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_sb.h"
  13#include "xfs_mount.h"
  14#include "xfs_btree.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
  23static struct xfs_btree_cur *
  24xfs_refcountbt_dup_cursor(
  25        struct xfs_btree_cur    *cur)
  26{
  27        return xfs_refcountbt_init_cursor(cur->bc_mp, cur->bc_tp,
  28                        cur->bc_private.a.agbp, cur->bc_private.a.agno);
  29}
  30
  31STATIC void
  32xfs_refcountbt_set_root(
  33        struct xfs_btree_cur    *cur,
  34        union xfs_btree_ptr     *ptr,
  35        int                     inc)
  36{
  37        struct xfs_buf          *agbp = cur->bc_private.a.agbp;
  38        struct xfs_agf          *agf = XFS_BUF_TO_AGF(agbp);
  39        xfs_agnumber_t          seqno = be32_to_cpu(agf->agf_seqno);
  40        struct xfs_perag        *pag = xfs_perag_get(cur->bc_mp, seqno);
  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        xfs_perag_put(pag);
  48
  49        xfs_alloc_log_agf(cur->bc_tp, agbp,
  50                        XFS_AGF_REFCOUNT_ROOT | XFS_AGF_REFCOUNT_LEVEL);
  51}
  52
  53STATIC int
  54xfs_refcountbt_alloc_block(
  55        struct xfs_btree_cur    *cur,
  56        union xfs_btree_ptr     *start,
  57        union xfs_btree_ptr     *new,
  58        int                     *stat)
  59{
  60        struct xfs_buf          *agbp = cur->bc_private.a.agbp;
  61        struct xfs_agf          *agf = XFS_BUF_TO_AGF(agbp);
  62        struct xfs_alloc_arg    args;           /* block allocation args */
  63        int                     error;          /* error return value */
  64
  65        memset(&args, 0, sizeof(args));
  66        args.tp = cur->bc_tp;
  67        args.mp = cur->bc_mp;
  68        args.type = XFS_ALLOCTYPE_NEAR_BNO;
  69        args.fsbno = XFS_AGB_TO_FSB(cur->bc_mp, cur->bc_private.a.agno,
  70                        xfs_refc_block(args.mp));
  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(&args);
  76        if (error)
  77                goto out_error;
  78        trace_xfs_refcountbt_alloc_block(cur->bc_mp, cur->bc_private.a.agno,
  79                        args.agbno, 1);
  80        if (args.fsbno == NULLFSBLOCK) {
  81                *stat = 0;
  82                return 0;
  83        }
  84        ASSERT(args.agno == cur->bc_private.a.agno);
  85        ASSERT(args.len == 1);
  86
  87        new->s = cpu_to_be32(args.agbno);
  88        be32_add_cpu(&agf->agf_refcount_blocks, 1);
  89        xfs_alloc_log_agf(cur->bc_tp, agbp, XFS_AGF_REFCOUNT_BLOCKS);
  90
  91        *stat = 1;
  92        return 0;
  93
  94out_error:
  95        return error;
  96}
  97
  98STATIC int
  99xfs_refcountbt_free_block(
 100        struct xfs_btree_cur    *cur,
 101        struct xfs_buf          *bp)
 102{
 103        struct xfs_mount        *mp = cur->bc_mp;
 104        struct xfs_buf          *agbp = cur->bc_private.a.agbp;
 105        struct xfs_agf          *agf = XFS_BUF_TO_AGF(agbp);
 106        xfs_fsblock_t           fsbno = XFS_DADDR_TO_FSB(mp, XFS_BUF_ADDR(bp));
 107        int                     error;
 108
 109        trace_xfs_refcountbt_free_block(cur->bc_mp, cur->bc_private.a.agno,
 110                        XFS_FSB_TO_AGBNO(cur->bc_mp, fsbno), 1);
 111        be32_add_cpu(&agf->agf_refcount_blocks, -1);
 112        xfs_alloc_log_agf(cur->bc_tp, agbp, XFS_AGF_REFCOUNT_BLOCKS);
 113        error = xfs_free_extent(cur->bc_tp, fsbno, 1, &XFS_RMAP_OINFO_REFC,
 114                        XFS_AG_RESV_METADATA);
 115        if (error)
 116                return error;
 117
 118        return error;
 119}
 120
 121STATIC int
 122xfs_refcountbt_get_minrecs(
 123        struct xfs_btree_cur    *cur,
 124        int                     level)
 125{
 126        return cur->bc_mp->m_refc_mnr[level != 0];
 127}
 128
 129STATIC int
 130xfs_refcountbt_get_maxrecs(
 131        struct xfs_btree_cur    *cur,
 132        int                     level)
 133{
 134        return cur->bc_mp->m_refc_mxr[level != 0];
 135}
 136
 137STATIC void
 138xfs_refcountbt_init_key_from_rec(
 139        union xfs_btree_key     *key,
 140        union xfs_btree_rec     *rec)
 141{
 142        key->refc.rc_startblock = rec->refc.rc_startblock;
 143}
 144
 145STATIC void
 146xfs_refcountbt_init_high_key_from_rec(
 147        union xfs_btree_key     *key,
 148        union xfs_btree_rec     *rec)
 149{
 150        __u32                   x;
 151
 152        x = be32_to_cpu(rec->refc.rc_startblock);
 153        x += be32_to_cpu(rec->refc.rc_blockcount) - 1;
 154        key->refc.rc_startblock = cpu_to_be32(x);
 155}
 156
 157STATIC void
 158xfs_refcountbt_init_rec_from_cur(
 159        struct xfs_btree_cur    *cur,
 160        union xfs_btree_rec     *rec)
 161{
 162        rec->refc.rc_startblock = cpu_to_be32(cur->bc_rec.rc.rc_startblock);
 163        rec->refc.rc_blockcount = cpu_to_be32(cur->bc_rec.rc.rc_blockcount);
 164        rec->refc.rc_refcount = cpu_to_be32(cur->bc_rec.rc.rc_refcount);
 165}
 166
 167STATIC void
 168xfs_refcountbt_init_ptr_from_cur(
 169        struct xfs_btree_cur    *cur,
 170        union xfs_btree_ptr     *ptr)
 171{
 172        struct xfs_agf          *agf = XFS_BUF_TO_AGF(cur->bc_private.a.agbp);
 173
 174        ASSERT(cur->bc_private.a.agno == be32_to_cpu(agf->agf_seqno));
 175
 176        ptr->s = agf->agf_refcount_root;
 177}
 178
 179STATIC int64_t
 180xfs_refcountbt_key_diff(
 181        struct xfs_btree_cur    *cur,
 182        union xfs_btree_key     *key)
 183{
 184        struct xfs_refcount_irec        *rec = &cur->bc_rec.rc;
 185        struct xfs_refcount_key         *kp = &key->refc;
 186
 187        return (int64_t)be32_to_cpu(kp->rc_startblock) - rec->rc_startblock;
 188}
 189
 190STATIC int64_t
 191xfs_refcountbt_diff_two_keys(
 192        struct xfs_btree_cur    *cur,
 193        union xfs_btree_key     *k1,
 194        union xfs_btree_key     *k2)
 195{
 196        return (int64_t)be32_to_cpu(k1->refc.rc_startblock) -
 197                          be32_to_cpu(k2->refc.rc_startblock);
 198}
 199
 200STATIC xfs_failaddr_t
 201xfs_refcountbt_verify(
 202        struct xfs_buf          *bp)
 203{
 204        struct xfs_mount        *mp = bp->b_mount;
 205        struct xfs_btree_block  *block = XFS_BUF_TO_BLOCK(bp);
 206        struct xfs_perag        *pag = bp->b_pag;
 207        xfs_failaddr_t          fa;
 208        unsigned int            level;
 209
 210        if (!xfs_verify_magic(bp, block->bb_magic))
 211                return __this_address;
 212
 213        if (!xfs_sb_version_hasreflink(&mp->m_sb))
 214                return __this_address;
 215        fa = xfs_btree_sblock_v5hdr_verify(bp);
 216        if (fa)
 217                return fa;
 218
 219        level = be16_to_cpu(block->bb_level);
 220        if (pag && pag->pagf_init) {
 221                if (level >= pag->pagf_refcount_level)
 222                        return __this_address;
 223        } else if (level >= mp->m_refc_maxlevels)
 224                return __this_address;
 225
 226        return xfs_btree_sblock_verify(bp, mp->m_refc_mxr[level != 0]);
 227}
 228
 229STATIC void
 230xfs_refcountbt_read_verify(
 231        struct xfs_buf  *bp)
 232{
 233        xfs_failaddr_t  fa;
 234
 235        if (!xfs_btree_sblock_verify_crc(bp))
 236                xfs_verifier_error(bp, -EFSBADCRC, __this_address);
 237        else {
 238                fa = xfs_refcountbt_verify(bp);
 239                if (fa)
 240                        xfs_verifier_error(bp, -EFSCORRUPTED, fa);
 241        }
 242
 243        if (bp->b_error)
 244                trace_xfs_btree_corrupt(bp, _RET_IP_);
 245}
 246
 247STATIC void
 248xfs_refcountbt_write_verify(
 249        struct xfs_buf  *bp)
 250{
 251        xfs_failaddr_t  fa;
 252
 253        fa = xfs_refcountbt_verify(bp);
 254        if (fa) {
 255                trace_xfs_btree_corrupt(bp, _RET_IP_);
 256                xfs_verifier_error(bp, -EFSCORRUPTED, fa);
 257                return;
 258        }
 259        xfs_btree_sblock_calc_crc(bp);
 260
 261}
 262
 263const struct xfs_buf_ops xfs_refcountbt_buf_ops = {
 264        .name                   = "xfs_refcountbt",
 265        .magic                  = { 0, cpu_to_be32(XFS_REFC_CRC_MAGIC) },
 266        .verify_read            = xfs_refcountbt_read_verify,
 267        .verify_write           = xfs_refcountbt_write_verify,
 268        .verify_struct          = xfs_refcountbt_verify,
 269};
 270
 271STATIC int
 272xfs_refcountbt_keys_inorder(
 273        struct xfs_btree_cur    *cur,
 274        union xfs_btree_key     *k1,
 275        union xfs_btree_key     *k2)
 276{
 277        return be32_to_cpu(k1->refc.rc_startblock) <
 278               be32_to_cpu(k2->refc.rc_startblock);
 279}
 280
 281STATIC int
 282xfs_refcountbt_recs_inorder(
 283        struct xfs_btree_cur    *cur,
 284        union xfs_btree_rec     *r1,
 285        union xfs_btree_rec     *r2)
 286{
 287        return  be32_to_cpu(r1->refc.rc_startblock) +
 288                be32_to_cpu(r1->refc.rc_blockcount) <=
 289                be32_to_cpu(r2->refc.rc_startblock);
 290}
 291
 292static const struct xfs_btree_ops xfs_refcountbt_ops = {
 293        .rec_len                = sizeof(struct xfs_refcount_rec),
 294        .key_len                = sizeof(struct xfs_refcount_key),
 295
 296        .dup_cursor             = xfs_refcountbt_dup_cursor,
 297        .set_root               = xfs_refcountbt_set_root,
 298        .alloc_block            = xfs_refcountbt_alloc_block,
 299        .free_block             = xfs_refcountbt_free_block,
 300        .get_minrecs            = xfs_refcountbt_get_minrecs,
 301        .get_maxrecs            = xfs_refcountbt_get_maxrecs,
 302        .init_key_from_rec      = xfs_refcountbt_init_key_from_rec,
 303        .init_high_key_from_rec = xfs_refcountbt_init_high_key_from_rec,
 304        .init_rec_from_cur      = xfs_refcountbt_init_rec_from_cur,
 305        .init_ptr_from_cur      = xfs_refcountbt_init_ptr_from_cur,
 306        .key_diff               = xfs_refcountbt_key_diff,
 307        .buf_ops                = &xfs_refcountbt_buf_ops,
 308        .diff_two_keys          = xfs_refcountbt_diff_two_keys,
 309        .keys_inorder           = xfs_refcountbt_keys_inorder,
 310        .recs_inorder           = xfs_refcountbt_recs_inorder,
 311};
 312
 313/*
 314 * Allocate a new refcount btree cursor.
 315 */
 316struct xfs_btree_cur *
 317xfs_refcountbt_init_cursor(
 318        struct xfs_mount        *mp,
 319        struct xfs_trans        *tp,
 320        struct xfs_buf          *agbp,
 321        xfs_agnumber_t          agno)
 322{
 323        struct xfs_agf          *agf = XFS_BUF_TO_AGF(agbp);
 324        struct xfs_btree_cur    *cur;
 325
 326        ASSERT(agno != NULLAGNUMBER);
 327        ASSERT(agno < mp->m_sb.sb_agcount);
 328        cur = kmem_zone_zalloc(xfs_btree_cur_zone, KM_NOFS);
 329
 330        cur->bc_tp = tp;
 331        cur->bc_mp = mp;
 332        cur->bc_btnum = XFS_BTNUM_REFC;
 333        cur->bc_blocklog = mp->m_sb.sb_blocklog;
 334        cur->bc_ops = &xfs_refcountbt_ops;
 335        cur->bc_statoff = XFS_STATS_CALC_INDEX(xs_refcbt_2);
 336
 337        cur->bc_nlevels = be32_to_cpu(agf->agf_refcount_level);
 338
 339        cur->bc_private.a.agbp = agbp;
 340        cur->bc_private.a.agno = agno;
 341        cur->bc_flags |= XFS_BTREE_CRC_BLOCKS;
 342
 343        cur->bc_private.a.priv.refc.nr_ops = 0;
 344        cur->bc_private.a.priv.refc.shape_changes = 0;
 345
 346        return cur;
 347}
 348
 349/*
 350 * Calculate the number of records in a refcount btree block.
 351 */
 352int
 353xfs_refcountbt_maxrecs(
 354        int                     blocklen,
 355        bool                    leaf)
 356{
 357        blocklen -= XFS_REFCOUNT_BLOCK_LEN;
 358
 359        if (leaf)
 360                return blocklen / sizeof(struct xfs_refcount_rec);
 361        return blocklen / (sizeof(struct xfs_refcount_key) +
 362                           sizeof(xfs_refcount_ptr_t));
 363}
 364
 365/* Compute the maximum height of a refcount btree. */
 366void
 367xfs_refcountbt_compute_maxlevels(
 368        struct xfs_mount                *mp)
 369{
 370        mp->m_refc_maxlevels = xfs_btree_compute_maxlevels(
 371                        mp->m_refc_mnr, mp->m_sb.sb_agblocks);
 372}
 373
 374/* Calculate the refcount btree size for some records. */
 375xfs_extlen_t
 376xfs_refcountbt_calc_size(
 377        struct xfs_mount        *mp,
 378        unsigned long long      len)
 379{
 380        return xfs_btree_calc_size(mp->m_refc_mnr, len);
 381}
 382
 383/*
 384 * Calculate the maximum refcount btree size.
 385 */
 386xfs_extlen_t
 387xfs_refcountbt_max_size(
 388        struct xfs_mount        *mp,
 389        xfs_agblock_t           agblocks)
 390{
 391        /* Bail out if we're uninitialized, which can happen in mkfs. */
 392        if (mp->m_refc_mxr[0] == 0)
 393                return 0;
 394
 395        return xfs_refcountbt_calc_size(mp, agblocks);
 396}
 397
 398/*
 399 * Figure out how many blocks to reserve and how many are used by this btree.
 400 */
 401int
 402xfs_refcountbt_calc_reserves(
 403        struct xfs_mount        *mp,
 404        struct xfs_trans        *tp,
 405        xfs_agnumber_t          agno,
 406        xfs_extlen_t            *ask,
 407        xfs_extlen_t            *used)
 408{
 409        struct xfs_buf          *agbp;
 410        struct xfs_agf          *agf;
 411        xfs_agblock_t           agblocks;
 412        xfs_extlen_t            tree_len;
 413        int                     error;
 414
 415        if (!xfs_sb_version_hasreflink(&mp->m_sb))
 416                return 0;
 417
 418
 419        error = xfs_alloc_read_agf(mp, tp, agno, 0, &agbp);
 420        if (error)
 421                return error;
 422
 423        agf = XFS_BUF_TO_AGF(agbp);
 424        agblocks = be32_to_cpu(agf->agf_length);
 425        tree_len = be32_to_cpu(agf->agf_refcount_blocks);
 426        xfs_trans_brelse(tp, agbp);
 427
 428        /*
 429         * The log is permanently allocated, so the space it occupies will
 430         * never be available for the kinds of things that would require btree
 431         * expansion.  We therefore can pretend the space isn't there.
 432         */
 433        if (mp->m_sb.sb_logstart &&
 434            XFS_FSB_TO_AGNO(mp, mp->m_sb.sb_logstart) == agno)
 435                agblocks -= mp->m_sb.sb_logblocks;
 436
 437        *ask += xfs_refcountbt_max_size(mp, agblocks);
 438        *used += tree_len;
 439
 440        return error;
 441}
 442