fs/xfs/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_alloc.h"
  17 #include "xfs_error.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         rec->refc.rc_startblock = cpu_to_be32(cur->bc_rec.rc.rc_startblock);
 164         rec->refc.rc_blockcount = cpu_to_be32(cur->bc_rec.rc.rc_blockcount);
 165         rec->refc.rc_refcount = cpu_to_be32(cur->bc_rec.rc.rc_refcount);
 166 }
 167
 168 STATIC void
 169 xfs_refcountbt_init_ptr_from_cur(
 170         struct xfs_btree_cur    *cur,
 171         union xfs_btree_ptr     *ptr)
 172 {
 173         struct xfs_agf          *agf = cur->bc_ag.agbp->b_addr;
 174
 175         ASSERT(cur->bc_ag.pag->pag_agno == be32_to_cpu(agf->agf_seqno));
 176
 177         ptr->s = agf->agf_refcount_root;
 178 }
 179
 180 STATIC int64_t
 181 xfs_refcountbt_key_diff(
 182         struct xfs_btree_cur            *cur,
 183         const union xfs_btree_key       *key)
 184 {
 185         struct xfs_refcount_irec        *rec = &cur->bc_rec.rc;
 186         const struct xfs_refcount_key   *kp = &key->refc;
 187
 188         return (int64_t)be32_to_cpu(kp->rc_startblock) - rec->rc_startblock;
 189 }
 190
 191 STATIC int64_t
 192 xfs_refcountbt_diff_two_keys(
 193         struct xfs_btree_cur            *cur,
 194         const union xfs_btree_key       *k1,
 195         const union xfs_btree_key       *k2)
 196 {
 197         return (int64_t)be32_to_cpu(k1->refc.rc_startblock) -
 198                           be32_to_cpu(k2->refc.rc_startblock);
 199 }
 200
 201 STATIC xfs_failaddr_t
 202 xfs_refcountbt_verify(
 203         struct xfs_buf          *bp)
 204 {
 205         struct xfs_mount        *mp = bp->b_mount;
 206         struct xfs_btree_block  *block = XFS_BUF_TO_BLOCK(bp);
 207         struct xfs_perag        *pag = bp->b_pag;
 208         xfs_failaddr_t          fa;
 209         unsigned int            level;
 210
 211         if (!xfs_verify_magic(bp, block->bb_magic))
 212                 return __this_address;
 213
 214         if (!xfs_has_reflink(mp))
 215                 return __this_address;
 216         fa = xfs_btree_sblock_v5hdr_verify(bp);
 217         if (fa)
 218                 return fa;
 219
 220         level = be16_to_cpu(block->bb_level);
 221         if (pag && pag->pagf_init) {
 222                 if (level >= pag->pagf_refcount_level)
 223                         return __this_address;
 224         } else if (level >= mp->m_refc_maxlevels)
 225                 return __this_address;
 226
 227         return xfs_btree_sblock_verify(bp, mp->m_refc_mxr[level != 0]);
 228 }
 229
 230 STATIC void
 231 xfs_refcountbt_read_verify(
 232         struct xfs_buf  *bp)
 233 {
 234         xfs_failaddr_t  fa;
 235
 236         if (!xfs_btree_sblock_verify_crc(bp))
 237                 xfs_verifier_error(bp, -EFSBADCRC, __this_address);
 238         else {
 239                 fa = xfs_refcountbt_verify(bp);
 240                 if (fa)
 241                         xfs_verifier_error(bp, -EFSCORRUPTED, fa);
 242         }
 243
 244         if (bp->b_error)
 245                 trace_xfs_btree_corrupt(bp, _RET_IP_);
 246 }
 247
 248 STATIC void
 249 xfs_refcountbt_write_verify(
 250         struct xfs_buf  *bp)
 251 {
 252         xfs_failaddr_t  fa;
 253
 254         fa = xfs_refcountbt_verify(bp);
 255         if (fa) {
 256                 trace_xfs_btree_corrupt(bp, _RET_IP_);
 257                 xfs_verifier_error(bp, -EFSCORRUPTED, fa);
 258                 return;
 259         }
 260         xfs_btree_sblock_calc_crc(bp);
 261
 262 }
 263
 264 const struct xfs_buf_ops xfs_refcountbt_buf_ops = {
 265         .name                   = "xfs_refcountbt",
 266         .magic                  = { 0, cpu_to_be32(XFS_REFC_CRC_MAGIC) },
 267         .verify_read            = xfs_refcountbt_read_verify,
 268         .verify_write           = xfs_refcountbt_write_verify,
 269         .verify_struct          = xfs_refcountbt_verify,
 270 };
 271
 272 STATIC int
 273 xfs_refcountbt_keys_inorder(
 274         struct xfs_btree_cur            *cur,
 275         const union xfs_btree_key       *k1,
 276         const union xfs_btree_key       *k2)
 277 {
 278         return be32_to_cpu(k1->refc.rc_startblock) <
 279                be32_to_cpu(k2->refc.rc_startblock);
 280 }
 281
 282 STATIC int
 283 xfs_refcountbt_recs_inorder(
 284         struct xfs_btree_cur            *cur,
 285         const union xfs_btree_rec       *r1,
 286         const union xfs_btree_rec       *r2)
 287 {
 288         return  be32_to_cpu(r1->refc.rc_startblock) +
 289                 be32_to_cpu(r1->refc.rc_blockcount) <=
 290                 be32_to_cpu(r2->refc.rc_startblock);
 291 }
 292
 293 static const struct xfs_btree_ops xfs_refcountbt_ops = {
 294         .rec_len                = sizeof(struct xfs_refcount_rec),
 295         .key_len                = sizeof(struct xfs_refcount_key),
 296
 297         .dup_cursor             = xfs_refcountbt_dup_cursor,
 298         .set_root               = xfs_refcountbt_set_root,
 299         .alloc_block            = xfs_refcountbt_alloc_block,
 300         .free_block             = xfs_refcountbt_free_block,
 301         .get_minrecs            = xfs_refcountbt_get_minrecs,
 302         .get_maxrecs            = xfs_refcountbt_get_maxrecs,
 303         .init_key_from_rec      = xfs_refcountbt_init_key_from_rec,
 304         .init_high_key_from_rec = xfs_refcountbt_init_high_key_from_rec,
 305         .init_rec_from_cur      = xfs_refcountbt_init_rec_from_cur,
 306         .init_ptr_from_cur      = xfs_refcountbt_init_ptr_from_cur,
 307         .key_diff               = xfs_refcountbt_key_diff,
 308         .buf_ops                = &xfs_refcountbt_buf_ops,
 309         .diff_two_keys          = xfs_refcountbt_diff_two_keys,
 310         .keys_inorder           = xfs_refcountbt_keys_inorder,
 311         .recs_inorder           = xfs_refcountbt_recs_inorder,
 312 };
 313
 314 /*
 315  * Initialize a new refcount btree cursor.
 316  */
 317 static struct xfs_btree_cur *
 318 xfs_refcountbt_init_common(
 319         struct xfs_mount        *mp,
 320         struct xfs_trans        *tp,
 321         struct xfs_perag        *pag)
 322 {
 323         struct xfs_btree_cur    *cur;
 324
 325         ASSERT(pag->pag_agno < mp->m_sb.sb_agcount);
 326
 327         cur = xfs_btree_alloc_cursor(mp, tp, XFS_BTNUM_REFC,
 328                         mp->m_refc_maxlevels, xfs_refcountbt_cur_cache);
 329         cur->bc_statoff = XFS_STATS_CALC_INDEX(xs_refcbt_2);
 330
 331         cur->bc_flags |= XFS_BTREE_CRC_BLOCKS;
 332
 333         /* take a reference for the cursor */
 334         atomic_inc(&pag->pag_ref);
 335         cur->bc_ag.pag = pag;
 336
 337         cur->bc_ag.refc.nr_ops = 0;
 338         cur->bc_ag.refc.shape_changes = 0;
 339         cur->bc_ops = &xfs_refcountbt_ops;
 340         return cur;
 341 }
 342
 343 /* Create a btree cursor. */
 344 struct xfs_btree_cur *
 345 xfs_refcountbt_init_cursor(
 346         struct xfs_mount        *mp,
 347         struct xfs_trans        *tp,
 348         struct xfs_buf          *agbp,
 349         struct xfs_perag        *pag)
 350 {
 351         struct xfs_agf          *agf = agbp->b_addr;
 352         struct xfs_btree_cur    *cur;
 353
 354         cur = xfs_refcountbt_init_common(mp, tp, pag);
 355         cur->bc_nlevels = be32_to_cpu(agf->agf_refcount_level);
 356         cur->bc_ag.agbp = agbp;
 357         return cur;
 358 }
 359
 360 /* Create a btree cursor with a fake root for staging. */
 361 struct xfs_btree_cur *
 362 xfs_refcountbt_stage_cursor(
 363         struct xfs_mount        *mp,
 364         struct xbtree_afakeroot *afake,
 365         struct xfs_perag        *pag)
 366 {
 367         struct xfs_btree_cur    *cur;
 368
 369         cur = xfs_refcountbt_init_common(mp, NULL, pag);
 370         xfs_btree_stage_afakeroot(cur, afake);
 371         return cur;
 372 }
 373
 374 /*
 375  * Swap in the new btree root.  Once we pass this point the newly rebuilt btree
 376  * is in place and we have to kill off all the old btree blocks.
 377  */
 378 void
 379 xfs_refcountbt_commit_staged_btree(
 380         struct xfs_btree_cur    *cur,
 381         struct xfs_trans        *tp,
 382         struct xfs_buf          *agbp)
 383 {
 384         struct xfs_agf          *agf = agbp->b_addr;
 385         struct xbtree_afakeroot *afake = cur->bc_ag.afake;
 386
 387         ASSERT(cur->bc_flags & XFS_BTREE_STAGING);
 388
 389         agf->agf_refcount_root = cpu_to_be32(afake->af_root);
 390         agf->agf_refcount_level = cpu_to_be32(afake->af_levels);
 391         agf->agf_refcount_blocks = cpu_to_be32(afake->af_blocks);
 392         xfs_alloc_log_agf(tp, agbp, XFS_AGF_REFCOUNT_BLOCKS |
 393                                     XFS_AGF_REFCOUNT_ROOT |
 394                                     XFS_AGF_REFCOUNT_LEVEL);
 395         xfs_btree_commit_afakeroot(cur, tp, agbp, &xfs_refcountbt_ops);
 396 }
 397
 398 /* Calculate number of records in a refcount btree block. */
 399 static inline unsigned int
 400 xfs_refcountbt_block_maxrecs(
 401         unsigned int            blocklen,
 402         bool                    leaf)
 403 {
 404         if (leaf)
 405                 return blocklen / sizeof(struct xfs_refcount_rec);
 406         return blocklen / (sizeof(struct xfs_refcount_key) +
 407                            sizeof(xfs_refcount_ptr_t));
 408 }
 409
 410 /*
 411  * Calculate the number of records in a refcount btree block.
 412  */
 413 int
 414 xfs_refcountbt_maxrecs(
 415         int                     blocklen,
 416         bool                    leaf)
 417 {
 418         blocklen -= XFS_REFCOUNT_BLOCK_LEN;
 419         return xfs_refcountbt_block_maxrecs(blocklen, leaf);
 420 }
 421
 422 /* Compute the max possible height of the maximally sized refcount btree. */
 423 unsigned int
 424 xfs_refcountbt_maxlevels_ondisk(void)
 425 {
 426         unsigned int            minrecs[2];
 427         unsigned int            blocklen;
 428
 429         blocklen = XFS_MIN_CRC_BLOCKSIZE - XFS_BTREE_SBLOCK_CRC_LEN;
 430
 431         minrecs[0] = xfs_refcountbt_block_maxrecs(blocklen, true) / 2;
 432         minrecs[1] = xfs_refcountbt_block_maxrecs(blocklen, false) / 2;
 433
 434         return xfs_btree_compute_maxlevels(minrecs, XFS_MAX_CRC_AG_BLOCKS);
 435 }
 436
 437 /* Compute the maximum height of a refcount btree. */
 438 void
 439 xfs_refcountbt_compute_maxlevels(
 440         struct xfs_mount                *mp)
 441 {
 442         if (!xfs_has_reflink(mp)) {
 443                 mp->m_refc_maxlevels = 0;
 444                 return;
 445         }
 446
 447         mp->m_refc_maxlevels = xfs_btree_compute_maxlevels(
 448                         mp->m_refc_mnr, mp->m_sb.sb_agblocks);
 449         ASSERT(mp->m_refc_maxlevels <= xfs_refcountbt_maxlevels_ondisk());
 450 }
 451
 452 /* Calculate the refcount btree size for some records. */
 453 xfs_extlen_t
 454 xfs_refcountbt_calc_size(
 455         struct xfs_mount        *mp,
 456         unsigned long long      len)
 457 {
 458         return xfs_btree_calc_size(mp->m_refc_mnr, len);
 459 }
 460
 461 /*
 462  * Calculate the maximum refcount btree size.
 463  */
 464 xfs_extlen_t
 465 xfs_refcountbt_max_size(
 466         struct xfs_mount        *mp,
 467         xfs_agblock_t           agblocks)
 468 {
 469         /* Bail out if we're uninitialized, which can happen in mkfs. */
 470         if (mp->m_refc_mxr[0] == 0)
 471                 return 0;
 472
 473         return xfs_refcountbt_calc_size(mp, agblocks);
 474 }
 475
 476 /*
 477  * Figure out how many blocks to reserve and how many are used by this btree.
 478  */
 479 int
 480 xfs_refcountbt_calc_reserves(
 481         struct xfs_mount        *mp,
 482         struct xfs_trans        *tp,
 483         struct xfs_perag        *pag,
 484         xfs_extlen_t            *ask,
 485         xfs_extlen_t            *used)
 486 {
 487         struct xfs_buf          *agbp;
 488         struct xfs_agf          *agf;
 489         xfs_agblock_t           agblocks;
 490         xfs_extlen_t            tree_len;
 491         int                     error;
 492
 493         if (!xfs_has_reflink(mp))
 494                 return 0;
 495
 496         error = xfs_alloc_read_agf(mp, tp, pag->pag_agno, 0, &agbp);
 497         if (error)
 498                 return error;
 499
 500         agf = agbp->b_addr;
 501         agblocks = be32_to_cpu(agf->agf_length);
 502         tree_len = be32_to_cpu(agf->agf_refcount_blocks);
 503         xfs_trans_brelse(tp, agbp);
 504
 505         /*
 506          * The log is permanently allocated, so the space it occupies will
 507          * never be available for the kinds of things that would require btree
 508          * expansion.  We therefore can pretend the space isn't there.
 509          */
 510         if (mp->m_sb.sb_logstart &&
 511             XFS_FSB_TO_AGNO(mp, mp->m_sb.sb_logstart) == pag->pag_agno)
 512                 agblocks -= mp->m_sb.sb_logblocks;
 513
 514         *ask += xfs_refcountbt_max_size(mp, agblocks);
 515         *used += tree_len;
 516
 517         return error;
 518 }
 519
 520 int __init
 521 xfs_refcountbt_init_cur_cache(void)
 522 {
 523         xfs_refcountbt_cur_cache = kmem_cache_create("xfs_refcbt_cur",
 524                         xfs_btree_cur_sizeof(xfs_refcountbt_maxlevels_ondisk()),
 525                         0, 0, NULL);
 526
 527         if (!xfs_refcountbt_cur_cache)
 528                 return -ENOMEM;
 529         return 0;
 530 }
 531
 532 void
 533 xfs_refcountbt_destroy_cur_cache(void)
 534 {
 535         kmem_cache_destroy(xfs_refcountbt_cur_cache);
 536         xfs_refcountbt_cur_cache = NULL;
 537 }