1 files changed, 91 insertions, 1 deletions

diff --git a/src/shared/sleep-config.c b/src/shared/sleep-config.c
index cd3238b405..d068bfce3c 100644
--- a/src/shared/sleep-config.c
+++ b/src/shared/sleep-config.c
@@ -163,6 +163,93 @@ int can_sleep_disk(char **types) {
         return false;
 }
 
+#define HIBERNATION_SWAP_THRESHOLD 0.98
+
+static int hibernation_partition_size(size_t *size, size_t *used) {
+        _cleanup_fclose_ FILE *f;
+        int i;
+
+        assert(size);
+        assert(used);
+
+        f = fopen("/proc/swaps", "r");
+        if (!f) {
+                log_full(errno == ENOENT ? LOG_DEBUG : LOG_WARNING,
+                         "Failed to retrieve open /proc/swaps: %m");
+                assert(errno > 0);
+                return -errno;
+        }
+
+        (void) fscanf(f, "%*s %*s %*s %*s %*s\n");
+
+        for (i = 1;; i++) {
+                _cleanup_free_ char *dev = NULL, *d = NULL, *type = NULL;
+                size_t size_field, used_field;
+                int k;
+
+                k = fscanf(f,
+                           "%ms "   /* device/file */
+                           "%ms "   /* type of swap */
+                           "%zd "   /* swap size */
+                           "%zd "   /* used */
+                           "%*i\n", /* priority */
+                           &dev, &type, &size_field, &used_field);
+                if (k != 4) {
+                        if (k == EOF)
+                                break;
+
+                        log_warning("Failed to parse /proc/swaps:%u", i);
+                        continue;
+                }
+
+                d = cunescape(dev);
+                if (!d)
+                        return -ENOMEM;
+
+                if (!streq(type, "partition")) {
+                        log_debug("Partition %s has type %s, ignoring.", d, type);
+                        continue;
+                }
+
+                *size = size_field;
+                *used = used_field;
+                return 0;
+        }
+
+        log_debug("No swap partitions were found.");
+        return -ENOSYS;
+}
+
+static bool enough_memory_for_hibernation(void) {
+        _cleanup_free_ char *active = NULL;
+        unsigned long long act;
+        size_t size, used;
+        int r;
+
+        r = hibernation_partition_size(&size, &used);
+        if (r < 0)
+                return false;
+
+        r = get_status_field("/proc/meminfo", "\nActive(anon):", &active);
+        if (r < 0) {
+                log_error("Failed to retrieve Active(anon) from /proc/meminfo: %s", strerror(-r));
+                return false;
+        }
+
+        r = safe_atollu(active, &act);
+        if (r < 0) {
+                log_error("Failed to parse Active(anon) from /proc/meminfo: %s: %s",
+                          active, strerror(-r));
+                return false;
+        }
+
+        r = act <= (size - used) * HIBERNATION_SWAP_THRESHOLD;
+        log_debug("Hibernation is %spossible, Active(anon)=%llu kB, size=%zu kB, used=%zu kB, threshold=%.2g%%",
+                  r ? "" : "im", act, size, used, 100*HIBERNATION_SWAP_THRESHOLD);
+
+        return r;
+}
+
 int can_sleep(const char *verb) {
         _cleanup_strv_free_ char **modes = NULL, **states = NULL;
         int r;
@@ -175,5 +262,8 @@ int can_sleep(const char *verb) {
         if (r < 0)
                 return false;
 
-        return can_sleep_state(states) && can_sleep_disk(modes);
+        if (!can_sleep_state(states) || !can_sleep_disk(modes))
+                return false;
+
+        return streq(verb, "suspend") || enough_memory_for_hibernation();
 }