Re: [Qemu-block] [PATCH v3 09/20] mirror: Update signature of mirror_clip_sectors()

[Kevin Wolf]

Am 27.06.2017 um 21:24 hat Eric Blake geschrieben:
> Rather than having a void function that modifies its input
> in-place as the output, change the signature to reduce a layer
> of indirection and return the result.
> 
> Suggested-by: John Snow 
> Signed-off-by: Eric Blake 
> Reviewed-by: John Snow 

Reviewed-by: Kevin Wolf 

Re: [Qemu-block] [PATCH v3 09/20] mirror: Update signature of mirror_clip_sectors()

[Jeff Cody]

On Tue, Jun 27, 2017 at 02:24:47PM -0500, Eric Blake wrote:
> Rather than having a void function that modifies its input
> in-place as the output, change the signature to reduce a layer
> of indirection and return the result.
> 
> Suggested-by: John Snow 
> Signed-off-by: Eric Blake 
> Reviewed-by: John Snow 
> 

Reviewed-by: Jeff Cody 

> ---
> v2: new patch
> ---
>  block/mirror.c | 15 ---
>  1 file changed, 8 insertions(+), 7 deletions(-)
> 
> diff --git a/block/mirror.c b/block/mirror.c
> index af27bcc..1a43304 100644
> --- a/block/mirror.c
> +++ b/block/mirror.c
> @@ -176,12 +176,12 @@ static void mirror_read_complete(void *opaque, int ret)
>  aio_context_release(blk_get_aio_context(s->common.blk));
>  }
> 
> -static inline void mirror_clip_sectors(MirrorBlockJob *s,
> -   int64_t sector_num,
> -   int *nb_sectors)
> +static inline int mirror_clip_sectors(MirrorBlockJob *s,
> +  int64_t sector_num,
> +  int nb_sectors)
>  {
> -*nb_sectors = MIN(*nb_sectors,
> -  s->bdev_length / BDRV_SECTOR_SIZE - sector_num);
> +return MIN(nb_sectors,
> +   s->bdev_length / BDRV_SECTOR_SIZE - sector_num);
>  }
> 
>  /* Round sector_num and/or nb_sectors to target cluster if COW is needed, and
> @@ -216,7 +216,8 @@ static int mirror_cow_align(MirrorBlockJob *s,
>  }
>  /* Clipping may result in align_nb_sectors unaligned to chunk boundary, 
> but
>   * that doesn't matter because it's already the end of source image. */
> -mirror_clip_sectors(s, align_sector_num, &align_nb_sectors);
> +align_nb_sectors = mirror_clip_sectors(s, align_sector_num,
> +   align_nb_sectors);
> 
>  ret = align_sector_num + align_nb_sectors - (*sector_num + *nb_sectors);
>  *sector_num = align_sector_num;
> @@ -445,7 +446,7 @@ static uint64_t coroutine_fn 
> mirror_iteration(MirrorBlockJob *s)
>  return 0;
>  }
> 
> -mirror_clip_sectors(s, sector_num, &io_sectors);
> +io_sectors = mirror_clip_sectors(s, sector_num, io_sectors);
>  switch (mirror_method) {
>  case MIRROR_METHOD_COPY:
>  io_sectors = mirror_do_read(s, sector_num, io_sectors);
> -- 
> 2.9.4
> 

[Qemu-block] [PATCH v3 09/20] mirror: Update signature of mirror_clip_sectors()

[Eric Blake]

Rather than having a void function that modifies its input
in-place as the output, change the signature to reduce a layer
of indirection and return the result.

Suggested-by: John Snow 
Signed-off-by: Eric Blake 
Reviewed-by: John Snow 

---
v2: new patch
---
 block/mirror.c | 15 ---
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/block/mirror.c b/block/mirror.c
index af27bcc..1a43304 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -176,12 +176,12 @@ static void mirror_read_complete(void *opaque, int ret)
 aio_context_release(blk_get_aio_context(s->common.blk));
 }

-static inline void mirror_clip_sectors(MirrorBlockJob *s,
-   int64_t sector_num,
-   int *nb_sectors)
+static inline int mirror_clip_sectors(MirrorBlockJob *s,
+  int64_t sector_num,
+  int nb_sectors)
 {
-*nb_sectors = MIN(*nb_sectors,
-  s->bdev_length / BDRV_SECTOR_SIZE - sector_num);
+return MIN(nb_sectors,
+   s->bdev_length / BDRV_SECTOR_SIZE - sector_num);
 }

 /* Round sector_num and/or nb_sectors to target cluster if COW is needed, and
@@ -216,7 +216,8 @@ static int mirror_cow_align(MirrorBlockJob *s,
 }
 /* Clipping may result in align_nb_sectors unaligned to chunk boundary, but
  * that doesn't matter because it's already the end of source image. */
-mirror_clip_sectors(s, align_sector_num, &align_nb_sectors);
+align_nb_sectors = mirror_clip_sectors(s, align_sector_num,
+   align_nb_sectors);

 ret = align_sector_num + align_nb_sectors - (*sector_num + *nb_sectors);
 *sector_num = align_sector_num;
@@ -445,7 +446,7 @@ static uint64_t coroutine_fn 
mirror_iteration(MirrorBlockJob *s)
 return 0;
 }

-mirror_clip_sectors(s, sector_num, &io_sectors);
+io_sectors = mirror_clip_sectors(s, sector_num, io_sectors);
 switch (mirror_method) {
 case MIRROR_METHOD_COPY:
 io_sectors = mirror_do_read(s, sector_num, io_sectors);
-- 
2.9.4