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| author | Max Reitz | 2019-07-24 19:12:30 +0200 |
|---|---|---|
| committer | Max Reitz | 2019-08-19 17:13:26 +0200 |
| commit | cdf3bc934ad1e5319b03f2c85f381f5ffd2f8ca8 (patch) | |
| tree | 2e8dc4f2b68d10a6439335c1f733e563aaf71ec6 /linux-user/syscall.c | |
| parent | qemu-img: Fix bdrv_has_zero_init() use in convert (diff) | |
| download | qemu-cdf3bc934ad1e5319b03f2c85f381f5ffd2f8ca8.tar.gz qemu-cdf3bc934ad1e5319b03f2c85f381f5ffd2f8ca8.tar.xz qemu-cdf3bc934ad1e5319b03f2c85f381f5ffd2f8ca8.zip | |
mirror: Fix bdrv_has_zero_init() use
bdrv_has_zero_init() only has meaning for newly created images or image
areas. If the mirror job itself did not create the image, it cannot
rely on bdrv_has_zero_init()'s result to carry any meaning.
This is the case for drive-mirror with mode=existing and always for
blockdev-mirror.
Note that we only have to zero-initialize the target with sync=full,
because other modes actually do not promise that the target will contain
the same data as the source after the job -- sync=top only promises to
copy anything allocated in the top layer, and sync=none will only copy
new I/O. (Which is how mirror has always handled it.)
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190724171239.8764-3-mreitz@redhat.com
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Diffstat (limited to 'linux-user/syscall.c')
0 files changed, 0 insertions, 0 deletions