Currently this field only set by qed and qcow2. But in fact, all
backing-supporting formats (parallels, qcow, qcow2, qed, vmdk) share
these semantics: on unallocated blocks, if there is no backing file they
just memset the buffer with zeroes.
So, document this behavior for .supports_backing and drop
.unallocated_blocks_are_zero
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200528094405.145708-10-vsementsov@virtuozzo.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Currently the implementation only supports amending the encryption
options, unlike the qemu-img version
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200608094030.670121-14-mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Now that we have all the infrastructure in place,
wire it in the qcow2 driver and expose this to the user.
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200608094030.670121-9-mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Some qcow2 create options can't be used for amend.
Remove them from the qcow2 create options and add generic logic to detect
such options in qemu-img
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
[mreitz: Dropped some iotests reference output hunks that became
unnecessary thanks to
"iotests: Make _filter_img_create more active"]
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200625125548.870061-12-mreitz@redhat.com>
Some options are only useful for creation
(or hard to be amended, like cluster size for qcow2), while some other
options are only useful for amend, like upcoming keyslot management
options for luks
Since currently only qcow2 supports amend, move all its options
to a common macro and then include it in each action option list.
In future it might be useful to remove some options which are
not supported anyway from amend list, which currently
cause an error message if amended.
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200608094030.670121-5-mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
'force' option will be used for some unsafe amend operations.
This includes things like erasing last keyslot in luks based formats
(which destroys the data, unless the master key is backed up
by external means), but that _might_ be desired result.
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200608094030.670121-4-mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
When resizing an image with qcow2_co_truncate() using the falloc or
full preallocation modes the code assumes that both the old and new
sizes are cluster-aligned.
There are two problems with this:
1) The calculation of how many clusters are involved does not always
get the right result.
Example: creating a 60KB image and resizing it (with
preallocation=full) to 80KB won't allocate the second cluster.
2) No copy-on-write is performed, so in the previous example if
there is a backing file then the first 60KB of the first cluster
won't be filled with data from the backing file.
This patch fixes both issues.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-Id: <20200617140036.20311-1-berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
It's useful to know how much space can be occupied by qcow2 persistent
bitmaps, even though such metadata is unrelated to the guest-visible
data. Report this value as an additional QMP field, present when
measuring an existing image and output format that both support
bitmaps. Update iotest 178 and 190 to updated output, as well as new
coverage in 190 demonstrating non-zero values made possible with the
recently-added qemu-img bitmap command (see 3b51ab4b).
The new 'bitmaps size:' field is displayed automatically as part of
'qemu-img measure' any time it is present in QMP (that is, any time
both the source image being measured and destination format support
bitmaps, even if the measurement is 0 because there are no bitmaps
present). If the field is absent, it means that no bitmaps can be
copied (source, destination, or both lack bitmaps, including when
measuring based on size rather than on a source image). This behavior
is compatible with an upcoming patch adding 'qemu-img convert
--bitmaps': that command will fail in the same situations where this
patch omits the field.
The addition of a new field demonstrates why we should always
zero-initialize qapi C structs; while the qcow2 driver still fully
populates all fields, the raw and crypto drivers had to be tweaked to
avoid uninitialized data.
Consideration was also given towards having a 'qemu-img measure
--bitmaps' which errors out when bitmaps are not possible, and
otherwise sums the bitmaps into the existing allocation totals rather
than displaying as a separate field, as a potential convenience
factor. But this was ultimately decided to be more complexity than
necessary when the QMP interface was sufficient enough with bitmaps
remaining a separate field.
See also: https://bugzilla.redhat.com/1779904
Reported-by: Nir Soffer <nsoffer@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200521192137.1120211-3-eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Upcoming patches will enhance bitmap support in qemu-img, but in doing
so, it turns out to be nice to suppress output when persistent bitmaps
make no sense (such as on a qcow2 v2 image). Add a hook to make this
easier to query.
This patch adds a new callback .bdrv_supports_persistent_dirty_bitmap,
rather than trying to shoehorn the answer in via existing callbacks.
In particular, while it might have been possible to overload
.bdrv_co_can_store_new_dirty_bitmap to special-case a NULL input to
answer whether any persistent bitmaps are supported, that is at odds
with whether a particular bitmap can be stored (for example, even on
an image that supports persistent bitmaps but has currently filled up
the maximum number of bitmaps, attempts to store another one should
fail); and the new functionality doesn't require coroutine safety.
Similarly, we could have added one more piece of information to
.bdrv_get_info, but then again, most callers to that function tend to
already discard extraneous information, and making it a catch-all
rather than a series of dedicated scalar queries hasn't really
simplified life.
In the future, when we improve the ability to look up bitmaps through
a filter, we will probably also want to teach the block layer to
automatically let filters pass this request on through.
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200513011648.166876-4-eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
bdrv_default_perms() can decide which permission profile to use based on
the BdrvChildRole, so block drivers do not need to select it explicitly.
The blkverify driver now no longer shares the WRITE permission for the
image to verify. We thus have to adjust two places in
test-block-iothread not to take it. (Note that in theory, blkverify
should behave like quorum in this regard and share neither WRITE nor
RESIZE for both of its children. In practice, it does not really
matter, because blkverify is used only for debugging, so we might as
well keep its permissions rather liberal.)
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200513110544.176672-30-mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Commonly, they need to pass the BDRV_CHILD_IMAGE set as the
BdrvChildRole; but there are exceptions for drivers with external data
files (qcow2 and vmdk).
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200513110544.176672-26-mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
For now, it is always set to 0. Later patches in this series will
ensure that all callers pass an appropriate combination of flags.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200513110544.176672-6-mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We want to unify child_format and child_file at some point. One of the
important things that set format drivers apart from other drivers is
that they do not expect other format nodes under them (except in the
backing chain), i.e. we must not probe formats inside of formats. That
means we need something on which to distinguish format drivers from
others, and hence this flag.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-Id: <20200513110544.176672-3-mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
zstd significantly reduces cluster compression time.
It provides better compression performance maintaining
the same level of the compression ratio in comparison with
zlib, which, at the moment, is the only compression
method available.
The performance test results:
Test compresses and decompresses qemu qcow2 image with just
installed rhel-7.6 guest.
Image cluster size: 64K. Image on disk size: 2.2G
The test was conducted with brd disk to reduce the influence
of disk subsystem to the test results.
The results is given in seconds.
compress cmd:
time ./qemu-img convert -O qcow2 -c -o compression_type=[zlib|zstd]
src.img [zlib|zstd]_compressed.img
decompress cmd
time ./qemu-img convert -O qcow2
[zlib|zstd]_compressed.img uncompressed.img
compression decompression
zlib zstd zlib zstd
------------------------------------------------------------
real 65.5 16.3 (-75 %) 1.9 1.6 (-16 %)
user 65.0 15.8 5.3 2.5
sys 3.3 0.2 2.0 2.0
Both ZLIB and ZSTD gave the same compression ratio: 1.57
compressed image size in both cases: 1.4G
Signed-off-by: Denis Plotnikov <dplotnikov@virtuozzo.com>
QAPI part:
Acked-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200507082521.29210-4-dplotnikov@virtuozzo.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
The patch adds some preparation parts for incompatible compression type
feature to qcow2 allowing the use different compression methods for
image clusters (de)compressing.
It is implied that the compression type is set on the image creation and
can be changed only later by image conversion, thus compression type
defines the only compression algorithm used for the image, and thus,
for all image clusters.
The goal of the feature is to add support of other compression methods
to qcow2. For example, ZSTD which is more effective on compression than ZLIB.
The default compression is ZLIB. Images created with ZLIB compression type
are backward compatible with older qemu versions.
Adding of the compression type breaks a number of tests because now the
compression type is reported on image creation and there are some changes
in the qcow2 header in size and offsets.
The tests are fixed in the following ways:
* filter out compression_type for many tests
* fix header size, feature table size and backing file offset
affected tests: 031, 036, 061, 080
header_size +=8: 1 byte compression type
7 bytes padding
feature_table += 48: incompatible feature compression type
backing_file_offset += 56 (8 + 48 -> header_change + feature_table_change)
* add "compression type" for test output matching when it isn't filtered
affected tests: 049, 060, 061, 065, 082, 085, 144, 182, 185, 198, 206,
242, 255, 274, 280
Signed-off-by: Denis Plotnikov <dplotnikov@virtuozzo.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
QAPI part:
Acked-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200507082521.29210-2-dplotnikov@virtuozzo.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Now that there are no clients of bdrv_has_zero_init_truncate, none of
the drivers need to worry about providing it.
What's more, this eliminates a source of some confusion: a literal
reading of the documentation as written in ceaca56f and implemented in
commit 1dcaf527 claims that a driver which returns 0 for
bdrv_has_zero_init_truncate() must not return 1 for
bdrv_has_zero_init(); this condition was violated for parallels, qcow,
and sometimes for vdi, although in practice it did not matter since
those drivers also lacked .bdrv_co_truncate.
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200428202905.770727-10-eblake@redhat.com>
Acked-by: Richard W.M. Jones <rjones@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Calling bdrv_getlength() to get the pre-truncate file size will not
really work on block devices, because they have always the same length,
and trying to write beyond it will fail with a rather cryptic error
message.
Instead, we should use qcow2_get_last_cluster() and bdrv_getlength()
only as a fallback.
Before this patch:
$ truncate -s 1G test.img
$ sudo losetup -f --show test.img
/dev/loop0
$ sudo qemu-img create -f qcow2 -o preallocation=full /dev/loop0 64M
Formatting '/dev/loop0', fmt=qcow2 size=67108864 cluster_size=65536
preallocation=full lazy_refcounts=off refcount_bits=16
qemu-img: /dev/loop0: Could not resize image: Failed to resize refcount
structures: No space left on device
With this patch:
$ sudo qemu-img create -f qcow2 -o preallocation=full /dev/loop0 64M
Formatting '/dev/loop0', fmt=qcow2 size=67108864 cluster_size=65536
preallocation=full lazy_refcounts=off refcount_bits=16
qemu-img: /dev/loop0: Could not resize image: Failed to resize
underlying file: Preallocation mode 'full' unsupported for this
non-regular file
So as you can see, it still fails, but now the problem is missing
support on the block device level, so we at least get a better error
message.
Note that we cannot preallocate block devices on truncate by design,
because we do not know what area to preallocate. Their length is always
the same, the truncate operation does not change it.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200505141801.1096763-1-mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
After commit f01643fb8b when an image is
extended and BDRV_REQ_ZERO_WRITE is set then the new clusters are
zeroized.
The code however does not detect correctly situations when the old and
the new end of the image are within the same cluster. The problem can
be reproduced with these steps:
qemu-img create -f qcow2 backing.qcow2 1M
qemu-img create -f qcow2 -F qcow2 -b backing.qcow2 top.qcow2
qemu-img resize --shrink top.qcow2 520k
qemu-img resize top.qcow2 567k
In the last step offset - zero_start causes an integer wraparound.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-Id: <20200504155217.10325-1-berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Our comment did not actually match the code. Rewrite the comment to
be less sensitive to any future changes to qcow2-bitmap.c that might
implement scenarios that we currently reject.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200428192648.749066-4-eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
We originally refused to allow resize of images with internal
snapshots because the v2 image format did not require the tracking of
snapshot size, making it impossible to safely revert to a snapshot
with a different size than the current view of the image. But the
snapshot size tracking was rectified in v3, and our recent fixes to
qemu-img amend (see 0a85af35) guarantee that we always have a valid
snapshot size. Thus, we no longer need to artificially limit image
resizes, but it does become one more thing that would prevent a
downgrade back to v2. And now that we support different-sized
snapshots, it's also easy to fix reverting to a snapshot to apply the
new size.
Upgrade iotest 61 to cover this (we previously had NO coverage of
refusal to resize while snapshots exist). Note that the amend process
can fail but still have effects: in particular, since we break things
into upgrade, resize, downgrade, a failure during resize does not roll
back changes made during upgrade, nor does failure in downgrade roll
back a resize. But this situation is pre-existing even without this
patch; and without journaling, the best we could do is minimize the
chance of partial failure by collecting all changes prior to doing any
writes - which adds a lot of complexity but could still fail with EIO.
On the other hand, we are careful that even if we have partial
modification but then fail, the image is left viable (that is, we are
careful to sequence things so that after each successful cluster
write, there may be transient leaked clusters but no corrupt
metadata). And complicating the code to make it more transaction-like
is not worth the effort: a user can always request multiple 'qemu-img
amend' changing one thing each, if they need finer-grained control
over detecting the first failure than what they get by letting qemu
decide how to sequence multiple changes.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200428192648.749066-3-eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
There are several callers that need to create a new block backend from
an existing BDS; make the task slightly easier with a common helper
routine.
Suggested-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200424190903.522087-2-eblake@redhat.com>
[mreitz: Set @ret only in error paths, see
https://lists.nongnu.org/archive/html/qemu-block/2020-04/msg01216.html]
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200428192648.749066-2-eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
The BDRV_REQ_ZERO_WRITE is currently implemented in a way that first the
image is possibly preallocated and then the zero flag is added to all
clusters. This means that a copy-on-write operation may be needed when
writing to these clusters, despite having used preallocation, negating
one of the major benefits of preallocation.
Instead, try to forward the BDRV_REQ_ZERO_WRITE to the protocol driver,
and if the protocol driver can ensure that the new area reads as zeros,
we can skip setting the zero flag in the qcow2 layer.
Unfortunately, the same approach doesn't work for metadata
preallocation, so we'll still set the zero flag there.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200424142701.67053-1-kwolf@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
If BDRV_REQ_ZERO_WRITE is set and we're extending the image, calling
qcow2_cluster_zeroize() with flags=0 does the right thing: It doesn't
undo any previous preallocation, but just adds the zero flag to all
relevant L2 entries. If an external data file is in use, a write_zeroes
request to the data file is made instead.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200424125448.63318-5-kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Now that node level interface bdrv_truncate() supports passing request
flags to the block driver, expose this on the BlockBackend level, too.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200424125448.63318-4-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Now that block drivers can support flags for .bdrv_co_truncate, expose
the parameter in the node level interfaces bdrv_co_truncate() and
bdrv_truncate().
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200424125448.63318-3-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This adds a new BdrvRequestFlags parameter to the .bdrv_co_truncate()
driver callbacks, and a supported_truncate_flags field in
BlockDriverState that allows drivers to advertise support for request
flags in the context of truncate.
For now, we always pass 0 and no drivers declare support for any flag.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200424125448.63318-2-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
When issuing a compressed write request the number of bytes must be a
multiple of the cluster size or reach the end of the last cluster.
With the current code such requests are allowed and we hit an
assertion:
$ qemu-img create -f qcow2 img.qcow2 1M
$ qemu-io -c 'write -c 0 32k' img.qcow2
qemu-io: block/qcow2.c:4257: qcow2_co_pwritev_compressed_task:
Assertion `bytes == s->cluster_size || (bytes < s->cluster_size &&
(offset + bytes == bs->total_sectors << BDRV_SECTOR_BITS))' failed.
Aborted
This patch fixes a regression introduced in 0d483dce38
Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-Id: <20200406143401.26854-1-berto@igalia.com>
Reviewed-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
A discard request deallocates the selected clusters so they read back
as zeroes. This is done by clearing the cluster offset field and
setting QCOW_OFLAG_ZERO in the L2 entry.
This flag is however only supported when qcow_version >= 3. In older
images the cluster is simply deallocated, exposing any possible stale
data from the backing file.
Since discard is an advisory operation it's safer to simply forbid it
in this scenario.
Note that we are adding this check to qcow2_co_pdiscard() and not to
qcow2_cluster_discard() or discard_in_l2_slice() because the last
two are also used by qcow2_snapshot_create() to discard the clusters
used by the VM state. In this case there's no risk of exposing stale
data to the guest and we really want that the clusters are always
discarded.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-Id: <20200331114345.29993-1-berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
As the feature name table can be quite large (over 9k if all 64 bits
of all three feature fields have names; a mere 8 features leaves only
8 bytes for a backing file name in a 512-byte cluster), it is unwise
to emit this optional header in images with small cluster sizes.
Update iotest 036 to skip running on small cluster sizes; meanwhile,
note that iotest 061 never passed on alternative cluster sizes
(however, I limited this patch to tests with output affected by adding
feature names, rather than auditing for other tests that are not
robust to alternative cluster sizes).
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-Id: <20200324174233.1622067-4-eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
The feature table is supposed to advertise the name of all feature
bits that we support; however, we forgot to update the table for
autoclear bits. While at it, move the table to read-only memory in
code, and tweak the qcow2 spec to name the second autoclear bit.
Update iotests that are affected by the longer header length.
Fixes: 88ddffae
Fixes: 93c24936
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200324174233.1622067-3-eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Various trivial typos noticed while working on this file.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-Id: <20200324174233.1622067-2-eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
This will allow the reuse of a single generic .bdrv_co_create
implementation for several drivers.
No functional changes.
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20200326011218.29230-2-mlevitsk@redhat.com>
Reviewed-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Max Reitz <mreitz@redhat.com>
data_file being NULL doesn't seem to be a correct state, but it's
better than dead pointer and simpler to debug.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200316060631.30052-3-vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
If we fail to get bitmap info, we must not leak the encryption info.
Fixes: b8968c875f
Fixes: Coverity CID 1421894
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200320183620.1112123-1-eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Tested-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
'crypto_opts' forgot to free in qcow2_close(), this patch fix the bellow leak stack:
Direct leak of 24 byte(s) in 1 object(s) allocated from:
#0 0x7f0edd81f970 in __interceptor_calloc (/lib64/libasan.so.5+0xef970)
#1 0x7f0edc6d149d in g_malloc0 (/lib64/libglib-2.0.so.0+0x5249d)
#2 0x55d7eaede63d in qobject_input_start_struct /mnt/sdb/qemu-new/qemu_test/qemu/qapi/qobject-input-visitor.c:295
#3 0x55d7eaed78b8 in visit_start_struct /mnt/sdb/qemu-new/qemu_test/qemu/qapi/qapi-visit-core.c:49
#4 0x55d7eaf5140b in visit_type_QCryptoBlockOpenOptions qapi/qapi-visit-crypto.c:290
#5 0x55d7eae43af3 in block_crypto_open_opts_init /mnt/sdb/qemu-new/qemu_test/qemu/block/crypto.c:163
#6 0x55d7eacd2924 in qcow2_update_options_prepare /mnt/sdb/qemu-new/qemu_test/qemu/block/qcow2.c:1148
#7 0x55d7eacd33f7 in qcow2_update_options /mnt/sdb/qemu-new/qemu_test/qemu/block/qcow2.c:1232
#8 0x55d7eacd9680 in qcow2_do_open /mnt/sdb/qemu-new/qemu_test/qemu/block/qcow2.c:1512
#9 0x55d7eacdc55e in qcow2_open_entry /mnt/sdb/qemu-new/qemu_test/qemu/block/qcow2.c:1792
#10 0x55d7eacdc8fe in qcow2_open /mnt/sdb/qemu-new/qemu_test/qemu/block/qcow2.c:1819
#11 0x55d7eac3742d in bdrv_open_driver /mnt/sdb/qemu-new/qemu_test/qemu/block.c:1317
#12 0x55d7eac3e990 in bdrv_open_common /mnt/sdb/qemu-new/qemu_test/qemu/block.c:1575
#13 0x55d7eac4442c in bdrv_open_inherit /mnt/sdb/qemu-new/qemu_test/qemu/block.c:3126
#14 0x55d7eac45c3f in bdrv_open /mnt/sdb/qemu-new/qemu_test/qemu/block.c:3219
#15 0x55d7ead8e8a4 in blk_new_open /mnt/sdb/qemu-new/qemu_test/qemu/block/block-backend.c:397
#16 0x55d7eacde74c in qcow2_co_create /mnt/sdb/qemu-new/qemu_test/qemu/block/qcow2.c:3534
#17 0x55d7eacdfa6d in qcow2_co_create_opts /mnt/sdb/qemu-new/qemu_test/qemu/block/qcow2.c:3668
#18 0x55d7eac1c678 in bdrv_create_co_entry /mnt/sdb/qemu-new/qemu_test/qemu/block.c:485
#19 0x55d7eb0024d2 in coroutine_trampoline /mnt/sdb/qemu-new/qemu_test/qemu/util/coroutine-ucontext.c:115
Reported-by: Euler Robot <euler.robot@huawei.com>
Signed-off-by: Pan Nengyuan <pannengyuan@huawei.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200227012950.12256-2-pannengyuan@huawei.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
The qcow2 .bdrv_measure() code calculates the crypto payload offset.
This logic really belongs in crypto/block.c where it can be reused by
other image formats.
The "luks" block driver will need this same logic in order to implement
.bdrv_measure(), so extract the qcrypto_block_calculate_payload_offset()
function now.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200221112522.1497712-2-stefanha@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
The bitmap code requires writing the 'file' child when the qcow2 driver
is reopened in read-write mode.
If the 'file' child is being reopened due to a permissions change, the
modification is commited yet when qcow2_reopen_commit is called. This
means that any attempt to write the 'file' child will end with EBADFD
as the original fd was already closed.
Moving bitmap reopening to the new callback which is called after
permission modifications are commited fixes this as the file descriptor
will be replaced with the correct one.
The above problem manifests itself when reopening 'qcow2' format layer
which uses a 'file-posix' file child which was opened with the
'auto-read-only' property set.
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Message-Id: <db118dbafe1955afbc0a18d3dd220931074ce349.1582893284.git.pkrempa@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
When initializing the LUKS header the size with default encryption
parameters will currently be 2068480 bytes. This is rounded up to
a multiple of the cluster size, 2081792, with 64k sectors. If the
end of the header is not the same as the end of the cluster we fill
the extra space with zeros. This was forgetting that not even the
space allocated for the header will be fully initialized, as we
only write key material for the first key slot. The space left
for the other 7 slots is never written to.
An optimization to the ref count checking code:
commit a5fff8d4b4 (refs/bisect/bad)
Author: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Date: Wed Feb 27 16:14:30 2019 +0300
qcow2-refcount: avoid eating RAM
made the assumption that every cluster which was allocated would
have at least some data written to it. This was violated by way
the LUKS header is only partially written, with much space simply
reserved for future use.
Depending on the cluster size this problem was masked by the
logic which wrote zeros between the end of the LUKS header and
the end of the cluster.
$ qemu-img create --object secret,id=cluster_encrypt0,data=123456 \
-f qcow2 -o cluster_size=2k,encrypt.iter-time=1,\
encrypt.format=luks,encrypt.key-secret=cluster_encrypt0 \
cluster_size_check.qcow2 100M
Formatting 'cluster_size_check.qcow2', fmt=qcow2 size=104857600
encrypt.format=luks encrypt.key-secret=cluster_encrypt0
encrypt.iter-time=1 cluster_size=2048 lazy_refcounts=off refcount_bits=16
$ qemu-img check --object secret,id=cluster_encrypt0,data=redhat \
'json:{"driver": "qcow2", "encrypt.format": "luks", \
"encrypt.key-secret": "cluster_encrypt0", \
"file.driver": "file", "file.filename": "cluster_size_check.qcow2"}'
ERROR: counting reference for region exceeding the end of the file by one cluster or more: offset 0x2000 size 0x1f9000
Leaked cluster 4 refcount=1 reference=0
...snip...
Leaked cluster 130 refcount=1 reference=0
1 errors were found on the image.
Data may be corrupted, or further writes to the image may corrupt it.
127 leaked clusters were found on the image.
This means waste of disk space, but no harm to data.
Image end offset: 268288
The problem only exists when the disk image is entirely empty. Writing
data to the disk image payload will solve the problem by causing the
end of the file to be extended further.
The change fixes it by ensuring that the entire allocated LUKS header
region is fully initialized with zeros. The qemu-img check will still
fail for any pre-existing disk images created prior to this change,
unless at least 1 byte of the payload is written to.
Fully writing zeros to the entire LUKS header is a good idea regardless
as it ensures that space has been allocated on the host filesystem (or
whatever block storage backend is used).
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20200207135520.2669430-1-berrange@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
I/O requests to encrypted media should be aligned to the sector size
used by the underlying encryption method, not to BDRV_SECTOR_SIZE.
Fortunately this doesn't break anything at the moment because
both existing QCRYPTO_BLOCK_*_SECTOR_SIZE have the same value as
BDRV_SECTOR_SIZE.
The checks in qcow2_co_preadv_encrypted() are also unnecessary because
they are repeated immediately afterwards in qcow2_co_encdec().
Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-Id: <20200213171646.15876-1-berto@igalia.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
qemu-img's convert_co_copy_range() operates at the sector level and
block_copy() operates at the cluster level so this condition is always
true, but it is not necessary to restrict this here, so let's leave it
to the driver implementation return an error if there is any.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-id: a4264aaee656910c84161a2965f7a501437379ca.1579374329.git.berto@igalia.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
qcow2_alloc_cluster_offset() and qcow2_get_cluster_offset() always
return offsets that are cluster-aligned so don't just check that they
are sector-aligned.
The check in qcow2_co_preadv_task() is also replaced by an assertion
for the same reason.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 558ba339965f858bede4c73ce3f50f0c0493597d.1579374329.git.berto@igalia.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
The L1 table is read from disk using the byte-based bdrv_pread() and
is never accessed beyond its last element, so there's no need to
allocate more memory than that.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: b2e27214ec7b03a585931bcf383ee1ac3a641a10.1579374329.git.berto@igalia.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
This is a bit more efficient than having to allocate and free memory
for each item.
The default size (60) is enough for all the existing incompatible
features or the "Unknown incompatible feature" message.
Suggested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 20200115135626.19442-1-berto@igalia.com
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
QEMU currently supports writing compressed data of the size equal to
one cluster. This patch allows writing QCOW2 compressed data that
exceed one cluster. Now, we split buffered data into separate clusters
and write them compressed using the block/aio_task API.
Suggested-by: Pavel Butsykin <pbutsykin@virtuozzo.com>
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: Max Reitz <mreitz@redhat.com>
Message-id: 1575288906-551879-3-git-send-email-andrey.shinkevich@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
The local_err check outside of the if block was necessary
when it was introduced in commit d1258dd0c8 because it needed to be
executed even if qcow2_load_autoloading_dirty_bitmaps() returned false.
After some modifications that all required the error check to remain
where it is, commit 9c98f145df finally moved the
qcow2_load_dirty_bitmaps() call into the if block, so now the error
check should be there, too.
Signed-off-by: Guoyi Tu <tu.guoyi@h3c.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
There's a couple of places left in the qcow2 code that still do the
calculation manually, so let's replace them.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
In the common case, qcow2_co_pwrite_zeroes() already only modifies
metadata case, so we're fine with or without BDRV_REQ_NO_FALLBACK set.
The only exception is when using an external data file, where the
request is passed down to the block driver of the external data file. We
are forwarding the BDRV_REQ_NO_FALLBACK flag there, though, so this is
fine, too.
Declare the flag supported therefore.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
This is a change in behavior, so all instances need a good
justification. The comments added here should explain my reasoning.
qed already had a comment that suggests it always expected
bdrv_truncate()/blk_truncate() to behave as if exact=true were passed
(c743849bee came eight months before 55b949c847), so it was simply
broken until now.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190918095144.955-8-mreitz@redhat.com
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
[mreitz: Changed comment in qed.c to explain why a new QED file must be
empty, as requested and suggested by Maxim]
Signed-off-by: Max Reitz <mreitz@redhat.com>
When truncating a format node, the @exact parameter is generally handled
simply by virtue of the format storing the new size in the image
metadata. Such formats do not need to pass on the parameter to their
file nodes.
There are exceptions, though:
- raw and crypto cannot store the image size, and thus must pass on
@exact.
- When using qcow2 with an external data file, it just makes sense to
keep its size in sync with the qcow2 virtual disk (because the
external data file is the virtual disk). Therefore, we should pass
@exact when truncating it.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190918095144.955-7-mreitz@redhat.com
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
We have two drivers (iscsi and file-posix) that (in some cases) return
success from their .bdrv_co_truncate() implementation if the block
device is larger than the requested offset, but cannot be shrunk. Some
callers do not want that behavior, so this patch adds a new parameter
that they can use to turn off that behavior.
This patch just adds the parameter and lets the block/io.c and
block/block-backend.c functions pass it around. All other callers
always pass false and none of the implementations evaluate it, so that
this patch does not change existing behavior. Future patches take care
of that.
Suggested-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190918095144.955-5-mreitz@redhat.com
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
There is no reason why the format drivers need to truncate the protocol
node when formatting it. When using the old .bdrv_co_create_ops()
interface, the file will be created with no size option anyway, which
generally gives it a size of 0. (Exceptions are block devices, which
cannot be truncated anyway.)
When using blockdev-create, the user must have given the file node some
size anyway, so there is no reason why we should override that.
qed is an exception, it needs the file to start completely empty (as
explained by c743849bee).
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190918095144.955-4-mreitz@redhat.com
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
qcow2_check_read_snapshot_table() can perform consistency checks, but it
cannot fix everything. Specifically, it cannot allocate new clusters,
because that should wait until the refcount structures are known to be
consistent (i.e., after qcow2_check_refcounts()). Thus, it cannot call
qcow2_write_snapshots().
Do that in qcow2_check_fix_snapshot_table(), which is called after
qcow2_check_refcounts().
Currently, there is nothing that would set result->corruptions, so this
is a no-op. A follow-up patch will change that.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20191011152814.14791-10-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reading the snapshot table can fail. That is a problem when we want to
repair the image.
Therefore, stop reading the snapshot table in qcow2_do_open() in check
mode. Instead, add a new function qcow2_check_read_snapshot_table()
that reads the snapshot table at a later point. In the future, we want
to handle errors here and fix them.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20191011152814.14791-9-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
qcow2 v3 requires every snapshot table entry to have two extra data
fields: The 64-bit VM state size, and the virtual disk size. Both are
optional for v2 images, so they may not be present.
qcow2_upgrade() therefore should update the snapshot table to ensure all
entries have these extra data fields.
Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=1727347
Reported-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20191011152814.14791-8-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
This does not make sense right now, but it will make sense once we need
to do more than to just update s->qcow_version.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20191011152814.14791-7-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20191011152814.14791-4-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
qcow2_detect_metadata_preallocation() calls qcow2_get_refcount() which
requires s->lock to be taken to protect its accesses to the refcount
table and refcount blocks. However, nothing in this code path actually
took the lock. This could cause the same cache entry to be used by two
requests at the same time, for different tables at different offsets,
resulting in image corruption.
As it would be preferable to base the detection on consistent data (even
though it's just heuristics), let's take the lock not only around the
qcow2_get_refcount() calls, but around the whole function.
This patch takes the lock in qcow2_co_block_status() earlier and asserts
in qcow2_detect_metadata_preallocation() that we hold the lock.
Fixes: 69f47505ee
Cc: qemu-stable@nongnu.org
Reported-by: Michael Weiser <michael.weiser@gmx.de>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Tested-by: Michael Weiser <michael.weiser@gmx.de>
Reviewed-by: Michael Weiser <michael.weiser@gmx.de>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
The only reason I can imagine for this strange code at the very-end of
bdrv_reopen_commit is the fact that bs->read_only updated after
calling drv->bdrv_reopen_commit in bdrv_reopen_commit. And in the same
time, prior to previous commit, qcow2_reopen_bitmaps_rw did a wrong
check for being writable, when actually it only need writable file
child not self.
So, as it's fixed, let's move things to correct place.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Acked-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190927122355.7344-10-vsementsov@virtuozzo.com
Signed-off-by: John Snow <jsnow@redhat.com>
qcow2_reopen_bitmaps_ro wants to store bitmaps and then mark them all
readonly. But the latter don't work, as
qcow2_store_persistent_dirty_bitmaps removes bitmaps after storing.
It's OK for inactivation but bad idea for reopen-ro. And this leads to
the following bug:
Assume we have persistent bitmap 'bitmap0'.
Create external snapshot
bitmap0 is stored and therefore removed
Commit snapshot
now we have no bitmaps
Do some writes from guest (*)
they are not marked in bitmap
Shutdown
Start
bitmap0 is loaded as valid, but it is actually broken! It misses
writes (*)
Incremental backup
it will be inconsistent
So, let's stop removing bitmaps on reopen-ro. But don't rejoice:
reopening bitmaps to rw is broken too, so the whole scenario will not
work after this patch and we can't enable corresponding test cases in
260 iotests still. Reopening bitmaps rw will be fixed in the following
patches.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 20190927122355.7344-7-vsementsov@virtuozzo.com
Signed-off-by: John Snow <jsnow@redhat.com>
qmp_block_dirty_bitmap_add and do_block_dirty_bitmap_remove do acquire
aio context since 0a6c86d024. But this is not enough: we also must
lock qcow2 mutex when access in-image metadata. Especially it concerns
freeing qcow2 clusters.
To achieve this, move qcow2_can_store_new_dirty_bitmap and
qcow2_remove_persistent_dirty_bitmap to coroutine context.
Since we work in coroutines in correct aio context, we don't need
context acquiring in blockdev.c anymore, drop it.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 20190920082543.23444-4-vsementsov@virtuozzo.com
Signed-off-by: John Snow <jsnow@redhat.com>
It improves performance for fragmented qcow2 images.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20190916175324.18478-6-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
Similarly to previous commit, prepare for parallelizing write-loop
iterations.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190916175324.18478-5-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
Further patch will run partial requests of iterations of
qcow2_co_preadv in parallel for performance reasons. To prepare for
this, separate part which may be parallelized into separate function
(qcow2_co_preadv_task).
While being here, also separate encrypted clusters reading to own
function, like it is done for compressed reading.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190916175324.18478-4-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
* Change the qcow2_co_{encrypt|decrypt} to just receive full host and
guest offsets and use this function directly instead of calling
do_perform_cow_encrypt (which is removed by that patch).
* Adjust qcow2_co_encdec to take full host and guest offsets as well.
* Document the qcow2_co_{encrypt|decrypt} arguments
to prevent the bug fixed in former commit from hopefully
happening again.
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-id: 20190915203655.21638-3-mlevitsk@redhat.com
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
[mreitz: Let perform_cow() return the error value returned by
qcow2_co_encrypt(), as proposed by Vladimir]
Signed-off-by: Max Reitz <mreitz@redhat.com>
Replace instances of:
(n & (BDRV_SECTOR_SIZE - 1)) == 0
And:
(n & ~BDRV_SECTOR_MASK) == 0
With:
QEMU_IS_ALIGNED(n, BDRV_SECTOR_SIZE)
Which reveals the intent of the code better, and makes it easier to
locate the code checking alignment.
Signed-off-by: Nir Soffer <nsoffer@redhat.com>
Message-id: 20190827185913.27427-2-nsoffer@redhat.com
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
The size of the qcow2 L2 cache defaults to 32 MB, which can be easily
larger than the maximum amount of L2 metadata that the image can have.
For example: with 64 KB clusters the user would need a qcow2 image
with a virtual size of 256 GB in order to have 32 MB of L2 metadata.
Because of that, since commit b749562d98
we forbid the L2 cache to become larger than the maximum amount of L2
metadata for the image, calculated using this formula:
uint64_t max_l2_cache = virtual_disk_size / (s->cluster_size / 8);
The problem with this formula is that the result should be rounded up
to the cluster size because an L2 table on disk always takes one full
cluster.
For example, a 1280 MB qcow2 image with 64 KB clusters needs exactly
160 KB of L2 metadata, but we need 192 KB on disk (3 clusters) even if
the last 32 KB of those are not going to be used.
However QEMU rounds the numbers down and only creates 2 cache tables
(128 KB), which is not enough for the image.
A quick test doing 4KB random writes on a 1280 MB image gives me
around 500 IOPS, while with the correct cache size I get 16K IOPS.
Cc: qemu-stable@nongnu.org
Signed-off-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Implement and use new interface to get rid of hd_qiov.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20190604161514.262241-13-vsementsov@virtuozzo.com
Message-Id: <20190604161514.262241-13-vsementsov@virtuozzo.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Implement and use new interface to get rid of hd_qiov.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20190604161514.262241-12-vsementsov@virtuozzo.com
Message-Id: <20190604161514.262241-12-vsementsov@virtuozzo.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Use buffer based io in encrypted case.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20190604161514.262241-11-vsementsov@virtuozzo.com
Message-Id: <20190604161514.262241-11-vsementsov@virtuozzo.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
If a qcow2 file is preallocated, it can no longer guarantee that it
initially appears as filled with zeroes.
So implement .bdrv_has_zero_init() by checking whether the file is
preallocated; if so, forward the call to the underlying storage node,
except for when it is encrypted: Encrypted preallocated images always
return effectively random data, so .bdrv_has_zero_init() must always
return 0 for them.
.bdrv_has_zero_init_truncate() can remain bdrv_has_zero_init_1(),
because it presupposes PREALLOC_MODE_OFF.
Reported-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190724171239.8764-7-mreitz@redhat.com
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
We need to implement .bdrv_has_zero_init_truncate() for every block
driver that supports truncation and has a .bdrv_has_zero_init()
implementation.
Implement it the same way each driver implements .bdrv_has_zero_init().
This is at least not any more unsafe than what we had before.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190724171239.8764-5-mreitz@redhat.com
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
In my "build everything" tree, changing qemu/main-loop.h triggers a
recompile of some 5600 out of 6600 objects (not counting tests and
objects that don't depend on qemu/osdep.h). It includes block/aio.h,
which in turn includes qemu/event_notifier.h, qemu/notify.h,
qemu/processor.h, qemu/qsp.h, qemu/queue.h, qemu/thread-posix.h,
qemu/thread.h, qemu/timer.h, and a few more.
Include qemu/main-loop.h only where it's needed. Touching it now
recompiles only some 1700 objects. For block/aio.h and
qemu/event_notifier.h, these numbers drop from 5600 to 2800. For the
others, they shrink only slightly.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190812052359.30071-21-armbru@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Commit b76b4f60 allowed '-o compat=v3' as an alias for the
less-appealing '-o compat=1.1' for 'qemu-img create' since we want to
use the QMP form as much as possible, but forgot to do likewise for
qemu-img amend. Also, it doesn't help that '-o help' doesn't list our
new preferred spellings.
Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This patch is used in the 'block/stream: introduce a bottom node'
that is following. Instead of the base node, the caller may pass
the node that has the base as its backing image to the function
bdrv_is_allocated_above() with a new parameter include_base = true
and get rid of the dependency on the base that may change during
commit/stream parallel jobs. Now, if the specified base is not
found in the backing image chain, the QEMU will abort.
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: 1559152576-281803-2-git-send-email-andrey.shinkevich@virtuozzo.com
[mreitz: Squashed in the following as a rebase on conflicting patches:]
Message-id: e3cf99ae-62e9-8b6e-5a06-d3c8b9363b85@redhat.com
Signed-off-by: Max Reitz <mreitz@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>
drv_co_block_status digs bs->file for additional, more accurate search
for hole inside region, reported as DATA by bs since 5daa74a6eb.
This accuracy is not free: assume we have qcow2 disk. Actually, qcow2
knows, where are holes and where is data. But every block_status
request calls lseek additionally. Assume a big disk, full of
data, in any iterative copying block job (or img convert) we'll call
lseek(HOLE) on every iteration, and each of these lseeks will have to
iterate through all metadata up to the end of file. It's obviously
ineffective behavior. And for many scenarios we don't need this lseek
at all.
However, lseek is needed when we have metadata-preallocated image.
So, let's detect metadata-preallocation case and don't dig qcow2's
protocol file in other cases.
The idea is to compare allocation size in POV of filesystem with
allocations size in POV of Qcow2 (by refcounts). If allocation in fs is
significantly lower, consider it as metadata-preallocation case.
102 iotest changed, as our detector can't detect shrinked file as
metadata-preallocation, which don't seem to be wrong, as with metadata
preallocation we always have valid file length.
Two other iotests have a slight change in their QMP output sequence:
Active 'block-commit' returns earlier because the job coroutine yields
earlier on a blocking operation. This operation is loading the refcount
blocks in qcow2_detect_metadata_preallocation().
Suggested-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
If COW areas of the newly allocated clusters are zeroes on the backing
image, efficient bdrv_write_zeroes(flags=BDRV_REQ_NO_FALLBACK) can be
used on the whole cluster instead of writing explicit zero buffers later
in perform_cow().
iotest 060:
write to the discarded cluster does not trigger COW anymore.
Use a backing image instead.
Signed-off-by: Anton Nefedov <anton.nefedov@virtuozzo.com>
Message-id: 20190516142749.81019-2-anton.nefedov@virtuozzo.com
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Do encryption/decryption in threads, like it is already done for
compression. This improves asynchronous encrypted io.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190506142741.41731-9-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
Encryption will be done in threads, to take benefit of it, we should
move it out of the lock first.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190506142741.41731-8-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
Background: decryption will be done in threads, to take benefit of it,
we should move it out of the lock first.
But let's go further: it turns out, that only
qcow2_get_cluster_offset() needs locking, so reduce locking to it.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20190506142741.41731-7-vsementsov@virtuozzo.com
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Move generic part out of qcow2_co_do_compress, to reuse it for
encryption and rename things that would be shared with encryption path.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190506142741.41731-6-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
Move compression-on-threads to separate file. Encryption will be in it
too.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190506142741.41731-3-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
qcow2.h depends on block_int.h. Compilation isn't broken currently only
due to block_int.h always included before qcow2.h. Though, it seems
better to directly include block_int.h in qcow2.h.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190506142741.41731-2-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
When an L2 table entry points to a compressed cluster the space used
by the data is specified in 512-byte sectors. This size is independent
from BDRV_SECTOR_SIZE and is specific to the qcow2 file format.
The QCOW2_COMPRESSED_SECTOR_SIZE constant defined in this patch makes
this explicit.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The last user of this field disappeared when we replace the
sector-based bdrv_write() with the byte-based bdrv_pwrite().
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This patch fixes a few things in the way error codes are handled in
the qcow2 compression code:
a) qcow2_co_pwritev_compressed() expects qcow2_co_compress() to only
return -1 or -2 on failure, but this is not correct. Since the
change from qcow2_compress() to qcow2_co_compress() in commit
ceb029cd6f the new code can also return -EINVAL (although
there does not seem to exist any code path that would cause that
error in the current implementation).
b) -1 and -2 are ad-hoc error codes defined in qcow2_compress().
This patch replaces them with standard constants from errno.h.
c) Both qcow2_compress() and qcow2_co_do_compress() return a negative
value on failure, but qcow2_co_pwritev_compressed() stores the
value in an unsigned data type.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
make_completely_empty() is an optimisated path for bdrv_make_empty()
where completely new metadata is created inside the image file instead
of going through all clusters and discarding them. For an external data
file, however, we actually need to do discard operations on the data
file; just overwriting the qcow2 file doesn't get rid of the data.
The necessary slow path with an explicit discard operation already
exists for other cases. Use it for external data files, too.
Cc: qemu-stable@nongnu.org
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
preallocate_co() already gave the data file the full size without
forwarding the requested preallocation mode to the protocol. When
bdrv_co_truncate() was called later with the preallocation mode, the
file didn't actually grow any more, so the data file stayed unallocated
even if full preallocation was requested.
Pass the right preallocation mode to preallocate_co() and remove the
second bdrv_co_truncate() to fix this. As a side effect, the ugly
one-byte write in preallocate_co() is replaced with a truncate call,
now leaving the last block unallocated on the protocol level as it
should be.
Cc: qemu-stable@nongnu.org
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
We'll add a bdrv_co_truncate() call in the next patch which can return
an Error that we don't want to discard. So add an errp parameter to
preallocate_co().
Cc: qemu-stable@nongnu.org
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Limiting the allocation to INT_MAX bytes isn't particularly clever
because it means that the final cluster will be a partial cluster which
will be completed through a COW operation. This results in unnecessary
data read and write requests which lead to an unwanted non-sparse
filesystem block for metadata preallocation.
Align the maximum allocation size down to the cluster size to avoid this
situation.
Cc: qemu-stable@nongnu.org
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
With an external data file, preallocate_co() must write the final byte
to the external data file, not to the qcow2 image file.
This is harmless for preallocation of newly created images (only the
qcow2 file size is increased to the virtual disk size while it should be
much smaller), but with preallocated resize, it could in theory cause
visible corruption if the metadata of the image is larger than the data
(e.g. lots of bitmaps).
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
We were trying to check whether bdrv_open_blockdev_ref() returned
success, but accidentally checked the wrong variable. Spotted by
Coverity (CID 1399703).
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
If we reopen a BlockDriverState and there is an option that is present
in bs->options but missing from the new set of options then we have to
return an error unless the driver is able to reset it to its default
value.
This patch adds a new 'mutable_opts' field to BlockDriver. This is
a list of runtime options that can be modified during reopen. If an
option in this list is unspecified on reopen then it must be reset (or
return an error).
Signed-off-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Since we now load all bitmaps into memory anyway, we can just truncate
them in-memory and then flush them back to disk. Just in case, we will
still check and enforce that this shortcut is valid -- i.e. that any
bitmap described on-disk is indeed in-memory and can be modified.
If there are any inconsistent bitmaps, we refuse to allow the truncate
as we do not actually load these bitmaps into memory, and it isn't safe
or reasonable to attempt to truncate corrupted data.
Signed-off-by: John Snow <jsnow@redhat.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20190311185147.52309-4-vsementsov@virtuozzo.com
[vsementsov: drop bitmap flushing, fix block comments style]
Signed-off-by: John Snow <jsnow@redhat.com>
Provide an option to force QEMU to always keep the external data file
consistent as a standalone read-only raw image.
At the moment, this means making sure that write_zeroes requests are
forwarded to the data file instead of just updating the metadata, and
checking that no backing file is used.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Rather than requiring that the external data file node is passed
explicitly when creating the qcow2 node, store the filename in the
designated header extension during .bdrv_create and read it from there
as a default during .bdrv_open.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
