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2 commits

Author SHA1 Message Date
Max Reitz 57284d2ada iotests: Enable fuse for many tests
Many tests (that do not support generic protocols) can run just fine
with FUSE-exported images, so allow them to.  Note that this is no
attempt at being definitely complete.  There are some tests that might
be modified to run on FUSE, but this patch still skips them.  This patch
only tries to pick the rather low-hanging fruits.

Note that 221 and 250 only pass when .lseek is correctly implemented,
which is only possible with a libfuse that is 3.8 or newer.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20201027190600.192171-20-mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-12-11 17:52:40 +01:00
Alberto Garcia f2208fdc5b block: Reject misaligned write requests with BDRV_REQ_NO_FALLBACK
The BDRV_REQ_NO_FALLBACK flag means that an operation should only be
performed if it can be offloaded or otherwise performed efficiently.

However a misaligned write request requires a RMW so we should return
an error and let the caller decide how to proceed.

This hits an assertion since commit c8bb23cbdb if the required
alignment is larger than the cluster size:

qemu-img create -f qcow2 -o cluster_size=2k img.qcow2 4G
qemu-io -c "open -o driver=qcow2,file.align=4k blkdebug::img.qcow2" \
        -c 'write 0 512'
qemu-io: block/io.c:1127: bdrv_driver_pwritev: Assertion `!(flags & BDRV_REQ_NO_FALLBACK)' failed.
Aborted

The reason is that when writing to an unallocated cluster we try to
skip the copy-on-write part and zeroize it using BDRV_REQ_NO_FALLBACK
instead, resulting in a write request that is too small (2KB cluster
size vs 4KB required alignment).

Signed-off-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-10-14 17:12:48 +02:00