Re: [Qemu-devel] [PATCH 4/6] block-backend: Add blk_aio_copy_range

[Stefan Hajnoczi]

On Fri, Jun 08, 2018 at 02:04:15PM +0800, Fam Zheng wrote:

Why is a new _aio_ interface needed?  Aren't the copy_range callers
coroutines?

> Signed-off-by: Fam Zheng <address@hidden>
> ---
>  block/block-backend.c          | 36 ++++++++++++++++++++++++++++++++++
>  include/sysemu/block-backend.h |  4 ++++
>  2 files changed, 40 insertions(+)
> 
> diff --git a/block/block-backend.c b/block/block-backend.c
> index e20a204bee..36d928e13d 100644
> --- a/block/block-backend.c
> +++ b/block/block-backend.c
> @@ -1213,6 +1213,14 @@ typedef struct BlkRwCo {
>              unsigned long int req;
>              void *buf;
>          } ioctl;
> +
> +        struct {
> +            BlockBackend *dst_blk;
> +            int64_t src_off;
> +            int64_t dst_off;
> +            int bytes;
> +            BdrvRequestFlags flags;
> +        } copy_range;
>      };
>  
>  } BlkRwCo;
> @@ -1505,6 +1513,34 @@ BlockAIOCB *blk_aio_pwritev(BlockBackend *blk, int64_t 
> offset,
>      return blk_aio_prwv(blk, &rwco, blk_aio_write_entry, cb, opaque);
>  }
>  
> +static void blk_aio_copy_range_entry(void *opaque)
> +{
> +    BlkAioEmAIOCB *acb = opaque;
> +    BlkRwCo *rwco = &acb->rwco;
> +
> +    rwco->ret = blk_co_copy_range(rwco->blk, rwco->copy_range.src_off,
> +                                  rwco->copy_range.dst_blk,
> +                                  rwco->copy_range.dst_off,
> +                                  rwco->copy_range.bytes,
> +                                  rwco->copy_range.flags);
> +    blk_aio_complete(acb);
> +}
> +
> +BlockAIOCB *blk_aio_copy_range(BlockBackend *src, int64_t src_offset,
> +                               BlockBackend *dst, int64_t dst_offset,
> +                               uint64_t bytes, BdrvRequestFlags flags,
> +                               BlockCompletionFunc *cb, void *opaque)
> +{
> +    BlkRwCo rwco = (BlkRwCo) {
> +        .copy_range.src_off = src_offset,
> +        .copy_range.dst_blk = dst,
> +        .copy_range.dst_off = dst_offset,
> +        .copy_range.bytes = bytes,
> +        .copy_range.flags = flags,
> +    };
> +    return blk_aio_prwv(src, &rwco, blk_aio_copy_range_entry, cb, opaque);
> +}
> +
>  static void blk_aio_flush_entry(void *opaque)
>  {
>      BlkAioEmAIOCB *acb = opaque;
> diff --git a/include/sysemu/block-backend.h b/include/sysemu/block-backend.h
> index 8d03d493c2..ea121eac3f 100644
> --- a/include/sysemu/block-backend.h
> +++ b/include/sysemu/block-backend.h
> @@ -147,6 +147,10 @@ BlockAIOCB *blk_aio_flush(BlockBackend *blk,
>                            BlockCompletionFunc *cb, void *opaque);
>  BlockAIOCB *blk_aio_pdiscard(BlockBackend *blk, int64_t offset, int bytes,
>                               BlockCompletionFunc *cb, void *opaque);
> +BlockAIOCB *blk_aio_copy_range(BlockBackend *src, int64_t src_offset,
> +                               BlockBackend *dst, int64_t dst_offset,
> +                               uint64_t bytes, BdrvRequestFlags flags,
> +                               BlockCompletionFunc *cb, void *opaque);
>  void blk_aio_cancel(BlockAIOCB *acb);
>  void blk_aio_cancel_async(BlockAIOCB *acb);
>  int blk_co_ioctl(BlockBackend *blk, unsigned long int req, void *buf);
> -- 
> 2.17.0
>

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