libcgroup: Add more debug statements

From: Vivek Goyal <vgoyal@redhat.com>

o Add some more debug statements

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
git-svn-id: https://libcg.svn.sourceforge.net/svnroot/libcg/trunk@115 4f4bb910-9a46-0410-90c8-c897d4f1cd53

diff --git a/api.c b/api.c
index acc00e56f85aa2f8acd78d921954de89aa02e368..150f186ea4a98c2ba44cd297eeb3e4f50ea4ac93 100644 (file)
--- a/api.c
+++ b/api.c
@@ -306,9 +306,10 @@ int cgroup_attach_task_pid(struct cgroup *cgroup, pid_t tid)
        FILE *tasks;
        int i;
 
-       if (!cgroup_initialized)
+       if (!cgroup_initialized) {
+               dbg ("libcgroup is not initialized\n");
                return ECGROUPNOTINITIALIZED;
-
+       }
        if(!cgroup)
        {
                pthread_rwlock_rdlock(&cg_mount_table_lock);
@@ -335,8 +336,11 @@ int cgroup_attach_task_pid(struct cgroup *cgroup, pid_t tid)
                pthread_rwlock_unlock(&cg_mount_table_lock);
        } else {
                for (i = 0; i < cgroup->index; i++) {
-                       if (!cgroup_test_subsys_mounted(cgroup->controller[i]->name))
+                       if (!cgroup_test_subsys_mounted(cgroup->controller[i]->name)) {
+                               dbg("subsystem %s is not mounted\n",
+                                       cgroup->controller[i]->name);
                                return ECGROUPSUBSYSNOTMOUNTED;
+                       }
                }
                for (i = 0; i < cgroup->index; i++) {
                        if (!cg_build_path(cgroup->name, path,
@@ -347,6 +351,9 @@ int cgroup_attach_task_pid(struct cgroup *cgroup, pid_t tid)
 
                        tasks = fopen(path, "w");
                        if (!tasks) {
+                               dbg("fopen failed for %s:%s", path,
+                                                       strerror(errno));
+
                                switch (errno) {
                                case EPERM:
                                        return ECGROUPNOTOWNER;
@@ -469,8 +476,11 @@ int cgroup_modify_cgroup(struct cgroup *cgroup)
                return ECGROUPNOTALLOWED;
 
        for (i = 0; i < cgroup->index; i++) {
-               if (!cgroup_test_subsys_mounted(cgroup->controller[i]->name))
+               if (!cgroup_test_subsys_mounted(cgroup->controller[i]->name)) {
+                       dbg("subsystem %s is not mounted\n",
+                               cgroup->controller[i]->name);
                        return ECGROUPSUBSYSNOTMOUNTED;
+               }
        }
 
        for (i = 0; i < cgroup->index; i++, strcpy(path, base)) {