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linux/fs/xfs/libxfs/xfs_btree.c
Darrick J. Wong a095686a23 xfs: support in-memory btrees 
Adapt the generic btree cursor code to be able to create a btree whose
buffers come from a (presumably in-memory) buftarg with a header block
that's specific to in-memory btrees.  We'll connect this to other parts
of online scrub in the next patches.

Note that in-memory btrees always have a block size matching the system
memory page size for efficiency reasons.  There are also a few things we
need to do to finalize a btree update; that's covered in the next patch.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-02-22 12:43:35 -08:00

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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"
#include "xfs_btree_staging.h"
#include "xfs_ag.h"
#include "xfs_alloc_btree.h"
#include "xfs_ialloc_btree.h"
#include "xfs_bmap_btree.h"
#include "xfs_rmap_btree.h"
#include "xfs_refcount_btree.h"
#include "xfs_health.h"
#include "xfs_buf_mem.h"
#include "xfs_btree_mem.h"
/*
* Btree magic numbers.
*/
uint32_t
xfs_btree_magic(
struct xfs_mount *mp,
const struct xfs_btree_ops *ops)
{
int idx = xfs_has_crc(mp) ? 1 : 0;
__be32 magic = ops->buf_ops->magic[idx];
/* Ensure we asked for crc for crc-only magics. */
ASSERT(magic != 0);
return be32_to_cpu(magic);
}
/*
* These sibling pointer checks are optimised for null sibling pointers. This
* happens a lot, and we don't need to byte swap at runtime if the sibling
* pointer is NULL.
*
* These are explicitly marked at inline because the cost of calling them as
* functions instead of inlining them is about 36 bytes extra code per call site
* on x86-64. Yes, gcc-11 fails to inline them, and explicit inlining of these
* two sibling check functions reduces the compiled code size by over 300
* bytes.
*/
static inline xfs_failaddr_t
xfs_btree_check_fsblock_siblings(
struct xfs_mount *mp,
xfs_fsblock_t fsb,
__be64 dsibling)
{
xfs_fsblock_t sibling;
if (dsibling == cpu_to_be64(NULLFSBLOCK))
return NULL;
sibling = be64_to_cpu(dsibling);
if (sibling == fsb)
return __this_address;
if (!xfs_verify_fsbno(mp, sibling))
return __this_address;
return NULL;
}
static inline xfs_failaddr_t
xfs_btree_check_memblock_siblings(
struct xfs_buftarg *btp,
xfbno_t bno,
__be64 dsibling)
{
xfbno_t sibling;
if (dsibling == cpu_to_be64(NULLFSBLOCK))
return NULL;
sibling = be64_to_cpu(dsibling);
if (sibling == bno)
return __this_address;
if (!xmbuf_verify_daddr(btp, xfbno_to_daddr(sibling)))
return __this_address;
return NULL;
}
static inline xfs_failaddr_t
xfs_btree_check_agblock_siblings(
struct xfs_perag *pag,
xfs_agblock_t agbno,
__be32 dsibling)
{
xfs_agblock_t sibling;
if (dsibling == cpu_to_be32(NULLAGBLOCK))
return NULL;
sibling = be32_to_cpu(dsibling);
if (sibling == agbno)
return __this_address;
if (!xfs_verify_agbno(pag, sibling))
return __this_address;
return NULL;
}
static xfs_failaddr_t
__xfs_btree_check_lblock_hdr(
struct xfs_btree_cur *cur,
struct xfs_btree_block *block,
int level,
struct xfs_buf *bp)
{
struct xfs_mount *mp = cur->bc_mp;
if (xfs_has_crc(mp)) {
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 ? xfs_buf_daddr(bp) : 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(mp, cur->bc_ops))
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;
return NULL;
}
/*
* Check a long btree block header. Return the address of the failing check,
* or NULL if everything is ok.
*/
static xfs_failaddr_t
__xfs_btree_check_fsblock(
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;
xfs_fsblock_t fsb;
fa = __xfs_btree_check_lblock_hdr(cur, block, level, bp);
if (fa)
return fa;
/*
* For inode-rooted btrees, the root block sits in the inode fork. In
* that case bp is NULL, and the block must not have any siblings.
*/
if (!bp) {
if (block->bb_u.l.bb_leftsib != cpu_to_be64(NULLFSBLOCK))
return __this_address;
if (block->bb_u.l.bb_rightsib != cpu_to_be64(NULLFSBLOCK))
return __this_address;
return NULL;
}
fsb = XFS_DADDR_TO_FSB(mp, xfs_buf_daddr(bp));
fa = xfs_btree_check_fsblock_siblings(mp, fsb,
block->bb_u.l.bb_leftsib);
if (!fa)
fa = xfs_btree_check_fsblock_siblings(mp, fsb,
block->bb_u.l.bb_rightsib);
return fa;
}
/*
* Check an in-memory btree block header. Return the address of the failing
* check, or NULL if everything is ok.
*/
static xfs_failaddr_t
__xfs_btree_check_memblock(
struct xfs_btree_cur *cur,
struct xfs_btree_block *block,
int level,
struct xfs_buf *bp)
{
struct xfs_buftarg *btp = cur->bc_mem.xfbtree->target;
xfs_failaddr_t fa;
xfbno_t bno;
fa = __xfs_btree_check_lblock_hdr(cur, block, level, bp);
if (fa)
return fa;
bno = xfs_daddr_to_xfbno(xfs_buf_daddr(bp));
fa = xfs_btree_check_memblock_siblings(btp, bno,
block->bb_u.l.bb_leftsib);
if (!fa)
fa = xfs_btree_check_memblock_siblings(btp, bno,
block->bb_u.l.bb_rightsib);
return fa;
}
/*
* Check a short btree block header. Return the address of the failing check,
* or NULL if everything is ok.
*/
static xfs_failaddr_t
__xfs_btree_check_agblock(
struct xfs_btree_cur *cur,
struct xfs_btree_block *block,
int level,
struct xfs_buf *bp)
{
struct xfs_mount *mp = cur->bc_mp;
struct xfs_perag *pag = cur->bc_ag.pag;
xfs_failaddr_t fa;
xfs_agblock_t agbno;
if (xfs_has_crc(mp)) {
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(xfs_buf_daddr(bp)))
return __this_address;
}
if (be32_to_cpu(block->bb_magic) != xfs_btree_magic(mp, cur->bc_ops))
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;
agbno = xfs_daddr_to_agbno(mp, xfs_buf_daddr(bp));
fa = xfs_btree_check_agblock_siblings(pag, agbno,
block->bb_u.s.bb_leftsib);
if (!fa)
fa = xfs_btree_check_agblock_siblings(pag, agbno,
block->bb_u.s.bb_rightsib);
return fa;
}
/*
* Internal btree block check.
*
* Return NULL if the block is ok or the address of the failed check otherwise.
*/
xfs_failaddr_t
__xfs_btree_check_block(
struct xfs_btree_cur *cur,
struct xfs_btree_block *block,
int level,
struct xfs_buf *bp)
{
switch (cur->bc_ops->type) {
case XFS_BTREE_TYPE_MEM:
return __xfs_btree_check_memblock(cur, block, level, bp);
case XFS_BTREE_TYPE_AG:
return __xfs_btree_check_agblock(cur, block, level, bp);
case XFS_BTREE_TYPE_INODE:
return __xfs_btree_check_fsblock(cur, block, level, bp);
default:
ASSERT(0);
return __this_address;
}
}
static inline unsigned int xfs_btree_block_errtag(struct xfs_btree_cur *cur)
{
if (cur->bc_ops->ptr_len == XFS_BTREE_SHORT_PTR_LEN)
return XFS_ERRTAG_BTREE_CHECK_SBLOCK;
return XFS_ERRTAG_BTREE_CHECK_LBLOCK;
}
/*
* 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 */
{
struct xfs_mount *mp = cur->bc_mp;
xfs_failaddr_t fa;
fa = __xfs_btree_check_block(cur, block, level, bp);
if (XFS_IS_CORRUPT(mp, fa != NULL) ||
XFS_TEST_ERROR(false, mp, xfs_btree_block_errtag(cur))) {
if (bp)
trace_xfs_btree_corrupt(bp, _RET_IP_);
xfs_btree_mark_sick(cur);
return -EFSCORRUPTED;
}
return 0;
}
int
__xfs_btree_check_ptr(
struct xfs_btree_cur *cur,
const union xfs_btree_ptr *ptr,
int index,
int level)
{
if (level <= 0)
return -EFSCORRUPTED;
switch (cur->bc_ops->type) {
case XFS_BTREE_TYPE_MEM:
if (!xfbtree_verify_bno(cur->bc_mem.xfbtree,
be64_to_cpu((&ptr->l)[index])))
return -EFSCORRUPTED;
break;
case XFS_BTREE_TYPE_INODE:
if (!xfs_verify_fsbno(cur->bc_mp,
be64_to_cpu((&ptr->l)[index])))
return -EFSCORRUPTED;
break;
case XFS_BTREE_TYPE_AG:
if (!xfs_verify_agbno(cur->bc_ag.pag,
be32_to_cpu((&ptr->s)[index])))
return -EFSCORRUPTED;
break;
}
return 0;
}
/*
* 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,
const union xfs_btree_ptr *ptr,
int index,
int level)
{
int error;
error = __xfs_btree_check_ptr(cur, ptr, index, level);
if (error) {
switch (cur->bc_ops->type) {
case XFS_BTREE_TYPE_MEM:
xfs_err(cur->bc_mp,
"In-memory: Corrupt %sbt flags 0x%x pointer at level %d index %d fa %pS.",
cur->bc_ops->name, cur->bc_flags, level, index,
__this_address);
break;
case XFS_BTREE_TYPE_INODE:
xfs_err(cur->bc_mp,
"Inode %llu fork %d: Corrupt %sbt pointer at level %d index %d.",
cur->bc_ino.ip->i_ino,
cur->bc_ino.whichfork, cur->bc_ops->name,
level, index);
break;
case XFS_BTREE_TYPE_AG:
xfs_err(cur->bc_mp,
"AG %u: Corrupt %sbt pointer at level %d index %d.",
cur->bc_ag.pag->pag_agno, cur->bc_ops->name,
level, index);
break;
}
xfs_btree_mark_sick(cur);
}
return error;
}
#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_fsblock_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_has_crc(bp->b_mount))
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_fsblock_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_has_crc(mp)) {
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_agblock_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_has_crc(bp->b_mount))
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_agblock_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_has_crc(mp)) {
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;
trace_xfs_btree_free_block(cur, bp);
/*
* Don't allow block freeing for a staging cursor, because staging
* cursors do not support regular btree modifications.
*/
if (unlikely(cur->bc_flags & XFS_BTREE_STAGING)) {
ASSERT(0);
return -EFSCORRUPTED;
}
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(
struct xfs_btree_cur *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 because of an error, 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_levels[i].bp)
xfs_trans_brelse(cur->bc_tp, cur->bc_levels[i].bp);
else if (!error)
break;
}
/*
* If we are doing a BMBT update, the number of unaccounted blocks
* allocated during this cursor life time should be zero. If it's not
* zero, then we should be shut down or on our way to shutdown due to
* cancelling a dirty transaction on error.
*/
ASSERT(!xfs_btree_is_bmap(cur->bc_ops) || cur->bc_bmap.allocated == 0 ||
xfs_is_shutdown(cur->bc_mp) || error != 0);
switch (cur->bc_ops->type) {
case XFS_BTREE_TYPE_AG:
if (cur->bc_ag.pag)
xfs_perag_put(cur->bc_ag.pag);
break;
case XFS_BTREE_TYPE_INODE:
/* nothing to do */
break;
case XFS_BTREE_TYPE_MEM:
if (cur->bc_mem.pag)
xfs_perag_put(cur->bc_mem.pag);
break;
}
kmem_cache_free(cur->bc_cache, cur);
}
/* Return the buffer target for this btree's buffer. */
static inline struct xfs_buftarg *
xfs_btree_buftarg(
struct xfs_btree_cur *cur)
{
if (cur->bc_ops->type == XFS_BTREE_TYPE_MEM)
return cur->bc_mem.xfbtree->target;
return cur->bc_mp->m_ddev_targp;
}
/* Return the block size (in units of 512b sectors) for this btree. */
static inline unsigned int
xfs_btree_bbsize(
struct xfs_btree_cur *cur)
{
if (cur->bc_ops->type == XFS_BTREE_TYPE_MEM)
return XFBNO_BBSIZE;
return cur->bc_mp->m_bsize;
}
/*
* Duplicate the btree cursor.
* Allocate a new one, copy the record, re-get the buffers.
*/
int /* error */
xfs_btree_dup_cursor(
struct xfs_btree_cur *cur, /* input cursor */
struct xfs_btree_cur **ncur) /* output cursor */
{
struct xfs_mount *mp = cur->bc_mp;
struct xfs_trans *tp = cur->bc_tp;
struct xfs_buf *bp;
struct xfs_btree_cur *new;
int error;
int i;
/*
* Don't allow staging cursors to be duplicated because they're supposed
* to be kept private to a single thread.
*/
if (unlikely(cur->bc_flags & XFS_BTREE_STAGING)) {
ASSERT(0);
return -EFSCORRUPTED;
}
/*
* 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_levels[i].ptr = cur->bc_levels[i].ptr;
new->bc_levels[i].ra = cur->bc_levels[i].ra;
bp = cur->bc_levels[i].bp;
if (bp) {
error = xfs_trans_read_buf(mp, tp,
xfs_btree_buftarg(cur),
xfs_buf_daddr(bp),
xfs_btree_bbsize(cur), 0, &bp,
cur->bc_ops->buf_ops);
if (xfs_metadata_is_sick(error))
xfs_btree_mark_sick(new);
if (error) {
xfs_btree_del_cursor(new, error);
*ncur = NULL;
return error;
}
}
new->bc_levels[i].bp = 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_BTGEO_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_ops->ptr_len == XFS_BTREE_LONG_PTR_LEN) {
if (xfs_has_crc(cur->bc_mp))
return XFS_BTREE_LBLOCK_CRC_LEN;
return XFS_BTREE_LBLOCK_LEN;
}
if (xfs_has_crc(cur->bc_mp))
return XFS_BTREE_SBLOCK_CRC_LEN;
return XFS_BTREE_SBLOCK_LEN;
}
/*
* 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) * cur->bc_ops->ptr_len;
}
/*
* 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));
}
struct xfs_ifork *
xfs_btree_ifork_ptr(
struct xfs_btree_cur *cur)
{
ASSERT(cur->bc_ops->type == XFS_BTREE_TYPE_INODE);
if (cur->bc_flags & XFS_BTREE_STAGING)
return cur->bc_ino.ifake->if_fork;
return xfs_ifork_ptr(cur->bc_ino.ip, cur->bc_ino.whichfork);
}
/*
* 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 = xfs_btree_ifork_ptr(cur);
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 (xfs_btree_at_iroot(cur, level)) {
*bpp = NULL;
return xfs_btree_get_iroot(cur);
}
*bpp = cur->bc_levels[level].bp;
return XFS_BUF_TO_BLOCK(*bpp);
}
/*
* 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(
struct xfs_btree_cur *cur, /* btree cursor */
int level) /* level to change */
{
struct xfs_btree_block *block; /* generic btree block pointer */
struct xfs_buf *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_levels[level].ptr = 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(
struct xfs_btree_cur *cur, /* btree cursor */
int level) /* level to change */
{
struct xfs_btree_block *block; /* generic btree block pointer */
struct xfs_buf *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_levels[level].ptr = 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(
uint32_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 */
uint32_t imask; /* mask for current bit number */
ASSERT(fields != 0);
/*
* Find the lowest bit, so the first byte offset.
*/
for (i = 0, imask = 1u; ; i++, imask <<= 1) {
if (imask & fields) {
*first = offsets[i];
break;
}
}
/*
* Find the highest bit, so the last byte offset.
*/
for (i = nbits - 1, imask = 1u << i; ; i--, imask >>= 1) {
if (imask & fields) {
*last = offsets[i + 1] - 1;
break;
}
}
}
STATIC int
xfs_btree_readahead_fsblock(
struct xfs_btree_cur *cur,
int lr,
struct xfs_btree_block *block)
{
struct xfs_mount *mp = cur->bc_mp;
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);
int rval = 0;
if ((lr & XFS_BTCUR_LEFTRA) && left != NULLFSBLOCK) {
xfs_buf_readahead(mp->m_ddev_targp, XFS_FSB_TO_DADDR(mp, left),
mp->m_bsize, cur->bc_ops->buf_ops);
rval++;
}
if ((lr & XFS_BTCUR_RIGHTRA) && right != NULLFSBLOCK) {
xfs_buf_readahead(mp->m_ddev_targp, XFS_FSB_TO_DADDR(mp, right),
mp->m_bsize, cur->bc_ops->buf_ops);
rval++;
}
return rval;
}
STATIC int
xfs_btree_readahead_memblock(
struct xfs_btree_cur *cur,
int lr,
struct xfs_btree_block *block)
{
struct xfs_buftarg *btp = cur->bc_mem.xfbtree->target;
xfbno_t left = be64_to_cpu(block->bb_u.l.bb_leftsib);
xfbno_t right = be64_to_cpu(block->bb_u.l.bb_rightsib);
int rval = 0;
if ((lr & XFS_BTCUR_LEFTRA) && left != NULLFSBLOCK) {
xfs_buf_readahead(btp, xfbno_to_daddr(left), XFBNO_BBSIZE,
cur->bc_ops->buf_ops);
rval++;
}
if ((lr & XFS_BTCUR_RIGHTRA) && right != NULLFSBLOCK) {
xfs_buf_readahead(btp, xfbno_to_daddr(right), XFBNO_BBSIZE,
cur->bc_ops->buf_ops);
rval++;
}
return rval;
}
STATIC int
xfs_btree_readahead_agblock(
struct xfs_btree_cur *cur,
int lr,
struct xfs_btree_block *block)
{
struct xfs_mount *mp = cur->bc_mp;
xfs_agnumber_t agno = cur->bc_ag.pag->pag_agno;
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);
int rval = 0;
if ((lr & XFS_BTCUR_LEFTRA) && left != NULLAGBLOCK) {
xfs_buf_readahead(mp->m_ddev_targp,
XFS_AGB_TO_DADDR(mp, agno, left),
mp->m_bsize, cur->bc_ops->buf_ops);
rval++;
}
if ((lr & XFS_BTCUR_RIGHTRA) && right != NULLAGBLOCK) {
xfs_buf_readahead(mp->m_ddev_targp,
XFS_AGB_TO_DADDR(mp, agno, right),
mp->m_bsize, 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 (xfs_btree_at_iroot(cur, lev))
return 0;
if ((cur->bc_levels[lev].ra | lr) == cur->bc_levels[lev].ra)
return 0;
cur->bc_levels[lev].ra |= lr;
block = XFS_BUF_TO_BLOCK(cur->bc_levels[lev].bp);
switch (cur->bc_ops->type) {
case XFS_BTREE_TYPE_AG:
return xfs_btree_readahead_agblock(cur, lr, block);
case XFS_BTREE_TYPE_INODE:
return xfs_btree_readahead_fsblock(cur, lr, block);
case XFS_BTREE_TYPE_MEM:
return xfs_btree_readahead_memblock(cur, lr, block);
default:
ASSERT(0);
return 0;
}
}
STATIC int
xfs_btree_ptr_to_daddr(
struct xfs_btree_cur *cur,
const union xfs_btree_ptr *ptr,
xfs_daddr_t *daddr)
{
int error;
error = xfs_btree_check_ptr(cur, ptr, 0, 1);
if (error)
return error;
switch (cur->bc_ops->type) {
case XFS_BTREE_TYPE_AG:
*daddr = XFS_AGB_TO_DADDR(cur->bc_mp, cur->bc_ag.pag->pag_agno,
be32_to_cpu(ptr->s));
break;
case XFS_BTREE_TYPE_INODE:
*daddr = XFS_FSB_TO_DADDR(cur->bc_mp, be64_to_cpu(ptr->l));
break;
case XFS_BTREE_TYPE_MEM:
*daddr = xfbno_to_daddr(be64_to_cpu(ptr->l));
break;
}
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(xfs_btree_buftarg(cur), daddr,
xfs_btree_bbsize(cur) * 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(
struct xfs_btree_cur *cur, /* btree cursor */
int lev, /* level in btree */
struct xfs_buf *bp) /* new buffer to set */
{
struct xfs_btree_block *b; /* btree block */
if (cur->bc_levels[lev].bp)
xfs_trans_brelse(cur->bc_tp, cur->bc_levels[lev].bp);
cur->bc_levels[lev].bp = bp;
cur->bc_levels[lev].ra = 0;
b = XFS_BUF_TO_BLOCK(bp);
if (cur->bc_ops->ptr_len == XFS_BTREE_LONG_PTR_LEN) {
if (b->bb_u.l.bb_leftsib == cpu_to_be64(NULLFSBLOCK))
cur->bc_levels[lev].ra |= XFS_BTCUR_LEFTRA;
if (b->bb_u.l.bb_rightsib == cpu_to_be64(NULLFSBLOCK))
cur->bc_levels[lev].ra |= XFS_BTCUR_RIGHTRA;
} else {
if (b->bb_u.s.bb_leftsib == cpu_to_be32(NULLAGBLOCK))
cur->bc_levels[lev].ra |= XFS_BTCUR_LEFTRA;
if (b->bb_u.s.bb_rightsib == cpu_to_be32(NULLAGBLOCK))
cur->bc_levels[lev].ra |= XFS_BTCUR_RIGHTRA;
}
}
bool
xfs_btree_ptr_is_null(
struct xfs_btree_cur *cur,
const union xfs_btree_ptr *ptr)
{
if (cur->bc_ops->ptr_len == XFS_BTREE_LONG_PTR_LEN)
return ptr->l == cpu_to_be64(NULLFSBLOCK);
else
return ptr->s == cpu_to_be32(NULLAGBLOCK);
}
void
xfs_btree_set_ptr_null(
struct xfs_btree_cur *cur,
union xfs_btree_ptr *ptr)
{
if (cur->bc_ops->ptr_len == XFS_BTREE_LONG_PTR_LEN)
ptr->l = cpu_to_be64(NULLFSBLOCK);
else
ptr->s = cpu_to_be32(NULLAGBLOCK);
}
static inline bool
xfs_btree_ptrs_equal(
struct xfs_btree_cur *cur,
union xfs_btree_ptr *ptr1,
union xfs_btree_ptr *ptr2)
{
if (cur->bc_ops->ptr_len == XFS_BTREE_LONG_PTR_LEN)
return ptr1->l == ptr2->l;
return ptr1->s == ptr2->s;
}
/*
* 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_ops->ptr_len == XFS_BTREE_LONG_PTR_LEN) {
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;
}
}
void
xfs_btree_set_sibling(
struct xfs_btree_cur *cur,
struct xfs_btree_block *block,
const union xfs_btree_ptr *ptr,
int lr)
{
ASSERT(lr == XFS_BB_LEFTSIB || lr == XFS_BB_RIGHTSIB);
if (cur->bc_ops->ptr_len == XFS_BTREE_LONG_PTR_LEN) {
if (lr == XFS_BB_RIGHTSIB)
block->bb_u.l.bb_rightsib = ptr->l;
else
block->bb_u.l.bb_leftsib = ptr->l;
} else {
if (lr == XFS_BB_RIGHTSIB)
block->bb_u.s.bb_rightsib = ptr->s;
else
block->bb_u.s.bb_leftsib = ptr->s;
}
}
static void
__xfs_btree_init_block(
struct xfs_mount *mp,
struct xfs_btree_block *buf,
const struct xfs_btree_ops *ops,
xfs_daddr_t blkno,
__u16 level,
__u16 numrecs,
__u64 owner)
{
bool crc = xfs_has_crc(mp);
__u32 magic = xfs_btree_magic(mp, ops);
buf->bb_magic = cpu_to_be32(magic);
buf->bb_level = cpu_to_be16(level);
buf->bb_numrecs = cpu_to_be16(numrecs);
if (ops->ptr_len == XFS_BTREE_LONG_PTR_LEN) {
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 {
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);
/* owner is a 32 bit value on short blocks */
buf->bb_u.s.bb_owner = cpu_to_be32((__u32)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_btree_block *block,
const struct xfs_btree_ops *ops,
__u16 level,
__u16 numrecs,
__u64 owner)
{
__xfs_btree_init_block(mp, block, ops, XFS_BUF_DADDR_NULL, level,
numrecs, owner);
}
void
xfs_btree_init_buf(
struct xfs_mount *mp,
struct xfs_buf *bp,
const struct xfs_btree_ops *ops,
__u16 level,
__u16 numrecs,
__u64 owner)
{
__xfs_btree_init_block(mp, XFS_BUF_TO_BLOCK(bp), ops,
xfs_buf_daddr(bp), level, numrecs, owner);
bp->b_ops = ops->buf_ops;
}
static inline __u64
xfs_btree_owner(
struct xfs_btree_cur *cur)
{
switch (cur->bc_ops->type) {
case XFS_BTREE_TYPE_MEM:
return cur->bc_mem.xfbtree->owner;
case XFS_BTREE_TYPE_INODE:
return cur->bc_ino.ip->i_ino;
case XFS_BTREE_TYPE_AG:
return cur->bc_ag.pag->pag_agno;
default:
ASSERT(0);
return 0;
}
}
void
xfs_btree_init_block_cur(
struct xfs_btree_cur *cur,
struct xfs_buf *bp,
int level,
int numrecs)
{
xfs_btree_init_buf(cur->bc_mp, bp, cur->bc_ops, level, numrecs,
xfs_btree_owner(cur));
}
/*
* 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_ops->geom_flags & XFS_BTGEO_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)
{
switch (cur->bc_ops->type) {
case XFS_BTREE_TYPE_AG:
ptr->s = cpu_to_be32(xfs_daddr_to_agbno(cur->bc_mp,
xfs_buf_daddr(bp)));
break;
case XFS_BTREE_TYPE_INODE:
ptr->l = cpu_to_be64(XFS_DADDR_TO_FSB(cur->bc_mp,
xfs_buf_daddr(bp)));
break;
case XFS_BTREE_TYPE_MEM:
ptr->l = cpu_to_be64(xfs_daddr_to_xfbno(xfs_buf_daddr(bp)));
break;
}
}
static inline void
xfs_btree_set_refs(
struct xfs_btree_cur *cur,
struct xfs_buf *bp)
{
xfs_buf_set_ref(bp, cur->bc_ops->lru_refs);
}
int
xfs_btree_get_buf_block(
struct xfs_btree_cur *cur,
const union xfs_btree_ptr *ptr,
struct xfs_btree_block **block,
struct xfs_buf **bpp)
{
xfs_daddr_t d;
int error;
error = xfs_btree_ptr_to_daddr(cur, ptr, &d);
if (error)
return error;
error = xfs_trans_get_buf(cur->bc_tp, xfs_btree_buftarg(cur), d,
xfs_btree_bbsize(cur), 0, bpp);
if (error)
return error;
(*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.
*/
int
xfs_btree_read_buf_block(
struct xfs_btree_cur *cur,
const 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, xfs_btree_buftarg(cur), d,
xfs_btree_bbsize(cur), flags, bpp,
cur->bc_ops->buf_ops);
if (xfs_metadata_is_sick(error))
xfs_btree_mark_sick(cur);
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.
*/
void
xfs_btree_copy_keys(
struct xfs_btree_cur *cur,
union xfs_btree_key *dst_key,
const 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.
*/
void
xfs_btree_copy_ptrs(
struct xfs_btree_cur *cur,
union xfs_btree_ptr *dst_ptr,
const union xfs_btree_ptr *src_ptr,
int numptrs)
{
ASSERT(numptrs >= 0);
memcpy(dst_ptr, src_ptr, numptrs * cur->bc_ops->ptr_len);
}
/*
* 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 * cur->bc_ops->ptr_len);
memmove(dst_ptr, ptr, numptrs * cur->bc_ops->ptr_len);
}
/*
* 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_ino.ip,
xfs_ilog_fbroot(cur->bc_ino.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_ino.ip,
xfs_ilog_fbroot(cur->bc_ino.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 */
uint32_t 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 (xfs_has_crc(cur->bc_mp)) {
/*
* 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_ops->ptr_len == XFS_BTREE_LONG_PTR_LEN) ?
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_ino.ip,
xfs_ilog_fbroot(cur->bc_ino.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_levels[level].ptr <= 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_levels[lev].ptr <= 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_ops->type == XFS_BTREE_TYPE_INODE)
goto out0;
ASSERT(0);
xfs_btree_mark_sick(cur);
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_levels[lev].ptr, 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_levels[lev].ptr = 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;
struct xfs_buf *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_levels[level].ptr > 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_levels[lev].ptr > 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_ops->type == XFS_BTREE_TYPE_INODE)
goto out0;
ASSERT(0);
xfs_btree_mark_sick(cur);
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_levels[lev].ptr, 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_levels[lev].ptr = xfs_btree_get_numrecs(block);
}
out1:
*stat = 1;
return 0;
out0:
*stat = 0;
return 0;
error0:
return error;
}
/*
* Check the btree block owner now that we have the context to know who the
* real owner is.
*/
static inline xfs_failaddr_t
xfs_btree_check_block_owner(
struct xfs_btree_cur *cur,
struct xfs_btree_block *block)
{
__u64 owner;
if (!xfs_has_crc(cur->bc_mp) ||
(cur->bc_flags & XFS_BTREE_BMBT_INVALID_OWNER))
return NULL;
owner = xfs_btree_owner(cur);
if (cur->bc_ops->ptr_len == XFS_BTREE_LONG_PTR_LEN) {
if (be64_to_cpu(block->bb_u.l.bb_owner) != owner)
return __this_address;
} else {
if (be32_to_cpu(block->bb_u.s.bb_owner) != owner)
return __this_address;
}
return NULL;
}
int
xfs_btree_lookup_get_block(
struct xfs_btree_cur *cur, /* btree cursor */
int level, /* level in the btree */
const 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 (xfs_btree_at_iroot(cur, level)) {
*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_levels[level].bp;
error = xfs_btree_ptr_to_daddr(cur, pp, &daddr);
if (error)
return error;
if (bp && xfs_buf_daddr(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_btree_check_block_owner(cur, *blkp) != NULL)
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_mark_corrupt(bp);
xfs_trans_brelse(cur->bc_tp, bp);
xfs_btree_mark_sick(cur);
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);
}
/*
* Initialize a pointer to the root block.
*/
void
xfs_btree_init_ptr_from_cur(
struct xfs_btree_cur *cur,
union xfs_btree_ptr *ptr)
{
if (cur->bc_ops->type == XFS_BTREE_TYPE_INODE) {
/*
* Inode-rooted btrees call xfs_btree_get_iroot to find the root
* in xfs_btree_lookup_get_block and don't need a pointer here.
*/
ptr->l = 0;
} else if (cur->bc_flags & XFS_BTREE_STAGING) {
ptr->s = cpu_to_be32(cur->bc_ag.afake->af_root);
} else {
cur->bc_ops->init_ptr_from_cur(cur, ptr);
}
}
/*
* 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)) {
xfs_btree_mark_sick(cur);
return -EFSCORRUPTED;
}
block = NULL;
keyno = 0;
/* initialise start pointer from cursor */
xfs_btree_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));
xfs_btree_mark_sick(cur);
return -EFSCORRUPTED;
}
cur->bc_levels[0].ptr = 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_levels[level].ptr = 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_levels[0].ptr = keyno;
error = xfs_btree_increment(cur, 0, &i);
if (error)
goto error0;
if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) {
xfs_btree_mark_sick(cur);
return -EFSCORRUPTED;
}
*stat = 1;
return 0;
}
} else if (dir == XFS_LOOKUP_LE && diff > 0)
keyno--;
cur->bc_levels[0].ptr = 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_ops->geom_flags & XFS_BTGEO_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_ops->geom_flags & XFS_BTGEO_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 (xfs_btree_keycmp_gt(cur, &hkey, &max_hkey))
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_ops->geom_flags & XFS_BTGEO_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 (xfs_btree_keycmp_gt(cur, hkey, max_hkey))
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_ops->geom_flags & XFS_BTGEO_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_ops->geom_flags & XFS_BTGEO_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_levels[level].ptr;
nlkey = xfs_btree_key_addr(cur, ptr, block);
nhkey = xfs_btree_high_key_addr(cur, ptr, block);
if (!force_all &&
xfs_btree_keycmp_eq(cur, nlkey, lkey) &&
xfs_btree_keycmp_eq(cur, nhkey, hkey))
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_ops->geom_flags & XFS_BTGEO_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_levels[level].ptr;
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_levels[0].ptr;
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 (xfs_btree_at_iroot(cur, level))
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_levels[level].ptr <= 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 */
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_ops->geom_flags & XFS_BTGEO_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)) {
xfs_btree_mark_sick(cur);
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_levels[level].ptr--;
*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 (xfs_btree_at_iroot(cur, level))
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_levels[level].ptr >= 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)) {
xfs_btree_mark_sick(cur);
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_ops->geom_flags & XFS_BTGEO_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;
}
static inline int
xfs_btree_alloc_block(
struct xfs_btree_cur *cur,
const union xfs_btree_ptr *hint_block,
union xfs_btree_ptr *new_block,
int *stat)
{
int error;
/*
* Don't allow block allocation for a staging cursor, because staging
* cursors do not support regular btree modifications.
*
* Bulk loading uses a separate callback to obtain new blocks from a
* preallocated list, which prevents ENOSPC failures during loading.
*/
if (unlikely(cur->bc_flags & XFS_BTREE_STAGING)) {
ASSERT(0);
return -EFSCORRUPTED;
}
error = cur->bc_ops->alloc_block(cur, hint_block, new_block, stat);
trace_xfs_btree_alloc_block(cur, new_block, *stat, 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 = xfs_btree_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_levels[level].ptr <= 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_ops->geom_flags & XFS_BTGEO_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_levels[level].ptr > lrecs + 1) {
xfs_btree_setbuf(cur, level, rbp);
cur->bc_levels[level].ptr -= 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_levels[level + 1].ptr++;
}
*ptrp = rptr;
*stat = 1;
return 0;
out0:
*stat = 0;
return 0;
error0:
return error;
}
#ifdef __KERNEL__
struct xfs_btree_split_args {
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 */
int result;
bool kswapd; /* allocation in kswapd context */
struct completion *done;
struct work_struct work;
};
/*
* Stack switching interfaces for allocation
*/
static void
xfs_btree_split_worker(
struct work_struct *work)
{
struct xfs_btree_split_args *args = container_of(work,
struct xfs_btree_split_args, work);
unsigned long pflags;
unsigned long new_pflags = 0;
/*
* we are in a transaction context here, but may also be doing work
* in kswapd context, and hence we may need to inherit that state
* temporarily to ensure that we don't block waiting for memory reclaim
* in any way.
*/
if (args->kswapd)
new_pflags |= PF_MEMALLOC | PF_KSWAPD;
current_set_flags_nested(&pflags, new_pflags);
xfs_trans_set_context(args->cur->bc_tp);
args->result = __xfs_btree_split(args->cur, args->level, args->ptrp,
args->key, args->curp, args->stat);
xfs_trans_clear_context(args->cur->bc_tp);
current_restore_flags_nested(&pflags, new_pflags);
/*
* Do not access args after complete() has run here. We don't own args
* and the owner may run and free args before we return here.
*/
complete(args->done);
}
/*
* BMBT split requests often come in with little stack to work on so we push
* them off to a worker thread so there is lots of stack to use. For the other
* btree types, just call directly to avoid the context switch overhead here.
*
* Care must be taken here - the work queue rescuer thread introduces potential
* AGF <> worker queue deadlocks if the BMBT block allocation has to lock new
* AGFs to allocate blocks. A task being run by the rescuer could attempt to
* lock an AGF that is already locked by a task queued to run by the rescuer,
* resulting in an ABBA deadlock as the rescuer cannot run the lock holder to
* release it until the current thread it is running gains the lock.
*
* To avoid this issue, we only ever queue BMBT splits that don't have an AGF
* already locked to allocate from. The only place that doesn't hold an AGF
* locked is unwritten extent conversion at IO completion, but that has already
* been offloaded to a worker thread and hence has no stack consumption issues
* we have to worry about.
*/
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 */
{
struct xfs_btree_split_args args;
DECLARE_COMPLETION_ONSTACK(done);
if (!xfs_btree_is_bmap(cur->bc_ops) ||
cur->bc_tp->t_highest_agno == NULLAGNUMBER)
return __xfs_btree_split(cur, level, ptrp, key, curp, stat);
args.cur = cur;
args.level = level;
args.ptrp = ptrp;
args.key = key;
args.curp = curp;
args.stat = stat;
args.done = &done;
args.kswapd = current_is_kswapd();
INIT_WORK_ONSTACK(&args.work, xfs_btree_split_worker);
queue_work(xfs_alloc_wq, &args.work);
wait_for_completion(&done);
destroy_work_on_stack(&args.work);
return args.result;
}
#else
#define xfs_btree_split __xfs_btree_split
#endif /* __KERNEL__ */
/*
* Copy the old inode root contents into a real block and make the
* broot point to it.
*/
int /* error */
xfs_btree_new_iroot(
struct xfs_btree_cur *cur, /* btree cursor */
int *logflags, /* logging flags for inode */
int *stat) /* return status - 0 fail */
{
struct xfs_buf *cbp; /* buffer for cblock */
struct xfs_btree_block *block; /* btree block */
struct xfs_btree_block *cblock; /* child btree block */
union xfs_btree_key *ckp; /* child key pointer */
union xfs_btree_ptr *cpp; /* child ptr pointer */
union xfs_btree_key *kp; /* pointer to btree key */
union xfs_btree_ptr *pp; /* pointer to block addr */
union xfs_btree_ptr nptr; /* new block addr */
int level; /* btree level */
int error; /* error return code */
int i; /* loop counter */
XFS_BTREE_STATS_INC(cur, newroot);
ASSERT(cur->bc_ops->type == XFS_BTREE_TYPE_INODE);
level = cur->bc_nlevels - 1;
block = xfs_btree_get_iroot(cur);
pp = xfs_btree_ptr_addr(cur, 1, block);
/* Allocate the new block. If we can't do it, we're toast. Give up. */
error = xfs_btree_alloc_block(cur, pp, &nptr, stat);
if (error)
goto error0;
if (*stat == 0)
return 0;
XFS_BTREE_STATS_INC(cur, alloc);
/* Copy the root into a real block. */
error = xfs_btree_get_buf_block(cur, &nptr, &cblock, &cbp);
if (error)
goto error0;
/*
* we can't just memcpy() the root in for CRC enabled btree blocks.
* In that case have to also ensure the blkno remains correct
*/
memcpy(cblock, block, xfs_btree_block_len(cur));
if (xfs_has_crc(cur->bc_mp)) {
__be64 bno = cpu_to_be64(xfs_buf_daddr(cbp));
if (cur->bc_ops->ptr_len == XFS_BTREE_LONG_PTR_LEN)
cblock->bb_u.l.bb_blkno = bno;
else
cblock->bb_u.s.bb_blkno = bno;
}
be16_add_cpu(&block->bb_level, 1);
xfs_btree_set_numrecs(block, 1);
cur->bc_nlevels++;
ASSERT(cur->bc_nlevels <= cur->bc_maxlevels);
cur->bc_levels[level + 1].ptr = 1;
kp = xfs_btree_key_addr(cur, 1, block);
ckp = xfs_btree_key_addr(cur, 1, cblock);
xfs_btree_copy_keys(cur, ckp, kp, xfs_btree_get_numrecs(cblock));
cpp = xfs_btree_ptr_addr(cur, 1, cblock);
for (i = 0; i < be16_to_cpu(cblock->bb_numrecs); i++) {
error = xfs_btree_debug_check_ptr(cur, pp, i, level);
if (error)
goto error0;
}
xfs_btree_copy_ptrs(cur, cpp, pp, xfs_btree_get_numrecs(cblock));
error = xfs_btree_debug_check_ptr(cur, &nptr, 0, level);
if (error)
goto error0;
xfs_btree_copy_ptrs(cur, pp, &nptr, 1);
xfs_iroot_realloc(cur->bc_ino.ip,
1 - xfs_btree_get_numrecs(cblock),
cur->bc_ino.whichfork);
xfs_btree_setbuf(cur, level, cbp);
/*
* Do all this logging at the end so that
* the root is at the right level.
*/
xfs_btree_log_block(cur, cbp, XFS_BB_ALL_BITS);
xfs_btree_log_keys(cur, cbp, 1, be16_to_cpu(cblock->bb_numrecs));
xfs_btree_log_ptrs(cur, cbp, 1, be16_to_cpu(cblock->bb_numrecs));
*logflags |=
XFS_ILOG_CORE | xfs_ilog_fbroot(cur->bc_ino.whichfork);
*stat = 1;
return 0;
error0:
return error;
}
static void
xfs_btree_set_root(
struct xfs_btree_cur *cur,
const union xfs_btree_ptr *ptr,
int inc)
{
if (cur->bc_flags & XFS_BTREE_STAGING) {
/* Update the btree root information for a per-AG fake root. */
cur->bc_ag.afake->af_root = be32_to_cpu(ptr->s);
cur->bc_ag.afake->af_levels += inc;
} else {
cur->bc_ops->set_root(cur, ptr, inc);
}
}
/*
* Allocate a new root block, fill it in.
*/
STATIC int /* error */
xfs_btree_new_root(
struct xfs_btree_cur *cur, /* btree cursor */
int *stat) /* success/failure */
{
struct xfs_btree_block *block; /* one half of the old root block */
struct xfs_buf *bp; /* buffer containing block */
int error; /* error return value */
struct xfs_buf *lbp; /* left buffer pointer */
struct xfs_btree_block *left; /* left btree block */
struct xfs_buf *nbp; /* new (root) buffer */
struct xfs_btree_block *new; /* new (root) btree block */
int nptr; /* new value for key index, 1 or 2 */
struct xfs_buf *rbp; /* right buffer pointer */
struct xfs_btree_block *right; /* right btree block */
union xfs_btree_ptr rptr;
union xfs_btree_ptr lptr;
XFS_BTREE_STATS_INC(cur, newroot);
/* initialise our start point from the cursor */
xfs_btree_init_ptr_from_cur(cur, &rptr);
/* Allocate the new block. If we can't do it, we're toast. Give up. */
error = xfs_btree_alloc_block(cur, &rptr, &lptr, stat);
if (error)
goto error0;
if (*stat == 0)
goto out0;
XFS_BTREE_STATS_INC(cur, alloc);
/* Set up the new block. */
error = xfs_btree_get_buf_block(cur, &lptr, &new, &nbp);
if (error)
goto error0;
/* Set the root in the holding structure increasing the level by 1. */
xfs_btree_set_root(cur, &lptr, 1);
/*
* At the previous root level there are now two blocks: the old root,
* and the new block generated when it was split. We don't know which
* one the cursor is pointing at, so we set up variables "left" and
* "right" for each case.
*/
block = xfs_btree_get_block(cur, cur->bc_nlevels - 1, &bp);
#ifdef DEBUG
error = xfs_btree_check_block(cur, block, cur->bc_nlevels - 1, bp);
if (error)
goto error0;
#endif
xfs_btree_get_sibling(cur, block, &rptr, XFS_BB_RIGHTSIB);
if (!xfs_btree_ptr_is_null(cur, &rptr)) {
/* Our block is left, pick up the right block. */
lbp = bp;
xfs_btree_buf_to_ptr(cur, lbp, &lptr);
left = block;
error = xfs_btree_read_buf_block(cur, &rptr, 0, &right, &rbp);
if (error)
goto error0;
bp = rbp;
nptr = 1;
} else {
/* Our block is right, pick up the left block. */
rbp = bp;
xfs_btree_buf_to_ptr(cur, rbp, &rptr);
right = block;
xfs_btree_get_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
error = xfs_btree_read_buf_block(cur, &lptr, 0, &left, &lbp);
if (error)
goto error0;
bp = lbp;
nptr = 2;
}
/* Fill in the new block's btree header and log it. */
xfs_btree_init_block_cur(cur, nbp, cur->bc_nlevels, 2);
xfs_btree_log_block(cur, nbp, XFS_BB_ALL_BITS);
ASSERT(!xfs_btree_ptr_is_null(cur, &lptr) &&
!xfs_btree_ptr_is_null(cur, &rptr));
/* Fill in the key data in the new root. */
if (xfs_btree_get_level(left) > 0) {
/*
* Get the keys for the left block's keys and put them directly
* in the parent block. Do the same for the right block.
*/
xfs_btree_get_node_keys(cur, left,
xfs_btree_key_addr(cur, 1, new));
xfs_btree_get_node_keys(cur, right,
xfs_btree_key_addr(cur, 2, new));
} else {
/*
* Get the keys for the left block's records and put them
* directly in the parent block. Do the same for the right
* block.
*/
xfs_btree_get_leaf_keys(cur, left,
xfs_btree_key_addr(cur, 1, new));
xfs_btree_get_leaf_keys(cur, right,
xfs_btree_key_addr(cur, 2, new));
}
xfs_btree_log_keys(cur, nbp, 1, 2);
/* Fill in the pointer data in the new root. */
xfs_btree_copy_ptrs(cur,
xfs_btree_ptr_addr(cur, 1, new), &lptr, 1);
xfs_btree_copy_ptrs(cur,
xfs_btree_ptr_addr(cur, 2, new), &rptr, 1);
xfs_btree_log_ptrs(cur, nbp, 1, 2);
/* Fix up the cursor. */
xfs_btree_setbuf(cur, cur->bc_nlevels, nbp);
cur->bc_levels[cur->bc_nlevels].ptr = nptr;
cur->bc_nlevels++;
ASSERT(cur->bc_nlevels <= cur->bc_maxlevels);
*stat = 1;
return 0;
error0:
return error;
out0:
*stat = 0;
return 0;
}
STATIC int
xfs_btree_make_block_unfull(
struct xfs_btree_cur *cur, /* btree cursor */
int level, /* btree level */
int numrecs,/* # of recs in block */
int *oindex,/* old tree index */
int *index, /* new tree index */
union xfs_btree_ptr *nptr, /* new btree ptr */
struct xfs_btree_cur **ncur, /* new btree cursor */
union xfs_btree_key *key, /* key of new block */
int *stat)
{
int error = 0;
if (xfs_btree_at_iroot(cur, level)) {
struct xfs_inode *ip = cur->bc_ino.ip;
if (numrecs < cur->bc_ops->get_dmaxrecs(cur, level)) {
/* A root block that can be made bigger. */
xfs_iroot_realloc(ip, 1, cur->bc_ino.whichfork);
*stat = 1;
} else {
/* A root block that needs replacing */
int logflags = 0;
error = xfs_btree_new_iroot(cur, &logflags, stat);
if (error || *stat == 0)
return error;
xfs_trans_log_inode(cur->bc_tp, ip, logflags);
}
return 0;
}
/* First, try shifting an entry to the right neighbor. */
error = xfs_btree_rshift(cur, level, stat);
if (error || *stat)
return error;
/* Next, try shifting an entry to the left neighbor. */
error = xfs_btree_lshift(cur, level, stat);
if (error)
return error;
if (*stat) {
*oindex = *index = cur->bc_levels[level].ptr;
return 0;
}
/*
* Next, try splitting the current block in half.
*
* If this works we have to re-set our variables because we
* could be in a different block now.
*/
error = xfs_btree_split(cur, level, nptr, key, ncur, stat);
if (error || *stat == 0)
return error;
*index = cur->bc_levels[level].ptr;
return 0;
}
/*
* Insert one record/level. Return information to the caller
* allowing the next level up to proceed if necessary.
*/
STATIC int
xfs_btree_insrec(
struct xfs_btree_cur *cur, /* btree cursor */
int level, /* level to insert record at */
union xfs_btree_ptr *ptrp, /* i/o: block number inserted */
union xfs_btree_rec *rec, /* record to insert */
union xfs_btree_key *key, /* i/o: block key for ptrp */
struct xfs_btree_cur **curp, /* output: new cursor replacing cur */
int *stat) /* success/failure */
{
struct xfs_btree_block *block; /* btree block */
struct xfs_buf *bp; /* buffer for block */
union xfs_btree_ptr nptr; /* new block ptr */
struct xfs_btree_cur *ncur = NULL; /* new btree cursor */
union xfs_btree_key nkey; /* new block key */
union xfs_btree_key *lkey;
int optr; /* old key/record index */
int ptr; /* key/record index */
int numrecs;/* number of records */
int error; /* error return value */
int i;
xfs_daddr_t old_bn;
ncur = NULL;
lkey = &nkey;
/*
* If we have an external root pointer, and we've made it to the
* root level, allocate a new root block and we're done.
*/
if (cur->bc_ops->type != XFS_BTREE_TYPE_INODE &&
level >= cur->bc_nlevels) {
error = xfs_btree_new_root(cur, stat);
xfs_btree_set_ptr_null(cur, ptrp);
return error;
}
/* If we're off the left edge, return failure. */
ptr = cur->bc_levels[level].ptr;
if (ptr == 0) {
*stat = 0;
return 0;
}
optr = ptr;
XFS_BTREE_STATS_INC(cur, insrec);
/* Get pointers to the btree buffer and block. */
block = xfs_btree_get_block(cur, level, &bp);
old_bn = bp ? xfs_buf_daddr(bp) : XFS_BUF_DADDR_NULL;
numrecs = xfs_btree_get_numrecs(block);
#ifdef DEBUG
error = xfs_btree_check_block(cur, block, level, bp);
if (error)
goto error0;
/* Check that the new entry is being inserted in the right place. */
if (ptr <= numrecs) {
if (level == 0) {
ASSERT(cur->bc_ops->recs_inorder(cur, rec,
xfs_btree_rec_addr(cur, ptr, block)));
} else {
ASSERT(cur->bc_ops->keys_inorder(cur, key,
xfs_btree_key_addr(cur, ptr, block)));
}
}
#endif
/*
* If the block is full, we can't insert the new entry until we
* make the block un-full.
*/
xfs_btree_set_ptr_null(cur, &nptr);
if (numrecs == cur->bc_ops->get_maxrecs(cur, level)) {
error = xfs_btree_make_block_unfull(cur, level, numrecs,
&optr, &ptr, &nptr, &ncur, lkey, stat);
if (error || *stat == 0)
goto error0;
}
/*
* The current block may have changed if the block was
* previously full and we have just made space in it.
*/
block = xfs_btree_get_block(cur, level, &bp);
numrecs = xfs_btree_get_numrecs(block);
#ifdef DEBUG
error = xfs_btree_check_block(cur, block, level, bp);
if (error)
goto error0;
#endif
/*
* At this point we know there's room for our new entry in the block
* we're pointing at.
*/
XFS_BTREE_STATS_ADD(cur, moves, numrecs - ptr + 1);
if (level > 0) {
/* It's a nonleaf. make a hole in the keys and ptrs */
union xfs_btree_key *kp;
union xfs_btree_ptr *pp;
kp = xfs_btree_key_addr(cur, ptr, block);
pp = xfs_btree_ptr_addr(cur, ptr, block);
for (i = numrecs - ptr; i >= 0; i--) {
error = xfs_btree_debug_check_ptr(cur, pp, i, level);
if (error)
goto error0;
}
xfs_btree_shift_keys(cur, kp, 1, numrecs - ptr + 1);
xfs_btree_shift_ptrs(cur, pp, 1, numrecs - ptr + 1);
error = xfs_btree_debug_check_ptr(cur, ptrp, 0, level);
if (error)
goto error0;
/* Now put the new data in, bump numrecs and log it. */
xfs_btree_copy_keys(cur, kp, key, 1);
xfs_btree_copy_ptrs(cur, pp, ptrp, 1);
numrecs++;
xfs_btree_set_numrecs(block, numrecs);
xfs_btree_log_ptrs(cur, bp, ptr, numrecs);
xfs_btree_log_keys(cur, bp, ptr, numrecs);
#ifdef DEBUG
if (ptr < numrecs) {
ASSERT(cur->bc_ops->keys_inorder(cur, kp,
xfs_btree_key_addr(cur, ptr + 1, block)));
}
#endif
} else {
/* It's a leaf. make a hole in the records */
union xfs_btree_rec *rp;
rp = xfs_btree_rec_addr(cur, ptr, block);
xfs_btree_shift_recs(cur, rp, 1, numrecs - ptr + 1);
/* Now put the new data in, bump numrecs and log it. */
xfs_btree_copy_recs(cur, rp, rec, 1);
xfs_btree_set_numrecs(block, ++numrecs);
xfs_btree_log_recs(cur, bp, ptr, numrecs);
#ifdef DEBUG
if (ptr < numrecs) {
ASSERT(cur->bc_ops->recs_inorder(cur, rp,
xfs_btree_rec_addr(cur, ptr + 1, block)));
}
#endif
}
/* Log the new number of records in the btree header. */
xfs_btree_log_block(cur, bp, XFS_BB_NUMRECS);
/*
* If we just inserted into a new tree block, we have to
* recalculate nkey here because nkey is out of date.
*
* Otherwise we're just updating an existing block (having shoved
* some records into the new tree block), so use the regular key
* update mechanism.
*/
if (bp && xfs_buf_daddr(bp) != old_bn) {
xfs_btree_get_keys(cur, block, lkey);
} else if (xfs_btree_needs_key_update(cur, optr)) {
error = xfs_btree_update_keys(cur, level);
if (error)
goto error0;
}
/*
* If we are tracking the last record in the tree and
* we are at the far right edge of the tree, update it.
*/
if (xfs_btree_is_lastrec(cur, block, level)) {
cur->bc_ops->update_lastrec(cur, block, rec,
ptr, LASTREC_INSREC);
}
/*
* Return the new block number, if any.
* If there is one, give back a record value and a cursor too.
*/
*ptrp = nptr;
if (!xfs_btree_ptr_is_null(cur, &nptr)) {
xfs_btree_copy_keys(cur, key, lkey, 1);
*curp = ncur;
}
*stat = 1;
return 0;
error0:
if (ncur)
xfs_btree_del_cursor(ncur, error);
return error;
}
/*
* Insert the record at the point referenced by cur.
*
* A multi-level split of the tree on insert will invalidate the original
* cursor. All callers of this function should assume that the cursor is
* no longer valid and revalidate it.
*/
int
xfs_btree_insert(
struct xfs_btree_cur *cur,
int *stat)
{
int error; /* error return value */
int i; /* result value, 0 for failure */
int level; /* current level number in btree */
union xfs_btree_ptr nptr; /* new block number (split result) */
struct xfs_btree_cur *ncur; /* new cursor (split result) */
struct xfs_btree_cur *pcur; /* previous level's cursor */
union xfs_btree_key bkey; /* key of block to insert */
union xfs_btree_key *key;
union xfs_btree_rec rec; /* record to insert */
level = 0;
ncur = NULL;
pcur = cur;
key = &bkey;
xfs_btree_set_ptr_null(cur, &nptr);
/* Make a key out of the record data to be inserted, and save it. */
cur->bc_ops->init_rec_from_cur(cur, &rec);
cur->bc_ops->init_key_from_rec(key, &rec);
/*
* Loop going up the tree, starting at the leaf level.
* Stop when we don't get a split block, that must mean that
* the insert is finished with this level.
*/
do {
/*
* Insert nrec/nptr into this level of the tree.
* Note if we fail, nptr will be null.
*/
error = xfs_btree_insrec(pcur, level, &nptr, &rec, key,
&ncur, &i);
if (error) {
if (pcur != cur)
xfs_btree_del_cursor(pcur, XFS_BTREE_ERROR);
goto error0;
}
if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) {
xfs_btree_mark_sick(cur);
error = -EFSCORRUPTED;
goto error0;
}
level++;
/*
* See if the cursor we just used is trash.
* Can't trash the caller's cursor, but otherwise we should
* if ncur is a new cursor or we're about to be done.
*/
if (pcur != cur &&
(ncur || xfs_btree_ptr_is_null(cur, &nptr))) {
/* Save the state from the cursor before we trash it */
if (cur->bc_ops->update_cursor &&
!(cur->bc_flags & XFS_BTREE_STAGING))
cur->bc_ops->update_cursor(pcur, cur);
cur->bc_nlevels = pcur->bc_nlevels;
xfs_btree_del_cursor(pcur, XFS_BTREE_NOERROR);
}
/* If we got a new cursor, switch to it. */
if (ncur) {
pcur = ncur;
ncur = NULL;
}
} while (!xfs_btree_ptr_is_null(cur, &nptr));
*stat = i;
return 0;
error0:
return error;
}
/*
* Try to merge a non-leaf block back into the inode root.
*
* Note: the killroot names comes from the fact that we're effectively
* killing the old root block. But because we can't just delete the
* inode we have to copy the single block it was pointing to into the
* inode.
*/
STATIC int
xfs_btree_kill_iroot(
struct xfs_btree_cur *cur)
{
int whichfork = cur->bc_ino.whichfork;
struct xfs_inode *ip = cur->bc_ino.ip;
struct xfs_ifork *ifp = xfs_ifork_ptr(ip, whichfork);
struct xfs_btree_block *block;
struct xfs_btree_block *cblock;
union xfs_btree_key *kp;
union xfs_btree_key *ckp;
union xfs_btree_ptr *pp;
union xfs_btree_ptr *cpp;
struct xfs_buf *cbp;
int level;
int index;
int numrecs;
int error;
#ifdef DEBUG
union xfs_btree_ptr ptr;
#endif
int i;
ASSERT(cur->bc_ops->type == XFS_BTREE_TYPE_INODE);
ASSERT(cur->bc_nlevels > 1);
/*
* Don't deal with the root block needs to be a leaf case.
* We're just going to turn the thing back into extents anyway.
*/
level = cur->bc_nlevels - 1;
if (level == 1)
goto out0;
/*
* Give up if the root has multiple children.
*/
block = xfs_btree_get_iroot(cur);
if (xfs_btree_get_numrecs(block) != 1)
goto out0;
cblock = xfs_btree_get_block(cur, level - 1, &cbp);
numrecs = xfs_btree_get_numrecs(cblock);
/*
* Only do this if the next level will fit.
* Then the data must be copied up to the inode,
* instead of freeing the root you free the next level.
*/
if (numrecs > cur->bc_ops->get_dmaxrecs(cur, level))
goto out0;
XFS_BTREE_STATS_INC(cur, killroot);
#ifdef DEBUG
xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_LEFTSIB);
ASSERT(xfs_btree_ptr_is_null(cur, &ptr));
xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB);
ASSERT(xfs_btree_ptr_is_null(cur, &ptr));
#endif
index = numrecs - cur->bc_ops->get_maxrecs(cur, level);
if (index) {
xfs_iroot_realloc(cur->bc_ino.ip, index,
cur->bc_ino.whichfork);
block = ifp->if_broot;
}
be16_add_cpu(&block->bb_numrecs, index);
ASSERT(block->bb_numrecs == cblock->bb_numrecs);
kp = xfs_btree_key_addr(cur, 1, block);
ckp = xfs_btree_key_addr(cur, 1, cblock);
xfs_btree_copy_keys(cur, kp, ckp, numrecs);
pp = xfs_btree_ptr_addr(cur, 1, block);
cpp = xfs_btree_ptr_addr(cur, 1, cblock);
for (i = 0; i < numrecs; i++) {
error = xfs_btree_debug_check_ptr(cur, cpp, i, level - 1);
if (error)
return error;
}
xfs_btree_copy_ptrs(cur, pp, cpp, numrecs);
error = xfs_btree_free_block(cur, cbp);
if (error)
return error;
cur->bc_levels[level - 1].bp = NULL;
be16_add_cpu(&block->bb_level, -1);
xfs_trans_log_inode(cur->bc_tp, ip,
XFS_ILOG_CORE | xfs_ilog_fbroot(cur->bc_ino.whichfork));
cur->bc_nlevels--;
out0:
return 0;
}
/*
* Kill the current root node, and replace it with it's only child node.
*/
STATIC int
xfs_btree_kill_root(
struct xfs_btree_cur *cur,
struct xfs_buf *bp,
int level,
union xfs_btree_ptr *newroot)
{
int error;
XFS_BTREE_STATS_INC(cur, killroot);
/*
* Update the root pointer, decreasing the level by 1 and then
* free the old root.
*/
xfs_btree_set_root(cur, newroot, -1);
error = xfs_btree_free_block(cur, bp);
if (error)
return error;
cur->bc_levels[level].bp = NULL;
cur->bc_levels[level].ra = 0;
cur->bc_nlevels--;
return 0;
}
STATIC int
xfs_btree_dec_cursor(
struct xfs_btree_cur *cur,
int level,
int *stat)
{
int error;
int i;
if (level > 0) {
error = xfs_btree_decrement(cur, level, &i);
if (error)
return error;
}
*stat = 1;
return 0;
}
/*
* Single level of the btree record deletion routine.
* Delete record pointed to by cur/level.
* Remove the record from its block then rebalance the tree.
* Return 0 for error, 1 for done, 2 to go on to the next level.
*/
STATIC int /* error */
xfs_btree_delrec(
struct xfs_btree_cur *cur, /* btree cursor */
int level, /* level removing record from */
int *stat) /* fail/done/go-on */
{
struct xfs_btree_block *block; /* btree block */
union xfs_btree_ptr cptr; /* current block ptr */
struct xfs_buf *bp; /* buffer for block */
int error; /* error return value */
int i; /* loop counter */
union xfs_btree_ptr lptr; /* left sibling block ptr */
struct xfs_buf *lbp; /* left buffer pointer */
struct xfs_btree_block *left; /* left btree block */
int lrecs = 0; /* left record count */
int ptr; /* key/record index */
union xfs_btree_ptr rptr; /* right sibling block ptr */
struct xfs_buf *rbp; /* right buffer pointer */
struct xfs_btree_block *right; /* right btree block */
struct xfs_btree_block *rrblock; /* right-right btree block */
struct xfs_buf *rrbp; /* right-right buffer pointer */
int rrecs = 0; /* right record count */
struct xfs_btree_cur *tcur; /* temporary btree cursor */
int numrecs; /* temporary numrec count */
tcur = NULL;
/* Get the index of the entry being deleted, check for nothing there. */
ptr = cur->bc_levels[level].ptr;
if (ptr == 0) {
*stat = 0;
return 0;
}
/* Get the buffer & block containing the record or key/ptr. */
block = xfs_btree_get_block(cur, level, &bp);
numrecs = xfs_btree_get_numrecs(block);
#ifdef DEBUG
error = xfs_btree_check_block(cur, block, level, bp);
if (error)
goto error0;
#endif
/* Fail if we're off the end of the block. */
if (ptr > numrecs) {
*stat = 0;
return 0;
}
XFS_BTREE_STATS_INC(cur, delrec);
XFS_BTREE_STATS_ADD(cur, moves, numrecs - ptr);
/* Excise the entries being deleted. */
if (level > 0) {
/* It's a nonleaf. operate on keys and ptrs */
union xfs_btree_key *lkp;
union xfs_btree_ptr *lpp;
lkp = xfs_btree_key_addr(cur, ptr + 1, block);
lpp = xfs_btree_ptr_addr(cur, ptr + 1, block);
for (i = 0; i < numrecs - ptr; i++) {
error = xfs_btree_debug_check_ptr(cur, lpp, i, level);
if (error)
goto error0;
}
if (ptr < numrecs) {
xfs_btree_shift_keys(cur, lkp, -1, numrecs - ptr);
xfs_btree_shift_ptrs(cur, lpp, -1, numrecs - ptr);
xfs_btree_log_keys(cur, bp, ptr, numrecs - 1);
xfs_btree_log_ptrs(cur, bp, ptr, numrecs - 1);
}
} else {
/* It's a leaf. operate on records */
if (ptr < numrecs) {
xfs_btree_shift_recs(cur,
xfs_btree_rec_addr(cur, ptr + 1, block),
-1, numrecs - ptr);
xfs_btree_log_recs(cur, bp, ptr, numrecs - 1);
}
}
/*
* Decrement and log the number of entries in the block.
*/
xfs_btree_set_numrecs(block, --numrecs);
xfs_btree_log_block(cur, bp, XFS_BB_NUMRECS);
/*
* If we are tracking the last record in the tree and
* we are at the far right edge of the tree, update it.
*/
if (xfs_btree_is_lastrec(cur, block, level)) {
cur->bc_ops->update_lastrec(cur, block, NULL,
ptr, LASTREC_DELREC);
}
/*
* We're at the root level. First, shrink the root block in-memory.
* Try to get rid of the next level down. If we can't then there's
* nothing left to do.
*/
if (xfs_btree_at_iroot(cur, level)) {
xfs_iroot_realloc(cur->bc_ino.ip, -1, cur->bc_ino.whichfork);
error = xfs_btree_kill_iroot(cur);
if (error)
goto error0;
error = xfs_btree_dec_cursor(cur, level, stat);
if (error)
goto error0;
*stat = 1;
return 0;
}
/*
* If this is the root level, and there's only one entry left, and it's
* NOT the leaf level, then we can get rid of this level.
*/
if (level == cur->bc_nlevels - 1) {
if (numrecs == 1 && level > 0) {
union xfs_btree_ptr *pp;
/*
* pp is still set to the first pointer in the block.
* Make it the new root of the btree.
*/
pp = xfs_btree_ptr_addr(cur, 1, block);
error = xfs_btree_kill_root(cur, bp, level, pp);
if (error)
goto error0;
} else if (level > 0) {
error = xfs_btree_dec_cursor(cur, level, stat);
if (error)
goto error0;
}
*stat = 1;
return 0;
}
/*
* If we deleted the leftmost entry in the block, update the
* key values above us in the tree.
*/
if (xfs_btree_needs_key_update(cur, ptr)) {
error = xfs_btree_update_keys(cur, level);
if (error)
goto error0;
}
/*
* If the number of records remaining in the block is at least
* the minimum, we're done.
*/
if (numrecs >= cur->bc_ops->get_minrecs(cur, level)) {
error = xfs_btree_dec_cursor(cur, level, stat);
if (error)
goto error0;
return 0;
}
/*
* Otherwise, we have to move some records around to keep the
* tree balanced. Look at the left and right sibling blocks to
* see if we can re-balance by moving only one record.
*/
xfs_btree_get_sibling(cur, block, &rptr, XFS_BB_RIGHTSIB);
xfs_btree_get_sibling(cur, block, &lptr, XFS_BB_LEFTSIB);
if (cur->bc_ops->type == XFS_BTREE_TYPE_INODE) {
/*
* One child of root, need to get a chance to copy its contents
* into the root and delete it. Can't go up to next level,
* there's nothing to delete there.
*/
if (xfs_btree_ptr_is_null(cur, &rptr) &&
xfs_btree_ptr_is_null(cur, &lptr) &&
level == cur->bc_nlevels - 2) {
error = xfs_btree_kill_iroot(cur);
if (!error)
error = xfs_btree_dec_cursor(cur, level, stat);
if (error)
goto error0;
return 0;
}
}
ASSERT(!xfs_btree_ptr_is_null(cur, &rptr) ||
!xfs_btree_ptr_is_null(cur, &lptr));
/*
* Duplicate the cursor so our btree manipulations here won't
* disrupt the next level up.
*/
error = xfs_btree_dup_cursor(cur, &tcur);
if (error)
goto error0;
/*
* If there's a right sibling, see if it's ok to shift an entry
* out of it.
*/
if (!xfs_btree_ptr_is_null(cur, &rptr)) {
/*
* Move the temp cursor to the last entry in the next block.
* Actually any entry but the first would suffice.
*/
i = xfs_btree_lastrec(tcur, level);
if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) {
xfs_btree_mark_sick(cur);
error = -EFSCORRUPTED;
goto error0;
}
error = xfs_btree_increment(tcur, level, &i);
if (error)
goto error0;
if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) {
xfs_btree_mark_sick(cur);
error = -EFSCORRUPTED;
goto error0;
}
i = xfs_btree_lastrec(tcur, level);
if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) {
xfs_btree_mark_sick(cur);
error = -EFSCORRUPTED;
goto error0;
}
/* Grab a pointer to the block. */
right = xfs_btree_get_block(tcur, level, &rbp);
#ifdef DEBUG
error = xfs_btree_check_block(tcur, right, level, rbp);
if (error)
goto error0;
#endif
/* Grab the current block number, for future use. */
xfs_btree_get_sibling(tcur, right, &cptr, XFS_BB_LEFTSIB);
/*
* If right block is full enough so that removing one entry
* won't make it too empty, and left-shifting an entry out
* of right to us works, we're done.
*/
if (xfs_btree_get_numrecs(right) - 1 >=
cur->bc_ops->get_minrecs(tcur, level)) {
error = xfs_btree_lshift(tcur, level, &i);
if (error)
goto error0;
if (i) {
ASSERT(xfs_btree_get_numrecs(block) >=
cur->bc_ops->get_minrecs(tcur, level));
xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
tcur = NULL;
error = xfs_btree_dec_cursor(cur, level, stat);
if (error)
goto error0;
return 0;
}
}
/*
* Otherwise, grab the number of records in right for
* future reference, and fix up the temp cursor to point
* to our block again (last record).
*/
rrecs = xfs_btree_get_numrecs(right);
if (!xfs_btree_ptr_is_null(cur, &lptr)) {
i = xfs_btree_firstrec(tcur, level);
if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) {
xfs_btree_mark_sick(cur);
error = -EFSCORRUPTED;
goto error0;
}
error = xfs_btree_decrement(tcur, level, &i);
if (error)
goto error0;
if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) {
xfs_btree_mark_sick(cur);
error = -EFSCORRUPTED;
goto error0;
}
}
}
/*
* If there's a left sibling, see if it's ok to shift an entry
* out of it.
*/
if (!xfs_btree_ptr_is_null(cur, &lptr)) {
/*
* Move the temp cursor to the first entry in the
* previous block.
*/
i = xfs_btree_firstrec(tcur, level);
if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) {
xfs_btree_mark_sick(cur);
error = -EFSCORRUPTED;
goto error0;
}
error = xfs_btree_decrement(tcur, level, &i);
if (error)
goto error0;
i = xfs_btree_firstrec(tcur, level);
if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) {
xfs_btree_mark_sick(cur);
error = -EFSCORRUPTED;
goto error0;
}
/* Grab a pointer to the block. */
left = xfs_btree_get_block(tcur, level, &lbp);
#ifdef DEBUG
error = xfs_btree_check_block(cur, left, level, lbp);
if (error)
goto error0;
#endif
/* Grab the current block number, for future use. */
xfs_btree_get_sibling(tcur, left, &cptr, XFS_BB_RIGHTSIB);
/*
* If left block is full enough so that removing one entry
* won't make it too empty, and right-shifting an entry out
* of left to us works, we're done.
*/
if (xfs_btree_get_numrecs(left) - 1 >=
cur->bc_ops->get_minrecs(tcur, level)) {
error = xfs_btree_rshift(tcur, level, &i);
if (error)
goto error0;
if (i) {
ASSERT(xfs_btree_get_numrecs(block) >=
cur->bc_ops->get_minrecs(tcur, level));
xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
tcur = NULL;
if (level == 0)
cur->bc_levels[0].ptr++;
*stat = 1;
return 0;
}
}
/*
* Otherwise, grab the number of records in right for
* future reference.
*/
lrecs = xfs_btree_get_numrecs(left);
}
/* Delete the temp cursor, we're done with it. */
xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
tcur = NULL;
/* If here, we need to do a join to keep the tree balanced. */
ASSERT(!xfs_btree_ptr_is_null(cur, &cptr));
if (!xfs_btree_ptr_is_null(cur, &lptr) &&
lrecs + xfs_btree_get_numrecs(block) <=
cur->bc_ops->get_maxrecs(cur, level)) {
/*
* Set "right" to be the starting block,
* "left" to be the left neighbor.
*/
rptr = cptr;
right = block;
rbp = bp;
error = xfs_btree_read_buf_block(cur, &lptr, 0, &left, &lbp);
if (error)
goto error0;
/*
* If that won't work, see if we can join with the right neighbor block.
*/
} else if (!xfs_btree_ptr_is_null(cur, &rptr) &&
rrecs + xfs_btree_get_numrecs(block) <=
cur->bc_ops->get_maxrecs(cur, level)) {
/*
* Set "left" to be the starting block,
* "right" to be the right neighbor.
*/
lptr = cptr;
left = block;
lbp = bp;
error = xfs_btree_read_buf_block(cur, &rptr, 0, &right, &rbp);
if (error)
goto error0;
/*
* Otherwise, we can't fix the imbalance.
* Just return. This is probably a logic error, but it's not fatal.
*/
} else {
error = xfs_btree_dec_cursor(cur, level, stat);
if (error)
goto error0;
return 0;
}
rrecs = xfs_btree_get_numrecs(right);
lrecs = xfs_btree_get_numrecs(left);
/*
* We're now going to join "left" and "right" by moving all the stuff
* in "right" to "left" and deleting "right".
*/
XFS_BTREE_STATS_ADD(cur, moves, rrecs);
if (level > 0) {
/* It's a non-leaf. Move keys and pointers. */
union xfs_btree_key *lkp; /* left btree key */
union xfs_btree_ptr *lpp; /* left address pointer */
union xfs_btree_key *rkp; /* right btree key */
union xfs_btree_ptr *rpp; /* right address pointer */
lkp = xfs_btree_key_addr(cur, lrecs + 1, left);
lpp = xfs_btree_ptr_addr(cur, lrecs + 1, left);
rkp = xfs_btree_key_addr(cur, 1, right);
rpp = xfs_btree_ptr_addr(cur, 1, right);
for (i = 1; i < rrecs; i++) {
error = xfs_btree_debug_check_ptr(cur, rpp, i, level);
if (error)
goto error0;
}
xfs_btree_copy_keys(cur, lkp, rkp, rrecs);
xfs_btree_copy_ptrs(cur, lpp, rpp, rrecs);
xfs_btree_log_keys(cur, lbp, lrecs + 1, lrecs + rrecs);
xfs_btree_log_ptrs(cur, lbp, lrecs + 1, lrecs + rrecs);
} else {
/* It's a leaf. Move records. */
union xfs_btree_rec *lrp; /* left record pointer */
union xfs_btree_rec *rrp; /* right record pointer */
lrp = xfs_btree_rec_addr(cur, lrecs + 1, left);
rrp = xfs_btree_rec_addr(cur, 1, right);
xfs_btree_copy_recs(cur, lrp, rrp, rrecs);
xfs_btree_log_recs(cur, lbp, lrecs + 1, lrecs + rrecs);
}
XFS_BTREE_STATS_INC(cur, join);
/*
* Fix up the number of records and right block pointer in the
* surviving block, and log it.
*/
xfs_btree_set_numrecs(left, lrecs + rrecs);
xfs_btree_get_sibling(cur, right, &cptr, XFS_BB_RIGHTSIB);
xfs_btree_set_sibling(cur, left, &cptr, XFS_BB_RIGHTSIB);
xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS | XFS_BB_RIGHTSIB);
/* If there is a right sibling, point it to the remaining block. */
xfs_btree_get_sibling(cur, left, &cptr, XFS_BB_RIGHTSIB);
if (!xfs_btree_ptr_is_null(cur, &cptr)) {
error = xfs_btree_read_buf_block(cur, &cptr, 0, &rrblock, &rrbp);
if (error)
goto error0;
xfs_btree_set_sibling(cur, rrblock, &lptr, XFS_BB_LEFTSIB);
xfs_btree_log_block(cur, rrbp, XFS_BB_LEFTSIB);
}
/* Free the deleted block. */
error = xfs_btree_free_block(cur, rbp);
if (error)
goto error0;
/*
* If we joined with the left neighbor, set the buffer in the
* cursor to the left block, and fix up the index.
*/
if (bp != lbp) {
cur->bc_levels[level].bp = lbp;
cur->bc_levels[level].ptr += lrecs;
cur->bc_levels[level].ra = 0;
}
/*
* If we joined with the right neighbor and there's a level above
* us, increment the cursor at that level.
*/
else if (cur->bc_ops->type == XFS_BTREE_TYPE_INODE ||
level + 1 < cur->bc_nlevels) {
error = xfs_btree_increment(cur, level + 1, &i);
if (error)
goto error0;
}
/*
* Readjust the ptr at this level if it's not a leaf, since it's
* still pointing at the deletion point, which makes the cursor
* inconsistent. If this makes the ptr 0, the caller fixes it up.
* We can't use decrement because it would change the next level up.
*/
if (level > 0)
cur->bc_levels[level].ptr--;
/*
* We combined blocks, so we have to update the parent keys if the
* btree supports overlapped intervals. However,
* bc_levels[level + 1].ptr points to the old block so that the caller
* knows which record to delete. Therefore, the caller must be savvy
* enough to call updkeys for us if we return stat == 2. The other
* exit points from this function don't require deletions further up
* the tree, so they can call updkeys directly.
*/
/* Return value means the next level up has something to do. */
*stat = 2;
return 0;
error0:
if (tcur)
xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR);
return error;
}
/*
* Delete the record pointed to by cur.
* The cursor refers to the place where the record was (could be inserted)
* when the operation returns.
*/
int /* error */
xfs_btree_delete(
struct xfs_btree_cur *cur,
int *stat) /* success/failure */
{
int error; /* error return value */
int level;
int i;
bool joined = false;
/*
* Go up the tree, starting at leaf level.
*
* If 2 is returned then a join was done; go to the next level.
* Otherwise we are done.
*/
for (level = 0, i = 2; i == 2; level++) {
error = xfs_btree_delrec(cur, level, &i);
if (error)
goto error0;
if (i == 2)
joined = true;
}
/*
* If we combined blocks as part of deleting the record, delrec won't
* have updated the parent high keys so we have to do that here.
*/
if (joined && (cur->bc_ops->geom_flags & XFS_BTGEO_OVERLAPPING)) {
error = xfs_btree_updkeys_force(cur, 0);
if (error)
goto error0;
}
if (i == 0) {
for (level = 1; level < cur->bc_nlevels; level++) {
if (cur->bc_levels[level].ptr == 0) {
error = xfs_btree_decrement(cur, level, &i);
if (error)
goto error0;
break;
}
}
}
*stat = i;
return 0;
error0:
return error;
}
/*
* Get the data from the pointed-to record.
*/
int /* error */
xfs_btree_get_rec(
struct xfs_btree_cur *cur, /* btree cursor */
union xfs_btree_rec **recp, /* output: btree record */
int *stat) /* output: success/failure */
{
struct xfs_btree_block *block; /* btree block */
struct xfs_buf *bp; /* buffer pointer */
int ptr; /* record number */
#ifdef DEBUG
int error; /* error return value */
#endif
ptr = cur->bc_levels[0].ptr;
block = xfs_btree_get_block(cur, 0, &bp);
#ifdef DEBUG
error = xfs_btree_check_block(cur, block, 0, bp);
if (error)
return error;
#endif
/*
* Off the right end or left end, return failure.
*/
if (ptr > xfs_btree_get_numrecs(block) || ptr <= 0) {
*stat = 0;
return 0;
}
/*
* Point to the record and extract its data.
*/
*recp = xfs_btree_rec_addr(cur, ptr, block);
*stat = 1;
return 0;
}
/* Visit a block in a btree. */
STATIC int
xfs_btree_visit_block(
struct xfs_btree_cur *cur,
int level,
xfs_btree_visit_blocks_fn fn,
void *data)
{
struct xfs_btree_block *block;
struct xfs_buf *bp;
union xfs_btree_ptr rptr, bufptr;
int error;
/* do right sibling readahead */
xfs_btree_readahead(cur, level, XFS_BTCUR_RIGHTRA);
block = xfs_btree_get_block(cur, level, &bp);
/* process the block */
error = fn(cur, level, data);
if (error)
return error;
/* now read rh sibling block for next iteration */
xfs_btree_get_sibling(cur, block, &rptr, XFS_BB_RIGHTSIB);
if (xfs_btree_ptr_is_null(cur, &rptr))
return -ENOENT;
/*
* We only visit blocks once in this walk, so we have to avoid the
* internal xfs_btree_lookup_get_block() optimisation where it will
* return the same block without checking if the right sibling points
* back to us and creates a cyclic reference in the btree.
*/
xfs_btree_buf_to_ptr(cur, bp, &bufptr);
if (xfs_btree_ptrs_equal(cur, &rptr, &bufptr)) {
xfs_btree_mark_sick(cur);
return -EFSCORRUPTED;
}
return xfs_btree_lookup_get_block(cur, level, &rptr, &block);
}
/* Visit every block in a btree. */
int
xfs_btree_visit_blocks(
struct xfs_btree_cur *cur,
xfs_btree_visit_blocks_fn fn,
unsigned int flags,
void *data)
{
union xfs_btree_ptr lptr;
int level;
struct xfs_btree_block *block = NULL;
int error = 0;
xfs_btree_init_ptr_from_cur(cur, &lptr);
/* for each level */
for (level = cur->bc_nlevels - 1; level >= 0; level--) {
/* grab the left hand block */
error = xfs_btree_lookup_get_block(cur, level, &lptr, &block);
if (error)
return error;
/* readahead the left most block for the next level down */
if (level > 0) {
union xfs_btree_ptr *ptr;
ptr = xfs_btree_ptr_addr(cur, 1, block);
xfs_btree_readahead_ptr(cur, ptr, 1);
/* save for the next iteration of the loop */
xfs_btree_copy_ptrs(cur, &lptr, ptr, 1);
if (!(flags & XFS_BTREE_VISIT_LEAVES))
continue;
} else if (!(flags & XFS_BTREE_VISIT_RECORDS)) {
continue;
}
/* for each buffer in the level */
do {
error = xfs_btree_visit_block(cur, level, fn, data);
} while (!error);
if (error != -ENOENT)
return error;
}
return 0;
}
/*
* Change the owner of a btree.
*
* The mechanism we use here is ordered buffer logging. Because we don't know
* how many buffers were are going to need to modify, we don't really want to
* have to make transaction reservations for the worst case of every buffer in a
* full size btree as that may be more space that we can fit in the log....
*
* We do the btree walk in the most optimal manner possible - we have sibling
* pointers so we can just walk all the blocks on each level from left to right
* in a single pass, and then move to the next level and do the same. We can
* also do readahead on the sibling pointers to get IO moving more quickly,
* though for slow disks this is unlikely to make much difference to performance
* as the amount of CPU work we have to do before moving to the next block is
* relatively small.
*
* For each btree block that we load, modify the owner appropriately, set the
* buffer as an ordered buffer and log it appropriately. We need to ensure that
* we mark the region we change dirty so that if the buffer is relogged in
* a subsequent transaction the changes we make here as an ordered buffer are
* correctly relogged in that transaction. If we are in recovery context, then
* just queue the modified buffer as delayed write buffer so the transaction
* recovery completion writes the changes to disk.
*/
struct xfs_btree_block_change_owner_info {
uint64_t new_owner;
struct list_head *buffer_list;
};
static int
xfs_btree_block_change_owner(
struct xfs_btree_cur *cur,
int level,
void *data)
{
struct xfs_btree_block_change_owner_info *bbcoi = data;
struct xfs_btree_block *block;
struct xfs_buf *bp;
/* modify the owner */
block = xfs_btree_get_block(cur, level, &bp);
if (cur->bc_ops->ptr_len == XFS_BTREE_LONG_PTR_LEN) {
if (block->bb_u.l.bb_owner == cpu_to_be64(bbcoi->new_owner))
return 0;
block->bb_u.l.bb_owner = cpu_to_be64(bbcoi->new_owner);
} else {
if (block->bb_u.s.bb_owner == cpu_to_be32(bbcoi->new_owner))
return 0;
block->bb_u.s.bb_owner = cpu_to_be32(bbcoi->new_owner);
}
/*
* If the block is a root block hosted in an inode, we might not have a
* buffer pointer here and we shouldn't attempt to log the change as the
* information is already held in the inode and discarded when the root
* block is formatted into the on-disk inode fork. We still change it,
* though, so everything is consistent in memory.
*/
if (!bp) {
ASSERT(cur->bc_ops->type == XFS_BTREE_TYPE_INODE);
ASSERT(level == cur->bc_nlevels - 1);
return 0;
}
if (cur->bc_tp) {
if (!xfs_trans_ordered_buf(cur->bc_tp, bp)) {
xfs_btree_log_block(cur, bp, XFS_BB_OWNER);
return -EAGAIN;
}
} else {
xfs_buf_delwri_queue(bp, bbcoi->buffer_list);
}
return 0;
}
int
xfs_btree_change_owner(
struct xfs_btree_cur *cur,
uint64_t new_owner,
struct list_head *buffer_list)
{
struct xfs_btree_block_change_owner_info bbcoi;
bbcoi.new_owner = new_owner;
bbcoi.buffer_list = buffer_list;
return xfs_btree_visit_blocks(cur, xfs_btree_block_change_owner,
XFS_BTREE_VISIT_ALL, &bbcoi);
}
/* Verify the v5 fields of a long-format btree block. */
xfs_failaddr_t
xfs_btree_fsblock_v5hdr_verify(
struct xfs_buf *bp,
uint64_t owner)
{
struct xfs_mount *mp = bp->b_mount;
struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
if (!xfs_has_crc(mp))
return __this_address;
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(xfs_buf_daddr(bp)))
return __this_address;
if (owner != XFS_RMAP_OWN_UNKNOWN &&
be64_to_cpu(block->bb_u.l.bb_owner) != owner)
return __this_address;
return NULL;
}
/* Verify a long-format btree block. */
xfs_failaddr_t
xfs_btree_fsblock_verify(
struct xfs_buf *bp,
unsigned int max_recs)
{
struct xfs_mount *mp = bp->b_mount;
struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
xfs_fsblock_t fsb;
xfs_failaddr_t fa;
ASSERT(!xfs_buftarg_is_mem(bp->b_target));
/* numrecs verification */
if (be16_to_cpu(block->bb_numrecs) > max_recs)
return __this_address;
/* sibling pointer verification */
fsb = XFS_DADDR_TO_FSB(mp, xfs_buf_daddr(bp));
fa = xfs_btree_check_fsblock_siblings(mp, fsb,
block->bb_u.l.bb_leftsib);
if (!fa)
fa = xfs_btree_check_fsblock_siblings(mp, fsb,
block->bb_u.l.bb_rightsib);
return fa;
}
/* Verify an in-memory btree block. */
xfs_failaddr_t
xfs_btree_memblock_verify(
struct xfs_buf *bp,
unsigned int max_recs)
{
struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
struct xfs_buftarg *btp = bp->b_target;
xfs_failaddr_t fa;
xfbno_t bno;
ASSERT(xfs_buftarg_is_mem(bp->b_target));
/* numrecs verification */
if (be16_to_cpu(block->bb_numrecs) > max_recs)
return __this_address;
/* sibling pointer verification */
bno = xfs_daddr_to_xfbno(xfs_buf_daddr(bp));
fa = xfs_btree_check_memblock_siblings(btp, bno,
block->bb_u.l.bb_leftsib);
if (fa)
return fa;
fa = xfs_btree_check_memblock_siblings(btp, bno,
block->bb_u.l.bb_rightsib);
if (fa)
return fa;
return NULL;
}
/**
* xfs_btree_agblock_v5hdr_verify() -- verify the v5 fields of a short-format
* btree block
*
* @bp: buffer containing the btree block
*/
xfs_failaddr_t
xfs_btree_agblock_v5hdr_verify(
struct xfs_buf *bp)
{
struct xfs_mount *mp = bp->b_mount;
struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
struct xfs_perag *pag = bp->b_pag;
if (!xfs_has_crc(mp))
return __this_address;
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(xfs_buf_daddr(bp)))
return __this_address;
if (pag && be32_to_cpu(block->bb_u.s.bb_owner) != pag->pag_agno)
return __this_address;
return NULL;
}
/**
* xfs_btree_agblock_verify() -- verify a short-format btree block
*
* @bp: buffer containing the btree block
* @max_recs: maximum records allowed in this btree node
*/
xfs_failaddr_t
xfs_btree_agblock_verify(
struct xfs_buf *bp,
unsigned int max_recs)
{
struct xfs_mount *mp = bp->b_mount;
struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
xfs_agblock_t agbno;
xfs_failaddr_t fa;
ASSERT(!xfs_buftarg_is_mem(bp->b_target));
/* numrecs verification */
if (be16_to_cpu(block->bb_numrecs) > max_recs)
return __this_address;
/* sibling pointer verification */
agbno = xfs_daddr_to_agbno(mp, xfs_buf_daddr(bp));
fa = xfs_btree_check_agblock_siblings(bp->b_pag, agbno,
block->bb_u.s.bb_leftsib);
if (!fa)
fa = xfs_btree_check_agblock_siblings(bp->b_pag, agbno,
block->bb_u.s.bb_rightsib);
return fa;
}
/*
* For the given limits on leaf and keyptr records per block, calculate the
* height of the tree needed to index the number of leaf records.
*/
unsigned int
xfs_btree_compute_maxlevels(
const unsigned int *limits,
unsigned long long records)
{
unsigned long long level_blocks = howmany_64(records, limits[0]);
unsigned int height = 1;
while (level_blocks > 1) {
level_blocks = howmany_64(level_blocks, limits[1]);
height++;
}
return height;
}
/*
* For the given limits on leaf and keyptr records per block, calculate the
* number of blocks needed to index the given number of leaf records.
*/
unsigned long long
xfs_btree_calc_size(
const unsigned int *limits,
unsigned long long records)
{
unsigned long long level_blocks = howmany_64(records, limits[0]);
unsigned long long blocks = level_blocks;
while (level_blocks > 1) {
level_blocks = howmany_64(level_blocks, limits[1]);
blocks += level_blocks;
}
return blocks;
}
/*
* Given a number of available blocks for the btree to consume with records and
* pointers, calculate the height of the tree needed to index all the records
* that space can hold based on the number of pointers each interior node
* holds.
*
* We start by assuming a single level tree consumes a single block, then track
* the number of blocks each node level consumes until we no longer have space
* to store the next node level. At this point, we are indexing all the leaf
* blocks in the space, and there's no more free space to split the tree any
* further. That's our maximum btree height.
*/
unsigned int
xfs_btree_space_to_height(
const unsigned int *limits,
unsigned long long leaf_blocks)
{
/*
* The root btree block can have fewer than minrecs pointers in it
* because the tree might not be big enough to require that amount of
* fanout. Hence it has a minimum size of 2 pointers, not limits[1].
*/
unsigned long long node_blocks = 2;
unsigned long long blocks_left = leaf_blocks - 1;
unsigned int height = 1;
if (leaf_blocks < 1)
return 0;
while (node_blocks < blocks_left) {
blocks_left -= node_blocks;
node_blocks *= limits[1];
height++;
}
return height;
}
/*
* Query a regular btree for all records overlapping a given interval.
* Start with a LE lookup of the key of low_rec and return all records
* until we find a record with a key greater than the key of high_rec.
*/
STATIC int
xfs_btree_simple_query_range(
struct xfs_btree_cur *cur,
const union xfs_btree_key *low_key,
const union xfs_btree_key *high_key,
xfs_btree_query_range_fn fn,
void *priv)
{
union xfs_btree_rec *recp;
union xfs_btree_key rec_key;
int stat;
bool firstrec = true;
int error;
ASSERT(cur->bc_ops->init_high_key_from_rec);
ASSERT(cur->bc_ops->diff_two_keys);
/*
* Find the leftmost record. The btree cursor must be set
* to the low record used to generate low_key.
*/
stat = 0;
error = xfs_btree_lookup(cur, XFS_LOOKUP_LE, &stat);
if (error)
goto out;
/* Nothing? See if there's anything to the right. */
if (!stat) {
error = xfs_btree_increment(cur, 0, &stat);
if (error)
goto out;
}
while (stat) {
/* Find the record. */
error = xfs_btree_get_rec(cur, &recp, &stat);
if (error || !stat)
break;
/* Skip if low_key > high_key(rec). */
if (firstrec) {
cur->bc_ops->init_high_key_from_rec(&rec_key, recp);
firstrec = false;
if (xfs_btree_keycmp_gt(cur, low_key, &rec_key))
goto advloop;
}
/* Stop if low_key(rec) > high_key. */
cur->bc_ops->init_key_from_rec(&rec_key, recp);
if (xfs_btree_keycmp_gt(cur, &rec_key, high_key))
break;
/* Callback */
error = fn(cur, recp, priv);
if (error)
break;
advloop:
/* Move on to the next record. */
error = xfs_btree_increment(cur, 0, &stat);
if (error)
break;
}
out:
return error;
}
/*
* Query an overlapped interval btree for all records overlapping a given
* interval. This function roughly follows the algorithm given in
* "Interval Trees" of _Introduction to Algorithms_, which is section
* 14.3 in the 2nd and 3rd editions.
*
* First, generate keys for the low and high records passed in.
*
* For any leaf node, generate the high and low keys for the record.
* If the record keys overlap with the query low/high keys, pass the
* record to the function iterator.
*
* For any internal node, compare the low and high keys of each
* pointer against the query low/high keys. If there's an overlap,
* follow the pointer.
*
* As an optimization, we stop scanning a block when we find a low key
* that is greater than the query's high key.
*/
STATIC int
xfs_btree_overlapped_query_range(
struct xfs_btree_cur *cur,
const union xfs_btree_key *low_key,
const union xfs_btree_key *high_key,
xfs_btree_query_range_fn fn,
void *priv)
{
union xfs_btree_ptr ptr;
union xfs_btree_ptr *pp;
union xfs_btree_key rec_key;
union xfs_btree_key rec_hkey;
union xfs_btree_key *lkp;
union xfs_btree_key *hkp;
union xfs_btree_rec *recp;
struct xfs_btree_block *block;
int level;
struct xfs_buf *bp;
int i;
int error;
/* Load the root of the btree. */
level = cur->bc_nlevels - 1;
xfs_btree_init_ptr_from_cur(cur, &ptr);
error = xfs_btree_lookup_get_block(cur, level, &ptr, &block);
if (error)
return error;
xfs_btree_get_block(cur, level, &bp);
trace_xfs_btree_overlapped_query_range(cur, level, bp);
#ifdef DEBUG
error = xfs_btree_check_block(cur, block, level, bp);
if (error)
goto out;
#endif
cur->bc_levels[level].ptr = 1;
while (level < cur->bc_nlevels) {
block = xfs_btree_get_block(cur, level, &bp);
/* End of node, pop back towards the root. */
if (cur->bc_levels[level].ptr >
be16_to_cpu(block->bb_numrecs)) {
pop_up:
if (level < cur->bc_nlevels - 1)
cur->bc_levels[level + 1].ptr++;
level++;
continue;
}
if (level == 0) {
/* Handle a leaf node. */
recp = xfs_btree_rec_addr(cur, cur->bc_levels[0].ptr,
block);
cur->bc_ops->init_high_key_from_rec(&rec_hkey, recp);
cur->bc_ops->init_key_from_rec(&rec_key, recp);
/*
* If (query's high key < record's low key), then there
* are no more interesting records in this block. Pop
* up to the leaf level to find more record blocks.
*
* If (record's high key >= query's low key) and
* (query's high key >= record's low key), then
* this record overlaps the query range; callback.
*/
if (xfs_btree_keycmp_lt(cur, high_key, &rec_key))
goto pop_up;
if (xfs_btree_keycmp_ge(cur, &rec_hkey, low_key)) {
error = fn(cur, recp, priv);
if (error)
break;
}
cur->bc_levels[level].ptr++;
continue;
}
/* Handle an internal node. */
lkp = xfs_btree_key_addr(cur, cur->bc_levels[level].ptr, block);
hkp = xfs_btree_high_key_addr(cur, cur->bc_levels[level].ptr,
block);
pp = xfs_btree_ptr_addr(cur, cur->bc_levels[level].ptr, block);
/*
* If (query's high key < pointer's low key), then there are no
* more interesting keys in this block. Pop up one leaf level
* to continue looking for records.
*
* If (pointer's high key >= query's low key) and
* (query's high key >= pointer's low key), then
* this record overlaps the query range; follow pointer.
*/
if (xfs_btree_keycmp_lt(cur, high_key, lkp))
goto pop_up;
if (xfs_btree_keycmp_ge(cur, hkp, low_key)) {
level--;
error = xfs_btree_lookup_get_block(cur, level, pp,
&block);
if (error)
goto out;
xfs_btree_get_block(cur, level, &bp);
trace_xfs_btree_overlapped_query_range(cur, level, bp);
#ifdef DEBUG
error = xfs_btree_check_block(cur, block, level, bp);
if (error)
goto out;
#endif
cur->bc_levels[level].ptr = 1;
continue;
}
cur->bc_levels[level].ptr++;
}
out:
/*
* If we don't end this function with the cursor pointing at a record
* block, a subsequent non-error cursor deletion will not release
* node-level buffers, causing a buffer leak. This is quite possible
* with a zero-results range query, so release the buffers if we
* failed to return any results.
*/
if (cur->bc_levels[0].bp == NULL) {
for (i = 0; i < cur->bc_nlevels; i++) {
if (cur->bc_levels[i].bp) {
xfs_trans_brelse(cur->bc_tp,
cur->bc_levels[i].bp);
cur->bc_levels[i].bp = NULL;
cur->bc_levels[i].ptr = 0;
cur->bc_levels[i].ra = 0;
}
}
}
return error;
}
static inline void
xfs_btree_key_from_irec(
struct xfs_btree_cur *cur,
union xfs_btree_key *key,
const union xfs_btree_irec *irec)
{
union xfs_btree_rec rec;
cur->bc_rec = *irec;
cur->bc_ops->init_rec_from_cur(cur, &rec);
cur->bc_ops->init_key_from_rec(key, &rec);
}
/*
* Query a btree for all records overlapping a given interval of keys. The
* supplied function will be called with each record found; return one of the
* XFS_BTREE_QUERY_RANGE_{CONTINUE,ABORT} values or the usual negative error
* code. This function returns -ECANCELED, zero, or a negative error code.
*/
int
xfs_btree_query_range(
struct xfs_btree_cur *cur,
const union xfs_btree_irec *low_rec,
const union xfs_btree_irec *high_rec,
xfs_btree_query_range_fn fn,
void *priv)
{
union xfs_btree_key low_key;
union xfs_btree_key high_key;
/* Find the keys of both ends of the interval. */
xfs_btree_key_from_irec(cur, &high_key, high_rec);
xfs_btree_key_from_irec(cur, &low_key, low_rec);
/* Enforce low key <= high key. */
if (!xfs_btree_keycmp_le(cur, &low_key, &high_key))
return -EINVAL;
if (!(cur->bc_ops->geom_flags & XFS_BTGEO_OVERLAPPING))
return xfs_btree_simple_query_range(cur, &low_key,
&high_key, fn, priv);
return xfs_btree_overlapped_query_range(cur, &low_key, &high_key,
fn, priv);
}
/* Query a btree for all records. */
int
xfs_btree_query_all(
struct xfs_btree_cur *cur,
xfs_btree_query_range_fn fn,
void *priv)
{
union xfs_btree_key low_key;
union xfs_btree_key high_key;
memset(&cur->bc_rec, 0, sizeof(cur->bc_rec));
memset(&low_key, 0, sizeof(low_key));
memset(&high_key, 0xFF, sizeof(high_key));
return xfs_btree_simple_query_range(cur, &low_key, &high_key, fn, priv);
}
static int
xfs_btree_count_blocks_helper(
struct xfs_btree_cur *cur,
int level,
void *data)
{
xfs_extlen_t *blocks = data;
(*blocks)++;
return 0;
}
/* Count the blocks in a btree and return the result in *blocks. */
int
xfs_btree_count_blocks(
struct xfs_btree_cur *cur,
xfs_extlen_t *blocks)
{
*blocks = 0;
return xfs_btree_visit_blocks(cur, xfs_btree_count_blocks_helper,
XFS_BTREE_VISIT_ALL, blocks);
}
/* Compare two btree pointers. */
int64_t
xfs_btree_diff_two_ptrs(
struct xfs_btree_cur *cur,
const union xfs_btree_ptr *a,
const union xfs_btree_ptr *b)
{
if (cur->bc_ops->ptr_len == XFS_BTREE_LONG_PTR_LEN)
return (int64_t)be64_to_cpu(a->l) - be64_to_cpu(b->l);
return (int64_t)be32_to_cpu(a->s) - be32_to_cpu(b->s);
}
struct xfs_btree_has_records {
/* Keys for the start and end of the range we want to know about. */
union xfs_btree_key start_key;
union xfs_btree_key end_key;
/* Mask for key comparisons, if desired. */
const union xfs_btree_key *key_mask;
/* Highest record key we've seen so far. */
union xfs_btree_key high_key;
enum xbtree_recpacking outcome;
};
STATIC int
xfs_btree_has_records_helper(
struct xfs_btree_cur *cur,
const union xfs_btree_rec *rec,
void *priv)
{
union xfs_btree_key rec_key;
union xfs_btree_key rec_high_key;
struct xfs_btree_has_records *info = priv;
enum xbtree_key_contig key_contig;
cur->bc_ops->init_key_from_rec(&rec_key, rec);
if (info->outcome == XBTREE_RECPACKING_EMPTY) {
info->outcome = XBTREE_RECPACKING_SPARSE;
/*
* If the first record we find does not overlap the start key,
* then there is a hole at the start of the search range.
* Classify this as sparse and stop immediately.
*/
if (xfs_btree_masked_keycmp_lt(cur, &info->start_key, &rec_key,
info->key_mask))
return -ECANCELED;
} else {
/*
* If a subsequent record does not overlap with the any record
* we've seen so far, there is a hole in the middle of the
* search range. Classify this as sparse and stop.
* If the keys overlap and this btree does not allow overlap,
* signal corruption.
*/
key_contig = cur->bc_ops->keys_contiguous(cur, &info->high_key,
&rec_key, info->key_mask);
if (key_contig == XBTREE_KEY_OVERLAP &&
!(cur->bc_ops->geom_flags & XFS_BTGEO_OVERLAPPING))
return -EFSCORRUPTED;
if (key_contig == XBTREE_KEY_GAP)
return -ECANCELED;
}
/*
* If high_key(rec) is larger than any other high key we've seen,
* remember it for later.
*/
cur->bc_ops->init_high_key_from_rec(&rec_high_key, rec);
if (xfs_btree_masked_keycmp_gt(cur, &rec_high_key, &info->high_key,
info->key_mask))
info->high_key = rec_high_key; /* struct copy */
return 0;
}
/*
* Scan part of the keyspace of a btree and tell us if that keyspace does not
* map to any records; is fully mapped to records; or is partially mapped to
* records. This is the btree record equivalent to determining if a file is
* sparse.
*
* For most btree types, the record scan should use all available btree key
* fields to compare the keys encountered. These callers should pass NULL for
* @mask. However, some callers (e.g. scanning physical space in the rmapbt)
* want to ignore some part of the btree record keyspace when performing the
* comparison. These callers should pass in a union xfs_btree_key object with
* the fields that *should* be a part of the comparison set to any nonzero
* value, and the rest zeroed.
*/
int
xfs_btree_has_records(
struct xfs_btree_cur *cur,
const union xfs_btree_irec *low,
const union xfs_btree_irec *high,
const union xfs_btree_key *mask,
enum xbtree_recpacking *outcome)
{
struct xfs_btree_has_records info = {
.outcome = XBTREE_RECPACKING_EMPTY,
.key_mask = mask,
};
int error;
/* Not all btrees support this operation. */
if (!cur->bc_ops->keys_contiguous) {
ASSERT(0);
return -EOPNOTSUPP;
}
xfs_btree_key_from_irec(cur, &info.start_key, low);
xfs_btree_key_from_irec(cur, &info.end_key, high);
error = xfs_btree_query_range(cur, low, high,
xfs_btree_has_records_helper, &info);
if (error == -ECANCELED)
goto out;
if (error)
return error;
if (info.outcome == XBTREE_RECPACKING_EMPTY)
goto out;
/*
* If the largest high_key(rec) we saw during the walk is greater than
* the end of the search range, classify this as full. Otherwise,
* there is a hole at the end of the search range.
*/
if (xfs_btree_masked_keycmp_ge(cur, &info.high_key, &info.end_key,
mask))
info.outcome = XBTREE_RECPACKING_FULL;
out:
*outcome = info.outcome;
return 0;
}
/* Are there more records in this btree? */
bool
xfs_btree_has_more_records(
struct xfs_btree_cur *cur)
{
struct xfs_btree_block *block;
struct xfs_buf *bp;
block = xfs_btree_get_block(cur, 0, &bp);
/* There are still records in this block. */
if (cur->bc_levels[0].ptr < xfs_btree_get_numrecs(block))
return true;
/* There are more record blocks. */
if (cur->bc_ops->ptr_len == XFS_BTREE_LONG_PTR_LEN)
return block->bb_u.l.bb_rightsib != cpu_to_be64(NULLFSBLOCK);
else
return block->bb_u.s.bb_rightsib != cpu_to_be32(NULLAGBLOCK);
}
/* Set up all the btree cursor caches. */
int __init
xfs_btree_init_cur_caches(void)
{
int error;
error = xfs_allocbt_init_cur_cache();
if (error)
return error;
error = xfs_inobt_init_cur_cache();
if (error)
goto err;
error = xfs_bmbt_init_cur_cache();
if (error)
goto err;
error = xfs_rmapbt_init_cur_cache();
if (error)
goto err;
error = xfs_refcountbt_init_cur_cache();
if (error)
goto err;
return 0;
err:
xfs_btree_destroy_cur_caches();
return error;
}
/* Destroy all the btree cursor caches, if they've been allocated. */
void
xfs_btree_destroy_cur_caches(void)
{
xfs_allocbt_destroy_cur_cache();
xfs_inobt_destroy_cur_cache();
xfs_bmbt_destroy_cur_cache();
xfs_rmapbt_destroy_cur_cache();
xfs_refcountbt_destroy_cur_cache();
}
/* Move the btree cursor before the first record. */
int
xfs_btree_goto_left_edge(
struct xfs_btree_cur *cur)
{
int stat = 0;
int error;
memset(&cur->bc_rec, 0, sizeof(cur->bc_rec));
error = xfs_btree_lookup(cur, XFS_LOOKUP_LE, &stat);
if (error)
return error;
if (!stat)
return 0;
error = xfs_btree_decrement(cur, 0, &stat);
if (error)
return error;
if (stat != 0) {
ASSERT(0);
xfs_btree_mark_sick(cur);
return -EFSCORRUPTED;
}
return 0;
}
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