block: Improve bdrv_aio_co_cancel_em

Instead of waiting for all requests to complete, wait just for the
specific request that should be cancelled.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
aio: Get rid of qemu_aio_flush()

There are no remaining users, and new users should probably be
using bdrv_drain_all() in the first place.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
block: Factor out bdrv_open_flags

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
block: Avoid second open for format probing

This fixes problems that are caused by the additional open/close cycle
of the existing format probing, for example related to qemu-nbd without
-t option or file descriptor passing.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
virtio-blk: Remove duplicate property definition

For the virtio-blk device (via virtio-pci) the property "config-wce" is
defined in two places.  First, it's defined from the
DEFINE_VIRTIO_BLK_FEATURES macro, second it's defined directly in
virtio-pci, just two lines above the call to that macro.

The direct definition in virtio-pci.c is broken, since it operates on the
'config_wce' field of VirtIOBlkConf, which is never used anywhere else.
Therefore, this patch removes both the extra property definition and the
redundant field it works on.

Cc: Kevin Wolf <kwolf@redhat.com>
Cc: Anthony Liguori <aliguori@us.ibm.com>
Cc: Paul 'Rusty' Russell <rusty@rustcorp.com.au>

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
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>
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>
raw-posix: inline paio_ioctl into hdev_aio_ioctl

clang now warns about an unused function:
  CC    block/raw-posix.o
block/raw-posix.c:707:26: warning: unused function paio_ioctl
[-Wunused-function]
static BlockDriverAIOCB *paio_ioctl(BlockDriverState *bs, int fd,
                         ^
1 warning generated.

because the only use of paio_ioctl() is inside a #if defined(__linux__)
guard and it is static now.

Reported-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>