From: Darrick J. Wong <djwong@xxxxxxxxxx> Move all the systemd service handling code to an object so that we can contain all the insanity^Wdetails in a single place. This also makes the killfuncs handling similar to starting background processes. Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx> Reviewed-by: Christoph Hellwig <hch@xxxxxx> --- scrub/xfs_scrub_all.in | 113 ++++++++++++++++++++++++++---------------------- 1 file changed, 61 insertions(+), 52 deletions(-) diff --git a/scrub/xfs_scrub_all.in b/scrub/xfs_scrub_all.in index 25286f57c..4130a98e9 100644 --- a/scrub/xfs_scrub_all.in +++ b/scrub/xfs_scrub_all.in @@ -149,63 +149,73 @@ def path_to_serviceunit(path, scrub_media): svcname = '@scrub_svcname@' cmd = ['systemd-escape', '--template', svcname, '--path', path] - try: - proc = subprocess.Popen(cmd, stdout = subprocess.PIPE) - proc.wait() - for line in proc.stdout: - return line.decode(sys.stdout.encoding).strip() - except: - return None + proc = subprocess.Popen(cmd, stdout = subprocess.PIPE) + proc.wait() + for line in proc.stdout: + return line.decode(sys.stdout.encoding).strip() -def systemctl_stop(unitname): - '''Stop a systemd unit.''' - cmd = ['systemctl', 'stop', unitname] - x = subprocess.Popen(cmd) - x.wait() +class scrub_service(scrub_control): + '''Control object for xfs_scrub systemd service.''' + def __init__(self, mnt, scrub_media): + self.unitname = path_to_serviceunit(mnt, scrub_media) -def systemctl_start(unitname, killfuncs): - '''Start a systemd unit and wait for it to complete.''' - stop_fn = None - cmd = ['systemctl', 'start', unitname] - try: - proc = subprocess.Popen(cmd, stdout = DEVNULL()) - stop_fn = lambda: systemctl_stop(unitname) - killfuncs.add(stop_fn) - proc.wait() - ret = proc.returncode - except: - if stop_fn is not None: - remove_killfunc(killfuncs, stop_fn) - return -1 + def wait(self, interval = 1): + '''Wait until the service finishes.''' - if ret != 1: - remove_killfunc(killfuncs, stop_fn) - return ret + # As of systemd 249, the is-active command returns any of the + # following states: active, reloading, inactive, failed, + # activating, deactivating, or maintenance. Apparently these + # strings are not localized. + while True: + try: + for l in backtick(['systemctl', 'is-active', self.unitname]): + if l == 'failed': + return 1 + if l == 'inactive': + return 0 + except: + return -1 - # If systemctl-start returns 1, it's possible that the service failed - # or that dbus/systemd restarted and the client program lost its - # connection -- according to the systemctl man page, 1 means "unit not - # failed". - # - # Either way, we switch to polling the service status to try to wait - # for the service to end. As of systemd 249, the is-active command - # returns any of the following states: active, reloading, inactive, - # failed, activating, deactivating, or maintenance. Apparently these - # strings are not localized. - while True: + time.sleep(interval) + + def start(self): + '''Start the service and wait for it to complete. Returns -1 + if the service was not started, 0 if it succeeded, or 1 if it + failed.''' + cmd = ['systemctl', 'start', self.unitname] try: - for l in backtick(['systemctl', 'is-active', unitname]): - if l == 'failed': - remove_killfunc(killfuncs, stop_fn) - return 1 - if l == 'inactive': - remove_killfunc(killfuncs, stop_fn) - return 0 + proc = subprocess.Popen(cmd, stdout = DEVNULL()) + proc.wait() + ret = proc.returncode except: - remove_killfunc(killfuncs, stop_fn) return -1 - time.sleep(1) + if ret != 1: + return ret + + # If systemctl-start returns 1, it's possible that the service + # failed or that dbus/systemd restarted and the client program + # lost its connection -- according to the systemctl man page, 1 + # means "unit not failed". + return self.wait() + + def stop(self): + '''Stop the service.''' + cmd = ['systemctl', 'stop', self.unitname] + x = subprocess.Popen(cmd) + x.wait() + +def run_service(mnt, scrub_media, killfuncs): + '''Run scrub as a service.''' + try: + svc = scrub_service(mnt, scrub_media) + except: + return -1 + + killfuncs.add(svc.stop) + retcode = svc.start() + remove_killfunc(killfuncs, svc.stop) + return retcode def run_scrub(mnt, cond, running_devs, mntdevs, killfuncs): '''Run a scrub process.''' @@ -222,9 +232,8 @@ def run_scrub(mnt, cond, running_devs, mntdevs, killfuncs): # Run per-mount systemd xfs_scrub service only if we ourselves # are running as a systemd service. - unitname = path_to_serviceunit(path, scrub_media) - if unitname is not None and 'SERVICE_MODE' in os.environ: - ret = systemctl_start(unitname, killfuncs) + if 'SERVICE_MODE' in os.environ: + ret = run_service(mnt, scrub_media, killfuncs) if ret == 0 or ret == 1: print("Scrubbing %s done, (err=%d)" % (mnt, ret)) sys.stdout.flush()