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_ZONE_FREEMAP_00 +
 176                        HAMMER2_ZONEFM_LEVEL4) * HAMMER2_PBUFSIZE;
 177                 break;
 178         case HAMMER2_FREEMAP_LEVEL3_RADIX:      /* 2PB */
 179                 KKASSERT(bref->type == HAMMER2_BREF_TYPE_FREEMAP_NODE);
 180                 KKASSERT(bytes == HAMMER2_FREEMAP_LEVELN_PSIZE);
 181                 off = H2FMBASE(bref->key, HAMMER2_FREEMAP_LEVEL3_RADIX) +
 182                       (index * 4 + HAMMER2_ZONE_FREEMAP_00 +
 183                        HAMMER2_ZONEFM_LEVEL3) * HAMMER2_PBUFSIZE;
 184                 break;
 185         case HAMMER2_FREEMAP_LEVEL2_RADIX:      /* 2TB */
 186                 KKASSERT(bref->type == HAMMER2_BREF_TYPE_FREEMAP_NODE);
 187                 KKASSERT(bytes == HAMMER2_FREEMAP_LEVELN_PSIZE);
 188                 off = H2FMBASE(bref->key, HAMMER2_FREEMAP_LEVEL2_RADIX) +
 189                       (index * 4 + HAMMER2_ZONE_FREEMAP_00 +
 190                        HAMMER2_ZONEFM_LEVEL2) * HAMMER2_PBUFSIZE;
 191                 break;
 192         case HAMMER2_FREEMAP_LEVEL1_RADIX:      /* 2GB */
 193                 KKASSERT(bref->type == HAMMER2_BREF_TYPE_FREEMAP_LEAF);
 194                 KKASSERT(bytes == HAMMER2_FREEMAP_LEVELN_PSIZE);
 195                 off = H2FMBASE(bref->key, HAMMER2_FREEMAP_LEVEL1_RADIX) +
 196                       (index * 4 + HAMMER2_ZONE_FREEMAP_00 +
 197                        HAMMER2_ZONEFM_LEVEL1) * HAMMER2_PBUFSIZE;
 198                 break;
 199         default:
 200                 panic("freemap: bad radix(2) %p %d\n", bref, bref->keybits);
 201                 /* NOT REACHED */
 202                 off = (hammer2_off_t)-1;
 203                 break;
 204         }
 205         bref->data_off = off | radix;
 206 #if 0
 207         kprintf("-> %016jx\n", bref->data_off);
 208 #endif
 209         return (0);
 210 }
 211
 212 /*
 213  * Normal freemap allocator
 214  *
 215  * Use available hints to allocate space using the freemap.  Create missing
 216  * freemap infrastructure on-the-fly as needed (including marking initial
 217  * allocations using the iterator as allocated, instantiating new 2GB zones,
 218  * and dealing with the end-of-media edge case).
 219  *
 220  * ip and bpref are only used as a heuristic to determine locality of
 221  * reference.  bref->key may also be used heuristically.
 222  *
 223  * WARNING! When called from a flush we have to use the 'live' sync_tid
 224  *          and not the flush sync_tid.  The live sync_tid is the flush
 225  *          sync_tid + 1.  That is, freemap allocations which occur during
 226  *          a flush are not part of the flush.  Crash-recovery will restore
 227  *          any lost allocations.
 228  */
 229 int
 230 hammer2_freemap_alloc(hammer2_trans_t *trans, hammer2_chain_t *chain,
 231                       size_t bytes)
 232 {
 233         hammer2_mount_t *hmp = chain->hmp;
 234         hammer2_blockref_t *bref = &chain->bref;
 235         hammer2_chain_t *parent;
 236         int radix;
 237         int error;
 238         unsigned int hindex;
 239         hammer2_fiterate_t iter;
 240
 241         /*
 242          * Validate the allocation size.  It must be a power of 2.
 243          *
 244          * For now require that the caller be aware of the minimum
 245          * allocation (1K).
 246          */
 247         radix = hammer2_getradix(bytes);
 248         KKASSERT((size_t)1 << radix == bytes);
 249
 250         /*
 251          * Freemap blocks themselves are simply assigned from the reserve
 252          * area, not allocated from the freemap.
 253          */
 254         if (bref->type == HAMMER2_BREF_TYPE_FREEMAP_NODE ||
 255             bref->type == HAMMER2_BREF_TYPE_FREEMAP_LEAF) {
 256                 return (hammer2_freemap_reserve(trans, chain, radix));
 257         }
 258
 259         /*
 260          * Mark previously allocated block as possibly freeable.  There might
 261          * be snapshots and other races so we can't just mark it fully free.
 262          * (XXX optimize this for the current-transaction create+delete case)
 263          */
 264         if (bref->data_off & ~HAMMER2_OFF_MASK_RADIX) {
 265                 hammer2_freemap_adjust(trans, hmp, bref,
 266                                        HAMMER2_FREEMAP_DOMAYFREE);
 267         }
 268
 269         /*
 270          * Setting ISALLOCATING ensures correct operation even when the
 271          * flusher itself is making allocations.
 272          */
 273         KKASSERT(bytes >= HAMMER2_MIN_ALLOC && bytes <= HAMMER2_MAX_ALLOC);
 274         KKASSERT((trans->flags & HAMMER2_TRANS_ISALLOCATING) == 0);
 275         atomic_set_int(&trans->flags, HAMMER2_TRANS_ISALLOCATING);
 276         if (trans->flags & HAMMER2_TRANS_ISFLUSH)
 277                 ++trans->sync_tid;
 278
 279         /*
 280          * Calculate the starting point for our allocation search.
 281          *
 282          * Each freemap leaf is dedicated to a specific freemap_radix.
 283          * The freemap_radix can be more fine-grained than the device buffer
 284          * radix which results in inodes being grouped together in their
 285          * own segment, terminal-data (16K or less) and initial indirect
 286          * block being grouped together, and then full-indirect and full-data
 287          * blocks (64K) being grouped together.
 288          *
 289          * The single most important aspect of this is the inode grouping
 290          * because that is what allows 'find' and 'ls' and other filesystem
 291          * topology operations to run fast.
 292          */
 293 #if 0
 294         if (bref->data_off & ~HAMMER2_OFF_MASK_RADIX)
 295                 bpref = bref->data_off & ~HAMMER2_OFF_MASK_RADIX;
 296         else if (trans->tmp_bpref)
 297                 bpref = trans->tmp_bpref;
 298         else if (trans->tmp_ip)
 299                 bpref = trans->tmp_ip->chain->bref.data_off;
 300         else
 301 #endif
 302         /*
 303          * Heuristic tracking index.  We would like one for each distinct
 304          * bref type if possible.  heur_freemap[] has room for two classes
 305          * for each type.  At a minimum we have to break-up our heuristic
 306          * by device block sizes.
 307          */
 308         hindex = hammer2_devblkradix(radix) - HAMMER2_MINIORADIX;
 309         KKASSERT(hindex < HAMMER2_FREEMAP_HEUR_NRADIX);
 310         hindex += bref->type * HAMMER2_FREEMAP_HEUR_NRADIX;
 311         hindex &= HAMMER2_FREEMAP_HEUR_TYPES * HAMMER2_FREEMAP_HEUR_NRADIX - 1;
 312         KKASSERT(hindex < HAMMER2_FREEMAP_HEUR);
 313
 314         iter.bpref = hmp->heur_freemap[hindex];
 315
 316         /*
 317          * Make sure bpref is in-bounds.  It's ok if bpref covers a zone's
 318          * reserved area, the try code will iterate past it.
 319          */
 320         if (iter.bpref > hmp->voldata.volu_size)
 321                 iter.bpref = hmp->voldata.volu_size - 1;
 322
 323         /*
 324          * Iterate the freemap looking for free space before and after.
 325          */
 326         parent = &hmp->fchain;
 327         hammer2_chain_lock(parent, HAMMER2_RESOLVE_ALWAYS);
 328         error = EAGAIN;
 329         iter.bnext = iter.bpref;
 330         iter.loops = 0;
 331
 332         while (error == EAGAIN) {
 333                 error = hammer2_freemap_try_alloc(trans, &parent, bref,
 334                                                   radix, &iter);
 335         }
 336         hmp->heur_freemap[hindex] = iter.bnext;
 337         hammer2_chain_unlock(parent);
 338
 339         atomic_clear_int(&trans->flags, HAMMER2_TRANS_ISALLOCATING);
 340         if (trans->flags & HAMMER2_TRANS_ISFLUSH)
 341                 --trans->sync_tid;
 342
 343         return (error);
 344 }
 345
 346 static int
 347 hammer2_freemap_try_alloc(hammer2_trans_t *trans, hammer2_chain_t **parentp,
 348                           hammer2_blockref_t *bref, int radix,
 349                           hammer2_fiterate_t *iter)
 350 {
 351         hammer2_mount_t *hmp = (*parentp)->hmp;
 352         hammer2_off_t l0size;
 353         hammer2_off_t l1size;
 354         hammer2_off_t l1mask;
 355         hammer2_key_t key_dummy;
 356         hammer2_chain_t *chain;
 357         hammer2_off_t key;
 358         size_t bytes;
 359         uint16_t class;
 360         int error = 0;
 361         int cache_index = -1;
 362
 363
 364         /*
 365          * Calculate the number of bytes being allocated, the number
 366          * of contiguous bits of bitmap being allocated, and the bitmap
 367          * mask.
 368          *
 369          * WARNING! cpu hardware may mask bits == 64 -> 0 and blow up the
 370          *          mask calculation.
 371          */
 372         bytes = (size_t)1 << radix;
 373         class = (bref->type << 8) | hammer2_devblkradix(radix);
 374
 375         /*
 376          * Lookup the level1 freemap chain, creating and initializing one
 377          * if necessary.  Intermediate levels will be created automatically
 378          * when necessary by hammer2_chain_create().
 379          */
 380         key = H2FMBASE(iter->bnext, HAMMER2_FREEMAP_LEVEL1_RADIX);
 381         l0size = H2FMSHIFT(HAMMER2_FREEMAP_LEVEL0_RADIX);
 382         l1size = H2FMSHIFT(HAMMER2_FREEMAP_LEVEL1_RADIX);
 383         l1mask = l1size - 1;
 384
 385         chain = hammer2_chain_lookup(parentp, &key_dummy, key, key + l1mask,
 386                                      &cache_index,
 387                                      HAMMER2_LOOKUP_ALWAYS |
 388                                      HAMMER2_LOOKUP_MATCHIND);
 389
 390         if (chain == NULL) {
 391                 /*
 392                  * Create the missing leaf, be sure to initialize
 393                  * the auxillary freemap tracking information in
 394                  * the bref.check.freemap structure.
 395                  */
 396 #if 0
 397                 kprintf("freemap create L1 @ %016jx bpref %016jx\n",
 398                         key, iter->bpref);
 399 #endif
 400                 error = hammer2_chain_create(trans, parentp, &chain,
 401                                      key, HAMMER2_FREEMAP_LEVEL1_RADIX,
 402                                      HAMMER2_BREF_TYPE_FREEMAP_LEAF,
 403                                      HAMMER2_FREEMAP_LEVELN_PSIZE);
 404                 KKASSERT(error == 0);
 405                 if (error == 0) {
 406                         hammer2_chain_modify(trans, &chain, 0);
 407                         bzero(&chain->data->bmdata[0],
 408                               HAMMER2_FREEMAP_LEVELN_PSIZE);
 409                         chain->bref.check.freemap.bigmask = (uint32_t)-1;
 410                         chain->bref.check.freemap.avail = l1size;
 411                         /* bref.methods should already be inherited */
 412
 413                         hammer2_freemap_init(trans, hmp, key, chain);
 414                 }
 415         } else if ((chain->bref.check.freemap.bigmask & (1 << radix)) == 0) {
 416                 /*
 417                  * Already flagged as not having enough space
 418                  */
 419                 error = ENOSPC;
 420         } else {
 421                 /*
 422                  * Modify existing chain to setup for adjustment.
 423                  */
 424                 hammer2_chain_modify(trans, &chain, 0);
 425         }
 426
 427         /*
 428          * Scan 2MB entries.
 429          */
 430         if (error == 0) {
 431                 hammer2_bmap_data_t *bmap;
 432                 hammer2_key_t base_key;
 433                 int count;
 434                 int start;
 435                 int n;
 436
 437                 KKASSERT(chain->bref.type == HAMMER2_BREF_TYPE_FREEMAP_LEAF);
 438                 start = (int)((iter->bnext - key) >>
 439                               HAMMER2_FREEMAP_LEVEL0_RADIX);
 440                 KKASSERT(start >= 0 && start < HAMMER2_FREEMAP_COUNT);
 441                 hammer2_chain_modify(trans, &chain, 0);
 442
 443                 error = ENOSPC;
 444                 for (count = 0; count < HAMMER2_FREEMAP_COUNT; ++count) {
 445                         if (start + count >= HAMMER2_FREEMAP_COUNT &&
 446                             start - count < 0) {
 447                                 break;
 448                         }
 449                         n = start + count;
 450                         bmap = &chain->data->bmdata[n];
 451                         if (n < HAMMER2_FREEMAP_COUNT && bmap->avail &&
 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                         n = start - count;
 463                         bmap = &chain->data->bmdata[n];
 464                         if (n >= 0 && bmap->avail &&
 465                             (bmap->class == 0 || bmap->class == class)) {
 466                                 base_key = key + n * l0size;
 467                                 error = hammer2_bmap_alloc(trans, hmp, bmap,
 468                                                            class, n, radix,
 469                                                            &base_key);
 470                                 if (error != ENOSPC) {
 471                                         key = base_key;
 472                                         break;
 473                                 }
 474                         }
 475                 }
 476                 if (error == ENOSPC)
 477                         chain->bref.check.freemap.bigmask &= ~(1 << radix);
 478                 /* XXX also scan down from original count */
 479         }
 480
 481         if (error == 0) {
 482                 /*
 483                  * Assert validity.  Must be beyond the static allocator used
 484                  * by newfs_hammer2 (and thus also beyond the aux area),
 485                  * not go past the volume size, and must not be in the
 486                  * reserved segment area for a zone.
 487                  */
 488                 KKASSERT(key >= hmp->voldata.allocator_beg &&
 489                          key + bytes <= hmp->voldata.volu_size);
 490                 KKASSERT((key & HAMMER2_ZONE_MASK64) >= HAMMER2_ZONE_SEG);
 491                 bref->data_off = key | radix;
 492
 493 #if 0
 494                 kprintf("alloc cp=%p %016jx %016jx using %016jx\n",
 495                         chain,
 496                         bref->key, bref->data_off, chain->bref.data_off);
 497 #endif
 498         } else if (error == ENOSPC) {
 499                 /*
 500                  * Return EAGAIN with next iteration in iter->bnext, or
 501                  * return ENOSPC if the allocation map has been exhausted.
 502                  */
 503                 error = hammer2_freemap_iterate(trans, parentp, &chain, iter);
 504         }
 505
 506         /*
 507          * Cleanup
 508          */
 509         if (chain)
 510                 hammer2_chain_unlock(chain);
 511         return (error);
 512 }
 513
 514 /*
 515  * Allocate (1<<radix) bytes from the bmap whos base data offset is (*basep).
 516  *
 517  * If the linear iterator is mid-block we use it directly (the bitmap should
 518  * already be marked allocated), otherwise we search for a block in the bitmap
 519  * that fits the allocation request.
 520  *
 521  * A partial bitmap allocation sets the minimum bitmap granularity (16KB)
 522  * to fully allocated and adjusts the linear allocator to allow the
 523  * remaining space to be allocated.
 524  */
 525 static
 526 int
 527 hammer2_bmap_alloc(hammer2_trans_t *trans, hammer2_mount_t *hmp,
 528                    hammer2_bmap_data_t *bmap,
 529                    uint16_t class, int n, int radix, hammer2_key_t *basep)
 530 {
 531         hammer2_io_t *dio;
 532         size_t size;
 533         size_t bsize;
 534         int bmradix;
 535         uint32_t bmmask;
 536         int offset;
 537         int error;
 538         int i;
 539         int j;
 540
 541         /*
 542          * Take into account 2-bits per block when calculating bmradix.
 543          */
 544         size = (size_t)1 << radix;
 545
 546         if (radix <= HAMMER2_FREEMAP_BLOCK_RADIX) {
 547                 bmradix = 2;
 548                 bsize = HAMMER2_FREEMAP_BLOCK_SIZE;
 549                 /* (16K) 2 bits per allocation block */
 550         } else {
 551                 bmradix = 2 << (radix - HAMMER2_FREEMAP_BLOCK_RADIX);
 552                 bsize = size;
 553                 /* (32K-256K) 4, 8, 16, 32 bits per allocation block */
 554         }
 555
 556         /*
 557          * Use the linear iterator to pack small allocations, otherwise
 558          * fall-back to finding a free 16KB chunk.  The linear iterator
 559          * is only valid when *NOT* on a freemap chunking boundary (16KB).
 560          * If it is the bitmap must be scanned.  It can become invalid
 561          * once we pack to the boundary.  We adjust it after a bitmap
 562          * allocation only for sub-16KB allocations (so the perfectly good
 563          * previous value can still be used for fragments when 16KB+
 564          * allocations are made).
 565          *
 566          * Beware of hardware artifacts when bmradix == 32 (intermediate
 567          * result can wind up being '1' instead of '0' if hardware masks
 568          * bit-count & 31).
 569          *
 570          * NOTE: j needs to be even in the j= calculation.  As an artifact
 571          *       of the /2 division, our bitmask has to clear bit 0.
 572          *
 573          * NOTE: TODO this can leave little unallocatable fragments lying
 574          *       around.
 575          */
 576         if (((uint32_t)bmap->linear & HAMMER2_FREEMAP_BLOCK_MASK) + size <=
 577             HAMMER2_FREEMAP_BLOCK_SIZE &&
 578             (bmap->linear & HAMMER2_FREEMAP_BLOCK_MASK) &&
 579             bmap->linear < HAMMER2_SEGSIZE) {
 580                 KKASSERT(bmap->linear >= 0 &&
 581                          bmap->linear + size <= HAMMER2_SEGSIZE &&
 582                          (bmap->linear & (HAMMER2_MIN_ALLOC - 1)) == 0);
 583                 offset = bmap->linear;
 584                 i = offset / (HAMMER2_SEGSIZE / 8);
 585                 j = (offset / (HAMMER2_FREEMAP_BLOCK_SIZE / 2)) & 30;
 586                 bmmask = (bmradix == 32) ?
 587                          0xFFFFFFFFU : (1 << bmradix) - 1;
 588                 bmmask <<= j;
 589                 bmap->linear = offset + size;
 590         } else {
 591                 for (i = 0; i < 8; ++i) {
 592                         bmmask = (bmradix == 32) ?
 593                                  0xFFFFFFFFU : (1 << bmradix) - 1;
 594                         for (j = 0; j < 32; j += bmradix) {
 595                                 if ((bmap->bitmap[i] & bmmask) == 0)
 596                                         goto success;
 597                                 bmmask <<= bmradix;
 598                         }
 599                 }
 600                 /*fragments might remain*/
 601                 /*KKASSERT(bmap->avail == 0);*/
 602                 return (ENOSPC);
 603 success:
 604                 offset = i * (HAMMER2_SEGSIZE / 8) +
 605                          (j * (HAMMER2_FREEMAP_BLOCK_SIZE / 2));
 606                 if (size & HAMMER2_FREEMAP_BLOCK_MASK)
 607                         bmap->linear = offset + size;
 608         }
 609
 610         KKASSERT(i >= 0 && i < 8);      /* 8 x 16 -> 128 x 16K -> 2MB */
 611
 612         /*
 613          * Optimize the buffer cache to avoid unnecessary read-before-write
 614          * operations.
 615          *
 616          * The device block size could be larger than the allocation size
 617          * so the actual bitmap test is somewhat more involved.  We have
 618          * to use a compatible buffer size for this operation.
 619          */
 620         if ((bmap->bitmap[i] & bmmask) == 0 &&
 621             hammer2_devblksize(size) != size) {
 622                 size_t psize = hammer2_devblksize(size);
 623                 hammer2_off_t pmask = (hammer2_off_t)psize - 1;
 624                 int pbmradix = 2 << (hammer2_devblkradix(radix) -
 625                                      HAMMER2_FREEMAP_BLOCK_RADIX);
 626                 uint32_t pbmmask;
 627                 int pradix = hammer2_getradix(psize);
 628
 629                 pbmmask = (pbmradix == 32) ? 0xFFFFFFFFU : (1 << pbmradix) - 1;
 630                 while ((pbmmask & bmmask) == 0)
 631                         pbmmask <<= pbmradix;
 632
 633 #if 0
 634                 kprintf("%016jx mask %08x %08x %08x (%zd/%zd)\n",
 635                         *basep + offset, bmap->bitmap[i],
 636                         pbmmask, bmmask, size, psize);
 637 #endif
 638
 639                 if ((bmap->bitmap[i] & pbmmask) == 0) {
 640                         error = hammer2_io_newq(hmp,
 641                                                 (*basep + (offset & ~pmask)) |
 642                                                  pradix,
 643                                                 psize, &dio);
 644                         hammer2_io_bqrelse(&dio);
 645                 }
 646         }
 647
 648 #if 0
 649         /*
 650          * When initializing a new inode segment also attempt to initialize
 651          * an adjacent segment.  Be careful not to index beyond the array
 652          * bounds.
 653          *
 654          * We do this to try to localize inode accesses to improve
 655          * directory scan rates.  XXX doesn't improve scan rates.
 656          */
 657         if (size == HAMMER2_INODE_BYTES) {
 658                 if (n & 1) {
 659                         if (bmap[-1].radix == 0 && bmap[-1].avail)
 660                                 bmap[-1].radix = radix;
 661                 } else {
 662                         if (bmap[1].radix == 0 && bmap[1].avail)
 663                                 bmap[1].radix = radix;
 664                 }
 665         }
 666 #endif
 667
 668         /*
 669          * Adjust the linear iterator, set the radix if necessary (might as
 670          * well just set it unconditionally), adjust *basep to return the
 671          * allocated data offset.
 672          */
 673         bmap->bitmap[i] |= bmmask;
 674         bmap->class = class;
 675         bmap->avail -= size;
 676         *basep += offset;
 677
 678         hammer2_voldata_lock(hmp);
 679         hmp->voldata.allocator_free -= size;  /* XXX */
 680         hammer2_voldata_unlock(hmp, 1);
 681
 682         return(0);
 683 }
 684
 685 static
 686 void
 687 hammer2_freemap_init(hammer2_trans_t *trans, hammer2_mount_t *hmp,
 688                      hammer2_key_t key, hammer2_chain_t *chain)
 689 {
 690         hammer2_off_t l1size;
 691         hammer2_off_t lokey;
 692         hammer2_off_t hikey;
 693         hammer2_bmap_data_t *bmap;
 694         int count;
 695
 696         l1size = H2FMSHIFT(HAMMER2_FREEMAP_LEVEL1_RADIX);
 697
 698         /*
 699          * Calculate the portion of the 2GB map that should be initialized
 700          * as free.  Portions below or after will be initialized as allocated.
 701          * SEGMASK-align the areas so we don't have to worry about sub-scans
 702          * or endianess when using memset.
 703          *
 704          * (1) Ensure that all statically allocated space from newfs_hammer2
 705          *     is marked allocated.
 706          *
 707          * (2) Ensure that the reserved area is marked allocated (typically
 708          *     the first 4MB of the 2GB area being represented).
 709          *
 710          * (3) Ensure that any trailing space at the end-of-volume is marked
 711          *     allocated.
 712          *
 713          * WARNING! It is possible for lokey to be larger than hikey if the
 714          *          entire 2GB segment is within the static allocation.
 715          */
 716         lokey = (hmp->voldata.allocator_beg + HAMMER2_SEGMASK64) &
 717                 ~HAMMER2_SEGMASK64;
 718
 719         if (lokey < H2FMBASE(key, HAMMER2_FREEMAP_LEVEL1_RADIX) +
 720                   HAMMER2_ZONE_SEG64) {
 721                 lokey = H2FMBASE(key, HAMMER2_FREEMAP_LEVEL1_RADIX) +
 722                         HAMMER2_ZONE_SEG64;
 723         }
 724
 725         hikey = key + H2FMSHIFT(HAMMER2_FREEMAP_LEVEL1_RADIX);
 726         if (hikey > hmp->voldata.volu_size) {
 727                 hikey = hmp->voldata.volu_size & ~HAMMER2_SEGMASK64;
 728         }
 729
 730         chain->bref.check.freemap.avail =
 731                 H2FMSHIFT(HAMMER2_FREEMAP_LEVEL1_RADIX);
 732         bmap = &chain->data->bmdata[0];
 733
 734         for (count = 0; count < HAMMER2_FREEMAP_COUNT; ++count) {
 735                 if (key < lokey || key >= hikey) {
 736                         memset(bmap->bitmap, -1,
 737                                sizeof(bmap->bitmap));
 738                         bmap->avail = 0;
 739                         bmap->linear = HAMMER2_SEGSIZE;
 740                         chain->bref.check.freemap.avail -=
 741                                 H2FMSHIFT(HAMMER2_FREEMAP_LEVEL0_RADIX);
 742                 } else {
 743                         bmap->avail = H2FMSHIFT(HAMMER2_FREEMAP_LEVEL0_RADIX);
 744                 }
 745                 key += H2FMSHIFT(HAMMER2_FREEMAP_LEVEL0_RADIX);
 746                 ++bmap;
 747         }
 748 }
 749
 750 /*
 751  * The current Level 1 freemap has been exhausted, iterate to the next
 752  * one, return ENOSPC if no freemaps remain.
 753  *
 754  * XXX this should rotate back to the beginning to handle freed-up space
 755  * XXX or use intermediate entries to locate free space. TODO
 756  */
 757 static int
 758 hammer2_freemap_iterate(hammer2_trans_t *trans, hammer2_chain_t **parentp,
 759                         hammer2_chain_t **chainp, hammer2_fiterate_t *iter)
 760 {
 761         hammer2_mount_t *hmp = (*parentp)->hmp;
 762
 763         iter->bnext &= ~(H2FMSHIFT(HAMMER2_FREEMAP_LEVEL1_RADIX) - 1);
 764         iter->bnext += H2FMSHIFT(HAMMER2_FREEMAP_LEVEL1_RADIX);
 765         if (iter->bnext >= hmp->voldata.volu_size) {
 766                 iter->bnext = 0;
 767                 if (++iter->loops == 2)
 768                         return (ENOSPC);
 769         }
 770         return(EAGAIN);
 771 }
 772
 773 /*
 774  * Free the specified blockref.  This code is only able to fully free
 775  * blocks when (how) is non-zero, otherwise the block is marked for
 776  * the bulk freeing pass to check.
 777  *
 778  * Normal use is to only mark inodes as possibly being free.  The underlying
 779  * file blocks are not necessarily marked.  The bulk freescan can
 780  * theoretically handle the case.
 781  *
 782  * XXX currently disabled when how == 0 (the normal real-time case).  At
 783  * the moment we depend on the bulk freescan to actually free blocks.  It
 784  * will still call this routine with a non-zero how to stage possible frees
 785  * and to do the actual free.
 786  *
 787  * WARNING! When called from a flush we have to use the 'live' sync_tid
 788  *          and not the flush sync_tid.  The live sync_tid is the flush
 789  *          sync_tid + 1.  That is, freemap allocations which occur during
 790  *          a flush are not part of the flush.  Crash-recovery will restore
 791  *          any lost allocations.
 792  */
 793 void
 794 hammer2_freemap_adjust(hammer2_trans_t *trans, hammer2_mount_t *hmp,
 795                        hammer2_blockref_t *bref, int how)
 796 {
 797         hammer2_off_t data_off = bref->data_off;
 798         hammer2_chain_t *chain;
 799         hammer2_chain_t *parent;
 800         hammer2_bmap_data_t *bmap;
 801         hammer2_key_t key;
 802         hammer2_key_t key_dummy;
 803         hammer2_off_t l0size;
 804         hammer2_off_t l1size;
 805         hammer2_off_t l1mask;
 806         uint32_t *bitmap;
 807         const uint32_t bmmask00 = 0;
 808         uint32_t bmmask01;
 809         uint32_t bmmask10;
 810         uint32_t bmmask11;
 811         size_t bytes;
 812         uint16_t class;
 813         int radix;
 814         int start;
 815         int count;
 816         int modified = 0;
 817         int cache_index = -1;
 818         int error;
 819
 820         radix = (int)data_off & HAMMER2_OFF_MASK_RADIX;
 821         data_off &= ~HAMMER2_OFF_MASK_RADIX;
 822         KKASSERT(radix <= HAMMER2_MAX_RADIX);
 823
 824         bytes = (size_t)1 << radix;
 825         class = (bref->type << 8) | hammer2_devblkradix(radix);
 826
 827         /*
 828          * We can't adjust thre freemap for data allocations made by
 829          * newfs_hammer2.
 830          */
 831         if (data_off < hmp->voldata.allocator_beg)
 832                 return;
 833
 834         KKASSERT((data_off & HAMMER2_ZONE_MASK64) >= HAMMER2_ZONE_SEG);
 835         KKASSERT((trans->flags & HAMMER2_TRANS_ISALLOCATING) == 0);
 836         atomic_set_int(&trans->flags, HAMMER2_TRANS_ISALLOCATING);
 837         if (trans->flags & HAMMER2_TRANS_ISFLUSH)
 838                 ++trans->sync_tid;
 839
 840         /*
 841          * Lookup the level1 freemap chain.  The chain must exist.
 842          */
 843         key = H2FMBASE(data_off, HAMMER2_FREEMAP_LEVEL1_RADIX);
 844         l0size = H2FMSHIFT(HAMMER2_FREEMAP_LEVEL0_RADIX);
 845         l1size = H2FMSHIFT(HAMMER2_FREEMAP_LEVEL1_RADIX);
 846         l1mask = l1size - 1;
 847
 848         parent = &hmp->fchain;
 849         hammer2_chain_lock(parent, HAMMER2_RESOLVE_ALWAYS);
 850
 851         chain = hammer2_chain_lookup(&parent, &key_dummy, key, key + l1mask,
 852                                      &cache_index,
 853                                      HAMMER2_LOOKUP_ALWAYS |
 854                                      HAMMER2_LOOKUP_MATCHIND);
 855
 856         /*
 857          * Stop early if we are trying to free something but no leaf exists.
 858          */
 859         if (chain == NULL && how != HAMMER2_FREEMAP_DORECOVER) {
 860                 kprintf("hammer2_freemap_adjust: %016jx: no chain\n",
 861                         (intmax_t)bref->data_off);
 862                 goto done;
 863         }
 864
 865         /*
 866          * Create any missing leaf(s) if we are doing a recovery (marking
 867          * the block(s) as being allocated instead of being freed).  Be sure
 868          * to initialize the auxillary freemap tracking info in the
 869          * bref.check.freemap structure.
 870          */
 871         if (chain == NULL && how == HAMMER2_FREEMAP_DORECOVER) {
 872                 error = hammer2_chain_create(trans, &parent, &chain,
 873                                      key, HAMMER2_FREEMAP_LEVEL1_RADIX,
 874                                      HAMMER2_BREF_TYPE_FREEMAP_LEAF,
 875                                      HAMMER2_FREEMAP_LEVELN_PSIZE);
 876
 877                 if (hammer2_debug & 0x0040) {
 878                         kprintf("fixup create chain %p %016jx:%d\n",
 879                                 chain, chain->bref.key, chain->bref.keybits);
 880                 }
 881
 882                 if (error == 0) {
 883                         hammer2_chain_modify(trans, &chain, 0);
 884                         bzero(&chain->data->bmdata[0],
 885                               HAMMER2_FREEMAP_LEVELN_PSIZE);
 886                         chain->bref.check.freemap.bigmask = (uint32_t)-1;
 887                         chain->bref.check.freemap.avail = l1size;
 888                         /* bref.methods should already be inherited */
 889
 890                         hammer2_freemap_init(trans, hmp, key, chain);
 891                 }
 892                 /* XXX handle error */
 893         }
 894
 895         /*
 896          * Calculate the bitmask (runs in 2-bit pairs).
 897          */
 898         start = ((int)(data_off >> HAMMER2_FREEMAP_BLOCK_RADIX) & 15) * 2;
 899         bmmask01 = 1 << start;
 900         bmmask10 = 2 << start;
 901         bmmask11 = 3 << start;
 902
 903         /*
 904          * Fixup the bitmap.  Partial blocks cannot be fully freed unless
 905          * a bulk scan is able to roll them up.
 906          */
 907         if (radix < HAMMER2_FREEMAP_BLOCK_RADIX) {
 908                 count = 1;
 909                 if (how == HAMMER2_FREEMAP_DOREALFREE)
 910                         how = HAMMER2_FREEMAP_DOMAYFREE;
 911         } else {
 912                 count = 1 << (radix - HAMMER2_FREEMAP_BLOCK_RADIX);
 913         }
 914
 915         /*
 916          * [re]load the bmap and bitmap pointers.  Each bmap entry covers
 917          * a 2MB swath.  The bmap itself (LEVEL1) covers 2GB.
 918          */
 919 again:
 920         bmap = &chain->data->bmdata[(int)(data_off >> HAMMER2_SEGRADIX) &
 921                                     (HAMMER2_FREEMAP_COUNT - 1)];
 922         bitmap = &bmap->bitmap[(int)(data_off >> (HAMMER2_SEGRADIX - 3)) & 7];
 923
 924
 925         while (count) {
 926                 KKASSERT(bmmask11);
 927                 if (how == HAMMER2_FREEMAP_DORECOVER) {
 928                         /*
 929                          * Recovery request, mark as allocated.
 930                          */
 931                         if ((*bitmap & bmmask11) != bmmask11) {
 932                                 if (modified == 0) {
 933                                         hammer2_chain_modify(trans, &chain, 0);
 934                                         modified = 1;
 935                                         goto again;
 936                                 }
 937                                 if ((*bitmap & bmmask11) == bmmask00)
 938                                         bmap->avail -= 1 << radix;
 939                                 if (bmap->class == 0)
 940                                         bmap->class = class;
 941                                 *bitmap |= bmmask11;
 942                                 if (hammer2_debug & 0x0040) {
 943                                         kprintf("hammer2_freemap_recover: "
 944                                                 "fixup type=%02x "
 945                                                 "block=%016jx/%zd\n",
 946                                                 bref->type, data_off, bytes);
 947                                 }
 948                         } else {
 949                                 /*
 950                                 kprintf("hammer2_freemap_recover:  good "
 951                                         "type=%02x block=%016jx/%zd\n",
 952                                         bref->type, data_off, bytes);
 953                                 */
 954                         }
 955                 } else if ((*bitmap & bmmask11) == bmmask11) {
 956                         /*
 957                          * Mayfree/Realfree request and bitmap is currently
 958                          * marked as being fully allocated.
 959                          */
 960                         if (!modified) {
 961                                 hammer2_chain_modify(trans, &chain, 0);
 962                                 modified = 1;
 963                                 goto again;
 964                         }
 965                         if (how == HAMMER2_FREEMAP_DOREALFREE)
 966                                 *bitmap &= ~bmmask11;
 967                         else
 968                                 *bitmap = (*bitmap & ~bmmask11) | bmmask10;
 969                 } else if ((*bitmap & bmmask11) == bmmask10) {
 970                         /*
 971                          * Mayfree/Realfree request and bitmap is currently
 972                          * marked as being possibly freeable.
 973                          */
 974                         if (how == HAMMER2_FREEMAP_DOREALFREE) {
 975                                 if (!modified) {
 976                                         hammer2_chain_modify(trans, &chain, 0);
 977                                         modified = 1;
 978                                         goto again;
 979                                 }
 980                                 *bitmap &= ~bmmask11;
 981                         }
 982                 } else {
 983                         /*
 984                          * 01 - Not implemented, currently illegal state
 985                          * 00 - Not allocated at all, illegal free.
 986                          */
 987                         panic("hammer2_freemap_adjust: "
 988                               "Illegal state %08x(%08x)",
 989                               *bitmap, *bitmap & bmmask11);
 990                 }
 991                 --count;
 992                 bmmask01 <<= 2;
 993                 bmmask10 <<= 2;
 994                 bmmask11 <<= 2;
 995         }
 996         if (how == HAMMER2_FREEMAP_DOREALFREE && modified) {
 997                 bmap->avail += 1 << radix;
 998                 KKASSERT(bmap->avail <= HAMMER2_SEGSIZE);
 999                 if (bmap->avail == HAMMER2_SEGSIZE &&
1000                     bmap->bitmap[0] == 0 &&
1001                     bmap->bitmap[1] == 0 &&
1002                     bmap->bitmap[2] == 0 &&
1003                     bmap->bitmap[3] == 0 &&
1004                     bmap->bitmap[4] == 0 &&
1005                     bmap->bitmap[5] == 0 &&
1006                     bmap->bitmap[6] == 0 &&
1007                     bmap->bitmap[7] == 0) {
1008                         key = H2FMBASE(data_off, HAMMER2_FREEMAP_LEVEL0_RADIX);
1009                         kprintf("Freeseg %016jx\n", (intmax_t)key);
1010                         bmap->class = 0;
1011                 }
1012         }
1013
1014         /*
1015          * chain->bref.check.freemap.bigmask (XXX)
1016          *
1017          * Setting bigmask is a hint to the allocation code that there might
1018          * be something allocatable.  We also set this in recovery... it
1019          * doesn't hurt and we might want to use the hint for other validation
1020          * operations later on.
1021          */
1022         if (modified)
1023                 chain->bref.check.freemap.bigmask |= 1 << radix;
1024
1025         hammer2_chain_unlock(chain);
1026 done:
1027         hammer2_chain_unlock(parent);
1028         atomic_clear_int(&trans->flags, HAMMER2_TRANS_ISALLOCATING);
1029         if (trans->flags & HAMMER2_TRANS_ISFLUSH)
1030                 --trans->sync_tid;
1031 }