Re: [PATCH 12/14] libxl: Check xc_sharing_* for proper return values.

[Ian Campbell <ian.campbell@citrix.com>]

On Mon, 2015-03-16 at 11:39 -0400, Konrad Rzeszutek Wilk wrote:
> If there is a negative return value - check for that and
> also use errno for the proper error value.

Was xc_sharing_freed_pages fixed earlier in the series (which is
strictly speaking a bisection hazard, but nevermind) or was the existing
check for l == -E... just buggy?

> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
> ---
>  tools/libxl/libxl.c                  |  4 ++--
>  tools/tests/mem-sharing/memshrtool.c | 12 ++++++++++--
>  2 files changed, 12 insertions(+), 4 deletions(-)
> 
> diff --git a/tools/libxl/libxl.c b/tools/libxl/libxl.c
> index 94b4d59..99a99e9 100644
> --- a/tools/libxl/libxl.c
> +++ b/tools/libxl/libxl.c
> @@ -5024,7 +5024,7 @@ int libxl_get_physinfo(libxl_ctx *ctx, libxl_physinfo *physinfo)
>      physinfo->scrub_pages = xcphysinfo.scrub_pages;
>      physinfo->outstanding_pages = xcphysinfo.outstanding_pages;
>      l = xc_sharing_freed_pages(ctx->xch);
> -    if (l == -ENOSYS) {
> +    if (l < 0 && errno == ENOSYS) {
>          l = 0;
>      } else if (l < 0) {
>          LIBXL__LOG_ERRNOVAL(ctx, LIBXL__LOG_ERROR, l,
> @@ -5033,7 +5033,7 @@ int libxl_get_physinfo(libxl_ctx *ctx, libxl_physinfo *physinfo)
>      }
>      physinfo->sharing_freed_pages = l;
>      l = xc_sharing_used_frames(ctx->xch);
> -    if (l == -ENOSYS) {
> +    if (l < 0 && errno == ENOSYS) {
>          l = 0;
>      } else if (l < 0) {
>          LIBXL__LOG_ERRNOVAL(ctx, LIBXL__LOG_ERROR, l,
> diff --git a/tools/tests/mem-sharing/memshrtool.c b/tools/tests/mem-sharing/memshrtool.c
> index db44294..d1dd8a2 100644
> --- a/tools/tests/mem-sharing/memshrtool.c
> +++ b/tools/tests/mem-sharing/memshrtool.c
> @@ -55,11 +55,19 @@ int main(int argc, const char** argv)
>  
>      if( !strcasecmp(cmd, "info") )
>      {
> +        long rc;
>          if( argc != 2 )
>              return usage(argv[0]);
>  
> -        printf("used = %ld\n", xc_sharing_used_frames(xch));
> -        printf("freed = %ld\n", xc_sharing_freed_pages(xch));
> +        rc = xc_sharing_freed_pages(xch);
> +        if ( rc < 0 )
> +            return errno;

Just return 1 please.

> +
> +        printf("used = %ld\n", rc);
> +        rc = xc_sharing_used_frames(xch);
> +        if ( rc < 0 )
> +            return errno;

Likewise.

> +        printf("freed = %ld\n", rc);
>      }
>      else if( !strcasecmp(cmd, "enable") )
>      {