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_migrate_offset;
  50         __u32   lsm_md_migrate_hash;
  51         __u32   lsm_md_default_count;
  52         __u32   lsm_md_default_index;
  53         char    lsm_md_pool_name[LOV_MAXPOOLNAME + 1];
  54         struct lmv_oinfo lsm_md_oinfo[0];
  55 };
  56
  57 static inline bool lmv_dir_striped(const struct lmv_stripe_md *lsm)
  58 {
  59         return lsm && lsm->lsm_md_magic == LMV_MAGIC;
  60 }
  61
  62 static inline bool lmv_dir_foreign(const struct lmv_stripe_md *lsm)
  63 {
  64         return lsm && lsm->lsm_md_magic == LMV_MAGIC_FOREIGN;
  65 }
  66
  67 static inline bool lmv_dir_migrating(const struct lmv_stripe_md *lsm)
  68 {
  69         return lmv_dir_striped(lsm) &&
  70                lsm->lsm_md_hash_type & LMV_HASH_FLAG_MIGRATION;
  71 }
  72
  73 static inline bool lmv_dir_bad_hash(const struct lmv_stripe_md *lsm)
  74 {
  75         if (!lmv_dir_striped(lsm))
  76                 return false;
  77
  78         if (lmv_dir_migrating(lsm) &&
  79             lsm->lsm_md_stripe_count - lsm->lsm_md_migrate_offset <= 1)
  80                 return false;
  81
  82         return !lmv_is_known_hash_type(lsm->lsm_md_hash_type);
  83 }
  84
  85 static inline bool
  86 lsm_md_eq(const struct lmv_stripe_md *lsm1, const struct lmv_stripe_md *lsm2)
  87 {
  88         __u32 idx;
  89
  90         if (lsm1->lsm_md_magic != lsm2->lsm_md_magic ||
  91             lsm1->lsm_md_stripe_count != lsm2->lsm_md_stripe_count ||
  92             lsm1->lsm_md_master_mdt_index !=
  93                                 lsm2->lsm_md_master_mdt_index ||
  94             lsm1->lsm_md_hash_type != lsm2->lsm_md_hash_type ||
  95             lsm1->lsm_md_layout_version !=
  96                                 lsm2->lsm_md_layout_version ||
  97             lsm1->lsm_md_migrate_offset !=
  98                                 lsm2->lsm_md_migrate_offset ||
  99             lsm1->lsm_md_migrate_hash !=
 100                                 lsm2->lsm_md_migrate_hash ||
 101             strncmp(lsm1->lsm_md_pool_name, lsm2->lsm_md_pool_name,
 102                     sizeof(lsm1->lsm_md_pool_name)) != 0)
 103                 return false;
 104
 105         if (lmv_dir_striped(lsm1)) {
 106                 for (idx = 0; idx < lsm1->lsm_md_stripe_count; idx++) {
 107                         if (!lu_fid_eq(&lsm1->lsm_md_oinfo[idx].lmo_fid,
 108                                        &lsm2->lsm_md_oinfo[idx].lmo_fid))
 109                                 return false;
 110                 }
 111         }
 112
 113         return true;
 114 }
 115
 116 static inline void lsm_md_dump(int mask, const struct lmv_stripe_md *lsm)
 117 {
 118         int i;
 119
 120         /* If lsm_md_magic == LMV_MAGIC_FOREIGN pool_name may not be a null
 121          * terminated string so only print LOV_MAXPOOLNAME bytes.
 122          */
 123         CDEBUG(mask,
 124                "magic %#x stripe count %d master mdt %d hash type %#x version %d migrate offset %d migrate hash %#x pool %.*s\n",
 125                lsm->lsm_md_magic, lsm->lsm_md_stripe_count,
 126                lsm->lsm_md_master_mdt_index, lsm->lsm_md_hash_type,
 127                lsm->lsm_md_layout_version, lsm->lsm_md_migrate_offset,
 128                lsm->lsm_md_migrate_hash,
 129                LOV_MAXPOOLNAME, lsm->lsm_md_pool_name);
 130
 131         if (!lmv_dir_striped(lsm))
 132                 return;
 133
 134         for (i = 0; i < lsm->lsm_md_stripe_count; i++)
 135                 CDEBUG(mask, "stripe[%d] "DFID"\n",
 136                        i, PFID(&lsm->lsm_md_oinfo[i].lmo_fid));
 137 }
 138
 139 union lmv_mds_md;
 140
 141 void lmv_free_memmd(struct lmv_stripe_md *lsm);
 142
 143 static inline void lmv1_le_to_cpu(struct lmv_mds_md_v1 *lmv_dst,
 144                                   const struct lmv_mds_md_v1 *lmv_src)
 145 {
 146         __u32 i;
 147
 148         lmv_dst->lmv_magic = le32_to_cpu(lmv_src->lmv_magic);
 149         lmv_dst->lmv_stripe_count = le32_to_cpu(lmv_src->lmv_stripe_count);
 150         lmv_dst->lmv_master_mdt_index =
 151                                 le32_to_cpu(lmv_src->lmv_master_mdt_index);
 152         lmv_dst->lmv_hash_type = le32_to_cpu(lmv_src->lmv_hash_type);
 153         lmv_dst->lmv_layout_version = le32_to_cpu(lmv_src->lmv_layout_version);
 154         for (i = 0; i < lmv_src->lmv_stripe_count; i++)
 155                 fid_le_to_cpu(&lmv_dst->lmv_stripe_fids[i],
 156                               &lmv_src->lmv_stripe_fids[i]);
 157 }
 158
 159 static inline void lmv_le_to_cpu(union lmv_mds_md *lmv_dst,
 160                                  const union lmv_mds_md *lmv_src)
 161 {
 162         switch (le32_to_cpu(lmv_src->lmv_magic)) {
 163         case LMV_MAGIC_V1:
 164                 lmv1_le_to_cpu(&lmv_dst->lmv_md_v1, &lmv_src->lmv_md_v1);
 165                 break;
 166         default:
 167                 break;
 168         }
 169 }
 170
 171 /* This hash is only for testing purpose */
 172 static inline unsigned int
 173 lmv_hash_all_chars(unsigned int count, const char *name, int namelen)
 174 {
 175         unsigned int c = 0;
 176         const unsigned char *p = (const unsigned char *)name;
 177
 178         while (--namelen >= 0)
 179                 c += p[namelen];
 180
 181         c = c % count;
 182
 183         return c;
 184 }
 185
 186 static inline unsigned int
 187 lmv_hash_fnv1a(unsigned int count, const char *name, int namelen)
 188 {
 189         __u64 hash;
 190
 191         hash = lustre_hash_fnv_1a_64(name, namelen);
 192
 193         return do_div(hash, count);
 194 }
 195
 196 static inline int lmv_name_to_stripe_index(__u32 lmv_hash_type,
 197                                            unsigned int stripe_count,
 198                                            const char *name, int namelen)
 199 {
 200         int idx;
 201
 202         LASSERT(namelen > 0);
 203
 204         if (stripe_count <= 1)
 205                 return 0;
 206
 207         switch (lmv_hash_type & LMV_HASH_TYPE_MASK) {
 208         case LMV_HASH_TYPE_ALL_CHARS:
 209                 idx = lmv_hash_all_chars(stripe_count, name, namelen);
 210                 break;
 211         case LMV_HASH_TYPE_FNV_1A_64:
 212                 idx = lmv_hash_fnv1a(stripe_count, name, namelen);
 213                 break;
 214         default:
 215                 idx = -EBADFD;
 216                 break;
 217         }
 218
 219         CDEBUG(D_INFO, "name %.*s hash_type %#x idx %d/%u\n", namelen, name,
 220                lmv_hash_type, idx, stripe_count);
 221
 222         return idx;
 223 }
 224
 225 static inline bool lmv_magic_supported(__u32 lum_magic)
 226 {
 227         return lum_magic == LMV_USER_MAGIC ||
 228                lum_magic == LMV_USER_MAGIC_SPECIFIC ||
 229                lum_magic == LMV_MAGIC_FOREIGN;
 230 }
 231
 232 #endif