Merge pull request #7381 from poettering/cgroup-unified-delegate-rework

Fix delegation in the unified hierarchy + more cgroup work

src/basic/cgroup-util.c

@@ -1104,6 +1104,11 @@ int cg_pid_get_path(const char *controller, pid_t pid, char **path) {
                 if (!p)
                         return -ENOMEM;
 
+                /* Truncate suffix indicating the process is a zombie */
+                e = endswith(p, " (deleted)");
+                if (e)
+                        *e = 0;
+
                 *path = p;
                 return 0;
         }
@@ -2369,21 +2374,29 @@ int cg_mask_supported(CGroupMask *ret) {
         return 0;
 }
 
-int cg_kernel_controllers(Set *controllers) {
+int cg_kernel_controllers(Set **ret) {
+        _cleanup_set_free_free_ Set *controllers = NULL;
         _cleanup_fclose_ FILE *f = NULL;
         int r;
 
-        assert(controllers);
+        assert(ret);
 
         /* Determines the full list of kernel-known controllers. Might
          * include controllers we don't actually support, arbitrary
          * named hierarchies and controllers that aren't currently
          * accessible (because not mounted). */
 
+        controllers = set_new(&string_hash_ops);
+        if (!controllers)
+                return -ENOMEM;
+
         f = fopen("/proc/cgroups", "re");
         if (!f) {
-                if (errno == ENOENT)
+                if (errno == ENOENT) {
+                        *ret = NULL;
                         return 0;
+                }
+
                 return -errno;
         }
 
@@ -2421,6 +2434,9 @@ int cg_kernel_controllers(Set *controllers) {
                         return r;
         }
 
+        *ret = controllers;
+        controllers = NULL;
+
         return 0;
 }
 
@@ -2530,6 +2546,7 @@ int cg_unified_flush(void) {
 }
 
 int cg_enable_everywhere(CGroupMask supported, CGroupMask mask, const char *p) {
+        _cleanup_fclose_ FILE *f = NULL;
         _cleanup_free_ char *fs = NULL;
         CGroupController c;
         int r;
@@ -2563,7 +2580,15 @@ int cg_enable_everywhere(CGroupMask supported, CGroupMask mask, const char *p) {
                         s[0] = mask & bit ? '+' : '-';
                         strcpy(s + 1, n);
 
-                        r = write_string_file(fs, s, 0);
+                        if (!f) {
+                                f = fopen(fs, "we");
+                                if (!f) {
+                                        log_debug_errno(errno, "Failed to open cgroup.subtree_control file of %s: %m", p);
+                                        break;
+                                }
+                        }
+
+                        r = write_string_stream(f, s, 0);
                         if (r < 0)
                                 log_debug_errno(r, "Failed to enable controller %s for %s (%s): %m", n, p, fs);
                 }

src/basic/cgroup-util.h

@@ -32,6 +32,10 @@
 #include "macro.h"
 #include "set.h"
 
+#define SYSTEMD_CGROUP_CONTROLLER_LEGACY "name=systemd"
+#define SYSTEMD_CGROUP_CONTROLLER_HYBRID "name=unified"
+#define SYSTEMD_CGROUP_CONTROLLER "_systemd"
+
 /* An enum of well known cgroup controllers */
 typedef enum CGroupController {
         CGROUP_CONTROLLER_CPU,
@@ -239,7 +243,7 @@ int cg_mask_supported(CGroupMask *ret);
 int cg_mask_from_string(const char *s, CGroupMask *ret);
 int cg_mask_to_string(CGroupMask mask, char **ret);
 
-int cg_kernel_controllers(Set *controllers);
+int cg_kernel_controllers(Set **controllers);
 
 bool cg_ns_supported(void);
 

src/basic/def.h

@@ -37,10 +37,6 @@
 /* The default value for the net.unix.max_dgram_qlen sysctl */
 #define DEFAULT_UNIX_MAX_DGRAM_QLEN 512UL
 
-#define SYSTEMD_CGROUP_CONTROLLER_LEGACY "name=systemd"
-#define SYSTEMD_CGROUP_CONTROLLER_HYBRID "name=unified"
-#define SYSTEMD_CGROUP_CONTROLLER "_systemd"
-
 #define SIGNALS_CRASH_HANDLER SIGSEGV,SIGILL,SIGFPE,SIGBUS,SIGQUIT,SIGABRT
 #define SIGNALS_IGNORE SIGPIPE