/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Copyright (c) 2000-2001,2005 Silicon Graphics, Inc.
 * All Rights Reserved.
 */
#ifndef __XFS_BTREE_H__
#define __XFS_BTREE_H__

struct xfs_buf;
struct xfs_inode;
struct xfs_mount;
struct xfs_trans;
struct xfs_ifork;
struct xfs_perag;

/*
 * 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 */
};

/*
 * The in-core btree key.  Overlapping btrees actually store two keys
 * per pointer, so we reserve enough memory to hold both.  The __*bigkey
 * items should never be accessed directly.
 */
union xfs_btree_key {
        struct xfs_bmbt_key             bmbt;
        xfs_bmdr_key_t                  bmbr;   /* bmbt root block */
        xfs_alloc_key_t                 alloc;
        struct xfs_inobt_key            inobt;
        struct xfs_rmap_key             rmap;
        struct xfs_rmap_key             __rmap_bigkey[2];
        struct xfs_refcount_key         refc;
};

union xfs_btree_rec {
        struct xfs_bmbt_rec             bmbt;
        xfs_bmdr_rec_t                  bmbr;   /* bmbt root block */
        struct xfs_alloc_rec            alloc;
        struct xfs_inobt_rec            inobt;
        struct xfs_rmap_rec             rmap;
        struct xfs_refcount_rec         refc;
};

/*
 * 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)

struct xfs_btree_ops;
uint32_t xfs_btree_magic(struct xfs_mount *mp, const struct xfs_btree_ops *ops);

/*
 * For logging record fields.
 */
#define XFS_BB_MAGIC            (1u << 0)
#define XFS_BB_LEVEL            (1u << 1)
#define XFS_BB_NUMRECS          (1u << 2)
#define XFS_BB_LEFTSIB          (1u << 3)
#define XFS_BB_RIGHTSIB         (1u << 4)
#define XFS_BB_BLKNO            (1u << 5)
#define XFS_BB_LSN              (1u << 6)
#define XFS_BB_UUID             (1u << 7)
#define XFS_BB_OWNER            (1u << 8)
#define XFS_BB_NUM_BITS         5
#define XFS_BB_ALL_BITS         ((1u << XFS_BB_NUM_BITS) - 1)
#define XFS_BB_NUM_BITS_CRC     9
#define XFS_BB_ALL_BITS_CRC     ((1u << XFS_BB_NUM_BITS_CRC) - 1)

/*
 * Generic stats interface
 */
#define XFS_BTREE_STATS_INC(cur, stat)  \
        XFS_STATS_INC_OFF((cur)->bc_mp, \
                (cur)->bc_ops->statoff + __XBTS_ ## stat)
#define XFS_BTREE_STATS_ADD(cur, stat, val)     \
        XFS_STATS_ADD_OFF((cur)->bc_mp, \
                (cur)->bc_ops->statoff + __XBTS_ ## stat, val)

enum xbtree_key_contig {
        XBTREE_KEY_GAP = 0,
        XBTREE_KEY_CONTIGUOUS,
        XBTREE_KEY_OVERLAP,
};

/*
 * Decide if these two numeric btree key fields are contiguous, overlapping,
 * or if there's a gap between them.  @x should be the field from the high
 * key and @y should be the field from the low key.
 */
static inline enum xbtree_key_contig xbtree_key_contig(uint64_t x, uint64_t y)
{
        x++;
        if (x < y)
                return XBTREE_KEY_GAP;
        if (x == y)
                return XBTREE_KEY_CONTIGUOUS;
        return XBTREE_KEY_OVERLAP;
}

#define XFS_BTREE_LONG_PTR_LEN          (sizeof(__be64))
#define XFS_BTREE_SHORT_PTR_LEN         (sizeof(__be32))

enum xfs_btree_type {
        XFS_BTREE_TYPE_AG,
        XFS_BTREE_TYPE_INODE,
        XFS_BTREE_TYPE_MEM,
};

struct xfs_btree_ops {
        const char              *name;

        /* Type of btree - AG-rooted or inode-rooted */
        enum xfs_btree_type     type;

        /* XFS_BTGEO_* flags that determine the geometry of the btree */
        unsigned int            geom_flags;

        /* size of the key, pointer, and record structures */
        size_t                  key_len;
        size_t                  ptr_len;
        size_t                  rec_len;

        /* LRU refcount to set on each btree buffer created */
        unsigned int            lru_refs;

        /* offset of btree stats array */
        unsigned int            statoff;

        /* sick mask for health reporting (not for bmap btrees) */
        unsigned int            sick_mask;

        /* 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,
                            const union xfs_btree_ptr *nptr, int level_change);

        /* block allocation / freeing */
        int     (*alloc_block)(struct xfs_btree_cur *cur,
                               const union xfs_btree_ptr *start_bno,
                               union xfs_btree_ptr *new_bno,
                               int *stat);
        int     (*free_block)(struct xfs_btree_cur *cur, struct xfs_buf *bp);

        /* 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,
                                     const 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);
        void    (*init_high_key_from_rec)(union xfs_btree_key *key,
                                          const union xfs_btree_rec *rec);

        /*
         * Compare key value and cursor value -- positive if key > cur,
         * negative if key < cur, and zero if equal.
         */
        int     (*cmp_key_with_cur)(struct xfs_btree_cur *cur,
                                    const union xfs_btree_key *key);

        /*
         * Compare key1 and key2 -- positive if key1 > key2, negative if
         * key1 < key2, and zero if equal.  If the @mask parameter is non NULL,
         * each key field to be used in the comparison must contain a nonzero
         * value.
         */
        int     (*cmp_two_keys)(struct xfs_btree_cur *cur,
                                const union xfs_btree_key *key1,
                                const union xfs_btree_key *key2,
                                const union xfs_btree_key *mask);

        const struct xfs_buf_ops        *buf_ops;

        /* check that k1 is lower than k2 */
        int     (*keys_inorder)(struct xfs_btree_cur *cur,
                                const union xfs_btree_key *k1,
                                const union xfs_btree_key *k2);

        /* check that r1 is lower than r2 */
        int     (*recs_inorder)(struct xfs_btree_cur *cur,
                                const union xfs_btree_rec *r1,
                                const union xfs_btree_rec *r2);

        /*
         * Are these two btree keys immediately adjacent?
         *
         * Given two btree keys @key1 and @key2, decide if it is impossible for
         * there to be a third btree key K satisfying the relationship
         * @key1 < K < @key2.  To determine if two btree records are
         * immediately adjacent, @key1 should be the high key of the first
         * record and @key2 should be the low key of the second record.
         * If the @mask parameter is non NULL, each key field to be used in the
         * comparison must contain a nonzero value.
         */
        enum xbtree_key_contig (*keys_contiguous)(struct xfs_btree_cur *cur,
                               const union xfs_btree_key *key1,
                               const union xfs_btree_key *key2,
                               const union xfs_btree_key *mask);

        /*
         * Reallocate the space for if_broot to fit the number of records.
         * Move the records and pointers in if_broot to fit the new size.  When
         * shrinking this will eliminate holes between the records and pointers
         * created by the caller.  When growing this will create holes to be
         * filled in by the caller.
         *
         * The caller must not request to add more records than would fit in
         * the on-disk inode root.  If the if_broot is currently NULL, then if
         * we are adding records, one will be allocated.  The caller must also
         * not request that the number of records go below zero, although it
         * can go to zero.
         */
        struct xfs_btree_block *(*broot_realloc)(struct xfs_btree_cur *cur,
                                unsigned int new_numrecs);
};

/* btree geometry flags */
#define XFS_BTGEO_OVERLAPPING           (1U << 0) /* overlapping intervals */
#define XFS_BTGEO_IROOT_RECORDS         (1U << 1) /* iroot can store records */

union xfs_btree_irec {
        struct xfs_alloc_rec_incore     a;
        struct xfs_bmbt_irec            b;
        struct xfs_inobt_rec_incore     i;
        struct xfs_rmap_irec            r;
        struct xfs_refcount_irec        rc;
};

struct xfs_btree_level {
        /* buffer pointer */
        struct xfs_buf          *bp;

        /* key/record number */
        uint16_t                ptr;

        /* readahead info */
#define XFS_BTCUR_LEFTRA        (1 << 0) /* left sibling has been read-ahead */
#define XFS_BTCUR_RIGHTRA       (1 << 1) /* right sibling has been read-ahead */
        uint16_t                ra;
};

/*
 * Btree cursor structure.
 * This collects all information needed by the btree code in one place.
 */
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;
        struct kmem_cache       *bc_cache; /* cursor cache */
        unsigned int            bc_flags; /* btree features - below */
        union xfs_btree_irec    bc_rec; /* current insert/search record value */
        uint8_t                 bc_nlevels; /* number of levels in the tree */
        uint8_t                 bc_maxlevels; /* maximum levels for this btree type */
        struct xfs_group        *bc_group;

        /* per-type information */
        union {
                struct {
                        struct xfs_inode        *ip;
                        short                   forksize;
                        char                    whichfork;
                        struct xbtree_ifakeroot *ifake; /* for staging cursor */
                } bc_ino;
                struct {
                        struct xfs_buf          *agbp;
                        struct xbtree_afakeroot *afake; /* for staging cursor */
                } bc_ag;
                struct {
                        struct xfbtree          *xfbtree;
                } bc_mem;
        };

        /* per-format private data */
        union {
                struct {
                        int             allocated;
                } bc_bmap;      /* bmapbt */
                struct {
                        unsigned int    nr_ops;         /* # record updates */
                        unsigned int    shape_changes;  /* # of extent splits */
                } bc_refc;      /* refcountbt/rtrefcountbt */
        };

        /* Must be at the end of the struct! */
        struct xfs_btree_level  bc_levels[];
};

/*
 * Compute the size of a btree cursor that can handle a btree of a given
 * height.  The bc_levels array handles node and leaf blocks, so its size
 * is exactly nlevels.
 */
static inline size_t
xfs_btree_cur_sizeof(unsigned int nlevels)
{
        return struct_size_t(struct xfs_btree_cur, bc_levels, nlevels);
}

/* cursor state flags */
/*
 * The root of this btree is a fakeroot structure so that we can stage a btree
 * rebuild without leaving it accessible via primary metadata.  The ops struct
 * is dynamically allocated and must be freed when the cursor is deleted.
 */
#define XFS_BTREE_STAGING               (1U << 0)

/* We are converting a delalloc reservation (only for bmbt btrees) */
#define XFS_BTREE_BMBT_WASDEL           (1U << 1)

/* For extent swap, ignore owner check in verifier (only for bmbt btrees) */
#define XFS_BTREE_BMBT_INVALID_OWNER    (1U << 2)

/* Cursor is active (only for allocbt btrees) */
#define XFS_BTREE_ALLOCBT_ACTIVE        (1U << 3)

#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))

xfs_failaddr_t __xfs_btree_check_block(struct xfs_btree_cur *cur,
                struct xfs_btree_block *block, int level, struct xfs_buf *bp);
int __xfs_btree_check_ptr(struct xfs_btree_cur *cur,
                const union xfs_btree_ptr *ptr, int index, int level);

/*
 * 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 */

/*
 * Delete the btree cursor.
 */
void
xfs_btree_del_cursor(
        struct xfs_btree_cur    *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(
        struct xfs_btree_cur            *cur,   /* input cursor */
        struct xfs_btree_cur            **ncur);/* output cursor */

/*
 * 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 */

/*
 * Initialise a new btree block header
 */
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);
void xfs_btree_init_block(struct xfs_mount *mp,
                struct xfs_btree_block *buf, const struct xfs_btree_ops *ops,
                __u16 level, __u16 numrecs, __u64 owner);

/*
 * 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 *);
int xfs_btree_change_owner(struct xfs_btree_cur *cur, uint64_t new_owner,
                           struct list_head *buffer_list);

/*
 * btree block CRC helpers
 */
void xfs_btree_fsblock_calc_crc(struct xfs_buf *);
bool xfs_btree_fsblock_verify_crc(struct xfs_buf *);
void xfs_btree_agblock_calc_crc(struct xfs_buf *);
bool xfs_btree_agblock_verify_crc(struct xfs_buf *);

/*
 * Internal btree helpers also used by xfs_bmap.c.
 */
void xfs_btree_log_block(struct xfs_btree_cur *, struct xfs_buf *, uint32_t);
void xfs_btree_log_recs(struct xfs_btree_cur *, struct xfs_buf *, int, int);

/*
 * Helpers.
 */
static inline int xfs_btree_get_numrecs(const 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(const 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))

xfs_failaddr_t xfs_btree_agblock_v5hdr_verify(struct xfs_buf *bp);
xfs_failaddr_t xfs_btree_agblock_verify(struct xfs_buf *bp,
                unsigned int max_recs);
xfs_failaddr_t xfs_btree_fsblock_v5hdr_verify(struct xfs_buf *bp,
                uint64_t owner);
xfs_failaddr_t xfs_btree_fsblock_verify(struct xfs_buf *bp,
                unsigned int max_recs);
xfs_failaddr_t xfs_btree_memblock_verify(struct xfs_buf *bp,
                unsigned int max_recs);

unsigned int xfs_btree_compute_maxlevels(const unsigned int *limits,
                unsigned long long records);
unsigned long long xfs_btree_calc_size(const unsigned int *limits,
                unsigned long long records);
unsigned int xfs_btree_space_to_height(const unsigned int *limits,
                unsigned long long blocks);

/*
 * Return codes for the query range iterator function are 0 to continue
 * iterating, and non-zero to stop iterating.  Any non-zero value will be
 * passed up to the _query_range caller.  The special value -ECANCELED can be
 * used to stop iteration, because _query_range never generates that error
 * code on its own.
 */
typedef int (*xfs_btree_query_range_fn)(struct xfs_btree_cur *cur,
                const union xfs_btree_rec *rec, void *priv);

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);
int xfs_btree_query_all(struct xfs_btree_cur *cur, xfs_btree_query_range_fn fn,
                void *priv);

typedef int (*xfs_btree_visit_blocks_fn)(struct xfs_btree_cur *cur, int level,
                void *data);
/* Visit record blocks. */
#define XFS_BTREE_VISIT_RECORDS         (1 << 0)
/* Visit leaf blocks. */
#define XFS_BTREE_VISIT_LEAVES          (1 << 1)
/* Visit all blocks. */
#define XFS_BTREE_VISIT_ALL             (XFS_BTREE_VISIT_RECORDS | \
                                         XFS_BTREE_VISIT_LEAVES)
int xfs_btree_visit_blocks(struct xfs_btree_cur *cur,
                xfs_btree_visit_blocks_fn fn, unsigned int flags, void *data);

int xfs_btree_count_blocks(struct xfs_btree_cur *cur, xfs_filblks_t *blocks);

union xfs_btree_rec *xfs_btree_rec_addr(struct xfs_btree_cur *cur, int n,
                struct xfs_btree_block *block);
union xfs_btree_key *xfs_btree_key_addr(struct xfs_btree_cur *cur, int n,
                struct xfs_btree_block *block);
union xfs_btree_key *xfs_btree_high_key_addr(struct xfs_btree_cur *cur, int n,
                struct xfs_btree_block *block);
union xfs_btree_ptr *xfs_btree_ptr_addr(struct xfs_btree_cur *cur, int n,
                struct xfs_btree_block *block);
int xfs_btree_lookup_get_block(struct xfs_btree_cur *cur, int level,
                const union xfs_btree_ptr *pp, struct xfs_btree_block **blkp);
struct xfs_btree_block *xfs_btree_get_block(struct xfs_btree_cur *cur,
                int level, struct xfs_buf **bpp);
bool xfs_btree_ptr_is_null(struct xfs_btree_cur *cur,
                const union xfs_btree_ptr *ptr);
int xfs_btree_cmp_two_ptrs(struct xfs_btree_cur *cur,
                           const union xfs_btree_ptr *a,
                           const union xfs_btree_ptr *b);
void xfs_btree_get_sibling(struct xfs_btree_cur *cur,
                           struct xfs_btree_block *block,
                           union xfs_btree_ptr *ptr, int lr);
void xfs_btree_get_keys(struct xfs_btree_cur *cur,
                struct xfs_btree_block *block, union xfs_btree_key *key);
union xfs_btree_key *xfs_btree_high_key_from_key(struct xfs_btree_cur *cur,
                union xfs_btree_key *key);
typedef bool (*xfs_btree_key_gap_fn)(struct xfs_btree_cur *cur,
                const union xfs_btree_key *key1,
                const union xfs_btree_key *key2);

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);

bool xfs_btree_has_more_records(struct xfs_btree_cur *cur);
struct xfs_ifork *xfs_btree_ifork_ptr(struct xfs_btree_cur *cur);

/* Key comparison helpers */
static inline bool
xfs_btree_keycmp_lt(
        struct xfs_btree_cur            *cur,
        const union xfs_btree_key       *key1,
        const union xfs_btree_key       *key2)
{
        return cur->bc_ops->cmp_two_keys(cur, key1, key2, NULL) < 0;
}

static inline bool
xfs_btree_keycmp_gt(
        struct xfs_btree_cur            *cur,
        const union xfs_btree_key       *key1,
        const union xfs_btree_key       *key2)
{
        return cur->bc_ops->cmp_two_keys(cur, key1, key2, NULL) > 0;
}

static inline bool
xfs_btree_keycmp_eq(
        struct xfs_btree_cur            *cur,
        const union xfs_btree_key       *key1,
        const union xfs_btree_key       *key2)
{
        return cur->bc_ops->cmp_two_keys(cur, key1, key2, NULL) == 0;
}

static inline bool
xfs_btree_keycmp_le(
        struct xfs_btree_cur            *cur,
        const union xfs_btree_key       *key1,
        const union xfs_btree_key       *key2)
{
        return !xfs_btree_keycmp_gt(cur, key1, key2);
}

static inline bool
xfs_btree_keycmp_ge(
        struct xfs_btree_cur            *cur,
        const union xfs_btree_key       *key1,
        const union xfs_btree_key       *key2)
{
        return !xfs_btree_keycmp_lt(cur, key1, key2);
}

static inline bool
xfs_btree_keycmp_ne(
        struct xfs_btree_cur            *cur,
        const union xfs_btree_key       *key1,
        const union xfs_btree_key       *key2)
{
        return !xfs_btree_keycmp_eq(cur, key1, key2);
}

/* Masked key comparison helpers */
static inline bool
xfs_btree_masked_keycmp_lt(
        struct xfs_btree_cur            *cur,
        const union xfs_btree_key       *key1,
        const union xfs_btree_key       *key2,
        const union xfs_btree_key       *mask)
{
        return cur->bc_ops->cmp_two_keys(cur, key1, key2, mask) < 0;
}

static inline bool
xfs_btree_masked_keycmp_gt(
        struct xfs_btree_cur            *cur,
        const union xfs_btree_key       *key1,
        const union xfs_btree_key       *key2,
        const union xfs_btree_key       *mask)
{
        return cur->bc_ops->cmp_two_keys(cur, key1, key2, mask) > 0;
}

static inline bool
xfs_btree_masked_keycmp_ge(
        struct xfs_btree_cur            *cur,
        const union xfs_btree_key       *key1,
        const union xfs_btree_key       *key2,
        const union xfs_btree_key       *mask)
{
        return !xfs_btree_masked_keycmp_lt(cur, key1, key2, mask);
}

/* Does this cursor point to the last block in the given level? */
static inline bool
xfs_btree_islastblock(
        struct xfs_btree_cur    *cur,
        int                     level)
{
        struct xfs_btree_block  *block;
        struct xfs_buf          *bp;

        block = xfs_btree_get_block(cur, level, &bp);

        if (cur->bc_ops->ptr_len == XFS_BTREE_LONG_PTR_LEN)
                return block->bb_u.l.bb_rightsib == cpu_to_be64(NULLFSBLOCK);
        return block->bb_u.s.bb_rightsib == cpu_to_be32(NULLAGBLOCK);
}

void xfs_btree_set_ptr_null(struct xfs_btree_cur *cur,
                union xfs_btree_ptr *ptr);
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);
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);
void xfs_btree_set_sibling(struct xfs_btree_cur *cur,
                struct xfs_btree_block *block, const union xfs_btree_ptr *ptr,
                int lr);
void xfs_btree_init_block_cur(struct xfs_btree_cur *cur,
                struct xfs_buf *bp, int level, int numrecs);
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);
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);
void xfs_btree_init_ptr_from_cur(struct xfs_btree_cur *cur,
                union xfs_btree_ptr *ptr);

static inline struct xfs_btree_cur *
xfs_btree_alloc_cursor(
        struct xfs_mount        *mp,
        struct xfs_trans        *tp,
        const struct xfs_btree_ops *ops,
        uint8_t                 maxlevels,
        struct kmem_cache       *cache)
{
        struct xfs_btree_cur    *cur;

        ASSERT(ops->ptr_len == XFS_BTREE_LONG_PTR_LEN ||
               ops->ptr_len == XFS_BTREE_SHORT_PTR_LEN);

        /* BMBT allocations can come through from non-transactional context. */
        cur = kmem_cache_zalloc(cache,
                        GFP_KERNEL | __GFP_NOLOCKDEP | __GFP_NOFAIL);
        cur->bc_ops = ops;
        cur->bc_tp = tp;
        cur->bc_mp = mp;
        cur->bc_maxlevels = maxlevels;
        cur->bc_cache = cache;

        return cur;
}

int __init xfs_btree_init_cur_caches(void);
void xfs_btree_destroy_cur_caches(void);

int xfs_btree_goto_left_edge(struct xfs_btree_cur *cur);

/* Does this level of the cursor point to the inode root (and not a block)? */
static inline bool
xfs_btree_at_iroot(
        const struct xfs_btree_cur      *cur,
        int                             level)
{
        return cur->bc_ops->type == XFS_BTREE_TYPE_INODE &&
               level == cur->bc_nlevels - 1;
}

int xfs_btree_alloc_metafile_block(struct xfs_btree_cur *cur,
                const union xfs_btree_ptr *start, union xfs_btree_ptr *newp,
                int *stat);
int xfs_btree_free_metafile_block(struct xfs_btree_cur *cur,
                struct xfs_buf *bp);

#endif  /* __XFS_BTREE_H__ */