sbin/hammer/cmd_show.c

   1 /*
   2  * Copyright (c) 2008 The DragonFly Project.  All rights reserved.
   3  *
   4  * This code is derived from software contributed to The DragonFly Project
   5  * by Matthew Dillon <dillon@backplane.com>
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  *
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in
  15  *    the documentation and/or other materials provided with the
  16  *    distribution.
  17  * 3. Neither the name of The DragonFly Project nor the names of its
  18  *    contributors may be used to endorse or promote products derived
  19  *    from this software without specific, prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  */
  34
  35 #include "hammer.h"
  36
  37 #define FLAG_TOOFARLEFT         0x0001
  38 #define FLAG_TOOFARRIGHT        0x0002
  39 #define FLAG_BADTYPE            0x0004
  40 #define FLAG_BADCHILDPARENT     0x0008
  41 #define FLAG_BADMIRRORTID       0x0010
  42
  43 typedef struct btree_search {
  44         u_int32_t       lo;
  45         int64_t         obj_id;
  46 } *btree_search_t;
  47
  48 static void print_btree_node(hammer_off_t node_offset, btree_search_t search,
  49                         int depth, hammer_tid_t mirror_tid,
  50                         hammer_base_elm_t left_bound,
  51                         hammer_base_elm_t right_bound);
  52 static const char *check_data_crc(hammer_btree_elm_t elm);
  53 static void print_record(hammer_btree_elm_t elm);
  54 static void print_btree_elm(hammer_btree_elm_t elm, int i, u_int8_t type,
  55                         int flags, const char *label, const char *ext);
  56 static int print_elm_flags(hammer_node_ondisk_t node, hammer_off_t node_offset,
  57                         hammer_btree_elm_t elm, u_int8_t btype,
  58                         hammer_base_elm_t left_bound,
  59                         hammer_base_elm_t right_bound);
  60 static void print_bigblock_fill(hammer_off_t offset);
  61
  62 void
  63 hammer_cmd_show(hammer_off_t node_offset, u_int32_t lo, int64_t obj_id,
  64                 int depth,
  65                 hammer_base_elm_t left_bound, hammer_base_elm_t right_bound)
  66 {
  67         struct volume_info *volume;
  68         struct btree_search search;
  69         btree_search_t searchp;
  70         int zone;
  71
  72         AssertOnFailure = 0;
  73
  74         if (node_offset == (hammer_off_t)-1) {
  75                 volume = get_volume(RootVolNo);
  76                 node_offset = volume->ondisk->vol0_btree_root;
  77                 if (QuietOpt < 3) {
  78                         printf("Volume header\trecords=%jd next_tid=%016jx\n",
  79                                (intmax_t)volume->ondisk->vol0_stat_records,
  80                                (uintmax_t)volume->ondisk->vol0_next_tid);
  81                         printf("\t\tbufoffset=%016jx\n",
  82                                (uintmax_t)volume->ondisk->vol_buf_beg);
  83                         for (zone = 0; zone < HAMMER_MAX_ZONES; ++zone) {
  84                                 printf("\t\tzone %d\tnext_offset=%016jx\n",
  85                                         zone,
  86                                         (uintmax_t)volume->ondisk->vol0_blockmap[zone].next_offset
  87                                 );
  88                         }
  89                 }
  90                 rel_volume(volume);
  91         }
  92
  93         if (lo == 0 && obj_id == (int64_t)HAMMER_MIN_OBJID) {
  94                 searchp = NULL;
  95                 printf("show %016jx depth %d\n", (uintmax_t)node_offset, depth);
  96         } else {
  97                 search.lo = lo;
  98                 search.obj_id = obj_id;
  99                 searchp = &search;
 100                 printf("show %016jx lo %08x obj_id %016jx depth %d\n",
 101                         (uintmax_t)node_offset, lo, (uintmax_t)obj_id, depth);
 102         }
 103         print_btree_node(node_offset, searchp, depth, HAMMER_MAX_TID,
 104                          left_bound, right_bound);
 105
 106         AssertOnFailure = 1;
 107 }
 108
 109 static void
 110 print_btree_node(hammer_off_t node_offset, btree_search_t search,
 111                 int depth, hammer_tid_t mirror_tid,
 112                 hammer_base_elm_t left_bound, hammer_base_elm_t right_bound)
 113 {
 114         struct buffer_info *buffer = NULL;
 115         hammer_node_ondisk_t node;
 116         hammer_btree_elm_t elm;
 117         int i;
 118         int flags;
 119         int maxcount;
 120         char badc;
 121         char badm;
 122         const char *ext;
 123
 124         node = get_node(node_offset, &buffer);
 125
 126         if (node == NULL) {
 127                 printf("BI   NODE %016jx (IO ERROR)\n",
 128                        (uintmax_t)node_offset);
 129                 return;
 130         }
 131
 132         if (crc32(&node->crc + 1, HAMMER_BTREE_CRCSIZE) == node->crc)
 133                 badc = ' ';
 134         else
 135                 badc = 'B';
 136
 137         if (node->mirror_tid <= mirror_tid) {
 138                 badm = ' ';
 139         } else {
 140                 badm = 'M';
 141                 badc = 'B';
 142         }
 143
 144         printf("%c%c   NODE %016jx cnt=%02d p=%016jx "
 145                "type=%c depth=%d",
 146                badc,
 147                badm,
 148                (uintmax_t)node_offset, node->count,
 149                (uintmax_t)node->parent,
 150                (node->type ? node->type : '?'), depth);
 151         printf(" mirror %016jx", (uintmax_t)node->mirror_tid);
 152         if (QuietOpt < 3) {
 153                 printf(" fill=");
 154                 print_bigblock_fill(node_offset);
 155         }
 156         printf(" {\n");
 157
 158         maxcount = (node->type == HAMMER_BTREE_TYPE_INTERNAL) ?
 159                    HAMMER_BTREE_INT_ELMS : HAMMER_BTREE_LEAF_ELMS;
 160
 161         for (i = 0; i < node->count && i < maxcount; ++i) {
 162                 elm = &node->elms[i];
 163
 164                 if (node->type != HAMMER_BTREE_TYPE_INTERNAL) {
 165                         ext = NULL;
 166                         if (search &&
 167                             elm->base.localization == search->lo &&
 168                              elm->base.obj_id == search->obj_id) {
 169                                 ext = " *";
 170                         }
 171                 } else if (search) {
 172                         ext = " *";
 173                         if (elm->base.localization > search->lo ||
 174                             (elm->base.localization == search->lo &&
 175                              elm->base.obj_id > search->obj_id)) {
 176                                 ext = NULL;
 177                         }
 178                         if (elm[1].base.localization < search->lo ||
 179                             (elm[1].base.localization == search->lo &&
 180                              elm[1].base.obj_id < search->obj_id)) {
 181                                 ext = NULL;
 182                         }
 183                 } else {
 184                         ext = NULL;
 185                 }
 186
 187                 flags = print_elm_flags(node, node_offset,
 188                                         elm, elm->base.btype,
 189                                         left_bound, right_bound);
 190                 print_btree_elm(elm, i, node->type, flags, "ELM", ext);
 191         }
 192         if (node->type == HAMMER_BTREE_TYPE_INTERNAL) {
 193                 elm = &node->elms[i];
 194
 195                 flags = print_elm_flags(node, node_offset,
 196                                         elm, 'I',
 197                                         left_bound, right_bound);
 198                 print_btree_elm(elm, i, node->type, flags, "RBN", NULL);
 199         }
 200         printf("     }\n");
 201
 202         for (i = 0; i < node->count; ++i) {
 203                 elm = &node->elms[i];
 204
 205                 switch(node->type) {
 206                 case HAMMER_BTREE_TYPE_INTERNAL:
 207                         if (search) {
 208                                 if (elm->base.localization > search->lo ||
 209                                     (elm->base.localization == search->lo &&
 210                                      elm->base.obj_id > search->obj_id)) {
 211                                         break;
 212                                 }
 213                                 if (elm[1].base.localization < search->lo ||
 214                                     (elm[1].base.localization == search->lo &&
 215                                      elm[1].base.obj_id < search->obj_id)) {
 216                                         break;
 217                                 }
 218                         }
 219                         if (elm->internal.subtree_offset) {
 220                                 print_btree_node(elm->internal.subtree_offset,
 221                                                  search, depth + 1,
 222                                                  elm->internal.mirror_tid,
 223                                                  &elm[0].base, &elm[1].base);
 224                                 /*
 225                                  * Cause show to iterate after seeking to
 226                                  * the lo:objid
 227                                  */
 228                                 search = NULL;
 229                         }
 230                         break;
 231                 default:
 232                         break;
 233                 }
 234         }
 235         rel_buffer(buffer);
 236 }
 237
 238 static
 239 void
 240 print_btree_elm(hammer_btree_elm_t elm, int i, u_int8_t type,
 241                 int flags, const char *label, const char *ext)
 242 {
 243         char flagstr[8] = { 0, '-', '-', '-', '-', '-', '-', 0 };
 244
 245         flagstr[0] = flags ? 'B' : 'G';
 246         if (flags & FLAG_TOOFARLEFT)
 247                 flagstr[2] = 'L';
 248         if (flags & FLAG_TOOFARRIGHT)
 249                 flagstr[3] = 'R';
 250         if (flags & FLAG_BADTYPE)
 251                 flagstr[4] = 'T';
 252         if (flags & FLAG_BADCHILDPARENT)
 253                 flagstr[5] = 'C';
 254         if (flags & FLAG_BADMIRRORTID)
 255                 flagstr[6] = 'M';
 256
 257         printf("%s\t%s %2d %c ",
 258                flagstr, label, i,
 259                (elm->base.btype ? elm->base.btype : '?'));
 260         printf("lo=%08x obj=%016jx rt=%02x key=%016jx ot=%02x\n",
 261                elm->base.localization,
 262                (uintmax_t)elm->base.obj_id,
 263                elm->base.rec_type,
 264                (uintmax_t)elm->base.key,
 265                elm->base.obj_type);
 266         printf("\t       %c tids %016jx:%016jx ",
 267                 (elm->base.delete_tid ? 'd' : ' '),
 268                (uintmax_t)elm->base.create_tid,
 269                (uintmax_t)elm->base.delete_tid);
 270
 271         switch(type) {
 272         case HAMMER_BTREE_TYPE_INTERNAL:
 273                 printf("suboff=%016jx",
 274                        (uintmax_t)elm->internal.subtree_offset);
 275                 if (QuietOpt < 3) {
 276                         printf(" mirror %016jx",
 277                                (uintmax_t)elm->internal.mirror_tid);
 278                 }
 279                 if (ext)
 280                         printf(" %s", ext);
 281                 break;
 282         case HAMMER_BTREE_TYPE_LEAF:
 283                 if (ext)
 284                         printf(" %s", ext);
 285                 switch(elm->base.btype) {
 286                 case HAMMER_BTREE_TYPE_RECORD:
 287                         if (QuietOpt < 3)
 288                                 printf("\n%s\t         ", check_data_crc(elm));
 289                         else
 290                                 printf("\n\t         ");
 291                         printf("dataoff=%016jx/%d",
 292                                (uintmax_t)elm->leaf.data_offset,
 293                                elm->leaf.data_len);
 294                         if (QuietOpt < 3) {
 295                                 printf(" crc=%04x", elm->leaf.data_crc);
 296                                 printf("\n\t         fills=");
 297                                 print_bigblock_fill(elm->leaf.data_offset);
 298                         }
 299                         if (QuietOpt < 2)
 300                                 print_record(elm);
 301                         break;
 302                 }
 303                 break;
 304         default:
 305                 break;
 306         }
 307         printf("\n");
 308 }
 309
 310 static
 311 int
 312 print_elm_flags(hammer_node_ondisk_t node, hammer_off_t node_offset,
 313                 hammer_btree_elm_t elm, u_int8_t btype,
 314                 hammer_base_elm_t left_bound, hammer_base_elm_t right_bound)
 315 {
 316         int flags = 0;
 317
 318         switch(node->type) {
 319         case HAMMER_BTREE_TYPE_INTERNAL:
 320                 if (elm->internal.subtree_offset) {
 321                         struct buffer_info *buffer = NULL;
 322                         hammer_node_ondisk_t subnode;
 323
 324                         subnode = get_node(elm->internal.subtree_offset,
 325                                            &buffer);
 326                         if (subnode == NULL)
 327                                 flags |= FLAG_BADCHILDPARENT;
 328                         else if (subnode->parent != node_offset)
 329                                 flags |= FLAG_BADCHILDPARENT;
 330                         rel_buffer(buffer);
 331                 }
 332                 if (elm->internal.mirror_tid > node->mirror_tid)
 333                         flags |= FLAG_BADMIRRORTID;
 334
 335                 switch(btype) {
 336                 case HAMMER_BTREE_TYPE_INTERNAL:
 337                         if (left_bound == NULL || right_bound == NULL)
 338                                 break;
 339                         if (hammer_btree_cmp(&elm->base, left_bound) < 0)
 340                                 flags |= FLAG_TOOFARLEFT;
 341                         if (hammer_btree_cmp(&elm->base, right_bound) > 0)
 342                                 flags |= FLAG_TOOFARRIGHT;
 343                         break;
 344                 case HAMMER_BTREE_TYPE_LEAF:
 345                         if (left_bound == NULL || right_bound == NULL)
 346                                 break;
 347                         if (hammer_btree_cmp(&elm->base, left_bound) < 0)
 348                                 flags |= FLAG_TOOFARLEFT;
 349                         if (hammer_btree_cmp(&elm->base, right_bound) >= 0)
 350                                 flags |= FLAG_TOOFARRIGHT;
 351                         break;
 352                 default:
 353                         flags |= FLAG_BADTYPE;
 354                         break;
 355                 }
 356                 break;
 357         case HAMMER_BTREE_TYPE_LEAF:
 358                 if (elm->base.create_tid &&
 359                     elm->base.create_tid > node->mirror_tid) {
 360                         flags |= FLAG_BADMIRRORTID;
 361                 }
 362                 if (elm->base.delete_tid &&
 363                     elm->base.delete_tid > node->mirror_tid) {
 364                         flags |= FLAG_BADMIRRORTID;
 365                 }
 366                 switch(btype) {
 367                 case HAMMER_BTREE_TYPE_RECORD:
 368                         if (left_bound == NULL || right_bound == NULL)
 369                                 break;
 370                         if (hammer_btree_cmp(&elm->base, left_bound) < 0)
 371                                 flags |= FLAG_TOOFARLEFT;
 372                         if (hammer_btree_cmp(&elm->base, right_bound) >= 0)
 373                                 flags |= FLAG_TOOFARRIGHT;
 374                         break;
 375                 default:
 376                         flags |= FLAG_BADTYPE;
 377                         break;
 378                 }
 379                 break;
 380         default:
 381                 flags |= FLAG_BADTYPE;
 382                 break;
 383         }
 384         return(flags);
 385 }
 386
 387 static
 388 void
 389 print_bigblock_fill(hammer_off_t offset)
 390 {
 391         struct hammer_blockmap_layer1 layer1;
 392         struct hammer_blockmap_layer2 layer2;
 393         int fill;
 394         int error;
 395
 396         blockmap_lookup(offset, &layer1, &layer2, &error);
 397         if (error) {
 398                 printf("z%d:%lld=BADZ",
 399                         HAMMER_ZONE_DECODE(offset),
 400                         (offset & ~HAMMER_OFF_ZONE_MASK) /
 401                             HAMMER_LARGEBLOCK_SIZE
 402                 );
 403         } else {
 404                 fill = layer2.bytes_free * 100 / HAMMER_LARGEBLOCK_SIZE;
 405                 fill = 100 - fill;
 406
 407                 printf("z%d:%lld=%d%%",
 408                         HAMMER_ZONE_DECODE(offset),
 409                         (offset & ~HAMMER_OFF_ZONE_MASK) /
 410                             HAMMER_LARGEBLOCK_SIZE,
 411                         fill
 412                 );
 413         }
 414 }
 415
 416 /*
 417  * Check the generic crc on a data element.  Inodes record types are
 418  * special in that some of their fields are not CRCed.
 419  *
 420  * Also check that the zone is valid.
 421  */
 422 static
 423 const char *
 424 check_data_crc(hammer_btree_elm_t elm)
 425 {
 426         struct buffer_info *data_buffer;
 427         hammer_off_t data_offset;
 428         int32_t data_len;
 429         int32_t len;
 430         u_int32_t crc;
 431         int error;
 432         char *ptr;
 433
 434         data_offset = elm->leaf.data_offset;
 435         data_len = elm->leaf.data_len;
 436         data_buffer = NULL;
 437         if (data_offset == 0 || data_len == 0)
 438                 return("Z");
 439
 440         crc = 0;
 441         error = 0;
 442         while (data_len) {
 443                 blockmap_lookup(data_offset, NULL, NULL, &error);
 444                 if (error)
 445                         break;
 446
 447                 ptr = get_buffer_data(data_offset, &data_buffer, 0);
 448                 len = HAMMER_BUFSIZE - ((int)data_offset & HAMMER_BUFMASK);
 449                 if (len > data_len)
 450                         len = (int)data_len;
 451                 if (elm->leaf.base.rec_type == HAMMER_RECTYPE_INODE &&
 452                     data_len == sizeof(struct hammer_inode_data)) {
 453                         crc = crc32_ext(ptr, HAMMER_INODE_CRCSIZE, crc);
 454                 } else {
 455                         crc = crc32_ext(ptr, len, crc);
 456                 }
 457                 data_len -= len;
 458                 data_offset += len;
 459         }
 460         if (data_buffer)
 461                 rel_buffer(data_buffer);
 462         if (error)
 463                 return("BO");           /* bad offset */
 464         if (crc == elm->leaf.data_crc)
 465                 return("");
 466         return("BX");                   /* bad crc */
 467 }
 468
 469 static
 470 void
 471 print_record(hammer_btree_elm_t elm)
 472 {
 473         struct buffer_info *data_buffer;
 474         hammer_off_t data_offset;
 475         int32_t data_len;
 476         hammer_data_ondisk_t data;
 477
 478         data_offset = elm->leaf.data_offset;
 479         data_len = elm->leaf.data_len;
 480         data_buffer = NULL;
 481
 482         if (data_offset)
 483                 data = get_buffer_data(data_offset, &data_buffer, 0);
 484         else
 485                 data = NULL;
 486
 487         switch(elm->leaf.base.rec_type) {
 488         case HAMMER_RECTYPE_INODE:
 489                 printf("\n%17s", "");
 490                 printf("size=%jd nlinks=%jd",
 491                        (intmax_t)data->inode.size,
 492                        (intmax_t)data->inode.nlinks);
 493                 if (QuietOpt < 1) {
 494                         printf(" mode=%05o uflags=%08x\n",
 495                                 data->inode.mode,
 496                                 data->inode.uflags);
 497                         printf("%17s", "");
 498                         printf("ctime=%016jx pobjid=%016jx obj_type=%d\n",
 499                                 (uintmax_t)data->inode.ctime,
 500                                 (uintmax_t)data->inode.parent_obj_id,
 501                                 data->inode.obj_type);
 502                         printf("%17s", "");
 503                         printf("mtime=%016jx", (uintmax_t)data->inode.mtime);
 504                         printf(" caps=%02x", data->inode.cap_flags);
 505                 }
 506                 break;
 507         case HAMMER_RECTYPE_DIRENTRY:
 508                 printf("\n%17s", "");
 509                 data_len -= HAMMER_ENTRY_NAME_OFF;
 510                 printf("dir-entry ino=%016jx lo=%08x name=\"%*.*s\"",
 511                        (uintmax_t)data->entry.obj_id,
 512                        data->entry.localization,
 513                        data_len, data_len, data->entry.name);
 514                 break;
 515         case HAMMER_RECTYPE_FIX:
 516                 switch(elm->leaf.base.key) {
 517                 case HAMMER_FIXKEY_SYMLINK:
 518                         data_len -= HAMMER_SYMLINK_NAME_OFF;
 519                         printf("\n%17s", "");
 520                         printf("symlink=\"%*.*s\"", data_len, data_len,
 521                                 data->symlink.name);
 522                         break;
 523                 default:
 524                         break;
 525                 }
 526                 break;
 527         default:
 528                 break;
 529         }
 530         if (data_buffer)
 531                 rel_buffer(data_buffer);
 532 }
 533
 534 /*
 535  * Dump the UNDO FIFO
 536  */
 537 void
 538 hammer_cmd_show_undo(void)
 539 {
 540         struct volume_info *volume;
 541         hammer_blockmap_t rootmap;
 542         hammer_off_t scan_offset;
 543         hammer_fifo_any_t head;
 544         struct buffer_info *data_buffer = NULL;
 545
 546         volume = get_volume(RootVolNo);
 547         rootmap = &volume->ondisk->vol0_blockmap[HAMMER_ZONE_UNDO_INDEX];
 548         printf("Volume header UNDO %016jx-%016jx/%016jx\n",
 549                 (intmax_t)rootmap->first_offset,
 550                 (intmax_t)rootmap->next_offset,
 551                 (intmax_t)rootmap->alloc_offset);
 552         printf("Undo map is %jdMB\n",
 553                 (intmax_t)((rootmap->alloc_offset & HAMMER_OFF_LONG_MASK) /
 554                            (1024 * 1024)));
 555         scan_offset = HAMMER_ZONE_ENCODE(HAMMER_ZONE_UNDO_INDEX, 0);
 556         while (scan_offset < rootmap->alloc_offset) {
 557                 head = get_buffer_data(scan_offset, &data_buffer, 0);
 558                 printf("%016jx ", scan_offset);
 559
 560                 switch(head->head.hdr_type) {
 561                 case HAMMER_HEAD_TYPE_PAD:
 562                         printf("PAD(%04x)\n", head->head.hdr_size);
 563                         break;
 564                 case HAMMER_HEAD_TYPE_DUMMY:
 565                         printf("DUMMY(%04x) seq=%08x\n",
 566                                 head->head.hdr_size, head->head.hdr_seq);
 567                         break;
 568                 case HAMMER_HEAD_TYPE_UNDO:
 569                         printf("UNDO(%04x) seq=%08x "
 570                                "dataoff=%016jx bytes=%d\n",
 571                                 head->head.hdr_size, head->head.hdr_seq,
 572                                 (intmax_t)head->undo.undo_offset,
 573                                 head->undo.undo_data_bytes);
 574                         break;
 575                 case HAMMER_HEAD_TYPE_REDO:
 576                         printf("REDO(%04x) seq=%08x flags=%08x "
 577                                "objid=%016jx logoff=%016jx bytes=%d\n",
 578                                 head->head.hdr_size, head->head.hdr_seq,
 579                                 head->redo.redo_flags,
 580                                 (intmax_t)head->redo.redo_objid,
 581                                 (intmax_t)head->redo.redo_offset,
 582                                 head->redo.redo_data_bytes);
 583                         break;
 584                 default:
 585                         printf("UNKNOWN(%04x,%04x) seq=%08x\n",
 586                                 head->head.hdr_type,
 587                                 head->head.hdr_size,
 588                                 head->head.hdr_seq);
 589                         break;
 590                 }
 591                 if ((head->head.hdr_size & HAMMER_HEAD_ALIGN_MASK) ||
 592                     head->head.hdr_size == 0 ||
 593                     head->head.hdr_size > HAMMER_UNDO_ALIGN -
 594                                     ((u_int)scan_offset & HAMMER_UNDO_MASK)) {
 595                         printf("Illegal size field, skipping to "
 596                                "next boundary\n");
 597                         scan_offset = (scan_offset + HAMMER_UNDO_MASK) &
 598                                         ~HAMMER_UNDO_MASK64;
 599                 } else {
 600                         scan_offset += head->head.hdr_size;
 601                 }
 602         }
 603         if (data_buffer)
 604                 rel_buffer(data_buffer);
 605 }