sys/kern/subr_disklabel64.c

   1 /*
   2  * Copyright (c) 2007 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 <sys/param.h>
  36 #include <sys/systm.h>
  37 #include <sys/kernel.h>
  38 #include <sys/conf.h>
  39 #include <sys/disklabel.h>
  40 #include <sys/disklabel64.h>
  41 #include <sys/diskslice.h>
  42 #include <sys/disk.h>
  43 #include <sys/kern_syscall.h>
  44 #include <sys/buf2.h>
  45
  46 /*
  47  * Alignment against physical start (verses slice start).  We use a megabyte
  48  * here.  Why do we use a megabyte?  Because SSDs already use large 128K
  49  * blocks internally (for MLC) and who the hell knows in the future.
  50  *
  51  * This way if the sysop picks sane values for partition sizes everything
  52  * will be nicely aligned, particularly swap for e.g. swapcache, and
  53  * clustered operations against larger physical sector sizes for newer HDs,
  54  * and so forth.
  55  */
  56 #define PALIGN_SIZE     (1024 * 1024)
  57 #define PALIGN_MASK     (PALIGN_SIZE - 1)
  58
  59 /*
  60  * Retrieve the partition start and extent, in blocks.  Return 0 on success,
  61  * EINVAL on error.
  62  */
  63 static int
  64 l64_getpartbounds(struct diskslices *ssp, disklabel_t lp, u_int32_t part,
  65                   u_int64_t *start, u_int64_t *blocks)
  66 {
  67         struct partition64 *pp;
  68
  69         if (part >= lp.lab64->d_npartitions)
  70                 return (EINVAL);
  71
  72         pp = &lp.lab64->d_partitions[part];
  73
  74         if ((pp->p_boffset & (ssp->dss_secsize - 1)) ||
  75             (pp->p_bsize & (ssp->dss_secsize - 1))) {
  76                 return (EINVAL);
  77         }
  78         *start = pp->p_boffset / ssp->dss_secsize;
  79         *blocks = pp->p_bsize / ssp->dss_secsize;
  80         return(0);
  81 }
  82
  83 /*
  84  * Get the filesystem type XXX - diskslices code needs to use uuids
  85  */
  86 static void
  87 l64_loadpartinfo(disklabel_t lp, u_int32_t part, struct partinfo *dpart)
  88 {
  89         struct partition64 *pp;
  90         const size_t uuid_size = sizeof(struct uuid);
  91
  92         if (part < lp.lab64->d_npartitions) {
  93                 pp = &lp.lab64->d_partitions[part];
  94                 dpart->fstype_uuid = pp->p_type_uuid;
  95                 dpart->storage_uuid = pp->p_stor_uuid;
  96                 dpart->fstype = pp->p_fstype;
  97         } else {
  98                 bzero(&dpart->fstype_uuid, uuid_size);
  99                 bzero(&dpart->storage_uuid, uuid_size);
 100                 dpart->fstype = 0;
 101         }
 102 }
 103
 104 /*
 105  * Get the number of partitions
 106  */
 107 static u_int32_t
 108 l64_getnumparts(disklabel_t lp)
 109 {
 110         return(lp.lab64->d_npartitions);
 111 }
 112
 113 static void
 114 l64_freedisklabel(disklabel_t *lpp)
 115 {
 116         kfree((*lpp).lab64, M_DEVBUF);
 117         (*lpp).lab64 = NULL;
 118 }
 119
 120 /*
 121  * Attempt to read a disk label from a device.  64 bit disklabels are
 122  * sector-agnostic and begin at offset 0 on the device.  64 bit disklabels
 123  * may only be used with GPT partitioning schemes.
 124  *
 125  * Returns NULL on sucess, and an error string on failure.
 126  */
 127 static const char *
 128 l64_readdisklabel(cdev_t dev, struct diskslice *sp, disklabel_t *lpp,
 129                   struct disk_info *info)
 130 {
 131         struct buf *bp;
 132         struct disklabel64 *dlp;
 133         const char *msg;
 134         uint32_t savecrc;
 135         size_t dlpcrcsize;
 136         size_t bpsize;
 137         int secsize;
 138
 139         /*
 140          * XXX I/O size is subject to device DMA limitations
 141          */
 142         secsize = info->d_media_blksize;
 143         bpsize = roundup2(sizeof(*dlp), secsize);
 144
 145         bp = geteblk(bpsize);
 146         bp->b_bio1.bio_offset = 0;
 147         bp->b_bio1.bio_done = biodone_sync;
 148         bp->b_bio1.bio_flags |= BIO_SYNC;
 149         bp->b_bcount = bpsize;
 150         bp->b_flags &= ~B_INVAL;
 151         bp->b_flags |= B_FAILONDIS;
 152         bp->b_cmd = BUF_CMD_READ;
 153         dev_dstrategy(dev, &bp->b_bio1);
 154
 155         if (biowait(&bp->b_bio1, "labrd")) {
 156                 msg = "I/O error";
 157         } else {
 158                 dlp = (struct disklabel64 *)bp->b_data;
 159                 dlpcrcsize = offsetof(struct disklabel64,
 160                                       d_partitions[dlp->d_npartitions]) -
 161                              offsetof(struct disklabel64, d_magic);
 162                 savecrc = dlp->d_crc;
 163                 dlp->d_crc = 0;
 164                 if (dlp->d_magic != DISKMAGIC64) {
 165                         msg = "no disk label";
 166                 } else if (dlp->d_npartitions > MAXPARTITIONS64) {
 167                         msg = "disklabel64 corrupted, too many partitions";
 168                 } else if (savecrc != crc32(&dlp->d_magic, dlpcrcsize)) {
 169                         msg = "disklabel64 corrupted, bad CRC";
 170                 } else {
 171                         dlp->d_crc = savecrc;
 172                         (*lpp).lab64 = kmalloc(sizeof(*dlp),
 173                                                M_DEVBUF, M_WAITOK|M_ZERO);
 174                         *(*lpp).lab64 = *dlp;
 175                         msg = NULL;
 176                 }
 177         }
 178         bp->b_flags |= B_INVAL | B_AGE;
 179         brelse(bp);
 180         return (msg);
 181 }
 182
 183 /*
 184  * If everything is good, copy olpx to nlpx.  Check to see if any
 185  * open partitions would change.
 186  */
 187 static int
 188 l64_setdisklabel(disklabel_t olpx, disklabel_t nlpx, struct diskslices *ssp,
 189                  struct diskslice *sp, u_int32_t *openmask)
 190 {
 191         struct disklabel64 *olp, *nlp;
 192         struct partition64 *opp, *npp;
 193         uint32_t savecrc;
 194         uint64_t slicebsize;
 195         size_t nlpcrcsize;
 196         int i;
 197
 198         olp = olpx.lab64;
 199         nlp = nlpx.lab64;
 200
 201         slicebsize = (uint64_t)sp->ds_size * ssp->dss_secsize;
 202
 203         if (nlp->d_magic != DISKMAGIC64)
 204                 return (EINVAL);
 205         if (nlp->d_npartitions > MAXPARTITIONS64)
 206                 return (EINVAL);
 207         savecrc = nlp->d_crc;
 208         nlp->d_crc = 0;
 209         nlpcrcsize = offsetof(struct disklabel64,
 210                               d_partitions[nlp->d_npartitions]) -
 211                      offsetof(struct disklabel64, d_magic);
 212         if (crc32(&nlp->d_magic, nlpcrcsize) != savecrc) {
 213                 nlp->d_crc = savecrc;
 214                 return (EINVAL);
 215         }
 216         nlp->d_crc = savecrc;
 217
 218         /*
 219          * Check if open partitions have changed
 220          */
 221         i = 0;
 222         while (i < MAXPARTITIONS64) {
 223                 if (openmask[i >> 5] == 0) {
 224                         i += 32;
 225                         continue;
 226                 }
 227                 if ((openmask[i >> 5] & (1 << (i & 31))) == 0) {
 228                         ++i;
 229                         continue;
 230                 }
 231                 if (nlp->d_npartitions <= i)
 232                         return (EBUSY);
 233                 opp = &olp->d_partitions[i];
 234                 npp = &nlp->d_partitions[i];
 235                 if (npp->p_boffset != opp->p_boffset ||
 236                     npp->p_bsize < opp->p_bsize) {
 237                         return (EBUSY);
 238                 }
 239
 240                 /*
 241                  * Do not allow p_type_uuid or p_stor_uuid to change if
 242                  * the partition is currently open.
 243                  */
 244                 if (bcmp(&npp->p_type_uuid, &opp->p_type_uuid,
 245                      sizeof(npp->p_type_uuid)) != 0) {
 246                         return (EBUSY);
 247                 }
 248                 if (bcmp(&npp->p_stor_uuid, &opp->p_stor_uuid,
 249                      sizeof(npp->p_stor_uuid)) != 0) {
 250                         return (EBUSY);
 251                 }
 252                 ++i;
 253         }
 254
 255         /*
 256          * Make sure the label and partition offsets and sizes are sane.
 257          */
 258         if (nlp->d_total_size > slicebsize)
 259                 return (ENOSPC);
 260         if (nlp->d_total_size & (ssp->dss_secsize - 1))
 261                 return (EINVAL);
 262         if (nlp->d_bbase & (ssp->dss_secsize - 1))
 263                 return (EINVAL);
 264         if (nlp->d_pbase & (ssp->dss_secsize - 1))
 265                 return (EINVAL);
 266         if (nlp->d_pstop & (ssp->dss_secsize - 1))
 267                 return (EINVAL);
 268         if (nlp->d_abase & (ssp->dss_secsize - 1))
 269                 return (EINVAL);
 270
 271         for (i = 0; i < nlp->d_npartitions; ++i) {
 272                 npp = &nlp->d_partitions[i];
 273                 if (npp->p_bsize == 0) {
 274                         if (npp->p_boffset != 0)
 275                                 return (EINVAL);
 276                         continue;
 277                 }
 278                 if (npp->p_boffset & (ssp->dss_secsize - 1))
 279                         return (EINVAL);
 280                 if (npp->p_bsize & (ssp->dss_secsize - 1))
 281                         return (EINVAL);
 282                 if (npp->p_boffset < nlp->d_pbase)
 283                         return (ENOSPC);
 284                 if (npp->p_boffset + npp->p_bsize > nlp->d_total_size)
 285                         return (ENOSPC);
 286         }
 287
 288         /*
 289          * Structurally we may add code to make modifications above in the
 290          * future, so regenerate the crc anyway.
 291          */
 292         nlp->d_crc = 0;
 293         nlp->d_crc = crc32(&nlp->d_magic, nlpcrcsize);
 294         *olp = *nlp;
 295
 296         return (0);
 297 }
 298
 299 /*
 300  * Write disk label back to device after modification.
 301  */
 302 static int
 303 l64_writedisklabel(cdev_t dev, struct diskslices *ssp,
 304                    struct diskslice *sp, disklabel_t lpx)
 305 {
 306         struct disklabel64 *lp;
 307         struct disklabel64 *dlp;
 308         struct buf *bp;
 309         int error = 0;
 310         size_t bpsize;
 311         int secsize;
 312
 313         lp = lpx.lab64;
 314
 315         /*
 316          * XXX I/O size is subject to device DMA limitations
 317          */
 318         secsize = ssp->dss_secsize;
 319         bpsize = roundup2(sizeof(*lp), secsize);
 320
 321         bp = geteblk(bpsize);
 322         bp->b_bio1.bio_offset = 0;
 323         bp->b_bio1.bio_done = biodone_sync;
 324         bp->b_bio1.bio_flags |= BIO_SYNC;
 325         bp->b_bcount = bpsize;
 326         bp->b_flags |= B_FAILONDIS;
 327
 328         /*
 329          * Because our I/O is larger then the label, and because we do not
 330          * write the d_reserved0[] area, do a read-modify-write.
 331          */
 332         bp->b_flags &= ~B_INVAL;
 333         bp->b_cmd = BUF_CMD_READ;
 334         KKASSERT(dkpart(dev) == WHOLE_SLICE_PART);
 335         dev_dstrategy(dev, &bp->b_bio1);
 336         error = biowait(&bp->b_bio1, "labrd");
 337         if (error)
 338                 goto done;
 339
 340         dlp = (void *)bp->b_data;
 341         bcopy(&lp->d_magic, &dlp->d_magic,
 342               sizeof(*lp) - offsetof(struct disklabel64, d_magic));
 343         bp->b_cmd = BUF_CMD_WRITE;
 344         bp->b_bio1.bio_done = biodone_sync;
 345         bp->b_bio1.bio_flags |= BIO_SYNC;
 346         KKASSERT(dkpart(dev) == WHOLE_SLICE_PART);
 347         dev_dstrategy(dev, &bp->b_bio1);
 348         error = biowait(&bp->b_bio1, "labwr");
 349 done:
 350         bp->b_flags |= B_INVAL | B_AGE;
 351         brelse(bp);
 352         return (error);
 353 }
 354
 355 /*
 356  * Create a disklabel based on a disk_info structure for the purposes of
 357  * DSO_COMPATLABEL - cases where no real label exists on the storage medium.
 358  *
 359  * If a diskslice is passed, the label is truncated to the slice.
 360  *
 361  * NOTE!  This is not a legal label because d_bbase and d_pbase are both
 362  * set to 0.
 363  */
 364 static disklabel_t
 365 l64_clone_label(struct disk_info *info, struct diskslice *sp)
 366 {
 367         struct disklabel64 *lp;
 368         disklabel_t res;
 369         uint32_t blksize = info->d_media_blksize;
 370         size_t lpcrcsize;
 371
 372         lp = kmalloc(sizeof *lp, M_DEVBUF, M_WAITOK | M_ZERO);
 373
 374         if (sp)
 375                 lp->d_total_size = (uint64_t)sp->ds_size * blksize;
 376         else
 377                 lp->d_total_size = info->d_media_blocks * blksize;
 378
 379         lp->d_magic = DISKMAGIC64;
 380         lp->d_align = blksize;
 381         lp->d_npartitions = MAXPARTITIONS64;
 382         lp->d_pstop = lp->d_total_size;
 383
 384         /*
 385          * Create a dummy 'c' part and a dummy 'a' part (if requested).
 386          * Note that the 'c' part is really a hack.  64 bit disklabels
 387          * do not use 'c' to mean the raw partition.
 388          */
 389
 390         lp->d_partitions[2].p_boffset = 0;
 391         lp->d_partitions[2].p_bsize = lp->d_total_size;
 392         /* XXX SET FS TYPE */
 393
 394         if (info->d_dsflags & DSO_COMPATPARTA) {
 395                 lp->d_partitions[0].p_boffset = 0;
 396                 lp->d_partitions[0].p_bsize = lp->d_total_size;
 397                 /* XXX SET FS TYPE */
 398         }
 399
 400         lpcrcsize = offsetof(struct disklabel64,
 401                              d_partitions[lp->d_npartitions]) -
 402                     offsetof(struct disklabel64, d_magic);
 403
 404         lp->d_crc = crc32(&lp->d_magic, lpcrcsize);
 405         res.lab64 = lp;
 406         return (res);
 407 }
 408
 409 /*
 410  * Create a virgin disklabel64 suitable for writing to the media.
 411  *
 412  * disklabel64 always reserves 32KB for a boot area and leaves room
 413  * for up to RESPARTITIONS64 partitions.
 414  */
 415 static void
 416 l64_makevirginlabel(disklabel_t lpx, struct diskslices *ssp,
 417                     struct diskslice *sp, struct disk_info *info)
 418 {
 419         struct disklabel64 *lp = lpx.lab64;
 420         struct partition64 *pp;
 421         uint32_t blksize;
 422         uint32_t ressize;
 423         uint64_t blkmask;       /* 64 bits so we can ~ */
 424         size_t lpcrcsize;
 425
 426         /*
 427          * Setup the initial label.  Use of a block size of at least 4KB
 428          * for calculating the initial reserved areas to allow some degree
 429          * of portability between media with different sector sizes.
 430          *
 431          * Note that the modified blksize is stored in d_align as a hint
 432          * to the disklabeling program.
 433          */
 434         bzero(lp, sizeof(*lp));
 435         if ((blksize = info->d_media_blksize) < 4096)
 436                 blksize = 4096;
 437         blkmask = blksize - 1;
 438
 439         if (sp)
 440                 lp->d_total_size = (uint64_t)sp->ds_size * ssp->dss_secsize;
 441         else
 442                 lp->d_total_size = info->d_media_blocks * info->d_media_blksize;
 443
 444         lp->d_magic = DISKMAGIC64;
 445         lp->d_align = blksize;
 446         lp->d_npartitions = MAXPARTITIONS64;
 447         kern_uuidgen(&lp->d_stor_uuid, 1);
 448
 449         ressize = offsetof(struct disklabel64, d_partitions[RESPARTITIONS64]);
 450         ressize = (ressize + (uint32_t)blkmask) & ~blkmask;
 451
 452         /*
 453          * NOTE: When calculating pbase take into account the slice offset
 454          *       so the partitions are at least 32K-aligned relative to the
 455          *       start of the physical disk.  This will accomodate efficient
 456          *       access to 4096 byte physical sector drives.
 457          */
 458         lp->d_bbase = ressize;
 459         lp->d_pbase = lp->d_bbase + ((32768 + blkmask) & ~blkmask);
 460         lp->d_pbase = (lp->d_pbase + PALIGN_MASK) & ~(uint64_t)PALIGN_MASK;
 461
 462         /* adjust for slice offset so we are physically aligned */
 463         lp->d_pbase += 32768 - (sp->ds_offset * info->d_media_blksize) % 32768;
 464
 465         lp->d_pstop = (lp->d_total_size - lp->d_bbase) & ~blkmask;
 466         lp->d_abase = lp->d_pstop;
 467
 468         /*
 469          * All partitions are left empty unless DSO_COMPATPARTA is set
 470          */
 471
 472         if (info->d_dsflags & DSO_COMPATPARTA) {
 473                 pp = &lp->d_partitions[0];
 474                 pp->p_boffset = lp->d_pbase;
 475                 pp->p_bsize = lp->d_pstop - lp->d_pbase;
 476                 /* XXX SET FS TYPE */
 477         }
 478
 479         lpcrcsize = offsetof(struct disklabel64,
 480                              d_partitions[lp->d_npartitions]) -
 481                     offsetof(struct disklabel64, d_magic);
 482         lp->d_crc = crc32(&lp->d_magic, lpcrcsize);
 483 }
 484
 485 /*
 486  * Set the number of blocks at the beginning of the slice which have
 487  * been reserved for label operations.  This area will be write-protected
 488  * when accessed via the slice.
 489  *
 490  * For now just protect the label area proper.  Do not protect the
 491  * boot area.  Note partitions in 64 bit disklabels do not overlap
 492  * the disklabel or boot area.
 493  */
 494 static void
 495 l64_adjust_label_reserved(struct diskslices *ssp, int slice,
 496                           struct diskslice *sp)
 497 {
 498         struct disklabel64 *lp = sp->ds_label.lab64;
 499
 500         sp->ds_reserved = lp->d_bbase / ssp->dss_secsize;
 501 }
 502
 503 struct disklabel_ops disklabel64_ops = {
 504         .labelsize = sizeof(struct disklabel64),
 505         .op_readdisklabel = l64_readdisklabel,
 506         .op_setdisklabel = l64_setdisklabel,
 507         .op_writedisklabel = l64_writedisklabel,
 508         .op_clone_label = l64_clone_label,
 509         .op_adjust_label_reserved = l64_adjust_label_reserved,
 510         .op_getpartbounds = l64_getpartbounds,
 511         .op_loadpartinfo = l64_loadpartinfo,
 512         .op_getnumparts = l64_getnumparts,
 513         .op_makevirginlabel = l64_makevirginlabel,
 514         .op_freedisklabel = l64_freedisklabel
 515 };
 516