1 files changed, 112 insertions, 0 deletions
diff --git a/drivers/staging/lustre/lustre/obdclass/mea.c b/drivers/staging/lustre/lustre/obdclass/mea.c
new file mode 100644
index 000000000000..c4f0dbc23611
--- /dev/null
+++ b/drivers/staging/lustre/lustre/obdclass/mea.c
@@ -0,0 +1,112 @@
+/*
+ * 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) 2004, 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.
+ */
+
+#define DEBUG_SUBSYSTEM S_CLASS
+#include <obd_class.h>
+#include <linux/kmod.h>   /* for request_module() */
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/pagemap.h>
+#include <lprocfs_status.h>
+#include <lustre/lustre_idl.h>
+
+static int mea_last_char_hash(int count, char *name, int namelen)
+{
+	unsigned int c;
+
+	c = name[namelen - 1];
+	if (c == 0)
+		CWARN("looks like wrong len is passed\n");
+	c = c % count;
+	return c;
+}
+
+static int mea_all_chars_hash(int count, char *name, int namelen)
+{
+	unsigned int c = 0;
+
+	while (--namelen >= 0)
+		c += name[namelen];
+	c = c % count;
+	return c;
+}
+
+int raw_name2idx(int hashtype, int count, const char *name, int namelen)
+{
+	unsigned int	c = 0;
+	int		idx;
+
+	LASSERT(namelen > 0);
+
+	if (filename_is_volatile(name, namelen, &idx)) {
+		if ((idx >= 0) && (idx < count))
+			return idx;
+		goto hashchoice;
+	}
+
+	if (count <= 1)
+		return 0;
+
+hashchoice:
+	switch (hashtype) {
+	case MEA_MAGIC_LAST_CHAR:
+		c = mea_last_char_hash(count, (char *)name, namelen);
+		break;
+	case MEA_MAGIC_ALL_CHARS:
+		c = mea_all_chars_hash(count, (char *)name, namelen);
+		break;
+	case MEA_MAGIC_HASH_SEGMENT:
+		CERROR("Unsupported hash type MEA_MAGIC_HASH_SEGMENT\n");
+		break;
+	default:
+		CERROR("Unknown hash type 0x%x\n", hashtype);
+	}
+
+	LASSERT(c < count);
+	return c;
+}
+EXPORT_SYMBOL(raw_name2idx);
+
+int mea_name2idx(struct lmv_stripe_md *mea, const char *name, int namelen)
+{
+	unsigned int c;
+
+	LASSERT(mea && mea->mea_count);
+
+	c = raw_name2idx(mea->mea_magic, mea->mea_count, name, namelen);
+
+	LASSERT(c < mea->mea_count);
+	return c;
+}
+EXPORT_SYMBOL(mea_name2idx);