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 "libxfs_priv.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_trace.h"
  30 #include "xfs_cksum.h"
  31 #include "xfs_trans.h"
  32
  33
  34 STATIC struct xfs_btree_cur *
  35 xfs_allocbt_dup_cursor(
  36         struct xfs_btree_cur    *cur)
  37 {
  38         return xfs_allocbt_init_cursor(cur->bc_mp, cur->bc_tp,
  39                         cur->bc_private.a.agbp, cur->bc_private.a.agno,
  40                         cur->bc_btnum);
  41 }
  42
  43 STATIC void
  44 xfs_allocbt_set_root(
  45         struct xfs_btree_cur    *cur,
  46         union xfs_btree_ptr     *ptr,
  47         int                     inc)
  48 {
  49         struct xfs_buf          *agbp = cur->bc_private.a.agbp;
  50         struct xfs_agf          *agf = XFS_BUF_TO_AGF(agbp);
  51         xfs_agnumber_t          seqno = be32_to_cpu(agf->agf_seqno);
  52         int                     btnum = cur->bc_btnum;
  53         struct xfs_perag        *pag = xfs_perag_get(cur->bc_mp, seqno);
  54
  55         ASSERT(ptr->s != 0);
  56
  57         agf->agf_roots[btnum] = ptr->s;
  58         be32_add_cpu(&agf->agf_levels[btnum], inc);
  59         pag->pagf_levels[btnum] += inc;
  60         xfs_perag_put(pag);
  61
  62         xfs_alloc_log_agf(cur->bc_tp, agbp, XFS_AGF_ROOTS | XFS_AGF_LEVELS);
  63 }
  64
  65 STATIC int
  66 xfs_allocbt_alloc_block(
  67         struct xfs_btree_cur    *cur,
  68         union xfs_btree_ptr     *start,
  69         union xfs_btree_ptr     *new,
  70         int                     *stat)
  71 {
  72         int                     error;
  73         xfs_agblock_t           bno;
  74
  75         XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
  76
  77         /* Allocate the new block from the freelist. If we can't, give up.  */
  78         error = xfs_alloc_get_freelist(cur->bc_tp, cur->bc_private.a.agbp,
  79                                        &bno, 1);
  80         if (error) {
  81                 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
  82                 return error;
  83         }
  84
  85         if (bno == NULLAGBLOCK) {
  86                 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
  87                 *stat = 0;
  88                 return 0;
  89         }
  90
  91         xfs_extent_busy_reuse(cur->bc_mp, cur->bc_private.a.agno, bno, 1, false);
  92
  93         xfs_trans_agbtree_delta(cur->bc_tp, 1);
  94         new->s = cpu_to_be32(bno);
  95
  96         XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
  97         *stat = 1;
  98         return 0;
  99 }
 100
 101 STATIC int
 102 xfs_allocbt_free_block(
 103         struct xfs_btree_cur    *cur,
 104         struct xfs_buf          *bp)
 105 {
 106         struct xfs_buf          *agbp = cur->bc_private.a.agbp;
 107         struct xfs_agf          *agf = XFS_BUF_TO_AGF(agbp);
 108         xfs_agblock_t           bno;
 109         int                     error;
 110
 111         bno = xfs_daddr_to_agbno(cur->bc_mp, XFS_BUF_ADDR(bp));
 112         error = xfs_alloc_put_freelist(cur->bc_tp, agbp, NULL, bno, 1);
 113         if (error)
 114                 return error;
 115
 116         xfs_extent_busy_insert(cur->bc_tp, be32_to_cpu(agf->agf_seqno), bno, 1,
 117                               XFS_EXTENT_BUSY_SKIP_DISCARD);
 118         xfs_trans_agbtree_delta(cur->bc_tp, -1);
 119         return 0;
 120 }
 121
 122 /*
 123  * Update the longest extent in the AGF
 124  */
 125 STATIC void
 126 xfs_allocbt_update_lastrec(
 127         struct xfs_btree_cur    *cur,
 128         struct xfs_btree_block  *block,
 129         union xfs_btree_rec     *rec,
 130         int                     ptr,
 131         int                     reason)
 132 {
 133         struct xfs_agf          *agf = XFS_BUF_TO_AGF(cur->bc_private.a.agbp);
 134         xfs_agnumber_t          seqno = be32_to_cpu(agf->agf_seqno);
 135         struct xfs_perag        *pag;
 136         __be32                  len;
 137         int                     numrecs;
 138
 139         ASSERT(cur->bc_btnum == XFS_BTNUM_CNT);
 140
 141         switch (reason) {
 142         case LASTREC_UPDATE:
 143                 /*
 144                  * If this is the last leaf block and it's the last record,
 145                  * then update the size of the longest extent in the AG.
 146                  */
 147                 if (ptr != xfs_btree_get_numrecs(block))
 148                         return;
 149                 len = rec->alloc.ar_blockcount;
 150                 break;
 151         case LASTREC_INSREC:
 152                 if (be32_to_cpu(rec->alloc.ar_blockcount) <=
 153                     be32_to_cpu(agf->agf_longest))
 154                         return;
 155                 len = rec->alloc.ar_blockcount;
 156                 break;
 157         case LASTREC_DELREC:
 158                 numrecs = xfs_btree_get_numrecs(block);
 159                 if (ptr <= numrecs)
 160                         return;
 161                 ASSERT(ptr == numrecs + 1);
 162
 163                 if (numrecs) {
 164                         xfs_alloc_rec_t *rrp;
 165
 166                         rrp = XFS_ALLOC_REC_ADDR(cur->bc_mp, block, numrecs);
 167                         len = rrp->ar_blockcount;
 168                 } else {
 169                         len = 0;
 170                 }
 171
 172                 break;
 173         default:
 174                 ASSERT(0);
 175                 return;
 176         }
 177
 178         agf->agf_longest = len;
 179         pag = xfs_perag_get(cur->bc_mp, seqno);
 180         pag->pagf_longest = be32_to_cpu(len);
 181         xfs_perag_put(pag);
 182         xfs_alloc_log_agf(cur->bc_tp, cur->bc_private.a.agbp, XFS_AGF_LONGEST);
 183 }
 184
 185 STATIC int
 186 xfs_allocbt_get_minrecs(
 187         struct xfs_btree_cur    *cur,
 188         int                     level)
 189 {
 190         return cur->bc_mp->m_alloc_mnr[level != 0];
 191 }
 192
 193 STATIC int
 194 xfs_allocbt_get_maxrecs(
 195         struct xfs_btree_cur    *cur,
 196         int                     level)
 197 {
 198         return cur->bc_mp->m_alloc_mxr[level != 0];
 199 }
 200
 201 STATIC void
 202 xfs_allocbt_init_key_from_rec(
 203         union xfs_btree_key     *key,
 204         union xfs_btree_rec     *rec)
 205 {
 206         ASSERT(rec->alloc.ar_startblock != 0);
 207
 208         key->alloc.ar_startblock = rec->alloc.ar_startblock;
 209         key->alloc.ar_blockcount = rec->alloc.ar_blockcount;
 210 }
 211
 212 STATIC void
 213 xfs_allocbt_init_rec_from_key(
 214         union xfs_btree_key     *key,
 215         union xfs_btree_rec     *rec)
 216 {
 217         ASSERT(key->alloc.ar_startblock != 0);
 218
 219         rec->alloc.ar_startblock = key->alloc.ar_startblock;
 220         rec->alloc.ar_blockcount = key->alloc.ar_blockcount;
 221 }
 222
 223 STATIC void
 224 xfs_allocbt_init_rec_from_cur(
 225         struct xfs_btree_cur    *cur,
 226         union xfs_btree_rec     *rec)
 227 {
 228         ASSERT(cur->bc_rec.a.ar_startblock != 0);
 229
 230         rec->alloc.ar_startblock = cpu_to_be32(cur->bc_rec.a.ar_startblock);
 231         rec->alloc.ar_blockcount = cpu_to_be32(cur->bc_rec.a.ar_blockcount);
 232 }
 233
 234 STATIC void
 235 xfs_allocbt_init_ptr_from_cur(
 236         struct xfs_btree_cur    *cur,
 237         union xfs_btree_ptr     *ptr)
 238 {
 239         struct xfs_agf          *agf = XFS_BUF_TO_AGF(cur->bc_private.a.agbp);
 240
 241         ASSERT(cur->bc_private.a.agno == be32_to_cpu(agf->agf_seqno));
 242         ASSERT(agf->agf_roots[cur->bc_btnum] != 0);
 243
 244         ptr->s = agf->agf_roots[cur->bc_btnum];
 245 }
 246
 247 STATIC __int64_t
 248 xfs_allocbt_key_diff(
 249         struct xfs_btree_cur    *cur,
 250         union xfs_btree_key     *key)
 251 {
 252         xfs_alloc_rec_incore_t  *rec = &cur->bc_rec.a;
 253         xfs_alloc_key_t         *kp = &key->alloc;
 254         __int64_t               diff;
 255
 256         if (cur->bc_btnum == XFS_BTNUM_BNO) {
 257                 return (__int64_t)be32_to_cpu(kp->ar_startblock) -
 258                                 rec->ar_startblock;
 259         }
 260
 261         diff = (__int64_t)be32_to_cpu(kp->ar_blockcount) - rec->ar_blockcount;
 262         if (diff)
 263                 return diff;
 264
 265         return (__int64_t)be32_to_cpu(kp->ar_startblock) - rec->ar_startblock;
 266 }
 267
 268 static bool
 269 xfs_allocbt_verify(
 270         struct xfs_buf          *bp)
 271 {
 272         struct xfs_mount        *mp = bp->b_target->bt_mount;
 273         struct xfs_btree_block  *block = XFS_BUF_TO_BLOCK(bp);
 274         struct xfs_perag        *pag = bp->b_pag;
 275         unsigned int            level;
 276
 277         /*
 278          * magic number and level verification
 279          *
 280          * During growfs operations, we can't verify the exact level or owner as
 281          * the perag is not fully initialised and hence not attached to the
 282          * buffer.  In this case, check against the maximum tree depth.
 283          *
 284          * Similarly, during log recovery we will have a perag structure
 285          * attached, but the agf information will not yet have been initialised
 286          * from the on disk AGF. Again, we can only check against maximum limits
 287          * in this case.
 288          */
 289         level = be16_to_cpu(block->bb_level);
 290         switch (block->bb_magic) {
 291         case cpu_to_be32(XFS_ABTB_CRC_MAGIC):
 292                 if (!xfs_sb_version_hascrc(&mp->m_sb))
 293                         return false;
 294                 if (!xfs_btree_sblock_v5hdr_verify(bp))
 295                         return false;
 296                 /* fall through */
 297         case cpu_to_be32(XFS_ABTB_MAGIC):
 298                 if (pag && pag->pagf_init) {
 299                         if (level >= pag->pagf_levels[XFS_BTNUM_BNOi])
 300                                 return false;
 301                 } else if (level >= mp->m_ag_maxlevels)
 302                         return false;
 303                 break;
 304         case cpu_to_be32(XFS_ABTC_CRC_MAGIC):
 305                 if (!xfs_sb_version_hascrc(&mp->m_sb))
 306                         return false;
 307                 if (!xfs_btree_sblock_v5hdr_verify(bp))
 308                         return false;
 309                 /* fall through */
 310         case cpu_to_be32(XFS_ABTC_MAGIC):
 311                 if (pag && pag->pagf_init) {
 312                         if (level >= pag->pagf_levels[XFS_BTNUM_CNTi])
 313                                 return false;
 314                 } else if (level >= mp->m_ag_maxlevels)
 315                         return false;
 316                 break;
 317         default:
 318                 return false;
 319         }
 320
 321         return xfs_btree_sblock_verify(bp, mp->m_alloc_mxr[level != 0]);
 322 }
 323
 324 static void
 325 xfs_allocbt_read_verify(
 326         struct xfs_buf  *bp)
 327 {
 328         if (!xfs_btree_sblock_verify_crc(bp))
 329                 xfs_buf_ioerror(bp, -EFSBADCRC);
 330         else if (!xfs_allocbt_verify(bp))
 331                 xfs_buf_ioerror(bp, -EFSCORRUPTED);
 332
 333         if (bp->b_error) {
 334                 trace_xfs_btree_corrupt(bp, _RET_IP_);
 335                 xfs_verifier_error(bp);
 336         }
 337 }
 338
 339 static void
 340 xfs_allocbt_write_verify(
 341         struct xfs_buf  *bp)
 342 {
 343         if (!xfs_allocbt_verify(bp)) {
 344                 trace_xfs_btree_corrupt(bp, _RET_IP_);
 345                 xfs_buf_ioerror(bp, -EFSCORRUPTED);
 346                 xfs_verifier_error(bp);
 347                 return;
 348         }
 349         xfs_btree_sblock_calc_crc(bp);
 350
 351 }
 352
 353 const struct xfs_buf_ops xfs_allocbt_buf_ops = {
 354         .name = "xfs_allocbt",
 355         .verify_read = xfs_allocbt_read_verify,
 356         .verify_write = xfs_allocbt_write_verify,
 357 };
 358
 359
 360 #if defined(DEBUG) || defined(XFS_WARN)
 361 STATIC int
 362 xfs_allocbt_keys_inorder(
 363         struct xfs_btree_cur    *cur,
 364         union xfs_btree_key     *k1,
 365         union xfs_btree_key     *k2)
 366 {
 367         if (cur->bc_btnum == XFS_BTNUM_BNO) {
 368                 return be32_to_cpu(k1->alloc.ar_startblock) <
 369                        be32_to_cpu(k2->alloc.ar_startblock);
 370         } else {
 371                 return be32_to_cpu(k1->alloc.ar_blockcount) <
 372                         be32_to_cpu(k2->alloc.ar_blockcount) ||
 373                         (k1->alloc.ar_blockcount == k2->alloc.ar_blockcount &&
 374                          be32_to_cpu(k1->alloc.ar_startblock) <
 375                          be32_to_cpu(k2->alloc.ar_startblock));
 376         }
 377 }
 378
 379 STATIC int
 380 xfs_allocbt_recs_inorder(
 381         struct xfs_btree_cur    *cur,
 382         union xfs_btree_rec     *r1,
 383         union xfs_btree_rec     *r2)
 384 {
 385         if (cur->bc_btnum == XFS_BTNUM_BNO) {
 386                 return be32_to_cpu(r1->alloc.ar_startblock) +
 387                         be32_to_cpu(r1->alloc.ar_blockcount) <=
 388                         be32_to_cpu(r2->alloc.ar_startblock);
 389         } else {
 390                 return be32_to_cpu(r1->alloc.ar_blockcount) <
 391                         be32_to_cpu(r2->alloc.ar_blockcount) ||
 392                         (r1->alloc.ar_blockcount == r2->alloc.ar_blockcount &&
 393                          be32_to_cpu(r1->alloc.ar_startblock) <
 394                          be32_to_cpu(r2->alloc.ar_startblock));
 395         }
 396 }
 397 #endif  /* DEBUG */
 398
 399 static const struct xfs_btree_ops xfs_allocbt_ops = {
 400         .rec_len                = sizeof(xfs_alloc_rec_t),
 401         .key_len                = sizeof(xfs_alloc_key_t),
 402
 403         .dup_cursor             = xfs_allocbt_dup_cursor,
 404         .set_root               = xfs_allocbt_set_root,
 405         .alloc_block            = xfs_allocbt_alloc_block,
 406         .free_block             = xfs_allocbt_free_block,
 407         .update_lastrec         = xfs_allocbt_update_lastrec,
 408         .get_minrecs            = xfs_allocbt_get_minrecs,
 409         .get_maxrecs            = xfs_allocbt_get_maxrecs,
 410         .init_key_from_rec      = xfs_allocbt_init_key_from_rec,
 411         .init_rec_from_key      = xfs_allocbt_init_rec_from_key,
 412         .init_rec_from_cur      = xfs_allocbt_init_rec_from_cur,
 413         .init_ptr_from_cur      = xfs_allocbt_init_ptr_from_cur,
 414         .key_diff               = xfs_allocbt_key_diff,
 415         .buf_ops                = &xfs_allocbt_buf_ops,
 416 #if defined(DEBUG) || defined(XFS_WARN)
 417         .keys_inorder           = xfs_allocbt_keys_inorder,
 418         .recs_inorder           = xfs_allocbt_recs_inorder,
 419 #endif
 420 };
 421
 422 /*
 423  * Allocate a new allocation btree cursor.
 424  */
 425 struct xfs_btree_cur *                  /* new alloc btree cursor */
 426 xfs_allocbt_init_cursor(
 427         struct xfs_mount        *mp,            /* file system mount point */
 428         struct xfs_trans        *tp,            /* transaction pointer */
 429         struct xfs_buf          *agbp,          /* buffer for agf structure */
 430         xfs_agnumber_t          agno,           /* allocation group number */
 431         xfs_btnum_t             btnum)          /* btree identifier */
 432 {
 433         struct xfs_agf          *agf = XFS_BUF_TO_AGF(agbp);
 434         struct xfs_btree_cur    *cur;
 435
 436         ASSERT(btnum == XFS_BTNUM_BNO || btnum == XFS_BTNUM_CNT);
 437
 438         cur = kmem_zone_zalloc(xfs_btree_cur_zone, KM_SLEEP);
 439
 440         cur->bc_tp = tp;
 441         cur->bc_mp = mp;
 442         cur->bc_btnum = btnum;
 443         cur->bc_blocklog = mp->m_sb.sb_blocklog;
 444         cur->bc_ops = &xfs_allocbt_ops;
 445
 446         if (btnum == XFS_BTNUM_CNT) {
 447                 cur->bc_nlevels = be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNT]);
 448                 cur->bc_flags = XFS_BTREE_LASTREC_UPDATE;
 449         } else {
 450                 cur->bc_nlevels = be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNO]);
 451         }
 452
 453         cur->bc_private.a.agbp = agbp;
 454         cur->bc_private.a.agno = agno;
 455
 456         if (xfs_sb_version_hascrc(&mp->m_sb))
 457                 cur->bc_flags |= XFS_BTREE_CRC_BLOCKS;
 458
 459         return cur;
 460 }
 461
 462 /*
 463  * Calculate number of records in an alloc btree block.
 464  */
 465 int
 466 xfs_allocbt_maxrecs(
 467         struct xfs_mount        *mp,
 468         int                     blocklen,
 469         int                     leaf)
 470 {
 471         blocklen -= XFS_ALLOC_BLOCK_LEN(mp);
 472
 473         if (leaf)
 474                 return blocklen / sizeof(xfs_alloc_rec_t);
 475         return blocklen / (sizeof(xfs_alloc_key_t) + sizeof(xfs_alloc_ptr_t));
 476 }