add mlab patch to add tasks to cpuacct cgroup, put os.environ before os.execv

[lxc-userspace.git] / lxcsu

diff --git a/lxcsu b/lxcsu
index 05899d2..dc24ec1 100755 (executable)
--- a/lxcsu
+++ b/lxcsu
@@ -3,11 +3,13 @@
 
 import setns
 import os
+import sys
 
-from optparse import OptionParser
+#from optparse import OptionParser
 
-drop_capabilities='cap_sys_admin,cap_net_admin,cap_sys_boot,cap_sys_module'
+drop_capabilities='cap_sys_admin,cap_sys_boot,cap_sys_module'.split(',')
 
+"""
 parser = OptionParser()
 parser.add_option("-n", "--net",
                   action="store_true", dest="netns", default=False,
@@ -20,6 +22,8 @@ parser.add_option("-p", "--pid",
                   help="Enter pid namespace")
 
 (options, args) = parser.parse_args()
+"""
+args = sys.argv[1:]
 
 try:
        slice_name = args[0]
@@ -56,11 +60,48 @@ if (not slice_spec or not pid):
     print "Not started: %s"%slice_name
     exit(1)
 
-r1 = setns.chcontext('/proc/%s/ns/utc'%pid)
+# Enter cgroups
+try:
+    for subsystem in ['cpuset','memory','blkio']:
+        open('/sys/fs/cgroup/%s/libvirt/lxc/%s/tasks'%(subsystem,slice_name),'w').write(str(os.getpid()))
+
+except:
+    print "Error assigning resources: %s"%slice_name
+    exit(1)
+
+try:
+    open('/sys/fs/cgroup/cpuacct/system/libvirtd.service/libvirt/lxc/%s/tasks'%slice_name,'w').write(str(os.getpid()))
+except:
+    print "Error assigning cpuacct: %s" % slice_name
+    exit(1)
+
+# If the slice is frozen, then we'll get an EBUSY when trying to write to the task
+# list for the freezer cgroup. Since the user couldn't do anything anyway, it's best
+# in this case to error out the shell. (an alternative would be to un-freeze it,
+# add the task, and re-freeze it)
+try:
+    f=open('/sys/fs/cgroup/freezer/libvirt/lxc/%s/tasks'%(slice_name),'w')
+    f.write(str(os.getpid()))
+    # note: we need to call f.close() explicitly, or we'll get an exception in
+    # the object destructor, which will not be caught
+    f.close()
+except:
+    print "Error adding task to freezer cgroup. Slice is probably frozen: %s" % slice_name
+    exit(1)
+
+r1 = setns.chcontext('/proc/%s/ns/uts'%pid)
 r2 = setns.chcontext('/proc/%s/ns/ipc'%pid)
-path = '/proc/%s/ns/net'%pid
-r3 = setns.chcontext(path)
+r3 = setns.chcontext('/proc/%s/ns/net'%pid)
 
 open('/proc/lxcsu','w').write(pid)
 open('/proc/pidsu','w').write(pid)
-os.execv('/usr/sbin/capsh',['--drop',drop_capabilities,'--'])
+
+pid = os.fork()
+
+cap_args = map(lambda c:'--drop='+c, drop_capabilities)
+    
+if (pid == 0):
+    os.environ['SHELL'] = '/bin/sh'
+    os.execv('/usr/sbin/capsh',cap_args+['--','--login']+args[1:])
+else:
+    os.waitpid(pid,0)