[Devel] [PATCH VZ10 v2 1/3] selftests/ve: Add namespace management helpers

[Vasileios Almpanis]

> When mount namespace is created in a child, it is destroyed
> when the child dies. We may need to keep it for a while to check
> how VE handles resources.
> 
> Instead of keeping a thread which lives in a new ve+mnt namespaces,
> let's store open namespace file descriptors to enter them later
> without keeping children alive.
> 
> https://virtuozzo.atlassian.net/browse/VSTOR-144504
> 
> Feature: ve selftests
> Signed-off-by: Vladimir Riabchun <vladimir.riabchun at virtuozzo.com>
>
> diff --git a/tools/testing/selftests/ve/ve_selftest.h b/tools/testing/selftests/ve/ve_selftest.h
> index c53bf7900d20..ee960f7db0b4 100644
> --- a/tools/testing/selftests/ve/ve_selftest.h
> +++ b/tools/testing/selftests/ve/ve_selftest.h
> @@ -31,6 +31,129 @@
>  #define VE_CONTROLLERS \
>  	"+cpuset +cpu +cpuacct +io +memory +hugetlb +pids +rdma +misc +ve"
>  
> +struct namespace_ctx {
> +	int ns_save_mask;	/* Mask of stored CLONE_NEW* namespaces. */
> +	/* Namespace file descriptors. Name should match /proc/PID/ns/NAME */
> +	int ve_fd;
> +	int mnt_fd;
> +};
> +
> +static inline void close_namespace_fds(struct namespace_ctx *ctx)
> +{
> +	if (ctx->ns_save_mask & CLONE_NEWVE)
> +		close(ctx->ve_fd);
> +	if (ctx->ns_save_mask & CLONE_NEWNS)
> +		close(ctx->mnt_fd);
> +
> +	ctx->ns_save_mask = 0;
> +}
> +
> +static inline int save_namespace_fds(struct namespace_ctx *ctx, int flags)
> +{
> +#define OPEN_NS(name, flag)                                                \
> +do {                                                                       \
> +	if (flags & flag) {                                                \

Parenthesise the macro argument, checkpatch complaints about it
	if (flags & (flag))

> +		ctx->name##_fd = open("/proc/self/ns/" #name, O_RDONLY);   \
> +		if (ctx->name##_fd < 0) {                                  \
> +			fprintf(stderr, "%s: could not open fd %s: %s\n",  \
> +				__func__, #name, strerror(errno));         \
> +			goto err;                                          \
> +		}                                                          \
> +		ctx->ns_save_mask |= flag;                                 \
> +	}                                                                  \
> +} while (0)
> +
> +	ctx->ns_save_mask = 0;
> +
> +	OPEN_NS(ve, CLONE_NEWVE);
> +	OPEN_NS(mnt, CLONE_NEWNS);

Add #undef OPEN_NS after the last call to not leak to all includers and
the same for JOIN_NS.

-- 
Vasileios Almpanis <vasileios.almpanis at virtuozzo.com>