// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2000-2003,2005 Silicon Graphics, Inc.
 * All Rights Reserved.
 */
#ifndef __XFS_INODE_FORK_H__
#define __XFS_INODE_FORK_H__

struct xfs_inode_log_item;
struct xfs_dinode;

/*
 * File incore extent information, present for each of data & attr forks.
 */
struct xfs_ifork {
        int64_t                 if_bytes;       /* bytes in if_data */
        struct xfs_btree_block  *if_broot;      /* file's incore btree root */
        unsigned int            if_seq;         /* fork mod counter */
        int                     if_height;      /* height of the extent tree */
        void                    *if_data;       /* extent tree root or
                                                   inline data */
        xfs_extnum_t            if_nextents;    /* # of extents in this fork */
        short                   if_broot_bytes; /* bytes allocated for root */
        int8_t                  if_format;      /* format of this fork */
        uint8_t                 if_needextents; /* extents have not been read */
};

/*
 * Worst-case increase in the fork extent count when we're adding a single
 * extent to a fork and there's no possibility of splitting an existing mapping.
 */
#define XFS_IEXT_ADD_NOSPLIT_CNT        (1)

/*
 * Punching out an extent from the middle of an existing extent can cause the
 * extent count to increase by 1.
 * i.e. | Old extent | Hole | Old extent |
 */
#define XFS_IEXT_PUNCH_HOLE_CNT         (1)

/*
 * Adding/removing an xattr can cause XFS_DA_NODE_MAXDEPTH extents to
 * be added. One extra extent for dabtree in case a local attr is
 * large enough to cause a double split.  It can also cause extent
 * count to increase proportional to the size of a remote xattr's
 * value.
 */
#define XFS_IEXT_ATTR_MANIP_CNT(rmt_blks) \
        (XFS_DA_NODE_MAXDEPTH + max(1, rmt_blks))

/*
 * A write to a sub-interval of an existing unwritten extent causes the original
 * extent to be split into 3 extents
 * i.e. | Unwritten | Real | Unwritten |
 * Hence extent count can increase by 2.
 */
#define XFS_IEXT_WRITE_UNWRITTEN_CNT    (2)


/*
 * Moving an extent to data fork can cause a sub-interval of an existing extent
 * to be unmapped. This will increase extent count by 1. Mapping in the new
 * extent can increase the extent count by 1 again i.e.
 * | Old extent | New extent | Old extent |
 * Hence number of extents increases by 2.
 */
#define XFS_IEXT_REFLINK_END_COW_CNT    (2)

/*
 * Removing an initial range of source/donor file's extent and adding a new
 * extent (from donor/source file) in its place will cause extent count to
 * increase by 1.
 */
#define XFS_IEXT_SWAP_RMAP_CNT          (1)

/*
 * Fork handling.
 */
#define XFS_IFORK_MAXEXT(ip, w) \
        (xfs_inode_fork_size(ip, w) / sizeof(xfs_bmbt_rec_t))

static inline bool xfs_ifork_has_extents(struct xfs_ifork *ifp)
{
        return ifp->if_format == XFS_DINODE_FMT_EXTENTS ||
                ifp->if_format == XFS_DINODE_FMT_BTREE;
}

static inline xfs_extnum_t xfs_ifork_nextents(struct xfs_ifork *ifp)
{
        if (!ifp)
                return 0;
        return ifp->if_nextents;
}

static inline int8_t xfs_ifork_format(struct xfs_ifork *ifp)
{
        if (!ifp)
                return XFS_DINODE_FMT_EXTENTS;
        return ifp->if_format;
}

static inline xfs_extnum_t xfs_iext_max_nextents(bool has_large_extent_counts,
                                int whichfork)
{
        switch (whichfork) {
        case XFS_DATA_FORK:
        case XFS_COW_FORK:
                if (has_large_extent_counts)
                        return XFS_MAX_EXTCNT_DATA_FORK_LARGE;
                return XFS_MAX_EXTCNT_DATA_FORK_SMALL;

        case XFS_ATTR_FORK:
                if (has_large_extent_counts)
                        return XFS_MAX_EXTCNT_ATTR_FORK_LARGE;
                return XFS_MAX_EXTCNT_ATTR_FORK_SMALL;

        default:
                ASSERT(0);
                return 0;
        }
}

static inline xfs_extnum_t
xfs_dfork_data_extents(
        struct xfs_dinode       *dip)
{
        if (xfs_dinode_has_large_extent_counts(dip))
                return be64_to_cpu(dip->di_big_nextents);

        return be32_to_cpu(dip->di_nextents);
}

static inline xfs_extnum_t
xfs_dfork_attr_extents(
        struct xfs_dinode       *dip)
{
        if (xfs_dinode_has_large_extent_counts(dip))
                return be32_to_cpu(dip->di_big_anextents);

        return be16_to_cpu(dip->di_anextents);
}

static inline xfs_extnum_t
xfs_dfork_nextents(
        struct xfs_dinode       *dip,
        int                     whichfork)
{
        switch (whichfork) {
        case XFS_DATA_FORK:
                return xfs_dfork_data_extents(dip);
        case XFS_ATTR_FORK:
                return xfs_dfork_attr_extents(dip);
        default:
                ASSERT(0);
                break;
        }

        return 0;
}

void xfs_ifork_zap_attr(struct xfs_inode *ip);
void xfs_ifork_init_attr(struct xfs_inode *ip, enum xfs_dinode_fmt format,
                xfs_extnum_t nextents);
struct xfs_ifork *xfs_iext_state_to_fork(struct xfs_inode *ip, int state);

int             xfs_iformat_data_fork(struct xfs_inode *, struct xfs_dinode *);
int             xfs_iformat_attr_fork(struct xfs_inode *, struct xfs_dinode *);
void            xfs_iflush_fork(struct xfs_inode *, struct xfs_dinode *,
                                struct xfs_inode_log_item *, int);
void            xfs_idestroy_fork(struct xfs_ifork *ifp);
void *          xfs_idata_realloc(struct xfs_inode *ip, int64_t byte_diff,
                                int whichfork);
struct xfs_btree_block *xfs_broot_alloc(struct xfs_ifork *ifp,
                                size_t new_size);
struct xfs_btree_block *xfs_broot_realloc(struct xfs_ifork *ifp,
                                size_t new_size);

int             xfs_iread_extents(struct xfs_trans *, struct xfs_inode *, int);
int             xfs_iextents_copy(struct xfs_inode *, struct xfs_bmbt_rec *,
                                  int);
void            xfs_init_local_fork(struct xfs_inode *ip, int whichfork,
                                const void *data, int64_t size);

xfs_extnum_t    xfs_iext_count(struct xfs_ifork *ifp);
void            xfs_iext_insert_raw(struct xfs_ifork *ifp,
                        struct xfs_iext_cursor *cur,
                        struct xfs_bmbt_irec *irec);
void            xfs_iext_insert(struct xfs_inode *, struct xfs_iext_cursor *cur,
                        struct xfs_bmbt_irec *, int);
void            xfs_iext_remove(struct xfs_inode *, struct xfs_iext_cursor *,
                        int);
void            xfs_iext_destroy(struct xfs_ifork *);

bool            xfs_iext_lookup_extent(struct xfs_inode *ip,
                        struct xfs_ifork *ifp, xfs_fileoff_t bno,
                        struct xfs_iext_cursor *cur,
                        struct xfs_bmbt_irec *gotp);
bool            xfs_iext_lookup_extent_before(struct xfs_inode *ip,
                        struct xfs_ifork *ifp, xfs_fileoff_t *end,
                        struct xfs_iext_cursor *cur,
                        struct xfs_bmbt_irec *gotp);
bool            xfs_iext_get_extent(struct xfs_ifork *ifp,
                        struct xfs_iext_cursor *cur,
                        struct xfs_bmbt_irec *gotp);
void            xfs_iext_update_extent(struct xfs_inode *ip, int state,
                        struct xfs_iext_cursor *cur,
                        struct xfs_bmbt_irec *gotp);

void            xfs_iext_first(struct xfs_ifork *, struct xfs_iext_cursor *);
void            xfs_iext_last(struct xfs_ifork *, struct xfs_iext_cursor *);
void            xfs_iext_next(struct xfs_ifork *, struct xfs_iext_cursor *);
void            xfs_iext_prev(struct xfs_ifork *, struct xfs_iext_cursor *);

static inline bool xfs_iext_next_extent(struct xfs_ifork *ifp,
                struct xfs_iext_cursor *cur, struct xfs_bmbt_irec *gotp)
{
        xfs_iext_next(ifp, cur);
        return xfs_iext_get_extent(ifp, cur, gotp);
}

static inline bool xfs_iext_prev_extent(struct xfs_ifork *ifp,
                struct xfs_iext_cursor *cur, struct xfs_bmbt_irec *gotp)
{
        xfs_iext_prev(ifp, cur);
        return xfs_iext_get_extent(ifp, cur, gotp);
}

/*
 * Return the extent after cur in gotp without updating the cursor.
 */
static inline bool xfs_iext_peek_next_extent(struct xfs_ifork *ifp,
                struct xfs_iext_cursor *cur, struct xfs_bmbt_irec *gotp)
{
        struct xfs_iext_cursor ncur = *cur;

        xfs_iext_next(ifp, &ncur);
        return xfs_iext_get_extent(ifp, &ncur, gotp);
}

/*
 * Return the extent before cur in gotp without updating the cursor.
 */
static inline bool xfs_iext_peek_prev_extent(struct xfs_ifork *ifp,
                struct xfs_iext_cursor *cur, struct xfs_bmbt_irec *gotp)
{
        struct xfs_iext_cursor ncur = *cur;

        xfs_iext_prev(ifp, &ncur);
        return xfs_iext_get_extent(ifp, &ncur, gotp);
}

#define for_each_xfs_iext(ifp, ext, got)                \
        for (xfs_iext_first((ifp), (ext));              \
             xfs_iext_get_extent((ifp), (ext), (got));  \
             xfs_iext_next((ifp), (ext)))

extern struct kmem_cache        *xfs_ifork_cache;

extern void xfs_ifork_init_cow(struct xfs_inode *ip);

int xfs_ifork_verify_local_data(struct xfs_inode *ip);
int xfs_ifork_verify_local_attr(struct xfs_inode *ip);
int xfs_iext_count_extend(struct xfs_trans *tp, struct xfs_inode *ip,
                int whichfork, uint nr_to_add);
bool xfs_ifork_is_realtime(struct xfs_inode *ip, int whichfork);

/* returns true if the fork has extents but they are not read in yet. */
static inline bool xfs_need_iread_extents(const struct xfs_ifork *ifp)
{
        /* see xfs_iformat_{data,attr}_fork() for needextents semantics */
        return smp_load_acquire(&ifp->if_needextents) != 0;
}

#endif  /* __XFS_INODE_FORK_H__ */