From 77d79754d914ce7d15d02d5fc9d9785609094850 Mon Sep 17 00:00:00 2001

From: Kotresh HR <khiremat@redhat.com>

Date: Thu, 7 Jun 2018 06:32:36 -0400

Subject: [PATCH 305/305] geo-rep: Fix geo-rep for older versions of unshare

Geo-rep mounts are private to worker. It uses

mount namespace using unshare command to achieve

the same. Well, the unshare command has to support

'--propagation' option. So geo-rep breaks on the

systems with older unshare version. The patch

makes it fall back to lazy umount behaviour if

the unshare does not support propagation option.

Backpor of:

  > Patch: https://review.gluster.org/20221

  > fixes: bz#1589782

  > Change-Id: Ia614f068aede288d63ac62fea4461b1865066054

  > Signed-off-by: Kotresh HR <khiremat@redhat.com>

BUG: 1569312

Change-Id: Ia614f068aede288d63ac62fea4461b1865066054

Signed-off-by: Kotresh HR <khiremat@redhat.com>

Reviewed-on: https://code.engineering.redhat.com/gerrit/142613

Tested-by: RHGS Build Bot <nigelb@redhat.com>

Reviewed-by: Aravinda Vishwanathapura Krishna Murthy <avishwan@redhat.com>

Reviewed-by: Atin Mukherjee <amukherj@redhat.com>

---

 geo-replication/syncdaemon/gsyncd.py     |  1 +

 geo-replication/syncdaemon/monitor.py    | 15 +++++++++++----

 geo-replication/syncdaemon/resource.py   | 21 ++++++++++++++++++---

 geo-replication/syncdaemon/syncdutils.py | 18 ++++++++++++++++++

 4 files changed, 48 insertions(+), 7 deletions(-)

diff --git a/geo-replication/syncdaemon/gsyncd.py b/geo-replication/syncdaemon/gsyncd.py

index b0ed0ae..fff193b 100644

--- a/geo-replication/syncdaemon/gsyncd.py

+++ b/geo-replication/syncdaemon/gsyncd.py

@@ -775,6 +775,7 @@ def main_i():

     elif remote:

         # master

         gconf.label = gconf.local_path

+        gconf.worker = True

     else:

         gconf.label = 'slave'

     startup(go_daemon=go_daemon, log_file=log_file, label=gconf.label)

diff --git a/geo-replication/syncdaemon/monitor.py b/geo-replication/syncdaemon/monitor.py

index 55f8330..9245572 100644

--- a/geo-replication/syncdaemon/monitor.py

+++ b/geo-replication/syncdaemon/monitor.py

@@ -29,7 +29,7 @@ from syncdutils import gf_event, EVENT_GEOREP_FAULTY

 from syncdutils import Volinfo, Popen

 from gsyncdstatus import GeorepStatus, set_monitor_status

-

+from syncdutils import unshare_propagation_supported

 ParseError = XET.ParseError if hasattr(XET, 'ParseError') else SyntaxError

@@ -247,9 +247,16 @@ class Monitor(object):

                 if access_mount:

                     os.execv(sys.executable, args_to_worker)

                 else:

-                    unshare_cmd = ['unshare', '-m', '--propagation', 'private']

-                    cmd = unshare_cmd + args_to_worker

-                    os.execvp("unshare", cmd)

+                    if unshare_propagation_supported():

+                        logging.debug("Worker would mount volume privately")

+                        unshare_cmd = ['unshare', '-m', '--propagation',

+                                       'private']

+                        cmd = unshare_cmd + args_to_worker

+                        os.execvp("unshare", cmd)

+                    else:

+                        logging.debug("Mount is not private. It would be lazy"

+                                      " umounted")

+                        os.execv(sys.executable, args_to_worker)

             cpids.add(cpid)

             agents.add(apid)

diff --git a/geo-replication/syncdaemon/resource.py b/geo-replication/syncdaemon/resource.py

index c4b5b53..00e62b7 100644

--- a/geo-replication/syncdaemon/resource.py

+++ b/geo-replication/syncdaemon/resource.py

@@ -40,6 +40,7 @@ from gsyncdstatus import GeorepStatus

 from syncdutils import get_master_and_slave_data_from_args

 from syncdutils import lf, Popen, sup, Volinfo

 from syncdutils import Xattr, matching_disk_gfid, get_gfid_from_mnt

+from syncdutils import unshare_propagation_supported

 UrlRX = re.compile('\A(\w+)://([^ *?[]*)\Z')

 HostRX = re.compile('[a-zA-Z\d](?:[a-zA-Z\d.-]*[a-zA-Z\d])?', re.I)

@@ -1302,15 +1303,29 @@ class GLUSTER(AbstractUrl, SlaveLocal, SlaveRemote):

                         assert(mntdata[-1] == '\0')

                         mntpt = mntdata[:-1]

                         assert(mntpt)

-                        if mounted and gconf.label == 'slave' \

+

+                        umount_master = False

+                        umount_slave = False

+                        master_access_mount = getattr(gconf, 'access_mount',

+                                                      False)

+                        worker = getattr(gconf, 'worker', None)

+

+                        if worker \

+                           and not unshare_propagation_supported() \

+                           and not boolify(master_access_mount):

+                            umount_master = True

+                        if gconf.label == 'slave' \

                            and not boolify(gconf.slave_access_mount):

+                            umount_slave = True

+

+                        if mounted and (umount_master or umount_slave):

                             po = self.umount_l(mntpt)

                             po.terminate_geterr(fail_on_err=False)

                             if po.returncode != 0:

                                 po.errlog()

                                 rv = po.returncode

-                        if gconf.label == 'slave' \

-                           and not boolify(gconf.slave_access_mount):

+                            logging.debug("Lazy umount done: %s" % mntpt)

+                        if umount_master or umount_slave:

                             self.cleanup_mntpt(mntpt)

                 except:

                     logging.exception('mount cleanup failure:')

diff --git a/geo-replication/syncdaemon/syncdutils.py b/geo-replication/syncdaemon/syncdutils.py

index a493c37..6dafb0a 100644

--- a/geo-replication/syncdaemon/syncdutils.py

+++ b/geo-replication/syncdaemon/syncdutils.py

@@ -76,6 +76,7 @@ CHANGELOG_AGENT_SERVER_VERSION = 1.0

 CHANGELOG_AGENT_CLIENT_VERSION = 1.0

 NodeID = None

 rsync_version = None

+unshare_mnt_propagation = None

 SPACE_ESCAPE_CHAR = "%20"

 NEWLINE_ESCAPE_CHAR = "%0A"

 PERCENTAGE_ESCAPE_CHAR = "%25"

@@ -637,6 +638,23 @@ def get_master_and_slave_data_from_args(args):

     return (master_name, slave_data)

+def unshare_propagation_supported():

+    global unshare_mnt_propagation

+    if unshare_mnt_propagation is not None:

+        return unshare_mnt_propagation

+

+    unshare_mnt_propagation = False

+    p = subprocess.Popen(["unshare", "--help"],

+                         stderr=subprocess.PIPE,

+                         stdout=subprocess.PIPE)

+    out, err = p.communicate()

+    if p.returncode == 0:

+        if "propagation" in out:

+            unshare_mnt_propagation = True

+

+    return unshare_mnt_propagation

+

+

 def get_rsync_version(rsync_cmd):

     global rsync_version

     if rsync_version is not None:

-- 

1.8.3.1