Re: [Qemu-block] [PATCH] qemu-img convert: Deprecate using -n and -o together

2019-08-12 Thread John Snow



On 8/9/19 5:11 AM, Kevin Wolf wrote:
> bdrv_create options specified with -o have no effect when skipping image
> creation with -n, so this doesn't make sense. Warn against the misuse
> and deprecate the combination so we can make it a hard error later.
> 
> Signed-off-by: Kevin Wolf 
> ---
>  qemu-img.c   | 5 +
>  qemu-deprecated.texi | 7 +++
>  2 files changed, 12 insertions(+)
> 
> diff --git a/qemu-img.c b/qemu-img.c
> index 79983772de..d9321f6418 100644
> --- a/qemu-img.c
> +++ b/qemu-img.c
> @@ -2231,6 +2231,11 @@ static int img_convert(int argc, char **argv)
>  goto fail_getopt;
>  }
>  
> +if (skip_create && options) {
> +warn_report("-o has no effect when skipping image creation");
> +warn_report("This will become an error in future QEMU versions.");
> +}
> +
>  s.src_num = argc - optind - 1;
>  out_filename = s.src_num >= 1 ? argv[argc - 1] : NULL;
>  
> diff --git a/qemu-deprecated.texi b/qemu-deprecated.texi
> index fff07bb2a3..7673d079c5 100644
> --- a/qemu-deprecated.texi
> +++ b/qemu-deprecated.texi
> @@ -305,6 +305,13 @@ to just export the entire image and then mount only 
> /dev/nbd0p1 than
>  it is to reinvoke @command{qemu-nbd -c /dev/nbd0} limited to just a
>  subset of the image.
>  
> +@subsection qemu-img convert -n -o (since 4.2.0)
> +
> +All options specified in @option{-o} are image creation options, so they
> +have no effect when used with @option{-n} to skip image creation. This
> +combination never made sense and shows that the user misunderstood the
> +effect of the options, so this will be made an error in future versions.
> +

I would avoid too much finger-wagging here. We can just say that the
combination never had a well-defined behavior, so it will now be treated
as an error.

Otherwise:

Reviewed-by: John Snow 



Re: [Qemu-block] [PATCH] qemu-img convert: Deprecate using -n and -o together

2019-08-09 Thread Nir Soffer
On Fri, Aug 9, 2019 at 12:11 PM Kevin Wolf  wrote:

> bdrv_create options specified with -o have no effect when skipping image
> creation with -n, so this doesn't make sense. Warn against the misuse
> and deprecate the combination so we can make it a hard error later.
>
> Signed-off-by: Kevin Wolf 
> ---
>  qemu-img.c   | 5 +
>  qemu-deprecated.texi | 7 +++
>  2 files changed, 12 insertions(+)
>
> diff --git a/qemu-img.c b/qemu-img.c
> index 79983772de..d9321f6418 100644
> --- a/qemu-img.c
> +++ b/qemu-img.c
> @@ -2231,6 +2231,11 @@ static int img_convert(int argc, char **argv)
>  goto fail_getopt;
>  }
>
> +if (skip_create && options) {
> +warn_report("-o has no effect when skipping image creation");
> +warn_report("This will become an error in future QEMU versions.");
> +}
> +
>  s.src_num = argc - optind - 1;
>  out_filename = s.src_num >= 1 ? argv[argc - 1] : NULL;
>
> diff --git a/qemu-deprecated.texi b/qemu-deprecated.texi
> index fff07bb2a3..7673d079c5 100644
> --- a/qemu-deprecated.texi
> +++ b/qemu-deprecated.texi
> @@ -305,6 +305,13 @@ to just export the entire image and then mount only
> /dev/nbd0p1 than
>  it is to reinvoke @command{qemu-nbd -c /dev/nbd0} limited to just a
>  subset of the image.
>
> +@subsection qemu-img convert -n -o (since 4.2.0)
> +
> +All options specified in @option{-o} are image creation options, so they
> +have no effect when used with @option{-n} to skip image creation. This
> +combination never made sense and shows that the user misunderstood the
> +effect of the options, so this will be made an error in future versions.
>

The user misunderstood by not reading qemu code?

Both the online help and the manual page do not mention anything about
that, so I think
they should be fixed to explain the behavior, and this text should mention
that the behavior
was never documented.

Nir


> +
>  @section Build system
>
>  @subsection Python 2 support (since 4.1.0)
> --
> 2.20.1
>
>
>


Re: [Qemu-block] [PATCH] qemu-img convert: Deprecate using -n and -o together

2019-08-09 Thread Max Reitz
On 09.08.19 11:11, Kevin Wolf wrote:
> bdrv_create options specified with -o have no effect when skipping image
> creation with -n, so this doesn't make sense. Warn against the misuse
> and deprecate the combination so we can make it a hard error later.
> 
> Signed-off-by: Kevin Wolf 
> ---
>  qemu-img.c   | 5 +
>  qemu-deprecated.texi | 7 +++
>  2 files changed, 12 insertions(+)

Reviewed-by: Max Reitz 



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[Qemu-block] [PATCH] qemu-img convert: Deprecate using -n and -o together

2019-08-09 Thread Kevin Wolf
bdrv_create options specified with -o have no effect when skipping image
creation with -n, so this doesn't make sense. Warn against the misuse
and deprecate the combination so we can make it a hard error later.

Signed-off-by: Kevin Wolf 
---
 qemu-img.c   | 5 +
 qemu-deprecated.texi | 7 +++
 2 files changed, 12 insertions(+)

diff --git a/qemu-img.c b/qemu-img.c
index 79983772de..d9321f6418 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -2231,6 +2231,11 @@ static int img_convert(int argc, char **argv)
 goto fail_getopt;
 }
 
+if (skip_create && options) {
+warn_report("-o has no effect when skipping image creation");
+warn_report("This will become an error in future QEMU versions.");
+}
+
 s.src_num = argc - optind - 1;
 out_filename = s.src_num >= 1 ? argv[argc - 1] : NULL;
 
diff --git a/qemu-deprecated.texi b/qemu-deprecated.texi
index fff07bb2a3..7673d079c5 100644
--- a/qemu-deprecated.texi
+++ b/qemu-deprecated.texi
@@ -305,6 +305,13 @@ to just export the entire image and then mount only 
/dev/nbd0p1 than
 it is to reinvoke @command{qemu-nbd -c /dev/nbd0} limited to just a
 subset of the image.
 
+@subsection qemu-img convert -n -o (since 4.2.0)
+
+All options specified in @option{-o} are image creation options, so they
+have no effect when used with @option{-n} to skip image creation. This
+combination never made sense and shows that the user misunderstood the
+effect of the options, so this will be made an error in future versions.
+
 @section Build system
 
 @subsection Python 2 support (since 4.1.0)
-- 
2.20.1