qemu-iotests: Always filter cluster_size out in _make_test_img

Some image formats do have a cluster size, others don't, but there are
tests that work with both sets of images and currently we get failures
because the qemu-img create output doesn't mention the cluster size for
some formats.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
qemu-iotests: Test bdrv_close while AIO is in flight

If the BlockDriverState is closed/freed without draining the AIO
requests first, the request coroutines may work on invalid data and file
descriptors or have some dangling pointers that cause segfaults.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
block: Drain requests in bdrv_close

If an AIO request is in flight that refers to a BlockDriverState that
has been closed and possibly even freed, more or less anything could
happen. I have seen segfaults, -EBADF return values and qcow2 sometimes
actually catches the situation in bdrv_close() and abort()s.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
qemu-io: use main_loop_wait

This will let timers run during aio_read and aio_write commands,
though not during synchronous commands.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
qemu-tool: map vm_clock to rt_clock

QED uses vm_clock timers so that images are not touched during and after
migration.  This however does not apply to qemu-io and qemu-img.
Treat vm_clock as a synonym for rt_clock there, and enable it.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
posix-aio: merge posix_aio_process_queue and posix_aio_read

posix_aio_read already calls qemu_aio_process_queue, and dually
qemu_aio_process_queue is always followed by a select loop that calls
posix_aio_read.

No races are possible, so there is no need for a separate process_queue
callback.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
aio: remove process_queue callback and qemu_aio_process_queue

Both unused after the previous patch.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
aio: return "AIO in progress" state from qemu_aio_wait

The definition of when qemu_aio_flush should loop is much simpler
than it looks.  It just has to call qemu_aio_wait until it makes
no progress and all flush callbacks return false.  qemu_aio_wait
is the logical place to tell the caller about this.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
aio: simplify qemu_aio_wait

The do...while loop can never loop, because select will just not return
0 when invoked with infinite timeout.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
block: add the support to drain throttled requests

Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
[ Iterate until all block devices have processed all requests,
  add comments. - Paolo ]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
block: add mode argument to blockdev-snapshot-sync

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
block: fail live snapshot if disk has no medium

Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
block: fix snapshot on QED

QED's opaque data includes a pointer back to the BlockDriverState.
This breaks when bdrv_append shuffles data between bs_new and bs_top.
To avoid this, add a "rebind" function that tells the driver about
the new relationship between the BlockDriverState and its opaque.

The patch also adds rebind to VVFAT for completeness, even though
it is not used with live snapshots.

Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
block: push bdrv_change_backing_file error checking up from drivers

This check applies to all drivers, but QED lacks it.

Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
block: update in-memory backing file and format

These are needed to print "info block" output correctly.  QCOW2 does this
because it needs it to write the header, but QED does not, and common code
is the right place to do it.

Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
block: open backing file as read-only when probing for size

bdrv_img_create will temporarily open the backing file to probe its size.
However, this could be done with a read-write open if the wrong flags are
passed to bdrv_img_create.  Since there is really no documentation on
what flags can be passed, assume that bdrv_img_create receives the flags
with which the new image will be opened; sanitize them when opening
the backing file.

Reported-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
block: fix allocation size for dirty bitmap

Also reuse elsewhere the new constant for sizeof(unsigned long) * 8.

The dirty bitmap is allocated in bits but declared as unsigned long.
Thus, its memory block is accessed beyond its end unless the image
is a multiple of 64 chunks (i.e. a multiple of 64 MB).

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
qemu-iotests: strip spaces from qemu-img/qemu-io/qemu command lines

A trailing space is left when qemu-img has no arguments, for example if
-nocache is not used.  This becomes an empty argument after split()
and causes qemu-io to fail.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
qemu-io: correctly print non-integer values as decimals

qemu-io's cvtstr function sometimes will incorrectly omit the
decimal part of the number, and sometimes will incorrectly include
it.  This patch fixes both.  The former is more serious, and can
be seen in the patch to 027.out.

The changes to all other files were scripted with sed, so there were
no "surprises" beyond 027.out.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
qemu-io: fix the alloc command

Because sector_num is not updated, the loop would either go on
forever or return garbage.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>