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