Re: [PATCH] block: BDRV_O_NO_IO for backing file on creation

[Kevin Wolf <kwolf@redhat.com>]

Am 22.06.2021 um 16:00 hat Max Reitz geschrieben:
> When creating an image file with a backing file, we generally try to
> open the backing file (unless -u was specified), mostly to verify that
> it is there, but also to get the file size if none was specified for the
> new image.
> 
> For neither of these things do we need data I/O, and so we can pass
> BDRV_O_NO_IO when opening the backing file.  This allows us to open even
> encrypted backing images without requiring the user to provide a secret.
> 
> This makes the -u switch in iotests 189 and 198 unnecessary (and the
> $size parameter), so drop it, because this way we get regression tests
> for this patch here.
> 
> Fixes: https://gitlab.com/qemu-project/qemu/-/issues/441
> Signed-off-by: Max Reitz <mreitz@redhat.com>

Thanks, applied to the block branch.

Kevin