LXR linux/drivers/staging/lustre/lustre/include/lustre

   1/*
   2 * GPL HEADER START
   3 *
   4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5 *
   6 * This program is free software; you can redistribute it and/or modify
   7 * it under the terms of the GNU General Public License version 2 only,
   8 * as published by the Free Software Foundation.
   9 *
  10 * This program is distributed in the hope that it will be useful,
  11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 * GNU General Public License version 2 for more details.  A copy is
  14 * included in the COPYING file that accompanied this code.
  15 *
  16 * You should have received a copy of the GNU General Public License
  17 * version 2 along with this program; If not, see
  18 * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
  19 *
  20 * GPL HEADER END
  21 */
  22/*
  23 * Copyright (c) 2013, Intel Corporation.
  24 */
  25/*
  26 * lustre/include/lustre_lmv.h
  27 *
  28 * Lustre LMV structures and functions.
  29 *
  30 * Author: Di Wang <di.wang@intel.com>
  31 */
  32
  33#ifndef _LUSTRE_LMV_H
  34#define _LUSTRE_LMV_H
  35#include "lustre/lustre_idl.h"
  36
  37struct lmv_oinfo {
  38        struct lu_fid   lmo_fid;
  39        u32             lmo_mds;
  40        struct inode    *lmo_root;
  41};
  42
  43struct lmv_stripe_md {
  44        __u32   lsm_md_magic;
  45        __u32   lsm_md_stripe_count;
  46        __u32   lsm_md_master_mdt_index;
  47        __u32   lsm_md_hash_type;
  48        __u32   lsm_md_layout_version;
  49        __u32   lsm_md_default_count;
  50        __u32   lsm_md_default_index;
  51        char    lsm_md_pool_name[LOV_MAXPOOLNAME + 1];
  52        struct lmv_oinfo lsm_md_oinfo[0];
  53};
  54
  55static inline bool
  56lsm_md_eq(const struct lmv_stripe_md *lsm1, const struct lmv_stripe_md *lsm2)
  57{
  58        __u32 idx;
  59
  60        if (lsm1->lsm_md_magic != lsm2->lsm_md_magic ||
  61            lsm1->lsm_md_stripe_count != lsm2->lsm_md_stripe_count ||
  62            lsm1->lsm_md_master_mdt_index != lsm2->lsm_md_master_mdt_index ||
  63            lsm1->lsm_md_hash_type != lsm2->lsm_md_hash_type ||
  64            lsm1->lsm_md_layout_version != lsm2->lsm_md_layout_version ||
  65            !strcmp(lsm1->lsm_md_pool_name, lsm2->lsm_md_pool_name))
  66                return false;
  67
  68        for (idx = 0; idx < lsm1->lsm_md_stripe_count; idx++) {
  69                if (!lu_fid_eq(&lsm1->lsm_md_oinfo[idx].lmo_fid,
  70                               &lsm2->lsm_md_oinfo[idx].lmo_fid))
  71                        return false;
  72        }
  73
  74        return true;
  75}
  76
  77union lmv_mds_md;
  78
  79void lmv_free_memmd(struct lmv_stripe_md *lsm);
  80
  81static inline void lmv1_le_to_cpu(struct lmv_mds_md_v1 *lmv_dst,
  82                                  const struct lmv_mds_md_v1 *lmv_src)
  83{
  84        __u32 i;
  85
  86        lmv_dst->lmv_magic = le32_to_cpu(lmv_src->lmv_magic);
  87        lmv_dst->lmv_stripe_count = le32_to_cpu(lmv_src->lmv_stripe_count);
  88        lmv_dst->lmv_master_mdt_index =
  89                le32_to_cpu(lmv_src->lmv_master_mdt_index);
  90        lmv_dst->lmv_hash_type = le32_to_cpu(lmv_src->lmv_hash_type);
  91        lmv_dst->lmv_layout_version = le32_to_cpu(lmv_src->lmv_layout_version);
  92
  93        for (i = 0; i < lmv_src->lmv_stripe_count; i++)
  94                fid_le_to_cpu(&lmv_dst->lmv_stripe_fids[i],
  95                              &lmv_src->lmv_stripe_fids[i]);
  96}
  97
  98static inline void lmv_le_to_cpu(union lmv_mds_md *lmv_dst,
  99                                 const union lmv_mds_md *lmv_src)
 100{
 101        switch (le32_to_cpu(lmv_src->lmv_magic)) {
 102        case LMV_MAGIC_V1:
 103                lmv1_le_to_cpu(&lmv_dst->lmv_md_v1, &lmv_src->lmv_md_v1);
 104                break;
 105        default:
 106                break;
 107        }
 108}
 109
 110/* This hash is only for testing purpose */
 111static inline unsigned int
 112lmv_hash_all_chars(unsigned int count, const char *name, int namelen)
 113{
 114        const unsigned char *p = (const unsigned char *)name;
 115        unsigned int c = 0;
 116
 117        while (--namelen >= 0)
 118                c += p[namelen];
 119
 120        c = c % count;
 121
 122        return c;
 123}
 124
 125static inline unsigned int
 126lmv_hash_fnv1a(unsigned int count, const char *name, int namelen)
 127{
 128        __u64 hash;
 129
 130        hash = lustre_hash_fnv_1a_64(name, namelen);
 131
 132        return do_div(hash, count);
 133}
 134
 135static inline int lmv_name_to_stripe_index(__u32 lmv_hash_type,
 136                                           unsigned int stripe_count,
 137                                           const char *name, int namelen)
 138{
 139        __u32 hash_type = lmv_hash_type & LMV_HASH_TYPE_MASK;
 140        int idx;
 141
 142        LASSERT(namelen > 0);
 143        if (stripe_count <= 1)
 144                return 0;
 145
 146        /* for migrating object, always start from 0 stripe */
 147        if (lmv_hash_type & LMV_HASH_FLAG_MIGRATION)
 148                return 0;
 149
 150        switch (hash_type) {
 151        case LMV_HASH_TYPE_ALL_CHARS:
 152                idx = lmv_hash_all_chars(stripe_count, name, namelen);
 153                break;
 154        case LMV_HASH_TYPE_FNV_1A_64:
 155                idx = lmv_hash_fnv1a(stripe_count, name, namelen);
 156                break;
 157        default:
 158                idx = -EBADFD;
 159                break;
 160        }
 161        CDEBUG(D_INFO, "name %.*s hash_type %d idx %d\n", namelen, name,
 162               hash_type, idx);
 163
 164        return idx;
 165}
 166
 167static inline bool lmv_is_known_hash_type(__u32 type)
 168{
 169        return (type & LMV_HASH_TYPE_MASK) == LMV_HASH_TYPE_FNV_1A_64 ||
 170               (type & LMV_HASH_TYPE_MASK) == LMV_HASH_TYPE_ALL_CHARS;
 171}
 172
 173#endif
 174