1 files changed, 153 insertions, 17 deletions

diff --git a/kernel/cgroup/debug.c b/kernel/cgroup/debug.c
index cbe77a2087c5..057d9b07f461 100644
--- a/kernel/cgroup/debug.c
+++ b/kernel/cgroup/debug.c
@@ -36,10 +36,37 @@ static u64 debug_taskcount_read(struct cgroup_subsys_state *css,
         return cgroup_task_count(css->cgroup);
 }
 
-static u64 current_css_set_read(struct cgroup_subsys_state *css,
-                                struct cftype *cft)
+static int current_css_set_read(struct seq_file *seq, void *v)
 {
-        return (u64)(unsigned long)current->cgroups;
+        struct css_set *cset;
+        struct cgroup_subsys *ss;
+        struct cgroup_subsys_state *css;
+        int i, refcnt;
+
+        mutex_lock(&cgroup_mutex);
+        spin_lock_irq(&css_set_lock);
+        rcu_read_lock();
+        cset = rcu_dereference(current->cgroups);
+        refcnt = refcount_read(&cset->refcount);
+        seq_printf(seq, "css_set %pK %d", cset, refcnt);
+        if (refcnt > cset->nr_tasks)
+                seq_printf(seq, " +%d", refcnt - cset->nr_tasks);
+        seq_puts(seq, "\n");
+
+        /*
+         * Print the css'es stored in the current css_set.
+         */
+        for_each_subsys(ss, i) {
+                css = cset->subsys[ss->id];
+                if (!css)
+                        continue;
+                seq_printf(seq, "%2d: %-4s\t- %lx[%d]\n", ss->id, ss->name,
+                          (unsigned long)css, css->id);
+        }
+        rcu_read_unlock();
+        spin_unlock_irq(&css_set_lock);
+        mutex_unlock(&cgroup_mutex);
+        return 0;
 }
 
 static u64 current_css_set_refcount_read(struct cgroup_subsys_state *css,
@@ -84,31 +111,126 @@ static int cgroup_css_links_read(struct seq_file *seq, void *v)
 {
         struct cgroup_subsys_state *css = seq_css(seq);
         struct cgrp_cset_link *link;
+        int dead_cnt = 0, extra_refs = 0;
 
         spin_lock_irq(&css_set_lock);
         list_for_each_entry(link, &css->cgroup->cset_links, cset_link) {
                 struct css_set *cset = link->cset;
                 struct task_struct *task;
                 int count = 0;
+                int refcnt = refcount_read(&cset->refcount);
 
-                seq_printf(seq, "css_set %pK\n", cset);
+                seq_printf(seq, " %d", refcnt);
+                if (refcnt - cset->nr_tasks > 0) {
+                        int extra = refcnt - cset->nr_tasks;
+
+                        seq_printf(seq, " +%d", extra);
+                        /*
+                         * Take out the one additional reference in
+                         * init_css_set.
+                         */
+                        if (cset == &init_css_set)
+                                extra--;
+                        extra_refs += extra;
+                }
+                seq_puts(seq, "\n");
 
                 list_for_each_entry(task, &cset->tasks, cg_list) {
-                        if (count++ > MAX_TASKS_SHOWN_PER_CSS)
-                                goto overflow;
-                        seq_printf(seq, "  task %d\n", task_pid_vnr(task));
+                        if (count++ <= MAX_TASKS_SHOWN_PER_CSS)
+                                seq_printf(seq, "  task %d\n",
+                                           task_pid_vnr(task));
                 }
 
                 list_for_each_entry(task, &cset->mg_tasks, cg_list) {
-                        if (count++ > MAX_TASKS_SHOWN_PER_CSS)
-                                goto overflow;
-                        seq_printf(seq, "  task %d\n", task_pid_vnr(task));
+                        if (count++ <= MAX_TASKS_SHOWN_PER_CSS)
+                                seq_printf(seq, "  task %d\n",
+                                           task_pid_vnr(task));
                 }
-                continue;
-        overflow:
-                seq_puts(seq, "  ...\n");
+                /* show # of overflowed tasks */
+                if (count > MAX_TASKS_SHOWN_PER_CSS)
+                        seq_printf(seq, "  ... (%d)\n",
+                                   count - MAX_TASKS_SHOWN_PER_CSS);
+
+                if (cset->dead) {
+                        seq_puts(seq, "    [dead]\n");
+                        dead_cnt++;
+                }
+
+                WARN_ON(count != cset->nr_tasks);
         }
         spin_unlock_irq(&css_set_lock);
+
+        if (!dead_cnt && !extra_refs)
+                return 0;
+
+        seq_puts(seq, "\n");
+        if (extra_refs)
+                seq_printf(seq, "extra references = %d\n", extra_refs);
+        if (dead_cnt)
+                seq_printf(seq, "dead css_sets = %d\n", dead_cnt);
+
+        return 0;
+}
+
+static int cgroup_subsys_states_read(struct seq_file *seq, void *v)
+{
+        struct cgroup *cgrp = seq_css(seq)->cgroup;
+        struct cgroup_subsys *ss;
+        struct cgroup_subsys_state *css;
+        char pbuf[16];
+        int i;
+
+        mutex_lock(&cgroup_mutex);
+        for_each_subsys(ss, i) {
+                css = rcu_dereference_check(cgrp->subsys[ss->id], true);
+                if (!css)
+                        continue;
+
+                pbuf[0] = '\0';
+
+                /* Show the parent CSS if applicable*/
+                if (css->parent)
+                        snprintf(pbuf, sizeof(pbuf) - 1, " P=%d",
+                                 css->parent->id);
+                seq_printf(seq, "%2d: %-4s\t- %lx[%d] %d%s\n", ss->id, ss->name,
+                          (unsigned long)css, css->id,
+                          atomic_read(&css->online_cnt), pbuf);
+        }
+        mutex_unlock(&cgroup_mutex);
+        return 0;
+}
+
+static int cgroup_masks_read(struct seq_file *seq, void *v)
+{
+        struct cgroup *cgrp = seq_css(seq)->cgroup;
+        struct cgroup_subsys *ss;
+        int i, j;
+        struct {
+                u16  *mask;
+                char *name;
+        } mask_list[] = {
+                { &cgrp->subtree_control,  "subtree_control"  },
+                { &cgrp->subtree_ss_mask,  "subtree_ss_mask"  },
+        };
+
+        mutex_lock(&cgroup_mutex);
+        for (i = 0; i < ARRAY_SIZE(mask_list); i++) {
+                u16 mask = *mask_list[i].mask;
+                bool first = true;
+
+                seq_printf(seq, "%-17s: ", mask_list[i].name);
+                for_each_subsys(ss, j) {
+                        if (!(mask & (1 << ss->id)))
+                                continue;
+                        if (!first)
+                                seq_puts(seq, ", ");
+                        seq_puts(seq, ss->name);
+                        first = false;
+                }
+                seq_putc(seq, '\n');
+        }
+
+        mutex_unlock(&cgroup_mutex);
         return 0;
 }
 
@@ -126,17 +248,20 @@ static struct cftype debug_files[] =  {
 
         {
                 .name = "current_css_set",
-                .read_u64 = current_css_set_read,
+                .seq_show = current_css_set_read,
+                .flags = CFTYPE_ONLY_ON_ROOT,
         },
 
         {
                 .name = "current_css_set_refcount",
                 .read_u64 = current_css_set_refcount_read,
+                .flags = CFTYPE_ONLY_ON_ROOT,
         },
 
         {
                 .name = "current_css_set_cg_links",
                 .seq_show = current_css_set_cg_links_read,
+                .flags = CFTYPE_ONLY_ON_ROOT,
         },
 
         {
@@ -145,6 +270,16 @@ static struct cftype debug_files[] =  {
         },
 
         {
+                .name = "cgroup_subsys_states",
+                .seq_show = cgroup_subsys_states_read,
+        },
+
+        {
+                .name = "cgroup_masks",
+                .seq_show = cgroup_masks_read,
+        },
+
+        {
                 .name = "releasable",
                 .read_u64 = releasable_read,
         },
@@ -153,7 +288,8 @@ static struct cftype debug_files[] =  {
 };
 
 struct cgroup_subsys debug_cgrp_subsys = {
-        .css_alloc = debug_css_alloc,
-        .css_free = debug_css_free,
-        .legacy_cftypes = debug_files,
+        .css_alloc      = debug_css_alloc,
+        .css_free       = debug_css_free,
+        .legacy_cftypes = debug_files,
+        .dfl_cftypes    = debug_files,
 };