XFS_ABTB_MAGIC, XFS_ABTC_MAGIC, XFS_BMAP_MAGIC, XFS_IBT_MAGIC
};
-/*
- * External routines.
- */
-
-#ifdef DEBUG
-/*
- * Debug routine: check that keys are in the right order.
- */
-void
-xfs_btree_check_key(
- xfs_btnum_t btnum, /* btree identifier */
- void *ak1, /* pointer to left (lower) key */
- void *ak2) /* pointer to right (higher) key */
-{
- switch (btnum) {
- case XFS_BTNUM_BNO: {
- xfs_alloc_key_t *k1;
- xfs_alloc_key_t *k2;
-
- k1 = ak1;
- k2 = ak2;
- ASSERT(be32_to_cpu(k1->ar_startblock) < be32_to_cpu(k2->ar_startblock));
- break;
- }
- case XFS_BTNUM_CNT: {
- xfs_alloc_key_t *k1;
- xfs_alloc_key_t *k2;
-
- k1 = ak1;
- k2 = ak2;
- ASSERT(be32_to_cpu(k1->ar_blockcount) < be32_to_cpu(k2->ar_blockcount) ||
- (k1->ar_blockcount == k2->ar_blockcount &&
- be32_to_cpu(k1->ar_startblock) < be32_to_cpu(k2->ar_startblock)));
- break;
- }
- case XFS_BTNUM_BMAP: {
- xfs_bmbt_key_t *k1;
- xfs_bmbt_key_t *k2;
-
- k1 = ak1;
- k2 = ak2;
- ASSERT(be64_to_cpu(k1->br_startoff) < be64_to_cpu(k2->br_startoff));
- break;
- }
- case XFS_BTNUM_INO: {
- xfs_inobt_key_t *k1;
- xfs_inobt_key_t *k2;
-
- k1 = ak1;
- k2 = ak2;
- ASSERT(be32_to_cpu(k1->ir_startino) < be32_to_cpu(k2->ir_startino));
- break;
- }
- default:
- ASSERT(0);
- }
-}
-
-/*
- * Debug routine: check that records are in the right order.
- */
-void
-xfs_btree_check_rec(
- xfs_btnum_t btnum, /* btree identifier */
- void *ar1, /* pointer to left (lower) record */
- void *ar2) /* pointer to right (higher) record */
-{
- switch (btnum) {
- case XFS_BTNUM_BNO: {
- xfs_alloc_rec_t *r1;
- xfs_alloc_rec_t *r2;
-
- r1 = ar1;
- r2 = ar2;
- ASSERT(be32_to_cpu(r1->ar_startblock) +
- be32_to_cpu(r1->ar_blockcount) <=
- be32_to_cpu(r2->ar_startblock));
- break;
- }
- case XFS_BTNUM_CNT: {
- xfs_alloc_rec_t *r1;
- xfs_alloc_rec_t *r2;
-
- r1 = ar1;
- r2 = ar2;
- ASSERT(be32_to_cpu(r1->ar_blockcount) < be32_to_cpu(r2->ar_blockcount) ||
- (r1->ar_blockcount == r2->ar_blockcount &&
- be32_to_cpu(r1->ar_startblock) < be32_to_cpu(r2->ar_startblock)));
- break;
- }
- case XFS_BTNUM_BMAP: {
- xfs_bmbt_rec_t *r1;
- xfs_bmbt_rec_t *r2;
-
- r1 = ar1;
- r2 = ar2;
- ASSERT(xfs_bmbt_disk_get_startoff(r1) +
- xfs_bmbt_disk_get_blockcount(r1) <=
- xfs_bmbt_disk_get_startoff(r2));
- break;
- }
- case XFS_BTNUM_INO: {
- xfs_inobt_rec_t *r1;
- xfs_inobt_rec_t *r2;
-
- r1 = ar1;
- r2 = ar2;
- ASSERT(be32_to_cpu(r1->ir_startino) + XFS_INODES_PER_CHUNK <=
- be32_to_cpu(r2->ir_startino));
- break;
- }
- default:
- ASSERT(0);
- }
-}
-#endif /* DEBUG */
-int /* error (0 or EFSCORRUPTED) */
+STATIC int /* error (0 or EFSCORRUPTED) */
xfs_btree_check_lblock(
struct xfs_btree_cur *cur, /* btree cursor */
- struct xfs_btree_lblock *block, /* btree long form block pointer */
+ struct xfs_btree_block *block, /* btree long form block pointer */
int level, /* level of the btree block */
struct xfs_buf *bp) /* buffer for block, if any */
{
be16_to_cpu(block->bb_level) == level &&
be16_to_cpu(block->bb_numrecs) <=
cur->bc_ops->get_maxrecs(cur, level) &&
- block->bb_leftsib &&
- (be64_to_cpu(block->bb_leftsib) == NULLDFSBNO ||
- XFS_FSB_SANITY_CHECK(mp, be64_to_cpu(block->bb_leftsib))) &&
- block->bb_rightsib &&
- (be64_to_cpu(block->bb_rightsib) == NULLDFSBNO ||
- XFS_FSB_SANITY_CHECK(mp, be64_to_cpu(block->bb_rightsib)));
+ block->bb_u.l.bb_leftsib &&
+ (be64_to_cpu(block->bb_u.l.bb_leftsib) == NULLDFSBNO ||
+ XFS_FSB_SANITY_CHECK(mp,
+ be64_to_cpu(block->bb_u.l.bb_leftsib))) &&
+ block->bb_u.l.bb_rightsib &&
+ (be64_to_cpu(block->bb_u.l.bb_rightsib) == NULLDFSBNO ||
+ XFS_FSB_SANITY_CHECK(mp,
+ be64_to_cpu(block->bb_u.l.bb_rightsib)));
if (unlikely(XFS_TEST_ERROR(!lblock_ok, mp,
XFS_ERRTAG_BTREE_CHECK_LBLOCK,
XFS_RANDOM_BTREE_CHECK_LBLOCK))) {
return 0;
}
-int /* error (0 or EFSCORRUPTED) */
+STATIC int /* error (0 or EFSCORRUPTED) */
xfs_btree_check_sblock(
struct xfs_btree_cur *cur, /* btree cursor */
- struct xfs_btree_sblock *block, /* btree short form block pointer */
+ struct xfs_btree_block *block, /* btree short form block pointer */
int level, /* level of the btree block */
struct xfs_buf *bp) /* buffer containing block */
{
be16_to_cpu(block->bb_level) == level &&
be16_to_cpu(block->bb_numrecs) <=
cur->bc_ops->get_maxrecs(cur, level) &&
- (be32_to_cpu(block->bb_leftsib) == NULLAGBLOCK ||
- be32_to_cpu(block->bb_leftsib) < agflen) &&
- block->bb_leftsib &&
- (be32_to_cpu(block->bb_rightsib) == NULLAGBLOCK ||
- be32_to_cpu(block->bb_rightsib) < agflen) &&
- block->bb_rightsib;
+ (be32_to_cpu(block->bb_u.s.bb_leftsib) == NULLAGBLOCK ||
+ be32_to_cpu(block->bb_u.s.bb_leftsib) < agflen) &&
+ block->bb_u.s.bb_leftsib &&
+ (be32_to_cpu(block->bb_u.s.bb_rightsib) == NULLAGBLOCK ||
+ be32_to_cpu(block->bb_u.s.bb_rightsib) < agflen) &&
+ block->bb_u.s.bb_rightsib;
if (unlikely(XFS_TEST_ERROR(!sblock_ok, cur->bc_mp,
XFS_ERRTAG_BTREE_CHECK_SBLOCK,
XFS_RANDOM_BTREE_CHECK_SBLOCK))) {
if (bp)
xfs_buftrace("SBTREE ERROR", bp);
- XFS_ERROR_REPORT("xfs_btree_check_sblock", XFS_ERRLEVEL_LOW,
- cur->bc_mp);
+ XFS_CORRUPTION_ERROR("xfs_btree_check_sblock",
+ XFS_ERRLEVEL_LOW, cur->bc_mp, block);
return XFS_ERROR(EFSCORRUPTED);
}
return 0;
int level, /* level of the btree block */
struct xfs_buf *bp) /* buffer containing block, if any */
{
- if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
- return xfs_btree_check_lblock(cur,
- (struct xfs_btree_lblock *)block, level, bp);
- } else {
- return xfs_btree_check_sblock(cur,
- (struct xfs_btree_sblock *)block, level, bp);
- }
+ if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
+ return xfs_btree_check_lblock(cur, block, level, bp);
+ else
+ return xfs_btree_check_sblock(cur, block, level, bp);
}
/*
return 0;
}
+#ifdef DEBUG
/*
* Check that (short) pointer is ok.
*/
-int /* error (0 or EFSCORRUPTED) */
+STATIC int /* error (0 or EFSCORRUPTED) */
xfs_btree_check_sptr(
struct xfs_btree_cur *cur, /* btree cursor */
xfs_agblock_t bno, /* btree block disk address */
/*
* Check that block ptr is ok.
*/
-int /* error (0 or EFSCORRUPTED) */
+STATIC int /* error (0 or EFSCORRUPTED) */
xfs_btree_check_ptr(
struct xfs_btree_cur *cur, /* btree cursor */
union xfs_btree_ptr *ptr, /* btree block disk address */
be32_to_cpu((&ptr->s)[index]), level);
}
}
+#endif
/*
* Delete the btree cursor.
static inline size_t xfs_btree_block_len(struct xfs_btree_cur *cur)
{
return (cur->bc_flags & XFS_BTREE_LONG_PTRS) ?
- sizeof(struct xfs_btree_lblock) :
- sizeof(struct xfs_btree_sblock);
+ XFS_BTREE_LBLOCK_LEN :
+ XFS_BTREE_SBLOCK_LEN;
}
/*
xfs_btree_cur_t *cur, /* btree cursor */
int level) /* level to check */
{
- xfs_btree_block_t *block; /* generic btree block pointer */
+ struct xfs_btree_block *block; /* generic btree block pointer */
xfs_buf_t *bp; /* buffer containing block */
block = xfs_btree_get_block(cur, level, &bp);
* Change the cursor to point to the first record at the given level.
* Other levels are unaffected.
*/
-int /* success=1, failure=0 */
+STATIC int /* success=1, failure=0 */
xfs_btree_firstrec(
xfs_btree_cur_t *cur, /* btree cursor */
int level) /* level to change */
{
- xfs_btree_block_t *block; /* generic btree block pointer */
+ struct xfs_btree_block *block; /* generic btree block pointer */
xfs_buf_t *bp; /* buffer containing block */
/*
* Change the cursor to point to the last record in the current block
* at the given level. Other levels are unaffected.
*/
-int /* success=1, failure=0 */
+STATIC int /* success=1, failure=0 */
xfs_btree_lastrec(
xfs_btree_cur_t *cur, /* btree cursor */
int level) /* level to change */
{
- xfs_btree_block_t *block; /* generic btree block pointer */
+ struct xfs_btree_block *block; /* generic btree block pointer */
xfs_buf_t *bp; /* buffer containing block */
/*
}
/*
- * Get a buffer for the block, return it read in.
- * Short-form addressing.
- */
-int /* error */
-xfs_btree_read_bufs(
- xfs_mount_t *mp, /* file system mount point */
- xfs_trans_t *tp, /* transaction pointer */
- xfs_agnumber_t agno, /* allocation group number */
- xfs_agblock_t agbno, /* allocation group block number */
- uint lock, /* lock flags for read_buf */
- xfs_buf_t **bpp, /* buffer for agno/agbno */
- int refval) /* ref count value for buffer */
-{
- xfs_buf_t *bp; /* return value */
- xfs_daddr_t d; /* real disk block address */
- int error;
-
- ASSERT(agno != NULLAGNUMBER);
- ASSERT(agbno != NULLAGBLOCK);
- d = XFS_AGB_TO_DADDR(mp, agno, agbno);
- if ((error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, d,
- mp->m_bsize, lock, &bp))) {
- return error;
- }
- ASSERT(!bp || !XFS_BUF_GETERROR(bp));
- if (bp != NULL) {
- switch (refval) {
- case XFS_ALLOC_BTREE_REF:
- XFS_BUF_SET_VTYPE_REF(bp, B_FS_MAP, refval);
- break;
- case XFS_INO_BTREE_REF:
- XFS_BUF_SET_VTYPE_REF(bp, B_FS_INOMAP, refval);
- break;
- }
- }
- *bpp = bp;
- return 0;
-}
-
-/*
* Read-ahead the block, don't wait for it, don't return a buffer.
* Long-form addressing.
*/
struct xfs_btree_block *block)
{
int rval = 0;
- xfs_fsblock_t left = be64_to_cpu(block->bb_u.l.bb_leftsib);
- xfs_fsblock_t right = be64_to_cpu(block->bb_u.l.bb_rightsib);
+ xfs_dfsbno_t left = be64_to_cpu(block->bb_u.l.bb_leftsib);
+ xfs_dfsbno_t right = be64_to_cpu(block->bb_u.l.bb_rightsib);
if ((lr & XFS_BTCUR_LEFTRA) && left != NULLDFSBNO) {
xfs_btree_reada_bufl(cur->bc_mp, left, 1);
* Read-ahead btree blocks, at the given level.
* Bits in lr are set from XFS_BTCUR_{LEFT,RIGHT}RA.
*/
-int
+STATIC int
xfs_btree_readahead(
struct xfs_btree_cur *cur, /* btree cursor */
int lev, /* level in btree */
int lev, /* level in btree */
xfs_buf_t *bp) /* new buffer to set */
{
- xfs_btree_block_t *b; /* btree block */
+ struct xfs_btree_block *b; /* btree block */
xfs_buf_t *obp; /* old buffer pointer */
obp = cur->bc_bufs[lev];
union xfs_btree_ptr *ptr)
{
if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
- return be64_to_cpu(ptr->l) == NULLFSBLOCK;
+ return be64_to_cpu(ptr->l) == NULLDFSBNO;
else
return be32_to_cpu(ptr->s) == NULLAGBLOCK;
}
union xfs_btree_ptr *ptr)
{
if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
- ptr->l = cpu_to_be64(NULLFSBLOCK);
+ ptr->l = cpu_to_be64(NULLDFSBNO);
else
ptr->s = cpu_to_be32(NULLAGBLOCK);
}
new->bb_numrecs = cpu_to_be16(numrecs);
if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
- new->bb_u.l.bb_leftsib = cpu_to_be64(NULLFSBLOCK);
- new->bb_u.l.bb_rightsib = cpu_to_be64(NULLFSBLOCK);
+ new->bb_u.l.bb_leftsib = cpu_to_be64(NULLDFSBNO);
+ new->bb_u.l.bb_rightsib = cpu_to_be64(NULLDFSBNO);
} else {
new->bb_u.s.bb_leftsib = cpu_to_be32(NULLAGBLOCK);
new->bb_u.s.bb_rightsib = cpu_to_be32(NULLAGBLOCK);
ptr->l = cpu_to_be64(XFS_DADDR_TO_FSB(cur->bc_mp,
XFS_BUF_ADDR(bp)));
else {
- ptr->s = cpu_to_be32(XFS_DADDR_TO_AGBNO(cur->bc_mp,
+ ptr->s = cpu_to_be32(xfs_daddr_to_agbno(cur->bc_mp,
XFS_BUF_ADDR(bp)));
}
}
union xfs_btree_ptr *ptr)
{
if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
- ASSERT(be64_to_cpu(ptr->l) != NULLFSBLOCK);
+ ASSERT(be64_to_cpu(ptr->l) != NULLDFSBNO);
return XFS_FSB_TO_DADDR(cur->bc_mp, be64_to_cpu(ptr->l));
} else {
/*
* Log record values from the btree block.
*/
-STATIC void
+void
xfs_btree_log_recs(
struct xfs_btree_cur *cur,
struct xfs_buf *bp,
/*
* Log fields from a btree block header.
*/
-STATIC void
+void
xfs_btree_log_block(
struct xfs_btree_cur *cur, /* btree cursor */
struct xfs_buf *bp, /* buffer containing btree block */
int first; /* first byte offset logged */
int last; /* last byte offset logged */
static const short soffsets[] = { /* table of offsets (short) */
- offsetof(struct xfs_btree_sblock, bb_magic),
- offsetof(struct xfs_btree_sblock, bb_level),
- offsetof(struct xfs_btree_sblock, bb_numrecs),
- offsetof(struct xfs_btree_sblock, bb_leftsib),
- offsetof(struct xfs_btree_sblock, bb_rightsib),
- sizeof(struct xfs_btree_sblock)
+ offsetof(struct xfs_btree_block, bb_magic),
+ offsetof(struct xfs_btree_block, bb_level),
+ offsetof(struct xfs_btree_block, bb_numrecs),
+ offsetof(struct xfs_btree_block, bb_u.s.bb_leftsib),
+ offsetof(struct xfs_btree_block, bb_u.s.bb_rightsib),
+ XFS_BTREE_SBLOCK_LEN
};
static const short loffsets[] = { /* table of offsets (long) */
- offsetof(struct xfs_btree_lblock, bb_magic),
- offsetof(struct xfs_btree_lblock, bb_level),
- offsetof(struct xfs_btree_lblock, bb_numrecs),
- offsetof(struct xfs_btree_lblock, bb_leftsib),
- offsetof(struct xfs_btree_lblock, bb_rightsib),
- sizeof(struct xfs_btree_lblock)
+ offsetof(struct xfs_btree_block, bb_magic),
+ offsetof(struct xfs_btree_block, bb_level),
+ offsetof(struct xfs_btree_block, bb_numrecs),
+ offsetof(struct xfs_btree_block, bb_u.l.bb_leftsib),
+ offsetof(struct xfs_btree_block, bb_u.l.bb_rightsib),
+ XFS_BTREE_LBLOCK_LEN
};
XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
/*
* Update keys at all levels from here to the root along the cursor's path.
*/
-int
+STATIC int
xfs_btree_updkey(
struct xfs_btree_cur *cur,
union xfs_btree_key *keyp,
* Move 1 record left from cur/level if possible.
* Update cur to reflect the new path.
*/
-int /* error */
+STATIC int /* error */
xfs_btree_lshift(
struct xfs_btree_cur *cur,
int level,
/*
* We add one entry to the left side and remove one for the right side.
- * Accout for it here, the changes will be updated on disk and logged
+ * Account for it here, the changes will be updated on disk and logged
* later.
*/
lrecs++;
xfs_btree_log_keys(cur, lbp, lrecs, lrecs);
xfs_btree_log_ptrs(cur, lbp, lrecs, lrecs);
- xfs_btree_check_key(cur->bc_btnum,
- xfs_btree_key_addr(cur, lrecs - 1, left),
- lkp);
+ ASSERT(cur->bc_ops->keys_inorder(cur,
+ xfs_btree_key_addr(cur, lrecs - 1, left), lkp));
} else {
/* It's a leaf. Move records. */
union xfs_btree_rec *lrp; /* left record pointer */
xfs_btree_copy_recs(cur, lrp, rrp, 1);
xfs_btree_log_recs(cur, lbp, lrecs, lrecs);
- xfs_btree_check_rec(cur->bc_btnum,
- xfs_btree_rec_addr(cur, lrecs - 1, left),
- lrp);
+ ASSERT(cur->bc_ops->recs_inorder(cur,
+ xfs_btree_rec_addr(cur, lrecs - 1, left), lrp));
}
xfs_btree_set_numrecs(left, lrecs);
* Move 1 record right from cur/level if possible.
* Update cur to reflect the new path.
*/
-int /* error */
+STATIC int /* error */
xfs_btree_rshift(
struct xfs_btree_cur *cur,
int level,
xfs_btree_log_keys(cur, rbp, 1, rrecs + 1);
xfs_btree_log_ptrs(cur, rbp, 1, rrecs + 1);
- xfs_btree_check_key(cur->bc_btnum, rkp,
- xfs_btree_key_addr(cur, 2, right));
+ ASSERT(cur->bc_ops->keys_inorder(cur, rkp,
+ xfs_btree_key_addr(cur, 2, right)));
} else {
/* It's a leaf. make a hole in the records */
union xfs_btree_rec *lrp;
cur->bc_ops->init_key_from_rec(&key, rrp);
rkp = &key;
- xfs_btree_check_rec(cur->bc_btnum, rrp,
- xfs_btree_rec_addr(cur, 2, right));
+ ASSERT(cur->bc_ops->recs_inorder(cur, rrp,
+ xfs_btree_rec_addr(cur, 2, right)));
}
/*
* Return new block number and the key to its first
* record (to be inserted into parent).
*/
-int /* error */
+STATIC int /* error */
xfs_btree_split(
struct xfs_btree_cur *cur,
int level,
xfs_btree_log_ptrs(cur, cbp, 1, be16_to_cpu(cblock->bb_numrecs));
*logflags |=
- XFS_ILOG_CORE | XFS_ILOG_FBROOT(cur->bc_private.b.whichfork);
+ XFS_ILOG_CORE | xfs_ilog_fbroot(cur->bc_private.b.whichfork);
*stat = 1;
XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
return 0;
/*
* Allocate a new root block, fill it in.
*/
-int /* error */
+STATIC int /* error */
xfs_btree_new_root(
struct xfs_btree_cur *cur, /* btree cursor */
int *stat) /* success/failure */
/* Check that the new entry is being inserted in the right place. */
if (ptr <= numrecs) {
if (level == 0) {
- xfs_btree_check_rec(cur->bc_btnum, recp,
- xfs_btree_rec_addr(cur, ptr, block));
+ ASSERT(cur->bc_ops->recs_inorder(cur, recp,
+ xfs_btree_rec_addr(cur, ptr, block)));
} else {
- xfs_btree_check_key(cur->bc_btnum, &key,
- xfs_btree_key_addr(cur, ptr, block));
+ ASSERT(cur->bc_ops->keys_inorder(cur, &key,
+ xfs_btree_key_addr(cur, ptr, block)));
}
}
#endif
xfs_btree_log_keys(cur, bp, ptr, numrecs);
#ifdef DEBUG
if (ptr < numrecs) {
- xfs_btree_check_key(cur->bc_btnum, kp,
- xfs_btree_key_addr(cur, ptr + 1, block));
+ ASSERT(cur->bc_ops->keys_inorder(cur, kp,
+ xfs_btree_key_addr(cur, ptr + 1, block)));
}
#endif
} else {
xfs_btree_log_recs(cur, bp, ptr, numrecs);
#ifdef DEBUG
if (ptr < numrecs) {
- xfs_btree_check_rec(cur->bc_btnum, rp,
- xfs_btree_rec_addr(cur, ptr + 1, block));
+ ASSERT(cur->bc_ops->recs_inorder(cur, rp,
+ xfs_btree_rec_addr(cur, ptr + 1, block)));
}
#endif
}
XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
return error;
}
+
+/*
+ * Try to merge a non-leaf block back into the inode root.
+ *
+ * Note: the killroot names comes from the fact that we're effectively
+ * killing the old root block. But because we can't just delete the
+ * inode we have to copy the single block it was pointing to into the
+ * inode.
+ */
+STATIC int
+xfs_btree_kill_iroot(
+ struct xfs_btree_cur *cur)
+{
+ int whichfork = cur->bc_private.b.whichfork;
+ struct xfs_inode *ip = cur->bc_private.b.ip;
+ struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, whichfork);
+ struct xfs_btree_block *block;
+ struct xfs_btree_block *cblock;
+ union xfs_btree_key *kp;
+ union xfs_btree_key *ckp;
+ union xfs_btree_ptr *pp;
+ union xfs_btree_ptr *cpp;
+ struct xfs_buf *cbp;
+ int level;
+ int index;
+ int numrecs;
+#ifdef DEBUG
+ union xfs_btree_ptr ptr;
+ int i;
+#endif
+
+ XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
+
+ ASSERT(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE);
+ ASSERT(cur->bc_nlevels > 1);
+
+ /*
+ * Don't deal with the root block needs to be a leaf case.
+ * We're just going to turn the thing back into extents anyway.
+ */
+ level = cur->bc_nlevels - 1;
+ if (level == 1)
+ goto out0;
+
+ /*
+ * Give up if the root has multiple children.
+ */
+ block = xfs_btree_get_iroot(cur);
+ if (xfs_btree_get_numrecs(block) != 1)
+ goto out0;
+
+ cblock = xfs_btree_get_block(cur, level - 1, &cbp);
+ numrecs = xfs_btree_get_numrecs(cblock);
+
+ /*
+ * Only do this if the next level will fit.
+ * Then the data must be copied up to the inode,
+ * instead of freeing the root you free the next level.
+ */
+ if (numrecs > cur->bc_ops->get_dmaxrecs(cur, level))
+ goto out0;
+
+ XFS_BTREE_STATS_INC(cur, killroot);
+
+#ifdef DEBUG
+ xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_LEFTSIB);
+ ASSERT(xfs_btree_ptr_is_null(cur, &ptr));
+ xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
+ ASSERT(xfs_btree_ptr_is_null(cur, &ptr));
+#endif
+
+ index = numrecs - cur->bc_ops->get_maxrecs(cur, level);
+ if (index) {
+ xfs_iroot_realloc(cur->bc_private.b.ip, index,
+ cur->bc_private.b.whichfork);
+ block = ifp->if_broot;
+ }
+
+ be16_add_cpu(&block->bb_numrecs, index);
+ ASSERT(block->bb_numrecs == cblock->bb_numrecs);
+
+ kp = xfs_btree_key_addr(cur, 1, block);
+ ckp = xfs_btree_key_addr(cur, 1, cblock);
+ xfs_btree_copy_keys(cur, kp, ckp, numrecs);
+
+ pp = xfs_btree_ptr_addr(cur, 1, block);
+ cpp = xfs_btree_ptr_addr(cur, 1, cblock);
+#ifdef DEBUG
+ for (i = 0; i < numrecs; i++) {
+ int error;
+
+ error = xfs_btree_check_ptr(cur, cpp, i, level - 1);
+ if (error) {
+ XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
+ return error;
+ }
+ }
+#endif
+ xfs_btree_copy_ptrs(cur, pp, cpp, numrecs);
+
+ cur->bc_ops->free_block(cur, cbp);
+ XFS_BTREE_STATS_INC(cur, free);
+
+ cur->bc_bufs[level - 1] = NULL;
+ be16_add_cpu(&block->bb_level, -1);
+ xfs_trans_log_inode(cur->bc_tp, ip,
+ XFS_ILOG_CORE | xfs_ilog_fbroot(cur->bc_private.b.whichfork));
+ cur->bc_nlevels--;
+out0:
+ XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
+ return 0;
+}
+
+STATIC int
+xfs_btree_dec_cursor(
+ struct xfs_btree_cur *cur,
+ int level,
+ int *stat)
+{
+ int error;
+ int i;
+
+ if (level > 0) {
+ error = xfs_btree_decrement(cur, level, &i);
+ if (error)
+ return error;
+ }
+
+ XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
+ *stat = 1;
+ return 0;
+}
+
+/*
+ * Single level of the btree record deletion routine.
+ * Delete record pointed to by cur/level.
+ * Remove the record from its block then rebalance the tree.
+ * Return 0 for error, 1 for done, 2 to go on to the next level.
+ */
+STATIC int /* error */
+xfs_btree_delrec(
+ struct xfs_btree_cur *cur, /* btree cursor */
+ int level, /* level removing record from */
+ int *stat) /* fail/done/go-on */
+{
+ struct xfs_btree_block *block; /* btree block */
+ union xfs_btree_ptr cptr; /* current block ptr */
+ struct xfs_buf *bp; /* buffer for block */
+ int error; /* error return value */
+ int i; /* loop counter */
+ union xfs_btree_key key; /* storage for keyp */
+ union xfs_btree_key *keyp = &key; /* passed to the next level */
+ union xfs_btree_ptr lptr; /* left sibling block ptr */
+ struct xfs_buf *lbp; /* left buffer pointer */
+ struct xfs_btree_block *left; /* left btree block */
+ int lrecs = 0; /* left record count */
+ int ptr; /* key/record index */
+ union xfs_btree_ptr rptr; /* right sibling block ptr */
+ struct xfs_buf *rbp; /* right buffer pointer */
+ struct xfs_btree_block *right; /* right btree block */
+ struct xfs_btree_block *rrblock; /* right-right btree block */
+ struct xfs_buf *rrbp; /* right-right buffer pointer */
+ int rrecs = 0; /* right record count */
+ struct xfs_btree_cur *tcur; /* temporary btree cursor */
+ int numrecs; /* temporary numrec count */
+
+ XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
+ XFS_BTREE_TRACE_ARGI(cur, level);
+
+ tcur = NULL;
+
+ /* Get the index of the entry being deleted, check for nothing there. */
+ ptr = cur->bc_ptrs[level];
+ if (ptr == 0) {
+ XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
+ *stat = 0;
+ return 0;
+ }
+
+ /* Get the buffer & block containing the record or key/ptr. */
+ block = xfs_btree_get_block(cur, level, &bp);
+ numrecs = xfs_btree_get_numrecs(block);
+
+#ifdef DEBUG
+ error = xfs_btree_check_block(cur, block, level, bp);
+ if (error)
+ goto error0;
+#endif
+
+ /* Fail if we're off the end of the block. */
+ if (ptr > numrecs) {
+ XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
+ *stat = 0;
+ return 0;
+ }
+
+ XFS_BTREE_STATS_INC(cur, delrec);
+ XFS_BTREE_STATS_ADD(cur, moves, numrecs - ptr);
+
+ /* Excise the entries being deleted. */
+ if (level > 0) {
+ /* It's a nonleaf. operate on keys and ptrs */
+ union xfs_btree_key *lkp;
+ union xfs_btree_ptr *lpp;
+
+ lkp = xfs_btree_key_addr(cur, ptr + 1, block);
+ lpp = xfs_btree_ptr_addr(cur, ptr + 1, block);
+
+#ifdef DEBUG
+ for (i = 0; i < numrecs - ptr; i++) {
+ error = xfs_btree_check_ptr(cur, lpp, i, level);
+ if (error)
+ goto error0;
+ }
+#endif
+
+ if (ptr < numrecs) {
+ xfs_btree_shift_keys(cur, lkp, -1, numrecs - ptr);
+ xfs_btree_shift_ptrs(cur, lpp, -1, numrecs - ptr);
+ xfs_btree_log_keys(cur, bp, ptr, numrecs - 1);
+ xfs_btree_log_ptrs(cur, bp, ptr, numrecs - 1);
+ }
+
+ /*
+ * If it's the first record in the block, we'll need to pass a
+ * key up to the next level (updkey).
+ */
+ if (ptr == 1)
+ keyp = xfs_btree_key_addr(cur, 1, block);
+ } else {
+ /* It's a leaf. operate on records */
+ if (ptr < numrecs) {
+ xfs_btree_shift_recs(cur,
+ xfs_btree_rec_addr(cur, ptr + 1, block),
+ -1, numrecs - ptr);
+ xfs_btree_log_recs(cur, bp, ptr, numrecs - 1);
+ }
+
+ /*
+ * If it's the first record in the block, we'll need a key
+ * structure to pass up to the next level (updkey).
+ */
+ if (ptr == 1) {
+ cur->bc_ops->init_key_from_rec(&key,
+ xfs_btree_rec_addr(cur, 1, block));
+ keyp = &key;
+ }
+ }
+
+ /*
+ * Decrement and log the number of entries in the block.
+ */
+ xfs_btree_set_numrecs(block, --numrecs);
+ xfs_btree_log_block(cur, bp, XFS_BB_NUMRECS);
+
+ /*
+ * If we are tracking the last record in the tree and
+ * we are at the far right edge of the tree, update it.
+ */
+ if (xfs_btree_is_lastrec(cur, block, level)) {
+ cur->bc_ops->update_lastrec(cur, block, NULL,
+ ptr, LASTREC_DELREC);
+ }
+
+ /*
+ * We're at the root level. First, shrink the root block in-memory.
+ * Try to get rid of the next level down. If we can't then there's
+ * nothing left to do.
+ */
+ if (level == cur->bc_nlevels - 1) {
+ if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) {
+ xfs_iroot_realloc(cur->bc_private.b.ip, -1,
+ cur->bc_private.b.whichfork);
+
+ error = xfs_btree_kill_iroot(cur);
+ if (error)
+ goto error0;
+
+ error = xfs_btree_dec_cursor(cur, level, stat);
+ if (error)
+ goto error0;
+ *stat = 1;
+ return 0;
+ }
+
+ /*
+ * If this is the root level, and there's only one entry left,
+ * and it's NOT the leaf level, then we can get rid of this
+ * level.
+ */
+ if (numrecs == 1 && level > 0) {
+ union xfs_btree_ptr *pp;
+ /*
+ * pp is still set to the first pointer in the block.
+ * Make it the new root of the btree.
+ */
+ pp = xfs_btree_ptr_addr(cur, 1, block);
+ error = cur->bc_ops->kill_root(cur, bp, level, pp);
+ if (error)
+ goto error0;
+ } else if (level > 0) {
+ error = xfs_btree_dec_cursor(cur, level, stat);
+ if (error)
+ goto error0;
+ }
+ *stat = 1;
+ return 0;
+ }
+
+ /*
+ * If we deleted the leftmost entry in the block, update the
+ * key values above us in the tree.
+ */
+ if (ptr == 1) {
+ error = xfs_btree_updkey(cur, keyp, level + 1);
+ if (error)
+ goto error0;
+ }
+
+ /*
+ * If the number of records remaining in the block is at least
+ * the minimum, we're done.
+ */
+ if (numrecs >= cur->bc_ops->get_minrecs(cur, level)) {
+ error = xfs_btree_dec_cursor(cur, level, stat);
+ if (error)
+ goto error0;
+ return 0;
+ }
+
+ /*
+ * Otherwise, we have to move some records around to keep the
+ * tree balanced. Look at the left and right sibling blocks to
+ * see if we can re-balance by moving only one record.
+ */
+ xfs_btree_get_sibling(cur, block, &rptr, XFS_BB_RIGHTSIB);
+ xfs_btree_get_sibling(cur, block, &lptr, XFS_BB_LEFTSIB);
+
+ if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) {
+ /*
+ * One child of root, need to get a chance to copy its contents
+ * into the root and delete it. Can't go up to next level,
+ * there's nothing to delete there.
+ */
+ if (xfs_btree_ptr_is_null(cur, &rptr) &&
+ xfs_btree_ptr_is_null(cur, &lptr) &&
+ level == cur->bc_nlevels - 2) {
+ error = xfs_btree_kill_iroot(cur);
+ if (!error)
+ error = xfs_btree_dec_cursor(cur, level, stat);
+ if (error)
+ goto error0;
+ return 0;
+ }
+ }
+
+ ASSERT(!xfs_btree_ptr_is_null(cur, &rptr) ||
+ !xfs_btree_ptr_is_null(cur, &lptr));
+
+ /*
+ * Duplicate the cursor so our btree manipulations here won't
+ * disrupt the next level up.
+ */
+ error = xfs_btree_dup_cursor(cur, &tcur);
+ if (error)
+ goto error0;
+
+ /*
+ * If there's a right sibling, see if it's ok to shift an entry
+ * out of it.
+ */
+ if (!xfs_btree_ptr_is_null(cur, &rptr)) {
+ /*
+ * Move the temp cursor to the last entry in the next block.
+ * Actually any entry but the first would suffice.
+ */
+ i = xfs_btree_lastrec(tcur, level);
+ XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
+
+ error = xfs_btree_increment(tcur, level, &i);
+ if (error)
+ goto error0;
+ XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
+
+ i = xfs_btree_lastrec(tcur, level);
+ XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
+
+ /* Grab a pointer to the block. */
+ right = xfs_btree_get_block(tcur, level, &rbp);
+#ifdef DEBUG
+ error = xfs_btree_check_block(tcur, right, level, rbp);
+ if (error)
+ goto error0;
+#endif
+ /* Grab the current block number, for future use. */
+ xfs_btree_get_sibling(tcur, right, &cptr, XFS_BB_LEFTSIB);
+
+ /*
+ * If right block is full enough so that removing one entry
+ * won't make it too empty, and left-shifting an entry out
+ * of right to us works, we're done.
+ */
+ if (xfs_btree_get_numrecs(right) - 1 >=
+ cur->bc_ops->get_minrecs(tcur, level)) {
+ error = xfs_btree_lshift(tcur, level, &i);
+ if (error)
+ goto error0;
+ if (i) {
+ ASSERT(xfs_btree_get_numrecs(block) >=
+ cur->bc_ops->get_minrecs(tcur, level));
+
+ xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
+ tcur = NULL;
+
+ error = xfs_btree_dec_cursor(cur, level, stat);
+ if (error)
+ goto error0;
+ return 0;
+ }
+ }
+
+ /*
+ * Otherwise, grab the number of records in right for
+ * future reference, and fix up the temp cursor to point
+ * to our block again (last record).
+ */
+ rrecs = xfs_btree_get_numrecs(right);
+ if (!xfs_btree_ptr_is_null(cur, &lptr)) {
+ i = xfs_btree_firstrec(tcur, level);
+ XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
+
+ error = xfs_btree_decrement(tcur, level, &i);
+ if (error)
+ goto error0;
+ XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
+ }
+ }
+
+ /*
+ * If there's a left sibling, see if it's ok to shift an entry
+ * out of it.
+ */
+ if (!xfs_btree_ptr_is_null(cur, &lptr)) {
+ /*
+ * Move the temp cursor to the first entry in the
+ * previous block.
+ */
+ i = xfs_btree_firstrec(tcur, level);
+ XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
+
+ error = xfs_btree_decrement(tcur, level, &i);
+ if (error)
+ goto error0;
+ i = xfs_btree_firstrec(tcur, level);
+ XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
+
+ /* Grab a pointer to the block. */
+ left = xfs_btree_get_block(tcur, level, &lbp);
+#ifdef DEBUG
+ error = xfs_btree_check_block(cur, left, level, lbp);
+ if (error)
+ goto error0;
+#endif
+ /* Grab the current block number, for future use. */
+ xfs_btree_get_sibling(tcur, left, &cptr, XFS_BB_RIGHTSIB);
+
+ /*
+ * If left block is full enough so that removing one entry
+ * won't make it too empty, and right-shifting an entry out
+ * of left to us works, we're done.
+ */
+ if (xfs_btree_get_numrecs(left) - 1 >=
+ cur->bc_ops->get_minrecs(tcur, level)) {
+ error = xfs_btree_rshift(tcur, level, &i);
+ if (error)
+ goto error0;
+ if (i) {
+ ASSERT(xfs_btree_get_numrecs(block) >=
+ cur->bc_ops->get_minrecs(tcur, level));
+ xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
+ tcur = NULL;
+ if (level == 0)
+ cur->bc_ptrs[0]++;
+ XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
+ *stat = 1;
+ return 0;
+ }
+ }
+
+ /*
+ * Otherwise, grab the number of records in right for
+ * future reference.
+ */
+ lrecs = xfs_btree_get_numrecs(left);
+ }
+
+ /* Delete the temp cursor, we're done with it. */
+ xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
+ tcur = NULL;
+
+ /* If here, we need to do a join to keep the tree balanced. */
+ ASSERT(!xfs_btree_ptr_is_null(cur, &cptr));
+
+ if (!xfs_btree_ptr_is_null(cur, &lptr) &&
+ lrecs + xfs_btree_get_numrecs(block) <=
+ cur->bc_ops->get_maxrecs(cur, level)) {
+ /*
+ * Set "right" to be the starting block,
+ * "left" to be the left neighbor.
+ */
+ rptr = cptr;
+ right = block;
+ rbp = bp;
+ error = xfs_btree_read_buf_block(cur, &lptr, level,
+ 0, &left, &lbp);
+ if (error)
+ goto error0;
+
+ /*
+ * If that won't work, see if we can join with the right neighbor block.
+ */
+ } else if (!xfs_btree_ptr_is_null(cur, &rptr) &&
+ rrecs + xfs_btree_get_numrecs(block) <=
+ cur->bc_ops->get_maxrecs(cur, level)) {
+ /*
+ * Set "left" to be the starting block,
+ * "right" to be the right neighbor.
+ */
+ lptr = cptr;
+ left = block;
+ lbp = bp;
+ error = xfs_btree_read_buf_block(cur, &rptr, level,
+ 0, &right, &rbp);
+ if (error)
+ goto error0;
+
+ /*
+ * Otherwise, we can't fix the imbalance.
+ * Just return. This is probably a logic error, but it's not fatal.
+ */
+ } else {
+ error = xfs_btree_dec_cursor(cur, level, stat);
+ if (error)
+ goto error0;
+ return 0;
+ }
+
+ rrecs = xfs_btree_get_numrecs(right);
+ lrecs = xfs_btree_get_numrecs(left);
+
+ /*
+ * We're now going to join "left" and "right" by moving all the stuff
+ * in "right" to "left" and deleting "right".
+ */
+ XFS_BTREE_STATS_ADD(cur, moves, rrecs);
+ if (level > 0) {
+ /* It's a non-leaf. Move keys and pointers. */
+ union xfs_btree_key *lkp; /* left btree key */
+ union xfs_btree_ptr *lpp; /* left address pointer */
+ union xfs_btree_key *rkp; /* right btree key */
+ union xfs_btree_ptr *rpp; /* right address pointer */
+
+ lkp = xfs_btree_key_addr(cur, lrecs + 1, left);
+ lpp = xfs_btree_ptr_addr(cur, lrecs + 1, left);
+ rkp = xfs_btree_key_addr(cur, 1, right);
+ rpp = xfs_btree_ptr_addr(cur, 1, right);
+#ifdef DEBUG
+ for (i = 1; i < rrecs; i++) {
+ error = xfs_btree_check_ptr(cur, rpp, i, level);
+ if (error)
+ goto error0;
+ }
+#endif
+ xfs_btree_copy_keys(cur, lkp, rkp, rrecs);
+ xfs_btree_copy_ptrs(cur, lpp, rpp, rrecs);
+
+ xfs_btree_log_keys(cur, lbp, lrecs + 1, lrecs + rrecs);
+ xfs_btree_log_ptrs(cur, lbp, lrecs + 1, lrecs + rrecs);
+ } else {
+ /* It's a leaf. Move records. */
+ union xfs_btree_rec *lrp; /* left record pointer */
+ union xfs_btree_rec *rrp; /* right record pointer */
+
+ lrp = xfs_btree_rec_addr(cur, lrecs + 1, left);
+ rrp = xfs_btree_rec_addr(cur, 1, right);
+
+ xfs_btree_copy_recs(cur, lrp, rrp, rrecs);
+ xfs_btree_log_recs(cur, lbp, lrecs + 1, lrecs + rrecs);
+ }
+
+ XFS_BTREE_STATS_INC(cur, join);
+
+ /*
+ * Fix up the number of records and right block pointer in the
+ * surviving block, and log it.
+ */
+ xfs_btree_set_numrecs(left, lrecs + rrecs);
+ xfs_btree_get_sibling(cur, right, &cptr, XFS_BB_RIGHTSIB),
+ xfs_btree_set_sibling(cur, left, &cptr, XFS_BB_RIGHTSIB);
+ xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS | XFS_BB_RIGHTSIB);
+
+ /* If there is a right sibling, point it to the remaining block. */
+ xfs_btree_get_sibling(cur, left, &cptr, XFS_BB_RIGHTSIB);
+ if (!xfs_btree_ptr_is_null(cur, &cptr)) {
+ error = xfs_btree_read_buf_block(cur, &cptr, level,
+ 0, &rrblock, &rrbp);
+ if (error)
+ goto error0;
+ xfs_btree_set_sibling(cur, rrblock, &lptr, XFS_BB_LEFTSIB);
+ xfs_btree_log_block(cur, rrbp, XFS_BB_LEFTSIB);
+ }
+
+ /* Free the deleted block. */
+ error = cur->bc_ops->free_block(cur, rbp);
+ if (error)
+ goto error0;
+ XFS_BTREE_STATS_INC(cur, free);
+
+ /*
+ * If we joined with the left neighbor, set the buffer in the
+ * cursor to the left block, and fix up the index.
+ */
+ if (bp != lbp) {
+ cur->bc_bufs[level] = lbp;
+ cur->bc_ptrs[level] += lrecs;
+ cur->bc_ra[level] = 0;
+ }
+ /*
+ * If we joined with the right neighbor and there's a level above
+ * us, increment the cursor at that level.
+ */
+ else if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) ||
+ (level + 1 < cur->bc_nlevels)) {
+ error = xfs_btree_increment(cur, level + 1, &i);
+ if (error)
+ goto error0;
+ }
+
+ /*
+ * Readjust the ptr at this level if it's not a leaf, since it's
+ * still pointing at the deletion point, which makes the cursor
+ * inconsistent. If this makes the ptr 0, the caller fixes it up.
+ * We can't use decrement because it would change the next level up.
+ */
+ if (level > 0)
+ cur->bc_ptrs[level]--;
+
+ XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
+ /* Return value means the next level up has something to do. */
+ *stat = 2;
+ return 0;
+
+error0:
+ XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
+ if (tcur)
+ xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR);
+ return error;
+}
+
+/*
+ * Delete the record pointed to by cur.
+ * The cursor refers to the place where the record was (could be inserted)
+ * when the operation returns.
+ */
+int /* error */
+xfs_btree_delete(
+ struct xfs_btree_cur *cur,
+ int *stat) /* success/failure */
+{
+ int error; /* error return value */
+ int level;
+ int i;
+
+ XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
+
+ /*
+ * Go up the tree, starting at leaf level.
+ *
+ * If 2 is returned then a join was done; go to the next level.
+ * Otherwise we are done.
+ */
+ for (level = 0, i = 2; i == 2; level++) {
+ error = xfs_btree_delrec(cur, level, &i);
+ if (error)
+ goto error0;
+ }
+
+ if (i == 0) {
+ for (level = 1; level < cur->bc_nlevels; level++) {
+ if (cur->bc_ptrs[level] == 0) {
+ error = xfs_btree_decrement(cur, level, &i);
+ if (error)
+ goto error0;
+ break;
+ }
+ }
+ }
+
+ XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
+ *stat = i;
+ return 0;
+error0:
+ XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
+ return error;
+}
+
+/*
+ * Get the data from the pointed-to record.
+ */
+int /* error */
+xfs_btree_get_rec(
+ struct xfs_btree_cur *cur, /* btree cursor */
+ union xfs_btree_rec **recp, /* output: btree record */
+ int *stat) /* output: success/failure */
+{
+ struct xfs_btree_block *block; /* btree block */
+ struct xfs_buf *bp; /* buffer pointer */
+ int ptr; /* record number */
+#ifdef DEBUG
+ int error; /* error return value */
+#endif
+
+ ptr = cur->bc_ptrs[0];
+ block = xfs_btree_get_block(cur, 0, &bp);
+
+#ifdef DEBUG
+ error = xfs_btree_check_block(cur, block, 0, bp);
+ if (error)
+ return error;
+#endif
+
+ /*
+ * Off the right end or left end, return failure.
+ */
+ if (ptr > xfs_btree_get_numrecs(block) || ptr <= 0) {
+ *stat = 0;
+ return 0;
+ }
+
+ /*
+ * Point to the record and extract its data.
+ */
+ *recp = xfs_btree_rec_addr(cur, ptr, block);
+ *stat = 1;
+ return 0;
+}