linux/fs/xfs/xfs_btree.c
<<
>>
Prefs
   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_trans.h"
  24#include "xfs_sb.h"
  25#include "xfs_ag.h"
  26#include "xfs_mount.h"
  27#include "xfs_bmap_btree.h"
  28#include "xfs_alloc_btree.h"
  29#include "xfs_ialloc_btree.h"
  30#include "xfs_dinode.h"
  31#include "xfs_inode.h"
  32#include "xfs_inode_item.h"
  33#include "xfs_buf_item.h"
  34#include "xfs_btree.h"
  35#include "xfs_error.h"
  36#include "xfs_trace.h"
  37#include "xfs_cksum.h"
  38
  39/*
  40 * Cursor allocation zone.
  41 */
  42kmem_zone_t     *xfs_btree_cur_zone;
  43
  44/*
  45 * Btree magic numbers.
  46 */
  47static const __uint32_t xfs_magics[2][XFS_BTNUM_MAX] = {
  48        { XFS_ABTB_MAGIC, XFS_ABTC_MAGIC, XFS_BMAP_MAGIC, XFS_IBT_MAGIC },
  49        { XFS_ABTB_CRC_MAGIC, XFS_ABTC_CRC_MAGIC,
  50          XFS_BMAP_CRC_MAGIC, XFS_IBT_CRC_MAGIC }
  51};
  52#define xfs_btree_magic(cur) \
  53        xfs_magics[!!((cur)->bc_flags & XFS_BTREE_CRC_BLOCKS)][cur->bc_btnum]
  54
  55
  56STATIC int                              /* error (0 or EFSCORRUPTED) */
  57xfs_btree_check_lblock(
  58        struct xfs_btree_cur    *cur,   /* btree cursor */
  59        struct xfs_btree_block  *block, /* btree long form block pointer */
  60        int                     level,  /* level of the btree block */
  61        struct xfs_buf          *bp)    /* buffer for block, if any */
  62{
  63        int                     lblock_ok = 1; /* block passes checks */
  64        struct xfs_mount        *mp;    /* file system mount point */
  65
  66        mp = cur->bc_mp;
  67
  68        if (xfs_sb_version_hascrc(&mp->m_sb)) {
  69                lblock_ok = lblock_ok &&
  70                        uuid_equal(&block->bb_u.l.bb_uuid, &mp->m_sb.sb_uuid) &&
  71                        block->bb_u.l.bb_blkno == cpu_to_be64(
  72                                bp ? bp->b_bn : XFS_BUF_DADDR_NULL);
  73        }
  74
  75        lblock_ok = lblock_ok &&
  76                be32_to_cpu(block->bb_magic) == xfs_btree_magic(cur) &&
  77                be16_to_cpu(block->bb_level) == level &&
  78                be16_to_cpu(block->bb_numrecs) <=
  79                        cur->bc_ops->get_maxrecs(cur, level) &&
  80                block->bb_u.l.bb_leftsib &&
  81                (block->bb_u.l.bb_leftsib == cpu_to_be64(NULLDFSBNO) ||
  82                 XFS_FSB_SANITY_CHECK(mp,
  83                        be64_to_cpu(block->bb_u.l.bb_leftsib))) &&
  84                block->bb_u.l.bb_rightsib &&
  85                (block->bb_u.l.bb_rightsib == cpu_to_be64(NULLDFSBNO) ||
  86                 XFS_FSB_SANITY_CHECK(mp,
  87                        be64_to_cpu(block->bb_u.l.bb_rightsib)));
  88
  89        if (unlikely(XFS_TEST_ERROR(!lblock_ok, mp,
  90                        XFS_ERRTAG_BTREE_CHECK_LBLOCK,
  91                        XFS_RANDOM_BTREE_CHECK_LBLOCK))) {
  92                if (bp)
  93                        trace_xfs_btree_corrupt(bp, _RET_IP_);
  94                XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_LOW, mp);
  95                return XFS_ERROR(EFSCORRUPTED);
  96        }
  97        return 0;
  98}
  99
 100STATIC int                              /* error (0 or EFSCORRUPTED) */
 101xfs_btree_check_sblock(
 102        struct xfs_btree_cur    *cur,   /* btree cursor */
 103        struct xfs_btree_block  *block, /* btree short form block pointer */
 104        int                     level,  /* level of the btree block */
 105        struct xfs_buf          *bp)    /* buffer containing block */
 106{
 107        struct xfs_mount        *mp;    /* file system mount point */
 108        struct xfs_buf          *agbp;  /* buffer for ag. freespace struct */
 109        struct xfs_agf          *agf;   /* ag. freespace structure */
 110        xfs_agblock_t           agflen; /* native ag. freespace length */
 111        int                     sblock_ok = 1; /* block passes checks */
 112
 113        mp = cur->bc_mp;
 114        agbp = cur->bc_private.a.agbp;
 115        agf = XFS_BUF_TO_AGF(agbp);
 116        agflen = be32_to_cpu(agf->agf_length);
 117
 118        if (xfs_sb_version_hascrc(&mp->m_sb)) {
 119                sblock_ok = sblock_ok &&
 120                        uuid_equal(&block->bb_u.s.bb_uuid, &mp->m_sb.sb_uuid) &&
 121                        block->bb_u.s.bb_blkno == cpu_to_be64(
 122                                bp ? bp->b_bn : XFS_BUF_DADDR_NULL);
 123        }
 124
 125        sblock_ok = sblock_ok &&
 126                be32_to_cpu(block->bb_magic) == xfs_btree_magic(cur) &&
 127                be16_to_cpu(block->bb_level) == level &&
 128                be16_to_cpu(block->bb_numrecs) <=
 129                        cur->bc_ops->get_maxrecs(cur, level) &&
 130                (block->bb_u.s.bb_leftsib == cpu_to_be32(NULLAGBLOCK) ||
 131                 be32_to_cpu(block->bb_u.s.bb_leftsib) < agflen) &&
 132                block->bb_u.s.bb_leftsib &&
 133                (block->bb_u.s.bb_rightsib == cpu_to_be32(NULLAGBLOCK) ||
 134                 be32_to_cpu(block->bb_u.s.bb_rightsib) < agflen) &&
 135                block->bb_u.s.bb_rightsib;
 136
 137        if (unlikely(XFS_TEST_ERROR(!sblock_ok, mp,
 138                        XFS_ERRTAG_BTREE_CHECK_SBLOCK,
 139                        XFS_RANDOM_BTREE_CHECK_SBLOCK))) {
 140                if (bp)
 141                        trace_xfs_btree_corrupt(bp, _RET_IP_);
 142                XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_LOW, mp);
 143                return XFS_ERROR(EFSCORRUPTED);
 144        }
 145        return 0;
 146}
 147
 148/*
 149 * Debug routine: check that block header is ok.
 150 */
 151int
 152xfs_btree_check_block(
 153        struct xfs_btree_cur    *cur,   /* btree cursor */
 154        struct xfs_btree_block  *block, /* generic btree block pointer */
 155        int                     level,  /* level of the btree block */
 156        struct xfs_buf          *bp)    /* buffer containing block, if any */
 157{
 158        if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
 159                return xfs_btree_check_lblock(cur, block, level, bp);
 160        else
 161                return xfs_btree_check_sblock(cur, block, level, bp);
 162}
 163
 164/*
 165 * Check that (long) pointer is ok.
 166 */
 167int                                     /* error (0 or EFSCORRUPTED) */
 168xfs_btree_check_lptr(
 169        struct xfs_btree_cur    *cur,   /* btree cursor */
 170        xfs_dfsbno_t            bno,    /* btree block disk address */
 171        int                     level)  /* btree block level */
 172{
 173        XFS_WANT_CORRUPTED_RETURN(
 174                level > 0 &&
 175                bno != NULLDFSBNO &&
 176                XFS_FSB_SANITY_CHECK(cur->bc_mp, bno));
 177        return 0;
 178}
 179
 180#ifdef DEBUG
 181/*
 182 * Check that (short) pointer is ok.
 183 */
 184STATIC int                              /* error (0 or EFSCORRUPTED) */
 185xfs_btree_check_sptr(
 186        struct xfs_btree_cur    *cur,   /* btree cursor */
 187        xfs_agblock_t           bno,    /* btree block disk address */
 188        int                     level)  /* btree block level */
 189{
 190        xfs_agblock_t           agblocks = cur->bc_mp->m_sb.sb_agblocks;
 191
 192        XFS_WANT_CORRUPTED_RETURN(
 193                level > 0 &&
 194                bno != NULLAGBLOCK &&
 195                bno != 0 &&
 196                bno < agblocks);
 197        return 0;
 198}
 199
 200/*
 201 * Check that block ptr is ok.
 202 */
 203STATIC int                              /* error (0 or EFSCORRUPTED) */
 204xfs_btree_check_ptr(
 205        struct xfs_btree_cur    *cur,   /* btree cursor */
 206        union xfs_btree_ptr     *ptr,   /* btree block disk address */
 207        int                     index,  /* offset from ptr to check */
 208        int                     level)  /* btree block level */
 209{
 210        if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
 211                return xfs_btree_check_lptr(cur,
 212                                be64_to_cpu((&ptr->l)[index]), level);
 213        } else {
 214                return xfs_btree_check_sptr(cur,
 215                                be32_to_cpu((&ptr->s)[index]), level);
 216        }
 217}
 218#endif
 219
 220/*
 221 * Calculate CRC on the whole btree block and stuff it into the
 222 * long-form btree header.
 223 *
 224 * Prior to calculting the CRC, pull the LSN out of the buffer log item and put
 225 * it into the buffer so recovery knows what the last modifcation was that made
 226 * it to disk.
 227 */
 228void
 229xfs_btree_lblock_calc_crc(
 230        struct xfs_buf          *bp)
 231{
 232        struct xfs_btree_block  *block = XFS_BUF_TO_BLOCK(bp);
 233        struct xfs_buf_log_item *bip = bp->b_fspriv;
 234
 235        if (!xfs_sb_version_hascrc(&bp->b_target->bt_mount->m_sb))
 236                return;
 237        if (bip)
 238                block->bb_u.l.bb_lsn = cpu_to_be64(bip->bli_item.li_lsn);
 239        xfs_update_cksum(bp->b_addr, BBTOB(bp->b_length),
 240                         XFS_BTREE_LBLOCK_CRC_OFF);
 241}
 242
 243bool
 244xfs_btree_lblock_verify_crc(
 245        struct xfs_buf          *bp)
 246{
 247        if (xfs_sb_version_hascrc(&bp->b_target->bt_mount->m_sb))
 248                return xfs_verify_cksum(bp->b_addr, BBTOB(bp->b_length),
 249                                        XFS_BTREE_LBLOCK_CRC_OFF);
 250        return true;
 251}
 252
 253/*
 254 * Calculate CRC on the whole btree block and stuff it into the
 255 * short-form btree header.
 256 *
 257 * Prior to calculting the CRC, pull the LSN out of the buffer log item and put
 258 * it into the buffer so recovery knows what the last modifcation was that made
 259 * it to disk.
 260 */
 261void
 262xfs_btree_sblock_calc_crc(
 263        struct xfs_buf          *bp)
 264{
 265        struct xfs_btree_block  *block = XFS_BUF_TO_BLOCK(bp);
 266        struct xfs_buf_log_item *bip = bp->b_fspriv;
 267
 268        if (!xfs_sb_version_hascrc(&bp->b_target->bt_mount->m_sb))
 269                return;
 270        if (bip)
 271                block->bb_u.s.bb_lsn = cpu_to_be64(bip->bli_item.li_lsn);
 272        xfs_update_cksum(bp->b_addr, BBTOB(bp->b_length),
 273                         XFS_BTREE_SBLOCK_CRC_OFF);
 274}
 275
 276bool
 277xfs_btree_sblock_verify_crc(
 278        struct xfs_buf          *bp)
 279{
 280        if (xfs_sb_version_hascrc(&bp->b_target->bt_mount->m_sb))
 281                return xfs_verify_cksum(bp->b_addr, BBTOB(bp->b_length),
 282                                        XFS_BTREE_SBLOCK_CRC_OFF);
 283        return true;
 284}
 285
 286/*
 287 * Delete the btree cursor.
 288 */
 289void
 290xfs_btree_del_cursor(
 291        xfs_btree_cur_t *cur,           /* btree cursor */
 292        int             error)          /* del because of error */
 293{
 294        int             i;              /* btree level */
 295
 296        /*
 297         * Clear the buffer pointers, and release the buffers.
 298         * If we're doing this in the face of an error, we
 299         * need to make sure to inspect all of the entries
 300         * in the bc_bufs array for buffers to be unlocked.
 301         * This is because some of the btree code works from
 302         * level n down to 0, and if we get an error along
 303         * the way we won't have initialized all the entries
 304         * down to 0.
 305         */
 306        for (i = 0; i < cur->bc_nlevels; i++) {
 307                if (cur->bc_bufs[i])
 308                        xfs_trans_brelse(cur->bc_tp, cur->bc_bufs[i]);
 309                else if (!error)
 310                        break;
 311        }
 312        /*
 313         * Can't free a bmap cursor without having dealt with the
 314         * allocated indirect blocks' accounting.
 315         */
 316        ASSERT(cur->bc_btnum != XFS_BTNUM_BMAP ||
 317               cur->bc_private.b.allocated == 0);
 318        /*
 319         * Free the cursor.
 320         */
 321        kmem_zone_free(xfs_btree_cur_zone, cur);
 322}
 323
 324/*
 325 * Duplicate the btree cursor.
 326 * Allocate a new one, copy the record, re-get the buffers.
 327 */
 328int                                     /* error */
 329xfs_btree_dup_cursor(
 330        xfs_btree_cur_t *cur,           /* input cursor */
 331        xfs_btree_cur_t **ncur)         /* output cursor */
 332{
 333        xfs_buf_t       *bp;            /* btree block's buffer pointer */
 334        int             error;          /* error return value */
 335        int             i;              /* level number of btree block */
 336        xfs_mount_t     *mp;            /* mount structure for filesystem */
 337        xfs_btree_cur_t *new;           /* new cursor value */
 338        xfs_trans_t     *tp;            /* transaction pointer, can be NULL */
 339
 340        tp = cur->bc_tp;
 341        mp = cur->bc_mp;
 342
 343        /*
 344         * Allocate a new cursor like the old one.
 345         */
 346        new = cur->bc_ops->dup_cursor(cur);
 347
 348        /*
 349         * Copy the record currently in the cursor.
 350         */
 351        new->bc_rec = cur->bc_rec;
 352
 353        /*
 354         * For each level current, re-get the buffer and copy the ptr value.
 355         */
 356        for (i = 0; i < new->bc_nlevels; i++) {
 357                new->bc_ptrs[i] = cur->bc_ptrs[i];
 358                new->bc_ra[i] = cur->bc_ra[i];
 359                bp = cur->bc_bufs[i];
 360                if (bp) {
 361                        error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp,
 362                                                   XFS_BUF_ADDR(bp), mp->m_bsize,
 363                                                   0, &bp,
 364                                                   cur->bc_ops->buf_ops);
 365                        if (error) {
 366                                xfs_btree_del_cursor(new, error);
 367                                *ncur = NULL;
 368                                return error;
 369                        }
 370                }
 371                new->bc_bufs[i] = bp;
 372        }
 373        *ncur = new;
 374        return 0;
 375}
 376
 377/*
 378 * XFS btree block layout and addressing:
 379 *
 380 * There are two types of blocks in the btree: leaf and non-leaf blocks.
 381 *
 382 * The leaf record start with a header then followed by records containing
 383 * the values.  A non-leaf block also starts with the same header, and
 384 * then first contains lookup keys followed by an equal number of pointers
 385 * to the btree blocks at the previous level.
 386 *
 387 *              +--------+-------+-------+-------+-------+-------+-------+
 388 * Leaf:        | header | rec 1 | rec 2 | rec 3 | rec 4 | rec 5 | rec N |
 389 *              +--------+-------+-------+-------+-------+-------+-------+
 390 *
 391 *              +--------+-------+-------+-------+-------+-------+-------+
 392 * Non-Leaf:    | header | key 1 | key 2 | key N | ptr 1 | ptr 2 | ptr N |
 393 *              +--------+-------+-------+-------+-------+-------+-------+
 394 *
 395 * The header is called struct xfs_btree_block for reasons better left unknown
 396 * and comes in different versions for short (32bit) and long (64bit) block
 397 * pointers.  The record and key structures are defined by the btree instances
 398 * and opaque to the btree core.  The block pointers are simple disk endian
 399 * integers, available in a short (32bit) and long (64bit) variant.
 400 *
 401 * The helpers below calculate the offset of a given record, key or pointer
 402 * into a btree block (xfs_btree_*_offset) or return a pointer to the given
 403 * record, key or pointer (xfs_btree_*_addr).  Note that all addressing
 404 * inside the btree block is done using indices starting at one, not zero!
 405 */
 406
 407/*
 408 * Return size of the btree block header for this btree instance.
 409 */
 410static inline size_t xfs_btree_block_len(struct xfs_btree_cur *cur)
 411{
 412        if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
 413                if (cur->bc_flags & XFS_BTREE_CRC_BLOCKS)
 414                        return XFS_BTREE_LBLOCK_CRC_LEN;
 415                return XFS_BTREE_LBLOCK_LEN;
 416        }
 417        if (cur->bc_flags & XFS_BTREE_CRC_BLOCKS)
 418                return XFS_BTREE_SBLOCK_CRC_LEN;
 419        return XFS_BTREE_SBLOCK_LEN;
 420}
 421
 422/*
 423 * Return size of btree block pointers for this btree instance.
 424 */
 425static inline size_t xfs_btree_ptr_len(struct xfs_btree_cur *cur)
 426{
 427        return (cur->bc_flags & XFS_BTREE_LONG_PTRS) ?
 428                sizeof(__be64) : sizeof(__be32);
 429}
 430
 431/*
 432 * Calculate offset of the n-th record in a btree block.
 433 */
 434STATIC size_t
 435xfs_btree_rec_offset(
 436        struct xfs_btree_cur    *cur,
 437        int                     n)
 438{
 439        return xfs_btree_block_len(cur) +
 440                (n - 1) * cur->bc_ops->rec_len;
 441}
 442
 443/*
 444 * Calculate offset of the n-th key in a btree block.
 445 */
 446STATIC size_t
 447xfs_btree_key_offset(
 448        struct xfs_btree_cur    *cur,
 449        int                     n)
 450{
 451        return xfs_btree_block_len(cur) +
 452                (n - 1) * cur->bc_ops->key_len;
 453}
 454
 455/*
 456 * Calculate offset of the n-th block pointer in a btree block.
 457 */
 458STATIC size_t
 459xfs_btree_ptr_offset(
 460        struct xfs_btree_cur    *cur,
 461        int                     n,
 462        int                     level)
 463{
 464        return xfs_btree_block_len(cur) +
 465                cur->bc_ops->get_maxrecs(cur, level) * cur->bc_ops->key_len +
 466                (n - 1) * xfs_btree_ptr_len(cur);
 467}
 468
 469/*
 470 * Return a pointer to the n-th record in the btree block.
 471 */
 472STATIC union xfs_btree_rec *
 473xfs_btree_rec_addr(
 474        struct xfs_btree_cur    *cur,
 475        int                     n,
 476        struct xfs_btree_block  *block)
 477{
 478        return (union xfs_btree_rec *)
 479                ((char *)block + xfs_btree_rec_offset(cur, n));
 480}
 481
 482/*
 483 * Return a pointer to the n-th key in the btree block.
 484 */
 485STATIC union xfs_btree_key *
 486xfs_btree_key_addr(
 487        struct xfs_btree_cur    *cur,
 488        int                     n,
 489        struct xfs_btree_block  *block)
 490{
 491        return (union xfs_btree_key *)
 492                ((char *)block + xfs_btree_key_offset(cur, n));
 493}
 494
 495/*
 496 * Return a pointer to the n-th block pointer in the btree block.
 497 */
 498STATIC union xfs_btree_ptr *
 499xfs_btree_ptr_addr(
 500        struct xfs_btree_cur    *cur,
 501        int                     n,
 502        struct xfs_btree_block  *block)
 503{
 504        int                     level = xfs_btree_get_level(block);
 505
 506        ASSERT(block->bb_level != 0);
 507
 508        return (union xfs_btree_ptr *)
 509                ((char *)block + xfs_btree_ptr_offset(cur, n, level));
 510}
 511
 512/*
 513 * Get a the root block which is stored in the inode.
 514 *
 515 * For now this btree implementation assumes the btree root is always
 516 * stored in the if_broot field of an inode fork.
 517 */
 518STATIC struct xfs_btree_block *
 519xfs_btree_get_iroot(
 520       struct xfs_btree_cur    *cur)
 521{
 522       struct xfs_ifork        *ifp;
 523
 524       ifp = XFS_IFORK_PTR(cur->bc_private.b.ip, cur->bc_private.b.whichfork);
 525       return (struct xfs_btree_block *)ifp->if_broot;
 526}
 527
 528/*
 529 * Retrieve the block pointer from the cursor at the given level.
 530 * This may be an inode btree root or from a buffer.
 531 */
 532STATIC struct xfs_btree_block *         /* generic btree block pointer */
 533xfs_btree_get_block(
 534        struct xfs_btree_cur    *cur,   /* btree cursor */
 535        int                     level,  /* level in btree */
 536        struct xfs_buf          **bpp)  /* buffer containing the block */
 537{
 538        if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
 539            (level == cur->bc_nlevels - 1)) {
 540                *bpp = NULL;
 541                return xfs_btree_get_iroot(cur);
 542        }
 543
 544        *bpp = cur->bc_bufs[level];
 545        return XFS_BUF_TO_BLOCK(*bpp);
 546}
 547
 548/*
 549 * Get a buffer for the block, return it with no data read.
 550 * Long-form addressing.
 551 */
 552xfs_buf_t *                             /* buffer for fsbno */
 553xfs_btree_get_bufl(
 554        xfs_mount_t     *mp,            /* file system mount point */
 555        xfs_trans_t     *tp,            /* transaction pointer */
 556        xfs_fsblock_t   fsbno,          /* file system block number */
 557        uint            lock)           /* lock flags for get_buf */
 558{
 559        xfs_buf_t       *bp;            /* buffer pointer (return value) */
 560        xfs_daddr_t             d;              /* real disk block address */
 561
 562        ASSERT(fsbno != NULLFSBLOCK);
 563        d = XFS_FSB_TO_DADDR(mp, fsbno);
 564        bp = xfs_trans_get_buf(tp, mp->m_ddev_targp, d, mp->m_bsize, lock);
 565        ASSERT(!xfs_buf_geterror(bp));
 566        return bp;
 567}
 568
 569/*
 570 * Get a buffer for the block, return it with no data read.
 571 * Short-form addressing.
 572 */
 573xfs_buf_t *                             /* buffer for agno/agbno */
 574xfs_btree_get_bufs(
 575        xfs_mount_t     *mp,            /* file system mount point */
 576        xfs_trans_t     *tp,            /* transaction pointer */
 577        xfs_agnumber_t  agno,           /* allocation group number */
 578        xfs_agblock_t   agbno,          /* allocation group block number */
 579        uint            lock)           /* lock flags for get_buf */
 580{
 581        xfs_buf_t       *bp;            /* buffer pointer (return value) */
 582        xfs_daddr_t             d;              /* real disk block address */
 583
 584        ASSERT(agno != NULLAGNUMBER);
 585        ASSERT(agbno != NULLAGBLOCK);
 586        d = XFS_AGB_TO_DADDR(mp, agno, agbno);
 587        bp = xfs_trans_get_buf(tp, mp->m_ddev_targp, d, mp->m_bsize, lock);
 588        ASSERT(!xfs_buf_geterror(bp));
 589        return bp;
 590}
 591
 592/*
 593 * Check for the cursor referring to the last block at the given level.
 594 */
 595int                                     /* 1=is last block, 0=not last block */
 596xfs_btree_islastblock(
 597        xfs_btree_cur_t         *cur,   /* btree cursor */
 598        int                     level)  /* level to check */
 599{
 600        struct xfs_btree_block  *block; /* generic btree block pointer */
 601        xfs_buf_t               *bp;    /* buffer containing block */
 602
 603        block = xfs_btree_get_block(cur, level, &bp);
 604        xfs_btree_check_block(cur, block, level, bp);
 605        if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
 606                return block->bb_u.l.bb_rightsib == cpu_to_be64(NULLDFSBNO);
 607        else
 608                return block->bb_u.s.bb_rightsib == cpu_to_be32(NULLAGBLOCK);
 609}
 610
 611/*
 612 * Change the cursor to point to the first record at the given level.
 613 * Other levels are unaffected.
 614 */
 615STATIC int                              /* success=1, failure=0 */
 616xfs_btree_firstrec(
 617        xfs_btree_cur_t         *cur,   /* btree cursor */
 618        int                     level)  /* level to change */
 619{
 620        struct xfs_btree_block  *block; /* generic btree block pointer */
 621        xfs_buf_t               *bp;    /* buffer containing block */
 622
 623        /*
 624         * Get the block pointer for this level.
 625         */
 626        block = xfs_btree_get_block(cur, level, &bp);
 627        xfs_btree_check_block(cur, block, level, bp);
 628        /*
 629         * It's empty, there is no such record.
 630         */
 631        if (!block->bb_numrecs)
 632                return 0;
 633        /*
 634         * Set the ptr value to 1, that's the first record/key.
 635         */
 636        cur->bc_ptrs[level] = 1;
 637        return 1;
 638}
 639
 640/*
 641 * Change the cursor to point to the last record in the current block
 642 * at the given level.  Other levels are unaffected.
 643 */
 644STATIC int                              /* success=1, failure=0 */
 645xfs_btree_lastrec(
 646        xfs_btree_cur_t         *cur,   /* btree cursor */
 647        int                     level)  /* level to change */
 648{
 649        struct xfs_btree_block  *block; /* generic btree block pointer */
 650        xfs_buf_t               *bp;    /* buffer containing block */
 651
 652        /*
 653         * Get the block pointer for this level.
 654         */
 655        block = xfs_btree_get_block(cur, level, &bp);
 656        xfs_btree_check_block(cur, block, level, bp);
 657        /*
 658         * It's empty, there is no such record.
 659         */
 660        if (!block->bb_numrecs)
 661                return 0;
 662        /*
 663         * Set the ptr value to numrecs, that's the last record/key.
 664         */
 665        cur->bc_ptrs[level] = be16_to_cpu(block->bb_numrecs);
 666        return 1;
 667}
 668
 669/*
 670 * Compute first and last byte offsets for the fields given.
 671 * Interprets the offsets table, which contains struct field offsets.
 672 */
 673void
 674xfs_btree_offsets(
 675        __int64_t       fields,         /* bitmask of fields */
 676        const short     *offsets,       /* table of field offsets */
 677        int             nbits,          /* number of bits to inspect */
 678        int             *first,         /* output: first byte offset */
 679        int             *last)          /* output: last byte offset */
 680{
 681        int             i;              /* current bit number */
 682        __int64_t       imask;          /* mask for current bit number */
 683
 684        ASSERT(fields != 0);
 685        /*
 686         * Find the lowest bit, so the first byte offset.
 687         */
 688        for (i = 0, imask = 1LL; ; i++, imask <<= 1) {
 689                if (imask & fields) {
 690                        *first = offsets[i];
 691                        break;
 692                }
 693        }
 694        /*
 695         * Find the highest bit, so the last byte offset.
 696         */
 697        for (i = nbits - 1, imask = 1LL << i; ; i--, imask >>= 1) {
 698                if (imask & fields) {
 699                        *last = offsets[i + 1] - 1;
 700                        break;
 701                }
 702        }
 703}
 704
 705/*
 706 * Get a buffer for the block, return it read in.
 707 * Long-form addressing.
 708 */
 709int
 710xfs_btree_read_bufl(
 711        struct xfs_mount        *mp,            /* file system mount point */
 712        struct xfs_trans        *tp,            /* transaction pointer */
 713        xfs_fsblock_t           fsbno,          /* file system block number */
 714        uint                    lock,           /* lock flags for read_buf */
 715        struct xfs_buf          **bpp,          /* buffer for fsbno */
 716        int                     refval,         /* ref count value for buffer */
 717        const struct xfs_buf_ops *ops)
 718{
 719        struct xfs_buf          *bp;            /* return value */
 720        xfs_daddr_t             d;              /* real disk block address */
 721        int                     error;
 722
 723        ASSERT(fsbno != NULLFSBLOCK);
 724        d = XFS_FSB_TO_DADDR(mp, fsbno);
 725        error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, d,
 726                                   mp->m_bsize, lock, &bp, ops);
 727        if (error)
 728                return error;
 729        ASSERT(!xfs_buf_geterror(bp));
 730        if (bp)
 731                xfs_buf_set_ref(bp, refval);
 732        *bpp = bp;
 733        return 0;
 734}
 735
 736/*
 737 * Read-ahead the block, don't wait for it, don't return a buffer.
 738 * Long-form addressing.
 739 */
 740/* ARGSUSED */
 741void
 742xfs_btree_reada_bufl(
 743        struct xfs_mount        *mp,            /* file system mount point */
 744        xfs_fsblock_t           fsbno,          /* file system block number */
 745        xfs_extlen_t            count,          /* count of filesystem blocks */
 746        const struct xfs_buf_ops *ops)
 747{
 748        xfs_daddr_t             d;
 749
 750        ASSERT(fsbno != NULLFSBLOCK);
 751        d = XFS_FSB_TO_DADDR(mp, fsbno);
 752        xfs_buf_readahead(mp->m_ddev_targp, d, mp->m_bsize * count, ops);
 753}
 754
 755/*
 756 * Read-ahead the block, don't wait for it, don't return a buffer.
 757 * Short-form addressing.
 758 */
 759/* ARGSUSED */
 760void
 761xfs_btree_reada_bufs(
 762        struct xfs_mount        *mp,            /* file system mount point */
 763        xfs_agnumber_t          agno,           /* allocation group number */
 764        xfs_agblock_t           agbno,          /* allocation group block number */
 765        xfs_extlen_t            count,          /* count of filesystem blocks */
 766        const struct xfs_buf_ops *ops)
 767{
 768        xfs_daddr_t             d;
 769
 770        ASSERT(agno != NULLAGNUMBER);
 771        ASSERT(agbno != NULLAGBLOCK);
 772        d = XFS_AGB_TO_DADDR(mp, agno, agbno);
 773        xfs_buf_readahead(mp->m_ddev_targp, d, mp->m_bsize * count, ops);
 774}
 775
 776STATIC int
 777xfs_btree_readahead_lblock(
 778        struct xfs_btree_cur    *cur,
 779        int                     lr,
 780        struct xfs_btree_block  *block)
 781{
 782        int                     rval = 0;
 783        xfs_dfsbno_t            left = be64_to_cpu(block->bb_u.l.bb_leftsib);
 784        xfs_dfsbno_t            right = be64_to_cpu(block->bb_u.l.bb_rightsib);
 785
 786        if ((lr & XFS_BTCUR_LEFTRA) && left != NULLDFSBNO) {
 787                xfs_btree_reada_bufl(cur->bc_mp, left, 1,
 788                                     cur->bc_ops->buf_ops);
 789                rval++;
 790        }
 791
 792        if ((lr & XFS_BTCUR_RIGHTRA) && right != NULLDFSBNO) {
 793                xfs_btree_reada_bufl(cur->bc_mp, right, 1,
 794                                     cur->bc_ops->buf_ops);
 795                rval++;
 796        }
 797
 798        return rval;
 799}
 800
 801STATIC int
 802xfs_btree_readahead_sblock(
 803        struct xfs_btree_cur    *cur,
 804        int                     lr,
 805        struct xfs_btree_block *block)
 806{
 807        int                     rval = 0;
 808        xfs_agblock_t           left = be32_to_cpu(block->bb_u.s.bb_leftsib);
 809        xfs_agblock_t           right = be32_to_cpu(block->bb_u.s.bb_rightsib);
 810
 811
 812        if ((lr & XFS_BTCUR_LEFTRA) && left != NULLAGBLOCK) {
 813                xfs_btree_reada_bufs(cur->bc_mp, cur->bc_private.a.agno,
 814                                     left, 1, cur->bc_ops->buf_ops);
 815                rval++;
 816        }
 817
 818        if ((lr & XFS_BTCUR_RIGHTRA) && right != NULLAGBLOCK) {
 819                xfs_btree_reada_bufs(cur->bc_mp, cur->bc_private.a.agno,
 820                                     right, 1, cur->bc_ops->buf_ops);
 821                rval++;
 822        }
 823
 824        return rval;
 825}
 826
 827/*
 828 * Read-ahead btree blocks, at the given level.
 829 * Bits in lr are set from XFS_BTCUR_{LEFT,RIGHT}RA.
 830 */
 831STATIC int
 832xfs_btree_readahead(
 833        struct xfs_btree_cur    *cur,           /* btree cursor */
 834        int                     lev,            /* level in btree */
 835        int                     lr)             /* left/right bits */
 836{
 837        struct xfs_btree_block  *block;
 838
 839        /*
 840         * No readahead needed if we are at the root level and the
 841         * btree root is stored in the inode.
 842         */
 843        if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
 844            (lev == cur->bc_nlevels - 1))
 845                return 0;
 846
 847        if ((cur->bc_ra[lev] | lr) == cur->bc_ra[lev])
 848                return 0;
 849
 850        cur->bc_ra[lev] |= lr;
 851        block = XFS_BUF_TO_BLOCK(cur->bc_bufs[lev]);
 852
 853        if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
 854                return xfs_btree_readahead_lblock(cur, lr, block);
 855        return xfs_btree_readahead_sblock(cur, lr, block);
 856}
 857
 858/*
 859 * Set the buffer for level "lev" in the cursor to bp, releasing
 860 * any previous buffer.
 861 */
 862STATIC void
 863xfs_btree_setbuf(
 864        xfs_btree_cur_t         *cur,   /* btree cursor */
 865        int                     lev,    /* level in btree */
 866        xfs_buf_t               *bp)    /* new buffer to set */
 867{
 868        struct xfs_btree_block  *b;     /* btree block */
 869
 870        if (cur->bc_bufs[lev])
 871                xfs_trans_brelse(cur->bc_tp, cur->bc_bufs[lev]);
 872        cur->bc_bufs[lev] = bp;
 873        cur->bc_ra[lev] = 0;
 874
 875        b = XFS_BUF_TO_BLOCK(bp);
 876        if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
 877                if (b->bb_u.l.bb_leftsib == cpu_to_be64(NULLDFSBNO))
 878                        cur->bc_ra[lev] |= XFS_BTCUR_LEFTRA;
 879                if (b->bb_u.l.bb_rightsib == cpu_to_be64(NULLDFSBNO))
 880                        cur->bc_ra[lev] |= XFS_BTCUR_RIGHTRA;
 881        } else {
 882                if (b->bb_u.s.bb_leftsib == cpu_to_be32(NULLAGBLOCK))
 883                        cur->bc_ra[lev] |= XFS_BTCUR_LEFTRA;
 884                if (b->bb_u.s.bb_rightsib == cpu_to_be32(NULLAGBLOCK))
 885                        cur->bc_ra[lev] |= XFS_BTCUR_RIGHTRA;
 886        }
 887}
 888
 889STATIC int
 890xfs_btree_ptr_is_null(
 891        struct xfs_btree_cur    *cur,
 892        union xfs_btree_ptr     *ptr)
 893{
 894        if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
 895                return ptr->l == cpu_to_be64(NULLDFSBNO);
 896        else
 897                return ptr->s == cpu_to_be32(NULLAGBLOCK);
 898}
 899
 900STATIC void
 901xfs_btree_set_ptr_null(
 902        struct xfs_btree_cur    *cur,
 903        union xfs_btree_ptr     *ptr)
 904{
 905        if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
 906                ptr->l = cpu_to_be64(NULLDFSBNO);
 907        else
 908                ptr->s = cpu_to_be32(NULLAGBLOCK);
 909}
 910
 911/*
 912 * Get/set/init sibling pointers
 913 */
 914STATIC void
 915xfs_btree_get_sibling(
 916        struct xfs_btree_cur    *cur,
 917        struct xfs_btree_block  *block,
 918        union xfs_btree_ptr     *ptr,
 919        int                     lr)
 920{
 921        ASSERT(lr == XFS_BB_LEFTSIB || lr == XFS_BB_RIGHTSIB);
 922
 923        if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
 924                if (lr == XFS_BB_RIGHTSIB)
 925                        ptr->l = block->bb_u.l.bb_rightsib;
 926                else
 927                        ptr->l = block->bb_u.l.bb_leftsib;
 928        } else {
 929                if (lr == XFS_BB_RIGHTSIB)
 930                        ptr->s = block->bb_u.s.bb_rightsib;
 931                else
 932                        ptr->s = block->bb_u.s.bb_leftsib;
 933        }
 934}
 935
 936STATIC void
 937xfs_btree_set_sibling(
 938        struct xfs_btree_cur    *cur,
 939        struct xfs_btree_block  *block,
 940        union xfs_btree_ptr     *ptr,
 941        int                     lr)
 942{
 943        ASSERT(lr == XFS_BB_LEFTSIB || lr == XFS_BB_RIGHTSIB);
 944
 945        if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
 946                if (lr == XFS_BB_RIGHTSIB)
 947                        block->bb_u.l.bb_rightsib = ptr->l;
 948                else
 949                        block->bb_u.l.bb_leftsib = ptr->l;
 950        } else {
 951                if (lr == XFS_BB_RIGHTSIB)
 952                        block->bb_u.s.bb_rightsib = ptr->s;
 953                else
 954                        block->bb_u.s.bb_leftsib = ptr->s;
 955        }
 956}
 957
 958void
 959xfs_btree_init_block_int(
 960        struct xfs_mount        *mp,
 961        struct xfs_btree_block  *buf,
 962        xfs_daddr_t             blkno,
 963        __u32                   magic,
 964        __u16                   level,
 965        __u16                   numrecs,
 966        __u64                   owner,
 967        unsigned int            flags)
 968{
 969        buf->bb_magic = cpu_to_be32(magic);
 970        buf->bb_level = cpu_to_be16(level);
 971        buf->bb_numrecs = cpu_to_be16(numrecs);
 972
 973        if (flags & XFS_BTREE_LONG_PTRS) {
 974                buf->bb_u.l.bb_leftsib = cpu_to_be64(NULLDFSBNO);
 975                buf->bb_u.l.bb_rightsib = cpu_to_be64(NULLDFSBNO);
 976                if (flags & XFS_BTREE_CRC_BLOCKS) {
 977                        buf->bb_u.l.bb_blkno = cpu_to_be64(blkno);
 978                        buf->bb_u.l.bb_owner = cpu_to_be64(owner);
 979                        uuid_copy(&buf->bb_u.l.bb_uuid, &mp->m_sb.sb_uuid);
 980                        buf->bb_u.l.bb_pad = 0;
 981                }
 982        } else {
 983                /* owner is a 32 bit value on short blocks */
 984                __u32 __owner = (__u32)owner;
 985
 986                buf->bb_u.s.bb_leftsib = cpu_to_be32(NULLAGBLOCK);
 987                buf->bb_u.s.bb_rightsib = cpu_to_be32(NULLAGBLOCK);
 988                if (flags & XFS_BTREE_CRC_BLOCKS) {
 989                        buf->bb_u.s.bb_blkno = cpu_to_be64(blkno);
 990                        buf->bb_u.s.bb_owner = cpu_to_be32(__owner);
 991                        uuid_copy(&buf->bb_u.s.bb_uuid, &mp->m_sb.sb_uuid);
 992                }
 993        }
 994}
 995
 996void
 997xfs_btree_init_block(
 998        struct xfs_mount *mp,
 999        struct xfs_buf  *bp,
1000        __u32           magic,
1001        __u16           level,
1002        __u16           numrecs,
1003        __u64           owner,
1004        unsigned int    flags)
1005{
1006        xfs_btree_init_block_int(mp, XFS_BUF_TO_BLOCK(bp), bp->b_bn,
1007                                 magic, level, numrecs, owner, flags);
1008}
1009
1010STATIC void
1011xfs_btree_init_block_cur(
1012        struct xfs_btree_cur    *cur,
1013        struct xfs_buf          *bp,
1014        int                     level,
1015        int                     numrecs)
1016{
1017        __u64 owner;
1018
1019        /*
1020         * we can pull the owner from the cursor right now as the different
1021         * owners align directly with the pointer size of the btree. This may
1022         * change in future, but is safe for current users of the generic btree
1023         * code.
1024         */
1025        if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
1026                owner = cur->bc_private.b.ip->i_ino;
1027        else
1028                owner = cur->bc_private.a.agno;
1029
1030        xfs_btree_init_block_int(cur->bc_mp, XFS_BUF_TO_BLOCK(bp), bp->b_bn,
1031                                 xfs_btree_magic(cur), level, numrecs,
1032                                 owner, cur->bc_flags);
1033}
1034
1035/*
1036 * Return true if ptr is the last record in the btree and
1037 * we need to track updates to this record.  The decision
1038 * will be further refined in the update_lastrec method.
1039 */
1040STATIC int
1041xfs_btree_is_lastrec(
1042        struct xfs_btree_cur    *cur,
1043        struct xfs_btree_block  *block,
1044        int                     level)
1045{
1046        union xfs_btree_ptr     ptr;
1047
1048        if (level > 0)
1049                return 0;
1050        if (!(cur->bc_flags & XFS_BTREE_LASTREC_UPDATE))
1051                return 0;
1052
1053        xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
1054        if (!xfs_btree_ptr_is_null(cur, &ptr))
1055                return 0;
1056        return 1;
1057}
1058
1059STATIC void
1060xfs_btree_buf_to_ptr(
1061        struct xfs_btree_cur    *cur,
1062        struct xfs_buf          *bp,
1063        union xfs_btree_ptr     *ptr)
1064{
1065        if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
1066                ptr->l = cpu_to_be64(XFS_DADDR_TO_FSB(cur->bc_mp,
1067                                        XFS_BUF_ADDR(bp)));
1068        else {
1069                ptr->s = cpu_to_be32(xfs_daddr_to_agbno(cur->bc_mp,
1070                                        XFS_BUF_ADDR(bp)));
1071        }
1072}
1073
1074STATIC xfs_daddr_t
1075xfs_btree_ptr_to_daddr(
1076        struct xfs_btree_cur    *cur,
1077        union xfs_btree_ptr     *ptr)
1078{
1079        if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
1080                ASSERT(ptr->l != cpu_to_be64(NULLDFSBNO));
1081
1082                return XFS_FSB_TO_DADDR(cur->bc_mp, be64_to_cpu(ptr->l));
1083        } else {
1084                ASSERT(cur->bc_private.a.agno != NULLAGNUMBER);
1085                ASSERT(ptr->s != cpu_to_be32(NULLAGBLOCK));
1086
1087                return XFS_AGB_TO_DADDR(cur->bc_mp, cur->bc_private.a.agno,
1088                                        be32_to_cpu(ptr->s));
1089        }
1090}
1091
1092STATIC void
1093xfs_btree_set_refs(
1094        struct xfs_btree_cur    *cur,
1095        struct xfs_buf          *bp)
1096{
1097        switch (cur->bc_btnum) {
1098        case XFS_BTNUM_BNO:
1099        case XFS_BTNUM_CNT:
1100                xfs_buf_set_ref(bp, XFS_ALLOC_BTREE_REF);
1101                break;
1102        case XFS_BTNUM_INO:
1103                xfs_buf_set_ref(bp, XFS_INO_BTREE_REF);
1104                break;
1105        case XFS_BTNUM_BMAP:
1106                xfs_buf_set_ref(bp, XFS_BMAP_BTREE_REF);
1107                break;
1108        default:
1109                ASSERT(0);
1110        }
1111}
1112
1113STATIC int
1114xfs_btree_get_buf_block(
1115        struct xfs_btree_cur    *cur,
1116        union xfs_btree_ptr     *ptr,
1117        int                     flags,
1118        struct xfs_btree_block  **block,
1119        struct xfs_buf          **bpp)
1120{
1121        struct xfs_mount        *mp = cur->bc_mp;
1122        xfs_daddr_t             d;
1123
1124        /* need to sort out how callers deal with failures first */
1125        ASSERT(!(flags & XBF_TRYLOCK));
1126
1127        d = xfs_btree_ptr_to_daddr(cur, ptr);
1128        *bpp = xfs_trans_get_buf(cur->bc_tp, mp->m_ddev_targp, d,
1129                                 mp->m_bsize, flags);
1130
1131        if (!*bpp)
1132                return ENOMEM;
1133
1134        (*bpp)->b_ops = cur->bc_ops->buf_ops;
1135        *block = XFS_BUF_TO_BLOCK(*bpp);
1136        return 0;
1137}
1138
1139/*
1140 * Read in the buffer at the given ptr and return the buffer and
1141 * the block pointer within the buffer.
1142 */
1143STATIC int
1144xfs_btree_read_buf_block(
1145        struct xfs_btree_cur    *cur,
1146        union xfs_btree_ptr     *ptr,
1147        int                     level,
1148        int                     flags,
1149        struct xfs_btree_block  **block,
1150        struct xfs_buf          **bpp)
1151{
1152        struct xfs_mount        *mp = cur->bc_mp;
1153        xfs_daddr_t             d;
1154        int                     error;
1155
1156        /* need to sort out how callers deal with failures first */
1157        ASSERT(!(flags & XBF_TRYLOCK));
1158
1159        d = xfs_btree_ptr_to_daddr(cur, ptr);
1160        error = xfs_trans_read_buf(mp, cur->bc_tp, mp->m_ddev_targp, d,
1161                                   mp->m_bsize, flags, bpp,
1162                                   cur->bc_ops->buf_ops);
1163        if (error)
1164                return error;
1165
1166        ASSERT(!xfs_buf_geterror(*bpp));
1167        xfs_btree_set_refs(cur, *bpp);
1168        *block = XFS_BUF_TO_BLOCK(*bpp);
1169        return 0;
1170}
1171
1172/*
1173 * Copy keys from one btree block to another.
1174 */
1175STATIC void
1176xfs_btree_copy_keys(
1177        struct xfs_btree_cur    *cur,
1178        union xfs_btree_key     *dst_key,
1179        union xfs_btree_key     *src_key,
1180        int                     numkeys)
1181{
1182        ASSERT(numkeys >= 0);
1183        memcpy(dst_key, src_key, numkeys * cur->bc_ops->key_len);
1184}
1185
1186/*
1187 * Copy records from one btree block to another.
1188 */
1189STATIC void
1190xfs_btree_copy_recs(
1191        struct xfs_btree_cur    *cur,
1192        union xfs_btree_rec     *dst_rec,
1193        union xfs_btree_rec     *src_rec,
1194        int                     numrecs)
1195{
1196        ASSERT(numrecs >= 0);
1197        memcpy(dst_rec, src_rec, numrecs * cur->bc_ops->rec_len);
1198}
1199
1200/*
1201 * Copy block pointers from one btree block to another.
1202 */
1203STATIC void
1204xfs_btree_copy_ptrs(
1205        struct xfs_btree_cur    *cur,
1206        union xfs_btree_ptr     *dst_ptr,
1207        union xfs_btree_ptr     *src_ptr,
1208        int                     numptrs)
1209{
1210        ASSERT(numptrs >= 0);
1211        memcpy(dst_ptr, src_ptr, numptrs * xfs_btree_ptr_len(cur));
1212}
1213
1214/*
1215 * Shift keys one index left/right inside a single btree block.
1216 */
1217STATIC void
1218xfs_btree_shift_keys(
1219        struct xfs_btree_cur    *cur,
1220        union xfs_btree_key     *key,
1221        int                     dir,
1222        int                     numkeys)
1223{
1224        char                    *dst_key;
1225
1226        ASSERT(numkeys >= 0);
1227        ASSERT(dir == 1 || dir == -1);
1228
1229        dst_key = (char *)key + (dir * cur->bc_ops->key_len);
1230        memmove(dst_key, key, numkeys * cur->bc_ops->key_len);
1231}
1232
1233/*
1234 * Shift records one index left/right inside a single btree block.
1235 */
1236STATIC void
1237xfs_btree_shift_recs(
1238        struct xfs_btree_cur    *cur,
1239        union xfs_btree_rec     *rec,
1240        int                     dir,
1241        int                     numrecs)
1242{
1243        char                    *dst_rec;
1244
1245        ASSERT(numrecs >= 0);
1246        ASSERT(dir == 1 || dir == -1);
1247
1248        dst_rec = (char *)rec + (dir * cur->bc_ops->rec_len);
1249        memmove(dst_rec, rec, numrecs * cur->bc_ops->rec_len);
1250}
1251
1252/*
1253 * Shift block pointers one index left/right inside a single btree block.
1254 */
1255STATIC void
1256xfs_btree_shift_ptrs(
1257        struct xfs_btree_cur    *cur,
1258        union xfs_btree_ptr     *ptr,
1259        int                     dir,
1260        int                     numptrs)
1261{
1262        char                    *dst_ptr;
1263
1264        ASSERT(numptrs >= 0);
1265        ASSERT(dir == 1 || dir == -1);
1266
1267        dst_ptr = (char *)ptr + (dir * xfs_btree_ptr_len(cur));
1268        memmove(dst_ptr, ptr, numptrs * xfs_btree_ptr_len(cur));
1269}
1270
1271/*
1272 * Log key values from the btree block.
1273 */
1274STATIC void
1275xfs_btree_log_keys(
1276        struct xfs_btree_cur    *cur,
1277        struct xfs_buf          *bp,
1278        int                     first,
1279        int                     last)
1280{
1281        XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1282        XFS_BTREE_TRACE_ARGBII(cur, bp, first, last);
1283
1284        if (bp) {
1285                xfs_trans_buf_set_type(cur->bc_tp, bp, XFS_BLFT_BTREE_BUF);
1286                xfs_trans_log_buf(cur->bc_tp, bp,
1287                                  xfs_btree_key_offset(cur, first),
1288                                  xfs_btree_key_offset(cur, last + 1) - 1);
1289        } else {
1290                xfs_trans_log_inode(cur->bc_tp, cur->bc_private.b.ip,
1291                                xfs_ilog_fbroot(cur->bc_private.b.whichfork));
1292        }
1293
1294        XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1295}
1296
1297/*
1298 * Log record values from the btree block.
1299 */
1300void
1301xfs_btree_log_recs(
1302        struct xfs_btree_cur    *cur,
1303        struct xfs_buf          *bp,
1304        int                     first,
1305        int                     last)
1306{
1307        XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1308        XFS_BTREE_TRACE_ARGBII(cur, bp, first, last);
1309
1310        xfs_trans_buf_set_type(cur->bc_tp, bp, XFS_BLFT_BTREE_BUF);
1311        xfs_trans_log_buf(cur->bc_tp, bp,
1312                          xfs_btree_rec_offset(cur, first),
1313                          xfs_btree_rec_offset(cur, last + 1) - 1);
1314
1315        XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1316}
1317
1318/*
1319 * Log block pointer fields from a btree block (nonleaf).
1320 */
1321STATIC void
1322xfs_btree_log_ptrs(
1323        struct xfs_btree_cur    *cur,   /* btree cursor */
1324        struct xfs_buf          *bp,    /* buffer containing btree block */
1325        int                     first,  /* index of first pointer to log */
1326        int                     last)   /* index of last pointer to log */
1327{
1328        XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1329        XFS_BTREE_TRACE_ARGBII(cur, bp, first, last);
1330
1331        if (bp) {
1332                struct xfs_btree_block  *block = XFS_BUF_TO_BLOCK(bp);
1333                int                     level = xfs_btree_get_level(block);
1334
1335                xfs_trans_buf_set_type(cur->bc_tp, bp, XFS_BLFT_BTREE_BUF);
1336                xfs_trans_log_buf(cur->bc_tp, bp,
1337                                xfs_btree_ptr_offset(cur, first, level),
1338                                xfs_btree_ptr_offset(cur, last + 1, level) - 1);
1339        } else {
1340                xfs_trans_log_inode(cur->bc_tp, cur->bc_private.b.ip,
1341                        xfs_ilog_fbroot(cur->bc_private.b.whichfork));
1342        }
1343
1344        XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1345}
1346
1347/*
1348 * Log fields from a btree block header.
1349 */
1350void
1351xfs_btree_log_block(
1352        struct xfs_btree_cur    *cur,   /* btree cursor */
1353        struct xfs_buf          *bp,    /* buffer containing btree block */
1354        int                     fields) /* mask of fields: XFS_BB_... */
1355{
1356        int                     first;  /* first byte offset logged */
1357        int                     last;   /* last byte offset logged */
1358        static const short      soffsets[] = {  /* table of offsets (short) */
1359                offsetof(struct xfs_btree_block, bb_magic),
1360                offsetof(struct xfs_btree_block, bb_level),
1361                offsetof(struct xfs_btree_block, bb_numrecs),
1362                offsetof(struct xfs_btree_block, bb_u.s.bb_leftsib),
1363                offsetof(struct xfs_btree_block, bb_u.s.bb_rightsib),
1364                offsetof(struct xfs_btree_block, bb_u.s.bb_blkno),
1365                offsetof(struct xfs_btree_block, bb_u.s.bb_lsn),
1366                offsetof(struct xfs_btree_block, bb_u.s.bb_uuid),
1367                offsetof(struct xfs_btree_block, bb_u.s.bb_owner),
1368                offsetof(struct xfs_btree_block, bb_u.s.bb_crc),
1369                XFS_BTREE_SBLOCK_CRC_LEN
1370        };
1371        static const short      loffsets[] = {  /* table of offsets (long) */
1372                offsetof(struct xfs_btree_block, bb_magic),
1373                offsetof(struct xfs_btree_block, bb_level),
1374                offsetof(struct xfs_btree_block, bb_numrecs),
1375                offsetof(struct xfs_btree_block, bb_u.l.bb_leftsib),
1376                offsetof(struct xfs_btree_block, bb_u.l.bb_rightsib),
1377                offsetof(struct xfs_btree_block, bb_u.l.bb_blkno),
1378                offsetof(struct xfs_btree_block, bb_u.l.bb_lsn),
1379                offsetof(struct xfs_btree_block, bb_u.l.bb_uuid),
1380                offsetof(struct xfs_btree_block, bb_u.l.bb_owner),
1381                offsetof(struct xfs_btree_block, bb_u.l.bb_crc),
1382                offsetof(struct xfs_btree_block, bb_u.l.bb_pad),
1383                XFS_BTREE_LBLOCK_CRC_LEN
1384        };
1385
1386        XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1387        XFS_BTREE_TRACE_ARGBI(cur, bp, fields);
1388
1389        if (bp) {
1390                int nbits;
1391
1392                if (cur->bc_flags & XFS_BTREE_CRC_BLOCKS) {
1393                        /*
1394                         * We don't log the CRC when updating a btree
1395                         * block but instead recreate it during log
1396                         * recovery.  As the log buffers have checksums
1397                         * of their own this is safe and avoids logging a crc
1398                         * update in a lot of places.
1399                         */
1400                        if (fields == XFS_BB_ALL_BITS)
1401                                fields = XFS_BB_ALL_BITS_CRC;
1402                        nbits = XFS_BB_NUM_BITS_CRC;
1403                } else {
1404                        nbits = XFS_BB_NUM_BITS;
1405                }
1406                xfs_btree_offsets(fields,
1407                                  (cur->bc_flags & XFS_BTREE_LONG_PTRS) ?
1408                                        loffsets : soffsets,
1409                                  nbits, &first, &last);
1410                xfs_trans_buf_set_type(cur->bc_tp, bp, XFS_BLFT_BTREE_BUF);
1411                xfs_trans_log_buf(cur->bc_tp, bp, first, last);
1412        } else {
1413                xfs_trans_log_inode(cur->bc_tp, cur->bc_private.b.ip,
1414                        xfs_ilog_fbroot(cur->bc_private.b.whichfork));
1415        }
1416
1417        XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1418}
1419
1420/*
1421 * Increment cursor by one record at the level.
1422 * For nonzero levels the leaf-ward information is untouched.
1423 */
1424int                                             /* error */
1425xfs_btree_increment(
1426        struct xfs_btree_cur    *cur,
1427        int                     level,
1428        int                     *stat)          /* success/failure */
1429{
1430        struct xfs_btree_block  *block;
1431        union xfs_btree_ptr     ptr;
1432        struct xfs_buf          *bp;
1433        int                     error;          /* error return value */
1434        int                     lev;
1435
1436        XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1437        XFS_BTREE_TRACE_ARGI(cur, level);
1438
1439        ASSERT(level < cur->bc_nlevels);
1440
1441        /* Read-ahead to the right at this level. */
1442        xfs_btree_readahead(cur, level, XFS_BTCUR_RIGHTRA);
1443
1444        /* Get a pointer to the btree block. */
1445        block = xfs_btree_get_block(cur, level, &bp);
1446
1447#ifdef DEBUG
1448        error = xfs_btree_check_block(cur, block, level, bp);
1449        if (error)
1450                goto error0;
1451#endif
1452
1453        /* We're done if we remain in the block after the increment. */
1454        if (++cur->bc_ptrs[level] <= xfs_btree_get_numrecs(block))
1455                goto out1;
1456
1457        /* Fail if we just went off the right edge of the tree. */
1458        xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
1459        if (xfs_btree_ptr_is_null(cur, &ptr))
1460                goto out0;
1461
1462        XFS_BTREE_STATS_INC(cur, increment);
1463
1464        /*
1465         * March up the tree incrementing pointers.
1466         * Stop when we don't go off the right edge of a block.
1467         */
1468        for (lev = level + 1; lev < cur->bc_nlevels; lev++) {
1469                block = xfs_btree_get_block(cur, lev, &bp);
1470
1471#ifdef DEBUG
1472                error = xfs_btree_check_block(cur, block, lev, bp);
1473                if (error)
1474                        goto error0;
1475#endif
1476
1477                if (++cur->bc_ptrs[lev] <= xfs_btree_get_numrecs(block))
1478                        break;
1479
1480                /* Read-ahead the right block for the next loop. */
1481                xfs_btree_readahead(cur, lev, XFS_BTCUR_RIGHTRA);
1482        }
1483
1484        /*
1485         * If we went off the root then we are either seriously
1486         * confused or have the tree root in an inode.
1487         */
1488        if (lev == cur->bc_nlevels) {
1489                if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE)
1490                        goto out0;
1491                ASSERT(0);
1492                error = EFSCORRUPTED;
1493                goto error0;
1494        }
1495        ASSERT(lev < cur->bc_nlevels);
1496
1497        /*
1498         * Now walk back down the tree, fixing up the cursor's buffer
1499         * pointers and key numbers.
1500         */
1501        for (block = xfs_btree_get_block(cur, lev, &bp); lev > level; ) {
1502                union xfs_btree_ptr     *ptrp;
1503
1504                ptrp = xfs_btree_ptr_addr(cur, cur->bc_ptrs[lev], block);
1505                error = xfs_btree_read_buf_block(cur, ptrp, --lev,
1506                                                        0, &block, &bp);
1507                if (error)
1508                        goto error0;
1509
1510                xfs_btree_setbuf(cur, lev, bp);
1511                cur->bc_ptrs[lev] = 1;
1512        }
1513out1:
1514        XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1515        *stat = 1;
1516        return 0;
1517
1518out0:
1519        XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1520        *stat = 0;
1521        return 0;
1522
1523error0:
1524        XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1525        return error;
1526}
1527
1528/*
1529 * Decrement cursor by one record at the level.
1530 * For nonzero levels the leaf-ward information is untouched.
1531 */
1532int                                             /* error */
1533xfs_btree_decrement(
1534        struct xfs_btree_cur    *cur,
1535        int                     level,
1536        int                     *stat)          /* success/failure */
1537{
1538        struct xfs_btree_block  *block;
1539        xfs_buf_t               *bp;
1540        int                     error;          /* error return value */
1541        int                     lev;
1542        union xfs_btree_ptr     ptr;
1543
1544        XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1545        XFS_BTREE_TRACE_ARGI(cur, level);
1546
1547        ASSERT(level < cur->bc_nlevels);
1548
1549        /* Read-ahead to the left at this level. */
1550        xfs_btree_readahead(cur, level, XFS_BTCUR_LEFTRA);
1551
1552        /* We're done if we remain in the block after the decrement. */
1553        if (--cur->bc_ptrs[level] > 0)
1554                goto out1;
1555
1556        /* Get a pointer to the btree block. */
1557        block = xfs_btree_get_block(cur, level, &bp);
1558
1559#ifdef DEBUG
1560        error = xfs_btree_check_block(cur, block, level, bp);
1561        if (error)
1562                goto error0;
1563#endif
1564
1565        /* Fail if we just went off the left edge of the tree. */
1566        xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_LEFTSIB);
1567        if (xfs_btree_ptr_is_null(cur, &ptr))
1568                goto out0;
1569
1570        XFS_BTREE_STATS_INC(cur, decrement);
1571
1572        /*
1573         * March up the tree decrementing pointers.
1574         * Stop when we don't go off the left edge of a block.
1575         */
1576        for (lev = level + 1; lev < cur->bc_nlevels; lev++) {
1577                if (--cur->bc_ptrs[lev] > 0)
1578                        break;
1579                /* Read-ahead the left block for the next loop. */
1580                xfs_btree_readahead(cur, lev, XFS_BTCUR_LEFTRA);
1581        }
1582
1583        /*
1584         * If we went off the root then we are seriously confused.
1585         * or the root of the tree is in an inode.
1586         */
1587        if (lev == cur->bc_nlevels) {
1588                if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE)
1589                        goto out0;
1590                ASSERT(0);
1591                error = EFSCORRUPTED;
1592                goto error0;
1593        }
1594        ASSERT(lev < cur->bc_nlevels);
1595
1596        /*
1597         * Now walk back down the tree, fixing up the cursor's buffer
1598         * pointers and key numbers.
1599         */
1600        for (block = xfs_btree_get_block(cur, lev, &bp); lev > level; ) {
1601                union xfs_btree_ptr     *ptrp;
1602
1603                ptrp = xfs_btree_ptr_addr(cur, cur->bc_ptrs[lev], block);
1604                error = xfs_btree_read_buf_block(cur, ptrp, --lev,
1605                                                        0, &block, &bp);
1606                if (error)
1607                        goto error0;
1608                xfs_btree_setbuf(cur, lev, bp);
1609                cur->bc_ptrs[lev] = xfs_btree_get_numrecs(block);
1610        }
1611out1:
1612        XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1613        *stat = 1;
1614        return 0;
1615
1616out0:
1617        XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1618        *stat = 0;
1619        return 0;
1620
1621error0:
1622        XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1623        return error;
1624}
1625
1626STATIC int
1627xfs_btree_lookup_get_block(
1628        struct xfs_btree_cur    *cur,   /* btree cursor */
1629        int                     level,  /* level in the btree */
1630        union xfs_btree_ptr     *pp,    /* ptr to btree block */
1631        struct xfs_btree_block  **blkp) /* return btree block */
1632{
1633        struct xfs_buf          *bp;    /* buffer pointer for btree block */
1634        int                     error = 0;
1635
1636        /* special case the root block if in an inode */
1637        if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
1638            (level == cur->bc_nlevels - 1)) {
1639                *blkp = xfs_btree_get_iroot(cur);
1640                return 0;
1641        }
1642
1643        /*
1644         * If the old buffer at this level for the disk address we are
1645         * looking for re-use it.
1646         *
1647         * Otherwise throw it away and get a new one.
1648         */
1649        bp = cur->bc_bufs[level];
1650        if (bp && XFS_BUF_ADDR(bp) == xfs_btree_ptr_to_daddr(cur, pp)) {
1651                *blkp = XFS_BUF_TO_BLOCK(bp);
1652                return 0;
1653        }
1654
1655        error = xfs_btree_read_buf_block(cur, pp, level, 0, blkp, &bp);
1656        if (error)
1657                return error;
1658
1659        xfs_btree_setbuf(cur, level, bp);
1660        return 0;
1661}
1662
1663/*
1664 * Get current search key.  For level 0 we don't actually have a key
1665 * structure so we make one up from the record.  For all other levels
1666 * we just return the right key.
1667 */
1668STATIC union xfs_btree_key *
1669xfs_lookup_get_search_key(
1670        struct xfs_btree_cur    *cur,
1671        int                     level,
1672        int                     keyno,
1673        struct xfs_btree_block  *block,
1674        union xfs_btree_key     *kp)
1675{
1676        if (level == 0) {
1677                cur->bc_ops->init_key_from_rec(kp,
1678                                xfs_btree_rec_addr(cur, keyno, block));
1679                return kp;
1680        }
1681
1682        return xfs_btree_key_addr(cur, keyno, block);
1683}
1684
1685/*
1686 * Lookup the record.  The cursor is made to point to it, based on dir.
1687 * Return 0 if can't find any such record, 1 for success.
1688 */
1689int                                     /* error */
1690xfs_btree_lookup(
1691        struct xfs_btree_cur    *cur,   /* btree cursor */
1692        xfs_lookup_t            dir,    /* <=, ==, or >= */
1693        int                     *stat)  /* success/failure */
1694{
1695        struct xfs_btree_block  *block; /* current btree block */
1696        __int64_t               diff;   /* difference for the current key */
1697        int                     error;  /* error return value */
1698        int                     keyno;  /* current key number */
1699        int                     level;  /* level in the btree */
1700        union xfs_btree_ptr     *pp;    /* ptr to btree block */
1701        union xfs_btree_ptr     ptr;    /* ptr to btree block */
1702
1703        XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1704        XFS_BTREE_TRACE_ARGI(cur, dir);
1705
1706        XFS_BTREE_STATS_INC(cur, lookup);
1707
1708        block = NULL;
1709        keyno = 0;
1710
1711        /* initialise start pointer from cursor */
1712        cur->bc_ops->init_ptr_from_cur(cur, &ptr);
1713        pp = &ptr;
1714
1715        /*
1716         * Iterate over each level in the btree, starting at the root.
1717         * For each level above the leaves, find the key we need, based
1718         * on the lookup record, then follow the corresponding block
1719         * pointer down to the next level.
1720         */
1721        for (level = cur->bc_nlevels - 1, diff = 1; level >= 0; level--) {
1722                /* Get the block we need to do the lookup on. */
1723                error = xfs_btree_lookup_get_block(cur, level, pp, &block);
1724                if (error)
1725                        goto error0;
1726
1727                if (diff == 0) {
1728                        /*
1729                         * If we already had a key match at a higher level, we
1730                         * know we need to use the first entry in this block.
1731                         */
1732                        keyno = 1;
1733                } else {
1734                        /* Otherwise search this block. Do a binary search. */
1735
1736                        int     high;   /* high entry number */
1737                        int     low;    /* low entry number */
1738
1739                        /* Set low and high entry numbers, 1-based. */
1740                        low = 1;
1741                        high = xfs_btree_get_numrecs(block);
1742                        if (!high) {
1743                                /* Block is empty, must be an empty leaf. */
1744                                ASSERT(level == 0 && cur->bc_nlevels == 1);
1745
1746                                cur->bc_ptrs[0] = dir != XFS_LOOKUP_LE;
1747                                XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1748                                *stat = 0;
1749                                return 0;
1750                        }
1751
1752                        /* Binary search the block. */
1753                        while (low <= high) {
1754                                union xfs_btree_key     key;
1755                                union xfs_btree_key     *kp;
1756
1757                                XFS_BTREE_STATS_INC(cur, compare);
1758
1759                                /* keyno is average of low and high. */
1760                                keyno = (low + high) >> 1;
1761
1762                                /* Get current search key */
1763                                kp = xfs_lookup_get_search_key(cur, level,
1764                                                keyno, block, &key);
1765
1766                                /*
1767                                 * Compute difference to get next direction:
1768                                 *  - less than, move right
1769                                 *  - greater than, move left
1770                                 *  - equal, we're done
1771                                 */
1772                                diff = cur->bc_ops->key_diff(cur, kp);
1773                                if (diff < 0)
1774                                        low = keyno + 1;
1775                                else if (diff > 0)
1776                                        high = keyno - 1;
1777                                else
1778                                        break;
1779                        }
1780                }
1781
1782                /*
1783                 * If there are more levels, set up for the next level
1784                 * by getting the block number and filling in the cursor.
1785                 */
1786                if (level > 0) {
1787                        /*
1788                         * If we moved left, need the previous key number,
1789                         * unless there isn't one.
1790                         */
1791                        if (diff > 0 && --keyno < 1)
1792                                keyno = 1;
1793                        pp = xfs_btree_ptr_addr(cur, keyno, block);
1794
1795#ifdef DEBUG
1796                        error = xfs_btree_check_ptr(cur, pp, 0, level);
1797                        if (error)
1798                                goto error0;
1799#endif
1800                        cur->bc_ptrs[level] = keyno;
1801                }
1802        }
1803
1804        /* Done with the search. See if we need to adjust the results. */
1805        if (dir != XFS_LOOKUP_LE && diff < 0) {
1806                keyno++;
1807                /*
1808                 * If ge search and we went off the end of the block, but it's
1809                 * not the last block, we're in the wrong block.
1810                 */
1811                xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
1812                if (dir == XFS_LOOKUP_GE &&
1813                    keyno > xfs_btree_get_numrecs(block) &&
1814                    !xfs_btree_ptr_is_null(cur, &ptr)) {
1815                        int     i;
1816
1817                        cur->bc_ptrs[0] = keyno;
1818                        error = xfs_btree_increment(cur, 0, &i);
1819                        if (error)
1820                                goto error0;
1821                        XFS_WANT_CORRUPTED_RETURN(i == 1);
1822                        XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1823                        *stat = 1;
1824                        return 0;
1825                }
1826        } else if (dir == XFS_LOOKUP_LE && diff > 0)
1827                keyno--;
1828        cur->bc_ptrs[0] = keyno;
1829
1830        /* Return if we succeeded or not. */
1831        if (keyno == 0 || keyno > xfs_btree_get_numrecs(block))
1832                *stat = 0;
1833        else if (dir != XFS_LOOKUP_EQ || diff == 0)
1834                *stat = 1;
1835        else
1836                *stat = 0;
1837        XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1838        return 0;
1839
1840error0:
1841        XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1842        return error;
1843}
1844
1845/*
1846 * Update keys at all levels from here to the root along the cursor's path.
1847 */
1848STATIC int
1849xfs_btree_updkey(
1850        struct xfs_btree_cur    *cur,
1851        union xfs_btree_key     *keyp,
1852        int                     level)
1853{
1854        struct xfs_btree_block  *block;
1855        struct xfs_buf          *bp;
1856        union xfs_btree_key     *kp;
1857        int                     ptr;
1858
1859        XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1860        XFS_BTREE_TRACE_ARGIK(cur, level, keyp);
1861
1862        ASSERT(!(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) || level >= 1);
1863
1864        /*
1865         * Go up the tree from this level toward the root.
1866         * At each level, update the key value to the value input.
1867         * Stop when we reach a level where the cursor isn't pointing
1868         * at the first entry in the block.
1869         */
1870        for (ptr = 1; ptr == 1 && level < cur->bc_nlevels; level++) {
1871#ifdef DEBUG
1872                int             error;
1873#endif
1874                block = xfs_btree_get_block(cur, level, &bp);
1875#ifdef DEBUG
1876                error = xfs_btree_check_block(cur, block, level, bp);
1877                if (error) {
1878                        XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1879                        return error;
1880                }
1881#endif
1882                ptr = cur->bc_ptrs[level];
1883                kp = xfs_btree_key_addr(cur, ptr, block);
1884                xfs_btree_copy_keys(cur, kp, keyp, 1);
1885                xfs_btree_log_keys(cur, bp, ptr, ptr);
1886        }
1887
1888        XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1889        return 0;
1890}
1891
1892/*
1893 * Update the record referred to by cur to the value in the
1894 * given record. This either works (return 0) or gets an
1895 * EFSCORRUPTED error.
1896 */
1897int
1898xfs_btree_update(
1899        struct xfs_btree_cur    *cur,
1900        union xfs_btree_rec     *rec)
1901{
1902        struct xfs_btree_block  *block;
1903        struct xfs_buf          *bp;
1904        int                     error;
1905        int                     ptr;
1906        union xfs_btree_rec     *rp;
1907
1908        XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1909        XFS_BTREE_TRACE_ARGR(cur, rec);
1910
1911        /* Pick up the current block. */
1912        block = xfs_btree_get_block(cur, 0, &bp);
1913
1914#ifdef DEBUG
1915        error = xfs_btree_check_block(cur, block, 0, bp);
1916        if (error)
1917                goto error0;
1918#endif
1919        /* Get the address of the rec to be updated. */
1920        ptr = cur->bc_ptrs[0];
1921        rp = xfs_btree_rec_addr(cur, ptr, block);
1922
1923        /* Fill in the new contents and log them. */
1924        xfs_btree_copy_recs(cur, rp, rec, 1);
1925        xfs_btree_log_recs(cur, bp, ptr, ptr);
1926
1927        /*
1928         * If we are tracking the last record in the tree and
1929         * we are at the far right edge of the tree, update it.
1930         */
1931        if (xfs_btree_is_lastrec(cur, block, 0)) {
1932                cur->bc_ops->update_lastrec(cur, block, rec,
1933                                            ptr, LASTREC_UPDATE);
1934        }
1935
1936        /* Updating first rec in leaf. Pass new key value up to our parent. */
1937        if (ptr == 1) {
1938                union xfs_btree_key     key;
1939
1940                cur->bc_ops->init_key_from_rec(&key, rec);
1941                error = xfs_btree_updkey(cur, &key, 1);
1942                if (error)
1943                        goto error0;
1944        }
1945
1946        XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
1947        return 0;
1948
1949error0:
1950        XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
1951        return error;
1952}
1953
1954/*
1955 * Move 1 record left from cur/level if possible.
1956 * Update cur to reflect the new path.
1957 */
1958STATIC int                                      /* error */
1959xfs_btree_lshift(
1960        struct xfs_btree_cur    *cur,
1961        int                     level,
1962        int                     *stat)          /* success/failure */
1963{
1964        union xfs_btree_key     key;            /* btree key */
1965        struct xfs_buf          *lbp;           /* left buffer pointer */
1966        struct xfs_btree_block  *left;          /* left btree block */
1967        int                     lrecs;          /* left record count */
1968        struct xfs_buf          *rbp;           /* right buffer pointer */
1969        struct xfs_btree_block  *right;         /* right btree block */
1970        int                     rrecs;          /* right record count */
1971        union xfs_btree_ptr     lptr;           /* left btree pointer */
1972        union xfs_btree_key     *rkp = NULL;    /* right btree key */
1973        union xfs_btree_ptr     *rpp = NULL;    /* right address pointer */
1974        union xfs_btree_rec     *rrp = NULL;    /* right record pointer */
1975        int                     error;          /* error return value */
1976
1977        XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
1978        XFS_BTREE_TRACE_ARGI(cur, level);
1979
1980        if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
1981            level == cur->bc_nlevels - 1)
1982                goto out0;
1983
1984        /* Set up variables for this block as "right". */
1985        right = xfs_btree_get_block(cur, level, &rbp);
1986
1987#ifdef DEBUG
1988        error = xfs_btree_check_block(cur, right, level, rbp);
1989        if (error)
1990                goto error0;
1991#endif
1992
1993        /* If we've got no left sibling then we can't shift an entry left. */
1994        xfs_btree_get_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
1995        if (xfs_btree_ptr_is_null(cur, &lptr))
1996                goto out0;
1997
1998        /*
1999         * If the cursor entry is the one that would be moved, don't
2000         * do it... it's too complicated.
2001         */
2002        if (cur->bc_ptrs[level] <= 1)
2003                goto out0;
2004
2005        /* Set up the left neighbor as "left". */
2006        error = xfs_btree_read_buf_block(cur, &lptr, level, 0, &left, &lbp);
2007        if (error)
2008                goto error0;
2009
2010        /* If it's full, it can't take another entry. */
2011        lrecs = xfs_btree_get_numrecs(left);
2012        if (lrecs == cur->bc_ops->get_maxrecs(cur, level))
2013                goto out0;
2014
2015        rrecs = xfs_btree_get_numrecs(right);
2016
2017        /*
2018         * We add one entry to the left side and remove one for the right side.
2019         * Account for it here, the changes will be updated on disk and logged
2020         * later.
2021         */
2022        lrecs++;
2023        rrecs--;
2024
2025        XFS_BTREE_STATS_INC(cur, lshift);
2026        XFS_BTREE_STATS_ADD(cur, moves, 1);
2027
2028        /*
2029         * If non-leaf, copy a key and a ptr to the left block.
2030         * Log the changes to the left block.
2031         */
2032        if (level > 0) {
2033                /* It's a non-leaf.  Move keys and pointers. */
2034                union xfs_btree_key     *lkp;   /* left btree key */
2035                union xfs_btree_ptr     *lpp;   /* left address pointer */
2036
2037                lkp = xfs_btree_key_addr(cur, lrecs, left);
2038                rkp = xfs_btree_key_addr(cur, 1, right);
2039
2040                lpp = xfs_btree_ptr_addr(cur, lrecs, left);
2041                rpp = xfs_btree_ptr_addr(cur, 1, right);
2042#ifdef DEBUG
2043                error = xfs_btree_check_ptr(cur, rpp, 0, level);
2044                if (error)
2045                        goto error0;
2046#endif
2047                xfs_btree_copy_keys(cur, lkp, rkp, 1);
2048                xfs_btree_copy_ptrs(cur, lpp, rpp, 1);
2049
2050                xfs_btree_log_keys(cur, lbp, lrecs, lrecs);
2051                xfs_btree_log_ptrs(cur, lbp, lrecs, lrecs);
2052
2053                ASSERT(cur->bc_ops->keys_inorder(cur,
2054                        xfs_btree_key_addr(cur, lrecs - 1, left), lkp));
2055        } else {
2056                /* It's a leaf.  Move records.  */
2057                union xfs_btree_rec     *lrp;   /* left record pointer */
2058
2059                lrp = xfs_btree_rec_addr(cur, lrecs, left);
2060                rrp = xfs_btree_rec_addr(cur, 1, right);
2061
2062                xfs_btree_copy_recs(cur, lrp, rrp, 1);
2063                xfs_btree_log_recs(cur, lbp, lrecs, lrecs);
2064
2065                ASSERT(cur->bc_ops->recs_inorder(cur,
2066                        xfs_btree_rec_addr(cur, lrecs - 1, left), lrp));
2067        }
2068
2069        xfs_btree_set_numrecs(left, lrecs);
2070        xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS);
2071
2072        xfs_btree_set_numrecs(right, rrecs);
2073        xfs_btree_log_block(cur, rbp, XFS_BB_NUMRECS);
2074
2075        /*
2076         * Slide the contents of right down one entry.
2077         */
2078        XFS_BTREE_STATS_ADD(cur, moves, rrecs - 1);
2079        if (level > 0) {
2080                /* It's a nonleaf. operate on keys and ptrs */
2081#ifdef DEBUG
2082                int                     i;              /* loop index */
2083
2084                for (i = 0; i < rrecs; i++) {
2085                        error = xfs_btree_check_ptr(cur, rpp, i + 1, level);
2086                        if (error)
2087                                goto error0;
2088                }
2089#endif
2090                xfs_btree_shift_keys(cur,
2091                                xfs_btree_key_addr(cur, 2, right),
2092                                -1, rrecs);
2093                xfs_btree_shift_ptrs(cur,
2094                                xfs_btree_ptr_addr(cur, 2, right),
2095                                -1, rrecs);
2096
2097                xfs_btree_log_keys(cur, rbp, 1, rrecs);
2098                xfs_btree_log_ptrs(cur, rbp, 1, rrecs);
2099        } else {
2100                /* It's a leaf. operate on records */
2101                xfs_btree_shift_recs(cur,
2102                        xfs_btree_rec_addr(cur, 2, right),
2103                        -1, rrecs);
2104                xfs_btree_log_recs(cur, rbp, 1, rrecs);
2105
2106                /*
2107                 * If it's the first record in the block, we'll need a key
2108                 * structure to pass up to the next level (updkey).
2109                 */
2110                cur->bc_ops->init_key_from_rec(&key,
2111                        xfs_btree_rec_addr(cur, 1, right));
2112                rkp = &key;
2113        }
2114
2115        /* Update the parent key values of right. */
2116        error = xfs_btree_updkey(cur, rkp, level + 1);
2117        if (error)
2118                goto error0;
2119
2120        /* Slide the cursor value left one. */
2121        cur->bc_ptrs[level]--;
2122
2123        XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2124        *stat = 1;
2125        return 0;
2126
2127out0:
2128        XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2129        *stat = 0;
2130        return 0;
2131
2132error0:
2133        XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2134        return error;
2135}
2136
2137/*
2138 * Move 1 record right from cur/level if possible.
2139 * Update cur to reflect the new path.
2140 */
2141STATIC int                                      /* error */
2142xfs_btree_rshift(
2143        struct xfs_btree_cur    *cur,
2144        int                     level,
2145        int                     *stat)          /* success/failure */
2146{
2147        union xfs_btree_key     key;            /* btree key */
2148        struct xfs_buf          *lbp;           /* left buffer pointer */
2149        struct xfs_btree_block  *left;          /* left btree block */
2150        struct xfs_buf          *rbp;           /* right buffer pointer */
2151        struct xfs_btree_block  *right;         /* right btree block */
2152        struct xfs_btree_cur    *tcur;          /* temporary btree cursor */
2153        union xfs_btree_ptr     rptr;           /* right block pointer */
2154        union xfs_btree_key     *rkp;           /* right btree key */
2155        int                     rrecs;          /* right record count */
2156        int                     lrecs;          /* left record count */
2157        int                     error;          /* error return value */
2158        int                     i;              /* loop counter */
2159
2160        XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2161        XFS_BTREE_TRACE_ARGI(cur, level);
2162
2163        if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
2164            (level == cur->bc_nlevels - 1))
2165                goto out0;
2166
2167        /* Set up variables for this block as "left". */
2168        left = xfs_btree_get_block(cur, level, &lbp);
2169
2170#ifdef DEBUG
2171        error = xfs_btree_check_block(cur, left, level, lbp);
2172        if (error)
2173                goto error0;
2174#endif
2175
2176        /* If we've got no right sibling then we can't shift an entry right. */
2177        xfs_btree_get_sibling(cur, left, &rptr, XFS_BB_RIGHTSIB);
2178        if (xfs_btree_ptr_is_null(cur, &rptr))
2179                goto out0;
2180
2181        /*
2182         * If the cursor entry is the one that would be moved, don't
2183         * do it... it's too complicated.
2184         */
2185        lrecs = xfs_btree_get_numrecs(left);
2186        if (cur->bc_ptrs[level] >= lrecs)
2187                goto out0;
2188
2189        /* Set up the right neighbor as "right". */
2190        error = xfs_btree_read_buf_block(cur, &rptr, level, 0, &right, &rbp);
2191        if (error)
2192                goto error0;
2193
2194        /* If it's full, it can't take another entry. */
2195        rrecs = xfs_btree_get_numrecs(right);
2196        if (rrecs == cur->bc_ops->get_maxrecs(cur, level))
2197                goto out0;
2198
2199        XFS_BTREE_STATS_INC(cur, rshift);
2200        XFS_BTREE_STATS_ADD(cur, moves, rrecs);
2201
2202        /*
2203         * Make a hole at the start of the right neighbor block, then
2204         * copy the last left block entry to the hole.
2205         */
2206        if (level > 0) {
2207                /* It's a nonleaf. make a hole in the keys and ptrs */
2208                union xfs_btree_key     *lkp;
2209                union xfs_btree_ptr     *lpp;
2210                union xfs_btree_ptr     *rpp;
2211
2212                lkp = xfs_btree_key_addr(cur, lrecs, left);
2213                lpp = xfs_btree_ptr_addr(cur, lrecs, left);
2214                rkp = xfs_btree_key_addr(cur, 1, right);
2215                rpp = xfs_btree_ptr_addr(cur, 1, right);
2216
2217#ifdef DEBUG
2218                for (i = rrecs - 1; i >= 0; i--) {
2219                        error = xfs_btree_check_ptr(cur, rpp, i, level);
2220                        if (error)
2221                                goto error0;
2222                }
2223#endif
2224
2225                xfs_btree_shift_keys(cur, rkp, 1, rrecs);
2226                xfs_btree_shift_ptrs(cur, rpp, 1, rrecs);
2227
2228#ifdef DEBUG
2229                error = xfs_btree_check_ptr(cur, lpp, 0, level);
2230                if (error)
2231                        goto error0;
2232#endif
2233
2234                /* Now put the new data in, and log it. */
2235                xfs_btree_copy_keys(cur, rkp, lkp, 1);
2236                xfs_btree_copy_ptrs(cur, rpp, lpp, 1);
2237
2238                xfs_btree_log_keys(cur, rbp, 1, rrecs + 1);
2239                xfs_btree_log_ptrs(cur, rbp, 1, rrecs + 1);
2240
2241                ASSERT(cur->bc_ops->keys_inorder(cur, rkp,
2242                        xfs_btree_key_addr(cur, 2, right)));
2243        } else {
2244                /* It's a leaf. make a hole in the records */
2245                union xfs_btree_rec     *lrp;
2246                union xfs_btree_rec     *rrp;
2247
2248                lrp = xfs_btree_rec_addr(cur, lrecs, left);
2249                rrp = xfs_btree_rec_addr(cur, 1, right);
2250
2251                xfs_btree_shift_recs(cur, rrp, 1, rrecs);
2252
2253                /* Now put the new data in, and log it. */
2254                xfs_btree_copy_recs(cur, rrp, lrp, 1);
2255                xfs_btree_log_recs(cur, rbp, 1, rrecs + 1);
2256
2257                cur->bc_ops->init_key_from_rec(&key, rrp);
2258                rkp = &key;
2259
2260                ASSERT(cur->bc_ops->recs_inorder(cur, rrp,
2261                        xfs_btree_rec_addr(cur, 2, right)));
2262        }
2263
2264        /*
2265         * Decrement and log left's numrecs, bump and log right's numrecs.
2266         */
2267        xfs_btree_set_numrecs(left, --lrecs);
2268        xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS);
2269
2270        xfs_btree_set_numrecs(right, ++rrecs);
2271        xfs_btree_log_block(cur, rbp, XFS_BB_NUMRECS);
2272
2273        /*
2274         * Using a temporary cursor, update the parent key values of the
2275         * block on the right.
2276         */
2277        error = xfs_btree_dup_cursor(cur, &tcur);
2278        if (error)
2279                goto error0;
2280        i = xfs_btree_lastrec(tcur, level);
2281        XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
2282
2283        error = xfs_btree_increment(tcur, level, &i);
2284        if (error)
2285                goto error1;
2286
2287        error = xfs_btree_updkey(tcur, rkp, level + 1);
2288        if (error)
2289                goto error1;
2290
2291        xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
2292
2293        XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2294        *stat = 1;
2295        return 0;
2296
2297out0:
2298        XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2299        *stat = 0;
2300        return 0;
2301
2302error0:
2303        XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2304        return error;
2305
2306error1:
2307        XFS_BTREE_TRACE_CURSOR(tcur, XBT_ERROR);
2308        xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR);
2309        return error;
2310}
2311
2312/*
2313 * Split cur/level block in half.
2314 * Return new block number and the key to its first
2315 * record (to be inserted into parent).
2316 */
2317STATIC int                                      /* error */
2318xfs_btree_split(
2319        struct xfs_btree_cur    *cur,
2320        int                     level,
2321        union xfs_btree_ptr     *ptrp,
2322        union xfs_btree_key     *key,
2323        struct xfs_btree_cur    **curp,
2324        int                     *stat)          /* success/failure */
2325{
2326        union xfs_btree_ptr     lptr;           /* left sibling block ptr */
2327        struct xfs_buf          *lbp;           /* left buffer pointer */
2328        struct xfs_btree_block  *left;          /* left btree block */
2329        union xfs_btree_ptr     rptr;           /* right sibling block ptr */
2330        struct xfs_buf          *rbp;           /* right buffer pointer */
2331        struct xfs_btree_block  *right;         /* right btree block */
2332        union xfs_btree_ptr     rrptr;          /* right-right sibling ptr */
2333        struct xfs_buf          *rrbp;          /* right-right buffer pointer */
2334        struct xfs_btree_block  *rrblock;       /* right-right btree block */
2335        int                     lrecs;
2336        int                     rrecs;
2337        int                     src_index;
2338        int                     error;          /* error return value */
2339#ifdef DEBUG
2340        int                     i;
2341#endif
2342
2343        XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2344        XFS_BTREE_TRACE_ARGIPK(cur, level, *ptrp, key);
2345
2346        XFS_BTREE_STATS_INC(cur, split);
2347
2348        /* Set up left block (current one). */
2349        left = xfs_btree_get_block(cur, level, &lbp);
2350
2351#ifdef DEBUG
2352        error = xfs_btree_check_block(cur, left, level, lbp);
2353        if (error)
2354                goto error0;
2355#endif
2356
2357        xfs_btree_buf_to_ptr(cur, lbp, &lptr);
2358
2359        /* Allocate the new block. If we can't do it, we're toast. Give up. */
2360        error = cur->bc_ops->alloc_block(cur, &lptr, &rptr, 1, stat);
2361        if (error)
2362                goto error0;
2363        if (*stat == 0)
2364                goto out0;
2365        XFS_BTREE_STATS_INC(cur, alloc);
2366
2367        /* Set up the new block as "right". */
2368        error = xfs_btree_get_buf_block(cur, &rptr, 0, &right, &rbp);
2369        if (error)
2370                goto error0;
2371
2372        /* Fill in the btree header for the new right block. */
2373        xfs_btree_init_block_cur(cur, rbp, xfs_btree_get_level(left), 0);
2374
2375        /*
2376         * Split the entries between the old and the new block evenly.
2377         * Make sure that if there's an odd number of entries now, that
2378         * each new block will have the same number of entries.
2379         */
2380        lrecs = xfs_btree_get_numrecs(left);
2381        rrecs = lrecs / 2;
2382        if ((lrecs & 1) && cur->bc_ptrs[level] <= rrecs + 1)
2383                rrecs++;
2384        src_index = (lrecs - rrecs + 1);
2385
2386        XFS_BTREE_STATS_ADD(cur, moves, rrecs);
2387
2388        /*
2389         * Copy btree block entries from the left block over to the
2390         * new block, the right. Update the right block and log the
2391         * changes.
2392         */
2393        if (level > 0) {
2394                /* It's a non-leaf.  Move keys and pointers. */
2395                union xfs_btree_key     *lkp;   /* left btree key */
2396                union xfs_btree_ptr     *lpp;   /* left address pointer */
2397                union xfs_btree_key     *rkp;   /* right btree key */
2398                union xfs_btree_ptr     *rpp;   /* right address pointer */
2399
2400                lkp = xfs_btree_key_addr(cur, src_index, left);
2401                lpp = xfs_btree_ptr_addr(cur, src_index, left);
2402                rkp = xfs_btree_key_addr(cur, 1, right);
2403                rpp = xfs_btree_ptr_addr(cur, 1, right);
2404
2405#ifdef DEBUG
2406                for (i = src_index; i < rrecs; i++) {
2407                        error = xfs_btree_check_ptr(cur, lpp, i, level);
2408                        if (error)
2409                                goto error0;
2410                }
2411#endif
2412
2413                xfs_btree_copy_keys(cur, rkp, lkp, rrecs);
2414                xfs_btree_copy_ptrs(cur, rpp, lpp, rrecs);
2415
2416                xfs_btree_log_keys(cur, rbp, 1, rrecs);
2417                xfs_btree_log_ptrs(cur, rbp, 1, rrecs);
2418
2419                /* Grab the keys to the entries moved to the right block */
2420                xfs_btree_copy_keys(cur, key, rkp, 1);
2421        } else {
2422                /* It's a leaf.  Move records.  */
2423                union xfs_btree_rec     *lrp;   /* left record pointer */
2424                union xfs_btree_rec     *rrp;   /* right record pointer */
2425
2426                lrp = xfs_btree_rec_addr(cur, src_index, left);
2427                rrp = xfs_btree_rec_addr(cur, 1, right);
2428
2429                xfs_btree_copy_recs(cur, rrp, lrp, rrecs);
2430                xfs_btree_log_recs(cur, rbp, 1, rrecs);
2431
2432                cur->bc_ops->init_key_from_rec(key,
2433                        xfs_btree_rec_addr(cur, 1, right));
2434        }
2435
2436
2437        /*
2438         * Find the left block number by looking in the buffer.
2439         * Adjust numrecs, sibling pointers.
2440         */
2441        xfs_btree_get_sibling(cur, left, &rrptr, XFS_BB_RIGHTSIB);
2442        xfs_btree_set_sibling(cur, right, &rrptr, XFS_BB_RIGHTSIB);
2443        xfs_btree_set_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
2444        xfs_btree_set_sibling(cur, left, &rptr, XFS_BB_RIGHTSIB);
2445
2446        lrecs -= rrecs;
2447        xfs_btree_set_numrecs(left, lrecs);
2448        xfs_btree_set_numrecs(right, xfs_btree_get_numrecs(right) + rrecs);
2449
2450        xfs_btree_log_block(cur, rbp, XFS_BB_ALL_BITS);
2451        xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS | XFS_BB_RIGHTSIB);
2452
2453        /*
2454         * If there's a block to the new block's right, make that block
2455         * point back to right instead of to left.
2456         */
2457        if (!xfs_btree_ptr_is_null(cur, &rrptr)) {
2458                error = xfs_btree_read_buf_block(cur, &rrptr, level,
2459                                                        0, &rrblock, &rrbp);
2460                if (error)
2461                        goto error0;
2462                xfs_btree_set_sibling(cur, rrblock, &rptr, XFS_BB_LEFTSIB);
2463                xfs_btree_log_block(cur, rrbp, XFS_BB_LEFTSIB);
2464        }
2465        /*
2466         * If the cursor is really in the right block, move it there.
2467         * If it's just pointing past the last entry in left, then we'll
2468         * insert there, so don't change anything in that case.
2469         */
2470        if (cur->bc_ptrs[level] > lrecs + 1) {
2471                xfs_btree_setbuf(cur, level, rbp);
2472                cur->bc_ptrs[level] -= lrecs;
2473        }
2474        /*
2475         * If there are more levels, we'll need another cursor which refers
2476         * the right block, no matter where this cursor was.
2477         */
2478        if (level + 1 < cur->bc_nlevels) {
2479                error = xfs_btree_dup_cursor(cur, curp);
2480                if (error)
2481                        goto error0;
2482                (*curp)->bc_ptrs[level + 1]++;
2483        }
2484        *ptrp = rptr;
2485        XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2486        *stat = 1;
2487        return 0;
2488out0:
2489        XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2490        *stat = 0;
2491        return 0;
2492
2493error0:
2494        XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2495        return error;
2496}
2497
2498/*
2499 * Copy the old inode root contents into a real block and make the
2500 * broot point to it.
2501 */
2502int                                             /* error */
2503xfs_btree_new_iroot(
2504        struct xfs_btree_cur    *cur,           /* btree cursor */
2505        int                     *logflags,      /* logging flags for inode */
2506        int                     *stat)          /* return status - 0 fail */
2507{
2508        struct xfs_buf          *cbp;           /* buffer for cblock */
2509        struct xfs_btree_block  *block;         /* btree block */
2510        struct xfs_btree_block  *cblock;        /* child btree block */
2511        union xfs_btree_key     *ckp;           /* child key pointer */
2512        union xfs_btree_ptr     *cpp;           /* child ptr pointer */
2513        union xfs_btree_key     *kp;            /* pointer to btree key */
2514        union xfs_btree_ptr     *pp;            /* pointer to block addr */
2515        union xfs_btree_ptr     nptr;           /* new block addr */
2516        int                     level;          /* btree level */
2517        int                     error;          /* error return code */
2518#ifdef DEBUG
2519        int                     i;              /* loop counter */
2520#endif
2521
2522        XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2523        XFS_BTREE_STATS_INC(cur, newroot);
2524
2525        ASSERT(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE);
2526
2527        level = cur->bc_nlevels - 1;
2528
2529        block = xfs_btree_get_iroot(cur);
2530        pp = xfs_btree_ptr_addr(cur, 1, block);
2531
2532        /* Allocate the new block. If we can't do it, we're toast. Give up. */
2533        error = cur->bc_ops->alloc_block(cur, pp, &nptr, 1, stat);
2534        if (error)
2535                goto error0;
2536        if (*stat == 0) {
2537                XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2538                return 0;
2539        }
2540        XFS_BTREE_STATS_INC(cur, alloc);
2541
2542        /* Copy the root into a real block. */
2543        error = xfs_btree_get_buf_block(cur, &nptr, 0, &cblock, &cbp);
2544        if (error)
2545                goto error0;
2546
2547        /*
2548         * we can't just memcpy() the root in for CRC enabled btree blocks.
2549         * In that case have to also ensure the blkno remains correct
2550         */
2551        memcpy(cblock, block, xfs_btree_block_len(cur));
2552        if (cur->bc_flags & XFS_BTREE_CRC_BLOCKS) {
2553                if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
2554                        cblock->bb_u.l.bb_blkno = cpu_to_be64(cbp->b_bn);
2555                else
2556                        cblock->bb_u.s.bb_blkno = cpu_to_be64(cbp->b_bn);
2557        }
2558
2559        be16_add_cpu(&block->bb_level, 1);
2560        xfs_btree_set_numrecs(block, 1);
2561        cur->bc_nlevels++;
2562        cur->bc_ptrs[level + 1] = 1;
2563
2564        kp = xfs_btree_key_addr(cur, 1, block);
2565        ckp = xfs_btree_key_addr(cur, 1, cblock);
2566        xfs_btree_copy_keys(cur, ckp, kp, xfs_btree_get_numrecs(cblock));
2567
2568        cpp = xfs_btree_ptr_addr(cur, 1, cblock);
2569#ifdef DEBUG
2570        for (i = 0; i < be16_to_cpu(cblock->bb_numrecs); i++) {
2571                error = xfs_btree_check_ptr(cur, pp, i, level);
2572                if (error)
2573                        goto error0;
2574        }
2575#endif
2576        xfs_btree_copy_ptrs(cur, cpp, pp, xfs_btree_get_numrecs(cblock));
2577
2578#ifdef DEBUG
2579        error = xfs_btree_check_ptr(cur, &nptr, 0, level);
2580        if (error)
2581                goto error0;
2582#endif
2583        xfs_btree_copy_ptrs(cur, pp, &nptr, 1);
2584
2585        xfs_iroot_realloc(cur->bc_private.b.ip,
2586                          1 - xfs_btree_get_numrecs(cblock),
2587                          cur->bc_private.b.whichfork);
2588
2589        xfs_btree_setbuf(cur, level, cbp);
2590
2591        /*
2592         * Do all this logging at the end so that
2593         * the root is at the right level.
2594         */
2595        xfs_btree_log_block(cur, cbp, XFS_BB_ALL_BITS);
2596        xfs_btree_log_keys(cur, cbp, 1, be16_to_cpu(cblock->bb_numrecs));
2597        xfs_btree_log_ptrs(cur, cbp, 1, be16_to_cpu(cblock->bb_numrecs));
2598
2599        *logflags |=
2600                XFS_ILOG_CORE | xfs_ilog_fbroot(cur->bc_private.b.whichfork);
2601        *stat = 1;
2602        XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2603        return 0;
2604error0:
2605        XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2606        return error;
2607}
2608
2609/*
2610 * Allocate a new root block, fill it in.
2611 */
2612STATIC int                              /* error */
2613xfs_btree_new_root(
2614        struct xfs_btree_cur    *cur,   /* btree cursor */
2615        int                     *stat)  /* success/failure */
2616{
2617        struct xfs_btree_block  *block; /* one half of the old root block */
2618        struct xfs_buf          *bp;    /* buffer containing block */
2619        int                     error;  /* error return value */
2620        struct xfs_buf          *lbp;   /* left buffer pointer */
2621        struct xfs_btree_block  *left;  /* left btree block */
2622        struct xfs_buf          *nbp;   /* new (root) buffer */
2623        struct xfs_btree_block  *new;   /* new (root) btree block */
2624        int                     nptr;   /* new value for key index, 1 or 2 */
2625        struct xfs_buf          *rbp;   /* right buffer pointer */
2626        struct xfs_btree_block  *right; /* right btree block */
2627        union xfs_btree_ptr     rptr;
2628        union xfs_btree_ptr     lptr;
2629
2630        XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2631        XFS_BTREE_STATS_INC(cur, newroot);
2632
2633        /* initialise our start point from the cursor */
2634        cur->bc_ops->init_ptr_from_cur(cur, &rptr);
2635
2636        /* Allocate the new block. If we can't do it, we're toast. Give up. */
2637        error = cur->bc_ops->alloc_block(cur, &rptr, &lptr, 1, stat);
2638        if (error)
2639                goto error0;
2640        if (*stat == 0)
2641                goto out0;
2642        XFS_BTREE_STATS_INC(cur, alloc);
2643
2644        /* Set up the new block. */
2645        error = xfs_btree_get_buf_block(cur, &lptr, 0, &new, &nbp);
2646        if (error)
2647                goto error0;
2648
2649        /* Set the root in the holding structure  increasing the level by 1. */
2650        cur->bc_ops->set_root(cur, &lptr, 1);
2651
2652        /*
2653         * At the previous root level there are now two blocks: the old root,
2654         * and the new block generated when it was split.  We don't know which
2655         * one the cursor is pointing at, so we set up variables "left" and
2656         * "right" for each case.
2657         */
2658        block = xfs_btree_get_block(cur, cur->bc_nlevels - 1, &bp);
2659
2660#ifdef DEBUG
2661        error = xfs_btree_check_block(cur, block, cur->bc_nlevels - 1, bp);
2662        if (error)
2663                goto error0;
2664#endif
2665
2666        xfs_btree_get_sibling(cur, block, &rptr, XFS_BB_RIGHTSIB);
2667        if (!xfs_btree_ptr_is_null(cur, &rptr)) {
2668                /* Our block is left, pick up the right block. */
2669                lbp = bp;
2670                xfs_btree_buf_to_ptr(cur, lbp, &lptr);
2671                left = block;
2672                error = xfs_btree_read_buf_block(cur, &rptr,
2673                                        cur->bc_nlevels - 1, 0, &right, &rbp);
2674                if (error)
2675                        goto error0;
2676                bp = rbp;
2677                nptr = 1;
2678        } else {
2679                /* Our block is right, pick up the left block. */
2680                rbp = bp;
2681                xfs_btree_buf_to_ptr(cur, rbp, &rptr);
2682                right = block;
2683                xfs_btree_get_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
2684                error = xfs_btree_read_buf_block(cur, &lptr,
2685                                        cur->bc_nlevels - 1, 0, &left, &lbp);
2686                if (error)
2687                        goto error0;
2688                bp = lbp;
2689                nptr = 2;
2690        }
2691        /* Fill in the new block's btree header and log it. */
2692        xfs_btree_init_block_cur(cur, nbp, cur->bc_nlevels, 2);
2693        xfs_btree_log_block(cur, nbp, XFS_BB_ALL_BITS);
2694        ASSERT(!xfs_btree_ptr_is_null(cur, &lptr) &&
2695                        !xfs_btree_ptr_is_null(cur, &rptr));
2696
2697        /* Fill in the key data in the new root. */
2698        if (xfs_btree_get_level(left) > 0) {
2699                xfs_btree_copy_keys(cur,
2700                                xfs_btree_key_addr(cur, 1, new),
2701                                xfs_btree_key_addr(cur, 1, left), 1);
2702                xfs_btree_copy_keys(cur,
2703                                xfs_btree_key_addr(cur, 2, new),
2704                                xfs_btree_key_addr(cur, 1, right), 1);
2705        } else {
2706                cur->bc_ops->init_key_from_rec(
2707                                xfs_btree_key_addr(cur, 1, new),
2708                                xfs_btree_rec_addr(cur, 1, left));
2709                cur->bc_ops->init_key_from_rec(
2710                                xfs_btree_key_addr(cur, 2, new),
2711                                xfs_btree_rec_addr(cur, 1, right));
2712        }
2713        xfs_btree_log_keys(cur, nbp, 1, 2);
2714
2715        /* Fill in the pointer data in the new root. */
2716        xfs_btree_copy_ptrs(cur,
2717                xfs_btree_ptr_addr(cur, 1, new), &lptr, 1);
2718        xfs_btree_copy_ptrs(cur,
2719                xfs_btree_ptr_addr(cur, 2, new), &rptr, 1);
2720        xfs_btree_log_ptrs(cur, nbp, 1, 2);
2721
2722        /* Fix up the cursor. */
2723        xfs_btree_setbuf(cur, cur->bc_nlevels, nbp);
2724        cur->bc_ptrs[cur->bc_nlevels] = nptr;
2725        cur->bc_nlevels++;
2726        XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2727        *stat = 1;
2728        return 0;
2729error0:
2730        XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
2731        return error;
2732out0:
2733        XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2734        *stat = 0;
2735        return 0;
2736}
2737
2738STATIC int
2739xfs_btree_make_block_unfull(
2740        struct xfs_btree_cur    *cur,   /* btree cursor */
2741        int                     level,  /* btree level */
2742        int                     numrecs,/* # of recs in block */
2743        int                     *oindex,/* old tree index */
2744        int                     *index, /* new tree index */
2745        union xfs_btree_ptr     *nptr,  /* new btree ptr */
2746        struct xfs_btree_cur    **ncur, /* new btree cursor */
2747        union xfs_btree_rec     *nrec,  /* new record */
2748        int                     *stat)
2749{
2750        union xfs_btree_key     key;    /* new btree key value */
2751        int                     error = 0;
2752
2753        if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
2754            level == cur->bc_nlevels - 1) {
2755                struct xfs_inode *ip = cur->bc_private.b.ip;
2756
2757                if (numrecs < cur->bc_ops->get_dmaxrecs(cur, level)) {
2758                        /* A root block that can be made bigger. */
2759
2760                        xfs_iroot_realloc(ip, 1, cur->bc_private.b.whichfork);
2761                } else {
2762                        /* A root block that needs replacing */
2763                        int     logflags = 0;
2764
2765                        error = xfs_btree_new_iroot(cur, &logflags, stat);
2766                        if (error || *stat == 0)
2767                                return error;
2768
2769                        xfs_trans_log_inode(cur->bc_tp, ip, logflags);
2770                }
2771
2772                return 0;
2773        }
2774
2775        /* First, try shifting an entry to the right neighbor. */
2776        error = xfs_btree_rshift(cur, level, stat);
2777        if (error || *stat)
2778                return error;
2779
2780        /* Next, try shifting an entry to the left neighbor. */
2781        error = xfs_btree_lshift(cur, level, stat);
2782        if (error)
2783                return error;
2784
2785        if (*stat) {
2786                *oindex = *index = cur->bc_ptrs[level];
2787                return 0;
2788        }
2789
2790        /*
2791         * Next, try splitting the current block in half.
2792         *
2793         * If this works we have to re-set our variables because we
2794         * could be in a different block now.
2795         */
2796        error = xfs_btree_split(cur, level, nptr, &key, ncur, stat);
2797        if (error || *stat == 0)
2798                return error;
2799
2800
2801        *index = cur->bc_ptrs[level];
2802        cur->bc_ops->init_rec_from_key(&key, nrec);
2803        return 0;
2804}
2805
2806/*
2807 * Insert one record/level.  Return information to the caller
2808 * allowing the next level up to proceed if necessary.
2809 */
2810STATIC int
2811xfs_btree_insrec(
2812        struct xfs_btree_cur    *cur,   /* btree cursor */
2813        int                     level,  /* level to insert record at */
2814        union xfs_btree_ptr     *ptrp,  /* i/o: block number inserted */
2815        union xfs_btree_rec     *recp,  /* i/o: record data inserted */
2816        struct xfs_btree_cur    **curp, /* output: new cursor replacing cur */
2817        int                     *stat)  /* success/failure */
2818{
2819        struct xfs_btree_block  *block; /* btree block */
2820        struct xfs_buf          *bp;    /* buffer for block */
2821        union xfs_btree_key     key;    /* btree key */
2822        union xfs_btree_ptr     nptr;   /* new block ptr */
2823        struct xfs_btree_cur    *ncur;  /* new btree cursor */
2824        union xfs_btree_rec     nrec;   /* new record count */
2825        int                     optr;   /* old key/record index */
2826        int                     ptr;    /* key/record index */
2827        int                     numrecs;/* number of records */
2828        int                     error;  /* error return value */
2829#ifdef DEBUG
2830        int                     i;
2831#endif
2832
2833        XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
2834        XFS_BTREE_TRACE_ARGIPR(cur, level, *ptrp, recp);
2835
2836        ncur = NULL;
2837
2838        /*
2839         * If we have an external root pointer, and we've made it to the
2840         * root level, allocate a new root block and we're done.
2841         */
2842        if (!(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
2843            (level >= cur->bc_nlevels)) {
2844                error = xfs_btree_new_root(cur, stat);
2845                xfs_btree_set_ptr_null(cur, ptrp);
2846
2847                XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2848                return error;
2849        }
2850
2851        /* If we're off the left edge, return failure. */
2852        ptr = cur->bc_ptrs[level];
2853        if (ptr == 0) {
2854                XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
2855                *stat = 0;
2856                return 0;
2857        }
2858
2859        /* Make a key out of the record data to be inserted, and save it. */
2860        cur->bc_ops->init_key_from_rec(&key, recp);
2861
2862        optr = ptr;
2863
2864        XFS_BTREE_STATS_INC(cur, insrec);
2865
2866        /* Get pointers to the btree buffer and block. */
2867        block = xfs_btree_get_block(cur, level, &bp);
2868        numrecs = xfs_btree_get_numrecs(block);
2869
2870#ifdef DEBUG
2871        error = xfs_btree_check_block(cur, block, level, bp);
2872        if (error)
2873                goto error0;
2874
2875        /* Check that the new entry is being inserted in the right place. */
2876        if (ptr <= numrecs) {
2877                if (level == 0) {
2878                        ASSERT(cur->bc_ops->recs_inorder(cur, recp,
2879                                xfs_btree_rec_addr(cur, ptr, block)));
2880                } else {
2881                        ASSERT(cur->bc_ops->keys_inorder(cur, &key,
2882                                xfs_btree_key_addr(cur, ptr, block)));
2883                }
2884        }
2885#endif
2886
2887        /*
2888         * If the block is full, we can't insert the new entry until we
2889         * make the block un-full.
2890         */
2891        xfs_btree_set_ptr_null(cur, &nptr);
2892        if (numrecs == cur->bc_ops->get_maxrecs(cur, level)) {
2893                error = xfs_btree_make_block_unfull(cur, level, numrecs,
2894                                        &optr, &ptr, &nptr, &ncur, &nrec, stat);
2895                if (error || *stat == 0)
2896                        goto error0;
2897        }
2898
2899        /*
2900         * The current block may have changed if the block was
2901         * previously full and we have just made space in it.
2902         */
2903        block = xfs_btree_get_block(cur, level, &bp);
2904        numrecs = xfs_btree_get_numrecs(block);
2905
2906#ifdef DEBUG
2907        error = xfs_btree_check_block(cur, block, level, bp);
2908        if (error)
2909                return error;
2910#endif
2911
2912        /*
2913         * At this point we know there's room for our new entry in the block
2914         * we're pointing at.
2915         */
2916        XFS_BTREE_STATS_ADD(cur, moves, numrecs - ptr + 1);
2917
2918        if (level > 0) {
2919                /* It's a nonleaf. make a hole in the keys and ptrs */
2920                union xfs_btree_key     *kp;
2921                union xfs_btree_ptr     *pp;
2922
2923                kp = xfs_btree_key_addr(cur, ptr, block);
2924                pp = xfs_btree_ptr_addr(cur, ptr, block);
2925
2926#ifdef DEBUG
2927                for (i = numrecs - ptr; i >= 0; i--) {
2928                        error = xfs_btree_check_ptr(cur, pp, i, level);
2929                        if (error)
2930                                return error;
2931                }
2932#endif
2933
2934                xfs_btree_shift_keys(cur, kp, 1, numrecs - ptr + 1);
2935                xfs_btree_shift_ptrs(cur, pp, 1, numrecs - ptr + 1);
2936
2937#ifdef DEBUG
2938                error = xfs_btree_check_ptr(cur, ptrp, 0, level);
2939                if (error)
2940                        goto error0;
2941#endif
2942
2943                /* Now put the new data in, bump numrecs and log it. */
2944                xfs_btree_copy_keys(cur, kp, &key, 1);
2945                xfs_btree_copy_ptrs(cur, pp, ptrp, 1);
2946                numrecs++;
2947                xfs_btree_set_numrecs(block, numrecs);
2948                xfs_btree_log_ptrs(cur, bp, ptr, numrecs);
2949                xfs_btree_log_keys(cur, bp, ptr, numrecs);
2950#ifdef DEBUG
2951                if (ptr < numrecs) {
2952                        ASSERT(cur->bc_ops->keys_inorder(cur, kp,
2953                                xfs_btree_key_addr(cur, ptr + 1, block)));
2954                }
2955#endif
2956        } else {
2957                /* It's a leaf. make a hole in the records */
2958                union xfs_btree_rec             *rp;
2959
2960                rp = xfs_btree_rec_addr(cur, ptr, block);
2961
2962                xfs_btree_shift_recs(cur, rp, 1, numrecs - ptr + 1);
2963
2964                /* Now put the new data in, bump numrecs and log it. */
2965                xfs_btree_copy_recs(cur, rp, recp, 1);
2966                xfs_btree_set_numrecs(block, ++numrecs);
2967                xfs_btree_log_recs(cur, bp, ptr, numrecs);
2968#ifdef DEBUG
2969                if (ptr < numrecs) {
2970                        ASSERT(cur->bc_ops->recs_inorder(cur, rp,
2971                                xfs_btree_rec_addr(cur, ptr + 1, block)));
2972                }
2973#endif
2974        }
2975
2976        /* Log the new number of records in the btree header. */
2977        xfs_btree_log_block(cur, bp, XFS_BB_NUMRECS);
2978
2979        /* If we inserted at the start of a block, update the parents' keys. */
2980        if (optr == 1) {
2981                error = xfs_btree_updkey(cur, &key, level + 1);
2982                if (error)
2983                        goto error0;
2984        }
2985
2986        /*
2987         * If we are tracking the last record in the tree and
2988         * we are at the far right edge of the tree, update it.
2989         */
2990        if (xfs_btree_is_lastrec(cur, block, level)) {
2991                cur->bc_ops->update_lastrec(cur, block, recp,
2992                                            ptr, LASTREC_INSREC);
2993        }
2994
2995        /*
2996         * Return the new block number, if any.
2997         * If there is one, give back a record value and a cursor too.
2998         */
2999        *ptrp = nptr;
3000        if (!xfs_btree_ptr_is_null(cur, &nptr)) {
3001                *recp = nrec;
3002                *curp = ncur;
3003        }
3004
3005        XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3006        *stat = 1;
3007        return 0;
3008
3009error0:
3010        XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3011        return error;
3012}
3013
3014/*
3015 * Insert the record at the point referenced by cur.
3016 *
3017 * A multi-level split of the tree on insert will invalidate the original
3018 * cursor.  All callers of this function should assume that the cursor is
3019 * no longer valid and revalidate it.
3020 */
3021int
3022xfs_btree_insert(
3023        struct xfs_btree_cur    *cur,
3024        int                     *stat)
3025{
3026        int                     error;  /* error return value */
3027        int                     i;      /* result value, 0 for failure */
3028        int                     level;  /* current level number in btree */
3029        union xfs_btree_ptr     nptr;   /* new block number (split result) */
3030        struct xfs_btree_cur    *ncur;  /* new cursor (split result) */
3031        struct xfs_btree_cur    *pcur;  /* previous level's cursor */
3032        union xfs_btree_rec     rec;    /* record to insert */
3033
3034        level = 0;
3035        ncur = NULL;
3036        pcur = cur;
3037
3038        xfs_btree_set_ptr_null(cur, &nptr);
3039        cur->bc_ops->init_rec_from_cur(cur, &rec);
3040
3041        /*
3042         * Loop going up the tree, starting at the leaf level.
3043         * Stop when we don't get a split block, that must mean that
3044         * the insert is finished with this level.
3045         */
3046        do {
3047                /*
3048                 * Insert nrec/nptr into this level of the tree.
3049                 * Note if we fail, nptr will be null.
3050                 */
3051                error = xfs_btree_insrec(pcur, level, &nptr, &rec, &ncur, &i);
3052                if (error) {
3053                        if (pcur != cur)
3054                                xfs_btree_del_cursor(pcur, XFS_BTREE_ERROR);
3055                        goto error0;
3056                }
3057
3058                XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3059                level++;
3060
3061                /*
3062                 * See if the cursor we just used is trash.
3063                 * Can't trash the caller's cursor, but otherwise we should
3064                 * if ncur is a new cursor or we're about to be done.
3065                 */
3066                if (pcur != cur &&
3067                    (ncur || xfs_btree_ptr_is_null(cur, &nptr))) {
3068                        /* Save the state from the cursor before we trash it */
3069                        if (cur->bc_ops->update_cursor)
3070                                cur->bc_ops->update_cursor(pcur, cur);
3071                        cur->bc_nlevels = pcur->bc_nlevels;
3072                        xfs_btree_del_cursor(pcur, XFS_BTREE_NOERROR);
3073                }
3074                /* If we got a new cursor, switch to it. */
3075                if (ncur) {
3076                        pcur = ncur;
3077                        ncur = NULL;
3078                }
3079        } while (!xfs_btree_ptr_is_null(cur, &nptr));
3080
3081        XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3082        *stat = i;
3083        return 0;
3084error0:
3085        XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3086        return error;
3087}
3088
3089/*
3090 * Try to merge a non-leaf block back into the inode root.
3091 *
3092 * Note: the killroot names comes from the fact that we're effectively
3093 * killing the old root block.  But because we can't just delete the
3094 * inode we have to copy the single block it was pointing to into the
3095 * inode.
3096 */
3097STATIC int
3098xfs_btree_kill_iroot(
3099        struct xfs_btree_cur    *cur)
3100{
3101        int                     whichfork = cur->bc_private.b.whichfork;
3102        struct xfs_inode        *ip = cur->bc_private.b.ip;
3103        struct xfs_ifork        *ifp = XFS_IFORK_PTR(ip, whichfork);
3104        struct xfs_btree_block  *block;
3105        struct xfs_btree_block  *cblock;
3106        union xfs_btree_key     *kp;
3107        union xfs_btree_key     *ckp;
3108        union xfs_btree_ptr     *pp;
3109        union xfs_btree_ptr     *cpp;
3110        struct xfs_buf          *cbp;
3111        int                     level;
3112        int                     index;
3113        int                     numrecs;
3114#ifdef DEBUG
3115        union xfs_btree_ptr     ptr;
3116        int                     i;
3117#endif
3118
3119        XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
3120
3121        ASSERT(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE);
3122        ASSERT(cur->bc_nlevels > 1);
3123
3124        /*
3125         * Don't deal with the root block needs to be a leaf case.
3126         * We're just going to turn the thing back into extents anyway.
3127         */
3128        level = cur->bc_nlevels - 1;
3129        if (level == 1)
3130                goto out0;
3131
3132        /*
3133         * Give up if the root has multiple children.
3134         */
3135        block = xfs_btree_get_iroot(cur);
3136        if (xfs_btree_get_numrecs(block) != 1)
3137                goto out0;
3138
3139        cblock = xfs_btree_get_block(cur, level - 1, &cbp);
3140        numrecs = xfs_btree_get_numrecs(cblock);
3141
3142        /*
3143         * Only do this if the next level will fit.
3144         * Then the data must be copied up to the inode,
3145         * instead of freeing the root you free the next level.
3146         */
3147        if (numrecs > cur->bc_ops->get_dmaxrecs(cur, level))
3148                goto out0;
3149
3150        XFS_BTREE_STATS_INC(cur, killroot);
3151
3152#ifdef DEBUG
3153        xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_LEFTSIB);
3154        ASSERT(xfs_btree_ptr_is_null(cur, &ptr));
3155        xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
3156        ASSERT(xfs_btree_ptr_is_null(cur, &ptr));
3157#endif
3158
3159        index = numrecs - cur->bc_ops->get_maxrecs(cur, level);
3160        if (index) {
3161                xfs_iroot_realloc(cur->bc_private.b.ip, index,
3162                                  cur->bc_private.b.whichfork);
3163                block = ifp->if_broot;
3164        }
3165
3166        be16_add_cpu(&block->bb_numrecs, index);
3167        ASSERT(block->bb_numrecs == cblock->bb_numrecs);
3168
3169        kp = xfs_btree_key_addr(cur, 1, block);
3170        ckp = xfs_btree_key_addr(cur, 1, cblock);
3171        xfs_btree_copy_keys(cur, kp, ckp, numrecs);
3172
3173        pp = xfs_btree_ptr_addr(cur, 1, block);
3174        cpp = xfs_btree_ptr_addr(cur, 1, cblock);
3175#ifdef DEBUG
3176        for (i = 0; i < numrecs; i++) {
3177                int             error;
3178
3179                error = xfs_btree_check_ptr(cur, cpp, i, level - 1);
3180                if (error) {
3181                        XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3182                        return error;
3183                }
3184        }
3185#endif
3186        xfs_btree_copy_ptrs(cur, pp, cpp, numrecs);
3187
3188        cur->bc_ops->free_block(cur, cbp);
3189        XFS_BTREE_STATS_INC(cur, free);
3190
3191        cur->bc_bufs[level - 1] = NULL;
3192        be16_add_cpu(&block->bb_level, -1);
3193        xfs_trans_log_inode(cur->bc_tp, ip,
3194                XFS_ILOG_CORE | xfs_ilog_fbroot(cur->bc_private.b.whichfork));
3195        cur->bc_nlevels--;
3196out0:
3197        XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3198        return 0;
3199}
3200
3201/*
3202 * Kill the current root node, and replace it with it's only child node.
3203 */
3204STATIC int
3205xfs_btree_kill_root(
3206        struct xfs_btree_cur    *cur,
3207        struct xfs_buf          *bp,
3208        int                     level,
3209        union xfs_btree_ptr     *newroot)
3210{
3211        int                     error;
3212
3213        XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
3214        XFS_BTREE_STATS_INC(cur, killroot);
3215
3216        /*
3217         * Update the root pointer, decreasing the level by 1 and then
3218         * free the old root.
3219         */
3220        cur->bc_ops->set_root(cur, newroot, -1);
3221
3222        error = cur->bc_ops->free_block(cur, bp);
3223        if (error) {
3224                XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3225                return error;
3226        }
3227
3228        XFS_BTREE_STATS_INC(cur, free);
3229
3230        cur->bc_bufs[level] = NULL;
3231        cur->bc_ra[level] = 0;
3232        cur->bc_nlevels--;
3233
3234        XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3235        return 0;
3236}
3237
3238STATIC int
3239xfs_btree_dec_cursor(
3240        struct xfs_btree_cur    *cur,
3241        int                     level,
3242        int                     *stat)
3243{
3244        int                     error;
3245        int                     i;
3246
3247        if (level > 0) {
3248                error = xfs_btree_decrement(cur, level, &i);
3249                if (error)
3250                        return error;
3251        }
3252
3253        XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3254        *stat = 1;
3255        return 0;
3256}
3257
3258/*
3259 * Single level of the btree record deletion routine.
3260 * Delete record pointed to by cur/level.
3261 * Remove the record from its block then rebalance the tree.
3262 * Return 0 for error, 1 for done, 2 to go on to the next level.
3263 */
3264STATIC int                                      /* error */
3265xfs_btree_delrec(
3266        struct xfs_btree_cur    *cur,           /* btree cursor */
3267        int                     level,          /* level removing record from */
3268        int                     *stat)          /* fail/done/go-on */
3269{
3270        struct xfs_btree_block  *block;         /* btree block */
3271        union xfs_btree_ptr     cptr;           /* current block ptr */
3272        struct xfs_buf          *bp;            /* buffer for block */
3273        int                     error;          /* error return value */
3274        int                     i;              /* loop counter */
3275        union xfs_btree_key     key;            /* storage for keyp */
3276        union xfs_btree_key     *keyp = &key;   /* passed to the next level */
3277        union xfs_btree_ptr     lptr;           /* left sibling block ptr */
3278        struct xfs_buf          *lbp;           /* left buffer pointer */
3279        struct xfs_btree_block  *left;          /* left btree block */
3280        int                     lrecs = 0;      /* left record count */
3281        int                     ptr;            /* key/record index */
3282        union xfs_btree_ptr     rptr;           /* right sibling block ptr */
3283        struct xfs_buf          *rbp;           /* right buffer pointer */
3284        struct xfs_btree_block  *right;         /* right btree block */
3285        struct xfs_btree_block  *rrblock;       /* right-right btree block */
3286        struct xfs_buf          *rrbp;          /* right-right buffer pointer */
3287        int                     rrecs = 0;      /* right record count */
3288        struct xfs_btree_cur    *tcur;          /* temporary btree cursor */
3289        int                     numrecs;        /* temporary numrec count */
3290
3291        XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
3292        XFS_BTREE_TRACE_ARGI(cur, level);
3293
3294        tcur = NULL;
3295
3296        /* Get the index of the entry being deleted, check for nothing there. */
3297        ptr = cur->bc_ptrs[level];
3298        if (ptr == 0) {
3299                XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3300                *stat = 0;
3301                return 0;
3302        }
3303
3304        /* Get the buffer & block containing the record or key/ptr. */
3305        block = xfs_btree_get_block(cur, level, &bp);
3306        numrecs = xfs_btree_get_numrecs(block);
3307
3308#ifdef DEBUG
3309        error = xfs_btree_check_block(cur, block, level, bp);
3310        if (error)
3311                goto error0;
3312#endif
3313
3314        /* Fail if we're off the end of the block. */
3315        if (ptr > numrecs) {
3316                XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3317                *stat = 0;
3318                return 0;
3319        }
3320
3321        XFS_BTREE_STATS_INC(cur, delrec);
3322        XFS_BTREE_STATS_ADD(cur, moves, numrecs - ptr);
3323
3324        /* Excise the entries being deleted. */
3325        if (level > 0) {
3326                /* It's a nonleaf. operate on keys and ptrs */
3327                union xfs_btree_key     *lkp;
3328                union xfs_btree_ptr     *lpp;
3329
3330                lkp = xfs_btree_key_addr(cur, ptr + 1, block);
3331                lpp = xfs_btree_ptr_addr(cur, ptr + 1, block);
3332
3333#ifdef DEBUG
3334                for (i = 0; i < numrecs - ptr; i++) {
3335                        error = xfs_btree_check_ptr(cur, lpp, i, level);
3336                        if (error)
3337                                goto error0;
3338                }
3339#endif
3340
3341                if (ptr < numrecs) {
3342                        xfs_btree_shift_keys(cur, lkp, -1, numrecs - ptr);
3343                        xfs_btree_shift_ptrs(cur, lpp, -1, numrecs - ptr);
3344                        xfs_btree_log_keys(cur, bp, ptr, numrecs - 1);
3345                        xfs_btree_log_ptrs(cur, bp, ptr, numrecs - 1);
3346                }
3347
3348                /*
3349                 * If it's the first record in the block, we'll need to pass a
3350                 * key up to the next level (updkey).
3351                 */
3352                if (ptr == 1)
3353                        keyp = xfs_btree_key_addr(cur, 1, block);
3354        } else {
3355                /* It's a leaf. operate on records */
3356                if (ptr < numrecs) {
3357                        xfs_btree_shift_recs(cur,
3358                                xfs_btree_rec_addr(cur, ptr + 1, block),
3359                                -1, numrecs - ptr);
3360                        xfs_btree_log_recs(cur, bp, ptr, numrecs - 1);
3361                }
3362
3363                /*
3364                 * If it's the first record in the block, we'll need a key
3365                 * structure to pass up to the next level (updkey).
3366                 */
3367                if (ptr == 1) {
3368                        cur->bc_ops->init_key_from_rec(&key,
3369                                        xfs_btree_rec_addr(cur, 1, block));
3370                        keyp = &key;
3371                }
3372        }
3373
3374        /*
3375         * Decrement and log the number of entries in the block.
3376         */
3377        xfs_btree_set_numrecs(block, --numrecs);
3378        xfs_btree_log_block(cur, bp, XFS_BB_NUMRECS);
3379
3380        /*
3381         * If we are tracking the last record in the tree and
3382         * we are at the far right edge of the tree, update it.
3383         */
3384        if (xfs_btree_is_lastrec(cur, block, level)) {
3385                cur->bc_ops->update_lastrec(cur, block, NULL,
3386                                            ptr, LASTREC_DELREC);
3387        }
3388
3389        /*
3390         * We're at the root level.  First, shrink the root block in-memory.
3391         * Try to get rid of the next level down.  If we can't then there's
3392         * nothing left to do.
3393         */
3394        if (level == cur->bc_nlevels - 1) {
3395                if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) {
3396                        xfs_iroot_realloc(cur->bc_private.b.ip, -1,
3397                                          cur->bc_private.b.whichfork);
3398
3399                        error = xfs_btree_kill_iroot(cur);
3400                        if (error)
3401                                goto error0;
3402
3403                        error = xfs_btree_dec_cursor(cur, level, stat);
3404                        if (error)
3405                                goto error0;
3406                        *stat = 1;
3407                        return 0;
3408                }
3409
3410                /*
3411                 * If this is the root level, and there's only one entry left,
3412                 * and it's NOT the leaf level, then we can get rid of this
3413                 * level.
3414                 */
3415                if (numrecs == 1 && level > 0) {
3416                        union xfs_btree_ptr     *pp;
3417                        /*
3418                         * pp is still set to the first pointer in the block.
3419                         * Make it the new root of the btree.
3420                         */
3421                        pp = xfs_btree_ptr_addr(cur, 1, block);
3422                        error = xfs_btree_kill_root(cur, bp, level, pp);
3423                        if (error)
3424                                goto error0;
3425                } else if (level > 0) {
3426                        error = xfs_btree_dec_cursor(cur, level, stat);
3427                        if (error)
3428                                goto error0;
3429                }
3430                *stat = 1;
3431                return 0;
3432        }
3433
3434        /*
3435         * If we deleted the leftmost entry in the block, update the
3436         * key values above us in the tree.
3437         */
3438        if (ptr == 1) {
3439                error = xfs_btree_updkey(cur, keyp, level + 1);
3440                if (error)
3441                        goto error0;
3442        }
3443
3444        /*
3445         * If the number of records remaining in the block is at least
3446         * the minimum, we're done.
3447         */
3448        if (numrecs >= cur->bc_ops->get_minrecs(cur, level)) {
3449                error = xfs_btree_dec_cursor(cur, level, stat);
3450                if (error)
3451                        goto error0;
3452                return 0;
3453        }
3454
3455        /*
3456         * Otherwise, we have to move some records around to keep the
3457         * tree balanced.  Look at the left and right sibling blocks to
3458         * see if we can re-balance by moving only one record.
3459         */
3460        xfs_btree_get_sibling(cur, block, &rptr, XFS_BB_RIGHTSIB);
3461        xfs_btree_get_sibling(cur, block, &lptr, XFS_BB_LEFTSIB);
3462
3463        if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) {
3464                /*
3465                 * One child of root, need to get a chance to copy its contents
3466                 * into the root and delete it. Can't go up to next level,
3467                 * there's nothing to delete there.
3468                 */
3469                if (xfs_btree_ptr_is_null(cur, &rptr) &&
3470                    xfs_btree_ptr_is_null(cur, &lptr) &&
3471                    level == cur->bc_nlevels - 2) {
3472                        error = xfs_btree_kill_iroot(cur);
3473                        if (!error)
3474                                error = xfs_btree_dec_cursor(cur, level, stat);
3475                        if (error)
3476                                goto error0;
3477                        return 0;
3478                }
3479        }
3480
3481        ASSERT(!xfs_btree_ptr_is_null(cur, &rptr) ||
3482               !xfs_btree_ptr_is_null(cur, &lptr));
3483
3484        /*
3485         * Duplicate the cursor so our btree manipulations here won't
3486         * disrupt the next level up.
3487         */
3488        error = xfs_btree_dup_cursor(cur, &tcur);
3489        if (error)
3490                goto error0;
3491
3492        /*
3493         * If there's a right sibling, see if it's ok to shift an entry
3494         * out of it.
3495         */
3496        if (!xfs_btree_ptr_is_null(cur, &rptr)) {
3497                /*
3498                 * Move the temp cursor to the last entry in the next block.
3499                 * Actually any entry but the first would suffice.
3500                 */
3501                i = xfs_btree_lastrec(tcur, level);
3502                XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3503
3504                error = xfs_btree_increment(tcur, level, &i);
3505                if (error)
3506                        goto error0;
3507                XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3508
3509                i = xfs_btree_lastrec(tcur, level);
3510                XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3511
3512                /* Grab a pointer to the block. */
3513                right = xfs_btree_get_block(tcur, level, &rbp);
3514#ifdef DEBUG
3515                error = xfs_btree_check_block(tcur, right, level, rbp);
3516                if (error)
3517                        goto error0;
3518#endif
3519                /* Grab the current block number, for future use. */
3520                xfs_btree_get_sibling(tcur, right, &cptr, XFS_BB_LEFTSIB);
3521
3522                /*
3523                 * If right block is full enough so that removing one entry
3524                 * won't make it too empty, and left-shifting an entry out
3525                 * of right to us works, we're done.
3526                 */
3527                if (xfs_btree_get_numrecs(right) - 1 >=
3528                    cur->bc_ops->get_minrecs(tcur, level)) {
3529                        error = xfs_btree_lshift(tcur, level, &i);
3530                        if (error)
3531                                goto error0;
3532                        if (i) {
3533                                ASSERT(xfs_btree_get_numrecs(block) >=
3534                                       cur->bc_ops->get_minrecs(tcur, level));
3535
3536                                xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
3537                                tcur = NULL;
3538
3539                                error = xfs_btree_dec_cursor(cur, level, stat);
3540                                if (error)
3541                                        goto error0;
3542                                return 0;
3543                        }
3544                }
3545
3546                /*
3547                 * Otherwise, grab the number of records in right for
3548                 * future reference, and fix up the temp cursor to point
3549                 * to our block again (last record).
3550                 */
3551                rrecs = xfs_btree_get_numrecs(right);
3552                if (!xfs_btree_ptr_is_null(cur, &lptr)) {
3553                        i = xfs_btree_firstrec(tcur, level);
3554                        XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3555
3556                        error = xfs_btree_decrement(tcur, level, &i);
3557                        if (error)
3558                                goto error0;
3559                        XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3560                }
3561        }
3562
3563        /*
3564         * If there's a left sibling, see if it's ok to shift an entry
3565         * out of it.
3566         */
3567        if (!xfs_btree_ptr_is_null(cur, &lptr)) {
3568                /*
3569                 * Move the temp cursor to the first entry in the
3570                 * previous block.
3571                 */
3572                i = xfs_btree_firstrec(tcur, level);
3573                XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3574
3575                error = xfs_btree_decrement(tcur, level, &i);
3576                if (error)
3577                        goto error0;
3578                i = xfs_btree_firstrec(tcur, level);
3579                XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
3580
3581                /* Grab a pointer to the block. */
3582                left = xfs_btree_get_block(tcur, level, &lbp);
3583#ifdef DEBUG
3584                error = xfs_btree_check_block(cur, left, level, lbp);
3585                if (error)
3586                        goto error0;
3587#endif
3588                /* Grab the current block number, for future use. */
3589                xfs_btree_get_sibling(tcur, left, &cptr, XFS_BB_RIGHTSIB);
3590
3591                /*
3592                 * If left block is full enough so that removing one entry
3593                 * won't make it too empty, and right-shifting an entry out
3594                 * of left to us works, we're done.
3595                 */
3596                if (xfs_btree_get_numrecs(left) - 1 >=
3597                    cur->bc_ops->get_minrecs(tcur, level)) {
3598                        error = xfs_btree_rshift(tcur, level, &i);
3599                        if (error)
3600                                goto error0;
3601                        if (i) {
3602                                ASSERT(xfs_btree_get_numrecs(block) >=
3603                                       cur->bc_ops->get_minrecs(tcur, level));
3604                                xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
3605                                tcur = NULL;
3606                                if (level == 0)
3607                                        cur->bc_ptrs[0]++;
3608                                XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3609                                *stat = 1;
3610                                return 0;
3611                        }
3612                }
3613
3614                /*
3615                 * Otherwise, grab the number of records in right for
3616                 * future reference.
3617                 */
3618                lrecs = xfs_btree_get_numrecs(left);
3619        }
3620
3621        /* Delete the temp cursor, we're done with it. */
3622        xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
3623        tcur = NULL;
3624
3625        /* If here, we need to do a join to keep the tree balanced. */
3626        ASSERT(!xfs_btree_ptr_is_null(cur, &cptr));
3627
3628        if (!xfs_btree_ptr_is_null(cur, &lptr) &&
3629            lrecs + xfs_btree_get_numrecs(block) <=
3630                        cur->bc_ops->get_maxrecs(cur, level)) {
3631                /*
3632                 * Set "right" to be the starting block,
3633                 * "left" to be the left neighbor.
3634                 */
3635                rptr = cptr;
3636                right = block;
3637                rbp = bp;
3638                error = xfs_btree_read_buf_block(cur, &lptr, level,
3639                                                        0, &left, &lbp);
3640                if (error)
3641                        goto error0;
3642
3643        /*
3644         * If that won't work, see if we can join with the right neighbor block.
3645         */
3646        } else if (!xfs_btree_ptr_is_null(cur, &rptr) &&
3647                   rrecs + xfs_btree_get_numrecs(block) <=
3648                        cur->bc_ops->get_maxrecs(cur, level)) {
3649                /*
3650                 * Set "left" to be the starting block,
3651                 * "right" to be the right neighbor.
3652                 */
3653                lptr = cptr;
3654                left = block;
3655                lbp = bp;
3656                error = xfs_btree_read_buf_block(cur, &rptr, level,
3657                                                        0, &right, &rbp);
3658                if (error)
3659                        goto error0;
3660
3661        /*
3662         * Otherwise, we can't fix the imbalance.
3663         * Just return.  This is probably a logic error, but it's not fatal.
3664         */
3665        } else {
3666                error = xfs_btree_dec_cursor(cur, level, stat);
3667                if (error)
3668                        goto error0;
3669                return 0;
3670        }
3671
3672        rrecs = xfs_btree_get_numrecs(right);
3673        lrecs = xfs_btree_get_numrecs(left);
3674
3675        /*
3676         * We're now going to join "left" and "right" by moving all the stuff
3677         * in "right" to "left" and deleting "right".
3678         */
3679        XFS_BTREE_STATS_ADD(cur, moves, rrecs);
3680        if (level > 0) {
3681                /* It's a non-leaf.  Move keys and pointers. */
3682                union xfs_btree_key     *lkp;   /* left btree key */
3683                union xfs_btree_ptr     *lpp;   /* left address pointer */
3684                union xfs_btree_key     *rkp;   /* right btree key */
3685                union xfs_btree_ptr     *rpp;   /* right address pointer */
3686
3687                lkp = xfs_btree_key_addr(cur, lrecs + 1, left);
3688                lpp = xfs_btree_ptr_addr(cur, lrecs + 1, left);
3689                rkp = xfs_btree_key_addr(cur, 1, right);
3690                rpp = xfs_btree_ptr_addr(cur, 1, right);
3691#ifdef DEBUG
3692                for (i = 1; i < rrecs; i++) {
3693                        error = xfs_btree_check_ptr(cur, rpp, i, level);
3694                        if (error)
3695                                goto error0;
3696                }
3697#endif
3698                xfs_btree_copy_keys(cur, lkp, rkp, rrecs);
3699                xfs_btree_copy_ptrs(cur, lpp, rpp, rrecs);
3700
3701                xfs_btree_log_keys(cur, lbp, lrecs + 1, lrecs + rrecs);
3702                xfs_btree_log_ptrs(cur, lbp, lrecs + 1, lrecs + rrecs);
3703        } else {
3704                /* It's a leaf.  Move records.  */
3705                union xfs_btree_rec     *lrp;   /* left record pointer */
3706                union xfs_btree_rec     *rrp;   /* right record pointer */
3707
3708                lrp = xfs_btree_rec_addr(cur, lrecs + 1, left);
3709                rrp = xfs_btree_rec_addr(cur, 1, right);
3710
3711                xfs_btree_copy_recs(cur, lrp, rrp, rrecs);
3712                xfs_btree_log_recs(cur, lbp, lrecs + 1, lrecs + rrecs);
3713        }
3714
3715        XFS_BTREE_STATS_INC(cur, join);
3716
3717        /*
3718         * Fix up the number of records and right block pointer in the
3719         * surviving block, and log it.
3720         */
3721        xfs_btree_set_numrecs(left, lrecs + rrecs);
3722        xfs_btree_get_sibling(cur, right, &cptr, XFS_BB_RIGHTSIB),
3723        xfs_btree_set_sibling(cur, left, &cptr, XFS_BB_RIGHTSIB);
3724        xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS | XFS_BB_RIGHTSIB);
3725
3726        /* If there is a right sibling, point it to the remaining block. */
3727        xfs_btree_get_sibling(cur, left, &cptr, XFS_BB_RIGHTSIB);
3728        if (!xfs_btree_ptr_is_null(cur, &cptr)) {
3729                error = xfs_btree_read_buf_block(cur, &cptr, level,
3730                                                        0, &rrblock, &rrbp);
3731                if (error)
3732                        goto error0;
3733                xfs_btree_set_sibling(cur, rrblock, &lptr, XFS_BB_LEFTSIB);
3734                xfs_btree_log_block(cur, rrbp, XFS_BB_LEFTSIB);
3735        }
3736
3737        /* Free the deleted block. */
3738        error = cur->bc_ops->free_block(cur, rbp);
3739        if (error)
3740                goto error0;
3741        XFS_BTREE_STATS_INC(cur, free);
3742
3743        /*
3744         * If we joined with the left neighbor, set the buffer in the
3745         * cursor to the left block, and fix up the index.
3746         */
3747        if (bp != lbp) {
3748                cur->bc_bufs[level] = lbp;
3749                cur->bc_ptrs[level] += lrecs;
3750                cur->bc_ra[level] = 0;
3751        }
3752        /*
3753         * If we joined with the right neighbor and there's a level above
3754         * us, increment the cursor at that level.
3755         */
3756        else if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) ||
3757                   (level + 1 < cur->bc_nlevels)) {
3758                error = xfs_btree_increment(cur, level + 1, &i);
3759                if (error)
3760                        goto error0;
3761        }
3762
3763        /*
3764         * Readjust the ptr at this level if it's not a leaf, since it's
3765         * still pointing at the deletion point, which makes the cursor
3766         * inconsistent.  If this makes the ptr 0, the caller fixes it up.
3767         * We can't use decrement because it would change the next level up.
3768         */
3769        if (level > 0)
3770                cur->bc_ptrs[level]--;
3771
3772        XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3773        /* Return value means the next level up has something to do. */
3774        *stat = 2;
3775        return 0;
3776
3777error0:
3778        XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3779        if (tcur)
3780                xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR);
3781        return error;
3782}
3783
3784/*
3785 * Delete the record pointed to by cur.
3786 * The cursor refers to the place where the record was (could be inserted)
3787 * when the operation returns.
3788 */
3789int                                     /* error */
3790xfs_btree_delete(
3791        struct xfs_btree_cur    *cur,
3792        int                     *stat)  /* success/failure */
3793{
3794        int                     error;  /* error return value */
3795        int                     level;
3796        int                     i;
3797
3798        XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
3799
3800        /*
3801         * Go up the tree, starting at leaf level.
3802         *
3803         * If 2 is returned then a join was done; go to the next level.
3804         * Otherwise we are done.
3805         */
3806        for (level = 0, i = 2; i == 2; level++) {
3807                error = xfs_btree_delrec(cur, level, &i);
3808                if (error)
3809                        goto error0;
3810        }
3811
3812        if (i == 0) {
3813                for (level = 1; level < cur->bc_nlevels; level++) {
3814                        if (cur->bc_ptrs[level] == 0) {
3815                                error = xfs_btree_decrement(cur, level, &i);
3816                                if (error)
3817                                        goto error0;
3818                                break;
3819                        }
3820                }
3821        }
3822
3823        XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
3824        *stat = i;
3825        return 0;
3826error0:
3827        XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
3828        return error;
3829}
3830
3831/*
3832 * Get the data from the pointed-to record.
3833 */
3834int                                     /* error */
3835xfs_btree_get_rec(
3836        struct xfs_btree_cur    *cur,   /* btree cursor */
3837        union xfs_btree_rec     **recp, /* output: btree record */
3838        int                     *stat)  /* output: success/failure */
3839{
3840        struct xfs_btree_block  *block; /* btree block */
3841        struct xfs_buf          *bp;    /* buffer pointer */
3842        int                     ptr;    /* record number */
3843#ifdef DEBUG
3844        int                     error;  /* error return value */
3845#endif
3846
3847        ptr = cur->bc_ptrs[0];
3848        block = xfs_btree_get_block(cur, 0, &bp);
3849
3850#ifdef DEBUG
3851        error = xfs_btree_check_block(cur, block, 0, bp);
3852        if (error)
3853                return error;
3854#endif
3855
3856        /*
3857         * Off the right end or left end, return failure.
3858         */
3859        if (ptr > xfs_btree_get_numrecs(block) || ptr <= 0) {
3860                *stat = 0;
3861                return 0;
3862        }
3863
3864        /*
3865         * Point to the record and extract its data.
3866         */
3867        *recp = xfs_btree_rec_addr(cur, ptr, block);
3868        *stat = 1;
3869        return 0;
3870}
3871
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.