New command: 'fallocate' to (pre-)allocate sized files.

[libguestfs.git] / daemon / fallocate.c

diff --git a/daemon/fallocate.c b/daemon/fallocate.c
new file mode 100644 (file)
index 0000000..47e84c6
--- /dev/null
+++ b/daemon/fallocate.c
@@ -0,0 +1,59 @@
+/* libguestfs - the guestfsd daemon
+ * Copyright (C) 2009 Red Hat Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <config.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <fcntl.h>
+
+#include "daemon.h"
+#include "actions.h"
+
+int
+do_fallocate (char *path, int len)
+{
+  int fd, r;
+
+  NEED_ROOT (-1);
+  ABS_PATH (path, -1);
+
+  CHROOT_IN;
+  fd = open (path, O_WRONLY | O_CREAT | O_TRUNC | O_NOCTTY, 0666);
+  CHROOT_OUT;
+  if (fd == -1) {
+    reply_with_perror (path);
+    return -1;
+  }
+
+  r = posix_fallocate (fd, 0, len);
+  if (r == -1) {
+    reply_with_perror ("posix_fallocate: %s", path);
+    close (fd);
+    return -1;
+  }
+
+  if (close (fd) == -1) {
+    reply_with_perror ("close: %s", path);
+    return -1;
+  }
+
+  return 0;
+}