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/*
* 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 "../include/obd_class.h"
#include <linux/kmod.h> /* for request_module() */
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/pagemap.h>
#include "../include/lprocfs_status.h"
#include "../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);
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