fs/xfs/libxfs/xfs_alloc_btree.c

   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_shared.h"
  21 #include "xfs_format.h"
  22 #include "xfs_log_format.h"
  23 #include "xfs_trans_resv.h"
  24 #include "xfs_sb.h"
  25 #include "xfs_mount.h"
  26 #include "xfs_btree.h"
  27 #include "xfs_alloc_btree.h"
  28 #include "xfs_alloc.h"
  29 #include "xfs_extent_busy.h"
  30 #include "xfs_error.h"
  31 #include "xfs_trace.h"
  32 #include "xfs_cksum.h"
  33 #include "xfs_trans.h"
  34
  35
  36 STATIC struct xfs_btree_cur *
  37 xfs_allocbt_dup_cursor(
  38         struct xfs_btree_cur    *cur)
  39 {
  40         return xfs_allocbt_init_cursor(cur->bc_mp, cur->bc_tp,
  41                         cur->bc_private.a.agbp, cur->bc_private.a.agno,
  42                         cur->bc_btnum);
  43 }
  44
  45 STATIC void
  46 xfs_allocbt_set_root(
  47         struct xfs_btree_cur    *cur,
  48         union xfs_btree_ptr     *ptr,
  49         int                     inc)
  50 {
  51         struct xfs_buf          *agbp = cur->bc_private.a.agbp;
  52         struct xfs_agf          *agf = XFS_BUF_TO_AGF(agbp);
  53         xfs_agnumber_t          seqno = be32_to_cpu(agf->agf_seqno);
  54         int                     btnum = cur->bc_btnum;
  55         struct xfs_perag        *pag = xfs_perag_get(cur->bc_mp, seqno);
  56
  57         ASSERT(ptr->s != 0);
  58
  59         agf->agf_roots[btnum] = ptr->s;
  60         be32_add_cpu(&agf->agf_levels[btnum], inc);
  61         pag->pagf_levels[btnum] += inc;
  62         xfs_perag_put(pag);
  63
  64         xfs_alloc_log_agf(cur->bc_tp, agbp, XFS_AGF_ROOTS | XFS_AGF_LEVELS);
  65 }
  66
  67 STATIC int
  68 xfs_allocbt_alloc_block(
  69         struct xfs_btree_cur    *cur,
  70         union xfs_btree_ptr     *start,
  71         union xfs_btree_ptr     *new,
  72         int                     *stat)
  73 {
  74         int                     error;
  75         xfs_agblock_t           bno;
  76
  77         XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
  78
  79         /* Allocate the new block from the freelist. If we can't, give up.  */
  80         error = xfs_alloc_get_freelist(cur->bc_tp, cur->bc_private.a.agbp,
  81                                        &bno, 1);
  82         if (error) {
  83                 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
  84                 return error;
  85         }
  86
  87         if (bno == NULLAGBLOCK) {
  88                 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
  89                 *stat = 0;
  90                 return 0;
  91         }
  92
  93         xfs_extent_busy_reuse(cur->bc_mp, cur->bc_private.a.agno, bno, 1, false);
  94
  95         xfs_trans_agbtree_delta(cur->bc_tp, 1);
  96         new->s = cpu_to_be32(bno);
  97
  98         XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
  99         *stat = 1;
 100         return 0;
 101 }
 102
 103 STATIC int
 104 xfs_allocbt_free_block(
 105         struct xfs_btree_cur    *cur,
 106         struct xfs_buf          *bp)
 107 {
 108         struct xfs_buf          *agbp = cur->bc_private.a.agbp;
 109         struct xfs_agf          *agf = XFS_BUF_TO_AGF(agbp);
 110         xfs_agblock_t           bno;
 111         int                     error;
 112
 113         bno = xfs_daddr_to_agbno(cur->bc_mp, XFS_BUF_ADDR(bp));
 114         error = xfs_alloc_put_freelist(cur->bc_tp, agbp, NULL, bno, 1);
 115         if (error)
 116                 return error;
 117
 118         xfs_extent_busy_insert(cur->bc_tp, be32_to_cpu(agf->agf_seqno), bno, 1,
 119                               XFS_EXTENT_BUSY_SKIP_DISCARD);
 120         xfs_trans_agbtree_delta(cur->bc_tp, -1);
 121
 122         xfs_trans_binval(cur->bc_tp, bp);
 123         return 0;
 124 }
 125
 126 /*
 127  * Update the longest extent in the AGF
 128  */
 129 STATIC void
 130 xfs_allocbt_update_lastrec(
 131         struct xfs_btree_cur    *cur,
 132         struct xfs_btree_block  *block,
 133         union xfs_btree_rec     *rec,
 134         int                     ptr,
 135         int                     reason)
 136 {
 137         struct xfs_agf          *agf = XFS_BUF_TO_AGF(cur->bc_private.a.agbp);
 138         xfs_agnumber_t          seqno = be32_to_cpu(agf->agf_seqno);
 139         struct xfs_perag        *pag;
 140         __be32                  len;
 141         int                     numrecs;
 142
 143         ASSERT(cur->bc_btnum == XFS_BTNUM_CNT);
 144
 145         switch (reason) {
 146         case LASTREC_UPDATE:
 147                 /*
 148                  * If this is the last leaf block and it's the last record,
 149                  * then update the size of the longest extent in the AG.
 150                  */
 151                 if (ptr != xfs_btree_get_numrecs(block))
 152                         return;
 153                 len = rec->alloc.ar_blockcount;
 154                 break;
 155         case LASTREC_INSREC:
 156                 if (be32_to_cpu(rec->alloc.ar_blockcount) <=
 157                     be32_to_cpu(agf->agf_longest))
 158                         return;
 159                 len = rec->alloc.ar_blockcount;
 160                 break;
 161         case LASTREC_DELREC:
 162                 numrecs = xfs_btree_get_numrecs(block);
 163                 if (ptr <= numrecs)
 164                         return;
 165                 ASSERT(ptr == numrecs + 1);
 166
 167                 if (numrecs) {
 168                         xfs_alloc_rec_t *rrp;
 169
 170                         rrp = XFS_ALLOC_REC_ADDR(cur->bc_mp, block, numrecs);
 171                         len = rrp->ar_blockcount;
 172                 } else {
 173                         len = 0;
 174                 }
 175
 176                 break;
 177         default:
 178                 ASSERT(0);
 179                 return;
 180         }
 181
 182         agf->agf_longest = len;
 183         pag = xfs_perag_get(cur->bc_mp, seqno);
 184         pag->pagf_longest = be32_to_cpu(len);
 185         xfs_perag_put(pag);
 186         xfs_alloc_log_agf(cur->bc_tp, cur->bc_private.a.agbp, XFS_AGF_LONGEST);
 187 }
 188
 189 STATIC int
 190 xfs_allocbt_get_minrecs(
 191         struct xfs_btree_cur    *cur,
 192         int                     level)
 193 {
 194         return cur->bc_mp->m_alloc_mnr[level != 0];
 195 }
 196
 197 STATIC int
 198 xfs_allocbt_get_maxrecs(
 199         struct xfs_btree_cur    *cur,
 200         int                     level)
 201 {
 202         return cur->bc_mp->m_alloc_mxr[level != 0];
 203 }
 204
 205 STATIC void
 206 xfs_allocbt_init_key_from_rec(
 207         union xfs_btree_key     *key,
 208         union xfs_btree_rec     *rec)
 209 {
 210         ASSERT(rec->alloc.ar_startblock != 0);
 211
 212         key->alloc.ar_startblock = rec->alloc.ar_startblock;
 213         key->alloc.ar_blockcount = rec->alloc.ar_blockcount;
 214 }
 215
 216 STATIC void
 217 xfs_allocbt_init_rec_from_key(
 218         union xfs_btree_key     *key,
 219         union xfs_btree_rec     *rec)
 220 {
 221         ASSERT(key->alloc.ar_startblock != 0);
 222
 223         rec->alloc.ar_startblock = key->alloc.ar_startblock;
 224         rec->alloc.ar_blockcount = key->alloc.ar_blockcount;
 225 }
 226
 227 STATIC void
 228 xfs_allocbt_init_rec_from_cur(
 229         struct xfs_btree_cur    *cur,
 230         union xfs_btree_rec     *rec)
 231 {
 232         ASSERT(cur->bc_rec.a.ar_startblock != 0);
 233
 234         rec->alloc.ar_startblock = cpu_to_be32(cur->bc_rec.a.ar_startblock);
 235         rec->alloc.ar_blockcount = cpu_to_be32(cur->bc_rec.a.ar_blockcount);
 236 }
 237
 238 STATIC void
 239 xfs_allocbt_init_ptr_from_cur(
 240         struct xfs_btree_cur    *cur,
 241         union xfs_btree_ptr     *ptr)
 242 {
 243         struct xfs_agf          *agf = XFS_BUF_TO_AGF(cur->bc_private.a.agbp);
 244
 245         ASSERT(cur->bc_private.a.agno == be32_to_cpu(agf->agf_seqno));
 246         ASSERT(agf->agf_roots[cur->bc_btnum] != 0);
 247
 248         ptr->s = agf->agf_roots[cur->bc_btnum];
 249 }
 250
 251 STATIC __int64_t
 252 xfs_allocbt_key_diff(
 253         struct xfs_btree_cur    *cur,
 254         union xfs_btree_key     *key)
 255 {
 256         xfs_alloc_rec_incore_t  *rec = &cur->bc_rec.a;
 257         xfs_alloc_key_t         *kp = &key->alloc;
 258         __int64_t               diff;
 259
 260         if (cur->bc_btnum == XFS_BTNUM_BNO) {
 261                 return (__int64_t)be32_to_cpu(kp->ar_startblock) -
 262                                 rec->ar_startblock;
 263         }
 264
 265         diff = (__int64_t)be32_to_cpu(kp->ar_blockcount) - rec->ar_blockcount;
 266         if (diff)
 267                 return diff;
 268
 269         return (__int64_t)be32_to_cpu(kp->ar_startblock) - rec->ar_startblock;
 270 }
 271
 272 static bool
 273 xfs_allocbt_verify(
 274         struct xfs_buf          *bp)
 275 {
 276         struct xfs_mount        *mp = bp->b_target->bt_mount;
 277         struct xfs_btree_block  *block = XFS_BUF_TO_BLOCK(bp);
 278         struct xfs_perag        *pag = bp->b_pag;
 279         unsigned int            level;
 280
 281         /*
 282          * magic number and level verification
 283          *
 284          * During growfs operations, we can't verify the exact level or owner as
 285          * the perag is not fully initialised and hence not attached to the
 286          * buffer.  In this case, check against the maximum tree depth.
 287          *
 288          * Similarly, during log recovery we will have a perag structure
 289          * attached, but the agf information will not yet have been initialised
 290          * from the on disk AGF. Again, we can only check against maximum limits
 291          * in this case.
 292          */
 293         level = be16_to_cpu(block->bb_level);
 294         switch (block->bb_magic) {
 295         case cpu_to_be32(XFS_ABTB_CRC_MAGIC):
 296                 if (!xfs_sb_version_hascrc(&mp->m_sb))
 297                         return false;
 298                 if (!uuid_equal(&block->bb_u.s.bb_uuid, &mp->m_sb.sb_meta_uuid))
 299                         return false;
 300                 if (block->bb_u.s.bb_blkno != cpu_to_be64(bp->b_bn))
 301                         return false;
 302                 if (pag &&
 303                     be32_to_cpu(block->bb_u.s.bb_owner) != pag->pag_agno)
 304                         return false;
 305                 /* fall through */
 306         case cpu_to_be32(XFS_ABTB_MAGIC):
 307                 if (pag && pag->pagf_init) {
 308                         if (level >= pag->pagf_levels[XFS_BTNUM_BNOi])
 309                                 return false;
 310                 } else if (level >= mp->m_ag_maxlevels)
 311                         return false;
 312                 break;
 313         case cpu_to_be32(XFS_ABTC_CRC_MAGIC):
 314                 if (!xfs_sb_version_hascrc(&mp->m_sb))
 315                         return false;
 316                 if (!uuid_equal(&block->bb_u.s.bb_uuid, &mp->m_sb.sb_meta_uuid))
 317                         return false;
 318                 if (block->bb_u.s.bb_blkno != cpu_to_be64(bp->b_bn))
 319                         return false;
 320                 if (pag &&
 321                     be32_to_cpu(block->bb_u.s.bb_owner) != pag->pag_agno)
 322                         return false;
 323                 /* fall through */
 324         case cpu_to_be32(XFS_ABTC_MAGIC):
 325                 if (pag && pag->pagf_init) {
 326                         if (level >= pag->pagf_levels[XFS_BTNUM_CNTi])
 327                                 return false;
 328                 } else if (level >= mp->m_ag_maxlevels)
 329                         return false;
 330                 break;
 331         default:
 332                 return false;
 333         }
 334
 335         /* numrecs verification */
 336         if (be16_to_cpu(block->bb_numrecs) > mp->m_alloc_mxr[level != 0])
 337                 return false;
 338
 339         /* sibling pointer verification */
 340         if (!block->bb_u.s.bb_leftsib ||
 341             (be32_to_cpu(block->bb_u.s.bb_leftsib) >= mp->m_sb.sb_agblocks &&
 342              block->bb_u.s.bb_leftsib != cpu_to_be32(NULLAGBLOCK)))
 343                 return false;
 344         if (!block->bb_u.s.bb_rightsib ||
 345             (be32_to_cpu(block->bb_u.s.bb_rightsib) >= mp->m_sb.sb_agblocks &&
 346              block->bb_u.s.bb_rightsib != cpu_to_be32(NULLAGBLOCK)))
 347                 return false;
 348
 349         return true;
 350 }
 351
 352 static void
 353 xfs_allocbt_read_verify(
 354         struct xfs_buf  *bp)
 355 {
 356         if (!xfs_btree_sblock_verify_crc(bp))
 357                 xfs_buf_ioerror(bp, -EFSBADCRC);
 358         else if (!xfs_allocbt_verify(bp))
 359                 xfs_buf_ioerror(bp, -EFSCORRUPTED);
 360
 361         if (bp->b_error) {
 362                 trace_xfs_btree_corrupt(bp, _RET_IP_);
 363                 xfs_verifier_error(bp);
 364         }
 365 }
 366
 367 static void
 368 xfs_allocbt_write_verify(
 369         struct xfs_buf  *bp)
 370 {
 371         if (!xfs_allocbt_verify(bp)) {
 372                 trace_xfs_btree_corrupt(bp, _RET_IP_);
 373                 xfs_buf_ioerror(bp, -EFSCORRUPTED);
 374                 xfs_verifier_error(bp);
 375                 return;
 376         }
 377         xfs_btree_sblock_calc_crc(bp);
 378
 379 }
 380
 381 const struct xfs_buf_ops xfs_allocbt_buf_ops = {
 382         .verify_read = xfs_allocbt_read_verify,
 383         .verify_write = xfs_allocbt_write_verify,
 384 };
 385
 386
 387 #if defined(DEBUG) || defined(XFS_WARN)
 388 STATIC int
 389 xfs_allocbt_keys_inorder(
 390         struct xfs_btree_cur    *cur,
 391         union xfs_btree_key     *k1,
 392         union xfs_btree_key     *k2)
 393 {
 394         if (cur->bc_btnum == XFS_BTNUM_BNO) {
 395                 return be32_to_cpu(k1->alloc.ar_startblock) <
 396                        be32_to_cpu(k2->alloc.ar_startblock);
 397         } else {
 398                 return be32_to_cpu(k1->alloc.ar_blockcount) <
 399                         be32_to_cpu(k2->alloc.ar_blockcount) ||
 400                         (k1->alloc.ar_blockcount == k2->alloc.ar_blockcount &&
 401                          be32_to_cpu(k1->alloc.ar_startblock) <
 402                          be32_to_cpu(k2->alloc.ar_startblock));
 403         }
 404 }
 405
 406 STATIC int
 407 xfs_allocbt_recs_inorder(
 408         struct xfs_btree_cur    *cur,
 409         union xfs_btree_rec     *r1,
 410         union xfs_btree_rec     *r2)
 411 {
 412         if (cur->bc_btnum == XFS_BTNUM_BNO) {
 413                 return be32_to_cpu(r1->alloc.ar_startblock) +
 414                         be32_to_cpu(r1->alloc.ar_blockcount) <=
 415                         be32_to_cpu(r2->alloc.ar_startblock);
 416         } else {
 417                 return be32_to_cpu(r1->alloc.ar_blockcount) <
 418                         be32_to_cpu(r2->alloc.ar_blockcount) ||
 419                         (r1->alloc.ar_blockcount == r2->alloc.ar_blockcount &&
 420                          be32_to_cpu(r1->alloc.ar_startblock) <
 421                          be32_to_cpu(r2->alloc.ar_startblock));
 422         }
 423 }
 424 #endif  /* DEBUG */
 425
 426 static const struct xfs_btree_ops xfs_allocbt_ops = {
 427         .rec_len                = sizeof(xfs_alloc_rec_t),
 428         .key_len                = sizeof(xfs_alloc_key_t),
 429
 430         .dup_cursor             = xfs_allocbt_dup_cursor,
 431         .set_root               = xfs_allocbt_set_root,
 432         .alloc_block            = xfs_allocbt_alloc_block,
 433         .free_block             = xfs_allocbt_free_block,
 434         .update_lastrec         = xfs_allocbt_update_lastrec,
 435         .get_minrecs            = xfs_allocbt_get_minrecs,
 436         .get_maxrecs            = xfs_allocbt_get_maxrecs,
 437         .init_key_from_rec      = xfs_allocbt_init_key_from_rec,
 438         .init_rec_from_key      = xfs_allocbt_init_rec_from_key,
 439         .init_rec_from_cur      = xfs_allocbt_init_rec_from_cur,
 440         .init_ptr_from_cur      = xfs_allocbt_init_ptr_from_cur,
 441         .key_diff               = xfs_allocbt_key_diff,
 442         .buf_ops                = &xfs_allocbt_buf_ops,
 443 #if defined(DEBUG) || defined(XFS_WARN)
 444         .keys_inorder           = xfs_allocbt_keys_inorder,
 445         .recs_inorder           = xfs_allocbt_recs_inorder,
 446 #endif
 447 };
 448
 449 /*
 450  * Allocate a new allocation btree cursor.
 451  */
 452 struct xfs_btree_cur *                  /* new alloc btree cursor */
 453 xfs_allocbt_init_cursor(
 454         struct xfs_mount        *mp,            /* file system mount point */
 455         struct xfs_trans        *tp,            /* transaction pointer */
 456         struct xfs_buf          *agbp,          /* buffer for agf structure */
 457         xfs_agnumber_t          agno,           /* allocation group number */
 458         xfs_btnum_t             btnum)          /* btree identifier */
 459 {
 460         struct xfs_agf          *agf = XFS_BUF_TO_AGF(agbp);
 461         struct xfs_btree_cur    *cur;
 462
 463         ASSERT(btnum == XFS_BTNUM_BNO || btnum == XFS_BTNUM_CNT);
 464
 465         cur = kmem_zone_zalloc(xfs_btree_cur_zone, KM_SLEEP);
 466
 467         cur->bc_tp = tp;
 468         cur->bc_mp = mp;
 469         cur->bc_btnum = btnum;
 470         cur->bc_blocklog = mp->m_sb.sb_blocklog;
 471         cur->bc_ops = &xfs_allocbt_ops;
 472
 473         if (btnum == XFS_BTNUM_CNT) {
 474                 cur->bc_nlevels = be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNT]);
 475                 cur->bc_flags = XFS_BTREE_LASTREC_UPDATE;
 476         } else {
 477                 cur->bc_nlevels = be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNO]);
 478         }
 479
 480         cur->bc_private.a.agbp = agbp;
 481         cur->bc_private.a.agno = agno;
 482
 483         if (xfs_sb_version_hascrc(&mp->m_sb))
 484                 cur->bc_flags |= XFS_BTREE_CRC_BLOCKS;
 485
 486         return cur;
 487 }
 488
 489 /*
 490  * Calculate number of records in an alloc btree block.
 491  */
 492 int
 493 xfs_allocbt_maxrecs(
 494         struct xfs_mount        *mp,
 495         int                     blocklen,
 496         int                     leaf)
 497 {
 498         blocklen -= XFS_ALLOC_BLOCK_LEN(mp);
 499
 500         if (leaf)
 501                 return blocklen / sizeof(xfs_alloc_rec_t);
 502         return blocklen / (sizeof(xfs_alloc_key_t) + sizeof(xfs_alloc_ptr_t));
 503 }