sbin/hammer/cmd_dedup.c

   1 /*
   2  * Copyright (c) 2010 The DragonFly Project.  All rights reserved.
   3  *
   4  * This code is derived from software contributed to The DragonFly Project
   5  * by Ilya Dryomov <idryomov@gmail.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 <libutil.h>
  36 #include <crypto/sha2/sha2.h>
  37
  38 #include "hammer.h"
  39
  40 #define DEDUP_BUF (64 * 1024)
  41
  42 /* Sorted list of block CRCs - light version for dedup-simulate */
  43 struct sim_dedup_entry_rb_tree;
  44 RB_HEAD(sim_dedup_entry_rb_tree, sim_dedup_entry) sim_dedup_tree =
  45                                         RB_INITIALIZER(&sim_dedup_tree);
  46 RB_PROTOTYPE2(sim_dedup_entry_rb_tree, sim_dedup_entry, rb_entry,
  47                 rb_sim_dedup_entry_compare, hammer_crc_t);
  48
  49 struct sim_dedup_entry {
  50         hammer_crc_t    crc;
  51         u_int64_t       ref_blks; /* number of blocks referenced */
  52         u_int64_t       ref_size; /* size of data referenced */
  53         RB_ENTRY(sim_dedup_entry) rb_entry;
  54 };
  55
  56 struct dedup_entry {
  57         struct hammer_btree_leaf_elm leaf;
  58         union {
  59                 struct {
  60                         u_int64_t ref_blks;
  61                         u_int64_t ref_size;
  62                 } de;
  63                 RB_HEAD(sha_dedup_entry_rb_tree, sha_dedup_entry) fict_root;
  64         } u;
  65         u_int8_t flags;
  66         RB_ENTRY(dedup_entry) rb_entry;
  67 };
  68
  69 #define HAMMER_DEDUP_ENTRY_FICTITIOUS   0x0001
  70
  71 struct sha_dedup_entry {
  72         struct hammer_btree_leaf_elm    leaf;
  73         u_int64_t                       ref_blks;
  74         u_int64_t                       ref_size;
  75         u_int8_t                        sha_hash[SHA256_DIGEST_LENGTH];
  76         RB_ENTRY(sha_dedup_entry)       fict_entry;
  77 };
  78
  79 /* Sorted list of HAMMER B-Tree keys */
  80 struct dedup_entry_rb_tree;
  81 struct sha_dedup_entry_rb_tree;
  82
  83 RB_HEAD(dedup_entry_rb_tree, dedup_entry) dedup_tree =
  84                                         RB_INITIALIZER(&dedup_tree);
  85 RB_PROTOTYPE2(dedup_entry_rb_tree, dedup_entry, rb_entry,
  86                 rb_dedup_entry_compare, hammer_crc_t);
  87
  88 RB_PROTOTYPE(sha_dedup_entry_rb_tree, sha_dedup_entry, fict_entry,
  89                 rb_sha_dedup_entry_compare);
  90
  91 /*
  92  * Pass2 list - contains entries that were not dedup'ed because ioctl failed
  93  */
  94 STAILQ_HEAD(, pass2_dedup_entry) pass2_dedup_queue =
  95                                 STAILQ_HEAD_INITIALIZER(pass2_dedup_queue);
  96
  97 struct pass2_dedup_entry {
  98         struct hammer_btree_leaf_elm    leaf;
  99         STAILQ_ENTRY(pass2_dedup_entry) sq_entry;
 100 };
 101
 102 #define DEDUP_PASS2     0x0001 /* process_btree_elm() mode */
 103
 104 static int SigInfoFlag;
 105 static int SigAlrmFlag;
 106 static int64_t DedupDataReads;
 107 static int64_t DedupCurrentRecords;
 108 static int64_t DedupTotalRecords;
 109 static u_int32_t DedupCrcStart;
 110 static u_int32_t DedupCrcEnd;
 111 static u_int64_t MemoryUse;
 112
 113 /* PFS global ids - we deal with just one PFS at a run */
 114 int glob_fd;
 115 struct hammer_ioc_pseudofs_rw glob_pfs;
 116
 117 /*
 118  * Global accounting variables
 119  *
 120  * Last three don't have to be 64-bit, just to be safe..
 121  */
 122 u_int64_t dedup_alloc_size = 0;
 123 u_int64_t dedup_ref_size = 0;
 124 u_int64_t dedup_skipped_size = 0;
 125 u_int64_t dedup_crc_failures = 0;
 126 u_int64_t dedup_sha_failures = 0;
 127 u_int64_t dedup_underflows = 0;
 128 u_int64_t dedup_successes_count = 0;
 129 u_int64_t dedup_successes_bytes = 0;
 130
 131 static int rb_sim_dedup_entry_compare(struct sim_dedup_entry *sim_de1,
 132                                 struct sim_dedup_entry *sim_de2);
 133 static int rb_dedup_entry_compare(struct dedup_entry *de1,
 134                                 struct dedup_entry *de2);
 135 static int rb_sha_dedup_entry_compare(struct sha_dedup_entry *sha_de1,
 136                                 struct sha_dedup_entry *sha_de2);
 137 typedef int (*scan_pfs_cb_t)(hammer_btree_leaf_elm_t scan_leaf, int flags);
 138 static void scan_pfs(char *filesystem, scan_pfs_cb_t func, const char *id);
 139 static int collect_btree_elm(hammer_btree_leaf_elm_t scan_leaf, int flags);
 140 static int count_btree_elm(hammer_btree_leaf_elm_t scan_leaf, int flags);
 141 static int process_btree_elm(hammer_btree_leaf_elm_t scan_leaf, int flags);
 142 static int upgrade_chksum(hammer_btree_leaf_elm_t leaf, u_int8_t *sha_hash);
 143 static void dump_simulated_dedup(void);
 144 static void dump_real_dedup(void);
 145 static void dedup_usage(int code);
 146
 147 RB_GENERATE2(sim_dedup_entry_rb_tree, sim_dedup_entry, rb_entry,
 148                 rb_sim_dedup_entry_compare, hammer_crc_t, crc);
 149 RB_GENERATE2(dedup_entry_rb_tree, dedup_entry, rb_entry,
 150                 rb_dedup_entry_compare, hammer_crc_t, leaf.data_crc);
 151 RB_GENERATE(sha_dedup_entry_rb_tree, sha_dedup_entry, fict_entry,
 152                 rb_sha_dedup_entry_compare);
 153
 154 static int
 155 rb_sim_dedup_entry_compare(struct sim_dedup_entry *sim_de1,
 156                         struct sim_dedup_entry *sim_de2)
 157 {
 158         if (sim_de1->crc < sim_de2->crc)
 159                 return (-1);
 160         if (sim_de1->crc > sim_de2->crc)
 161                 return (1);
 162
 163         return (0);
 164 }
 165
 166 static int
 167 rb_dedup_entry_compare(struct dedup_entry *de1, struct dedup_entry *de2)
 168 {
 169         if (de1->leaf.data_crc < de2->leaf.data_crc)
 170                 return (-1);
 171         if (de1->leaf.data_crc > de2->leaf.data_crc)
 172                 return (1);
 173
 174         return (0);
 175 }
 176
 177 static int
 178 rb_sha_dedup_entry_compare(struct sha_dedup_entry *sha_de1,
 179                         struct sha_dedup_entry *sha_de2)
 180 {
 181         unsigned long *h1 = (unsigned long *)&sha_de1->sha_hash;
 182         unsigned long *h2 = (unsigned long *)&sha_de2->sha_hash;
 183         int i;
 184
 185         for (i = 0; i < SHA256_DIGEST_LENGTH / (int)sizeof(unsigned long); ++i) {
 186                 if (h1[i] < h2[i])
 187                         return (-1);
 188                 if (h1[i] > h2[i])
 189                         return (1);
 190         }
 191
 192         return (0);
 193 }
 194
 195 /*
 196  * dedup-simulate <filesystem>
 197  */
 198 void
 199 hammer_cmd_dedup_simulate(char **av, int ac)
 200 {
 201         struct sim_dedup_entry *sim_de;
 202
 203         if (ac != 1)
 204                 dedup_usage(1);
 205
 206         glob_fd = getpfs(&glob_pfs, av[0]);
 207
 208         /*
 209          * Collection passes (memory limited)
 210          */
 211         printf("Dedup-simulate running\n");
 212         do {
 213                 DedupCrcStart = DedupCrcEnd;
 214                 DedupCrcEnd = 0;
 215                 MemoryUse = 0;
 216
 217                 if (VerboseOpt) {
 218                         printf("B-Tree pass  crc-range %08x-max\n",
 219                                 DedupCrcStart);
 220                         fflush(stdout);
 221                 }
 222                 scan_pfs(av[0], collect_btree_elm, "simu-pass");
 223
 224                 if (VerboseOpt >= 2)
 225                         dump_simulated_dedup();
 226
 227                 /*
 228                  * Calculate simulated dedup ratio and get rid of the tree
 229                  */
 230                 while ((sim_de = RB_ROOT(&sim_dedup_tree)) != NULL) {
 231                         assert(sim_de->ref_blks != 0);
 232                         dedup_ref_size += sim_de->ref_size;
 233                         dedup_alloc_size += sim_de->ref_size / sim_de->ref_blks;
 234
 235                         RB_REMOVE(sim_dedup_entry_rb_tree, &sim_dedup_tree, sim_de);
 236                         free(sim_de);
 237                 }
 238                 if (DedupCrcEnd && VerboseOpt == 0)
 239                         printf(".");
 240         } while (DedupCrcEnd);
 241
 242         printf("Dedup-simulate %s succeeded\n", av[0]);
 243         relpfs(glob_fd, &glob_pfs);
 244
 245         printf("Simulated dedup ratio = %.2f\n",
 246             (dedup_alloc_size != 0) ?
 247                 (double)dedup_ref_size / dedup_alloc_size : 0);
 248 }
 249
 250 /*
 251  * dedup <filesystem>
 252  */
 253 void
 254 hammer_cmd_dedup(char **av, int ac)
 255 {
 256         struct dedup_entry *de;
 257         struct sha_dedup_entry *sha_de;
 258         struct pass2_dedup_entry *pass2_de;
 259         char *tmp;
 260         char buf[8];
 261         int needfree = 0;
 262
 263         if (TimeoutOpt > 0)
 264                 alarm(TimeoutOpt);
 265
 266         if (ac != 1)
 267                 dedup_usage(1);
 268
 269         STAILQ_INIT(&pass2_dedup_queue);
 270
 271         glob_fd = getpfs(&glob_pfs, av[0]);
 272
 273         /*
 274          * A cycle file is _required_ for resuming dedup after the timeout
 275          * specified with -t has expired. If no -c option, then place a
 276          * .dedup.cycle file either in the PFS snapshots directory or in
 277          * the default snapshots directory.
 278          */
 279         if (!CyclePath) {
 280                 if (glob_pfs.ondisk->snapshots[0] != '/')
 281                         asprintf(&tmp, "%s/%s/.dedup.cycle",
 282                             SNAPSHOTS_BASE, av[0]);
 283                 else
 284                         asprintf(&tmp, "%s/.dedup.cycle",
 285                             glob_pfs.ondisk->snapshots);
 286                 CyclePath = tmp;
 287                 needfree = 1;
 288         }
 289
 290         /*
 291          * Pre-pass to cache the btree
 292          */
 293         scan_pfs(av[0], count_btree_elm, "pre-pass ");
 294         DedupTotalRecords = DedupCurrentRecords;
 295
 296         /*
 297          * Collection passes (memory limited)
 298          */
 299         printf("Dedup running\n");
 300         do {
 301                 DedupCrcStart = DedupCrcEnd;
 302                 DedupCrcEnd = 0;
 303                 MemoryUse = 0;
 304
 305                 if (VerboseOpt) {
 306                         printf("B-Tree pass  crc-range %08x-max\n",
 307                                 DedupCrcStart);
 308                         fflush(stdout);
 309                 }
 310                 scan_pfs(av[0], process_btree_elm, "main-pass");
 311
 312                 while ((pass2_de = STAILQ_FIRST(&pass2_dedup_queue)) != NULL) {
 313                         if (process_btree_elm(&pass2_de->leaf, DEDUP_PASS2))
 314                                 dedup_skipped_size -= pass2_de->leaf.data_len;
 315
 316                         STAILQ_REMOVE_HEAD(&pass2_dedup_queue, sq_entry);
 317                         free(pass2_de);
 318                 }
 319                 assert(STAILQ_EMPTY(&pass2_dedup_queue));
 320
 321                 if (VerboseOpt >= 2)
 322                         dump_real_dedup();
 323
 324                 /*
 325                  * Calculate dedup ratio and get rid of the trees
 326                  */
 327                 while ((de = RB_ROOT(&dedup_tree)) != NULL) {
 328                         if (de->flags & HAMMER_DEDUP_ENTRY_FICTITIOUS) {
 329                                 while ((sha_de = RB_ROOT(&de->u.fict_root)) != NULL) {
 330                                         assert(sha_de->ref_blks != 0);
 331                                         dedup_ref_size += sha_de->ref_size;
 332                                         dedup_alloc_size += sha_de->ref_size / sha_de->ref_blks;
 333
 334                                         RB_REMOVE(sha_dedup_entry_rb_tree,
 335                                                         &de->u.fict_root, sha_de);
 336                                         free(sha_de);
 337                                 }
 338                                 assert(RB_EMPTY(&de->u.fict_root));
 339                         } else {
 340                                 assert(de->u.de.ref_blks != 0);
 341                                 dedup_ref_size += de->u.de.ref_size;
 342                                 dedup_alloc_size += de->u.de.ref_size / de->u.de.ref_blks;
 343                         }
 344
 345                         RB_REMOVE(dedup_entry_rb_tree, &dedup_tree, de);
 346                         free(de);
 347                 }
 348                 assert(RB_EMPTY(&dedup_tree));
 349                 if (DedupCrcEnd && VerboseOpt == 0)
 350                         printf(".");
 351         } while (DedupCrcEnd);
 352
 353         printf("Dedup %s succeeded\n", av[0]);
 354         relpfs(glob_fd, &glob_pfs);
 355
 356         humanize_unsigned(buf, sizeof(buf), dedup_ref_size, "B", 1024);
 357         printf("Dedup ratio = %.2f (in this run)\n"
 358                "    %8s referenced\n",
 359                ((dedup_alloc_size != 0) ?
 360                         (double)dedup_ref_size / dedup_alloc_size : 0),
 361                buf
 362         );
 363         humanize_unsigned(buf, sizeof(buf), dedup_alloc_size, "B", 1024);
 364         printf("    %8s allocated\n", buf);
 365         humanize_unsigned(buf, sizeof(buf), dedup_skipped_size, "B", 1024);
 366         printf("    %8s skipped\n", buf);
 367         printf("    %8jd CRC collisions\n"
 368                "    %8jd SHA collisions\n"
 369                "    %8jd big-block underflows\n"
 370                "    %8jd new dedup records\n"
 371                "    %8jd new dedup bytes\n",
 372                (intmax_t)dedup_crc_failures,
 373                (intmax_t)dedup_sha_failures,
 374                (intmax_t)dedup_underflows,
 375                (intmax_t)dedup_successes_count,
 376                (intmax_t)dedup_successes_bytes
 377         );
 378
 379         /* Once completed remove cycle file */
 380         hammer_reset_cycle();
 381
 382         /* We don't want to mess up with other directives */
 383         if (needfree) {
 384                 free(tmp);
 385                 CyclePath = NULL;
 386         }
 387 }
 388
 389 static int
 390 count_btree_elm(hammer_btree_leaf_elm_t scan_leaf __unused, int flags __unused)
 391 {
 392         return(1);
 393 }
 394
 395 static int
 396 collect_btree_elm(hammer_btree_leaf_elm_t scan_leaf, int flags __unused)
 397 {
 398         struct sim_dedup_entry *sim_de;
 399
 400         /*
 401          * If we are using too much memory we have to clean some out, which
 402          * will cause the run to use multiple passes.  Be careful of integer
 403          * overflows!
 404          */
 405         if (MemoryUse > MemoryLimit) {
 406                 DedupCrcEnd = DedupCrcStart +
 407                               (u_int32_t)(DedupCrcEnd - DedupCrcStart - 1) / 2;
 408                 if (VerboseOpt) {
 409                         printf("memory limit  crc-range %08x-%08x\n",
 410                                 DedupCrcStart, DedupCrcEnd);
 411                         fflush(stdout);
 412                 }
 413                 for (;;) {
 414                         sim_de = RB_MAX(sim_dedup_entry_rb_tree,
 415                                         &sim_dedup_tree);
 416                         if (sim_de == NULL || sim_de->crc < DedupCrcEnd)
 417                                 break;
 418                         RB_REMOVE(sim_dedup_entry_rb_tree,
 419                                   &sim_dedup_tree, sim_de);
 420                         MemoryUse -= sizeof(*sim_de);
 421                         free(sim_de);
 422                 }
 423         }
 424
 425         /*
 426          * Collect statistics based on the CRC only, do not try to read
 427          * any data blocks or run SHA hashes.
 428          */
 429         sim_de = RB_LOOKUP(sim_dedup_entry_rb_tree, &sim_dedup_tree,
 430                            scan_leaf->data_crc);
 431
 432         if (sim_de == NULL) {
 433                 sim_de = calloc(sizeof(*sim_de), 1);
 434                 sim_de->crc = scan_leaf->data_crc;
 435                 RB_INSERT(sim_dedup_entry_rb_tree, &sim_dedup_tree, sim_de);
 436                 MemoryUse += sizeof(*sim_de);
 437         }
 438
 439         sim_de->ref_blks += 1;
 440         sim_de->ref_size += scan_leaf->data_len;
 441         return (1);
 442 }
 443
 444 static __inline int
 445 validate_dedup_pair(hammer_btree_leaf_elm_t p, hammer_btree_leaf_elm_t q)
 446 {
 447         if ((p->data_offset & HAMMER_OFF_ZONE_MASK) !=
 448             (q->data_offset & HAMMER_OFF_ZONE_MASK)) {
 449                 return (1);
 450         }
 451         if (p->data_len != q->data_len) {
 452                 return (1);
 453         }
 454
 455         return (0);
 456 }
 457
 458 #define DEDUP_TECH_FAILURE      1
 459 #define DEDUP_CMP_FAILURE       2
 460 #define DEDUP_INVALID_ZONE      3
 461 #define DEDUP_UNDERFLOW         4
 462 #define DEDUP_VERS_FAILURE      5
 463
 464 static __inline int
 465 deduplicate(hammer_btree_leaf_elm_t p, hammer_btree_leaf_elm_t q)
 466 {
 467         struct hammer_ioc_dedup dedup;
 468
 469         bzero(&dedup, sizeof(dedup));
 470
 471         /*
 472          * If data_offset fields are the same there is no need to run ioctl,
 473          * candidate is already dedup'ed.
 474          */
 475         if (p->data_offset == q->data_offset) {
 476                 return (0);
 477         }
 478
 479         dedup.elm1 = p->base;
 480         dedup.elm2 = q->base;
 481         RunningIoctl = 1;
 482         if (ioctl(glob_fd, HAMMERIOC_DEDUP, &dedup) < 0) {
 483                 if (errno == EOPNOTSUPP) {
 484                         /* must be at least version 5 */
 485                         return (DEDUP_VERS_FAILURE);
 486                 }
 487                 /* Technical failure - locking or w/e */
 488                 return (DEDUP_TECH_FAILURE);
 489         }
 490         if (dedup.head.flags & HAMMER_IOC_DEDUP_CMP_FAILURE) {
 491                 return (DEDUP_CMP_FAILURE);
 492         }
 493         if (dedup.head.flags & HAMMER_IOC_DEDUP_INVALID_ZONE) {
 494                 return (DEDUP_INVALID_ZONE);
 495         }
 496         if (dedup.head.flags & HAMMER_IOC_DEDUP_UNDERFLOW) {
 497                 return (DEDUP_UNDERFLOW);
 498         }
 499         RunningIoctl = 0;
 500         ++dedup_successes_count;
 501         dedup_successes_bytes += p->data_len;
 502         return (0);
 503 }
 504
 505 static int
 506 process_btree_elm(hammer_btree_leaf_elm_t scan_leaf, int flags)
 507 {
 508         struct dedup_entry *de;
 509         struct sha_dedup_entry *sha_de, temp;
 510         struct pass2_dedup_entry *pass2_de;
 511         int error;
 512
 513         /*
 514          * If we are using too much memory we have to clean some out, which
 515          * will cause the run to use multiple passes.  Be careful of integer
 516          * overflows!
 517          */
 518         while (MemoryUse > MemoryLimit) {
 519                 DedupCrcEnd = DedupCrcStart +
 520                               (u_int32_t)(DedupCrcEnd - DedupCrcStart - 1) / 2;
 521                 if (VerboseOpt) {
 522                         printf("memory limit  crc-range %08x-%08x\n",
 523                                 DedupCrcStart, DedupCrcEnd);
 524                         fflush(stdout);
 525                 }
 526
 527                 for (;;) {
 528                         de = RB_MAX(dedup_entry_rb_tree, &dedup_tree);
 529                         if (de == NULL || de->leaf.data_crc < DedupCrcEnd)
 530                                 break;
 531                         if (de->flags & HAMMER_DEDUP_ENTRY_FICTITIOUS) {
 532                                 while ((sha_de = RB_ROOT(&de->u.fict_root)) !=
 533                                        NULL) {
 534                                         RB_REMOVE(sha_dedup_entry_rb_tree,
 535                                                   &de->u.fict_root, sha_de);
 536                                         MemoryUse -= sizeof(*sha_de);
 537                                         free(sha_de);
 538                                 }
 539                         }
 540                         RB_REMOVE(dedup_entry_rb_tree, &dedup_tree, de);
 541                         MemoryUse -= sizeof(*de);
 542                         free(de);
 543                 }
 544         }
 545
 546         /*
 547          * Collect statistics based on the CRC.  Colliding CRCs usually
 548          * cause a SHA sub-tree to be created under the de.
 549          *
 550          * Trivial case if de not found.
 551          */
 552         de = RB_LOOKUP(dedup_entry_rb_tree, &dedup_tree, scan_leaf->data_crc);
 553         if (de == NULL) {
 554                 de = calloc(sizeof(*de), 1);
 555                 de->leaf = *scan_leaf;
 556                 RB_INSERT(dedup_entry_rb_tree, &dedup_tree, de);
 557                 MemoryUse += sizeof(*de);
 558                 goto upgrade_stats;
 559         }
 560
 561         /*
 562          * Found entry in CRC tree
 563          */
 564         if (de->flags & HAMMER_DEDUP_ENTRY_FICTITIOUS) {
 565                 /*
 566                  * Optimize the case where a CRC failure results in multiple
 567                  * SHA entries.  If we unconditionally issue a data-read a
 568                  * degenerate situation where a colliding CRC's second SHA
 569                  * entry contains the lion's share of the deduplication
 570                  * candidates will result in excessive data block reads.
 571                  *
 572                  * Deal with the degenerate case by looking for a matching
 573                  * data_offset/data_len in the SHA elements we already have
 574                  * before reading the data block and generating a new SHA.
 575                  */
 576                 RB_FOREACH(sha_de, sha_dedup_entry_rb_tree, &de->u.fict_root) {
 577                         if (sha_de->leaf.data_offset ==
 578                                                 scan_leaf->data_offset &&
 579                             sha_de->leaf.data_len == scan_leaf->data_len) {
 580                                 memcpy(temp.sha_hash, sha_de->sha_hash,
 581                                         SHA256_DIGEST_LENGTH);
 582                                 break;
 583                         }
 584                 }
 585
 586                 /*
 587                  * Entry in CRC tree is fictitious, so we already had problems
 588                  * with this CRC. Upgrade (compute SHA) the candidate and
 589                  * dive into SHA subtree. If upgrade fails insert the candidate
 590                  * into Pass2 list (it will be processed later).
 591                  */
 592                 if (sha_de == NULL) {
 593                         if (upgrade_chksum(scan_leaf, temp.sha_hash))
 594                                 goto pass2_insert;
 595
 596                         sha_de = RB_FIND(sha_dedup_entry_rb_tree,
 597                                          &de->u.fict_root, &temp);
 598                 }
 599
 600                 /*
 601                  * Nothing in SHA subtree so far, so this is a new
 602                  * 'dataset'. Insert new entry into SHA subtree.
 603                  */
 604                 if (sha_de == NULL) {
 605                         sha_de = calloc(sizeof(*sha_de), 1);
 606                         sha_de->leaf = *scan_leaf;
 607                         memcpy(sha_de->sha_hash, temp.sha_hash,
 608                                SHA256_DIGEST_LENGTH);
 609                         RB_INSERT(sha_dedup_entry_rb_tree, &de->u.fict_root,
 610                                   sha_de);
 611                         MemoryUse += sizeof(*sha_de);
 612                         goto upgrade_stats_sha;
 613                 }
 614
 615                 /*
 616                  * Found entry in SHA subtree, it means we have a potential
 617                  * dedup pair. Validate it (zones have to match and data_len
 618                  * field have to be the same too. If validation fails, treat
 619                  * it as a SHA collision (jump to sha256_failure).
 620                  */
 621                 if (validate_dedup_pair(&sha_de->leaf, scan_leaf))
 622                         goto sha256_failure;
 623
 624                 /*
 625                  * We have a valid dedup pair (SHA match, validated).
 626                  *
 627                  * In case of technical failure (dedup pair was good, but
 628                  * ioctl failed anyways) insert the candidate into Pass2 list
 629                  * (we will try to dedup it after we are done with the rest of
 630                  * the tree).
 631                  *
 632                  * If ioctl fails because either of blocks is in the non-dedup
 633                  * zone (we can dedup only in LARGE_DATA and SMALL_DATA) don't
 634                  * bother with the candidate and terminate early.
 635                  *
 636                  * If ioctl fails because of big-block underflow replace the
 637                  * leaf node that found dedup entry represents with scan_leaf.
 638                  */
 639                 error = deduplicate(&sha_de->leaf, scan_leaf);
 640                 switch(error) {
 641                 case 0:
 642                         goto upgrade_stats_sha;
 643                 case DEDUP_TECH_FAILURE:
 644                         goto pass2_insert;
 645                 case DEDUP_CMP_FAILURE:
 646                         goto sha256_failure;
 647                 case DEDUP_INVALID_ZONE:
 648                         goto terminate_early;
 649                 case DEDUP_UNDERFLOW:
 650                         ++dedup_underflows;
 651                         sha_de->leaf = *scan_leaf;
 652                         memcpy(sha_de->sha_hash, temp.sha_hash,
 653                                 SHA256_DIGEST_LENGTH);
 654                         goto upgrade_stats_sha;
 655                 case DEDUP_VERS_FAILURE:
 656                         fprintf(stderr,
 657                                 "HAMMER filesystem must be at least "
 658                                 "version 5 to dedup\n");
 659                         exit (1);
 660                 default:
 661                         fprintf(stderr, "Unknown error\n");
 662                         goto terminate_early;
 663                 }
 664
 665                 /*
 666                  * Ooh la la.. SHA-256 collision. Terminate early, there's
 667                  * nothing we can do here.
 668                  */
 669 sha256_failure:
 670                 ++dedup_sha_failures;
 671                 goto terminate_early;
 672         } else {
 673                 /*
 674                  * Candidate CRC is good for now (we found an entry in CRC
 675                  * tree and it's not fictitious). This means we have a
 676                  * potential dedup pair.
 677                  */
 678                 if (validate_dedup_pair(&de->leaf, scan_leaf))
 679                         goto crc_failure;
 680
 681                 /*
 682                  * We have a valid dedup pair (CRC match, validated)
 683                  */
 684                 error = deduplicate(&de->leaf, scan_leaf);
 685                 switch(error) {
 686                 case 0:
 687                         goto upgrade_stats;
 688                 case DEDUP_TECH_FAILURE:
 689                         goto pass2_insert;
 690                 case DEDUP_CMP_FAILURE:
 691                         goto crc_failure;
 692                 case DEDUP_INVALID_ZONE:
 693                         goto terminate_early;
 694                 case DEDUP_UNDERFLOW:
 695                         ++dedup_underflows;
 696                         de->leaf = *scan_leaf;
 697                         goto upgrade_stats;
 698                 case DEDUP_VERS_FAILURE:
 699                         fprintf(stderr,
 700                                 "HAMMER filesystem must be at least "
 701                                 "version 5 to dedup\n");
 702                         exit (1);
 703                 default:
 704                         fprintf(stderr, "Unknown error\n");
 705                         goto terminate_early;
 706                 }
 707
 708 crc_failure:
 709                 /*
 710                  * We got a CRC collision - either ioctl failed because of
 711                  * the comparison failure or validation of the potential
 712                  * dedup pair went bad. In all cases insert both blocks
 713                  * into SHA subtree (this requires checksum upgrade) and mark
 714                  * entry that corresponds to this CRC in the CRC tree
 715                  * fictitious, so that all futher operations with this CRC go
 716                  * through SHA subtree.
 717                  */
 718                 ++dedup_crc_failures;
 719
 720                 /*
 721                  * Insert block that was represented by now fictitious dedup
 722                  * entry (create a new SHA entry and preserve stats of the
 723                  * old CRC one). If checksum upgrade fails insert the
 724                  * candidate into Pass2 list and return - keep both trees
 725                  * unmodified.
 726                  */
 727                 sha_de = calloc(sizeof(*sha_de), 1);
 728                 sha_de->leaf = de->leaf;
 729                 sha_de->ref_blks = de->u.de.ref_blks;
 730                 sha_de->ref_size = de->u.de.ref_size;
 731                 if (upgrade_chksum(&sha_de->leaf, sha_de->sha_hash)) {
 732                         free(sha_de);
 733                         goto pass2_insert;
 734                 }
 735                 MemoryUse += sizeof(*sha_de);
 736
 737                 RB_INIT(&de->u.fict_root);
 738                 /*
 739                  * Here we can insert without prior checking because the tree
 740                  * is empty at this point
 741                  */
 742                 RB_INSERT(sha_dedup_entry_rb_tree, &de->u.fict_root, sha_de);
 743
 744                 /*
 745                  * Mark entry in CRC tree fictitious
 746                  */
 747                 de->flags |= HAMMER_DEDUP_ENTRY_FICTITIOUS;
 748
 749                 /*
 750                  * Upgrade checksum of the candidate and insert it into
 751                  * SHA subtree. If upgrade fails insert the candidate into
 752                  * Pass2 list.
 753                  */
 754                 if (upgrade_chksum(scan_leaf, temp.sha_hash)) {
 755                         goto pass2_insert;
 756                 }
 757                 sha_de = RB_FIND(sha_dedup_entry_rb_tree, &de->u.fict_root,
 758                                  &temp);
 759                 if (sha_de != NULL)
 760                         /* There is an entry with this SHA already, but the only
 761                          * RB-tree element at this point is that entry we just
 762                          * added. We know for sure these blocks are different
 763                          * (this is crc_failure branch) so treat it as SHA
 764                          * collision.
 765                          */
 766                         goto sha256_failure;
 767
 768                 sha_de = calloc(sizeof(*sha_de), 1);
 769                 sha_de->leaf = *scan_leaf;
 770                 memcpy(sha_de->sha_hash, temp.sha_hash, SHA256_DIGEST_LENGTH);
 771                 RB_INSERT(sha_dedup_entry_rb_tree, &de->u.fict_root, sha_de);
 772                 MemoryUse += sizeof(*sha_de);
 773                 goto upgrade_stats_sha;
 774         }
 775
 776 upgrade_stats:
 777         de->u.de.ref_blks += 1;
 778         de->u.de.ref_size += scan_leaf->data_len;
 779         return (1);
 780
 781 upgrade_stats_sha:
 782         sha_de->ref_blks += 1;
 783         sha_de->ref_size += scan_leaf->data_len;
 784         return (1);
 785
 786 pass2_insert:
 787         /*
 788          * If in pass2 mode don't insert anything, fall through to
 789          * terminate_early
 790          */
 791         if ((flags & DEDUP_PASS2) == 0) {
 792                 pass2_de = calloc(sizeof(*pass2_de), 1);
 793                 pass2_de->leaf = *scan_leaf;
 794                 STAILQ_INSERT_TAIL(&pass2_dedup_queue, pass2_de, sq_entry);
 795                 dedup_skipped_size += scan_leaf->data_len;
 796                 return (1);
 797         }
 798
 799 terminate_early:
 800         /*
 801          * Early termination path. Fixup stats.
 802          */
 803         dedup_alloc_size += scan_leaf->data_len;
 804         dedup_ref_size += scan_leaf->data_len;
 805         return (0);
 806 }
 807
 808 static int
 809 upgrade_chksum(hammer_btree_leaf_elm_t leaf, u_int8_t *sha_hash)
 810 {
 811         struct hammer_ioc_data data;
 812         char *buf = malloc(DEDUP_BUF);
 813         SHA256_CTX ctx;
 814         int error;
 815
 816         bzero(&data, sizeof(data));
 817         data.elm = leaf->base;
 818         data.ubuf = buf;
 819         data.size = DEDUP_BUF;
 820
 821         error = 0;
 822         if (ioctl(glob_fd, HAMMERIOC_GET_DATA, &data) < 0) {
 823                 fprintf(stderr, "Get-data failed: %s\n", strerror(errno));
 824                 error = 1;
 825                 goto done;
 826         }
 827         DedupDataReads += leaf->data_len;
 828
 829         if (data.leaf.data_len != leaf->data_len) {
 830                 error = 1;
 831                 goto done;
 832         }
 833
 834         if (data.leaf.base.btype == HAMMER_BTREE_TYPE_RECORD &&
 835             data.leaf.base.rec_type == HAMMER_RECTYPE_DATA) {
 836                 SHA256_Init(&ctx);
 837                 SHA256_Update(&ctx, (void *)buf, data.leaf.data_len);
 838                 SHA256_Final(sha_hash, &ctx);
 839         }
 840
 841 done:
 842         free(buf);
 843         return (error);
 844 }
 845
 846 static void
 847 sigAlrm(int signo __unused)
 848 {
 849         SigAlrmFlag = 1;
 850 }
 851
 852 static void
 853 sigInfo(int signo __unused)
 854 {
 855         SigInfoFlag = 1;
 856 }
 857
 858 static void
 859 scan_pfs(char *filesystem, scan_pfs_cb_t func, const char *id)
 860 {
 861         struct hammer_ioc_mirror_rw mirror;
 862         hammer_ioc_mrecord_any_t mrec;
 863         struct hammer_btree_leaf_elm elm;
 864         char *buf = malloc(DEDUP_BUF);
 865         char buf1[8];
 866         char buf2[8];
 867         int offset, bytes;
 868
 869         SigInfoFlag = 0;
 870         DedupDataReads = 0;
 871         DedupCurrentRecords = 0;
 872         signal(SIGINFO, sigInfo);
 873         signal(SIGALRM, sigAlrm);
 874
 875         /*
 876          * Deduplication happens per element so hammer(8) is in full
 877          * control of the ioctl()s to actually perform it. SIGALRM
 878          * needs to be handled within hammer(8) but a checkpoint
 879          * is needed for resuming. Use cycle file for that.
 880          *
 881          * Try to obtain the previous obj_id from the cycle file and
 882          * if not available just start from the beginning.
 883          */
 884         bzero(&mirror, sizeof(mirror));
 885         hammer_key_beg_init(&mirror.key_beg);
 886         hammer_get_cycle(&mirror.key_beg, &mirror.tid_beg);
 887
 888         if (mirror.key_beg.obj_id != (int64_t)HAMMER_MIN_OBJID) {
 889                 if (VerboseOpt)
 890                         fprintf(stderr, "%s: mirror-read: Resuming at object %016jx\n",
 891                             id, (uintmax_t)mirror.key_beg.obj_id);
 892         }
 893
 894         hammer_key_end_init(&mirror.key_end);
 895
 896         mirror.tid_beg = glob_pfs.ondisk->sync_beg_tid;
 897         mirror.tid_end = glob_pfs.ondisk->sync_end_tid;
 898         mirror.head.flags |= HAMMER_IOC_MIRROR_NODATA; /* we want only keys */
 899         mirror.ubuf = buf;
 900         mirror.size = DEDUP_BUF;
 901         mirror.pfs_id = glob_pfs.pfs_id;
 902         mirror.shared_uuid = glob_pfs.ondisk->shared_uuid;
 903
 904         if (VerboseOpt && DedupCrcStart == 0) {
 905                 printf("%s %s: objspace %016jx:%04x %016jx:%04x\n",
 906                         id, filesystem,
 907                         (uintmax_t)mirror.key_beg.obj_id,
 908                         mirror.key_beg.localization,
 909                         (uintmax_t)mirror.key_end.obj_id,
 910                         mirror.key_end.localization);
 911                 printf("%s %s: pfs_id %d\n",
 912                         id, filesystem, glob_pfs.pfs_id);
 913         }
 914         fflush(stdout);
 915         fflush(stderr);
 916
 917         do {
 918                 mirror.count = 0;
 919                 mirror.pfs_id = glob_pfs.pfs_id;
 920                 mirror.shared_uuid = glob_pfs.ondisk->shared_uuid;
 921                 if (ioctl(glob_fd, HAMMERIOC_MIRROR_READ, &mirror) < 0) {
 922                         fprintf(stderr, "Mirror-read %s failed: %s\n",
 923                                 filesystem, strerror(errno));
 924                         exit(1);
 925                 }
 926                 if (mirror.head.flags & HAMMER_IOC_HEAD_ERROR) {
 927                         fprintf(stderr, "Mirror-read %s fatal error %d\n",
 928                                 filesystem, mirror.head.error);
 929                         exit(1);
 930                 }
 931                 if (mirror.count) {
 932                         offset = 0;
 933                         while (offset < mirror.count) {
 934                                 mrec = (void *)((char *)buf + offset);
 935                                 bytes = HAMMER_HEAD_DOALIGN(mrec->head.rec_size);
 936                                 if (offset + bytes > mirror.count) {
 937                                         fprintf(stderr, "Misaligned record\n");
 938                                         exit(1);
 939                                 }
 940                                 assert((mrec->head.type &
 941                                        HAMMER_MRECF_TYPE_MASK) ==
 942                                        HAMMER_MREC_TYPE_REC);
 943                                 offset += bytes;
 944                                 elm = mrec->rec.leaf;
 945                                 if (elm.base.btype != HAMMER_BTREE_TYPE_RECORD)
 946                                         continue;
 947                                 if (elm.base.rec_type != HAMMER_RECTYPE_DATA)
 948                                         continue;
 949                                 ++DedupCurrentRecords;
 950                                 if (DedupCrcStart != DedupCrcEnd) {
 951                                         if (elm.data_crc < DedupCrcStart)
 952                                                 continue;
 953                                         if (DedupCrcEnd &&
 954                                             elm.data_crc >= DedupCrcEnd) {
 955                                                 continue;
 956                                         }
 957                                 }
 958                                 func(&elm, 0);
 959                         }
 960                 }
 961                 mirror.key_beg = mirror.key_cur;
 962                 if (DidInterrupt || SigAlrmFlag) {
 963                         if (VerboseOpt)
 964                                 fprintf(stderr, "%s\n",
 965                                     (DidInterrupt ? "Interrupted" : "Timeout"));
 966                         hammer_set_cycle(&mirror.key_cur, mirror.tid_beg);
 967                         if (VerboseOpt)
 968                                 fprintf(stderr, "Cyclefile %s updated for "
 969                                     "continuation\n", CyclePath);
 970                         exit(1);
 971                 }
 972                 if (SigInfoFlag) {
 973                         if (DedupTotalRecords) {
 974                                 humanize_unsigned(buf1, sizeof(buf1),
 975                                                   DedupDataReads,
 976                                                   "B", 1024);
 977                                 humanize_unsigned(buf2, sizeof(buf2),
 978                                                   dedup_successes_bytes,
 979                                                   "B", 1024);
 980                                 fprintf(stderr, "%s count %7jd/%jd "
 981                                                 "(%02d.%02d%%) "
 982                                                 "ioread %s newddup %s\n",
 983                                         id,
 984                                         (intmax_t)DedupCurrentRecords,
 985                                         (intmax_t)DedupTotalRecords,
 986                                         (int)(DedupCurrentRecords * 100 /
 987                                                 DedupTotalRecords),
 988                                         (int)(DedupCurrentRecords * 10000 /
 989                                                 DedupTotalRecords % 100),
 990                                         buf1, buf2);
 991                         } else {
 992                                 fprintf(stderr, "%s count %-7jd\n",
 993                                         id,
 994                                         (intmax_t)DedupCurrentRecords);
 995                         }
 996                         SigInfoFlag = 0;
 997                 }
 998         } while (mirror.count != 0);
 999
1000         signal(SIGINFO, SIG_IGN);
1001         signal(SIGALRM, SIG_IGN);
1002
1003         free(buf);
1004 }
1005
1006 static void
1007 dump_simulated_dedup(void)
1008 {
1009         struct sim_dedup_entry *sim_de;
1010
1011         printf("=== Dumping simulated dedup entries:\n");
1012         RB_FOREACH(sim_de, sim_dedup_entry_rb_tree, &sim_dedup_tree) {
1013                 printf("\tcrc=%08x cnt=%ju size=%ju\n",
1014                         sim_de->crc,
1015                         (intmax_t)sim_de->ref_blks,
1016                         (intmax_t)sim_de->ref_size);
1017         }
1018         printf("end of dump ===\n");
1019 }
1020
1021 static void
1022 dump_real_dedup(void)
1023 {
1024         struct dedup_entry *de;
1025         struct sha_dedup_entry *sha_de;
1026         int i;
1027
1028         printf("=== Dumping dedup entries:\n");
1029         RB_FOREACH(de, dedup_entry_rb_tree, &dedup_tree) {
1030                 if (de->flags & HAMMER_DEDUP_ENTRY_FICTITIOUS) {
1031                         printf("\tcrc=%08x fictitious\n", de->leaf.data_crc);
1032
1033                         RB_FOREACH(sha_de, sha_dedup_entry_rb_tree, &de->u.fict_root) {
1034                                 printf("\t\tcrc=%08x cnt=%ju size=%ju\n\t"
1035                                        "\t\tsha=",
1036                                        sha_de->leaf.data_crc,
1037                                        (intmax_t)sha_de->ref_blks,
1038                                        (intmax_t)sha_de->ref_size);
1039                                 for (i = 0; i < SHA256_DIGEST_LENGTH; ++i)
1040                                         printf("%02x", sha_de->sha_hash[i]);
1041                                 printf("\n");
1042                         }
1043                 } else {
1044                         printf("\tcrc=%08x cnt=%ju size=%ju\n",
1045                                de->leaf.data_crc,
1046                                (intmax_t)de->u.de.ref_blks,
1047                                (intmax_t)de->u.de.ref_size);
1048                 }
1049         }
1050         printf("end of dump ===\n");
1051 }
1052
1053 static void
1054 dedup_usage(int code)
1055 {
1056         fprintf(stderr,
1057                 "hammer dedup-simulate <filesystem>\n"
1058                 "hammer dedup <filesystem>\n"
1059         );
1060         exit(code);
1061 }