Libguestfs - May 2019 - [nbdkit PATCH] extents: Do not shorten overlaps by 0

When offset + length == exts->end the code which is shortening the extents is
subtracting 0 from length.  And it is not optimized out.

Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
---
 server/extents.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/server/extents.c b/server/extents.c
index d3d1a15ab97c..c422491601f0 100644
--- a/server/extents.c
+++ b/server/extents.c
@@ -168,7 +168,7 @@ nbdkit_add_extent (struct nbdkit_extents *exts,
     return 0;
 
   /* Shorten extents that overlap the end of the range. */
-  if (offset + length >= exts->end) {
+  if (offset + length > exts->end) {
     overlap = offset + length - exts->end;
     length -= overlap;
   }
-- 
2.21.0

On 5/15/19 7:46 AM, Martin Kletzander wrote:
> When offset + length == exts->end the code which is shortening the
extents is
> subtracting 0 from length.  And it is not optimized out.
> 
> Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
> ---
>  server/extents.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
ACK.
> 
> diff --git a/server/extents.c b/server/extents.c
> index d3d1a15ab97c..c422491601f0 100644
> --- a/server/extents.c
> +++ b/server/extents.c
> @@ -168,7 +168,7 @@ nbdkit_add_extent (struct nbdkit_extents *exts,
>      return 0;
>  
>    /* Shorten extents that overlap the end of the range. */
> -  if (offset + length >= exts->end) {
> +  if (offset + length > exts->end) {
>      overlap = offset + length - exts->end;
>      length -= overlap;
>    }
> 
-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
Virtualization:  qemu.org | libvirt.org

On Wed, May 15, 2019 at 02:46:13PM +0200, Martin Kletzander
wrote:
> When offset + length == exts->end the code which is shortening the
extents is
> subtracting 0 from length.  And it is not optimized out.
> 
> Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
> ---
>  server/extents.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/server/extents.c b/server/extents.c
> index d3d1a15ab97c..c422491601f0 100644
> --- a/server/extents.c
> +++ b/server/extents.c
> @@ -168,7 +168,7 @@ nbdkit_add_extent (struct nbdkit_extents *exts,
>      return 0;
>  
>    /* Shorten extents that overlap the end of the range. */
> -  if (offset + length >= exts->end) {
> +  if (offset + length > exts->end) {
>      overlap = offset + length - exts->end;
>      length -= overlap;
>    }
ACK too.

I have pushed this, thanks.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
virt-df lists disk usage of guests without needing to install any
software inside the virtual machine.  Supports Linux and Windows.
http://people.redhat.com/~rjones/virt-df/