linux/fs/xfs/xfs_alloc_btree.c
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   1/*
   2 * Copyright (c) 2000-2001,2005 Silicon Graphics, Inc.
   3 * All Rights Reserved.
   4 *
   5 * This program is free software; you can redistribute it and/or
   6 * modify it under the terms of the GNU General Public License as
   7 * published by the Free Software Foundation.
   8 *
   9 * This program is distributed in the hope that it would be useful,
  10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 * GNU General Public License for more details.
  13 *
  14 * You should have received a copy of the GNU General Public License
  15 * along with this program; if not, write the Free Software Foundation,
  16 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  17 */
  18#include "xfs.h"
  19#include "xfs_fs.h"
  20#include "xfs_types.h"
  21#include "xfs_log.h"
  22#include "xfs_trans.h"
  23#include "xfs_sb.h"
  24#include "xfs_ag.h"
  25#include "xfs_mount.h"
  26#include "xfs_bmap_btree.h"
  27#include "xfs_alloc_btree.h"
  28#include "xfs_ialloc_btree.h"
  29#include "xfs_dinode.h"
  30#include "xfs_inode.h"
  31#include "xfs_btree.h"
  32#include "xfs_alloc.h"
  33#include "xfs_extent_busy.h"
  34#include "xfs_error.h"
  35#include "xfs_trace.h"
  36
  37
  38STATIC struct xfs_btree_cur *
  39xfs_allocbt_dup_cursor(
  40        struct xfs_btree_cur    *cur)
  41{
  42        return xfs_allocbt_init_cursor(cur->bc_mp, cur->bc_tp,
  43                        cur->bc_private.a.agbp, cur->bc_private.a.agno,
  44                        cur->bc_btnum);
  45}
  46
  47STATIC void
  48xfs_allocbt_set_root(
  49        struct xfs_btree_cur    *cur,
  50        union xfs_btree_ptr     *ptr,
  51        int                     inc)
  52{
  53        struct xfs_buf          *agbp = cur->bc_private.a.agbp;
  54        struct xfs_agf          *agf = XFS_BUF_TO_AGF(agbp);
  55        xfs_agnumber_t          seqno = be32_to_cpu(agf->agf_seqno);
  56        int                     btnum = cur->bc_btnum;
  57        struct xfs_perag        *pag = xfs_perag_get(cur->bc_mp, seqno);
  58
  59        ASSERT(ptr->s != 0);
  60
  61        agf->agf_roots[btnum] = ptr->s;
  62        be32_add_cpu(&agf->agf_levels[btnum], inc);
  63        pag->pagf_levels[btnum] += inc;
  64        xfs_perag_put(pag);
  65
  66        xfs_alloc_log_agf(cur->bc_tp, agbp, XFS_AGF_ROOTS | XFS_AGF_LEVELS);
  67}
  68
  69STATIC int
  70xfs_allocbt_alloc_block(
  71        struct xfs_btree_cur    *cur,
  72        union xfs_btree_ptr     *start,
  73        union xfs_btree_ptr     *new,
  74        int                     length,
  75        int                     *stat)
  76{
  77        int                     error;
  78        xfs_agblock_t           bno;
  79
  80        XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
  81
  82        /* Allocate the new block from the freelist. If we can't, give up.  */
  83        error = xfs_alloc_get_freelist(cur->bc_tp, cur->bc_private.a.agbp,
  84                                       &bno, 1);
  85        if (error) {
  86                XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
  87                return error;
  88        }
  89
  90        if (bno == NULLAGBLOCK) {
  91                XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
  92                *stat = 0;
  93                return 0;
  94        }
  95
  96        xfs_extent_busy_reuse(cur->bc_mp, cur->bc_private.a.agno, bno, 1, false);
  97
  98        xfs_trans_agbtree_delta(cur->bc_tp, 1);
  99        new->s = cpu_to_be32(bno);
 100
 101        XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
 102        *stat = 1;
 103        return 0;
 104}
 105
 106STATIC int
 107xfs_allocbt_free_block(
 108        struct xfs_btree_cur    *cur,
 109        struct xfs_buf          *bp)
 110{
 111        struct xfs_buf          *agbp = cur->bc_private.a.agbp;
 112        struct xfs_agf          *agf = XFS_BUF_TO_AGF(agbp);
 113        xfs_agblock_t           bno;
 114        int                     error;
 115
 116        bno = xfs_daddr_to_agbno(cur->bc_mp, XFS_BUF_ADDR(bp));
 117        error = xfs_alloc_put_freelist(cur->bc_tp, agbp, NULL, bno, 1);
 118        if (error)
 119                return error;
 120
 121        xfs_extent_busy_insert(cur->bc_tp, be32_to_cpu(agf->agf_seqno), bno, 1,
 122                              XFS_EXTENT_BUSY_SKIP_DISCARD);
 123        xfs_trans_agbtree_delta(cur->bc_tp, -1);
 124
 125        xfs_trans_binval(cur->bc_tp, bp);
 126        return 0;
 127}
 128
 129/*
 130 * Update the longest extent in the AGF
 131 */
 132STATIC void
 133xfs_allocbt_update_lastrec(
 134        struct xfs_btree_cur    *cur,
 135        struct xfs_btree_block  *block,
 136        union xfs_btree_rec     *rec,
 137        int                     ptr,
 138        int                     reason)
 139{
 140        struct xfs_agf          *agf = XFS_BUF_TO_AGF(cur->bc_private.a.agbp);
 141        xfs_agnumber_t          seqno = be32_to_cpu(agf->agf_seqno);
 142        struct xfs_perag        *pag;
 143        __be32                  len;
 144        int                     numrecs;
 145
 146        ASSERT(cur->bc_btnum == XFS_BTNUM_CNT);
 147
 148        switch (reason) {
 149        case LASTREC_UPDATE:
 150                /*
 151                 * If this is the last leaf block and it's the last record,
 152                 * then update the size of the longest extent in the AG.
 153                 */
 154                if (ptr != xfs_btree_get_numrecs(block))
 155                        return;
 156                len = rec->alloc.ar_blockcount;
 157                break;
 158        case LASTREC_INSREC:
 159                if (be32_to_cpu(rec->alloc.ar_blockcount) <=
 160                    be32_to_cpu(agf->agf_longest))
 161                        return;
 162                len = rec->alloc.ar_blockcount;
 163                break;
 164        case LASTREC_DELREC:
 165                numrecs = xfs_btree_get_numrecs(block);
 166                if (ptr <= numrecs)
 167                        return;
 168                ASSERT(ptr == numrecs + 1);
 169
 170                if (numrecs) {
 171                        xfs_alloc_rec_t *rrp;
 172
 173                        rrp = XFS_ALLOC_REC_ADDR(cur->bc_mp, block, numrecs);
 174                        len = rrp->ar_blockcount;
 175                } else {
 176                        len = 0;
 177                }
 178
 179                break;
 180        default:
 181                ASSERT(0);
 182                return;
 183        }
 184
 185        agf->agf_longest = len;
 186        pag = xfs_perag_get(cur->bc_mp, seqno);
 187        pag->pagf_longest = be32_to_cpu(len);
 188        xfs_perag_put(pag);
 189        xfs_alloc_log_agf(cur->bc_tp, cur->bc_private.a.agbp, XFS_AGF_LONGEST);
 190}
 191
 192STATIC int
 193xfs_allocbt_get_minrecs(
 194        struct xfs_btree_cur    *cur,
 195        int                     level)
 196{
 197        return cur->bc_mp->m_alloc_mnr[level != 0];
 198}
 199
 200STATIC int
 201xfs_allocbt_get_maxrecs(
 202        struct xfs_btree_cur    *cur,
 203        int                     level)
 204{
 205        return cur->bc_mp->m_alloc_mxr[level != 0];
 206}
 207
 208STATIC void
 209xfs_allocbt_init_key_from_rec(
 210        union xfs_btree_key     *key,
 211        union xfs_btree_rec     *rec)
 212{
 213        ASSERT(rec->alloc.ar_startblock != 0);
 214
 215        key->alloc.ar_startblock = rec->alloc.ar_startblock;
 216        key->alloc.ar_blockcount = rec->alloc.ar_blockcount;
 217}
 218
 219STATIC void
 220xfs_allocbt_init_rec_from_key(
 221        union xfs_btree_key     *key,
 222        union xfs_btree_rec     *rec)
 223{
 224        ASSERT(key->alloc.ar_startblock != 0);
 225
 226        rec->alloc.ar_startblock = key->alloc.ar_startblock;
 227        rec->alloc.ar_blockcount = key->alloc.ar_blockcount;
 228}
 229
 230STATIC void
 231xfs_allocbt_init_rec_from_cur(
 232        struct xfs_btree_cur    *cur,
 233        union xfs_btree_rec     *rec)
 234{
 235        ASSERT(cur->bc_rec.a.ar_startblock != 0);
 236
 237        rec->alloc.ar_startblock = cpu_to_be32(cur->bc_rec.a.ar_startblock);
 238        rec->alloc.ar_blockcount = cpu_to_be32(cur->bc_rec.a.ar_blockcount);
 239}
 240
 241STATIC void
 242xfs_allocbt_init_ptr_from_cur(
 243        struct xfs_btree_cur    *cur,
 244        union xfs_btree_ptr     *ptr)
 245{
 246        struct xfs_agf          *agf = XFS_BUF_TO_AGF(cur->bc_private.a.agbp);
 247
 248        ASSERT(cur->bc_private.a.agno == be32_to_cpu(agf->agf_seqno));
 249        ASSERT(agf->agf_roots[cur->bc_btnum] != 0);
 250
 251        ptr->s = agf->agf_roots[cur->bc_btnum];
 252}
 253
 254STATIC __int64_t
 255xfs_allocbt_key_diff(
 256        struct xfs_btree_cur    *cur,
 257        union xfs_btree_key     *key)
 258{
 259        xfs_alloc_rec_incore_t  *rec = &cur->bc_rec.a;
 260        xfs_alloc_key_t         *kp = &key->alloc;
 261        __int64_t               diff;
 262
 263        if (cur->bc_btnum == XFS_BTNUM_BNO) {
 264                return (__int64_t)be32_to_cpu(kp->ar_startblock) -
 265                                rec->ar_startblock;
 266        }
 267
 268        diff = (__int64_t)be32_to_cpu(kp->ar_blockcount) - rec->ar_blockcount;
 269        if (diff)
 270                return diff;
 271
 272        return (__int64_t)be32_to_cpu(kp->ar_startblock) - rec->ar_startblock;
 273}
 274
 275static void
 276xfs_allocbt_verify(
 277        struct xfs_buf          *bp)
 278{
 279        struct xfs_mount        *mp = bp->b_target->bt_mount;
 280        struct xfs_btree_block  *block = XFS_BUF_TO_BLOCK(bp);
 281        struct xfs_perag        *pag = bp->b_pag;
 282        unsigned int            level;
 283        int                     sblock_ok; /* block passes checks */
 284
 285        /*
 286         * magic number and level verification
 287         *
 288         * During growfs operations, we can't verify the exact level as the
 289         * perag is not fully initialised and hence not attached to the buffer.
 290         * In this case, check against the maximum tree depth.
 291         */
 292        level = be16_to_cpu(block->bb_level);
 293        switch (block->bb_magic) {
 294        case cpu_to_be32(XFS_ABTB_MAGIC):
 295                if (pag)
 296                        sblock_ok = level < pag->pagf_levels[XFS_BTNUM_BNOi];
 297                else
 298                        sblock_ok = level < mp->m_ag_maxlevels;
 299                break;
 300        case cpu_to_be32(XFS_ABTC_MAGIC):
 301                if (pag)
 302                        sblock_ok = level < pag->pagf_levels[XFS_BTNUM_CNTi];
 303                else
 304                        sblock_ok = level < mp->m_ag_maxlevels;
 305                break;
 306        default:
 307                sblock_ok = 0;
 308                break;
 309        }
 310
 311        /* numrecs verification */
 312        sblock_ok = sblock_ok &&
 313                be16_to_cpu(block->bb_numrecs) <= mp->m_alloc_mxr[level != 0];
 314
 315        /* sibling pointer verification */
 316        sblock_ok = sblock_ok &&
 317                (block->bb_u.s.bb_leftsib == cpu_to_be32(NULLAGBLOCK) ||
 318                 be32_to_cpu(block->bb_u.s.bb_leftsib) < mp->m_sb.sb_agblocks) &&
 319                block->bb_u.s.bb_leftsib &&
 320                (block->bb_u.s.bb_rightsib == cpu_to_be32(NULLAGBLOCK) ||
 321                 be32_to_cpu(block->bb_u.s.bb_rightsib) < mp->m_sb.sb_agblocks) &&
 322                block->bb_u.s.bb_rightsib;
 323
 324        if (!sblock_ok) {
 325                trace_xfs_btree_corrupt(bp, _RET_IP_);
 326                XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, block);
 327                xfs_buf_ioerror(bp, EFSCORRUPTED);
 328        }
 329}
 330
 331static void
 332xfs_allocbt_read_verify(
 333        struct xfs_buf  *bp)
 334{
 335        xfs_allocbt_verify(bp);
 336}
 337
 338static void
 339xfs_allocbt_write_verify(
 340        struct xfs_buf  *bp)
 341{
 342        xfs_allocbt_verify(bp);
 343}
 344
 345const struct xfs_buf_ops xfs_allocbt_buf_ops = {
 346        .verify_read = xfs_allocbt_read_verify,
 347        .verify_write = xfs_allocbt_write_verify,
 348};
 349
 350
 351#ifdef DEBUG
 352STATIC int
 353xfs_allocbt_keys_inorder(
 354        struct xfs_btree_cur    *cur,
 355        union xfs_btree_key     *k1,
 356        union xfs_btree_key     *k2)
 357{
 358        if (cur->bc_btnum == XFS_BTNUM_BNO) {
 359                return be32_to_cpu(k1->alloc.ar_startblock) <
 360                       be32_to_cpu(k2->alloc.ar_startblock);
 361        } else {
 362                return be32_to_cpu(k1->alloc.ar_blockcount) <
 363                        be32_to_cpu(k2->alloc.ar_blockcount) ||
 364                        (k1->alloc.ar_blockcount == k2->alloc.ar_blockcount &&
 365                         be32_to_cpu(k1->alloc.ar_startblock) <
 366                         be32_to_cpu(k2->alloc.ar_startblock));
 367        }
 368}
 369
 370STATIC int
 371xfs_allocbt_recs_inorder(
 372        struct xfs_btree_cur    *cur,
 373        union xfs_btree_rec     *r1,
 374        union xfs_btree_rec     *r2)
 375{
 376        if (cur->bc_btnum == XFS_BTNUM_BNO) {
 377                return be32_to_cpu(r1->alloc.ar_startblock) +
 378                        be32_to_cpu(r1->alloc.ar_blockcount) <=
 379                        be32_to_cpu(r2->alloc.ar_startblock);
 380        } else {
 381                return be32_to_cpu(r1->alloc.ar_blockcount) <
 382                        be32_to_cpu(r2->alloc.ar_blockcount) ||
 383                        (r1->alloc.ar_blockcount == r2->alloc.ar_blockcount &&
 384                         be32_to_cpu(r1->alloc.ar_startblock) <
 385                         be32_to_cpu(r2->alloc.ar_startblock));
 386        }
 387}
 388#endif  /* DEBUG */
 389
 390static const struct xfs_btree_ops xfs_allocbt_ops = {
 391        .rec_len                = sizeof(xfs_alloc_rec_t),
 392        .key_len                = sizeof(xfs_alloc_key_t),
 393
 394        .dup_cursor             = xfs_allocbt_dup_cursor,
 395        .set_root               = xfs_allocbt_set_root,
 396        .alloc_block            = xfs_allocbt_alloc_block,
 397        .free_block             = xfs_allocbt_free_block,
 398        .update_lastrec         = xfs_allocbt_update_lastrec,
 399        .get_minrecs            = xfs_allocbt_get_minrecs,
 400        .get_maxrecs            = xfs_allocbt_get_maxrecs,
 401        .init_key_from_rec      = xfs_allocbt_init_key_from_rec,
 402        .init_rec_from_key      = xfs_allocbt_init_rec_from_key,
 403        .init_rec_from_cur      = xfs_allocbt_init_rec_from_cur,
 404        .init_ptr_from_cur      = xfs_allocbt_init_ptr_from_cur,
 405        .key_diff               = xfs_allocbt_key_diff,
 406        .buf_ops                = &xfs_allocbt_buf_ops,
 407#ifdef DEBUG
 408        .keys_inorder           = xfs_allocbt_keys_inorder,
 409        .recs_inorder           = xfs_allocbt_recs_inorder,
 410#endif
 411};
 412
 413/*
 414 * Allocate a new allocation btree cursor.
 415 */
 416struct xfs_btree_cur *                  /* new alloc btree cursor */
 417xfs_allocbt_init_cursor(
 418        struct xfs_mount        *mp,            /* file system mount point */
 419        struct xfs_trans        *tp,            /* transaction pointer */
 420        struct xfs_buf          *agbp,          /* buffer for agf structure */
 421        xfs_agnumber_t          agno,           /* allocation group number */
 422        xfs_btnum_t             btnum)          /* btree identifier */
 423{
 424        struct xfs_agf          *agf = XFS_BUF_TO_AGF(agbp);
 425        struct xfs_btree_cur    *cur;
 426
 427        ASSERT(btnum == XFS_BTNUM_BNO || btnum == XFS_BTNUM_CNT);
 428
 429        cur = kmem_zone_zalloc(xfs_btree_cur_zone, KM_SLEEP);
 430
 431        cur->bc_tp = tp;
 432        cur->bc_mp = mp;
 433        cur->bc_btnum = btnum;
 434        cur->bc_blocklog = mp->m_sb.sb_blocklog;
 435        cur->bc_ops = &xfs_allocbt_ops;
 436
 437        if (btnum == XFS_BTNUM_CNT) {
 438                cur->bc_nlevels = be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNT]);
 439                cur->bc_flags = XFS_BTREE_LASTREC_UPDATE;
 440        } else {
 441                cur->bc_nlevels = be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNO]);
 442        }
 443
 444        cur->bc_private.a.agbp = agbp;
 445        cur->bc_private.a.agno = agno;
 446
 447        return cur;
 448}
 449
 450/*
 451 * Calculate number of records in an alloc btree block.
 452 */
 453int
 454xfs_allocbt_maxrecs(
 455        struct xfs_mount        *mp,
 456        int                     blocklen,
 457        int                     leaf)
 458{
 459        blocklen -= XFS_ALLOC_BLOCK_LEN(mp);
 460
 461        if (leaf)
 462                return blocklen / sizeof(xfs_alloc_rec_t);
 463        return blocklen / (sizeof(xfs_alloc_key_t) + sizeof(xfs_alloc_ptr_t));
 464}
 465
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