Commit Graph
81 Commits
Author SHA1 Message Date
Kevin Wolf beb6f0de7a Fix QEMU_WARN_UNUSED_RESULT
Since commit 747bbdf7 QEMU_WARN_UNUSED_RESULT is never defined as it is
conditional on a define from config-host.h which is included only later.
Include that file earlier to get the warnings back.

Reactivating it unfortunately leads to some warnings about unused qdev_init
results. These calls are changed to qdev_init_nofail to avoid build failures.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2010-01-19 16:31:04 -06:00
Kevin Wolf f8012c135e qcow/qcow2: implement bdrv_aio_flush
Now that we do not have to flush the backing device anymore implementing
the bdrv_aio_flush method for image formats is trivial.

[hch: forward ported to qemu mainline from a product tree]

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2010-01-13 17:14:15 -06:00
Kevin Wolf 347ed55cd1 osdep.c: Fix accept4 fallback
Commit 3a03bfa5 added a fallback in case the Linux kernel running qemu is older
than the kernel of the build system. Unfortunately, v1 was committed instead of
v2, so the code has a bug that was revealed in the review (checking for the
wrong error code).

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2010-01-13 17:14:15 -06:00
Kevin Wolf 3e85c6fd71 qemu-img rebase
This adds a rebase subcommand to qemu-img which allows to change the backing
file of an image.

In default mode, both the current and the new backing file need to exist, and
after the rebase, the COW image is guaranteed to have the same guest visible
content as before. To achieve this, old and new backing file are compared and,
if necessary, data is copied from the old backing file into the COW image.

With -u an unsafe mode is enabled that doesn't require the backing files to
exist. It merely changes the backing file reference in the COW image. This is
useful for renaming or moving the backing file. The user is responsible to make
sure that the new backing file has no changes compared to the old one, or
corruption may occur.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2010-01-13 17:14:15 -06:00
Kevin Wolf 756e6736a1 block: Add bdrv_change_backing_file
Introduce the functions needed to change the backing file of an image. The
function is implemented for qcow2.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2010-01-13 17:14:15 -06:00
Kevin Wolf b783e409bf block: Introduce BDRV_O_NO_BACKING
If an image references a backing file that doesn't exist, qemu-img info fails
to open this image. Exactly in this case the info would be valuable, though:
the user might want to find out which file is missing.

This patch introduces a BDRV_O_NO_BACKING flag to ignore the backing file when
opening the image. qemu-img info is the first user and provides info now even
if the backing file is invalid.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2010-01-13 17:14:15 -06:00
Kevin Wolf 092493be3c Fix loading of ELF multiboot kernels
The multiboot implementation assumed that there is only one program header
(which contains the entry point) and that the entry point is at the start of
the code. This doesn't hold true generally and caused too little data to be
loaded.

Fix the loading code to pass the whole loaded data to the Multiboot Option ROM.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-12-18 11:26:26 -06:00
Kevin Wolf 75f1247539 Revert "Rename DriveInfo.onerror to on_write_error" (fix mismerge)
Part of the first patch of the -drive rerror series has been merged once more
on top of the rest of the series. This effectively disables the rerror option
and always goes with the default value. Reverting the commit re-enables the
option.

This reverts commit fc072ec4df.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-12-18 11:26:26 -06:00
Kevin Wolf 40a0d7c395 qemu-io: Fix memory leak
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-12-18 11:26:26 -06:00
Kevin Wolf 5f370b1463 multiboot: Use signed type for negative error numbers
In mb_mod_length a return value is stored that is negative in error case. With
an unsigned type the check goes wrong.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-12-03 15:26:00 -06:00
Kevin Wolf 6769da29c7 posix-aio-compat: Fix error check
Checking for nbytes < 0 is pointless as long as it's a size_t. If we want to
use negative numbers for error codes, we should use signed types.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-12-03 15:26:00 -06:00
Kevin Wolf 7078dead94 qemu-img: Fix memory leak
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-12-03 15:26:00 -06:00
Kevin Wolf fc072ec4df Rename DriveInfo.onerror to on_write_error
Either rename variables and functions to refer to write errors (which is what
they actually do) or introduce a parameter to distinguish reads and writes.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-12-03 15:25:57 -06:00
Kevin Wolf 40ff6d7e8d Don't leak file descriptors
We're leaking file descriptors to child processes. Set FD_CLOEXEC on file
descriptors that don't need to be passed to children to stop this misbehaviour.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-12-03 11:45:50 -06:00
Kevin Wolf 12c09b8ce2 qemu-img: There is more than one host device driver
I haven't heard yet of anyone using qemu-img to copy an image to a real floppy,
but it's a valid use case.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-12-03 11:45:50 -06:00
Kevin Wolf 702ef63f3e qcow2: Fix some more qemu_malloc fallout
Oh joy...

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-12-03 11:45:50 -06:00
Kevin Wolf e1c7f0e3f9 qcow2: Store exact backing format length
Currently qcow2 unnecessarily rounds up the length of the backing format string
to the next multiple of 8. At the same time, the array in BlockDriverState can
only hold 15 characters, so in effect backing formats with 9 characters or more
don't work (e.g. host_device).

Save the real string length and things start to work for all valid image format
names.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-12-03 11:45:49 -06:00
Kevin Wolf f35d68f0e7 virtio-blk: Implement rerror option
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-12-03 11:45:49 -06:00
Kevin Wolf ce4b6522f7 ide: Implement rerror option
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-12-03 11:45:49 -06:00
Kevin Wolf e9b2e81889 Introduce rerror option for drives
rerror controls the action to be taken when an error occurs while accessing the
guest image file. It corresponds to werror which already controls the action
take for write errors.

This purely introduces parsing rerror command line option into the right
structures, real support for it in the device emulation is added in the
following patches.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-12-03 11:45:49 -06:00
Kevin Wolf f785009961 Rename DriveInfo.onerror to on_write_error
Either rename variables and functions to refer to write errors (which is what
they actually do) or introduce a parameter to distinguish reads and writes.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-12-03 11:45:49 -06:00
Kevin Wolf 49c3c8dca7 virtio-blk: Pass read errors to the guest
We need to signal not only write errors, but also read errors to the guest
driver. This fixes a regression introduced by 869a5c6d.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-11-12 11:23:55 -06:00
Kevin Wolf cb499fb295 savevm: Delete existing snapshots in all images
When creating a snapshot we can run into the situation that the first disk
doesn't have a snapshot, but the second one does have one with the same name as
the new snapshot.

In this case, qemu doesn't recognize that there is a snapshot to be
overwritten, so it starts to save the new snapshot and errors out later when it
tries to snapshot the second image. With this patch, snapshots on secondary
images are overwritten just like on the first image.

Reported-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-11-12 11:23:55 -06:00
Kevin Wolf 3e03236438 Documentation: Add options to image format descriptions
Explain the existing format specific options that can be used with qemu-img
create/convert -o ...

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-11-09 08:43:12 -06:00
Kevin Wolf 8063d0fe3b Documentation: Don't mention old qemu-img options
The old options are still supported for compatibility, but they are
inconsistent (for example create -b vs. convert -B for backing files) and
incomplete (-F only exists for create) which tends to confuse people. Remove
all references to the old options from the documentation to guide users to the
more consistent -o options.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-11-09 08:43:12 -06:00
Kevin Wolf f932c04039 Documentation: Move image format descriptions to own section
The description of the image formats is too long to be a subitem of a parameter
description. It will become even longer when we include the options provided by
the respective format.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-11-09 08:43:12 -06:00
Kevin Wolf 9f56640c85 qemu-img: Allow creating zero sized images
A size of 0 should be valid and cannot be treated as "missing value". Use -1
for this purpose instead.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-11-09 08:43:03 -06:00
Kevin Wolf 1e5b9d2fcc Remove aio_ctx from paio_* interface
The context parameter in paio_submit isn't used anyway, so there is no reason
why block drivers should need to remember it. This also avoids passing a Linux
AIO context to paio_submit (which doesn't do any harm as long as the parameter
is unused, but it is highly confusing).

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-10-30 08:39:34 -05:00
Kevin Wolf 72ecf02d7d Revert "qcow2: Bring synchronous read/write back to life"
It was merely a workaround and the real fix is done now.
This reverts commit ef845c3bf4.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-10-27 12:28:59 -05:00
Kevin Wolf db0ffc2402 linux-aio: Honour AsyncContext
Also for Linux AIO, don't call callbacks that don't belong to the active
AsyncContext.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-10-27 12:28:59 -05:00
Kevin Wolf e5f37649c6 posix-aio-compat: Honour AsyncContext
Don't call callbacks that don't belong to the active AsyncContext.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-10-27 12:28:59 -05:00
Kevin Wolf 65d6b3d885 block: Use new AsyncContext for bdrv_read/write emulation
bdrv_read/write emulation is used as the perfect example why we need something
like AsyncContexts. So maybe they better start using it.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-10-27 12:28:59 -05:00
Kevin Wolf 9a1e948129 Introduce contexts for asynchronous callbacks
Add the possibility to use AIO and BHs without allowing foreign callbacks to be
run. Basically, you put your own AIOs and BHs in a separate context. For
details see the comments in the source.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-10-27 12:28:59 -05:00
Kevin Wolf 4f999d05f5 Split out bottom halves
Instead of putting more and more stuff into vl.c, let's have the generic
functions that deal with asynchronous callbacks in their own file.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-10-27 12:28:59 -05:00
Kevin Wolf 8febfa2684 Add qemu_aio_process_queue()
We'll leave some AIO completions unhandled when we can't call the callback.
qemu_aio_process_queue() is used later to run any callbacks that are left and
can be run then.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-10-27 12:28:59 -05:00
Kevin Wolf 59c7b155aa posix-aio-compat: Split out posix_aio_process_queue
We need to process the request queue and run callbacks separately from reading
out the queue in a later patch, so split it out.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-10-27 12:28:58 -05:00
Kevin Wolf d2e4634504 raw/linux-aio: Also initialize POSIX AIO
When using Linux AIO raw still falls back to POSIX AIO sometimes, so we should
initialize it.

Not initializing it happens to work if POSIX AIO is used by another drive, or
if the format is not specified (probing the format uses POSIX AIO) or by pure
luck (e.g. it doesn't seem to happen any more with qcow2 since we have re-added
synchronous qcow2 functions).

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-10-27 12:28:35 -05:00
Kevin Wolf c5baaa489f qcow2: Fix grow_refcount_table error handling
In case of failure, we haven't increased the refcount for the newly allocated
cluster yet. Therefore we must not free the cluster or its refcount will become
negative (and endless recursion is possible).

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-10-27 12:28:35 -05:00
Kevin Wolf ef845c3bf4 qcow2: Bring synchronous read/write back to life
When the synchronous read and write functions were dropped, they were replaced
by generic emulation functions. Unfortunately, these emulation functions don't
provide the same semantics as the original functions did.

The original bdrv_read would mean that we read some data synchronously and that
we won't be interrupted during this read. The latter assumption is no longer
true with the emulation function which needs to use qemu_aio_poll and therefore
allows the callback of any other concurrent AIO request to be run during the
read. Which in turn means that (meta)data read earlier could have changed and
be invalid now. qcow2 is not prepared to work in this way and it's just scary
how many places there are where other requests could run.

I'm not sure yet where exactly it breaks, but you'll see breakage with virtio
on qcow2 with a backing file. Providing synchronous functions again fixes the
problem for me.

Patchworks-ID: 35437
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-10-15 09:32:04 -05:00
Kevin Wolf be8b28a940 Documentation: Move msmouse description to an appropriate place
Putting it right in the middle of the explanation for "-serial udp" probably
wasn't the best idea.

Patchworks-ID: 35603
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-10-15 09:32:03 -05:00
Kevin Wolf 4e257e5e81 Documentation: Add missing tags to placeholders
Not all placeholders in options descriptions had the @var tag on them. Add the
tag so that it's clearly visible that they are placeholders.

Patchworks-ID: 35602
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-10-15 09:32:03 -05:00
Kevin Wolf b3f046c296 Documentation: Highlight placeholders in suboptions
Currently, suboptions (i.e. something like file=file for -drive) are rendered
as @code, so we're losing any @var highlighting in the man pages.

Replace them by @option, so that you actually can see what is a placeholder and
what is meant verbatim.

Patchworks-ID: 35601
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-10-15 09:32:03 -05:00
Kevin Wolf 0b4ce02eb2 block/raw: Add create_options for host_device
Today host_devices have a create function, so they also need a create_options
field to prevent qemu-img from complaining.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-10-05 14:20:34 -05:00
Kevin Wolf 7f1e9d4e13 eepro100: Don't allow guests to fail assertions
The idea of using assert() for input validation is rather questionable.
Let's remove it from eepro100, so that guests need to find more interesting
ways if they want to crash qemu.

This patch replaces asserts that are directly dependent on guest-accessible
data by other means of error handling.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-10-05 09:32:52 -05:00
Kevin Wolf 80ee15a6b2 qcow2: Increase maximum cluster size to 2 MB
This patch increases the maximum qcow2 cluster size to 2 MB. Starting with 128k
clusters, L2 tables span 2 GB or more of virtual disk space, causing 32 bit
truncation and wraparound of signed integers. Therefore some variables need to
use a larger data type.

While being at reviewing data types, change some integers that are used for
array indices to unsigned. In some places they were checked against some upper
limit but not for negative values. This could avoid potential segfaults with
corrupted qcow2 images.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-10-05 09:32:52 -05:00
Kevin Wolf 91553dcc9e virtio-blk: Use bdrv_aio_multiwrite
It is quite common for virtio-blk to submit more than one write request in a
row to the qemu block layer. Use bdrv_aio_multiwrite to allow block drivers to
optimize its handling of the requests.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-09-11 10:18:06 -05:00
Kevin Wolf 40b4f53967 Add bdrv_aio_multiwrite
One performance problem of qcow2 during the initial image growth are
sequential writes that are not cluster aligned. In this case, when a first
requests requires to allocate a new cluster but writes only to the first
couple of sectors in that cluster, the rest of the cluster is zeroed - just
to be overwritten by the following second request that fills up the cluster.

Let's try to merge sequential write requests to the same cluster, so we can
avoid to write the zero padding to the disk in the first place.

As a nice side effect, also other formats take advantage of dealing with less
and larger requests.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-09-11 10:18:06 -05:00
Kevin Wolf f214978a42 qcow2: Order concurrent AIO requests on the same unallocated cluster
When two AIO requests write to the same cluster, and this cluster is
unallocated, currently both requests allocate a new cluster and the second one
merges the first one when it is completed. This means an cluster allocation, a
read and a cluster deallocation which cause some overhead. If we simply let the
second request wait until the first one is done, we improve overall performance
with AIO requests (specifially, qcow2/virtio combinations).

This patch maintains a list of in-flight requests that have allocated new
clusters. A second request touching the same cluster is limited so that it
either doesn't touch the allocation of the first request (so it can have a
non-overlapping allocation) or it waits for the first request to complete.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-09-09 17:31:26 -05:00
Kevin Wolf ea80b906f4 qcow2: Fix metadata preallocation
The wrong version of the preallocation patch has been applied, so this is the
remaining diff.

We can't use truncate to grow the image file to the right size because we don't
know if metadata has been written after the last data cluster. In this case
truncate would shrink the file and destroy its metadata. Write a zero sector at
the end of the virtual disk instead to ensure that the file is big enough.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-09-09 17:31:26 -05:00
Kevin Wolf a35e1c177d qcow2: Metadata preallocation
This introduces a qemu-img create option for qcow2 which allows the metadata to
be preallocated, i.e. clusters are reserved in the refcount table and L1/L2
tables, but no data is written to them. Metadata is quite small, so this
happens in almost no time.

Especially with qcow2 on virtio this helps to gain a bit of performance during
the initial writes. However, as soon as create a snapshot, we're back to the
normal slow speed, obviously. So this isn't the real fix, but kind of a cheat
while we're still having trouble with qcow2 on virtio.

Note that the option is disabled by default and needs to be specified
explicitly using qemu-img create -f qcow2 -o preallocation=metadata.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-08-27 20:30:20 -05:00
Kevin Wolf a7824a886e qemu-io: Rework alloc command
The alloc command in qemu-io is mostly useless currently. Instead of doing a
single call to bdrv_is_allocated, we must call bdrv_is_allocated in a loop
until we have found out for each requested sector if it is allocated or not
(bdrv_is_allocated returns a number of sectors that are known to be in the same
state as the first one, but it is not required to include all of them)

This changes the output format of the alloc command so that a change to the
expected output of qemu-iotests 019 is necessary once this is included.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-07-22 10:58:47 -05:00
Kevin Wolf b171271a50 vmdk: Fix backing file handling
Instead of storing the backing file in its own BlockDriverState, VMDK uses the
BlockDriverState of the raw image file it opened. This is wrong and breaks
functions that access the backing file or protocols. This fix replaces all
occurrences of s->hd->backing_* with bs->backing_*.

This fixes qemu-iotests failure in 020 (Commit changes to backing file).

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-07-22 10:58:47 -05:00
Kevin Wolf ca94dbc753 qemu-io: Implement bdrv_load_vmstate/bdrv_save_vmstate
The load_vmstate and save_vmstate functions are implemented as a
variation of the normal read/write operation, enabled by the -b option.
This is the same mechanism as is used to switch from read/write to
pread/pwrite.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-07-16 17:28:50 -05:00
Kevin Wolf 3f6a3ee51e qcow2: Fix L1 table memory allocation
Contrary to what one could expect, the size of L1 tables is not cluster
aligned. So as we're writing whole sectors now instead of single entries,
we need to ensure that the L1 table in memory is large enough; otherwise
write would access memory after the end of the L1 table.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-07-10 13:44:29 -05:00
Kevin Wolf c53ffce91b qcow1: Fix qcow_aio_writev
Pass is_write = 1 to qcow_aio_setup when writing.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-07-10 13:44:29 -05:00
Kevin Wolf 7d8abfcb50 qemu-io: fix memory leak
qemu-io leaks the request buffer whenever the read or write function isn't
executed completely down the "normal" code path.

[hch: also fix the aio and vectored variants the same way]

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2009-07-10 12:25:36 -05:00
Kevin Wolf 0aa217e461 qcow2: Make cache=writethrough default
The performance of qcow2 has improved meanwhile, so we don't need to
special-case it any more. Switch the default to write-through caching
like all other block drivers.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-07-09 16:06:37 -05:00
Kevin Wolf 3b88e52b41 qcow2: Cache refcount blocks during snapshot creation
The really time consuming part of snapshotting is to adjust the reference count
of all clusters. Currently after each adjusted cluster the refcount block is
written to disk.

Don't write each single byte immediately to disk but cache all writes to the
refcount block and write them out once we're done with the block.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-06-29 14:18:07 -05:00
Kevin Wolf 22afa7b5b6 block-raw: Allow pread beyond the end of growable images
When using O_DIRECT, qcow2 snapshots didn't work any more for me. In the
process of creating the snapshot, qcow2 tries to pwrite some new information
(e.g. new L1 table) which will often end up being after the old end of the
image file. Now pwrite tries to align things and reads the old contents of the
file, read returns 0 because there is nothing to read after the end of file and
pwrite is stuck in an endless loop.

This patch allows to pread beyond the end of an image file. Whenever the
given offset is after the end of the image file, the read succeeds and fills
the buffer with zeros.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-06-29 14:18:07 -05:00
Kevin Wolf 9923e05e1a update_refcount: Write complete sectors
When updating the refcount blocks in update_refcount(), write complete sectors
instead of updating single entries.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-06-16 15:18:37 -05:00
Kevin Wolf 4c1612d954 alloc_cluster_link_l2: Write complete sectors
When updating the L2 tables in alloc_cluster_link_l2(), write complete
sectors instead of updating single entries.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-06-16 15:18:36 -05:00
Kevin Wolf 6583e3c7e8 l2_allocate: Write complete sectors
When modifying the L1 table, l2_allocate() needs to write complete sectors
instead of single entries. The L1 table is already in memory, reading it from
disk in the block layer to align the request is wasted performance.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-06-16 15:18:36 -05:00
Kevin Wolf ed6ccf0f51 qcow2: Rename global functions
The qcow2 source is now split into several more manageable files. During the
conversion quite some functions that were static before needed to be changed to
be global to make the source compile again.

We were lucky enough not to get name conflicts with these additional global
names, but they are not nice. This patch adds a qcow2_ prefix to all of the
global functions in qcow2.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-06-16 15:18:36 -05:00
Kevin Wolf c142442b06 qcow2: Split out snapshot functions
qcow2-snapshot.c contains the code related to snapshotting.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-06-16 15:18:36 -05:00
Kevin Wolf 45aba42fba qcow2: Split out guest cluster functions
qcow2-cluster.c contains all functions related to the management of guest
clusters, i.e. what the guest sees on its virtual disk. This code is about
mapping these guest clusters to host clusters in the image file using the
two-level lookup tables.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-06-16 15:18:36 -05:00
Kevin Wolf f7d0fe0239 qcow2: Split out refcount handling
qcow2-refcount.c contains all functions which are related to cluster
allocation and management in the image file. A large part of this is the
reference counting of these clusters.

Also a header file qcow2.h is introduced which will contain the interface of
the split qcow2 modules.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-06-16 15:18:36 -05:00
Kevin Wolf 9ccb258e28 qcow2: Change default cluster size to 64k
Larger cluster sizes mean less metadata. This has been discussion a few times,
let's do it now. This turns 64k clusters on by default for new images.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-06-16 15:18:36 -05:00
Kevin Wolf eff442662d Document changes in qemu-img interface
Update the documentation to reflect the introduction of format specific options
with -o. Don't advertise -e or -6 any more, they exist only for compatibility
reasons and can be replaced by the corresponding -o options.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2009-06-06 18:39:02 +03:00
Kevin Wolf db08adf526 qemu-img: Print available options with -o ?
This patch adds a small help text to each of the options in the block drivers
which can be displayed by using qemu-img create -f fmt -o ?

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2009-06-06 18:38:57 +03:00
Kevin Wolf 91a073a975 Drop bdrv_create2
This patch converts the remaining users of bdrv_create2 to bdrv_create and
removes the now unused function.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-05-27 09:45:23 -05:00
Kevin Wolf a980c98cf1 qcow2: Update multiple refcounts at once
Don't write each single changed refcount block entry to the disk after it is
written, but update all entries of the block and write all of them at once.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-05-27 09:45:20 -05:00
Kevin Wolf 44ff42de1c qcow2: Refactor update_refcount
This is a preparation patch with no functional changes. It moves the allocation
of new refcounts block to a new function and makes update_cluster_refcount (for
one cluster) call update_refcount (for multiple clusters) instead the other way
round.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-05-27 09:45:15 -05:00
Kevin Wolf ade406775d qcow/qcow2: Drop synchronous qcow_write()
There is only one (internal) user left and it can be switched to the normal
emulation provided in block.c

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-05-27 09:45:10 -05:00
Kevin Wolf 8cf07dcbe7 Fix output of uninitialized strings
Commit ffad4116b9 removed the "scratch buffer"
from check_params, but didn't care for the error messages which actually
included this string to tell the user which option was wrong. Now this string
is uninitialized, so this patch removes it from the message.

This means that the user is only told the whole parameter string and has to
pick the wrong option by himself as the callers of check_params can't know this
value any more. An alternative approach would be to revert that commit and do
whatever is needed to fix the original problem without changing check_params.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-05-27 09:44:51 -05:00
Kevin Wolf 73c632edc4 qcow2: Allow different cluster sizes
Add an option to specify the cluster size of a newly created qcow2 image.
Default is 4k which is the same value that was hard-coded before.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-05-22 10:50:32 -05:00
Kevin Wolf efa84d43cc Convert qemu-img convert to new bdrv_create
This is part two of the qemu-img conversion. This really works the same as the
previous conversion of qemu-img create: It introduces a new -o option for the
generic approach and adds the old-style options to this option set.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-05-22 10:50:32 -05:00
Kevin Wolf 9ea2ea7146 Convert qemu-img create to new bdrv_create
This patch changes qemu-img to actually use the new bdrv_create interface. It
translates the old-style qemu-img options which have been bdrv_create2
parameters or flags so far to option structures. As the generic approach, it
introduces an -o option which accepts any parameter the driver knows.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-05-22 10:50:31 -05:00
Kevin Wolf 0e7e1989f7 Convert all block drivers to new bdrv_create
Now we can make use of the newly introduced option structures. Instead of
having bdrv_create carry more and more parameters (which are format specific in
most cases), just pass a option structure as defined by the driver itself.

bdrv_create2() contains an emulation of the old interface to simplify the
transition.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-05-22 10:50:31 -05:00
Kevin Wolf d3f243676a Create qemu-option.h
This patch creates a new header file and the corresponding implementation file
for parsing of parameter strings for options (like used in -drive). Part of
this is code moved from vl.c (so qemu-img can use it later).

The idea is to have a data structure describing all accepted parameters. When
parsing a parameter string, the structure is copied and filled with the
parameter values.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-05-22 10:50:31 -05:00
Kevin Wolf fbb7b4e080 Improve block range checks
This patch makes the range checks for block requests more strict: It fixes a
potential integer overflow and checks for negative offsets. Also, it adds the
check for compressed writes.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-05-08 16:02:18 -05:00
Kevin Wolf d9654a5857 qemu-io: Optionally verify only part of read data
There are reasonable test cases where a read must span areas that are not
uniformly filled with one pattern but contains several parts. This makes -P
useless for them currently.

Introducing additional options which determine the part of the read data that
should be verified with the given pattern allows to check such reads.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-05-01 09:44:11 -05:00