lustre/lod/lod_lov.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,
  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  2009 Sun Microsystems, Inc. All rights reserved
  24  * Use is subject to license terms.
  25  */
  26 /*
  27  * lustre/lod/lod_lov.c
  28  *
  29  * Author: Alex Zhuravlev <alexey.zhuravlev@intel.com>
  30  */
  31
  32 #ifndef EXPORT_SYMTAB
  33 # define EXPORT_SYMTAB
  34 #endif
  35 #define DEBUG_SUBSYSTEM S_MDS
  36
  37 #include <obd_class.h>
  38 #include <obd_lov.h>
  39
  40 #include "lod_internal.h"
  41
  42 /*
  43  * Keep a refcount of lod->lod_osts usage to prevent racing with
  44  * addition/deletion. Any function that expects lov_tgts to remain stationary
  45  * must take a ref.
  46  *
  47  * \param lod - is the lod device from which we want to grab a reference
  48  */
  49 void lod_getref(struct lod_device *lod)
  50 {
  51         cfs_down_read(&lod->lod_rw_sem);
  52         cfs_mutex_lock(&lod->lod_mutex);
  53         lod->lod_refcount++;
  54         cfs_mutex_unlock(&lod->lod_mutex);
  55 }
  56
  57 /*
  58  * Companion of lod_getref() to release a reference on the lod table.
  59  * If this is the last reference and the ost entry was scheduled for deletion,
  60  * the descriptor is removed from the array.
  61  *
  62  * \param lod - is the lod device from which we release a reference
  63  */
  64 void lod_putref(struct lod_device *lod)
  65 {
  66         cfs_mutex_lock(&lod->lod_mutex);
  67         lod->lod_refcount--;
  68         if (lod->lod_refcount == 0 && lod->lod_death_row) {
  69                 struct lod_ost_desc *ost_desc, *tmp;
  70                 int                  idx;
  71                 CFS_LIST_HEAD(kill);
  72
  73                 CDEBUG(D_CONFIG, "destroying %d lod desc\n",
  74                        lod->lod_death_row);
  75
  76                 cfs_foreach_bit(lod->lod_ost_bitmap, idx) {
  77                         ost_desc = OST_TGT(lod, idx);
  78                         LASSERT(ost_desc);
  79
  80                         if (!ost_desc->ltd_reap)
  81                                 continue;
  82
  83                         cfs_list_add(&ost_desc->ltd_kill, &kill);
  84                         /* XXX: remove from the pool */
  85                         OST_TGT(lod, idx) = NULL;
  86                         lod->lod_ostnr--;
  87                         cfs_bitmap_clear(lod->lod_ost_bitmap, idx);
  88                         if (ost_desc->ltd_active)
  89                                 lod->lod_desc.ld_active_tgt_count--;
  90                         lod->lod_death_row--;
  91                 }
  92                 cfs_mutex_unlock(&lod->lod_mutex);
  93                 cfs_up_read(&lod->lod_rw_sem);
  94
  95                 cfs_list_for_each_entry_safe(ost_desc, tmp, &kill, ltd_kill) {
  96                         int rc;
  97                         cfs_list_del(&ost_desc->ltd_kill);
  98                         /* XXX: remove from QoS structures */
  99                         /* disconnect from OSP */
 100                         rc = obd_disconnect(ost_desc->ltd_exp);
 101                         if (rc)
 102                                 CERROR("%s: failed to disconnect %s (%d)\n",
 103                                        lod2obd(lod)->obd_name,
 104                                        obd_uuid2str(&ost_desc->ltd_uuid), rc);
 105                         OBD_FREE_PTR(ost_desc);
 106                 }
 107         } else {
 108                 cfs_mutex_unlock(&lod->lod_mutex);
 109                 cfs_up_read(&lod->lod_rw_sem);
 110         }
 111 }
 112