Re: [PATCH] block/copy-before-write: use uint64_t for timeout in nanoseconds

[Philippe Mathieu-Daudé]

Hi Fiona,

On 29/4/24 16:19, Fiona Ebner wrote:

Not everybody uses an email client that shows the patch content just
after the subject (your first lines wasn't making sense at first).

Simply duplicating the subject helps to understand:

  Use uint64_t for timeout in nanoseconds ...

> rather than the uint32_t for which the maximum is slightly more than 4
> seconds and larger values would overflow. The QAPI interface allows
> specifying the number of seconds, so only values 0 to 4 are safe right
> now, other values lead to a much lower timeout than a user expects.
>
> The block_copy() call where this is used already takes a uint64_t for
> the timeout, so no change required there.
>
> Fixes: 6db7fd1ca9 ("block/copy-before-write: implement cbw-timeout option")
> Reported-by: Friedrich Weber <f.weber@proxmox.com>
> Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
> ---
>   block/copy-before-write.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/block/copy-before-write.c b/block/copy-before-write.c
> index 8aba27a71d..026fa9840f 100644
> --- a/block/copy-before-write.c
> +++ b/block/copy-before-write.c
> @@ -43,7 +43,7 @@ typedef struct BDRVCopyBeforeWriteState {
>       BlockCopyState *bcs;
>       BdrvChild *target;
>       OnCbwError on_cbw_error;
> -    uint32_t cbw_timeout_ns;
> +    uint64_t cbw_timeout_ns;

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