sys/vfs/hammer2/hammer2_freemap.c

   1 /*
   2  * Copyright (c) 2011-2013 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 struct hammer2_fiterate {
  49         hammer2_off_t   bpref;
  50         hammer2_off_t   bnext;
  51         int             loops;
  52 };
  53
  54 typedef struct hammer2_fiterate hammer2_fiterate_t;
  55
  56 static int hammer2_freemap_try_alloc(hammer2_trans_t *trans,
  57                         hammer2_chain_t **parentp, hammer2_blockref_t *bref,
  58                         int radix, hammer2_fiterate_t *iter);
  59 static void hammer2_freemap_init(hammer2_trans_t *trans, hammer2_mount_t *hmp,
  60                         hammer2_key_t key, hammer2_chain_t *chain);
  61 static int hammer2_bmap_alloc(hammer2_trans_t *trans, hammer2_mount_t *hmp,
  62                         hammer2_bmap_data_t *bmap, uint16_t class,
  63                         int n, int radix, hammer2_key_t *basep);
  64 static int hammer2_freemap_iterate(hammer2_trans_t *trans,
  65                         hammer2_chain_t **parentp, hammer2_chain_t **chainp,
  66                         hammer2_fiterate_t *iter);
  67
  68 static __inline
  69 int
  70 hammer2_freemapradix(int radix)
  71 {
  72         return(radix);
  73 }
  74
  75 /*
  76  * Calculate the device offset for the specified FREEMAP_NODE or FREEMAP_LEAF
  77  * bref.  Return a combined media offset and physical size radix.  Freemap
  78  * chains use fixed storage offsets in the 4MB reserved area at the
  79  * beginning of each 2GB zone
  80  *
  81  * Rotate between four possibilities.  Theoretically this means we have three
  82  * good freemaps in case of a crash which we can use as a base for the fixup
  83  * scan at mount-time.
  84  */
  85 #define H2FMBASE(key, radix)    ((key) & ~(((hammer2_off_t)1 << (radix)) - 1))
  86 #define H2FMSHIFT(radix)        ((hammer2_off_t)1 << (radix))
  87
  88 static
  89 int
  90 hammer2_freemap_reserve(hammer2_trans_t *trans, hammer2_chain_t *chain,
  91                         int radix)
  92 {
  93         hammer2_blockref_t *bref = &chain->bref;
  94         hammer2_off_t off;
  95         int index;
  96         size_t bytes;
  97
  98         /*
  99          * Physical allocation size -> radix.  Typically either 256 for
 100          * a level 0 freemap leaf or 65536 for a level N freemap node.
 101          *
 102          * NOTE: A 256 byte bitmap represents 256 x 8 x 1024 = 2MB of storage.
 103          *       Do not use hammer2_allocsize() here as it has a min cap.
 104          */
 105         bytes = 1 << radix;
 106
 107         /*
 108          * Calculate block selection index 0..7 of current block.
 109          */
 110         if ((bref->data_off & ~HAMMER2_OFF_MASK_RADIX) == 0) {
 111                 index = 0;
 112         } else {
 113                 off = bref->data_off & ~HAMMER2_OFF_MASK_RADIX &
 114                       (((hammer2_off_t)1 << HAMMER2_FREEMAP_LEVEL1_RADIX) - 1);
 115                 off = off / HAMMER2_PBUFSIZE;
 116                 KKASSERT(off >= HAMMER2_ZONE_FREEMAP_00 &&
 117                          off < HAMMER2_ZONE_FREEMAP_END);
 118                 index = (int)(off - HAMMER2_ZONE_FREEMAP_00) / 4;
 119                 KKASSERT(index >= 0 && index < HAMMER2_ZONE_FREEMAP_COPIES);
 120         }
 121
 122         /*
 123          * Calculate new index (our 'allocation').  We have to be careful
 124          * here as there can be two different transaction ids running
 125          * concurrently when a flush is in-progress.
 126          *
 127          * We also want to make sure, for algorithmic repeatability, that
 128          * the index sequences are monotonic with transaction ids.  Some
 129          * skipping is allowed as long as we ensure that all four volume
 130          * header backups have consistent freemaps.
 131          *
 132          * FLUSH  NORMAL FLUSH  NORMAL FLUSH  NORMAL FLUSH  NORMAL
 133          * N+=1   N+=2
 134          * (0->1) (1->3) (3->4) (4->6) (6->7) (7->9) (9->10) (10->12)
 135          *
 136          * [-concurrent-][-concurrent-][-concurrent-][-concurrent-]
 137          *
 138          * (alternative first NORMAL might be 0->2 if flush had not yet
 139          *  modified the chain, this is the worst case).
 140          */
 141         if ((trans->flags & HAMMER2_TRANS_ISFLUSH) == 0) {
 142                 /*
 143                  * Normal transactions always run with the highest TID.
 144                  * But if a flush is in-progress we want to reserve a slot
 145                  * for the flush with a lower TID running concurrently to
 146                  * do a delete-duplicate.
 147                  */
 148                 index = (index + 2) % HAMMER2_ZONE_FREEMAP_COPIES;
 149         } else if (trans->flags & HAMMER2_TRANS_ISALLOCATING) {
 150                 /*
 151                  * Flush transaction, hammer2_freemap.c itself is doing a
 152                  * delete-duplicate during an allocation within the freemap.
 153                  */
 154                 index = (index + 1) % HAMMER2_ZONE_FREEMAP_COPIES;
 155         } else {
 156                 /*
 157                  * Flush transaction, hammer2_flush.c is doing a
 158                  * delete-duplicate on the freemap while flushing
 159                  * hmp->fchain.
 160                  */
 161                 index = (index + 1) % HAMMER2_ZONE_FREEMAP_COPIES;
 162         }
 163
 164         /*
 165          * Calculate the block offset of the reserved block.  This will
 166          * point into the 4MB reserved area at the base of the appropriate
 167          * 2GB zone, once added to the FREEMAP_x selection above.
 168          */
 169         switch(bref->keybits) {
 170         /* case HAMMER2_FREEMAP_LEVEL5_RADIX: not applicable */
 171         case HAMMER2_FREEMAP_LEVEL4_RADIX:      /* 2EB */
 172                 KKASSERT(bref->type == HAMMER2_BREF_TYPE_FREEMAP_NODE);
 173                 KKASSERT(bytes == HAMMER2_FREEMAP_LEVELN_PSIZE);
 174                 off = H2FMBASE(bref->key, HAMMER2_FREEMAP_LEVEL4_RADIX) +
 175                       (index * 4 + HAMMER2_ZONEFM_LEVEL4) * HAMMER2_PBUFSIZE;
 176                 break;
 177         case HAMMER2_FREEMAP_LEVEL3_RADIX:      /* 2PB */
 178                 KKASSERT(bref->type == HAMMER2_BREF_TYPE_FREEMAP_NODE);
 179                 KKASSERT(bytes == HAMMER2_FREEMAP_LEVELN_PSIZE);
 180                 off = H2FMBASE(bref->key, HAMMER2_FREEMAP_LEVEL3_RADIX) +
 181                       (index * 4 + HAMMER2_ZONEFM_LEVEL3) * HAMMER2_PBUFSIZE;
 182                 break;
 183         case HAMMER2_FREEMAP_LEVEL2_RADIX:      /* 2TB */
 184                 KKASSERT(bref->type == HAMMER2_BREF_TYPE_FREEMAP_NODE);
 185                 KKASSERT(bytes == HAMMER2_FREEMAP_LEVELN_PSIZE);
 186                 off = H2FMBASE(bref->key, HAMMER2_FREEMAP_LEVEL2_RADIX) +
 187                       (index * 4 + HAMMER2_ZONEFM_LEVEL2) * HAMMER2_PBUFSIZE;
 188                 break;
 189         case HAMMER2_FREEMAP_LEVEL1_RADIX:      /* 2GB */
 190                 KKASSERT(bref->type == HAMMER2_BREF_TYPE_FREEMAP_LEAF);
 191                 KKASSERT(bytes == HAMMER2_FREEMAP_LEVELN_PSIZE);
 192                 off = H2FMBASE(bref->key, HAMMER2_FREEMAP_LEVEL1_RADIX) +
 193                       (index * 4 + HAMMER2_ZONEFM_LEVEL1) * HAMMER2_PBUFSIZE;
 194                 break;
 195         default:
 196                 panic("freemap: bad radix(2) %p %d\n", bref, bref->keybits);
 197                 /* NOT REACHED */
 198                 off = (hammer2_off_t)-1;
 199                 break;
 200         }
 201         bref->data_off = off | radix;
 202 #if 0
 203         kprintf("-> %016jx\n", bref->data_off);
 204 #endif
 205         return (0);
 206 }
 207
 208 /*
 209  * Normal freemap allocator
 210  *
 211  * Use available hints to allocate space using the freemap.  Create missing
 212  * freemap infrastructure on-the-fly as needed (including marking initial
 213  * allocations using the iterator as allocated, instantiating new 2GB zones,
 214  * and dealing with the end-of-media edge case).
 215  *
 216  * ip and bpref are only used as a heuristic to determine locality of
 217  * reference.  bref->key may also be used heuristically.
 218  *
 219  * WARNING! When called from a flush we have to use the 'live' sync_tid
 220  *          and not the flush sync_tid.  The live sync_tid is the flush
 221  *          sync_tid + 1.  That is, freemap allocations which occur during
 222  *          a flush are not part of the flush.  Crash-recovery will restore
 223  *          any lost allocations.
 224  */
 225 int
 226 hammer2_freemap_alloc(hammer2_trans_t *trans, hammer2_chain_t *chain,
 227                       size_t bytes)
 228 {
 229         hammer2_mount_t *hmp = chain->hmp;
 230         hammer2_blockref_t *bref = &chain->bref;
 231         hammer2_chain_t *parent;
 232         int radix;
 233         int error;
 234         unsigned int hindex;
 235         hammer2_fiterate_t iter;
 236
 237         /*
 238          * Validate the allocation size.  It must be a power of 2.
 239          *
 240          * For now require that the caller be aware of the minimum
 241          * allocation (1K).
 242          */
 243         radix = hammer2_getradix(bytes);
 244         KKASSERT((size_t)1 << radix == bytes);
 245
 246         /*
 247          * Freemap blocks themselves are simply assigned from the reserve
 248          * area, not allocated from the freemap.
 249          */
 250         if (bref->type == HAMMER2_BREF_TYPE_FREEMAP_NODE ||
 251             bref->type == HAMMER2_BREF_TYPE_FREEMAP_LEAF) {
 252                 return (hammer2_freemap_reserve(trans, chain, radix));
 253         }
 254
 255         /*
 256          * Mark previously allocated block as possibly freeable.  There might
 257          * be snapshots and other races so we can't just mark it fully free.
 258          * (XXX optimize this for the current-transaction create+delete case)
 259          */
 260         if (bref->data_off & ~HAMMER2_OFF_MASK_RADIX) {
 261                 hammer2_freemap_adjust(trans, hmp, bref,
 262                                        HAMMER2_FREEMAP_DOMAYFREE);
 263         }
 264
 265         /*
 266          * Setting ISALLOCATING ensures correct operation even when the
 267          * flusher itself is making allocations.
 268          */
 269         KKASSERT(bytes >= HAMMER2_MIN_ALLOC && bytes <= HAMMER2_MAX_ALLOC);
 270         KKASSERT((trans->flags & HAMMER2_TRANS_ISALLOCATING) == 0);
 271         atomic_set_int(&trans->flags, HAMMER2_TRANS_ISALLOCATING);
 272         if (trans->flags & HAMMER2_TRANS_ISFLUSH)
 273                 ++trans->sync_tid;
 274
 275         /*
 276          * Calculate the starting point for our allocation search.
 277          *
 278          * Each freemap leaf is dedicated to a specific freemap_radix.
 279          * The freemap_radix can be more fine-grained than the device buffer
 280          * radix which results in inodes being grouped together in their
 281          * own segment, terminal-data (16K or less) and initial indirect
 282          * block being grouped together, and then full-indirect and full-data
 283          * blocks (64K) being grouped together.
 284          *
 285          * The single most important aspect of this is the inode grouping
 286          * because that is what allows 'find' and 'ls' and other filesystem
 287          * topology operations to run fast.
 288          */
 289 #if 0
 290         if (bref->data_off & ~HAMMER2_OFF_MASK_RADIX)
 291                 bpref = bref->data_off & ~HAMMER2_OFF_MASK_RADIX;
 292         else if (trans->tmp_bpref)
 293                 bpref = trans->tmp_bpref;
 294         else if (trans->tmp_ip)
 295                 bpref = trans->tmp_ip->chain->bref.data_off;
 296         else
 297 #endif
 298         /*
 299          * Heuristic tracking index.  We would like one for each distinct
 300          * bref type if possible.  heur_freemap[] has room for two classes
 301          * for each type.  At a minimum we have to break-up our heuristic
 302          * by device block sizes.
 303          */
 304         hindex = hammer2_devblkradix(radix) - HAMMER2_MINIORADIX;
 305         KKASSERT(hindex < HAMMER2_FREEMAP_HEUR_NRADIX);
 306         hindex += bref->type * HAMMER2_FREEMAP_HEUR_NRADIX;
 307         hindex &= HAMMER2_FREEMAP_HEUR_TYPES * HAMMER2_FREEMAP_HEUR_NRADIX - 1;
 308         KKASSERT(hindex < HAMMER2_FREEMAP_HEUR);
 309
 310         iter.bpref = hmp->heur_freemap[hindex];
 311
 312         /*
 313          * Make sure bpref is in-bounds.  It's ok if bpref covers a zone's
 314          * reserved area, the try code will iterate past it.
 315          */
 316         if (iter.bpref > hmp->voldata.volu_size)
 317                 iter.bpref = hmp->voldata.volu_size - 1;
 318
 319         /*
 320          * Iterate the freemap looking for free space before and after.
 321          */
 322         parent = &hmp->fchain;
 323         hammer2_chain_lock(parent, HAMMER2_RESOLVE_ALWAYS);
 324         error = EAGAIN;
 325         iter.bnext = iter.bpref;
 326         iter.loops = 0;
 327
 328         while (error == EAGAIN) {
 329                 error = hammer2_freemap_try_alloc(trans, &parent, bref,
 330                                                   radix, &iter);
 331         }
 332         hmp->heur_freemap[hindex] = iter.bnext;
 333         hammer2_chain_unlock(parent);
 334
 335         atomic_clear_int(&trans->flags, HAMMER2_TRANS_ISALLOCATING);
 336         if (trans->flags & HAMMER2_TRANS_ISFLUSH)
 337                 --trans->sync_tid;
 338
 339         return (error);
 340 }
 341
 342 static int
 343 hammer2_freemap_try_alloc(hammer2_trans_t *trans, hammer2_chain_t **parentp,
 344                           hammer2_blockref_t *bref, int radix,
 345                           hammer2_fiterate_t *iter)
 346 {
 347         hammer2_mount_t *hmp = (*parentp)->hmp;
 348         hammer2_off_t l0size;
 349         hammer2_off_t l1size;
 350         hammer2_off_t l1mask;
 351         hammer2_key_t key_dummy;
 352         hammer2_chain_t *chain;
 353         hammer2_off_t key;
 354         size_t bytes;
 355         uint16_t class;
 356         int error = 0;
 357         int cache_index = -1;
 358
 359
 360         /*
 361          * Calculate the number of bytes being allocated, the number
 362          * of contiguous bits of bitmap being allocated, and the bitmap
 363          * mask.
 364          *
 365          * WARNING! cpu hardware may mask bits == 64 -> 0 and blow up the
 366          *          mask calculation.
 367          */
 368         bytes = (size_t)1 << radix;
 369         class = (bref->type << 8) | hammer2_devblkradix(radix);
 370
 371         /*
 372          * Lookup the level1 freemap chain, creating and initializing one
 373          * if necessary.  Intermediate levels will be created automatically
 374          * when necessary by hammer2_chain_create().
 375          */
 376         key = H2FMBASE(iter->bnext, HAMMER2_FREEMAP_LEVEL1_RADIX);
 377         l0size = H2FMSHIFT(HAMMER2_FREEMAP_LEVEL0_RADIX);
 378         l1size = H2FMSHIFT(HAMMER2_FREEMAP_LEVEL1_RADIX);
 379         l1mask = l1size - 1;
 380
 381         chain = hammer2_chain_lookup(parentp, &key_dummy, key, key + l1mask,
 382                                      &cache_index,
 383                                      HAMMER2_LOOKUP_ALWAYS |
 384                                      HAMMER2_LOOKUP_MATCHIND);
 385
 386         if (chain == NULL) {
 387                 /*
 388                  * Create the missing leaf, be sure to initialize
 389                  * the auxillary freemap tracking information in
 390                  * the bref.check.freemap structure.
 391                  */
 392 #if 0
 393                 kprintf("freemap create L1 @ %016jx bpref %016jx\n",
 394                         key, iter->bpref);
 395 #endif
 396                 error = hammer2_chain_create(trans, parentp, &chain,
 397                                      key, HAMMER2_FREEMAP_LEVEL1_RADIX,
 398                                      HAMMER2_BREF_TYPE_FREEMAP_LEAF,
 399                                      HAMMER2_FREEMAP_LEVELN_PSIZE);
 400                 KKASSERT(error == 0);
 401                 if (error == 0) {
 402                         hammer2_chain_modify(trans, &chain, 0);
 403                         bzero(&chain->data->bmdata[0],
 404                               HAMMER2_FREEMAP_LEVELN_PSIZE);
 405                         chain->bref.check.freemap.bigmask = (uint32_t)-1;
 406                         chain->bref.check.freemap.avail = l1size;
 407                         /* bref.methods should already be inherited */
 408
 409                         hammer2_freemap_init(trans, hmp, key, chain);
 410                 }
 411         } else if ((chain->bref.check.freemap.bigmask & (1 << radix)) == 0) {
 412                 /*
 413                  * Already flagged as not having enough space
 414                  */
 415                 error = ENOSPC;
 416         } else {
 417                 /*
 418                  * Modify existing chain to setup for adjustment.
 419                  */
 420                 hammer2_chain_modify(trans, &chain, 0);
 421         }
 422
 423         /*
 424          * Scan 2MB entries.
 425          */
 426         if (error == 0) {
 427                 hammer2_bmap_data_t *bmap;
 428                 hammer2_key_t base_key;
 429                 int count;
 430                 int start;
 431                 int n;
 432
 433                 KKASSERT(chain->bref.type == HAMMER2_BREF_TYPE_FREEMAP_LEAF);
 434                 start = (int)((iter->bnext - key) >>
 435                               HAMMER2_FREEMAP_LEVEL0_RADIX);
 436                 KKASSERT(start >= 0 && start < HAMMER2_FREEMAP_COUNT);
 437                 hammer2_chain_modify(trans, &chain, 0);
 438
 439                 error = ENOSPC;
 440                 for (count = 0; count < HAMMER2_FREEMAP_COUNT; ++count) {
 441                         if (start + count >= HAMMER2_FREEMAP_COUNT &&
 442                             start - count < 0) {
 443                                 break;
 444                         }
 445                         n = start + count;
 446                         bmap = &chain->data->bmdata[n];
 447                         if (n < HAMMER2_FREEMAP_COUNT && bmap->avail &&
 448                             (bmap->class == 0 || bmap->class == class)) {
 449                                 base_key = key + n * l0size;
 450                                 error = hammer2_bmap_alloc(trans, hmp, bmap,
 451                                                            class, n, radix,
 452                                                            &base_key);
 453                                 if (error != ENOSPC) {
 454                                         key = base_key;
 455                                         break;
 456                                 }
 457                         }
 458                         n = start - count;
 459                         bmap = &chain->data->bmdata[n];
 460                         if (n >= 0 && bmap->avail &&
 461                             (bmap->class == 0 || bmap->class == class)) {
 462                                 base_key = key + n * l0size;
 463                                 error = hammer2_bmap_alloc(trans, hmp, bmap,
 464                                                            class, n, radix,
 465                                                            &base_key);
 466                                 if (error != ENOSPC) {
 467                                         key = base_key;
 468                                         break;
 469                                 }
 470                         }
 471                 }
 472                 if (error == ENOSPC)
 473                         chain->bref.check.freemap.bigmask &= ~(1 << radix);
 474                 /* XXX also scan down from original count */
 475         }
 476
 477         if (error == 0) {
 478                 /*
 479                  * Assert validity.  Must be beyond the static allocator used
 480                  * by newfs_hammer2 (and thus also beyond the aux area),
 481                  * not go past the volume size, and must not be in the
 482                  * reserved segment area for a zone.
 483                  */
 484                 KKASSERT(key >= hmp->voldata.allocator_beg &&
 485                          key + bytes <= hmp->voldata.volu_size);
 486                 KKASSERT((key & HAMMER2_ZONE_MASK64) >= HAMMER2_ZONE_SEG);
 487                 bref->data_off = key | radix;
 488
 489 #if 0
 490                 kprintf("alloc cp=%p %016jx %016jx using %016jx\n",
 491                         chain,
 492                         bref->key, bref->data_off, chain->bref.data_off);
 493 #endif
 494         } else if (error == ENOSPC) {
 495                 /*
 496                  * Return EAGAIN with next iteration in iter->bnext, or
 497                  * return ENOSPC if the allocation map has been exhausted.
 498                  */
 499                 error = hammer2_freemap_iterate(trans, parentp, &chain, iter);
 500         }
 501
 502         /*
 503          * Cleanup
 504          */
 505         if (chain)
 506                 hammer2_chain_unlock(chain);
 507         return (error);
 508 }
 509
 510 /*
 511  * Allocate (1<<radix) bytes from the bmap whos base data offset is (*basep).
 512  *
 513  * If the linear iterator is mid-block we use it directly (the bitmap should
 514  * already be marked allocated), otherwise we search for a block in the bitmap
 515  * that fits the allocation request.
 516  *
 517  * A partial bitmap allocation sets the minimum bitmap granularity (16KB)
 518  * to fully allocated and adjusts the linear allocator to allow the
 519  * remaining space to be allocated.
 520  */
 521 static
 522 int
 523 hammer2_bmap_alloc(hammer2_trans_t *trans, hammer2_mount_t *hmp,
 524                    hammer2_bmap_data_t *bmap,
 525                    uint16_t class, int n, int radix, hammer2_key_t *basep)
 526 {
 527         hammer2_io_t *dio;
 528         size_t size;
 529         size_t bsize;
 530         int bmradix;
 531         uint32_t bmmask;
 532         int offset;
 533         int error;
 534         int i;
 535         int j;
 536
 537         /*
 538          * Take into account 2-bits per block when calculating bmradix.
 539          */
 540         size = (size_t)1 << radix;
 541
 542         if (radix <= HAMMER2_FREEMAP_BLOCK_RADIX) {
 543                 bmradix = 2;
 544                 bsize = HAMMER2_FREEMAP_BLOCK_SIZE;
 545                 /* (16K) 2 bits per allocation block */
 546         } else {
 547                 bmradix = 2 << (radix - HAMMER2_FREEMAP_BLOCK_RADIX);
 548                 bsize = size;
 549                 /* (32K-256K) 4, 8, 16, 32 bits per allocation block */
 550         }
 551
 552         /*
 553          * Use the linear iterator to pack small allocations, otherwise
 554          * fall-back to finding a free 16KB chunk.  The linear iterator
 555          * is only valid when *NOT* on a freemap chunking boundary (16KB).
 556          * If it is the bitmap must be scanned.  It can become invalid
 557          * once we pack to the boundary.  We adjust it after a bitmap
 558          * allocation only for sub-16KB allocations (so the perfectly good
 559          * previous value can still be used for fragments when 16KB+
 560          * allocations are made).
 561          *
 562          * Beware of hardware artifacts when bmradix == 32 (intermediate
 563          * result can wind up being '1' instead of '0' if hardware masks
 564          * bit-count & 31).
 565          *
 566          * NOTE: j needs to be even in the j= calculation.  As an artifact
 567          *       of the /2 division, our bitmask has to clear bit 0.
 568          *
 569          * NOTE: TODO this can leave little unallocatable fragments lying
 570          *       around.
 571          */
 572         if (((uint32_t)bmap->linear & HAMMER2_FREEMAP_BLOCK_MASK) + size <=
 573             HAMMER2_FREEMAP_BLOCK_SIZE &&
 574             (bmap->linear & HAMMER2_FREEMAP_BLOCK_MASK) &&
 575             bmap->linear < HAMMER2_SEGSIZE) {
 576                 KKASSERT(bmap->linear >= 0 &&
 577                          bmap->linear + size <= HAMMER2_SEGSIZE &&
 578                          (bmap->linear & (HAMMER2_MIN_ALLOC - 1)) == 0);
 579                 offset = bmap->linear;
 580                 i = offset / (HAMMER2_SEGSIZE / 8);
 581                 j = (offset / (HAMMER2_FREEMAP_BLOCK_SIZE / 2)) & 30;
 582                 bmmask = (bmradix == 32) ?
 583                          0xFFFFFFFFU : (1 << bmradix) - 1;
 584                 bmmask <<= j;
 585                 bmap->linear = offset + size;
 586         } else {
 587                 for (i = 0; i < 8; ++i) {
 588                         bmmask = (bmradix == 32) ?
 589                                  0xFFFFFFFFU : (1 << bmradix) - 1;
 590                         for (j = 0; j < 32; j += bmradix) {
 591                                 if ((bmap->bitmap[i] & bmmask) == 0)
 592                                         goto success;
 593                                 bmmask <<= bmradix;
 594                         }
 595                 }
 596                 /*fragments might remain*/
 597                 /*KKASSERT(bmap->avail == 0);*/
 598                 return (ENOSPC);
 599 success:
 600                 offset = i * (HAMMER2_SEGSIZE / 8) +
 601                          (j * (HAMMER2_FREEMAP_BLOCK_SIZE / 2));
 602                 if (size & HAMMER2_FREEMAP_BLOCK_MASK)
 603                         bmap->linear = offset + size;
 604         }
 605
 606         KKASSERT(i >= 0 && i < 8);      /* 8 x 16 -> 128 x 16K -> 2MB */
 607
 608         /*
 609          * Optimize the buffer cache to avoid unnecessary read-before-write
 610          * operations.
 611          *
 612          * The device block size could be larger than the allocation size
 613          * so the actual bitmap test is somewhat more involved.  We have
 614          * to use a compatible buffer size for this operation.
 615          */
 616         if ((bmap->bitmap[i] & bmmask) == 0 &&
 617             hammer2_devblksize(size) != size) {
 618                 size_t psize = hammer2_devblksize(size);
 619                 hammer2_off_t pmask = (hammer2_off_t)psize - 1;
 620                 int pbmradix = 2 << (hammer2_devblkradix(radix) -
 621                                      HAMMER2_FREEMAP_BLOCK_RADIX);
 622                 uint32_t pbmmask;
 623                 int pradix = hammer2_getradix(psize);
 624
 625                 pbmmask = (pbmradix == 32) ? 0xFFFFFFFFU : (1 << pbmradix) - 1;
 626                 while ((pbmmask & bmmask) == 0)
 627                         pbmmask <<= pbmradix;
 628
 629 #if 0
 630                 kprintf("%016jx mask %08x %08x %08x (%zd/%zd)\n",
 631                         *basep + offset, bmap->bitmap[i],
 632                         pbmmask, bmmask, size, psize);
 633 #endif
 634
 635                 if ((bmap->bitmap[i] & pbmmask) == 0) {
 636                         error = hammer2_io_newq(hmp,
 637                                                 (*basep + (offset & ~pmask)) |
 638                                                  pradix,
 639                                                 psize, &dio);
 640                         hammer2_io_bqrelse(&dio);
 641                 }
 642         }
 643
 644 #if 0
 645         /*
 646          * When initializing a new inode segment also attempt to initialize
 647          * an adjacent segment.  Be careful not to index beyond the array
 648          * bounds.
 649          *
 650          * We do this to try to localize inode accesses to improve
 651          * directory scan rates.  XXX doesn't improve scan rates.
 652          */
 653         if (size == HAMMER2_INODE_BYTES) {
 654                 if (n & 1) {
 655                         if (bmap[-1].radix == 0 && bmap[-1].avail)
 656                                 bmap[-1].radix = radix;
 657                 } else {
 658                         if (bmap[1].radix == 0 && bmap[1].avail)
 659                                 bmap[1].radix = radix;
 660                 }
 661         }
 662 #endif
 663
 664         /*
 665          * Adjust the linear iterator, set the radix if necessary (might as
 666          * well just set it unconditionally), adjust *basep to return the
 667          * allocated data offset.
 668          */
 669         bmap->bitmap[i] |= bmmask;
 670         bmap->class = class;
 671         bmap->avail -= size;
 672         *basep += offset;
 673
 674         hammer2_voldata_lock(hmp);
 675         hmp->voldata.allocator_free -= size;  /* XXX */
 676         hammer2_voldata_unlock(hmp, 1);
 677
 678         return(0);
 679 }
 680
 681 static
 682 void
 683 hammer2_freemap_init(hammer2_trans_t *trans, hammer2_mount_t *hmp,
 684                      hammer2_key_t key, hammer2_chain_t *chain)
 685 {
 686         hammer2_off_t l1size;
 687         hammer2_off_t lokey;
 688         hammer2_off_t hikey;
 689         hammer2_bmap_data_t *bmap;
 690         int count;
 691
 692         l1size = H2FMSHIFT(HAMMER2_FREEMAP_LEVEL1_RADIX);
 693
 694         /*
 695          * Calculate the portion of the 2GB map that should be initialized
 696          * as free.  Portions below or after will be initialized as allocated.
 697          * SEGMASK-align the areas so we don't have to worry about sub-scans
 698          * or endianess when using memset.
 699          *
 700          * (1) Ensure that all statically allocated space from newfs_hammer2
 701          *     is marked allocated.
 702          *
 703          * (2) Ensure that the reserved area is marked allocated (typically
 704          *     the first 4MB of the 2GB area being represented).
 705          *
 706          * (3) Ensure that any trailing space at the end-of-volume is marked
 707          *     allocated.
 708          *
 709          * WARNING! It is possible for lokey to be larger than hikey if the
 710          *          entire 2GB segment is within the static allocation.
 711          */
 712         lokey = (hmp->voldata.allocator_beg + HAMMER2_SEGMASK64) &
 713                 ~HAMMER2_SEGMASK64;
 714
 715         if (lokey < H2FMBASE(key, HAMMER2_FREEMAP_LEVEL1_RADIX) +
 716                   HAMMER2_ZONE_SEG64) {
 717                 lokey = H2FMBASE(key, HAMMER2_FREEMAP_LEVEL1_RADIX) +
 718                         HAMMER2_ZONE_SEG64;
 719         }
 720
 721         hikey = key + H2FMSHIFT(HAMMER2_FREEMAP_LEVEL1_RADIX);
 722         if (hikey > hmp->voldata.volu_size) {
 723                 hikey = hmp->voldata.volu_size & ~HAMMER2_SEGMASK64;
 724         }
 725
 726         chain->bref.check.freemap.avail =
 727                 H2FMSHIFT(HAMMER2_FREEMAP_LEVEL1_RADIX);
 728         bmap = &chain->data->bmdata[0];
 729
 730         for (count = 0; count < HAMMER2_FREEMAP_COUNT; ++count) {
 731                 if (key < lokey || key >= hikey) {
 732                         memset(bmap->bitmap, -1,
 733                                sizeof(bmap->bitmap));
 734                         bmap->avail = 0;
 735                         bmap->linear = HAMMER2_SEGSIZE;
 736                         chain->bref.check.freemap.avail -=
 737                                 H2FMSHIFT(HAMMER2_FREEMAP_LEVEL0_RADIX);
 738                 } else {
 739                         bmap->avail = H2FMSHIFT(HAMMER2_FREEMAP_LEVEL0_RADIX);
 740                 }
 741                 key += H2FMSHIFT(HAMMER2_FREEMAP_LEVEL0_RADIX);
 742                 ++bmap;
 743         }
 744 }
 745
 746 /*
 747  * The current Level 1 freemap has been exhausted, iterate to the next
 748  * one, return ENOSPC if no freemaps remain.
 749  *
 750  * XXX this should rotate back to the beginning to handle freed-up space
 751  * XXX or use intermediate entries to locate free space. TODO
 752  */
 753 static int
 754 hammer2_freemap_iterate(hammer2_trans_t *trans, hammer2_chain_t **parentp,
 755                         hammer2_chain_t **chainp, hammer2_fiterate_t *iter)
 756 {
 757         hammer2_mount_t *hmp = (*parentp)->hmp;
 758
 759         iter->bnext &= ~(H2FMSHIFT(HAMMER2_FREEMAP_LEVEL1_RADIX) - 1);
 760         iter->bnext += H2FMSHIFT(HAMMER2_FREEMAP_LEVEL1_RADIX);
 761         if (iter->bnext >= hmp->voldata.volu_size) {
 762                 iter->bnext = 0;
 763                 if (++iter->loops == 2)
 764                         return (ENOSPC);
 765         }
 766         return(EAGAIN);
 767 }
 768
 769 /*
 770  * Free the specified blockref.  This code is only able to fully free
 771  * blocks when (how) is non-zero, otherwise the block is marked for
 772  * the bulk freeing pass to check.
 773  *
 774  * Normal use is to only mark inodes as possibly being free.  The underlying
 775  * file blocks are not necessarily marked.  The bulk freescan can
 776  * theoretically handle the case.
 777  *
 778  * XXX currently disabled when how == 0 (the normal real-time case).  At
 779  * the moment we depend on the bulk freescan to actually free blocks.  It
 780  * will still call this routine with a non-zero how to stage possible frees
 781  * and to do the actual free.
 782  *
 783  * WARNING! When called from a flush we have to use the 'live' sync_tid
 784  *          and not the flush sync_tid.  The live sync_tid is the flush
 785  *          sync_tid + 1.  That is, freemap allocations which occur during
 786  *          a flush are not part of the flush.  Crash-recovery will restore
 787  *          any lost allocations.
 788  */
 789 void
 790 hammer2_freemap_adjust(hammer2_trans_t *trans, hammer2_mount_t *hmp,
 791                        hammer2_blockref_t *bref, int how)
 792 {
 793         hammer2_off_t data_off = bref->data_off;
 794         hammer2_chain_t *chain;
 795         hammer2_chain_t *parent;
 796         hammer2_bmap_data_t *bmap;
 797         hammer2_key_t key;
 798         hammer2_key_t key_dummy;
 799         hammer2_off_t l0size;
 800         hammer2_off_t l1size;
 801         hammer2_off_t l1mask;
 802         uint32_t *bitmap;
 803         const uint32_t bmmask00 = 0;
 804         uint32_t bmmask01;
 805         uint32_t bmmask10;
 806         uint32_t bmmask11;
 807         size_t bytes;
 808         uint16_t class;
 809         int radix;
 810         int start;
 811         int count;
 812         int modified = 0;
 813         int cache_index = -1;
 814         int error;
 815
 816         radix = (int)data_off & HAMMER2_OFF_MASK_RADIX;
 817         data_off &= ~HAMMER2_OFF_MASK_RADIX;
 818         KKASSERT(radix <= HAMMER2_MAX_RADIX);
 819
 820         bytes = (size_t)1 << radix;
 821         class = (bref->type << 8) | hammer2_devblkradix(radix);
 822
 823         /*
 824          * We can't adjust thre freemap for data allocations made by
 825          * newfs_hammer2.
 826          */
 827         if (data_off < hmp->voldata.allocator_beg)
 828                 return;
 829
 830         KKASSERT((data_off & HAMMER2_ZONE_MASK64) >= HAMMER2_ZONE_SEG);
 831         KKASSERT((trans->flags & HAMMER2_TRANS_ISALLOCATING) == 0);
 832         atomic_set_int(&trans->flags, HAMMER2_TRANS_ISALLOCATING);
 833         if (trans->flags & HAMMER2_TRANS_ISFLUSH)
 834                 ++trans->sync_tid;
 835
 836         /*
 837          * Lookup the level1 freemap chain.  The chain must exist.
 838          */
 839         key = H2FMBASE(data_off, HAMMER2_FREEMAP_LEVEL1_RADIX);
 840         l0size = H2FMSHIFT(HAMMER2_FREEMAP_LEVEL0_RADIX);
 841         l1size = H2FMSHIFT(HAMMER2_FREEMAP_LEVEL1_RADIX);
 842         l1mask = l1size - 1;
 843
 844         parent = &hmp->fchain;
 845         hammer2_chain_lock(parent, HAMMER2_RESOLVE_ALWAYS);
 846
 847         chain = hammer2_chain_lookup(&parent, &key_dummy, key, key + l1mask,
 848                                      &cache_index,
 849                                      HAMMER2_LOOKUP_ALWAYS |
 850                                      HAMMER2_LOOKUP_MATCHIND);
 851
 852         /*
 853          * Stop early if we are trying to free something but no leaf exists.
 854          */
 855         if (chain == NULL && how != HAMMER2_FREEMAP_DORECOVER) {
 856                 kprintf("hammer2_freemap_adjust: %016jx: no chain\n",
 857                         (intmax_t)bref->data_off);
 858                 goto done;
 859         }
 860
 861         /*
 862          * Create any missing leaf(s) if we are doing a recovery (marking
 863          * the block(s) as being allocated instead of being freed).  Be sure
 864          * to initialize the auxillary freemap tracking info in the
 865          * bref.check.freemap structure.
 866          */
 867         if (chain == NULL && how == HAMMER2_FREEMAP_DORECOVER) {
 868                 error = hammer2_chain_create(trans, &parent, &chain,
 869                                      key, HAMMER2_FREEMAP_LEVEL1_RADIX,
 870                                      HAMMER2_BREF_TYPE_FREEMAP_LEAF,
 871                                      HAMMER2_FREEMAP_LEVELN_PSIZE);
 872
 873                 if (hammer2_debug & 0x0040) {
 874                         kprintf("fixup create chain %p %016jx:%d\n",
 875                                 chain, chain->bref.key, chain->bref.keybits);
 876                 }
 877
 878                 if (error == 0) {
 879                         hammer2_chain_modify(trans, &chain, 0);
 880                         bzero(&chain->data->bmdata[0],
 881                               HAMMER2_FREEMAP_LEVELN_PSIZE);
 882                         chain->bref.check.freemap.bigmask = (uint32_t)-1;
 883                         chain->bref.check.freemap.avail = l1size;
 884                         /* bref.methods should already be inherited */
 885
 886                         hammer2_freemap_init(trans, hmp, key, chain);
 887                 }
 888                 /* XXX handle error */
 889         }
 890
 891         /*
 892          * Calculate the bitmask (runs in 2-bit pairs).
 893          */
 894         start = ((int)(data_off >> HAMMER2_FREEMAP_BLOCK_RADIX) & 15) * 2;
 895         bmmask01 = 1 << start;
 896         bmmask10 = 2 << start;
 897         bmmask11 = 3 << start;
 898
 899         /*
 900          * Fixup the bitmap.  Partial blocks cannot be fully freed unless
 901          * a bulk scan is able to roll them up.
 902          */
 903         if (radix < HAMMER2_FREEMAP_BLOCK_RADIX) {
 904                 count = 1;
 905                 if (how == HAMMER2_FREEMAP_DOREALFREE)
 906                         how = HAMMER2_FREEMAP_DOMAYFREE;
 907         } else {
 908                 count = 1 << (radix - HAMMER2_FREEMAP_BLOCK_RADIX);
 909         }
 910
 911         /*
 912          * [re]load the bmap and bitmap pointers.  Each bmap entry covers
 913          * a 2MB swath.  The bmap itself (LEVEL1) covers 2GB.
 914          */
 915 again:
 916         bmap = &chain->data->bmdata[(int)(data_off >> HAMMER2_SEGRADIX) &
 917                                     (HAMMER2_FREEMAP_COUNT - 1)];
 918         bitmap = &bmap->bitmap[(int)(data_off >> (HAMMER2_SEGRADIX - 3)) & 7];
 919
 920
 921         while (count) {
 922                 KKASSERT(bmmask11);
 923                 if (how == HAMMER2_FREEMAP_DORECOVER) {
 924                         /*
 925                          * Recovery request, mark as allocated.
 926                          */
 927                         if ((*bitmap & bmmask11) != bmmask11) {
 928                                 if (modified == 0) {
 929                                         hammer2_chain_modify(trans, &chain, 0);
 930                                         modified = 1;
 931                                         goto again;
 932                                 }
 933                                 if ((*bitmap & bmmask11) == bmmask00)
 934                                         bmap->avail -= 1 << radix;
 935                                 if (bmap->class == 0)
 936                                         bmap->class = class;
 937                                 *bitmap |= bmmask11;
 938                                 if (hammer2_debug & 0x0040) {
 939                                         kprintf("hammer2_freemap_recover: "
 940                                                 "fixup type=%02x "
 941                                                 "block=%016jx/%zd\n",
 942                                                 bref->type, data_off, bytes);
 943                                 }
 944                         } else {
 945                                 /*
 946                                 kprintf("hammer2_freemap_recover:  good "
 947                                         "type=%02x block=%016jx/%zd\n",
 948                                         bref->type, data_off, bytes);
 949                                 */
 950                         }
 951                 } else if ((*bitmap & bmmask11) == bmmask11) {
 952                         /*
 953                          * Mayfree/Realfree request and bitmap is currently
 954                          * marked as being fully allocated.
 955                          */
 956                         if (!modified) {
 957                                 hammer2_chain_modify(trans, &chain, 0);
 958                                 modified = 1;
 959                                 goto again;
 960                         }
 961                         if (how == HAMMER2_FREEMAP_DOREALFREE)
 962                                 *bitmap &= ~bmmask11;
 963                         else
 964                                 *bitmap = (*bitmap & ~bmmask11) | bmmask10;
 965                 } else if ((*bitmap & bmmask11) == bmmask10) {
 966                         /*
 967                          * Mayfree/Realfree request and bitmap is currently
 968                          * marked as being possibly freeable.
 969                          */
 970                         if (how == HAMMER2_FREEMAP_DOREALFREE) {
 971                                 if (!modified) {
 972                                         hammer2_chain_modify(trans, &chain, 0);
 973                                         modified = 1;
 974                                         goto again;
 975                                 }
 976                                 *bitmap &= ~bmmask11;
 977                         }
 978                 } else {
 979                         /*
 980                          * 01 - Not implemented, currently illegal state
 981                          * 00 - Not allocated at all, illegal free.
 982                          */
 983                         panic("hammer2_freemap_adjust: "
 984                               "Illegal state %08x(%08x)",
 985                               *bitmap, *bitmap & bmmask11);
 986                 }
 987                 --count;
 988                 bmmask01 <<= 2;
 989                 bmmask10 <<= 2;
 990                 bmmask11 <<= 2;
 991         }
 992         if (how == HAMMER2_FREEMAP_DOREALFREE && modified) {
 993                 bmap->avail += 1 << radix;
 994                 KKASSERT(bmap->avail <= HAMMER2_SEGSIZE);
 995                 if (bmap->avail == HAMMER2_SEGSIZE &&
 996                     bmap->bitmap[0] == 0 &&
 997                     bmap->bitmap[1] == 0 &&
 998                     bmap->bitmap[2] == 0 &&
 999                     bmap->bitmap[3] == 0 &&
1000                     bmap->bitmap[4] == 0 &&
1001                     bmap->bitmap[5] == 0 &&
1002                     bmap->bitmap[6] == 0 &&
1003                     bmap->bitmap[7] == 0) {
1004                         key = H2FMBASE(data_off, HAMMER2_FREEMAP_LEVEL0_RADIX);
1005                         kprintf("Freeseg %016jx\n", (intmax_t)key);
1006                         bmap->class = 0;
1007                 }
1008         }
1009
1010         /*
1011          * chain->bref.check.freemap.bigmask (XXX)
1012          *
1013          * Setting bigmask is a hint to the allocation code that there might
1014          * be something allocatable.  We also set this in recovery... it
1015          * doesn't hurt and we might want to use the hint for other validation
1016          * operations later on.
1017          */
1018         if (modified)
1019                 chain->bref.check.freemap.bigmask |= 1 << radix;
1020
1021         hammer2_chain_unlock(chain);
1022 done:
1023         hammer2_chain_unlock(parent);
1024         atomic_clear_int(&trans->flags, HAMMER2_TRANS_ISALLOCATING);
1025         if (trans->flags & HAMMER2_TRANS_ISFLUSH)
1026                 --trans->sync_tid;
1027 }