Monitor commands can handle errors, so they can easily be converted to
using the safer bdrv_try_set_aio_context() function.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This adds a new parameter to blk_new() which requires its callers to
declare from which AioContext this BlockBackend is going to be used (or
the locks of which AioContext need to be taken anyway).
The given context is only stored and kept up to date when changing
AioContexts. Actually applying the stored AioContext to the root node
is saved for another commit.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
If the bitmap can't be used for whatever reason, we skip putting down
the reference. Fix that.
In practice, this means that if you attempt to gracefully exit QEMU
after a backup command being rejected, bdrv_close_all will fail and
tell you some unpleasant things via assert().
Reported-by: aihua liang <aliang@redhat.com>
Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1703916
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Add new optional parameter making possible to merge bitmaps from
different nodes. It is needed to maintain external snapshots during
incremental backup chain history.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 20190517152111.206494-2-vsementsov@virtuozzo.com
Signed-off-by: John Snow <jsnow@redhat.com>
We mandate that the source node must be a root node; but there's no reason
I am aware of that it needs to be restricted to such. In some cases, we need
to make sure that there's a medium present, but in the general case we can
allow the backup job itself to do the graph checking.
This patch helps improve the error message when you try to backup from
the same node more than once, which is reflected in the change to test
056.
For backups with bitmaps, it will also show a better error message that
the bitmap is in use instead of giving you something cryptic like "need
a root node."
Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1707303
Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 20190521210053.8864-1-jsnow@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
Command line help explicitly requested by the user should be printed
to stdout, not stderr. We do elsewhere. Adjust -drive to match: use
qemu_printf() instead of error_printf(). Plain printf() would be
wrong because we need to print to the current monitor for "drive_add
... format=help".
Cc: Kevin Wolf <kwolf@redhat.com>
Cc: Max Reitz <mreitz@redhat.com>
Cc: qemu-block@nongnu.org
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20190417190641.26814-13-armbru@redhat.com>
There is no reason why the constraints we put on @replaces should be
limited to drive-mirror. Therefore, move the sanity checks from
qmp_drive_mirror() to blockdev_mirror_common() so they apply to
blockdev-mirror as well.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This command allows reopening an arbitrary BlockDriverState with a
new set of options. Some options (e.g node-name) cannot be changed
and some block drivers don't allow reopening, but otherwise this
command is modelled after 'blockdev-add' and the state of the reopened
BlockDriverState should generally be the same as if it had just been
added by 'blockdev-add' with the same set of options.
One notable exception is the 'backing' option: 'x-blockdev-reopen'
requires that it is always present unless the BlockDriverState in
question doesn't have a current or default backing file.
This command allows reconfiguring the graph by using the appropriate
options to change the children of a node. At the moment it's possible
to change a backing file by setting the 'backing' option to the name
of the new node, but it should also be possible to add a similar
functionality to other block drivers (e.g. Quorum, blkverify).
Although the API is unlikely to change, this command is marked
experimental for the time being so there's room to see if the
semantics need changes.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Drop x- and x_ prefixes for latency histograms and update version to
4.0
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Commit a88b179f introduced the ability to set and query bitmap
persistence, but with an atypical spelling.
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-id: 20190308205845.25734-1-eblake@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
Remove is an inherently RW operation, so this will fail anyway, but
we can fail it very quickly instead of trying and failing, so do so.
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20190301191545.8728-6-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
drive and blockdev backup cannot use readonly bitmaps, because the
sync=incremental mechanism actually edits the bitmaps on success.
If you really want to do this operation, use a copied bitmap.
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20190301191545.8728-5-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
Instead of checking against busy, inconsistent, or read only directly,
use a check function with permissions bits that let us streamline the
checks without reproducing them in many places.
Included in this patch are permissions changes that simply add the
inconsistent check to existing permissions call spots, without
addressing existing bugs.
In general, this means that busy+readonly checks become BDRV_BITMAP_DEFAULT,
which checks against all three conditions. busy-only checks become
BDRV_BITMAP_ALLOW_RO.
Notably, remove allows inconsistent bitmaps, so it doesn't follow the pattern.
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20190301191545.8728-4-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
This field isn't present anymore.
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20190223000614.13894-10-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
These mean the same thing now. Unify them and rename the merged call
bdrv_dirty_bitmap_busy to indicate semantically what we are describing,
as well as help disambiguate from the various _locked and _unlocked
versions of bitmap helpers that refer to mutex locks.
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20190223000614.13894-8-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
bdrv_iterate_format (which is currently only used for printing out the
formats supported by the block layer) doesn't take format whitelisting
into account.
This creates a problem for tests: they enumerate supported formats to
decide which tests to enable, but then discover that QEMU doesn't let
them actually use some of those formats.
To avoid that, exclude formats that are not whitelisted from
enumeration, if whitelisting is in use. Since we have separate
whitelists for r/w and r/o, take this a parameter to
bdrv_iterate_format, and print two lists of supported formats (r/w and
r/o) in main qemu.
Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Before this patch, bdrv_refresh_filename() is used in a pushing manner:
Whenever the BDS graph is modified, the parents of the modified edges
are supposed to be updated (recursively upwards). However, that is
nonviable, considering that we want child changes not to concern
parents.
Also, in the long run we want a pull model anyway: Here, we would have a
bdrv_filename() function which returns a BDS's filename, freshly
constructed.
This patch is an intermediate step. It adds bdrv_refresh_filename()
calls before every place a BDS.filename value is used. The only
exceptions are protocol drivers that use their own filename, which
clearly would not profit from refreshing that filename before.
Also, bdrv_get_encrypted_filename() is removed along the way (as a user
of BDS.filename), since it is completely unused.
In turn, all of the calls to bdrv_refresh_filename() before this patch
are removed, because we no longer have to call this function on graph
changes.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190201192935.18394-2-mreitz@redhat.com
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
When bitmaps are persistent, they may incur a disk read or write when bitmaps
are added or removed. For configurations like virtio-dataplane, failing to
acquire this lock will abort QEMU when disk IO occurs.
We used to acquire aio_context as part of the bitmap lookup, so re-introduce
the lock for just the cases that have an IO penalty. Commit 2119882c removed
these locks, and I failed to notice this when we committed fd5ae4cc, so this
has been broken since persistent bitmaps were introduced.
Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1672010
Reported-By: Aihua Liang <aliang@redhat.com>
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20190218233154.19303-1-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
Add a new command, returning block nodes (and their users) graph.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20181221170909.25584-2-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
The 'x' prefix was added because I was uncertain of the direction we'd
take for the libvirt API. With the general approach solidified, I feel
comfortable committing to this API for 4.0.
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20181221093529.23855-5-jsnow@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Especially outside of transactions, it is helpful to provide
all-or-nothing semantics for bitmap merges. This facilitates
the coalescing of multiple bitmaps into a single target for
the "checkpoint" interpretation when assembling bitmaps that
represent arbitrary points in time from component bitmaps.
This is an incompatible change from the preliminary version
of the API.
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20181221093529.23855-4-jsnow@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Presently, we abort transactions in the same order they were processed in.
Bitmap commands, though, attempt to restore backup data structures on abort.
That's not valid, they need to be aborted in reverse chronological order.
Replace the QSIMPLEQ data structure with a QTAILQ one, so we can iterate
in reverse for the abort phase of the transaction.
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20181221093529.23855-2-jsnow@redhat.com>
[eblake: rebase]
Signed-off-by: Eric Blake <eblake@redhat.com>
Most list head structs need not be given a name. In most cases the
name is given just in case one is going to use QTAILQ_LAST, QTAILQ_PREV
or reverse iteration, but this does not apply to lists of other kinds,
and even for QTAILQ in practice this is only rarely needed. In addition,
we will soon reimplement those macros completely so that they do not
need a name for the head struct. So clean up everything, not giving a
name except in the rare case where it is necessary.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Use the QTAILQ_IN_USE macro instead, it does the same thing but the next
patch will change it to a different definition.
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This patch replaces the bdrv_reopen() call that set and remove the
BDRV_O_RDWR flag with the new bdrv_reopen_set_read_only() function.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This patch replaces the bdrv_reopen() calls that set and remove the
BDRV_O_RDWR flag with the new bdrv_reopen_set_read_only() function.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
In the function external_snapshot_prepare() we have a
BlockdevSnapshotSync struct, which has the usual combination
of has_snapshot_node_name and snapshot_node_name fields for an
optional field. We set up a local variable
const char *snapshot_node_name =
s->has_snapshot_node_name ? s->snapshot_node_name : NULL;
and then mostly use "if (!snapshot_node_name)" for checking
whether we have a snapshot node name. The exception is that in
one place we check s->has_snapshot_node_name instead. This
confuses Coverity (CID 1396473), which thinks it might be
possible to get here with s->has_snapshot_node_name true but
snapshot_node_name NULL, and warns that the call to
qdict_put_str() will segfault in that case.
Make the code consistent and unconfuse Coverity by using
the same check for this conditional that we do in the rest
of the surrounding code.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Function block_latency_histogram_set may return error, but qapi ignore this.
This can be reproduced easily by qmp command:
virsh qemu-monitor-command INSTANCE '{"execute":"x-block-latency-histogram-set",
"arguments":{"device":"drive-virtio-disk1","boundaries":[10,200,40]}}'
In fact this command does not work, but we still get success result.
qmp_x_block_latency_histogram_set is a batch setting API, report error ASAP.
Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
While we want machine interfaces like -blockdev and QMP blockdev-add to
add as little auto-detection as possible so that management tools are
explicit about their needs, -drive is a convenience option for human
users. Enabling auto-read-only=on by default there enables users to use
read-only images for read-only guest devices without having to specify
read-only=on explicitly. If they try to attach the image to a read-write
device, they will still get an error message.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
If a management application builds the block graph node by node, the
protocol layer doesn't inherit its read-only option from the format
layer any more, so it must be set explicitly.
Backing files should work on read-only storage, but at the same time, a
block job like commit should be able to reopen them read-write if they
are on read-write storage. However, without option inheritance, reopen
only changes the read-only option for the root node (typically the
format layer), but not the protocol layer, so reopening fails (the
format layer wants to get write permissions, but the protocol layer is
still read-only).
A simple workaround for the problem in the management tool would be to
open the protocol layer always read-write and to make only the format
layer read-only for backing files. However, sometimes the file is
actually stored on read-only storage and we don't know whether the image
can be opened read-write (for example, for NBD it depends on the server
we're trying to connect to). This adds an option that makes QEMU try to
open the image read-write, but allows it to degrade to a read-only mode
without returning an error.
The documentation for this option is consciously phrased in a way that
allows QEMU to switch to a better model eventually: Instead of trying
when the image is first opened, making the read-only flag dynamic and
changing it automatically whenever the first BLK_PERM_WRITE user is
attached or the last one is detached would be much more useful
behaviour.
Unfortunately, this more useful behaviour is also a lot harder to
implement, and libvirt needs a solution now before it can switch to
-blockdev, so let's start with this easier approach for now.
Instead of adding a new auto-read-only option, turning the existing
read-only into an enum (with a bool alternate for compatibility) was
considered, but it complicated the implementation to the point that it
didn't seem to be worth it.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
If the bitmap is frozen, we shouldn't touch it.
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20181002230218.13949-6-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
We're not being consistent about this. If it's in use by an operation,
the user should not be able to change the behavior of that bitmap.
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20181002230218.13949-5-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
Similarly to merge, it's OK to allow clear operations on disabled
bitmaps, as this condition only means that they are not recording
new writes. We are free to clear it if the user requests it.
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20181002230218.13949-4-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
Instead of both frozen and qmp_locked checks, wrap it into one check.
frozen implies the bitmap is split in two (for backup), and shouldn't
be modified. qmp_locked implies it's being used by another operation,
like being exported over NBD. In both cases it means we shouldn't allow
the user to modify it in any meaningful way.
Replace any usages where we check both frozen and qmp_locked with the
new check.
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20181002230218.13949-2-jsnow@redhat.com
[w/edits Suggested-By: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>]
Signed-off-by: John Snow <jsnow@redhat.com>
New action is like clean action: do the whole thing in .prepare and
undo in .abort. This behavior for bitmap-changing actions is needed
because backup job actions use bitmap in .prepare.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Rename block-dirty-bitmap-clear transaction handlers to reuse them for
x-block-dirty-bitmap-merge transaction in the following patch.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Add backup parameter to bdrv_merge_dirty_bitmap() to be used then with
bdrv_restore_dirty_bitmap() if it needed to restore the bitmap after
merge operation.
This is needed to implement bitmap merge transaction action in further
commit.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Use more generic names to reuse the function for bitmap merge in the
following commit.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Move checks from qmp_x_block_dirty_bitmap_merge() to
bdrv_merge_dirty_bitmap(), to share them with dirty bitmap merge
transaction action in future commit.
Note: for now, only qmp_x_block_dirty_bitmap_merge() calls
bdrv_merge_dirty_bitmap().
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
It is only an oversight that we don't allow incremental backup with
blockdev-backup. Add the bitmap argument which enables this.
Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 20180830211605.13683-2-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
Calling error_report() from within a function that takes an Error **
argument is suspicious. drive_new() calls error_report() even though
it can run within drive_init_func(), which takes an Error ** argument.
drive_init_func()'s caller main(), via qemu_opts_foreach(), is fine
with it, but clean it up anyway:
* Convert drive_new() to Error
* Update add_init_drive() to report the error received from
drive_new()
* Make main() pass &error_fatal through qemu_opts_foreach(),
drive_init_func() to drive_new()
* Make default_drive() pass &error_abort through qemu_opts_foreach(),
drive_init_func() to drive_new()
Cc: Kevin Wolf <kwolf@redhat.com>
Cc: Max Reitz <mreitz@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20181017082702.5581-34-armbru@redhat.com>
The block-commit QMP command required specifying the top and base nodes
of the commit jobs using the file name of that node. While this works
in simple cases (local files with absolute paths), the file names
generated for more complicated setups can be hard to predict.
The block-commit command has more problems than just this, so we want to
replace it altogether in the long run, but libvirt needs a reliable way
to address nodes now. So we don't want to wait for a new, cleaner
command, but just add the minimal thing needed right now.
This adds two new options top-node and base-node to the command, which
allow specifying node names instead. They are mutually exclusive with
the old options.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Presently only the backup job really guarantees what one would consider
transactional semantics. To guard against someone helpfully adding them
in the future, document that there are shortcomings in the model that
would need to be audited at that time.
Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 20180906130225.5118-17-jsnow@redhat.com
Reviewed-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20180906130225.5118-15-jsnow@redhat.com
Reviewed-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20180906130225.5118-14-jsnow@redhat.com
Reviewed-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20180906130225.5118-13-jsnow@redhat.com
Reviewed-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
