bitmap.c

   1 /*
   2  * mdadm - manage Linux "md" devices aka RAID arrays.
   3  *
   4  * Copyright (C) 2004 Paul Clements, SteelEye Technology, Inc.
   5  *
   6  *    This program is free software; you can redistribute it and/or modify
   7  *    it under the terms of the GNU General Public License as published by
   8  *    the Free Software Foundation; either version 2 of the License, or
   9  *    (at your option) any later version.
  10  *
  11  *    This program is distributed in the hope that it will be useful,
  12  *    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *    GNU General Public License for more details.
  15  *
  16  *    You should have received a copy of the GNU General Public License
  17  *    along with this program; if not, write to the Free Software
  18  *    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20
  21 #include "mdadm.h"
  22
  23 static inline void sb_le_to_cpu(bitmap_super_t *sb)
  24 {
  25         sb->magic = __le32_to_cpu(sb->magic);
  26         sb->version = __le32_to_cpu(sb->version);
  27         /* uuid gets no translation */
  28         sb->events = __le64_to_cpu(sb->events);
  29         sb->events_cleared = __le64_to_cpu(sb->events_cleared);
  30         sb->state = __le32_to_cpu(sb->state);
  31         sb->chunksize = __le32_to_cpu(sb->chunksize);
  32         sb->daemon_sleep = __le32_to_cpu(sb->daemon_sleep);
  33         sb->sync_size = __le64_to_cpu(sb->sync_size);
  34         sb->write_behind = __le32_to_cpu(sb->write_behind);
  35         sb->nodes = __le32_to_cpu(sb->nodes);
  36         sb->sectors_reserved = __le32_to_cpu(sb->sectors_reserved);
  37 }
  38
  39 static inline void sb_cpu_to_le(bitmap_super_t *sb)
  40 {
  41         sb_le_to_cpu(sb); /* these are really the same thing */
  42 }
  43
  44 mapping_t bitmap_states[] = {
  45         { "OK", 0 },
  46         { "Out of date", 2 },
  47         { NULL, -1 }
  48 };
  49
  50 const char *bitmap_state(int state_num)
  51 {
  52         char *state = map_num(bitmap_states, state_num);
  53         return state ? state : "Unknown";
  54 }
  55
  56 const char *human_chunksize(unsigned long bytes)
  57 {
  58         static char buf[16];
  59         char *suffixes[] = { "B", "KB", "MB", "GB", "TB", NULL };
  60         int i = 0;
  61
  62         while (bytes >> 10) {
  63                 bytes >>= 10;
  64                 i++;
  65         }
  66
  67         snprintf(buf, sizeof(buf), "%lu %s", bytes, suffixes[i]);
  68
  69         return buf;
  70 }
  71
  72 typedef struct bitmap_info_s {
  73         bitmap_super_t sb;
  74         unsigned long long total_bits;
  75         unsigned long long dirty_bits;
  76 } bitmap_info_t;
  77
  78 /* count the dirty bits in the first num_bits of byte */
  79 static inline int count_dirty_bits_byte(char byte, int num_bits)
  80 {
  81         int num = 0;
  82
  83         switch (num_bits) { /* fall through... */
  84                 case 8: if (byte & 128) num++;
  85                 case 7: if (byte &  64) num++;
  86                 case 6: if (byte &  32) num++;
  87                 case 5: if (byte &  16) num++;
  88                 case 4: if (byte &   8) num++;
  89                 case 3: if (byte &   4) num++;
  90                 case 2: if (byte &   2) num++;
  91                 case 1: if (byte &   1) num++;
  92                 default: break;
  93         }
  94
  95         return num;
  96 }
  97
  98 int count_dirty_bits(char *buf, int num_bits)
  99 {
 100         int i, num = 0;
 101
 102         for (i = 0; i < num_bits / 8; i++)
 103                 num += count_dirty_bits_byte(buf[i], 8);
 104
 105         if (num_bits % 8) /* not an even byte boundary */
 106                 num += count_dirty_bits_byte(buf[i], num_bits % 8);
 107
 108         return num;
 109 }
 110
 111 /* calculate the size of the bitmap given the array size and bitmap chunksize */
 112 unsigned long long bitmap_bits(unsigned long long array_size,
 113                                 unsigned long chunksize)
 114 {
 115         return (array_size * 512 + chunksize - 1) / chunksize;
 116 }
 117
 118 unsigned long bitmap_sectors(struct bitmap_super_s *bsb)
 119 {
 120         unsigned long long bits = bitmap_bits(__le64_to_cpu(bsb->sync_size),
 121                                               __le32_to_cpu(bsb->chunksize));
 122         int bits_per_sector = 8*512;
 123         return (bits + bits_per_sector - 1) / bits_per_sector;
 124 }
 125
 126 bitmap_info_t *bitmap_fd_read(int fd, int brief)
 127 {
 128         /* Note: fd might be open O_DIRECT, so we must be
 129          * careful to align reads properly
 130          */
 131         unsigned long long total_bits = 0, read_bits = 0, dirty_bits = 0;
 132         bitmap_info_t *info;
 133         void *buf;
 134         unsigned int n, skip;
 135
 136         if (posix_memalign(&buf, 4096, 8192) != 0) {
 137                 pr_err("failed to allocate 8192 bytes\n");
 138                 return NULL;
 139         }
 140         n = read(fd, buf, 8192);
 141
 142         info = xmalloc(sizeof(*info));
 143
 144         if (n < sizeof(info->sb)) {
 145                 pr_err("failed to read superblock of bitmap file: %s\n", strerror(errno));
 146                 free(info);
 147                 free(buf);
 148                 return NULL;
 149         }
 150         memcpy(&info->sb, buf, sizeof(info->sb));
 151         skip = sizeof(info->sb);
 152
 153         sb_le_to_cpu(&info->sb); /* convert superblock to CPU byte ordering */
 154
 155         if (brief || info->sb.sync_size == 0 || info->sb.chunksize == 0)
 156                 goto out;
 157
 158         /* read the rest of the file counting total bits and dirty bits --
 159          * we stop when either:
 160          * 1) we hit EOF, in which case we assume the rest of the bits (if any)
 161          *    are dirty
 162          * 2) we've read the full bitmap, in which case we ignore any trailing
 163          *    data in the file
 164          */
 165         total_bits = bitmap_bits(info->sb.sync_size, info->sb.chunksize);
 166
 167         while(read_bits < total_bits) {
 168                 unsigned long long remaining = total_bits - read_bits;
 169
 170                 if (n == 0) {
 171                         n = read(fd, buf, 8192);
 172                         skip = 0;
 173                         if (n <= 0)
 174                                 break;
 175                 }
 176                 if (remaining > (n-skip) * 8) /* we want the full buffer */
 177                         remaining = (n-skip) * 8;
 178
 179                 dirty_bits += count_dirty_bits(buf+skip, remaining);
 180
 181                 read_bits += remaining;
 182                 n = 0;
 183         }
 184
 185         if (read_bits < total_bits) { /* file truncated... */
 186                 pr_err("WARNING: bitmap file is not large enough for array size %llu!\n\n",
 187                         (unsigned long long)info->sb.sync_size);
 188                 total_bits = read_bits;
 189         }
 190 out:
 191         free(buf);
 192         info->total_bits = total_bits;
 193         info->dirty_bits = dirty_bits;
 194         return info;
 195 }
 196
 197 int bitmap_file_open(char *filename, struct supertype **stp, int node_num)
 198 {
 199         int fd;
 200         struct stat stb;
 201         struct supertype *st = *stp;
 202
 203         if (stat(filename, &stb) < 0) {
 204                 pr_err("failed to find file %s: %s\n",
 205                         filename, strerror(errno));
 206                 return -1;
 207         }
 208         if ((S_IFMT & stb.st_mode) == S_IFBLK) {
 209                 fd = open(filename, O_RDONLY|O_DIRECT);
 210                 if (fd < 0) {
 211                         pr_err("failed to open bitmap file %s: %s\n",
 212                                 filename, strerror(errno));
 213                         return -1;
 214                 }
 215                 /* block device, so we are probably after an internal bitmap */
 216                 if (!st) st = guess_super(fd);
 217                 if (!st) {
 218                         /* just look at device... */
 219                         lseek(fd, 0, 0);
 220                 } else if (!st->ss->locate_bitmap) {
 221                         pr_err("No bitmap possible with %s metadata\n",
 222                                 st->ss->name);
 223                         close(fd);
 224                         return -1;
 225                 } else {
 226                         if (st->ss->locate_bitmap(st, fd, node_num)) {
 227                                 pr_err("%s doesn't have bitmap\n", filename);
 228                                 close(fd);
 229                                 fd = -1;
 230                         }
 231                 }
 232
 233                 *stp = st;
 234         } else {
 235                 fd = open(filename, O_RDONLY|O_DIRECT);
 236                 if (fd < 0) {
 237                         pr_err("failed to open bitmap file %s: %s\n",
 238                                 filename, strerror(errno));
 239                         return -1;
 240                 }
 241         }
 242
 243         return fd;
 244 }
 245
 246 __u32 swapl(__u32 l)
 247 {
 248         char *c = (char*)&l;
 249         char t= c[0];
 250         c[0] = c[3];
 251         c[3] = t;
 252
 253         t = c[1];
 254         c[1] = c[2];
 255         c[2] = t;
 256         return l;
 257 }
 258 int ExamineBitmap(char *filename, int brief, struct supertype *st)
 259 {
 260         /*
 261          * Read the bitmap file and display its contents
 262          */
 263
 264         bitmap_super_t *sb;
 265         bitmap_info_t *info;
 266         int rv = 1;
 267         char buf[64];
 268         int swap;
 269         int fd, i;
 270         __u32 uuid32[4];
 271
 272         fd = bitmap_file_open(filename, &st, 0);
 273         if (fd < 0)
 274                 return rv;
 275
 276         info = bitmap_fd_read(fd, brief);
 277         if (!info)
 278                 return rv;
 279         sb = &info->sb;
 280         if (sb->magic != BITMAP_MAGIC && md_get_version(fd) > 0) {
 281                 pr_err("This is an md array.  To view a bitmap you need to examine\n");
 282                 pr_err("a member device, not the array.\n");
 283                 pr_err("Reporting bitmap that would be used if this array were used\n");
 284                 pr_err("as a member of some other array\n");
 285         }
 286         close(fd);
 287         printf("        Filename : %s\n", filename);
 288         printf("           Magic : %08x\n", sb->magic);
 289         if (sb->magic != BITMAP_MAGIC) {
 290                 pr_err("invalid bitmap magic 0x%x, the bitmap file appears\n",
 291                        sb->magic);
 292                 pr_err("to be corrupted or missing.\n");
 293         }
 294         printf("         Version : %d\n", sb->version);
 295         if (sb->version < BITMAP_MAJOR_LO ||
 296             sb->version > BITMAP_MAJOR_CLUSTERED) {
 297                 pr_err("unknown bitmap version %d, either the bitmap file\n",
 298                        sb->version);
 299                 pr_err("is corrupted or you need to upgrade your tools\n");
 300                 goto free_info;
 301         }
 302
 303         rv = 0;
 304         if (st)
 305                 swap = st->ss->swapuuid;
 306         else
 307 #if __BYTE_ORDER == BIG_ENDIAN
 308                 swap = 0;
 309 #else
 310                 swap = 1;
 311 #endif
 312         memcpy(uuid32, sb->uuid, 16);
 313         if (swap)
 314                 printf("            UUID : %08x:%08x:%08x:%08x\n",
 315                        swapl(uuid32[0]),
 316                        swapl(uuid32[1]),
 317                        swapl(uuid32[2]),
 318                        swapl(uuid32[3]));
 319         else
 320                 printf("            UUID : %08x:%08x:%08x:%08x\n",
 321                        uuid32[0],
 322                        uuid32[1],
 323                        uuid32[2],
 324                        uuid32[3]);
 325
 326         if (sb->nodes == 0) {
 327                 printf("          Events : %llu\n", (unsigned long long)sb->events);
 328                 printf("  Events Cleared : %llu\n", (unsigned long long)sb->events_cleared);
 329                 printf("           State : %s\n", bitmap_state(sb->state));
 330
 331         }
 332
 333         printf("       Chunksize : %s\n", human_chunksize(sb->chunksize));
 334         printf("          Daemon : %ds flush period\n", sb->daemon_sleep);
 335         if (sb->write_behind)
 336                 sprintf(buf, "Allow write behind, max %d", sb->write_behind);
 337         else
 338                 sprintf(buf, "Normal");
 339         printf("      Write Mode : %s\n", buf);
 340         printf("       Sync Size : %llu%s\n", (unsigned long long)sb->sync_size/2,
 341                                         human_size(sb->sync_size * 512));
 342
 343         if (sb->nodes == 0) {
 344                 if (brief)
 345                         goto free_info;
 346                 printf("          Bitmap : %llu bits (chunks), %llu dirty (%2.1f%%)\n",
 347                        info->total_bits, info->dirty_bits,
 348                        100.0 * info->dirty_bits / (info->total_bits?:1));
 349         } else {
 350                 printf("   Cluster nodes : %d\n", sb->nodes);
 351                 printf("    Cluster name : %-64s\n", sb->cluster_name);
 352                 for (i = 0; i < (int)sb->nodes; i++) {
 353                         st = NULL;
 354                         free(info);
 355                         fd = bitmap_file_open(filename, &st, i);
 356                         info = bitmap_fd_read(fd, brief);
 357                         sb = &info->sb;
 358                         if (sb->magic != BITMAP_MAGIC)
 359                                 pr_err("invalid bitmap magic 0x%x, the bitmap file appears to be corrupted\n", sb->magic);
 360
 361                         printf("       Node Slot : %d\n", i);
 362                         printf("          Events : %llu\n",
 363                                (unsigned long long)sb->events);
 364                         printf("  Events Cleared : %llu\n",
 365                                (unsigned long long)sb->events_cleared);
 366                         printf("           State : %s\n", bitmap_state(sb->state));
 367                         if (brief)
 368                                 continue;
 369                         printf("          Bitmap : %llu bits (chunks), %llu dirty (%2.1f%%)\n",
 370                                info->total_bits, info->dirty_bits,
 371                                100.0 * info->dirty_bits / (info->total_bits?:1));
 372                          close(fd);
 373                 }
 374         }
 375
 376 free_info:
 377         free(info);
 378         return rv;
 379 }
 380
 381 int CreateBitmap(char *filename, int force, char uuid[16],
 382                  unsigned long chunksize, unsigned long daemon_sleep,
 383                  unsigned long write_behind,
 384                  unsigned long long array_size /* sectors */,
 385                  int major)
 386 {
 387         /*
 388          * Create a bitmap file with a superblock and (optionally) a full bitmap
 389          */
 390
 391         FILE *fp;
 392         int rv = 1;
 393         char block[512];
 394         bitmap_super_t sb;
 395         long long bytes, filesize;
 396
 397         if (!force && access(filename, F_OK) == 0) {
 398                 pr_err("bitmap file %s already exists, use --force to overwrite\n", filename);
 399                 return rv;
 400         }
 401
 402         fp = fopen(filename, "w");
 403         if (fp == NULL) {
 404                 pr_err("failed to open bitmap file %s: %s\n",
 405                         filename, strerror(errno));
 406                 return rv;
 407         }
 408
 409         if (chunksize == UnSet) {
 410                 /* We don't want more than 2^21 chunks, as 2^11 fill up one
 411                  * 4K page (2 bytes per chunk), and 2^10 address of those
 412                  * fill up a 4K indexing page.  2^20 might be safer, especially
 413                  * on 64bit hosts, so use that.
 414                  */
 415                 chunksize = DEFAULT_BITMAP_CHUNK;
 416                 /* <<20 for 2^20 chunks, >>9 to convert bytes to sectors */
 417                 while (array_size > ((unsigned long long)chunksize << (20-9)))
 418                         chunksize <<= 1;
 419         }
 420
 421         memset(&sb, 0, sizeof(sb));
 422         sb.magic = BITMAP_MAGIC;
 423         sb.version = major;
 424         if (uuid != NULL)
 425                 memcpy(sb.uuid, uuid, 16);
 426         sb.chunksize = chunksize;
 427         sb.daemon_sleep = daemon_sleep;
 428         sb.write_behind = write_behind;
 429         sb.sync_size = array_size;
 430
 431         sb_cpu_to_le(&sb); /* convert to on-disk byte ordering */
 432
 433         if (fwrite(&sb, sizeof(sb), 1, fp) != 1) {
 434                 pr_err("failed to write superblock to bitmap file %s: %s\n", filename, strerror(errno));
 435                 goto out;
 436         }
 437
 438         /* calculate the size of the bitmap and write it to disk */
 439         bytes = (bitmap_bits(array_size, chunksize) + 7) / 8;
 440         if (!bytes) {
 441                 rv = 0;
 442                 goto out;
 443         }
 444
 445         filesize = bytes + sizeof(sb);
 446
 447         memset(block, 0xff, sizeof(block));
 448
 449         while (bytes > 0) {
 450                 if (fwrite(block, sizeof(block), 1, fp) != 1) {
 451                         pr_err("failed to write bitmap file %s: %s\n", filename, strerror(errno));
 452                         goto out;
 453                 }
 454                 bytes -= sizeof(block);
 455         }
 456
 457         rv = 0;
 458         fflush(fp);
 459         /* make the file be the right size (well, to the nearest byte) */
 460         if (ftruncate(fileno(fp), filesize))
 461                 perror("ftrunace");
 462 out:
 463         fclose(fp);
 464         if (rv)
 465                 unlink(filename); /* possibly corrupted, better get rid of it */
 466         return rv;
 467 }
 468
 469 int bitmap_update_uuid(int fd, int *uuid, int swap)
 470 {
 471         struct bitmap_super_s bm;
 472         if (lseek(fd, 0, 0) != 0)
 473                 return 1;
 474         if (read(fd, &bm, sizeof(bm)) != sizeof(bm))
 475                 return 1;
 476         if (bm.magic != __cpu_to_le32(BITMAP_MAGIC))
 477                 return 1;
 478         copy_uuid(bm.uuid, uuid, swap);
 479         if (lseek(fd, 0, 0) != 0)
 480                 return 2;
 481         if (write(fd, &bm, sizeof(bm)) != sizeof(bm)) {
 482                 lseek(fd, 0, 0);
 483                 return 2;
 484         }
 485         lseek(fd, 0, 0);
 486         return 0;
 487 }