fs/ocfs2/slot_map.c

   1 /* -*- mode: c; c-basic-offset: 8; -*-
   2  * vim: noexpandtab sw=8 ts=8 sts=0:
   3  *
   4  * slot_map.c
   5  *
   6  *
   7  *
   8  * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
   9  *
  10  * This program is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU General Public
  12  * License as published by the Free Software Foundation; either
  13  * version 2 of the License, or (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18  * General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public
  21  * License along with this program; if not, write to the
  22  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  23  * Boston, MA 021110-1307, USA.
  24  */
  25
  26 #include <linux/types.h>
  27 #include <linux/slab.h>
  28 #include <linux/highmem.h>
  29 #include <linux/smp_lock.h>
  30
  31 #define MLOG_MASK_PREFIX ML_SUPER
  32 #include <cluster/masklog.h>
  33
  34 #include "ocfs2.h"
  35
  36 #include "dlmglue.h"
  37 #include "extent_map.h"
  38 #include "heartbeat.h"
  39 #include "inode.h"
  40 #include "slot_map.h"
  41 #include "super.h"
  42 #include "sysfile.h"
  43
  44 #include "buffer_head_io.h"
  45
  46 static s16 __ocfs2_node_num_to_slot(struct ocfs2_slot_info *si,
  47                                     s16 global);
  48 static void __ocfs2_fill_slot(struct ocfs2_slot_info *si,
  49                               s16 slot_num,
  50                               s16 node_num);
  51
  52 /* Use the slot information we've collected to create a map of mounted
  53  * nodes. Should be holding an EX on super block. assumes slot info is
  54  * up to date. Note that we call this *after* we find a slot, so our
  55  * own node should be set in the map too... */
  56 void ocfs2_populate_mounted_map(struct ocfs2_super *osb)
  57 {
  58         int i;
  59         struct ocfs2_slot_info *si = osb->slot_info;
  60
  61         spin_lock(&si->si_lock);
  62
  63         for (i = 0; i < si->si_size; i++)
  64                 if (si->si_global_node_nums[i] != OCFS2_INVALID_SLOT)
  65                         ocfs2_node_map_set_bit(osb, &osb->mounted_map,
  66                                               si->si_global_node_nums[i]);
  67
  68         spin_unlock(&si->si_lock);
  69 }
  70
  71 /* post the slot information on disk into our slot_info struct. */
  72 void ocfs2_update_slot_info(struct ocfs2_slot_info *si)
  73 {
  74         int i;
  75         __le16 *disk_info;
  76
  77         /* we don't read the slot block here as ocfs2_super_lock
  78          * should've made sure we have the most recent copy. */
  79         spin_lock(&si->si_lock);
  80         disk_info = (__le16 *) si->si_bh->b_data;
  81
  82         for (i = 0; i < si->si_size; i++)
  83                 si->si_global_node_nums[i] = le16_to_cpu(disk_info[i]);
  84
  85         spin_unlock(&si->si_lock);
  86 }
  87
  88 /* post the our slot info stuff into it's destination bh and write it
  89  * out. */
  90 int ocfs2_update_disk_slots(struct ocfs2_super *osb,
  91                             struct ocfs2_slot_info *si)
  92 {
  93         int status, i;
  94         __le16 *disk_info = (__le16 *) si->si_bh->b_data;
  95
  96         spin_lock(&si->si_lock);
  97         for (i = 0; i < si->si_size; i++)
  98                 disk_info[i] = cpu_to_le16(si->si_global_node_nums[i]);
  99         spin_unlock(&si->si_lock);
 100
 101         status = ocfs2_write_block(osb, si->si_bh, si->si_inode);
 102         if (status < 0)
 103                 mlog_errno(status);
 104
 105         return status;
 106 }
 107
 108 /* try to find global node in the slot info. Returns
 109  * OCFS2_INVALID_SLOT if nothing is found. */
 110 static s16 __ocfs2_node_num_to_slot(struct ocfs2_slot_info *si,
 111                                     s16 global)
 112 {
 113         int i;
 114         s16 ret = OCFS2_INVALID_SLOT;
 115
 116         for(i = 0; i < si->si_num_slots; i++) {
 117                 if (global == si->si_global_node_nums[i]) {
 118                         ret = (s16) i;
 119                         break;
 120                 }
 121         }
 122         return ret;
 123 }
 124
 125 static s16 __ocfs2_find_empty_slot(struct ocfs2_slot_info *si)
 126 {
 127         int i;
 128         s16 ret = OCFS2_INVALID_SLOT;
 129
 130         for(i = 0; i < si->si_num_slots; i++) {
 131                 if (OCFS2_INVALID_SLOT == si->si_global_node_nums[i]) {
 132                         ret = (s16) i;
 133                         break;
 134                 }
 135         }
 136         return ret;
 137 }
 138
 139 s16 ocfs2_node_num_to_slot(struct ocfs2_slot_info *si,
 140                            s16 global)
 141 {
 142         s16 ret;
 143
 144         spin_lock(&si->si_lock);
 145         ret = __ocfs2_node_num_to_slot(si, global);
 146         spin_unlock(&si->si_lock);
 147         return ret;
 148 }
 149
 150 static void __ocfs2_fill_slot(struct ocfs2_slot_info *si,
 151                               s16 slot_num,
 152                               s16 node_num)
 153 {
 154         BUG_ON(slot_num == OCFS2_INVALID_SLOT);
 155         BUG_ON(slot_num >= si->si_num_slots);
 156         BUG_ON((node_num != O2NM_INVALID_NODE_NUM) &&
 157                (node_num >= O2NM_MAX_NODES));
 158
 159         si->si_global_node_nums[slot_num] = node_num;
 160 }
 161
 162 void ocfs2_clear_slot(struct ocfs2_slot_info *si,
 163                       s16 slot_num)
 164 {
 165         spin_lock(&si->si_lock);
 166         __ocfs2_fill_slot(si, slot_num, OCFS2_INVALID_SLOT);
 167         spin_unlock(&si->si_lock);
 168 }
 169
 170 int ocfs2_init_slot_info(struct ocfs2_super *osb)
 171 {
 172         int status, i;
 173         u64 blkno;
 174         struct inode *inode = NULL;
 175         struct buffer_head *bh = NULL;
 176         struct ocfs2_slot_info *si;
 177
 178         si = kcalloc(1, sizeof(struct ocfs2_slot_info), GFP_KERNEL);
 179         if (!si) {
 180                 status = -ENOMEM;
 181                 mlog_errno(status);
 182                 goto bail;
 183         }
 184
 185         spin_lock_init(&si->si_lock);
 186         si->si_num_slots = osb->max_slots;
 187         si->si_size = OCFS2_MAX_SLOTS;
 188
 189         for(i = 0; i < si->si_num_slots; i++)
 190                 si->si_global_node_nums[i] = OCFS2_INVALID_SLOT;
 191
 192         inode = ocfs2_get_system_file_inode(osb, SLOT_MAP_SYSTEM_INODE,
 193                                             OCFS2_INVALID_SLOT);
 194         if (!inode) {
 195                 status = -EINVAL;
 196                 mlog_errno(status);
 197                 goto bail;
 198         }
 199
 200         status = ocfs2_extent_map_get_blocks(inode, 0ULL, 1, &blkno, NULL);
 201         if (status < 0) {
 202                 mlog_errno(status);
 203                 goto bail;
 204         }
 205
 206         status = ocfs2_read_block(osb, blkno, &bh, 0, inode);
 207         if (status < 0) {
 208                 mlog_errno(status);
 209                 goto bail;
 210         }
 211
 212         si->si_inode = inode;
 213         si->si_bh = bh;
 214         osb->slot_info = si;
 215 bail:
 216         if (status < 0 && si)
 217                 ocfs2_free_slot_info(si);
 218
 219         return status;
 220 }
 221
 222 void ocfs2_free_slot_info(struct ocfs2_slot_info *si)
 223 {
 224         if (si->si_inode)
 225                 iput(si->si_inode);
 226         if (si->si_bh)
 227                 brelse(si->si_bh);
 228         kfree(si);
 229 }
 230
 231 int ocfs2_find_slot(struct ocfs2_super *osb)
 232 {
 233         int status;
 234         s16 slot;
 235         struct ocfs2_slot_info *si;
 236
 237         mlog_entry_void();
 238
 239         si = osb->slot_info;
 240
 241         ocfs2_update_slot_info(si);
 242
 243         spin_lock(&si->si_lock);
 244         /* search for ourselves first and take the slot if it already
 245          * exists. Perhaps we need to mark this in a variable for our
 246          * own journal recovery? Possibly not, though we certainly
 247          * need to warn to the user */
 248         slot = __ocfs2_node_num_to_slot(si, osb->node_num);
 249         if (slot == OCFS2_INVALID_SLOT) {
 250                 /* if no slot yet, then just take 1st available
 251                  * one. */
 252                 slot = __ocfs2_find_empty_slot(si);
 253                 if (slot == OCFS2_INVALID_SLOT) {
 254                         spin_unlock(&si->si_lock);
 255                         mlog(ML_ERROR, "no free slots available!\n");
 256                         status = -EINVAL;
 257                         goto bail;
 258                 }
 259         } else
 260                 mlog(ML_NOTICE, "slot %d is already allocated to this node!\n",
 261                      slot);
 262
 263         __ocfs2_fill_slot(si, slot, osb->node_num);
 264         osb->slot_num = slot;
 265         spin_unlock(&si->si_lock);
 266
 267         mlog(0, "taking node slot %d\n", osb->slot_num);
 268
 269         status = ocfs2_update_disk_slots(osb, si);
 270         if (status < 0)
 271                 mlog_errno(status);
 272
 273 bail:
 274         mlog_exit(status);
 275         return status;
 276 }
 277
 278 void ocfs2_put_slot(struct ocfs2_super *osb)
 279 {
 280         int status;
 281         struct ocfs2_slot_info *si = osb->slot_info;
 282
 283         if (!si)
 284                 return;
 285
 286         ocfs2_update_slot_info(si);
 287
 288         spin_lock(&si->si_lock);
 289         __ocfs2_fill_slot(si, osb->slot_num, OCFS2_INVALID_SLOT);
 290         osb->slot_num = OCFS2_INVALID_SLOT;
 291         spin_unlock(&si->si_lock);
 292
 293         status = ocfs2_update_disk_slots(osb, si);
 294         if (status < 0) {
 295                 mlog_errno(status);
 296                 goto bail;
 297         }
 298
 299 bail:
 300         osb->slot_info = NULL;
 301         ocfs2_free_slot_info(si);
 302 }
 303