Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / drivers / staging / lustre / lustre / llite / vvp_lock.c

diff --git a/kernel/drivers/staging/lustre/lustre/llite/vvp_lock.c b/kernel/drivers/staging/lustre/lustre/llite/vvp_lock.c
new file mode 100644 (file)
index 0000000..f354e82
--- /dev/null
+++ b/kernel/drivers/staging/lustre/lustre/llite/vvp_lock.c
@@ -0,0 +1,85 @@
+/*
+ * GPL HEADER START
+ *
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 only,
+ * as published by the Free Software Foundation.
+ *
+ * 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 version 2 for more details (a copy is included
+ * in the LICENSE file that accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License
+ * version 2 along with this program; If not, see
+ * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ * GPL HEADER END
+ */
+/*
+ * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Use is subject to license terms.
+ */
+/*
+ * This file is part of Lustre, http://www.lustre.org/
+ * Lustre is a trademark of Sun Microsystems, Inc.
+ *
+ * Implementation of cl_lock for VVP layer.
+ *
+ *   Author: Nikita Danilov <nikita.danilov@sun.com>
+ */
+
+#define DEBUG_SUBSYSTEM S_LLITE
+
+
+#include "../include/obd.h"
+#include "../include/lustre_lite.h"
+
+#include "vvp_internal.h"
+
+/*****************************************************************************
+ *
+ * Vvp lock functions.
+ *
+ */
+
+/**
+ * Estimates lock value for the purpose of managing the lock cache during
+ * memory shortages.
+ *
+ * Locks for memory mapped files are almost infinitely precious, others are
+ * junk. "Mapped locks" are heavy, but not infinitely heavy, so that they are
+ * ordered within themselves by weights assigned from other layers.
+ */
+static unsigned long vvp_lock_weigh(const struct lu_env *env,
+                                   const struct cl_lock_slice *slice)
+{
+       struct ccc_object *cob = cl2ccc(slice->cls_obj);
+
+       return atomic_read(&cob->cob_mmap_cnt) > 0 ? ~0UL >> 2 : 0;
+}
+
+static const struct cl_lock_operations vvp_lock_ops = {
+       .clo_delete    = ccc_lock_delete,
+       .clo_fini      = ccc_lock_fini,
+       .clo_enqueue   = ccc_lock_enqueue,
+       .clo_wait      = ccc_lock_wait,
+       .clo_use       = ccc_lock_use,
+       .clo_unuse     = ccc_lock_unuse,
+       .clo_fits_into = ccc_lock_fits_into,
+       .clo_state     = ccc_lock_state,
+       .clo_weigh     = vvp_lock_weigh
+};
+
+int vvp_lock_init(const struct lu_env *env, struct cl_object *obj,
+                 struct cl_lock *lock, const struct cl_io *io)
+{
+       return ccc_lock_init(env, obj, lock, io, &vvp_lock_ops);
+}