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 #include <cluster/masklog.h>
  31
  32 #include "ocfs2.h"
  33
  34 #include "dlmglue.h"
  35 #include "extent_map.h"
  36 #include "heartbeat.h"
  37 #include "inode.h"
  38 #include "slot_map.h"
  39 #include "super.h"
  40 #include "sysfile.h"
  41 #include "ocfs2_trace.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         trace_ocfs2_refresh_slot_info(si->si_blocks);
 146
 147         /*
 148          * We pass -1 as blocknr because we expect all of si->si_bh to
 149          * be !NULL.  Thus, ocfs2_read_blocks() will ignore blocknr.  If
 150          * this is not true, the read of -1 (UINT64_MAX) will fail.
 151          */
 152         ret = ocfs2_read_blocks(INODE_CACHE(si->si_inode), -1, si->si_blocks,
 153                                 si->si_bh, OCFS2_BH_IGNORE_CACHE, NULL);
 154         if (ret == 0) {
 155                 spin_lock(&osb->osb_lock);
 156                 ocfs2_update_slot_info(si);
 157                 spin_unlock(&osb->osb_lock);
 158         }
 159
 160         return ret;
 161 }
 162
 163 /* post the our slot info stuff into it's destination bh and write it
 164  * out. */
 165 static void ocfs2_update_disk_slot_extended(struct ocfs2_slot_info *si,
 166                                             int slot_num,
 167                                             struct buffer_head **bh)
 168 {
 169         int blkind = slot_num / si->si_slots_per_block;
 170         int slotno = slot_num % si->si_slots_per_block;
 171         struct ocfs2_slot_map_extended *se;
 172
 173         BUG_ON(blkind >= si->si_blocks);
 174
 175         se = (struct ocfs2_slot_map_extended *)si->si_bh[blkind]->b_data;
 176         se->se_slots[slotno].es_valid = si->si_slots[slot_num].sl_valid;
 177         if (si->si_slots[slot_num].sl_valid)
 178                 se->se_slots[slotno].es_node_num =
 179                         cpu_to_le32(si->si_slots[slot_num].sl_node_num);
 180         *bh = si->si_bh[blkind];
 181 }
 182
 183 static void ocfs2_update_disk_slot_old(struct ocfs2_slot_info *si,
 184                                        int slot_num,
 185                                        struct buffer_head **bh)
 186 {
 187         int i;
 188         struct ocfs2_slot_map *sm;
 189
 190         sm = (struct ocfs2_slot_map *)si->si_bh[0]->b_data;
 191         for (i = 0; i < si->si_num_slots; i++) {
 192                 if (si->si_slots[i].sl_valid)
 193                         sm->sm_slots[i] =
 194                                 cpu_to_le16(si->si_slots[i].sl_node_num);
 195                 else
 196                         sm->sm_slots[i] = cpu_to_le16(OCFS2_INVALID_SLOT);
 197         }
 198         *bh = si->si_bh[0];
 199 }
 200
 201 static int ocfs2_update_disk_slot(struct ocfs2_super *osb,
 202                                   struct ocfs2_slot_info *si,
 203                                   int slot_num)
 204 {
 205         int status;
 206         struct buffer_head *bh;
 207
 208         spin_lock(&osb->osb_lock);
 209         if (si->si_extended)
 210                 ocfs2_update_disk_slot_extended(si, slot_num, &bh);
 211         else
 212                 ocfs2_update_disk_slot_old(si, slot_num, &bh);
 213         spin_unlock(&osb->osb_lock);
 214
 215         status = ocfs2_write_block(osb, bh, INODE_CACHE(si->si_inode));
 216         if (status < 0)
 217                 mlog_errno(status);
 218
 219         return status;
 220 }
 221
 222 /*
 223  * Calculate how many bytes are needed by the slot map.  Returns
 224  * an error if the slot map file is too small.
 225  */
 226 static int ocfs2_slot_map_physical_size(struct ocfs2_super *osb,
 227                                         struct inode *inode,
 228                                         unsigned long long *bytes)
 229 {
 230         unsigned long long bytes_needed;
 231
 232         if (ocfs2_uses_extended_slot_map(osb)) {
 233                 bytes_needed = osb->max_slots *
 234                         sizeof(struct ocfs2_extended_slot);
 235         } else {
 236                 bytes_needed = osb->max_slots * sizeof(__le16);
 237         }
 238         if (bytes_needed > i_size_read(inode)) {
 239                 mlog(ML_ERROR,
 240                      "Slot map file is too small!  (size %llu, needed %llu)\n",
 241                      i_size_read(inode), bytes_needed);
 242                 return -ENOSPC;
 243         }
 244
 245         *bytes = bytes_needed;
 246         return 0;
 247 }
 248
 249 /* try to find global node in the slot info. Returns -ENOENT
 250  * if nothing is found. */
 251 static int __ocfs2_node_num_to_slot(struct ocfs2_slot_info *si,
 252                                     unsigned int node_num)
 253 {
 254         int i, ret = -ENOENT;
 255
 256         for(i = 0; i < si->si_num_slots; i++) {
 257                 if (si->si_slots[i].sl_valid &&
 258                     (node_num == si->si_slots[i].sl_node_num)) {
 259                         ret = i;
 260                         break;
 261                 }
 262         }
 263
 264         return ret;
 265 }
 266
 267 static int __ocfs2_find_empty_slot(struct ocfs2_slot_info *si,
 268                                    int preferred)
 269 {
 270         int i, ret = -ENOSPC;
 271
 272         if ((preferred >= 0) && (preferred < si->si_num_slots)) {
 273                 if (!si->si_slots[preferred].sl_valid) {
 274                         ret = preferred;
 275                         goto out;
 276                 }
 277         }
 278
 279         for(i = 0; i < si->si_num_slots; i++) {
 280                 if (!si->si_slots[i].sl_valid) {
 281                         ret = i;
 282                         break;
 283                 }
 284         }
 285 out:
 286         return ret;
 287 }
 288
 289 int ocfs2_node_num_to_slot(struct ocfs2_super *osb, unsigned int node_num)
 290 {
 291         int slot;
 292         struct ocfs2_slot_info *si = osb->slot_info;
 293
 294         spin_lock(&osb->osb_lock);
 295         slot = __ocfs2_node_num_to_slot(si, node_num);
 296         spin_unlock(&osb->osb_lock);
 297
 298         return slot;
 299 }
 300
 301 int ocfs2_slot_to_node_num_locked(struct ocfs2_super *osb, int slot_num,
 302                                   unsigned int *node_num)
 303 {
 304         struct ocfs2_slot_info *si = osb->slot_info;
 305
 306         assert_spin_locked(&osb->osb_lock);
 307
 308         BUG_ON(slot_num < 0);
 309         BUG_ON(slot_num > osb->max_slots);
 310
 311         if (!si->si_slots[slot_num].sl_valid)
 312                 return -ENOENT;
 313
 314         *node_num = si->si_slots[slot_num].sl_node_num;
 315         return 0;
 316 }
 317
 318 static void __ocfs2_free_slot_info(struct ocfs2_slot_info *si)
 319 {
 320         unsigned int i;
 321
 322         if (si == NULL)
 323                 return;
 324
 325         if (si->si_inode)
 326                 iput(si->si_inode);
 327         if (si->si_bh) {
 328                 for (i = 0; i < si->si_blocks; i++) {
 329                         if (si->si_bh[i]) {
 330                                 brelse(si->si_bh[i]);
 331                                 si->si_bh[i] = NULL;
 332                         }
 333                 }
 334                 kfree(si->si_bh);
 335         }
 336
 337         kfree(si);
 338 }
 339
 340 int ocfs2_clear_slot(struct ocfs2_super *osb, int slot_num)
 341 {
 342         struct ocfs2_slot_info *si = osb->slot_info;
 343
 344         if (si == NULL)
 345                 return 0;
 346
 347         spin_lock(&osb->osb_lock);
 348         ocfs2_invalidate_slot(si, slot_num);
 349         spin_unlock(&osb->osb_lock);
 350
 351         return ocfs2_update_disk_slot(osb, osb->slot_info, slot_num);
 352 }
 353
 354 static int ocfs2_map_slot_buffers(struct ocfs2_super *osb,
 355                                   struct ocfs2_slot_info *si)
 356 {
 357         int status = 0;
 358         u64 blkno;
 359         unsigned long long blocks, bytes = 0;
 360         unsigned int i;
 361         struct buffer_head *bh;
 362
 363         status = ocfs2_slot_map_physical_size(osb, si->si_inode, &bytes);
 364         if (status)
 365                 goto bail;
 366
 367         blocks = ocfs2_blocks_for_bytes(si->si_inode->i_sb, bytes);
 368         BUG_ON(blocks > UINT_MAX);
 369         si->si_blocks = blocks;
 370         if (!si->si_blocks)
 371                 goto bail;
 372
 373         if (si->si_extended)
 374                 si->si_slots_per_block =
 375                         (osb->sb->s_blocksize /
 376                          sizeof(struct ocfs2_extended_slot));
 377         else
 378                 si->si_slots_per_block = osb->sb->s_blocksize / sizeof(__le16);
 379
 380         /* The size checks above should ensure this */
 381         BUG_ON((osb->max_slots / si->si_slots_per_block) > blocks);
 382
 383         trace_ocfs2_map_slot_buffers(bytes, si->si_blocks);
 384
 385         si->si_bh = kzalloc(sizeof(struct buffer_head *) * si->si_blocks,
 386                             GFP_KERNEL);
 387         if (!si->si_bh) {
 388                 status = -ENOMEM;
 389                 mlog_errno(status);
 390                 goto bail;
 391         }
 392
 393         for (i = 0; i < si->si_blocks; i++) {
 394                 status = ocfs2_extent_map_get_blocks(si->si_inode, i,
 395                                                      &blkno, NULL, NULL);
 396                 if (status < 0) {
 397                         mlog_errno(status);
 398                         goto bail;
 399                 }
 400
 401                 trace_ocfs2_map_slot_buffers_block((unsigned long long)blkno, i);
 402
 403                 bh = NULL;  /* Acquire a fresh bh */
 404                 status = ocfs2_read_blocks(INODE_CACHE(si->si_inode), blkno,
 405                                            1, &bh, OCFS2_BH_IGNORE_CACHE, NULL);
 406                 if (status < 0) {
 407                         mlog_errno(status);
 408                         goto bail;
 409                 }
 410
 411                 si->si_bh[i] = bh;
 412         }
 413
 414 bail:
 415         return status;
 416 }
 417
 418 int ocfs2_init_slot_info(struct ocfs2_super *osb)
 419 {
 420         int status;
 421         struct inode *inode = NULL;
 422         struct ocfs2_slot_info *si;
 423
 424         si = kzalloc(sizeof(struct ocfs2_slot_info) +
 425                      (sizeof(struct ocfs2_slot) * osb->max_slots),
 426                      GFP_KERNEL);
 427         if (!si) {
 428                 status = -ENOMEM;
 429                 mlog_errno(status);
 430                 goto bail;
 431         }
 432
 433         si->si_extended = ocfs2_uses_extended_slot_map(osb);
 434         si->si_num_slots = osb->max_slots;
 435         si->si_slots = (struct ocfs2_slot *)((char *)si +
 436                                              sizeof(struct ocfs2_slot_info));
 437
 438         inode = ocfs2_get_system_file_inode(osb, SLOT_MAP_SYSTEM_INODE,
 439                                             OCFS2_INVALID_SLOT);
 440         if (!inode) {
 441                 status = -EINVAL;
 442                 mlog_errno(status);
 443                 goto bail;
 444         }
 445
 446         si->si_inode = inode;
 447         status = ocfs2_map_slot_buffers(osb, si);
 448         if (status < 0) {
 449                 mlog_errno(status);
 450                 goto bail;
 451         }
 452
 453         osb->slot_info = (struct ocfs2_slot_info *)si;
 454 bail:
 455         if (status < 0 && si)
 456                 __ocfs2_free_slot_info(si);
 457
 458         return status;
 459 }
 460
 461 void ocfs2_free_slot_info(struct ocfs2_super *osb)
 462 {
 463         struct ocfs2_slot_info *si = osb->slot_info;
 464
 465         osb->slot_info = NULL;
 466         __ocfs2_free_slot_info(si);
 467 }
 468
 469 int ocfs2_find_slot(struct ocfs2_super *osb)
 470 {
 471         int status;
 472         int slot;
 473         struct ocfs2_slot_info *si;
 474
 475         si = osb->slot_info;
 476
 477         spin_lock(&osb->osb_lock);
 478         ocfs2_update_slot_info(si);
 479
 480         /* search for ourselves first and take the slot if it already
 481          * exists. Perhaps we need to mark this in a variable for our
 482          * own journal recovery? Possibly not, though we certainly
 483          * need to warn to the user */
 484         slot = __ocfs2_node_num_to_slot(si, osb->node_num);
 485         if (slot < 0) {
 486                 /* if no slot yet, then just take 1st available
 487                  * one. */
 488                 slot = __ocfs2_find_empty_slot(si, osb->preferred_slot);
 489                 if (slot < 0) {
 490                         spin_unlock(&osb->osb_lock);
 491                         mlog(ML_ERROR, "no free slots available!\n");
 492                         status = -EINVAL;
 493                         goto bail;
 494                 }
 495         } else
 496                 mlog(ML_NOTICE, "slot %d is already allocated to this node!\n",
 497                      slot);
 498
 499         ocfs2_set_slot(si, slot, osb->node_num);
 500         osb->slot_num = slot;
 501         spin_unlock(&osb->osb_lock);
 502
 503         trace_ocfs2_find_slot(osb->slot_num);
 504
 505         status = ocfs2_update_disk_slot(osb, si, osb->slot_num);
 506         if (status < 0)
 507                 mlog_errno(status);
 508
 509 bail:
 510         return status;
 511 }
 512
 513 void ocfs2_put_slot(struct ocfs2_super *osb)
 514 {
 515         int status, slot_num;
 516         struct ocfs2_slot_info *si = osb->slot_info;
 517
 518         if (!si)
 519                 return;
 520
 521         spin_lock(&osb->osb_lock);
 522         ocfs2_update_slot_info(si);
 523
 524         slot_num = osb->slot_num;
 525         ocfs2_invalidate_slot(si, osb->slot_num);
 526         osb->slot_num = OCFS2_INVALID_SLOT;
 527         spin_unlock(&osb->osb_lock);
 528
 529         status = ocfs2_update_disk_slot(osb, si, slot_num);
 530         if (status < 0) {
 531                 mlog_errno(status);
 532                 goto bail;
 533         }
 534
 535 bail:
 536         ocfs2_free_slot_info(osb);
 537 }
 538