Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into staging

Block layer patches:

- qcow2: Fix preallocation on block devices
- backup: Make sure that source and target size match
-

Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into staging

Block layer patches:

- qcow2: Fix preallocation on block devices
- backup: Make sure that source and target size match
- vmdk: Fix zero cluster handling
- Follow-up cleanups and fixes for the truncate changes
- iotests: Skip more tests if required drivers are missing

# gpg: Signature made Fri 08 May 2020 13:39:55 BST
# gpg: using RSA key DC3DEB159A9AF95D3D7456FE7F09B272C88F2FD6
# gpg: issuer "kwolf@redhat.com"
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>" [full]
# Primary key fingerprint: DC3D EB15 9A9A F95D 3D74 56FE 7F09 B272 C88F 2FD6

* remotes/kevin/tags/for-upstream: (30 commits)
block: Drop unused .bdrv_has_zero_init_truncate
vhdx: Rework truncation logic
parallels: Rework truncation logic
ssh: Support BDRV_REQ_ZERO_WRITE for truncate
sheepdog: Support BDRV_REQ_ZERO_WRITE for truncate
rbd: Support BDRV_REQ_ZERO_WRITE for truncate
nfs: Support BDRV_REQ_ZERO_WRITE for truncate
file-win32: Support BDRV_REQ_ZERO_WRITE for truncate
gluster: Drop useless has_zero_init callback
qcow2: Fix preallocation on block devices
iotests/055: Use cache.no-flush for vmdk target
iotests: Backup with different source/target size
backup: Make sure that source and target size match
backup: Improve error for bdrv_getlength() failure
iotests/283: Use consistent size for source and target
iotests: vmdk: Enable zeroed_grained=on by default
vmdk: Flush only once in vmdk_L2update()
vmdk: Don't update L2 table for zero write on zero cluster
vmdk: Fix partial overwrite of zero cluster
vmdk: Fix zero cluster allocation
...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

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qcow2: Avoid integer wraparound in qcow2_co_truncate()

After commit f01643fb8b47e8a70c04bbf45e0f12a9e5bc54de when an image is
extended and BDRV_REQ_ZERO_WRITE is set then the new clusters are
zeroiz

qcow2: Avoid integer wraparound in qcow2_co_truncate()

After commit f01643fb8b47e8a70c04bbf45e0f12a9e5bc54de when an image is
extended and BDRV_REQ_ZERO_WRITE is set then the new clusters are
zeroized.

The code however does not detect correctly situations when the old and
the new end of the image are within the same cluster. The problem can
be reproduced with these steps:

qemu-img create -f qcow2 backing.qcow2 1M
qemu-img create -f qcow2 -F qcow2 -b backing.qcow2 top.qcow2
qemu-img resize --shrink top.qcow2 520k
qemu-img resize top.qcow2 567k

In the last step offset - zero_start causes an integer wraparound.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-Id: <20200504155217.10325-1-berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...