Re: [PATCH] block: allocate aligned write buffer for 'truncate -m full'

["Denis V. Lunev" <den@virtuozzo.com>]

On 12/11/23 11:55, Andrey Drobyshev wrote:
> In case we're truncating an image opened with O_DIRECT, we might get
> -EINVAL on write with unaligned buffer.  In particular, when running
> iotests/298 with '-nocache' we get:
>
> qemu-io: Failed to resize underlying file: Could not write zeros for
> preallocation: Invalid argument
>
> Let's just allocate the buffer using qemu_blockalign0() instead.
>
> Signed-off-by: Andrey Drobyshev <andrey.drobyshev@virtuozzo.com>
> ---
>   block/file-posix.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/block/file-posix.c b/block/file-posix.c
> index b862406c71..cee8de510b 100644
> --- a/block/file-posix.c
> +++ b/block/file-posix.c
> @@ -2354,7 +2354,7 @@ static int handle_aiocb_truncate(void *opaque)
>               goto out;
>           }
>   
> -        buf = g_malloc0(65536);
> +        buf = qemu_blockalign0(aiocb->bs, 65536);
>   
>           seek_result = lseek(fd, current_length, SEEK_SET);
>           if (seek_result < 0) {
> @@ -2413,7 +2413,7 @@ out:
>           }
>       }
>   
> -    g_free(buf);
> +    qemu_vfree(buf);
>       return result;
>   }
>   
Reviewed-by: Denis V. Lunev <den@openvz.org>