Re: [Qemu-devel] [PATCH 09/10] qemu-ga: bios_supports_mode(): improve error reporting

[mdroth <mdroth@linux.vnet.ibm.com>]

On Tue, Nov 27, 2012 at 11:02:03AM -0200, Luiz Capitulino wrote:
> Most errors are QERR_UNDEFINED_ERROR today.
> 
> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>

Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>

> ---
>  qga/commands-posix.c | 46 +++++++++++++++++++++++++++-------------------
>  1 file changed, 27 insertions(+), 19 deletions(-)
> 
> diff --git a/qga/commands-posix.c b/qga/commands-posix.c
> index c399f02..5a7e308 100644
> --- a/qga/commands-posix.c
> +++ b/qga/commands-posix.c
> @@ -618,8 +618,9 @@ error:
>  static void bios_supports_mode(const char *pmutils_bin, const char *pmutils_arg,
>                                 const char *sysfile_str, Error **err)
>  {
> +    Error *local_err = NULL;
>      char *pmutils_path;
> -    pid_t pid, rpid;
> +    pid_t pid;
>      int status;
> 
>      pmutils_path = g_find_program_in_path(pmutils_bin);
> @@ -664,31 +665,38 @@ static void bios_supports_mode(const char *pmutils_bin, const char *pmutils_arg,
>          }
> 
>          _exit(SUSPEND_NOT_SUPPORTED);
> +    } else if (pid < 0) {
> +        error_setg_errno(err, errno, "failed to create child process");
> +        goto out;
>      }
> 
> -    g_free(pmutils_path);
> +    ga_wait_child(pid, &status, &local_err);
> +    if (error_is_set(&local_err)) {
> +        error_propagate(err, local_err);
> +        goto out;
> +    }
> 
> -    if (pid < 0) {
> -        goto undef_err;
> +    if (!WIFEXITED(status)) {
> +        error_setg(err, "child process has terminated abnormally");
> +        goto out;
>      }
> 
> -    do {
> -        rpid = waitpid(pid, &status, 0);
> -    } while (rpid == -1 && errno == EINTR);
> -    if (rpid == pid && WIFEXITED(status)) {
> -        switch (WEXITSTATUS(status)) {
> -        case SUSPEND_SUPPORTED:
> -            return;
> -        case SUSPEND_NOT_SUPPORTED:
> -            error_set(err, QERR_UNSUPPORTED);
> -            return;
> -        default:
> -            goto undef_err;
> -        }
> +    switch (WEXITSTATUS(status)) {
> +    case SUSPEND_SUPPORTED:
> +        goto out;
> +    case SUSPEND_NOT_SUPPORTED:
> +        error_setg(err,
> +                   "the requested suspend mode is not supported by the guest");
> +        goto out;
> +    default:
> +        error_setg(err,
> +                   "the helper program '%s' returned an unexpected exit status"
> +                   " code (%d)", pmutils_path, WEXITSTATUS(status));
> +        goto out;
>      }
> 
> -undef_err:
> -    error_set(err, QERR_UNDEFINED_ERROR);
> +out:
> +    g_free(pmutils_path);
>  }
> 
>  static void guest_suspend(const char *pmutils_bin, const char *sysfile_str,
> -- 
> 1.8.0
>