The 'qemu-img convert -h' advertise that the default cache mode is
'writeback', while in fact it is 'unsafe'.

This patch 1) fix the help manual and 2) let bdrv_close() call bdrv_flush()

2) is needed because some backend storage doesn't have a self-flush
mechanism(for e.g., sheepdog), so we need to call bdrv_flush() to make
sure the image is really writen to the storage instead of hanging around
writeback cache forever.
Signed-off-by: NLiu Yuan <tailai.ly@taobao.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Some block drivers can verify their image files are clean or not. So we can show
it while using "qemu-img info".
Signed-off-by: NDong Xu Wang <wdongxu@linux.vnet.ibm.com>
Reviewed-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Discussion can be found at:
http://patchwork.ozlabs.org/patch/128730/

This patch add image fragmentation statistics while using qemu-img check.
Signed-off-by: NDong Xu Wang <wdongxu@linux.vnet.ibm.com>
Reviewed-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

qemu-img resize has some limitations with qcow2, but the user is only
told that "this image format does not support resize". Quite confusing,
so add some more detailed error_report() calls and change "this image
format" into "this image".
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>

[root@f15 qemu]# qemu-img info /home/zwu/work/misc/rh6.img
image: /home/zwu/work/misc/rh6.img
file format: qed
virtual size: 4.0G (4294967296 bytes)
disk size: 1.2G
cluster_size: 65536
Segmentation fault (core dumped)

Today when i were fixing another issue, i found this issue; After simple
investigation, i found that the required clock vm_clock is not created
for qemu tool.
Signed-off-by: NZhi Yong Wu <wuzhy@linux.vnet.ibm.com>
Reviewed-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

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: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin 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: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NStefan 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: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NAnthony 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: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NStefan 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: NKevin Wolf <kwolf@redhat.com>

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

qemu_malloc/qemu_free no longer exist after this commit.
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.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: NFam Zheng <famcool@gmail.com>
Reviewed-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin 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: NFederico Simoncelli <fsimonce@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

error_report() prepends the location already.  Example:

$ qemu-img convert -6
qemu-img: qemu-img: option -6 is deprecated, please use '-o compat6' instead!
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.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: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NStefan 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: NDmitry Konishchev <konishchev@gmail.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Signed-off-by: NJes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: NKevin 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: NKevin 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: NAnthony Liguori <aliguori@us.ibm.com>
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

bdrv_delete must not be called for a NULL BlockDriverState.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NStefan 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: NJes Sorensen <Jes.Sorensen@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin 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: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NAnthony 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: NJes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: NKevin 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: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>

It's an indirect call to qemu_malloc, which never returns an error.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Signed-off-by: NJes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.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: NJes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: NKevin 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: NKevin 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: NJes Sorensen <Jes.Sorensen@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin 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: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Free option parameter lists in the img_create() error return path.
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin 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: NJes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Signed-off-by: NJes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: NKevin 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: NJes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Signed-off-by: NJes Sorensen <Jes.Sorensen@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin 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: NJes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>