fs/xfs/xfs_btree.c

   1 /*
   2  * Copyright (c) 2000-2002,2005 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_bit.h"
  22 #include "xfs_log.h"
  23 #include "xfs_inum.h"
  24 #include "xfs_trans.h"
  25 #include "xfs_sb.h"
  26 #include "xfs_ag.h"
  27 #include "xfs_dir2.h"
  28 #include "xfs_dmapi.h"
  29 #include "xfs_mount.h"
  30 #include "xfs_bmap_btree.h"
  31 #include "xfs_alloc_btree.h"
  32 #include "xfs_ialloc_btree.h"
  33 #include "xfs_dir2_sf.h"
  34 #include "xfs_attr_sf.h"
  35 #include "xfs_dinode.h"
  36 #include "xfs_inode.h"
  37 #include "xfs_inode_item.h"
  38 #include "xfs_btree.h"
  39 #include "xfs_btree_trace.h"
  40 #include "xfs_ialloc.h"
  41 #include "xfs_error.h"
  42
  43 /*
  44  * Cursor allocation zone.
  45  */
  46 kmem_zone_t     *xfs_btree_cur_zone;
  47
  48 /*
  49  * Btree magic numbers.
  50  */
  51 const __uint32_t xfs_magics[XFS_BTNUM_MAX] = {
  52         XFS_ABTB_MAGIC, XFS_ABTC_MAGIC, XFS_BMAP_MAGIC, XFS_IBT_MAGIC
  53 };
  54
  55 /*
  56  * External routines.
  57  */
  58
  59 #ifdef DEBUG
  60 /*
  61  * Debug routine: check that keys are in the right order.
  62  */
  63 void
  64 xfs_btree_check_key(
  65         xfs_btnum_t     btnum,          /* btree identifier */
  66         void            *ak1,           /* pointer to left (lower) key */
  67         void            *ak2)           /* pointer to right (higher) key */
  68 {
  69         switch (btnum) {
  70         case XFS_BTNUM_BNO: {
  71                 xfs_alloc_key_t *k1;
  72                 xfs_alloc_key_t *k2;
  73
  74                 k1 = ak1;
  75                 k2 = ak2;
  76                 ASSERT(be32_to_cpu(k1->ar_startblock) < be32_to_cpu(k2->ar_startblock));
  77                 break;
  78             }
  79         case XFS_BTNUM_CNT: {
  80                 xfs_alloc_key_t *k1;
  81                 xfs_alloc_key_t *k2;
  82
  83                 k1 = ak1;
  84                 k2 = ak2;
  85                 ASSERT(be32_to_cpu(k1->ar_blockcount) < be32_to_cpu(k2->ar_blockcount) ||
  86                        (k1->ar_blockcount == k2->ar_blockcount &&
  87                         be32_to_cpu(k1->ar_startblock) < be32_to_cpu(k2->ar_startblock)));
  88                 break;
  89             }
  90         case XFS_BTNUM_BMAP: {
  91                 xfs_bmbt_key_t  *k1;
  92                 xfs_bmbt_key_t  *k2;
  93
  94                 k1 = ak1;
  95                 k2 = ak2;
  96                 ASSERT(be64_to_cpu(k1->br_startoff) < be64_to_cpu(k2->br_startoff));
  97                 break;
  98             }
  99         case XFS_BTNUM_INO: {
 100                 xfs_inobt_key_t *k1;
 101                 xfs_inobt_key_t *k2;
 102
 103                 k1 = ak1;
 104                 k2 = ak2;
 105                 ASSERT(be32_to_cpu(k1->ir_startino) < be32_to_cpu(k2->ir_startino));
 106                 break;
 107             }
 108         default:
 109                 ASSERT(0);
 110         }
 111 }
 112
 113 /*
 114  * Debug routine: check that records are in the right order.
 115  */
 116 void
 117 xfs_btree_check_rec(
 118         xfs_btnum_t     btnum,          /* btree identifier */
 119         void            *ar1,           /* pointer to left (lower) record */
 120         void            *ar2)           /* pointer to right (higher) record */
 121 {
 122         switch (btnum) {
 123         case XFS_BTNUM_BNO: {
 124                 xfs_alloc_rec_t *r1;
 125                 xfs_alloc_rec_t *r2;
 126
 127                 r1 = ar1;
 128                 r2 = ar2;
 129                 ASSERT(be32_to_cpu(r1->ar_startblock) +
 130                        be32_to_cpu(r1->ar_blockcount) <=
 131                        be32_to_cpu(r2->ar_startblock));
 132                 break;
 133             }
 134         case XFS_BTNUM_CNT: {
 135                 xfs_alloc_rec_t *r1;
 136                 xfs_alloc_rec_t *r2;
 137
 138                 r1 = ar1;
 139                 r2 = ar2;
 140                 ASSERT(be32_to_cpu(r1->ar_blockcount) < be32_to_cpu(r2->ar_blockcount) ||
 141                        (r1->ar_blockcount == r2->ar_blockcount &&
 142                         be32_to_cpu(r1->ar_startblock) < be32_to_cpu(r2->ar_startblock)));
 143                 break;
 144             }
 145         case XFS_BTNUM_BMAP: {
 146                 xfs_bmbt_rec_t  *r1;
 147                 xfs_bmbt_rec_t  *r2;
 148
 149                 r1 = ar1;
 150                 r2 = ar2;
 151                 ASSERT(xfs_bmbt_disk_get_startoff(r1) +
 152                        xfs_bmbt_disk_get_blockcount(r1) <=
 153                        xfs_bmbt_disk_get_startoff(r2));
 154                 break;
 155             }
 156         case XFS_BTNUM_INO: {
 157                 xfs_inobt_rec_t *r1;
 158                 xfs_inobt_rec_t *r2;
 159
 160                 r1 = ar1;
 161                 r2 = ar2;
 162                 ASSERT(be32_to_cpu(r1->ir_startino) + XFS_INODES_PER_CHUNK <=
 163                        be32_to_cpu(r2->ir_startino));
 164                 break;
 165             }
 166         default:
 167                 ASSERT(0);
 168         }
 169 }
 170 #endif  /* DEBUG */
 171
 172 int                                     /* error (0 or EFSCORRUPTED) */
 173 xfs_btree_check_lblock(
 174         struct xfs_btree_cur    *cur,   /* btree cursor */
 175         struct xfs_btree_lblock *block, /* btree long form block pointer */
 176         int                     level,  /* level of the btree block */
 177         struct xfs_buf          *bp)    /* buffer for block, if any */
 178 {
 179         int                     lblock_ok; /* block passes checks */
 180         struct xfs_mount        *mp;    /* file system mount point */
 181
 182         mp = cur->bc_mp;
 183         lblock_ok =
 184                 be32_to_cpu(block->bb_magic) == xfs_magics[cur->bc_btnum] &&
 185                 be16_to_cpu(block->bb_level) == level &&
 186                 be16_to_cpu(block->bb_numrecs) <=
 187                         cur->bc_ops->get_maxrecs(cur, level) &&
 188                 block->bb_leftsib &&
 189                 (be64_to_cpu(block->bb_leftsib) == NULLDFSBNO ||
 190                  XFS_FSB_SANITY_CHECK(mp, be64_to_cpu(block->bb_leftsib))) &&
 191                 block->bb_rightsib &&
 192                 (be64_to_cpu(block->bb_rightsib) == NULLDFSBNO ||
 193                  XFS_FSB_SANITY_CHECK(mp, be64_to_cpu(block->bb_rightsib)));
 194         if (unlikely(XFS_TEST_ERROR(!lblock_ok, mp,
 195                         XFS_ERRTAG_BTREE_CHECK_LBLOCK,
 196                         XFS_RANDOM_BTREE_CHECK_LBLOCK))) {
 197                 if (bp)
 198                         xfs_buftrace("LBTREE ERROR", bp);
 199                 XFS_ERROR_REPORT("xfs_btree_check_lblock", XFS_ERRLEVEL_LOW,
 200                                  mp);
 201                 return XFS_ERROR(EFSCORRUPTED);
 202         }
 203         return 0;
 204 }
 205
 206 int                                     /* error (0 or EFSCORRUPTED) */
 207 xfs_btree_check_sblock(
 208         struct xfs_btree_cur    *cur,   /* btree cursor */
 209         struct xfs_btree_sblock *block, /* btree short form block pointer */
 210         int                     level,  /* level of the btree block */
 211         struct xfs_buf          *bp)    /* buffer containing block */
 212 {
 213         struct xfs_buf          *agbp;  /* buffer for ag. freespace struct */
 214         struct xfs_agf          *agf;   /* ag. freespace structure */
 215         xfs_agblock_t           agflen; /* native ag. freespace length */
 216         int                     sblock_ok; /* block passes checks */
 217
 218         agbp = cur->bc_private.a.agbp;
 219         agf = XFS_BUF_TO_AGF(agbp);
 220         agflen = be32_to_cpu(agf->agf_length);
 221         sblock_ok =
 222                 be32_to_cpu(block->bb_magic) == xfs_magics[cur->bc_btnum] &&
 223                 be16_to_cpu(block->bb_level) == level &&
 224                 be16_to_cpu(block->bb_numrecs) <=
 225                         cur->bc_ops->get_maxrecs(cur, level) &&
 226                 (be32_to_cpu(block->bb_leftsib) == NULLAGBLOCK ||
 227                  be32_to_cpu(block->bb_leftsib) < agflen) &&
 228                 block->bb_leftsib &&
 229                 (be32_to_cpu(block->bb_rightsib) == NULLAGBLOCK ||
 230                  be32_to_cpu(block->bb_rightsib) < agflen) &&
 231                 block->bb_rightsib;
 232         if (unlikely(XFS_TEST_ERROR(!sblock_ok, cur->bc_mp,
 233                         XFS_ERRTAG_BTREE_CHECK_SBLOCK,
 234                         XFS_RANDOM_BTREE_CHECK_SBLOCK))) {
 235                 if (bp)
 236                         xfs_buftrace("SBTREE ERROR", bp);
 237                 XFS_ERROR_REPORT("xfs_btree_check_sblock", XFS_ERRLEVEL_LOW,
 238                                  cur->bc_mp);
 239                 return XFS_ERROR(EFSCORRUPTED);
 240         }
 241         return 0;
 242 }
 243
 244 /*
 245  * Debug routine: check that block header is ok.
 246  */
 247 int
 248 xfs_btree_check_block(
 249         struct xfs_btree_cur    *cur,   /* btree cursor */
 250         struct xfs_btree_block  *block, /* generic btree block pointer */
 251         int                     level,  /* level of the btree block */
 252         struct xfs_buf          *bp)    /* buffer containing block, if any */
 253 {
 254         if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
 255                 return xfs_btree_check_lblock(cur,
 256                                 (struct xfs_btree_lblock *)block, level, bp);
 257         } else {
 258                 return xfs_btree_check_sblock(cur,
 259                                 (struct xfs_btree_sblock *)block, level, bp);
 260         }
 261 }
 262
 263 /*
 264  * Check that (long) pointer is ok.
 265  */
 266 int                                     /* error (0 or EFSCORRUPTED) */
 267 xfs_btree_check_lptr(
 268         struct xfs_btree_cur    *cur,   /* btree cursor */
 269         xfs_dfsbno_t            bno,    /* btree block disk address */
 270         int                     level)  /* btree block level */
 271 {
 272         XFS_WANT_CORRUPTED_RETURN(
 273                 level > 0 &&
 274                 bno != NULLDFSBNO &&
 275                 XFS_FSB_SANITY_CHECK(cur->bc_mp, bno));
 276         return 0;
 277 }
 278
 279 /*
 280  * Check that (short) pointer is ok.
 281  */
 282 int                                     /* error (0 or EFSCORRUPTED) */
 283 xfs_btree_check_sptr(
 284         struct xfs_btree_cur    *cur,   /* btree cursor */
 285         xfs_agblock_t           bno,    /* btree block disk address */
 286         int                     level)  /* btree block level */
 287 {
 288         xfs_agblock_t           agblocks = cur->bc_mp->m_sb.sb_agblocks;
 289
 290         XFS_WANT_CORRUPTED_RETURN(
 291                 level > 0 &&
 292                 bno != NULLAGBLOCK &&
 293                 bno != 0 &&
 294                 bno < agblocks);
 295         return 0;
 296 }
 297
 298 /*
 299  * Check that block ptr is ok.
 300  */
 301 int                                     /* error (0 or EFSCORRUPTED) */
 302 xfs_btree_check_ptr(
 303         struct xfs_btree_cur    *cur,   /* btree cursor */
 304         union xfs_btree_ptr     *ptr,   /* btree block disk address */
 305         int                     index,  /* offset from ptr to check */
 306         int                     level)  /* btree block level */
 307 {
 308         if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
 309                 return xfs_btree_check_lptr(cur,
 310                                 be64_to_cpu((&ptr->l)[index]), level);
 311         } else {
 312                 return xfs_btree_check_sptr(cur,
 313                                 be32_to_cpu((&ptr->s)[index]), level);
 314         }
 315 }
 316
 317 /*
 318  * Delete the btree cursor.
 319  */
 320 void
 321 xfs_btree_del_cursor(
 322         xfs_btree_cur_t *cur,           /* btree cursor */
 323         int             error)          /* del because of error */
 324 {
 325         int             i;              /* btree level */
 326
 327         /*
 328          * Clear the buffer pointers, and release the buffers.
 329          * If we're doing this in the face of an error, we
 330          * need to make sure to inspect all of the entries
 331          * in the bc_bufs array for buffers to be unlocked.
 332          * This is because some of the btree code works from
 333          * level n down to 0, and if we get an error along
 334          * the way we won't have initialized all the entries
 335          * down to 0.
 336          */
 337         for (i = 0; i < cur->bc_nlevels; i++) {
 338                 if (cur->bc_bufs[i])
 339                         xfs_btree_setbuf(cur, i, NULL);
 340                 else if (!error)
 341                         break;
 342         }
 343         /*
 344          * Can't free a bmap cursor without having dealt with the
 345          * allocated indirect blocks' accounting.
 346          */
 347         ASSERT(cur->bc_btnum != XFS_BTNUM_BMAP ||
 348                cur->bc_private.b.allocated == 0);
 349         /*
 350          * Free the cursor.
 351          */
 352         kmem_zone_free(xfs_btree_cur_zone, cur);
 353 }
 354
 355 /*
 356  * Duplicate the btree cursor.
 357  * Allocate a new one, copy the record, re-get the buffers.
 358  */
 359 int                                     /* error */
 360 xfs_btree_dup_cursor(
 361         xfs_btree_cur_t *cur,           /* input cursor */
 362         xfs_btree_cur_t **ncur)         /* output cursor */
 363 {
 364         xfs_buf_t       *bp;            /* btree block's buffer pointer */
 365         int             error;          /* error return value */
 366         int             i;              /* level number of btree block */
 367         xfs_mount_t     *mp;            /* mount structure for filesystem */
 368         xfs_btree_cur_t *new;           /* new cursor value */
 369         xfs_trans_t     *tp;            /* transaction pointer, can be NULL */
 370
 371         tp = cur->bc_tp;
 372         mp = cur->bc_mp;
 373
 374         /*
 375          * Allocate a new cursor like the old one.
 376          */
 377         new = cur->bc_ops->dup_cursor(cur);
 378
 379         /*
 380          * Copy the record currently in the cursor.
 381          */
 382         new->bc_rec = cur->bc_rec;
 383
 384         /*
 385          * For each level current, re-get the buffer and copy the ptr value.
 386          */
 387         for (i = 0; i < new->bc_nlevels; i++) {
 388                 new->bc_ptrs[i] = cur->bc_ptrs[i];
 389                 new->bc_ra[i] = cur->bc_ra[i];
 390                 if ((bp = cur->bc_bufs[i])) {
 391                         if ((error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp,
 392                                 XFS_BUF_ADDR(bp), mp->m_bsize, 0, &bp))) {
 393                                 xfs_btree_del_cursor(new, error);
 394                                 *ncur = NULL;
 395                                 return error;
 396                         }
 397                         new->bc_bufs[i] = bp;
 398                         ASSERT(bp);
 399                         ASSERT(!XFS_BUF_GETERROR(bp));
 400                 } else
 401                         new->bc_bufs[i] = NULL;
 402         }
 403         *ncur = new;
 404         return 0;
 405 }
 406
 407 /*
 408  * XFS btree block layout and addressing:
 409  *
 410  * There are two types of blocks in the btree: leaf and non-leaf blocks.
 411  *
 412  * The leaf record start with a header then followed by records containing
 413  * the values.  A non-leaf block also starts with the same header, and
 414  * then first contains lookup keys followed by an equal number of pointers
 415  * to the btree blocks at the previous level.
 416  *
 417  *              +--------+-------+-------+-------+-------+-------+-------+
 418  * Leaf:        | header | rec 1 | rec 2 | rec 3 | rec 4 | rec 5 | rec N |
 419  *              +--------+-------+-------+-------+-------+-------+-------+
 420  *
 421  *              +--------+-------+-------+-------+-------+-------+-------+
 422  * Non-Leaf:    | header | key 1 | key 2 | key N | ptr 1 | ptr 2 | ptr N |
 423  *              +--------+-------+-------+-------+-------+-------+-------+
 424  *
 425  * The header is called struct xfs_btree_block for reasons better left unknown
 426  * and comes in different versions for short (32bit) and long (64bit) block
 427  * pointers.  The record and key structures are defined by the btree instances
 428  * and opaque to the btree core.  The block pointers are simple disk endian
 429  * integers, available in a short (32bit) and long (64bit) variant.
 430  *
 431  * The helpers below calculate the offset of a given record, key or pointer
 432  * into a btree block (xfs_btree_*_offset) or return a pointer to the given
 433  * record, key or pointer (xfs_btree_*_addr).  Note that all addressing
 434  * inside the btree block is done using indices starting at one, not zero!
 435  */
 436
 437 /*
 438  * Return size of the btree block header for this btree instance.
 439  */
 440 static inline size_t xfs_btree_block_len(struct xfs_btree_cur *cur)
 441 {
 442         return (cur->bc_flags & XFS_BTREE_LONG_PTRS) ?
 443                 sizeof(struct xfs_btree_lblock) :
 444                 sizeof(struct xfs_btree_sblock);
 445 }
 446
 447 /*
 448  * Return size of btree block pointers for this btree instance.
 449  */
 450 static inline size_t xfs_btree_ptr_len(struct xfs_btree_cur *cur)
 451 {
 452         return (cur->bc_flags & XFS_BTREE_LONG_PTRS) ?
 453                 sizeof(__be64) : sizeof(__be32);
 454 }
 455
 456 /*
 457  * Calculate offset of the n-th record in a btree block.
 458  */
 459 STATIC size_t
 460 xfs_btree_rec_offset(
 461         struct xfs_btree_cur    *cur,
 462         int                     n)
 463 {
 464         return xfs_btree_block_len(cur) +
 465                 (n - 1) * cur->bc_ops->rec_len;
 466 }
 467
 468 /*
 469  * Calculate offset of the n-th key in a btree block.
 470  */
 471 STATIC size_t
 472 xfs_btree_key_offset(
 473         struct xfs_btree_cur    *cur,
 474         int                     n)
 475 {
 476         return xfs_btree_block_len(cur) +
 477                 (n - 1) * cur->bc_ops->key_len;
 478 }
 479
 480 /*
 481  * Calculate offset of the n-th block pointer in a btree block.
 482  */
 483 STATIC size_t
 484 xfs_btree_ptr_offset(
 485         struct xfs_btree_cur    *cur,
 486         int                     n,
 487         int                     level)
 488 {
 489         return xfs_btree_block_len(cur) +
 490                 cur->bc_ops->get_maxrecs(cur, level) * cur->bc_ops->key_len +
 491                 (n - 1) * xfs_btree_ptr_len(cur);
 492 }
 493
 494 /*
 495  * Return a pointer to the n-th record in the btree block.
 496  */
 497 STATIC union xfs_btree_rec *
 498 xfs_btree_rec_addr(
 499         struct xfs_btree_cur    *cur,
 500         int                     n,
 501         struct xfs_btree_block  *block)
 502 {
 503         return (union xfs_btree_rec *)
 504                 ((char *)block + xfs_btree_rec_offset(cur, n));
 505 }
 506
 507 /*
 508  * Return a pointer to the n-th key in the btree block.
 509  */
 510 STATIC union xfs_btree_key *
 511 xfs_btree_key_addr(
 512         struct xfs_btree_cur    *cur,
 513         int                     n,
 514         struct xfs_btree_block  *block)
 515 {
 516         return (union xfs_btree_key *)
 517                 ((char *)block + xfs_btree_key_offset(cur, n));
 518 }
 519
 520 /*
 521  * Return a pointer to the n-th block pointer in the btree block.
 522  */
 523 STATIC union xfs_btree_ptr *
 524 xfs_btree_ptr_addr(
 525         struct xfs_btree_cur    *cur,
 526         int                     n,
 527         struct xfs_btree_block  *block)
 528 {
 529         int                     level = xfs_btree_get_level(block);
 530
 531         ASSERT(block->bb_level != 0);
 532
 533         return (union xfs_btree_ptr *)
 534                 ((char *)block + xfs_btree_ptr_offset(cur, n, level));
 535 }
 536
 537 /*
 538  * Get a the root block which is stored in the inode.
 539  *
 540  * For now this btree implementation assumes the btree root is always
 541  * stored in the if_broot field of an inode fork.
 542  */
 543 STATIC struct xfs_btree_block *
 544 xfs_btree_get_iroot(
 545        struct xfs_btree_cur    *cur)
 546 {
 547        struct xfs_ifork        *ifp;
 548
 549        ifp = XFS_IFORK_PTR(cur->bc_private.b.ip, cur->bc_private.b.whichfork);
 550        return (struct xfs_btree_block *)ifp->if_broot;
 551 }
 552
 553 /*
 554  * Retrieve the block pointer from the cursor at the given level.
 555  * This may be an inode btree root or from a buffer.
 556  */
 557 STATIC struct xfs_btree_block *         /* generic btree block pointer */
 558 xfs_btree_get_block(
 559         struct xfs_btree_cur    *cur,   /* btree cursor */
 560         int                     level,  /* level in btree */
 561         struct xfs_buf          **bpp)  /* buffer containing the block */
 562 {
 563         if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
 564             (level == cur->bc_nlevels - 1)) {
 565                 *bpp = NULL;
 566                 return xfs_btree_get_iroot(cur);
 567         }
 568
 569         *bpp = cur->bc_bufs[level];
 570         return XFS_BUF_TO_BLOCK(*bpp);
 571 }
 572
 573 /*
 574  * Get a buffer for the block, return it with no data read.
 575  * Long-form addressing.
 576  */
 577 xfs_buf_t *                             /* buffer for fsbno */
 578 xfs_btree_get_bufl(
 579         xfs_mount_t     *mp,            /* file system mount point */
 580         xfs_trans_t     *tp,            /* transaction pointer */
 581         xfs_fsblock_t   fsbno,          /* file system block number */
 582         uint            lock)           /* lock flags for get_buf */
 583 {
 584         xfs_buf_t       *bp;            /* buffer pointer (return value) */
 585         xfs_daddr_t             d;              /* real disk block address */
 586
 587         ASSERT(fsbno != NULLFSBLOCK);
 588         d = XFS_FSB_TO_DADDR(mp, fsbno);
 589         bp = xfs_trans_get_buf(tp, mp->m_ddev_targp, d, mp->m_bsize, lock);
 590         ASSERT(bp);
 591         ASSERT(!XFS_BUF_GETERROR(bp));
 592         return bp;
 593 }
 594
 595 /*
 596  * Get a buffer for the block, return it with no data read.
 597  * Short-form addressing.
 598  */
 599 xfs_buf_t *                             /* buffer for agno/agbno */
 600 xfs_btree_get_bufs(
 601         xfs_mount_t     *mp,            /* file system mount point */
 602         xfs_trans_t     *tp,            /* transaction pointer */
 603         xfs_agnumber_t  agno,           /* allocation group number */
 604         xfs_agblock_t   agbno,          /* allocation group block number */
 605         uint            lock)           /* lock flags for get_buf */
 606 {
 607         xfs_buf_t       *bp;            /* buffer pointer (return value) */
 608         xfs_daddr_t             d;              /* real disk block address */
 609
 610         ASSERT(agno != NULLAGNUMBER);
 611         ASSERT(agbno != NULLAGBLOCK);
 612         d = XFS_AGB_TO_DADDR(mp, agno, agbno);
 613         bp = xfs_trans_get_buf(tp, mp->m_ddev_targp, d, mp->m_bsize, lock);
 614         ASSERT(bp);
 615         ASSERT(!XFS_BUF_GETERROR(bp));
 616         return bp;
 617 }
 618
 619 /*
 620  * Check for the cursor referring to the last block at the given level.
 621  */
 622 int                                     /* 1=is last block, 0=not last block */
 623 xfs_btree_islastblock(
 624         xfs_btree_cur_t         *cur,   /* btree cursor */
 625         int                     level)  /* level to check */
 626 {
 627         xfs_btree_block_t       *block; /* generic btree block pointer */
 628         xfs_buf_t               *bp;    /* buffer containing block */
 629
 630         block = xfs_btree_get_block(cur, level, &bp);
 631         xfs_btree_check_block(cur, block, level, bp);
 632         if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
 633                 return be64_to_cpu(block->bb_u.l.bb_rightsib) == NULLDFSBNO;
 634         else
 635                 return be32_to_cpu(block->bb_u.s.bb_rightsib) == NULLAGBLOCK;
 636 }
 637
 638 /*
 639  * Change the cursor to point to the first record at the given level.
 640  * Other levels are unaffected.
 641  */
 642 int                                     /* success=1, failure=0 */
 643 xfs_btree_firstrec(
 644         xfs_btree_cur_t         *cur,   /* btree cursor */
 645         int                     level)  /* level to change */
 646 {
 647         xfs_btree_block_t       *block; /* generic btree block pointer */
 648         xfs_buf_t               *bp;    /* buffer containing block */
 649
 650         /*
 651          * Get the block pointer for this level.
 652          */
 653         block = xfs_btree_get_block(cur, level, &bp);
 654         xfs_btree_check_block(cur, block, level, bp);
 655         /*
 656          * It's empty, there is no such record.
 657          */
 658         if (!block->bb_numrecs)
 659                 return 0;
 660         /*
 661          * Set the ptr value to 1, that's the first record/key.
 662          */
 663         cur->bc_ptrs[level] = 1;
 664         return 1;
 665 }
 666
 667 /*
 668  * Change the cursor to point to the last record in the current block
 669  * at the given level.  Other levels are unaffected.
 670  */
 671 int                                     /* success=1, failure=0 */
 672 xfs_btree_lastrec(
 673         xfs_btree_cur_t         *cur,   /* btree cursor */
 674         int                     level)  /* level to change */
 675 {
 676         xfs_btree_block_t       *block; /* generic btree block pointer */
 677         xfs_buf_t               *bp;    /* buffer containing block */
 678
 679         /*
 680          * Get the block pointer for this level.
 681          */
 682         block = xfs_btree_get_block(cur, level, &bp);
 683         xfs_btree_check_block(cur, block, level, bp);
 684         /*
 685          * It's empty, there is no such record.
 686          */
 687         if (!block->bb_numrecs)
 688                 return 0;
 689         /*
 690          * Set the ptr value to numrecs, that's the last record/key.
 691          */
 692         cur->bc_ptrs[level] = be16_to_cpu(block->bb_numrecs);
 693         return 1;
 694 }
 695
 696 /*
 697  * Compute first and last byte offsets for the fields given.
 698  * Interprets the offsets table, which contains struct field offsets.
 699  */
 700 void
 701 xfs_btree_offsets(
 702         __int64_t       fields,         /* bitmask of fields */
 703         const short     *offsets,       /* table of field offsets */
 704         int             nbits,          /* number of bits to inspect */
 705         int             *first,         /* output: first byte offset */
 706         int             *last)          /* output: last byte offset */
 707 {
 708         int             i;              /* current bit number */
 709         __int64_t       imask;          /* mask for current bit number */
 710
 711         ASSERT(fields != 0);
 712         /*
 713          * Find the lowest bit, so the first byte offset.
 714          */
 715         for (i = 0, imask = 1LL; ; i++, imask <<= 1) {
 716                 if (imask & fields) {
 717                         *first = offsets[i];
 718                         break;
 719                 }
 720         }
 721         /*
 722          * Find the highest bit, so the last byte offset.
 723          */
 724         for (i = nbits - 1, imask = 1LL << i; ; i--, imask >>= 1) {
 725                 if (imask & fields) {
 726                         *last = offsets[i + 1] - 1;
 727                         break;
 728                 }
 729         }
 730 }
 731
 732 /*
 733  * Get a buffer for the block, return it read in.
 734  * Long-form addressing.
 735  */
 736 int                                     /* error */
 737 xfs_btree_read_bufl(
 738         xfs_mount_t     *mp,            /* file system mount point */
 739         xfs_trans_t     *tp,            /* transaction pointer */
 740         xfs_fsblock_t   fsbno,          /* file system block number */
 741         uint            lock,           /* lock flags for read_buf */
 742         xfs_buf_t       **bpp,          /* buffer for fsbno */
 743         int             refval)         /* ref count value for buffer */
 744 {
 745         xfs_buf_t       *bp;            /* return value */
 746         xfs_daddr_t             d;              /* real disk block address */
 747         int             error;
 748
 749         ASSERT(fsbno != NULLFSBLOCK);
 750         d = XFS_FSB_TO_DADDR(mp, fsbno);
 751         if ((error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, d,
 752                         mp->m_bsize, lock, &bp))) {
 753                 return error;
 754         }
 755         ASSERT(!bp || !XFS_BUF_GETERROR(bp));
 756         if (bp != NULL) {
 757                 XFS_BUF_SET_VTYPE_REF(bp, B_FS_MAP, refval);
 758         }
 759         *bpp = bp;
 760         return 0;
 761 }
 762
 763 /*
 764  * Get a buffer for the block, return it read in.
 765  * Short-form addressing.
 766  */
 767 int                                     /* error */
 768 xfs_btree_read_bufs(
 769         xfs_mount_t     *mp,            /* file system mount point */
 770         xfs_trans_t     *tp,            /* transaction pointer */
 771         xfs_agnumber_t  agno,           /* allocation group number */
 772         xfs_agblock_t   agbno,          /* allocation group block number */
 773         uint            lock,           /* lock flags for read_buf */
 774         xfs_buf_t       **bpp,          /* buffer for agno/agbno */
 775         int             refval)         /* ref count value for buffer */
 776 {
 777         xfs_buf_t       *bp;            /* return value */
 778         xfs_daddr_t     d;              /* real disk block address */
 779         int             error;
 780
 781         ASSERT(agno != NULLAGNUMBER);
 782         ASSERT(agbno != NULLAGBLOCK);
 783         d = XFS_AGB_TO_DADDR(mp, agno, agbno);
 784         if ((error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, d,
 785                                         mp->m_bsize, lock, &bp))) {
 786                 return error;
 787         }
 788         ASSERT(!bp || !XFS_BUF_GETERROR(bp));
 789         if (bp != NULL) {
 790                 switch (refval) {
 791                 case XFS_ALLOC_BTREE_REF:
 792                         XFS_BUF_SET_VTYPE_REF(bp, B_FS_MAP, refval);
 793                         break;
 794                 case XFS_INO_BTREE_REF:
 795                         XFS_BUF_SET_VTYPE_REF(bp, B_FS_INOMAP, refval);
 796                         break;
 797                 }
 798         }
 799         *bpp = bp;
 800         return 0;
 801 }
 802
 803 /*
 804  * Read-ahead the block, don't wait for it, don't return a buffer.
 805  * Long-form addressing.
 806  */
 807 /* ARGSUSED */
 808 void
 809 xfs_btree_reada_bufl(
 810         xfs_mount_t     *mp,            /* file system mount point */
 811         xfs_fsblock_t   fsbno,          /* file system block number */
 812         xfs_extlen_t    count)          /* count of filesystem blocks */
 813 {
 814         xfs_daddr_t             d;
 815
 816         ASSERT(fsbno != NULLFSBLOCK);
 817         d = XFS_FSB_TO_DADDR(mp, fsbno);
 818         xfs_baread(mp->m_ddev_targp, d, mp->m_bsize * count);
 819 }
 820
 821 /*
 822  * Read-ahead the block, don't wait for it, don't return a buffer.
 823  * Short-form addressing.
 824  */
 825 /* ARGSUSED */
 826 void
 827 xfs_btree_reada_bufs(
 828         xfs_mount_t     *mp,            /* file system mount point */
 829         xfs_agnumber_t  agno,           /* allocation group number */
 830         xfs_agblock_t   agbno,          /* allocation group block number */
 831         xfs_extlen_t    count)          /* count of filesystem blocks */
 832 {
 833         xfs_daddr_t             d;
 834
 835         ASSERT(agno != NULLAGNUMBER);
 836         ASSERT(agbno != NULLAGBLOCK);
 837         d = XFS_AGB_TO_DADDR(mp, agno, agbno);
 838         xfs_baread(mp->m_ddev_targp, d, mp->m_bsize * count);
 839 }
 840
 841 STATIC int
 842 xfs_btree_readahead_lblock(
 843         struct xfs_btree_cur    *cur,
 844         int                     lr,
 845         struct xfs_btree_block  *block)
 846 {
 847         int                     rval = 0;
 848         xfs_fsblock_t           left = be64_to_cpu(block->bb_u.l.bb_leftsib);
 849         xfs_fsblock_t           right = be64_to_cpu(block->bb_u.l.bb_rightsib);
 850
 851         if ((lr & XFS_BTCUR_LEFTRA) && left != NULLDFSBNO) {
 852                 xfs_btree_reada_bufl(cur->bc_mp, left, 1);
 853                 rval++;
 854         }
 855
 856         if ((lr & XFS_BTCUR_RIGHTRA) && right != NULLDFSBNO) {
 857                 xfs_btree_reada_bufl(cur->bc_mp, right, 1);
 858                 rval++;
 859         }
 860
 861         return rval;
 862 }
 863
 864 STATIC int
 865 xfs_btree_readahead_sblock(
 866         struct xfs_btree_cur    *cur,
 867         int                     lr,
 868         struct xfs_btree_block *block)
 869 {
 870         int                     rval = 0;
 871         xfs_agblock_t           left = be32_to_cpu(block->bb_u.s.bb_leftsib);
 872         xfs_agblock_t           right = be32_to_cpu(block->bb_u.s.bb_rightsib);
 873
 874
 875         if ((lr & XFS_BTCUR_LEFTRA) && left != NULLAGBLOCK) {
 876                 xfs_btree_reada_bufs(cur->bc_mp, cur->bc_private.a.agno,
 877                                      left, 1);
 878                 rval++;
 879         }
 880
 881         if ((lr & XFS_BTCUR_RIGHTRA) && right != NULLAGBLOCK) {
 882                 xfs_btree_reada_bufs(cur->bc_mp, cur->bc_private.a.agno,
 883                                      right, 1);
 884                 rval++;
 885         }
 886
 887         return rval;
 888 }
 889
 890 /*
 891  * Read-ahead btree blocks, at the given level.
 892  * Bits in lr are set from XFS_BTCUR_{LEFT,RIGHT}RA.
 893  */
 894 int
 895 xfs_btree_readahead(
 896         struct xfs_btree_cur    *cur,           /* btree cursor */
 897         int                     lev,            /* level in btree */
 898         int                     lr)             /* left/right bits */
 899 {
 900         struct xfs_btree_block  *block;
 901
 902         /*
 903          * No readahead needed if we are at the root level and the
 904          * btree root is stored in the inode.
 905          */
 906         if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
 907             (lev == cur->bc_nlevels - 1))
 908                 return 0;
 909
 910         if ((cur->bc_ra[lev] | lr) == cur->bc_ra[lev])
 911                 return 0;
 912
 913         cur->bc_ra[lev] |= lr;
 914         block = XFS_BUF_TO_BLOCK(cur->bc_bufs[lev]);
 915
 916         if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
 917                 return xfs_btree_readahead_lblock(cur, lr, block);
 918         return xfs_btree_readahead_sblock(cur, lr, block);
 919 }
 920
 921 /*
 922  * Set the buffer for level "lev" in the cursor to bp, releasing
 923  * any previous buffer.
 924  */
 925 void
 926 xfs_btree_setbuf(
 927         xfs_btree_cur_t         *cur,   /* btree cursor */
 928         int                     lev,    /* level in btree */
 929         xfs_buf_t               *bp)    /* new buffer to set */
 930 {
 931         xfs_btree_block_t       *b;     /* btree block */
 932         xfs_buf_t               *obp;   /* old buffer pointer */
 933
 934         obp = cur->bc_bufs[lev];
 935         if (obp)
 936                 xfs_trans_brelse(cur->bc_tp, obp);
 937         cur->bc_bufs[lev] = bp;
 938         cur->bc_ra[lev] = 0;
 939         if (!bp)
 940                 return;
 941         b = XFS_BUF_TO_BLOCK(bp);
 942         if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
 943                 if (be64_to_cpu(b->bb_u.l.bb_leftsib) == NULLDFSBNO)
 944                         cur->bc_ra[lev] |= XFS_BTCUR_LEFTRA;
 945                 if (be64_to_cpu(b->bb_u.l.bb_rightsib) == NULLDFSBNO)
 946                         cur->bc_ra[lev] |= XFS_BTCUR_RIGHTRA;
 947         } else {
 948                 if (be32_to_cpu(b->bb_u.s.bb_leftsib) == NULLAGBLOCK)
 949                         cur->bc_ra[lev] |= XFS_BTCUR_LEFTRA;
 950                 if (be32_to_cpu(b->bb_u.s.bb_rightsib) == NULLAGBLOCK)
 951                         cur->bc_ra[lev] |= XFS_BTCUR_RIGHTRA;
 952         }
 953 }
 954
 955 STATIC int
 956 xfs_btree_ptr_is_null(
 957         struct xfs_btree_cur    *cur,
 958         union xfs_btree_ptr     *ptr)
 959 {
 960         if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
 961                 return be64_to_cpu(ptr->l) == NULLFSBLOCK;
 962         else
 963                 return be32_to_cpu(ptr->s) == NULLAGBLOCK;
 964 }
 965
 966 STATIC void
 967 xfs_btree_set_ptr_null(
 968         struct xfs_btree_cur    *cur,
 969         union xfs_btree_ptr     *ptr)
 970 {
 971         if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
 972                 ptr->l = cpu_to_be64(NULLFSBLOCK);
 973         else
 974                 ptr->s = cpu_to_be32(NULLAGBLOCK);
 975 }
 976
 977 /*
 978  * Get/set/init sibling pointers
 979  */
 980 STATIC void
 981 xfs_btree_get_sibling(
 982         struct xfs_btree_cur    *cur,
 983         struct xfs_btree_block  *block,
 984         union xfs_btree_ptr     *ptr,
 985         int                     lr)
 986 {
 987         ASSERT(lr == XFS_BB_LEFTSIB || lr == XFS_BB_RIGHTSIB);
 988
 989         if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
 990                 if (lr == XFS_BB_RIGHTSIB)
 991                         ptr->l = block->bb_u.l.bb_rightsib;
 992                 else
 993                         ptr->l = block->bb_u.l.bb_leftsib;
 994         } else {
 995                 if (lr == XFS_BB_RIGHTSIB)
 996                         ptr->s = block->bb_u.s.bb_rightsib;
 997                 else
 998                         ptr->s = block->bb_u.s.bb_leftsib;
 999         }
1000 }
1001
1002 STATIC void
1003 xfs_btree_set_sibling(
1004         struct xfs_btree_cur    *cur,
1005         struct xfs_btree_block  *block,
1006         union xfs_btree_ptr     *ptr,
1007         int                     lr)
1008 {
1009         ASSERT(lr == XFS_BB_LEFTSIB || lr == XFS_BB_RIGHTSIB);
1010
1011         if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
1012                 if (lr == XFS_BB_RIGHTSIB)
1013                         block->bb_u.l.bb_rightsib = ptr->l;
1014                 else
1015                         block->bb_u.l.bb_leftsib = ptr->l;
1016         } else {
1017                 if (lr == XFS_BB_RIGHTSIB)
1018                         block->bb_u.s.bb_rightsib = ptr->s;
1019                 else
1020                         block->bb_u.s.bb_leftsib = ptr->s;
1021         }
1022 }
1023
1024 STATIC void
1025 xfs_btree_init_block(
1026         struct xfs_btree_cur    *cur,
1027         int                     level,
1028         int                     numrecs,
1029         struct xfs_btree_block  *new)   /* new block */
1030 {
1031         new->bb_magic = cpu_to_be32(xfs_magics[cur->bc_btnum]);
1032         new->bb_level = cpu_to_be16(level);
1033         new->bb_numrecs = cpu_to_be16(numrecs);
1034
1035         if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
1036                 new->bb_u.l.bb_leftsib = cpu_to_be64(NULLFSBLOCK);
1037                 new->bb_u.l.bb_rightsib = cpu_to_be64(NULLFSBLOCK);
1038         } else {
1039                 new->bb_u.s.bb_leftsib = cpu_to_be32(NULLAGBLOCK);
1040                 new->bb_u.s.bb_rightsib = cpu_to_be32(NULLAGBLOCK);
1041         }
1042 }
1043
1044 /*
1045  * Return true if ptr is the last record in the btree and
1046  * we need to track updateѕ to this record.  The decision
1047  * will be further refined in the update_lastrec method.
1048  */
1049 STATIC int
1050 xfs_btree_is_lastrec(
1051         struct xfs_btree_cur    *cur,
1052         struct xfs_btree_block  *block,
1053         int                     level)
1054 {
1055         union xfs_btree_ptr     ptr;
1056
1057         if (level > 0)
1058                 return 0;
1059         if (!(cur->bc_flags & XFS_BTREE_LASTREC_UPDATE))
1060                 return 0;
1061
1062         xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
1063         if (!xfs_btree_ptr_is_null(cur, &ptr))
1064                 return 0;
1065         return 1;
1066 }
1067
1068 STATIC void
1069 xfs_btree_buf_to_ptr(
1070         struct xfs_btree_cur    *cur,
1071         struct xfs_buf          *bp,
1072         union xfs_btree_ptr     *ptr)
1073 {
1074         if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
1075                 ptr->l = cpu_to_be64(XFS_DADDR_TO_FSB(cur->bc_mp,
1076                                         XFS_BUF_ADDR(bp)));
1077         else {
1078                 ptr->s = cpu_to_be32(XFS_DADDR_TO_AGBNO(cur->bc_mp,
1079                                         XFS_BUF_ADDR(bp)));
1080         }
1081 }
1082
1083 STATIC xfs_daddr_t
1084 xfs_btree_ptr_to_daddr(
1085         struct xfs_btree_cur    *cur,
1086         union xfs_btree_ptr     *ptr)
1087 {
1088         if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
1089                 ASSERT(be64_to_cpu(ptr->l) != NULLFSBLOCK);
1090
1091                 return XFS_FSB_TO_DADDR(cur->bc_mp, be64_to_cpu(ptr->l));
1092         } else {
1093                 ASSERT(cur->bc_private.a.agno != NULLAGNUMBER);
1094                 ASSERT(be32_to_cpu(ptr->s) != NULLAGBLOCK);
1095
1096                 return XFS_AGB_TO_DADDR(cur->bc_mp, cur->bc_private.a.agno,
1097                                         be32_to_cpu(ptr->s));
1098         }
1099 }
1100
1101 STATIC void
1102 xfs_btree_set_refs(
1103         struct xfs_btree_cur    *cur,
1104         struct xfs_buf          *bp)
1105 {
1106         switch (cur->bc_btnum) {
1107         case XFS_BTNUM_BNO:
1108         case XFS_BTNUM_CNT:
1109                 XFS_BUF_SET_VTYPE_REF(*bpp, B_FS_MAP, XFS_ALLOC_BTREE_REF);
1110                 break;
1111         case XFS_BTNUM_INO:
1112                 XFS_BUF_SET_VTYPE_REF(*bpp, B_FS_INOMAP, XFS_INO_BTREE_REF);
1113                 break;
1114         case XFS_BTNUM_BMAP:
1115                 XFS_BUF_SET_VTYPE_REF(*bpp, B_FS_MAP, XFS_BMAP_BTREE_REF);
1116                 break;
1117         default:
1118                 ASSERT(0);
1119         }
1120 }
1121
1122 STATIC int
1123 xfs_btree_get_buf_block(
1124         struct xfs_btree_cur    *cur,
1125         union xfs_btree_ptr     *ptr,
1126         int                     flags,
1127         struct xfs_btree_block  **block,
1128         struct xfs_buf          **bpp)
1129 {
1130         struct xfs_mount        *mp = cur->bc_mp;
1131         xfs_daddr_t             d;
1132
1133         /* need to sort out how callers deal with failures first */
1134         ASSERT(!(flags & XFS_BUF_TRYLOCK));
1135
1136         d = xfs_btree_ptr_to_daddr(cur, ptr);
1137         *bpp = xfs_trans_get_buf(cur->bc_tp, mp->m_ddev_targp, d,
1138                                  mp->m_bsize, flags);
1139
1140         ASSERT(*bpp);
1141         ASSERT(!XFS_BUF_GETERROR(*bpp));
1142
1143         *block = XFS_BUF_TO_BLOCK(*bpp);
1144         return 0;
1145 }
1146
1147 /*
1148  * Read in the buffer at the given ptr and return the buffer and
1149  * the block pointer within the buffer.
1150  */
1151 STATIC int
1152 xfs_btree_read_buf_block(
1153         struct xfs_btree_cur    *cur,
1154         union xfs_btree_ptr     *ptr,
1155         int                     level,
1156         int                     flags,
1157         struct xfs_btree_block  **block,
1158         struct xfs_buf          **bpp)
1159 {
1160         struct xfs_mount        *mp = cur->bc_mp;
1161         xfs_daddr_t             d;
1162         int                     error;
1163
1164         /* need to sort out how callers deal with failures first */
1165         ASSERT(!(flags & XFS_BUF_TRYLOCK));
1166
1167         d = xfs_btree_ptr_to_daddr(cur, ptr);
1168         error = xfs_trans_read_buf(mp, cur->bc_tp, mp->m_ddev_targp, d,
1169                                    mp->m_bsize, flags, bpp);
1170         if (error)
1171                 return error;
1172
1173         ASSERT(*bpp != NULL);
1174         ASSERT(!XFS_BUF_GETERROR(*bpp));
1175
1176         xfs_btree_set_refs(cur, *bpp);
1177         *block = XFS_BUF_TO_BLOCK(*bpp);
1178
1179         error = xfs_btree_check_block(cur, *block, level, *bpp);
1180         if (error)
1181                 xfs_trans_brelse(cur->bc_tp, *bpp);
1182         return error;
1183 }
1184
1185 /*
1186  * Copy keys from one btree block to another.
1187  */
1188 STATIC void
1189 xfs_btree_copy_keys(
1190         struct xfs_btree_cur    *cur,
1191         union xfs_btree_key     *dst_key,
1192         union xfs_btree_key     *src_key,
1193         int                     numkeys)
1194 {
1195         ASSERT(numkeys >= 0);
1196         memcpy(dst_key, src_key, numkeys * cur->bc_ops->key_len);
1197 }
1198
1199 /*
1200  * Copy records from one btree block to another.
1201  */
1202 STATIC void
1203 xfs_btree_copy_recs(
1204         struct xfs_btree_cur    *cur,
1205         union xfs_btree_rec     *dst_rec,
1206         union xfs_btree_rec     *src_rec,
1207         int                     numrecs)
1208 {
1209         ASSERT(numrecs >= 0);
1210         memcpy(dst_rec, src_rec, numrecs * cur->bc_ops->rec_len);
1211 }
1212
1213 /*
1214  * Copy block pointers from one btree block to another.
1215  */
1216 STATIC void
1217 xfs_btree_copy_ptrs(
1218         struct xfs_btree_cur    *cur,
1219         union xfs_btree_ptr     *dst_ptr,
1220         union xfs_btree_ptr     *src_ptr,
1221         int                     numptrs)
1222 {
1223         ASSERT(numptrs >= 0);
1224         memcpy(dst_ptr, src_ptr, numptrs * xfs_btree_ptr_len(cur));
1225 }
1226
1227 /*
1228  * Shift keys one index left/right inside a single btree block.
1229  */
1230 STATIC void
1231 xfs_btree_shift_keys(
1232         struct xfs_btree_cur    *cur,
1233         union xfs_btree_key     *key,
1234         int                     dir,
1235         int                     numkeys)
1236 {
1237         char                    *dst_key;
1238
1239         ASSERT(numkeys >= 0);
1240         ASSERT(dir == 1 || dir == -1);
1241
1242         dst_key = (char *)key + (dir * cur->bc_ops->key_len);
1243         memmove(dst_key, key, numkeys * cur->bc_ops->key_len);
1244 }
1245
1246 /*
1247  * Shift records one index left/right inside a single btree block.
1248  */
1249 STATIC void
1250 xfs_btree_shift_recs(
1251         struct xfs_btree_cur    *cur,
1252         union xfs_btree_rec     *rec,
1253         int                     dir,
1254         int                     numrecs)
1255 {
1256         char                    *dst_rec;
1257
1258         ASSERT(numrecs >= 0);
1259         ASSERT(dir == 1 || dir == -1);
1260
1261         dst_rec = (char *)rec + (dir * cur->bc_ops->rec_len);
1262         memmove(dst_rec, rec, numrecs * cur->bc_ops->rec_len);
1263 }
1264
1265 /*
1266  * Shift block pointers one index left/right inside a single btree block.
1267  */
1268 STATIC void
1269 xfs_btree_shift_ptrs(
1270         struct xfs_btree_cur    *cur,
1271         union xfs_btree_ptr     *ptr,
1272         int                     dir,
1273         int                     numptrs)
1274 {
1275         char                    *dst_ptr;
1276
1277         ASSERT(numptrs >= 0);
1278         ASSERT(dir == 1 || dir == -1);
1279
1280         dst_ptr = (char *)ptr + (dir * xfs_btree_ptr_len(cur));
1281         memmove(dst_ptr, ptr, numptrs * xfs_btree_ptr_len(cur));
1282 }
1283
1284 /*
1285  * Log key values from the btree block.
1286  */
1287 STATIC void
1288 xfs_btree_log_keys(
1289         struct xfs_btree_cur    *cur,
1290         struct xfs_buf          *bp,
1291         int                     first,
1292         int                     last)
1293 {
1294         XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1295         XFS_BTREE_TRACE_ARGBII(cur, bp, first, last);
1296
1297         if (bp) {
1298                 xfs_trans_log_buf(cur->bc_tp, bp,
1299                                   xfs_btree_key_offset(cur, first),
1300                                   xfs_btree_key_offset(cur, last + 1) - 1);
1301         } else {
1302                 xfs_trans_log_inode(cur->bc_tp, cur->bc_private.b.ip,
1303                                 xfs_ilog_fbroot(cur->bc_private.b.whichfork));
1304         }
1305
1306         XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1307 }
1308
1309 /*
1310  * Log record values from the btree block.
1311  */
1312 void
1313 xfs_btree_log_recs(
1314         struct xfs_btree_cur    *cur,
1315         struct xfs_buf          *bp,
1316         int                     first,
1317         int                     last)
1318 {
1319         XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1320         XFS_BTREE_TRACE_ARGBII(cur, bp, first, last);
1321
1322         xfs_trans_log_buf(cur->bc_tp, bp,
1323                           xfs_btree_rec_offset(cur, first),
1324                           xfs_btree_rec_offset(cur, last + 1) - 1);
1325
1326         XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1327 }
1328
1329 /*
1330  * Log block pointer fields from a btree block (nonleaf).
1331  */
1332 STATIC void
1333 xfs_btree_log_ptrs(
1334         struct xfs_btree_cur    *cur,   /* btree cursor */
1335         struct xfs_buf          *bp,    /* buffer containing btree block */
1336         int                     first,  /* index of first pointer to log */
1337         int                     last)   /* index of last pointer to log */
1338 {
1339         XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1340         XFS_BTREE_TRACE_ARGBII(cur, bp, first, last);
1341
1342         if (bp) {
1343                 struct xfs_btree_block  *block = XFS_BUF_TO_BLOCK(bp);
1344                 int                     level = xfs_btree_get_level(block);
1345
1346                 xfs_trans_log_buf(cur->bc_tp, bp,
1347                                 xfs_btree_ptr_offset(cur, first, level),
1348                                 xfs_btree_ptr_offset(cur, last + 1, level) - 1);
1349         } else {
1350                 xfs_trans_log_inode(cur->bc_tp, cur->bc_private.b.ip,
1351                         xfs_ilog_fbroot(cur->bc_private.b.whichfork));
1352         }
1353
1354         XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1355 }
1356
1357 /*
1358  * Log fields from a btree block header.
1359  */
1360 void
1361 xfs_btree_log_block(
1362         struct xfs_btree_cur    *cur,   /* btree cursor */
1363         struct xfs_buf          *bp,    /* buffer containing btree block */
1364         int                     fields) /* mask of fields: XFS_BB_... */
1365 {
1366         int                     first;  /* first byte offset logged */
1367         int                     last;   /* last byte offset logged */
1368         static const short      soffsets[] = {  /* table of offsets (short) */
1369                 offsetof(struct xfs_btree_sblock, bb_magic),
1370                 offsetof(struct xfs_btree_sblock, bb_level),
1371                 offsetof(struct xfs_btree_sblock, bb_numrecs),
1372                 offsetof(struct xfs_btree_sblock, bb_leftsib),
1373                 offsetof(struct xfs_btree_sblock, bb_rightsib),
1374                 sizeof(struct xfs_btree_sblock)
1375         };
1376         static const short      loffsets[] = {  /* table of offsets (long) */
1377                 offsetof(struct xfs_btree_lblock, bb_magic),
1378                 offsetof(struct xfs_btree_lblock, bb_level),
1379                 offsetof(struct xfs_btree_lblock, bb_numrecs),
1380                 offsetof(struct xfs_btree_lblock, bb_leftsib),
1381                 offsetof(struct xfs_btree_lblock, bb_rightsib),
1382                 sizeof(struct xfs_btree_lblock)
1383         };
1384
1385         XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1386         XFS_BTREE_TRACE_ARGBI(cur, bp, fields);
1387
1388         if (bp) {
1389                 xfs_btree_offsets(fields,
1390                                   (cur->bc_flags & XFS_BTREE_LONG_PTRS) ?
1391                                         loffsets : soffsets,
1392                                   XFS_BB_NUM_BITS, &first, &last);
1393                 xfs_trans_log_buf(cur->bc_tp, bp, first, last);
1394         } else {
1395                 xfs_trans_log_inode(cur->bc_tp, cur->bc_private.b.ip,
1396                         xfs_ilog_fbroot(cur->bc_private.b.whichfork));
1397         }
1398
1399         XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1400 }
1401
1402 /*
1403  * Increment cursor by one record at the level.
1404  * For nonzero levels the leaf-ward information is untouched.
1405  */
1406 int                                             /* error */
1407 xfs_btree_increment(
1408         struct xfs_btree_cur    *cur,
1409         int                     level,
1410         int                     *stat)          /* success/failure */
1411 {
1412         struct xfs_btree_block  *block;
1413         union xfs_btree_ptr     ptr;
1414         struct xfs_buf          *bp;
1415         int                     error;          /* error return value */
1416         int                     lev;
1417
1418         XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1419         XFS_BTREE_TRACE_ARGI(cur, level);
1420
1421         ASSERT(level < cur->bc_nlevels);
1422
1423         /* Read-ahead to the right at this level. */
1424         xfs_btree_readahead(cur, level, XFS_BTCUR_RIGHTRA);
1425
1426         /* Get a pointer to the btree block. */
1427         block = xfs_btree_get_block(cur, level, &bp);
1428
1429 #ifdef DEBUG
1430         error = xfs_btree_check_block(cur, block, level, bp);
1431         if (error)
1432                 goto error0;
1433 #endif
1434
1435         /* We're done if we remain in the block after the increment. */
1436         if (++cur->bc_ptrs[level] <= xfs_btree_get_numrecs(block))
1437                 goto out1;
1438
1439         /* Fail if we just went off the right edge of the tree. */
1440         xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
1441         if (xfs_btree_ptr_is_null(cur, &ptr))
1442                 goto out0;
1443
1444         XFS_BTREE_STATS_INC(cur, increment);
1445
1446         /*
1447          * March up the tree incrementing pointers.
1448          * Stop when we don't go off the right edge of a block.
1449          */
1450         for (lev = level + 1; lev < cur->bc_nlevels; lev++) {
1451                 block = xfs_btree_get_block(cur, lev, &bp);
1452
1453 #ifdef DEBUG
1454                 error = xfs_btree_check_block(cur, block, lev, bp);
1455                 if (error)
1456                         goto error0;
1457 #endif
1458
1459                 if (++cur->bc_ptrs[lev] <= xfs_btree_get_numrecs(block))
1460                         break;
1461
1462                 /* Read-ahead the right block for the next loop. */
1463                 xfs_btree_readahead(cur, lev, XFS_BTCUR_RIGHTRA);
1464         }
1465
1466         /*
1467          * If we went off the root then we are either seriously
1468          * confused or have the tree root in an inode.
1469          */
1470         if (lev == cur->bc_nlevels) {
1471                 if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE)
1472                         goto out0;
1473                 ASSERT(0);
1474                 error = EFSCORRUPTED;
1475                 goto error0;
1476         }
1477         ASSERT(lev < cur->bc_nlevels);
1478
1479         /*
1480          * Now walk back down the tree, fixing up the cursor's buffer
1481          * pointers and key numbers.
1482          */
1483         for (block = xfs_btree_get_block(cur, lev, &bp); lev > level; ) {
1484                 union xfs_btree_ptr     *ptrp;
1485
1486                 ptrp = xfs_btree_ptr_addr(cur, cur->bc_ptrs[lev], block);
1487                 error = xfs_btree_read_buf_block(cur, ptrp, --lev,
1488                                                         0, &block, &bp);
1489                 if (error)
1490                         goto error0;
1491
1492                 xfs_btree_setbuf(cur, lev, bp);
1493                 cur->bc_ptrs[lev] = 1;
1494         }
1495 out1:
1496         XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1497         *stat = 1;
1498         return 0;
1499
1500 out0:
1501         XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1502         *stat = 0;
1503         return 0;
1504
1505 error0:
1506         XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1507         return error;
1508 }
1509
1510 /*
1511  * Decrement cursor by one record at the level.
1512  * For nonzero levels the leaf-ward information is untouched.
1513  */
1514 int                                             /* error */
1515 xfs_btree_decrement(
1516         struct xfs_btree_cur    *cur,
1517         int                     level,
1518         int                     *stat)          /* success/failure */
1519 {
1520         struct xfs_btree_block  *block;
1521         xfs_buf_t               *bp;
1522         int                     error;          /* error return value */
1523         int                     lev;
1524         union xfs_btree_ptr     ptr;
1525
1526         XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1527         XFS_BTREE_TRACE_ARGI(cur, level);
1528
1529         ASSERT(level < cur->bc_nlevels);
1530
1531         /* Read-ahead to the left at this level. */
1532         xfs_btree_readahead(cur, level, XFS_BTCUR_LEFTRA);
1533
1534         /* We're done if we remain in the block after the decrement. */
1535         if (--cur->bc_ptrs[level] > 0)
1536                 goto out1;
1537
1538         /* Get a pointer to the btree block. */
1539         block = xfs_btree_get_block(cur, level, &bp);
1540
1541 #ifdef DEBUG
1542         error = xfs_btree_check_block(cur, block, level, bp);
1543         if (error)
1544                 goto error0;
1545 #endif
1546
1547         /* Fail if we just went off the left edge of the tree. */
1548         xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_LEFTSIB);
1549         if (xfs_btree_ptr_is_null(cur, &ptr))
1550                 goto out0;
1551
1552         XFS_BTREE_STATS_INC(cur, decrement);
1553
1554         /*
1555          * March up the tree decrementing pointers.
1556          * Stop when we don't go off the left edge of a block.
1557          */
1558         for (lev = level + 1; lev < cur->bc_nlevels; lev++) {
1559                 if (--cur->bc_ptrs[lev] > 0)
1560                         break;
1561                 /* Read-ahead the left block for the next loop. */
1562                 xfs_btree_readahead(cur, lev, XFS_BTCUR_LEFTRA);
1563         }
1564
1565         /*
1566          * If we went off the root then we are seriously confused.
1567          * or the root of the tree is in an inode.
1568          */
1569         if (lev == cur->bc_nlevels) {
1570                 if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE)
1571                         goto out0;
1572                 ASSERT(0);
1573                 error = EFSCORRUPTED;
1574                 goto error0;
1575         }
1576         ASSERT(lev < cur->bc_nlevels);
1577
1578         /*
1579          * Now walk back down the tree, fixing up the cursor's buffer
1580          * pointers and key numbers.
1581          */
1582         for (block = xfs_btree_get_block(cur, lev, &bp); lev > level; ) {
1583                 union xfs_btree_ptr     *ptrp;
1584
1585                 ptrp = xfs_btree_ptr_addr(cur, cur->bc_ptrs[lev], block);
1586                 error = xfs_btree_read_buf_block(cur, ptrp, --lev,
1587                                                         0, &block, &bp);
1588                 if (error)
1589                         goto error0;
1590                 xfs_btree_setbuf(cur, lev, bp);
1591                 cur->bc_ptrs[lev] = xfs_btree_get_numrecs(block);
1592         }
1593 out1:
1594         XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1595         *stat = 1;
1596         return 0;
1597
1598 out0:
1599         XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1600         *stat = 0;
1601         return 0;
1602
1603 error0:
1604         XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1605         return error;
1606 }
1607
1608 STATIC int
1609 xfs_btree_lookup_get_block(
1610         struct xfs_btree_cur    *cur,   /* btree cursor */
1611         int                     level,  /* level in the btree */
1612         union xfs_btree_ptr     *pp,    /* ptr to btree block */
1613         struct xfs_btree_block  **blkp) /* return btree block */
1614 {
1615         struct xfs_buf          *bp;    /* buffer pointer for btree block */
1616         int                     error = 0;
1617
1618         /* special case the root block if in an inode */
1619         if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
1620             (level == cur->bc_nlevels - 1)) {
1621                 *blkp = xfs_btree_get_iroot(cur);
1622                 return 0;
1623         }
1624
1625         /*
1626          * If the old buffer at this level for the disk address we are
1627          * looking for re-use it.
1628          *
1629          * Otherwise throw it away and get a new one.
1630          */
1631         bp = cur->bc_bufs[level];
1632         if (bp && XFS_BUF_ADDR(bp) == xfs_btree_ptr_to_daddr(cur, pp)) {
1633                 *blkp = XFS_BUF_TO_BLOCK(bp);
1634                 return 0;
1635         }
1636
1637         error = xfs_btree_read_buf_block(cur, pp, level, 0, blkp, &bp);
1638         if (error)
1639                 return error;
1640
1641         xfs_btree_setbuf(cur, level, bp);
1642         return 0;
1643 }
1644
1645 /*
1646  * Get current search key.  For level 0 we don't actually have a key
1647  * structure so we make one up from the record.  For all other levels
1648  * we just return the right key.
1649  */
1650 STATIC union xfs_btree_key *
1651 xfs_lookup_get_search_key(
1652         struct xfs_btree_cur    *cur,
1653         int                     level,
1654         int                     keyno,
1655         struct xfs_btree_block  *block,
1656         union xfs_btree_key     *kp)
1657 {
1658         if (level == 0) {
1659                 cur->bc_ops->init_key_from_rec(kp,
1660                                 xfs_btree_rec_addr(cur, keyno, block));
1661                 return kp;
1662         }
1663
1664         return xfs_btree_key_addr(cur, keyno, block);
1665 }
1666
1667 /*
1668  * Lookup the record.  The cursor is made to point to it, based on dir.
1669  * Return 0 if can't find any such record, 1 for success.
1670  */
1671 int                                     /* error */
1672 xfs_btree_lookup(
1673         struct xfs_btree_cur    *cur,   /* btree cursor */
1674         xfs_lookup_t            dir,    /* <=, ==, or >= */
1675         int                     *stat)  /* success/failure */
1676 {
1677         struct xfs_btree_block  *block; /* current btree block */
1678         __int64_t               diff;   /* difference for the current key */
1679         int                     error;  /* error return value */
1680         int                     keyno;  /* current key number */
1681         int                     level;  /* level in the btree */
1682         union xfs_btree_ptr     *pp;    /* ptr to btree block */
1683         union xfs_btree_ptr     ptr;    /* ptr to btree block */
1684
1685         XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1686         XFS_BTREE_TRACE_ARGI(cur, dir);
1687
1688         XFS_BTREE_STATS_INC(cur, lookup);
1689
1690         block = NULL;
1691         keyno = 0;
1692
1693         /* initialise start pointer from cursor */
1694         cur->bc_ops->init_ptr_from_cur(cur, &ptr);
1695         pp = &ptr;
1696
1697         /*
1698          * Iterate over each level in the btree, starting at the root.
1699          * For each level above the leaves, find the key we need, based
1700          * on the lookup record, then follow the corresponding block
1701          * pointer down to the next level.
1702          */
1703         for (level = cur->bc_nlevels - 1, diff = 1; level >= 0; level--) {
1704                 /* Get the block we need to do the lookup on. */
1705                 error = xfs_btree_lookup_get_block(cur, level, pp, &block);
1706                 if (error)
1707                         goto error0;
1708
1709                 if (diff == 0) {
1710                         /*
1711                          * If we already had a key match at a higher level, we
1712                          * know we need to use the first entry in this block.
1713                          */
1714                         keyno = 1;
1715                 } else {
1716                         /* Otherwise search this block. Do a binary search. */
1717
1718                         int     high;   /* high entry number */
1719                         int     low;    /* low entry number */
1720
1721                         /* Set low and high entry numbers, 1-based. */
1722                         low = 1;
1723                         high = xfs_btree_get_numrecs(block);
1724                         if (!high) {
1725                                 /* Block is empty, must be an empty leaf. */
1726                                 ASSERT(level == 0 && cur->bc_nlevels == 1);
1727
1728                                 cur->bc_ptrs[0] = dir != XFS_LOOKUP_LE;
1729                                 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1730                                 *stat = 0;
1731                                 return 0;
1732                         }
1733
1734                         /* Binary search the block. */
1735                         while (low <= high) {
1736                                 union xfs_btree_key     key;
1737                                 union xfs_btree_key     *kp;
1738
1739                                 XFS_BTREE_STATS_INC(cur, compare);
1740
1741                                 /* keyno is average of low and high. */
1742                                 keyno = (low + high) >> 1;
1743
1744                                 /* Get current search key */
1745                                 kp = xfs_lookup_get_search_key(cur, level,
1746                                                 keyno, block, &key);
1747
1748                                 /*
1749                                  * Compute difference to get next direction:
1750                                  *  - less than, move right
1751                                  *  - greater than, move left
1752                                  *  - equal, we're done
1753                                  */
1754                                 diff = cur->bc_ops->key_diff(cur, kp);
1755                                 if (diff < 0)
1756                                         low = keyno + 1;
1757                                 else if (diff > 0)
1758                                         high = keyno - 1;
1759                                 else
1760                                         break;
1761                         }
1762                 }
1763
1764                 /*
1765                  * If there are more levels, set up for the next level
1766                  * by getting the block number and filling in the cursor.
1767                  */
1768                 if (level > 0) {
1769                         /*
1770                          * If we moved left, need the previous key number,
1771                          * unless there isn't one.
1772                          */
1773                         if (diff > 0 && --keyno < 1)
1774                                 keyno = 1;
1775                         pp = xfs_btree_ptr_addr(cur, keyno, block);
1776
1777 #ifdef DEBUG
1778                         error = xfs_btree_check_ptr(cur, pp, 0, level);
1779                         if (error)
1780                                 goto error0;
1781 #endif
1782                         cur->bc_ptrs[level] = keyno;
1783                 }
1784         }
1785
1786         /* Done with the search. See if we need to adjust the results. */
1787         if (dir != XFS_LOOKUP_LE && diff < 0) {
1788                 keyno++;
1789                 /*
1790                  * If ge search and we went off the end of the block, but it's
1791                  * not the last block, we're in the wrong block.
1792                  */
1793                 xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
1794                 if (dir == XFS_LOOKUP_GE &&
1795                     keyno > xfs_btree_get_numrecs(block) &&
1796                     !xfs_btree_ptr_is_null(cur, &ptr)) {
1797                         int     i;
1798
1799                         cur->bc_ptrs[0] = keyno;
1800                         error = xfs_btree_increment(cur, 0, &i);
1801                         if (error)
1802                                 goto error0;
1803                         XFS_WANT_CORRUPTED_RETURN(i == 1);
1804                         XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1805                         *stat = 1;
1806                         return 0;
1807                 }
1808         } else if (dir == XFS_LOOKUP_LE && diff > 0)
1809                 keyno--;
1810         cur->bc_ptrs[0] = keyno;
1811
1812         /* Return if we succeeded or not. */
1813         if (keyno == 0 || keyno > xfs_btree_get_numrecs(block))
1814                 *stat = 0;
1815         else if (dir != XFS_LOOKUP_EQ || diff == 0)
1816                 *stat = 1;
1817         else
1818                 *stat = 0;
1819         XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1820         return 0;
1821
1822 error0:
1823         XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1824         return error;
1825 }
1826
1827 /*
1828  * Update keys at all levels from here to the root along the cursor's path.
1829  */
1830 int
1831 xfs_btree_updkey(
1832         struct xfs_btree_cur    *cur,
1833         union xfs_btree_key     *keyp,
1834         int                     level)
1835 {
1836         struct xfs_btree_block  *block;
1837         struct xfs_buf          *bp;
1838         union xfs_btree_key     *kp;
1839         int                     ptr;
1840
1841         XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1842         XFS_BTREE_TRACE_ARGIK(cur, level, keyp);
1843
1844         ASSERT(!(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) || level >= 1);
1845
1846         /*
1847          * Go up the tree from this level toward the root.
1848          * At each level, update the key value to the value input.
1849          * Stop when we reach a level where the cursor isn't pointing
1850          * at the first entry in the block.
1851          */
1852         for (ptr = 1; ptr == 1 && level < cur->bc_nlevels; level++) {
1853 #ifdef DEBUG
1854                 int             error;
1855 #endif
1856                 block = xfs_btree_get_block(cur, level, &bp);
1857 #ifdef DEBUG
1858                 error = xfs_btree_check_block(cur, block, level, bp);
1859                 if (error) {
1860                         XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1861                         return error;
1862                 }
1863 #endif
1864                 ptr = cur->bc_ptrs[level];
1865                 kp = xfs_btree_key_addr(cur, ptr, block);
1866                 xfs_btree_copy_keys(cur, kp, keyp, 1);
1867                 xfs_btree_log_keys(cur, bp, ptr, ptr);
1868         }
1869
1870         XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1871         return 0;
1872 }
1873
1874 /*
1875  * Update the record referred to by cur to the value in the
1876  * given record. This either works (return 0) or gets an
1877  * EFSCORRUPTED error.
1878  */
1879 int
1880 xfs_btree_update(
1881         struct xfs_btree_cur    *cur,
1882         union xfs_btree_rec     *rec)
1883 {
1884         struct xfs_btree_block  *block;
1885         struct xfs_buf          *bp;
1886         int                     error;
1887         int                     ptr;
1888         union xfs_btree_rec     *rp;
1889
1890         XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1891         XFS_BTREE_TRACE_ARGR(cur, rec);
1892
1893         /* Pick up the current block. */
1894         block = xfs_btree_get_block(cur, 0, &bp);
1895
1896 #ifdef DEBUG
1897         error = xfs_btree_check_block(cur, block, 0, bp);
1898         if (error)
1899                 goto error0;
1900 #endif
1901         /* Get the address of the rec to be updated. */
1902         ptr = cur->bc_ptrs[0];
1903         rp = xfs_btree_rec_addr(cur, ptr, block);
1904
1905         /* Fill in the new contents and log them. */
1906         xfs_btree_copy_recs(cur, rp, rec, 1);
1907         xfs_btree_log_recs(cur, bp, ptr, ptr);
1908
1909         /*
1910          * If we are tracking the last record in the tree and
1911          * we are at the far right edge of the tree, update it.
1912          */
1913         if (xfs_btree_is_lastrec(cur, block, 0)) {
1914                 cur->bc_ops->update_lastrec(cur, block, rec,
1915                                             ptr, LASTREC_UPDATE);
1916         }
1917
1918         /* Updating first rec in leaf. Pass new key value up to our parent. */
1919         if (ptr == 1) {
1920                 union xfs_btree_key     key;
1921
1922                 cur->bc_ops->init_key_from_rec(&key, rec);
1923                 error = xfs_btree_updkey(cur, &key, 1);
1924                 if (error)
1925                         goto error0;
1926         }
1927
1928         XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1929         return 0;
1930
1931 error0:
1932         XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1933         return error;
1934 }
1935
1936 /*
1937  * Move 1 record left from cur/level if possible.
1938  * Update cur to reflect the new path.
1939  */
1940 int                                     /* error */
1941 xfs_btree_lshift(
1942         struct xfs_btree_cur    *cur,
1943         int                     level,
1944         int                     *stat)          /* success/failure */
1945 {
1946         union xfs_btree_key     key;            /* btree key */
1947         struct xfs_buf          *lbp;           /* left buffer pointer */
1948         struct xfs_btree_block  *left;          /* left btree block */
1949         int                     lrecs;          /* left record count */
1950         struct xfs_buf          *rbp;           /* right buffer pointer */
1951         struct xfs_btree_block  *right;         /* right btree block */
1952         int                     rrecs;          /* right record count */
1953         union xfs_btree_ptr     lptr;           /* left btree pointer */
1954         union xfs_btree_key     *rkp = NULL;    /* right btree key */
1955         union xfs_btree_ptr     *rpp = NULL;    /* right address pointer */
1956         union xfs_btree_rec     *rrp = NULL;    /* right record pointer */
1957         int                     error;          /* error return value */
1958
1959         XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1960         XFS_BTREE_TRACE_ARGI(cur, level);
1961
1962         if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
1963             level == cur->bc_nlevels - 1)
1964                 goto out0;
1965
1966         /* Set up variables for this block as "right". */
1967         right = xfs_btree_get_block(cur, level, &rbp);
1968
1969 #ifdef DEBUG
1970         error = xfs_btree_check_block(cur, right, level, rbp);
1971         if (error)
1972                 goto error0;
1973 #endif
1974
1975         /* If we've got no left sibling then we can't shift an entry left. */
1976         xfs_btree_get_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
1977         if (xfs_btree_ptr_is_null(cur, &lptr))
1978                 goto out0;
1979
1980         /*
1981          * If the cursor entry is the one that would be moved, don't
1982          * do it... it's too complicated.
1983          */
1984         if (cur->bc_ptrs[level] <= 1)
1985                 goto out0;
1986
1987         /* Set up the left neighbor as "left". */
1988         error = xfs_btree_read_buf_block(cur, &lptr, level, 0, &left, &lbp);
1989         if (error)
1990                 goto error0;
1991
1992         /* If it's full, it can't take another entry. */
1993         lrecs = xfs_btree_get_numrecs(left);
1994         if (lrecs == cur->bc_ops->get_maxrecs(cur, level))
1995                 goto out0;
1996
1997         rrecs = xfs_btree_get_numrecs(right);
1998
1999         /*
2000          * We add one entry to the left side and remove one for the right side.
2001          * Accout for it here, the changes will be updated on disk and logged
2002          * later.
2003          */
2004         lrecs++;
2005         rrecs--;
2006
2007         XFS_BTREE_STATS_INC(cur, lshift);
2008         XFS_BTREE_STATS_ADD(cur, moves, 1);
2009
2010         /*
2011          * If non-leaf, copy a key and a ptr to the left block.
2012          * Log the changes to the left block.
2013          */
2014         if (level > 0) {
2015                 /* It's a non-leaf.  Move keys and pointers. */
2016                 union xfs_btree_key     *lkp;   /* left btree key */
2017                 union xfs_btree_ptr     *lpp;   /* left address pointer */
2018
2019                 lkp = xfs_btree_key_addr(cur, lrecs, left);
2020                 rkp = xfs_btree_key_addr(cur, 1, right);
2021
2022                 lpp = xfs_btree_ptr_addr(cur, lrecs, left);
2023                 rpp = xfs_btree_ptr_addr(cur, 1, right);
2024 #ifdef DEBUG
2025                 error = xfs_btree_check_ptr(cur, rpp, 0, level);
2026                 if (error)
2027                         goto error0;
2028 #endif
2029                 xfs_btree_copy_keys(cur, lkp, rkp, 1);
2030                 xfs_btree_copy_ptrs(cur, lpp, rpp, 1);
2031
2032                 xfs_btree_log_keys(cur, lbp, lrecs, lrecs);
2033                 xfs_btree_log_ptrs(cur, lbp, lrecs, lrecs);
2034
2035                 xfs_btree_check_key(cur->bc_btnum,
2036                                     xfs_btree_key_addr(cur, lrecs - 1, left),
2037                                     lkp);
2038         } else {
2039                 /* It's a leaf.  Move records.  */
2040                 union xfs_btree_rec     *lrp;   /* left record pointer */
2041
2042                 lrp = xfs_btree_rec_addr(cur, lrecs, left);
2043                 rrp = xfs_btree_rec_addr(cur, 1, right);
2044
2045                 xfs_btree_copy_recs(cur, lrp, rrp, 1);
2046                 xfs_btree_log_recs(cur, lbp, lrecs, lrecs);
2047
2048                 xfs_btree_check_rec(cur->bc_btnum,
2049                                     xfs_btree_rec_addr(cur, lrecs - 1, left),
2050                                     lrp);
2051         }
2052
2053         xfs_btree_set_numrecs(left, lrecs);
2054         xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS);
2055
2056         xfs_btree_set_numrecs(right, rrecs);
2057         xfs_btree_log_block(cur, rbp, XFS_BB_NUMRECS);
2058
2059         /*
2060          * Slide the contents of right down one entry.
2061          */
2062         XFS_BTREE_STATS_ADD(cur, moves, rrecs - 1);
2063         if (level > 0) {
2064                 /* It's a nonleaf. operate on keys and ptrs */
2065 #ifdef DEBUG
2066                 int                     i;              /* loop index */
2067
2068                 for (i = 0; i < rrecs; i++) {
2069                         error = xfs_btree_check_ptr(cur, rpp, i + 1, level);
2070                         if (error)
2071                                 goto error0;
2072                 }
2073 #endif
2074                 xfs_btree_shift_keys(cur,
2075                                 xfs_btree_key_addr(cur, 2, right),
2076                                 -1, rrecs);
2077                 xfs_btree_shift_ptrs(cur,
2078                                 xfs_btree_ptr_addr(cur, 2, right),
2079                                 -1, rrecs);
2080
2081                 xfs_btree_log_keys(cur, rbp, 1, rrecs);
2082                 xfs_btree_log_ptrs(cur, rbp, 1, rrecs);
2083         } else {
2084                 /* It's a leaf. operate on records */
2085                 xfs_btree_shift_recs(cur,
2086                         xfs_btree_rec_addr(cur, 2, right),
2087                         -1, rrecs);
2088                 xfs_btree_log_recs(cur, rbp, 1, rrecs);
2089
2090                 /*
2091                  * If it's the first record in the block, we'll need a key
2092                  * structure to pass up to the next level (updkey).
2093                  */
2094                 cur->bc_ops->init_key_from_rec(&key,
2095                         xfs_btree_rec_addr(cur, 1, right));
2096                 rkp = &key;
2097         }
2098
2099         /* Update the parent key values of right. */
2100         error = xfs_btree_updkey(cur, rkp, level + 1);
2101         if (error)
2102                 goto error0;
2103
2104         /* Slide the cursor value left one. */
2105         cur->bc_ptrs[level]--;
2106
2107         XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2108         *stat = 1;
2109         return 0;
2110
2111 out0:
2112         XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2113         *stat = 0;
2114         return 0;
2115
2116 error0:
2117         XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2118         return error;
2119 }
2120
2121 /*
2122  * Move 1 record right from cur/level if possible.
2123  * Update cur to reflect the new path.
2124  */
2125 int                                     /* error */
2126 xfs_btree_rshift(
2127         struct xfs_btree_cur    *cur,
2128         int                     level,
2129         int                     *stat)          /* success/failure */
2130 {
2131         union xfs_btree_key     key;            /* btree key */
2132         struct xfs_buf          *lbp;           /* left buffer pointer */
2133         struct xfs_btree_block  *left;          /* left btree block */
2134         struct xfs_buf          *rbp;           /* right buffer pointer */
2135         struct xfs_btree_block  *right;         /* right btree block */
2136         struct xfs_btree_cur    *tcur;          /* temporary btree cursor */
2137         union xfs_btree_ptr     rptr;           /* right block pointer */
2138         union xfs_btree_key     *rkp;           /* right btree key */
2139         int                     rrecs;          /* right record count */
2140         int                     lrecs;          /* left record count */
2141         int                     error;          /* error return value */
2142         int                     i;              /* loop counter */
2143
2144         XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2145         XFS_BTREE_TRACE_ARGI(cur, level);
2146
2147         if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
2148             (level == cur->bc_nlevels - 1))
2149                 goto out0;
2150
2151         /* Set up variables for this block as "left". */
2152         left = xfs_btree_get_block(cur, level, &lbp);
2153
2154 #ifdef DEBUG
2155         error = xfs_btree_check_block(cur, left, level, lbp);
2156         if (error)
2157                 goto error0;
2158 #endif
2159
2160         /* If we've got no right sibling then we can't shift an entry right. */
2161         xfs_btree_get_sibling(cur, left, &rptr, XFS_BB_RIGHTSIB);
2162         if (xfs_btree_ptr_is_null(cur, &rptr))
2163                 goto out0;
2164
2165         /*
2166          * If the cursor entry is the one that would be moved, don't
2167          * do it... it's too complicated.
2168          */
2169         lrecs = xfs_btree_get_numrecs(left);
2170         if (cur->bc_ptrs[level] >= lrecs)
2171                 goto out0;
2172
2173         /* Set up the right neighbor as "right". */
2174         error = xfs_btree_read_buf_block(cur, &rptr, level, 0, &right, &rbp);
2175         if (error)
2176                 goto error0;
2177
2178         /* If it's full, it can't take another entry. */
2179         rrecs = xfs_btree_get_numrecs(right);
2180         if (rrecs == cur->bc_ops->get_maxrecs(cur, level))
2181                 goto out0;
2182
2183         XFS_BTREE_STATS_INC(cur, rshift);
2184         XFS_BTREE_STATS_ADD(cur, moves, rrecs);
2185
2186         /*
2187          * Make a hole at the start of the right neighbor block, then
2188          * copy the last left block entry to the hole.
2189          */
2190         if (level > 0) {
2191                 /* It's a nonleaf. make a hole in the keys and ptrs */
2192                 union xfs_btree_key     *lkp;
2193                 union xfs_btree_ptr     *lpp;
2194                 union xfs_btree_ptr     *rpp;
2195
2196                 lkp = xfs_btree_key_addr(cur, lrecs, left);
2197                 lpp = xfs_btree_ptr_addr(cur, lrecs, left);
2198                 rkp = xfs_btree_key_addr(cur, 1, right);
2199                 rpp = xfs_btree_ptr_addr(cur, 1, right);
2200
2201 #ifdef DEBUG
2202                 for (i = rrecs - 1; i >= 0; i--) {
2203                         error = xfs_btree_check_ptr(cur, rpp, i, level);
2204                         if (error)
2205                                 goto error0;
2206                 }
2207 #endif
2208
2209                 xfs_btree_shift_keys(cur, rkp, 1, rrecs);
2210                 xfs_btree_shift_ptrs(cur, rpp, 1, rrecs);
2211
2212 #ifdef DEBUG
2213                 error = xfs_btree_check_ptr(cur, lpp, 0, level);
2214                 if (error)
2215                         goto error0;
2216 #endif
2217
2218                 /* Now put the new data in, and log it. */
2219                 xfs_btree_copy_keys(cur, rkp, lkp, 1);
2220                 xfs_btree_copy_ptrs(cur, rpp, lpp, 1);
2221
2222                 xfs_btree_log_keys(cur, rbp, 1, rrecs + 1);
2223                 xfs_btree_log_ptrs(cur, rbp, 1, rrecs + 1);
2224
2225                 xfs_btree_check_key(cur->bc_btnum, rkp,
2226                                     xfs_btree_key_addr(cur, 2, right));
2227         } else {
2228                 /* It's a leaf. make a hole in the records */
2229                 union xfs_btree_rec     *lrp;
2230                 union xfs_btree_rec     *rrp;
2231
2232                 lrp = xfs_btree_rec_addr(cur, lrecs, left);
2233                 rrp = xfs_btree_rec_addr(cur, 1, right);
2234
2235                 xfs_btree_shift_recs(cur, rrp, 1, rrecs);
2236
2237                 /* Now put the new data in, and log it. */
2238                 xfs_btree_copy_recs(cur, rrp, lrp, 1);
2239                 xfs_btree_log_recs(cur, rbp, 1, rrecs + 1);
2240
2241                 cur->bc_ops->init_key_from_rec(&key, rrp);
2242                 rkp = &key;
2243
2244                 xfs_btree_check_rec(cur->bc_btnum, rrp,
2245                                     xfs_btree_rec_addr(cur, 2, right));
2246         }
2247
2248         /*
2249          * Decrement and log left's numrecs, bump and log right's numrecs.
2250          */
2251         xfs_btree_set_numrecs(left, --lrecs);
2252         xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS);
2253
2254         xfs_btree_set_numrecs(right, ++rrecs);
2255         xfs_btree_log_block(cur, rbp, XFS_BB_NUMRECS);
2256
2257         /*
2258          * Using a temporary cursor, update the parent key values of the
2259          * block on the right.
2260          */
2261         error = xfs_btree_dup_cursor(cur, &tcur);
2262         if (error)
2263                 goto error0;
2264         i = xfs_btree_lastrec(tcur, level);
2265         XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
2266
2267         error = xfs_btree_increment(tcur, level, &i);
2268         if (error)
2269                 goto error1;
2270
2271         error = xfs_btree_updkey(tcur, rkp, level + 1);
2272         if (error)
2273                 goto error1;
2274
2275         xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
2276
2277         XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2278         *stat = 1;
2279         return 0;
2280
2281 out0:
2282         XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2283         *stat = 0;
2284         return 0;
2285
2286 error0:
2287         XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2288         return error;
2289
2290 error1:
2291         XFS_BTREE_TRACE_CURSOR(tcur, XBT_ERROR);
2292         xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR);
2293         return error;
2294 }
2295
2296 /*
2297  * Split cur/level block in half.
2298  * Return new block number and the key to its first
2299  * record (to be inserted into parent).
2300  */
2301 int                                             /* error */
2302 xfs_btree_split(
2303         struct xfs_btree_cur    *cur,
2304         int                     level,
2305         union xfs_btree_ptr     *ptrp,
2306         union xfs_btree_key     *key,
2307         struct xfs_btree_cur    **curp,
2308         int                     *stat)          /* success/failure */
2309 {
2310         union xfs_btree_ptr     lptr;           /* left sibling block ptr */
2311         struct xfs_buf          *lbp;           /* left buffer pointer */
2312         struct xfs_btree_block  *left;          /* left btree block */
2313         union xfs_btree_ptr     rptr;           /* right sibling block ptr */
2314         struct xfs_buf          *rbp;           /* right buffer pointer */
2315         struct xfs_btree_block  *right;         /* right btree block */
2316         union xfs_btree_ptr     rrptr;          /* right-right sibling ptr */
2317         struct xfs_buf          *rrbp;          /* right-right buffer pointer */
2318         struct xfs_btree_block  *rrblock;       /* right-right btree block */
2319         int                     lrecs;
2320         int                     rrecs;
2321         int                     src_index;
2322         int                     error;          /* error return value */
2323 #ifdef DEBUG
2324         int                     i;
2325 #endif
2326
2327         XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2328         XFS_BTREE_TRACE_ARGIPK(cur, level, *ptrp, key);
2329
2330         XFS_BTREE_STATS_INC(cur, split);
2331
2332         /* Set up left block (current one). */
2333         left = xfs_btree_get_block(cur, level, &lbp);
2334
2335 #ifdef DEBUG
2336         error = xfs_btree_check_block(cur, left, level, lbp);
2337         if (error)
2338                 goto error0;
2339 #endif
2340
2341         xfs_btree_buf_to_ptr(cur, lbp, &lptr);
2342
2343         /* Allocate the new block. If we can't do it, we're toast. Give up. */
2344         error = cur->bc_ops->alloc_block(cur, &lptr, &rptr, 1, stat);
2345         if (error)
2346                 goto error0;
2347         if (*stat == 0)
2348                 goto out0;
2349         XFS_BTREE_STATS_INC(cur, alloc);
2350
2351         /* Set up the new block as "right". */
2352         error = xfs_btree_get_buf_block(cur, &rptr, 0, &right, &rbp);
2353         if (error)
2354                 goto error0;
2355
2356         /* Fill in the btree header for the new right block. */
2357         xfs_btree_init_block(cur, xfs_btree_get_level(left), 0, right);
2358
2359         /*
2360          * Split the entries between the old and the new block evenly.
2361          * Make sure that if there's an odd number of entries now, that
2362          * each new block will have the same number of entries.
2363          */
2364         lrecs = xfs_btree_get_numrecs(left);
2365         rrecs = lrecs / 2;
2366         if ((lrecs & 1) && cur->bc_ptrs[level] <= rrecs + 1)
2367                 rrecs++;
2368         src_index = (lrecs - rrecs + 1);
2369
2370         XFS_BTREE_STATS_ADD(cur, moves, rrecs);
2371
2372         /*
2373          * Copy btree block entries from the left block over to the
2374          * new block, the right. Update the right block and log the
2375          * changes.
2376          */
2377         if (level > 0) {
2378                 /* It's a non-leaf.  Move keys and pointers. */
2379                 union xfs_btree_key     *lkp;   /* left btree key */
2380                 union xfs_btree_ptr     *lpp;   /* left address pointer */
2381                 union xfs_btree_key     *rkp;   /* right btree key */
2382                 union xfs_btree_ptr     *rpp;   /* right address pointer */
2383
2384                 lkp = xfs_btree_key_addr(cur, src_index, left);
2385                 lpp = xfs_btree_ptr_addr(cur, src_index, left);
2386                 rkp = xfs_btree_key_addr(cur, 1, right);
2387                 rpp = xfs_btree_ptr_addr(cur, 1, right);
2388
2389 #ifdef DEBUG
2390                 for (i = src_index; i < rrecs; i++) {
2391                         error = xfs_btree_check_ptr(cur, lpp, i, level);
2392                         if (error)
2393                                 goto error0;
2394                 }
2395 #endif
2396
2397                 xfs_btree_copy_keys(cur, rkp, lkp, rrecs);
2398                 xfs_btree_copy_ptrs(cur, rpp, lpp, rrecs);
2399
2400                 xfs_btree_log_keys(cur, rbp, 1, rrecs);
2401                 xfs_btree_log_ptrs(cur, rbp, 1, rrecs);
2402
2403                 /* Grab the keys to the entries moved to the right block */
2404                 xfs_btree_copy_keys(cur, key, rkp, 1);
2405         } else {
2406                 /* It's a leaf.  Move records.  */
2407                 union xfs_btree_rec     *lrp;   /* left record pointer */
2408                 union xfs_btree_rec     *rrp;   /* right record pointer */
2409
2410                 lrp = xfs_btree_rec_addr(cur, src_index, left);
2411                 rrp = xfs_btree_rec_addr(cur, 1, right);
2412
2413                 xfs_btree_copy_recs(cur, rrp, lrp, rrecs);
2414                 xfs_btree_log_recs(cur, rbp, 1, rrecs);
2415
2416                 cur->bc_ops->init_key_from_rec(key,
2417                         xfs_btree_rec_addr(cur, 1, right));
2418         }
2419
2420
2421         /*
2422          * Find the left block number by looking in the buffer.
2423          * Adjust numrecs, sibling pointers.
2424          */
2425         xfs_btree_get_sibling(cur, left, &rrptr, XFS_BB_RIGHTSIB);
2426         xfs_btree_set_sibling(cur, right, &rrptr, XFS_BB_RIGHTSIB);
2427         xfs_btree_set_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
2428         xfs_btree_set_sibling(cur, left, &rptr, XFS_BB_RIGHTSIB);
2429
2430         lrecs -= rrecs;
2431         xfs_btree_set_numrecs(left, lrecs);
2432         xfs_btree_set_numrecs(right, xfs_btree_get_numrecs(right) + rrecs);
2433
2434         xfs_btree_log_block(cur, rbp, XFS_BB_ALL_BITS);
2435         xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS | XFS_BB_RIGHTSIB);
2436
2437         /*
2438          * If there's a block to the new block's right, make that block
2439          * point back to right instead of to left.
2440          */
2441         if (!xfs_btree_ptr_is_null(cur, &rrptr)) {
2442                 error = xfs_btree_read_buf_block(cur, &rrptr, level,
2443                                                         0, &rrblock, &rrbp);
2444                 if (error)
2445                         goto error0;
2446                 xfs_btree_set_sibling(cur, rrblock, &rptr, XFS_BB_LEFTSIB);
2447                 xfs_btree_log_block(cur, rrbp, XFS_BB_LEFTSIB);
2448         }
2449         /*
2450          * If the cursor is really in the right block, move it there.
2451          * If it's just pointing past the last entry in left, then we'll
2452          * insert there, so don't change anything in that case.
2453          */
2454         if (cur->bc_ptrs[level] > lrecs + 1) {
2455                 xfs_btree_setbuf(cur, level, rbp);
2456                 cur->bc_ptrs[level] -= lrecs;
2457         }
2458         /*
2459          * If there are more levels, we'll need another cursor which refers
2460          * the right block, no matter where this cursor was.
2461          */
2462         if (level + 1 < cur->bc_nlevels) {
2463                 error = xfs_btree_dup_cursor(cur, curp);
2464                 if (error)
2465                         goto error0;
2466                 (*curp)->bc_ptrs[level + 1]++;
2467         }
2468         *ptrp = rptr;
2469         XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2470         *stat = 1;
2471         return 0;
2472 out0:
2473         XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2474         *stat = 0;
2475         return 0;
2476
2477 error0:
2478         XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2479         return error;
2480 }
2481
2482 /*
2483  * Copy the old inode root contents into a real block and make the
2484  * broot point to it.
2485  */
2486 int                                             /* error */
2487 xfs_btree_new_iroot(
2488         struct xfs_btree_cur    *cur,           /* btree cursor */
2489         int                     *logflags,      /* logging flags for inode */
2490         int                     *stat)          /* return status - 0 fail */
2491 {
2492         struct xfs_buf          *cbp;           /* buffer for cblock */
2493         struct xfs_btree_block  *block;         /* btree block */
2494         struct xfs_btree_block  *cblock;        /* child btree block */
2495         union xfs_btree_key     *ckp;           /* child key pointer */
2496         union xfs_btree_ptr     *cpp;           /* child ptr pointer */
2497         union xfs_btree_key     *kp;            /* pointer to btree key */
2498         union xfs_btree_ptr     *pp;            /* pointer to block addr */
2499         union xfs_btree_ptr     nptr;           /* new block addr */
2500         int                     level;          /* btree level */
2501         int                     error;          /* error return code */
2502 #ifdef DEBUG
2503         int                     i;              /* loop counter */
2504 #endif
2505
2506         XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2507         XFS_BTREE_STATS_INC(cur, newroot);
2508
2509         ASSERT(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE);
2510
2511         level = cur->bc_nlevels - 1;
2512
2513         block = xfs_btree_get_iroot(cur);
2514         pp = xfs_btree_ptr_addr(cur, 1, block);
2515
2516         /* Allocate the new block. If we can't do it, we're toast. Give up. */
2517         error = cur->bc_ops->alloc_block(cur, pp, &nptr, 1, stat);
2518         if (error)
2519                 goto error0;
2520         if (*stat == 0) {
2521                 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2522                 return 0;
2523         }
2524         XFS_BTREE_STATS_INC(cur, alloc);
2525
2526         /* Copy the root into a real block. */
2527         error = xfs_btree_get_buf_block(cur, &nptr, 0, &cblock, &cbp);
2528         if (error)
2529                 goto error0;
2530
2531         memcpy(cblock, block, xfs_btree_block_len(cur));
2532
2533         be16_add_cpu(&block->bb_level, 1);
2534         xfs_btree_set_numrecs(block, 1);
2535         cur->bc_nlevels++;
2536         cur->bc_ptrs[level + 1] = 1;
2537
2538         kp = xfs_btree_key_addr(cur, 1, block);
2539         ckp = xfs_btree_key_addr(cur, 1, cblock);
2540         xfs_btree_copy_keys(cur, ckp, kp, xfs_btree_get_numrecs(cblock));
2541
2542         cpp = xfs_btree_ptr_addr(cur, 1, cblock);
2543 #ifdef DEBUG
2544         for (i = 0; i < be16_to_cpu(cblock->bb_numrecs); i++) {
2545                 error = xfs_btree_check_ptr(cur, pp, i, level);
2546                 if (error)
2547                         goto error0;
2548         }
2549 #endif
2550         xfs_btree_copy_ptrs(cur, cpp, pp, xfs_btree_get_numrecs(cblock));
2551
2552 #ifdef DEBUG
2553         error = xfs_btree_check_ptr(cur, &nptr, 0, level);
2554         if (error)
2555                 goto error0;
2556 #endif
2557         xfs_btree_copy_ptrs(cur, pp, &nptr, 1);
2558
2559         xfs_iroot_realloc(cur->bc_private.b.ip,
2560                           1 - xfs_btree_get_numrecs(cblock),
2561                           cur->bc_private.b.whichfork);
2562
2563         xfs_btree_setbuf(cur, level, cbp);
2564
2565         /*
2566          * Do all this logging at the end so that
2567          * the root is at the right level.
2568          */
2569         xfs_btree_log_block(cur, cbp, XFS_BB_ALL_BITS);
2570         xfs_btree_log_keys(cur, cbp, 1, be16_to_cpu(cblock->bb_numrecs));
2571         xfs_btree_log_ptrs(cur, cbp, 1, be16_to_cpu(cblock->bb_numrecs));
2572
2573         *logflags |=
2574                 XFS_ILOG_CORE | XFS_ILOG_FBROOT(cur->bc_private.b.whichfork);
2575         *stat = 1;
2576         XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2577         return 0;
2578 error0:
2579         XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2580         return error;
2581 }
2582
2583 /*
2584  * Allocate a new root block, fill it in.
2585  */
2586 int                             /* error */
2587 xfs_btree_new_root(
2588         struct xfs_btree_cur    *cur,   /* btree cursor */
2589         int                     *stat)  /* success/failure */
2590 {
2591         struct xfs_btree_block  *block; /* one half of the old root block */
2592         struct xfs_buf          *bp;    /* buffer containing block */
2593         int                     error;  /* error return value */
2594         struct xfs_buf          *lbp;   /* left buffer pointer */
2595         struct xfs_btree_block  *left;  /* left btree block */
2596         struct xfs_buf          *nbp;   /* new (root) buffer */
2597         struct xfs_btree_block  *new;   /* new (root) btree block */
2598         int                     nptr;   /* new value for key index, 1 or 2 */
2599         struct xfs_buf          *rbp;   /* right buffer pointer */
2600         struct xfs_btree_block  *right; /* right btree block */
2601         union xfs_btree_ptr     rptr;
2602         union xfs_btree_ptr     lptr;
2603
2604         XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2605         XFS_BTREE_STATS_INC(cur, newroot);
2606
2607         /* initialise our start point from the cursor */
2608         cur->bc_ops->init_ptr_from_cur(cur, &rptr);
2609
2610         /* Allocate the new block. If we can't do it, we're toast. Give up. */
2611         error = cur->bc_ops->alloc_block(cur, &rptr, &lptr, 1, stat);
2612         if (error)
2613                 goto error0;
2614         if (*stat == 0)
2615                 goto out0;
2616         XFS_BTREE_STATS_INC(cur, alloc);
2617
2618         /* Set up the new block. */
2619         error = xfs_btree_get_buf_block(cur, &lptr, 0, &new, &nbp);
2620         if (error)
2621                 goto error0;
2622
2623         /* Set the root in the holding structure  increasing the level by 1. */
2624         cur->bc_ops->set_root(cur, &lptr, 1);
2625
2626         /*
2627          * At the previous root level there are now two blocks: the old root,
2628          * and the new block generated when it was split.  We don't know which
2629          * one the cursor is pointing at, so we set up variables "left" and
2630          * "right" for each case.
2631          */
2632         block = xfs_btree_get_block(cur, cur->bc_nlevels - 1, &bp);
2633
2634 #ifdef DEBUG
2635         error = xfs_btree_check_block(cur, block, cur->bc_nlevels - 1, bp);
2636         if (error)
2637                 goto error0;
2638 #endif
2639
2640         xfs_btree_get_sibling(cur, block, &rptr, XFS_BB_RIGHTSIB);
2641         if (!xfs_btree_ptr_is_null(cur, &rptr)) {
2642                 /* Our block is left, pick up the right block. */
2643                 lbp = bp;
2644                 xfs_btree_buf_to_ptr(cur, lbp, &lptr);
2645                 left = block;
2646                 error = xfs_btree_read_buf_block(cur, &rptr,
2647                                         cur->bc_nlevels - 1, 0, &right, &rbp);
2648                 if (error)
2649                         goto error0;
2650                 bp = rbp;
2651                 nptr = 1;
2652         } else {
2653                 /* Our block is right, pick up the left block. */
2654                 rbp = bp;
2655                 xfs_btree_buf_to_ptr(cur, rbp, &rptr);
2656                 right = block;
2657                 xfs_btree_get_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
2658                 error = xfs_btree_read_buf_block(cur, &lptr,
2659                                         cur->bc_nlevels - 1, 0, &left, &lbp);
2660                 if (error)
2661                         goto error0;
2662                 bp = lbp;
2663                 nptr = 2;
2664         }
2665         /* Fill in the new block's btree header and log it. */
2666         xfs_btree_init_block(cur, cur->bc_nlevels, 2, new);
2667         xfs_btree_log_block(cur, nbp, XFS_BB_ALL_BITS);
2668         ASSERT(!xfs_btree_ptr_is_null(cur, &lptr) &&
2669                         !xfs_btree_ptr_is_null(cur, &rptr));
2670
2671         /* Fill in the key data in the new root. */
2672         if (xfs_btree_get_level(left) > 0) {
2673                 xfs_btree_copy_keys(cur,
2674                                 xfs_btree_key_addr(cur, 1, new),
2675                                 xfs_btree_key_addr(cur, 1, left), 1);
2676                 xfs_btree_copy_keys(cur,
2677                                 xfs_btree_key_addr(cur, 2, new),
2678                                 xfs_btree_key_addr(cur, 1, right), 1);
2679         } else {
2680                 cur->bc_ops->init_key_from_rec(
2681                                 xfs_btree_key_addr(cur, 1, new),
2682                                 xfs_btree_rec_addr(cur, 1, left));
2683                 cur->bc_ops->init_key_from_rec(
2684                                 xfs_btree_key_addr(cur, 2, new),
2685                                 xfs_btree_rec_addr(cur, 1, right));
2686         }
2687         xfs_btree_log_keys(cur, nbp, 1, 2);
2688
2689         /* Fill in the pointer data in the new root. */
2690         xfs_btree_copy_ptrs(cur,
2691                 xfs_btree_ptr_addr(cur, 1, new), &lptr, 1);
2692         xfs_btree_copy_ptrs(cur,
2693                 xfs_btree_ptr_addr(cur, 2, new), &rptr, 1);
2694         xfs_btree_log_ptrs(cur, nbp, 1, 2);
2695
2696         /* Fix up the cursor. */
2697         xfs_btree_setbuf(cur, cur->bc_nlevels, nbp);
2698         cur->bc_ptrs[cur->bc_nlevels] = nptr;
2699         cur->bc_nlevels++;
2700         XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2701         *stat = 1;
2702         return 0;
2703 error0:
2704         XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2705         return error;
2706 out0:
2707         XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2708         *stat = 0;
2709         return 0;
2710 }
2711
2712 STATIC int
2713 xfs_btree_make_block_unfull(
2714         struct xfs_btree_cur    *cur,   /* btree cursor */
2715         int                     level,  /* btree level */
2716         int                     numrecs,/* # of recs in block */
2717         int                     *oindex,/* old tree index */
2718         int                     *index, /* new tree index */
2719         union xfs_btree_ptr     *nptr,  /* new btree ptr */
2720         struct xfs_btree_cur    **ncur, /* new btree cursor */
2721         union xfs_btree_rec     *nrec,  /* new record */
2722         int                     *stat)
2723 {
2724         union xfs_btree_key     key;    /* new btree key value */
2725         int                     error = 0;
2726
2727         if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
2728             level == cur->bc_nlevels - 1) {
2729                 struct xfs_inode *ip = cur->bc_private.b.ip;
2730
2731                 if (numrecs < cur->bc_ops->get_dmaxrecs(cur, level)) {
2732                         /* A root block that can be made bigger. */
2733
2734                         xfs_iroot_realloc(ip, 1, cur->bc_private.b.whichfork);
2735                 } else {
2736                         /* A root block that needs replacing */
2737                         int     logflags = 0;
2738
2739                         error = xfs_btree_new_iroot(cur, &logflags, stat);
2740                         if (error || *stat == 0)
2741                                 return error;
2742
2743                         xfs_trans_log_inode(cur->bc_tp, ip, logflags);
2744                 }
2745
2746                 return 0;
2747         }
2748
2749         /* First, try shifting an entry to the right neighbor. */
2750         error = xfs_btree_rshift(cur, level, stat);
2751         if (error || *stat)
2752                 return error;
2753
2754         /* Next, try shifting an entry to the left neighbor. */
2755         error = xfs_btree_lshift(cur, level, stat);
2756         if (error)
2757                 return error;
2758
2759         if (*stat) {
2760                 *oindex = *index = cur->bc_ptrs[level];
2761                 return 0;
2762         }
2763
2764         /*
2765          * Next, try splitting the current block in half.
2766          *
2767          * If this works we have to re-set our variables because we
2768          * could be in a different block now.
2769          */
2770         error = xfs_btree_split(cur, level, nptr, &key, ncur, stat);
2771         if (error || *stat == 0)
2772                 return error;
2773
2774
2775         *index = cur->bc_ptrs[level];
2776         cur->bc_ops->init_rec_from_key(&key, nrec);
2777         return 0;
2778 }
2779
2780 /*
2781  * Insert one record/level.  Return information to the caller
2782  * allowing the next level up to proceed if necessary.
2783  */
2784 STATIC int
2785 xfs_btree_insrec(
2786         struct xfs_btree_cur    *cur,   /* btree cursor */
2787         int                     level,  /* level to insert record at */
2788         union xfs_btree_ptr     *ptrp,  /* i/o: block number inserted */
2789         union xfs_btree_rec     *recp,  /* i/o: record data inserted */
2790         struct xfs_btree_cur    **curp, /* output: new cursor replacing cur */
2791         int                     *stat)  /* success/failure */
2792 {
2793         struct xfs_btree_block  *block; /* btree block */
2794         struct xfs_buf          *bp;    /* buffer for block */
2795         union xfs_btree_key     key;    /* btree key */
2796         union xfs_btree_ptr     nptr;   /* new block ptr */
2797         struct xfs_btree_cur    *ncur;  /* new btree cursor */
2798         union xfs_btree_rec     nrec;   /* new record count */
2799         int                     optr;   /* old key/record index */
2800         int                     ptr;    /* key/record index */
2801         int                     numrecs;/* number of records */
2802         int                     error;  /* error return value */
2803 #ifdef DEBUG
2804         int                     i;
2805 #endif
2806
2807         XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2808         XFS_BTREE_TRACE_ARGIPR(cur, level, *ptrp, recp);
2809
2810         ncur = NULL;
2811
2812         /*
2813          * If we have an external root pointer, and we've made it to the
2814          * root level, allocate a new root block and we're done.
2815          */
2816         if (!(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
2817             (level >= cur->bc_nlevels)) {
2818                 error = xfs_btree_new_root(cur, stat);
2819                 xfs_btree_set_ptr_null(cur, ptrp);
2820
2821                 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2822                 return error;
2823         }
2824
2825         /* If we're off the left edge, return failure. */
2826         ptr = cur->bc_ptrs[level];
2827         if (ptr == 0) {
2828                 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2829                 *stat = 0;
2830                 return 0;
2831         }
2832
2833         /* Make a key out of the record data to be inserted, and save it. */
2834         cur->bc_ops->init_key_from_rec(&key, recp);
2835
2836         optr = ptr;
2837
2838         XFS_BTREE_STATS_INC(cur, insrec);
2839
2840         /* Get pointers to the btree buffer and block. */
2841         block = xfs_btree_get_block(cur, level, &bp);
2842         numrecs = xfs_btree_get_numrecs(block);
2843
2844 #ifdef DEBUG
2845         error = xfs_btree_check_block(cur, block, level, bp);
2846         if (error)
2847                 goto error0;
2848
2849         /* Check that the new entry is being inserted in the right place. */
2850         if (ptr <= numrecs) {
2851                 if (level == 0) {
2852                         xfs_btree_check_rec(cur->bc_btnum, recp,
2853                                         xfs_btree_rec_addr(cur, ptr, block));
2854                 } else {
2855                         xfs_btree_check_key(cur->bc_btnum, &key,
2856                                         xfs_btree_key_addr(cur, ptr, block));
2857                 }
2858         }
2859 #endif
2860
2861         /*
2862          * If the block is full, we can't insert the new entry until we
2863          * make the block un-full.
2864          */
2865         xfs_btree_set_ptr_null(cur, &nptr);
2866         if (numrecs == cur->bc_ops->get_maxrecs(cur, level)) {
2867                 error = xfs_btree_make_block_unfull(cur, level, numrecs,
2868                                         &optr, &ptr, &nptr, &ncur, &nrec, stat);
2869                 if (error || *stat == 0)
2870                         goto error0;
2871         }
2872
2873         /*
2874          * The current block may have changed if the block was
2875          * previously full and we have just made space in it.
2876          */
2877         block = xfs_btree_get_block(cur, level, &bp);
2878         numrecs = xfs_btree_get_numrecs(block);
2879
2880 #ifdef DEBUG
2881         error = xfs_btree_check_block(cur, block, level, bp);
2882         if (error)
2883                 return error;
2884 #endif
2885
2886         /*
2887          * At this point we know there's room for our new entry in the block
2888          * we're pointing at.
2889          */
2890         XFS_BTREE_STATS_ADD(cur, moves, numrecs - ptr + 1);
2891
2892         if (level > 0) {
2893                 /* It's a nonleaf. make a hole in the keys and ptrs */
2894                 union xfs_btree_key     *kp;
2895                 union xfs_btree_ptr     *pp;
2896
2897                 kp = xfs_btree_key_addr(cur, ptr, block);
2898                 pp = xfs_btree_ptr_addr(cur, ptr, block);
2899
2900 #ifdef DEBUG
2901                 for (i = numrecs - ptr; i >= 0; i--) {
2902                         error = xfs_btree_check_ptr(cur, pp, i, level);
2903                         if (error)
2904                                 return error;
2905                 }
2906 #endif
2907
2908                 xfs_btree_shift_keys(cur, kp, 1, numrecs - ptr + 1);
2909                 xfs_btree_shift_ptrs(cur, pp, 1, numrecs - ptr + 1);
2910
2911 #ifdef DEBUG
2912                 error = xfs_btree_check_ptr(cur, ptrp, 0, level);
2913                 if (error)
2914                         goto error0;
2915 #endif
2916
2917                 /* Now put the new data in, bump numrecs and log it. */
2918                 xfs_btree_copy_keys(cur, kp, &key, 1);
2919                 xfs_btree_copy_ptrs(cur, pp, ptrp, 1);
2920                 numrecs++;
2921                 xfs_btree_set_numrecs(block, numrecs);
2922                 xfs_btree_log_ptrs(cur, bp, ptr, numrecs);
2923                 xfs_btree_log_keys(cur, bp, ptr, numrecs);
2924 #ifdef DEBUG
2925                 if (ptr < numrecs) {
2926                         xfs_btree_check_key(cur->bc_btnum, kp,
2927                                 xfs_btree_key_addr(cur, ptr + 1, block));
2928                 }
2929 #endif
2930         } else {
2931                 /* It's a leaf. make a hole in the records */
2932                 union xfs_btree_rec             *rp;
2933
2934                 rp = xfs_btree_rec_addr(cur, ptr, block);
2935
2936                 xfs_btree_shift_recs(cur, rp, 1, numrecs - ptr + 1);
2937
2938                 /* Now put the new data in, bump numrecs and log it. */
2939                 xfs_btree_copy_recs(cur, rp, recp, 1);
2940                 xfs_btree_set_numrecs(block, ++numrecs);
2941                 xfs_btree_log_recs(cur, bp, ptr, numrecs);
2942 #ifdef DEBUG
2943                 if (ptr < numrecs) {
2944                         xfs_btree_check_rec(cur->bc_btnum, rp,
2945                                 xfs_btree_rec_addr(cur, ptr + 1, block));
2946                 }
2947 #endif
2948         }
2949
2950         /* Log the new number of records in the btree header. */
2951         xfs_btree_log_block(cur, bp, XFS_BB_NUMRECS);
2952
2953         /* If we inserted at the start of a block, update the parents' keys. */
2954         if (optr == 1) {
2955                 error = xfs_btree_updkey(cur, &key, level + 1);
2956                 if (error)
2957                         goto error0;
2958         }
2959
2960         /*
2961          * If we are tracking the last record in the tree and
2962          * we are at the far right edge of the tree, update it.
2963          */
2964         if (xfs_btree_is_lastrec(cur, block, level)) {
2965                 cur->bc_ops->update_lastrec(cur, block, recp,
2966                                             ptr, LASTREC_INSREC);
2967         }
2968
2969         /*
2970          * Return the new block number, if any.
2971          * If there is one, give back a record value and a cursor too.
2972          */
2973         *ptrp = nptr;
2974         if (!xfs_btree_ptr_is_null(cur, &nptr)) {
2975                 *recp = nrec;
2976                 *curp = ncur;
2977         }
2978
2979         XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2980         *stat = 1;
2981         return 0;
2982
2983 error0:
2984         XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2985         return error;
2986 }
2987
2988 /*
2989  * Insert the record at the point referenced by cur.
2990  *
2991  * A multi-level split of the tree on insert will invalidate the original
2992  * cursor.  All callers of this function should assume that the cursor is
2993  * no longer valid and revalidate it.
2994  */
2995 int
2996 xfs_btree_insert(
2997         struct xfs_btree_cur    *cur,
2998         int                     *stat)
2999 {
3000         int                     error;  /* error return value */
3001         int                     i;      /* result value, 0 for failure */
3002         int                     level;  /* current level number in btree */
3003         union xfs_btree_ptr     nptr;   /* new block number (split result) */
3004         struct xfs_btree_cur    *ncur;  /* new cursor (split result) */
3005         struct xfs_btree_cur    *pcur;  /* previous level's cursor */
3006         union xfs_btree_rec     rec;    /* record to insert */
3007
3008         level = 0;
3009         ncur = NULL;
3010         pcur = cur;
3011
3012         xfs_btree_set_ptr_null(cur, &nptr);
3013         cur->bc_ops->init_rec_from_cur(cur, &rec);
3014
3015         /*
3016          * Loop going up the tree, starting at the leaf level.
3017          * Stop when we don't get a split block, that must mean that
3018          * the insert is finished with this level.
3019          */
3020         do {
3021                 /*
3022                  * Insert nrec/nptr into this level of the tree.
3023                  * Note if we fail, nptr will be null.
3024                  */
3025                 error = xfs_btree_insrec(pcur, level, &nptr, &rec, &ncur, &i);
3026                 if (error) {
3027                         if (pcur != cur)
3028                                 xfs_btree_del_cursor(pcur, XFS_BTREE_ERROR);
3029                         goto error0;
3030                 }
3031
3032                 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3033                 level++;
3034
3035                 /*
3036                  * See if the cursor we just used is trash.
3037                  * Can't trash the caller's cursor, but otherwise we should
3038                  * if ncur is a new cursor or we're about to be done.
3039                  */
3040                 if (pcur != cur &&
3041                     (ncur || xfs_btree_ptr_is_null(cur, &nptr))) {
3042                         /* Save the state from the cursor before we trash it */
3043                         if (cur->bc_ops->update_cursor)
3044                                 cur->bc_ops->update_cursor(pcur, cur);
3045                         cur->bc_nlevels = pcur->bc_nlevels;
3046                         xfs_btree_del_cursor(pcur, XFS_BTREE_NOERROR);
3047                 }
3048                 /* If we got a new cursor, switch to it. */
3049                 if (ncur) {
3050                         pcur = ncur;
3051                         ncur = NULL;
3052                 }
3053         } while (!xfs_btree_ptr_is_null(cur, &nptr));
3054
3055         XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3056         *stat = i;
3057         return 0;
3058 error0:
3059         XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3060         return error;
3061 }
3062
3063 /*
3064  * Try to merge a non-leaf block back into the inode root.
3065  *
3066  * Note: the killroot names comes from the fact that we're effectively
3067  * killing the old root block.  But because we can't just delete the
3068  * inode we have to copy the single block it was pointing to into the
3069  * inode.
3070  */
3071 int
3072 xfs_btree_kill_iroot(
3073         struct xfs_btree_cur    *cur)
3074 {
3075         int                     whichfork = cur->bc_private.b.whichfork;
3076         struct xfs_inode        *ip = cur->bc_private.b.ip;
3077         struct xfs_ifork        *ifp = XFS_IFORK_PTR(ip, whichfork);
3078         struct xfs_btree_block  *block;
3079         struct xfs_btree_block  *cblock;
3080         union xfs_btree_key     *kp;
3081         union xfs_btree_key     *ckp;
3082         union xfs_btree_ptr     *pp;
3083         union xfs_btree_ptr     *cpp;
3084         struct xfs_buf          *cbp;
3085         int                     level;
3086         int                     index;
3087         int                     numrecs;
3088 #ifdef DEBUG
3089         union xfs_btree_ptr     ptr;
3090         int                     i;
3091 #endif
3092
3093         XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
3094
3095         ASSERT(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE);
3096         ASSERT(cur->bc_nlevels > 1);
3097
3098         /*
3099          * Don't deal with the root block needs to be a leaf case.
3100          * We're just going to turn the thing back into extents anyway.
3101          */
3102         level = cur->bc_nlevels - 1;
3103         if (level == 1)
3104                 goto out0;
3105
3106         /*
3107          * Give up if the root has multiple children.
3108          */
3109         block = xfs_btree_get_iroot(cur);
3110         if (xfs_btree_get_numrecs(block) != 1)
3111                 goto out0;
3112
3113         cblock = xfs_btree_get_block(cur, level - 1, &cbp);
3114         numrecs = xfs_btree_get_numrecs(cblock);
3115
3116         /*
3117          * Only do this if the next level will fit.
3118          * Then the data must be copied up to the inode,
3119          * instead of freeing the root you free the next level.
3120          */
3121         if (numrecs > cur->bc_ops->get_dmaxrecs(cur, level))
3122                 goto out0;
3123
3124         XFS_BTREE_STATS_INC(cur, killroot);
3125
3126 #ifdef DEBUG
3127         xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_LEFTSIB);
3128         ASSERT(xfs_btree_ptr_is_null(cur, &ptr));
3129         xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
3130         ASSERT(xfs_btree_ptr_is_null(cur, &ptr));
3131 #endif
3132
3133         index = numrecs - cur->bc_ops->get_maxrecs(cur, level);
3134         if (index) {
3135                 xfs_iroot_realloc(cur->bc_private.b.ip, index,
3136                                   cur->bc_private.b.whichfork);
3137                 block = (struct xfs_btree_block *)ifp->if_broot;
3138         }
3139
3140         be16_add_cpu(&block->bb_numrecs, index);
3141         ASSERT(block->bb_numrecs == cblock->bb_numrecs);
3142
3143         kp = xfs_btree_key_addr(cur, 1, block);
3144         ckp = xfs_btree_key_addr(cur, 1, cblock);
3145         xfs_btree_copy_keys(cur, kp, ckp, numrecs);
3146
3147         pp = xfs_btree_ptr_addr(cur, 1, block);
3148         cpp = xfs_btree_ptr_addr(cur, 1, cblock);
3149 #ifdef DEBUG
3150         for (i = 0; i < numrecs; i++) {
3151                 int             error;
3152
3153                 error = xfs_btree_check_ptr(cur, cpp, i, level - 1);
3154                 if (error) {
3155                         XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3156                         return error;
3157                 }
3158         }
3159 #endif
3160         xfs_btree_copy_ptrs(cur, pp, cpp, numrecs);
3161
3162         cur->bc_ops->free_block(cur, cbp);
3163         XFS_BTREE_STATS_INC(cur, free);
3164
3165         cur->bc_bufs[level - 1] = NULL;
3166         be16_add_cpu(&block->bb_level, -1);
3167         xfs_trans_log_inode(cur->bc_tp, ip,
3168                 XFS_ILOG_CORE | XFS_ILOG_FBROOT(cur->bc_private.b.whichfork));
3169         cur->bc_nlevels--;
3170 out0:
3171         XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3172         return 0;
3173 }
3174
3175 STATIC int
3176 xfs_btree_dec_cursor(
3177         struct xfs_btree_cur    *cur,
3178         int                     level,
3179         int                     *stat)
3180 {
3181         int                     error;
3182         int                     i;
3183
3184         if (level > 0) {
3185                 error = xfs_btree_decrement(cur, level, &i);
3186                 if (error)
3187                         return error;
3188         }
3189
3190         XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3191         *stat = 1;
3192         return 0;
3193 }
3194
3195 /*
3196  * Single level of the btree record deletion routine.
3197  * Delete record pointed to by cur/level.
3198  * Remove the record from its block then rebalance the tree.
3199  * Return 0 for error, 1 for done, 2 to go on to the next level.
3200  */
3201 STATIC int                                      /* error */
3202 xfs_btree_delrec(
3203         struct xfs_btree_cur    *cur,           /* btree cursor */
3204         int                     level,          /* level removing record from */
3205         int                     *stat)          /* fail/done/go-on */
3206 {
3207         struct xfs_btree_block  *block;         /* btree block */
3208         union xfs_btree_ptr     cptr;           /* current block ptr */
3209         struct xfs_buf          *bp;            /* buffer for block */
3210         int                     error;          /* error return value */
3211         int                     i;              /* loop counter */
3212         union xfs_btree_key     key;            /* storage for keyp */
3213         union xfs_btree_key     *keyp = &key;   /* passed to the next level */
3214         union xfs_btree_ptr     lptr;           /* left sibling block ptr */
3215         struct xfs_buf          *lbp;           /* left buffer pointer */
3216         struct xfs_btree_block  *left;          /* left btree block */
3217         int                     lrecs = 0;      /* left record count */
3218         int                     ptr;            /* key/record index */
3219         union xfs_btree_ptr     rptr;           /* right sibling block ptr */
3220         struct xfs_buf          *rbp;           /* right buffer pointer */
3221         struct xfs_btree_block  *right;         /* right btree block */
3222         struct xfs_btree_block  *rrblock;       /* right-right btree block */
3223         struct xfs_buf          *rrbp;          /* right-right buffer pointer */
3224         int                     rrecs = 0;      /* right record count */
3225         struct xfs_btree_cur    *tcur;          /* temporary btree cursor */
3226         int                     numrecs;        /* temporary numrec count */
3227
3228         XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
3229         XFS_BTREE_TRACE_ARGI(cur, level);
3230
3231         tcur = NULL;
3232
3233         /* Get the index of the entry being deleted, check for nothing there. */
3234         ptr = cur->bc_ptrs[level];
3235         if (ptr == 0) {
3236                 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3237                 *stat = 0;
3238                 return 0;
3239         }
3240
3241         /* Get the buffer & block containing the record or key/ptr. */
3242         block = xfs_btree_get_block(cur, level, &bp);
3243         numrecs = xfs_btree_get_numrecs(block);
3244
3245 #ifdef DEBUG
3246         error = xfs_btree_check_block(cur, block, level, bp);
3247         if (error)
3248                 goto error0;
3249 #endif
3250
3251         /* Fail if we're off the end of the block. */
3252         if (ptr > numrecs) {
3253                 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3254                 *stat = 0;
3255                 return 0;
3256         }
3257
3258         XFS_BTREE_STATS_INC(cur, delrec);
3259         XFS_BTREE_STATS_ADD(cur, moves, numrecs - ptr);
3260
3261         /* Excise the entries being deleted. */
3262         if (level > 0) {
3263                 /* It's a nonleaf. operate on keys and ptrs */
3264                 union xfs_btree_key     *lkp;
3265                 union xfs_btree_ptr     *lpp;
3266
3267                 lkp = xfs_btree_key_addr(cur, ptr + 1, block);
3268                 lpp = xfs_btree_ptr_addr(cur, ptr + 1, block);
3269
3270 #ifdef DEBUG
3271                 for (i = 0; i < numrecs - ptr; i++) {
3272                         error = xfs_btree_check_ptr(cur, lpp, i, level);
3273                         if (error)
3274                                 goto error0;
3275                 }
3276 #endif
3277
3278                 if (ptr < numrecs) {
3279                         xfs_btree_shift_keys(cur, lkp, -1, numrecs - ptr);
3280                         xfs_btree_shift_ptrs(cur, lpp, -1, numrecs - ptr);
3281                         xfs_btree_log_keys(cur, bp, ptr, numrecs - 1);
3282                         xfs_btree_log_ptrs(cur, bp, ptr, numrecs - 1);
3283                 }
3284
3285                 /*
3286                  * If it's the first record in the block, we'll need to pass a
3287                  * key up to the next level (updkey).
3288                  */
3289                 if (ptr == 1)
3290                         keyp = xfs_btree_key_addr(cur, 1, block);
3291         } else {
3292                 /* It's a leaf. operate on records */
3293                 if (ptr < numrecs) {
3294                         xfs_btree_shift_recs(cur,
3295                                 xfs_btree_rec_addr(cur, ptr + 1, block),
3296                                 -1, numrecs - ptr);
3297                         xfs_btree_log_recs(cur, bp, ptr, numrecs - 1);
3298                 }
3299
3300                 /*
3301                  * If it's the first record in the block, we'll need a key
3302                  * structure to pass up to the next level (updkey).
3303                  */
3304                 if (ptr == 1) {
3305                         cur->bc_ops->init_key_from_rec(&key,
3306                                         xfs_btree_rec_addr(cur, 1, block));
3307                         keyp = &key;
3308                 }
3309         }
3310
3311         /*
3312          * Decrement and log the number of entries in the block.
3313          */
3314         xfs_btree_set_numrecs(block, --numrecs);
3315         xfs_btree_log_block(cur, bp, XFS_BB_NUMRECS);
3316
3317         /*
3318          * If we are tracking the last record in the tree and
3319          * we are at the far right edge of the tree, update it.
3320          */
3321         if (xfs_btree_is_lastrec(cur, block, level)) {
3322                 cur->bc_ops->update_lastrec(cur, block, NULL,
3323                                             ptr, LASTREC_DELREC);
3324         }
3325
3326         /*
3327          * We're at the root level.  First, shrink the root block in-memory.
3328          * Try to get rid of the next level down.  If we can't then there's
3329          * nothing left to do.
3330          */
3331         if (level == cur->bc_nlevels - 1) {
3332                 if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) {
3333                         xfs_iroot_realloc(cur->bc_private.b.ip, -1,
3334                                           cur->bc_private.b.whichfork);
3335
3336                         error = xfs_btree_kill_iroot(cur);
3337                         if (error)
3338                                 goto error0;
3339
3340                         error = xfs_btree_dec_cursor(cur, level, stat);
3341                         if (error)
3342                                 goto error0;
3343                         *stat = 1;
3344                         return 0;
3345                 }
3346
3347                 /*
3348                  * If this is the root level, and there's only one entry left,
3349                  * and it's NOT the leaf level, then we can get rid of this
3350                  * level.
3351                  */
3352                 if (numrecs == 1 && level > 0) {
3353                         union xfs_btree_ptr     *pp;
3354                         /*
3355                          * pp is still set to the first pointer in the block.
3356                          * Make it the new root of the btree.
3357                          */
3358                         pp = xfs_btree_ptr_addr(cur, 1, block);
3359                         error = cur->bc_ops->kill_root(cur, bp, level, pp);
3360                         if (error)
3361                                 goto error0;
3362                 } else if (level > 0) {
3363                         error = xfs_btree_dec_cursor(cur, level, stat);
3364                         if (error)
3365                                 goto error0;
3366                 }
3367                 *stat = 1;
3368                 return 0;
3369         }
3370
3371         /*
3372          * If we deleted the leftmost entry in the block, update the
3373          * key values above us in the tree.
3374          */
3375         if (ptr == 1) {
3376                 error = xfs_btree_updkey(cur, keyp, level + 1);
3377                 if (error)
3378                         goto error0;
3379         }
3380
3381         /*
3382          * If the number of records remaining in the block is at least
3383          * the minimum, we're done.
3384          */
3385         if (numrecs >= cur->bc_ops->get_minrecs(cur, level)) {
3386                 error = xfs_btree_dec_cursor(cur, level, stat);
3387                 if (error)
3388                         goto error0;
3389                 return 0;
3390         }
3391
3392         /*
3393          * Otherwise, we have to move some records around to keep the
3394          * tree balanced.  Look at the left and right sibling blocks to
3395          * see if we can re-balance by moving only one record.
3396          */
3397         xfs_btree_get_sibling(cur, block, &rptr, XFS_BB_RIGHTSIB);
3398         xfs_btree_get_sibling(cur, block, &lptr, XFS_BB_LEFTSIB);
3399
3400         if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) {
3401                 /*
3402                  * One child of root, need to get a chance to copy its contents
3403                  * into the root and delete it. Can't go up to next level,
3404                  * there's nothing to delete there.
3405                  */
3406                 if (xfs_btree_ptr_is_null(cur, &rptr) &&
3407                     xfs_btree_ptr_is_null(cur, &lptr) &&
3408                     level == cur->bc_nlevels - 2) {
3409                         error = xfs_btree_kill_iroot(cur);
3410                         if (!error)
3411                                 error = xfs_btree_dec_cursor(cur, level, stat);
3412                         if (error)
3413                                 goto error0;
3414                         return 0;
3415                 }
3416         }
3417
3418         ASSERT(!xfs_btree_ptr_is_null(cur, &rptr) ||
3419                !xfs_btree_ptr_is_null(cur, &lptr));
3420
3421         /*
3422          * Duplicate the cursor so our btree manipulations here won't
3423          * disrupt the next level up.
3424          */
3425         error = xfs_btree_dup_cursor(cur, &tcur);
3426         if (error)
3427                 goto error0;
3428
3429         /*
3430          * If there's a right sibling, see if it's ok to shift an entry
3431          * out of it.
3432          */
3433         if (!xfs_btree_ptr_is_null(cur, &rptr)) {
3434                 /*
3435                  * Move the temp cursor to the last entry in the next block.
3436                  * Actually any entry but the first would suffice.
3437                  */
3438                 i = xfs_btree_lastrec(tcur, level);
3439                 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3440
3441                 error = xfs_btree_increment(tcur, level, &i);
3442                 if (error)
3443                         goto error0;
3444                 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3445
3446                 i = xfs_btree_lastrec(tcur, level);
3447                 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3448
3449                 /* Grab a pointer to the block. */
3450                 right = xfs_btree_get_block(tcur, level, &rbp);
3451 #ifdef DEBUG
3452                 error = xfs_btree_check_block(tcur, right, level, rbp);
3453                 if (error)
3454                         goto error0;
3455 #endif
3456                 /* Grab the current block number, for future use. */
3457                 xfs_btree_get_sibling(tcur, right, &cptr, XFS_BB_LEFTSIB);
3458
3459                 /*
3460                  * If right block is full enough so that removing one entry
3461                  * won't make it too empty, and left-shifting an entry out
3462                  * of right to us works, we're done.
3463                  */
3464                 if (xfs_btree_get_numrecs(right) - 1 >=
3465                     cur->bc_ops->get_minrecs(tcur, level)) {
3466                         error = xfs_btree_lshift(tcur, level, &i);
3467                         if (error)
3468                                 goto error0;
3469                         if (i) {
3470                                 ASSERT(xfs_btree_get_numrecs(block) >=
3471                                        cur->bc_ops->get_minrecs(tcur, level));
3472
3473                                 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
3474                                 tcur = NULL;
3475
3476                                 error = xfs_btree_dec_cursor(cur, level, stat);
3477                                 if (error)
3478                                         goto error0;
3479                                 return 0;
3480                         }
3481                 }
3482
3483                 /*
3484                  * Otherwise, grab the number of records in right for
3485                  * future reference, and fix up the temp cursor to point
3486                  * to our block again (last record).
3487                  */
3488                 rrecs = xfs_btree_get_numrecs(right);
3489                 if (!xfs_btree_ptr_is_null(cur, &lptr)) {
3490                         i = xfs_btree_firstrec(tcur, level);
3491                         XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3492
3493                         error = xfs_btree_decrement(tcur, level, &i);
3494                         if (error)
3495                                 goto error0;
3496                         XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3497                 }
3498         }
3499
3500         /*
3501          * If there's a left sibling, see if it's ok to shift an entry
3502          * out of it.
3503          */
3504         if (!xfs_btree_ptr_is_null(cur, &lptr)) {
3505                 /*
3506                  * Move the temp cursor to the first entry in the
3507                  * previous block.
3508                  */
3509                 i = xfs_btree_firstrec(tcur, level);
3510                 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3511
3512                 error = xfs_btree_decrement(tcur, level, &i);
3513                 if (error)
3514                         goto error0;
3515                 i = xfs_btree_firstrec(tcur, level);
3516                 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3517
3518                 /* Grab a pointer to the block. */
3519                 left = xfs_btree_get_block(tcur, level, &lbp);
3520 #ifdef DEBUG
3521                 error = xfs_btree_check_block(cur, left, level, lbp);
3522                 if (error)
3523                         goto error0;
3524 #endif
3525                 /* Grab the current block number, for future use. */
3526                 xfs_btree_get_sibling(tcur, left, &cptr, XFS_BB_RIGHTSIB);
3527
3528                 /*
3529                  * If left block is full enough so that removing one entry
3530                  * won't make it too empty, and right-shifting an entry out
3531                  * of left to us works, we're done.
3532                  */
3533                 if (xfs_btree_get_numrecs(left) - 1 >=
3534                     cur->bc_ops->get_minrecs(tcur, level)) {
3535                         error = xfs_btree_rshift(tcur, level, &i);
3536                         if (error)
3537                                 goto error0;
3538                         if (i) {
3539                                 ASSERT(xfs_btree_get_numrecs(block) >=
3540                                        cur->bc_ops->get_minrecs(tcur, level));
3541                                 xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
3542                                 tcur = NULL;
3543                                 if (level == 0)
3544                                         cur->bc_ptrs[0]++;
3545                                 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3546                                 *stat = 1;
3547                                 return 0;
3548                         }
3549                 }
3550
3551                 /*
3552                  * Otherwise, grab the number of records in right for
3553                  * future reference.
3554                  */
3555                 lrecs = xfs_btree_get_numrecs(left);
3556         }
3557
3558         /* Delete the temp cursor, we're done with it. */
3559         xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
3560         tcur = NULL;
3561
3562         /* If here, we need to do a join to keep the tree balanced. */
3563         ASSERT(!xfs_btree_ptr_is_null(cur, &cptr));
3564
3565         if (!xfs_btree_ptr_is_null(cur, &lptr) &&
3566             lrecs + xfs_btree_get_numrecs(block) <=
3567                         cur->bc_ops->get_maxrecs(cur, level)) {
3568                 /*
3569                  * Set "right" to be the starting block,
3570                  * "left" to be the left neighbor.
3571                  */
3572                 rptr = cptr;
3573                 right = block;
3574                 rbp = bp;
3575                 error = xfs_btree_read_buf_block(cur, &lptr, level,
3576                                                         0, &left, &lbp);
3577                 if (error)
3578                         goto error0;
3579
3580         /*
3581          * If that won't work, see if we can join with the right neighbor block.
3582          */
3583         } else if (!xfs_btree_ptr_is_null(cur, &rptr) &&
3584                    rrecs + xfs_btree_get_numrecs(block) <=
3585                         cur->bc_ops->get_maxrecs(cur, level)) {
3586                 /*
3587                  * Set "left" to be the starting block,
3588                  * "right" to be the right neighbor.
3589                  */
3590                 lptr = cptr;
3591                 left = block;
3592                 lbp = bp;
3593                 error = xfs_btree_read_buf_block(cur, &rptr, level,
3594                                                         0, &right, &rbp);
3595                 if (error)
3596                         goto error0;
3597
3598         /*
3599          * Otherwise, we can't fix the imbalance.
3600          * Just return.  This is probably a logic error, but it's not fatal.
3601          */
3602         } else {
3603                 error = xfs_btree_dec_cursor(cur, level, stat);
3604                 if (error)
3605                         goto error0;
3606                 return 0;
3607         }
3608
3609         rrecs = xfs_btree_get_numrecs(right);
3610         lrecs = xfs_btree_get_numrecs(left);
3611
3612         /*
3613          * We're now going to join "left" and "right" by moving all the stuff
3614          * in "right" to "left" and deleting "right".
3615          */
3616         XFS_BTREE_STATS_ADD(cur, moves, rrecs);
3617         if (level > 0) {
3618                 /* It's a non-leaf.  Move keys and pointers. */
3619                 union xfs_btree_key     *lkp;   /* left btree key */
3620                 union xfs_btree_ptr     *lpp;   /* left address pointer */
3621                 union xfs_btree_key     *rkp;   /* right btree key */
3622                 union xfs_btree_ptr     *rpp;   /* right address pointer */
3623
3624                 lkp = xfs_btree_key_addr(cur, lrecs + 1, left);
3625                 lpp = xfs_btree_ptr_addr(cur, lrecs + 1, left);
3626                 rkp = xfs_btree_key_addr(cur, 1, right);
3627                 rpp = xfs_btree_ptr_addr(cur, 1, right);
3628 #ifdef DEBUG
3629                 for (i = 1; i < rrecs; i++) {
3630                         error = xfs_btree_check_ptr(cur, rpp, i, level);
3631                         if (error)
3632                                 goto error0;
3633                 }
3634 #endif
3635                 xfs_btree_copy_keys(cur, lkp, rkp, rrecs);
3636                 xfs_btree_copy_ptrs(cur, lpp, rpp, rrecs);
3637
3638                 xfs_btree_log_keys(cur, lbp, lrecs + 1, lrecs + rrecs);
3639                 xfs_btree_log_ptrs(cur, lbp, lrecs + 1, lrecs + rrecs);
3640         } else {
3641                 /* It's a leaf.  Move records.  */
3642                 union xfs_btree_rec     *lrp;   /* left record pointer */
3643                 union xfs_btree_rec     *rrp;   /* right record pointer */
3644
3645                 lrp = xfs_btree_rec_addr(cur, lrecs + 1, left);
3646                 rrp = xfs_btree_rec_addr(cur, 1, right);
3647
3648                 xfs_btree_copy_recs(cur, lrp, rrp, rrecs);
3649                 xfs_btree_log_recs(cur, lbp, lrecs + 1, lrecs + rrecs);
3650         }
3651
3652         XFS_BTREE_STATS_INC(cur, join);
3653
3654         /*
3655          * Fix up the the number of records and right block pointer in the
3656          * surviving block, and log it.
3657          */
3658         xfs_btree_set_numrecs(left, lrecs + rrecs);
3659         xfs_btree_get_sibling(cur, right, &cptr, XFS_BB_RIGHTSIB),
3660         xfs_btree_set_sibling(cur, left, &cptr, XFS_BB_RIGHTSIB);
3661         xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS | XFS_BB_RIGHTSIB);
3662
3663         /* If there is a right sibling, point it to the remaining block. */
3664         xfs_btree_get_sibling(cur, left, &cptr, XFS_BB_RIGHTSIB);
3665         if (!xfs_btree_ptr_is_null(cur, &cptr)) {
3666                 error = xfs_btree_read_buf_block(cur, &cptr, level,
3667                                                         0, &rrblock, &rrbp);
3668                 if (error)
3669                         goto error0;
3670                 xfs_btree_set_sibling(cur, rrblock, &lptr, XFS_BB_LEFTSIB);
3671                 xfs_btree_log_block(cur, rrbp, XFS_BB_LEFTSIB);
3672         }
3673
3674         /* Free the deleted block. */
3675         error = cur->bc_ops->free_block(cur, rbp);
3676         if (error)
3677                 goto error0;
3678         XFS_BTREE_STATS_INC(cur, free);
3679
3680         /*
3681          * If we joined with the left neighbor, set the buffer in the
3682          * cursor to the left block, and fix up the index.
3683          */
3684         if (bp != lbp) {
3685                 cur->bc_bufs[level] = lbp;
3686                 cur->bc_ptrs[level] += lrecs;
3687                 cur->bc_ra[level] = 0;
3688         }
3689         /*
3690          * If we joined with the right neighbor and there's a level above
3691          * us, increment the cursor at that level.
3692          */
3693         else if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) ||
3694                    (level + 1 < cur->bc_nlevels)) {
3695                 error = xfs_btree_increment(cur, level + 1, &i);
3696                 if (error)
3697                         goto error0;
3698         }
3699
3700         /*
3701          * Readjust the ptr at this level if it's not a leaf, since it's
3702          * still pointing at the deletion point, which makes the cursor
3703          * inconsistent.  If this makes the ptr 0, the caller fixes it up.
3704          * We can't use decrement because it would change the next level up.
3705          */
3706         if (level > 0)
3707                 cur->bc_ptrs[level]--;
3708
3709         XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3710         /* Return value means the next level up has something to do. */
3711         *stat = 2;
3712         return 0;
3713
3714 error0:
3715         XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3716         if (tcur)
3717                 xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR);
3718         return error;
3719 }
3720
3721 /*
3722  * Delete the record pointed to by cur.
3723  * The cursor refers to the place where the record was (could be inserted)
3724  * when the operation returns.
3725  */
3726 int                                     /* error */
3727 xfs_btree_delete(
3728         struct xfs_btree_cur    *cur,
3729         int                     *stat)  /* success/failure */
3730 {
3731         int                     error;  /* error return value */
3732         int                     level;
3733         int                     i;
3734
3735         XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
3736
3737         /*
3738          * Go up the tree, starting at leaf level.
3739          *
3740          * If 2 is returned then a join was done; go to the next level.
3741          * Otherwise we are done.
3742          */
3743         for (level = 0, i = 2; i == 2; level++) {
3744                 error = xfs_btree_delrec(cur, level, &i);
3745                 if (error)
3746                         goto error0;
3747         }
3748
3749         if (i == 0) {
3750                 for (level = 1; level < cur->bc_nlevels; level++) {
3751                         if (cur->bc_ptrs[level] == 0) {
3752                                 error = xfs_btree_decrement(cur, level, &i);
3753                                 if (error)
3754                                         goto error0;
3755                                 break;
3756                         }
3757                 }
3758         }
3759
3760         XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3761         *stat = i;
3762         return 0;
3763 error0:
3764         XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3765         return error;
3766 }
3767
3768 /*
3769  * Get the data from the pointed-to record.
3770  */
3771 int                                     /* error */
3772 xfs_btree_get_rec(
3773         struct xfs_btree_cur    *cur,   /* btree cursor */
3774         union xfs_btree_rec     **recp, /* output: btree record */
3775         int                     *stat)  /* output: success/failure */
3776 {
3777         struct xfs_btree_block  *block; /* btree block */
3778         struct xfs_buf          *bp;    /* buffer pointer */
3779         int                     ptr;    /* record number */
3780 #ifdef DEBUG
3781         int                     error;  /* error return value */
3782 #endif
3783
3784         ptr = cur->bc_ptrs[0];
3785         block = xfs_btree_get_block(cur, 0, &bp);
3786
3787 #ifdef DEBUG
3788         error = xfs_btree_check_block(cur, block, 0, bp);
3789         if (error)
3790                 return error;
3791 #endif
3792
3793         /*
3794          * Off the right end or left end, return failure.
3795          */
3796         if (ptr > xfs_btree_get_numrecs(block) || ptr <= 0) {
3797                 *stat = 0;
3798                 return 0;
3799         }
3800
3801         /*
3802          * Point to the record and extract its data.
3803          */
3804         *recp = xfs_btree_rec_addr(cur, ptr, block);
3805         *stat = 1;
3806         return 0;
3807 }