linux/fs/xfs/xfs_btree.c

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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_inum.h"
#include "xfs_trans.h"
#include "xfs_sb.h"
#include "xfs_ag.h"
#include "xfs_dir2.h"
#include "xfs_dmapi.h"
#include "xfs_mount.h"
#include "xfs_bmap_btree.h"
#include "xfs_alloc_btree.h"
#include "xfs_ialloc_btree.h"
#include "xfs_dir2_sf.h"
#include "xfs_attr_sf.h"
#include "xfs_dinode.h"
#include "xfs_inode.h"
#include "xfs_btree.h"
#include "xfs_ialloc.h"
#include "xfs_error.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
};
/*
* External routines.
*/
#ifdef DEBUG
/*
* Debug routine: check that keys are in the right order.
*/
void
xfs_btree_check_key(
xfs_btnum_t btnum, /* btree identifier */
void *ak1, /* pointer to left (lower) key */
void *ak2) /* pointer to right (higher) key */
{
switch (btnum) {
case XFS_BTNUM_BNO: {
xfs_alloc_key_t *k1;
xfs_alloc_key_t *k2;
k1 = ak1;
k2 = ak2;
ASSERT(be32_to_cpu(k1->ar_startblock) < be32_to_cpu(k2->ar_startblock));
break;
}
case XFS_BTNUM_CNT: {
xfs_alloc_key_t *k1;
xfs_alloc_key_t *k2;
k1 = ak1;
k2 = ak2;
ASSERT(be32_to_cpu(k1->ar_blockcount) < be32_to_cpu(k2->ar_blockcount) ||
(k1->ar_blockcount == k2->ar_blockcount &&
be32_to_cpu(k1->ar_startblock) < be32_to_cpu(k2->ar_startblock)));
break;
}
case XFS_BTNUM_BMAP: {
xfs_bmbt_key_t *k1;
xfs_bmbt_key_t *k2;
k1 = ak1;
k2 = ak2;
ASSERT(be64_to_cpu(k1->br_startoff) < be64_to_cpu(k2->br_startoff));
break;
}
case XFS_BTNUM_INO: {
xfs_inobt_key_t *k1;
xfs_inobt_key_t *k2;
k1 = ak1;
k2 = ak2;
ASSERT(be32_to_cpu(k1->ir_startino) < be32_to_cpu(k2->ir_startino));
break;
}
default:
ASSERT(0);
}
}
/*
* Debug routine: check that records are in the right order.
*/
void
xfs_btree_check_rec(
xfs_btnum_t btnum, /* btree identifier */
void *ar1, /* pointer to left (lower) record */
void *ar2) /* pointer to right (higher) record */
{
switch (btnum) {
case XFS_BTNUM_BNO: {
xfs_alloc_rec_t *r1;
xfs_alloc_rec_t *r2;
r1 = ar1;
r2 = ar2;
ASSERT(be32_to_cpu(r1->ar_startblock) +
be32_to_cpu(r1->ar_blockcount) <=
be32_to_cpu(r2->ar_startblock));
break;
}
case XFS_BTNUM_CNT: {
xfs_alloc_rec_t *r1;
xfs_alloc_rec_t *r2;
r1 = ar1;
r2 = ar2;
ASSERT(be32_to_cpu(r1->ar_blockcount) < be32_to_cpu(r2->ar_blockcount) ||
(r1->ar_blockcount == r2->ar_blockcount &&
be32_to_cpu(r1->ar_startblock) < be32_to_cpu(r2->ar_startblock)));
break;
}
case XFS_BTNUM_BMAP: {
xfs_bmbt_rec_t *r1;
xfs_bmbt_rec_t *r2;
r1 = ar1;
r2 = ar2;
ASSERT(xfs_bmbt_disk_get_startoff(r1) +
xfs_bmbt_disk_get_blockcount(r1) <=
xfs_bmbt_disk_get_startoff(r2));
break;
}
case XFS_BTNUM_INO: {
xfs_inobt_rec_t *r1;
xfs_inobt_rec_t *r2;
r1 = ar1;
r2 = ar2;
ASSERT(be32_to_cpu(r1->ir_startino) + XFS_INODES_PER_CHUNK <=
be32_to_cpu(r2->ir_startino));
break;
}
default:
ASSERT(0);
}
}
#endif /* DEBUG */
int /* error (0 or EFSCORRUPTED) */
xfs_btree_check_lblock(
struct xfs_btree_cur *cur, /* btree cursor */
struct xfs_btree_lblock *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_leftsib &&
(be64_to_cpu(block->bb_leftsib) == NULLDFSBNO ||
XFS_FSB_SANITY_CHECK(mp, be64_to_cpu(block->bb_leftsib))) &&
block->bb_rightsib &&
(be64_to_cpu(block->bb_rightsib) == NULLDFSBNO ||
XFS_FSB_SANITY_CHECK(mp, be64_to_cpu(block->bb_rightsib)));
if (unlikely(XFS_TEST_ERROR(!lblock_ok, mp,
XFS_ERRTAG_BTREE_CHECK_LBLOCK,
XFS_RANDOM_BTREE_CHECK_LBLOCK))) {
if (bp)
xfs_buftrace("LBTREE ERROR", bp);
XFS_ERROR_REPORT("xfs_btree_check_lblock", XFS_ERRLEVEL_LOW,
mp);
return XFS_ERROR(EFSCORRUPTED);
}
return 0;
}
int /* error (0 or EFSCORRUPTED) */
xfs_btree_check_sblock(
struct xfs_btree_cur *cur, /* btree cursor */
struct xfs_btree_sblock *block, /* btree short form block pointer */
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_leftsib) == NULLAGBLOCK ||
be32_to_cpu(block->bb_leftsib) < agflen) &&
block->bb_leftsib &&
(be32_to_cpu(block->bb_rightsib) == NULLAGBLOCK ||
be32_to_cpu(block->bb_rightsib) < agflen) &&
block->bb_rightsib;
if (unlikely(XFS_TEST_ERROR(!sblock_ok, cur->bc_mp,
XFS_ERRTAG_BTREE_CHECK_SBLOCK,
XFS_RANDOM_BTREE_CHECK_SBLOCK))) {
if (bp)
xfs_buftrace("SBTREE ERROR", bp);
XFS_ERROR_REPORT("xfs_btree_check_sblock", XFS_ERRLEVEL_LOW,
cur->bc_mp);
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,
(struct xfs_btree_lblock *)block, level, bp);
} else {
return xfs_btree_check_sblock(cur,
(struct xfs_btree_sblock *)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;
}
/*
* Check that (short) pointer is ok.
*/
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.
*/
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);
}
}
/*
* 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_btree_setbuf(cur, i, NULL);
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) ?
sizeof(struct xfs_btree_lblock) :
sizeof(struct xfs_btree_sblock);
}
/*
* 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 */
{
xfs_btree_block_t *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.
*/
int /* success=1, failure=0 */
xfs_btree_firstrec(
xfs_btree_cur_t *cur, /* btree cursor */
int level) /* level to change */
{
xfs_btree_block_t *block; /* generic btree block pointer */
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.
*/
int /* success=1, failure=0 */
xfs_btree_lastrec(
xfs_btree_cur_t *cur, /* btree cursor */
int level) /* level to change */
{
xfs_btree_block_t *block; /* generic btree block pointer */
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 != NULL) {
XFS_BUF_SET_VTYPE_REF(bp, B_FS_MAP, refval);
}
*bpp = bp;
return 0;
}
/*
* Get a buffer for the block, return it read in.
* Short-form addressing.
*/
int /* error */
xfs_btree_read_bufs(
xfs_mount_t *mp, /* file system mount point */
xfs_trans_t *tp, /* transaction pointer */
xfs_agnumber_t agno, /* allocation group number */
xfs_agblock_t agbno, /* allocation group block number */
uint lock, /* lock flags for read_buf */
xfs_buf_t **bpp, /* buffer for agno/agbno */
int refval) /* ref count value for buffer */
{
xfs_buf_t *bp; /* return value */
xfs_daddr_t d; /* real disk block address */
int error;
ASSERT(agno != NULLAGNUMBER);
ASSERT(agbno != NULLAGBLOCK);
d = XFS_AGB_TO_DADDR(mp, agno, agbno);
if ((error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, d,
mp->m_bsize, lock, &bp))) {
return error;
}
ASSERT(!bp || !XFS_BUF_GETERROR(bp));
if (bp != NULL) {
switch (refval) {
case XFS_ALLOC_BTREE_REF:
XFS_BUF_SET_VTYPE_REF(bp, B_FS_MAP, refval);
break;
case XFS_INO_BTREE_REF:
XFS_BUF_SET_VTYPE_REF(bp, B_FS_INOMAP, refval);
break;
}
}
*bpp = bp;
return 0;
}
/*
* Read-ahead the block, don't wait for it, don't return a buffer.
* Long-form addressing.
*/
/* 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_baread(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_baread(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_fsblock_t left = be64_to_cpu(block->bb_u.l.bb_leftsib);
xfs_fsblock_t right = be64_to_cpu(block->bb_u.l.bb_rightsib);
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.
*/
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.
*/
void
xfs_btree_setbuf(
xfs_btree_cur_t *cur, /* btree cursor */
int lev, /* level in btree */
xfs_buf_t *bp) /* new buffer to set */
{
xfs_btree_block_t *b; /* btree block */
xfs_buf_t *obp; /* old buffer pointer */
obp = cur->bc_bufs[lev];
if (obp)
xfs_trans_brelse(cur->bc_tp, obp);
cur->bc_bufs[lev] = bp;
cur->bc_ra[lev] = 0;
if (!bp)
return;
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;
}
}