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