+static int user_plock(struct ocfs2_cluster_connection *conn,
+ u64 ino,
+ struct file *file,
+ int cmd,
+ struct file_lock *fl)
+{
+ /*
+ * This more or less just demuxes the plock request into any
+ * one of three dlm calls.
+ *
+ * Internally, fs/dlm will pass these to a misc device, which
+ * a userspace daemon will read and write to.
+ *
+ * For now, cancel requests (which happen internally only),
+ * are turned into unlocks. Most of this function taken from
+ * gfs2_lock.
+ */
+
+ if (cmd == F_CANCELLK) {
+ cmd = F_SETLK;
+ fl->fl_type = F_UNLCK;
+ }
+
+ if (IS_GETLK(cmd))
+ return dlm_posix_get(conn->cc_lockspace, ino, file, fl);
+ else if (fl->fl_type == F_UNLCK)
+ return dlm_posix_unlock(conn->cc_lockspace, ino, file, fl);
+ else
+ return dlm_posix_lock(conn->cc_lockspace, ino, file, cmd, fl);
+}
+