The qemu-img.c:is_not_zero() function checks if a buffer contains all
zeroes. This function will come in handy for zero-detection in the
block layer, so clean it up and move it to cutils.c.
Note that the function now returns true if the buffer is all zeroes.
This avoids the double-negatives (i.e. !is_not_zero()) that the old
function can cause in callers.
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Backing files may be smaller than the corresponding COW file. When
reading directly from the backing file, qemu-img rebase must consider
this and assume zero sectors after the end of backing files.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
strtosz_suffix() fails unless the size is followed by 0, whitespace or
','. Useless here, because we need to fail for any junk following the
size, even if it starts with whitespace or ','. Check manually.
Things like "qemu-img create xxx 1024," and "qemu-img convert -S '1024
junk'" are now caught.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Only qcow and qcow2 can do compression at all, and they require unallocated
clusters when writing the compressed data.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
By default, require 4k of consecutive zero bytes for qemu-img to make the
output file sparse by not issuing a write request for the zeroed parts. Add an
-S option to allow users to tune this setting.
This helps to avoid situations where a lot of zero sectors and data sectors are
mixed and qemu-img tended to issue many tiny 512 byte writes.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Now that you can use cache=none for the output file in qemu-img, we should
properly align our buffers so that raw-posix doesn't have to use its (smaller)
bounce buffer.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
This patch adds -drive cache=directsync for O_DIRECT | O_SYNC host file
I/O with no disk write cache presented to the guest.
This mode is useful when guests may not be sending flushes when
appropriate and therefore leave data at risk in case of power failure.
When cache=directsync is used, write operations are only completed to
the guest when data is safely on disk.
This new mode is like cache=writethrough but it bypasses the host page
cache.
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This patch introduces bdrv_parse_cache_flags() which sets open flags
given a cache mode. Previously this was duplicated in blockdev.c and
qemu-img.c.
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
qemu-img.c wants to count allocated file size of image. Previously it
counts a single bs->file by 'stat' or Window API. As VMDK introduces
multiple file support, the operation becomes format specific with
platform specific meanwhile.
The functions are moved to block/raw-{posix,win32}.c and qemu-img.c calls
bdrv_get_allocated_file_size to count the bs. And also added VMDK code
to count his own extents.
Signed-off-by: Fam Zheng <famcool@gmail.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
qemu-img currently writes disk images using writeback and filling
up the cache buffers which are then flushed by the kernel preventing
other processes from accessing the storage.
This is particularly bad in cluster environments where time-based
algorithms might be in place and accessing the storage within
certain timeouts is critical.
This patch adds the option to choose a cache method when writing
disk images.
Signed-off-by: Federico Simoncelli <fsimonce@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
error_report() prepends location, and appends a newline. The message
constructed from the arguments should not contain a newline. Fix the
obvious offenders.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
I run qemu-img under profiler and realized, that most of CPU time is
consumed by is_not_zero() function. I had made a couple of optimizations
on it and got the following output for `time qemu-img convert -O qcow2
volume.qcow2 snapshot.qcow2`:
Original qemu-img:
real 0m56.159s
user 0m34.670s
sys 0m12.079s
Patched qemu-img:
real 0m34.805s
user 0m18.445s
sys 0m12.552s
Signed-off-by: Dmitry Konishchev <konishchev@gmail.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
For shrinking images, you're supposed to use a negative size. However, the
leading minus makes getopt think that it's an option and so you get the help
text if you don't use -- like in 'qemu-img resize test.img -- -1G'.
This patch handles the size first and removes it from the argument list so that
getopt won't even try to interpret it and you don't need -- any more.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
QEMU can drop a backing file so that an image file no longer depends on
the backing file, but this feature has not been exposed in qemu-img.
This is useful in an image streaming usecase or when an image file has
been fully allocated and no reads can hit the backing file anymore.
Since the dropping the backing file can make the image unusable, only
allow this when the unsafe flag has been set.
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
bdrv_delete must not be called for a NULL BlockDriverState.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
This adds the basic infrastructure for supporting progress output
on the command line, as well as progress support for qemu-img commands
'rebase' and 'convert'.
Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Output the error message string of the bdrv_open return code. Also set a
non-empty device name for the images because the unknown feature error message
includes it.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Anthony Liguori <aliguori@us.ibm.com>
strtosz() needs to return a 64 bit type even on 32 bit
architectures. Otherwise qemu-img will fail to create disk
images >= 2GB
Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
None of the other qemu-img subcommands uses writethrough, and there's no reason
why snapshot should be special.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
This patch re-factors img_create() moving the code doing the actual
work into block.c where it can be shared with QEMU. This is needed to
be able to create images from QEMU to be used for live snapshots.
Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Call error_set_progname during the qemu-img initialization, so that error
messages printed with error_report() use the right prefix.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This cleans up the handling of image size in img_create() by parsing
the value early, and then only setting it once if a value has been
added as the last argument to the command line.
Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The qemu-img create command should check the backing format to ensure
only image files with valid backing formats are created. By checking in
qemu-img.c we can print a useful error message.
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Free option parameter lists in the img_create() error return path.
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
If -6 or -e is specified, an error message is printed and we exit. It
does not print help() to avoid the error message getting lost in the
noise.
Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This patch changes qemu-img to exit if an unknown option is detected,
instead of trying to continue with a set of arguments which may be
incorrect.
Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This consolidates the printing of block driver options in
print_block_option_help() which is called from both img_create() and
img_convert().
This allows for the "?" detection to be done just after the parsing of
options and the filename, instead of half way down the codepath of
these functions.
Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This allows for jumping to 'out:' consistently for error exit.
Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The old -B option caused a backing file to be used for the converted image and
to avoid copying clusters from the old backing file. When replaced with
-obacking_file, qemu-img convert does assign the backing file to the new image,
but it doesn't realize that it should avoid copying clusters from the backing
file.
This patch checks the -o options for a backing_file and applies the same logic
as for -B in this case.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
In order to backup snapshots, created from QCOW2 iamge, we want to copy snapshots out of QCOW2 disk to a seperate storage.
The following patch adds a new option in "qemu-img": qemu-img convert -f qcow2 -O qcow2 -s snapshot_name src_img bck_img.
Right now, it only supports to copy the full snapshot, delta snapshot is on the way.
Changes from V1: all the comments from Kevin are addressed:
Add read-only checking
Fix coding style
Change the name from bdrv_snapshot_load to bdrv_snapshot_load_tmp
Signed-off-by: Disheng Su <edison@cloud.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
If qemu-img crashes during the conversion, the user will throw away the broken
output file anyway and start over. So no need to be too cautious.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We never write to a backing file, so opening rw is useless. It just means that
you can't rebase on top of a file for which you don't have write permissions.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
People think that their images are corrupted when in fact there are just some
leaked clusters. Differentiating several error cases should make the messages
more comprehensible.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This patch removes exit(1) from error(), and properly releases
resources such as a block driver and an allocated memory.
For testing the Sheepdog block driver with qemu-iotests, it is
necessary to call bdrv_delete() before the program exits. Because the
driver releases the lock of VM images in the close handler.
Signed-off-by: MORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This patch enables protocol drivers to use their create options which
are not supported by the format. For example, protcol drivers can use
a backing_file option with raw format.
Signed-off-by: MORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
qemu-img rebase must always give clusters in the COW file priority over those
in the backing file. As it failed to use number of non-allocated clusters but
assumed the maximum, it was possible that allocated clusters were taken from
the backing file instead, leading to a corrupted output image.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This patch adds a 'resize' command to grow/shrink disk images. This
allows changing the size of disk images without copying to a new image
file. Currently only raw files support resize.
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This fixes the problem that qemu-img's use of no_zero_init only considered the
no_zero_init flag of the format driver, but not of the underlying protocols.
Between the raw/file split and this fix, converting to host devices is broken.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
