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
  30 #define MLOG_MASK_PREFIX ML_SUPER
  31 #include <cluster/masklog.h>
  32
  33 #include "ocfs2.h"
  34
  35 #include "dlmglue.h"
  36 #include "extent_map.h"
  37 #include "heartbeat.h"
  38 #include "inode.h"
  39 #include "slot_map.h"
  40 #include "super.h"
  41 #include "sysfile.h"
  42
  43 #include "buffer_head_io.h"
  44
  45 static s16 __ocfs2_node_num_to_slot(struct ocfs2_slot_info *si,
  46                                     s16 global);
  47 static void __ocfs2_fill_slot(struct ocfs2_slot_info *si,
  48                               s16 slot_num,
  49                               s16 node_num);
  50
  51 /* Use the slot information we've collected to create a map of mounted
  52  * nodes. Should be holding an EX on super block. assumes slot info is
  53  * up to date. Note that we call this *after* we find a slot, so our
  54  * own node should be set in the map too... */
  55 void ocfs2_populate_mounted_map(struct ocfs2_super *osb)
  56 {
  57         int i;
  58         struct ocfs2_slot_info *si = osb->slot_info;
  59
  60         spin_lock(&si->si_lock);
  61
  62         for (i = 0; i < si->si_size; i++)
  63                 if (si->si_global_node_nums[i] != OCFS2_INVALID_SLOT)
  64                         ocfs2_node_map_set_bit(osb, &osb->mounted_map,
  65                                               si->si_global_node_nums[i]);
  66
  67         spin_unlock(&si->si_lock);
  68 }
  69
  70 /* post the slot information on disk into our slot_info struct. */
  71 void ocfs2_update_slot_info(struct ocfs2_slot_info *si)
  72 {
  73         int i;
  74         __le16 *disk_info;
  75
  76         /* we don't read the slot block here as ocfs2_super_lock
  77          * should've made sure we have the most recent copy. */
  78         spin_lock(&si->si_lock);
  79         disk_info = (__le16 *) si->si_bh->b_data;
  80
  81         for (i = 0; i < si->si_size; i++)
  82                 si->si_global_node_nums[i] = le16_to_cpu(disk_info[i]);
  83
  84         spin_unlock(&si->si_lock);
  85 }
  86
  87 /* post the our slot info stuff into it's destination bh and write it
  88  * out. */
  89 int ocfs2_update_disk_slots(struct ocfs2_super *osb,
  90                             struct ocfs2_slot_info *si)
  91 {
  92         int status, i;
  93         __le16 *disk_info = (__le16 *) si->si_bh->b_data;
  94
  95         spin_lock(&si->si_lock);
  96         for (i = 0; i < si->si_size; i++)
  97                 disk_info[i] = cpu_to_le16(si->si_global_node_nums[i]);
  98         spin_unlock(&si->si_lock);
  99
 100         status = ocfs2_write_block(osb, si->si_bh, si->si_inode);
 101         if (status < 0)
 102                 mlog_errno(status);
 103
 104         return status;
 105 }
 106
 107 /* try to find global node in the slot info. Returns
 108  * OCFS2_INVALID_SLOT if nothing is found. */
 109 static s16 __ocfs2_node_num_to_slot(struct ocfs2_slot_info *si,
 110                                     s16 global)
 111 {
 112         int i;
 113         s16 ret = OCFS2_INVALID_SLOT;
 114
 115         for(i = 0; i < si->si_num_slots; i++) {
 116                 if (global == si->si_global_node_nums[i]) {
 117                         ret = (s16) i;
 118                         break;
 119                 }
 120         }
 121         return ret;
 122 }
 123
 124 static s16 __ocfs2_find_empty_slot(struct ocfs2_slot_info *si, s16 preferred)
 125 {
 126         int i;
 127         s16 ret = OCFS2_INVALID_SLOT;
 128
 129         if (preferred >= 0 && preferred < si->si_num_slots) {
 130                 if (OCFS2_INVALID_SLOT == si->si_global_node_nums[preferred]) {
 131                         ret = preferred;
 132                         goto out;
 133                 }
 134         }
 135
 136         for(i = 0; i < si->si_num_slots; i++) {
 137                 if (OCFS2_INVALID_SLOT == si->si_global_node_nums[i]) {
 138                         ret = (s16) i;
 139                         break;
 140                 }
 141         }
 142 out:
 143         return ret;
 144 }
 145
 146 s16 ocfs2_node_num_to_slot(struct ocfs2_slot_info *si,
 147                            s16 global)
 148 {
 149         s16 ret;
 150
 151         spin_lock(&si->si_lock);
 152         ret = __ocfs2_node_num_to_slot(si, global);
 153         spin_unlock(&si->si_lock);
 154         return ret;
 155 }
 156
 157 static void __ocfs2_fill_slot(struct ocfs2_slot_info *si,
 158                               s16 slot_num,
 159                               s16 node_num)
 160 {
 161         BUG_ON(slot_num == OCFS2_INVALID_SLOT);
 162         BUG_ON(slot_num >= si->si_num_slots);
 163         BUG_ON((node_num != O2NM_INVALID_NODE_NUM) &&
 164                (node_num >= O2NM_MAX_NODES));
 165
 166         si->si_global_node_nums[slot_num] = node_num;
 167 }
 168
 169 void ocfs2_clear_slot(struct ocfs2_slot_info *si,
 170                       s16 slot_num)
 171 {
 172         spin_lock(&si->si_lock);
 173         __ocfs2_fill_slot(si, slot_num, OCFS2_INVALID_SLOT);
 174         spin_unlock(&si->si_lock);
 175 }
 176
 177 int ocfs2_init_slot_info(struct ocfs2_super *osb)
 178 {
 179         int status, i;
 180         u64 blkno;
 181         struct inode *inode = NULL;
 182         struct buffer_head *bh = NULL;
 183         struct ocfs2_slot_info *si;
 184
 185         si = kzalloc(sizeof(struct ocfs2_slot_info), GFP_KERNEL);
 186         if (!si) {
 187                 status = -ENOMEM;
 188                 mlog_errno(status);
 189                 goto bail;
 190         }
 191
 192         spin_lock_init(&si->si_lock);
 193         si->si_num_slots = osb->max_slots;
 194         si->si_size = OCFS2_MAX_SLOTS;
 195
 196         for(i = 0; i < si->si_num_slots; i++)
 197                 si->si_global_node_nums[i] = OCFS2_INVALID_SLOT;
 198
 199         inode = ocfs2_get_system_file_inode(osb, SLOT_MAP_SYSTEM_INODE,
 200                                             OCFS2_INVALID_SLOT);
 201         if (!inode) {
 202                 status = -EINVAL;
 203                 mlog_errno(status);
 204                 goto bail;
 205         }
 206
 207         status = ocfs2_extent_map_get_blocks(inode, 0ULL, &blkno, NULL, NULL);
 208         if (status < 0) {
 209                 mlog_errno(status);
 210                 goto bail;
 211         }
 212
 213         status = ocfs2_read_block(osb, blkno, &bh, 0, inode);
 214         if (status < 0) {
 215                 mlog_errno(status);
 216                 goto bail;
 217         }
 218
 219         si->si_inode = inode;
 220         si->si_bh = bh;
 221         osb->slot_info = si;
 222 bail:
 223         if (status < 0 && si)
 224                 ocfs2_free_slot_info(si);
 225
 226         return status;
 227 }
 228
 229 void ocfs2_free_slot_info(struct ocfs2_slot_info *si)
 230 {
 231         if (si->si_inode)
 232                 iput(si->si_inode);
 233         if (si->si_bh)
 234                 brelse(si->si_bh);
 235         kfree(si);
 236 }
 237
 238 int ocfs2_find_slot(struct ocfs2_super *osb)
 239 {
 240         int status;
 241         s16 slot;
 242         struct ocfs2_slot_info *si;
 243
 244         mlog_entry_void();
 245
 246         si = osb->slot_info;
 247
 248         ocfs2_update_slot_info(si);
 249
 250         spin_lock(&si->si_lock);
 251         /* search for ourselves first and take the slot if it already
 252          * exists. Perhaps we need to mark this in a variable for our
 253          * own journal recovery? Possibly not, though we certainly
 254          * need to warn to the user */
 255         slot = __ocfs2_node_num_to_slot(si, osb->node_num);
 256         if (slot == OCFS2_INVALID_SLOT) {
 257                 /* if no slot yet, then just take 1st available
 258                  * one. */
 259                 slot = __ocfs2_find_empty_slot(si, osb->preferred_slot);
 260                 if (slot == OCFS2_INVALID_SLOT) {
 261                         spin_unlock(&si->si_lock);
 262                         mlog(ML_ERROR, "no free slots available!\n");
 263                         status = -EINVAL;
 264                         goto bail;
 265                 }
 266         } else
 267                 mlog(ML_NOTICE, "slot %d is already allocated to this node!\n",
 268                      slot);
 269
 270         __ocfs2_fill_slot(si, slot, osb->node_num);
 271         osb->slot_num = slot;
 272         spin_unlock(&si->si_lock);
 273
 274         mlog(0, "taking node slot %d\n", osb->slot_num);
 275
 276         status = ocfs2_update_disk_slots(osb, si);
 277         if (status < 0)
 278                 mlog_errno(status);
 279
 280 bail:
 281         mlog_exit(status);
 282         return status;
 283 }
 284
 285 void ocfs2_put_slot(struct ocfs2_super *osb)
 286 {
 287         int status;
 288         struct ocfs2_slot_info *si = osb->slot_info;
 289
 290         if (!si)
 291                 return;
 292
 293         ocfs2_update_slot_info(si);
 294
 295         spin_lock(&si->si_lock);
 296         __ocfs2_fill_slot(si, osb->slot_num, OCFS2_INVALID_SLOT);
 297         osb->slot_num = OCFS2_INVALID_SLOT;
 298         spin_unlock(&si->si_lock);
 299
 300         status = ocfs2_update_disk_slots(osb, si);
 301         if (status < 0) {
 302                 mlog_errno(status);
 303                 goto bail;
 304         }
 305
 306 bail:
 307         osb->slot_info = NULL;
 308         ocfs2_free_slot_info(si);
 309 }
 310