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 /* NB: LMV_HASH_TYPE_SPACE is set in default LMV only */
  58 static inline bool lmv_is_known_hash_type(__u32 type)
  59 {
  60         return (type & LMV_HASH_TYPE_MASK) == LMV_HASH_TYPE_FNV_1A_64 ||
  61                (type & LMV_HASH_TYPE_MASK) == LMV_HASH_TYPE_ALL_CHARS;
  62 }
  63
  64 static inline bool lmv_dir_striped(const struct lmv_stripe_md *lsm)
  65 {
  66         return lsm && lsm->lsm_md_magic == LMV_MAGIC;
  67 }
  68
  69 static inline bool lmv_dir_foreign(const struct lmv_stripe_md *lsm)
  70 {
  71         return lsm && lsm->lsm_md_magic == LMV_MAGIC_FOREIGN;
  72 }
  73
  74 static inline bool lmv_dir_migrating(const struct lmv_stripe_md *lsm)
  75 {
  76         return lmv_dir_striped(lsm) &&
  77                lsm->lsm_md_hash_type & LMV_HASH_FLAG_MIGRATION;
  78 }
  79
  80 static inline bool lmv_dir_bad_hash(const struct lmv_stripe_md *lsm)
  81 {
  82         if (!lmv_dir_striped(lsm))
  83                 return false;
  84
  85         if (lmv_dir_migrating(lsm) &&
  86             lsm->lsm_md_stripe_count - lsm->lsm_md_migrate_offset <= 1)
  87                 return false;
  88
  89         return !lmv_is_known_hash_type(lsm->lsm_md_hash_type);
  90 }
  91
  92 /* NB, this is checking directory default LMV */
  93 static inline bool lmv_dir_space_hashed(const struct lmv_stripe_md *lsm)
  94 {
  95         return lsm && lsm->lsm_md_hash_type == LMV_HASH_TYPE_SPACE;
  96 }
  97
  98 static inline bool
  99 lsm_md_eq(const struct lmv_stripe_md *lsm1, const struct lmv_stripe_md *lsm2)
 100 {
 101         __u32 idx;
 102
 103         if (lsm1->lsm_md_magic != lsm2->lsm_md_magic ||
 104             lsm1->lsm_md_stripe_count != lsm2->lsm_md_stripe_count ||
 105             lsm1->lsm_md_master_mdt_index !=
 106                                 lsm2->lsm_md_master_mdt_index ||
 107             lsm1->lsm_md_hash_type != lsm2->lsm_md_hash_type ||
 108             lsm1->lsm_md_layout_version !=
 109                                 lsm2->lsm_md_layout_version ||
 110             lsm1->lsm_md_migrate_offset !=
 111                                 lsm2->lsm_md_migrate_offset ||
 112             lsm1->lsm_md_migrate_hash !=
 113                                 lsm2->lsm_md_migrate_hash ||
 114             strcmp(lsm1->lsm_md_pool_name,
 115                       lsm2->lsm_md_pool_name) != 0)
 116                 return false;
 117
 118         if (lmv_dir_striped(lsm1)) {
 119                 for (idx = 0; idx < lsm1->lsm_md_stripe_count; idx++) {
 120                         if (!lu_fid_eq(&lsm1->lsm_md_oinfo[idx].lmo_fid,
 121                                        &lsm2->lsm_md_oinfo[idx].lmo_fid))
 122                                 return false;
 123                 }
 124         }
 125
 126         return true;
 127 }
 128
 129 static inline void lsm_md_dump(int mask, const struct lmv_stripe_md *lsm)
 130 {
 131         int i;
 132
 133         CDEBUG(mask, "magic %#x stripe count %d master mdt %d hash type %#x "
 134                 "version %d migrate offset %d migrate hash %#x pool %s\n",
 135                 lsm->lsm_md_magic, lsm->lsm_md_stripe_count,
 136                 lsm->lsm_md_master_mdt_index, lsm->lsm_md_hash_type,
 137                 lsm->lsm_md_layout_version, lsm->lsm_md_migrate_offset,
 138                 lsm->lsm_md_migrate_hash, lsm->lsm_md_pool_name);
 139
 140         if (!lmv_dir_striped(lsm))
 141                 return;
 142
 143         for (i = 0; i < lsm->lsm_md_stripe_count; i++)
 144                 CDEBUG(mask, "stripe[%d] "DFID"\n",
 145                        i, PFID(&lsm->lsm_md_oinfo[i].lmo_fid));
 146 }
 147
 148 union lmv_mds_md;
 149
 150 void lmv_free_memmd(struct lmv_stripe_md *lsm);
 151
 152 static inline void lmv1_le_to_cpu(struct lmv_mds_md_v1 *lmv_dst,
 153                                   const struct lmv_mds_md_v1 *lmv_src)
 154 {
 155         __u32 i;
 156
 157         lmv_dst->lmv_magic = le32_to_cpu(lmv_src->lmv_magic);
 158         lmv_dst->lmv_stripe_count = le32_to_cpu(lmv_src->lmv_stripe_count);
 159         lmv_dst->lmv_master_mdt_index =
 160                                 le32_to_cpu(lmv_src->lmv_master_mdt_index);
 161         lmv_dst->lmv_hash_type = le32_to_cpu(lmv_src->lmv_hash_type);
 162         lmv_dst->lmv_layout_version = le32_to_cpu(lmv_src->lmv_layout_version);
 163         for (i = 0; i < lmv_src->lmv_stripe_count; i++)
 164                 fid_le_to_cpu(&lmv_dst->lmv_stripe_fids[i],
 165                               &lmv_src->lmv_stripe_fids[i]);
 166 }
 167
 168 static inline void lmv_le_to_cpu(union lmv_mds_md *lmv_dst,
 169                                  const union lmv_mds_md *lmv_src)
 170 {
 171         switch (le32_to_cpu(lmv_src->lmv_magic)) {
 172         case LMV_MAGIC_V1:
 173                 lmv1_le_to_cpu(&lmv_dst->lmv_md_v1, &lmv_src->lmv_md_v1);
 174                 break;
 175         default:
 176                 break;
 177         }
 178 }
 179
 180 /* This hash is only for testing purpose */
 181 static inline unsigned int
 182 lmv_hash_all_chars(unsigned int count, const char *name, int namelen)
 183 {
 184         unsigned int c = 0;
 185         const unsigned char *p = (const unsigned char *)name;
 186
 187         while (--namelen >= 0)
 188                 c += p[namelen];
 189
 190         c = c % count;
 191
 192         return c;
 193 }
 194
 195 static inline unsigned int
 196 lmv_hash_fnv1a(unsigned int count, const char *name, int namelen)
 197 {
 198         __u64 hash;
 199
 200         hash = lustre_hash_fnv_1a_64(name, namelen);
 201
 202         return do_div(hash, count);
 203 }
 204
 205 static inline int lmv_name_to_stripe_index(__u32 lmv_hash_type,
 206                                            unsigned int stripe_count,
 207                                            const char *name, int namelen)
 208 {
 209         int idx;
 210
 211         LASSERT(namelen > 0);
 212
 213         if (stripe_count <= 1)
 214                 return 0;
 215
 216         switch (lmv_hash_type & LMV_HASH_TYPE_MASK) {
 217         case LMV_HASH_TYPE_ALL_CHARS:
 218                 idx = lmv_hash_all_chars(stripe_count, name, namelen);
 219                 break;
 220         case LMV_HASH_TYPE_FNV_1A_64:
 221                 idx = lmv_hash_fnv1a(stripe_count, name, namelen);
 222                 break;
 223         default:
 224                 idx = -EBADFD;
 225                 break;
 226         }
 227
 228         CDEBUG(D_INFO, "name %.*s hash_type %#x idx %d/%u\n", namelen, name,
 229                lmv_hash_type, idx, stripe_count);
 230
 231         return idx;
 232 }
 233
 234 static inline bool lmv_magic_supported(__u32 lum_magic)
 235 {
 236         return lum_magic == LMV_USER_MAGIC ||
 237                lum_magic == LMV_USER_MAGIC_SPECIFIC ||
 238                lum_magic == LMV_MAGIC_FOREIGN;
 239 }
 240
 241 #endif