Commit Graph

58 Commits

Author SHA1 Message Date
Stefan Hajnoczi a4127c428e vpc: fix beX_to_cpu() and cpu_to_beX() confusion
The beX_to_cpu() and cpu_to_beX() functions perform the same operation -
they do a byteswap if the host CPU endianness is little-endian or a
nothing otherwise.

The point of two names for the same operation is that it documents which
direction the data is being converted.  This makes it clear whether the
data is suitable for CPU processing or in its external representation.

This patch fixes incorrect beX_to_cpu()/cpu_to_beX() usage.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-09-25 15:24:14 +02:00
Hu Tao c2eb918e32 block: round up file size to nearest sector
Currently the file size requested by user is rounded down to nearest
sector, causing the actual file size could be a bit less than the size
user requested. Since some formats (like qcow2) record virtual disk
size in bytes, this can make the last few bytes cannot be accessed.

This patch fixes it by rounding up file size to nearest sector so that
the actual file size is no less than the requested file size.

Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
Reviewed-by: Kevin Wolf <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>
2014-09-12 15:43:06 +02:00
Xiaodong Gong 0d4cc3e715 Fix improper usage of cpu_to_be32 in vpc
cpu_to_be32() is wrong since vhd_type is an enum constant
(just a regular CPU-endian integer).

Signed-off-by: Xiaodong Gong <gordongong0350@gmail.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-09-10 10:41:29 +02:00
Kevin Wolf 5fb09cd586 vpc: Handle failure for potentially large allocations
Some code in the block layer makes potentially huge allocations. Failure
is not completely unexpected there, so avoid aborting qemu and handle
out-of-memory situations gracefully.

This patch addresses the allocations in the vpc block driver.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net>
2014-08-15 15:07:16 +02:00
Jeff Cody fef6070eff block: vpc - use block layer ops in vpc_create, instead of posix calls
Use the block layer to create, and write to, the image file in the VPC
.bdrv_create() operation.

This has a couple of benefits: Images can now be created over protocols,
and hacks such as NOCOW are not needed in the image format driver, and
the underlying file protocol appropriate for the host OS can be relied
upon.

Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-08-15 15:07:15 +02:00
Chunyan Liu 4ab1559085 qemu-img create: add 'nocow' option
Add 'nocow' option so that users could have a chance to set NOCOW flag to
newly created files. It's useful on btrfs file system to enhance performance.

Btrfs has low performance when hosting VM images, even more when the guest
in those VM are also using btrfs as file system. One way to mitigate this bad
performance is to turn off COW attributes on VM files. Generally, there are
two ways to turn off NOCOW on btrfs: a) by mounting fs with nodatacow, then
all newly created files will be NOCOW. b) per file. Add the NOCOW file
attribute. It could only be done to empty or new files.

This patch tries the second way, according to the option, it could add NOCOW
per file.

For most block drivers, since the create file step is in raw-posix.c, so we
can do setting NOCOW flag ioctl in raw-posix.c only.

But there are some exceptions, like block/vpc.c and block/vdi.c, they are
creating file by calling qemu_open directly. For them, do the same setting
NOCOW flag ioctl work in them separately.

[Fixed up 082.out due to the new 'nocow' creation option
--Stefan]

Signed-off-by: Chunyan Liu <cyliu@suse.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-07-01 10:15:12 +02:00
Chunyan Liu c282e1fdf7 cleanup QEMUOptionParameter
Now that all backend drivers are using QemuOpts, remove all
QEMUOptionParameter related codes.

Signed-off-by: Dong Xu Wang <wdongxu@linux.vnet.ibm.com>
Signed-off-by: Chunyan Liu <cyliu@suse.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-06-16 17:23:21 +08:00
Chunyan Liu fec9921f0a vpc.c: replace QEMUOptionParameter with QemuOpts
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Dong Xu Wang <wdongxu@linux.vnet.ibm.com>
Signed-off-by: Chunyan Liu <cyliu@suse.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-06-16 17:23:21 +08:00
Kevin Wolf 5e71dfad76 vpc: Validate block size (CVE-2014-0142)
This fixes some cases of division by zero crashes.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-04-01 13:59:47 +02:00
Jeff Cody 97f1c45c6f vpc/vhd: add bounds check for max_table_entries and block_size (CVE-2014-0144)
This adds checks to make sure that max_table_entries and block_size
are in sane ranges.  Memory is allocated based on max_table_entries,
and block_size is used to calculate indices into that allocated
memory, so if these values are incorrect that can lead to potential
unbounded memory allocation, or invalid memory accesses.

Also, the allocation of the pagetable is changed from g_malloc0()
to qemu_blockalign().

Signed-off-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-04-01 13:59:47 +02:00
Paolo Bonzini 76abe4071d block: do not abuse EMEDIUMTYPE
Returning "Wrong medium type" for an image that does not have a valid
header is a bit weird.  Improve the error by mentioning what format
was trying to open it.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-02-21 21:02:24 +01:00
Paolo Bonzini 95de6d7078 block drivers: add discard/write_zeroes properties to bdrv_get_info implementation
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-12-03 15:26:49 +01:00
Paolo Bonzini 97b00e2851 vpc, vhdx: add get_info
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-12-03 15:26:49 +01:00
Peter Lieven 0173e7bbf3 block/vpc: fix virtual size for images created with disk2vhd
Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-11-07 13:58:58 +01:00
Peter Lieven fb8fe35f63 block/vpc: check that the image has not been truncated
this adds a check that a dynamic VHD file has not been
accidently truncated (e.g. during transfer or upload).

Signed-off-by: Peter Lieven <pl@kamp.de>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-10-24 17:34:48 +02:00
Jeff Cody e54835c06d block: vpc - use QEMU_PACKED for on-disk structures
The VHD footer and header structs (vhd_footer and vhd_dyndisk_header)
are on-disk structures for the image format, and as such should be
packed.

Go ahead and make these typedefs as well, with the preferred QEMU
naming convention, so that the packed attribute is used consistently
with the struct.

Signed-off-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-09-25 20:51:10 +02:00
Max Reitz d5124c00d8 bdrv: Use "Error" for creating images
Add an Error ** parameter to BlockDriver.bdrv_create to allow more
specific error messages.

Signed-off-by: Max Reitz <mreitz@redhat.com>
2013-09-12 10:12:48 +02:00
Max Reitz 015a1036a7 bdrv: Use "Error" for opening images
Add an Error ** parameter to BlockDriver.bdrv_open and
BlockDriver.bdrv_file_open to allow more specific error messages.

Signed-off-by: Max Reitz <mreitz@redhat.com>
2013-09-12 10:12:47 +02:00
Kevin Wolf 72c6cc94da vpc: Implement .bdrv_has_zero_init
Depending on the subformat, has_zero_init on VHD must behave like raw
and query the underlying storage (fixed) or like other sparse formats
that can always return 1 (dynamic, differencing).

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-06-28 10:21:00 +02:00
Kevin Wolf 1a86938f04 block: Add options QDict to .bdrv_open()
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-03-15 16:07:49 +01:00
Stefan Hajnoczi 33ccf6675f Revert "block/vpc: Fix size calculation"
This reverts commit f880defbb0.

Jeff Cody's testing revealed that the interpretation of size differs
even between VirtualPC and HyperV.  Revert this so there is time to
consider the impact of any backwards incompatible behavior this change
creates.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-02-12 12:25:15 +01:00
Stefan Weil f880defbb0 block/vpc: Fix size calculation
The size calculated from the CHS values is not the real image (disk) size,
but usually a smaller value. This is caused by rounding effects.

Only older operating systems use CHS. Such guests won't be able to use
the whole disk. All modern operating systems use the real size.

This patch fixes https://bugs.launchpad.net/qemu/+bug/1105670/.

Signed-off-by: Stefan Weil <sw@weilnetz.de>
Message-id: 1360265212-22037-1-git-send-email-sw@weilnetz.de
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-02-11 08:14:41 -06:00
Kevin Wolf 59294e4659 vpc: Fix bdrv_open() error handling
Return -errno instead of -1 on errors. While touching the
code, fix a memory leak.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-02-01 14:58:28 +01:00
Paolo Bonzini 1de7afc984 misc: move include files to include/qemu/
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-12-19 08:32:39 +01:00
Paolo Bonzini caf71f86a3 migration: move include files to include/migration/
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-12-19 08:31:32 +01:00
Paolo Bonzini 737e150e89 block: move include files to include/block/
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-12-19 08:31:31 +01:00
Charles Arnold 258d2edbcd block: vpc support for ~2 TB disks
The VHD specification allows for up to a 2 TB disk size. The current
implementation in qemu emulates EIDE and ATA-2 hardware which only allows
for up to 127 GB.  This disk size limitation can be overridden by allowing
up to 255 heads instead of the normal 4 bit limitation of 16.  Doing so
allows disk images to be created of up to nearly 2 TB.  This change does
not violate the VHD format specification nor does it change how smaller
disks (ie, <=127GB) are defined.

[Charles Arnold also writes: "In analyzing a 160 GB VHD fixed disk image
created on Windows 2008 R2, it appears that MS is also ignoring the CHS
values in the footer geometry field in whatever driver they use for
accessing the image.  The CHS values are set at 65535,16,255 which
obviously doesn't represent an image size of 160 GB." -- Stefan]

Signed-off-by: Charles Arnold <carnold@suse.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2012-12-11 11:04:26 +01:00
Charles Arnold 1fe1fa510a block: vpc initialize the uuid footer field
Initialize the uuid field in the footer with a generated uuid.

Signed-off-by: Charles Arnold <carnold@suse.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2012-12-11 11:04:25 +01:00
Jeff Cody 3fe4b70008 block: vpc image file reopen
There is currently nothing that needs to be done for VPC image
file reopen.

Signed-off-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-09-24 15:15:12 +02:00
Corey Bryant 2e1e79dae7 block: Convert close calls to qemu_close
This patch converts all block layer close calls, that correspond
to qemu_open calls, to qemu_close.

Signed-off-by: Corey Bryant <coreyb@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-08-15 10:48:57 +02:00
Corey Bryant 6165f4d85d block: Convert open calls to qemu_open
This patch converts all block layer open calls to qemu_open.

Note that this adds the O_CLOEXEC flag to the changed open paths
when the O_CLOEXEC macro is defined.

Signed-off-by: Corey Bryant <coreyb@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-08-15 10:48:57 +02:00
Zhang Shengju c088b69136 block/vpc: write checksum back to footer after check
After validation check, the 'checksum' is not written back
to footer, which leave it with zero.

This results in errors while loadding it under Microsoft's
Hyper-V environment, and also errors from utilities like
Citrix's vhd-util.

Signed-off-by: Zhang Shengju <sean_zhang@trendmicro.com.cn>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-05 14:54:40 +02:00
Paolo Bonzini 29cdb2513c block: push recursive flushing up from drivers
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-05 14:54:39 +02:00
Kevin Wolf ecd880d9ee vpc: Round up image size during fixed image creation
The geometry calculation algorithm from the VHD spec rounds the image
size down if it doesn't exactly match a geometry. During image
conversion, this causes the image to be truncated. For dynamic images,
we already have code in place to round up instead, let's do the same for
fixed images.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-02-09 16:17:51 +01:00
Charles Arnold 24da78dbb5 vpc: Add support for Fixed Disk type
The Virtual Hard Disk Image Format Specification allows for three
types of hard disk formats, Fixed, Dynamic, and Differencing.  Qemu
currently only supports Dynamic disks.  This patch adds support for
the Fixed Disk format.

Usage:
    Example 1: qemu-img create -f vpc -o type=fixed <filename> [size]
    Example 2: qemu-img convert -O vpc -o type=fixed <input filename> <output filename>

While it is also allowed to specify '-o type=dynamic', the default disk type
remains Dynamic and is what is used when the type is left unspecified.

Signed-off-by: Charles Arnold <carnold@suse.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-02-09 16:17:51 +01:00
Kevin Wolf 5bb1cbac4f vpc: Add missing error handling in alloc_block
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2011-11-23 17:04:06 +01:00
Kevin Wolf 612ff3d887 vpc: Add migration blocker
vpc caches the BAT. For migration to work, it would have to be
invalidated. Block migration for now.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-11-23 17:04:04 +01:00
Kevin Wolf c68b89acd6 block: Rename bdrv_co_flush to bdrv_co_flush_to_disk
There are two different types of flush that you can do: Flushing one level up
to the OS (i.e. writing data to the host page cache) or flushing it all the way
down to the disk. The existing functions flush to the disk, reflect this in the
function name.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-11-11 14:02:59 +01:00
Charles Arnold 78439f6af1 block: Fix vpc initialization of the Dynamic Disk Header
The Data Offset field in the Dynamic Disk Header is an 8 byte field.
Although the specification (2006-10-11) gives an example of initializing
only the first 4 bytes, images generated by Microsoft on Windows initialize
all 8 bytes.

Failure to initialize all 8 bytes results in errors from utilities
like Citrix's vhd-util which checks specifically for the proper Data
Offset field initialization.

Signed-off-by: Charles Arnold <carnold@suse.com>
Reviewed-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-11-11 14:02:58 +01:00
Paolo Bonzini 8b94ff8573 block: change flush to co_flush
Since coroutine operation is now mandatory, convert all bdrv_flush
implementations to coroutines.  For qcow2, this means taking the lock.
Other implementations are simpler and just forward bdrv_flush to the
underlying protocol, so they can avoid the lock.

The bdrv_flush callback is then unused and can be eliminated.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-10-21 17:34:14 +02:00
Paolo Bonzini e183ef75cc block: take lock around bdrv_write implementations
This does the first part of the conversion to coroutines, by
wrapping bdrv_write implementations to take the mutex.

Drivers that implement bdrv_write rather than bdrv_co_writev can
then benefit from asynchronous operation (at least if the underlying
protocol supports it, which is not the case for raw-win32), even
though they still operate with a bounce buffer.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-10-21 17:34:14 +02:00
Paolo Bonzini 2914caa088 block: take lock around bdrv_read implementations
This does the first part of the conversion to coroutines, by
wrapping bdrv_read implementations to take the mutex.

Drivers that implement bdrv_read rather than bdrv_co_readv can
then benefit from asynchronous operation (at least if the underlying
protocol supports it, which is not the case for raw-win32), even
though they still operate with a bounce buffer.

raw-win32 does not need the lock, because it cannot yield.
nbd also doesn't probably, but better be safe.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-10-21 17:34:14 +02:00
Paolo Bonzini 848c66e8f5 block: add a CoMutex to synchronous read drivers
The big conversion of bdrv_read/write to coroutines caused the two
homonymous callbacks in BlockDriver to become reentrant.  It goes
like this:

1) bdrv_read is now called in a coroutine, and calls bdrv_read or
bdrv_pread.

2) the nested bdrv_read goes through the fast path in bdrv_rw_co_entry;

3) in the common case when the protocol is file, bdrv_co_do_readv calls
bdrv_co_readv_em (and from here goes to bdrv_co_io_em), which yields
until the AIO operation is complete;

4) if bdrv_read had been called from a bottom half, the main loop
is free to iterate again: a device model or another bottom half
can then come and call bdrv_read again.

This applies to all four of read/write/flush/discard.  It would also
apply to is_allocated, but it is not used from within coroutines:
besides qemu-img.c and qemu-io.c, which operate synchronously, the
only user is the monitor.  Copy-on-read will introduce a use in the
block layer, and will require converting it.

The solution is "simply" to convert all drivers to coroutines!  We
just need to add a CoMutex that is taken around affected operations.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-10-21 17:34:13 +02:00
Anthony Liguori 7267c0947d Use glib memory allocation and free functions
qemu_malloc/qemu_free no longer exist after this commit.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2011-08-20 23:01:08 -05:00
Serge E. Hallyn efc8243d00 block/vpc.c: Detect too-large vpc file
VHD files technically can be up to 2Tb, but virtual pc is limited
to 127G.  Currently qemu-img refused to create vpc files > 127G,
but it is failing to return error when converting from a non-vpc
VHD file which is >127G.  It returns success, but creates a truncated
converted image.  Also, qemu-img info claims the vpc file is 127G
(and clean).

This patch detects a too-large vpc file and returns -EFBIG.  Without
this patch,

=============================================================
root@ip-10-38-123-242:~/qemu-fixed# qemu-img info /mnt/140g-dynamic.vhd
image: /mnt/140g-dynamic.vhd
file format: vpc
virtual size: 127G (136899993600 bytes)
disk size: 284K
root@ip-10-38-123-242:~/qemu-fixed# qemu-img convert -f vpc -O raw /mnt/140g-dynamic.vhd /mnt/y
root@ip-10-38-123-242:~/qemu-fixed# echo $?
0
root@ip-10-38-123-242:~/qemu-fixed# qemu-img info /mnt/y
image: /mnt/y
file format: raw
virtual size: 127G (136899993600 bytes)
disk size: 0
=============================================================

(The 140G image was truncated with no warning or error.)

With the patch, I get:

=============================================================
root@ip-10-38-123-242:~/qemu-fixed# ./qemu-img info /mnt/140g-dynamic.vhd
qemu-img: Could not open '/mnt/140g-dynamic.vhd': File too large
root@ip-10-38-123-242:~/qemu-fixed# ./qemu-img convert -f vpc -O raw /mnt/140g-dynamic.vhd /mnt/y
qemu-img: Could not open '/mnt/140g-dynamic.vhd': File too large
qemu-img: Could not open '/mnt/140g-dynamic.vhd'
=============================================================

See https://bugs.launchpad.net/qemu/+bug/814222 for details.

Signed-off-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-08-01 12:10:28 +02:00
Mitnick Lyu 2d56a546a7 vpc.c: Use get_option_parameter() does the search
Use get_option_parameter() to instead of duplicating the loop, and
use BDRV_SECTOR_SIZE to instead of 512

Signed-off-by: Mitnick Lyu <mitnick.lyu@gmail.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-04-13 12:31:41 +02:00
Blue Swirl f0ff243a16 vpc: fix a file descriptor leak
Fix a file descriptor leak, reported by cppcheck:
[/src/qemu/block/vpc.c:524]: (error) Resource leak: fd

Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2011-01-12 19:49:00 +00:00
Kevin Wolf 80465c5016 block: Remove unused s->hd in various drivers
All drivers use bs->file instead of s->hd for quite a while now, so it's time
to remove s->hd.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2010-11-24 17:31:06 +01:00
Kevin Wolf 4a4111851f vpc: Implement bdrv_flush
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-11-04 12:52:16 +01:00
Kevin Wolf 078a458e07 vpc: Use bdrv_(p)write_sync for metadata writes
Use bdrv_(p)write_sync to ensure metadata integrity in case of a crash.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-06-22 14:38:02 +02:00