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: NKevin 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: NDisheng Su <edison@cloud.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Signed-off-by: NStefan Weil <weil@mail.berlios.de>
Signed-off-by: NBlue Swirl <blauwirbel@gmail.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: NKevin 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: NKevin 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: NKevin 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: NMORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp>
Signed-off-by: NKevin 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: NMORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Signed-off-by: NBlue Swirl <blauwirbel@gmail.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: NKevin 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: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin 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: NKevin Wolf <kwolf@redhat.com>

It should be BDRV_O_FLAGS instead of BRDV_O_FLAGS.
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Several commands have code to create a BlockDriverState and open a file.
The bdrv_new_open() function can be used to perform these steps.  This
patch converts the qemu-img commands to actually use bdrv_new_open().

Replaced the bdrv_new_open() 'readonly' argument with bdrv_open()-style
flags to support generic flags like BDRV_O_NO_BACKING.
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

What is known today as bdrv_open2 becomes the new bdrv_open. All remaining
callers of the old function are converted to the new one. In some places they
even know the right format, so they should have used bdrv_open2 from the
beginning.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Now that we changed all create calls to return errno, just print it.
Signed-off-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Allow the user to specify the format of the image to rebase.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

When qemu-img can't open the new backing file for a rebase, it prints an error
message which contains the file name of the old backing file. This is wrong,
obviously.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

This fixes a possible read beyond the end of the temporary buffers used for
comparing data in the old and the new backing file.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

The default stack size of PE is 1MB on win32 and IO_BUF_SIZE in
img_convert() & img_rebase() is 2MB, so qemu-img will crash when doing
"convert" & "rebase" on win32.
Although we can improve the stack size of PE to resolve it, I think we
should avoid using the huge stack variables.
Signed-off-by: NTeLeMan <geleman@gmail.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Commit 03cbdac7 "Disable fall-back to read-only when cannot open drive's
file for read-write" result in read-only image can't be used as backed
image in qemu-img.

Cc: Naphtali Sprei <nsprei@redhat.com>
Signed-off-by: NSheng Yang <sheng@linux.intel.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Other choices include using "(printf)", but this one is not bad in
terms of readability.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Nmalc <av1474@comtv.ru>

This reverts commit bc5b6004.

Signed-off-by: Nmalc <av1474@comtv.ru>

Found some places that seems needs this explicitly, now that
read-write is not the default.
Signed-off-by: NNaphtali Sprei <nsprei@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Clean-up a little bit the RW related bits of BDRV_O_FLAGS. BDRV_O_RDONLY gone (and so is BDRV_O_ACCESS). Default value for bdrv_flags (0/zero) is READ-ONLY. Need to explicitly request READ-WRITE.

Instead of using the field 'readonly' of the BlockDriverState struct for passing the request,
pass the request in the flags parameter to the function.
Signed-off-by: NNaphtali Sprei <nsprei@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

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: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

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: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Valid description taken from qemu-img.texi, although it would be better
to have this information recorded in only one place.
Signed-off-by: NPierre Riteau <Pierre.Riteau@irisa.fr>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

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: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

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: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

A size of 0 should be valid and cannot be treated as "missing value". Use -1
for this purpose instead.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

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: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

In the very least, a change like this requires discussion on the list.

The naming convention is goofy and it causes a massive merge problem.  Something
like this _must_ be presented on the list first so people can provide input
and cope with it.

This reverts commit 99a0949b.
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Some not so obvious bits, slirp and Xen were left alone for the time
being.
Signed-off-by: Nmalc <av1474@comtv.ru>

Make 'qemu-img convert' copies unallocated parts of the source image
when -B option was not specified.
Signed-off-by: NAkkarit Sangpetch <asangpet@andrew.cmu.edu>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Use hxtool to generate the 'command syntax' section of qemu-img's help
message, and the corresponding section of the texinfo documentation.

This has the side-effect of adding 'check' to this list of commands in
the texinfo documentation.
Signed-off-by: NStuart Brady <stuart.brady@gmail.com>

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: NKevin Wolf <kwolf@redhat.com>

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: NKevin Wolf <kwolf@redhat.com>