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
  58 lsm_md_eq(const struct lmv_stripe_md *lsm1, const struct lmv_stripe_md *lsm2)
  59 {
  60         __u32 idx;
  61
  62         if (lsm1->lsm_md_magic != lsm2->lsm_md_magic ||
  63             lsm1->lsm_md_stripe_count != lsm2->lsm_md_stripe_count ||
  64             lsm1->lsm_md_master_mdt_index !=
  65                                 lsm2->lsm_md_master_mdt_index ||
  66             lsm1->lsm_md_hash_type != lsm2->lsm_md_hash_type ||
  67             lsm1->lsm_md_layout_version !=
  68                                 lsm2->lsm_md_layout_version ||
  69             lsm1->lsm_md_migrate_offset !=
  70                                 lsm2->lsm_md_migrate_offset ||
  71             lsm1->lsm_md_migrate_hash !=
  72                                 lsm2->lsm_md_migrate_hash ||
  73             strcmp(lsm1->lsm_md_pool_name,
  74                       lsm2->lsm_md_pool_name) != 0)
  75                 return false;
  76
  77         for (idx = 0; idx < lsm1->lsm_md_stripe_count; idx++) {
  78                 if (!lu_fid_eq(&lsm1->lsm_md_oinfo[idx].lmo_fid,
  79                                &lsm2->lsm_md_oinfo[idx].lmo_fid))
  80                         return false;
  81         }
  82
  83         return true;
  84 }
  85 union lmv_mds_md;
  86
  87 void lmv_free_memmd(struct lmv_stripe_md *lsm);
  88
  89 static inline void lmv1_le_to_cpu(struct lmv_mds_md_v1 *lmv_dst,
  90                                   const struct lmv_mds_md_v1 *lmv_src)
  91 {
  92         __u32 i;
  93
  94         lmv_dst->lmv_magic = le32_to_cpu(lmv_src->lmv_magic);
  95         lmv_dst->lmv_stripe_count = le32_to_cpu(lmv_src->lmv_stripe_count);
  96         lmv_dst->lmv_master_mdt_index =
  97                                 le32_to_cpu(lmv_src->lmv_master_mdt_index);
  98         lmv_dst->lmv_hash_type = le32_to_cpu(lmv_src->lmv_hash_type);
  99         lmv_dst->lmv_layout_version = le32_to_cpu(lmv_src->lmv_layout_version);
 100         for (i = 0; i < lmv_src->lmv_stripe_count; i++)
 101                 fid_le_to_cpu(&lmv_dst->lmv_stripe_fids[i],
 102                               &lmv_src->lmv_stripe_fids[i]);
 103 }
 104
 105 static inline void lmv_le_to_cpu(union lmv_mds_md *lmv_dst,
 106                                  const union lmv_mds_md *lmv_src)
 107 {
 108         switch (le32_to_cpu(lmv_src->lmv_magic)) {
 109         case LMV_MAGIC_V1:
 110                 lmv1_le_to_cpu(&lmv_dst->lmv_md_v1, &lmv_src->lmv_md_v1);
 111                 break;
 112         default:
 113                 break;
 114         }
 115 }
 116
 117 /* This hash is only for testing purpose */
 118 static inline unsigned int
 119 lmv_hash_all_chars(unsigned int count, const char *name, int namelen)
 120 {
 121         unsigned int c = 0;
 122         const unsigned char *p = (const unsigned char *)name;
 123
 124         while (--namelen >= 0)
 125                 c += p[namelen];
 126
 127         c = c % count;
 128
 129         return c;
 130 }
 131
 132 static inline unsigned int
 133 lmv_hash_fnv1a(unsigned int count, const char *name, int namelen)
 134 {
 135         __u64 hash;
 136
 137         hash = lustre_hash_fnv_1a_64(name, namelen);
 138
 139         return do_div(hash, count);
 140 }
 141
 142 static inline int lmv_name_to_stripe_index(__u32 lmv_hash_type,
 143                                            unsigned int stripe_count,
 144                                            const char *name, int namelen)
 145 {
 146         int idx;
 147
 148         LASSERT(namelen > 0);
 149
 150         if (stripe_count <= 1)
 151                 return 0;
 152
 153         switch (lmv_hash_type & LMV_HASH_TYPE_MASK) {
 154         case LMV_HASH_TYPE_ALL_CHARS:
 155                 idx = lmv_hash_all_chars(stripe_count, name, namelen);
 156                 break;
 157         case LMV_HASH_TYPE_FNV_1A_64:
 158                 idx = lmv_hash_fnv1a(stripe_count, name, namelen);
 159                 break;
 160         default:
 161                 idx = -EBADFD;
 162                 break;
 163         }
 164
 165         CDEBUG(D_INFO, "name %.*s hash_type %#x idx %d/%u\n", namelen, name,
 166                lmv_hash_type, idx, stripe_count);
 167
 168         return idx;
 169 }
 170
 171 static inline bool lmv_is_known_hash_type(__u32 type)
 172 {
 173         return (type & LMV_HASH_TYPE_MASK) == LMV_HASH_TYPE_FNV_1A_64 ||
 174                (type & LMV_HASH_TYPE_MASK) == LMV_HASH_TYPE_ALL_CHARS;
 175 }
 176
 177 #endif