Re: [Qemu-devel] [PATCH v3 12/29] block: write: Handle COR dependency after I/O throttling

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

Le Friday 17 Jan 2014 à 15:15:02 (+0100), Kevin Wolf a écrit :
> First waiting for all COR requests to complete and calling the
> throttling function afterwards means that the request could be delayed
> and we still need to wait for the COR request even if it was issued only
> after the throttled write request.
> 
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> Reviewed-by: Max Reitz <mreitz@redhat.com>
> ---
>  block.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/block.c b/block.c
> index 70b72f0..fe55217 100644
> --- a/block.c
> +++ b/block.c
> @@ -2979,6 +2979,10 @@ static int coroutine_fn bdrv_aligned_pwritev(BlockDriverState *bs,
>      assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
>      assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
>  
> +    if (bs->copy_on_read_in_flight) {
> +        wait_for_overlapping_requests(bs, sector_num, nb_sectors);
> +    }
> +
>      tracked_request_begin(&req, bs, sector_num, nb_sectors, true);
>  
>      ret = notifier_with_return_list_notify(&bs->before_write_notifiers, &req);
> @@ -3028,10 +3032,6 @@ static int coroutine_fn bdrv_co_do_writev(BlockDriverState *bs,
>          return -EIO;
>      }
>  
> -    if (bs->copy_on_read_in_flight) {
> -        wait_for_overlapping_requests(bs, sector_num, nb_sectors);
> -    }
> -
>      /* throttling disk I/O */
>      if (bs->io_limits_enabled) {
>          bdrv_io_limits_intercept(bs, nb_sectors, true);
> -- 
> 1.8.1.4
> 
> 

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