fs/xfs/xfs_ialloc_btree.c

   1 /*
   2  * Copyright (c) 2000-2001,2005 Silicon Graphics, Inc.
   3  * All Rights Reserved.
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it would be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write the Free Software Foundation,
  16  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  17  */
  18 #include "xfs.h"
  19 #include "xfs_fs.h"
  20 #include "xfs_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_btree.h"
  38 #include "xfs_btree_trace.h"
  39 #include "xfs_ialloc.h"
  40 #include "xfs_alloc.h"
  41 #include "xfs_error.h"
  42
  43 STATIC void xfs_inobt_log_block(xfs_trans_t *, xfs_buf_t *, int);
  44 STATIC void xfs_inobt_log_keys(xfs_btree_cur_t *, xfs_buf_t *, int, int);
  45 STATIC void xfs_inobt_log_ptrs(xfs_btree_cur_t *, xfs_buf_t *, int, int);
  46 STATIC void xfs_inobt_log_recs(xfs_btree_cur_t *, xfs_buf_t *, int, int);
  47
  48 /*
  49  * Single level of the xfs_inobt_delete record deletion routine.
  50  * Delete record pointed to by cur/level.
  51  * Remove the record from its block then rebalance the tree.
  52  * Return 0 for error, 1 for done, 2 to go on to the next level.
  53  */
  54 STATIC int                              /* error */
  55 xfs_inobt_delrec(
  56         xfs_btree_cur_t         *cur,   /* btree cursor */
  57         int                     level,  /* level removing record from */
  58         int                     *stat)  /* fail/done/go-on */
  59 {
  60         xfs_buf_t               *agbp;  /* buffer for a.g. inode header */
  61         xfs_mount_t             *mp;    /* mount structure */
  62         xfs_agi_t               *agi;   /* allocation group inode header */
  63         xfs_inobt_block_t       *block; /* btree block record/key lives in */
  64         xfs_agblock_t           bno;    /* btree block number */
  65         xfs_buf_t               *bp;    /* buffer for block */
  66         int                     error;  /* error return value */
  67         int                     i;      /* loop index */
  68         xfs_inobt_key_t         key;    /* kp points here if block is level 0 */
  69         xfs_inobt_key_t         *kp = NULL;     /* pointer to btree keys */
  70         xfs_agblock_t           lbno;   /* left block's block number */
  71         xfs_buf_t               *lbp;   /* left block's buffer pointer */
  72         xfs_inobt_block_t       *left;  /* left btree block */
  73         xfs_inobt_key_t         *lkp;   /* left block key pointer */
  74         xfs_inobt_ptr_t         *lpp;   /* left block address pointer */
  75         int                     lrecs = 0;      /* number of records in left block */
  76         xfs_inobt_rec_t         *lrp;   /* left block record pointer */
  77         xfs_inobt_ptr_t         *pp = NULL;     /* pointer to btree addresses */
  78         int                     ptr;    /* index in btree block for this rec */
  79         xfs_agblock_t           rbno;   /* right block's block number */
  80         xfs_buf_t               *rbp;   /* right block's buffer pointer */
  81         xfs_inobt_block_t       *right; /* right btree block */
  82         xfs_inobt_key_t         *rkp;   /* right block key pointer */
  83         xfs_inobt_rec_t         *rp;    /* pointer to btree records */
  84         xfs_inobt_ptr_t         *rpp;   /* right block address pointer */
  85         int                     rrecs = 0;      /* number of records in right block */
  86         int                     numrecs;
  87         xfs_inobt_rec_t         *rrp;   /* right block record pointer */
  88         xfs_btree_cur_t         *tcur;  /* temporary btree cursor */
  89
  90         mp = cur->bc_mp;
  91
  92         /*
  93          * Get the index of the entry being deleted, check for nothing there.
  94          */
  95         ptr = cur->bc_ptrs[level];
  96         if (ptr == 0) {
  97                 *stat = 0;
  98                 return 0;
  99         }
 100
 101         /*
 102          * Get the buffer & block containing the record or key/ptr.
 103          */
 104         bp = cur->bc_bufs[level];
 105         block = XFS_BUF_TO_INOBT_BLOCK(bp);
 106 #ifdef DEBUG
 107         if ((error = xfs_btree_check_sblock(cur, block, level, bp)))
 108                 return error;
 109 #endif
 110         /*
 111          * Fail if we're off the end of the block.
 112          */
 113
 114         numrecs = be16_to_cpu(block->bb_numrecs);
 115         if (ptr > numrecs) {
 116                 *stat = 0;
 117                 return 0;
 118         }
 119         /*
 120          * It's a nonleaf.  Excise the key and ptr being deleted, by
 121          * sliding the entries past them down one.
 122          * Log the changed areas of the block.
 123          */
 124         if (level > 0) {
 125                 kp = XFS_INOBT_KEY_ADDR(block, 1, cur);
 126                 pp = XFS_INOBT_PTR_ADDR(block, 1, cur);
 127 #ifdef DEBUG
 128                 for (i = ptr; i < numrecs; i++) {
 129                         if ((error = xfs_btree_check_sptr(cur, be32_to_cpu(pp[i]), level)))
 130                                 return error;
 131                 }
 132 #endif
 133                 if (ptr < numrecs) {
 134                         memmove(&kp[ptr - 1], &kp[ptr],
 135                                 (numrecs - ptr) * sizeof(*kp));
 136                         memmove(&pp[ptr - 1], &pp[ptr],
 137                                 (numrecs - ptr) * sizeof(*kp));
 138                         xfs_inobt_log_keys(cur, bp, ptr, numrecs - 1);
 139                         xfs_inobt_log_ptrs(cur, bp, ptr, numrecs - 1);
 140                 }
 141         }
 142         /*
 143          * It's a leaf.  Excise the record being deleted, by sliding the
 144          * entries past it down one.  Log the changed areas of the block.
 145          */
 146         else {
 147                 rp = XFS_INOBT_REC_ADDR(block, 1, cur);
 148                 if (ptr < numrecs) {
 149                         memmove(&rp[ptr - 1], &rp[ptr],
 150                                 (numrecs - ptr) * sizeof(*rp));
 151                         xfs_inobt_log_recs(cur, bp, ptr, numrecs - 1);
 152                 }
 153                 /*
 154                  * If it's the first record in the block, we'll need a key
 155                  * structure to pass up to the next level (updkey).
 156                  */
 157                 if (ptr == 1) {
 158                         key.ir_startino = rp->ir_startino;
 159                         kp = &key;
 160                 }
 161         }
 162         /*
 163          * Decrement and log the number of entries in the block.
 164          */
 165         numrecs--;
 166         block->bb_numrecs = cpu_to_be16(numrecs);
 167         xfs_inobt_log_block(cur->bc_tp, bp, XFS_BB_NUMRECS);
 168         /*
 169          * Is this the root level?  If so, we're almost done.
 170          */
 171         if (level == cur->bc_nlevels - 1) {
 172                 /*
 173                  * If this is the root level,
 174                  * and there's only one entry left,
 175                  * and it's NOT the leaf level,
 176                  * then we can get rid of this level.
 177                  */
 178                 if (numrecs == 1 && level > 0) {
 179                         agbp = cur->bc_private.a.agbp;
 180                         agi = XFS_BUF_TO_AGI(agbp);
 181                         /*
 182                          * pp is still set to the first pointer in the block.
 183                          * Make it the new root of the btree.
 184                          */
 185                         bno = be32_to_cpu(agi->agi_root);
 186                         agi->agi_root = *pp;
 187                         be32_add_cpu(&agi->agi_level, -1);
 188                         /*
 189                          * Free the block.
 190                          */
 191                         if ((error = xfs_free_extent(cur->bc_tp,
 192                                 XFS_AGB_TO_FSB(mp, cur->bc_private.a.agno, bno), 1)))
 193                                 return error;
 194                         xfs_trans_binval(cur->bc_tp, bp);
 195                         xfs_ialloc_log_agi(cur->bc_tp, agbp,
 196                                 XFS_AGI_ROOT | XFS_AGI_LEVEL);
 197                         /*
 198                          * Update the cursor so there's one fewer level.
 199                          */
 200                         cur->bc_bufs[level] = NULL;
 201                         cur->bc_nlevels--;
 202                 } else if (level > 0 &&
 203                            (error = xfs_btree_decrement(cur, level, &i)))
 204                         return error;
 205                 *stat = 1;
 206                 return 0;
 207         }
 208         /*
 209          * If we deleted the leftmost entry in the block, update the
 210          * key values above us in the tree.
 211          */
 212         if (ptr == 1 && (error = xfs_btree_updkey(cur, (union xfs_btree_key *)kp, level + 1)))
 213                 return error;
 214         /*
 215          * If the number of records remaining in the block is at least
 216          * the minimum, we're done.
 217          */
 218         if (numrecs >= XFS_INOBT_BLOCK_MINRECS(level, cur)) {
 219                 if (level > 0 &&
 220                     (error = xfs_btree_decrement(cur, level, &i)))
 221                         return error;
 222                 *stat = 1;
 223                 return 0;
 224         }
 225         /*
 226          * Otherwise, we have to move some records around to keep the
 227          * tree balanced.  Look at the left and right sibling blocks to
 228          * see if we can re-balance by moving only one record.
 229          */
 230         rbno = be32_to_cpu(block->bb_rightsib);
 231         lbno = be32_to_cpu(block->bb_leftsib);
 232         bno = NULLAGBLOCK;
 233         ASSERT(rbno != NULLAGBLOCK || lbno != NULLAGBLOCK);
 234         /*
 235          * Duplicate the cursor so our btree manipulations here won't
 236          * disrupt the next level up.
 237          */
 238         if ((error = xfs_btree_dup_cursor(cur, &tcur)))
 239                 return error;
 240         /*
 241          * If there's a right sibling, see if it's ok to shift an entry
 242          * out of it.
 243          */
 244         if (rbno != NULLAGBLOCK) {
 245                 /*
 246                  * Move the temp cursor to the last entry in the next block.
 247                  * Actually any entry but the first would suffice.
 248                  */
 249                 i = xfs_btree_lastrec(tcur, level);
 250                 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
 251                 if ((error = xfs_btree_increment(tcur, level, &i)))
 252                         goto error0;
 253                 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
 254                 i = xfs_btree_lastrec(tcur, level);
 255                 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
 256                 /*
 257                  * Grab a pointer to the block.
 258                  */
 259                 rbp = tcur->bc_bufs[level];
 260                 right = XFS_BUF_TO_INOBT_BLOCK(rbp);
 261 #ifdef DEBUG
 262                 if ((error = xfs_btree_check_sblock(cur, right, level, rbp)))
 263                         goto error0;
 264 #endif
 265                 /*
 266                  * Grab the current block number, for future use.
 267                  */
 268                 bno = be32_to_cpu(right->bb_leftsib);
 269                 /*
 270                  * If right block is full enough so that removing one entry
 271                  * won't make it too empty, and left-shifting an entry out
 272                  * of right to us works, we're done.
 273                  */
 274                 if (be16_to_cpu(right->bb_numrecs) - 1 >=
 275                      XFS_INOBT_BLOCK_MINRECS(level, cur)) {
 276                         if ((error = xfs_btree_lshift(tcur, level, &i)))
 277                                 goto error0;
 278                         if (i) {
 279                                 ASSERT(be16_to_cpu(block->bb_numrecs) >=
 280                                        XFS_INOBT_BLOCK_MINRECS(level, cur));
 281                                 xfs_btree_del_cursor(tcur,
 282                                                      XFS_BTREE_NOERROR);
 283                                 if (level > 0 &&
 284                                     (error = xfs_btree_decrement(cur, level,
 285                                                 &i)))
 286                                         return error;
 287                                 *stat = 1;
 288                                 return 0;
 289                         }
 290                 }
 291                 /*
 292                  * Otherwise, grab the number of records in right for
 293                  * future reference, and fix up the temp cursor to point
 294                  * to our block again (last record).
 295                  */
 296                 rrecs = be16_to_cpu(right->bb_numrecs);
 297                 if (lbno != NULLAGBLOCK) {
 298                         xfs_btree_firstrec(tcur, level);
 299                         if ((error = xfs_btree_decrement(tcur, level, &i)))
 300                                 goto error0;
 301                 }
 302         }
 303         /*
 304          * If there's a left sibling, see if it's ok to shift an entry
 305          * out of it.
 306          */
 307         if (lbno != NULLAGBLOCK) {
 308                 /*
 309                  * Move the temp cursor to the first entry in the
 310                  * previous block.
 311                  */
 312                 xfs_btree_firstrec(tcur, level);
 313                 if ((error = xfs_btree_decrement(tcur, level, &i)))
 314                         goto error0;
 315                 xfs_btree_firstrec(tcur, level);
 316                 /*
 317                  * Grab a pointer to the block.
 318                  */
 319                 lbp = tcur->bc_bufs[level];
 320                 left = XFS_BUF_TO_INOBT_BLOCK(lbp);
 321 #ifdef DEBUG
 322                 if ((error = xfs_btree_check_sblock(cur, left, level, lbp)))
 323                         goto error0;
 324 #endif
 325                 /*
 326                  * Grab the current block number, for future use.
 327                  */
 328                 bno = be32_to_cpu(left->bb_rightsib);
 329                 /*
 330                  * If left block is full enough so that removing one entry
 331                  * won't make it too empty, and right-shifting an entry out
 332                  * of left to us works, we're done.
 333                  */
 334                 if (be16_to_cpu(left->bb_numrecs) - 1 >=
 335                      XFS_INOBT_BLOCK_MINRECS(level, cur)) {
 336                         if ((error = xfs_btree_rshift(tcur, level, &i)))
 337                                 goto error0;
 338                         if (i) {
 339                                 ASSERT(be16_to_cpu(block->bb_numrecs) >=
 340                                        XFS_INOBT_BLOCK_MINRECS(level, cur));
 341                                 xfs_btree_del_cursor(tcur,
 342                                                      XFS_BTREE_NOERROR);
 343                                 if (level == 0)
 344                                         cur->bc_ptrs[0]++;
 345                                 *stat = 1;
 346                                 return 0;
 347                         }
 348                 }
 349                 /*
 350                  * Otherwise, grab the number of records in right for
 351                  * future reference.
 352                  */
 353                 lrecs = be16_to_cpu(left->bb_numrecs);
 354         }
 355         /*
 356          * Delete the temp cursor, we're done with it.
 357          */
 358         xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
 359         /*
 360          * If here, we need to do a join to keep the tree balanced.
 361          */
 362         ASSERT(bno != NULLAGBLOCK);
 363         /*
 364          * See if we can join with the left neighbor block.
 365          */
 366         if (lbno != NULLAGBLOCK &&
 367             lrecs + numrecs <= XFS_INOBT_BLOCK_MAXRECS(level, cur)) {
 368                 /*
 369                  * Set "right" to be the starting block,
 370                  * "left" to be the left neighbor.
 371                  */
 372                 rbno = bno;
 373                 right = block;
 374                 rrecs = be16_to_cpu(right->bb_numrecs);
 375                 rbp = bp;
 376                 if ((error = xfs_btree_read_bufs(mp, cur->bc_tp,
 377                                 cur->bc_private.a.agno, lbno, 0, &lbp,
 378                                 XFS_INO_BTREE_REF)))
 379                         return error;
 380                 left = XFS_BUF_TO_INOBT_BLOCK(lbp);
 381                 lrecs = be16_to_cpu(left->bb_numrecs);
 382                 if ((error = xfs_btree_check_sblock(cur, left, level, lbp)))
 383                         return error;
 384         }
 385         /*
 386          * If that won't work, see if we can join with the right neighbor block.
 387          */
 388         else if (rbno != NULLAGBLOCK &&
 389                  rrecs + numrecs <= XFS_INOBT_BLOCK_MAXRECS(level, cur)) {
 390                 /*
 391                  * Set "left" to be the starting block,
 392                  * "right" to be the right neighbor.
 393                  */
 394                 lbno = bno;
 395                 left = block;
 396                 lrecs = be16_to_cpu(left->bb_numrecs);
 397                 lbp = bp;
 398                 if ((error = xfs_btree_read_bufs(mp, cur->bc_tp,
 399                                 cur->bc_private.a.agno, rbno, 0, &rbp,
 400                                 XFS_INO_BTREE_REF)))
 401                         return error;
 402                 right = XFS_BUF_TO_INOBT_BLOCK(rbp);
 403                 rrecs = be16_to_cpu(right->bb_numrecs);
 404                 if ((error = xfs_btree_check_sblock(cur, right, level, rbp)))
 405                         return error;
 406         }
 407         /*
 408          * Otherwise, we can't fix the imbalance.
 409          * Just return.  This is probably a logic error, but it's not fatal.
 410          */
 411         else {
 412                 if (level > 0 && (error = xfs_btree_decrement(cur, level, &i)))
 413                         return error;
 414                 *stat = 1;
 415                 return 0;
 416         }
 417         /*
 418          * We're now going to join "left" and "right" by moving all the stuff
 419          * in "right" to "left" and deleting "right".
 420          */
 421         if (level > 0) {
 422                 /*
 423                  * It's a non-leaf.  Move keys and pointers.
 424                  */
 425                 lkp = XFS_INOBT_KEY_ADDR(left, lrecs + 1, cur);
 426                 lpp = XFS_INOBT_PTR_ADDR(left, lrecs + 1, cur);
 427                 rkp = XFS_INOBT_KEY_ADDR(right, 1, cur);
 428                 rpp = XFS_INOBT_PTR_ADDR(right, 1, cur);
 429 #ifdef DEBUG
 430                 for (i = 0; i < rrecs; i++) {
 431                         if ((error = xfs_btree_check_sptr(cur, be32_to_cpu(rpp[i]), level)))
 432                                 return error;
 433                 }
 434 #endif
 435                 memcpy(lkp, rkp, rrecs * sizeof(*lkp));
 436                 memcpy(lpp, rpp, rrecs * sizeof(*lpp));
 437                 xfs_inobt_log_keys(cur, lbp, lrecs + 1, lrecs + rrecs);
 438                 xfs_inobt_log_ptrs(cur, lbp, lrecs + 1, lrecs + rrecs);
 439         } else {
 440                 /*
 441                  * It's a leaf.  Move records.
 442                  */
 443                 lrp = XFS_INOBT_REC_ADDR(left, lrecs + 1, cur);
 444                 rrp = XFS_INOBT_REC_ADDR(right, 1, cur);
 445                 memcpy(lrp, rrp, rrecs * sizeof(*lrp));
 446                 xfs_inobt_log_recs(cur, lbp, lrecs + 1, lrecs + rrecs);
 447         }
 448         /*
 449          * If we joined with the left neighbor, set the buffer in the
 450          * cursor to the left block, and fix up the index.
 451          */
 452         if (bp != lbp) {
 453                 xfs_btree_setbuf(cur, level, lbp);
 454                 cur->bc_ptrs[level] += lrecs;
 455         }
 456         /*
 457          * If we joined with the right neighbor and there's a level above
 458          * us, increment the cursor at that level.
 459          */
 460         else if (level + 1 < cur->bc_nlevels &&
 461                  (error = xfs_btree_increment(cur, level + 1, &i)))
 462                 return error;
 463         /*
 464          * Fix up the number of records in the surviving block.
 465          */
 466         lrecs += rrecs;
 467         left->bb_numrecs = cpu_to_be16(lrecs);
 468         /*
 469          * Fix up the right block pointer in the surviving block, and log it.
 470          */
 471         left->bb_rightsib = right->bb_rightsib;
 472         xfs_inobt_log_block(cur->bc_tp, lbp, XFS_BB_NUMRECS | XFS_BB_RIGHTSIB);
 473         /*
 474          * If there is a right sibling now, make it point to the
 475          * remaining block.
 476          */
 477         if (be32_to_cpu(left->bb_rightsib) != NULLAGBLOCK) {
 478                 xfs_inobt_block_t       *rrblock;
 479                 xfs_buf_t               *rrbp;
 480
 481                 if ((error = xfs_btree_read_bufs(mp, cur->bc_tp,
 482                                 cur->bc_private.a.agno, be32_to_cpu(left->bb_rightsib), 0,
 483                                 &rrbp, XFS_INO_BTREE_REF)))
 484                         return error;
 485                 rrblock = XFS_BUF_TO_INOBT_BLOCK(rrbp);
 486                 if ((error = xfs_btree_check_sblock(cur, rrblock, level, rrbp)))
 487                         return error;
 488                 rrblock->bb_leftsib = cpu_to_be32(lbno);
 489                 xfs_inobt_log_block(cur->bc_tp, rrbp, XFS_BB_LEFTSIB);
 490         }
 491         /*
 492          * Free the deleting block.
 493          */
 494         if ((error = xfs_free_extent(cur->bc_tp, XFS_AGB_TO_FSB(mp,
 495                                      cur->bc_private.a.agno, rbno), 1)))
 496                 return error;
 497         xfs_trans_binval(cur->bc_tp, rbp);
 498         /*
 499          * Readjust the ptr at this level if it's not a leaf, since it's
 500          * still pointing at the deletion point, which makes the cursor
 501          * inconsistent.  If this makes the ptr 0, the caller fixes it up.
 502          * We can't use decrement because it would change the next level up.
 503          */
 504         if (level > 0)
 505                 cur->bc_ptrs[level]--;
 506         /*
 507          * Return value means the next level up has something to do.
 508          */
 509         *stat = 2;
 510         return 0;
 511
 512 error0:
 513         xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR);
 514         return error;
 515 }
 516
 517 /*
 518  * Insert one record/level.  Return information to the caller
 519  * allowing the next level up to proceed if necessary.
 520  */
 521 STATIC int                              /* error */
 522 xfs_inobt_insrec(
 523         xfs_btree_cur_t         *cur,   /* btree cursor */
 524         int                     level,  /* level to insert record at */
 525         xfs_agblock_t           *bnop,  /* i/o: block number inserted */
 526         xfs_inobt_rec_t         *recp,  /* i/o: record data inserted */
 527         xfs_btree_cur_t         **curp, /* output: new cursor replacing cur */
 528         int                     *stat)  /* success/failure */
 529 {
 530         xfs_inobt_block_t       *block; /* btree block record/key lives in */
 531         xfs_buf_t               *bp;    /* buffer for block */
 532         int                     error;  /* error return value */
 533         int                     i;      /* loop index */
 534         xfs_inobt_key_t         key;    /* key value being inserted */
 535         xfs_inobt_key_t         *kp=NULL;       /* pointer to btree keys */
 536         xfs_agblock_t           nbno;   /* block number of allocated block */
 537         xfs_btree_cur_t         *ncur;  /* new cursor to be used at next lvl */
 538         xfs_inobt_key_t         nkey;   /* new key value, from split */
 539         xfs_inobt_rec_t         nrec;   /* new record value, for caller */
 540         int                     numrecs;
 541         int                     optr;   /* old ptr value */
 542         xfs_inobt_ptr_t         *pp;    /* pointer to btree addresses */
 543         int                     ptr;    /* index in btree block for this rec */
 544         xfs_inobt_rec_t         *rp=NULL;       /* pointer to btree records */
 545
 546         /*
 547          * GCC doesn't understand the (arguably complex) control flow in
 548          * this function and complains about uninitialized structure fields
 549          * without this.
 550          */
 551         memset(&nrec, 0, sizeof(nrec));
 552
 553         /*
 554          * If we made it to the root level, allocate a new root block
 555          * and we're done.
 556          */
 557         if (level >= cur->bc_nlevels) {
 558                 error = xfs_btree_new_root(cur, &i);
 559                 *bnop = NULLAGBLOCK;
 560                 *stat = i;
 561                 return error;
 562         }
 563         /*
 564          * Make a key out of the record data to be inserted, and save it.
 565          */
 566         key.ir_startino = recp->ir_startino;
 567         optr = ptr = cur->bc_ptrs[level];
 568         /*
 569          * If we're off the left edge, return failure.
 570          */
 571         if (ptr == 0) {
 572                 *stat = 0;
 573                 return 0;
 574         }
 575         /*
 576          * Get pointers to the btree buffer and block.
 577          */
 578         bp = cur->bc_bufs[level];
 579         block = XFS_BUF_TO_INOBT_BLOCK(bp);
 580         numrecs = be16_to_cpu(block->bb_numrecs);
 581 #ifdef DEBUG
 582         if ((error = xfs_btree_check_sblock(cur, block, level, bp)))
 583                 return error;
 584         /*
 585          * Check that the new entry is being inserted in the right place.
 586          */
 587         if (ptr <= numrecs) {
 588                 if (level == 0) {
 589                         rp = XFS_INOBT_REC_ADDR(block, ptr, cur);
 590                         xfs_btree_check_rec(cur->bc_btnum, recp, rp);
 591                 } else {
 592                         kp = XFS_INOBT_KEY_ADDR(block, ptr, cur);
 593                         xfs_btree_check_key(cur->bc_btnum, &key, kp);
 594                 }
 595         }
 596 #endif
 597         nbno = NULLAGBLOCK;
 598         ncur = NULL;
 599         /*
 600          * If the block is full, we can't insert the new entry until we
 601          * make the block un-full.
 602          */
 603         if (numrecs == XFS_INOBT_BLOCK_MAXRECS(level, cur)) {
 604                 /*
 605                  * First, try shifting an entry to the right neighbor.
 606                  */
 607                 if ((error = xfs_btree_rshift(cur, level, &i)))
 608                         return error;
 609                 if (i) {
 610                         /* nothing */
 611                 }
 612                 /*
 613                  * Next, try shifting an entry to the left neighbor.
 614                  */
 615                 else {
 616                         if ((error = xfs_btree_lshift(cur, level, &i)))
 617                                 return error;
 618                         if (i) {
 619                                 optr = ptr = cur->bc_ptrs[level];
 620                         } else {
 621                                 union xfs_btree_ptr bno = { .s = cpu_to_be32(nbno) };
 622                                 /*
 623                                  * Next, try splitting the current block
 624                                  * in half. If this works we have to
 625                                  * re-set our variables because
 626                                  * we could be in a different block now.
 627                                  */
 628                                 if ((error = xfs_btree_split(cur, level, &bno,
 629                                                 (union xfs_btree_key *)&nkey,
 630                                                 &ncur, &i)))
 631                                         return error;
 632                                 nbno = be32_to_cpu(bno.s);
 633                                 if (i) {
 634                                         bp = cur->bc_bufs[level];
 635                                         block = XFS_BUF_TO_INOBT_BLOCK(bp);
 636 #ifdef DEBUG
 637                                         if ((error = xfs_btree_check_sblock(cur,
 638                                                         block, level, bp)))
 639                                                 return error;
 640 #endif
 641                                         ptr = cur->bc_ptrs[level];
 642                                         nrec.ir_startino = nkey.ir_startino;
 643                                 } else {
 644                                         /*
 645                                          * Otherwise the insert fails.
 646                                          */
 647                                         *stat = 0;
 648                                         return 0;
 649                                 }
 650                         }
 651                 }
 652         }
 653         /*
 654          * At this point we know there's room for our new entry in the block
 655          * we're pointing at.
 656          */
 657         numrecs = be16_to_cpu(block->bb_numrecs);
 658         if (level > 0) {
 659                 /*
 660                  * It's a non-leaf entry.  Make a hole for the new data
 661                  * in the key and ptr regions of the block.
 662                  */
 663                 kp = XFS_INOBT_KEY_ADDR(block, 1, cur);
 664                 pp = XFS_INOBT_PTR_ADDR(block, 1, cur);
 665 #ifdef DEBUG
 666                 for (i = numrecs; i >= ptr; i--) {
 667                         if ((error = xfs_btree_check_sptr(cur, be32_to_cpu(pp[i - 1]), level)))
 668                                 return error;
 669                 }
 670 #endif
 671                 memmove(&kp[ptr], &kp[ptr - 1],
 672                         (numrecs - ptr + 1) * sizeof(*kp));
 673                 memmove(&pp[ptr], &pp[ptr - 1],
 674                         (numrecs - ptr + 1) * sizeof(*pp));
 675                 /*
 676                  * Now stuff the new data in, bump numrecs and log the new data.
 677                  */
 678 #ifdef DEBUG
 679                 if ((error = xfs_btree_check_sptr(cur, *bnop, level)))
 680                         return error;
 681 #endif
 682                 kp[ptr - 1] = key;
 683                 pp[ptr - 1] = cpu_to_be32(*bnop);
 684                 numrecs++;
 685                 block->bb_numrecs = cpu_to_be16(numrecs);
 686                 xfs_inobt_log_keys(cur, bp, ptr, numrecs);
 687                 xfs_inobt_log_ptrs(cur, bp, ptr, numrecs);
 688         } else {
 689                 /*
 690                  * It's a leaf entry.  Make a hole for the new record.
 691                  */
 692                 rp = XFS_INOBT_REC_ADDR(block, 1, cur);
 693                 memmove(&rp[ptr], &rp[ptr - 1],
 694                         (numrecs - ptr + 1) * sizeof(*rp));
 695                 /*
 696                  * Now stuff the new record in, bump numrecs
 697                  * and log the new data.
 698                  */
 699                 rp[ptr - 1] = *recp;
 700                 numrecs++;
 701                 block->bb_numrecs = cpu_to_be16(numrecs);
 702                 xfs_inobt_log_recs(cur, bp, ptr, numrecs);
 703         }
 704         /*
 705          * Log the new number of records in the btree header.
 706          */
 707         xfs_inobt_log_block(cur->bc_tp, bp, XFS_BB_NUMRECS);
 708 #ifdef DEBUG
 709         /*
 710          * Check that the key/record is in the right place, now.
 711          */
 712         if (ptr < numrecs) {
 713                 if (level == 0)
 714                         xfs_btree_check_rec(cur->bc_btnum, rp + ptr - 1,
 715                                 rp + ptr);
 716                 else
 717                         xfs_btree_check_key(cur->bc_btnum, kp + ptr - 1,
 718                                 kp + ptr);
 719         }
 720 #endif
 721         /*
 722          * If we inserted at the start of a block, update the parents' keys.
 723          */
 724         if (optr == 1 && (error = xfs_btree_updkey(cur, (union xfs_btree_key *)&key, level + 1)))
 725                 return error;
 726         /*
 727          * Return the new block number, if any.
 728          * If there is one, give back a record value and a cursor too.
 729          */
 730         *bnop = nbno;
 731         if (nbno != NULLAGBLOCK) {
 732                 *recp = nrec;
 733                 *curp = ncur;
 734         }
 735         *stat = 1;
 736         return 0;
 737 }
 738
 739 /*
 740  * Log header fields from a btree block.
 741  */
 742 STATIC void
 743 xfs_inobt_log_block(
 744         xfs_trans_t             *tp,    /* transaction pointer */
 745         xfs_buf_t               *bp,    /* buffer containing btree block */
 746         int                     fields) /* mask of fields: XFS_BB_... */
 747 {
 748         int                     first;  /* first byte offset logged */
 749         int                     last;   /* last byte offset logged */
 750         static const short      offsets[] = {   /* table of offsets */
 751                 offsetof(xfs_inobt_block_t, bb_magic),
 752                 offsetof(xfs_inobt_block_t, bb_level),
 753                 offsetof(xfs_inobt_block_t, bb_numrecs),
 754                 offsetof(xfs_inobt_block_t, bb_leftsib),
 755                 offsetof(xfs_inobt_block_t, bb_rightsib),
 756                 sizeof(xfs_inobt_block_t)
 757         };
 758
 759         xfs_btree_offsets(fields, offsets, XFS_BB_NUM_BITS, &first, &last);
 760         xfs_trans_log_buf(tp, bp, first, last);
 761 }
 762
 763 /*
 764  * Log keys from a btree block (nonleaf).
 765  */
 766 STATIC void
 767 xfs_inobt_log_keys(
 768         xfs_btree_cur_t         *cur,   /* btree cursor */
 769         xfs_buf_t               *bp,    /* buffer containing btree block */
 770         int                     kfirst, /* index of first key to log */
 771         int                     klast)  /* index of last key to log */
 772 {
 773         xfs_inobt_block_t       *block; /* btree block to log from */
 774         int                     first;  /* first byte offset logged */
 775         xfs_inobt_key_t         *kp;    /* key pointer in btree block */
 776         int                     last;   /* last byte offset logged */
 777
 778         block = XFS_BUF_TO_INOBT_BLOCK(bp);
 779         kp = XFS_INOBT_KEY_ADDR(block, 1, cur);
 780         first = (int)((xfs_caddr_t)&kp[kfirst - 1] - (xfs_caddr_t)block);
 781         last = (int)(((xfs_caddr_t)&kp[klast] - 1) - (xfs_caddr_t)block);
 782         xfs_trans_log_buf(cur->bc_tp, bp, first, last);
 783 }
 784
 785 /*
 786  * Log block pointer fields from a btree block (nonleaf).
 787  */
 788 STATIC void
 789 xfs_inobt_log_ptrs(
 790         xfs_btree_cur_t         *cur,   /* btree cursor */
 791         xfs_buf_t               *bp,    /* buffer containing btree block */
 792         int                     pfirst, /* index of first pointer to log */
 793         int                     plast)  /* index of last pointer to log */
 794 {
 795         xfs_inobt_block_t       *block; /* btree block to log from */
 796         int                     first;  /* first byte offset logged */
 797         int                     last;   /* last byte offset logged */
 798         xfs_inobt_ptr_t         *pp;    /* block-pointer pointer in btree blk */
 799
 800         block = XFS_BUF_TO_INOBT_BLOCK(bp);
 801         pp = XFS_INOBT_PTR_ADDR(block, 1, cur);
 802         first = (int)((xfs_caddr_t)&pp[pfirst - 1] - (xfs_caddr_t)block);
 803         last = (int)(((xfs_caddr_t)&pp[plast] - 1) - (xfs_caddr_t)block);
 804         xfs_trans_log_buf(cur->bc_tp, bp, first, last);
 805 }
 806
 807 /*
 808  * Log records from a btree block (leaf).
 809  */
 810 STATIC void
 811 xfs_inobt_log_recs(
 812         xfs_btree_cur_t         *cur,   /* btree cursor */
 813         xfs_buf_t               *bp,    /* buffer containing btree block */
 814         int                     rfirst, /* index of first record to log */
 815         int                     rlast)  /* index of last record to log */
 816 {
 817         xfs_inobt_block_t       *block; /* btree block to log from */
 818         int                     first;  /* first byte offset logged */
 819         int                     last;   /* last byte offset logged */
 820         xfs_inobt_rec_t         *rp;    /* record pointer for btree block */
 821
 822         block = XFS_BUF_TO_INOBT_BLOCK(bp);
 823         rp = XFS_INOBT_REC_ADDR(block, 1, cur);
 824         first = (int)((xfs_caddr_t)&rp[rfirst - 1] - (xfs_caddr_t)block);
 825         last = (int)(((xfs_caddr_t)&rp[rlast] - 1) - (xfs_caddr_t)block);
 826         xfs_trans_log_buf(cur->bc_tp, bp, first, last);
 827 }
 828
 829
 830 /*
 831  * Externally visible routines.
 832  */
 833
 834 /*
 835  * Delete the record pointed to by cur.
 836  * The cursor refers to the place where the record was (could be inserted)
 837  * when the operation returns.
 838  */
 839 int                                     /* error */
 840 xfs_inobt_delete(
 841         xfs_btree_cur_t *cur,           /* btree cursor */
 842         int             *stat)          /* success/failure */
 843 {
 844         int             error;
 845         int             i;              /* result code */
 846         int             level;          /* btree level */
 847
 848         /*
 849          * Go up the tree, starting at leaf level.
 850          * If 2 is returned then a join was done; go to the next level.
 851          * Otherwise we are done.
 852          */
 853         for (level = 0, i = 2; i == 2; level++) {
 854                 if ((error = xfs_inobt_delrec(cur, level, &i)))
 855                         return error;
 856         }
 857         if (i == 0) {
 858                 for (level = 1; level < cur->bc_nlevels; level++) {
 859                         if (cur->bc_ptrs[level] == 0) {
 860                                 if ((error = xfs_btree_decrement(cur, level, &i)))
 861                                         return error;
 862                                 break;
 863                         }
 864                 }
 865         }
 866         *stat = i;
 867         return 0;
 868 }
 869
 870
 871 /*
 872  * Get the data from the pointed-to record.
 873  */
 874 int                                     /* error */
 875 xfs_inobt_get_rec(
 876         xfs_btree_cur_t         *cur,   /* btree cursor */
 877         xfs_agino_t             *ino,   /* output: starting inode of chunk */
 878         __int32_t               *fcnt,  /* output: number of free inodes */
 879         xfs_inofree_t           *free,  /* output: free inode mask */
 880         int                     *stat)  /* output: success/failure */
 881 {
 882         xfs_inobt_block_t       *block; /* btree block */
 883         xfs_buf_t               *bp;    /* buffer containing btree block */
 884 #ifdef DEBUG
 885         int                     error;  /* error return value */
 886 #endif
 887         int                     ptr;    /* record number */
 888         xfs_inobt_rec_t         *rec;   /* record data */
 889
 890         bp = cur->bc_bufs[0];
 891         ptr = cur->bc_ptrs[0];
 892         block = XFS_BUF_TO_INOBT_BLOCK(bp);
 893 #ifdef DEBUG
 894         if ((error = xfs_btree_check_sblock(cur, block, 0, bp)))
 895                 return error;
 896 #endif
 897         /*
 898          * Off the right end or left end, return failure.
 899          */
 900         if (ptr > be16_to_cpu(block->bb_numrecs) || ptr <= 0) {
 901                 *stat = 0;
 902                 return 0;
 903         }
 904         /*
 905          * Point to the record and extract its data.
 906          */
 907         rec = XFS_INOBT_REC_ADDR(block, ptr, cur);
 908         *ino = be32_to_cpu(rec->ir_startino);
 909         *fcnt = be32_to_cpu(rec->ir_freecount);
 910         *free = be64_to_cpu(rec->ir_free);
 911         *stat = 1;
 912         return 0;
 913 }
 914
 915 /*
 916  * Insert the current record at the point referenced by cur.
 917  * The cursor may be inconsistent on return if splits have been done.
 918  */
 919 int                                     /* error */
 920 xfs_inobt_insert(
 921         xfs_btree_cur_t *cur,           /* btree cursor */
 922         int             *stat)          /* success/failure */
 923 {
 924         int             error;          /* error return value */
 925         int             i;              /* result value, 0 for failure */
 926         int             level;          /* current level number in btree */
 927         xfs_agblock_t   nbno;           /* new block number (split result) */
 928         xfs_btree_cur_t *ncur;          /* new cursor (split result) */
 929         xfs_inobt_rec_t nrec;           /* record being inserted this level */
 930         xfs_btree_cur_t *pcur;          /* previous level's cursor */
 931
 932         level = 0;
 933         nbno = NULLAGBLOCK;
 934         nrec.ir_startino = cpu_to_be32(cur->bc_rec.i.ir_startino);
 935         nrec.ir_freecount = cpu_to_be32(cur->bc_rec.i.ir_freecount);
 936         nrec.ir_free = cpu_to_be64(cur->bc_rec.i.ir_free);
 937         ncur = NULL;
 938         pcur = cur;
 939         /*
 940          * Loop going up the tree, starting at the leaf level.
 941          * Stop when we don't get a split block, that must mean that
 942          * the insert is finished with this level.
 943          */
 944         do {
 945                 /*
 946                  * Insert nrec/nbno into this level of the tree.
 947                  * Note if we fail, nbno will be null.
 948                  */
 949                 if ((error = xfs_inobt_insrec(pcur, level++, &nbno, &nrec, &ncur,
 950                                 &i))) {
 951                         if (pcur != cur)
 952                                 xfs_btree_del_cursor(pcur, XFS_BTREE_ERROR);
 953                         return error;
 954                 }
 955                 /*
 956                  * See if the cursor we just used is trash.
 957                  * Can't trash the caller's cursor, but otherwise we should
 958                  * if ncur is a new cursor or we're about to be done.
 959                  */
 960                 if (pcur != cur && (ncur || nbno == NULLAGBLOCK)) {
 961                         cur->bc_nlevels = pcur->bc_nlevels;
 962                         xfs_btree_del_cursor(pcur, XFS_BTREE_NOERROR);
 963                 }
 964                 /*
 965                  * If we got a new cursor, switch to it.
 966                  */
 967                 if (ncur) {
 968                         pcur = ncur;
 969                         ncur = NULL;
 970                 }
 971         } while (nbno != NULLAGBLOCK);
 972         *stat = i;
 973         return 0;
 974 }
 975
 976 STATIC struct xfs_btree_cur *
 977 xfs_inobt_dup_cursor(
 978         struct xfs_btree_cur    *cur)
 979 {
 980         return xfs_inobt_init_cursor(cur->bc_mp, cur->bc_tp,
 981                         cur->bc_private.a.agbp, cur->bc_private.a.agno);
 982 }
 983
 984 STATIC void
 985 xfs_inobt_set_root(
 986         struct xfs_btree_cur    *cur,
 987         union xfs_btree_ptr     *nptr,
 988         int                     inc)    /* level change */
 989 {
 990         struct xfs_buf          *agbp = cur->bc_private.a.agbp;
 991         struct xfs_agi          *agi = XFS_BUF_TO_AGI(agbp);
 992
 993         agi->agi_root = nptr->s;
 994         be32_add_cpu(&agi->agi_level, inc);
 995         xfs_ialloc_log_agi(cur->bc_tp, agbp, XFS_AGI_ROOT | XFS_AGI_LEVEL);
 996 }
 997
 998 STATIC int
 999 xfs_inobt_alloc_block(
1000         struct xfs_btree_cur    *cur,
1001         union xfs_btree_ptr     *start,
1002         union xfs_btree_ptr     *new,
1003         int                     length,
1004         int                     *stat)
1005 {
1006         xfs_alloc_arg_t         args;           /* block allocation args */
1007         int                     error;          /* error return value */
1008         xfs_agblock_t           sbno = be32_to_cpu(start->s);
1009
1010         XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1011
1012         memset(&args, 0, sizeof(args));
1013         args.tp = cur->bc_tp;
1014         args.mp = cur->bc_mp;
1015         args.fsbno = XFS_AGB_TO_FSB(args.mp, cur->bc_private.a.agno, sbno);
1016         args.minlen = 1;
1017         args.maxlen = 1;
1018         args.prod = 1;
1019         args.type = XFS_ALLOCTYPE_NEAR_BNO;
1020
1021         error = xfs_alloc_vextent(&args);
1022         if (error) {
1023                 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1024                 return error;
1025         }
1026         if (args.fsbno == NULLFSBLOCK) {
1027                 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1028                 *stat = 0;
1029                 return 0;
1030         }
1031         ASSERT(args.len == 1);
1032         XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1033
1034         new->s = cpu_to_be32(XFS_FSB_TO_AGBNO(args.mp, args.fsbno));
1035         *stat = 1;
1036         return 0;
1037 }
1038
1039
1040 STATIC int
1041 xfs_inobt_get_maxrecs(
1042         struct xfs_btree_cur    *cur,
1043         int                     level)
1044 {
1045         return cur->bc_mp->m_inobt_mxr[level != 0];
1046 }
1047
1048 STATIC void
1049 xfs_inobt_init_key_from_rec(
1050         union xfs_btree_key     *key,
1051         union xfs_btree_rec     *rec)
1052 {
1053         key->inobt.ir_startino = rec->inobt.ir_startino;
1054 }
1055
1056 /*
1057  * intial value of ptr for lookup
1058  */
1059 STATIC void
1060 xfs_inobt_init_ptr_from_cur(
1061         struct xfs_btree_cur    *cur,
1062         union xfs_btree_ptr     *ptr)
1063 {
1064         struct xfs_agi          *agi = XFS_BUF_TO_AGI(cur->bc_private.a.agbp);
1065
1066         ASSERT(cur->bc_private.a.agno == be32_to_cpu(agi->agi_seqno));
1067
1068         ptr->s = agi->agi_root;
1069 }
1070
1071 STATIC __int64_t
1072 xfs_inobt_key_diff(
1073         struct xfs_btree_cur    *cur,
1074         union xfs_btree_key     *key)
1075 {
1076         return (__int64_t)be32_to_cpu(key->inobt.ir_startino) -
1077                           cur->bc_rec.i.ir_startino;
1078 }
1079
1080 #ifdef XFS_BTREE_TRACE
1081 ktrace_t        *xfs_inobt_trace_buf;
1082
1083 STATIC void
1084 xfs_inobt_trace_enter(
1085         struct xfs_btree_cur    *cur,
1086         const char              *func,
1087         char                    *s,
1088         int                     type,
1089         int                     line,
1090         __psunsigned_t          a0,
1091         __psunsigned_t          a1,
1092         __psunsigned_t          a2,
1093         __psunsigned_t          a3,
1094         __psunsigned_t          a4,
1095         __psunsigned_t          a5,
1096         __psunsigned_t          a6,
1097         __psunsigned_t          a7,
1098         __psunsigned_t          a8,
1099         __psunsigned_t          a9,
1100         __psunsigned_t          a10)
1101 {
1102         ktrace_enter(xfs_inobt_trace_buf, (void *)(__psint_t)type,
1103                 (void *)func, (void *)s, NULL, (void *)cur,
1104                 (void *)a0, (void *)a1, (void *)a2, (void *)a3,
1105                 (void *)a4, (void *)a5, (void *)a6, (void *)a7,
1106                 (void *)a8, (void *)a9, (void *)a10);
1107 }
1108
1109 STATIC void
1110 xfs_inobt_trace_cursor(
1111         struct xfs_btree_cur    *cur,
1112         __uint32_t              *s0,
1113         __uint64_t              *l0,
1114         __uint64_t              *l1)
1115 {
1116         *s0 = cur->bc_private.a.agno;
1117         *l0 = cur->bc_rec.i.ir_startino;
1118         *l1 = cur->bc_rec.i.ir_free;
1119 }
1120
1121 STATIC void
1122 xfs_inobt_trace_key(
1123         struct xfs_btree_cur    *cur,
1124         union xfs_btree_key     *key,
1125         __uint64_t              *l0,
1126         __uint64_t              *l1)
1127 {
1128         *l0 = be32_to_cpu(key->inobt.ir_startino);
1129         *l1 = 0;
1130 }
1131
1132 STATIC void
1133 xfs_inobt_trace_record(
1134         struct xfs_btree_cur    *cur,
1135         union xfs_btree_rec     *rec,
1136         __uint64_t              *l0,
1137         __uint64_t              *l1,
1138         __uint64_t              *l2)
1139 {
1140         *l0 = be32_to_cpu(rec->inobt.ir_startino);
1141         *l1 = be32_to_cpu(rec->inobt.ir_freecount);
1142         *l2 = be64_to_cpu(rec->inobt.ir_free);
1143 }
1144 #endif /* XFS_BTREE_TRACE */
1145
1146 static const struct xfs_btree_ops xfs_inobt_ops = {
1147         .rec_len                = sizeof(xfs_inobt_rec_t),
1148         .key_len                = sizeof(xfs_inobt_key_t),
1149
1150         .dup_cursor             = xfs_inobt_dup_cursor,
1151         .set_root               = xfs_inobt_set_root,
1152         .alloc_block            = xfs_inobt_alloc_block,
1153         .get_maxrecs            = xfs_inobt_get_maxrecs,
1154         .init_key_from_rec      = xfs_inobt_init_key_from_rec,
1155         .init_ptr_from_cur      = xfs_inobt_init_ptr_from_cur,
1156         .key_diff               = xfs_inobt_key_diff,
1157
1158 #ifdef XFS_BTREE_TRACE
1159         .trace_enter            = xfs_inobt_trace_enter,
1160         .trace_cursor           = xfs_inobt_trace_cursor,
1161         .trace_key              = xfs_inobt_trace_key,
1162         .trace_record           = xfs_inobt_trace_record,
1163 #endif
1164 };
1165
1166 /*
1167  * Allocate a new inode btree cursor.
1168  */
1169 struct xfs_btree_cur *                          /* new inode btree cursor */
1170 xfs_inobt_init_cursor(
1171         struct xfs_mount        *mp,            /* file system mount point */
1172         struct xfs_trans        *tp,            /* transaction pointer */
1173         struct xfs_buf          *agbp,          /* buffer for agi structure */
1174         xfs_agnumber_t          agno)           /* allocation group number */
1175 {
1176         struct xfs_agi          *agi = XFS_BUF_TO_AGI(agbp);
1177         struct xfs_btree_cur    *cur;
1178
1179         cur = kmem_zone_zalloc(xfs_btree_cur_zone, KM_SLEEP);
1180
1181         cur->bc_tp = tp;
1182         cur->bc_mp = mp;
1183         cur->bc_nlevels = be32_to_cpu(agi->agi_level);
1184         cur->bc_btnum = XFS_BTNUM_INO;
1185         cur->bc_blocklog = mp->m_sb.sb_blocklog;
1186
1187         cur->bc_ops = &xfs_inobt_ops;
1188
1189         cur->bc_private.a.agbp = agbp;
1190         cur->bc_private.a.agno = agno;
1191
1192         return cur;
1193 }