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  46         { "Out of date", 2 },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                         return -1;
 224                 } else {
 225                         if (st->ss->locate_bitmap(st, fd, node_num)) {
 226                                 pr_err("%s doesn't have bitmap\n", filename);
 227                                 fd = -1;
 228                         }
 229                 }
 230
 231                 *stp = st;
 232         } else {
 233                 fd = open(filename, O_RDONLY|O_DIRECT);
 234                 if (fd < 0) {
 235                         pr_err("failed to open bitmap file %s: %s\n",
 236                                 filename, strerror(errno));
 237                         return -1;
 238                 }
 239         }
 240
 241         return fd;
 242 }
 243
 244 __u32 swapl(__u32 l)
 245 {
 246         char *c = (char*)&l;
 247         char t= c[0];
 248         c[0] = c[3];
 249         c[3] = t;
 250
 251         t = c[1];
 252         c[1] = c[2];
 253         c[2] = t;
 254         return l;
 255 }
 256 int ExamineBitmap(char *filename, int brief, struct supertype *st)
 257 {
 258         /*
 259          * Read the bitmap file and display its contents
 260          */
 261
 262         bitmap_super_t *sb;
 263         bitmap_info_t *info;
 264         int rv = 1;
 265         char buf[64];
 266         int swap;
 267         int fd, i;
 268         __u32 uuid32[4];
 269
 270         fd = bitmap_file_open(filename, &st, 0);
 271         if (fd < 0)
 272                 return rv;
 273
 274         info = bitmap_fd_read(fd, brief);
 275         if (!info)
 276                 return rv;
 277         sb = &info->sb;
 278         if (sb->magic != BITMAP_MAGIC && md_get_version(fd) > 0) {
 279                 pr_err("This is an md array.  To view a bitmap you need to examine\n");
 280                 pr_err("a member device, not the array.\n");
 281                 pr_err("Reporting bitmap that would be used if this array were used\n");
 282                 pr_err("as a member of some other array\n");
 283         }
 284         close(fd);
 285         printf("        Filename : %s\n", filename);
 286         printf("           Magic : %08x\n", sb->magic);
 287         if (sb->magic != BITMAP_MAGIC) {
 288                 pr_err("invalid bitmap magic 0x%x, the bitmap file appears\n",
 289                        sb->magic);
 290                 pr_err("to be corrupted or missing.\n");
 291         }
 292         printf("         Version : %d\n", sb->version);
 293         if (sb->version < BITMAP_MAJOR_LO ||
 294             sb->version > BITMAP_MAJOR_CLUSTERED) {
 295                 pr_err("unknown bitmap version %d, either the bitmap file\n",
 296                        sb->version);
 297                 pr_err("is corrupted or you need to upgrade your tools\n");
 298                 goto free_info;
 299         }
 300
 301         rv = 0;
 302         if (st)
 303                 swap = st->ss->swapuuid;
 304         else
 305 #if __BYTE_ORDER == BIG_ENDIAN
 306                 swap = 0;
 307 #else
 308                 swap = 1;
 309 #endif
 310         memcpy(uuid32, sb->uuid, 16);
 311         if (swap)
 312                 printf("            UUID : %08x:%08x:%08x:%08x\n",
 313                        swapl(uuid32[0]),
 314                        swapl(uuid32[1]),
 315                        swapl(uuid32[2]),
 316                        swapl(uuid32[3]));
 317         else
 318                 printf("            UUID : %08x:%08x:%08x:%08x\n",
 319                        uuid32[0],
 320                        uuid32[1],
 321                        uuid32[2],
 322                        uuid32[3]);
 323
 324         if (sb->nodes == 0) {
 325                 printf("          Events : %llu\n", (unsigned long long)sb->events);
 326                 printf("  Events Cleared : %llu\n", (unsigned long long)sb->events_cleared);
 327                 printf("           State : %s\n", bitmap_state(sb->state));
 328
 329         }
 330
 331         printf("       Chunksize : %s\n", human_chunksize(sb->chunksize));
 332         printf("          Daemon : %ds flush period\n", sb->daemon_sleep);
 333         if (sb->write_behind)
 334                 sprintf(buf, "Allow write behind, max %d", sb->write_behind);
 335         else
 336                 sprintf(buf, "Normal");
 337         printf("      Write Mode : %s\n", buf);
 338         printf("       Sync Size : %llu%s\n", (unsigned long long)sb->sync_size/2,
 339                                         human_size(sb->sync_size * 512));
 340
 341         if (sb->nodes == 0) {
 342                 if (brief)
 343                         goto free_info;
 344                 printf("          Bitmap : %llu bits (chunks), %llu dirty (%2.1f%%)\n",
 345                        info->total_bits, info->dirty_bits,
 346                        100.0 * info->dirty_bits / (info->total_bits?:1));
 347         } else {
 348                 printf("   Cluster nodes : %d\n", sb->nodes);
 349                 printf("    Cluster name : %-64s\n", sb->cluster_name);
 350                 for (i = 0; i < (int)sb->nodes; i++) {
 351                         st = NULL;
 352                         free(info);
 353                         fd = bitmap_file_open(filename, &st, i);
 354                         info = bitmap_fd_read(fd, brief);
 355                         sb = &info->sb;
 356                         if (sb->magic != BITMAP_MAGIC)
 357                                 pr_err("invalid bitmap magic 0x%x, the bitmap file appears to be corrupted\n", sb->magic);
 358
 359                         printf("       Node Slot : %d\n", i);
 360                         printf("          Events : %llu\n",
 361                                (unsigned long long)sb->events);
 362                         printf("  Events Cleared : %llu\n",
 363                                (unsigned long long)sb->events_cleared);
 364                         printf("           State : %s\n", bitmap_state(sb->state));
 365                         if (brief)
 366                                 continue;
 367                         printf("          Bitmap : %llu bits (chunks), %llu dirty (%2.1f%%)\n",
 368                                info->total_bits, info->dirty_bits,
 369                                100.0 * info->dirty_bits / (info->total_bits?:1));
 370                          close(fd);
 371                 }
 372         }
 373
 374 free_info:
 375         free(info);
 376         return rv;
 377 }
 378
 379 int CreateBitmap(char *filename, int force, char uuid[16],
 380                  unsigned long chunksize, unsigned long daemon_sleep,
 381                  unsigned long write_behind,
 382                  unsigned long long array_size /* sectors */,
 383                  int major)
 384 {
 385         /*
 386          * Create a bitmap file with a superblock and (optionally) a full bitmap
 387          */
 388
 389         FILE *fp;
 390         int rv = 1;
 391         char block[512];
 392         bitmap_super_t sb;
 393         long long bytes, filesize;
 394
 395         if (!force && access(filename, F_OK) == 0) {
 396                 pr_err("bitmap file %s already exists, use --force to overwrite\n", filename);
 397                 return rv;
 398         }
 399
 400         fp = fopen(filename, "w");
 401         if (fp == NULL) {
 402                 pr_err("failed to open bitmap file %s: %s\n",
 403                         filename, strerror(errno));
 404                 return rv;
 405         }
 406
 407         if (chunksize == UnSet) {
 408                 /* We don't want more than 2^21 chunks, as 2^11 fill up one
 409                  * 4K page (2 bytes per chunk), and 2^10 address of those
 410                  * fill up a 4K indexing page.  2^20 might be safer, especially
 411                  * on 64bit hosts, so use that.
 412                  */
 413                 chunksize = DEFAULT_BITMAP_CHUNK;
 414                 /* <<20 for 2^20 chunks, >>9 to convert bytes to sectors */
 415                 while (array_size > ((unsigned long long)chunksize << (20-9)))
 416                         chunksize <<= 1;
 417         }
 418
 419         memset(&sb, 0, sizeof(sb));
 420         sb.magic = BITMAP_MAGIC;
 421         sb.version = major;
 422         if (uuid != NULL)
 423                 memcpy(sb.uuid, uuid, 16);
 424         sb.chunksize = chunksize;
 425         sb.daemon_sleep = daemon_sleep;
 426         sb.write_behind = write_behind;
 427         sb.sync_size = array_size;
 428
 429         sb_cpu_to_le(&sb); /* convert to on-disk byte ordering */
 430
 431         if (fwrite(&sb, sizeof(sb), 1, fp) != 1) {
 432                 pr_err("failed to write superblock to bitmap file %s: %s\n", filename, strerror(errno));
 433                 goto out;
 434         }
 435
 436         /* calculate the size of the bitmap and write it to disk */
 437         bytes = (bitmap_bits(array_size, chunksize) + 7) / 8;
 438         if (!bytes) {
 439                 rv = 0;
 440                 goto out;
 441         }
 442
 443         filesize = bytes + sizeof(sb);
 444
 445         memset(block, 0xff, sizeof(block));
 446
 447         while (bytes > 0) {
 448                 if (fwrite(block, sizeof(block), 1, fp) != 1) {
 449                         pr_err("failed to write bitmap file %s: %s\n", filename, strerror(errno));
 450                         goto out;
 451                 }
 452                 bytes -= sizeof(block);
 453         }
 454
 455         rv = 0;
 456         fflush(fp);
 457         /* make the file be the right size (well, to the nearest byte) */
 458         if (ftruncate(fileno(fp), filesize))
 459                 perror("ftrunace");
 460 out:
 461         fclose(fp);
 462         if (rv)
 463                 unlink(filename); /* possibly corrupted, better get rid of it */
 464         return rv;
 465 }
 466
 467 int bitmap_update_uuid(int fd, int *uuid, int swap)
 468 {
 469         struct bitmap_super_s bm;
 470         if (lseek(fd, 0, 0) != 0)
 471                 return 1;
 472         if (read(fd, &bm, sizeof(bm)) != sizeof(bm))
 473                 return 1;
 474         if (bm.magic != __cpu_to_le32(BITMAP_MAGIC))
 475                 return 1;
 476         copy_uuid(bm.uuid, uuid, swap);
 477         if (lseek(fd, 0, 0) != 0)
 478                 return 2;
 479         if (write(fd, &bm, sizeof(bm)) != sizeof(bm)) {
 480                 lseek(fd, 0, 0);
 481                 return 2;
 482         }
 483         lseek(fd, 0, 0);
 484         return 0;
 485 }