On 9/3/20 8:22 AM, Daniel P. Berrangé wrote:
> Currently at startup if using cache=none on a filesystem lacking
> O_DIRECT such as tmpfs, at startup QEMU prints
>
> qemu-system-x86_64: -drive file=/tmp/foo.img,cache=none: file system may not
> support O_DIRECT
> qemu-system-x86_64: -drive file=/tmp/foo.img,cache=none: Could not open
> '/tmp/foo.img': Invalid argument
>
> while at QMP level the hint is missing, so QEMU reports just
>
> "error": {
> "class": "GenericError",
> "desc": "Could not open '/tmp/foo.img': Invalid argument"
> }
>
> which is close to useless for the end user trying to figure out what
> they did wrong.
>
> With this change at startup QEMU prints
>
> qemu-system-x86_64: -drive file=/tmp/foo.img,cache=none: Unable to open
> '/tmp/foo.img': filesystem does not support O_DIRECT
>
> while at the QMP level QEMU reports a massively more informative
>
> "error": {
> "class": "GenericError",
> "desc": "Unable to open '/tmp/foo.img': filesystem does not support
> O_DIRECT"
> }
>
> Reviewed-by: Eric Blake <ebl...@redhat.com>
> Reviewed-by: Philippe Mathieu-Daudé <phi...@redhat.com>
> Reviewed-by: Markus Armbruster <arm...@redhat.com>
> Signed-off-by: Daniel P. Berrangé <berra...@redhat.com>
> ---
Reviewed-by: Richard Henderson <richard.hender...@linaro.org>
r~
