation if the requested
image was raw but didn't take into account the encryption.

This manifested itself e.g. when attempting to do a virsh blockcopy with
the following XML:

    <disk type='file' device='disk'>
      <driver name='qemu' type='raw'/>
      <source file='/tmp/enccpy'>
        <encryption format='luks'>
          <secret type='passphrase' uuid='0a81f5b2-8403-7b23-c8d6-21ccc2f80d6f'/>
        </encryption>
      </source>
    </disk>

Where qemu would report the following error:

 unable to execute QEMU command 'blockdev-add': Volume is not in LUKS format

rather than actually formatting the image first.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

The waiting loop used QEMU_ASYNC_JOB_NONE rather than 'asyncJob' passed
from the caller.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NDaniel P. Berrangé <berrange@redhat.com>

Now, that we have everything prepared, we can generate command
line for NVMe disks.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NCole Robinson <crobinso@redhat.com>

To simplify implementation, some restrictions are added. For
instance, an NVMe disk can't go to any bus but virtio and has to
be type of 'disk' and can't have startupPolicy set.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NCole Robinson <crobinso@redhat.com>

This function looks up a named bitmap for a virStorageSource in the data
returned from query-named-block-nodes.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

This previous commit introduced a simpler free callback for
hash data with only 1 arg, the value to free:

  commit 49288fac
  Author: Peter Krempa <pkrempa@redhat.com>
  Date:   Wed Oct 9 15:26:37 2019 +0200

    util: hash: Add possibility to use simpler data free function in virHash

It missed two functions in the hash table code which need
to call the alternate data free function, virHashRemoveEntry
and virHashRemoveSet.

After the previous patch though, there is no code that
makes functional use of the 2nd key arg in the data
free function. There is merely one log message that can
be dropped.

We can thus purge the current virHashDataFree callback
entirely, and rename virHashDataFreeSimple to replace
it.
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

There are four places where we remove image XATTRs and in all of
them we have the same for() loop with the same body. Move it into
a separate function because I'm about to introduce fifth place
where the same needs to be done.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NPeter Krempa <pkrempa@redhat.com>

Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NDaniel Henrique Barboza <danielhb413@gmail.com>

Calling the monitor was convenient for the implementation in
qemuDomainBlockCopyCommon, but causes the snapshot code to call
query-named-block-nodes for every disk.

Fix this by removing the monitor call from
qemuBlockStorageSourceCreateDetectSize so that the data can be reused in
loops.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
ACKed-by: NEric Blake <eblake@redhat.com>

Replace all occurrences of
  if (VIR_STRDUP(a, b) < 0)
     /* effectively dead code */
with:
  a = g_strdup(b);
Signed-off-by: NJán Tomko <jtomko@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

Replace all the occurrences of
  ignore_value(VIR_STRDUP(a, b));
with
  a = g_strdup(b);
Signed-off-by: NJán Tomko <jtomko@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

Signed-off-by: NJán Tomko <jtomko@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

Prefer:
    return g_steal_pointer(&ptr);
Signed-off-by: NJán Tomko <jtomko@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

Since commit 44e7f029
    util: rewrite auto cleanup macros to use glib's equivalent

VIR_AUTOPTR aliases to g_autoptr. Replace all of its use by the GLib
macro version.
Signed-off-by: NJán Tomko <jtomko@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

Since commit 44e7f029
    util: rewrite auto cleanup macros to use glib's equivalent

VIR_AUTOPTR aliases to g_autoptr. Replace all uses of VIR_DEFINE_AUTOPTR_FUNC
with G_DEFINE_AUTOPTR_CLEANUP_FUNC in preparation for replacing the
rest.
Signed-off-by: NJán Tomko <jtomko@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

Since commit 44e7f029
    util: rewrite auto cleanup macros to use glib's equivalent

VIR_AUTOFREE is just an alias for g_autofree. Use the GLib macros
directly instead of our custom aliases.
Signed-off-by: NJán Tomko <jtomko@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

Use G_GNUC_UNUSED from GLib instead of ATTRIBUTE_UNUSED.
Signed-off-by: NJán Tomko <jtomko@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

Use the new generator residing in the monitor code rather than directly
using qemuMonitorJSONTransactionAdd.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

Pass backing store as an argument rather than extracting it locally and
fix the callers.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Pass in backing store explicitly to qemuBlockStorageSourceGetBlockdevProps
and fix the callers.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Move all bits of the formatting of the 'backing' attribute to a single
condition and make it use a single extracted copy of the backing store.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

The 'u' modifier creates an unsigned int JSON attribute but the disk size
and capacity fields are unsigned long long. If the size of the created
image would be more than 4GiB we'd overflow and create sub-4G image.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

QEMU finally exposes an interface which allows us to instruct it to
format or create arbitrary images. This is required for blockdev
integration of block copy and snapshots as we need to pre-format images
prior to use with blockdev-add.

This path introduces job handling and also helpers for formatting and
attaching a whole image described by a virStorageSource.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

In case when the backing store can be represented with something
simpler such as a URI we can use it rather than falling back to the
json: pseudo-protocol.

In cases when it's not worth it (e.g. with the old ugly NBD or RBD
strings) let's switch to json.

The function is exported as we'll need it when overwriting the ugly
strings qemu would come up with during blockjobs.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

For the modern use cases we are going to use 'blockdev-snapshot' instead
of 'blockdev-snapshot-sync'.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

QEMU allows us to create storage on certain network protocols which
allow image creation through their API. Wire up the generator for using
it with libvirt as well as for local files.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

'blockdev-add' allows us to use qemu to format images to our desired
format. This patch implements helpers which convert a
virStorageSourcePtr into JSON objects describing the required
configuration.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

To allow using -blockdev with blockjobs QEMU needs to reopen files in
read-write mode when modifying the backing chain. To achieve this we
need to use 'auto-read-only' for the backing files rather than the
normal 'read-only' property. That way qemu knows that the files need to
be reopened.

Note that the format drivers (e.g. qcow2) are still opened with the
read-only property enabled when being a member of the backing chain
since they are supposed to be immutable unless a block job is started.

QEMU v4.0 (since commit 23dece19da4) allows also dynamic behaviour for
auto-read-only which allows us to use sVirt as we only grant write
permissions to files when doing a blockjob.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

To allow reusing the formatters in the code for creating JSON properties
for 'blockdev-create' we need to create everything except the 'driver'
attribute.

Use the new helper virJSONValueObjectPrependString to put the driver at
the same place so that we don't change any output.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

When formatting new qcow2 images we need to provide the backing store
string which should not contain any authentication or irrelevant data.

Add a flag for qemuBlockStorageSourceGetBackendProps which allows to
skip the irrelevant data.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Split up the addition of a storage source into the following sub-steps:
1) storage access dependencies (TLS transport, persistent reservation)
2) storage acccess node (file/gluster/nbd...)
3) format driver dependencies (encryption secret)
4) format driver node (qcow2, raw, ...)

The functions split out will be later reused when implementing support
for 'blockdev-create' as we'll need the dependencies plugged in first,
then blockdev-create will be called and after that successfully finishes
blockdev-add will be added.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

These are meant to replace the ad-hoc helpers qemuHotplugDiskSourceAttach...
and the open-coded version in qemu_command.c for use in command line
generation.

The functions for preparing for attach of chains unfortunately need to
be in qemu_command.c as they use function defined by that file and
inclusion hierarchy.

In this patch new functions are introduced and subsequent patches then
refactor individual parts to use them.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Move it to qemu_block.c and call it qemuBlockStorageSourceDetachPrepare.
It will be reused in other parts as well.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Demonstrate how VIR_RETURN_PTR is used by refactoring qemu_block.c
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

This is a locally used helper struct but we can make use of automatic
freeing for it.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>