[PATCH v4 4/7] qga/commands-posix: qmp_guest_set_time: use ga_run_command helper

[Andrey Drobyshev <andrey.drobyshev@virtuozzo.com>]

There's no need to check for the existence of "/sbin/hwclock", the
exec() call will do that for us.

Signed-off-by: Andrey Drobyshev <andrey.drobyshev@virtuozzo.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
---
 qga/commands-posix.c | 43 +++----------------------------------------
 1 file changed, 3 insertions(+), 40 deletions(-)

diff --git a/qga/commands-posix.c b/qga/commands-posix.c
index cb9eed9a0b..545f3c99dc 100644
--- a/qga/commands-posix.c
+++ b/qga/commands-posix.c
@@ -279,21 +279,9 @@ void qmp_guest_shutdown(const char *mode, Error **errp)
 void qmp_guest_set_time(bool has_time, int64_t time_ns, Error **errp)
 {
     int ret;
-    int status;
-    pid_t pid;
     Error *local_err = NULL;
     struct timeval tv;
-    static const char hwclock_path[] = "/sbin/hwclock";
-    static int hwclock_available = -1;
-
-    if (hwclock_available < 0) {
-        hwclock_available = (access(hwclock_path, X_OK) == 0);
-    }
-
-    if (!hwclock_available) {
-        error_setg(errp, QERR_UNSUPPORTED);
-        return;
-    }
+    const char *argv[] = {"/sbin/hwclock", has_time ? "-w" : "-s", NULL};
 
     /* If user has passed a time, validate and set it. */
     if (has_time) {
@@ -324,37 +312,12 @@ void qmp_guest_set_time(bool has_time, int64_t time_ns, Error **errp)
      * just need to synchronize the hardware clock. However, if no time was
      * passed, user is requesting the opposite: set the system time from the
      * hardware clock (RTC). */
-    pid = fork();
-    if (pid == 0) {
-        setsid();
-        reopen_fd_to_null(0);
-        reopen_fd_to_null(1);
-        reopen_fd_to_null(2);
-
-        /* Use '/sbin/hwclock -w' to set RTC from the system time,
-         * or '/sbin/hwclock -s' to set the system time from RTC. */
-        execl(hwclock_path, "hwclock", has_time ? "-w" : "-s", NULL);
-        _exit(EXIT_FAILURE);
-    } else if (pid < 0) {
-        error_setg_errno(errp, errno, "failed to create child process");
-        return;
-    }
-
-    ga_wait_child(pid, &status, &local_err);
+    ga_run_command(argv, NULL, "set hardware clock to system time",
+                   &local_err);
     if (local_err) {
         error_propagate(errp, local_err);
         return;
     }
-
-    if (!WIFEXITED(status)) {
-        error_setg(errp, "child process has terminated abnormally");
-        return;
-    }
-
-    if (WEXITSTATUS(status)) {
-        error_setg(errp, "hwclock failed to set hardware clock to system time");
-        return;
-    }
 }
 
 typedef enum {
-- 
2.39.3