[sheepdog] [PATCH v2 2/2] block: deprecate the sheepdog block driver

[Philippe Mathieu-Daudé]

On 9/22/20 6:16 PM, Daniel P. Berrangé wrote:
> This thread from a little over a year ago:
> 
>   http://lists.wpkg.org/pipermail/sheepdog/2019-March/thread.html
> 
> states that sheepdog is no longer actively developed. The only mentioned
> users are some companies who are said to have it for legacy reasons with
> plans to replace it by Ceph. There is talk about cutting out existing
> features to turn it into a simple demo of how to write a distributed
> block service. There is no evidence of anyone working on that idea:
> 
>   https://github.com/sheepdog/sheepdog/commits/master
> 
> No real commits to git since Jan 2018, and before then just some minor
> technical debt cleanup..
> 
> There is essentially no activity on the mailing list aside from
> patches to QEMU that get CC'd due to our MAINTAINERS entry.
> 
> Fedora packages for sheepdog failed to build from upstream source
> because of the more strict linker that no longer merges duplicate
> global symbols. Fedora patches it to add the missing "extern"
> annotations and presumably other distros do to, but upstream source
> remains broken.
> 
> There is only basic compile testing, no functional testing of the
> driver.
> 
> Since there are no build pre-requisites the sheepdog driver is currently
> enabled unconditionally. This would result in configure issuing a
> deprecation warning by default for all users. Thus the configure default
> is changed to disable it, requiring users to pass --enable-sheepdog to
> build the driver.
> 
> Signed-off-by: Daniel P. Berrangé <berrange at redhat.com>
> ---
>  block/sheepdog.c           | 15 +++++++++++++++
>  configure                  |  5 +++--
>  docs/system/deprecated.rst |  9 +++++++++
>  3 files changed, 27 insertions(+), 2 deletions(-)
> 
> diff --git a/block/sheepdog.c b/block/sheepdog.c
> index cbbebc1aaf..7f68bd6a1a 100644
> --- a/block/sheepdog.c
> +++ b/block/sheepdog.c
> @@ -242,6 +242,17 @@ typedef struct SheepdogInode {
>   */
>  #define FNV1A_64_INIT ((uint64_t)0xcbf29ce484222325ULL)
>  
> +static void deprecation_warning(void)
> +{
> +    static bool warned = false;

Checkpatch warns there is no need to initialize static bool to false,
otherwise:

Reviewed-by: Philippe Mathieu-Daudé <philmd at redhat.com>

> +
> +    if (!warned) {
> +        warn_report("the sheepdog block driver is deprecated and will be "
> +                    "removed in a future release");
> +        warned = true;
> +    }
> +}
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