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, 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
  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 int lmv_pack_md(union lmv_mds_md **lmmp, const struct lmv_stripe_md *lsm,
  82                        int stripe_count);
  83 int lmv_alloc_md(union lmv_mds_md **lmmp, int stripe_count);
  84 void lmv_free_md(union lmv_mds_md *lmm);
  85 int lmv_alloc_memmd(struct lmv_stripe_md **lsmp, int stripe_count);
  86 void lmv_free_memmd(struct lmv_stripe_md *lsm);
  87
  88 int lmvea_load_shards(const struct lu_env *env, struct dt_object *obj,
  89                       struct lu_dirent *ent, struct lu_buf *buf,
  90                       bool resize);
  91
  92 static inline void lmv1_le_to_cpu(struct lmv_mds_md_v1 *lmv_dst,
  93                                   const struct lmv_mds_md_v1 *lmv_src)
  94 {
  95         __u32 i;
  96
  97         lmv_dst->lmv_magic = le32_to_cpu(lmv_src->lmv_magic);
  98         lmv_dst->lmv_stripe_count = le32_to_cpu(lmv_src->lmv_stripe_count);
  99         lmv_dst->lmv_master_mdt_index =
 100                                 le32_to_cpu(lmv_src->lmv_master_mdt_index);
 101         lmv_dst->lmv_hash_type = le32_to_cpu(lmv_src->lmv_hash_type);
 102         lmv_dst->lmv_layout_version = le32_to_cpu(lmv_src->lmv_layout_version);
 103         for (i = 0; i < lmv_src->lmv_stripe_count; i++)
 104                 fid_le_to_cpu(&lmv_dst->lmv_stripe_fids[i],
 105                               &lmv_src->lmv_stripe_fids[i]);
 106 }
 107
 108 static inline void lmv_le_to_cpu(union lmv_mds_md *lmv_dst,
 109                                  const union lmv_mds_md *lmv_src)
 110 {
 111         switch (le32_to_cpu(lmv_src->lmv_magic)) {
 112         case LMV_MAGIC_V1:
 113                 lmv1_le_to_cpu(&lmv_dst->lmv_md_v1, &lmv_src->lmv_md_v1);
 114                 break;
 115         default:
 116                 break;
 117         }
 118 }
 119
 120 /* This hash is only for testing purpose */
 121 static inline unsigned int
 122 lmv_hash_all_chars(unsigned int count, const char *name, int namelen)
 123 {
 124         unsigned int c = 0;
 125         const unsigned char *p = (const unsigned char *)name;
 126
 127         while (--namelen >= 0)
 128                 c += p[namelen];
 129
 130         c = c % count;
 131
 132         return c;
 133 }
 134
 135 static inline unsigned int
 136 lmv_hash_fnv1a(unsigned int count, const char *name, int namelen)
 137 {
 138         __u64   hash;
 139
 140         hash = lustre_hash_fnv_1a_64(name, namelen);
 141
 142         hash = hash % count;
 143
 144         return hash;
 145 }
 146
 147 static inline int lmv_name_to_stripe_index(__u32 lmv_hash_type,
 148                                            unsigned int stripe_count,
 149                                            const char *name, int namelen)
 150 {
 151         int     idx;
 152         __u32   hash_type = lmv_hash_type & LMV_HASH_TYPE_MASK;
 153
 154         LASSERT(namelen > 0);
 155         if (stripe_count <= 1)
 156                 return 0;
 157
 158         /* for migrating object, always start from 0 stripe */
 159         if (lmv_hash_type & LMV_HASH_FLAG_MIGRATION)
 160                 return 0;
 161
 162         switch (hash_type) {
 163         case LMV_HASH_TYPE_ALL_CHARS:
 164                 idx = lmv_hash_all_chars(stripe_count, name, namelen);
 165                 break;
 166         case LMV_HASH_TYPE_FNV_1A_64:
 167                 idx = lmv_hash_fnv1a(stripe_count, name, namelen);
 168                 break;
 169         default:
 170                 idx = -EBADFD;
 171                 break;
 172         }
 173
 174         CDEBUG(D_INFO, "name %.*s hash_type %d idx %d\n", namelen, name,
 175                hash_type, idx);
 176
 177         return idx;
 178 }
 179
 180 static inline bool lmv_is_known_hash_type(__u32 type)
 181 {
 182         return (type & LMV_HASH_TYPE_MASK) == LMV_HASH_TYPE_FNV_1A_64 ||
 183                (type & LMV_HASH_TYPE_MASK) == LMV_HASH_TYPE_ALL_CHARS;
 184 }
 185
 186 #endif