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_impl.h>
  26 #include <libzfs.h>
  27 #include <libzutil.h>
  28 #include <stddef.h>
  29 #include <stdio.h>
  30 #include <stdlib.h>
  31 #include <strings.h>
  32 #include <umem.h>
  33 #include <unistd.h>
  34 #include <sys/debug.h>
  35 #include <sys/stat.h>
  36 #include <sys/zfs_ioctl.h>
  37 #include <sys/zio_checksum.h>
  38 #include "zfs_fletcher.h"
  39 #include "zstream.h"
  40
  41
  42 #define MAX_RDT_PHYSMEM_PERCENT         20
  43 #define SMALLEST_POSSIBLE_MAX_RDT_MB            128
  44
  45 typedef struct redup_entry {
  46         struct redup_entry      *rde_next;
  47         uint64_t rde_guid;
  48         uint64_t rde_object;
  49         uint64_t rde_offset;
  50         uint64_t rde_stream_offset;
  51 } redup_entry_t;
  52
  53 typedef struct redup_table {
  54         redup_entry_t   **redup_hash_array;
  55         umem_cache_t    *ddecache;
  56         uint64_t        ddt_count;
  57         int             numhashbits;
  58 } redup_table_t;
  59
  60 int
  61 highbit64(uint64_t i)
  62 {
  63         if (i == 0)
  64                 return (0);
  65
  66         return (NBBY * sizeof (uint64_t) - __builtin_clzll(i));
  67 }
  68
  69 static void *
  70 safe_calloc(size_t n)
  71 {
  72         void *rv = calloc(1, n);
  73         if (rv == NULL) {
  74                 fprintf(stderr,
  75                     "Error: could not allocate %u bytes of memory\n",
  76                     (int)n);
  77                 exit(1);
  78         }
  79         return (rv);
  80 }
  81
  82 /*
  83  * Safe version of fread(), exits on error.
  84  */
  85 static int
  86 sfread(void *buf, size_t size, FILE *fp)
  87 {
  88         int rv = fread(buf, size, 1, fp);
  89         if (rv == 0 && ferror(fp)) {
  90                 (void) fprintf(stderr, "Error while reading file: %s\n",
  91                     strerror(errno));
  92                 exit(1);
  93         }
  94         return (rv);
  95 }
  96
  97 /*
  98  * Safe version of pread(), exits on error.
  99  */
 100 static void
 101 spread(int fd, void *buf, size_t count, off_t offset)
 102 {
 103         ssize_t err = pread(fd, buf, count, offset);
 104         if (err == -1) {
 105                 (void) fprintf(stderr,
 106                     "Error while reading file: %s\n",
 107                     strerror(errno));
 108                 exit(1);
 109         } else if (err != count) {
 110                 (void) fprintf(stderr,
 111                     "Error while reading file: short read\n");
 112                 exit(1);
 113         }
 114 }
 115
 116 static int
 117 dump_record(dmu_replay_record_t *drr, void *payload, int payload_len,
 118     zio_cksum_t *zc, int outfd)
 119 {
 120         assert(offsetof(dmu_replay_record_t, drr_u.drr_checksum.drr_checksum)
 121             == sizeof (dmu_replay_record_t) - sizeof (zio_cksum_t));
 122         fletcher_4_incremental_native(drr,
 123             offsetof(dmu_replay_record_t, drr_u.drr_checksum.drr_checksum), zc);
 124         if (drr->drr_type != DRR_BEGIN) {
 125                 assert(ZIO_CHECKSUM_IS_ZERO(&drr->drr_u.
 126                     drr_checksum.drr_checksum));
 127                 drr->drr_u.drr_checksum.drr_checksum = *zc;
 128         }
 129         fletcher_4_incremental_native(&drr->drr_u.drr_checksum.drr_checksum,
 130             sizeof (zio_cksum_t), zc);
 131         if (write(outfd, drr, sizeof (*drr)) == -1)
 132                 return (errno);
 133         if (payload_len != 0) {
 134                 fletcher_4_incremental_native(payload, payload_len, zc);
 135                 if (write(outfd, payload, payload_len) == -1)
 136                         return (errno);
 137         }
 138         return (0);
 139 }
 140
 141 static void
 142 rdt_insert(redup_table_t *rdt,
 143     uint64_t guid, uint64_t object, uint64_t offset, uint64_t stream_offset)
 144 {
 145         uint64_t ch = cityhash4(guid, object, offset, 0);
 146         uint64_t hashcode = BF64_GET(ch, 0, rdt->numhashbits);
 147         redup_entry_t **rdepp;
 148
 149         rdepp = &(rdt->redup_hash_array[hashcode]);
 150         redup_entry_t *rde = umem_cache_alloc(rdt->ddecache, UMEM_NOFAIL);
 151         rde->rde_next = *rdepp;
 152         rde->rde_guid = guid;
 153         rde->rde_object = object;
 154         rde->rde_offset = offset;
 155         rde->rde_stream_offset = stream_offset;
 156         *rdepp = rde;
 157         rdt->ddt_count++;
 158 }
 159
 160 static void
 161 rdt_lookup(redup_table_t *rdt,
 162     uint64_t guid, uint64_t object, uint64_t offset,
 163     uint64_t *stream_offsetp)
 164 {
 165         uint64_t ch = cityhash4(guid, object, offset, 0);
 166         uint64_t hashcode = BF64_GET(ch, 0, rdt->numhashbits);
 167
 168         for (redup_entry_t *rde = rdt->redup_hash_array[hashcode];
 169             rde != NULL; rde = rde->rde_next) {
 170                 if (rde->rde_guid == guid &&
 171                     rde->rde_object == object &&
 172                     rde->rde_offset == offset) {
 173                         *stream_offsetp = rde->rde_stream_offset;
 174                         return;
 175                 }
 176         }
 177         assert(!"could not find expected redup table entry");
 178 }
 179
 180 /*
 181  * Convert a dedup stream (generated by "zfs send -D") to a
 182  * non-deduplicated stream.  The entire infd will be converted, including
 183  * any substreams in a stream package (generated by "zfs send -RD"). The
 184  * infd must be seekable.
 185  */
 186 static void
 187 zfs_redup_stream(int infd, int outfd, boolean_t verbose)
 188 {
 189         int bufsz = SPA_MAXBLOCKSIZE;
 190         dmu_replay_record_t thedrr = { 0 };
 191         dmu_replay_record_t *drr = &thedrr;
 192         redup_table_t rdt;
 193         zio_cksum_t stream_cksum;
 194         uint64_t numbuckets;
 195         uint64_t num_records = 0;
 196         uint64_t num_write_byref_records = 0;
 197
 198 #ifdef _ILP32
 199         uint64_t max_rde_size = SMALLEST_POSSIBLE_MAX_RDT_MB << 20;
 200 #else
 201         uint64_t physmem = sysconf(_SC_PHYS_PAGES) * sysconf(_SC_PAGESIZE);
 202         uint64_t max_rde_size =
 203             MAX((physmem * MAX_RDT_PHYSMEM_PERCENT) / 100,
 204             SMALLEST_POSSIBLE_MAX_RDT_MB << 20);
 205 #endif
 206
 207         numbuckets = max_rde_size / (sizeof (redup_entry_t));
 208
 209         /*
 210          * numbuckets must be a power of 2.  Increase number to
 211          * a power of 2 if necessary.
 212          */
 213         if (!ISP2(numbuckets))
 214                 numbuckets = 1ULL << highbit64(numbuckets);
 215
 216         rdt.redup_hash_array =
 217             safe_calloc(numbuckets * sizeof (redup_entry_t *));
 218         rdt.ddecache = umem_cache_create("rde", sizeof (redup_entry_t), 0,
 219             NULL, NULL, NULL, NULL, NULL, 0);
 220         rdt.numhashbits = highbit64(numbuckets) - 1;
 221         rdt.ddt_count = 0;
 222
 223         char *buf = safe_calloc(bufsz);
 224         FILE *ofp = fdopen(infd, "r");
 225         long offset = ftell(ofp);
 226         while (sfread(drr, sizeof (*drr), ofp) != 0) {
 227                 num_records++;
 228
 229                 /*
 230                  * We need to regenerate the checksum.
 231                  */
 232                 if (drr->drr_type != DRR_BEGIN) {
 233                         bzero(&drr->drr_u.drr_checksum.drr_checksum,
 234                             sizeof (drr->drr_u.drr_checksum.drr_checksum));
 235                 }
 236
 237                 uint64_t payload_size = 0;
 238                 switch (drr->drr_type) {
 239                 case DRR_BEGIN:
 240                 {
 241                         struct drr_begin *drrb = &drr->drr_u.drr_begin;
 242                         int fflags;
 243                         ZIO_SET_CHECKSUM(&stream_cksum, 0, 0, 0, 0);
 244
 245                         assert(drrb->drr_magic == DMU_BACKUP_MAGIC);
 246
 247                         /* clear the DEDUP feature flag for this stream */
 248                         fflags = DMU_GET_FEATUREFLAGS(drrb->drr_versioninfo);
 249                         fflags &= ~(DMU_BACKUP_FEATURE_DEDUP |
 250                             DMU_BACKUP_FEATURE_DEDUPPROPS);
 251                         DMU_SET_FEATUREFLAGS(drrb->drr_versioninfo, fflags);
 252
 253                         int sz = drr->drr_payloadlen;
 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                          * Use the recalculated checksum, unless this is
 271                          * the END record of a stream package, which has
 272                          * no checksum.
 273                          */
 274                         if (!ZIO_CHECKSUM_IS_ZERO(&drre->drr_checksum))
 275                                 drre->drr_checksum = stream_cksum;
 276                         break;
 277                 }
 278
 279                 case DRR_OBJECT:
 280                 {
 281                         struct drr_object *drro = &drr->drr_u.drr_object;
 282
 283                         if (drro->drr_bonuslen > 0) {
 284                                 payload_size = DRR_OBJECT_PAYLOAD_SIZE(drro);
 285                                 (void) sfread(buf, payload_size, ofp);
 286                         }
 287                         break;
 288                 }
 289
 290                 case DRR_SPILL:
 291                 {
 292                         struct drr_spill *drrs = &drr->drr_u.drr_spill;
 293                         payload_size = DRR_SPILL_PAYLOAD_SIZE(drrs);
 294                         (void) sfread(buf, payload_size, ofp);
 295                         break;
 296                 }
 297
 298                 case DRR_WRITE_BYREF:
 299                 {
 300                         struct drr_write_byref drrwb =
 301                             drr->drr_u.drr_write_byref;
 302
 303                         num_write_byref_records++;
 304
 305                         /*
 306                          * Look up in hash table by drrwb->drr_refguid,
 307                          * drr_refobject, drr_refoffset.  Replace this
 308                          * record with the found WRITE record, but with
 309                          * drr_object,drr_offset,drr_toguid replaced with ours.
 310                          */
 311                         uint64_t stream_offset = 0;
 312                         rdt_lookup(&rdt, drrwb.drr_refguid,
 313                             drrwb.drr_refobject, drrwb.drr_refoffset,
 314                             &stream_offset);
 315
 316                         spread(infd, drr, sizeof (*drr), stream_offset);
 317
 318                         assert(drr->drr_type == DRR_WRITE);
 319                         struct drr_write *drrw = &drr->drr_u.drr_write;
 320                         assert(drrw->drr_toguid == drrwb.drr_refguid);
 321                         assert(drrw->drr_object == drrwb.drr_refobject);
 322                         assert(drrw->drr_offset == drrwb.drr_refoffset);
 323
 324                         payload_size = DRR_WRITE_PAYLOAD_SIZE(drrw);
 325                         spread(infd, buf, payload_size,
 326                             stream_offset + sizeof (*drr));
 327
 328                         drrw->drr_toguid = drrwb.drr_toguid;
 329                         drrw->drr_object = drrwb.drr_object;
 330                         drrw->drr_offset = drrwb.drr_offset;
 331                         break;
 332                 }
 333
 334                 case DRR_WRITE:
 335                 {
 336                         struct drr_write *drrw = &drr->drr_u.drr_write;
 337                         payload_size = DRR_WRITE_PAYLOAD_SIZE(drrw);
 338                         (void) sfread(buf, payload_size, ofp);
 339
 340                         rdt_insert(&rdt, drrw->drr_toguid,
 341                             drrw->drr_object, drrw->drr_offset, offset);
 342                         break;
 343                 }
 344
 345                 case DRR_WRITE_EMBEDDED:
 346                 {
 347                         struct drr_write_embedded *drrwe =
 348                             &drr->drr_u.drr_write_embedded;
 349                         payload_size =
 350                             P2ROUNDUP((uint64_t)drrwe->drr_psize, 8);
 351                         (void) sfread(buf, payload_size, ofp);
 352                         break;
 353                 }
 354
 355                 case DRR_FREEOBJECTS:
 356                 case DRR_FREE:
 357                 case DRR_OBJECT_RANGE:
 358                         break;
 359
 360                 default:
 361                         (void) fprintf(stderr, "INVALID record type 0x%x\n",
 362                             drr->drr_type);
 363                         /* should never happen, so assert */
 364                         assert(B_FALSE);
 365                 }
 366
 367                 if (feof(ofp)) {
 368                         fprintf(stderr, "Error: unexpected end-of-file\n");
 369                         exit(1);
 370                 }
 371                 if (ferror(ofp)) {
 372                         fprintf(stderr, "Error while reading file: %s\n",
 373                             strerror(errno));
 374                         exit(1);
 375                 }
 376
 377                 /*
 378                  * We need to recalculate the checksum, and it needs to be
 379                  * initially zero to do that.  BEGIN records don't have
 380                  * a checksum.
 381                  */
 382                 if (drr->drr_type != DRR_BEGIN) {
 383                         bzero(&drr->drr_u.drr_checksum.drr_checksum,
 384                             sizeof (drr->drr_u.drr_checksum.drr_checksum));
 385                 }
 386                 if (dump_record(drr, buf, payload_size,
 387                     &stream_cksum, outfd) != 0)
 388                         break;
 389                 if (drr->drr_type == DRR_END) {
 390                         /*
 391                          * Typically the END record is either the last
 392                          * thing in the stream, or it is followed
 393                          * by a BEGIN record (which also zeros the checksum).
 394                          * However, a stream package ends with two END
 395                          * records.  The last END record's checksum starts
 396                          * from zero.
 397                          */
 398                         ZIO_SET_CHECKSUM(&stream_cksum, 0, 0, 0, 0);
 399                 }
 400                 offset = ftell(ofp);
 401         }
 402
 403         if (verbose) {
 404                 char mem_str[16];
 405                 zfs_nicenum(rdt.ddt_count * sizeof (redup_entry_t),
 406                     mem_str, sizeof (mem_str));
 407                 fprintf(stderr, "converted stream with %llu total records, "
 408                     "including %llu dedup records, using %sB memory.\n",
 409                     (long long)num_records,
 410                     (long long)num_write_byref_records,
 411                     mem_str);
 412         }
 413
 414         umem_cache_destroy(rdt.ddecache);
 415         free(rdt.redup_hash_array);
 416         free(buf);
 417         (void) fclose(ofp);
 418 }
 419
 420 int
 421 zstream_do_redup(int argc, char *argv[])
 422 {
 423         boolean_t verbose = B_FALSE;
 424         char c;
 425
 426         while ((c = getopt(argc, argv, "v")) != -1) {
 427                 switch (c) {
 428                 case 'v':
 429                         verbose = B_TRUE;
 430                         break;
 431                 case '?':
 432                         (void) fprintf(stderr, "invalid option '%c'\n",
 433                             optopt);
 434                         zstream_usage();
 435                         break;
 436                 }
 437         }
 438
 439         argc -= optind;
 440         argv += optind;
 441
 442         if (argc != 1)
 443                 zstream_usage();
 444
 445         const char *filename = argv[0];
 446
 447         if (isatty(STDOUT_FILENO)) {
 448                 (void) fprintf(stderr,
 449                     "Error: Stream can not be written to a terminal.\n"
 450                     "You must redirect standard output.\n");
 451                 return (1);
 452         }
 453
 454         int fd = open(filename, O_RDONLY);
 455         if (fd == -1) {
 456                 (void) fprintf(stderr,
 457                     "Error while opening file '%s': %s\n",
 458                     filename, strerror(errno));
 459                 exit(1);
 460         }
 461
 462         fletcher_4_init();
 463         zfs_redup_stream(fd, STDOUT_FILENO, verbose);
 464         fletcher_4_fini();
 465
 466         close(fd);
 467
 468         return (0);
 469 }