All callers of get_sector_offset() pass write=false and err=NULL. Remove
the parameters.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
Based on my block branch, specifically Peter's 'block/vpc.c: Handle write
failures in get_image_offset()'

 block/vpc.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/block/vpc.c b/block/vpc.c
index bccc981..471f9ab 100644
--- a/block/vpc.c
+++ b/block/vpc.c
@@ -508,10 +508,9 @@ static inline int64_t get_image_offset(BlockDriverState *bs, uint64_t offset,
 }
 
 static inline int64_t get_sector_offset(BlockDriverState *bs,
-                                        int64_t sector_num, bool write,
-                                        int *err)
+                                        int64_t sector_num)
 {
-    return get_image_offset(bs, sector_num * BDRV_SECTOR_SIZE, write, err);
+    return get_image_offset(bs, sector_num * BDRV_SECTOR_SIZE, false, NULL);
 }
 
 /*
@@ -721,7 +720,7 @@ static int64_t coroutine_fn vpc_co_get_block_status(BlockDriverState *bs,
                (sector_num << BDRV_SECTOR_BITS);
     }
 
-    offset = get_sector_offset(bs, sector_num, false, NULL);
+    offset = get_sector_offset(bs, sector_num);
     start = offset;
     allocated = (offset != -1);
     *pnum = 0;
@@ -744,7 +743,7 @@ static int64_t coroutine_fn vpc_co_get_block_status(BlockDriverState *bs,
         if (nb_sectors == 0) {
             break;
         }
-        offset = get_sector_offset(bs, sector_num, false, NULL);
+        offset = get_sector_offset(bs, sector_num);
     } while (offset == -1);
 
     return 0;
-- 
1.8.3.1

On 13 July 2017 at 13:37, Kevin Wolf <kwolf@redhat.com> wrote:
> All callers of get_sector_offset() pass write=false and err=NULL. Remove
> the parameters.
>
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> ---
> Based on my block branch, specifically Peter's 'block/vpc.c: Handle write
> failures in get_image_offset()'
>
>  block/vpc.c | 9 ++++-----
>  1 file changed, 4 insertions(+), 5 deletions(-)
>
> diff --git a/block/vpc.c b/block/vpc.c
> index bccc981..471f9ab 100644
> --- a/block/vpc.c
> +++ b/block/vpc.c
> @@ -508,10 +508,9 @@ static inline int64_t get_image_offset(BlockDriverState *bs, uint64_t offset,
>  }
>
>  static inline int64_t get_sector_offset(BlockDriverState *bs,
> -                                        int64_t sector_num, bool write,
> -                                        int *err)
> +                                        int64_t sector_num)
>  {
> -    return get_image_offset(bs, sector_num * BDRV_SECTOR_SIZE, write, err);
> +    return get_image_offset(bs, sector_num * BDRV_SECTOR_SIZE, false, NULL);
>  }
>
>  /*
> @@ -721,7 +720,7 @@ static int64_t coroutine_fn vpc_co_get_block_status(BlockDriverState *bs,
>                 (sector_num << BDRV_SECTOR_BITS);
>      }
>
> -    offset = get_sector_offset(bs, sector_num, false, NULL);
> +    offset = get_sector_offset(bs, sector_num);
>      start = offset;
>      allocated = (offset != -1);
>      *pnum = 0;
> @@ -744,7 +743,7 @@ static int64_t coroutine_fn vpc_co_get_block_status(BlockDriverState *bs,
>          if (nb_sectors == 0) {
>              break;
>          }
> -        offset = get_sector_offset(bs, sector_num, false, NULL);
> +        offset = get_sector_offset(bs, sector_num);
>      } while (offset == -1);
>
>      return 0;

Just to copy my remark over from the other thread:
this turns a function that could be used for writes into a function
that doesn't look like it cares whether it's used for reads or
writes but which will actually silently cause disk image
corruption if you do ever use it in a write codepath. That's
a bit of a bear trap as API design goes, which is why I opted
to add the 'err' argument to get_image_offset() rather than
just removing the 'write' argument.

thanks
-- PMM

Am 13.07.2017 um 14:42 hat Peter Maydell geschrieben:
> On 13 July 2017 at 13:37, Kevin Wolf <kwolf@redhat.com> wrote:
> > All callers of get_sector_offset() pass write=false and err=NULL. Remove
> > the parameters.
> >
> > Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> > ---
> > Based on my block branch, specifically Peter's 'block/vpc.c: Handle write
> > failures in get_image_offset()'
> >
> >  block/vpc.c | 9 ++++-----
> >  1 file changed, 4 insertions(+), 5 deletions(-)
> >
> > diff --git a/block/vpc.c b/block/vpc.c
> > index bccc981..471f9ab 100644
> > --- a/block/vpc.c
> > +++ b/block/vpc.c
> > @@ -508,10 +508,9 @@ static inline int64_t get_image_offset(BlockDriverState *bs, uint64_t offset,
> >  }
> >
> >  static inline int64_t get_sector_offset(BlockDriverState *bs,
> > -                                        int64_t sector_num, bool write,
> > -                                        int *err)
> > +                                        int64_t sector_num)
> >  {
> > -    return get_image_offset(bs, sector_num * BDRV_SECTOR_SIZE, write, err);
> > +    return get_image_offset(bs, sector_num * BDRV_SECTOR_SIZE, false, NULL);
> >  }
> >
> >  /*
> > @@ -721,7 +720,7 @@ static int64_t coroutine_fn vpc_co_get_block_status(BlockDriverState *bs,
> >                 (sector_num << BDRV_SECTOR_BITS);
> >      }
> >
> > -    offset = get_sector_offset(bs, sector_num, false, NULL);
> > +    offset = get_sector_offset(bs, sector_num);
> >      start = offset;
> >      allocated = (offset != -1);
> >      *pnum = 0;
> > @@ -744,7 +743,7 @@ static int64_t coroutine_fn vpc_co_get_block_status(BlockDriverState *bs,
> >          if (nb_sectors == 0) {
> >              break;
> >          }
> > -        offset = get_sector_offset(bs, sector_num, false, NULL);
> > +        offset = get_sector_offset(bs, sector_num);
> >      } while (offset == -1);
> >
> >      return 0;
> 
> Just to copy my remark over from the other thread:
> this turns a function that could be used for writes into a function
> that doesn't look like it cares whether it's used for reads or
> writes but which will actually silently cause disk image
> corruption if you do ever use it in a write codepath. That's
> a bit of a bear trap as API design goes, which is why I opted
> to add the 'err' argument to get_image_offset() rather than
> just removing the 'write' argument.

Not sure if this is a problem in practice, but I'll leave it alone for
now. Once all of Eric's patches are in and make .bdrv_get_block_status
byte-based, the function should just go away anyway.

Kevin