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linux/fs/xfs/xfs_btree.h

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/*
* Copyright (c) 2000-2001,2005 Silicon Graphics, Inc.
* All Rights Reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it would be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef __XFS_BTREE_H__
#define __XFS_BTREE_H__
struct xfs_buf;
struct xfs_bmap_free;
struct xfs_inode;
struct xfs_mount;
struct xfs_trans;
extern kmem_zone_t *xfs_btree_cur_zone;
/*
* This nonsense is to make -wlint happy.
*/
#define XFS_LOOKUP_EQ ((xfs_lookup_t)XFS_LOOKUP_EQi)
#define XFS_LOOKUP_LE ((xfs_lookup_t)XFS_LOOKUP_LEi)
#define XFS_LOOKUP_GE ((xfs_lookup_t)XFS_LOOKUP_GEi)
#define XFS_BTNUM_BNO ((xfs_btnum_t)XFS_BTNUM_BNOi)
#define XFS_BTNUM_CNT ((xfs_btnum_t)XFS_BTNUM_CNTi)
#define XFS_BTNUM_BMAP ((xfs_btnum_t)XFS_BTNUM_BMAPi)
#define XFS_BTNUM_INO ((xfs_btnum_t)XFS_BTNUM_INOi)
/*
* Generic btree header.
*
* This is a combination of the actual format used on disk for short and long
* format btrees. The first three fields are shared by both format, but
* the pointers are different and should be used with care.
*
* To get the size of the actual short or long form headers please use
* the size macros below. Never use sizeof(xfs_btree_block).
*/
struct xfs_btree_block {
__be32 bb_magic; /* magic number for block type */
__be16 bb_level; /* 0 is a leaf */
__be16 bb_numrecs; /* current # of data records */
union {
struct {
__be32 bb_leftsib;
__be32 bb_rightsib;
} s; /* short form pointers */
struct {
__be64 bb_leftsib;
__be64 bb_rightsib;
} l; /* long form pointers */
} bb_u; /* rest */
};
#define XFS_BTREE_SBLOCK_LEN 16 /* size of a short form block */
#define XFS_BTREE_LBLOCK_LEN 24 /* size of a long form block */
/*
* Generic key, ptr and record wrapper structures.
*
* These are disk format structures, and are converted where necessary
* by the btree specific code that needs to interpret them.
*/
union xfs_btree_ptr {
__be32 s; /* short form ptr */
__be64 l; /* long form ptr */
};
union xfs_btree_key {
xfs_bmbt_key_t bmbt;
xfs_bmdr_key_t bmbr; /* bmbt root block */
xfs_alloc_key_t alloc;
xfs_inobt_key_t inobt;
};
union xfs_btree_rec {
xfs_bmbt_rec_t bmbt;
xfs_bmdr_rec_t bmbr; /* bmbt root block */
xfs_alloc_rec_t alloc;
xfs_inobt_rec_t inobt;
};
/*
* For logging record fields.
*/
#define XFS_BB_MAGIC 0x01
#define XFS_BB_LEVEL 0x02
#define XFS_BB_NUMRECS 0x04
#define XFS_BB_LEFTSIB 0x08
#define XFS_BB_RIGHTSIB 0x10
#define XFS_BB_NUM_BITS 5
#define XFS_BB_ALL_BITS ((1 << XFS_BB_NUM_BITS) - 1)
/*
* Magic numbers for btree blocks.
*/
extern const __uint32_t xfs_magics[];
/*
* Generic stats interface
*/
#define __XFS_BTREE_STATS_INC(type, stat) \
XFS_STATS_INC(xs_ ## type ## _2_ ## stat)
#define XFS_BTREE_STATS_INC(cur, stat) \
do { \
switch (cur->bc_btnum) { \
case XFS_BTNUM_BNO: __XFS_BTREE_STATS_INC(abtb, stat); break; \
case XFS_BTNUM_CNT: __XFS_BTREE_STATS_INC(abtc, stat); break; \
case XFS_BTNUM_BMAP: __XFS_BTREE_STATS_INC(bmbt, stat); break; \
case XFS_BTNUM_INO: __XFS_BTREE_STATS_INC(ibt, stat); break; \
case XFS_BTNUM_MAX: ASSERT(0); /* fucking gcc */ ; break; \
} \
} while (0)
#define __XFS_BTREE_STATS_ADD(type, stat, val) \
XFS_STATS_ADD(xs_ ## type ## _2_ ## stat, val)
#define XFS_BTREE_STATS_ADD(cur, stat, val) \
do { \
switch (cur->bc_btnum) { \
case XFS_BTNUM_BNO: __XFS_BTREE_STATS_ADD(abtb, stat, val); break; \
case XFS_BTNUM_CNT: __XFS_BTREE_STATS_ADD(abtc, stat, val); break; \
case XFS_BTNUM_BMAP: __XFS_BTREE_STATS_ADD(bmbt, stat, val); break; \
case XFS_BTNUM_INO: __XFS_BTREE_STATS_ADD(ibt, stat, val); break; \
case XFS_BTNUM_MAX: ASSERT(0); /* fucking gcc */ ; break; \
} \
} while (0)
#define XFS_BTREE_MAXLEVELS 8 /* max of all btrees */
struct xfs_btree_ops {
/* size of the key and record structures */
size_t key_len;
size_t rec_len;
/* cursor operations */
struct xfs_btree_cur *(*dup_cursor)(struct xfs_btree_cur *);
void (*update_cursor)(struct xfs_btree_cur *src,
struct xfs_btree_cur *dst);
/* update btree root pointer */
void (*set_root)(struct xfs_btree_cur *cur,
union xfs_btree_ptr *nptr, int level_change);
/* block allocation / freeing */
int (*alloc_block)(struct xfs_btree_cur *cur,
union xfs_btree_ptr *start_bno,
union xfs_btree_ptr *new_bno,
int length, int *stat);
int (*free_block)(struct xfs_btree_cur *cur, struct xfs_buf *bp);
/* update last record information */
void (*update_lastrec)(struct xfs_btree_cur *cur,
struct xfs_btree_block *block,
union xfs_btree_rec *rec,
int ptr, int reason);
/* records in block/level */
int (*get_minrecs)(struct xfs_btree_cur *cur, int level);
int (*get_maxrecs)(struct xfs_btree_cur *cur, int level);
/* records on disk. Matter for the root in inode case. */
int (*get_dmaxrecs)(struct xfs_btree_cur *cur, int level);
/* init values of btree structures */
void (*init_key_from_rec)(union xfs_btree_key *key,
union xfs_btree_rec *rec);
void (*init_rec_from_key)(union xfs_btree_key *key,
union xfs_btree_rec *rec);
void (*init_rec_from_cur)(struct xfs_btree_cur *cur,
union xfs_btree_rec *rec);
void (*init_ptr_from_cur)(struct xfs_btree_cur *cur,
union xfs_btree_ptr *ptr);
/* difference between key value and cursor value */
__int64_t (*key_diff)(struct xfs_btree_cur *cur,
union xfs_btree_key *key);
#ifdef DEBUG
/* check that k1 is lower than k2 */
int (*keys_inorder)(struct xfs_btree_cur *cur,
union xfs_btree_key *k1,
union xfs_btree_key *k2);
/* check that r1 is lower than r2 */
int (*recs_inorder)(struct xfs_btree_cur *cur,
union xfs_btree_rec *r1,
union xfs_btree_rec *r2);
#endif
};
/*
* Reasons for the update_lastrec method to be called.
*/
#define LASTREC_UPDATE 0
#define LASTREC_INSREC 1
#define LASTREC_DELREC 2
/*
* Btree cursor structure.
* This collects all information needed by the btree code in one place.
*/
typedef struct xfs_btree_cur
{
struct xfs_trans *bc_tp; /* transaction we're in, if any */
struct xfs_mount *bc_mp; /* file system mount struct */
const struct xfs_btree_ops *bc_ops;
uint bc_flags; /* btree features - below */
union {
xfs_alloc_rec_incore_t a;
xfs_bmbt_irec_t b;
xfs_inobt_rec_incore_t i;
} bc_rec; /* current insert/search record value */
struct xfs_buf *bc_bufs[XFS_BTREE_MAXLEVELS]; /* buf ptr per level */
int bc_ptrs[XFS_BTREE_MAXLEVELS]; /* key/record # */
__uint8_t bc_ra[XFS_BTREE_MAXLEVELS]; /* readahead bits */
#define XFS_BTCUR_LEFTRA 1 /* left sibling has been read-ahead */
#define XFS_BTCUR_RIGHTRA 2 /* right sibling has been read-ahead */
__uint8_t bc_nlevels; /* number of levels in the tree */
__uint8_t bc_blocklog; /* log2(blocksize) of btree blocks */
xfs_btnum_t bc_btnum; /* identifies which btree type */
union {
struct { /* needed for BNO, CNT, INO */
struct xfs_buf *agbp; /* agf/agi buffer pointer */
xfs_agnumber_t agno; /* ag number */
} a;
struct { /* needed for BMAP */
struct xfs_inode *ip; /* pointer to our inode */
struct xfs_bmap_free *flist; /* list to free after */
xfs_fsblock_t firstblock; /* 1st blk allocated */
int allocated; /* count of alloced */
short forksize; /* fork's inode space */
char whichfork; /* data or attr fork */
char flags; /* flags */
#define XFS_BTCUR_BPRV_WASDEL 1 /* was delayed */
} b;
} bc_private; /* per-btree type data */
} xfs_btree_cur_t;
/* cursor flags */
#define XFS_BTREE_LONG_PTRS (1<<0) /* pointers are 64bits long */
#define XFS_BTREE_ROOT_IN_INODE (1<<1) /* root may be variable size */
#define XFS_BTREE_LASTREC_UPDATE (1<<2) /* track last rec externally */
#define XFS_BTREE_NOERROR 0
#define XFS_BTREE_ERROR 1
/*
* Convert from buffer to btree block header.
*/
#define XFS_BUF_TO_BLOCK(bp) ((struct xfs_btree_block *)((bp)->b_addr))
/*
* 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 */
/*
* Check that (long) pointer is ok.
*/
int /* error (0 or EFSCORRUPTED) */
xfs_btree_check_lptr(
struct xfs_btree_cur *cur, /* btree cursor */
xfs_dfsbno_t ptr, /* btree block disk address */
int level); /* btree block level */
/*
* Delete the btree cursor.
*/
void
xfs_btree_del_cursor(
xfs_btree_cur_t *cur, /* btree cursor */
int error); /* del because of error */
/*
* Duplicate the btree cursor.
* Allocate a new one, copy the record, re-get the buffers.
*/
int /* error */
xfs_btree_dup_cursor(
xfs_btree_cur_t *cur, /* input cursor */
xfs_btree_cur_t **ncur);/* output cursor */
/*
* Get a buffer for the block, return it with no data read.
* Long-form addressing.
*/
struct xfs_buf * /* buffer for fsbno */
xfs_btree_get_bufl(
struct xfs_mount *mp, /* file system mount point */
struct xfs_trans *tp, /* transaction pointer */
xfs_fsblock_t fsbno, /* file system block number */
uint lock); /* lock flags for get_buf */
/*
* Get a buffer for the block, return it with no data read.
* Short-form addressing.
*/
struct xfs_buf * /* buffer for agno/agbno */
xfs_btree_get_bufs(
struct xfs_mount *mp, /* file system mount point */
struct xfs_trans *tp, /* transaction pointer */
xfs_agnumber_t agno, /* allocation group number */
xfs_agblock_t agbno, /* allocation group block number */
uint lock); /* lock flags for get_buf */
/*
* Check for the cursor referring to the last block at the given level.
*/
int /* 1=is last block, 0=not last block */
xfs_btree_islastblock(
xfs_btree_cur_t *cur, /* btree cursor */
int level); /* level to check */
/*
* Compute first and last byte offsets for the fields given.
* Interprets the offsets table, which contains struct field offsets.
*/
void
xfs_btree_offsets(
__int64_t fields, /* bitmask of fields */
const short *offsets,/* table of field offsets */
int nbits, /* number of bits to inspect */
int *first, /* output: first byte offset */
int *last); /* output: last byte offset */
/*
* Get a buffer for the block, return it read in.
* Long-form addressing.
*/
int /* error */
xfs_btree_read_bufl(
struct xfs_mount *mp, /* file system mount point */
struct xfs_trans *tp, /* transaction pointer */
xfs_fsblock_t fsbno, /* file system block number */
uint lock, /* lock flags for read_buf */
struct xfs_buf **bpp, /* buffer for fsbno */
int refval);/* ref count value for buffer */
/*
* Read-ahead the block, don't wait for it, don't return a buffer.
* Long-form addressing.
*/
void /* error */
xfs_btree_reada_bufl(
struct xfs_mount *mp, /* file system mount point */
xfs_fsblock_t fsbno, /* file system block number */
xfs_extlen_t count); /* count of filesystem blocks */
/*
* Read-ahead the block, don't wait for it, don't return a buffer.
* Short-form addressing.
*/
void /* error */
xfs_btree_reada_bufs(
struct xfs_mount *mp, /* file system mount point */
xfs_agnumber_t agno, /* allocation group number */
xfs_agblock_t agbno, /* allocation group block number */
xfs_extlen_t count); /* count of filesystem blocks */
/*
* Common btree core entry points.
*/
int xfs_btree_increment(struct xfs_btree_cur *, int, int *);
int xfs_btree_decrement(struct xfs_btree_cur *, int, int *);
int xfs_btree_lookup(struct xfs_btree_cur *, xfs_lookup_t, int *);
int xfs_btree_update(struct xfs_btree_cur *, union xfs_btree_rec *);
int xfs_btree_new_iroot(struct xfs_btree_cur *, int *, int *);
int xfs_btree_insert(struct xfs_btree_cur *, int *);
int xfs_btree_delete(struct xfs_btree_cur *, int *);
int xfs_btree_get_rec(struct xfs_btree_cur *, union xfs_btree_rec **, int *);
/*
* Internal btree helpers also used by xfs_bmap.c.
*/
void xfs_btree_log_block(struct xfs_btree_cur *, struct xfs_buf *, int);
void xfs_btree_log_recs(struct xfs_btree_cur *, struct xfs_buf *, int, int);
/*
* Helpers.
*/
static inline int xfs_btree_get_numrecs(struct xfs_btree_block *block)
{
return be16_to_cpu(block->bb_numrecs);
}
static inline void xfs_btree_set_numrecs(struct xfs_btree_block *block,
__uint16_t numrecs)
{
block->bb_numrecs = cpu_to_be16(numrecs);
}
static inline int xfs_btree_get_level(struct xfs_btree_block *block)
{
return be16_to_cpu(block->bb_level);
}
/*
* Min and max functions for extlen, agblock, fileoff, and filblks types.
*/
#define XFS_EXTLEN_MIN(a,b) min_t(xfs_extlen_t, (a), (b))
#define XFS_EXTLEN_MAX(a,b) max_t(xfs_extlen_t, (a), (b))
#define XFS_AGBLOCK_MIN(a,b) min_t(xfs_agblock_t, (a), (b))
#define XFS_AGBLOCK_MAX(a,b) max_t(xfs_agblock_t, (a), (b))
#define XFS_FILEOFF_MIN(a,b) min_t(xfs_fileoff_t, (a), (b))
#define XFS_FILEOFF_MAX(a,b) max_t(xfs_fileoff_t, (a), (b))
#define XFS_FILBLKS_MIN(a,b) min_t(xfs_filblks_t, (a), (b))
#define XFS_FILBLKS_MAX(a,b) max_t(xfs_filblks_t, (a), (b))
#define XFS_FSB_SANITY_CHECK(mp,fsb) \
(XFS_FSB_TO_AGNO(mp, fsb) < mp->m_sb.sb_agcount && \
XFS_FSB_TO_AGBNO(mp, fsb) < mp->m_sb.sb_agblocks)
/*
* Trace hooks. Currently not implemented as they need to be ported
* over to the generic tracing functionality, which is some effort.
*
* i,j = integer (32 bit)
* b = btree block buffer (xfs_buf_t)
* p = btree ptr
* r = btree record
* k = btree key
*/
#define XFS_BTREE_TRACE_ARGBI(c, b, i)
#define XFS_BTREE_TRACE_ARGBII(c, b, i, j)
#define XFS_BTREE_TRACE_ARGI(c, i)
#define XFS_BTREE_TRACE_ARGIPK(c, i, p, s)
#define XFS_BTREE_TRACE_ARGIPR(c, i, p, r)
#define XFS_BTREE_TRACE_ARGIK(c, i, k)
#define XFS_BTREE_TRACE_ARGR(c, r)
#define XFS_BTREE_TRACE_CURSOR(c, t)
#endif /* __XFS_BTREE_H__ */
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