Advertise hibernation only if there's enough free swap

Condition that is checked is taken from upower:
  active(anon) < free swap * 0.98

This is really stupid, because the kernel knows the situation better,
e.g. there could be two swap files, and then hibernation would be
impossible despite passing this check, or the kernel could start
supporting compressed swap and/or compressed hibernation images, and
then this this check would be too stringent. Nevertheless, until
we have something better, this should at least return a true negative
if there's no swap.

Logging of capabilities in the journal is changed to not strip leading
zeros. I consider this more readable anyway.

http://cgit.freedesktop.org/upower/tree/src/up-daemon.c#n613
https://bugzilla.redhat.com/show_bug.cgi?id=1007059

1 files changed, 34 insertions, 0 deletions

diff --git a/src/shared/fileio.c b/src/shared/fileio.c
index 77fd05955a..4e2b4442db 100644
--- a/src/shared/fileio.c
+++ b/src/shared/fileio.c
@@ -648,3 +648,37 @@ int executable_is_script(const char *path, char **interpreter) {
         *interpreter = ans;
         return 1;
 }
+
+/**
+ * Retrieve one field from a file like /proc/self/status.
+ * pattern should start with '\n' and end with ':'. Whitespace
+ * after ':' will be skipped. field must be freed afterwards.
+ */
+int get_status_field(const char *filename, const char *pattern, char **field) {
+        _cleanup_free_ char *status = NULL;
+        char *t;
+        size_t len;
+        int r;
+
+        assert(filename);
+        assert(field);
+
+        r = read_full_file(filename, &status, NULL);
+        if (r < 0)
+                return r;
+
+        t = strstr(status, pattern);
+        if (!t)
+                return -ENOENT;
+
+        t += strlen(pattern);
+        t += strspn(t, WHITESPACE);
+
+        len = strcspn(t, WHITESPACE);
+
+        *field = strndup(t, len);
+        if (!*field)
+                return -ENOMEM;
+
+        return 0;
+}