geo-rep: Optionally allow access to mounts

In order to improve debuggability, it is important
to have access to geo-rep master and slave mounts.
With the default behaviour, geo-rep lazy unmounts
the mounts after changing the current working
directory into the mount point. It also cleans
up the mount points. So only geo-rep worker has
the access and it becomes impossible to take the
client profile info and do any other client statck
analysis. Hence the following new config is being
introduced to allow access to mounts.

gluster vol geo-rep <mastervol> <slavehost>::<slavevol> \
config access_mount true

The default value of 'access_mount' is false.

Change-Id: I53dce4ea86a6ffc979c82f9330e8954327180ca3
BUG: 1433506
Signed-off-by: Kotresh HR <khiremat@redhat.com>
Reviewed-on: https://review.gluster.org/16912
Smoke: Gluster Build System <jenkins@build.gluster.org>
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>

3 files changed, 20 insertions, 4 deletions

diff --git a/geo-replication/syncdaemon/gsyncd.py b/geo-replication/syncdaemon/gsyncd.py
index 1fd475dfba..adc48f146a 100644
--- a/geo-replication/syncdaemon/gsyncd.py
+++ b/geo-replication/syncdaemon/gsyncd.py
@@ -269,6 +269,7 @@ def main_i():
                   type=str, action='callback', callback=store_abs)
     op.add_option('--georep-session-working-dir', metavar='STATF',
                   type=str, action='callback', callback=store_abs)
+    op.add_option('--access-mount', default=False, action='store_true')
     op.add_option('--ignore-deletes', default=False, action='store_true')
     op.add_option('--isolated-slave', default=False, action='store_true')
     op.add_option('--use-rsync-xattrs', default=False, action='store_true')
@@ -415,7 +416,7 @@ def main_i():
                     o.get_opt_string() not in ('--version', '--help'))]
     remote_tunables = ['listen', 'go_daemon', 'timeout',
                        'session_owner', 'config_file', 'use_rsync_xattrs',
-                       'local_id', 'local_node']
+                       'local_id', 'local_node', 'access_mount']
     rq_remote_tunables = {'listen': True}
 
     # precedence for sources of values: 1) commandline, 2) cfg file, 3)
diff --git a/geo-replication/syncdaemon/resource.py b/geo-replication/syncdaemon/resource.py
index 977496318d..306742e53f 100644
--- a/geo-replication/syncdaemon/resource.py
+++ b/geo-replication/syncdaemon/resource.py
@@ -41,6 +41,7 @@ from syncdutils import get_changelog_log_level
 from syncdutils import CHANGELOG_AGENT_CLIENT_VERSION
 from gsyncdstatus import GeorepStatus
 from syncdutils import get_master_and_slave_data_from_args
+from syncdutils import mntpt_list
 
 UrlRX = re.compile('\A(\w+)://([^ *?[]*)\Z')
 HostRX = re.compile('[a-zA-Z\d](?:[a-zA-Z\d.-]*[a-zA-Z\d])?', re.I)
@@ -1014,6 +1015,8 @@ class SlaveRemote(object):
             extra_opts += ['--local-node', ln]
         if boolify(gconf.use_rsync_xattrs):
             extra_opts.append('--use-rsync-xattrs')
+        if boolify(gconf.access_mount):
+            extra_opts.append('--access-mount')
         po = Popen(rargs + gconf.remote_gsyncd.split() + extra_opts +
                    ['-N', '--listen', '--timeout', str(gconf.timeout),
                     slave],
@@ -1373,13 +1376,14 @@ class GLUSTER(AbstractUrl, SlaveLocal, SlaveRemote):
                         assert(mntdata[-1] == '\0')
                         mntpt = mntdata[:-1]
                         assert(mntpt)
-                        if mounted:
+                        if mounted and not boolify(gconf.access_mount):
                             po = self.umount_l(mntpt)
                             po.terminate_geterr(fail_on_err=False)
                             if po.returncode != 0:
                                 po.errlog()
                                 rv = po.returncode
-                        self.cleanup_mntpt(mntpt)
+                        if not boolify(gconf.access_mount):
+                            self.cleanup_mntpt(mntpt)
                 except:
                     logging.exception('mount cleanup failure:')
                     rv = 200
@@ -1399,6 +1403,7 @@ class GLUSTER(AbstractUrl, SlaveLocal, SlaveRemote):
 
         def make_mount_argv(self):
             self.mntpt = tempfile.mkdtemp(prefix='gsyncd-aux-mount-')
+            mntpt_list.append(self.mntpt)
             return [self.get_glusterprog()] + \
                 ['--' + p for p in self.params] + [self.mntpt]
 
diff --git a/geo-replication/syncdaemon/syncdutils.py b/geo-replication/syncdaemon/syncdutils.py
index 292cd0aea1..4d981f9fe5 100644
--- a/geo-replication/syncdaemon/syncdutils.py
+++ b/geo-replication/syncdaemon/syncdutils.py
@@ -16,6 +16,7 @@ import fcntl
 import shutil
 import logging
 import socket
+import subprocess
 from threading import Lock, Thread as baseThread
 from errno import EACCES, EAGAIN, EPIPE, ENOTCONN, ECONNABORTED
 from errno import EINTR, ENOENT, EPERM, ESTALE, errorcode
@@ -189,12 +190,13 @@ def grabpidfile(fname=None, setpid=True):
 
 final_lock = Lock()
 
-
+mntpt_list = []
 def finalize(*a, **kw):
     """all those messy final steps we go trough upon termination
 
     Do away with pidfile, ssh control dir and logging.
     """
+
     final_lock.acquire()
     if getattr(gconf, 'pid_file', None):
         rm_pidf = gconf.pid_file_owned
@@ -234,6 +236,13 @@ def finalize(*a, **kw):
             if sys.exc_info()[0] == OSError:
                 pass
 
+    """ Unmount if not done """
+    for mnt in mntpt_list:
+        p0 = subprocess.Popen (["umount", "-l", mnt], stderr=subprocess.PIPE)
+        _, errdata = p0.communicate()
+        if p0.returncode == 0:
+            os.rmdir(mnt)
+
     if gconf.log_exit:
         logging.info("exiting.")
     sys.stdout.flush()
@@ -241,6 +250,7 @@ def finalize(*a, **kw):
     os._exit(kw.get('exval', 0))
 
 
+
 def log_raise_exception(excont):
     """top-level exception handler