Re: [Qemu-devel] [PATCH v3 13/29] block: Introduce bdrv_co_do_pwritev()

["Benoît Canet" <benoit.canet@irqsave.net>]

Le Friday 17 Jan 2014 à 15:15:03 (+0100), Kevin Wolf a écrit :
> This is going to become the bdrv_co_do_preadv() equivalent for writes.
> In this patch, however, just a function taking byte offsets is created,
> it doesn't align anything yet.
> 
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> ---
>  block.c | 24 ++++++++++++++++++------
>  1 file changed, 18 insertions(+), 6 deletions(-)
> 
> diff --git a/block.c b/block.c
> index fe55217..328f592 100644
> --- a/block.c
> +++ b/block.c
> @@ -3016,8 +3016,8 @@ static int coroutine_fn bdrv_aligned_pwritev(BlockDriverState *bs,
>  /*
>   * Handle a write request in coroutine context
>   */
> -static int coroutine_fn bdrv_co_do_writev(BlockDriverState *bs,
> -    int64_t sector_num, int nb_sectors, QEMUIOVector *qiov,
> +static int coroutine_fn bdrv_co_do_pwritev(BlockDriverState *bs,
> +    int64_t offset, unsigned int bytes, QEMUIOVector *qiov,
>      BdrvRequestFlags flags)
>  {
>      int ret;
> @@ -3028,21 +3028,33 @@ static int coroutine_fn bdrv_co_do_writev(BlockDriverState *bs,
>      if (bs->read_only) {
>          return -EACCES;
>      }
> -    if (bdrv_check_request(bs, sector_num, nb_sectors)) {
> +    if (bdrv_check_byte_request(bs, offset, bytes)) {
>          return -EIO;
>      }
>  
>      /* throttling disk I/O */
>      if (bs->io_limits_enabled) {
> -        bdrv_io_limits_intercept(bs, nb_sectors, true);
> +        /* TODO Switch to byte granularity */
> +        bdrv_io_limits_intercept(bs, bytes >> BDRV_SECTOR_BITS, true);
>      }
>  
> -    ret = bdrv_aligned_pwritev(bs, sector_num << BDRV_SECTOR_BITS,
> -                               nb_sectors << BDRV_SECTOR_BITS, qiov, flags);
> +    ret = bdrv_aligned_pwritev(bs, offset, bytes, qiov, flags);
>  
>      return ret;
>  }
>  
> +static int coroutine_fn bdrv_co_do_writev(BlockDriverState *bs,
> +    int64_t sector_num, int nb_sectors, QEMUIOVector *qiov,
> +    BdrvRequestFlags flags)
> +{
> +    if (nb_sectors < 0 || nb_sectors > (INT_MAX >> BDRV_SECTOR_BITS)) {
> +        return -EINVAL;
> +    }
> +
> +    return bdrv_co_do_pwritev(bs, sector_num << BDRV_SECTOR_BITS,
> +                              nb_sectors << BDRV_SECTOR_BITS, qiov, flags);
> +}
> +
>  int coroutine_fn bdrv_co_writev(BlockDriverState *bs, int64_t sector_num,
>      int nb_sectors, QEMUIOVector *qiov)
>  {
> -- 
> 1.8.1.4
> 
> 

Reviewed-by: Benoit Canet <benoit@irqsave.net>