cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
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xfs_btree.h (19302B)


      1/* SPDX-License-Identifier: GPL-2.0 */
      2/*
      3 * Copyright (c) 2000-2001,2005 Silicon Graphics, Inc.
      4 * All Rights Reserved.
      5 */
      6#ifndef __XFS_BTREE_H__
      7#define	__XFS_BTREE_H__
      8
      9struct xfs_buf;
     10struct xfs_inode;
     11struct xfs_mount;
     12struct xfs_trans;
     13struct xfs_ifork;
     14struct xfs_perag;
     15
     16/*
     17 * Generic key, ptr and record wrapper structures.
     18 *
     19 * These are disk format structures, and are converted where necessary
     20 * by the btree specific code that needs to interpret them.
     21 */
     22union xfs_btree_ptr {
     23	__be32			s;	/* short form ptr */
     24	__be64			l;	/* long form ptr */
     25};
     26
     27/*
     28 * The in-core btree key.  Overlapping btrees actually store two keys
     29 * per pointer, so we reserve enough memory to hold both.  The __*bigkey
     30 * items should never be accessed directly.
     31 */
     32union xfs_btree_key {
     33	struct xfs_bmbt_key		bmbt;
     34	xfs_bmdr_key_t			bmbr;	/* bmbt root block */
     35	xfs_alloc_key_t			alloc;
     36	struct xfs_inobt_key		inobt;
     37	struct xfs_rmap_key		rmap;
     38	struct xfs_rmap_key		__rmap_bigkey[2];
     39	struct xfs_refcount_key		refc;
     40};
     41
     42union xfs_btree_rec {
     43	struct xfs_bmbt_rec		bmbt;
     44	xfs_bmdr_rec_t			bmbr;	/* bmbt root block */
     45	struct xfs_alloc_rec		alloc;
     46	struct xfs_inobt_rec		inobt;
     47	struct xfs_rmap_rec		rmap;
     48	struct xfs_refcount_rec		refc;
     49};
     50
     51/*
     52 * This nonsense is to make -wlint happy.
     53 */
     54#define	XFS_LOOKUP_EQ	((xfs_lookup_t)XFS_LOOKUP_EQi)
     55#define	XFS_LOOKUP_LE	((xfs_lookup_t)XFS_LOOKUP_LEi)
     56#define	XFS_LOOKUP_GE	((xfs_lookup_t)XFS_LOOKUP_GEi)
     57
     58#define	XFS_BTNUM_BNO	((xfs_btnum_t)XFS_BTNUM_BNOi)
     59#define	XFS_BTNUM_CNT	((xfs_btnum_t)XFS_BTNUM_CNTi)
     60#define	XFS_BTNUM_BMAP	((xfs_btnum_t)XFS_BTNUM_BMAPi)
     61#define	XFS_BTNUM_INO	((xfs_btnum_t)XFS_BTNUM_INOi)
     62#define	XFS_BTNUM_FINO	((xfs_btnum_t)XFS_BTNUM_FINOi)
     63#define	XFS_BTNUM_RMAP	((xfs_btnum_t)XFS_BTNUM_RMAPi)
     64#define	XFS_BTNUM_REFC	((xfs_btnum_t)XFS_BTNUM_REFCi)
     65
     66uint32_t xfs_btree_magic(int crc, xfs_btnum_t btnum);
     67
     68/*
     69 * For logging record fields.
     70 */
     71#define	XFS_BB_MAGIC		(1u << 0)
     72#define	XFS_BB_LEVEL		(1u << 1)
     73#define	XFS_BB_NUMRECS		(1u << 2)
     74#define	XFS_BB_LEFTSIB		(1u << 3)
     75#define	XFS_BB_RIGHTSIB		(1u << 4)
     76#define	XFS_BB_BLKNO		(1u << 5)
     77#define	XFS_BB_LSN		(1u << 6)
     78#define	XFS_BB_UUID		(1u << 7)
     79#define	XFS_BB_OWNER		(1u << 8)
     80#define	XFS_BB_NUM_BITS		5
     81#define	XFS_BB_ALL_BITS		((1u << XFS_BB_NUM_BITS) - 1)
     82#define	XFS_BB_NUM_BITS_CRC	9
     83#define	XFS_BB_ALL_BITS_CRC	((1u << XFS_BB_NUM_BITS_CRC) - 1)
     84
     85/*
     86 * Generic stats interface
     87 */
     88#define XFS_BTREE_STATS_INC(cur, stat)	\
     89	XFS_STATS_INC_OFF((cur)->bc_mp, (cur)->bc_statoff + __XBTS_ ## stat)
     90#define XFS_BTREE_STATS_ADD(cur, stat, val)	\
     91	XFS_STATS_ADD_OFF((cur)->bc_mp, (cur)->bc_statoff + __XBTS_ ## stat, val)
     92
     93struct xfs_btree_ops {
     94	/* size of the key and record structures */
     95	size_t	key_len;
     96	size_t	rec_len;
     97
     98	/* cursor operations */
     99	struct xfs_btree_cur *(*dup_cursor)(struct xfs_btree_cur *);
    100	void	(*update_cursor)(struct xfs_btree_cur *src,
    101				 struct xfs_btree_cur *dst);
    102
    103	/* update btree root pointer */
    104	void	(*set_root)(struct xfs_btree_cur *cur,
    105			    const union xfs_btree_ptr *nptr, int level_change);
    106
    107	/* block allocation / freeing */
    108	int	(*alloc_block)(struct xfs_btree_cur *cur,
    109			       const union xfs_btree_ptr *start_bno,
    110			       union xfs_btree_ptr *new_bno,
    111			       int *stat);
    112	int	(*free_block)(struct xfs_btree_cur *cur, struct xfs_buf *bp);
    113
    114	/* update last record information */
    115	void	(*update_lastrec)(struct xfs_btree_cur *cur,
    116				  const struct xfs_btree_block *block,
    117				  const union xfs_btree_rec *rec,
    118				  int ptr, int reason);
    119
    120	/* records in block/level */
    121	int	(*get_minrecs)(struct xfs_btree_cur *cur, int level);
    122	int	(*get_maxrecs)(struct xfs_btree_cur *cur, int level);
    123
    124	/* records on disk.  Matter for the root in inode case. */
    125	int	(*get_dmaxrecs)(struct xfs_btree_cur *cur, int level);
    126
    127	/* init values of btree structures */
    128	void	(*init_key_from_rec)(union xfs_btree_key *key,
    129				     const union xfs_btree_rec *rec);
    130	void	(*init_rec_from_cur)(struct xfs_btree_cur *cur,
    131				     union xfs_btree_rec *rec);
    132	void	(*init_ptr_from_cur)(struct xfs_btree_cur *cur,
    133				     union xfs_btree_ptr *ptr);
    134	void	(*init_high_key_from_rec)(union xfs_btree_key *key,
    135					  const union xfs_btree_rec *rec);
    136
    137	/* difference between key value and cursor value */
    138	int64_t (*key_diff)(struct xfs_btree_cur *cur,
    139			    const union xfs_btree_key *key);
    140
    141	/*
    142	 * Difference between key2 and key1 -- positive if key1 > key2,
    143	 * negative if key1 < key2, and zero if equal.
    144	 */
    145	int64_t (*diff_two_keys)(struct xfs_btree_cur *cur,
    146				 const union xfs_btree_key *key1,
    147				 const union xfs_btree_key *key2);
    148
    149	const struct xfs_buf_ops	*buf_ops;
    150
    151	/* check that k1 is lower than k2 */
    152	int	(*keys_inorder)(struct xfs_btree_cur *cur,
    153				const union xfs_btree_key *k1,
    154				const union xfs_btree_key *k2);
    155
    156	/* check that r1 is lower than r2 */
    157	int	(*recs_inorder)(struct xfs_btree_cur *cur,
    158				const union xfs_btree_rec *r1,
    159				const union xfs_btree_rec *r2);
    160};
    161
    162/*
    163 * Reasons for the update_lastrec method to be called.
    164 */
    165#define LASTREC_UPDATE	0
    166#define LASTREC_INSREC	1
    167#define LASTREC_DELREC	2
    168
    169
    170union xfs_btree_irec {
    171	struct xfs_alloc_rec_incore	a;
    172	struct xfs_bmbt_irec		b;
    173	struct xfs_inobt_rec_incore	i;
    174	struct xfs_rmap_irec		r;
    175	struct xfs_refcount_irec	rc;
    176};
    177
    178/* Per-AG btree information. */
    179struct xfs_btree_cur_ag {
    180	struct xfs_perag		*pag;
    181	union {
    182		struct xfs_buf		*agbp;
    183		struct xbtree_afakeroot	*afake;	/* for staging cursor */
    184	};
    185	union {
    186		struct {
    187			unsigned int	nr_ops;	/* # record updates */
    188			unsigned int	shape_changes;	/* # of extent splits */
    189		} refc;
    190		struct {
    191			bool		active;	/* allocation cursor state */
    192		} abt;
    193	};
    194};
    195
    196/* Btree-in-inode cursor information */
    197struct xfs_btree_cur_ino {
    198	struct xfs_inode		*ip;
    199	struct xbtree_ifakeroot		*ifake;	/* for staging cursor */
    200	int				allocated;
    201	short				forksize;
    202	char				whichfork;
    203	char				flags;
    204/* We are converting a delalloc reservation */
    205#define	XFS_BTCUR_BMBT_WASDEL		(1 << 0)
    206
    207/* For extent swap, ignore owner check in verifier */
    208#define	XFS_BTCUR_BMBT_INVALID_OWNER	(1 << 1)
    209};
    210
    211struct xfs_btree_level {
    212	/* buffer pointer */
    213	struct xfs_buf		*bp;
    214
    215	/* key/record number */
    216	uint16_t		ptr;
    217
    218	/* readahead info */
    219#define XFS_BTCUR_LEFTRA	(1 << 0) /* left sibling has been read-ahead */
    220#define XFS_BTCUR_RIGHTRA	(1 << 1) /* right sibling has been read-ahead */
    221	uint16_t		ra;
    222};
    223
    224/*
    225 * Btree cursor structure.
    226 * This collects all information needed by the btree code in one place.
    227 */
    228struct xfs_btree_cur
    229{
    230	struct xfs_trans	*bc_tp;	/* transaction we're in, if any */
    231	struct xfs_mount	*bc_mp;	/* file system mount struct */
    232	const struct xfs_btree_ops *bc_ops;
    233	struct kmem_cache	*bc_cache; /* cursor cache */
    234	unsigned int		bc_flags; /* btree features - below */
    235	xfs_btnum_t		bc_btnum; /* identifies which btree type */
    236	union xfs_btree_irec	bc_rec;	/* current insert/search record value */
    237	uint8_t			bc_nlevels; /* number of levels in the tree */
    238	uint8_t			bc_maxlevels; /* maximum levels for this btree type */
    239	int			bc_statoff; /* offset of btree stats array */
    240
    241	/*
    242	 * Short btree pointers need an agno to be able to turn the pointers
    243	 * into physical addresses for IO, so the btree cursor switches between
    244	 * bc_ino and bc_ag based on whether XFS_BTREE_LONG_PTRS is set for the
    245	 * cursor.
    246	 */
    247	union {
    248		struct xfs_btree_cur_ag	bc_ag;
    249		struct xfs_btree_cur_ino bc_ino;
    250	};
    251
    252	/* Must be at the end of the struct! */
    253	struct xfs_btree_level	bc_levels[];
    254};
    255
    256/*
    257 * Compute the size of a btree cursor that can handle a btree of a given
    258 * height.  The bc_levels array handles node and leaf blocks, so its size
    259 * is exactly nlevels.
    260 */
    261static inline size_t
    262xfs_btree_cur_sizeof(unsigned int nlevels)
    263{
    264	return struct_size((struct xfs_btree_cur *)NULL, bc_levels, nlevels);
    265}
    266
    267/* cursor flags */
    268#define XFS_BTREE_LONG_PTRS		(1<<0)	/* pointers are 64bits long */
    269#define XFS_BTREE_ROOT_IN_INODE		(1<<1)	/* root may be variable size */
    270#define XFS_BTREE_LASTREC_UPDATE	(1<<2)	/* track last rec externally */
    271#define XFS_BTREE_CRC_BLOCKS		(1<<3)	/* uses extended btree blocks */
    272#define XFS_BTREE_OVERLAPPING		(1<<4)	/* overlapping intervals */
    273/*
    274 * The root of this btree is a fakeroot structure so that we can stage a btree
    275 * rebuild without leaving it accessible via primary metadata.  The ops struct
    276 * is dynamically allocated and must be freed when the cursor is deleted.
    277 */
    278#define XFS_BTREE_STAGING		(1<<5)
    279
    280#define	XFS_BTREE_NOERROR	0
    281#define	XFS_BTREE_ERROR		1
    282
    283/*
    284 * Convert from buffer to btree block header.
    285 */
    286#define	XFS_BUF_TO_BLOCK(bp)	((struct xfs_btree_block *)((bp)->b_addr))
    287
    288/*
    289 * Internal long and short btree block checks.  They return NULL if the
    290 * block is ok or the address of the failed check otherwise.
    291 */
    292xfs_failaddr_t __xfs_btree_check_lblock(struct xfs_btree_cur *cur,
    293		struct xfs_btree_block *block, int level, struct xfs_buf *bp);
    294xfs_failaddr_t __xfs_btree_check_sblock(struct xfs_btree_cur *cur,
    295		struct xfs_btree_block *block, int level, struct xfs_buf *bp);
    296
    297/*
    298 * Check that block header is ok.
    299 */
    300int
    301xfs_btree_check_block(
    302	struct xfs_btree_cur	*cur,	/* btree cursor */
    303	struct xfs_btree_block	*block,	/* generic btree block pointer */
    304	int			level,	/* level of the btree block */
    305	struct xfs_buf		*bp);	/* buffer containing block, if any */
    306
    307/*
    308 * Check that (long) pointer is ok.
    309 */
    310bool					/* error (0 or EFSCORRUPTED) */
    311xfs_btree_check_lptr(
    312	struct xfs_btree_cur	*cur,	/* btree cursor */
    313	xfs_fsblock_t		fsbno,	/* btree block disk address */
    314	int			level);	/* btree block level */
    315
    316/*
    317 * Check that (short) pointer is ok.
    318 */
    319bool					/* error (0 or EFSCORRUPTED) */
    320xfs_btree_check_sptr(
    321	struct xfs_btree_cur	*cur,	/* btree cursor */
    322	xfs_agblock_t		agbno,	/* btree block disk address */
    323	int			level);	/* btree block level */
    324
    325/*
    326 * Delete the btree cursor.
    327 */
    328void
    329xfs_btree_del_cursor(
    330	struct xfs_btree_cur	*cur,	/* btree cursor */
    331	int			error);	/* del because of error */
    332
    333/*
    334 * Duplicate the btree cursor.
    335 * Allocate a new one, copy the record, re-get the buffers.
    336 */
    337int					/* error */
    338xfs_btree_dup_cursor(
    339	struct xfs_btree_cur		*cur,	/* input cursor */
    340	struct xfs_btree_cur		**ncur);/* output cursor */
    341
    342/*
    343 * Compute first and last byte offsets for the fields given.
    344 * Interprets the offsets table, which contains struct field offsets.
    345 */
    346void
    347xfs_btree_offsets(
    348	uint32_t		fields,	/* bitmask of fields */
    349	const short		*offsets,/* table of field offsets */
    350	int			nbits,	/* number of bits to inspect */
    351	int			*first,	/* output: first byte offset */
    352	int			*last);	/* output: last byte offset */
    353
    354/*
    355 * Get a buffer for the block, return it read in.
    356 * Long-form addressing.
    357 */
    358int					/* error */
    359xfs_btree_read_bufl(
    360	struct xfs_mount	*mp,	/* file system mount point */
    361	struct xfs_trans	*tp,	/* transaction pointer */
    362	xfs_fsblock_t		fsbno,	/* file system block number */
    363	struct xfs_buf		**bpp,	/* buffer for fsbno */
    364	int			refval,	/* ref count value for buffer */
    365	const struct xfs_buf_ops *ops);
    366
    367/*
    368 * Read-ahead the block, don't wait for it, don't return a buffer.
    369 * Long-form addressing.
    370 */
    371void					/* error */
    372xfs_btree_reada_bufl(
    373	struct xfs_mount	*mp,	/* file system mount point */
    374	xfs_fsblock_t		fsbno,	/* file system block number */
    375	xfs_extlen_t		count,	/* count of filesystem blocks */
    376	const struct xfs_buf_ops *ops);
    377
    378/*
    379 * Read-ahead the block, don't wait for it, don't return a buffer.
    380 * Short-form addressing.
    381 */
    382void					/* error */
    383xfs_btree_reada_bufs(
    384	struct xfs_mount	*mp,	/* file system mount point */
    385	xfs_agnumber_t		agno,	/* allocation group number */
    386	xfs_agblock_t		agbno,	/* allocation group block number */
    387	xfs_extlen_t		count,	/* count of filesystem blocks */
    388	const struct xfs_buf_ops *ops);
    389
    390/*
    391 * Initialise a new btree block header
    392 */
    393void
    394xfs_btree_init_block(
    395	struct xfs_mount *mp,
    396	struct xfs_buf	*bp,
    397	xfs_btnum_t	btnum,
    398	__u16		level,
    399	__u16		numrecs,
    400	__u64		owner);
    401
    402void
    403xfs_btree_init_block_int(
    404	struct xfs_mount	*mp,
    405	struct xfs_btree_block	*buf,
    406	xfs_daddr_t		blkno,
    407	xfs_btnum_t		btnum,
    408	__u16			level,
    409	__u16			numrecs,
    410	__u64			owner,
    411	unsigned int		flags);
    412
    413/*
    414 * Common btree core entry points.
    415 */
    416int xfs_btree_increment(struct xfs_btree_cur *, int, int *);
    417int xfs_btree_decrement(struct xfs_btree_cur *, int, int *);
    418int xfs_btree_lookup(struct xfs_btree_cur *, xfs_lookup_t, int *);
    419int xfs_btree_update(struct xfs_btree_cur *, union xfs_btree_rec *);
    420int xfs_btree_new_iroot(struct xfs_btree_cur *, int *, int *);
    421int xfs_btree_insert(struct xfs_btree_cur *, int *);
    422int xfs_btree_delete(struct xfs_btree_cur *, int *);
    423int xfs_btree_get_rec(struct xfs_btree_cur *, union xfs_btree_rec **, int *);
    424int xfs_btree_change_owner(struct xfs_btree_cur *cur, uint64_t new_owner,
    425			   struct list_head *buffer_list);
    426
    427/*
    428 * btree block CRC helpers
    429 */
    430void xfs_btree_lblock_calc_crc(struct xfs_buf *);
    431bool xfs_btree_lblock_verify_crc(struct xfs_buf *);
    432void xfs_btree_sblock_calc_crc(struct xfs_buf *);
    433bool xfs_btree_sblock_verify_crc(struct xfs_buf *);
    434
    435/*
    436 * Internal btree helpers also used by xfs_bmap.c.
    437 */
    438void xfs_btree_log_block(struct xfs_btree_cur *, struct xfs_buf *, uint32_t);
    439void xfs_btree_log_recs(struct xfs_btree_cur *, struct xfs_buf *, int, int);
    440
    441/*
    442 * Helpers.
    443 */
    444static inline int xfs_btree_get_numrecs(const struct xfs_btree_block *block)
    445{
    446	return be16_to_cpu(block->bb_numrecs);
    447}
    448
    449static inline void xfs_btree_set_numrecs(struct xfs_btree_block *block,
    450		uint16_t numrecs)
    451{
    452	block->bb_numrecs = cpu_to_be16(numrecs);
    453}
    454
    455static inline int xfs_btree_get_level(const struct xfs_btree_block *block)
    456{
    457	return be16_to_cpu(block->bb_level);
    458}
    459
    460
    461/*
    462 * Min and max functions for extlen, agblock, fileoff, and filblks types.
    463 */
    464#define	XFS_EXTLEN_MIN(a,b)	min_t(xfs_extlen_t, (a), (b))
    465#define	XFS_EXTLEN_MAX(a,b)	max_t(xfs_extlen_t, (a), (b))
    466#define	XFS_AGBLOCK_MIN(a,b)	min_t(xfs_agblock_t, (a), (b))
    467#define	XFS_AGBLOCK_MAX(a,b)	max_t(xfs_agblock_t, (a), (b))
    468#define	XFS_FILEOFF_MIN(a,b)	min_t(xfs_fileoff_t, (a), (b))
    469#define	XFS_FILEOFF_MAX(a,b)	max_t(xfs_fileoff_t, (a), (b))
    470#define	XFS_FILBLKS_MIN(a,b)	min_t(xfs_filblks_t, (a), (b))
    471#define	XFS_FILBLKS_MAX(a,b)	max_t(xfs_filblks_t, (a), (b))
    472
    473xfs_failaddr_t xfs_btree_sblock_v5hdr_verify(struct xfs_buf *bp);
    474xfs_failaddr_t xfs_btree_sblock_verify(struct xfs_buf *bp,
    475		unsigned int max_recs);
    476xfs_failaddr_t xfs_btree_lblock_v5hdr_verify(struct xfs_buf *bp,
    477		uint64_t owner);
    478xfs_failaddr_t xfs_btree_lblock_verify(struct xfs_buf *bp,
    479		unsigned int max_recs);
    480
    481unsigned int xfs_btree_compute_maxlevels(const unsigned int *limits,
    482		unsigned long long records);
    483unsigned long long xfs_btree_calc_size(const unsigned int *limits,
    484		unsigned long long records);
    485unsigned int xfs_btree_space_to_height(const unsigned int *limits,
    486		unsigned long long blocks);
    487
    488/*
    489 * Return codes for the query range iterator function are 0 to continue
    490 * iterating, and non-zero to stop iterating.  Any non-zero value will be
    491 * passed up to the _query_range caller.  The special value -ECANCELED can be
    492 * used to stop iteration, because _query_range never generates that error
    493 * code on its own.
    494 */
    495typedef int (*xfs_btree_query_range_fn)(struct xfs_btree_cur *cur,
    496		const union xfs_btree_rec *rec, void *priv);
    497
    498int xfs_btree_query_range(struct xfs_btree_cur *cur,
    499		const union xfs_btree_irec *low_rec,
    500		const union xfs_btree_irec *high_rec,
    501		xfs_btree_query_range_fn fn, void *priv);
    502int xfs_btree_query_all(struct xfs_btree_cur *cur, xfs_btree_query_range_fn fn,
    503		void *priv);
    504
    505typedef int (*xfs_btree_visit_blocks_fn)(struct xfs_btree_cur *cur, int level,
    506		void *data);
    507/* Visit record blocks. */
    508#define XFS_BTREE_VISIT_RECORDS		(1 << 0)
    509/* Visit leaf blocks. */
    510#define XFS_BTREE_VISIT_LEAVES		(1 << 1)
    511/* Visit all blocks. */
    512#define XFS_BTREE_VISIT_ALL		(XFS_BTREE_VISIT_RECORDS | \
    513					 XFS_BTREE_VISIT_LEAVES)
    514int xfs_btree_visit_blocks(struct xfs_btree_cur *cur,
    515		xfs_btree_visit_blocks_fn fn, unsigned int flags, void *data);
    516
    517int xfs_btree_count_blocks(struct xfs_btree_cur *cur, xfs_extlen_t *blocks);
    518
    519union xfs_btree_rec *xfs_btree_rec_addr(struct xfs_btree_cur *cur, int n,
    520		struct xfs_btree_block *block);
    521union xfs_btree_key *xfs_btree_key_addr(struct xfs_btree_cur *cur, int n,
    522		struct xfs_btree_block *block);
    523union xfs_btree_key *xfs_btree_high_key_addr(struct xfs_btree_cur *cur, int n,
    524		struct xfs_btree_block *block);
    525union xfs_btree_ptr *xfs_btree_ptr_addr(struct xfs_btree_cur *cur, int n,
    526		struct xfs_btree_block *block);
    527int xfs_btree_lookup_get_block(struct xfs_btree_cur *cur, int level,
    528		const union xfs_btree_ptr *pp, struct xfs_btree_block **blkp);
    529struct xfs_btree_block *xfs_btree_get_block(struct xfs_btree_cur *cur,
    530		int level, struct xfs_buf **bpp);
    531bool xfs_btree_ptr_is_null(struct xfs_btree_cur *cur,
    532		const union xfs_btree_ptr *ptr);
    533int64_t xfs_btree_diff_two_ptrs(struct xfs_btree_cur *cur,
    534				const union xfs_btree_ptr *a,
    535				const union xfs_btree_ptr *b);
    536void xfs_btree_get_sibling(struct xfs_btree_cur *cur,
    537			   struct xfs_btree_block *block,
    538			   union xfs_btree_ptr *ptr, int lr);
    539void xfs_btree_get_keys(struct xfs_btree_cur *cur,
    540		struct xfs_btree_block *block, union xfs_btree_key *key);
    541union xfs_btree_key *xfs_btree_high_key_from_key(struct xfs_btree_cur *cur,
    542		union xfs_btree_key *key);
    543int xfs_btree_has_record(struct xfs_btree_cur *cur,
    544		const union xfs_btree_irec *low,
    545		const union xfs_btree_irec *high, bool *exists);
    546bool xfs_btree_has_more_records(struct xfs_btree_cur *cur);
    547struct xfs_ifork *xfs_btree_ifork_ptr(struct xfs_btree_cur *cur);
    548
    549/* Does this cursor point to the last block in the given level? */
    550static inline bool
    551xfs_btree_islastblock(
    552	struct xfs_btree_cur	*cur,
    553	int			level)
    554{
    555	struct xfs_btree_block	*block;
    556	struct xfs_buf		*bp;
    557
    558	block = xfs_btree_get_block(cur, level, &bp);
    559	ASSERT(block && xfs_btree_check_block(cur, block, level, bp) == 0);
    560
    561	if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
    562		return block->bb_u.l.bb_rightsib == cpu_to_be64(NULLFSBLOCK);
    563	return block->bb_u.s.bb_rightsib == cpu_to_be32(NULLAGBLOCK);
    564}
    565
    566void xfs_btree_set_ptr_null(struct xfs_btree_cur *cur,
    567		union xfs_btree_ptr *ptr);
    568int xfs_btree_get_buf_block(struct xfs_btree_cur *cur,
    569		const union xfs_btree_ptr *ptr, struct xfs_btree_block **block,
    570		struct xfs_buf **bpp);
    571void xfs_btree_set_sibling(struct xfs_btree_cur *cur,
    572		struct xfs_btree_block *block, const union xfs_btree_ptr *ptr,
    573		int lr);
    574void xfs_btree_init_block_cur(struct xfs_btree_cur *cur,
    575		struct xfs_buf *bp, int level, int numrecs);
    576void xfs_btree_copy_ptrs(struct xfs_btree_cur *cur,
    577		union xfs_btree_ptr *dst_ptr,
    578		const union xfs_btree_ptr *src_ptr, int numptrs);
    579void xfs_btree_copy_keys(struct xfs_btree_cur *cur,
    580		union xfs_btree_key *dst_key,
    581		const union xfs_btree_key *src_key, int numkeys);
    582
    583static inline struct xfs_btree_cur *
    584xfs_btree_alloc_cursor(
    585	struct xfs_mount	*mp,
    586	struct xfs_trans	*tp,
    587	xfs_btnum_t		btnum,
    588	uint8_t			maxlevels,
    589	struct kmem_cache	*cache)
    590{
    591	struct xfs_btree_cur	*cur;
    592
    593	cur = kmem_cache_zalloc(cache, GFP_NOFS | __GFP_NOFAIL);
    594	cur->bc_tp = tp;
    595	cur->bc_mp = mp;
    596	cur->bc_btnum = btnum;
    597	cur->bc_maxlevels = maxlevels;
    598	cur->bc_cache = cache;
    599
    600	return cur;
    601}
    602
    603int __init xfs_btree_init_cur_caches(void);
    604void xfs_btree_destroy_cur_caches(void);
    605
    606#endif	/* __XFS_BTREE_H__ */