sd-daemon: split off sd_readahead() since it is not a feature of systemd itself but...

[elogind.git] / src / sd-readahead.c

diff --git a/src/sd-readahead.c b/src/sd-readahead.c
new file mode 100644 (file)
index 0000000..41e6d3d
--- /dev/null
+++ b/src/sd-readahead.c
@@ -0,0 +1,76 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  Copyright 2010 Lennart Poettering
+
+  Permission is hereby granted, free of charge, to any person
+  obtaining a copy of this software and associated documentation files
+  (the "Software"), to deal in the Software without restriction,
+  including without limitation the rights to use, copy, modify, merge,
+  publish, distribute, sublicense, and/or sell copies of the Software,
+  and to permit persons to whom the Software is furnished to do so,
+  subject to the following conditions:
+
+  The above copyright notice and this permission notice shall be
+  included in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+  BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+  ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+  CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+  SOFTWARE.
+***/
+
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+
+#include <unistd.h>
+#include <errno.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <fcntl.h>
+#include <string.h>
+
+#include "sd-readahead.h"
+
+static int touch(const char *path) {
+
+#if !defined(DISABLE_SYSTEMD) && defined(__linux__)
+        int fd;
+
+        mkdir("/dev/.systemd", 0755);
+        mkdir("/dev/.systemd/readahead", 0755);
+
+        if ((fd = open(path, O_WRONLY|O_CREAT|O_CLOEXEC|O_NOCTTY, 0666)) < 0)
+                return -errno;
+
+        for (;;) {
+                if (close(fd) >= 0)
+                        break;
+
+                if (errno != -EINTR)
+                        return -errno;
+        }
+
+#endif
+        return 0;
+}
+
+int sd_readahead(const char *action) {
+
+        if (!action)
+                return -EINVAL;
+
+        if (strcmp(action, "cancel") == 0)
+                return touch("/dev/.systemd/readahead/cancel");
+        else if (strcmp(action, "done") == 0)
+                return touch("/dev/.systemd/readahead/done");
+        else if (strcmp(action, "noreplay") == 0)
+                return touch("/dev/.systemd/readahead/noreplay");
+
+        return -EINVAL;
+}