From f34429036800574328097bb957d6c493bd5d7260 Mon Sep 17 00:00:00 2001
From: Bob Lantz <rlantz@cs.stanford.edu>
Date: Sun, 7 Jul 2013 15:27:49 -0700
Subject: [PATCH] Change API for more efficient remount and unmount.
---
examples/bind.py | 72 ++++++++++++++++++++++++++++++++++--------------
1 file changed, 51 insertions(+), 21 deletions(-)
diff --git a/examples/bind.py b/examples/bind.py
index 142eec40..d4d28a44 100755
--- a/examples/bind.py
+++ b/examples/bind.py
@@ -7,17 +7,20 @@
"""
from mininet.net import Mininet
-from mininet.node import Host, Switch, Controller
+from mininet.node import Host
from mininet.cli import CLI
from mininet.util import errFail, quietRun, errRun
from mininet.topo import SingleSwitchTopo
from mininet.log import setLogLevel, info, debug
-from os.path import join, realpath
+from os.path import realpath
from functools import partial
+
# Utility functions for unmounting a tree
+MNRUNDIR = realpath( '/var/run/mn' )
+
def mountPoints():
"Return list of mounted file systems"
mtab, _err, _ret = errFail( 'cat /proc/mounts' )
@@ -31,7 +34,7 @@ def mountPoints():
mounts.append( mount )
return mounts
-def unmountAll( dir='/var/run/mn' ):
+def unmountAll( dir=MNRUNDIR ):
"Unmount all mounts under a directory tree"
dir = realpath( dir )
# Find all mounts below dir
@@ -53,11 +56,17 @@ def unmountAll( dir='/var/run/mn' ):
class HostWithPrivateDirs( Host ):
"Host with private directories"
- mnRunDir = realpath( '/var/run/mn' )
+ mnRunDir = MNRUNDIR
def __init__(self, name, *args, **kwargs ):
- "privateDirs: list of private directories"
+ """privateDirs: list of private directories
+ remounts: dirs to remount
+ unmount: unmount dirs in cleanup? (True)
+ Note: if unmount is False, you must call unmountAll()
+ manually."""
self.privateDirs = kwargs.pop( 'privateDirs', [] )
+ self.remounts = kwargs.pop( 'remounts', [] )
+ self.unmount = kwargs.pop( 'unmount', True )
Host.__init__( self, name, *args, **kwargs )
self.rundir = '%s/%s' % ( self.mnRunDir, name )
if self.privateDirs:
@@ -86,19 +95,28 @@ def mountPrivateDirs( self ):
errFail( 'mount -B %s %s' %
( privateDir, mountPoint) )
- def remountDirs( self, fstypes=[ 'nfs' ] ):
- "Remount mounted file systems"
- dirs = self.cmd( 'cat /proc/mounts' ).strip().split( '\n' )
+ def mountDirs( self, dirs ):
+ "Mount a list of directories"
+ for dir in dirs:
+ mountpoint = self.root + dir
+ errFail( 'mount -B %s %s' %
+ ( dir, mountpoint ) )
+
+ @classmethod
+ def findRemounts( cls, fstypes=[ 'nfs' ] ):
+ """Identify mount points in /proc/mounts to remount
+ fstypes: file system types to match"""
+ dirs = quietRun( 'cat /proc/mounts' ).strip().split( '\n' )
+ remounts = []
for dir in dirs:
line = dir.split()
mountpoint, fstype = line[ 1 ], line[ 2 ]
# Don't re-remount directories!!!
- if mountpoint.find( self.mnRunDir ) == 0:
+ if mountpoint.find( cls.mnRunDir ) == 0:
continue
if fstype in fstypes:
- print "remounting:", mountpoint
- errFail( 'mount -B %s %s' % (
- mountpoint, self.root + mountpoint ) )
+ remounts.append( mountpoint )
+ return remounts
def createBindMounts( self ):
"""Create a chroot directory structure,
@@ -113,7 +131,7 @@ def createBindMounts( self ):
# Recursively mount / in private doort
# note we'll remount /sys and /proc later
errFail( 'mount -B / ' + self.root )
- self.remountDirs()
+ self.mountDirs( self.remounts )
self.mountPrivateDirs()
def unmountBindMounts( self ):
@@ -131,33 +149,45 @@ def popen( self, *args, **kwargs ):
return Host.popen( self, *args, **kwargs )
def cleanup( self ):
- "Clean up, then unmount bind mounts"
+ """Clean up, then unmount bind mounts
+ unmount: actually unmount bind mounts?"""
# Wait for process to actually terminate
self.shell.wait()
Host.cleanup( self )
- self.unmountBindMounts()
- errFail( 'rmdir ' + self.root )
+ if self.unmount:
+ self.unmountBindMounts()
+ errFail( 'rmdir ' + self.root )
+
+
+# Convenience aliases
+
+findRemounts = HostWithPrivateDirs.findRemounts
+
# Sample usage
def testHostWithPrivateDirs():
"Test bind mounts"
- topo = SingleSwitchTopo( 2 )
+ topo = SingleSwitchTopo( 10 )
+ remounts = findRemounts( fstypes=[ 'nfs' ] )
privateDirs = [ '/var/log', '/var/run' ]
- host = partial( HostWithPrivateDirs, privateDirs=privateDirs )
+ host = partial( HostWithPrivateDirs, remounts=remounts,
+ privateDirs=privateDirs, unmount=False )
net = Mininet( topo=topo, host=host )
net.start()
- print 'Private Directories:', privateDirs
+ info( 'Private Directories:', privateDirs, '\n' )
CLI( net )
net.stop()
+ # We do this all at once to save a bit of time
+ info( 'Unmounting host bind mounts...\n' )
+ unmountAll()
if __name__ == '__main__':
unmountAll()
setLogLevel( 'info' )
testHostWithPrivateDirs()
- unmountAll()
-
+ info( 'Done.\n')
--
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