cgls: don't show empty cgroups by default

3 files changed, 70 insertions, 49 deletions

diff --git a/src/shared/cgroup-show.c b/src/shared/cgroup-show.c
index 550a2f5f31..5b639e06c8 100644
--- a/src/shared/cgroup-show.c
+++ b/src/shared/cgroup-show.c
@@ -160,7 +160,7 @@ finish:
         return r;
 }
 
-int show_cgroup_by_path(const char *path, const char *prefix, unsigned n_columns, bool kernel_threads) {
+int show_cgroup_by_path(const char *path, const char *prefix, unsigned n_columns, bool kernel_threads, bool all) {
         DIR *d;
         char *last = NULL;
         char *p1 = NULL, *p2 = NULL, *fn = NULL, *gn = NULL;
@@ -173,15 +173,31 @@ int show_cgroup_by_path(const char *path, const char *prefix, unsigned n_columns
         if (!prefix)
                 prefix = "";
 
-        if ((r = cg_fix_path(path, &fn)) < 0)
+        r = cg_fix_path(path, &fn);
+        if (r < 0)
                 return r;
 
-        if (!(d = opendir(fn))) {
+        d = opendir(fn);
+        if (!d) {
                 free(fn);
                 return -errno;
         }
 
         while ((r = cg_read_subgroup(d, &gn)) > 0) {
+                char *k;
+
+                r = asprintf(&k, "%s/%s", fn, gn);
+                free(gn);
+
+                if (r < 0) {
+                        r = -ENOMEM;
+                        goto finish;
+                }
+
+                if (!all && cg_is_empty_recursive(NULL, k, false) > 0) {
+                        free(k);
+                        continue;
+                }
 
                 if (!shown_pids) {
                         show_cgroup_one_by_path(path, prefix, n_columns, true, kernel_threads);
@@ -191,25 +207,20 @@ int show_cgroup_by_path(const char *path, const char *prefix, unsigned n_columns
                 if (last) {
                         printf("%s\342\224\234 %s\n", prefix, file_name_from_path(last));
 
-                        if (!p1)
-                                if (!(p1 = strappend(prefix, "\342\224\202 "))) {
+                        if (!p1) {
+                                p1 = strappend(prefix, "\342\224\202 ");
+                                if (!p1) {
+                                        free(k);
                                         r = -ENOMEM;
                                         goto finish;
                                 }
+                        }
 
-                        show_cgroup_by_path(last, p1, n_columns-2, kernel_threads);
-
+                        show_cgroup_by_path(last, p1, n_columns-2, kernel_threads, all);
                         free(last);
-                        last = NULL;
                 }
 
-                r = asprintf(&last, "%s/%s", fn, gn);
-                free(gn);
-
-                if (r < 0) {
-                        r = -ENOMEM;
-                        goto finish;
-                }
+                last = k;
         }
 
         if (r < 0)
@@ -221,13 +232,15 @@ int show_cgroup_by_path(const char *path, const char *prefix, unsigned n_columns
         if (last) {
                 printf("%s\342\224\224 %s\n", prefix, file_name_from_path(last));
 
-                if (!p2)
-                        if (!(p2 = strappend(prefix, "  "))) {
+                if (!p2) {
+                        p2 = strappend(prefix, "  ");
+                        if (!p2) {
                                 r = -ENOMEM;
                                 goto finish;
                         }
+                }
 
-                show_cgroup_by_path(last, p2, n_columns-2, kernel_threads);
+                show_cgroup_by_path(last, p2, n_columns-2, kernel_threads, all);
         }
 
         r = 0;
@@ -243,7 +256,7 @@ finish:
         return r;
 }
 
-int show_cgroup(const char *controller, const char *path, const char *prefix, unsigned n_columns, bool kernel_threads) {
+int show_cgroup(const char *controller, const char *path, const char *prefix, unsigned n_columns, bool kernel_threads, bool all) {
         char *p;
         int r;
 
@@ -254,7 +267,7 @@ int show_cgroup(const char *controller, const char *path, const char *prefix, un
         if (r < 0)
                 return r;
 
-        r = show_cgroup_by_path(p, prefix, n_columns, kernel_threads);
+        r = show_cgroup_by_path(p, prefix, n_columns, kernel_threads, all);
         free(p);
 
         return r;
diff --git a/src/shared/cgroup-show.h b/src/shared/cgroup-show.h
index 5433f46a53..e1d67a3291 100644
--- a/src/shared/cgroup-show.h
+++ b/src/shared/cgroup-show.h
@@ -24,7 +24,7 @@
 
 #include <stdbool.h>
 
-int show_cgroup_by_path(const char *path, const char *prefix, unsigned columns, bool kernel_threads);
-int show_cgroup(const char *controller, const char *path, const char *prefix, unsigned columns, bool kernel_threads);
+int show_cgroup_by_path(const char *path, const char *prefix, unsigned columns, bool kernel_threads, bool all);
+int show_cgroup(const char *controller, const char *path, const char *prefix, unsigned columns, bool kernel_threads, bool all);
 
 #endif
diff --git a/src/shared/cgroup-util.c b/src/shared/cgroup-util.c
index b2fb324a18..48da4cb3b7 100644
--- a/src/shared/cgroup-util.c
+++ b/src/shared/cgroup-util.c
@@ -40,11 +40,11 @@ int cg_enumerate_processes(const char *controller, const char *path, FILE **_f)
         int r;
         FILE *f;
 
-        assert(controller);
         assert(path);
         assert(_f);
 
-        if ((r = cg_get_path(controller, path, "cgroup.procs", &fs)) < 0)
+        r = cg_get_path(controller, path, "cgroup.procs", &fs);
+        if (r < 0)
                 return r;
 
         f = fopen(fs, "re");
@@ -62,11 +62,11 @@ int cg_enumerate_tasks(const char *controller, const char *path, FILE **_f) {
         int r;
         FILE *f;
 
-        assert(controller);
         assert(path);
         assert(_f);
 
-        if ((r = cg_get_path(controller, path, "tasks", &fs)) < 0)
+        r = cg_get_path(controller, path, "tasks", &fs);
+        if (r < 0)
                 return r;
 
         f = fopen(fs, "re");
@@ -106,13 +106,13 @@ int cg_enumerate_subgroups(const char *controller, const char *path, DIR **_d) {
         int r;
         DIR *d;
 
-        assert(controller);
         assert(path);
         assert(_d);
 
         /* This is not recursive! */
 
-        if ((r = cg_get_path(controller, path, NULL, &fs)) < 0)
+        r = cg_get_path(controller, path, NULL, &fs);
+        if (r < 0)
                 return r;
 
         d = opendir(fs);
@@ -515,14 +515,24 @@ static const char *normalize_controller(const char *controller) {
 static int join_path(const char *controller, const char *path, const char *suffix, char **fs) {
         char *t;
 
-        if (path && suffix)
-                t = join("/sys/fs/cgroup/", controller, "/", path, "/", suffix, NULL);
-        else if (path)
-                t = join("/sys/fs/cgroup/", controller, "/", path, NULL);
-        else if (suffix)
-                t = join("/sys/fs/cgroup/", controller, "/", suffix, NULL);
-        else
-                t = join("/sys/fs/cgroup/", controller, NULL);
+        if (!(controller || path))
+                return -EINVAL;
+
+        if (controller) {
+                if (path && suffix)
+                        t = join("/sys/fs/cgroup/", controller, "/", path, "/", suffix, NULL);
+                else if (path)
+                        t = join("/sys/fs/cgroup/", controller, "/", path, NULL);
+                else if (suffix)
+                        t = join("/sys/fs/cgroup/", controller, "/", suffix, NULL);
+                else
+                        t = join("/sys/fs/cgroup/", controller, NULL);
+        } else {
+                if (path && suffix)
+                        t = join(path, "/", suffix, NULL);
+                else if (path)
+                        t = strdup(path);
+        }
 
         if (!t)
                 return -ENOMEM;
@@ -537,12 +547,8 @@ int cg_get_path(const char *controller, const char *path, const char *suffix, ch
         const char *p;
         static __thread bool good = false;
 
-        assert(controller);
         assert(fs);
 
-        if (isempty(controller))
-                return -EINVAL;
-
         if (_unlikely_(!good)) {
                 int r;
 
@@ -554,8 +560,7 @@ int cg_get_path(const char *controller, const char *path, const char *suffix, ch
                 good = true;
         }
 
-        p = normalize_controller(controller);
-
+        p = controller ? normalize_controller(controller) : NULL;
         return join_path(p, path, suffix, fs);
 }
 
@@ -883,20 +888,22 @@ finish:
 }
 
 int cg_is_empty(const char *controller, const char *path, bool ignore_self) {
-        pid_t pid = 0;
+        pid_t pid = 0, self_pid;
         int r;
         FILE *f = NULL;
         bool found = false;
 
-        assert(controller);
         assert(path);
 
-        if ((r = cg_enumerate_tasks(controller, path, &f)) < 0)
+        r = cg_enumerate_tasks(controller, path, &f);
+        if (r < 0)
                 return r == -ENOENT ? 1 : r;
 
+        self_pid = getpid();
+
         while ((r = cg_read_pid(f, &pid)) > 0) {
 
-                if (ignore_self && pid == getpid())
+                if (ignore_self && pid == self_pid)
                         continue;
 
                 found = true;
@@ -916,13 +923,14 @@ int cg_is_empty_recursive(const char *controller, const char *path, bool ignore_
         DIR *d = NULL;
         char *fn;
 
-        assert(controller);
         assert(path);
 
-        if ((r = cg_is_empty(controller, path, ignore_self)) <= 0)
+        r = cg_is_empty(controller, path, ignore_self);
+        if (r <= 0)
                 return r;
 
-        if ((r = cg_enumerate_subgroups(controller, path, &d)) < 0)
+        r = cg_enumerate_subgroups(controller, path, &d);
+        if (r < 0)
                 return r == -ENOENT ? 1 : r;
 
         while ((r = cg_read_subgroup(d, &fn)) > 0) {