check return codes and print warnings when suspicius
[lxc-userspace.git] / lxcsu
diff --git a/lxcsu b/lxcsu
index 078d275..a9ff3d6 100755 (executable)
--- a/lxcsu
+++ b/lxcsu
@@ -3,6 +3,7 @@
 import sys
 import os
 import setns
+import pdb
 
 from argparse import ArgumentParser
 
@@ -11,129 +12,6 @@ drop_capabilities='cap_sys_admin,cap_sys_boot,cap_sys_module'
 # can set to True here, but also use the -d option
 debug = False
 
-#################### should go into a separate libvirtsystemd.py
-# but we want to keep packaging simple for now
-
-# reproducing libvirt's systemd-oriented escaping mechanism
-# http://code.metager.de/source/xref/lib/virt/src/util/virsystemd.c
-# (see original code at the end of this file)
-
-def virSystemdEscapeName (name):
-    result=''
-    def ESCAPE(c,s):
-        # replace hex's output '0x..' into '\x..' 
-        return s+hex(ord(c)).replace('0','\\',1)
-    VALID_CHARS = \
-        "0123456789" + \
-        "abcdefghijklmnopqrstuvwxyz" + \
-        "ABCDEFGHIJKLMNOPQRSTUVWXYZ" + \
-        ":-_.\\"
-    for c in name:
-        if c=='/': 
-            result += '-'
-        elif c in '-\\' or c not in VALID_CHARS:
-            result=ESCAPE(c,result)
-        else:
-            result += c
-    return result
-
-#35static void virSystemdEscapeName(virBufferPtr buf,
-#36                                 const char *name)
-#37{
-#38    static const char hextable[16] = "0123456789abcdef";
-#39
-#40#define ESCAPE(c)                                                       \
-#41    do {                                                                \
-#42        virBufferAddChar(buf, '\\');                                    \
-#43        virBufferAddChar(buf, 'x');                                     \
-#44        virBufferAddChar(buf, hextable[(c >> 4) & 15]);                 \
-#45        virBufferAddChar(buf, hextable[c & 15]);                        \
-#46    } while (0)
-#47
-#48#define VALID_CHARS                             \
-#49        "0123456789"                            \
-#50        "abcdefghijklmnopqrstuvwxyz"            \
-#51        "ABCDEFGHIJKLMNOPQRSTUVWXYZ"            \
-#52        ":-_.\\"
-#53
-#54    if (*name == '.') {
-#55        ESCAPE(*name);
-#56        name++;
-#57    }
-#58
-#59    while (*name) {
-#60        if (*name == '/')
-#61            virBufferAddChar(buf, '-');
-#62        else if (*name == '-' ||
-#63                 *name == '\\' ||
-#64                 !strchr(VALID_CHARS, *name))
-#65            ESCAPE(*name);
-#66        else
-#67            virBufferAddChar(buf, *name);
-#68        name++;
-#69    }
-#70
-#71#undef ESCAPE
-#72#undef VALID_CHARS
-#73}
-
-def virSystemdMakeScopeName (name, drivername, partition):
-    result=''
-    result += virSystemdEscapeName (partition)
-    result += '-'
-    result += virSystemdEscapeName (drivername)
-    result += '\\x2d'
-    result += virSystemdEscapeName (name)
-    result += '.scope'
-    return result
-
-#76char *virSystemdMakeScopeName(const char *name,
-#77                              const char *drivername,
-#78                              const char *partition)
-#79{
-#80    virBuffer buf = VIR_BUFFER_INITIALIZER;
-#81
-#82    if (*partition == '/')
-#83        partition++;
-#84
-#85    virSystemdEscapeName(&buf, partition);
-#86    virBufferAddChar(&buf, '-');
-#87    virSystemdEscapeName(&buf, drivername);
-#88    virBufferAddLit(&buf, "\\x2d");
-#89    virSystemdEscapeName(&buf, name);
-#90    virBufferAddLit(&buf, ".scope");
-#91
-#92    if (virBufferError(&buf)) {
-#93        virReportOOMError();
-#94        return NULL;
-#95    }
-#96
-#97    return virBufferContentAndReset(&buf);
-#98}
-
-### our own additions
-import os.path
-def find_first_dir (candidates):
-    for candidate in candidates:
-        if os.path.isdir(candidate): return candidate
-    raise Exception,"Cannot find valid dir among %s"%'\n'.join(candidates)
-
-def find_sysfs_scope (subsystem, slice_name):
-    subsystem1=subsystem
-    subsystem2=subsystem
-    if subsystem=='cpuacct':
-        subsystem2='cpu,cpuacct'
-    candidates = [ 
-        # for f16 and our locally brewed libvirt 1.0.4
-        "/sys/fs/cgroup/%s/libvirt/lxc/%s"%(subsystem1, slice_name),
-        # f20 and libvirt 1.1.3
-        "/sys/fs/cgroup/%s/machine.slice/%s"%(subsystem2, 
-                                              virSystemdMakeScopeName(slice_name,'lxc','machine')),
-        ]
-    return find_first_dir (candidates)
-
-#################### end of libvirtsystemd.py
-
 def getarch(f):
     output = os.popen('readelf -h %s 2>&1'%f).readlines()
     classlines = [x for x in output if ('Class' in x.split(':')[0])]
@@ -146,6 +24,22 @@ def getarch(f):
     else:
         raise Exception('Could not determine architecture')
 
+def get_cgroup_subdirs_for_pid(pid):
+    cgroup_info_file = '/proc/%s/cgroup'%pid
+    cgroup_lines = open(cgroup_info_file).read().splitlines()
+    
+    subdirs = {}
+    for line in cgroup_lines:
+        try:
+            _, cgroup_name, subdir = line.split(':')
+            subdirs[cgroup_name] = subdir
+        except Exception, e:
+            print "Error reading cgroup info: %s"%str(e)
+            pass
+    
+    return subdirs
+        
+    
 def umount(fs_dir, opts=''):
     output = os.popen('/bin/umount %s %s 2>&1'%(opts, fs_dir)).read()
     return ('device is busy' not in output)
@@ -210,7 +104,7 @@ def main ():
         cmd = '/usr/bin/virsh --connect lxc:/// domid %s'%slice_name
        pidnum = int(os.popen(cmd).read().rstrip())
     except:
-        print "Error finding slice %s"%slice_name
+        print "Domain %s not found"%slice_name
        exit(1)
 
     pid = '%s'%pidnum
@@ -219,7 +113,7 @@ def main ():
     arch = getarch('/proc/%s/exe'%pid)
 
     if (not pid):
-        print "Not started: %s"%slice_name
+        print "Domain %s not started"%slice_name
        exit(1)
 
     if arch is None:
@@ -238,49 +132,69 @@ def main ():
                sysctl_val = open(sysctl_file).read()
                sysctls.append((sysctl_file, sysctl_name, sysctl_val))
 
-    # Enter cgroups
-    try:
-       for subsystem in ['cpuset','memory','blkio']:
-            open( find_sysfs_scope (subsystem, slice_name)+"/tasks", 'w').write(str(os.getpid()))
-
-    except Exception,e:
-       if debug: print e 
-       print "Error assigning resources: %s"%slice_name
-       exit(1)
-
-    try:
-        open ( find_sysfs_scope ('cpuacct', slice_name)+"/tasks", 'w').write(str(os.getpid()))
-    except Exception,e:
-       if debug: print e 
-       print "Error assigning cpuacct: %s" % slice_name
-       exit(1)
+    subdirs = get_cgroup_subdirs_for_pid(pid) 
+    sysfs_root = '/sys/fs/cgroup'
 
     # 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( find_sysfs_scope ('freezer', slice_name)+"/tasks", '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 Exception,e:
-       if debug: print e 
-       print "Error adding task to freezer cgroup. Slice is probably frozen: %s" % slice_name
-       exit(1)
+    # Enter cgroups
+    current_cgroup = ''
+    for subsystem in ['cpuset','memory','blkio','cpuacct','cpuacct,cpu','freezer']:
+        try:
+            current_cgroup = subsystem
+
+            # There seems to be a bug in the cgroup schema: cpuacct,cpu can become cpu,cpuacct
+            # We need to handle both
+            task_path_alt = None
+            try:
+               subsystem_comps = subsystem.split(',')
+               subsystem_comps.reverse()
+               subsystem_alt = ','.join(subsystem_comps)
+               tasks_path_alt = [sysfs_root, subsystem_alt, subdirs[subsystem], 'tasks']
+            except Exception,e:
+                pass
+               
+            tasks_path = [sysfs_root,subsystem,subdirs[subsystem],'tasks']
+            tasks_path_str = '/'.join(tasks_path)
+     
+            try:
+                f = open(tasks_path_str, 'w')
+            except:
+                tasks_path_alt_str = '/'.join(tasks_path_alt)
+                f = open(tasks_path_alt_str, 'w')
+
+            f.write(str(os.getpid()))
+            if (subsystem=='freezer'):
+                f.close()
+
+        except Exception,e:
+            if (not subdirs.has_key(subsystem)):
+                pass
+            else:
+                if debug: print e 
+                print "Error assigning cgroup %s (%s) for slice %s"%(current_cgroup,pid, slice_name)
+                exit(1)
+
+
+    def chcontext (path):
+        retcod = setns.chcontext (path)
+        if retcod != 0:
+            print 'WARNING - setns(%s)=>%s (ignored)'%(path,retcod)
+        return retcod
 
-    setns.chcontext('/proc/%s/ns/uts'%pid)
-    setns.chcontext('/proc/%s/ns/ipc'%pid)
+    chcontext('/proc/%s/ns/uts'%pid)
+    chcontext('/proc/%s/ns/ipc'%pid)
        
     if (not args.pidns):
-       setns.chcontext('/proc/%s/ns/pid'%pid)
+       chcontext('/proc/%s/ns/pid'%pid)
 
     if (not args.netns):
-       setns.chcontext('/proc/%s/ns/net'%pid)
+       chcontext('/proc/%s/ns/net'%pid)
 
     if (not args.mntns):
-       setns.chcontext('/proc/%s/ns/mnt'%pid)
+       chcontext('/proc/%s/ns/mnt'%pid)
 
     proc_mounted = False
     if (not os.access('/proc/self',0)):
@@ -302,6 +216,7 @@ def main ():
     for subsystem in ['cpuset','cpu,cpuacct','memory','devices','freezer','net_cls','blkio','perf_event','systemd']:
        fs_path = '/sys/fs/cgroup/%s'%subsystem
        if (not umount(fs_path,'-l')):
+            print 'WARNING - umount failed (ignored) with path=',fs_path
            pass
            # Leaving these comments for historical reference
            #print "Error disabling cgroup access"