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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2000-2002,2005 Silicon Graphics, Inc.
* All Rights Reserved.
*/
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_shared.h"
#include "xfs_format.h"
#include "xfs_log_format.h"
#include "xfs_trans_resv.h"
#include "xfs_bit.h"
#include "xfs_mount.h"
#include "xfs_inode.h"
#include "xfs_trans.h"
#include "xfs_buf_item.h"
#include "xfs_btree.h"
#include "xfs_errortag.h"
#include "xfs_error.h"
#include "xfs_trace.h"
#include "xfs_alloc.h"
#include "xfs_log.h"
/*
* Cursor allocation zone.
*/
kmem_zone_t *xfs_btree_cur_zone;
/*
* Btree magic numbers.
*/
static const uint32_t xfs_magics[2][XFS_BTNUM_MAX] = {
{ XFS_ABTB_MAGIC, XFS_ABTC_MAGIC, 0, XFS_BMAP_MAGIC, XFS_IBT_MAGIC,
XFS_FIBT_MAGIC, 0 },
{ XFS_ABTB_CRC_MAGIC, XFS_ABTC_CRC_MAGIC, XFS_RMAP_CRC_MAGIC,
XFS_BMAP_CRC_MAGIC, XFS_IBT_CRC_MAGIC, XFS_FIBT_CRC_MAGIC,
XFS_REFC_CRC_MAGIC }
};
uint32_t
xfs_btree_magic(
int crc,
xfs_btnum_t btnum)
{
uint32_t magic = xfs_magics[crc][btnum];
/* Ensure we asked for crc for crc-only magics. */
ASSERT(magic != 0);
return magic;
}
/*
* Check a long btree block header. Return the address of the failing check,
* or NULL if everything is ok.
*/
xfs_failaddr_t
__xfs_btree_check_lblock(
struct xfs_btree_cur *cur,
struct xfs_btree_block *block,
int level,
struct xfs_buf *bp)
{
struct xfs_mount *mp = cur->bc_mp;
xfs_btnum_t btnum = cur->bc_btnum;
int crc = xfs_sb_version_hascrc(&mp->m_sb);
if (crc) {
if (!uuid_equal(&block->bb_u.l.bb_uuid, &mp->m_sb.sb_meta_uuid))
return __this_address;
if (block->bb_u.l.bb_blkno !=
cpu_to_be64(bp ? bp->b_bn : XFS_BUF_DADDR_NULL))
return __this_address;
if (block->bb_u.l.bb_pad != cpu_to_be32(0))
return __this_address;
}
if (be32_to_cpu(block->bb_magic) != xfs_btree_magic(crc, btnum))
return __this_address;
if (be16_to_cpu(block->bb_level) != level)
return __this_address;
if (be16_to_cpu(block->bb_numrecs) >
cur->bc_ops->get_maxrecs(cur, level))
return __this_address;
if (block->bb_u.l.bb_leftsib != cpu_to_be64(NULLFSBLOCK) &&
!xfs_btree_check_lptr(cur, be64_to_cpu(block->bb_u.l.bb_leftsib),
level + 1))
return __this_address;
if (block->bb_u.l.bb_rightsib != cpu_to_be64(NULLFSBLOCK) &&
!xfs_btree_check_lptr(cur, be64_to_cpu(block->bb_u.l.bb_rightsib),
level + 1))
return __this_address;
return NULL;
}
/* Check a long btree block header. */
static int
xfs_btree_check_lblock(
struct xfs_btree_cur *cur,
struct xfs_btree_block *block,
int level,
struct xfs_buf *bp)
{
struct xfs_mount *mp = cur->bc_mp;
xfs_failaddr_t fa;
fa = __xfs_btree_check_lblock(cur, block, level, bp);
if (XFS_IS_CORRUPT(mp, fa != NULL) ||
XFS_TEST_ERROR(false, mp, XFS_ERRTAG_BTREE_CHECK_LBLOCK)) {
if (bp)
trace_xfs_btree_corrupt(bp, _RET_IP_);
return -EFSCORRUPTED;
}
return 0;
}
/*
* Check a short btree block header. Return the address of the failing check,
* or NULL if everything is ok.
*/
xfs_failaddr_t
__xfs_btree_check_sblock(
struct xfs_btree_cur *cur,
struct xfs_btree_block *block,
int level,
struct xfs_buf *bp)
{
struct xfs_mount *mp = cur->bc_mp;
xfs_btnum_t btnum = cur->bc_btnum;
int crc = xfs_sb_version_hascrc(&mp->m_sb);
if (crc) {
if (!uuid_equal(&block->bb_u.s.bb_uuid, &mp->m_sb.sb_meta_uuid))
return __this_address;
if (block->bb_u.s.bb_blkno !=
cpu_to_be64(bp ? bp->b_bn : XFS_BUF_DADDR_NULL))
return __this_address;
}
if (be32_to_cpu(block->bb_magic) != xfs_btree_magic(crc, btnum))
return __this_address;
if (be16_to_cpu(block->bb_level) != level)
return __this_address;
if (be16_to_cpu(block->bb_numrecs) >
cur->bc_ops->get_maxrecs(cur, level))
return __this_address;
if (block->bb_u.s.bb_leftsib != cpu_to_be32(NULLAGBLOCK) &&
!xfs_btree_check_sptr(cur, be32_to_cpu(block->bb_u.s.bb_leftsib),
level + 1))
return __this_address;
if (block->bb_u.s.bb_rightsib != cpu_to_be32(NULLAGBLOCK) &&
!xfs_btree_check_sptr(cur, be32_to_cpu(block->bb_u.s.bb_rightsib),
level + 1))
return __this_address;
return NULL;
}
/* Check a short btree block header. */
STATIC int
xfs_btree_check_sblock(
struct xfs_btree_cur *cur,
struct xfs_btree_block *block,
int level,
struct xfs_buf *bp)
{
struct xfs_mount *mp = cur->bc_mp;
xfs_failaddr_t fa;
fa = __xfs_btree_check_sblock(cur, block, level, bp);
if (XFS_IS_CORRUPT(mp, fa != NULL) ||
XFS_TEST_ERROR(false, mp, XFS_ERRTAG_BTREE_CHECK_SBLOCK)) {
if (bp)
trace_xfs_btree_corrupt(bp, _RET_IP_);
return -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 this long pointer is valid and points within the fs. */
bool
xfs_btree_check_lptr(
struct xfs_btree_cur *cur,
xfs_fsblock_t fsbno,
int level)
{
if (level <= 0)
return false;
return xfs_verify_fsbno(cur->bc_mp, fsbno);
}
/* Check that this short pointer is valid and points within the AG. */
bool
xfs_btree_check_sptr(
struct xfs_btree_cur *cur,
xfs_agblock_t agbno,
int level)
{
if (level <= 0)
return false;
return xfs_verify_agbno(cur->bc_mp, cur->bc_private.a.agno, agbno);
}
/*
* Check that a given (indexed) btree pointer at a certain level of a
* btree is valid and doesn't point past where it should.
*/
static int
xfs_btree_check_ptr(
struct xfs_btree_cur *cur,
union xfs_btree_ptr *ptr,
int index,
int level)
{
if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
if (xfs_btree_check_lptr(cur, be64_to_cpu((&ptr->l)[index]),
level))
return 0;
xfs_err(cur->bc_mp,
"Inode %llu fork %d: Corrupt btree %d pointer at level %d index %d.",
cur->bc_private.b.ip->i_ino,
cur->bc_private.b.whichfork, cur->bc_btnum,
level, index);
} else {
if (xfs_btree_check_sptr(cur, be32_to_cpu((&ptr->s)[index]),
level))
return 0;
xfs_err(cur->bc_mp,
"AG %u: Corrupt btree %d pointer at level %d index %d.",
cur->bc_private.a.agno, cur->bc_btnum,
level, index);
}
return -EFSCORRUPTED;
}
#ifdef DEBUG
# define xfs_btree_debug_check_ptr xfs_btree_check_ptr
#else
# define xfs_btree_debug_check_ptr(...) (0)
#endif
/*
* Calculate CRC on the whole btree block and stuff it into the
* long-form btree header.
*
* Prior to calculting the CRC, pull the LSN out of the buffer log item and put
* it into the buffer so recovery knows what the last modification was that made
* it to disk.
*/
void
xfs_btree_lblock_calc_crc(
struct xfs_buf *bp)
{
struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
struct xfs_buf_log_item *bip = bp->b_log_item;
if (!xfs_sb_version_hascrc(&bp->b_mount->m_sb))
return;
if (bip)
block->bb_u.l.bb_lsn = cpu_to_be64(bip->bli_item.li_lsn);
xfs_buf_update_cksum(bp, XFS_BTREE_LBLOCK_CRC_OFF);
}
bool
xfs_btree_lblock_verify_crc(
struct xfs_buf *bp)
{
struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
struct xfs_mount *mp = bp->b_mount;
if (xfs_sb_version_hascrc(&mp->m_sb)) {
if (!xfs_log_check_lsn(mp, be64_to_cpu(block->bb_u.l.bb_lsn)))
return false;
return xfs_buf_verify_cksum(bp, XFS_BTREE_LBLOCK_CRC_OFF);
}
return true;
}
/*
* Calculate CRC on the whole btree block and stuff it into the
* short-form btree header.
*
* Prior to calculting the CRC, pull the LSN out of the buffer log item and put
* it into the buffer so recovery knows what the last modification was that made
* it to disk.
*/
void
xfs_btree_sblock_calc_crc(
struct xfs_buf *bp)
{
struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
struct xfs_buf_log_item *bip = bp->b_log_item;
if (!xfs_sb_version_hascrc(&bp->b_mount->m_sb))
return;
if (bip)
block->bb_u.s.bb_lsn = cpu_to_be64(bip->bli_item.li_lsn);
xfs_buf_update_cksum(bp, XFS_BTREE_SBLOCK_CRC_OFF);
}
bool
xfs_btree_sblock_verify_crc(
struct xfs_buf *bp)
{
struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
struct xfs_mount *mp = bp->b_mount;
if (xfs_sb_version_hascrc(&mp->m_sb)) {
if (!xfs_log_check_lsn(mp, be64_to_cpu(block->bb_u.s.bb_lsn)))
return false;
return xfs_buf_verify_cksum(bp, XFS_BTREE_SBLOCK_CRC_OFF);
}
return true;
}
static int
xfs_btree_free_block(
struct xfs_btree_cur *cur,
struct xfs_buf *bp)
{
int error;
error = cur->bc_ops->free_block(cur, bp);
if (!error) {
xfs_trans_binval(cur->bc_tp, bp);
XFS_BTREE_STATS_INC(cur, free);
}
return error;
}
/*
* 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_cache_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,
cur->bc_ops->buf_ops);
if (error) {
xfs_btree_del_cursor(new, error);
*ncur = NULL;
return error;
}
}
new->bc_bufs[i] = bp;
}
*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!
*
* If XFS_BTREE_OVERLAPPING is set, then this btree supports keys containing
* overlapping intervals. In such a tree, records are still sorted lowest to
* highest and indexed by the smallest key value that refers to the record.
* However, nodes are different: each pointer has two associated keys -- one
* indexing the lowest key available in the block(s) below (the same behavior
* as the key in a regular btree) and another indexing the highest key
* available in the block(s) below. Because records are /not/ sorted by the
* highest key, all leaf block updates require us to compute the highest key
* that matches any record in the leaf and to recursively update the high keys
* in the nodes going further up in the tree, if necessary. Nodes look like
* this:
*
* +--------+-----+-----+-----+-----+-----+-------+-------+-----+
* Non-Leaf: | header | lo1 | hi1 | lo2 | hi2 | ... | ptr 1 | ptr 2 | ... |
* +--------+-----+-----+-----+-----+-----+-------+-------+-----+
*
* To perform an interval query on an overlapped tree, perform the usual
* depth-first search and use the low and high keys to decide if we can skip
* that particular node. If a leaf node is reached, return the records that
* intersect the interval. Note that an interval query may return numerous
* entries. For a non-overlapped tree, simply search for the record associated
* with the lowest key and iterate forward until a non-matching record is
* found. Section 14.3 ("Interval Trees") of _Introduction to Algorithms_ by
* Cormen, Leiserson, Rivest, and Stein (2nd or 3rd ed. only) discuss this in
* more detail.
*
* Why do we care about overlapping intervals? Let's say you have a bunch of
* reverse mapping records on a reflink filesystem:
*
* 1: +- file A startblock B offset C length D -----------+
* 2: +- file E startblock F offset G length H --------------+
* 3: +- file I startblock F offset J length K --+
* 4: +- file L... --+
*
* Now say we want to map block (B+D) into file A at offset (C+D). Ideally,
* we'd simply increment the length of record 1. But how do we find the record
* that ends at (B+D-1) (i.e. record 1)? A LE lookup of (B+D-1) would return
* record 3 because the keys are ordered first by startblock. An interval
* query would return records 1 and 2 because they both overlap (B+D-1), and
* from that we can pick out record 1 as the appropriate left neighbor.
*
* In the non-overlapped case you can do a LE lookup and decrement the cursor
* because a record's interval must end before the next record.
*/
/*
* Return size of the btree block header for this btree instance.
*/
static inline size_t xfs_btree_block_len(struct xfs_btree_cur *cur)
{
if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
if (cur->bc_flags & XFS_BTREE_CRC_BLOCKS)
return XFS_BTREE_LBLOCK_CRC_LEN;
return XFS_BTREE_LBLOCK_LEN;
}
if (cur->bc_flags & XFS_BTREE_CRC_BLOCKS)
return XFS_BTREE_SBLOCK_CRC_LEN;
return 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 high key in a btree block.
*/
STATIC size_t
xfs_btree_high_key_offset(
struct xfs_btree_cur *cur,
int n)
{
return xfs_btree_block_len(cur) +
(n - 1) * cur->bc_ops->key_len + (cur->bc_ops->key_len / 2);
}
/*
* 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.
*/
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.
*/
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 high key in the btree block.
*/
union xfs_btree_key *
xfs_btree_high_key_addr(
struct xfs_btree_cur *cur,
int n,
struct xfs_btree_block *block)
{
return (union xfs_btree_key *)
((char *)block + xfs_btree_high_key_offset(cur, n));
}
/*
* Return a pointer to the n-th block pointer in the btree block.
*/
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 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.
*/
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 */
{
xfs_daddr_t d; /* real disk block address */
ASSERT(fsbno != NULLFSBLOCK);
d = XFS_FSB_TO_DADDR(mp, fsbno);
return xfs_trans_get_buf(tp, mp->m_ddev_targp, d, mp->m_bsize, 0);
}
/*
* 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 */
{
xfs_daddr_t d; /* real disk block address */
ASSERT(agno != NULLAGNUMBER);
ASSERT(agbno != NULLAGBLOCK);
d = XFS_AGB_TO_DADDR(mp, agno, agbno);
return xfs_trans_get_buf(tp, mp->m_ddev_targp, d, mp->m_bsize, 0);
}
/*
* 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);
if (xfs_btree_check_block(cur, block, level, bp))
return 0;
/*
* 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);
if (xfs_btree_check_block(cur, block, level, bp))
return 0;
/*
* 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
xfs_btree_read_bufl(
struct xfs_mount *mp, /* file system mount point */
struct xfs_trans *tp, /* transaction pointer */
xfs_fsblock_t fsbno, /* file system block number */
struct xfs_buf **bpp, /* buffer for fsbno */
int refval, /* ref count value for buffer */
const struct xfs_buf_ops *ops)
{
struct xfs_buf *bp; /* return value */
xfs_daddr_t d; /* real disk block address */
int error;
if (!xfs_verify_fsbno(mp, fsbno))
return -EFSCORRUPTED;
d = XFS_FSB_TO_DADDR(mp, fsbno);
error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, d,
mp->m_bsize, 0, &bp, ops);
if (error)
return error;
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(
struct xfs_mount *mp, /* file system mount point */
xfs_fsblock_t fsbno, /* file system block number */
xfs_extlen_t count, /* count of filesystem blocks */
const struct xfs_buf_ops *ops)
{
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, ops);
}
/*
* Read-ahead the block, don't wait for it, don't return a buffer.
* Short-form addressing.
*/
/* ARGSUSED */
void
xfs_btree_reada_bufs(
struct xfs_mount *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 */
const struct xfs_buf_ops *ops)
{
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, ops);
}
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 != NULLFSBLOCK) {
xfs_btree_reada_bufl(cur->bc_mp, left, 1,
cur->bc_ops->buf_ops);
rval++;
}
if ((lr & XFS_BTCUR_RIGHTRA) && right != NULLFSBLOCK) {
xfs_btree_reada_bufl(cur->bc_mp, right, 1,
cur->bc_ops->buf_ops);
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, cur->bc_ops->buf_ops);
rval++;
}
if ((lr & XFS_BTCUR_RIGHTRA) && right != NULLAGBLOCK) {
xfs_btree_reada_bufs(cur->bc_mp, cur->bc_private.a.agno,
right, 1, cur->bc_ops->buf_ops);
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);
}
STATIC int
xfs_btree_ptr_to_daddr(
struct xfs_btree_cur *cur,
union xfs_btree_ptr *ptr,
xfs_daddr_t *daddr)
{
xfs_fsblock_t fsbno;
xfs_agblock_t agbno;
int error;
error = xfs_btree_check_ptr(cur, ptr, 0, 1);
if (error)
return error;
if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
fsbno = be64_to_cpu(ptr->l);
*daddr = XFS_FSB_TO_DADDR(cur->bc_mp, fsbno);
} else {
agbno = be32_to_cpu(ptr->s);
*daddr = XFS_AGB_TO_DADDR(cur->bc_mp, cur->bc_private.a.agno,
agbno);
}
return 0;
}
/*
* Readahead @count btree blocks at the given @ptr location.
*
* We don't need to care about long or short form btrees here as we have a
* method of converting the ptr directly to a daddr available to us.
*/
STATIC void
xfs_btree_readahead_ptr(
struct xfs_btree_cur *cur,
union xfs_btree_ptr *ptr,
xfs_extlen_t count)
{
xfs_daddr_t daddr;
if (xfs_btree_ptr_to_daddr(cur, ptr, &daddr))
return;
xfs_buf_readahead(cur->bc_mp->m_ddev_targp, daddr,
cur->bc_mp->m_bsize * count, cur->bc_ops->buf_ops);
}
/*
* 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(NULLFSBLOCK))
cur->bc_ra[lev] |= XFS_BTCUR_LEFTRA;
if (b->bb_u.l.bb_rightsib == cpu_to_be64(NULLFSBLOCK))
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;
}
}
bool
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(NULLFSBLOCK);
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(NULLFSBLOCK);
else
ptr->s = cpu_to_be32(NULLAGBLOCK);
}
/*
* Get/set/init sibling pointers
*/
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_int(
struct xfs_mount *mp,
struct xfs_btree_block *buf,
xfs_daddr_t blkno,
xfs_btnum_t btnum,
__u16 level,
__u16 numrecs,
__u64 owner,
unsigned int flags)
{
int crc = xfs_sb_version_hascrc(&mp->m_sb);
__u32 magic = xfs_btree_magic(crc, btnum);
buf->bb_magic = cpu_to_be32(magic);
buf->bb_level = cpu_to_be16(level);
buf->bb_numrecs = cpu_to_be16(numrecs);
if (flags & XFS_BTREE_LONG_PTRS) {
buf->bb_u.l.bb_leftsib = cpu_to_be64(NULLFSBLOCK);
buf->bb_u.l.bb_rightsib = cpu_to_be64(NULLFSBLOCK);
if (crc) {
buf->bb_u.l.bb_blkno = cpu_to_be64(blkno);
buf->bb_u.l.bb_owner = cpu_to_be64(owner);
uuid_copy(&buf->bb_u.l.bb_uuid, &mp->m_sb.sb_meta_uuid);
buf->bb_u.l.bb_pad = 0;
buf->bb_u.l.bb_lsn = 0;
}
} else {
/* owner is a 32 bit value on short blocks */
__u32 __owner = (__u32)owner;
buf->bb_u.s.bb_leftsib = cpu_to_be32(NULLAGBLOCK);
buf->bb_u.s.bb_rightsib = cpu_to_be32(NULLAGBLOCK);
if (crc) {
buf->bb_u.s.bb_blkno = cpu_to_be64(blkno);
buf->bb_u.s.bb_owner = cpu_to_be32(__owner);
uuid_copy(&buf->bb_u.s.bb_uuid, &mp->m_sb.sb_meta_uuid);
buf->bb_u.s.bb_lsn = 0;
}
}
}
void
xfs_btree_init_block(
struct xfs_mount *mp,
struct xfs_buf *bp,
xfs_btnum_t btnum,
__u16 level,
__u16 numrecs,
__u64 owner)
{
xfs_btree_init_block_int(mp, XFS_BUF_TO_BLOCK(bp), bp->b_bn,
btnum, level, numrecs, owner, 0);
}
STATIC void
xfs_btree_init_block_cur(
struct xfs_btree_cur *cur,
struct xfs_buf *bp,
int level,
int numrecs)
{
__u64 owner;
/*
* we can pull the owner from the cursor right now as the different
* owners align directly with the pointer size of the btree. This may
* change in future, but is safe for current users of the generic btree
* code.
*/
if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
owner = cur->bc_private.b.ip->i_ino;
else
owner = cur->bc_private.a.agno;
xfs_btree_init_block_int(cur->bc_mp, XFS_BUF_TO_BLOCK(bp), bp->b_bn,
cur->bc_btnum, level, numrecs,
owner, cur->bc_flags);
}
/*
* Return true if ptr is the last record in the btree and
* we need to track updates 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 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:
case XFS_BTNUM_FINO:
xfs_buf_set_ref(bp, XFS_INO_BTREE_REF);
break;
case XFS_BTNUM_BMAP:
xfs_buf_set_ref(bp, XFS_BMAP_BTREE_REF);
break;
case XFS_BTNUM_RMAP:
xfs_buf_set_ref(bp, XFS_RMAP_BTREE_REF);
break;
case XFS_BTNUM_REFC:
xfs_buf_set_ref(bp, XFS_REFC_BTREE_REF);
break;
default:
ASSERT(0);
}
}
STATIC int
xfs_btree_get_buf_block(
struct xfs_btree_cur *cur,
union xfs_btree_ptr *ptr,
struct xfs_btree_block **block,
struct xfs_buf **bpp)
{
struct xfs_mount *mp = cur->bc_mp;
xfs_daddr_t d;
int error;
error = xfs_btree_ptr_to_daddr(cur, ptr, &d);
if (error)
return error;
*bpp = xfs_trans_get_buf(cur->bc_tp, mp->m_ddev_targp, d,
mp->m_bsize, 0);
if (!*bpp)
return -ENOMEM;
(*bpp)->b_ops = cur->bc_ops->buf_ops;
*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 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));
error = xfs_btree_ptr_to_daddr(cur, ptr, &d);
if (error)
return error;
error = xfs_trans_read_buf(mp, cur->bc_tp, mp->m_ddev_targp, d,
mp->m_bsize, flags, bpp,
cur->bc_ops->buf_ops);
if (error)
return error;
xfs_btree_set_refs(cur, *bpp);
*block = XFS_BUF_TO_BLOCK(*bpp);
return 0;
}
/*
* 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)
{
if (bp) {
xfs_trans_buf_set_type(cur->bc_tp, bp, XFS_BLFT_BTREE_BUF);
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));
}
}
/*
* 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_trans_buf_set_type(cur->bc_tp, bp, XFS_BLFT_BTREE_BUF);
xfs_trans_log_buf(cur->bc_tp, bp,
xfs_btree_rec_offset(cur, first),
xfs_btree_rec_offset(cur, last + 1) - 1);
}
/*
* 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 */
{
if (bp) {
struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
int level = xfs_btree_get_level(block);
xfs_trans_buf_set_type(cur->bc_tp, bp, XFS_BLFT_BTREE_BUF);
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));
}
}
/*
* 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),
offsetof(struct xfs_btree_block, bb_u.s.bb_blkno),
offsetof(struct xfs_btree_block, bb_u.s.bb_lsn),
offsetof(struct xfs_btree_block, bb_u.s.bb_uuid),
offsetof(struct xfs_btree_block, bb_u.s.bb_owner),
offsetof(struct xfs_btree_block, bb_u.s.bb_crc),
XFS_BTREE_SBLOCK_CRC_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),
offsetof(struct xfs_btree_block, bb_u.l.bb_blkno),
offsetof(struct xfs_btree_block, bb_u.l.bb_lsn),
offsetof(struct xfs_btree_block, bb_u.l.bb_uuid),
offsetof(struct xfs_btree_block, bb_u.l.bb_owner),
offsetof(struct xfs_btree_block, bb_u.l.bb_crc),
offsetof(struct xfs_btree_block, bb_u.l.bb_pad),
XFS_BTREE_LBLOCK_CRC_LEN
};
if (bp) {
int nbits;
if (cur->bc_flags & XFS_BTREE_CRC_BLOCKS) {
/*
* We don't log the CRC when updating a btree
* block but instead recreate it during log
* recovery. As the log buffers have checksums
* of their own this is safe and avoids logging a crc
* update in a lot of places.
*/
if (fields == XFS_BB_ALL_BITS)
fields = XFS_BB_ALL_BITS_CRC;
nbits = XFS_BB_NUM_BITS_CRC;
} else {
nbits = XFS_BB_NUM_BITS;
}
xfs_btree_offsets(fields,
(cur->bc_flags & XFS_BTREE_LONG_PTRS) ?
loffsets : soffsets,
nbits, &first, &last);
xfs_trans_buf_set_type(cur->bc_tp, bp, XFS_BLFT_BTREE_BUF);
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));
}
}
/*
* 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;
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);
--lev;
error = xfs_btree_read_buf_block(cur, ptrp, 0, &block, &bp);
if (error)
goto error0;
xfs_btree_setbuf(cur, lev, bp);
cur->bc_ptrs[lev] = 1;
}
out1:
*stat = 1;
return 0;
out0:
*stat = 0;
return 0;
error0:
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;
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);
--lev;
error = xfs_btree_read_buf_block(cur, ptrp, 0, &block, &bp);
if (error)
goto error0;
xfs_btree_setbuf(cur, lev, bp);
cur->bc_ptrs[lev] = xfs_btree_get_numrecs(block);
}
out1:
*stat = 1;
return 0;
out0:
*stat = 0;
return 0;
error0:
return error;
}
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 */
xfs_daddr_t daddr;
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];
error = xfs_btree_ptr_to_daddr(cur, pp, &daddr);
if (error)
return error;
if (bp && XFS_BUF_ADDR(bp) == daddr) {
*blkp = XFS_BUF_TO_BLOCK(bp);
return 0;
}
error = xfs_btree_read_buf_block(cur, pp, 0, blkp, &bp);
if (error)
return error;
/* Check the inode owner since the verifiers don't. */
if (xfs_sb_version_hascrc(&cur->bc_mp->m_sb) &&
!(cur->bc_private.b.flags & XFS_BTCUR_BPRV_INVALID_OWNER) &&
(cur->bc_flags & XFS_BTREE_LONG_PTRS) &&
be64_to_cpu((*blkp)->bb_u.l.bb_owner) !=
cur->bc_private.b.ip->i_ino)
goto out_bad;
/* Did we get the level we were looking for? */
if (be16_to_cpu((*blkp)->bb_level) != level)
goto out_bad;
/* Check that internal nodes have at least one record. */
if (level != 0 && be16_to_cpu((*blkp)->bb_numrecs) == 0)
goto out_bad;
xfs_btree_setbuf(cur, level, bp);
return 0;
out_bad:
*blkp = NULL;
xfs_buf_corruption_error(bp);
xfs_trans_brelse(cur->bc_tp, bp);
return -EFSCORRUPTED;
}
/*
* 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.
* stat is set to 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_STATS_INC(cur, lookup);
/* No such thing as a zero-level tree. */
if (XFS_IS_CORRUPT(cur->bc_mp, cur->bc_nlevels == 0))
return -EFSCORRUPTED;
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. */
if (level != 0 || cur->bc_nlevels != 1) {
XFS_CORRUPTION_ERROR(__func__,
XFS_ERRLEVEL_LOW,
cur->bc_mp, block,
sizeof(*block));
return -EFSCORRUPTED;
}
cur->bc_ptrs[0] = dir != XFS_LOOKUP_LE;
*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);
error = xfs_btree_debug_check_ptr(cur, pp, 0, level);
if (error)
goto error0;
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;
if (XFS_IS_CORRUPT(cur->bc_mp, i != 1))
return -EFSCORRUPTED;
*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;
return 0;
error0:
return error;
}
/* Find the high key storage area from a regular key. */
union xfs_btree_key *
xfs_btree_high_key_from_key(
struct xfs_btree_cur *cur,
union xfs_btree_key *key)
{
ASSERT(cur->bc_flags & XFS_BTREE_OVERLAPPING);
return (union xfs_btree_key *)((char *)key +
(cur->bc_ops->key_len / 2));
}
/* Determine the low (and high if overlapped) keys of a leaf block */
STATIC void
xfs_btree_get_leaf_keys(
struct xfs_btree_cur *cur,
struct xfs_btree_block *block,
union xfs_btree_key *key)
{
union xfs_btree_key max_hkey;
union xfs_btree_key hkey;
union xfs_btree_rec *rec;
union xfs_btree_key *high;
int n;
rec = xfs_btree_rec_addr(cur, 1, block);
cur->bc_ops->init_key_from_rec(key, rec);
if (cur->bc_flags & XFS_BTREE_OVERLAPPING) {
cur->bc_ops->init_high_key_from_rec(&max_hkey, rec);
for (n = 2; n <= xfs_btree_get_numrecs(block); n++) {
rec = xfs_btree_rec_addr(cur, n, block);
cur->bc_ops->init_high_key_from_rec(&hkey, rec);
if (cur->bc_ops->diff_two_keys(cur, &hkey, &max_hkey)
> 0)
max_hkey = hkey;
}
high = xfs_btree_high_key_from_key(cur, key);
memcpy(high, &max_hkey, cur->bc_ops->key_len / 2);
}
}
/* Determine the low (and high if overlapped) keys of a node block */
STATIC void
xfs_btree_get_node_keys(
struct xfs_btree_cur *cur,
struct xfs_btree_block *block,
union xfs_btree_key *key)
{
union xfs_btree_key *hkey;
union xfs_btree_key *max_hkey;
union xfs_btree_key *high;
int n;
if (cur->bc_flags & XFS_BTREE_OVERLAPPING) {
memcpy(key, xfs_btree_key_addr(cur, 1, block),
cur->bc_ops->key_len / 2);
max_hkey = xfs_btree_high_key_addr(cur, 1, block);
for (n = 2; n <= xfs_btree_get_numrecs(block); n++) {
hkey = xfs_btree_high_key_addr(cur, n, block);
if (cur->bc_ops->diff_two_keys(cur, hkey, max_hkey) > 0)
max_hkey = hkey;
}
high = xfs_btree_high_key_from_key(cur, key);
memcpy(high, max_hkey, cur->bc_ops->key_len / 2);
} else {
memcpy(key, xfs_btree_key_addr(cur, 1, block),
cur->bc_ops->key_len);
}
}
/* Derive the keys for any btree block. */
void
xfs_btree_get_keys(
struct xfs_btree_cur *cur,
struct xfs_btree_block *block,
union xfs_btree_key *key)
{
if (be16_to_cpu(block->bb_level) == 0)
xfs_btree_get_leaf_keys(cur, block, key);
else
xfs_btree_get_node_keys(cur, block, key);
}
/*
* Decide if we need to update the parent keys of a btree block. For
* a standard btree this is only necessary if we're updating the first
* record/key. For an overlapping btree, we must always update the
* keys because the highest key can be in any of the records or keys
* in the block.
*/
static inline bool
xfs_btree_needs_key_update(
struct xfs_btree_cur *cur,
int ptr)
{
return (cur->bc_flags & XFS_BTREE_OVERLAPPING) || ptr == 1;
}
/*
* Update the low and high parent keys of the given level, progressing
* towards the root. If force_all is false, stop if the keys for a given
* level do not need updating.
*/
STATIC int
__xfs_btree_updkeys(
struct xfs_btree_cur *cur,
int level,
struct xfs_btree_block *block,
struct xfs_buf *bp0,
bool force_all)
{
union xfs_btree_key key; /* keys from current level */
union xfs_btree_key *lkey; /* keys from the next level up */
union xfs_btree_key *hkey;
union xfs_btree_key *nlkey; /* keys from the next level up */
union xfs_btree_key *nhkey;
struct xfs_buf *bp;
int ptr;
ASSERT(cur->bc_flags & XFS_BTREE_OVERLAPPING);
/* Exit if there aren't any parent levels to update. */
if (level + 1 >= cur->bc_nlevels)
return 0;
trace_xfs_btree_updkeys(cur, level, bp0);
lkey = &key;
hkey = xfs_btree_high_key_from_key(cur, lkey);
xfs_btree_get_keys(cur, block, lkey);
for (level++; level < cur->bc_nlevels; level++) {
#ifdef DEBUG
int error;
#endif
block = xfs_btree_get_block(cur, level, &bp);
trace_xfs_btree_updkeys(cur, level, bp);
#ifdef DEBUG
error = xfs_btree_check_block(cur, block, level, bp);
if (error)
return error;
#endif
ptr = cur->bc_ptrs[level];
nlkey = xfs_btree_key_addr(cur, ptr, block);
nhkey = xfs_btree_high_key_addr(cur, ptr, block);
if (!force_all &&
!(cur->bc_ops->diff_two_keys(cur, nlkey, lkey) != 0 ||
cur->bc_ops->diff_two_keys(cur, nhkey, hkey) != 0))
break;
xfs_btree_copy_keys(cur, nlkey, lkey, 1);
xfs_btree_log_keys(cur, bp, ptr, ptr);
if (level + 1 >= cur->bc_nlevels)
break;
xfs_btree_get_node_keys(cur, block, lkey);
}
return 0;
}
/* Update all the keys from some level in cursor back to the root. */
STATIC int
xfs_btree_updkeys_force(
struct xfs_btree_cur *cur,
int level)
{
struct xfs_buf *bp;
struct xfs_btree_block *block;
block = xfs_btree_get_block(cur, level, &bp);
return __xfs_btree_updkeys(cur, level, block, bp, true);
}
/*
* Update the parent keys of the given level, progressing towards the root.
*/
STATIC int
xfs_btree_update_keys(
struct xfs_btree_cur *cur,
int level)
{
struct xfs_btree_block *block;
struct xfs_buf *bp;
union xfs_btree_key *kp;
union xfs_btree_key key;
int ptr;
ASSERT(level >= 0);
block = xfs_btree_get_block(cur, level, &bp);
if (cur->bc_flags & XFS_BTREE_OVERLAPPING)
return __xfs_btree_updkeys(cur, level, block, bp, false);
/*
* 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.
*/
xfs_btree_get_keys(cur, block, &key);
for (level++, 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)
return error;
#endif
ptr = cur->bc_ptrs[level];
kp = xfs_btree_key_addr(cur, ptr, block);
xfs_btree_copy_keys(cur, kp, &key, 1);
xfs_btree_log_keys(cur, bp, ptr, ptr);
}
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;
/* 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);
}
/* Pass new key value up to our parent. */
if (xfs_btree_needs_key_update(cur, ptr)) {
error = xfs_btree_update_keys(cur, 0);
if (error)
goto error0;
}
return 0;
error0:
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 */
{
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 */
struct xfs_btree_cur *tcur; /* temporary btree cursor */
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 */
int i;
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, 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);
error = xfs_btree_debug_check_ptr(cur, rpp, 0, level);
if (error)
goto error0;
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 */
int i; /* loop index */
for (i = 0; i < rrecs; i++) {
error = xfs_btree_debug_check_ptr(cur, rpp, i + 1, level);
if (error)
goto error0;
}
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);
}
/*
* Using a temporary cursor, update the parent key values of the
* block on the left.
*/
if (cur->bc_flags & XFS_BTREE_OVERLAPPING) {
error = xfs_btree_dup_cursor(cur, &tcur);
if (error)
goto error0;
i = xfs_btree_firstrec(tcur, level);
if (XFS_IS_CORRUPT(tcur->bc_mp, i != 1)) {
error = -EFSCORRUPTED;
goto error0;
}
error = xfs_btree_decrement(tcur, level, &i);
if (error)
goto error1;
/* Update the parent high keys of the left block, if needed. */
error = xfs_btree_update_keys(tcur, level);
if (error)
goto error1;
xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
}
/* Update the parent keys of the right block. */
error = xfs_btree_update_keys(cur, level);
if (error)
goto error0;
/* Slide the cursor value left one. */
cur->bc_ptrs[level]--;
*stat = 1;
return 0;
out0:
*stat = 0;
return 0;
error0:
return error;
error1:
xfs_btree_del_cursor(tcur, XFS_BTREE_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 */
{
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 */
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, 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);
for (i = rrecs - 1; i >= 0; i--) {
error = xfs_btree_debug_check_ptr(cur, rpp, i, level);
if (error)
goto error0;
}
xfs_btree_shift_keys(cur, rkp, 1, rrecs);
xfs_btree_shift_ptrs(cur, rpp, 1, rrecs);
error = xfs_btree_debug_check_ptr(cur, lpp, 0, level);
if (error)
goto error0;
/* 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);
}
/*
* 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);
if (XFS_IS_CORRUPT(tcur->bc_mp, i != 1)) {
error = -EFSCORRUPTED;
goto error0;
}
error = xfs_btree_increment(tcur, level, &i);
if (error)
goto error1;
/* Update the parent high keys of the left block, if needed. */
if (cur->bc_flags & XFS_BTREE_OVERLAPPING) {
error = xfs_btree_update_keys(cur, level);
if (error)
goto error1;
}
/* Update the parent keys of the right block. */
error = xfs_btree_update_keys(tcur, level);
if (error)
goto error1;
xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
*stat = 1;
return 0;
out0:
*stat = 0;
return 0;
error0:
return error;
error1:
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 */
int i;
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, 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, &right, &rbp);
if (error)
goto error0;
/* Fill in the btree header for the new right block. */
xfs_btree_init_block_cur(cur, rbp, xfs_btree_get_level(left), 0);
/*
* 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);
/* Adjust numrecs for the later get_*_keys() calls. */
lrecs -= rrecs;
xfs_btree_set_numrecs(left, lrecs);
xfs_btree_set_numrecs(right, xfs_btree_get_numrecs(right) + 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);
for (i = src_index; i < rrecs; i++) {
error = xfs_btree_debug_check_ptr(cur, lpp, i, level);
if (error)
goto error0;
}
/* Copy the keys & pointers to the new block. */
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);
/* Stash the keys of the new block for later insertion. */
xfs_btree_get_node_keys(cur, right, key);
} 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);
/* Copy records to the new block. */
xfs_btree_copy_recs(cur, rrp, lrp, rrecs);
xfs_btree_log_recs(cur, rbp, 1, rrecs);
/* Stash the keys of the new block for later insertion. */
xfs_btree_get_leaf_keys(cur, right, key);
}
/*
* Find the left block number by looking in the buffer.
* Adjust 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);
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,
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);
}
/* Update the parent high keys of the left block, if needed. */
if (cur->bc_flags & XFS_BTREE_OVERLAPPING) {
error = xfs_btree_update_keys(cur, level);
if (error)
goto error0;
}
/*
* 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;
*stat = 1;
return 0;
out0:
*stat = 0;
return 0;
error0:
return error;
}
struct xfs_btree_split_args {
struct xfs_btree_cur *cur;
int level;
union xfs_btree_ptr *ptrp;
union xfs_btree_key *key;