sys/vfs/hammer2/hammer2_freemap.c

   1 /*
   2  * Copyright (c) 2011-2014 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 };
  55
  56 typedef struct hammer2_fiterate hammer2_fiterate_t;
  57
  58 static int hammer2_freemap_try_alloc(hammer2_trans_t *trans,
  59                         hammer2_chain_t **parentp, hammer2_blockref_t *bref,
  60                         int radix, hammer2_fiterate_t *iter);
  61 static void hammer2_freemap_init(hammer2_trans_t *trans, hammer2_dev_t *hmp,
  62                         hammer2_key_t key, hammer2_chain_t *chain);
  63 static int hammer2_bmap_alloc(hammer2_trans_t *trans, hammer2_dev_t *hmp,
  64                         hammer2_bmap_data_t *bmap, uint16_t class,
  65                         int n, int radix, hammer2_key_t *basep);
  66 static int hammer2_freemap_iterate(hammer2_trans_t *trans,
  67                         hammer2_chain_t **parentp, hammer2_chain_t **chainp,
  68                         hammer2_fiterate_t *iter);
  69
  70 static __inline
  71 int
  72 hammer2_freemapradix(int radix)
  73 {
  74         return(radix);
  75 }
  76
  77 /*
  78  * Calculate the device offset for the specified FREEMAP_NODE or FREEMAP_LEAF
  79  * bref.  Return a combined media offset and physical size radix.  Freemap
  80  * chains use fixed storage offsets in the 4MB reserved area at the
  81  * beginning of each 2GB zone
  82  *
  83  * Rotate between four possibilities.  Theoretically this means we have three
  84  * good freemaps in case of a crash which we can use as a base for the fixup
  85  * scan at mount-time.
  86  */
  87 #define H2FMBASE(key, radix)    ((key) & ~(((hammer2_off_t)1 << (radix)) - 1))
  88 #define H2FMSHIFT(radix)        ((hammer2_off_t)1 << (radix))
  89
  90 static
  91 int
  92 hammer2_freemap_reserve(hammer2_trans_t *trans, hammer2_chain_t *chain,
  93                         int radix)
  94 {
  95         hammer2_blockref_t *bref = &chain->bref;
  96         hammer2_off_t off;
  97         int index;
  98         size_t bytes;
  99
 100         /*
 101          * Physical allocation size -> radix.  Typically either 256 for
 102          * a level 0 freemap leaf or 65536 for a level N freemap node.
 103          *
 104          * NOTE: A 256 byte bitmap represents 256 x 8 x 1024 = 2MB of storage.
 105          *       Do not use hammer2_allocsize() here as it has a min cap.
 106          */
 107         bytes = 1 << radix;
 108
 109         /*
 110          * Calculate block selection index 0..7 of current block.  If this
 111          * is the first allocation of the block (verses a modification of an
 112          * existing block), we use index 0, otherwise we use the next rotating
 113          * index.
 114          */
 115         if ((bref->data_off & ~HAMMER2_OFF_MASK_RADIX) == 0) {
 116                 index = 0;
 117         } else {
 118                 off = bref->data_off & ~HAMMER2_OFF_MASK_RADIX &
 119                       (((hammer2_off_t)1 <<
 120                         HAMMER2_FREEMAP_LEVEL1_RADIX) - 1);
 121                 off = off / HAMMER2_PBUFSIZE;
 122                 KKASSERT(off >= HAMMER2_ZONE_FREEMAP_00 &&
 123                          off < HAMMER2_ZONE_FREEMAP_END);
 124                 index = (int)(off - HAMMER2_ZONE_FREEMAP_00) / 4;
 125                 KKASSERT(index >= 0 && index < HAMMER2_NFREEMAPS);
 126                 if (++index == HAMMER2_NFREEMAPS)
 127                         index = 0;
 128         }
 129
 130         /*
 131          * Calculate the block offset of the reserved block.  This will
 132          * point into the 4MB reserved area at the base of the appropriate
 133          * 2GB zone, once added to the FREEMAP_x selection above.
 134          */
 135         switch(bref->keybits) {
 136         /* case HAMMER2_FREEMAP_LEVEL5_RADIX: not applicable */
 137         case HAMMER2_FREEMAP_LEVEL4_RADIX:      /* 2EB */
 138                 KKASSERT(bref->type == HAMMER2_BREF_TYPE_FREEMAP_NODE);
 139                 KKASSERT(bytes == HAMMER2_FREEMAP_LEVELN_PSIZE);
 140                 off = H2FMBASE(bref->key, HAMMER2_FREEMAP_LEVEL4_RADIX) +
 141                       (index * 4 + HAMMER2_ZONE_FREEMAP_00 +
 142                        HAMMER2_ZONEFM_LEVEL4) * HAMMER2_PBUFSIZE;
 143                 break;
 144         case HAMMER2_FREEMAP_LEVEL3_RADIX:      /* 2PB */
 145                 KKASSERT(bref->type == HAMMER2_BREF_TYPE_FREEMAP_NODE);
 146                 KKASSERT(bytes == HAMMER2_FREEMAP_LEVELN_PSIZE);
 147                 off = H2FMBASE(bref->key, HAMMER2_FREEMAP_LEVEL3_RADIX) +
 148                       (index * 4 + HAMMER2_ZONE_FREEMAP_00 +
 149                        HAMMER2_ZONEFM_LEVEL3) * HAMMER2_PBUFSIZE;
 150                 break;
 151         case HAMMER2_FREEMAP_LEVEL2_RADIX:      /* 2TB */
 152                 KKASSERT(bref->type == HAMMER2_BREF_TYPE_FREEMAP_NODE);
 153                 KKASSERT(bytes == HAMMER2_FREEMAP_LEVELN_PSIZE);
 154                 off = H2FMBASE(bref->key, HAMMER2_FREEMAP_LEVEL2_RADIX) +
 155                       (index * 4 + HAMMER2_ZONE_FREEMAP_00 +
 156                        HAMMER2_ZONEFM_LEVEL2) * HAMMER2_PBUFSIZE;
 157                 break;
 158         case HAMMER2_FREEMAP_LEVEL1_RADIX:      /* 2GB */
 159                 KKASSERT(bref->type == HAMMER2_BREF_TYPE_FREEMAP_LEAF);
 160                 KKASSERT(bytes == HAMMER2_FREEMAP_LEVELN_PSIZE);
 161                 off = H2FMBASE(bref->key, HAMMER2_FREEMAP_LEVEL1_RADIX) +
 162                       (index * 4 + HAMMER2_ZONE_FREEMAP_00 +
 163                        HAMMER2_ZONEFM_LEVEL1) * HAMMER2_PBUFSIZE;
 164                 break;
 165         default:
 166                 panic("freemap: bad radix(2) %p %d\n", bref, bref->keybits);
 167                 /* NOT REACHED */
 168                 off = (hammer2_off_t)-1;
 169                 break;
 170         }
 171         bref->data_off = off | radix;
 172 #if FREEMAP_DEBUG
 173         kprintf("FREEMAP BLOCK TYPE %d %016jx/%d DATA_OFF=%016jx\n",
 174                 bref->type, bref->key, bref->keybits, bref->data_off);
 175 #endif
 176         return (0);
 177 }
 178
 179 /*
 180  * Normal freemap allocator
 181  *
 182  * Use available hints to allocate space using the freemap.  Create missing
 183  * freemap infrastructure on-the-fly as needed (including marking initial
 184  * allocations using the iterator as allocated, instantiating new 2GB zones,
 185  * and dealing with the end-of-media edge case).
 186  *
 187  * ip and bpref are only used as a heuristic to determine locality of
 188  * reference.  bref->key may also be used heuristically.
 189  */
 190 int
 191 hammer2_freemap_alloc(hammer2_trans_t *trans, hammer2_chain_t *chain,
 192                       size_t bytes)
 193 {
 194         hammer2_dev_t *hmp = chain->hmp;
 195         hammer2_blockref_t *bref = &chain->bref;
 196         hammer2_chain_t *parent;
 197         int radix;
 198         int error;
 199         unsigned int hindex;
 200         hammer2_fiterate_t iter;
 201
 202         /*
 203          * Validate the allocation size.  It must be a power of 2.
 204          *
 205          * For now require that the caller be aware of the minimum
 206          * allocation (1K).
 207          */
 208         radix = hammer2_getradix(bytes);
 209         KKASSERT((size_t)1 << radix == bytes);
 210
 211         if (bref->type == HAMMER2_BREF_TYPE_FREEMAP_NODE ||
 212             bref->type == HAMMER2_BREF_TYPE_FREEMAP_LEAF) {
 213                 /*
 214                  * Freemap blocks themselves are assigned from the reserve
 215                  * area, not allocated from the freemap.
 216                  */
 217                 error = hammer2_freemap_reserve(trans, chain, radix);
 218                 return error;
 219         }
 220
 221         KKASSERT(bytes >= HAMMER2_ALLOC_MIN && bytes <= HAMMER2_ALLOC_MAX);
 222
 223         if (trans->flags & (HAMMER2_TRANS_ISFLUSH | HAMMER2_TRANS_PREFLUSH))
 224                 ++trans->sync_xid;
 225
 226         /*
 227          * Calculate the starting point for our allocation search.
 228          *
 229          * Each freemap leaf is dedicated to a specific freemap_radix.
 230          * The freemap_radix can be more fine-grained than the device buffer
 231          * radix which results in inodes being grouped together in their
 232          * own segment, terminal-data (16K or less) and initial indirect
 233          * block being grouped together, and then full-indirect and full-data
 234          * blocks (64K) being grouped together.
 235          *
 236          * The single most important aspect of this is the inode grouping
 237          * because that is what allows 'find' and 'ls' and other filesystem
 238          * topology operations to run fast.
 239          */
 240 #if 0
 241         if (bref->data_off & ~HAMMER2_OFF_MASK_RADIX)
 242                 bpref = bref->data_off & ~HAMMER2_OFF_MASK_RADIX;
 243         else if (trans->tmp_bpref)
 244                 bpref = trans->tmp_bpref;
 245         else if (trans->tmp_ip)
 246                 bpref = trans->tmp_ip->chain->bref.data_off;
 247         else
 248 #endif
 249         /*
 250          * Heuristic tracking index.  We would like one for each distinct
 251          * bref type if possible.  heur_freemap[] has room for two classes
 252          * for each type.  At a minimum we have to break-up our heuristic
 253          * by device block sizes.
 254          */
 255         hindex = hammer2_devblkradix(radix) - HAMMER2_MINIORADIX;
 256         KKASSERT(hindex < HAMMER2_FREEMAP_HEUR_NRADIX);
 257         hindex += bref->type * HAMMER2_FREEMAP_HEUR_NRADIX;
 258         hindex &= HAMMER2_FREEMAP_HEUR_TYPES * HAMMER2_FREEMAP_HEUR_NRADIX - 1;
 259         KKASSERT(hindex < HAMMER2_FREEMAP_HEUR);
 260
 261         iter.bpref = hmp->heur_freemap[hindex];
 262
 263         /*
 264          * Make sure bpref is in-bounds.  It's ok if bpref covers a zone's
 265          * reserved area, the try code will iterate past it.
 266          */
 267         if (iter.bpref > hmp->voldata.volu_size)
 268                 iter.bpref = hmp->voldata.volu_size - 1;
 269
 270         /*
 271          * Iterate the freemap looking for free space before and after.
 272          */
 273         parent = &hmp->fchain;
 274         hammer2_chain_lock(parent, HAMMER2_RESOLVE_ALWAYS);
 275         error = EAGAIN;
 276         iter.bnext = iter.bpref;
 277         iter.loops = 0;
 278
 279         while (error == EAGAIN) {
 280                 error = hammer2_freemap_try_alloc(trans, &parent, bref,
 281                                                   radix, &iter);
 282         }
 283         hmp->heur_freemap[hindex] = iter.bnext;
 284         hammer2_chain_unlock(parent);
 285
 286         if (trans->flags & (HAMMER2_TRANS_ISFLUSH | HAMMER2_TRANS_PREFLUSH))
 287                 --trans->sync_xid;
 288
 289         return (error);
 290 }
 291
 292 static int
 293 hammer2_freemap_try_alloc(hammer2_trans_t *trans, hammer2_chain_t **parentp,
 294                           hammer2_blockref_t *bref, int radix,
 295                           hammer2_fiterate_t *iter)
 296 {
 297         hammer2_dev_t *hmp = (*parentp)->hmp;
 298         hammer2_off_t l0size;
 299         hammer2_off_t l1size;
 300         hammer2_off_t l1mask;
 301         hammer2_key_t key_dummy;
 302         hammer2_chain_t *chain;
 303         hammer2_off_t key;
 304         size_t bytes;
 305         uint16_t class;
 306         int error = 0;
 307         int cache_index = -1;
 308         int ddflag;
 309
 310
 311         /*
 312          * Calculate the number of bytes being allocated, the number
 313          * of contiguous bits of bitmap being allocated, and the bitmap
 314          * mask.
 315          *
 316          * WARNING! cpu hardware may mask bits == 64 -> 0 and blow up the
 317          *          mask calculation.
 318          */
 319         bytes = (size_t)1 << radix;
 320         class = (bref->type << 8) | hammer2_devblkradix(radix);
 321
 322         /*
 323          * Lookup the level1 freemap chain, creating and initializing one
 324          * if necessary.  Intermediate levels will be created automatically
 325          * when necessary by hammer2_chain_create().
 326          */
 327         key = H2FMBASE(iter->bnext, HAMMER2_FREEMAP_LEVEL1_RADIX);
 328         l0size = H2FMSHIFT(HAMMER2_FREEMAP_LEVEL0_RADIX);
 329         l1size = H2FMSHIFT(HAMMER2_FREEMAP_LEVEL1_RADIX);
 330         l1mask = l1size - 1;
 331
 332         chain = hammer2_chain_lookup(parentp, &key_dummy, key, key + l1mask,
 333                                      &cache_index,
 334                                      HAMMER2_LOOKUP_ALWAYS |
 335                                      HAMMER2_LOOKUP_MATCHIND, &ddflag);
 336
 337         if (chain == NULL) {
 338                 /*
 339                  * Create the missing leaf, be sure to initialize
 340                  * the auxillary freemap tracking information in
 341                  * the bref.check.freemap structure.
 342                  */
 343 #if 0
 344                 kprintf("freemap create L1 @ %016jx bpref %016jx\n",
 345                         key, iter->bpref);
 346 #endif
 347                 error = hammer2_chain_create(trans, parentp, &chain, hmp->spmp,
 348                                      key, HAMMER2_FREEMAP_LEVEL1_RADIX,
 349                                      HAMMER2_BREF_TYPE_FREEMAP_LEAF,
 350                                      HAMMER2_FREEMAP_LEVELN_PSIZE,
 351                                      0);
 352                 KKASSERT(error == 0);
 353                 if (error == 0) {
 354                         hammer2_chain_modify(trans, chain, 0);
 355                         bzero(&chain->data->bmdata[0],
 356                               HAMMER2_FREEMAP_LEVELN_PSIZE);
 357                         chain->bref.check.freemap.bigmask = (uint32_t)-1;
 358                         chain->bref.check.freemap.avail = l1size;
 359                         /* bref.methods should already be inherited */
 360
 361                         hammer2_freemap_init(trans, hmp, key, chain);
 362                 }
 363         } else if ((chain->bref.check.freemap.bigmask & (1 << radix)) == 0) {
 364                 /*
 365                  * Already flagged as not having enough space
 366                  */
 367                 error = ENOSPC;
 368         } else {
 369                 /*
 370                  * Modify existing chain to setup for adjustment.
 371                  */
 372                 hammer2_chain_modify(trans, chain, 0);
 373         }
 374
 375         /*
 376          * Scan 2MB entries.
 377          */
 378         if (error == 0) {
 379                 hammer2_bmap_data_t *bmap;
 380                 hammer2_key_t base_key;
 381                 int count;
 382                 int start;
 383                 int n;
 384
 385                 KKASSERT(chain->bref.type == HAMMER2_BREF_TYPE_FREEMAP_LEAF);
 386                 start = (int)((iter->bnext - key) >>
 387                               HAMMER2_FREEMAP_LEVEL0_RADIX);
 388                 KKASSERT(start >= 0 && start < HAMMER2_FREEMAP_COUNT);
 389                 hammer2_chain_modify(trans, chain, 0);
 390
 391                 error = ENOSPC;
 392                 for (count = 0; count < HAMMER2_FREEMAP_COUNT; ++count) {
 393                         int availchk;
 394
 395                         if (start + count >= HAMMER2_FREEMAP_COUNT &&
 396                             start - count < 0) {
 397                                 break;
 398                         }
 399
 400                         /*
 401                          * Calculate bmap pointer
 402                          *
 403                          * NOTE: bmap pointer is invalid if n >= FREEMAP_COUNT.
 404                          */
 405                         n = start + count;
 406                         bmap = &chain->data->bmdata[n];
 407
 408                         if (n >= HAMMER2_FREEMAP_COUNT) {
 409                                 availchk = 0;
 410                         } else if (bmap->avail) {
 411                                 availchk = 1;
 412                         } else if (radix < HAMMER2_FREEMAP_BLOCK_RADIX &&
 413                                   (bmap->linear & HAMMER2_FREEMAP_BLOCK_MASK)) {
 414                                 availchk = 1;
 415                         } else {
 416                                 availchk = 0;
 417                         }
 418
 419                         if (availchk &&
 420                             (bmap->class == 0 || bmap->class == class)) {
 421                                 base_key = key + n * l0size;
 422                                 error = hammer2_bmap_alloc(trans, hmp, bmap,
 423                                                            class, n, radix,
 424                                                            &base_key);
 425                                 if (error != ENOSPC) {
 426                                         key = base_key;
 427                                         break;
 428                                 }
 429                         }
 430
 431                         /*
 432                          * Must recalculate after potentially having called
 433                          * hammer2_bmap_alloc() above in case chain was
 434                          * reallocated.
 435                          *
 436                          * NOTE: bmap pointer is invalid if n < 0.
 437                          */
 438                         n = start - count;
 439                         bmap = &chain->data->bmdata[n];
 440                         if (n < 0) {
 441                                 availchk = 0;
 442                         } else if (bmap->avail) {
 443                                 availchk = 1;
 444                         } else if (radix < HAMMER2_FREEMAP_BLOCK_RADIX &&
 445                                   (bmap->linear & HAMMER2_FREEMAP_BLOCK_MASK)) {
 446                                 availchk = 1;
 447                         } else {
 448                                 availchk = 0;
 449                         }
 450
 451                         if (availchk &&
 452                             (bmap->class == 0 || bmap->class == class)) {
 453                                 base_key = key + n * l0size;
 454                                 error = hammer2_bmap_alloc(trans, hmp, bmap,
 455                                                            class, n, radix,
 456                                                            &base_key);
 457                                 if (error != ENOSPC) {
 458                                         key = base_key;
 459                                         break;
 460                                 }
 461                         }
 462                 }
 463                 if (error == ENOSPC)
 464                         chain->bref.check.freemap.bigmask &= ~(1 << radix);
 465                 /* XXX also scan down from original count */
 466         }
 467
 468         if (error == 0) {
 469                 /*
 470                  * Assert validity.  Must be beyond the static allocator used
 471                  * by newfs_hammer2 (and thus also beyond the aux area),
 472                  * not go past the volume size, and must not be in the
 473                  * reserved segment area for a zone.
 474                  */
 475                 KKASSERT(key >= hmp->voldata.allocator_beg &&
 476                          key + bytes <= hmp->voldata.volu_size);
 477                 KKASSERT((key & HAMMER2_ZONE_MASK64) >= HAMMER2_ZONE_SEG);
 478                 bref->data_off = key | radix;
 479
 480 #if 0
 481                 kprintf("alloc cp=%p %016jx %016jx using %016jx\n",
 482                         chain,
 483                         bref->key, bref->data_off, chain->bref.data_off);
 484 #endif
 485         } else if (error == ENOSPC) {
 486                 /*
 487                  * Return EAGAIN with next iteration in iter->bnext, or
 488                  * return ENOSPC if the allocation map has been exhausted.
 489                  */
 490                 error = hammer2_freemap_iterate(trans, parentp, &chain, iter);
 491         }
 492
 493         /*
 494          * Cleanup
 495          */
 496         if (chain)
 497                 hammer2_chain_unlock(chain);
 498         return (error);
 499 }
 500
 501 /*
 502  * Allocate (1<<radix) bytes from the bmap whos base data offset is (*basep).
 503  *
 504  * If the linear iterator is mid-block we use it directly (the bitmap should
 505  * already be marked allocated), otherwise we search for a block in the bitmap
 506  * that fits the allocation request.
 507  *
 508  * A partial bitmap allocation sets the minimum bitmap granularity (16KB)
 509  * to fully allocated and adjusts the linear allocator to allow the
 510  * remaining space to be allocated.
 511  */
 512 static
 513 int
 514 hammer2_bmap_alloc(hammer2_trans_t *trans, hammer2_dev_t *hmp,
 515                    hammer2_bmap_data_t *bmap,
 516                    uint16_t class, int n, int radix, hammer2_key_t *basep)
 517 {
 518         hammer2_io_t *dio;
 519         size_t size;
 520         size_t bgsize;
 521         int bmradix;
 522         uint32_t bmmask;
 523         int offset;
 524         int error;
 525         int i;
 526         int j;
 527
 528         /*
 529          * Take into account 2-bits per block when calculating bmradix.
 530          */
 531         size = (size_t)1 << radix;
 532
 533         if (radix <= HAMMER2_FREEMAP_BLOCK_RADIX) {
 534                 bmradix = 2;
 535                 /* (16K) 2 bits per allocation block */
 536         } else {
 537                 bmradix = 2 << (radix - HAMMER2_FREEMAP_BLOCK_RADIX);
 538                 /* (32K-256K) 4, 8, 16, 32 bits per allocation block */
 539         }
 540
 541         /*
 542          * Use the linear iterator to pack small allocations, otherwise
 543          * fall-back to finding a free 16KB chunk.  The linear iterator
 544          * is only valid when *NOT* on a freemap chunking boundary (16KB).
 545          * If it is the bitmap must be scanned.  It can become invalid
 546          * once we pack to the boundary.  We adjust it after a bitmap
 547          * allocation only for sub-16KB allocations (so the perfectly good
 548          * previous value can still be used for fragments when 16KB+
 549          * allocations are made).
 550          *
 551          * Beware of hardware artifacts when bmradix == 32 (intermediate
 552          * result can wind up being '1' instead of '0' if hardware masks
 553          * bit-count & 31).
 554          *
 555          * NOTE: j needs to be even in the j= calculation.  As an artifact
 556          *       of the /2 division, our bitmask has to clear bit 0.
 557          *
 558          * NOTE: TODO this can leave little unallocatable fragments lying
 559          *       around.
 560          */
 561         if (((uint32_t)bmap->linear & HAMMER2_FREEMAP_BLOCK_MASK) + size <=
 562             HAMMER2_FREEMAP_BLOCK_SIZE &&
 563             (bmap->linear & HAMMER2_FREEMAP_BLOCK_MASK) &&
 564             bmap->linear < HAMMER2_SEGSIZE) {
 565                 KKASSERT(bmap->linear >= 0 &&
 566                          bmap->linear + size <= HAMMER2_SEGSIZE &&
 567                          (bmap->linear & (HAMMER2_ALLOC_MIN - 1)) == 0);
 568                 offset = bmap->linear;
 569                 i = offset / (HAMMER2_SEGSIZE / 8);
 570                 j = (offset / (HAMMER2_FREEMAP_BLOCK_SIZE / 2)) & 30;
 571                 bmmask = (bmradix == 32) ?
 572                          0xFFFFFFFFU : (1 << bmradix) - 1;
 573                 bmmask <<= j;
 574                 bmap->linear = offset + size;
 575         } else {
 576                 for (i = 0; i < 8; ++i) {
 577                         bmmask = (bmradix == 32) ?
 578                                  0xFFFFFFFFU : (1 << bmradix) - 1;
 579                         for (j = 0; j < 32; j += bmradix) {
 580                                 if ((bmap->bitmap[i] & bmmask) == 0)
 581                                         goto success;
 582                                 bmmask <<= bmradix;
 583                         }
 584                 }
 585                 /*fragments might remain*/
 586                 /*KKASSERT(bmap->avail == 0);*/
 587                 return (ENOSPC);
 588 success:
 589                 offset = i * (HAMMER2_SEGSIZE / 8) +
 590                          (j * (HAMMER2_FREEMAP_BLOCK_SIZE / 2));
 591                 if (size & HAMMER2_FREEMAP_BLOCK_MASK)
 592                         bmap->linear = offset + size;
 593         }
 594
 595         KKASSERT(i >= 0 && i < 8);      /* 8 x 16 -> 128 x 16K -> 2MB */
 596
 597         /*
 598          * Optimize the buffer cache to avoid unnecessary read-before-write
 599          * operations.
 600          *
 601          * The device block size could be larger than the allocation size
 602          * so the actual bitmap test is somewhat more involved.  We have
 603          * to use a compatible buffer size for this operation.
 604          */
 605         if ((bmap->bitmap[i] & bmmask) == 0 &&
 606             hammer2_devblksize(size) != size) {
 607                 size_t psize = hammer2_devblksize(size);
 608                 hammer2_off_t pmask = (hammer2_off_t)psize - 1;
 609                 int pbmradix = 2 << (hammer2_devblkradix(radix) -
 610                                      HAMMER2_FREEMAP_BLOCK_RADIX);
 611                 uint32_t pbmmask;
 612                 int pradix = hammer2_getradix(psize);
 613
 614                 pbmmask = (pbmradix == 32) ? 0xFFFFFFFFU : (1 << pbmradix) - 1;
 615                 while ((pbmmask & bmmask) == 0)
 616                         pbmmask <<= pbmradix;
 617
 618 #if 0
 619                 kprintf("%016jx mask %08x %08x %08x (%zd/%zd)\n",
 620                         *basep + offset, bmap->bitmap[i],
 621                         pbmmask, bmmask, size, psize);
 622 #endif
 623
 624                 if ((bmap->bitmap[i] & pbmmask) == 0) {
 625                         error = hammer2_io_newq(hmp,
 626                                                 (*basep + (offset & ~pmask)) |
 627                                                  pradix,
 628                                                 psize, &dio);
 629                         hammer2_io_bqrelse(&dio);
 630                 }
 631         }
 632
 633 #if 0
 634         /*
 635          * When initializing a new inode segment also attempt to initialize
 636          * an adjacent segment.  Be careful not to index beyond the array
 637          * bounds.
 638          *
 639          * We do this to try to localize inode accesses to improve
 640          * directory scan rates.  XXX doesn't improve scan rates.
 641          */
 642         if (size == HAMMER2_INODE_BYTES) {
 643                 if (n & 1) {
 644                         if (bmap[-1].radix == 0 && bmap[-1].avail)
 645                                 bmap[-1].radix = radix;
 646                 } else {
 647                         if (bmap[1].radix == 0 && bmap[1].avail)
 648                                 bmap[1].radix = radix;
 649                 }
 650         }
 651 #endif
 652         /*
 653          * Calculate the bitmap-granular change in bgsize for the volume
 654          * header.  We cannot use the fine-grained change here because
 655          * the bulkfree code can't undo it.  If the bitmap element is already
 656          * marked allocated it has already been accounted for.
 657          */
 658         if (radix < HAMMER2_FREEMAP_BLOCK_RADIX) {
 659                 if (bmap->bitmap[i] & bmmask)
 660                         bgsize = 0;
 661                 else
 662                         bgsize = HAMMER2_FREEMAP_BLOCK_SIZE;
 663         } else {
 664                 bgsize = size;
 665         }
 666
 667         /*
 668          * Adjust the bitmap, set the class (it might have been 0),
 669          * and available bytes, update the allocation offset (*basep)
 670          * from the L0 base to the actual offset.
 671          *
 672          * avail must reflect the bitmap-granular availability.  The allocator
 673          * tests will also check the linear iterator.
 674          */
 675         bmap->bitmap[i] |= bmmask;
 676         bmap->class = class;
 677         bmap->avail -= bgsize;
 678         *basep += offset;
 679
 680         /*
 681          * Adjust the volume header's allocator_free parameter.  This
 682          * parameter has to be fixed up by bulkfree which has no way to
 683          * figure out sub-16K chunking, so it must be adjusted by the
 684          * bitmap-granular size.
 685          */
 686         if (bgsize) {
 687                 hammer2_voldata_lock(hmp);
 688                 hammer2_voldata_modify(hmp);
 689                 hmp->voldata.allocator_free -= bgsize;
 690                 hammer2_voldata_unlock(hmp);
 691         }
 692
 693         return(0);
 694 }
 695
 696 static
 697 void
 698 hammer2_freemap_init(hammer2_trans_t *trans, hammer2_dev_t *hmp,
 699                      hammer2_key_t key, hammer2_chain_t *chain)
 700 {
 701         hammer2_off_t l1size;
 702         hammer2_off_t lokey;
 703         hammer2_off_t hikey;
 704         hammer2_bmap_data_t *bmap;
 705         int count;
 706
 707         l1size = H2FMSHIFT(HAMMER2_FREEMAP_LEVEL1_RADIX);
 708
 709         /*
 710          * Calculate the portion of the 2GB map that should be initialized
 711          * as free.  Portions below or after will be initialized as allocated.
 712          * SEGMASK-align the areas so we don't have to worry about sub-scans
 713          * or endianess when using memset.
 714          *
 715          * (1) Ensure that all statically allocated space from newfs_hammer2
 716          *     is marked allocated.
 717          *
 718          * (2) Ensure that the reserved area is marked allocated (typically
 719          *     the first 4MB of the 2GB area being represented).
 720          *
 721          * (3) Ensure that any trailing space at the end-of-volume is marked
 722          *     allocated.
 723          *
 724          * WARNING! It is possible for lokey to be larger than hikey if the
 725          *          entire 2GB segment is within the static allocation.
 726          */
 727         lokey = (hmp->voldata.allocator_beg + HAMMER2_SEGMASK64) &
 728                 ~HAMMER2_SEGMASK64;
 729
 730         if (lokey < H2FMBASE(key, HAMMER2_FREEMAP_LEVEL1_RADIX) +
 731                   HAMMER2_ZONE_SEG64) {
 732                 lokey = H2FMBASE(key, HAMMER2_FREEMAP_LEVEL1_RADIX) +
 733                         HAMMER2_ZONE_SEG64;
 734         }
 735
 736         hikey = key + H2FMSHIFT(HAMMER2_FREEMAP_LEVEL1_RADIX);
 737         if (hikey > hmp->voldata.volu_size) {
 738                 hikey = hmp->voldata.volu_size & ~HAMMER2_SEGMASK64;
 739         }
 740
 741         chain->bref.check.freemap.avail =
 742                 H2FMSHIFT(HAMMER2_FREEMAP_LEVEL1_RADIX);
 743         bmap = &chain->data->bmdata[0];
 744
 745         for (count = 0; count < HAMMER2_FREEMAP_COUNT; ++count) {
 746                 if (key < lokey || key >= hikey) {
 747                         memset(bmap->bitmap, -1,
 748                                sizeof(bmap->bitmap));
 749                         bmap->avail = 0;
 750                         bmap->linear = HAMMER2_SEGSIZE;
 751                         chain->bref.check.freemap.avail -=
 752                                 H2FMSHIFT(HAMMER2_FREEMAP_LEVEL0_RADIX);
 753                 } else {
 754                         bmap->avail = H2FMSHIFT(HAMMER2_FREEMAP_LEVEL0_RADIX);
 755                 }
 756                 key += H2FMSHIFT(HAMMER2_FREEMAP_LEVEL0_RADIX);
 757                 ++bmap;
 758         }
 759 }
 760
 761 /*
 762  * The current Level 1 freemap has been exhausted, iterate to the next
 763  * one, return ENOSPC if no freemaps remain.
 764  *
 765  * XXX this should rotate back to the beginning to handle freed-up space
 766  * XXX or use intermediate entries to locate free space. TODO
 767  */
 768 static int
 769 hammer2_freemap_iterate(hammer2_trans_t *trans, hammer2_chain_t **parentp,
 770                         hammer2_chain_t **chainp, hammer2_fiterate_t *iter)
 771 {
 772         hammer2_dev_t *hmp = (*parentp)->hmp;
 773
 774         iter->bnext &= ~(H2FMSHIFT(HAMMER2_FREEMAP_LEVEL1_RADIX) - 1);
 775         iter->bnext += H2FMSHIFT(HAMMER2_FREEMAP_LEVEL1_RADIX);
 776         if (iter->bnext >= hmp->voldata.volu_size) {
 777                 iter->bnext = 0;
 778                 if (++iter->loops == 2)
 779                         return (ENOSPC);
 780         }
 781         return(EAGAIN);
 782 }
 783
 784 /*
 785  * Adjust the bit-pattern for data in the freemap bitmap according to
 786  * (how).  This code is called from on-mount recovery to fixup (mark
 787  * as allocated) blocks whos freemap upates might not have been committed
 788  * in the last crash and is used by the bulk freemap scan to stage frees.
 789  *
 790  * XXX currently disabled when how == 0 (the normal real-time case).  At
 791  * the moment we depend on the bulk freescan to actually free blocks.  It
 792  * will still call this routine with a non-zero how to stage possible frees
 793  * and to do the actual free.
 794  */
 795 void
 796 hammer2_freemap_adjust(hammer2_trans_t *trans, hammer2_dev_t *hmp,
 797                        hammer2_blockref_t *bref, int how)
 798 {
 799         hammer2_off_t data_off = bref->data_off;
 800         hammer2_chain_t *chain;
 801         hammer2_chain_t *parent;
 802         hammer2_bmap_data_t *bmap;
 803         hammer2_key_t key;
 804         hammer2_key_t key_dummy;
 805         hammer2_off_t l0size;
 806         hammer2_off_t l1size;
 807         hammer2_off_t l1mask;
 808         uint32_t *bitmap;
 809         const uint32_t bmmask00 = 0;
 810         uint32_t bmmask01;
 811         uint32_t bmmask10;
 812         uint32_t bmmask11;
 813         size_t bytes;
 814         uint16_t class;
 815         int radix;
 816         int start;
 817         int count;
 818         int modified = 0;
 819         int cache_index = -1;
 820         int error;
 821         int ddflag;
 822
 823         KKASSERT(how == HAMMER2_FREEMAP_DORECOVER);
 824
 825         radix = (int)data_off & HAMMER2_OFF_MASK_RADIX;
 826         data_off &= ~HAMMER2_OFF_MASK_RADIX;
 827         KKASSERT(radix <= HAMMER2_RADIX_MAX);
 828
 829         bytes = (size_t)1 << radix;
 830         class = (bref->type << 8) | hammer2_devblkradix(radix);
 831
 832         /*
 833          * We can't adjust thre freemap for data allocations made by
 834          * newfs_hammer2.
 835          */
 836         if (data_off < hmp->voldata.allocator_beg)
 837                 return;
 838
 839         KKASSERT((data_off & HAMMER2_ZONE_MASK64) >= HAMMER2_ZONE_SEG);
 840
 841         /*
 842          * Lookup the level1 freemap chain.  The chain must exist.
 843          */
 844         key = H2FMBASE(data_off, HAMMER2_FREEMAP_LEVEL1_RADIX);
 845         l0size = H2FMSHIFT(HAMMER2_FREEMAP_LEVEL0_RADIX);
 846         l1size = H2FMSHIFT(HAMMER2_FREEMAP_LEVEL1_RADIX);
 847         l1mask = l1size - 1;
 848
 849         parent = &hmp->fchain;
 850         hammer2_chain_lock(parent, HAMMER2_RESOLVE_ALWAYS);
 851
 852         chain = hammer2_chain_lookup(&parent, &key_dummy, key, key + l1mask,
 853                                      &cache_index,
 854                                      HAMMER2_LOOKUP_ALWAYS |
 855                                      HAMMER2_LOOKUP_MATCHIND, &ddflag);
 856
 857         /*
 858          * Stop early if we are trying to free something but no leaf exists.
 859          */
 860         if (chain == NULL && how != HAMMER2_FREEMAP_DORECOVER) {
 861                 kprintf("hammer2_freemap_adjust: %016jx: no chain\n",
 862                         (intmax_t)bref->data_off);
 863                 goto done;
 864         }
 865
 866         /*
 867          * Create any missing leaf(s) if we are doing a recovery (marking
 868          * the block(s) as being allocated instead of being freed).  Be sure
 869          * to initialize the auxillary freemap tracking info in the
 870          * bref.check.freemap structure.
 871          */
 872         if (chain == NULL && how == HAMMER2_FREEMAP_DORECOVER) {
 873                 error = hammer2_chain_create(trans, &parent, &chain, hmp->spmp,
 874                                      key, HAMMER2_FREEMAP_LEVEL1_RADIX,
 875                                      HAMMER2_BREF_TYPE_FREEMAP_LEAF,
 876                                      HAMMER2_FREEMAP_LEVELN_PSIZE,
 877                                      0);
 878
 879                 if (hammer2_debug & 0x0040) {
 880                         kprintf("fixup create chain %p %016jx:%d\n",
 881                                 chain, chain->bref.key, chain->bref.keybits);
 882                 }
 883
 884                 if (error == 0) {
 885                         hammer2_chain_modify(trans, chain, 0);
 886                         bzero(&chain->data->bmdata[0],
 887                               HAMMER2_FREEMAP_LEVELN_PSIZE);
 888                         chain->bref.check.freemap.bigmask = (uint32_t)-1;
 889                         chain->bref.check.freemap.avail = l1size;
 890                         /* bref.methods should already be inherited */
 891
 892                         hammer2_freemap_init(trans, hmp, key, chain);
 893                 }
 894                 /* XXX handle error */
 895         }
 896
 897 #if FREEMAP_DEBUG
 898         kprintf("FREEMAP ADJUST TYPE %d %016jx/%d DATA_OFF=%016jx\n",
 899                 chain->bref.type, chain->bref.key,
 900                 chain->bref.keybits, chain->bref.data_off);
 901 #endif
 902
 903         /*
 904          * Calculate the bitmask (runs in 2-bit pairs).
 905          */
 906         start = ((int)(data_off >> HAMMER2_FREEMAP_BLOCK_RADIX) & 15) * 2;
 907         bmmask01 = 1 << start;
 908         bmmask10 = 2 << start;
 909         bmmask11 = 3 << start;
 910
 911         /*
 912          * Fixup the bitmap.  Partial blocks cannot be fully freed unless
 913          * a bulk scan is able to roll them up.
 914          */
 915         if (radix < HAMMER2_FREEMAP_BLOCK_RADIX) {
 916                 count = 1;
 917                 if (how == HAMMER2_FREEMAP_DOREALFREE)
 918                         how = HAMMER2_FREEMAP_DOMAYFREE;
 919         } else {
 920                 count = 1 << (radix - HAMMER2_FREEMAP_BLOCK_RADIX);
 921         }
 922
 923         /*
 924          * [re]load the bmap and bitmap pointers.  Each bmap entry covers
 925          * a 2MB swath.  The bmap itself (LEVEL1) covers 2GB.
 926          *
 927          * Be sure to reset the linear iterator to ensure that the adjustment
 928          * is not ignored.
 929          */
 930 again:
 931         bmap = &chain->data->bmdata[(int)(data_off >> HAMMER2_SEGRADIX) &
 932                                     (HAMMER2_FREEMAP_COUNT - 1)];
 933         bitmap = &bmap->bitmap[(int)(data_off >> (HAMMER2_SEGRADIX - 3)) & 7];
 934
 935         if (modified)
 936                 bmap->linear = 0;
 937
 938         while (count) {
 939                 KKASSERT(bmmask11);
 940                 if (how == HAMMER2_FREEMAP_DORECOVER) {
 941                         /*
 942                          * Recovery request, mark as allocated.
 943                          */
 944                         if ((*bitmap & bmmask11) != bmmask11) {
 945                                 if (modified == 0) {
 946                                         hammer2_chain_modify(trans, chain, 0);
 947                                         modified = 1;
 948                                         goto again;
 949                                 }
 950                                 if ((*bitmap & bmmask11) == bmmask00) {
 951                                         bmap->avail -=
 952                                                 HAMMER2_FREEMAP_BLOCK_SIZE;
 953                                 }
 954                                 if (bmap->class == 0)
 955                                         bmap->class = class;
 956                                 *bitmap |= bmmask11;
 957                                 if (hammer2_debug & 0x0040) {
 958                                         kprintf("hammer2_freemap_recover: "
 959                                                 "fixup type=%02x "
 960                                                 "block=%016jx/%zd\n",
 961                                                 bref->type, data_off, bytes);
 962                                 }
 963                         } else {
 964                                 /*
 965                                 kprintf("hammer2_freemap_recover:  good "
 966                                         "type=%02x block=%016jx/%zd\n",
 967                                         bref->type, data_off, bytes);
 968                                 */
 969                         }
 970                 }
 971 #if 0
 972                 /*
 973                  * XXX this stuff doesn't work, avail is miscalculated and
 974                  * code 10 means something else now.
 975                  */
 976                 else if ((*bitmap & bmmask11) == bmmask11) {
 977                         /*
 978                          * Mayfree/Realfree request and bitmap is currently
 979                          * marked as being fully allocated.
 980                          */
 981                         if (!modified) {
 982                                 hammer2_chain_modify(trans, chain, 0);
 983                                 modified = 1;
 984                                 goto again;
 985                         }
 986                         if (how == HAMMER2_FREEMAP_DOREALFREE)
 987                                 *bitmap &= ~bmmask11;
 988                         else
 989                                 *bitmap = (*bitmap & ~bmmask11) | bmmask10;
 990                 } else if ((*bitmap & bmmask11) == bmmask10) {
 991                         /*
 992                          * Mayfree/Realfree request and bitmap is currently
 993                          * marked as being possibly freeable.
 994                          */
 995                         if (how == HAMMER2_FREEMAP_DOREALFREE) {
 996                                 if (!modified) {
 997                                         hammer2_chain_modify(trans, chain, 0);
 998                                         modified = 1;
 999                                         goto again;
1000                                 }
1001                                 *bitmap &= ~bmmask11;
1002                         }
1003                 } else {
1004                         /*
1005                          * 01 - Not implemented, currently illegal state
1006                          * 00 - Not allocated at all, illegal free.
1007                          */
1008                         panic("hammer2_freemap_adjust: "
1009                               "Illegal state %08x(%08x)",
1010                               *bitmap, *bitmap & bmmask11);
1011                 }
1012 #endif
1013                 --count;
1014                 bmmask01 <<= 2;
1015                 bmmask10 <<= 2;
1016                 bmmask11 <<= 2;
1017         }
1018         if (how == HAMMER2_FREEMAP_DOREALFREE && modified) {
1019                 bmap->avail += 1 << radix;
1020                 KKASSERT(bmap->avail <= HAMMER2_SEGSIZE);
1021                 if (bmap->avail == HAMMER2_SEGSIZE &&
1022                     bmap->bitmap[0] == 0 &&
1023                     bmap->bitmap[1] == 0 &&
1024                     bmap->bitmap[2] == 0 &&
1025                     bmap->bitmap[3] == 0 &&
1026                     bmap->bitmap[4] == 0 &&
1027                     bmap->bitmap[5] == 0 &&
1028                     bmap->bitmap[6] == 0 &&
1029                     bmap->bitmap[7] == 0) {
1030                         key = H2FMBASE(data_off, HAMMER2_FREEMAP_LEVEL0_RADIX);
1031                         kprintf("Freeseg %016jx\n", (intmax_t)key);
1032                         bmap->class = 0;
1033                 }
1034         }
1035
1036         /*
1037          * chain->bref.check.freemap.bigmask (XXX)
1038          *
1039          * Setting bigmask is a hint to the allocation code that there might
1040          * be something allocatable.  We also set this in recovery... it
1041          * doesn't hurt and we might want to use the hint for other validation
1042          * operations later on.
1043          */
1044         if (modified)
1045                 chain->bref.check.freemap.bigmask |= 1 << radix;
1046
1047         hammer2_chain_unlock(chain);
1048 done:
1049         hammer2_chain_unlock(parent);
1050 }
1051
1052 /*
1053  * Validate the freemap, in three stages.
1054  *
1055  * stage-1      ALLOCATED     -> POSSIBLY FREE
1056  *              POSSIBLY FREE -> POSSIBLY FREE (type corrected)
1057  *
1058  *      This transitions bitmap entries from ALLOCATED to POSSIBLY FREE.
1059  *      The POSSIBLY FREE state does not mean that a block is actually free
1060  *      and may be transitioned back to ALLOCATED in stage-2.
1061  *
1062  *      This is typically done during normal filesystem operations when
1063  *      something is deleted or a block is replaced.
1064  *
1065  *      This is done by bulkfree in-bulk after a memory-bounded meta-data
1066  *      scan to try to determine what might be freeable.
1067  *
1068  *      This can be done unconditionally through a freemap scan when the
1069  *      intention is to brute-force recover the proper state of the freemap.
1070  *
1071  * stage-2      POSSIBLY FREE -> ALLOCATED      (scan metadata topology)
1072  *
1073  *      This is done by bulkfree during a meta-data scan to ensure that
1074  *      all blocks still actually allocated by the filesystem are marked
1075  *      as such.
1076  *
1077  *      NOTE! Live filesystem transitions to POSSIBLY FREE can occur while
1078  *            the bulkfree stage-2 and stage-3 is running.  The live filesystem
1079  *            will use the alternative POSSIBLY FREE type (2) to prevent
1080  *            stage-3 from improperly transitioning unvetted possibly-free
1081  *            blocks to FREE.
1082  *
1083  * stage-3      POSSIBLY FREE (type 1) -> FREE  (scan freemap)
1084  *
1085  *      This is done by bulkfree to finalize POSSIBLY FREE states.
1086  *
1087  */