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c3f8fc73ac
linux/fs/xfs/xfs_btree.c
Dave Chinner c3f8fc73ac xfs: make buffer read verication an IO completion function 
Add a verifier function callback capability to the buffer read
interfaces.  This will be used by the callers to supply a function
that verifies the contents of the buffer when it is read from disk.
This patch does not provide callback functions, but simply modifies
the interfaces to allow them to be called.

The reason for adding this to the read interfaces is that it is very
difficult to tell fom the outside is a buffer was just read from
disk or whether we just pulled it out of cache. Supplying a callbck
allows the buffer cache to use it's internal knowledge of the buffer
to execute it only when the buffer is read from disk.

It is intended that the verifier functions will mark the buffer with
an EFSCORRUPTED error when verification fails. This allows the
reading context to distinguish a verification error from an IO
error, and potentially take further actions on the buffer (e.g.
attempt repair) based on the error reported.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Phil White <pwhite@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-15 21:34:02 -06:00

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/*
* 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_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_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 &&
(block->bb_u.l.bb_leftsib == cpu_to_be64(NULLDFSBNO) ||
XFS_FSB_SANITY_CHECK(mp,
be64_to_cpu(block->bb_u.l.bb_leftsib))) &&
block->bb_u.l.bb_rightsib &&
(block->bb_u.l.bb_rightsib == cpu_to_be64(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) &&
(block->bb_u.s.bb_leftsib == cpu_to_be32(NULLAGBLOCK) ||
be32_to_cpu(block->bb_u.s.bb_leftsib) < agflen) &&
block->bb_u.s.bb_leftsib &&
(block->bb_u.s.bb_rightsib == cpu_to_be32(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];
bp = cur->bc_bufs[i];
if (bp) {
error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp,
XFS_BUF_ADDR(bp), mp->m_bsize,
0, &bp, NULL);
if (error) {
xfs_btree_del_cursor(new, error);
*ncur = NULL;
return error;
}
new->bc_bufs[i] = 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(!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(!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 block->bb_u.l.bb_rightsib == cpu_to_be64(NULLDFSBNO);
else
return block->bb_u.s.bb_rightsib == cpu_to_be32(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);
error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, d,
mp->m_bsize, lock, &bp, NULL);
if (error)
return error;
ASSERT(!xfs_buf_geterror(bp));
if (bp)
xfs_buf_set_ref(bp, 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, NULL);
}
/*
* 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, NULL);
}
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 (b->bb_u.l.bb_leftsib == cpu_to_be64(NULLDFSBNO))
cur->bc_ra[lev] |= XFS_BTCUR_LEFTRA;
if (b->bb_u.l.bb_rightsib == cpu_to_be64(NULLDFSBNO))
cur->bc_ra[lev] |= XFS_BTCUR_RIGHTRA;
} else {
if (b->bb_u.s.bb_leftsib == cpu_to_be32(NULLAGBLOCK))
cur->bc_ra[lev] |= XFS_BTCUR_LEFTRA;
if (b->bb_u.s.bb_rightsib == cpu_to_be32(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 ptr->l == cpu_to_be64(NULLDFSBNO);
else
return ptr->s == cpu_to_be32(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;
}
}
void
xfs_btree_init_block(
struct xfs_mount *mp,
struct xfs_buf *bp,
__u32 magic,
__u16 level,
__u16 numrecs,
unsigned int flags)
{
struct xfs_btree_block *new = XFS_BUF_TO_BLOCK(bp);
new->bb_magic = cpu_to_be32(magic);
new->bb_level = cpu_to_be16(level);
new->bb_numrecs = cpu_to_be16(numrecs);
if (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);
}
}
STATIC void
xfs_btree_init_block_cur(
struct xfs_btree_cur *cur,
int level,
int numrecs,
struct xfs_buf *bp)
{
xfs_btree_init_block(cur->bc_mp, bp, xfs_magics[cur->bc_btnum],
level, numrecs, cur->bc_flags);
}
/*
* 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(ptr->l != cpu_to_be64(NULLDFSBNO));
return XFS_FSB_TO_DADDR(cur->bc_mp, be64_to_cpu(ptr->l));
} else {
ASSERT(cur->bc_private.a.agno != NULLAGNUMBER);
ASSERT(ptr->s != cpu_to_be32(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_ref(bp, XFS_ALLOC_BTREE_REF);
break;
case XFS_BTNUM_INO:
xfs_buf_set_ref(bp, XFS_INO_BTREE_REF);
break;
case XFS_BTNUM_BMAP:
xfs_buf_set_ref(bp, 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);
if (!*bpp)
return ENOMEM;
*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, NULL);
if (error)
return error;
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(cur, xfs_btree_get_level(left), 0, rbp);
/*
* 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, cur->bc_nlevels, 2, nbp);
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;
}
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