- 根目录:
- fs
- xfs
- xfs_btree.c
/*
* Copyright (c) 2000-2002,2005 Silicon Graphics, Inc.
* All Rights Reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it would be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_types.h"
#include "xfs_bit.h"
#include "xfs_log.h"
#include "xfs_inum.h"
#include "xfs_trans.h"
#include "xfs_sb.h"
#include "xfs_ag.h"
#include "xfs_mount.h"
#include "xfs_bmap_btree.h"
#include "xfs_alloc_btree.h"
#include "xfs_ialloc_btree.h"
#include "xfs_dinode.h"
#include "xfs_inode.h"
#include "xfs_inode_item.h"
#include "xfs_btree.h"
#include "xfs_btree_trace.h"
#include "xfs_error.h"
#include "xfs_trace.h"
/*
* Cursor allocation zone.
*/
kmem_zone_t *xfs_btree_cur_zone;
/*
* Btree magic numbers.
*/
const __uint32_t xfs_magics[XFS_BTNUM_MAX] = {
XFS_ABTB_MAGIC, XFS_ABTC_MAGIC, XFS_BMAP_MAGIC, XFS_IBT_MAGIC
};
STATIC int /* error (0 or EFSCORRUPTED) */
xfs_btree_check_lblock(
struct xfs_btree_cur *cur, /* btree cursor */
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 */
{
int lblock_ok; /* block passes checks */
struct xfs_mount *mp; /* file system mount point */
mp = cur->bc_mp;
lblock_ok =
be32_to_cpu(block->bb_magic) == xfs_magics[cur->bc_btnum] &&
be16_to_cpu(block->bb_level) == level &&
be16_to_cpu(block->bb_numrecs) <=
cur->bc_ops->get_maxrecs(cur, level) &&
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))) {
if (bp)
trace_xfs_btree_corrupt(bp, _RET_IP_);
XFS_ERROR_REPORT("xfs_btree_check_lblock", XFS_ERRLEVEL_LOW,
mp);
return XFS_ERROR(EFSCORRUPTED);
}
return 0;
}
STATIC int /* error (0 or EFSCORRUPTED) */
xfs_btree_check_sblock(
struct xfs_btree_cur *cur, /* btree cursor */
struct xfs_btree_block *block, /* btree short form block pointer */
int level, /* level of the btree block */
struct xfs_buf *bp) /* buffer containing block */
{
struct xfs_buf *agbp; /* buffer for ag. freespace struct */
struct xfs_agf *agf; /* ag. freespace structure */
xfs_agblock_t agflen; /* native ag. freespace length */
int sblock_ok; /* block passes checks */
agbp = cur->bc_private.a.agbp;
agf = XFS_BUF_TO_AGF(agbp);
agflen = be32_to_cpu(agf->agf_length);
sblock_ok =
be32_to_cpu(block->bb_magic) == xfs_magics[cur->bc_btnum] &&
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_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)
trace_xfs_btree_corrupt(bp, _RET_IP_);
XFS_CORRUPTION_ERROR("xfs_btree_check_sblock",
XFS_ERRLEVEL_LOW, cur->bc_mp, block);
return XFS_ERROR(EFSCORRUPTED);
}
return 0;
}
/*
* Debug routine: check that block header is ok.
*/
int
xfs_btree_check_block(
struct xfs_btree_cur *cur, /* btree cursor */
struct xfs_btree_block *block, /* generic btree block pointer */
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, block, level, bp);
else
return xfs_btree_check_sblock(cur, block, level, bp);
}
/*
* Check that (long) pointer is ok.
*/
int /* error (0 or EFSCORRUPTED) */
xfs_btree_check_lptr(
struct xfs_btree_cur *cur, /* btree cursor */
xfs_dfsbno_t bno, /* btree block disk address */
int level) /* btree block level */
{
XFS_WANT_CORRUPTED_RETURN(
level > 0 &&
bno != NULLDFSBNO &&
XFS_FSB_SANITY_CHECK(cur->bc_mp, bno));
return 0;
}
#ifdef DEBUG
/*
* Check that (short) pointer is ok.
*/
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 */
int level) /* btree block level */
{
xfs_agblock_t agblocks = cur->bc_mp->m_sb.sb_agblocks;
XFS_WANT_CORRUPTED_RETURN(
level > 0 &&
bno != NULLAGBLOCK &&
bno != 0 &&
bno < agblocks);
return 0;
}
/*
* Check that block ptr is ok.
*/
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 */
int index, /* offset from ptr to check */
int level) /* btree block level */
{
if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
return xfs_btree_check_lptr(cur,
be64_to_cpu((&ptr->l)[index]), level);
} else {
return xfs_btree_check_sptr(cur,
be32_to_cpu((&ptr->s)[index]), level);
}
}
#endif
/*
* Delete the btree cursor.
*/
void
xfs_btree_del_cursor(
xfs_btree_cur_t *cur, /* btree cursor */
int error) /* del because of error */
{
int i; /* btree level */
/*
* Clear the buffer pointers, and release the buffers.
* If we're doing this in the face of an error, we
* need to make sure to inspect all of the entries
* in the bc_bufs array for buffers to be unlocked.
* This is because some of the btree code works from
* level n down to 0, and if we get an error along
* the way we won't have initialized all the entries
* down to 0.
*/
for (i = 0; i < cur->bc_nlevels; i++) {
if (cur->bc_bufs[i])
xfs_trans_brelse(cur->bc_tp, cur->bc_bufs[i]);
else if (!error)
break;
}
/*
* Can't free a bmap cursor without having dealt with the
* allocated indirect blocks' accounting.
*/
ASSERT(cur->bc_btnum != XFS_BTNUM_BMAP ||
cur->bc_private.b.allocated == 0);
/*
* Free the cursor.
*/
kmem_zone_free(xfs_btree_cur_zone, cur);
}
/*
* Duplicate the btree cursor.
* Allocate a new one, copy the record, re-get the buffers.
*/
int /* error */
xfs_btree_dup_cursor(
xfs_btree_cur_t *cur, /* input cursor */
xfs_btree_cur_t **ncur) /* output cursor */
{
xfs_buf_t *bp; /* btree block's buffer pointer */
int error; /* error return value */
int i; /* level number of btree block */
xfs_mount_t *mp; /* mount structure for filesystem */
xfs_btree_cur_t *new; /* new cursor value */
xfs_trans_t *tp; /* transaction pointer, can be NULL */
tp = cur->bc_tp;
mp = cur->bc_mp;
/*
* Allocate a new cursor like the old one.
*/
new = cur->bc_ops->dup_cursor(cur);
/*
* Copy the record currently in the cursor.
*/
new->bc_rec = cur->bc_rec;
/*
* For each level current, re-get the buffer and copy the ptr value.
*/
for (i = 0; i < new->bc_nlevels; i++) {
new->bc_ptrs[i] = cur->bc_ptrs[i];
new->bc_ra[i] = cur->bc_ra[i];
if ((bp = cur->bc_bufs[i])) {
if ((error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp,
XFS_BUF_ADDR(bp), mp->m_bsize, 0, &bp))) {
xfs_btree_del_cursor(new, error);
*ncur = NULL;
return error;
}
new->bc_bufs[i] = bp;
ASSERT(bp);
ASSERT(!XFS_BUF_GETERROR(bp));
} else
new->bc_bufs[i] = NULL;
}
*ncur = new;
return 0;
}
/*
* XFS btree block layout and addressing:
*
* There are two types of blocks in the btree: leaf and non-leaf blocks.
*
* The leaf record start with a header then followed by records containing
* the values. A non-leaf block also starts with the same header, and
* then first contains lookup keys followed by an equal number of pointers
* to the btree blocks at the previous level.
*
* +--------+-------+-------+-------+-------+-------+-------+
* Leaf: | header | rec 1 | rec 2 | rec 3 | rec 4 | rec 5 | rec N |
* +--------+-------+-------+-------+-------+-------+-------+
*
* +--------+-------+-------+-------+-------+-------+-------+
* Non-Leaf: | header | key 1 | key 2 | key N | ptr 1 | ptr 2 | ptr N |
* +--------+-------+-------+-------+-------+-------+-------+
*
* The header is called struct xfs_btree_block for reasons better left unknown
* and comes in different versions for short (32bit) and long (64bit) block
* pointers. The record and key structures are defined by the btree instances
* and opaque to the btree core. The block pointers are simple disk endian
* integers, available in a short (32bit) and long (64bit) variant.
*
* The helpers below calculate the offset of a given record, key or pointer
* into a btree block (xfs_btree_*_offset) or return a pointer to the given
* record, key or pointer (xfs_btree_*_addr). Note that all addressing
* inside the btree block is done using indices starting at one, not zero!
*/
/*
* Return size of the btree block header for this btree instance.
*/
static inline size_t xfs_btree_block_len(struct xfs_btree_cur *cur)
{
return (cur->bc_flags & XFS_BTREE_LONG_PTRS) ?
XFS_BTREE_LBLOCK_LEN :
XFS_BTREE_SBLOCK_LEN;
}
/*
* Return size of btree block pointers for this btree instance.
*/
static inline size_t xfs_btree_ptr_len(struct xfs_btree_cur *cur)
{
return (cur->bc_flags & XFS_BTREE_LONG_PTRS) ?
sizeof(__be64) : sizeof(__be32);
}
/*
* Calculate offset of the n-th record in a btree block.
*/
STATIC size_t
xfs_btree_rec_offset(
struct xfs_btree_cur *cur,
int n)
{
return xfs_btree_block_len(cur) +
(n - 1) * cur->bc_ops->rec_len;
}
/*
* Calculate offset of the n-th key in a btree block.
*/
STATIC size_t
xfs_btree_key_offset(
struct xfs_btree_cur *cur,
int n)
{
return xfs_btree_block_len(cur) +
(n - 1) * cur->bc_ops->key_len;
}
/*
* Calculate offset of the n-th block pointer in a btree block.
*/
STATIC size_t
xfs_btree_ptr_offset(
struct xfs_btree_cur *cur,
int n,
int level)
{
return xfs_btree_block_len(cur) +
cur->bc_ops->get_maxrecs(cur, level) * cur->bc_ops->key_len +
(n - 1) * xfs_btree_ptr_len(cur);
}
/*
* Return a pointer to the n-th record in the btree block.
*/
STATIC union xfs_btree_rec *
xfs_btree_rec_addr(
struct xfs_btree_cur *cur,
int n,
struct xfs_btree_block *block)
{
return (union xfs_btree_rec *)
((char *)block + xfs_btree_rec_offset(cur, n));
}
/*
* Return a pointer to the n-th key in the btree block.
*/
STATIC union xfs_btree_key *
xfs_btree_key_addr(
struct xfs_btree_cur *cur,
int n,
struct xfs_btree_block *block)
{
return (union xfs_btree_key *)
((char *)block + xfs_btree_key_offset(cur, n));
}
/*
* Return a pointer to the n-th block pointer in the btree block.
*/
STATIC union xfs_btree_ptr *
xfs_btree_ptr_addr(
struct xfs_btree_cur *cur,
int n,
struct xfs_btree_block *block)
{
int level = xfs_btree_get_level(block);
ASSERT(block->bb_level != 0);
return (union xfs_btree_ptr *)
((char *)block + xfs_btree_ptr_offset(cur, n, level));
}
/*
* Get a the root block which is stored in the inode.
*
* For now this btree implementation assumes the btree root is always
* stored in the if_broot field of an inode fork.
*/
STATIC struct xfs_btree_block *
xfs_btree_get_iroot(
struct xfs_btree_cur *cur)
{
struct xfs_ifork *ifp;
ifp = XFS_IFORK_PTR(cur->bc_private.b.ip, cur->bc_private.b.whichfork);
return (struct xfs_btree_block *)ifp->if_broot;
}
/*
* Retrieve the block pointer from the cursor at the given level.
* This may be an inode btree root or from a buffer.
*/
STATIC struct xfs_btree_block * /* generic btree block pointer */
xfs_btree_get_block(
struct xfs_btree_cur *cur, /* btree cursor */
int level, /* level in btree */
struct xfs_buf **bpp) /* buffer containing the block */
{
if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
(level == cur->bc_nlevels - 1)) {
*bpp = NULL;
return xfs_btree_get_iroot(cur);
}
*bpp = cur->bc_bufs[level];
return XFS_BUF_TO_BLOCK(*bpp);
}
/*
* Get a buffer for the block, return it with no data read.
* Long-form addressing.
*/
xfs_buf_t * /* buffer for fsbno */
xfs_btree_get_bufl(
xfs_mount_t *mp, /* file system mount point */
xfs_trans_t *tp, /* transaction pointer */
xfs_fsblock_t fsbno, /* file system block number */
uint lock) /* lock flags for get_buf */
{
xfs_buf_t *bp; /* buffer pointer (return value) */
xfs_daddr_t d; /* real disk block address */
ASSERT(fsbno != NULLFSBLOCK);
d = XFS_FSB_TO_DADDR(mp, fsbno);
bp = xfs_trans_get_buf(tp, mp->m_ddev_targp, d, mp->m_bsize, lock);
ASSERT(bp);
ASSERT(!XFS_BUF_GETERROR(bp));
return bp;
}
/*
* Get a buffer for the block, return it with no data read.
* Short-form addressing.
*/
xfs_buf_t * /* buffer for agno/agbno */
xfs_btree_get_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 get_buf */
{
xfs_buf_t *bp; /* buffer pointer (return value) */
xfs_daddr_t d; /* real disk block address */
ASSERT(agno != NULLAGNUMBER);
ASSERT(agbno != NULLAGBLOCK);
d = XFS_AGB_TO_DADDR(mp, agno, agbno);
bp = xfs_trans_get_buf(tp, mp->m_ddev_targp, d, mp->m_bsize, lock);
ASSERT(bp);
ASSERT(!XFS_BUF_GETERROR(bp));
return bp;
}
/*
* Check for the cursor referring to the last block at the given level.
*/
int /* 1=is last block, 0=not last block */
xfs_btree_islastblock(
xfs_btree_cur_t *cur, /* btree cursor */
int level) /* level to check */
{
struct xfs_btree_block *block; /* generic btree block pointer */
xfs_buf_t *bp; /* buffer containing block */
block = xfs_btree_get_block(cur, level, &bp);
xfs_btree_check_block(cur, block, level, bp);
if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
return be64_to_cpu(block->bb_u.l.bb_rightsib) == NULLDFSBNO;
else
return be32_to_cpu(block->bb_u.s.bb_rightsib) == NULLAGBLOCK;
}
/*
* Change the cursor to point to the first record at the given level.
* Other levels are unaffected.
*/
STATIC int /* success=1, failure=0 */
xfs_btree_firstrec(
xfs_btree_cur_t *cur, /* btree cursor */
int level) /* level to change */
{
struct xfs_btree_block *block; /* generic btree block pointer */
xfs_buf_t *bp; /* buffer containing block */
/*
* Get the block pointer for this level.
*/
block = xfs_btree_get_block(cur, level, &bp);
xfs_btree_check_block(cur, block, level, bp);
/*
* It's empty, there is no such record.
*/
if (!block->bb_numrecs)
return 0;
/*
* Set the ptr value to 1, that's the first record/key.
*/
cur->bc_ptrs[level] = 1;
return 1;
}
/*
* Change the cursor to point to the last record in the current block
* at the given level. Other levels are unaffected.
*/
STATIC int /* success=1, failure=0 */
xfs_btree_lastrec(
xfs_btree_cur_t *cur, /* btree cursor */
int level) /* level to change */
{
struct xfs_btree_block *block; /* generic btree block pointer */
xfs_buf_t *bp; /* buffer containing block */
/*
* Get the block pointer for this level.
*/
block = xfs_btree_get_block(cur, level, &bp);
xfs_btree_check_block(cur, block, level, bp);
/*
* It's empty, there is no such record.
*/
if (!block->bb_numrecs)
return 0;
/*
* Set the ptr value to numrecs, that's the last record/key.
*/
cur->bc_ptrs[level] = be16_to_cpu(block->bb_numrecs);
return 1;
}
/*
* Compute first and last byte offsets for the fields given.
* Interprets the offsets table, which contains struct field offsets.
*/
void
xfs_btree_offsets(
__int64_t fields, /* bitmask of fields */
const short *offsets, /* table of field offsets */
int nbits, /* number of bits to inspect */
int *first, /* output: first byte offset */
int *last) /* output: last byte offset */
{
int i; /* current bit number */
__int64_t imask; /* mask for current bit number */
ASSERT(fields != 0);
/*
* Find the lowest bit, so the first byte offset.
*/
for (i = 0, imask = 1LL; ; i++, imask <<= 1) {
if (imask & fields) {
*first = offsets[i];
break;
}
}
/*
* Find the highest bit, so the last byte offset.
*/
for (i = nbits - 1, imask = 1LL << i; ; i--, imask >>= 1) {
if (imask & fields) {
*last = offsets[i + 1] - 1;
break;
}
}
}
/*
* Get a buffer for the block, return it read in.
* Long-form addressing.
*/
int /* error */
xfs_btree_read_bufl(
xfs_mount_t *mp, /* file system mount point */
xfs_trans_t *tp, /* transaction pointer */
xfs_fsblock_t fsbno, /* file system block number */
uint lock, /* lock flags for read_buf */
xfs_buf_t **bpp, /* buffer for fsbno */
int refval) /* ref count value for buffer */
{
xfs_buf_t *bp; /* return value */
xfs_daddr_t d; /* real disk block address */
int error;
ASSERT(fsbno != NULLFSBLOCK);
d = XFS_FSB_TO_DADDR(mp, fsbno);
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)
XFS_BUF_SET_VTYPE_REF(bp, B_FS_MAP, refval);
*bpp = bp;
return 0;
}
/*
* Read-ahead the block, don't wait for it, don't return a buffer.
* Long-form addressing.
*/
/* ARGSUSED */
void
xfs_btree_reada_bufl(
xfs_mount_t *mp, /* file system mount point */
xfs_fsblock_t fsbno, /* file system block number */
xfs_extlen_t count) /* count of filesystem blocks */
{
xfs_daddr_t d;
ASSERT(fsbno != NULLFSBLOCK);
d = XFS_FSB_TO_DADDR(mp, fsbno);
xfs_buf_readahead(mp->m_ddev_targp, d, mp->m_bsize * count);
}
/*
* Read-ahead the block, don't wait for it, don't return a buffer.
* Short-form addressing.
*/
/* ARGSUSED */
void
xfs_btree_reada_bufs(
xfs_mount_t *mp, /* file system mount point */
xfs_agnumber_t agno, /* allocation group number */
xfs_agblock_t agbno, /* allocation group block number */
xfs_extlen_t count) /* count of filesystem blocks */
{
xfs_daddr_t d;
ASSERT(agno != NULLAGNUMBER);
ASSERT(agbno != NULLAGBLOCK);
d = XFS_AGB_TO_DADDR(mp, agno, agbno);
xfs_buf_readahead(mp->m_ddev_targp, d, mp->m_bsize * count);
}
STATIC int
xfs_btree_readahead_lblock(
struct xfs_btree_cur *cur,
int lr,
struct xfs_btree_block *block)
{
int rval = 0;
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);
rval++;
}
if ((lr & XFS_BTCUR_RIGHTRA) && right != NULLDFSBNO) {
xfs_btree_reada_bufl(cur->bc_mp, right, 1);
rval++;
}
return rval;
}
STATIC int
xfs_btree_readahead_sblock(
struct xfs_btree_cur *cur,
int lr,
struct xfs_btree_block *block)
{
int rval = 0;
xfs_agblock_t left = be32_to_cpu(block->bb_u.s.bb_leftsib);
xfs_agblock_t right = be32_to_cpu(block->bb_u.s.bb_rightsib);
if ((lr & XFS_BTCUR_LEFTRA) && left != NULLAGBLOCK) {
xfs_btree_reada_bufs(cur->bc_mp, cur->bc_private.a.agno,
left, 1);
rval++;
}
if ((lr & XFS_BTCUR_RIGHTRA) && right != NULLAGBLOCK) {
xfs_btree_reada_bufs(cur->bc_mp, cur->bc_private.a.agno,
right, 1);
rval++;
}
return rval;
}
/*
* Read-ahead btree blocks, at the given level.
* Bits in lr are set from XFS_BTCUR_{LEFT,RIGHT}RA.
*/
STATIC int
xfs_btree_readahead(
struct xfs_btree_cur *cur, /* btree cursor */
int lev, /* level in btree */
int lr) /* left/right bits */
{
struct xfs_btree_block *block;
/*
* No readahead needed if we are at the root level and the
* btree root is stored in the inode.
*/
if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
(lev == cur->bc_nlevels - 1))
return 0;
if ((cur->bc_ra[lev] | lr) == cur->bc_ra[lev])
return 0;
cur->bc_ra[lev] |= lr;
block = XFS_BUF_TO_BLOCK(cur->bc_bufs[lev]);
if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
return xfs_btree_readahead_lblock(cur, lr, block);
return xfs_btree_readahead_sblock(cur, lr, block);
}
/*
* Set the buffer for level "lev" in the cursor to bp, releasing
* any previous buffer.
*/
STATIC void
xfs_btree_setbuf(
xfs_btree_cur_t *cur, /* btree cursor */
int lev, /* level in btree */
xfs_buf_t *bp) /* new buffer to set */
{
struct xfs_btree_block *b; /* btree block */
if (cur->bc_bufs[lev])
xfs_trans_brelse(cur->bc_tp, cur->bc_bufs[lev]);
cur->bc_bufs[lev] = bp;
cur->bc_ra[lev] = 0;
b = XFS_BUF_TO_BLOCK(bp);
if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
if (be64_to_cpu(b->bb_u.l.bb_leftsib) == NULLDFSBNO)
cur->bc_ra[lev] |= XFS_BTCUR_LEFTRA;
if (be64_to_cpu(b->bb_u.l.bb_rightsib) == NULLDFSBNO)
cur->bc_ra[lev] |= XFS_BTCUR_RIGHTRA;
} else {
if (be32_to_cpu(b->bb_u.s.bb_leftsib) == NULLAGBLOCK)
cur->bc_ra[lev] |= XFS_BTCUR_LEFTRA;
if (be32_to_cpu(b->bb_u.s.bb_rightsib) == NULLAGBLOCK)
cur->bc_ra[lev] |= XFS_BTCUR_RIGHTRA;
}
}
STATIC int
xfs_btree_ptr_is_null(
struct xfs_btree_cur *cur,
union xfs_btree_ptr *ptr)
{
if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
return be64_to_cpu(ptr->l) == NULLDFSBNO;
else
return be32_to_cpu(ptr->s) == NULLAGBLOCK;
}
STATIC void
xfs_btree_set_ptr_null(
struct xfs_btree_cur *cur,
union xfs_btree_ptr *ptr)
{
if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
ptr->l = cpu_to_be64(NULLDFSBNO);
else
ptr->s = cpu_to_be32(NULLAGBLOCK);
}
/*
* Get/set/init sibling pointers
*/
STATIC void
xfs_btree_get_sibling(
struct xfs_btree_cur *cur,
struct xfs_btree_block *block,
union xfs_btree_ptr *ptr,
int lr)
{
ASSERT(lr == XFS_BB_LEFTSIB || lr == XFS_BB_RIGHTSIB);
if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
if (lr == XFS_BB_RIGHTSIB)
ptr->l = block->bb_u.l.bb_rightsib;
else
ptr->l = block->bb_u.l.bb_leftsib;
} else {
if (lr == XFS_BB_RIGHTSIB)
ptr->s = block->bb_u.s.bb_rightsib;
else
ptr->s = block->bb_u.s.bb_leftsib;
}
}
STATIC void
xfs_btree_set_sibling(
struct xfs_btree_cur *cur,
struct xfs_btree_block *block,
union xfs_btree_ptr *ptr,
int lr)
{
ASSERT(lr == XFS_BB_LEFTSIB || lr == XFS_BB_RIGHTSIB);
if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
if (lr == XFS_BB_RIGHTSIB)
block->bb_u.l.bb_rightsib = ptr->l;
else
block->bb_u.l.bb_leftsib = ptr->l;
} else {
if (lr == XFS_BB_RIGHTSIB)
block->bb_u.s.bb_rightsib = ptr->s;
else
block->bb_u.s.bb_leftsib = ptr->s;
}
}
STATIC void
xfs_btree_init_block(
struct xfs_btree_cur *cur,
int level,
int numrecs,
struct xfs_btree_block *new) /* new block */
{
new->bb_magic = cpu_to_be32(xfs_magics[cur->bc_btnum]);
new->bb_level = cpu_to_be16(level);
new->bb_numrecs = cpu_to_be16(numrecs);
if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
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);
}
}
/*
* Return true if ptr is the last record in the btree and
* we need to track updateѕ to this record. The decision
* will be further refined in the update_lastrec method.
*/
STATIC int
xfs_btree_is_lastrec(
struct xfs_btree_cur *cur,
struct xfs_btree_block *block,
int level)
{
union xfs_btree_ptr ptr;
if (level > 0)
return 0;
if (!(cur->bc_flags & XFS_BTREE_LASTREC_UPDATE))
return 0;
xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
if (!xfs_btree_ptr_is_null(cur, &ptr))
return 0;
return 1;
}
STATIC void
xfs_btree_buf_to_ptr(
struct xfs_btree_cur *cur,
struct xfs_buf *bp,
union xfs_btree_ptr *ptr)
{
if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
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,
XFS_BUF_ADDR(bp)));
}
}
STATIC xfs_daddr_t
xfs_btree_ptr_to_daddr(
struct xfs_btree_cur *cur,
union xfs_btree_ptr *ptr)
{
if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
ASSERT(be64_to_cpu(ptr->l) != NULLDFSBNO);
return XFS_FSB_TO_DADDR(cur->bc_mp, be64_to_cpu(ptr->l));
} else {
ASSERT(cur->bc_private.a.agno != NULLAGNUMBER);
ASSERT(be32_to_cpu(ptr->s) != NULLAGBLOCK);
return XFS_AGB_TO_DADDR(cur->bc_mp, cur->bc_private.a.agno,
be32_to_cpu(ptr->s));
}
}
STATIC void
xfs_btree_set_refs(
struct xfs_btree_cur *cur,
struct xfs_buf *bp)
{
switch (cur->bc_btnum) {
case XFS_BTNUM_BNO:
case XFS_BTNUM_CNT:
XFS_BUF_SET_VTYPE_REF(bp, B_FS_MAP, XFS_ALLOC_BTREE_REF);
break;
case XFS_BTNUM_INO:
XFS_BUF_SET_VTYPE_REF(bp, B_FS_INOMAP, XFS_INO_BTREE_REF);
break;
case XFS_BTNUM_BMAP:
XFS_BUF_SET_VTYPE_REF(bp, B_FS_MAP, XFS_BMAP_BTREE_REF);
break;
default:
ASSERT(0);
}
}
STATIC int
xfs_btree_get_buf_block(
struct xfs_btree_cur *cur,
union xfs_btree_ptr *ptr,
int flags,
struct xfs_btree_block **block,
struct xfs_buf **bpp)
{
struct xfs_mount *mp = cur->bc_mp;
xfs_daddr_t d;
/* need to sort out how callers deal with failures first */
ASSERT(!(flags & XBF_TRYLOCK));
d = xfs_btree_ptr_to_daddr(cur, ptr);
*bpp = xfs_trans_get_buf(cur->bc_tp, mp->m_ddev_targp, d,
mp->m_bsize, flags);
ASSERT(*bpp);
ASSERT(!XFS_BUF_GETERROR(*bpp));
*block = XFS_BUF_TO_BLOCK(*bpp);
return 0;
}
/*
* Read in the buffer at the given ptr and return the buffer and
* the block pointer within the buffer.
*/
STATIC int
xfs_btree_read_buf_block(
struct xfs_btree_cur *cur,
union xfs_btree_ptr *ptr,
int level,
int flags,
struct xfs_btree_block **block,
struct xfs_buf **bpp)
{
struct xfs_mount *mp = cur->bc_mp;
xfs_daddr_t d;
int error;
/* need to sort out how callers deal with failures first */
ASSERT(!(flags & XBF_TRYLOCK));
d = xfs_btree_ptr_to_daddr(cur, ptr);
error = xfs_trans_read_buf(mp, cur->bc_tp, mp->m_ddev_targp, d,
mp->m_bsize, flags, bpp);
if (error)
return error;
ASSERT(*bpp != NULL);
ASSERT(!XFS_BUF_GETERROR(*bpp));
xfs_btree_set_refs(cur, *bpp);
*block = XFS_BUF_TO_BLOCK(*bpp);
error = xfs_btree_check_block(cur, *block, level, *bpp);
if (error)
xfs_trans_brelse(cur->bc_tp, *bpp);
return error;
}
/*
* Copy keys from one btree block to another.
*/
STATIC void
xfs_btree_copy_keys(
struct xfs_btree_cur *cur,
union xfs_btree_key *dst_key,
union xfs_btree_key *src_key,
int numkeys)
{
ASSERT(numkeys >= 0);
memcpy(dst_key, src_key, numkeys * cur->bc_ops->key_len);
}
/*
* Copy records from one btree block to another.
*/
STATIC void
xfs_btree_copy_recs(
struct xfs_btree_cur *cur,
union xfs_btree_rec *dst_rec,
union xfs_btree_rec *src_rec,
int numrecs)
{
ASSERT(numrecs >= 0);
memcpy(dst_rec, src_rec, numrecs * cur->bc_ops->rec_len);
}
/*
* Copy block pointers from one btree block to another.
*/
STATIC void
xfs_btree_copy_ptrs(
struct xfs_btree_cur *cur,
union xfs_btree_ptr *dst_ptr,
union xfs_btree_ptr *src_ptr,
int numptrs)
{
ASSERT(numptrs >= 0);
memcpy(dst_ptr, src_ptr, numptrs * xfs_btree_ptr_len(cur));
}
/*
* Shift keys one index left/right inside a single btree block.
*/
STATIC void
xfs_btree_shift_keys(
struct xfs_btree_cur *cur,
union xfs_btree_key *key,
int dir,
int numkeys)
{
char *dst_key;
ASSERT(numkeys >= 0);
ASSERT(dir == 1 || dir == -1);
dst_key = (char *)key + (dir * cur->bc_ops->key_len);
memmove(dst_key, key, numkeys * cur->bc_ops->key_len);
}
/*
* Shift records one index left/right inside a single btree block.
*/
STATIC void
xfs_btree_shift_recs(
struct xfs_btree_cur *cur,
union xfs_btree_rec *rec,
int dir,
int numrecs)
{
char *dst_rec;
ASSERT(numrecs >= 0);
ASSERT(dir == 1 || dir == -1);
dst_rec = (char *)rec + (dir * cur->bc_ops->rec_len);
memmove(dst_rec, rec, numrecs * cur->bc_ops->rec_len);
}
/*
* Shift block pointers one index left/right inside a single btree block.
*/
STATIC void
xfs_btree_shift_ptrs(
struct xfs_btree_cur *cur,
union xfs_btree_ptr *ptr,
int dir,
int numptrs)
{
char *dst_ptr;
ASSERT(numptrs >= 0);
ASSERT(dir == 1 || dir == -1);
dst_ptr = (char *)ptr + (dir * xfs_btree_ptr_len(cur));
memmove(dst_ptr, ptr, numptrs * xfs_btree_ptr_len(cur));
}
/*
* Log key values from the btree block.
*/
STATIC void
xfs_btree_log_keys(
struct xfs_btree_cur *cur,
struct xfs_buf *bp,
int first,
int last)
{
XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
XFS_BTREE_TRACE_ARGBII(cur, bp, first, last);
if (bp) {
xfs_trans_log_buf(cur->bc_tp, bp,
xfs_btree_key_offset(cur, first),
xfs_btree_key_offset(cur, last + 1) - 1);
} else {
xfs_trans_log_inode(cur->bc_tp, cur->bc_private.b.ip,
xfs_ilog_fbroot(cur->bc_private.b.whichfork));
}
XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
}
/*
* Log record values from the btree block.
*/
void
xfs_btree_log_recs(
struct xfs_btree_cur *cur,
struct xfs_buf *bp,
int first,
int last)
{
XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
XFS_BTREE_TRACE_ARGBII(cur, bp, first, last);
xfs_trans_log_buf(cur->bc_tp, bp,
xfs_btree_rec_offset(cur, first),
xfs_btree_rec_offset(cur, last + 1) - 1);
XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
}
/*
* Log block pointer fields from a btree block (nonleaf).
*/
STATIC void
xfs_btree_log_ptrs(
struct xfs_btree_cur *cur, /* btree cursor */
struct xfs_buf *bp, /* buffer containing btree block */
int first, /* index of first pointer to log */
int last) /* index of last pointer to log */
{
XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
XFS_BTREE_TRACE_ARGBII(cur, bp, first, last);
if (bp) {
struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
int level = xfs_btree_get_level(block);
xfs_trans_log_buf(cur->bc_tp, bp,
xfs_btree_ptr_offset(cur, first, level),
xfs_btree_ptr_offset(cur, last + 1, level) - 1);
} else {
xfs_trans_log_inode(cur->bc_tp, cur->bc_private.b.ip,
xfs_ilog_fbroot(cur->bc_private.b.whichfork));
}
XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
}
/*
* Log fields from a btree block header.
*/
void
xfs_btree_log_block(
struct xfs_btree_cur *cur, /* btree cursor */
struct xfs_buf *bp, /* buffer containing btree block */
int fields) /* mask of fields: XFS_BB_... */
{
int first; /* first byte offset logged */
int last; /* last byte offset logged */
static const short soffsets[] = { /* table of offsets (short) */
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_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);
XFS_BTREE_TRACE_ARGBI(cur, bp, fields);
if (bp) {
xfs_btree_offsets(fields,
(cur->bc_flags & XFS_BTREE_LONG_PTRS) ?
loffsets : soffsets,
XFS_BB_NUM_BITS, &first, &last);
xfs_trans_log_buf(cur->bc_tp, bp, first, last);
} else {
xfs_trans_log_inode(cur->bc_tp, cur->bc_private.b.ip,
xfs_ilog_fbroot(cur->bc_private.b.whichfork));
}
XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
}
/*
* Increment cursor by one record at the level.
* For nonzero levels the leaf-ward information is untouched.
*/
int /* error */
xfs_btree_increment(
struct xfs_btree_cur *cur,
int level,
int *stat) /* success/failure */
{
struct xfs_btree_block *block;
union xfs_btree_ptr ptr;
struct xfs_buf *bp;
int error; /* error return value */
int lev;
XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
XFS_BTREE_TRACE_ARGI(cur, level);
ASSERT(level < cur->bc_nlevels);
/* Read-ahead to the right at this level. */
xfs_btree_readahead(cur, level, XFS_BTCUR_RIGHTRA);
/* Get a pointer to the btree block. */
block = xfs_btree_get_block(cur, level, &bp);
#ifdef DEBUG
error = xfs_btree_check_block(cur, block, level, bp);
if (error)
goto error0;
#endif
/* We're done if we remain in the block after the increment. */
if (++cur->bc_ptrs[level] <= xfs_btree_get_numrecs(block))
goto out1;
/* Fail if we just went off the right edge of the tree. */
xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
if (xfs_btree_ptr_is_null(cur, &ptr))
goto out0;
XFS_BTREE_STATS_INC(cur, increment);
/*
* March up the tree incrementing pointers.
* Stop when we don't go off the right edge of a block.
*/
for (lev = level + 1; lev < cur->bc_nlevels; lev++) {
block = xfs_btree_get_block(cur, lev, &bp);
#ifdef DEBUG
error = xfs_btree_check_block(cur, block, lev, bp);
if (error)
goto error0;
#endif
if (++cur->bc_ptrs[lev] <= xfs_btree_get_numrecs(block))
break;
/* Read-ahead the right block for the next loop. */
xfs_btree_readahead(cur, lev, XFS_BTCUR_RIGHTRA);
}
/*
* If we went off the root then we are either seriously
* confused or have the tree root in an inode.
*/
if (lev == cur->bc_nlevels) {
if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE)
goto out0;
ASSERT(0);
error = EFSCORRUPTED;
goto error0;
}
ASSERT(lev < cur->bc_nlevels);
/*
* Now walk back down the tree, fixing up the cursor's buffer
* pointers and key numbers.
*/
for (block = xfs_btree_get_block(cur, lev, &bp); lev > level; ) {
union xfs_btree_ptr *ptrp;
ptrp = xfs_btree_ptr_addr(cur, cur->bc_ptrs[lev], block);
error = xfs_btree_read_buf_block(cur, ptrp, --lev,
0, &block, &bp);
if (error)
goto error0;
xfs_btree_setbuf(cur, lev, bp);
cur->bc_ptrs[lev] = 1;
}
out1:
XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
*stat = 1;
return 0;
out0:
XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
*stat = 0;
return 0;
error0:
XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
return error;
}
/*
* Decrement cursor by one record at the level.
* For nonzero levels the leaf-ward information is untouched.
*/
int /* error */
xfs_btree_decrement(
struct xfs_btree_cur *cur,
int level,
int *stat) /* success/failure */
{
struct xfs_btree_block *block;
xfs_buf_t *bp;
int error; /* error return value */
int lev;
union xfs_btree_ptr ptr;
XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
XFS_BTREE_TRACE_ARGI(cur, level);
ASSERT(level < cur->bc_nlevels);
/* Read-ahead to the left at this level. */
xfs_btree_readahead(cur, level, XFS_BTCUR_LEFTRA);
/* We're done if we remain in the block after the decrement. */
if (--cur->bc_ptrs[level] > 0)
goto out1;
/* Get a pointer to the btree block. */
block = xfs_btree_get_block(cur, level, &bp);
#ifdef DEBUG
error = xfs_btree_check_block(cur, block, level, bp);
if (error)
goto error0;
#endif
/* Fail if we just went off the left edge of the tree. */
xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_LEFTSIB);
if (xfs_btree_ptr_is_null(cur, &ptr))
goto out0;
XFS_BTREE_STATS_INC(cur, decrement);
/*
* March up the tree decrementing pointers.
* Stop when we don't go off the left edge of a block.
*/
for (lev = level + 1; lev < cur->bc_nlevels; lev++) {
if (--cur->bc_ptrs[lev] > 0)
break;
/* Read-ahead the left block for the next loop. */
xfs_btree_readahead(cur, lev, XFS_BTCUR_LEFTRA);
}
/*
* If we went off the root then we are seriously confused.
* or the root of the tree is in an inode.
*/
if (lev == cur->bc_nlevels) {
if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE)
goto out0;
ASSERT(0);
error = EFSCORRUPTED;
goto error0;
}
ASSERT(lev < cur->bc_nlevels);
/*
* Now walk back down the tree, fixing up the cursor's buffer
* pointers and key numbers.
*/
for (block = xfs_btree_get_block(cur, lev, &bp); lev > level; ) {
union xfs_btree_ptr *ptrp;
ptrp = xfs_btree_ptr_addr(cur, cur->bc_ptrs[lev], block);
error = xfs_btree_read_buf_block(cur, ptrp, --lev,
0, &block, &bp);
if (error)
goto error0;
xfs_btree_setbuf(cur, lev, bp);
cur->bc_ptrs[lev] = xfs_btree_get_numrecs(block);
}
out1:
XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
*stat = 1;
return 0;
out0:
XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
*stat = 0;
return 0;
error0:
XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
return error;
}
STATIC int
xfs_btree_lookup_get_block(
struct xfs_btree_cur *cur, /* btree cursor */
int level, /* level in the btree */
union xfs_btree_ptr *pp, /* ptr to btree block */
struct xfs_btree_block **blkp) /* return btree block */
{
struct xfs_buf *bp; /* buffer pointer for btree block */
int error = 0;
/* special case the root block if in an inode */
if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
(level == cur->bc_nlevels - 1)) {
*blkp = xfs_btree_get_iroot(cur);
return 0;
}
/*
* If the old buffer at this level for the disk address we are
* looking for re-use it.
*
* Otherwise throw it away and get a new one.
*/
bp = cur->bc_bufs[level];
if (bp && XFS_BUF_ADDR(bp) == xfs_btree_ptr_to_daddr(cur, pp)) {
*blkp = XFS_BUF_TO_BLOCK(bp);
return 0;
}
error = xfs_btree_read_buf_block(cur, pp, level, 0, blkp, &bp);
if (error)
return error;
xfs_btree_setbuf(cur, level, bp);
return 0;
}
/*
* Get current search key. For level 0 we don't actually have a key
* structure so we make one up from the record. For all other levels
* we just return the right key.
*/
STATIC union xfs_btree_key *
xfs_lookup_get_search_key(
struct xfs_btree_cur *cur,
int level,
int keyno,
struct xfs_btree_block *block,
union xfs_btree_key *kp)
{
if (level == 0) {
cur->bc_ops->init_key_from_rec(kp,
xfs_btree_rec_addr(cur, keyno, block));
return kp;
}
return xfs_btree_key_addr(cur, keyno, block);
}
/*
* Lookup the record. The cursor is made to point to it, based on dir.
* Return 0 if can't find any such record, 1 for success.
*/
int /* error */
xfs_btree_lookup(
struct xfs_btree_cur *cur, /* btree cursor */
xfs_lookup_t dir, /* <=, ==, or >= */
int *stat) /* success/failure */
{
struct xfs_btree_block *block; /* current btree block */
__int64_t diff; /* difference for the current key */
int error; /* error return value */
int keyno; /* current key number */
int level; /* level in the btree */
union xfs_btree_ptr *pp; /* ptr to btree block */
union xfs_btree_ptr ptr; /* ptr to btree block */
XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
XFS_BTREE_TRACE_ARGI(cur, dir);
XFS_BTREE_STATS_INC(cur, lookup);
block = NULL;
keyno = 0;
/* initialise start pointer from cursor */
cur->bc_ops->init_ptr_from_cur(cur, &ptr);
pp = &ptr;
/*
* Iterate over each level in the btree, starting at the root.
* For each level above the leaves, find the key we need, based
* on the lookup record, then follow the corresponding block
* pointer down to the next level.
*/
for (level = cur->bc_nlevels - 1, diff = 1; level >= 0; level--) {
/* Get the block we need to do the lookup on. */
error = xfs_btree_lookup_get_block(cur, level, pp, &block);
if (error)
goto error0;
if (diff == 0) {
/*
* If we already had a key match at a higher level, we
* know we need to use the first entry in this block.
*/
keyno = 1;
} else {
/* Otherwise search this block. Do a binary search. */
int high; /* high entry number */
int low; /* low entry number */
/* Set low and high entry numbers, 1-based. */
low = 1;
high = xfs_btree_get_numrecs(block);
if (!high) {
/* Block is empty, must be an empty leaf. */
ASSERT(level == 0 && cur->bc_nlevels == 1);
cur->bc_ptrs[0] = dir != XFS_LOOKUP_LE;
XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
*stat = 0;
return 0;
}
/* Binary search the block. */
while (low <= high) {
union xfs_btree_key key;
union xfs_btree_key *kp;
XFS_BTREE_STATS_INC(cur, compare);
/* keyno is average of low and high. */
keyno = (low + high) >> 1;
/* Get current search key */
kp = xfs_lookup_get_search_key(cur, level,
keyno, block, &key);
/*
* Compute difference to get next direction:
* - less than, move right
* - greater than, move left
* - equal, we're done
*/
diff = cur->bc_ops->key_diff(cur, kp);
if (diff < 0)
low = keyno + 1;
else if (diff > 0)
high = keyno - 1;
else
break;
}
}
/*
* If there are more levels, set up for the next level
* by getting the block number and filling in the cursor.
*/
if (level > 0) {
/*
* If we moved left, need the previous key number,
* unless there isn't one.
*/
if (diff > 0 && --keyno < 1)
keyno = 1;
pp = xfs_btree_ptr_addr(cur, keyno, block);
#ifdef DEBUG
error = xfs_btree_check_ptr(cur, pp, 0, level);
if (error)
goto error0;
#endif
cur->bc_ptrs[level] = keyno;
}
}
/* Done with the search. See if we need to adjust the results. */
if (dir != XFS_LOOKUP_LE && diff < 0) {
keyno++;
/*
* If ge search and we went off the end of the block, but it's
* not the last block, we're in the wrong block.
*/
xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
if (dir == XFS_LOOKUP_GE &&
keyno > xfs_btree_get_numrecs(block) &&
!xfs_btree_ptr_is_null(cur, &ptr)) {
int i;
cur->bc_ptrs[0] = keyno;
error = xfs_btree_increment(cur, 0, &i);
if (error)
goto error0;
XFS_WANT_CORRUPTED_RETURN(i == 1);
XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
*stat = 1;
return 0;
}
} else if (dir == XFS_LOOKUP_LE && diff > 0)
keyno--;
cur->bc_ptrs[0] = keyno;
/* Return if we succeeded or not. */
if (keyno == 0 || keyno > xfs_btree_get_numrecs(block))
*stat = 0;
else if (dir != XFS_LOOKUP_EQ || diff == 0)
*stat = 1;
else
*stat = 0;
XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
return 0;
error0:
XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
return error;
}
/*
* Update keys at all levels from here to the root along the cursor's path.
*/
STATIC int
xfs_btree_updkey(
struct xfs_btree_cur *cur,
union xfs_btree_key *keyp,
int level)
{
struct xfs_btree_block *block;
struct xfs_buf *bp;
union xfs_btree_key *kp;
int ptr;
XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
XFS_BTREE_TRACE_ARGIK(cur, level, keyp);
ASSERT(!(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) || level >= 1);
/*
* Go up the tree from this level toward the root.
* At each level, update the key value to the value input.
* Stop when we reach a level where the cursor isn't pointing
* at the first entry in the block.
*/
for (ptr = 1; ptr == 1 && level < cur->bc_nlevels; level++) {
#ifdef DEBUG
int error;
#endif
block = xfs_btree_get_block(cur, level, &bp);
#ifdef DEBUG
error = xfs_btree_check_block(cur, block, level, bp);
if (error) {
XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
return error;
}
#endif
ptr = cur->bc_ptrs[level];
kp = xfs_btree_key_addr(cur, ptr, block);
xfs_btree_copy_keys(cur, kp, keyp, 1);
xfs_btree_log_keys(cur, bp, ptr, ptr);
}
XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
return 0;
}
/*
* Update the record referred to by cur to the value in the
* given record. This either works (return 0) or gets an
* EFSCORRUPTED error.
*/
int
xfs_btree_update(
struct xfs_btree_cur *cur,
union xfs_btree_rec *rec)
{
struct xfs_btree_block *block;
struct xfs_buf *bp;
int error;
int ptr;
union xfs_btree_rec *rp;
XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
XFS_BTREE_TRACE_ARGR(cur, rec);
/* Pick up the current block. */
block = xfs_btree_get_block(cur, 0, &bp);
#ifdef DEBUG
error = xfs_btree_check_block(cur, block, 0, bp);
if (error)
goto error0;
#endif
/* Get the address of the rec to be updated. */
ptr = cur->bc_ptrs[0];
rp = xfs_btree_rec_addr(cur, ptr, block);
/* Fill in the new contents and log them. */
xfs_btree_copy_recs(cur, rp, rec, 1);
xfs_btree_log_recs(cur, bp, ptr, ptr);
/*
* 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, 0)) {
cur->bc_ops->update_lastrec(cur, block, rec,
ptr, LASTREC_UPDATE);
}
/* Updating first rec in leaf. Pass new key value up to our parent. */
if (ptr == 1) {
union xfs_btree_key key;
cur->bc_ops->init_key_from_rec(&key, rec);
error = xfs_btree_updkey(cur, &key, 1);
if (error)
goto error0;
}
XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
return 0;
error0:
XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
return error;
}
/*
* Move 1 record left from cur/level if possible.
* Update cur to reflect the new path.
*/
STATIC int /* error */
xfs_btree_lshift(
struct xfs_btree_cur *cur,
int level,
int *stat) /* success/failure */
{
union xfs_btree_key key; /* btree key */
struct xfs_buf *lbp; /* left buffer pointer */
struct xfs_btree_block *left; /* left btree block */
int lrecs; /* left record count */
struct xfs_buf *rbp; /* right buffer pointer */
struct xfs_btree_block *right; /* right btree block */
int rrecs; /* right record count */
union xfs_btree_ptr lptr; /* left btree pointer */
union xfs_btree_key *rkp = NULL; /* right btree key */
union xfs_btree_ptr *rpp = NULL; /* right address pointer */
union xfs_btree_rec *rrp = NULL; /* right record pointer */
int error; /* error return value */
XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
XFS_BTREE_TRACE_ARGI(cur, level);
if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
level == cur->bc_nlevels - 1)
goto out0;
/* Set up variables for this block as "right". */
right = xfs_btree_get_block(cur, level, &rbp);
#ifdef DEBUG
error = xfs_btree_check_block(cur, right, level, rbp);
if (error)
goto error0;
#endif
/* If we've got no left sibling then we can't shift an entry left. */
xfs_btree_get_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
if (xfs_btree_ptr_is_null(cur, &lptr))
goto out0;
/*
* If the cursor entry is the one that would be moved, don't
* do it... it's too complicated.
*/
if (cur->bc_ptrs[level] <= 1)
goto out0;
/* Set up the left neighbor as "left". */
error = xfs_btree_read_buf_block(cur, &lptr, level, 0, &left, &lbp);
if (error)
goto error0;
/* If it's full, it can't take another entry. */
lrecs = xfs_btree_get_numrecs(left);
if (lrecs == cur->bc_ops->get_maxrecs(cur, level))
goto out0;
rrecs = xfs_btree_get_numrecs(right);
/*
* We add one entry to the left side and remove one for the right side.
* Account for it here, the changes will be updated on disk and logged
* later.
*/
lrecs++;
rrecs--;
XFS_BTREE_STATS_INC(cur, lshift);
XFS_BTREE_STATS_ADD(cur, moves, 1);
/*
* If non-leaf, copy a key and a ptr to the left block.
* Log the changes to the left block.
*/
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 */
lkp = xfs_btree_key_addr(cur, lrecs, left);
rkp = xfs_btree_key_addr(cur, 1, right);
lpp = xfs_btree_ptr_addr(cur, lrecs, left);
rpp = xfs_btree_ptr_addr(cur, 1, right);
#ifdef DEBUG
error = xfs_btree_check_ptr(cur, rpp, 0, level);
if (error)
goto error0;
#endif
xfs_btree_copy_keys(cur, lkp, rkp, 1);
xfs_btree_copy_ptrs(cur, lpp, rpp, 1);
xfs_btree_log_keys(cur, lbp, lrecs, lrecs);
xfs_btree_log_ptrs(cur, lbp, lrecs, lrecs);
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 */
lrp = xfs_btree_rec_addr(cur, lrecs, left);
rrp = xfs_btree_rec_addr(cur, 1, right);
xfs_btree_copy_recs(cur, lrp, rrp, 1);
xfs_btree_log_recs(cur, lbp, lrecs, lrecs);
ASSERT(cur->bc_ops->recs_inorder(cur,
xfs_btree_rec_addr(cur, lrecs - 1, left), lrp));
}
xfs_btree_set_numrecs(left, lrecs);
xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS);
xfs_btree_set_numrecs(right, rrecs);
xfs_btree_log_block(cur, rbp, XFS_BB_NUMRECS);
/*
* Slide the contents of right down one entry.
*/
XFS_BTREE_STATS_ADD(cur, moves, rrecs - 1);
if (level > 0) {
/* It's a nonleaf. operate on keys and ptrs */
#ifdef DEBUG
int i; /* loop index */
for (i = 0; i < rrecs; i++) {
error = xfs_btree_check_ptr(cur, rpp, i + 1, level);
if (error)
goto error0;
}
#endif
xfs_btree_shift_keys(cur,
xfs_btree_key_addr(cur, 2, right),
-1, rrecs);
xfs_btree_shift_ptrs(cur,
xfs_btree_ptr_addr(cur, 2, right),
-1, rrecs);
xfs_btree_log_keys(cur, rbp, 1, rrecs);
xfs_btree_log_ptrs(cur, rbp, 1, rrecs);
} else {
/* It's a leaf. operate on records */
xfs_btree_shift_recs(cur,
xfs_btree_rec_addr(cur, 2, right),
-1, rrecs);
xfs_btree_log_recs(cur, rbp, 1, rrecs);
/*
* If it's the first record in the block, we'll need a key
* structure to pass up to the next level (updkey).
*/
cur->bc_ops->init_key_from_rec(&key,
xfs_btree_rec_addr(cur, 1, right));
rkp = &key;
}
/* Update the parent key values of right. */
error = xfs_btree_updkey(cur, rkp, level + 1);
if (error)
goto error0;
/* Slide the cursor value left one. */
cur->bc_ptrs[level]--;
XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
*stat = 1;
return 0;
out0:
XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
*stat = 0;
return 0;
error0:
XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
return error;
}
/*
* Move 1 record right from cur/level if possible.
* Update cur to reflect the new path.
*/
STATIC int /* error */
xfs_btree_rshift(
struct xfs_btree_cur *cur,
int level,
int *stat) /* success/failure */
{
union xfs_btree_key key; /* btree key */
struct xfs_buf *lbp; /* left buffer pointer */
struct xfs_btree_block *left; /* left btree block */
struct xfs_buf *rbp; /* right buffer pointer */
struct xfs_btree_block *right; /* right btree block */
struct xfs_btree_cur *tcur; /* temporary btree cursor */
union xfs_btree_ptr rptr; /* right block pointer */
union xfs_btree_key *rkp; /* right btree key */
int rrecs; /* right record count */
int lrecs; /* left record count */
int error; /* error return value */
int i; /* loop counter */
XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
XFS_BTREE_TRACE_ARGI(cur, level);
if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
(level == cur->bc_nlevels - 1))
goto out0;
/* Set up variables for this block as "left". */
left = xfs_btree_get_block(cur, level, &lbp);
#ifdef DEBUG
error = xfs_btree_check_block(cur, left, level, lbp);
if (error)
goto error0;
#endif
/* If we've got no right sibling then we can't shift an entry right. */
xfs_btree_get_sibling(cur, left, &rptr, XFS_BB_RIGHTSIB);
if (xfs_btree_ptr_is_null(cur, &rptr))
goto out0;
/*
* If the cursor entry is the one that would be moved, don't
* do it... it's too complicated.
*/
lrecs = xfs_btree_get_numrecs(left);
if (cur->bc_ptrs[level] >= lrecs)
goto out0;
/* Set up the right neighbor as "right". */
error = xfs_btree_read_buf_block(cur, &rptr, level, 0, &right, &rbp);
if (error)
goto error0;
/* If it's full, it can't take another entry. */
rrecs = xfs_btree_get_numrecs(right);
if (rrecs == cur->bc_ops->get_maxrecs(cur, level))
goto out0;
XFS_BTREE_STATS_INC(cur, rshift);
XFS_BTREE_STATS_ADD(cur, moves, rrecs);
/*
* Make a hole at the start of the right neighbor block, then
* copy the last left block entry to the hole.
*/
if (level > 0) {
/* It's a nonleaf. make a hole in the keys and ptrs */
union xfs_btree_key *lkp;
union xfs_btree_ptr *lpp;
union xfs_btree_ptr *rpp;
lkp = xfs_btree_key_addr(cur, lrecs, left);
lpp = xfs_btree_ptr_addr(cur, lrecs, left);
rkp = xfs_btree_key_addr(cur, 1, right);
rpp = xfs_btree_ptr_addr(cur, 1, right);
#ifdef DEBUG
for (i = rrecs - 1; i >= 0; i--) {
error = xfs_btree_check_ptr(cur, rpp, i, level);
if (error)
goto error0;
}
#endif
xfs_btree_shift_keys(cur, rkp, 1, rrecs);
xfs_btree_shift_ptrs(cur, rpp, 1, rrecs);
#ifdef DEBUG
error = xfs_btree_check_ptr(cur, lpp, 0, level);
if (error)
goto error0;
#endif
/* Now put the new data in, and log it. */
xfs_btree_copy_keys(cur, rkp, lkp, 1);
xfs_btree_copy_ptrs(cur, rpp, lpp, 1);
xfs_btree_log_keys(cur, rbp, 1, rrecs + 1);
xfs_btree_log_ptrs(cur, rbp, 1, rrecs + 1);
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;
union xfs_btree_rec *rrp;
lrp = xfs_btree_rec_addr(cur, lrecs, left);
rrp = xfs_btree_rec_addr(cur, 1, right);
xfs_btree_shift_recs(cur, rrp, 1, rrecs);
/* Now put the new data in, and log it. */
xfs_btree_copy_recs(cur, rrp, lrp, 1);
xfs_btree_log_recs(cur, rbp, 1, rrecs + 1);
cur->bc_ops->init_key_from_rec(&key, rrp);
rkp = &key;
ASSERT(cur->bc_ops->recs_inorder(cur, rrp,
xfs_btree_rec_addr(cur, 2, right)));
}
/*
* Decrement and log left's numrecs, bump and log right's numrecs.
*/
xfs_btree_set_numrecs(left, --lrecs);
xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS);
xfs_btree_set_numrecs(right, ++rrecs);
xfs_btree_log_block(cur, rbp, XFS_BB_NUMRECS);
/*
* Using a temporary cursor, update the parent key values of the
* block on the right.
*/
error = xfs_btree_dup_cursor(cur, &tcur);
if (error)
goto error0;
i = xfs_btree_lastrec(tcur, level);
XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
error = xfs_btree_increment(tcur, level, &i);
if (error)
goto error1;
error = xfs_btree_updkey(tcur, rkp, level + 1);
if (error)
goto error1;
xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
*stat = 1;
return 0;
out0:
XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
*stat = 0;
return 0;
error0:
XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
return error;
error1:
XFS_BTREE_TRACE_CURSOR(tcur, XBT_ERROR);
xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR);
return error;
}
/*
* Split cur/level block in half.
* Return new block number and the key to its first
* record (to be inserted into parent).
*/
STATIC int /* error */
xfs_btree_split(
struct xfs_btree_cur *cur,
int level,
union xfs_btree_ptr *ptrp,
union xfs_btree_key *key,
struct xfs_btree_cur **curp,
int *stat) /* success/failure */
{
union xfs_btree_ptr lptr; /* left sibling block ptr */
struct xfs_buf *lbp; /* left buffer pointer */
struct xfs_btree_block *left; /* left btree block */
union xfs_btree_ptr rptr; /* right sibling block ptr */
struct xfs_buf *rbp; /* right buffer pointer */
struct xfs_btree_block *right; /* right btree block */
union xfs_btree_ptr rrptr; /* right-right sibling ptr */
struct xfs_buf *rrbp; /* right-right buffer pointer */
struct xfs_btree_block *rrblock; /* right-right btree block */
int lrecs;
int rrecs;
int src_index;
int error; /* error return value */
#ifdef DEBUG
int i;
#endif
XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
XFS_BTREE_TRACE_ARGIPK(cur, level, *ptrp, key);
XFS_BTREE_STATS_INC(cur, split);
/* Set up left block (current one). */
left = xfs_btree_get_block(cur, level, &lbp);
#ifdef DEBUG
error = xfs_btree_check_block(cur, left, level, lbp);
if (error)
goto error0;
#endif
xfs_btree_buf_to_ptr(cur, lbp, &lptr);
/* Allocate the new block. If we can't do it, we're toast. Give up. */
error = cur->bc_ops->alloc_block(cur, &lptr, &rptr, 1, stat);
if (error)
goto error0;
if (*stat == 0)
goto out0;
XFS_BTREE_STATS_INC(cur, alloc);
/* Set up the new block as "right". */
error = xfs_btree_get_buf_block(cur, &rptr, 0, &right, &rbp);
if (error)
goto error0;
/* Fill in the btree header for the new right block. */
xfs_btree_init_block(cur, xfs_btree_get_level(left), 0, right);
/*
* Split the entries between the old and the new block evenly.
* Make sure that if there's an odd number of entries now, that
* each new block will have the same number of entries.
*/
lrecs = xfs_btree_get_numrecs(left);
rrecs = lrecs / 2;
if ((lrecs & 1) && cur->bc_ptrs[level] <= rrecs + 1)
rrecs++;
src_index = (lrecs - rrecs + 1);
XFS_BTREE_STATS_ADD(cur, moves, rrecs);
/*
* Copy btree block entries from the left block over to the
* new block, the right. Update the right block and log the
* changes.
*/
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, src_index, left);
lpp = xfs_btree_ptr_addr(cur, src_index, left);
rkp = xfs_btree_key_addr(cur, 1, right);
rpp = xfs_btree_ptr_addr(cur, 1, right);
#ifdef DEBUG
for (i = src_index; i < rrecs; i++) {
error = xfs_btree_check_ptr(cur, lpp, i, level);
if (error)
goto error0;
}
#endif
xfs_btree_copy_keys(cur, rkp, lkp, rrecs);
xfs_btree_copy_ptrs(cur, rpp, lpp, rrecs);
xfs_btree_log_keys(cur, rbp, 1, rrecs);
xfs_btree_log_ptrs(cur, rbp, 1, rrecs);
/* Grab the keys to the entries moved to the right block */
xfs_btree_copy_keys(cur, key, rkp, 1);
} 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, src_index, left);
rrp = xfs_btree_rec_addr(cur, 1, right);
xfs_btree_copy_recs(cur, rrp, lrp, rrecs);
xfs_btree_log_recs(cur, rbp, 1, rrecs);
cur->bc_ops->init_key_from_rec(key,
xfs_btree_rec_addr(cur, 1, right));
}
/*
* Find the left block number by looking in the buffer.
* Adjust numrecs, sibling pointers.
*/
xfs_btree_get_sibling(cur, left, &rrptr, XFS_BB_RIGHTSIB);
xfs_btree_set_sibling(cur, right, &rrptr, XFS_BB_RIGHTSIB);
xfs_btree_set_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
xfs_btree_set_sibling(cur, left, &rptr, XFS_BB_RIGHTSIB);
lrecs -= rrecs;
xfs_btree_set_numrecs(left, lrecs);
xfs_btree_set_numrecs(right, xfs_btree_get_numrecs(right) + rrecs);
xfs_btree_log_block(cur, rbp, XFS_BB_ALL_BITS);
xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS | XFS_BB_RIGHTSIB);
/*
* If there's a block to the new block's right, make that block
* point back to right instead of to left.
*/
if (!xfs_btree_ptr_is_null(cur, &rrptr)) {
error = xfs_btree_read_buf_block(cur, &rrptr, level,
0, &rrblock, &rrbp);
if (error)
goto error0;
xfs_btree_set_sibling(cur, rrblock, &rptr, XFS_BB_LEFTSIB);
xfs_btree_log_block(cur, rrbp, XFS_BB_LEFTSIB);
}
/*
* If the cursor is really in the right block, move it there.
* If it's just pointing past the last entry in left, then we'll
* insert there, so don't change anything in that case.
*/
if (cur->bc_ptrs[level] > lrecs + 1) {
xfs_btree_setbuf(cur, level, rbp);
cur->bc_ptrs[level] -= lrecs;
}
/*
* If there are more levels, we'll need another cursor which refers
* the right block, no matter where this cursor was.
*/
if (level + 1 < cur->bc_nlevels) {
error = xfs_btree_dup_cursor(cur, curp);
if (error)
goto error0;
(*curp)->bc_ptrs[level + 1]++;
}
*ptrp = rptr;
XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
*stat = 1;
return 0;
out0:
XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
*stat = 0;
return 0;
error0:
XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
return error;
}
/*
* Copy the old inode root contents into a real block and make the
* broot point to it.
*/
int /* error */
xfs_btree_new_iroot(
struct xfs_btree_cur *cur, /* btree cursor */
int *logflags, /* logging flags for inode */
int *stat) /* return status - 0 fail */
{
struct xfs_buf *cbp; /* buffer for cblock */
struct xfs_btree_block *block; /* btree block */
struct xfs_btree_block *cblock; /* child btree block */
union xfs_btree_key *ckp; /* child key pointer */
union xfs_btree_ptr *cpp; /* child ptr pointer */
union xfs_btree_key *kp; /* pointer to btree key */
union xfs_btree_ptr *pp; /* pointer to block addr */
union xfs_btree_ptr nptr; /* new block addr */
int level; /* btree level */
int error; /* error return code */
#ifdef DEBUG
int i; /* loop counter */
#endif
XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
XFS_BTREE_STATS_INC(cur, newroot);
ASSERT(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE);
level = cur->bc_nlevels - 1;
block = xfs_btree_get_iroot(cur);
pp = xfs_btree_ptr_addr(cur, 1, block);
/* Allocate the new block. If we can't do it, we're toast. Give up. */
error = cur->bc_ops->alloc_block(cur, pp, &nptr, 1, stat);
if (error)
goto error0;
if (*stat == 0) {
XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
return 0;
}
XFS_BTREE_STATS_INC(cur, alloc);
/* Copy the root into a real block. */
error = xfs_btree_get_buf_block(cur, &nptr, 0, &cblock, &cbp);
if (error)
goto error0;
memcpy(cblock, block, xfs_btree_block_len(cur));
be16_add_cpu(&block->bb_level, 1);
xfs_btree_set_numrecs(block, 1);
cur->bc_nlevels++;
cur->bc_ptrs[level + 1] = 1;
kp = xfs_btree_key_addr(cur, 1, block);
ckp = xfs_btree_key_addr(cur, 1, cblock);
xfs_btree_copy_keys(cur, ckp, kp, xfs_btree_get_numrecs(cblock));
cpp = xfs_btree_ptr_addr(cur, 1, cblock);
#ifdef DEBUG
for (i = 0; i < be16_to_cpu(cblock->bb_numrecs); i++) {
error = xfs_btree_check_ptr(cur, pp, i, level);
if (error)
goto error0;
}
#endif
xfs_btree_copy_ptrs(cur, cpp, pp, xfs_btree_get_numrecs(cblock));
#ifdef DEBUG
error = xfs_btree_check_ptr(cur, &nptr, 0, level);
if (error)
goto error0;
#endif
xfs_btree_copy_ptrs(cur, pp, &nptr, 1);
xfs_iroot_realloc(cur->bc_private.b.ip,
1 - xfs_btree_get_numrecs(cblock),
cur->bc_private.b.whichfork);
xfs_btree_setbuf(cur, level, cbp);
/*
* Do all this logging at the end so that
* the root is at the right level.
*/
xfs_btree_log_block(cur, cbp, XFS_BB_ALL_BITS);
xfs_btree_log_keys(cur, cbp, 1, be16_to_cpu(cblock->bb_numrecs));
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);
*stat = 1;
XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
return 0;
error0:
XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
return error;
}
/*
* Allocate a new root block, fill it in.
*/
STATIC int /* error */
xfs_btree_new_root(
struct xfs_btree_cur *cur, /* btree cursor */
int *stat) /* success/failure */
{
struct xfs_btree_block *block; /* one half of the old root block */
struct xfs_buf *bp; /* buffer containing block */
int error; /* error return value */
struct xfs_buf *lbp; /* left buffer pointer */
struct xfs_btree_block *left; /* left btree block */
struct xfs_buf *nbp; /* new (root) buffer */
struct xfs_btree_block *new; /* new (root) btree block */
int nptr; /* new value for key index, 1 or 2 */
struct xfs_buf *rbp; /* right buffer pointer */
struct xfs_btree_block *right; /* right btree block */
union xfs_btree_ptr rptr;
union xfs_btree_ptr lptr;
XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
XFS_BTREE_STATS_INC(cur, newroot);
/* initialise our start point from the cursor */
cur->bc_ops->init_ptr_from_cur(cur, &rptr);
/* Allocate the new block. If we can't do it, we're toast. Give up. */
error = cur->bc_ops->alloc_block(cur, &rptr, &lptr, 1, stat);
if (error)
goto error0;
if (*stat == 0)
goto out0;
XFS_BTREE_STATS_INC(cur, alloc);
/* Set up the new block. */
error = xfs_btree_get_buf_block(cur, &lptr, 0, &new, &nbp);
if (error)
goto error0;
/* Set the root in the holding structure increasing the level by 1. */
cur->bc_ops->set_root(cur, &lptr, 1);
/*
* At the previous root level there are now two blocks: the old root,
* and the new block generated when it was split. We don't know which
* one the cursor is pointing at, so we set up variables "left" and
* "right" for each case.
*/
block = xfs_btree_get_block(cur, cur->bc_nlevels - 1, &bp);
#ifdef DEBUG
error = xfs_btree_check_block(cur, block, cur->bc_nlevels - 1, bp);
if (error)
goto error0;
#endif
xfs_btree_get_sibling(cur, block, &rptr, XFS_BB_RIGHTSIB);
if (!xfs_btree_ptr_is_null(cur, &rptr)) {
/* Our block is left, pick up the right block. */
lbp = bp;
xfs_btree_buf_to_ptr(cur, lbp, &lptr);
left = block;
error = xfs_btree_read_buf_block(cur, &rptr,
cur->bc_nlevels - 1, 0, &right, &rbp);
if (error)
goto error0;
bp = rbp;
nptr = 1;
} else {
/* Our block is right, pick up the left block. */
rbp = bp;
xfs_btree_buf_to_ptr(cur, rbp, &rptr);
right = block;
xfs_btree_get_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
error = xfs_btree_read_buf_block(cur, &lptr,
cur->bc_nlevels - 1, 0, &left, &lbp);
if (error)
goto error0;
bp = lbp;
nptr = 2;
}
/* Fill in the new block's btree header and log it. */
xfs_btree_init_block(cur, cur->bc_nlevels, 2, new);
xfs_btree_log_block(cur, nbp, XFS_BB_ALL_BITS);
ASSERT(!xfs_btree_ptr_is_null(cur, &lptr) &&
!xfs_btree_ptr_is_null(cur, &rptr));
/* Fill in the key data in the new root. */
if (xfs_btree_get_level(left) > 0) {
xfs_btree_copy_keys(cur,
xfs_btree_key_addr(cur, 1, new),
xfs_btree_key_addr(cur, 1, left), 1);
xfs_btree_copy_keys(cur,
xfs_btree_key_addr(cur, 2, new),
xfs_btree_key_addr(cur, 1, right), 1);
} else {
cur->bc_ops->init_key_from_rec(
xfs_btree_key_addr(cur, 1, new),
xfs_btree_rec_addr(cur, 1, left));
cur->bc_ops->init_key_from_rec(
xfs_btree_key_addr(cur, 2, new),
xfs_btree_rec_addr(cur, 1, right));
}
xfs_btree_log_keys(cur, nbp, 1, 2);
/* Fill in the pointer data in the new root. */
xfs_btree_copy_ptrs(cur,
xfs_btree_ptr_addr(cur, 1, new), &lptr, 1);
xfs_btree_copy_ptrs(cur,
xfs_btree_ptr_addr(cur, 2, new), &rptr, 1);
xfs_btree_log_ptrs(cur, nbp, 1, 2);
/* Fix up the cursor. */
xfs_btree_setbuf(cur, cur->bc_nlevels, nbp);
cur->bc_ptrs[cur->bc_nlevels] = nptr;
cur->bc_nlevels++;
XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
*stat = 1;
return 0;
error0:
XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
return error;
out0:
XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
*stat = 0;
return 0;
}
STATIC int
xfs_btree_make_block_unfull(
struct xfs_btree_cur *cur, /* btree cursor */
int level, /* btree level */
int numrecs,/* # of recs in block */
int *oindex,/* old tree index */
int *index, /* new tree index */
union xfs_btree_ptr *nptr, /* new btree ptr */
struct xfs_btree_cur **ncur, /* new btree cursor */
union xfs_btree_rec *nrec, /* new record */
int *stat)
{
union xfs_btree_key key; /* new btree key value */
int error = 0;
if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
level == cur->bc_nlevels - 1) {
struct xfs_inode *ip = cur->bc_private.b.ip;
if (numrecs < cur->bc_ops->get_dmaxrecs(cur, level)) {
/* A root block that can be made bigger. */
xfs_iroot_realloc(ip, 1, cur->bc_private.b.whichfork);
} else {
/* A root block that needs replacing */
int logflags = 0;
error = xfs_btree_new_iroot(cur, &logflags, stat);
if (error || *stat == 0)
return error;
xfs_trans_log_inode(cur->bc_tp, ip, logflags);
}
return 0;
}
/* First, try shifting an entry to the right neighbor. */
error = xfs_btree_rshift(cur, level, stat);
if (error || *stat)
return error;
/* Next, try shifting an entry to the left neighbor. */
error = xfs_btree_lshift(cur, level, stat);
if (error)
return error;
if (*stat) {
*oindex = *index = cur->bc_ptrs[level];
return 0;
}
/*
* Next, try splitting the current block in half.
*
* If this works we have to re-set our variables because we
* could be in a different block now.
*/
error = xfs_btree_split(cur, level, nptr, &key, ncur, stat);
if (error || *stat == 0)
return error;
*index = cur->bc_ptrs[level];
cur->bc_ops->init_rec_from_key(&key, nrec);
return 0;
}
/*
* Insert one record/level. Return information to the caller
* allowing the next level up to proceed if necessary.
*/
STATIC int
xfs_btree_insrec(
struct xfs_btree_cur *cur, /* btree cursor */
int level, /* level to insert record at */
union xfs_btree_ptr *ptrp, /* i/o: block number inserted */
union xfs_btree_rec *recp, /* i/o: record data inserted */
struct xfs_btree_cur **curp, /* output: new cursor replacing cur */
int *stat) /* success/failure */
{
struct xfs_btree_block *block; /* btree block */
struct xfs_buf *bp; /* buffer for block */
union xfs_btree_key key; /* btree key */
union xfs_btree_ptr nptr; /* new block ptr */
struct xfs_btree_cur *ncur; /* new btree cursor */
union xfs_btree_rec nrec; /* new record count */
int optr; /* old key/record index */
int ptr; /* key/record index */
int numrecs;/* number of records */
int error; /* error return value */
#ifdef DEBUG
int i;
#endif
XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
XFS_BTREE_TRACE_ARGIPR(cur, level, *ptrp, recp);
ncur = NULL;
/*
* If we have an external root pointer, and we've made it to the
* root level, allocate a new root block and we're done.
*/
if (!(cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
(level >= cur->bc_nlevels)) {
error = xfs_btree_new_root(cur, stat);
xfs_btree_set_ptr_null(cur, ptrp);
XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
return error;
}
/* If we're off the left edge, return failure. */
ptr = cur->bc_ptrs[level];
if (ptr == 0) {
XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
*stat = 0;
return 0;
}
/* Make a key out of the record data to be inserted, and save it. */
cur->bc_ops->init_key_from_rec(&key, recp);
optr = ptr;
XFS_BTREE_STATS_INC(cur, insrec);
/* Get pointers to the btree buffer and block. */
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;
/* Check that the new entry is being inserted in the right place. */
if (ptr <= numrecs) {
if (level == 0) {
ASSERT(cur->bc_ops->recs_inorder(cur, recp,
xfs_btree_rec_addr(cur, ptr, block)));
} else {
ASSERT(cur->bc_ops->keys_inorder(cur, &key,
xfs_btree_key_addr(cur, ptr, block)));
}
}
#endif
/*
* If the block is full, we can't insert the new entry until we
* make the block un-full.
*/
xfs_btree_set_ptr_null(cur, &nptr);
if (numrecs == cur->bc_ops->get_maxrecs(cur, level)) {
error = xfs_btree_make_block_unfull(cur, level, numrecs,
&optr, &ptr, &nptr, &ncur, &nrec, stat);
if (error || *stat == 0)
goto error0;
}
/*
* The current block may have changed if the block was
* previously full and we have just made space in it.
*/
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)
return error;
#endif
/*
* At this point we know there's room for our new entry in the block
* we're pointing at.
*/
XFS_BTREE_STATS_ADD(cur, moves, numrecs - ptr + 1);
if (level > 0) {
/* It's a nonleaf. make a hole in the keys and ptrs */
union xfs_btree_key *kp;
union xfs_btree_ptr *pp;
kp = xfs_btree_key_addr(cur, ptr, block);
pp = xfs_btree_ptr_addr(cur, ptr, block);
#ifdef DEBUG
for (i = numrecs - ptr; i >= 0; i--) {
error = xfs_btree_check_ptr(cur, pp, i, level);
if (error)
return error;
}
#endif
xfs_btree_shift_keys(cur, kp, 1, numrecs - ptr + 1);
xfs_btree_shift_ptrs(cur, pp, 1, numrecs - ptr + 1);
#ifdef DEBUG
error = xfs_btree_check_ptr(cur, ptrp, 0, level);
if (error)
goto error0;
#endif
/* Now put the new data in, bump numrecs and log it. */
xfs_btree_copy_keys(cur, kp, &key, 1);
xfs_btree_copy_ptrs(cur, pp, ptrp, 1);
numrecs++;
xfs_btree_set_numrecs(block, numrecs);
xfs_btree_log_ptrs(cur, bp, ptr, numrecs);
xfs_btree_log_keys(cur, bp, ptr, numrecs);
#ifdef DEBUG
if (ptr < numrecs) {
ASSERT(cur->bc_ops->keys_inorder(cur, kp,
xfs_btree_key_addr(cur, ptr + 1, block)));
}
#endif
} else {
/* It's a leaf. make a hole in the records */
union xfs_btree_rec *rp;
rp = xfs_btree_rec_addr(cur, ptr, block);
xfs_btree_shift_recs(cur, rp, 1, numrecs - ptr + 1);
/* Now put the new data in, bump numrecs and log it. */
xfs_btree_copy_recs(cur, rp, recp, 1);
xfs_btree_set_numrecs(block, ++numrecs);
xfs_btree_log_recs(cur, bp, ptr, numrecs);
#ifdef DEBUG
if (ptr < numrecs) {
ASSERT(cur->bc_ops->recs_inorder(cur, rp,
xfs_btree_rec_addr(cur, ptr + 1, block)));
}
#endif
}
/* Log the new number of records in the btree header. */
xfs_btree_log_block(cur, bp, XFS_BB_NUMRECS);
/* If we inserted at the start of a block, update the parents' keys. */
if (optr == 1) {
error = xfs_btree_updkey(cur, &key, level + 1);
if (error)
goto error0;
}
/*
* 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, recp,
ptr, LASTREC_INSREC);
}
/*
* Return the new block number, if any.
* If there is one, give back a record value and a cursor too.
*/
*ptrp = nptr;
if (!xfs_btree_ptr_is_null(cur, &nptr)) {
*recp = nrec;
*curp = ncur;
}
XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
*stat = 1;
return 0;
error0:
XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
return error;
}
/*
* Insert the record at the point referenced by cur.
*
* A multi-level split of the tree on insert will invalidate the original
* cursor. All callers of this function should assume that the cursor is
* no longer valid and revalidate it.
*/
int
xfs_btree_insert(
struct xfs_btree_cur *cur,
int *stat)
{
int error; /* error return value */
int i; /* result value, 0 for failure */
int level; /* current level number in btree */
union xfs_btree_ptr nptr; /* new block number (split result) */
struct xfs_btree_cur *ncur; /* new cursor (split result) */
struct xfs_btree_cur *pcur; /* previous level's cursor */
union xfs_btree_rec rec; /* record to insert */
level = 0;
ncur = NULL;
pcur = cur;
xfs_btree_set_ptr_null(cur, &nptr);
cur->bc_ops->init_rec_from_cur(cur, &rec);
/*
* Loop going up the tree, starting at the leaf level.
* Stop when we don't get a split block, that must mean that
* the insert is finished with this level.
*/
do {
/*
* Insert nrec/nptr into this level of the tree.
* Note if we fail, nptr will be null.
*/
error = xfs_btree_insrec(pcur, level, &nptr, &rec, &ncur, &i);
if (error) {
if (pcur != cur)
xfs_btree_del_cursor(pcur, XFS_BTREE_ERROR);
goto error0;
}
XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
level++;
/*
* See if the cursor we just used is trash.
* Can't trash the caller's cursor, but otherwise we should
* if ncur is a new cursor or we're about to be done.
*/
if (pcur != cur &&
(ncur || xfs_btree_ptr_is_null(cur, &nptr))) {
/* Save the state from the cursor before we trash it */
if (cur->bc_ops->update_cursor)
cur->bc_ops->update_cursor(pcur, cur);
cur->bc_nlevels = pcur->bc_nlevels;
xfs_btree_del_cursor(pcur, XFS_BTREE_NOERROR);
}
/* If we got a new cursor, switch to it. */
if (ncur) {
pcur = ncur;
ncur = NULL;
}
} while (!xfs_btree_ptr_is_null(cur, &nptr));
XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
*stat = i;
return 0;
error0:
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;
}
/*
* Kill the current root node, and replace it with it's only child node.
*/
STATIC int
xfs_btree_kill_root(
struct xfs_btree_cur *cur,
struct xfs_buf *bp,
int level,
union xfs_btree_ptr *newroot)
{
int error;
XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
XFS_BTREE_STATS_INC(cur, killroot);
/*
* Update the root pointer, decreasing the level by 1 and then
* free the old root.
*/
cur->bc_ops->set_root(cur, newroot, -1);
error = cur->bc_ops->free_block(cur, bp);
if (error) {
XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
return error;
}
XFS_BTREE_STATS_INC(cur, free);
cur->bc_bufs[level] = NULL;
cur->bc_ra[level] = 0;
cur->bc_nlevels--;
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 = xfs_btree_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;
}