release/src-rt-6.x.4708/linux/linux-2.6.36/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
  46 struct ocfs2_slot {
  47         int sl_valid;
  48         unsigned int sl_node_num;
  49 };
  50
  51 struct ocfs2_slot_info {
  52         int si_extended;
  53         int si_slots_per_block;
  54         struct inode *si_inode;
  55         unsigned int si_blocks;
  56         struct buffer_head **si_bh;
  57         unsigned int si_num_slots;
  58         struct ocfs2_slot *si_slots;
  59 };
  60
  61
  62 static int __ocfs2_node_num_to_slot(struct ocfs2_slot_info *si,
  63                                     unsigned int node_num);
  64
  65 static void ocfs2_invalidate_slot(struct ocfs2_slot_info *si,
  66                                   int slot_num)
  67 {
  68         BUG_ON((slot_num < 0) || (slot_num >= si->si_num_slots));
  69         si->si_slots[slot_num].sl_valid = 0;
  70 }
  71
  72 static void ocfs2_set_slot(struct ocfs2_slot_info *si,
  73                            int slot_num, unsigned int node_num)
  74 {
  75         BUG_ON((slot_num < 0) || (slot_num >= si->si_num_slots));
  76
  77         si->si_slots[slot_num].sl_valid = 1;
  78         si->si_slots[slot_num].sl_node_num = node_num;
  79 }
  80
  81 /* This version is for the extended slot map */
  82 static void ocfs2_update_slot_info_extended(struct ocfs2_slot_info *si)
  83 {
  84         int b, i, slotno;
  85         struct ocfs2_slot_map_extended *se;
  86
  87         slotno = 0;
  88         for (b = 0; b < si->si_blocks; b++) {
  89                 se = (struct ocfs2_slot_map_extended *)si->si_bh[b]->b_data;
  90                 for (i = 0;
  91                      (i < si->si_slots_per_block) &&
  92                      (slotno < si->si_num_slots);
  93                      i++, slotno++) {
  94                         if (se->se_slots[i].es_valid)
  95                                 ocfs2_set_slot(si, slotno,
  96                                                le32_to_cpu(se->se_slots[i].es_node_num));
  97                         else
  98                                 ocfs2_invalidate_slot(si, slotno);
  99                 }
 100         }
 101 }
 102
 103 /*
 104  * Post the slot information on disk into our slot_info struct.
 105  * Must be protected by osb_lock.
 106  */
 107 static void ocfs2_update_slot_info_old(struct ocfs2_slot_info *si)
 108 {
 109         int i;
 110         struct ocfs2_slot_map *sm;
 111
 112         sm = (struct ocfs2_slot_map *)si->si_bh[0]->b_data;
 113
 114         for (i = 0; i < si->si_num_slots; i++) {
 115                 if (le16_to_cpu(sm->sm_slots[i]) == (u16)OCFS2_INVALID_SLOT)
 116                         ocfs2_invalidate_slot(si, i);
 117                 else
 118                         ocfs2_set_slot(si, i, le16_to_cpu(sm->sm_slots[i]));
 119         }
 120 }
 121
 122 static void ocfs2_update_slot_info(struct ocfs2_slot_info *si)
 123 {
 124         /*
 125          * The slot data will have been refreshed when ocfs2_super_lock
 126          * was taken.
 127          */
 128         if (si->si_extended)
 129                 ocfs2_update_slot_info_extended(si);
 130         else
 131                 ocfs2_update_slot_info_old(si);
 132 }
 133
 134 int ocfs2_refresh_slot_info(struct ocfs2_super *osb)
 135 {
 136         int ret;
 137         struct ocfs2_slot_info *si = osb->slot_info;
 138
 139         if (si == NULL)
 140                 return 0;
 141
 142         BUG_ON(si->si_blocks == 0);
 143         BUG_ON(si->si_bh == NULL);
 144
 145         mlog(0, "Refreshing slot map, reading %u block(s)\n",
 146              si->si_blocks);
 147
 148         /*
 149          * We pass -1 as blocknr because we expect all of si->si_bh to
 150          * be !NULL.  Thus, ocfs2_read_blocks() will ignore blocknr.  If
 151          * this is not true, the read of -1 (UINT64_MAX) will fail.
 152          */
 153         ret = ocfs2_read_blocks(INODE_CACHE(si->si_inode), -1, si->si_blocks,
 154                                 si->si_bh, OCFS2_BH_IGNORE_CACHE, NULL);
 155         if (ret == 0) {
 156                 spin_lock(&osb->osb_lock);
 157                 ocfs2_update_slot_info(si);
 158                 spin_unlock(&osb->osb_lock);
 159         }
 160
 161         return ret;
 162 }
 163
 164 /* post the our slot info stuff into it's destination bh and write it
 165  * out. */
 166 static void ocfs2_update_disk_slot_extended(struct ocfs2_slot_info *si,
 167                                             int slot_num,
 168                                             struct buffer_head **bh)
 169 {
 170         int blkind = slot_num / si->si_slots_per_block;
 171         int slotno = slot_num % si->si_slots_per_block;
 172         struct ocfs2_slot_map_extended *se;
 173
 174         BUG_ON(blkind >= si->si_blocks);
 175
 176         se = (struct ocfs2_slot_map_extended *)si->si_bh[blkind]->b_data;
 177         se->se_slots[slotno].es_valid = si->si_slots[slot_num].sl_valid;
 178         if (si->si_slots[slot_num].sl_valid)
 179                 se->se_slots[slotno].es_node_num =
 180                         cpu_to_le32(si->si_slots[slot_num].sl_node_num);
 181         *bh = si->si_bh[blkind];
 182 }
 183
 184 static void ocfs2_update_disk_slot_old(struct ocfs2_slot_info *si,
 185                                        int slot_num,
 186                                        struct buffer_head **bh)
 187 {
 188         int i;
 189         struct ocfs2_slot_map *sm;
 190
 191         sm = (struct ocfs2_slot_map *)si->si_bh[0]->b_data;
 192         for (i = 0; i < si->si_num_slots; i++) {
 193                 if (si->si_slots[i].sl_valid)
 194                         sm->sm_slots[i] =
 195                                 cpu_to_le16(si->si_slots[i].sl_node_num);
 196                 else
 197                         sm->sm_slots[i] = cpu_to_le16(OCFS2_INVALID_SLOT);
 198         }
 199         *bh = si->si_bh[0];
 200 }
 201
 202 static int ocfs2_update_disk_slot(struct ocfs2_super *osb,
 203                                   struct ocfs2_slot_info *si,
 204                                   int slot_num)
 205 {
 206         int status;
 207         struct buffer_head *bh;
 208
 209         spin_lock(&osb->osb_lock);
 210         if (si->si_extended)
 211                 ocfs2_update_disk_slot_extended(si, slot_num, &bh);
 212         else
 213                 ocfs2_update_disk_slot_old(si, slot_num, &bh);
 214         spin_unlock(&osb->osb_lock);
 215
 216         status = ocfs2_write_block(osb, bh, INODE_CACHE(si->si_inode));
 217         if (status < 0)
 218                 mlog_errno(status);
 219
 220         return status;
 221 }
 222
 223 /*
 224  * Calculate how many bytes are needed by the slot map.  Returns
 225  * an error if the slot map file is too small.
 226  */
 227 static int ocfs2_slot_map_physical_size(struct ocfs2_super *osb,
 228                                         struct inode *inode,
 229                                         unsigned long long *bytes)
 230 {
 231         unsigned long long bytes_needed;
 232
 233         if (ocfs2_uses_extended_slot_map(osb)) {
 234                 bytes_needed = osb->max_slots *
 235                         sizeof(struct ocfs2_extended_slot);
 236         } else {
 237                 bytes_needed = osb->max_slots * sizeof(__le16);
 238         }
 239         if (bytes_needed > i_size_read(inode)) {
 240                 mlog(ML_ERROR,
 241                      "Slot map file is too small!  (size %llu, needed %llu)\n",
 242                      i_size_read(inode), bytes_needed);
 243                 return -ENOSPC;
 244         }
 245
 246         *bytes = bytes_needed;
 247         return 0;
 248 }
 249
 250 /* try to find global node in the slot info. Returns -ENOENT
 251  * if nothing is found. */
 252 static int __ocfs2_node_num_to_slot(struct ocfs2_slot_info *si,
 253                                     unsigned int node_num)
 254 {
 255         int i, ret = -ENOENT;
 256
 257         for(i = 0; i < si->si_num_slots; i++) {
 258                 if (si->si_slots[i].sl_valid &&
 259                     (node_num == si->si_slots[i].sl_node_num)) {
 260                         ret = i;
 261                         break;
 262                 }
 263         }
 264
 265         return ret;
 266 }
 267
 268 static int __ocfs2_find_empty_slot(struct ocfs2_slot_info *si,
 269                                    int preferred)
 270 {
 271         int i, ret = -ENOSPC;
 272
 273         if ((preferred >= 0) && (preferred < si->si_num_slots)) {
 274                 if (!si->si_slots[preferred].sl_valid) {
 275                         ret = preferred;
 276                         goto out;
 277                 }
 278         }
 279
 280         for(i = 0; i < si->si_num_slots; i++) {
 281                 if (!si->si_slots[i].sl_valid) {
 282                         ret = i;
 283                         break;
 284                 }
 285         }
 286 out:
 287         return ret;
 288 }
 289
 290 int ocfs2_node_num_to_slot(struct ocfs2_super *osb, unsigned int node_num)
 291 {
 292         int slot;
 293         struct ocfs2_slot_info *si = osb->slot_info;
 294
 295         spin_lock(&osb->osb_lock);
 296         slot = __ocfs2_node_num_to_slot(si, node_num);
 297         spin_unlock(&osb->osb_lock);
 298
 299         return slot;
 300 }
 301
 302 int ocfs2_slot_to_node_num_locked(struct ocfs2_super *osb, int slot_num,
 303                                   unsigned int *node_num)
 304 {
 305         struct ocfs2_slot_info *si = osb->slot_info;
 306
 307         assert_spin_locked(&osb->osb_lock);
 308
 309         BUG_ON(slot_num < 0);
 310         BUG_ON(slot_num > osb->max_slots);
 311
 312         if (!si->si_slots[slot_num].sl_valid)
 313                 return -ENOENT;
 314
 315         *node_num = si->si_slots[slot_num].sl_node_num;
 316         return 0;
 317 }
 318
 319 static void __ocfs2_free_slot_info(struct ocfs2_slot_info *si)
 320 {
 321         unsigned int i;
 322
 323         if (si == NULL)
 324                 return;
 325
 326         if (si->si_inode)
 327                 iput(si->si_inode);
 328         if (si->si_bh) {
 329                 for (i = 0; i < si->si_blocks; i++) {
 330                         if (si->si_bh[i]) {
 331                                 brelse(si->si_bh[i]);
 332                                 si->si_bh[i] = NULL;
 333                         }
 334                 }
 335                 kfree(si->si_bh);
 336         }
 337
 338         kfree(si);
 339 }
 340
 341 int ocfs2_clear_slot(struct ocfs2_super *osb, int slot_num)
 342 {
 343         struct ocfs2_slot_info *si = osb->slot_info;
 344
 345         if (si == NULL)
 346                 return 0;
 347
 348         spin_lock(&osb->osb_lock);
 349         ocfs2_invalidate_slot(si, slot_num);
 350         spin_unlock(&osb->osb_lock);
 351
 352         return ocfs2_update_disk_slot(osb, osb->slot_info, slot_num);
 353 }
 354
 355 static int ocfs2_map_slot_buffers(struct ocfs2_super *osb,
 356                                   struct ocfs2_slot_info *si)
 357 {
 358         int status = 0;
 359         u64 blkno;
 360         unsigned long long blocks, bytes;
 361         unsigned int i;
 362         struct buffer_head *bh;
 363
 364         status = ocfs2_slot_map_physical_size(osb, si->si_inode, &bytes);
 365         if (status)
 366                 goto bail;
 367
 368         blocks = ocfs2_blocks_for_bytes(si->si_inode->i_sb, bytes);
 369         BUG_ON(blocks > UINT_MAX);
 370         si->si_blocks = blocks;
 371         if (!si->si_blocks)
 372                 goto bail;
 373
 374         if (si->si_extended)
 375                 si->si_slots_per_block =
 376                         (osb->sb->s_blocksize /
 377                          sizeof(struct ocfs2_extended_slot));
 378         else
 379                 si->si_slots_per_block = osb->sb->s_blocksize / sizeof(__le16);
 380
 381         /* The size checks above should ensure this */
 382         BUG_ON((osb->max_slots / si->si_slots_per_block) > blocks);
 383
 384         mlog(0, "Slot map needs %u buffers for %llu bytes\n",
 385              si->si_blocks, bytes);
 386
 387         si->si_bh = kzalloc(sizeof(struct buffer_head *) * si->si_blocks,
 388                             GFP_KERNEL);
 389         if (!si->si_bh) {
 390                 status = -ENOMEM;
 391                 mlog_errno(status);
 392                 goto bail;
 393         }
 394
 395         for (i = 0; i < si->si_blocks; i++) {
 396                 status = ocfs2_extent_map_get_blocks(si->si_inode, i,
 397                                                      &blkno, NULL, NULL);
 398                 if (status < 0) {
 399                         mlog_errno(status);
 400                         goto bail;
 401                 }
 402
 403                 mlog(0, "Reading slot map block %u at %llu\n", i,
 404                      (unsigned long long)blkno);
 405
 406                 bh = NULL;  /* Acquire a fresh bh */
 407                 status = ocfs2_read_blocks(INODE_CACHE(si->si_inode), blkno,
 408                                            1, &bh, OCFS2_BH_IGNORE_CACHE, NULL);
 409                 if (status < 0) {
 410                         mlog_errno(status);
 411                         goto bail;
 412                 }
 413
 414                 si->si_bh[i] = bh;
 415         }
 416
 417 bail:
 418         return status;
 419 }
 420
 421 int ocfs2_init_slot_info(struct ocfs2_super *osb)
 422 {
 423         int status;
 424         struct inode *inode = NULL;
 425         struct ocfs2_slot_info *si;
 426
 427         si = kzalloc(sizeof(struct ocfs2_slot_info) +
 428                      (sizeof(struct ocfs2_slot) * osb->max_slots),
 429                      GFP_KERNEL);
 430         if (!si) {
 431                 status = -ENOMEM;
 432                 mlog_errno(status);
 433                 goto bail;
 434         }
 435
 436         si->si_extended = ocfs2_uses_extended_slot_map(osb);
 437         si->si_num_slots = osb->max_slots;
 438         si->si_slots = (struct ocfs2_slot *)((char *)si +
 439                                              sizeof(struct ocfs2_slot_info));
 440
 441         inode = ocfs2_get_system_file_inode(osb, SLOT_MAP_SYSTEM_INODE,
 442                                             OCFS2_INVALID_SLOT);
 443         if (!inode) {
 444                 status = -EINVAL;
 445                 mlog_errno(status);
 446                 goto bail;
 447         }
 448
 449         si->si_inode = inode;
 450         status = ocfs2_map_slot_buffers(osb, si);
 451         if (status < 0) {
 452                 mlog_errno(status);
 453                 goto bail;
 454         }
 455
 456         osb->slot_info = (struct ocfs2_slot_info *)si;
 457 bail:
 458         if (status < 0 && si)
 459                 __ocfs2_free_slot_info(si);
 460
 461         return status;
 462 }
 463
 464 void ocfs2_free_slot_info(struct ocfs2_super *osb)
 465 {
 466         struct ocfs2_slot_info *si = osb->slot_info;
 467
 468         osb->slot_info = NULL;
 469         __ocfs2_free_slot_info(si);
 470 }
 471
 472 int ocfs2_find_slot(struct ocfs2_super *osb)
 473 {
 474         int status;
 475         int slot;
 476         struct ocfs2_slot_info *si;
 477
 478         mlog_entry_void();
 479
 480         si = osb->slot_info;
 481
 482         spin_lock(&osb->osb_lock);
 483         ocfs2_update_slot_info(si);
 484
 485         /* search for ourselves first and take the slot if it already
 486          * exists. Perhaps we need to mark this in a variable for our
 487          * own journal recovery? Possibly not, though we certainly
 488          * need to warn to the user */
 489         slot = __ocfs2_node_num_to_slot(si, osb->node_num);
 490         if (slot < 0) {
 491                 /* if no slot yet, then just take 1st available
 492                  * one. */
 493                 slot = __ocfs2_find_empty_slot(si, osb->preferred_slot);
 494                 if (slot < 0) {
 495                         spin_unlock(&osb->osb_lock);
 496                         mlog(ML_ERROR, "no free slots available!\n");
 497                         status = -EINVAL;
 498                         goto bail;
 499                 }
 500         } else
 501                 mlog(ML_NOTICE, "slot %d is already allocated to this node!\n",
 502                      slot);
 503
 504         ocfs2_set_slot(si, slot, osb->node_num);
 505         osb->slot_num = slot;
 506         spin_unlock(&osb->osb_lock);
 507
 508         mlog(0, "taking node slot %d\n", osb->slot_num);
 509
 510         status = ocfs2_update_disk_slot(osb, si, osb->slot_num);
 511         if (status < 0)
 512                 mlog_errno(status);
 513
 514 bail:
 515         mlog_exit(status);
 516         return status;
 517 }
 518
 519 void ocfs2_put_slot(struct ocfs2_super *osb)
 520 {
 521         int status, slot_num;
 522         struct ocfs2_slot_info *si = osb->slot_info;
 523
 524         if (!si)
 525                 return;
 526
 527         spin_lock(&osb->osb_lock);
 528         ocfs2_update_slot_info(si);
 529
 530         slot_num = osb->slot_num;
 531         ocfs2_invalidate_slot(si, osb->slot_num);
 532         osb->slot_num = OCFS2_INVALID_SLOT;
 533         spin_unlock(&osb->osb_lock);
 534
 535         status = ocfs2_update_disk_slot(osb, si, slot_num);
 536         if (status < 0) {
 537                 mlog_errno(status);
 538                 goto bail;
 539         }
 540
 541 bail:
 542         ocfs2_free_slot_info(osb);
 543 }