sys/vfs/hammer2/hammer2_freemap.c

   1 /*
   2  * Copyright (c) 2011-2018 The DragonFly Project.  All rights reserved.
   3  *
   4  * This code is derived from software contributed to The DragonFly Project
   5  * by Matthew Dillon <dillon@dragonflybsd.org>
   6  * by Venkatesh Srinivas <vsrinivas@dragonflybsd.org>
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  *
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in
  16  *    the documentation and/or other materials provided with the
  17  *    distribution.
  18  * 3. Neither the name of The DragonFly Project nor the names of its
  19  *    contributors may be used to endorse or promote products derived
  20  *    from this software without specific, prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  23  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  24  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  25  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  26  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  27  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  28  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  29  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  30  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  31  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  32  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  */
  35 #include <sys/param.h>
  36 #include <sys/systm.h>
  37 #include <sys/kernel.h>
  38 #include <sys/fcntl.h>
  39 #include <sys/buf.h>
  40 #include <sys/proc.h>
  41 #include <sys/namei.h>
  42 #include <sys/mount.h>
  43 #include <sys/vnode.h>
  44 #include <sys/mountctl.h>
  45
  46 #include "hammer2.h"
  47
  48 #define FREEMAP_DEBUG   0
  49
  50 struct hammer2_fiterate {
  51         hammer2_off_t   bpref;
  52         hammer2_off_t   bnext;
  53         int             loops;
  54         int             relaxed;
  55 };
  56
  57 typedef struct hammer2_fiterate hammer2_fiterate_t;
  58
  59 static int hammer2_freemap_try_alloc(hammer2_chain_t **parentp,
  60                         hammer2_blockref_t *bref, int radix,
  61                         hammer2_fiterate_t *iter, hammer2_tid_t mtid);
  62 static void hammer2_freemap_init(hammer2_dev_t *hmp,
  63                         hammer2_key_t key, hammer2_chain_t *chain);
  64 static int hammer2_bmap_alloc(hammer2_dev_t *hmp,
  65                         hammer2_bmap_data_t *bmap, uint16_t class,
  66                         int n, int sub_key, int radix, hammer2_key_t *basep);
  67 static int hammer2_freemap_iterate(hammer2_chain_t **parentp,
  68                         hammer2_chain_t **chainp,
  69                         hammer2_fiterate_t *iter);
  70
  71 static __inline
  72 int
  73 hammer2_freemapradix(int radix)
  74 {
  75         return(radix);
  76 }
  77
  78 /*
  79  * Calculate the device offset for the specified FREEMAP_NODE or FREEMAP_LEAF
  80  * bref.  Return a combined media offset and physical size radix.  Freemap
  81  * chains use fixed storage offsets in the 4MB reserved area at the
  82  * beginning of each 2GB zone
  83  *
  84  * XXX I made a mistake and made the reserved area begin at each LEVEL1 zone,
  85  *     which is on a 1GB demark.  This will eat a little more space but for
  86  *     now we retain compatibility and make FMZONEBASE every 1GB
  87  *
  88  *     (see same thing in hammer2_bulkfree.c near the top, as well as in
  89  *     newfs_hammer2).
  90  *
  91  * Rotate between four possibilities.  Theoretically this means we have three
  92  * good freemaps in case of a crash which we can use as a base for the fixup
  93  * scan at mount-time.
  94  */
  95 #define H2FMZONEBASE(key)       ((key) & ~HAMMER2_FREEMAP_LEVEL1_MASK)
  96 #define H2FMBASE(key, radix)    ((key) & ~(((hammer2_off_t)1 << (radix)) - 1))
  97 #define H2FMSHIFT(radix)        ((hammer2_off_t)1 << (radix))
  98
  99 static
 100 int
 101 hammer2_freemap_reserve(hammer2_chain_t *chain, int radix)
 102 {
 103         hammer2_blockref_t *bref = &chain->bref;
 104         hammer2_off_t off;
 105         int index;
 106         int index_inc;
 107         size_t bytes;
 108
 109         /*
 110          * Physical allocation size.
 111          */
 112         bytes = (size_t)1 << radix;
 113
 114         /*
 115          * Calculate block selection index 0..7 of current block.  If this
 116          * is the first allocation of the block (verses a modification of an
 117          * existing block), we use index 0, otherwise we use the next rotating
 118          * index.
 119          */
 120         if ((bref->data_off & ~HAMMER2_OFF_MASK_RADIX) == 0) {
 121                 index = 0;
 122         } else {
 123                 off = bref->data_off & ~HAMMER2_OFF_MASK_RADIX &
 124                       (((hammer2_off_t)1 <<
 125                         HAMMER2_FREEMAP_LEVEL1_RADIX) - 1);
 126                 off = off / HAMMER2_PBUFSIZE;
 127                 KKASSERT(off >= HAMMER2_ZONE_FREEMAP_00 &&
 128                          off < HAMMER2_ZONE_FREEMAP_END);
 129                 index = (int)(off - HAMMER2_ZONE_FREEMAP_00) /
 130                         HAMMER2_ZONE_FREEMAP_INC;
 131                 KKASSERT(index >= 0 && index < HAMMER2_NFREEMAPS);
 132                 if (++index == HAMMER2_NFREEMAPS)
 133                         index = 0;
 134         }
 135
 136         /*
 137          * Calculate the block offset of the reserved block.  This will
 138          * point into the 4MB reserved area at the base of the appropriate
 139          * 2GB zone, once added to the FREEMAP_x selection above.
 140          */
 141         index_inc = index * HAMMER2_ZONE_FREEMAP_INC;
 142
 143         switch(bref->keybits) {
 144         /* case HAMMER2_FREEMAP_LEVEL6_RADIX: not applicable */
 145         case HAMMER2_FREEMAP_LEVEL5_RADIX:      /* 2EB */
 146                 KKASSERT(bref->type == HAMMER2_BREF_TYPE_FREEMAP_NODE);
 147                 KKASSERT(bytes == HAMMER2_FREEMAP_LEVELN_PSIZE);
 148                 off = H2FMBASE(bref->key, HAMMER2_FREEMAP_LEVEL5_RADIX) +
 149                       (index_inc + HAMMER2_ZONE_FREEMAP_00 +
 150                        HAMMER2_ZONEFM_LEVEL5) * HAMMER2_PBUFSIZE;
 151                 break;
 152         case HAMMER2_FREEMAP_LEVEL4_RADIX:      /* 2EB */
 153                 KKASSERT(bref->type == HAMMER2_BREF_TYPE_FREEMAP_NODE);
 154                 KKASSERT(bytes == HAMMER2_FREEMAP_LEVELN_PSIZE);
 155                 off = H2FMBASE(bref->key, HAMMER2_FREEMAP_LEVEL4_RADIX) +
 156                       (index_inc + HAMMER2_ZONE_FREEMAP_00 +
 157                        HAMMER2_ZONEFM_LEVEL4) * HAMMER2_PBUFSIZE;
 158                 break;
 159         case HAMMER2_FREEMAP_LEVEL3_RADIX:      /* 2PB */
 160                 KKASSERT(bref->type == HAMMER2_BREF_TYPE_FREEMAP_NODE);
 161                 KKASSERT(bytes == HAMMER2_FREEMAP_LEVELN_PSIZE);
 162                 off = H2FMBASE(bref->key, HAMMER2_FREEMAP_LEVEL3_RADIX) +
 163                       (index_inc + HAMMER2_ZONE_FREEMAP_00 +
 164                        HAMMER2_ZONEFM_LEVEL3) * HAMMER2_PBUFSIZE;
 165                 break;
 166         case HAMMER2_FREEMAP_LEVEL2_RADIX:      /* 2TB */
 167                 KKASSERT(bref->type == HAMMER2_BREF_TYPE_FREEMAP_NODE);
 168                 KKASSERT(bytes == HAMMER2_FREEMAP_LEVELN_PSIZE);
 169                 off = H2FMBASE(bref->key, HAMMER2_FREEMAP_LEVEL2_RADIX) +
 170                       (index_inc + HAMMER2_ZONE_FREEMAP_00 +
 171                        HAMMER2_ZONEFM_LEVEL2) * HAMMER2_PBUFSIZE;
 172                 break;
 173         case HAMMER2_FREEMAP_LEVEL1_RADIX:      /* 2GB */
 174                 KKASSERT(bref->type == HAMMER2_BREF_TYPE_FREEMAP_LEAF);
 175                 KKASSERT(bytes == HAMMER2_FREEMAP_LEVELN_PSIZE);
 176                 off = H2FMBASE(bref->key, HAMMER2_FREEMAP_LEVEL1_RADIX) +
 177                       (index_inc + HAMMER2_ZONE_FREEMAP_00 +
 178                        HAMMER2_ZONEFM_LEVEL1) * HAMMER2_PBUFSIZE;
 179                 break;
 180         default:
 181                 panic("freemap: bad radix(2) %p %d\n", bref, bref->keybits);
 182                 /* NOT REACHED */
 183                 off = (hammer2_off_t)-1;
 184                 break;
 185         }
 186         bref->data_off = off | radix;
 187 #if FREEMAP_DEBUG
 188         kprintf("FREEMAP BLOCK TYPE %d %016jx/%d DATA_OFF=%016jx\n",
 189                 bref->type, bref->key, bref->keybits, bref->data_off);
 190 #endif
 191         return (0);
 192 }
 193
 194 /*
 195  * Normal freemap allocator
 196  *
 197  * Use available hints to allocate space using the freemap.  Create missing
 198  * freemap infrastructure on-the-fly as needed (including marking initial
 199  * allocations using the iterator as allocated, instantiating new 2GB zones,
 200  * and dealing with the end-of-media edge case).
 201  *
 202  * ip and bpref are only used as a heuristic to determine locality of
 203  * reference.  bref->key may also be used heuristically.
 204  *
 205  * This function is a NOP if bytes is 0.
 206  */
 207 int
 208 hammer2_freemap_alloc(hammer2_chain_t *chain, size_t bytes)
 209 {
 210         hammer2_dev_t *hmp = chain->hmp;
 211         hammer2_blockref_t *bref = &chain->bref;
 212         hammer2_chain_t *parent;
 213         hammer2_tid_t mtid;
 214         int radix;
 215         int error;
 216         unsigned int hindex;
 217         hammer2_fiterate_t iter;
 218
 219         /*
 220          * If allocating or downsizing to zero we just get rid of whatever
 221          * data_off we had.
 222          */
 223         if (bytes == 0) {
 224                 chain->bref.data_off = 0;
 225                 return 0;
 226         }
 227
 228         KKASSERT(hmp->spmp);
 229         mtid = hammer2_trans_sub(hmp->spmp);
 230
 231         /*
 232          * Validate the allocation size.  It must be a power of 2.
 233          *
 234          * For now require that the caller be aware of the minimum
 235          * allocation (1K).
 236          */
 237         radix = hammer2_getradix(bytes);
 238         KKASSERT((size_t)1 << radix == bytes);
 239
 240         if (bref->type == HAMMER2_BREF_TYPE_FREEMAP_NODE ||
 241             bref->type == HAMMER2_BREF_TYPE_FREEMAP_LEAF) {
 242                 /*
 243                  * Freemap blocks themselves are assigned from the reserve
 244                  * area, not allocated from the freemap.
 245                  */
 246                 error = hammer2_freemap_reserve(chain, radix);
 247
 248                 return error;
 249         }
 250
 251         KKASSERT(bytes >= HAMMER2_ALLOC_MIN && bytes <= HAMMER2_ALLOC_MAX);
 252
 253         /*
 254          * Calculate the starting point for our allocation search.
 255          *
 256          * Each freemap leaf is dedicated to a specific freemap_radix.
 257          * The freemap_radix can be more fine-grained than the device buffer
 258          * radix which results in inodes being grouped together in their
 259          * own segment, terminal-data (16K or less) and initial indirect
 260          * block being grouped together, and then full-indirect and full-data
 261          * blocks (64K) being grouped together.
 262          *
 263          * The single most important aspect of this is the inode grouping
 264          * because that is what allows 'find' and 'ls' and other filesystem
 265          * topology operations to run fast.
 266          */
 267 #if 0
 268         if (bref->data_off & ~HAMMER2_OFF_MASK_RADIX)
 269                 bpref = bref->data_off & ~HAMMER2_OFF_MASK_RADIX;
 270         else if (trans->tmp_bpref)
 271                 bpref = trans->tmp_bpref;
 272         else if (trans->tmp_ip)
 273                 bpref = trans->tmp_ip->chain->bref.data_off;
 274         else
 275 #endif
 276         /*
 277          * Heuristic tracking index.  We would like one for each distinct
 278          * bref type if possible.  heur_freemap[] has room for two classes
 279          * for each type.  At a minimum we have to break-up our heuristic
 280          * by device block sizes.
 281          */
 282         hindex = hammer2_devblkradix(radix) - HAMMER2_MINIORADIX;
 283         KKASSERT(hindex < HAMMER2_FREEMAP_HEUR_NRADIX);
 284         hindex += bref->type * HAMMER2_FREEMAP_HEUR_NRADIX;
 285         hindex &= HAMMER2_FREEMAP_HEUR_TYPES * HAMMER2_FREEMAP_HEUR_NRADIX - 1;
 286         KKASSERT(hindex < HAMMER2_FREEMAP_HEUR_SIZE);
 287
 288         iter.bpref = hmp->heur_freemap[hindex];
 289         iter.relaxed = hmp->freemap_relaxed;
 290
 291         /*
 292          * Make sure bpref is in-bounds.  It's ok if bpref covers a zone's
 293          * reserved area, the try code will iterate past it.
 294          */
 295         if (iter.bpref > hmp->voldata.volu_size)
 296                 iter.bpref = hmp->voldata.volu_size - 1;
 297
 298         /*
 299          * Iterate the freemap looking for free space before and after.
 300          */
 301         parent = &hmp->fchain;
 302         hammer2_chain_ref(parent);
 303         hammer2_chain_lock(parent, HAMMER2_RESOLVE_ALWAYS);
 304         error = HAMMER2_ERROR_EAGAIN;
 305         iter.bnext = iter.bpref;
 306         iter.loops = 0;
 307
 308         while (error == HAMMER2_ERROR_EAGAIN) {
 309                 error = hammer2_freemap_try_alloc(&parent, bref, radix,
 310                                                   &iter, mtid);
 311         }
 312         hmp->freemap_relaxed |= iter.relaxed;   /* heuristical, SMP race ok */
 313         hmp->heur_freemap[hindex] = iter.bnext;
 314         hammer2_chain_unlock(parent);
 315         hammer2_chain_drop(parent);
 316
 317         return (error);
 318 }
 319
 320 static int
 321 hammer2_freemap_try_alloc(hammer2_chain_t **parentp,
 322                           hammer2_blockref_t *bref, int radix,
 323                           hammer2_fiterate_t *iter, hammer2_tid_t mtid)
 324 {
 325         hammer2_dev_t *hmp = (*parentp)->hmp;
 326         hammer2_off_t l0size;
 327         hammer2_off_t l1size;
 328         hammer2_off_t l1mask;
 329         hammer2_key_t key_dummy;
 330         hammer2_chain_t *chain;
 331         hammer2_off_t key;
 332         size_t bytes;
 333         uint16_t class;
 334         int error;
 335
 336         /*
 337          * Calculate the number of bytes being allocated, the number
 338          * of contiguous bits of bitmap being allocated, and the bitmap
 339          * mask.
 340          *
 341          * WARNING! cpu hardware may mask bits == 64 -> 0 and blow up the
 342          *          mask calculation.
 343          */
 344         bytes = (size_t)1 << radix;
 345         class = (bref->type << 8) | hammer2_devblkradix(radix);
 346
 347         /*
 348          * Lookup the level1 freemap chain, creating and initializing one
 349          * if necessary.  Intermediate levels will be created automatically
 350          * when necessary by hammer2_chain_create().
 351          */
 352         key = H2FMBASE(iter->bnext, HAMMER2_FREEMAP_LEVEL1_RADIX);
 353         l0size = H2FMSHIFT(HAMMER2_FREEMAP_LEVEL0_RADIX);
 354         l1size = H2FMSHIFT(HAMMER2_FREEMAP_LEVEL1_RADIX);
 355         l1mask = l1size - 1;
 356
 357         chain = hammer2_chain_lookup(parentp, &key_dummy, key, key + l1mask,
 358                                      &error,
 359                                      HAMMER2_LOOKUP_ALWAYS |
 360                                      HAMMER2_LOOKUP_MATCHIND);
 361
 362         if (chain == NULL) {
 363                 /*
 364                  * Create the missing leaf, be sure to initialize
 365                  * the auxillary freemap tracking information in
 366                  * the bref.check.freemap structure.
 367                  */
 368 #if 0
 369                 kprintf("freemap create L1 @ %016jx bpref %016jx\n",
 370                         key, iter->bpref);
 371 #endif
 372                 error = hammer2_chain_create(parentp, &chain,
 373                                      hmp->spmp, HAMMER2_METH_DEFAULT,
 374                                      key, HAMMER2_FREEMAP_LEVEL1_RADIX,
 375                                      HAMMER2_BREF_TYPE_FREEMAP_LEAF,
 376                                      HAMMER2_FREEMAP_LEVELN_PSIZE,
 377                                      mtid, 0, 0);
 378                 KKASSERT(error == 0);
 379                 if (error == 0) {
 380                         hammer2_chain_modify(chain, mtid, 0, 0);
 381                         bzero(&chain->data->bmdata[0],
 382                               HAMMER2_FREEMAP_LEVELN_PSIZE);
 383                         chain->bref.check.freemap.bigmask = (uint32_t)-1;
 384                         chain->bref.check.freemap.avail = l1size;
 385                         /* bref.methods should already be inherited */
 386
 387                         hammer2_freemap_init(hmp, key, chain);
 388                 }
 389         } else if (chain->error) {
 390                 /*
 391                  * Error during lookup.
 392                  */
 393                 kprintf("hammer2_freemap_try_alloc: %016jx: error %s\n",
 394                         (intmax_t)bref->data_off,
 395                         hammer2_error_str(chain->error));
 396                 error = HAMMER2_ERROR_EIO;
 397         } else if ((chain->bref.check.freemap.bigmask &
 398                    ((size_t)1 << radix)) == 0) {
 399                 /*
 400                  * Already flagged as not having enough space
 401                  */
 402                 error = HAMMER2_ERROR_ENOSPC;
 403         } else {
 404                 /*
 405                  * Modify existing chain to setup for adjustment.
 406                  */
 407                 hammer2_chain_modify(chain, mtid, 0, 0);
 408         }
 409
 410         /*
 411          * Scan 4MB entries.
 412          */
 413         if (error == 0) {
 414                 hammer2_bmap_data_t *bmap;
 415                 hammer2_key_t base_key;
 416                 int count;
 417                 int start;
 418                 int n;
 419
 420                 KKASSERT(chain->bref.type == HAMMER2_BREF_TYPE_FREEMAP_LEAF);
 421                 start = (int)((iter->bnext - key) >>
 422                               HAMMER2_FREEMAP_LEVEL0_RADIX);
 423                 KKASSERT(start >= 0 && start < HAMMER2_FREEMAP_COUNT);
 424                 hammer2_chain_modify(chain, mtid, 0, 0);
 425
 426                 error = HAMMER2_ERROR_ENOSPC;
 427                 for (count = 0; count < HAMMER2_FREEMAP_COUNT; ++count) {
 428                         int availchk;
 429
 430                         if (start + count >= HAMMER2_FREEMAP_COUNT &&
 431                             start - count < 0) {
 432                                 break;
 433                         }
 434
 435                         /*
 436                          * Calculate bmap pointer from thart starting index
 437                          * forwards.
 438                          *
 439                          * NOTE: bmap pointer is invalid if n >= FREEMAP_COUNT.
 440                          */
 441                         n = start + count;
 442                         bmap = &chain->data->bmdata[n];
 443
 444                         if (n >= HAMMER2_FREEMAP_COUNT) {
 445                                 availchk = 0;
 446                         } else if (bmap->avail) {
 447                                 availchk = 1;
 448                         } else if (radix < HAMMER2_FREEMAP_BLOCK_RADIX &&
 449                                   (bmap->linear & HAMMER2_FREEMAP_BLOCK_MASK)) {
 450                                 availchk = 1;
 451                         } else {
 452                                 availchk = 0;
 453                         }
 454
 455                         /*
 456                          * Try to allocate from a matching freemap class
 457                          * superblock.  If we are in relaxed mode we allocate
 458                          * from any freemap class superblock.
 459                          */
 460                         if (availchk &&
 461                             (bmap->class == 0 || bmap->class == class ||
 462                              iter->relaxed)) {
 463                                 base_key = key + n * l0size;
 464                                 error = hammer2_bmap_alloc(hmp, bmap,
 465                                                            class, n,
 466                                                            (int)bref->key,
 467                                                            radix,
 468                                                            &base_key);
 469                                 if (error != HAMMER2_ERROR_ENOSPC) {
 470                                         key = base_key;
 471                                         break;
 472                                 }
 473                         }
 474
 475                         /*
 476                          * Calculate bmap pointer from thart starting index
 477                          * backwards (locality).
 478                          *
 479                          * Must recalculate after potentially having called
 480                          * hammer2_bmap_alloc() above in case chain was
 481                          * reallocated.
 482                          *
 483                          * NOTE: bmap pointer is invalid if n < 0.
 484                          */
 485                         n = start - count;
 486                         bmap = &chain->data->bmdata[n];
 487                         if (n < 0) {
 488                                 availchk = 0;
 489                         } else if (bmap->avail) {
 490                                 availchk = 1;
 491                         } else if (radix < HAMMER2_FREEMAP_BLOCK_RADIX &&
 492                                   (bmap->linear & HAMMER2_FREEMAP_BLOCK_MASK)) {
 493                                 availchk = 1;
 494                         } else {
 495                                 availchk = 0;
 496                         }
 497
 498                         /*
 499                          * Try to allocate from a matching freemap class
 500                          * superblock.  If we are in relaxed mode we allocate
 501                          * from any freemap class superblock.
 502                          */
 503                         if (availchk &&
 504                             (bmap->class == 0 || bmap->class == class ||
 505                             iter->relaxed)) {
 506                                 base_key = key + n * l0size;
 507                                 error = hammer2_bmap_alloc(hmp, bmap,
 508                                                            class, n,
 509                                                            (int)bref->key,
 510                                                            radix,
 511                                                            &base_key);
 512                                 if (error != HAMMER2_ERROR_ENOSPC) {
 513                                         key = base_key;
 514                                         break;
 515                                 }
 516                         }
 517                 }
 518
 519                 /*
 520                  * We only know for sure that we can clear the bitmap bit
 521                  * if we scanned the entire array (start == 0).
 522                  */
 523                 if (error == HAMMER2_ERROR_ENOSPC && start == 0) {
 524                         chain->bref.check.freemap.bigmask &=
 525                                 (uint32_t)~((size_t)1 << radix);
 526                 }
 527                 /* XXX also scan down from original count */
 528         }
 529
 530         if (error == 0) {
 531                 /*
 532                  * Assert validity.  Must be beyond the static allocator used
 533                  * by newfs_hammer2 (and thus also beyond the aux area),
 534                  * not go past the volume size, and must not be in the
 535                  * reserved segment area for a zone.
 536                  */
 537                 KKASSERT(key >= hmp->voldata.allocator_beg &&
 538                          key + bytes <= hmp->voldata.volu_size);
 539                 KKASSERT((key & HAMMER2_ZONE_MASK64) >= HAMMER2_ZONE_SEG);
 540                 bref->data_off = key | radix;
 541
 542                 /*
 543                  * Record dedupability.  The dedup bits are cleared
 544                  * when bulkfree transitions the freemap from 11->10,
 545                  * and asserted to be clear on the 10->00 transition.
 546                  *
 547                  * We must record the bitmask with the chain locked
 548                  * at the time we set the allocation bits to avoid
 549                  * racing a bulkfree.
 550                  */
 551                 if (bref->type == HAMMER2_BREF_TYPE_DATA)
 552                         hammer2_io_dedup_set(hmp, bref);
 553 #if 0
 554                 kprintf("alloc cp=%p %016jx %016jx using %016jx\n",
 555                         chain,
 556                         bref->key, bref->data_off, chain->bref.data_off);
 557 #endif
 558         } else if (error == HAMMER2_ERROR_ENOSPC) {
 559                 /*
 560                  * Return EAGAIN with next iteration in iter->bnext, or
 561                  * return ENOSPC if the allocation map has been exhausted.
 562                  */
 563                 error = hammer2_freemap_iterate(parentp, &chain, iter);
 564         }
 565
 566         /*
 567          * Cleanup
 568          */
 569         if (chain) {
 570                 hammer2_chain_unlock(chain);
 571                 hammer2_chain_drop(chain);
 572         }
 573         return (error);
 574 }
 575
 576 /*
 577  * Allocate (1<<radix) bytes from the bmap whos base data offset is (*basep).
 578  *
 579  * If the linear iterator is mid-block we use it directly (the bitmap should
 580  * already be marked allocated), otherwise we search for a block in the
 581  * bitmap that fits the allocation request.
 582  *
 583  * A partial bitmap allocation sets the minimum bitmap granularity (16KB)
 584  * to fully allocated and adjusts the linear allocator to allow the
 585  * remaining space to be allocated.
 586  *
 587  * sub_key is the lower 32 bits of the chain->bref.key for the chain whos
 588  * bref is being allocated.  If the radix represents an allocation >= 16KB
 589  * (aka HAMMER2_FREEMAP_BLOCK_RADIX) we try to use this key to select the
 590  * blocks directly out of the bmap.
 591  */
 592 static
 593 int
 594 hammer2_bmap_alloc(hammer2_dev_t *hmp, hammer2_bmap_data_t *bmap,
 595                    uint16_t class, int n, int sub_key,
 596                    int radix, hammer2_key_t *basep)
 597 {
 598         size_t size;
 599         size_t bgsize;
 600         int bmradix;
 601         hammer2_bitmap_t bmmask;
 602         int offset;
 603         int i;
 604         int j;
 605
 606         /*
 607          * Take into account 2-bits per block when calculating bmradix.
 608          */
 609         size = (size_t)1 << radix;
 610
 611         if (radix <= HAMMER2_FREEMAP_BLOCK_RADIX) {
 612                 bmradix = 2;
 613                 /* (16K) 2 bits per allocation block */
 614         } else {
 615                 bmradix = (hammer2_bitmap_t)2 <<
 616                           (radix - HAMMER2_FREEMAP_BLOCK_RADIX);
 617                 /* (32K-256K) 4, 8, 16, 32 bits per allocation block */
 618         }
 619
 620         /*
 621          * Use the linear iterator to pack small allocations, otherwise
 622          * fall-back to finding a free 16KB chunk.  The linear iterator
 623          * is only valid when *NOT* on a freemap chunking boundary (16KB).
 624          * If it is the bitmap must be scanned.  It can become invalid
 625          * once we pack to the boundary.  We adjust it after a bitmap
 626          * allocation only for sub-16KB allocations (so the perfectly good
 627          * previous value can still be used for fragments when 16KB+
 628          * allocations are made inbetween fragmentary allocations).
 629          *
 630          * Beware of hardware artifacts when bmradix == 64 (intermediate
 631          * result can wind up being '1' instead of '0' if hardware masks
 632          * bit-count & 63).
 633          *
 634          * NOTE: j needs to be even in the j= calculation.  As an artifact
 635          *       of the /2 division, our bitmask has to clear bit 0.
 636          *
 637          * NOTE: TODO this can leave little unallocatable fragments lying
 638          *       around.
 639          */
 640         if (((uint32_t)bmap->linear & HAMMER2_FREEMAP_BLOCK_MASK) + size <=
 641             HAMMER2_FREEMAP_BLOCK_SIZE &&
 642             (bmap->linear & HAMMER2_FREEMAP_BLOCK_MASK) &&
 643             bmap->linear < HAMMER2_SEGSIZE) {
 644                 /*
 645                  * Use linear iterator if it is not block-aligned to avoid
 646                  * wasting space.
 647                  */
 648                 KKASSERT(bmap->linear >= 0 &&
 649                          bmap->linear + size <= HAMMER2_SEGSIZE &&
 650                          (bmap->linear & (HAMMER2_ALLOC_MIN - 1)) == 0);
 651                 offset = bmap->linear;
 652                 i = offset / (HAMMER2_SEGSIZE / 8);
 653                 j = (offset / (HAMMER2_FREEMAP_BLOCK_SIZE / 2)) & 30;
 654                 bmmask = (bmradix == HAMMER2_BMAP_BITS_PER_ELEMENT) ?
 655                          HAMMER2_BMAP_ALLONES :
 656                          ((hammer2_bitmap_t)1 << bmradix) - 1;
 657                 bmmask <<= j;
 658                 bmap->linear = offset + size;
 659         } else {
 660                 /*
 661                  * Try to index a starting point based on sub_key.  This
 662                  * attempts to restore sequential block ordering on-disk
 663                  * whenever possible, even if data is committed out of
 664                  * order.
 665                  *
 666                  * i - Index bitmapq[], full data range represented is
 667                  *     HAMMER2_BMAP_SIZE.
 668                  *
 669                  * j - Index within bitmapq[i], full data range represented is
 670                  *     HAMMER2_BMAP_INDEX_SIZE.
 671                  *
 672                  * WARNING!
 673                  */
 674                 i = -1;
 675                 j = -1;
 676
 677                 switch(class >> 8) {
 678                 case HAMMER2_BREF_TYPE_DATA:
 679                         if (radix >= HAMMER2_FREEMAP_BLOCK_RADIX) {
 680                                 i = (sub_key & HAMMER2_BMAP_MASK) /
 681                                     (HAMMER2_BMAP_SIZE / HAMMER2_BMAP_ELEMENTS);
 682                                 j = (sub_key & HAMMER2_BMAP_INDEX_MASK) /
 683                                     (HAMMER2_BMAP_INDEX_SIZE /
 684                                      HAMMER2_BMAP_BLOCKS_PER_ELEMENT);
 685                                 j = j * 2;
 686                         }
 687                         break;
 688                 case HAMMER2_BREF_TYPE_INODE:
 689                         break;
 690                 default:
 691                         break;
 692                 }
 693                 if (i >= 0) {
 694                         KKASSERT(i < HAMMER2_BMAP_ELEMENTS &&
 695                                  j < 2 * HAMMER2_BMAP_BLOCKS_PER_ELEMENT);
 696                         KKASSERT(j + bmradix <= HAMMER2_BMAP_BITS_PER_ELEMENT);
 697                         bmmask = (bmradix == HAMMER2_BMAP_BITS_PER_ELEMENT) ?
 698                                  HAMMER2_BMAP_ALLONES :
 699                                  ((hammer2_bitmap_t)1 << bmradix) - 1;
 700                         bmmask <<= j;
 701
 702                         if ((bmap->bitmapq[i] & bmmask) == 0)
 703                                 goto success;
 704                 }
 705
 706                 /*
 707                  * General element scan.
 708                  *
 709                  * WARNING: (j) is iterating a bit index (by 2's)
 710                  */
 711                 for (i = 0; i < HAMMER2_BMAP_ELEMENTS; ++i) {
 712                         bmmask = (bmradix == HAMMER2_BMAP_BITS_PER_ELEMENT) ?
 713                                  HAMMER2_BMAP_ALLONES :
 714                                  ((hammer2_bitmap_t)1 << bmradix) - 1;
 715                         for (j = 0;
 716                              j < HAMMER2_BMAP_BITS_PER_ELEMENT;
 717                              j += bmradix) {
 718                                 if ((bmap->bitmapq[i] & bmmask) == 0)
 719                                         goto success;
 720                                 bmmask <<= bmradix;
 721                         }
 722                 }
 723                 /*fragments might remain*/
 724                 /*KKASSERT(bmap->avail == 0);*/
 725                 return (HAMMER2_ERROR_ENOSPC);
 726 success:
 727                 offset = i * (HAMMER2_SEGSIZE / HAMMER2_BMAP_ELEMENTS) +
 728                          (j * (HAMMER2_FREEMAP_BLOCK_SIZE / 2));
 729                 if (size & HAMMER2_FREEMAP_BLOCK_MASK)
 730                         bmap->linear = offset + size;
 731         }
 732
 733         /* 8 x (64/2) -> 256 x 16K -> 4MB */
 734         KKASSERT(i >= 0 && i < HAMMER2_BMAP_ELEMENTS);
 735
 736         /*
 737          * Optimize the buffer cache to avoid unnecessary read-before-write
 738          * operations.
 739          *
 740          * The device block size could be larger than the allocation size
 741          * so the actual bitmap test is somewhat more involved.  We have
 742          * to use a compatible buffer size for this operation.
 743          */
 744         if ((bmap->bitmapq[i] & bmmask) == 0 &&
 745             hammer2_devblksize(size) != size) {
 746                 size_t psize = hammer2_devblksize(size);
 747                 hammer2_off_t pmask = (hammer2_off_t)psize - 1;
 748                 int pbmradix = (hammer2_bitmap_t)2 <<
 749                                         (hammer2_devblkradix(radix) -
 750                                HAMMER2_FREEMAP_BLOCK_RADIX);
 751                 hammer2_bitmap_t pbmmask;
 752                 int pradix = hammer2_getradix(psize);
 753
 754                 pbmmask = (pbmradix == HAMMER2_BMAP_BITS_PER_ELEMENT) ?
 755                         HAMMER2_BMAP_ALLONES :
 756                         ((hammer2_bitmap_t)1 << pbmradix) - 1;
 757                 while ((pbmmask & bmmask) == 0)
 758                         pbmmask <<= pbmradix;
 759
 760 #if 0
 761                 kprintf("%016jx mask %016jx %016jx %016jx (%zd/%zd)\n",
 762                         *basep + offset, bmap->bitmapq[i],
 763                         pbmmask, bmmask, size, psize);
 764 #endif
 765
 766                 if ((bmap->bitmapq[i] & pbmmask) == 0) {
 767                         hammer2_io_t *dio;
 768
 769                         hammer2_io_newnz(hmp, class >> 8,
 770                                         (*basep + (offset & ~pmask)) |
 771                                         pradix, psize, &dio);
 772                         hammer2_io_putblk(&dio);
 773                 }
 774         }
 775
 776 #if 0
 777         /*
 778          * When initializing a new inode segment also attempt to initialize
 779          * an adjacent segment.  Be careful not to index beyond the array
 780          * bounds.
 781          *
 782          * We do this to try to localize inode accesses to improve
 783          * directory scan rates.  XXX doesn't improve scan rates.
 784          */
 785         if (size == HAMMER2_INODE_BYTES) {
 786                 if (n & 1) {
 787                         if (bmap[-1].radix == 0 && bmap[-1].avail)
 788                                 bmap[-1].radix = radix;
 789                 } else {
 790                         if (bmap[1].radix == 0 && bmap[1].avail)
 791                                 bmap[1].radix = radix;
 792                 }
 793         }
 794 #endif
 795         /*
 796          * Calculate the bitmap-granular change in bgsize for the volume
 797          * header.  We cannot use the fine-grained change here because
 798          * the bulkfree code can't undo it.  If the bitmap element is already
 799          * marked allocated it has already been accounted for.
 800          */
 801         if (radix < HAMMER2_FREEMAP_BLOCK_RADIX) {
 802                 if (bmap->bitmapq[i] & bmmask)
 803                         bgsize = 0;
 804                 else
 805                         bgsize = HAMMER2_FREEMAP_BLOCK_SIZE;
 806         } else {
 807                 bgsize = size;
 808         }
 809
 810         /*
 811          * Adjust the bitmap, set the class (it might have been 0),
 812          * and available bytes, update the allocation offset (*basep)
 813          * from the L0 base to the actual offset.
 814          *
 815          * Do not override the class if doing a relaxed class allocation.
 816          *
 817          * avail must reflect the bitmap-granular availability.  The allocator
 818          * tests will also check the linear iterator.
 819          */
 820         bmap->bitmapq[i] |= bmmask;
 821         if (bmap->class == 0)
 822                 bmap->class = class;
 823         bmap->avail -= bgsize;
 824         *basep += offset;
 825
 826         /*
 827          * Adjust the volume header's allocator_free parameter.  This
 828          * parameter has to be fixed up by bulkfree which has no way to
 829          * figure out sub-16K chunking, so it must be adjusted by the
 830          * bitmap-granular size.
 831          */
 832         if (bgsize) {
 833                 hammer2_voldata_lock(hmp);
 834                 hammer2_voldata_modify(hmp);
 835                 hmp->voldata.allocator_free -= bgsize;
 836                 hammer2_voldata_unlock(hmp);
 837         }
 838
 839         return(0);
 840 }
 841
 842 /*
 843  * Initialize a freemap for the storage area (in bytes) that begins at (key).
 844  */
 845 static
 846 void
 847 hammer2_freemap_init(hammer2_dev_t *hmp, hammer2_key_t key,
 848                      hammer2_chain_t *chain)
 849 {
 850         hammer2_off_t l1size;
 851         hammer2_off_t lokey;
 852         hammer2_off_t hikey;
 853         hammer2_bmap_data_t *bmap;
 854         int count;
 855
 856         /*
 857          * LEVEL1 is 1GB, there are two level1 1GB freemaps per 2GB zone.
 858          */
 859         l1size = H2FMSHIFT(HAMMER2_FREEMAP_LEVEL1_RADIX);
 860
 861         /*
 862          * Calculate the portion of the 1GB map that should be initialized
 863          * as free.  Portions below or after will be initialized as allocated.
 864          * SEGMASK-align the areas so we don't have to worry about sub-scans
 865          * or endianess when using memset.
 866          *
 867          * WARNING! It is possible for lokey to be larger than hikey if the
 868          *          entire 2GB segment is within the static allocation.
 869          */
 870         /*
 871          * (1) Ensure that all statically allocated space from newfs_hammer2
 872          *     is marked allocated, and take it up to the level1 base for
 873          *     this key.
 874          */
 875         lokey = (hmp->voldata.allocator_beg + HAMMER2_SEGMASK64) &
 876                 ~HAMMER2_SEGMASK64;
 877         if (lokey < H2FMBASE(key, HAMMER2_FREEMAP_LEVEL1_RADIX))
 878                 lokey = H2FMBASE(key, HAMMER2_FREEMAP_LEVEL1_RADIX);
 879
 880         /*
 881          * (2) Ensure that the reserved area is marked allocated (typically
 882          *     the first 4MB of each 2GB area being represented).  Since
 883          *     each LEAF represents 1GB of storage and the zone is 2GB, we
 884          *     have to adjust lowkey upward every other LEAF sequentially.
 885          */
 886         if (lokey < H2FMZONEBASE(key) + HAMMER2_ZONE_SEG64)
 887                 lokey = H2FMZONEBASE(key) + HAMMER2_ZONE_SEG64;
 888
 889         /*
 890          * (3) Ensure that any trailing space at the end-of-volume is marked
 891          *     allocated.
 892          */
 893         hikey = key + H2FMSHIFT(HAMMER2_FREEMAP_LEVEL1_RADIX);
 894         if (hikey > hmp->voldata.volu_size) {
 895                 hikey = hmp->voldata.volu_size & ~HAMMER2_SEGMASK64;
 896         }
 897
 898         /*
 899          * Heuristic highest possible value
 900          */
 901         chain->bref.check.freemap.avail =
 902                 H2FMSHIFT(HAMMER2_FREEMAP_LEVEL1_RADIX);
 903         bmap = &chain->data->bmdata[0];
 904
 905         /*
 906          * Initialize bitmap (bzero'd by caller)
 907          */
 908         for (count = 0; count < HAMMER2_FREEMAP_COUNT; ++count) {
 909                 if (key < lokey || key >= hikey) {
 910                         memset(bmap->bitmapq, -1,
 911                                sizeof(bmap->bitmapq));
 912                         bmap->avail = 0;
 913                         bmap->linear = HAMMER2_SEGSIZE;
 914                         chain->bref.check.freemap.avail -=
 915                                 H2FMSHIFT(HAMMER2_FREEMAP_LEVEL0_RADIX);
 916                 } else {
 917                         bmap->avail = H2FMSHIFT(HAMMER2_FREEMAP_LEVEL0_RADIX);
 918                 }
 919                 key += H2FMSHIFT(HAMMER2_FREEMAP_LEVEL0_RADIX);
 920                 ++bmap;
 921         }
 922 }
 923
 924 /*
 925  * The current Level 1 freemap has been exhausted, iterate to the next
 926  * one, return ENOSPC if no freemaps remain.
 927  *
 928  * At least two loops are required.  If we are not in relaxed mode and
 929  * we run out of storage we enter relaxed mode and do a third loop.
 930  * The relaxed mode is recorded back in the hmp so once we enter the mode
 931  * we remain relaxed until stuff begins to get freed and only do 2 loops.
 932  *
 933  * XXX this should rotate back to the beginning to handle freed-up space
 934  * XXX or use intermediate entries to locate free space. TODO
 935  */
 936 static int
 937 hammer2_freemap_iterate(hammer2_chain_t **parentp, hammer2_chain_t **chainp,
 938                         hammer2_fiterate_t *iter)
 939 {
 940         hammer2_dev_t *hmp = (*parentp)->hmp;
 941
 942         iter->bnext &= ~(H2FMSHIFT(HAMMER2_FREEMAP_LEVEL1_RADIX) - 1);
 943         iter->bnext += H2FMSHIFT(HAMMER2_FREEMAP_LEVEL1_RADIX);
 944         if (iter->bnext >= hmp->voldata.volu_size) {
 945                 iter->bnext = 0;
 946                 if (++iter->loops >= 2) {
 947                         if (iter->relaxed == 0)
 948                                 iter->relaxed = 1;
 949                         else
 950                                 return (HAMMER2_ERROR_ENOSPC);
 951                 }
 952         }
 953         return(HAMMER2_ERROR_EAGAIN);
 954 }
 955
 956 /*
 957  * Adjust the bit-pattern for data in the freemap bitmap according to
 958  * (how).  This code is called from on-mount recovery to fixup (mark
 959  * as allocated) blocks whos freemap upates might not have been committed
 960  * in the last crash and is used by the bulk freemap scan to stage frees.
 961  *
 962  * WARNING! Cannot be called with a empty-data bref (radix == 0).
 963  *
 964  * XXX currently disabled when how == 0 (the normal real-time case).  At
 965  * the moment we depend on the bulk freescan to actually free blocks.  It
 966  * will still call this routine with a non-zero how to stage possible frees
 967  * and to do the actual free.
 968  */
 969 void
 970 hammer2_freemap_adjust(hammer2_dev_t *hmp, hammer2_blockref_t *bref,
 971                        int how)
 972 {
 973         hammer2_off_t data_off = bref->data_off;
 974         hammer2_chain_t *chain;
 975         hammer2_chain_t *parent;
 976         hammer2_bmap_data_t *bmap;
 977         hammer2_key_t key;
 978         hammer2_key_t key_dummy;
 979         hammer2_off_t l0size;
 980         hammer2_off_t l1size;
 981         hammer2_off_t l1mask;
 982         hammer2_tid_t mtid;
 983         hammer2_bitmap_t *bitmap;
 984         const hammer2_bitmap_t bmmask00 = 0;
 985         hammer2_bitmap_t bmmask01;
 986         hammer2_bitmap_t bmmask10;
 987         hammer2_bitmap_t bmmask11;
 988         size_t bytes;
 989         uint16_t class;
 990         int radix;
 991         int start;
 992         int count;
 993         int modified = 0;
 994         int error;
 995         size_t bgsize = 0;
 996
 997         KKASSERT(how == HAMMER2_FREEMAP_DORECOVER);
 998
 999         KKASSERT(hmp->spmp);
1000         mtid = hammer2_trans_sub(hmp->spmp);
1001
1002         radix = (int)data_off & HAMMER2_OFF_MASK_RADIX;
1003         KKASSERT(radix != 0);
1004         data_off &= ~HAMMER2_OFF_MASK_RADIX;
1005         KKASSERT(radix <= HAMMER2_RADIX_MAX);
1006
1007         if (radix)
1008                 bytes = (size_t)1 << radix;
1009         else
1010                 bytes = 0;
1011         class = (bref->type << 8) | hammer2_devblkradix(radix);
1012
1013         /*
1014          * We can't adjust the freemap for data allocations made by
1015          * newfs_hammer2.
1016          */
1017         if (data_off < hmp->voldata.allocator_beg)
1018                 return;
1019
1020         KKASSERT((data_off & HAMMER2_ZONE_MASK64) >= HAMMER2_ZONE_SEG);
1021
1022         /*
1023          * Lookup the level1 freemap chain.  The chain must exist.
1024          */
1025         key = H2FMBASE(data_off, HAMMER2_FREEMAP_LEVEL1_RADIX);
1026         l0size = H2FMSHIFT(HAMMER2_FREEMAP_LEVEL0_RADIX);
1027         l1size = H2FMSHIFT(HAMMER2_FREEMAP_LEVEL1_RADIX);
1028         l1mask = l1size - 1;
1029
1030         parent = &hmp->fchain;
1031         hammer2_chain_ref(parent);
1032         hammer2_chain_lock(parent, HAMMER2_RESOLVE_ALWAYS);
1033
1034         chain = hammer2_chain_lookup(&parent, &key_dummy, key, key + l1mask,
1035                                      &error,
1036                                      HAMMER2_LOOKUP_ALWAYS |
1037                                      HAMMER2_LOOKUP_MATCHIND);
1038
1039         /*
1040          * Stop early if we are trying to free something but no leaf exists.
1041          */
1042         if (chain == NULL && how != HAMMER2_FREEMAP_DORECOVER) {
1043                 kprintf("hammer2_freemap_adjust: %016jx: no chain\n",
1044                         (intmax_t)bref->data_off);
1045                 goto done;
1046         }
1047         if (chain->error) {
1048                 kprintf("hammer2_freemap_adjust: %016jx: error %s\n",
1049                         (intmax_t)bref->data_off,
1050                         hammer2_error_str(chain->error));
1051                 hammer2_chain_unlock(chain);
1052                 hammer2_chain_drop(chain);
1053                 chain = NULL;
1054                 goto done;
1055         }
1056
1057         /*
1058          * Create any missing leaf(s) if we are doing a recovery (marking
1059          * the block(s) as being allocated instead of being freed).  Be sure
1060          * to initialize the auxillary freemap tracking info in the
1061          * bref.check.freemap structure.
1062          */
1063         if (chain == NULL && how == HAMMER2_FREEMAP_DORECOVER) {
1064                 error = hammer2_chain_create(&parent, &chain,
1065                                      hmp->spmp, HAMMER2_METH_DEFAULT,
1066                                      key, HAMMER2_FREEMAP_LEVEL1_RADIX,
1067                                      HAMMER2_BREF_TYPE_FREEMAP_LEAF,
1068                                      HAMMER2_FREEMAP_LEVELN_PSIZE,
1069                                      mtid, 0, 0);
1070
1071                 if (hammer2_debug & 0x0040) {
1072                         kprintf("fixup create chain %p %016jx:%d\n",
1073                                 chain, chain->bref.key, chain->bref.keybits);
1074                 }
1075
1076                 if (error == 0) {
1077                         error = hammer2_chain_modify(chain, mtid, 0, 0);
1078                         KKASSERT(error == 0);
1079                         bzero(&chain->data->bmdata[0],
1080                               HAMMER2_FREEMAP_LEVELN_PSIZE);
1081                         chain->bref.check.freemap.bigmask = (uint32_t)-1;
1082                         chain->bref.check.freemap.avail = l1size;
1083                         /* bref.methods should already be inherited */
1084
1085                         hammer2_freemap_init(hmp, key, chain);
1086                 }
1087                 /* XXX handle error */
1088         }
1089
1090 #if FREEMAP_DEBUG
1091         kprintf("FREEMAP ADJUST TYPE %d %016jx/%d DATA_OFF=%016jx\n",
1092                 chain->bref.type, chain->bref.key,
1093                 chain->bref.keybits, chain->bref.data_off);
1094 #endif
1095
1096         /*
1097          * Calculate the bitmask (runs in 2-bit pairs).
1098          */
1099         start = ((int)(data_off >> HAMMER2_FREEMAP_BLOCK_RADIX) & 15) * 2;
1100         bmmask01 = (hammer2_bitmap_t)1 << start;
1101         bmmask10 = (hammer2_bitmap_t)2 << start;
1102         bmmask11 = (hammer2_bitmap_t)3 << start;
1103
1104         /*
1105          * Fixup the bitmap.  Partial blocks cannot be fully freed unless
1106          * a bulk scan is able to roll them up.
1107          */
1108         if (radix < HAMMER2_FREEMAP_BLOCK_RADIX) {
1109                 count = 1;
1110                 if (how == HAMMER2_FREEMAP_DOREALFREE)
1111                         how = HAMMER2_FREEMAP_DOMAYFREE;
1112         } else {
1113                 count = 1 << (radix - HAMMER2_FREEMAP_BLOCK_RADIX);
1114         }
1115
1116         /*
1117          * [re]load the bmap and bitmap pointers.  Each bmap entry covers
1118          * a 4MB swath.  The bmap itself (LEVEL1) covers 2GB.
1119          *
1120          * Be sure to reset the linear iterator to ensure that the adjustment
1121          * is not ignored.
1122          */
1123 again:
1124         bmap = &chain->data->bmdata[(int)(data_off >> HAMMER2_SEGRADIX) &
1125                                     (HAMMER2_FREEMAP_COUNT - 1)];
1126         bitmap = &bmap->bitmapq[(int)(data_off >> (HAMMER2_SEGRADIX - 3)) & 7];
1127
1128         if (modified)
1129                 bmap->linear = 0;
1130
1131         while (count) {
1132                 KKASSERT(bmmask11);
1133                 if (how == HAMMER2_FREEMAP_DORECOVER) {
1134                         /*
1135                          * Recovery request, mark as allocated.
1136                          */
1137                         if ((*bitmap & bmmask11) != bmmask11) {
1138                                 if (modified == 0) {
1139                                         hammer2_chain_modify(chain, mtid, 0, 0);
1140                                         modified = 1;
1141                                         goto again;
1142                                 }
1143                                 if ((*bitmap & bmmask11) == bmmask00) {
1144                                         bmap->avail -=
1145                                                 HAMMER2_FREEMAP_BLOCK_SIZE;
1146                                         bgsize += HAMMER2_FREEMAP_BLOCK_SIZE;
1147                                 }
1148                                 if (bmap->class == 0)
1149                                         bmap->class = class;
1150                                 *bitmap |= bmmask11;
1151                                 if (hammer2_debug & 0x0040) {
1152                                         kprintf("hammer2_freemap_recover: "
1153                                                 "fixup type=%02x "
1154                                                 "block=%016jx/%zd\n",
1155                                                 bref->type, data_off, bytes);
1156                                 }
1157                         } else {
1158                                 /*
1159                                 kprintf("hammer2_freemap_recover:  good "
1160                                         "type=%02x block=%016jx/%zd\n",
1161                                         bref->type, data_off, bytes);
1162                                 */
1163                         }
1164                 }
1165 #if 0
1166                 /*
1167                  * XXX this stuff doesn't work, avail is miscalculated and
1168                  * code 10 means something else now.
1169                  */
1170                 else if ((*bitmap & bmmask11) == bmmask11) {
1171                         /*
1172                          * Mayfree/Realfree request and bitmap is currently
1173                          * marked as being fully allocated.
1174                          */
1175                         if (!modified) {
1176                                 hammer2_chain_modify(chain, 0);
1177                                 modified = 1;
1178                                 goto again;
1179                         }
1180                         if (how == HAMMER2_FREEMAP_DOREALFREE)
1181                                 *bitmap &= ~bmmask11;
1182                         else
1183                                 *bitmap = (*bitmap & ~bmmask11) | bmmask10;
1184                 } else if ((*bitmap & bmmask11) == bmmask10) {
1185                         /*
1186                          * Mayfree/Realfree request and bitmap is currently
1187                          * marked as being possibly freeable.
1188                          */
1189                         if (how == HAMMER2_FREEMAP_DOREALFREE) {
1190                                 if (!modified) {
1191                                         hammer2_chain_modify(chain, 0);
1192                                         modified = 1;
1193                                         goto again;
1194                                 }
1195                                 *bitmap &= ~bmmask11;
1196                         }
1197                 } else {
1198                         /*
1199                          * 01 - Not implemented, currently illegal state
1200                          * 00 - Not allocated at all, illegal free.
1201                          */
1202                         panic("hammer2_freemap_adjust: "
1203                               "Illegal state %08x(%08x)",
1204                               *bitmap, *bitmap & bmmask11);
1205                 }
1206 #endif
1207                 --count;
1208                 bmmask01 <<= 2;
1209                 bmmask10 <<= 2;
1210                 bmmask11 <<= 2;
1211         }
1212 #if HAMMER2_BMAP_ELEMENTS != 8
1213 #error "hammer2_freemap.c: HAMMER2_BMAP_ELEMENTS expected to be 8"
1214 #endif
1215         if (how == HAMMER2_FREEMAP_DOREALFREE && modified) {
1216                 bmap->avail += 1 << radix;
1217                 KKASSERT(bmap->avail <= HAMMER2_SEGSIZE);
1218                 if (bmap->avail == HAMMER2_SEGSIZE &&
1219                     bmap->bitmapq[0] == 0 &&
1220                     bmap->bitmapq[1] == 0 &&
1221                     bmap->bitmapq[2] == 0 &&
1222                     bmap->bitmapq[3] == 0 &&
1223                     bmap->bitmapq[4] == 0 &&
1224                     bmap->bitmapq[5] == 0 &&
1225                     bmap->bitmapq[6] == 0 &&
1226                     bmap->bitmapq[7] == 0) {
1227                         key = H2FMBASE(data_off, HAMMER2_FREEMAP_LEVEL0_RADIX);
1228                         kprintf("Freeseg %016jx\n", (intmax_t)key);
1229                         bmap->class = 0;
1230                 }
1231         }
1232
1233         /*
1234          * chain->bref.check.freemap.bigmask (XXX)
1235          *
1236          * Setting bigmask is a hint to the allocation code that there might
1237          * be something allocatable.  We also set this in recovery... it
1238          * doesn't hurt and we might want to use the hint for other validation
1239          * operations later on.
1240          *
1241          * We could calculate the largest possible allocation and set the
1242          * radii that could fit, but its easier just to set bigmask to -1.
1243          */
1244         if (modified) {
1245                 chain->bref.check.freemap.bigmask = -1;
1246                 hmp->freemap_relaxed = 0;       /* reset heuristic */
1247         }
1248
1249         hammer2_chain_unlock(chain);
1250         hammer2_chain_drop(chain);
1251 done:
1252         hammer2_chain_unlock(parent);
1253         hammer2_chain_drop(parent);
1254
1255         if (bgsize) {
1256                 hammer2_voldata_lock(hmp);
1257                 hammer2_voldata_modify(hmp);
1258                 hmp->voldata.allocator_free -= bgsize;
1259                 hammer2_voldata_unlock(hmp);
1260         }
1261 }
1262
1263 /*
1264  * Validate the freemap, in three stages.
1265  *
1266  * stage-1      ALLOCATED     -> POSSIBLY FREE
1267  *              POSSIBLY FREE -> POSSIBLY FREE (type corrected)
1268  *
1269  *      This transitions bitmap entries from ALLOCATED to POSSIBLY FREE.
1270  *      The POSSIBLY FREE state does not mean that a block is actually free
1271  *      and may be transitioned back to ALLOCATED in stage-2.
1272  *
1273  *      This is typically done during normal filesystem operations when
1274  *      something is deleted or a block is replaced.
1275  *
1276  *      This is done by bulkfree in-bulk after a memory-bounded meta-data
1277  *      scan to try to determine what might be freeable.
1278  *
1279  *      This can be done unconditionally through a freemap scan when the
1280  *      intention is to brute-force recover the proper state of the freemap.
1281  *
1282  * stage-2      POSSIBLY FREE -> ALLOCATED      (scan metadata topology)
1283  *
1284  *      This is done by bulkfree during a meta-data scan to ensure that
1285  *      all blocks still actually allocated by the filesystem are marked
1286  *      as such.
1287  *
1288  *      NOTE! Live filesystem transitions to POSSIBLY FREE can occur while
1289  *            the bulkfree stage-2 and stage-3 is running.  The live filesystem
1290  *            will use the alternative POSSIBLY FREE type (2) to prevent
1291  *            stage-3 from improperly transitioning unvetted possibly-free
1292  *            blocks to FREE.
1293  *
1294  * stage-3      POSSIBLY FREE (type 1) -> FREE  (scan freemap)
1295  *
1296  *      This is done by bulkfree to finalize POSSIBLY FREE states.
1297  *
1298  */