1 files changed, 67 insertions, 13 deletions

diff --git a/src/basic/util.c b/src/basic/util.c
index 756c663be4..09d16697b7 100644
--- a/src/basic/util.c
+++ b/src/basic/util.c
@@ -36,6 +36,7 @@
 
 #include "alloc-util.h"
 #include "build.h"
+#include "cgroup-util.h"
 #include "def.h"
 #include "dirent-util.h"
 #include "fd-util.h"
@@ -64,6 +65,7 @@ assert_cc(EAGAIN == EWOULDBLOCK);
 
 int saved_argc = 0;
 char **saved_argv = NULL;
+static int saved_in_initrd = -1;
 
 size_t page_size(void) {
         static thread_local size_t pgsz = 0;
@@ -454,11 +456,10 @@ int fork_agent(pid_t *pid, const int except[], unsigned n_except, const char *pa
 }
 
 bool in_initrd(void) {
-        static int saved = -1;
         struct statfs s;
 
-        if (saved >= 0)
-                return saved;
+        if (saved_in_initrd >= 0)
+                return saved_in_initrd;
 
         /* We make two checks here:
          *
@@ -470,11 +471,15 @@ bool in_initrd(void) {
          * emptying when transititioning to the main systemd.
          */
 
-        saved = access("/etc/initrd-release", F_OK) >= 0 &&
-                statfs("/", &s) >= 0 &&
-                is_temporary_fs(&s);
+        saved_in_initrd = access("/etc/initrd-release", F_OK) >= 0 &&
+                          statfs("/", &s) >= 0 &&
+                          is_temporary_fs(&s);
 
-        return saved;
+        return saved_in_initrd;
+}
+
+void in_initrd_force(bool value) {
+        saved_in_initrd = value;
 }
 
 /* hey glibc, APIs with callbacks without a user pointer are so useless */
@@ -767,15 +772,64 @@ int namespace_enter(int pidns_fd, int mntns_fd, int netns_fd, int userns_fd, int
 }
 
 uint64_t physical_memory(void) {
-        long mem;
+        _cleanup_free_ char *root = NULL, *value = NULL;
+        uint64_t mem, lim;
+        size_t ps;
+        long sc;
+
+        /* We return this as uint64_t in case we are running as 32bit process on a 64bit kernel with huge amounts of
+         * memory.
+         *
+         * In order to support containers nicely that have a configured memory limit we'll take the minimum of the
+         * physically reported amount of memory and the limit configured for the root cgroup, if there is any. */
+
+        sc = sysconf(_SC_PHYS_PAGES);
+        assert(sc > 0);
+
+        ps = page_size();
+        mem = (uint64_t) sc * (uint64_t) ps;
+
+        if (cg_get_root_path(&root) < 0)
+                return mem;
+
+        if (cg_get_attribute("memory", root, "memory.limit_in_bytes", &value))
+                return mem;
+
+        if (safe_atou64(value, &lim) < 0)
+                return mem;
+
+        /* Make sure the limit is a multiple of our own page size */
+        lim /= ps;
+        lim *= ps;
+
+        return MIN(mem, lim);
+}
+
+uint64_t physical_memory_scale(uint64_t v, uint64_t max) {
+        uint64_t p, m, ps, r;
+
+        assert(max > 0);
+
+        /* Returns the physical memory size, multiplied by v divided by max. Returns UINT64_MAX on overflow. On success
+         * the result is a multiple of the page size (rounds down). */
+
+        ps = page_size();
+        assert(ps > 0);
+
+        p = physical_memory() / ps;
+        assert(p > 0);
+
+        m = p * v;
+        if (m / p != v)
+                return UINT64_MAX;
 
-        /* We return this as uint64_t in case we are running as 32bit
-         * process on a 64bit kernel with huge amounts of memory */
+        m /= max;
 
-        mem = sysconf(_SC_PHYS_PAGES);
-        assert(mem > 0);
+        r = m * ps;
+        if (r / ps != m)
+                return UINT64_MAX;
 
-        return (uint64_t) mem * (uint64_t) page_size();
+        return r;
 }
 
 int update_reboot_parameter_and_warn(const char *param) {