cmd/zstream/zstream_redup.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * This file and its contents are supplied under the terms of the
   5  * Common Development and Distribution License ("CDDL"), version 1.0.
   6  * You may only use this file in accordance with the terms of version
   7  * 1.0 of the CDDL.
   8  *
   9  * A full copy of the text of the CDDL should have accompanied this
  10  * source.  A copy of the CDDL is also available via the Internet at
  11  * http://www.illumos.org/license/CDDL.
  12  *
  13  * CDDL HEADER END
  14  */
  15
  16 /*
  17  * Copyright (c) 2020 by Delphix. All rights reserved.
  18  */
  19
  20 #include <assert.h>
  21 #include <cityhash.h>
  22 #include <ctype.h>
  23 #include <errno.h>
  24 #include <fcntl.h>
  25 #include <libzfs.h>
  26 #include <libzutil.h>
  27 #include <stddef.h>
  28 #include <stdio.h>
  29 #include <stdlib.h>
  30 #include <string.h>
  31 #include <umem.h>
  32 #include <unistd.h>
  33 #include <sys/debug.h>
  34 #include <sys/stat.h>
  35 #include <sys/zfs_ioctl.h>
  36 #include <sys/zio_checksum.h>
  37 #include "zfs_fletcher.h"
  38 #include "zstream.h"
  39
  40
  41 #define MAX_RDT_PHYSMEM_PERCENT         20
  42 #define SMALLEST_POSSIBLE_MAX_RDT_MB            128
  43
  44 typedef struct redup_entry {
  45         struct redup_entry      *rde_next;
  46         uint64_t rde_guid;
  47         uint64_t rde_object;
  48         uint64_t rde_offset;
  49         uint64_t rde_stream_offset;
  50 } redup_entry_t;
  51
  52 typedef struct redup_table {
  53         redup_entry_t   **redup_hash_array;
  54         umem_cache_t    *ddecache;
  55         uint64_t        ddt_count;
  56         int             numhashbits;
  57 } redup_table_t;
  58
  59 void *
  60 safe_calloc(size_t n)
  61 {
  62         void *rv = calloc(1, n);
  63         if (rv == NULL) {
  64                 fprintf(stderr,
  65                     "Error: could not allocate %u bytes of memory\n",
  66                     (int)n);
  67                 exit(1);
  68         }
  69         return (rv);
  70 }
  71
  72 /*
  73  * Safe version of fread(), exits on error.
  74  */
  75 int
  76 sfread(void *buf, size_t size, FILE *fp)
  77 {
  78         int rv = fread(buf, size, 1, fp);
  79         if (rv == 0 && ferror(fp)) {
  80                 (void) fprintf(stderr, "Error while reading file: %s\n",
  81                     strerror(errno));
  82                 exit(1);
  83         }
  84         return (rv);
  85 }
  86
  87 /*
  88  * Safe version of pread(), exits on error.
  89  */
  90 static void
  91 spread(int fd, void *buf, size_t count, off_t offset)
  92 {
  93         ssize_t err = pread(fd, buf, count, offset);
  94         if (err == -1) {
  95                 (void) fprintf(stderr,
  96                     "Error while reading file: %s\n",
  97                     strerror(errno));
  98                 exit(1);
  99         } else if (err != count) {
 100                 (void) fprintf(stderr,
 101                     "Error while reading file: short read\n");
 102                 exit(1);
 103         }
 104 }
 105
 106 static int
 107 dump_record(dmu_replay_record_t *drr, void *payload, int payload_len,
 108     zio_cksum_t *zc, int outfd)
 109 {
 110         assert(offsetof(dmu_replay_record_t, drr_u.drr_checksum.drr_checksum)
 111             == sizeof (dmu_replay_record_t) - sizeof (zio_cksum_t));
 112         fletcher_4_incremental_native(drr,
 113             offsetof(dmu_replay_record_t, drr_u.drr_checksum.drr_checksum), zc);
 114         if (drr->drr_type != DRR_BEGIN) {
 115                 assert(ZIO_CHECKSUM_IS_ZERO(&drr->drr_u.
 116                     drr_checksum.drr_checksum));
 117                 drr->drr_u.drr_checksum.drr_checksum = *zc;
 118         }
 119         fletcher_4_incremental_native(&drr->drr_u.drr_checksum.drr_checksum,
 120             sizeof (zio_cksum_t), zc);
 121         if (write(outfd, drr, sizeof (*drr)) == -1)
 122                 return (errno);
 123         if (payload_len != 0) {
 124                 fletcher_4_incremental_native(payload, payload_len, zc);
 125                 if (write(outfd, payload, payload_len) == -1)
 126                         return (errno);
 127         }
 128         return (0);
 129 }
 130
 131 static void
 132 rdt_insert(redup_table_t *rdt,
 133     uint64_t guid, uint64_t object, uint64_t offset, uint64_t stream_offset)
 134 {
 135         uint64_t ch = cityhash3(guid, object, offset);
 136         uint64_t hashcode = BF64_GET(ch, 0, rdt->numhashbits);
 137         redup_entry_t **rdepp;
 138
 139         rdepp = &(rdt->redup_hash_array[hashcode]);
 140         redup_entry_t *rde = umem_cache_alloc(rdt->ddecache, UMEM_NOFAIL);
 141         rde->rde_next = *rdepp;
 142         rde->rde_guid = guid;
 143         rde->rde_object = object;
 144         rde->rde_offset = offset;
 145         rde->rde_stream_offset = stream_offset;
 146         *rdepp = rde;
 147         rdt->ddt_count++;
 148 }
 149
 150 static void
 151 rdt_lookup(redup_table_t *rdt,
 152     uint64_t guid, uint64_t object, uint64_t offset,
 153     uint64_t *stream_offsetp)
 154 {
 155         uint64_t ch = cityhash3(guid, object, offset);
 156         uint64_t hashcode = BF64_GET(ch, 0, rdt->numhashbits);
 157
 158         for (redup_entry_t *rde = rdt->redup_hash_array[hashcode];
 159             rde != NULL; rde = rde->rde_next) {
 160                 if (rde->rde_guid == guid &&
 161                     rde->rde_object == object &&
 162                     rde->rde_offset == offset) {
 163                         *stream_offsetp = rde->rde_stream_offset;
 164                         return;
 165                 }
 166         }
 167         assert(!"could not find expected redup table entry");
 168 }
 169
 170 /*
 171  * Convert a dedup stream (generated by "zfs send -D") to a
 172  * non-deduplicated stream.  The entire infd will be converted, including
 173  * any substreams in a stream package (generated by "zfs send -RD"). The
 174  * infd must be seekable.
 175  */
 176 static void
 177 zfs_redup_stream(int infd, int outfd, boolean_t verbose)
 178 {
 179         int bufsz = SPA_MAXBLOCKSIZE;
 180         dmu_replay_record_t thedrr;
 181         dmu_replay_record_t *drr = &thedrr;
 182         redup_table_t rdt;
 183         zio_cksum_t stream_cksum;
 184         uint64_t numbuckets;
 185         uint64_t num_records = 0;
 186         uint64_t num_write_byref_records = 0;
 187
 188         memset(&thedrr, 0, sizeof (dmu_replay_record_t));
 189
 190 #ifdef _ILP32
 191         uint64_t max_rde_size = SMALLEST_POSSIBLE_MAX_RDT_MB << 20;
 192 #else
 193         uint64_t physmem = sysconf(_SC_PHYS_PAGES) * sysconf(_SC_PAGESIZE);
 194         uint64_t max_rde_size =
 195             MAX((physmem * MAX_RDT_PHYSMEM_PERCENT) / 100,
 196             SMALLEST_POSSIBLE_MAX_RDT_MB << 20);
 197 #endif
 198
 199         numbuckets = max_rde_size / (sizeof (redup_entry_t));
 200
 201         /*
 202          * numbuckets must be a power of 2.  Increase number to
 203          * a power of 2 if necessary.
 204          */
 205         if (!ISP2(numbuckets))
 206                 numbuckets = 1ULL << highbit64(numbuckets);
 207
 208         rdt.redup_hash_array =
 209             safe_calloc(numbuckets * sizeof (redup_entry_t *));
 210         rdt.ddecache = umem_cache_create("rde", sizeof (redup_entry_t), 0,
 211             NULL, NULL, NULL, NULL, NULL, 0);
 212         rdt.numhashbits = highbit64(numbuckets) - 1;
 213         rdt.ddt_count = 0;
 214
 215         char *buf = safe_calloc(bufsz);
 216         FILE *ofp = fdopen(infd, "r");
 217         long offset = ftell(ofp);
 218         int begin = 0;
 219         boolean_t seen = B_FALSE;
 220         while (sfread(drr, sizeof (*drr), ofp) != 0) {
 221                 num_records++;
 222
 223                 /*
 224                  * We need to regenerate the checksum.
 225                  */
 226                 if (drr->drr_type != DRR_BEGIN) {
 227                         memset(&drr->drr_u.drr_checksum.drr_checksum, 0,
 228                             sizeof (drr->drr_u.drr_checksum.drr_checksum));
 229                 }
 230
 231                 uint64_t payload_size = 0;
 232                 switch (drr->drr_type) {
 233                 case DRR_BEGIN:
 234                 {
 235                         struct drr_begin *drrb = &drr->drr_u.drr_begin;
 236                         int fflags;
 237                         ZIO_SET_CHECKSUM(&stream_cksum, 0, 0, 0, 0);
 238                         VERIFY0(begin++);
 239                         seen = B_TRUE;
 240
 241                         assert(drrb->drr_magic == DMU_BACKUP_MAGIC);
 242
 243                         /* clear the DEDUP feature flag for this stream */
 244                         fflags = DMU_GET_FEATUREFLAGS(drrb->drr_versioninfo);
 245                         fflags &= ~(DMU_BACKUP_FEATURE_DEDUP |
 246                             DMU_BACKUP_FEATURE_DEDUPPROPS);
 247                         /* cppcheck-suppress syntaxError */
 248                         DMU_SET_FEATUREFLAGS(drrb->drr_versioninfo, fflags);
 249
 250                         uint32_t sz = drr->drr_payloadlen;
 251
 252                         VERIFY3U(sz, <=, 1U << 28);
 253
 254                         if (sz != 0) {
 255                                 if (sz > bufsz) {
 256                                         free(buf);
 257                                         buf = safe_calloc(sz);
 258                                         bufsz = sz;
 259                                 }
 260                                 (void) sfread(buf, sz, ofp);
 261                         }
 262                         payload_size = sz;
 263                         break;
 264                 }
 265
 266                 case DRR_END:
 267                 {
 268                         struct drr_end *drre = &drr->drr_u.drr_end;
 269                         /*
 270                          * We would prefer to just check --begin == 0, but
 271                          * replication streams have an end of stream END
 272                          * record, so we must avoid tripping it.
 273                          */
 274                         VERIFY3B(seen, ==, B_TRUE);
 275                         begin--;
 276                         /*
 277                          * Use the recalculated checksum, unless this is
 278                          * the END record of a stream package, which has
 279                          * no checksum.
 280                          */
 281                         if (!ZIO_CHECKSUM_IS_ZERO(&drre->drr_checksum))
 282                                 drre->drr_checksum = stream_cksum;
 283                         break;
 284                 }
 285
 286                 case DRR_OBJECT:
 287                 {
 288                         struct drr_object *drro = &drr->drr_u.drr_object;
 289                         VERIFY3S(begin, ==, 1);
 290
 291                         if (drro->drr_bonuslen > 0) {
 292                                 payload_size = DRR_OBJECT_PAYLOAD_SIZE(drro);
 293                                 (void) sfread(buf, payload_size, ofp);
 294                         }
 295                         break;
 296                 }
 297
 298                 case DRR_SPILL:
 299                 {
 300                         struct drr_spill *drrs = &drr->drr_u.drr_spill;
 301                         VERIFY3S(begin, ==, 1);
 302                         payload_size = DRR_SPILL_PAYLOAD_SIZE(drrs);
 303                         (void) sfread(buf, payload_size, ofp);
 304                         break;
 305                 }
 306
 307                 case DRR_WRITE_BYREF:
 308                 {
 309                         struct drr_write_byref drrwb =
 310                             drr->drr_u.drr_write_byref;
 311                         VERIFY3S(begin, ==, 1);
 312
 313                         num_write_byref_records++;
 314
 315                         /*
 316                          * Look up in hash table by drrwb->drr_refguid,
 317                          * drr_refobject, drr_refoffset.  Replace this
 318                          * record with the found WRITE record, but with
 319                          * drr_object,drr_offset,drr_toguid replaced with ours.
 320                          */
 321                         uint64_t stream_offset = 0;
 322                         rdt_lookup(&rdt, drrwb.drr_refguid,
 323                             drrwb.drr_refobject, drrwb.drr_refoffset,
 324                             &stream_offset);
 325
 326                         spread(infd, drr, sizeof (*drr), stream_offset);
 327
 328                         assert(drr->drr_type == DRR_WRITE);
 329                         struct drr_write *drrw = &drr->drr_u.drr_write;
 330                         assert(drrw->drr_toguid == drrwb.drr_refguid);
 331                         assert(drrw->drr_object == drrwb.drr_refobject);
 332                         assert(drrw->drr_offset == drrwb.drr_refoffset);
 333
 334                         payload_size = DRR_WRITE_PAYLOAD_SIZE(drrw);
 335                         spread(infd, buf, payload_size,
 336                             stream_offset + sizeof (*drr));
 337
 338                         drrw->drr_toguid = drrwb.drr_toguid;
 339                         drrw->drr_object = drrwb.drr_object;
 340                         drrw->drr_offset = drrwb.drr_offset;
 341                         break;
 342                 }
 343
 344                 case DRR_WRITE:
 345                 {
 346                         struct drr_write *drrw = &drr->drr_u.drr_write;
 347                         VERIFY3S(begin, ==, 1);
 348                         payload_size = DRR_WRITE_PAYLOAD_SIZE(drrw);
 349                         (void) sfread(buf, payload_size, ofp);
 350
 351                         rdt_insert(&rdt, drrw->drr_toguid,
 352                             drrw->drr_object, drrw->drr_offset, offset);
 353                         break;
 354                 }
 355
 356                 case DRR_WRITE_EMBEDDED:
 357                 {
 358                         struct drr_write_embedded *drrwe =
 359                             &drr->drr_u.drr_write_embedded;
 360                         VERIFY3S(begin, ==, 1);
 361                         payload_size =
 362                             P2ROUNDUP((uint64_t)drrwe->drr_psize, 8);
 363                         (void) sfread(buf, payload_size, ofp);
 364                         break;
 365                 }
 366
 367                 case DRR_FREEOBJECTS:
 368                 case DRR_FREE:
 369                 case DRR_OBJECT_RANGE:
 370                         VERIFY3S(begin, ==, 1);
 371                         break;
 372
 373                 default:
 374                         (void) fprintf(stderr, "INVALID record type 0x%x\n",
 375                             drr->drr_type);
 376                         /* should never happen, so assert */
 377                         assert(B_FALSE);
 378                 }
 379
 380                 if (feof(ofp)) {
 381                         fprintf(stderr, "Error: unexpected end-of-file\n");
 382                         exit(1);
 383                 }
 384                 if (ferror(ofp)) {
 385                         fprintf(stderr, "Error while reading file: %s\n",
 386                             strerror(errno));
 387                         exit(1);
 388                 }
 389
 390                 /*
 391                  * We need to recalculate the checksum, and it needs to be
 392                  * initially zero to do that.  BEGIN records don't have
 393                  * a checksum.
 394                  */
 395                 if (drr->drr_type != DRR_BEGIN) {
 396                         memset(&drr->drr_u.drr_checksum.drr_checksum, 0,
 397                             sizeof (drr->drr_u.drr_checksum.drr_checksum));
 398                 }
 399                 if (dump_record(drr, buf, payload_size,
 400                     &stream_cksum, outfd) != 0)
 401                         break;
 402                 if (drr->drr_type == DRR_END) {
 403                         /*
 404                          * Typically the END record is either the last
 405                          * thing in the stream, or it is followed
 406                          * by a BEGIN record (which also zeros the checksum).
 407                          * However, a stream package ends with two END
 408                          * records.  The last END record's checksum starts
 409                          * from zero.
 410                          */
 411                         ZIO_SET_CHECKSUM(&stream_cksum, 0, 0, 0, 0);
 412                 }
 413                 offset = ftell(ofp);
 414         }
 415
 416         if (verbose) {
 417                 char mem_str[16];
 418                 zfs_nicenum(rdt.ddt_count * sizeof (redup_entry_t),
 419                     mem_str, sizeof (mem_str));
 420                 fprintf(stderr, "converted stream with %llu total records, "
 421                     "including %llu dedup records, using %sB memory.\n",
 422                     (long long)num_records,
 423                     (long long)num_write_byref_records,
 424                     mem_str);
 425         }
 426
 427         umem_cache_destroy(rdt.ddecache);
 428         free(rdt.redup_hash_array);
 429         free(buf);
 430         (void) fclose(ofp);
 431 }
 432
 433 int
 434 zstream_do_redup(int argc, char *argv[])
 435 {
 436         boolean_t verbose = B_FALSE;
 437         int c;
 438
 439         while ((c = getopt(argc, argv, "v")) != -1) {
 440                 switch (c) {
 441                 case 'v':
 442                         verbose = B_TRUE;
 443                         break;
 444                 case '?':
 445                         (void) fprintf(stderr, "invalid option '%c'\n",
 446                             optopt);
 447                         zstream_usage();
 448                         break;
 449                 }
 450         }
 451
 452         argc -= optind;
 453         argv += optind;
 454
 455         if (argc != 1)
 456                 zstream_usage();
 457
 458         const char *filename = argv[0];
 459
 460         if (isatty(STDOUT_FILENO)) {
 461                 (void) fprintf(stderr,
 462                     "Error: Stream can not be written to a terminal.\n"
 463                     "You must redirect standard output.\n");
 464                 return (1);
 465         }
 466
 467         int fd = open(filename, O_RDONLY);
 468         if (fd == -1) {
 469                 (void) fprintf(stderr,
 470                     "Error while opening file '%s': %s\n",
 471                     filename, strerror(errno));
 472                 exit(1);
 473         }
 474
 475         fletcher_4_init();
 476         zfs_redup_stream(fd, STDOUT_FILENO, verbose);
 477         fletcher_4_fini();
 478
 479         close(fd);
 480
 481         return (0);
 482 }