libxfs/xfs_refcount_btree.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright (C) 2016 Oracle.  All Rights Reserved.
   4  * Author: Darrick J. Wong <darrick.wong@oracle.com>
   5  */
   6 #include "xfs.h"
   7 #include "xfs_fs.h"
   8 #include "xfs_shared.h"
   9 #include "xfs_format.h"
  10 #include "xfs_log_format.h"
  11 #include "xfs_trans_resv.h"
  12 #include "xfs_mount.h"
  13 #include "xfs_btree.h"
  14 #include "xfs_btree_staging.h"
  15 #include "xfs_refcount_btree.h"
  16 #include "xfs_refcount.h"
  17 #include "xfs_alloc.h"
  18 #include "xfs_error.h"
  19 #include "xfs_trace.h"
  20 #include "xfs_trans.h"
  21 #include "xfs_bit.h"
  22 #include "xfs_rmap.h"
  23 #include "xfs_ag.h"
  24
  25 static struct kmem_cache        *xfs_refcountbt_cur_cache;
  26
  27 static struct xfs_btree_cur *
  28 xfs_refcountbt_dup_cursor(
  29         struct xfs_btree_cur    *cur)
  30 {
  31         return xfs_refcountbt_init_cursor(cur->bc_mp, cur->bc_tp,
  32                         cur->bc_ag.agbp, cur->bc_ag.pag);
  33 }
  34
  35 STATIC void
  36 xfs_refcountbt_set_root(
  37         struct xfs_btree_cur            *cur,
  38         const union xfs_btree_ptr       *ptr,
  39         int                             inc)
  40 {
  41         struct xfs_buf          *agbp = cur->bc_ag.agbp;
  42         struct xfs_agf          *agf = agbp->b_addr;
  43         struct xfs_perag        *pag = agbp->b_pag;
  44
  45         ASSERT(ptr->s != 0);
  46
  47         agf->agf_refcount_root = ptr->s;
  48         be32_add_cpu(&agf->agf_refcount_level, inc);
  49         pag->pagf_refcount_level += inc;
  50
  51         xfs_alloc_log_agf(cur->bc_tp, agbp,
  52                         XFS_AGF_REFCOUNT_ROOT | XFS_AGF_REFCOUNT_LEVEL);
  53 }
  54
  55 STATIC int
  56 xfs_refcountbt_alloc_block(
  57         struct xfs_btree_cur            *cur,
  58         const union xfs_btree_ptr       *start,
  59         union xfs_btree_ptr             *new,
  60         int                             *stat)
  61 {
  62         struct xfs_buf          *agbp = cur->bc_ag.agbp;
  63         struct xfs_agf          *agf = agbp->b_addr;
  64         struct xfs_alloc_arg    args;           /* block allocation args */
  65         int                     error;          /* error return value */
  66
  67         memset(&args, 0, sizeof(args));
  68         args.tp = cur->bc_tp;
  69         args.mp = cur->bc_mp;
  70         args.pag = cur->bc_ag.pag;
  71         args.oinfo = XFS_RMAP_OINFO_REFC;
  72         args.minlen = args.maxlen = args.prod = 1;
  73         args.resv = XFS_AG_RESV_METADATA;
  74
  75         error = xfs_alloc_vextent_near_bno(&args,
  76                         XFS_AGB_TO_FSB(args.mp, args.pag->pag_agno,
  77                                         xfs_refc_block(args.mp)));
  78         if (error)
  79                 goto out_error;
  80         trace_xfs_refcountbt_alloc_block(cur->bc_mp, cur->bc_ag.pag->pag_agno,
  81                         args.agbno, 1);
  82         if (args.fsbno == NULLFSBLOCK) {
  83                 *stat = 0;
  84                 return 0;
  85         }
  86         ASSERT(args.agno == cur->bc_ag.pag->pag_agno);
  87         ASSERT(args.len == 1);
  88
  89         new->s = cpu_to_be32(args.agbno);
  90         be32_add_cpu(&agf->agf_refcount_blocks, 1);
  91         xfs_alloc_log_agf(cur->bc_tp, agbp, XFS_AGF_REFCOUNT_BLOCKS);
  92
  93         *stat = 1;
  94         return 0;
  95
  96 out_error:
  97         return error;
  98 }
  99
 100 STATIC int
 101 xfs_refcountbt_free_block(
 102         struct xfs_btree_cur    *cur,
 103         struct xfs_buf          *bp)
 104 {
 105         struct xfs_mount        *mp = cur->bc_mp;
 106         struct xfs_buf          *agbp = cur->bc_ag.agbp;
 107         struct xfs_agf          *agf = agbp->b_addr;
 108         xfs_fsblock_t           fsbno = XFS_DADDR_TO_FSB(mp, xfs_buf_daddr(bp));
 109
 110         trace_xfs_refcountbt_free_block(cur->bc_mp, cur->bc_ag.pag->pag_agno,
 111                         XFS_FSB_TO_AGBNO(cur->bc_mp, fsbno), 1);
 112         be32_add_cpu(&agf->agf_refcount_blocks, -1);
 113         xfs_alloc_log_agf(cur->bc_tp, agbp, XFS_AGF_REFCOUNT_BLOCKS);
 114         return xfs_free_extent_later(cur->bc_tp, fsbno, 1,
 115                         &XFS_RMAP_OINFO_REFC, XFS_AG_RESV_METADATA, false);
 116 }
 117
 118 STATIC int
 119 xfs_refcountbt_get_minrecs(
 120         struct xfs_btree_cur    *cur,
 121         int                     level)
 122 {
 123         return cur->bc_mp->m_refc_mnr[level != 0];
 124 }
 125
 126 STATIC int
 127 xfs_refcountbt_get_maxrecs(
 128         struct xfs_btree_cur    *cur,
 129         int                     level)
 130 {
 131         return cur->bc_mp->m_refc_mxr[level != 0];
 132 }
 133
 134 STATIC void
 135 xfs_refcountbt_init_key_from_rec(
 136         union xfs_btree_key             *key,
 137         const union xfs_btree_rec       *rec)
 138 {
 139         key->refc.rc_startblock = rec->refc.rc_startblock;
 140 }
 141
 142 STATIC void
 143 xfs_refcountbt_init_high_key_from_rec(
 144         union xfs_btree_key             *key,
 145         const union xfs_btree_rec       *rec)
 146 {
 147         __u32                           x;
 148
 149         x = be32_to_cpu(rec->refc.rc_startblock);
 150         x += be32_to_cpu(rec->refc.rc_blockcount) - 1;
 151         key->refc.rc_startblock = cpu_to_be32(x);
 152 }
 153
 154 STATIC void
 155 xfs_refcountbt_init_rec_from_cur(
 156         struct xfs_btree_cur    *cur,
 157         union xfs_btree_rec     *rec)
 158 {
 159         const struct xfs_refcount_irec *irec = &cur->bc_rec.rc;
 160         uint32_t                start;
 161
 162         start = xfs_refcount_encode_startblock(irec->rc_startblock,
 163                         irec->rc_domain);
 164         rec->refc.rc_startblock = cpu_to_be32(start);
 165         rec->refc.rc_blockcount = cpu_to_be32(cur->bc_rec.rc.rc_blockcount);
 166         rec->refc.rc_refcount = cpu_to_be32(cur->bc_rec.rc.rc_refcount);
 167 }
 168
 169 STATIC void
 170 xfs_refcountbt_init_ptr_from_cur(
 171         struct xfs_btree_cur    *cur,
 172         union xfs_btree_ptr     *ptr)
 173 {
 174         struct xfs_agf          *agf = cur->bc_ag.agbp->b_addr;
 175
 176         ASSERT(cur->bc_ag.pag->pag_agno == be32_to_cpu(agf->agf_seqno));
 177
 178         ptr->s = agf->agf_refcount_root;
 179 }
 180
 181 STATIC int64_t
 182 xfs_refcountbt_key_diff(
 183         struct xfs_btree_cur            *cur,
 184         const union xfs_btree_key       *key)
 185 {
 186         const struct xfs_refcount_key   *kp = &key->refc;
 187         const struct xfs_refcount_irec  *irec = &cur->bc_rec.rc;
 188         uint32_t                        start;
 189
 190         start = xfs_refcount_encode_startblock(irec->rc_startblock,
 191                         irec->rc_domain);
 192         return (int64_t)be32_to_cpu(kp->rc_startblock) - start;
 193 }
 194
 195 STATIC int64_t
 196 xfs_refcountbt_diff_two_keys(
 197         struct xfs_btree_cur            *cur,
 198         const union xfs_btree_key       *k1,
 199         const union xfs_btree_key       *k2,
 200         const union xfs_btree_key       *mask)
 201 {
 202         ASSERT(!mask || mask->refc.rc_startblock);
 203
 204         return (int64_t)be32_to_cpu(k1->refc.rc_startblock) -
 205                         be32_to_cpu(k2->refc.rc_startblock);
 206 }
 207
 208 STATIC xfs_failaddr_t
 209 xfs_refcountbt_verify(
 210         struct xfs_buf          *bp)
 211 {
 212         struct xfs_mount        *mp = bp->b_mount;
 213         struct xfs_btree_block  *block = XFS_BUF_TO_BLOCK(bp);
 214         struct xfs_perag        *pag = bp->b_pag;
 215         xfs_failaddr_t          fa;
 216         unsigned int            level;
 217
 218         if (!xfs_verify_magic(bp, block->bb_magic))
 219                 return __this_address;
 220
 221         if (!xfs_has_reflink(mp))
 222                 return __this_address;
 223         fa = xfs_btree_sblock_v5hdr_verify(bp);
 224         if (fa)
 225                 return fa;
 226
 227         level = be16_to_cpu(block->bb_level);
 228         if (pag && xfs_perag_initialised_agf(pag)) {
 229                 unsigned int    maxlevel = pag->pagf_refcount_level;
 230
 231 #ifdef CONFIG_XFS_ONLINE_REPAIR
 232                 /*
 233                  * Online repair could be rewriting the refcount btree, so
 234                  * we'll validate against the larger of either tree while this
 235                  * is going on.
 236                  */
 237                 maxlevel = max_t(unsigned int, maxlevel,
 238                                 pag->pagf_repair_refcount_level);
 239 #endif
 240                 if (level >= maxlevel)
 241                         return __this_address;
 242         } else if (level >= mp->m_refc_maxlevels)
 243                 return __this_address;
 244
 245         return xfs_btree_sblock_verify(bp, mp->m_refc_mxr[level != 0]);
 246 }
 247
 248 STATIC void
 249 xfs_refcountbt_read_verify(
 250         struct xfs_buf  *bp)
 251 {
 252         xfs_failaddr_t  fa;
 253
 254         if (!xfs_btree_sblock_verify_crc(bp))
 255                 xfs_verifier_error(bp, -EFSBADCRC, __this_address);
 256         else {
 257                 fa = xfs_refcountbt_verify(bp);
 258                 if (fa)
 259                         xfs_verifier_error(bp, -EFSCORRUPTED, fa);
 260         }
 261
 262         if (bp->b_error)
 263                 trace_xfs_btree_corrupt(bp, _RET_IP_);
 264 }
 265
 266 STATIC void
 267 xfs_refcountbt_write_verify(
 268         struct xfs_buf  *bp)
 269 {
 270         xfs_failaddr_t  fa;
 271
 272         fa = xfs_refcountbt_verify(bp);
 273         if (fa) {
 274                 trace_xfs_btree_corrupt(bp, _RET_IP_);
 275                 xfs_verifier_error(bp, -EFSCORRUPTED, fa);
 276                 return;
 277         }
 278         xfs_btree_sblock_calc_crc(bp);
 279
 280 }
 281
 282 const struct xfs_buf_ops xfs_refcountbt_buf_ops = {
 283         .name                   = "xfs_refcountbt",
 284         .magic                  = { 0, cpu_to_be32(XFS_REFC_CRC_MAGIC) },
 285         .verify_read            = xfs_refcountbt_read_verify,
 286         .verify_write           = xfs_refcountbt_write_verify,
 287         .verify_struct          = xfs_refcountbt_verify,
 288 };
 289
 290 STATIC int
 291 xfs_refcountbt_keys_inorder(
 292         struct xfs_btree_cur            *cur,
 293         const union xfs_btree_key       *k1,
 294         const union xfs_btree_key       *k2)
 295 {
 296         return be32_to_cpu(k1->refc.rc_startblock) <
 297                be32_to_cpu(k2->refc.rc_startblock);
 298 }
 299
 300 STATIC int
 301 xfs_refcountbt_recs_inorder(
 302         struct xfs_btree_cur            *cur,
 303         const union xfs_btree_rec       *r1,
 304         const union xfs_btree_rec       *r2)
 305 {
 306         return  be32_to_cpu(r1->refc.rc_startblock) +
 307                 be32_to_cpu(r1->refc.rc_blockcount) <=
 308                 be32_to_cpu(r2->refc.rc_startblock);
 309 }
 310
 311 STATIC enum xbtree_key_contig
 312 xfs_refcountbt_keys_contiguous(
 313         struct xfs_btree_cur            *cur,
 314         const union xfs_btree_key       *key1,
 315         const union xfs_btree_key       *key2,
 316         const union xfs_btree_key       *mask)
 317 {
 318         ASSERT(!mask || mask->refc.rc_startblock);
 319
 320         return xbtree_key_contig(be32_to_cpu(key1->refc.rc_startblock),
 321                                  be32_to_cpu(key2->refc.rc_startblock));
 322 }
 323
 324 static const struct xfs_btree_ops xfs_refcountbt_ops = {
 325         .rec_len                = sizeof(struct xfs_refcount_rec),
 326         .key_len                = sizeof(struct xfs_refcount_key),
 327
 328         .dup_cursor             = xfs_refcountbt_dup_cursor,
 329         .set_root               = xfs_refcountbt_set_root,
 330         .alloc_block            = xfs_refcountbt_alloc_block,
 331         .free_block             = xfs_refcountbt_free_block,
 332         .get_minrecs            = xfs_refcountbt_get_minrecs,
 333         .get_maxrecs            = xfs_refcountbt_get_maxrecs,
 334         .init_key_from_rec      = xfs_refcountbt_init_key_from_rec,
 335         .init_high_key_from_rec = xfs_refcountbt_init_high_key_from_rec,
 336         .init_rec_from_cur      = xfs_refcountbt_init_rec_from_cur,
 337         .init_ptr_from_cur      = xfs_refcountbt_init_ptr_from_cur,
 338         .key_diff               = xfs_refcountbt_key_diff,
 339         .buf_ops                = &xfs_refcountbt_buf_ops,
 340         .diff_two_keys          = xfs_refcountbt_diff_two_keys,
 341         .keys_inorder           = xfs_refcountbt_keys_inorder,
 342         .recs_inorder           = xfs_refcountbt_recs_inorder,
 343         .keys_contiguous        = xfs_refcountbt_keys_contiguous,
 344 };
 345
 346 /*
 347  * Initialize a new refcount btree cursor.
 348  */
 349 static struct xfs_btree_cur *
 350 xfs_refcountbt_init_common(
 351         struct xfs_mount        *mp,
 352         struct xfs_trans        *tp,
 353         struct xfs_perag        *pag)
 354 {
 355         struct xfs_btree_cur    *cur;
 356
 357         ASSERT(pag->pag_agno < mp->m_sb.sb_agcount);
 358
 359         cur = xfs_btree_alloc_cursor(mp, tp, XFS_BTNUM_REFC,
 360                         mp->m_refc_maxlevels, xfs_refcountbt_cur_cache);
 361         cur->bc_statoff = XFS_STATS_CALC_INDEX(xs_refcbt_2);
 362
 363         cur->bc_flags |= XFS_BTREE_CRC_BLOCKS;
 364
 365         cur->bc_ag.pag = xfs_perag_hold(pag);
 366         cur->bc_ag.refc.nr_ops = 0;
 367         cur->bc_ag.refc.shape_changes = 0;
 368         cur->bc_ops = &xfs_refcountbt_ops;
 369         return cur;
 370 }
 371
 372 /* Create a btree cursor. */
 373 struct xfs_btree_cur *
 374 xfs_refcountbt_init_cursor(
 375         struct xfs_mount        *mp,
 376         struct xfs_trans        *tp,
 377         struct xfs_buf          *agbp,
 378         struct xfs_perag        *pag)
 379 {
 380         struct xfs_agf          *agf = agbp->b_addr;
 381         struct xfs_btree_cur    *cur;
 382
 383         cur = xfs_refcountbt_init_common(mp, tp, pag);
 384         cur->bc_nlevels = be32_to_cpu(agf->agf_refcount_level);
 385         cur->bc_ag.agbp = agbp;
 386         return cur;
 387 }
 388
 389 /* Create a btree cursor with a fake root for staging. */
 390 struct xfs_btree_cur *
 391 xfs_refcountbt_stage_cursor(
 392         struct xfs_mount        *mp,
 393         struct xbtree_afakeroot *afake,
 394         struct xfs_perag        *pag)
 395 {
 396         struct xfs_btree_cur    *cur;
 397
 398         cur = xfs_refcountbt_init_common(mp, NULL, pag);
 399         xfs_btree_stage_afakeroot(cur, afake);
 400         return cur;
 401 }
 402
 403 /*
 404  * Swap in the new btree root.  Once we pass this point the newly rebuilt btree
 405  * is in place and we have to kill off all the old btree blocks.
 406  */
 407 void
 408 xfs_refcountbt_commit_staged_btree(
 409         struct xfs_btree_cur    *cur,
 410         struct xfs_trans        *tp,
 411         struct xfs_buf          *agbp)
 412 {
 413         struct xfs_agf          *agf = agbp->b_addr;
 414         struct xbtree_afakeroot *afake = cur->bc_ag.afake;
 415
 416         ASSERT(cur->bc_flags & XFS_BTREE_STAGING);
 417
 418         agf->agf_refcount_root = cpu_to_be32(afake->af_root);
 419         agf->agf_refcount_level = cpu_to_be32(afake->af_levels);
 420         agf->agf_refcount_blocks = cpu_to_be32(afake->af_blocks);
 421         xfs_alloc_log_agf(tp, agbp, XFS_AGF_REFCOUNT_BLOCKS |
 422                                     XFS_AGF_REFCOUNT_ROOT |
 423                                     XFS_AGF_REFCOUNT_LEVEL);
 424         xfs_btree_commit_afakeroot(cur, tp, agbp, &xfs_refcountbt_ops);
 425 }
 426
 427 /* Calculate number of records in a refcount btree block. */
 428 static inline unsigned int
 429 xfs_refcountbt_block_maxrecs(
 430         unsigned int            blocklen,
 431         bool                    leaf)
 432 {
 433         if (leaf)
 434                 return blocklen / sizeof(struct xfs_refcount_rec);
 435         return blocklen / (sizeof(struct xfs_refcount_key) +
 436                            sizeof(xfs_refcount_ptr_t));
 437 }
 438
 439 /*
 440  * Calculate the number of records in a refcount btree block.
 441  */
 442 int
 443 xfs_refcountbt_maxrecs(
 444         int                     blocklen,
 445         bool                    leaf)
 446 {
 447         blocklen -= XFS_REFCOUNT_BLOCK_LEN;
 448         return xfs_refcountbt_block_maxrecs(blocklen, leaf);
 449 }
 450
 451 /* Compute the max possible height of the maximally sized refcount btree. */
 452 unsigned int
 453 xfs_refcountbt_maxlevels_ondisk(void)
 454 {
 455         unsigned int            minrecs[2];
 456         unsigned int            blocklen;
 457
 458         blocklen = XFS_MIN_CRC_BLOCKSIZE - XFS_BTREE_SBLOCK_CRC_LEN;
 459
 460         minrecs[0] = xfs_refcountbt_block_maxrecs(blocklen, true) / 2;
 461         minrecs[1] = xfs_refcountbt_block_maxrecs(blocklen, false) / 2;
 462
 463         return xfs_btree_compute_maxlevels(minrecs, XFS_MAX_CRC_AG_BLOCKS);
 464 }
 465
 466 /* Compute the maximum height of a refcount btree. */
 467 void
 468 xfs_refcountbt_compute_maxlevels(
 469         struct xfs_mount                *mp)
 470 {
 471         if (!xfs_has_reflink(mp)) {
 472                 mp->m_refc_maxlevels = 0;
 473                 return;
 474         }
 475
 476         mp->m_refc_maxlevels = xfs_btree_compute_maxlevels(
 477                         mp->m_refc_mnr, mp->m_sb.sb_agblocks);
 478         ASSERT(mp->m_refc_maxlevels <= xfs_refcountbt_maxlevels_ondisk());
 479 }
 480
 481 /* Calculate the refcount btree size for some records. */
 482 xfs_extlen_t
 483 xfs_refcountbt_calc_size(
 484         struct xfs_mount        *mp,
 485         unsigned long long      len)
 486 {
 487         return xfs_btree_calc_size(mp->m_refc_mnr, len);
 488 }
 489
 490 /*
 491  * Calculate the maximum refcount btree size.
 492  */
 493 xfs_extlen_t
 494 xfs_refcountbt_max_size(
 495         struct xfs_mount        *mp,
 496         xfs_agblock_t           agblocks)
 497 {
 498         /* Bail out if we're uninitialized, which can happen in mkfs. */
 499         if (mp->m_refc_mxr[0] == 0)
 500                 return 0;
 501
 502         return xfs_refcountbt_calc_size(mp, agblocks);
 503 }
 504
 505 /*
 506  * Figure out how many blocks to reserve and how many are used by this btree.
 507  */
 508 int
 509 xfs_refcountbt_calc_reserves(
 510         struct xfs_mount        *mp,
 511         struct xfs_trans        *tp,
 512         struct xfs_perag        *pag,
 513         xfs_extlen_t            *ask,
 514         xfs_extlen_t            *used)
 515 {
 516         struct xfs_buf          *agbp;
 517         struct xfs_agf          *agf;
 518         xfs_agblock_t           agblocks;
 519         xfs_extlen_t            tree_len;
 520         int                     error;
 521
 522         if (!xfs_has_reflink(mp))
 523                 return 0;
 524
 525         error = xfs_alloc_read_agf(pag, tp, 0, &agbp);
 526         if (error)
 527                 return error;
 528
 529         agf = agbp->b_addr;
 530         agblocks = be32_to_cpu(agf->agf_length);
 531         tree_len = be32_to_cpu(agf->agf_refcount_blocks);
 532         xfs_trans_brelse(tp, agbp);
 533
 534         /*
 535          * The log is permanently allocated, so the space it occupies will
 536          * never be available for the kinds of things that would require btree
 537          * expansion.  We therefore can pretend the space isn't there.
 538          */
 539         if (xfs_ag_contains_log(mp, pag->pag_agno))
 540                 agblocks -= mp->m_sb.sb_logblocks;
 541
 542         *ask += xfs_refcountbt_max_size(mp, agblocks);
 543         *used += tree_len;
 544
 545         return error;
 546 }
 547
 548 int __init
 549 xfs_refcountbt_init_cur_cache(void)
 550 {
 551         xfs_refcountbt_cur_cache = kmem_cache_create("xfs_refcbt_cur",
 552                         xfs_btree_cur_sizeof(xfs_refcountbt_maxlevels_ondisk()),
 553                         0, 0, NULL);
 554
 555         if (!xfs_refcountbt_cur_cache)
 556                 return -ENOMEM;
 557         return 0;
 558 }
 559
 560 void
 561 xfs_refcountbt_destroy_cur_cache(void)
 562 {
 563         kmem_cache_destroy(xfs_refcountbt_cur_cache);
 564         xfs_refcountbt_cur_cache = NULL;
 565 }