Opening the backing image for the second time is bad, especially here
when it is also in use as the active image as the source. The
drive-backup job itself doesn't read from target->backing for COW,
instead it gets data from the write notifier, so it's not a big problem.
However, exporting the target to NBD etc. won't work, because of the
likely stale metadata cache.

Use BDRV_O_NO_BACKING in this case and manually set up the backing
BdrvChild.

Cc: qemu-stable@nongnu.org
Signed-off-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

We now have macros in place to make it less verbose to add a scalar
to QDict and QList, so use them.

Patch created mechanically via:
  spatch --sp-file scripts/coccinelle/qobject.cocci \
    --macro-file scripts/cocci-macro-file.h --dir . --in-place
then touched up manually to fix a couple of '?:' back to original
spacing, as well as avoiding a long line in monitor.c.
Signed-off-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>
Message-Id: <20170427215821.19397-7-eblake@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: NAlberto Garcia <berto@igalia.com>
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>

For one thing, this allows us to drop the error message generation from
qemu-img.c and blockdev.c and instead have it unified in
bdrv_truncate().
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Message-id: 20170328205129.15138-3-mreitz@redhat.com
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NMax Reitz <mreitz@redhat.com>

Signed-off-by: NFam Zheng <famz@redhat.com>
Message-Id: <20170421122710.15373-9-famz@redhat.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>

Signed-off-by: NFam Zheng <famz@redhat.com>
Message-Id: <20170421122710.15373-6-famz@redhat.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>

bdrv_replace_child_noperm tries to hand over the quiesce_counter state
from old bs to the new one, but if they are not on the same aio context
this causes unbalance.

Fix this by setting the correct aio context before calling
bdrv_append().
Reported-by: NEd Swierk <eswierk@skyportsystems.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

It's been a long journey, but here we are.

The supported blockdev-add is not compatible to its experimental
predecessors; bump all Since: tags to 2.9.

x-blockdev-remove-medium, x-blockdev-insert-medium and
x-blockdev-change need a bit more work, so leave them alone for now.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

Only undo the action if we actually prepared the action.
Signed-off-by: NJohn Snow <jsnow@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

When adding an Error parameter, bdrv_replace_in_backing_chain() would
become nothing more than a wrapper around change_parent_backing_link().
So make the latter public, renamed as bdrv_replace_node(), and remove
bdrv_replace_in_backing_chain().

Most of the callers just remove a node from the graph that they just
inserted, so they can use &error_abort, but completion of a mirror job
with 'replaces' set can actually fail.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

For blockdev-snapshot, external_snapshot_prepare() accepts an arbitrary
node reference at first and only checks later whether it already has a
backing file. Between those places, other errors can occur.

Therefore checking in external_snapshot_abort() whether state->new_bs
has a backing file is not sufficient to tell whether bdrv_append() was
already completed or not. Trying to undo the bdrv_append() when it
wasn't even executed is wrong.

Introduce a new boolean flag in the state to fix this.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

Aborting on error in bdrv_append() isn't correct. This patch fixes it
and lets the callers handle failures.

Test case 085 needs a reference output update. This is caused by the
reversed order of bdrv_set_backing_hd() and change_parent_backing_link()
in bdrv_append(): When the backing file of the new node is set, the
parent nodes are still pointing to the old top, so the backing blocker
is now initialised with the node name rather than the BlockBackend name.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Acked-by: NFam Zheng <famz@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>

Management tools need to be able to know about every node in the graph
and need a way to address them. Changing the graph structure was okay
because libvirt doesn't really manage the node level yet, but future
libvirt versions need to deal with both new and old version of qemu.

This new option to blockdev-commit allows the client to set a node-name
for the automatically inserted filter driver, and at the same time
serves as a witness for a future libvirt that this version of qemu does
automatically insert a filter driver.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Acked-by: NFam Zheng <famz@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>

Management tools need to be able to know about every node in the graph
and need a way to address them. Changing the graph structure was okay
because libvirt doesn't really manage the node level yet, but future
libvirt versions need to deal with both new and old version of qemu.

This new option to blockdev-mirror allows the client to set a node-name
for the automatically inserted filter driver, and at the same time
serves as a witness for a future libvirt that this version of qemu does
automatically insert a filter driver.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Acked-by: NFam Zheng <famz@redhat.com>

Some devices allow a media change between read-only and read-write
media. They need to adapt the permissions in their .change_media_cb()
implementation, which can fail. So add an Error parameter to the
function.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Acked-by: NFam Zheng <famz@redhat.com>

Now that blk_insert_bs() requests the BlockBackend permissions for the
node it attaches to, it can fail. Instead of aborting, pass the errors
to the callers.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Acked-by: NFam Zheng <famz@redhat.com>

We want every user to be specific about the permissions it needs, so
we'll pass the initial permissions as parameters to blk_new(). A user
only needs to call blk_set_perm() if it wants to change the permissions
after the fact.

The permissions are stored in the BlockBackend and applied whenever a
BlockDriverState should be attached in blk_insert_bs().

This does not include actually choosing the right set of permissions
everywhere yet. Instead, the usual FIXME comment is added to each place
and will be addressed in individual patches.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Acked-by: NFam Zheng <famz@redhat.com>

This patch removes the redundant throttle code that was present in
block and fsdev device files. Now the common code is moved
to a single file.
Signed-off-by: NPradeep Jagadeesh <pradeep.jagadeesh@huawei.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: NAlberto Garcia <berto@igalia.com>
(fix indent nit, Greg Kurz)
Signed-off-by: NGreg Kurz <groug@kaod.org>

In order to be able to do permission checking and to keep working with
the BdrvChild based bdrv_truncate() that this involves, we need to
create a temporary BlockBackend to resize the image.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>

Block backends defined with "-drive if=T" with T other than "none" are
meant to be picked up by machine initialization code: a suitable
frontend gets created and wired up automatically.

If machine initialization code doesn't comply, the block backend
remains unused.  This triggers a warning since commit a66c9dc7, v2.2.0.
Drives created by default are exempted; use -nodefaults to get rid of
them.

Turn this warning into an error.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Message-Id: <1487153147-11530-8-git-send-email-armbru@redhat.com>
Reviewed-by: NJohn Snow <jsnow@redhat.com>

We warn when a -drive isn't supported by the machine type (commit
a66c9dc7):

    $ qemu-system-x86_64 -S -display none -drive if=mtd
    Warning: Orphaned drive without device: id=mtd0,file=,if=mtd,bus=0,unit=0

Improve this to point to the offending bit of configuration:

    qemu-system-x86_64: -drive if=mtd: warning: machine type does not support if=mtd,bus=0,unit=0

Especially nice when it's hidden behind -readconfig foo.cfg:

    qemu-system-x86_64:foo.cfg:140: warning: machine type does not support if=mtd,bus=0,unit=0
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Message-Id: <1487153147-11530-7-git-send-email-armbru@redhat.com>
Reviewed-by: NJohn Snow <jsnow@redhat.com>

Introduce rules in the top level Makefile that are able to generate
trace.[ch] files in every subdirectory which has a trace-events file.

The top level directory is handled specially, so instead of creating
trace.h, it creates trace-root.h. This allows sub-directories to
include the top level trace-root.h file, without ambiguity wrt to
the trace.g file in the current sub-dir.
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>
Message-id: 20170125161417.31949-7-berrange@redhat.com
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Refactor backup_start as backup_job_create, which only creates the job,
but does not automatically start it. The old interface, 'backup_start',
is not kept in favor of limiting the number of nearly-identical interfaces
that would have to be edited to keep up with QAPI changes in the future.

Callers that wish to synchronously start the backup_block_job can
instead just call block_job_start immediately after calling
backup_job_create.

Transactions are updated to use the new interface, calling block_job_start
only during the .commit phase, which helps prevent race conditions where
jobs may finish before we even finish building the transaction. This may
happen, for instance, during empty block backup jobs.
Reported-by: NVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: NJohn Snow <jsnow@redhat.com>
Message-id: 1478587839-9834-6-git-send-email-jsnow@redhat.com
Signed-off-by: NJeff Cody <jcody@redhat.com>

BlockJobs will begin hiding their state in preparation for some
refactorings anyway, so let's internalize the user_pause mechanism
instead of leaving it to callers to correctly manage.
Signed-off-by: NJohn Snow <jsnow@redhat.com>
Reviewed-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NJeff Cody <jcody@redhat.com>
Message-id: 1477584421-1399-6-git-send-email-jsnow@redhat.com
Signed-off-by: NJeff Cody <jcody@redhat.com>

There's no reason to leave this to blockdev; we can do it in blockjobs
directly and get rid of an extra callback for most users.

All non-internal events, even those created outside of QMP, will
consistently emit events.
Signed-off-by: NJohn Snow <jsnow@redhat.com>
Reviewed-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NJeff Cody <jcody@redhat.com>
Message-id: 1477584421-1399-5-git-send-email-jsnow@redhat.com
Signed-off-by: NJeff Cody <jcody@redhat.com>

Bubble up the internal interface to commit and backup jobs, then switch
replication tasks over to using this methodology.
Signed-off-by: NJohn Snow <jsnow@redhat.com>
Reviewed-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NJeff Cody <jcody@redhat.com>
Message-id: 1477584421-1399-4-git-send-email-jsnow@redhat.com
Signed-off-by: NJeff Cody <jcody@redhat.com>

If jobs are not created directly by the user, do not allow them to be
seen by the user/management utility. At the moment, 'internal' jobs are
those that do not have an ID. As of this patch it is impossible to
create such jobs.
Signed-off-by: NJohn Snow <jsnow@redhat.com>
Message-id: 1477584421-1399-2-git-send-email-jsnow@redhat.com
Signed-off-by: NJeff Cody <jcody@redhat.com>

The way to specify the node from which to copy data in the
block-stream operation is by using the 'base' parameter. This
parameter however takes a file name, not a node name.

Since we want to be able to perform this operation using only node
names, this patch adds a new 'base-node' parameter.
Signed-off-by: NAlberto Garcia <berto@igalia.com>
Reviewed-by: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

This patch makes the 'device' parameter of the 'block-stream' command
accept a node name that is not a root node. The presence of this
feature can't be directly tested with introspection; soon we'll
introduce a 'base-node' parameter whose presence can be checked for
this purpose.

In addition to that, operation blockers will be checked in all
intermediate nodes between the top and the base node.
Signed-off-by: NAlberto Garcia <berto@igalia.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

qmp_block_commit() checks for op blockers in the active and
destination (base) images. However all nodes between top_bs and base
are also involved, and they are removed from the chain afterwards.

In addition to that, if top_bs is not the active layer then top_bs's
overlay also needs to be checked because it's involved in the job (its
backing image string needs to be updated to point to 'base').

This patch checks that none of those nodes are blocked.
Signed-off-by: NAlberto Garcia <berto@igalia.com>
Reviewed-by: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

The QmpOutputVisitor has no direct dependency on QMP. It is
valid to use it anywhere that one wants a QObject. Rename it
to better reflect its functionality as a generic QAPI
to QObject converter.

The commit before previous renamed the files, this one renames C
identifiers.
Reviewed-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>
Message-Id: <1475246744-29302-6-git-send-email-berrange@redhat.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>
[Split into file rename and identifier rename]
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>

The QMP visitors have no direct dependency on QMP. It is
valid to use them anywhere that one has a QObject. Rename them
to better reflect their functionality as a generic QObject
to QAPI converter.

This is the first of three parts: rename the files.  The next two
parts will rename C identifiers.  The split is necessary to make git
rename detection work.
Reviewed-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>
[Split into file and identifier rename, two comments touched up]
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>

The remaining options in qemu_root_bds_opts (aio and copy-on-read)
aren't used any more, the QAPI schema doesn't contain them. Therefore
all the code processing qemu_root_bds_opts options is dead and can be
removed.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>

This enables its use for nested child nodes. The compatibility
between the 'discard' and 'detect-zeroes' setting is checked in
bdrv_open_common() now as the former setting isn't available before
calling bdrv_open() any more.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>

Instead of modifying the new BDS after it has been opened, use the newly
supported 'detect-zeroes' option in bdrv_open_common() so that all
requirements are checked (detect-zeroes=unmap requires discard=unmap).
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>

Amongst others, this means that you can now use the 'detect-zeroes'
option for non-top-level nodes in blockdev-add, like the QAPI schema
promises.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>

The TODO comment has been addressed a while ago and this is now checked
in raw-posix, so we don't have to special case this in blockdev-add any
more.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>

Commit 00949bab incorrectly changed one instance of &err into errp while
touching the line. Change it back.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>

With this patch, blockdev-add always works on a node level, i.e. it
creates a BDS, but no BB. Consequently, x-blockdev-del doesn't need the
'device' option any more, but 'node-name' becomes mandatory.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

Even for nodes that have a BlockBackend attached, bdrv_get_parent_name()
can return NULL if the BB is anonymous (e.g. it belongs to a block job
or a device that was created with a drive=<node-name> option).

Remove the information from the error message. The user probably knows
already why the node is still in use.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

In order to remove the need for BlockBackend names in the external API,
we want to allow qdev device names in all device related commands.

This converts block_set_io_throttle to accept a qdev device name.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>