systemctl: don't show cgroup field for a unit if cgroup is empty

[elogind.git] / src / shared / cgroup-util.c

diff --git a/src/shared/cgroup-util.c b/src/shared/cgroup-util.c
index d34c142729da00f229d4e9dc103fd4ba2c5711d1..18cbf0412ab823ec5d9045c1b0ef2f8238857e71 100644 (file)
--- a/src/shared/cgroup-util.c
+++ b/src/shared/cgroup-util.c
@@ -34,6 +34,7 @@
 #include "set.h"
 #include "macro.h"
 #include "util.h"
+#include "path-util.h"
 #include "strv.h"
 
 int cg_enumerate_processes(const char *controller, const char *path, FILE **_f) {
@@ -521,16 +522,16 @@ static int join_path(const char *controller, const char *path, const char *suffi
 
         if (controller) {
                 if (path && suffix)
-                        t = join("/sys/fs/cgroup/", controller, "/", path, "/", suffix, NULL);
+                        t = strjoin("/sys/fs/cgroup/", controller, "/", path, "/", suffix, NULL);
                 else if (path)
-                        t = join("/sys/fs/cgroup/", controller, "/", path, NULL);
+                        t = strjoin("/sys/fs/cgroup/", controller, "/", path, NULL);
                 else if (suffix)
-                        t = join("/sys/fs/cgroup/", controller, "/", suffix, NULL);
+                        t = strjoin("/sys/fs/cgroup/", controller, "/", suffix, NULL);
                 else
-                        t = join("/sys/fs/cgroup/", controller, NULL);
+                        t = strjoin("/sys/fs/cgroup/", controller, NULL);
         } else {
                 if (path && suffix)
-                        t = join(path, "/", suffix, NULL);
+                        t = strjoin(path, "/", suffix, NULL);
                 else if (path)
                         t = strdup(path);
         }
@@ -565,9 +566,23 @@ int cg_get_path(const char *controller, const char *path, const char *suffix, ch
         return join_path(p, path, suffix, fs);
 }
 
+static int check(const char *p) {
+        char *cc;
+
+        assert(p);
+
+        /* Check if this controller actually really exists */
+        cc = alloca(sizeof("/sys/fs/cgroup/") + strlen(p));
+        strcpy(stpcpy(cc, "/sys/fs/cgroup/"), p);
+        if (access(cc, F_OK) < 0)
+                return -errno;
+
+        return 0;
+}
+
 int cg_get_path_and_check(const char *controller, const char *path, const char *suffix, char **fs) {
         const char *p;
-        char *cc;
+        int r;
 
         assert(controller);
         assert(fs);
@@ -575,13 +590,13 @@ int cg_get_path_and_check(const char *controller, const char *path, const char *
         if (isempty(controller))
                 return -EINVAL;
 
+        /* Normalize the controller syntax */
         p = normalize_controller(controller);
 
         /* Check if this controller actually really exists */
-        cc = alloca(sizeof("/sys/fs/cgroup/") + strlen(p));
-        strcpy(stpcpy(cc, "/sys/fs/cgroup/"), p);
-        if (access(cc, F_OK) < 0)
-                return -errno;
+        r = check(p);
+        if (r < 0)
+                return r;
 
         return join_path(p, path, suffix, fs);
 }
@@ -659,7 +674,7 @@ int cg_delete(const char *controller, const char *path) {
         assert(controller);
         assert(path);
 
-        if ((r = parent_of_path(path, &parent)) < 0)
+        if ((r = path_get_parent(path, &parent)) < 0)
                 return r;
 
         r = cg_migrate_recursive(controller, path, parent, false, true);
@@ -919,6 +934,20 @@ int cg_is_empty(const char *controller, const char *path, bool ignore_self) {
         return !found;
 }
 
+int cg_is_empty_by_spec(const char *spec, bool ignore_self) {
+        int r;
+        _cleanup_free_ char *controller = NULL, *path = NULL;
+
+        assert(spec);
+
+        r = cg_split_spec(spec, &controller, &path);
+        if (r < 0)
+                return r;
+
+        return cg_is_empty(controller, path, ignore_self);
+}
+
+
 int cg_is_empty_recursive(const char *controller, const char *path, bool ignore_self) {
         int r;
         DIR *d = NULL;
@@ -1111,17 +1140,18 @@ char **cg_shorten_controllers(char **controllers) {
                 return controllers;
 
         for (f = controllers, t = controllers; *f; f++) {
-                char *cc;
+                int r;
+                const char *p;
 
                 if (streq(*f, "systemd") || streq(*f, SYSTEMD_CGROUP_CONTROLLER)) {
                         free(*f);
                         continue;
                 }
 
-                cc = alloca(sizeof("/sys/fs/cgroup/") + strlen(*f));
-                strcpy(stpcpy(cc, "/sys/fs/cgroup/"), *f);
+                p = normalize_controller(*f);
 
-                if (access(cc, F_OK) < 0) {
+                r = check(p);
+                if (r < 0) {
                         log_debug("Controller %s is not available, removing from controllers list.", *f);
                         free(*f);
                         continue;
@@ -1133,3 +1163,108 @@ char **cg_shorten_controllers(char **controllers) {
         *t = NULL;
         return controllers;
 }
+
+int cg_pid_get_cgroup(pid_t pid, char **root, char **cgroup) {
+        char *cg_process, *cg_init, *p;
+        int r;
+
+        assert(pid >= 0);
+
+        if (pid == 0)
+                pid = getpid();
+
+        r = cg_get_by_pid(SYSTEMD_CGROUP_CONTROLLER, pid, &cg_process);
+        if (r < 0)
+                return r;
+
+        r = cg_get_by_pid(SYSTEMD_CGROUP_CONTROLLER, 1, &cg_init);
+        if (r < 0) {
+                free(cg_process);
+                return r;
+        }
+
+        if (endswith(cg_init, "/system"))
+                cg_init[strlen(cg_init)-7] = 0;
+        else if (streq(cg_init, "/"))
+                cg_init[0] = 0;
+
+        if (startswith(cg_process, cg_init))
+                p = cg_process + strlen(cg_init);
+        else
+                p = cg_process;
+
+        free(cg_init);
+
+        if (cgroup) {
+                char* c;
+
+                c = strdup(p);
+                if (!c) {
+                        free(cg_process);
+                        return -ENOMEM;
+                }
+
+                *cgroup = c;
+        }
+
+        if (root) {
+                cg_process[p-cg_process] = 0;
+                *root = cg_process;
+        } else
+                free(cg_process);
+
+        return 0;
+}
+
+int cg_pid_get_unit(pid_t pid, char **unit) {
+        int r;
+        char *cgroup, *p, *at, *b;
+        size_t k;
+
+        assert(pid >= 0);
+        assert(unit);
+
+        r = cg_pid_get_cgroup(pid, NULL, &cgroup);
+        if (r < 0)
+                return r;
+
+        if (!startswith(cgroup, "/system/")) {
+                free(cgroup);
+                return -ENOENT;
+        }
+
+        p = cgroup + 8;
+        k = strcspn(p, "/");
+
+        at = memchr(p, '@', k);
+        if (at && at[1] == '.') {
+                size_t j;
+
+                /* This is a templated service */
+                if (p[k] != '/') {
+                        free(cgroup);
+                        return -EIO;
+                }
+
+                j = strcspn(p+k+1, "/");
+
+                b = malloc(k + j + 1);
+
+                if (b) {
+                        memcpy(b, p, at - p + 1);
+                        memcpy(b + (at - p) + 1, p + k + 1, j);
+                        memcpy(b + (at - p) + 1 + j, at + 1, k - (at - p) - 1);
+                        b[k+j] = 0;
+                }
+        } else
+                  b = strndup(p, k);
+
+        free(cgroup);
+
+        if (!b)
+                return -ENOMEM;
+
+        *unit = b;
+        return 0;
+
+}