readahead: avoid running of readahead services if readahead is already done

src/readahead/sd-readahead.c

@@ -57,7 +57,8 @@ static int touch(const char *path) {
         mkdir("/run/systemd", 0755);
         mkdir("/run/systemd/readahead", 0755);
 
-        if ((fd = open(path, O_WRONLY|O_CREAT|O_CLOEXEC|O_NOCTTY, 0666)) < 0)
+        fd = open(path, O_WRONLY|O_CREAT|O_CLOEXEC|O_NOCTTY, 0666);
+        if (fd < 0)
                 return -errno;
 
         for (;;) {

units/systemd-readahead-collect.service.in

@@ -11,6 +11,8 @@ DefaultDependencies=no
 Wants=systemd-readahead-done.timer
 Conflicts=shutdown.target
 Before=sysinit.target shutdown.target
+ConditionFileExists=!/run/systemd/readahead/cancel
+ConditionFileExists=!/run/systemd/readahead/done
 ConditionVirtualization=no
 
 [Service]

units/systemd-readahead-replay.service.in

@@ -10,6 +10,7 @@ Description=Replay Read-Ahead Data
 DefaultDependencies=no
 Conflicts=shutdown.target
 Before=sysinit.target shutdown.target
+ConditionPathExists=!/run/systemd/readahead/noreplay
 ConditionPathExists=/.readahead
 ConditionVirtualization=no