lustre/ptlrpc/nodemap_member.c

   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, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License version 2 for more details (a copy is included
  14  * in the LICENSE file that accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * version 2 along with this program; If not, see
  18  * http://www.gnu.org/licenses/gpl-2.0.html
  19  *
  20  * GPL HEADER END
  21  */
  22 /*
  23  * Copyright (C) 2013, Trustees of Indiana University
  24  * Author: Joshua Walgenbach <jjw@iu.edu>
  25  */
  26 #include <linux/module.h>
  27 #include <lustre_net.h>
  28 #include <obd_class.h>
  29 #include "nodemap_internal.h"
  30
  31 #define HASH_NODEMAP_MEMBER_BKT_BITS 3
  32 #define HASH_NODEMAP_MEMBER_CUR_BITS 3
  33 #define HASH_NODEMAP_MEMBER_MAX_BITS 7
  34
  35 /**
  36  * Delete a member from a member list
  37  *
  38  * \param       nodemap         nodemap containing list
  39  * \param       exp             export member to delete
  40  */
  41 void nm_member_del(struct lu_nodemap *nodemap, struct obd_export *exp)
  42 {
  43         mutex_lock(&nodemap->nm_member_list_lock);
  44         list_del_init(&exp->exp_target_data.ted_nodemap_member);
  45         mutex_unlock(&nodemap->nm_member_list_lock);
  46
  47         exp->exp_target_data.ted_nodemap = NULL;
  48         class_export_put(exp);
  49 }
  50
  51 /**
  52  * Delete a member list from a nodemap
  53  *
  54  * \param       nodemap         nodemap to remove the list from
  55  */
  56 void nm_member_delete_list(struct lu_nodemap *nodemap)
  57 {
  58         struct obd_export *exp;
  59         struct obd_export *tmp;
  60
  61         mutex_lock(&nodemap->nm_member_list_lock);
  62         list_for_each_entry_safe(exp, tmp, &nodemap->nm_member_list,
  63                                  exp_target_data.ted_nodemap_member) {
  64                 exp->exp_target_data.ted_nodemap = NULL;
  65                 list_del_init(&exp->exp_target_data.ted_nodemap_member);
  66                 class_export_put(exp);
  67         }
  68         mutex_unlock(&nodemap->nm_member_list_lock);
  69 }
  70
  71 /**
  72  * Add a member export to a nodemap
  73  *
  74  * \param       nodemap         nodemap to add to
  75  * \param       exp             obd_export to add
  76  * \retval      -EEXIST         export is already part of a different nodemap
  77  * \retval      -EINVAL         export is NULL
  78  */
  79 int nm_member_add(struct lu_nodemap *nodemap, struct obd_export *exp)
  80 {
  81         if (exp == NULL) {
  82                 CWARN("attempted to add null export to nodemap %s\n",
  83                       nodemap->nm_name);
  84                 return -EINVAL;
  85         }
  86
  87         if (exp->exp_target_data.ted_nodemap != NULL &&
  88             !list_empty(&exp->exp_target_data.ted_nodemap_member)) {
  89                 /* export is already member of nodemap */
  90                 if (exp->exp_target_data.ted_nodemap == nodemap)
  91                         return 0;
  92
  93                 /* possibly reconnecting while about to be reclassified */
  94                 CWARN("export %p %s already hashed, failed to add to "
  95                       "nodemap %s already member of %s\n", exp,
  96                       exp->exp_client_uuid.uuid,
  97                       nodemap->nm_name,
  98                       (exp->exp_target_data.ted_nodemap == NULL) ? "unknown" :
  99                                 exp->exp_target_data.ted_nodemap->nm_name);
 100                 return -EEXIST;
 101         }
 102
 103         class_export_get(exp);
 104         exp->exp_target_data.ted_nodemap = nodemap;
 105         mutex_lock(&nodemap->nm_member_list_lock);
 106         list_add(&exp->exp_target_data.ted_nodemap_member,
 107                  &nodemap->nm_member_list);
 108         mutex_unlock(&nodemap->nm_member_list_lock);
 109
 110         return 0;
 111 }
 112
 113 /**
 114  * Revokes the locks on an export if it is attached to an MDT and not in
 115  * recovery. As a performance enhancement, the lock revoking process could
 116  * revoke only the locks that cover files affected by the nodemap change.
 117  */
 118 static void nm_member_exp_revoke(struct obd_export *exp)
 119 {
 120         struct obd_type *type = exp->exp_obd->obd_type;
 121         if (strcmp(type->typ_name, LUSTRE_MDT_NAME) != 0)
 122                 return;
 123         if (exp->exp_obd->obd_recovering)
 124                 return;
 125
 126         ldlm_revoke_export_locks(exp);
 127 }
 128
 129 /**
 130  * Reclassify the members of a nodemap after range changes or activation.
 131  * This function reclassifies the members of a nodemap based on the member
 132  * export's NID and the nodemap's new NID ranges. Exports that are no longer
 133  * classified as being part of this nodemap are moved to the nodemap whose
 134  * NID ranges contain the export's NID, and their locks are revoked.
 135  *
 136  * Callers should hold the active_config_lock and active_config
 137  * nmc_range_tree_lock.
 138  *
 139  * \param       nodemap         nodemap with members to reclassify
 140  */
 141 void nm_member_reclassify_nodemap(struct lu_nodemap *nodemap)
 142 {
 143         struct obd_export *exp;
 144         struct obd_export *tmp;
 145         struct lu_nodemap *new_nodemap;
 146
 147         mutex_lock(&nodemap->nm_member_list_lock);
 148         list_for_each_entry_safe(exp, tmp, &nodemap->nm_member_list,
 149                                  exp_target_data.ted_nodemap_member) {
 150                 lnet_nid_t nid = exp->exp_connection->c_peer.nid;
 151
 152                 /* nodemap_classify_nid requires nmc_range_tree_lock */
 153                 new_nodemap = nodemap_classify_nid(nid);
 154                 if (new_nodemap != nodemap) {
 155                         /* don't use member_del because ted_nodemap
 156                          * should never be null
 157                          */
 158                         list_del_init(&exp->exp_target_data.ted_nodemap_member);
 159                         exp->exp_target_data.ted_nodemap = new_nodemap;
 160
 161                         /* could deadlock if new_nodemap also reclassifying */
 162                         mutex_lock(&new_nodemap->nm_member_list_lock);
 163                         list_add(&exp->exp_target_data.ted_nodemap_member,
 164                                  &new_nodemap->nm_member_list);
 165                         mutex_unlock(&new_nodemap->nm_member_list_lock);
 166                         nm_member_exp_revoke(exp);
 167                 }
 168
 169                 /* This put won't destroy new_nodemap because any nodemap_del
 170                  * call done on new_nodemap blocks on our active_config_lock
 171                  */
 172                 nodemap_putref(new_nodemap);
 173         }
 174         mutex_unlock(&nodemap->nm_member_list_lock);
 175 }
 176
 177 /**
 178  * Revoke the locks for member exports. Changing the idmap is
 179  * akin to deleting the security context. If the locks are not
 180  * canceled, the client could cache permissions that are no
 181  * longer correct with the map.
 182  *
 183  * \param       nodemap         nodemap that has been altered
 184  */
 185 void nm_member_revoke_locks(struct lu_nodemap *nodemap)
 186 {
 187         struct obd_export *exp;
 188         struct obd_export *tmp;
 189
 190         mutex_lock(&nodemap->nm_member_list_lock);
 191         list_for_each_entry_safe(exp, tmp, &nodemap->nm_member_list,
 192                             exp_target_data.ted_nodemap_member)
 193                 nm_member_exp_revoke(exp);
 194         mutex_unlock(&nodemap->nm_member_list_lock);
 195 }