Re: [Qemu-devel] [PATCH v1 3/6] qga: guest_suspend: decoupling pm-utils and sys logic

[Marc-André Lureau]

Hi

On Tue, Jun 19, 2018 at 9:38 PM, Daniel Henrique Barboza
<address@hidden> wrote:
> Following the same logic of the previous patch, let's also
> decouple the suspend logic from guest_suspend into specialized
> functions, one for each strategy we support at this moment.
>
> Signed-off-by: Daniel Henrique Barboza <address@hidden>
> ---
>  qga/commands-posix.c | 170 +++++++++++++++++++++++++++----------------
>  1 file changed, 108 insertions(+), 62 deletions(-)
>
> diff --git a/qga/commands-posix.c b/qga/commands-posix.c
> index 89ffd8dc88..a2870f9ab9 100644
> --- a/qga/commands-posix.c
> +++ b/qga/commands-posix.c
> @@ -1509,6 +1509,65 @@ out:
>      return ret;
>  }
>
> +static void pmutils_suspend(int suspend_mode, Error **errp)
> +{
> +    Error *local_err = NULL;
> +    const char *pmutils_bin;
> +    char *pmutils_path;
> +    pid_t pid;
> +    int status;
> +
> +    switch (suspend_mode) {
> +
> +    case SUSPEND_MODE_DISK:
> +        pmutils_bin = "pm-hibernate";
> +        break;
> +    case SUSPEND_MODE_RAM:
> +        pmutils_bin = "pm-suspend";
> +        break;
> +    case SUSPEND_MODE_HYBRID:
> +        pmutils_bin = "pm-suspend-hybrid";
> +        break;
> +    default:
> +        error_setg(errp, "unknown guest suspend mode");
> +        return;
> +    }
> +
> +    pmutils_path = g_find_program_in_path(pmutils_bin);
> +    if (!pmutils_path) {
> +        error_setg(errp, "the helper program '%s' was not found", 
> pmutils_bin);
> +        return;
> +    }
> +
> +    pid = fork();
> +    if (!pid) {
> +        setsid();
> +        execle(pmutils_path, pmutils_bin, NULL, environ);
> +        /*
> +         * If we get here execle() has failed.
> +         */
> +        _exit(EXIT_FAILURE);
> +    } else if (pid < 0) {
> +        error_setg_errno(errp, errno, "failed to create child process");
> +        goto out;
> +    }
> +
> +    ga_wait_child(pid, &status, &local_err);
> +    if (local_err) {
> +        error_propagate(errp, local_err);
> +        goto out;
> +    }
> +
> +    if (WEXITSTATUS(status)) {
> +        error_setg(errp,
> +                   "the helper program '%s' returned an unexpected exit 
> status"
> +                   " code (%d)", pmutils_path, WEXITSTATUS(status));
> +    }
> +
> +out:
> +    g_free(pmutils_path);
> +}
> +
>  static bool linux_sys_state_supports_mode(int suspend_mode, Error **errp)
>  {
>      const char *sysfile_str;
> @@ -1545,64 +1604,28 @@ static bool linux_sys_state_supports_mode(int 
> suspend_mode, Error **errp)
>      return false;
>  }
>
> -static void bios_supports_mode(int suspend_mode, Error **errp)
> -{
> -    Error *local_err = NULL;
> -    bool ret;
> -
> -    ret = pmutils_supports_mode(suspend_mode, &local_err);
> -    if (ret) {
> -        return;
> -    }
> -    if (local_err) {
> -        error_propagate(errp, local_err);
> -        return;
> -    }
> -    ret = linux_sys_state_supports_mode(suspend_mode, errp);
> -    if (!ret) {
> -        error_setg(errp,
> -                   "the requested suspend mode is not supported by the 
> guest");
> -        return;
> -    }
> -}
> -
> -static void guest_suspend(int suspend_mode, Error **errp)
> +static void linux_sys_state_suspend(int suspend_mode, Error **errp)
>  {
>      Error *local_err = NULL;
> -    const char *pmutils_bin, *sysfile_str;
> -    char *pmutils_path;
> +    const char *sysfile_str;
>      pid_t pid;
>      int status;
>
> -    bios_supports_mode(suspend_mode, &local_err);
> -    if (local_err) {
> -        error_propagate(errp, local_err);
> -        return;
> -    }
> -
>      switch (suspend_mode) {
>
>      case SUSPEND_MODE_DISK:
> -        pmutils_bin = "pm-hibernate";
>          sysfile_str = "disk";
>          break;
>      case SUSPEND_MODE_RAM:
> -        pmutils_bin = "pm-suspend";
>          sysfile_str = "mem";
>          break;
> -    case SUSPEND_MODE_HYBRID:
> -        pmutils_bin = "pm-suspend-hybrid";
> -        sysfile_str = NULL;
> -        break;
>      default:
>          error_setg(errp, "unknown guest suspend mode");
>          return;
>      }
>
> -    pmutils_path = g_find_program_in_path(pmutils_bin);
> -
>      pid = fork();
> -    if (pid == 0) {
> +    if (!pid) {
>          /* child */
>          int fd;
>
> @@ -1611,19 +1634,6 @@ static void guest_suspend(int suspend_mode, Error 
> **errp)
>          reopen_fd_to_null(1);
>          reopen_fd_to_null(2);
>
> -        if (pmutils_path) {
> -            execle(pmutils_path, pmutils_bin, NULL, environ);
> -        }
> -
> -        /*
> -         * If we get here either pm-utils is not installed or execle() has
> -         * failed. Let's try the manual method if the caller wants it.
> -         */
> -
> -        if (!sysfile_str) {
> -            _exit(EXIT_FAILURE);
> -        }
> -
>          fd = open(LINUX_SYS_STATE_FILE, O_WRONLY);
>          if (fd < 0) {
>              _exit(EXIT_FAILURE);
> @@ -1636,27 +1646,63 @@ static void guest_suspend(int suspend_mode, Error 
> **errp)
>          _exit(EXIT_SUCCESS);
>      } else if (pid < 0) {
>          error_setg_errno(errp, errno, "failed to create child process");
> -        goto out;
> +        return;
>      }
>
>      ga_wait_child(pid, &status, &local_err);
>      if (local_err) {
>          error_propagate(errp, local_err);
> -        goto out;
> -    }
> -
> -    if (!WIFEXITED(status)) {
> -        error_setg(errp, "child process has terminated abnormally");
> -        goto out;
> +        return;
>      }
>
>      if (WEXITSTATUS(status)) {
>          error_setg(errp, "child process has failed to suspend");
> -        goto out;
>      }
>
> -out:
> -    g_free(pmutils_path);
> +}
> +
> +static void bios_supports_mode(int suspend_mode, Error **errp)
> +{
> +    Error *local_err = NULL;
> +    bool ret;
> +
> +    ret = pmutils_supports_mode(suspend_mode, &local_err);
> +    if (ret) {
> +        return;
> +    }
> +    if (local_err) {
> +        error_propagate(errp, local_err);
> +        return;
> +    }
> +    ret = linux_sys_state_supports_mode(suspend_mode, errp);
> +    if (!ret) {
> +        error_setg(errp,
> +                   "the requested suspend mode is not supported by the 
> guest");
> +        return;
> +    }
> +}
> +
> +static void guest_suspend(int suspend_mode, Error **errp)
> +{
> +    Error *local_err = NULL;
> +
> +    bios_supports_mode(suspend_mode, &local_err);
> +    if (local_err) {
> +        error_propagate(errp, local_err);
> +        return;
> +    }
> +
> +    pmutils_suspend(suspend_mode, &local_err);
> +    if (!local_err) {
> +        return;
> +    }
> +
> +    local_err = NULL;

You should error_free(). Same in later patches.

> +
> +    linux_sys_state_suspend(suspend_mode, &local_err);
> +    if (local_err) {
> +        error_propagate(errp, local_err);
> +    }
>  }
>
>  void qmp_guest_suspend_disk(Error **errp)
> --
> 2.17.1
>
>



-- 
Marc-André Lureau