Re: [PATCH] hw/usb/dev-mtp: Correctly report free space

[Philippe Mathieu-Daudé]

On 18/6/24 02:36, Fabio D'Urso wrote:
> In order to compute the amount of free space (in bytes), the number
> of available blocks (f_bavail) should be multiplied by the block
> size (f_frsize) instead of the total number of blocks (f_blocks).
>
> Signed-off-by: Fabio D'Urso <fdurso@google.com>
> ---
>   hw/usb/dev-mtp.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/hw/usb/dev-mtp.c b/hw/usb/dev-mtp.c
> index 7e4a0765ae..554b397e88 100644
> --- a/hw/usb/dev-mtp.c
> +++ b/hw/usb/dev-mtp.c
> @@ -886,7 +886,7 @@ static MTPData *usb_mtp_get_storage_info(MTPState *s, 
> MTPControl *c)
>       rc = statvfs(s->root, &buf);
>       if (rc == 0) {
>           usb_mtp_add_u64(d, (uint64_t)buf.f_frsize * buf.f_blocks);
> -        usb_mtp_add_u64(d, (uint64_t)buf.f_bavail * buf.f_blocks);
> +        usb_mtp_add_u64(d, (uint64_t)buf.f_frsize * buf.f_bavail);

Indeed (USB MTP Spec v1.1, 5.2.2.5 "Free Space In Bytes").

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>

>           usb_mtp_add_u32(d, buf.f_ffree);
>       } else {
>           usb_mtp_add_u64(d, 0xffffffff);