lustre/include/lustre_lmv.h

   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  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  19  *
  20  * GPL HEADER END
  21  */
  22 /*
  23  * Copyright (c) 2014, 2016, 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 <uapi/linux/lustre/lustre_idl.h>
  36
  37 struct lmv_oinfo {
  38         struct lu_fid   lmo_fid;
  39         u32             lmo_mds;
  40         struct inode    *lmo_root;
  41 };
  42
  43 struct 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
  55 static inline bool
  56 lsm_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 !=
  63                                 lsm2->lsm_md_master_mdt_index ||
  64             lsm1->lsm_md_hash_type != lsm2->lsm_md_hash_type ||
  65             lsm1->lsm_md_layout_version !=
  66                                 lsm2->lsm_md_layout_version ||
  67             strcmp(lsm1->lsm_md_pool_name,
  68                       lsm2->lsm_md_pool_name) != 0)
  69                 return false;
  70
  71         for (idx = 0; idx < lsm1->lsm_md_stripe_count; idx++) {
  72                 if (!lu_fid_eq(&lsm1->lsm_md_oinfo[idx].lmo_fid,
  73                                &lsm2->lsm_md_oinfo[idx].lmo_fid))
  74                         return false;
  75         }
  76
  77         return true;
  78 }
  79 union lmv_mds_md;
  80
  81 void lmv_free_memmd(struct lmv_stripe_md *lsm);
  82
  83 int lmvea_load_shards(const struct lu_env *env, struct dt_object *obj,
  84                       struct lu_dirent *ent, struct lu_buf *buf,
  85                       bool resize);
  86
  87 static inline void lmv1_le_to_cpu(struct lmv_mds_md_v1 *lmv_dst,
  88                                   const struct lmv_mds_md_v1 *lmv_src)
  89 {
  90         __u32 i;
  91
  92         lmv_dst->lmv_magic = le32_to_cpu(lmv_src->lmv_magic);
  93         lmv_dst->lmv_stripe_count = le32_to_cpu(lmv_src->lmv_stripe_count);
  94         lmv_dst->lmv_master_mdt_index =
  95                                 le32_to_cpu(lmv_src->lmv_master_mdt_index);
  96         lmv_dst->lmv_hash_type = le32_to_cpu(lmv_src->lmv_hash_type);
  97         lmv_dst->lmv_layout_version = le32_to_cpu(lmv_src->lmv_layout_version);
  98         for (i = 0; i < lmv_src->lmv_stripe_count; i++)
  99                 fid_le_to_cpu(&lmv_dst->lmv_stripe_fids[i],
 100                               &lmv_src->lmv_stripe_fids[i]);
 101 }
 102
 103 static inline void lmv_le_to_cpu(union lmv_mds_md *lmv_dst,
 104                                  const union lmv_mds_md *lmv_src)
 105 {
 106         switch (le32_to_cpu(lmv_src->lmv_magic)) {
 107         case LMV_MAGIC_V1:
 108                 lmv1_le_to_cpu(&lmv_dst->lmv_md_v1, &lmv_src->lmv_md_v1);
 109                 break;
 110         default:
 111                 break;
 112         }
 113 }
 114
 115 /* This hash is only for testing purpose */
 116 static inline unsigned int
 117 lmv_hash_all_chars(unsigned int count, const char *name, int namelen)
 118 {
 119         unsigned int c = 0;
 120         const unsigned char *p = (const unsigned char *)name;
 121
 122         while (--namelen >= 0)
 123                 c += p[namelen];
 124
 125         c = c % count;
 126
 127         return c;
 128 }
 129
 130 static inline unsigned int
 131 lmv_hash_fnv1a(unsigned int count, const char *name, int namelen)
 132 {
 133         __u64 hash;
 134
 135         hash = lustre_hash_fnv_1a_64(name, namelen);
 136
 137         return do_div(hash, count);
 138 }
 139
 140 static inline int lmv_name_to_stripe_index(__u32 lmv_hash_type,
 141                                            unsigned int stripe_count,
 142                                            const char *name, int namelen)
 143 {
 144         int     idx;
 145         __u32   hash_type = lmv_hash_type & LMV_HASH_TYPE_MASK;
 146
 147         LASSERT(namelen > 0);
 148         if (stripe_count <= 1)
 149                 return 0;
 150
 151         /* for migrating object, always start from 0 stripe */
 152         if (lmv_hash_type & LMV_HASH_FLAG_MIGRATION)
 153                 return 0;
 154
 155         switch (hash_type) {
 156         case LMV_HASH_TYPE_ALL_CHARS:
 157                 idx = lmv_hash_all_chars(stripe_count, name, namelen);
 158                 break;
 159         case LMV_HASH_TYPE_FNV_1A_64:
 160                 idx = lmv_hash_fnv1a(stripe_count, name, namelen);
 161                 break;
 162         default:
 163                 idx = -EBADFD;
 164                 break;
 165         }
 166
 167         CDEBUG(D_INFO, "name %.*s hash_type %d idx %d\n", namelen, name,
 168                hash_type, idx);
 169
 170         return idx;
 171 }
 172
 173 static inline bool lmv_is_known_hash_type(__u32 type)
 174 {
 175         return (type & LMV_HASH_TYPE_MASK) == LMV_HASH_TYPE_FNV_1A_64 ||
 176                (type & LMV_HASH_TYPE_MASK) == LMV_HASH_TYPE_ALL_CHARS;
 177 }
 178
 179 #endif