In case when get_image_offset() returns -1, we do zero out the
corresponding chunk of qiov. So, this should be reported as ZERO.
Note that this changes visible output of "qemu-img map --output=json"
and "qemu-io -c map" commands. For qemu-img map, the change is obvious:
we just mark as zero what is really zero. For qemu-io it's less
obvious: what was unallocated now is allocated.
There is an inconsistency in understanding of unallocated regions in
Qemu: backing-supporting format-drivers return 0 block-status to report
go-to-backing logic for this area. Some protocol-drivers (iscsi) return
0 to report fs-unallocated-non-zero status (i.e., don't occupy space on
disk, read result is undefined).
BDRV_BLOCK_ALLOCATED is defined as something more close to
go-to-backing logic. Still it is calculated as ZERO | DATA, so 0 from
iscsi is treated as unallocated. It doesn't influence backing-chain
behavior, as iscsi can't have backing file. But it does influence
"qemu-io -c map".
We should solve this inconsistency at some future point. Now, let's
just make backing-not-supporting format drivers (vdi in the previous
patch and vpc now) to behave more like backing-supporting drivers
and not report 0 block-status. More over, returning ZERO status is
absolutely valid thing, and again, corresponds to how the other
format-drivers (backing-supporting) work.
After block-status update, it never reports 0, so setting
unallocated_blocks_are_zero doesn't make sense (as the only user of it
is bdrv_co_block_status and it checks unallocated_blocks_are_zero only
for unallocated areas). Drop it.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200528094405.145708-5-vsementsov@virtuozzo.com>
[mreitz: qemu-io -c map as used by iotest 146 now reports everything as
allocated; in order to make the test do something useful, we
use qemu-img map --output=json now]
Signed-off-by: Max Reitz <mreitz@redhat.com>
Commit bff5554843 added "force_size" into the common.filter for
_filter_img_create(), but test 146 still expects it in the output.
Signed-off-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Mixing byte offset and sector allocation counts is a bit
confusing. Also, reporting n/m sectors, where m decreases
according to the remaining size of the file, isn't really
adding any useful information; and reporting an offset at
both the front and end of the line, with large amounts of
whitespace, is pointless. Update the output to use byte
counts and shorter lines, then adjust the affected tests
(./check -qcow2 102, ./check -vpc 146).
Note that 'qemu-io map' is MUCH weaker than 'qemu-img map';
the former only shows which regions of the active layer are
allocated, without regards to where the allocation comes from
or whether the allocated portion is known to read as zero
(because it is using the weaker bdrv_is_allocated()); while the
latter (especially in --output=json mode) reports more details
from bdrv_get_block_status().
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-id: 20170429191419.30051-4-eblake@redhat.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
This tests auto-detection, and overrides, of VHD image sizes created
by Virtual PC, Hyper-V, and Disk2vhd.
This adds three sample images:
hyperv2012r2-dynamic.vhd.bz2 - dynamic VHD image created with Hyper-V
virtualpc-dynamic.vhd.bz2 - dynamic VHD image created with Virtual PC
d2v-zerofilled.vhd.bz2 - dynamic VHD image created with Disk2vhd
Signed-off-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
