Parts of the block layer treat BDS.backing_file as if it were whatever
the image header says (i.e., if it is a relative path, it is relative to
the overlay), other parts treat it like a cache for
bs->backing->bs->filename (relative paths are relative to the CWD).
Considering bs->backing->bs->filename exists, let us make it mean the
former.
Among other things, this now allows the user to specify a base when
using qemu-img to commit an image file in a directory that is not the
CWD (assuming, everything uses relative filenames).
Before this patch:
$ ./qemu-img create -f qcow2 foo/bot.qcow2 1M
$ ./qemu-img create -f qcow2 -b bot.qcow2 foo/mid.qcow2
$ ./qemu-img create -f qcow2 -b mid.qcow2 foo/top.qcow2
$ ./qemu-img commit -b mid.qcow2 foo/top.qcow2
qemu-img: Did not find 'mid.qcow2' in the backing chain of 'foo/top.qcow2'
$ ./qemu-img commit -b foo/mid.qcow2 foo/top.qcow2
qemu-img: Did not find 'foo/mid.qcow2' in the backing chain of 'foo/top.qcow2'
$ ./qemu-img commit -b $PWD/foo/mid.qcow2 foo/top.qcow2
qemu-img: Did not find '[...]/foo/mid.qcow2' in the backing chain of 'foo/top.qcow2'
After this patch:
$ ./qemu-img commit -b mid.qcow2 foo/top.qcow2
Image committed.
$ ./qemu-img commit -b foo/mid.qcow2 foo/top.qcow2
qemu-img: Did not find 'foo/mid.qcow2' in the backing chain of 'foo/top.qcow2'
$ ./qemu-img commit -b $PWD/foo/mid.qcow2 foo/top.qcow2
Image committed.
With this change, bdrv_find_backing_image() must look at whether the
user has overridden a BDS's backing file. If so, it can no longer use
bs->backing_file, but must instead compare the given filename against
the backing node's filename directly.
Note that this changes the QAPI output for a node's backing_file. We
had very inconsistent output there (sometimes what the image header
said, sometimes the actual filename of the backing image). This
inconsistent output was effectively useless, so we have to decide one
way or the other. Considering that bs->backing_file usually at runtime
contained the path to the image relative to qemu's CWD (or absolute),
this patch changes QAPI's backing_file to always report the
bs->backing->bs->filename from now on. If you want to receive the image
header information, you have to refer to full-backing-filename.
This necessitates a change to iotest 228. The interesting information
it really wanted is the image header, and it can get that now, but it
has to use full-backing-filename instead of backing_file. Because of
this patch's changes to bs->backing_file's behavior, we also need some
reference output changes.
Along with the changes to bs->backing_file, stop updating
BDS.backing_format in bdrv_backing_attach() as well. This way,
ImageInfo's backing-filename and backing-filename-format fields will
represent what the image header says and nothing else.
iotest 245 changes in behavior: With the backing node no longer
overriding the parent node's backing_file string, you can now omit the
@backing option when reopening a node with neither a default nor a
current backing file even if it used to have a backing node at some
point.
273 also changes: The base image is opened without a format layer, so
ImageInfo.backing-filename-format used to report "file" for the base
image's overlay after blockdev-snapshot. However, the image header
never says "file" anywhere, so it now reports $IMGFMT.
Signed-off-by: Max Reitz <mreitz@redhat.com>
There are many existing qcow2 images that specify a backing file but
no format. This has been the source of CVEs in the past, but has
become more prominent of a problem now that libvirt has switched to
-blockdev. With older -drive, at least the probing was always done by
qemu (so the only risk of a changed format between successive boots of
a guest was if qemu was upgraded and probed differently). But with
newer -blockdev, libvirt must specify a format; if libvirt guesses raw
where the image was formatted, this results in data corruption visible
to the guest; conversely, if libvirt guesses qcow2 where qemu was
using raw, this can result in potential security holes, so modern
libvirt instead refuses to use images without explicit backing format.
The change in libvirt to reject images without explicit backing format
has pointed out that a number of tools have been far too reliant on
probing in the past. It's time to set a better example in our own
iotests of properly setting this parameter.
iotest calls to create, rebase, and convert are all impacted to some
degree. It's a bit annoying that we are inconsistent on command line
- while all of those accept -o backing_file=...,backing_fmt=..., the
shortcuts are different: create and rebase have -b and -F, while
convert has -B but no -F. (amend has no shortcuts, but the previous
patch just deprecated the use of amend to change backing chains).
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200706203954.341758-9-eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We can turn logging on/off globally instead of per-function.
Remove use_log from run_job, and use python logging to turn on
diffable output when we run through a script entry point.
iotest 245 changes output order due to buffering reasons.
An extended note on python logging:
A NullHandler is added to `qemu.iotests` to stop output from being
generated if this code is used as a library without configuring logging.
A NullHandler is only needed at the root, so a duplicate handler is not
needed for `qemu.iotests.diff_io`.
When logging is not configured, messages at the 'WARNING' levels or
above are printed with default settings. The NullHandler stops this from
occurring, which is considered good hygiene for code used as a library.
See https://docs.python.org/3/howto/logging.html#library-config
When logging is actually enabled (always at the behest of an explicit
call by a client script), a root logger is implicitly created at the
root, which allows messages to propagate upwards and be handled/emitted
from the root logger with default settings.
When we want iotest logging, we attach a handler to the
qemu.iotests.diff_io logger and disable propagation to avoid possible
double-printing.
For more information on python logging infrastructure, I highly
recommend downloading the pip package `logging_tree`, which provides
convenient visualizations of the hierarchical logging configuration
under different circumstances.
See https://pypi.org/project/logging_tree/ for more information.
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200331000014.11581-15-jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
This patch allows bdrv_reopen() (and therefore the x-blockdev-reopen QMP
command) to attach a node as the new backing file even if the node is in
a different AioContext than the parent if one of both nodes can be moved
to the AioContext of the other node.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Tested-by: Peter Krempa <pkrempa@redhat.com>
Message-Id: <20200306141413.30705-3-kwolf@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We'll want to test more than one successful case in the future, so
prepare the test for that by a refactoring that runs each scenario in a
separate VM.
test_iothreads_switch_{backing,overlay} currently produce errors, but
these are cases that should actually work, by switching either the
backing file node or the overlay node to the AioContext of the other
node.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Tested-by: Peter Krempa <pkrempa@redhat.com>
Message-Id: <20200306141413.30705-2-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Scripts that have a Python shebang are meant to be executed directly from the
shell; give them 755 permissions.
Cc: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200204160237.16889-1-pbonzini@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Use the program search path to find the Python 3 interpreter.
Patch created mechanically by running:
$ sed -i "s,^#\!/usr/bin/\(env\ \)\?python$,#\!/usr/bin/env python3," \
$(git grep -l 'if __name__.*__main__')
Reported-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Suggested-by: Daniel P. Berrangé <berrange@redhat.com>
Suggested-by: Stefan Hajnoczi <stefanha@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200130163232.10446-4-philmd@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
The python code already contains a possibility to skip tests if the
corresponding driver is not available in the qemu binary - use it
in more spots to avoid that the tests are failing if the driver has
been disabled.
While we're at it, we can now also remove some of the old checks that
were using iotests.supports_quorum() - and which were apparently not
working as expected since the tests aborted instead of being skipped
when "quorum" was missing in the QEMU binary.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We use null-co basically everywhere in the iotests. Unless we want to
test null-aio specifically, we should use it instead (for consistency).
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-id: 20190917092004.999-2-mreitz@redhat.com
Reviewed-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Most of our Python unittest-style tests only support the file protocol.
You can run them with any other protocol, but the test will simply
ignore your choice and use file anyway.
We should let them signal that they require the file protocol so they
are skipped when you want to test some other protocol.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The bottom node is the intermediate block device that has the base as its
backing image. It is used instead of the base node while a block stream
job is running to avoid dependency on the base that may change due to the
parallel jobs. The change may take place due to a filter node as well that
is inserted between the base and the intermediate bottom node. It occurs
when the base node is the top one for another commit or stream job.
After the introduction of the bottom node, don't freeze its backing child,
that's the base, anymore.
Suggested-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 1559152576-281803-4-git-send-email-andrey.shinkevich@virtuozzo.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Sometimes, 245 fails for me because some stream job has already finished
while the test expects it to still be active. (With -c none, it fails
basically every time.) The most reliable way to fix this is to simply
set auto_finalize=false so the job will remain in the block graph as
long as we need it. This allows us to drop the rate limiting, too,
which makes the test faster.
The only problem with this is that there is a single place that yields a
different error message depending on whether the stream job is still
copying data (so COR is enabled) or not (COR has been disabled, but the
job still has the WRITE_UNCHANGED permission on the target node). We
can easily address that by expecting either error message.
Note that we do not need auto_finalize=false (or rate limiting) for the
active commit job, because It never completes without an explicit
block-job-complete anyway.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
tmpfs does not support O_DIRECT. Detect this case, and skip flipping
@direct if the filesystem does not support it.
Fixes: bf3e50f623
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This patch adds several tests for the x-blockdev-reopen QMP command.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
