root/fs/xfs/libxfs/xfs_bmap.h
/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Copyright (c) 2000-2006 Silicon Graphics, Inc.
 * All Rights Reserved.
 */
#ifndef __XFS_BMAP_H__
#define __XFS_BMAP_H__

struct getbmap;
struct xfs_bmbt_irec;
struct xfs_ifork;
struct xfs_inode;
struct xfs_mount;
struct xfs_trans;
struct xfs_alloc_arg;

/*
 * Argument structure for xfs_bmap_alloc.
 */
struct xfs_bmalloca {
        struct xfs_trans        *tp;    /* transaction pointer */
        struct xfs_inode        *ip;    /* incore inode pointer */
        struct xfs_bmbt_irec    prev;   /* extent before the new one */
        struct xfs_bmbt_irec    got;    /* extent after, or delayed */

        xfs_fileoff_t           offset; /* offset in file filling in */
        xfs_extlen_t            length; /* i/o length asked/allocated */
        xfs_fsblock_t           blkno;  /* starting block of new extent */

        struct xfs_btree_cur    *cur;   /* btree cursor */
        struct xfs_iext_cursor  icur;   /* incore extent cursor */
        int                     nallocs;/* number of extents alloc'd */
        int                     logflags;/* flags for transaction logging */

        xfs_extlen_t            total;  /* total blocks needed for xaction */
        xfs_extlen_t            minlen; /* minimum allocation size (blocks) */
        xfs_extlen_t            minleft; /* amount must be left after alloc */
        bool                    eof;    /* set if allocating past last extent */
        bool                    wasdel; /* replacing a delayed allocation */
        bool                    aeof;   /* allocated space at eof */
        bool                    conv;   /* overwriting unwritten extents */
        int                     datatype;/* data type being allocated */
        uint32_t                flags;
};

#define XFS_BMAP_MAX_NMAP       4

/*
 * Flags for xfs_bmapi_*
 */
#define XFS_BMAPI_ENTIRE        (1u << 0) /* return entire extent untrimmed */
#define XFS_BMAPI_METADATA      (1u << 1) /* mapping metadata not user data */
#define XFS_BMAPI_ATTRFORK      (1u << 2) /* use attribute fork not data */
#define XFS_BMAPI_PREALLOC      (1u << 3) /* preallocating unwritten space */
#define XFS_BMAPI_CONTIG        (1u << 4) /* must allocate only one extent */
/*
 * unwritten extent conversion - this needs write cache flushing and no additional
 * allocation alignments. When specified with XFS_BMAPI_PREALLOC it converts
 * from written to unwritten, otherwise convert from unwritten to written.
 */
#define XFS_BMAPI_CONVERT       (1u << 5)

/*
 * allocate zeroed extents - this requires all newly allocated user data extents
 * to be initialised to zero. It will be ignored if XFS_BMAPI_METADATA is set.
 * Use in conjunction with XFS_BMAPI_CONVERT to convert unwritten extents found
 * during the allocation range to zeroed written extents.
 */
#define XFS_BMAPI_ZERO          (1u << 6)

/*
 * Map the inode offset to the block given in ap->firstblock.  Primarily
 * used for reflink.  The range must be in a hole, and this flag cannot be
 * turned on with PREALLOC or CONVERT, and cannot be used on the attr fork.
 *
 * For bunmapi, this flag unmaps the range without adjusting quota, reducing
 * refcount, or freeing the blocks.
 */
#define XFS_BMAPI_REMAP         (1u << 7)

/* Map something in the CoW fork. */
#define XFS_BMAPI_COWFORK       (1u << 8)

/* Skip online discard of freed extents */
#define XFS_BMAPI_NODISCARD     (1u << 9)

/* Do not update the rmap btree.  Used for reconstructing bmbt from rmapbt. */
#define XFS_BMAPI_NORMAP        (1u << 10)

/* Try to align allocations to the extent size hint */
#define XFS_BMAPI_EXTSZALIGN    (1u << 11)

#define XFS_BMAPI_FLAGS \
        { XFS_BMAPI_ENTIRE,     "ENTIRE" }, \
        { XFS_BMAPI_METADATA,   "METADATA" }, \
        { XFS_BMAPI_ATTRFORK,   "ATTRFORK" }, \
        { XFS_BMAPI_PREALLOC,   "PREALLOC" }, \
        { XFS_BMAPI_CONTIG,     "CONTIG" }, \
        { XFS_BMAPI_CONVERT,    "CONVERT" }, \
        { XFS_BMAPI_ZERO,       "ZERO" }, \
        { XFS_BMAPI_REMAP,      "REMAP" }, \
        { XFS_BMAPI_COWFORK,    "COWFORK" }, \
        { XFS_BMAPI_NODISCARD,  "NODISCARD" }, \
        { XFS_BMAPI_NORMAP,     "NORMAP" },\
        { XFS_BMAPI_EXTSZALIGN, "EXTSZALIGN" }


static inline int xfs_bmapi_aflag(int w)
{
        return (w == XFS_ATTR_FORK ? XFS_BMAPI_ATTRFORK :
               (w == XFS_COW_FORK ? XFS_BMAPI_COWFORK : 0));
}

static inline int xfs_bmapi_whichfork(uint32_t bmapi_flags)
{
        if (bmapi_flags & XFS_BMAPI_COWFORK)
                return XFS_COW_FORK;
        else if (bmapi_flags & XFS_BMAPI_ATTRFORK)
                return XFS_ATTR_FORK;
        return XFS_DATA_FORK;
}

void xfs_bmap_alloc_account(struct xfs_bmalloca *ap);

/*
 * Special values for xfs_bmbt_irec_t br_startblock field.
 */
#define DELAYSTARTBLOCK         ((xfs_fsblock_t)-1LL)
#define HOLESTARTBLOCK          ((xfs_fsblock_t)-2LL)

/*
 * Flags for xfs_bmap_add_extent*.
 */
#define BMAP_LEFT_CONTIG        (1u << 0)
#define BMAP_RIGHT_CONTIG       (1u << 1)
#define BMAP_LEFT_FILLING       (1u << 2)
#define BMAP_RIGHT_FILLING      (1u << 3)
#define BMAP_LEFT_DELAY         (1u << 4)
#define BMAP_RIGHT_DELAY        (1u << 5)
#define BMAP_LEFT_VALID         (1u << 6)
#define BMAP_RIGHT_VALID        (1u << 7)
#define BMAP_ATTRFORK           (1u << 8)
#define BMAP_COWFORK            (1u << 9)

#define XFS_BMAP_EXT_FLAGS \
        { BMAP_LEFT_CONTIG,     "LC" }, \
        { BMAP_RIGHT_CONTIG,    "RC" }, \
        { BMAP_LEFT_FILLING,    "LF" }, \
        { BMAP_RIGHT_FILLING,   "RF" }, \
        { BMAP_ATTRFORK,        "ATTR" }, \
        { BMAP_COWFORK,         "COW" }

/* Return true if the extent is an allocated extent, written or not. */
static inline bool xfs_bmap_is_real_extent(const struct xfs_bmbt_irec *irec)
{
        return irec->br_startblock != HOLESTARTBLOCK &&
                irec->br_startblock != DELAYSTARTBLOCK &&
                !isnullstartblock(irec->br_startblock);
}

/*
 * Return true if the extent is a real, allocated extent, or false if it is  a
 * delayed allocation, and unwritten extent or a hole.
 */
static inline bool xfs_bmap_is_written_extent(const struct xfs_bmbt_irec *irec)
{
        return xfs_bmap_is_real_extent(irec) &&
               irec->br_state != XFS_EXT_UNWRITTEN;
}

/*
 * Check the mapping for obviously garbage allocations that could trash the
 * filesystem immediately.
 */
#define xfs_valid_startblock(ip, startblock) \
        ((startblock) != 0 || XFS_IS_REALTIME_INODE(ip))

int     xfs_bmap_longest_free_extent(struct xfs_perag *pag,
                struct xfs_trans *tp, xfs_extlen_t *blen);
void    xfs_trim_extent(struct xfs_bmbt_irec *irec, xfs_fileoff_t bno,
                xfs_filblks_t len);
unsigned int xfs_bmap_compute_attr_offset(struct xfs_mount *mp);
int     xfs_bmap_add_attrfork(struct xfs_trans *tp, struct xfs_inode *ip,
                int size, int rsvd);
void    xfs_bmap_local_to_extents_empty(struct xfs_trans *tp,
                struct xfs_inode *ip, int whichfork);
int xfs_bmap_local_to_extents(struct xfs_trans *tp, struct xfs_inode *ip,
                xfs_extlen_t total, int *logflagsp, int whichfork,
                void (*init_fn)(struct xfs_trans *tp, struct xfs_buf *bp,
                                struct xfs_inode *ip, struct xfs_ifork *ifp,
                                void *priv),
                void *priv);
void    xfs_bmap_compute_maxlevels(struct xfs_mount *mp, int whichfork);
int     xfs_bmap_first_unused(struct xfs_trans *tp, struct xfs_inode *ip,
                xfs_extlen_t len, xfs_fileoff_t *unused, int whichfork);
int     xfs_bmap_last_before(struct xfs_trans *tp, struct xfs_inode *ip,
                xfs_fileoff_t *last_block, int whichfork);
int     xfs_bmap_last_offset(struct xfs_inode *ip, xfs_fileoff_t *unused,
                int whichfork);
int     xfs_bmapi_read(struct xfs_inode *ip, xfs_fileoff_t bno,
                xfs_filblks_t len, struct xfs_bmbt_irec *mval,
                int *nmap, uint32_t flags);
int     xfs_bmapi_write(struct xfs_trans *tp, struct xfs_inode *ip,
                xfs_fileoff_t bno, xfs_filblks_t len, uint32_t flags,
                xfs_extlen_t total, struct xfs_bmbt_irec *mval, int *nmap);
int     xfs_bunmapi(struct xfs_trans *tp, struct xfs_inode *ip,
                xfs_fileoff_t bno, xfs_filblks_t len, uint32_t flags,
                xfs_extnum_t nexts, int *done);
void    xfs_bmap_del_extent_delay(struct xfs_inode *ip, int whichfork,
                struct xfs_iext_cursor *cur, struct xfs_bmbt_irec *got,
                struct xfs_bmbt_irec *del, uint32_t bflags);
void    xfs_bmap_del_extent_cow(struct xfs_inode *ip,
                struct xfs_iext_cursor *cur, struct xfs_bmbt_irec *got,
                struct xfs_bmbt_irec *del);
uint    xfs_default_attroffset(struct xfs_inode *ip);
int     xfs_bmap_collapse_extents(struct xfs_trans *tp, struct xfs_inode *ip,
                xfs_fileoff_t *next_fsb, xfs_fileoff_t offset_shift_fsb,
                bool *done);
int     xfs_bmap_can_insert_extents(struct xfs_inode *ip, xfs_fileoff_t off,
                xfs_fileoff_t shift);
int     xfs_bmap_insert_extents(struct xfs_trans *tp, struct xfs_inode *ip,
                xfs_fileoff_t *next_fsb, xfs_fileoff_t offset_shift_fsb,
                bool *done, xfs_fileoff_t stop_fsb);
int     xfs_bmap_split_extent(struct xfs_trans *tp, struct xfs_inode *ip,
                xfs_fileoff_t split_offset);
int     xfs_bmapi_convert_delalloc(struct xfs_inode *ip, int whichfork,
                xfs_off_t offset, struct iomap *iomap, unsigned int *seq);
int     xfs_bmap_add_extent_unwritten_real(struct xfs_trans *tp,
                struct xfs_inode *ip, int whichfork,
                struct xfs_iext_cursor *icur, struct xfs_btree_cur **curp,
                struct xfs_bmbt_irec *new, int *logflagsp);
xfs_extlen_t xfs_bmapi_minleft(struct xfs_trans *tp, struct xfs_inode *ip,
                int fork);
int     xfs_bmap_btalloc_low_space(struct xfs_bmalloca *ap,
                struct xfs_alloc_arg *args);
xfs_filblks_t xfs_bmap_worst_indlen(struct xfs_inode *ip, xfs_filblks_t len);

enum xfs_bmap_intent_type {
        XFS_BMAP_MAP = 1,
        XFS_BMAP_UNMAP,
};

#define XFS_BMAP_INTENT_STRINGS \
        { XFS_BMAP_MAP,         "map" }, \
        { XFS_BMAP_UNMAP,       "unmap" }

struct xfs_bmap_intent {
        struct list_head                        bi_list;
        enum xfs_bmap_intent_type               bi_type;
        int                                     bi_whichfork;
        struct xfs_inode                        *bi_owner;
        struct xfs_group                        *bi_group;
        struct xfs_bmbt_irec                    bi_bmap;
};

int     xfs_bmap_finish_one(struct xfs_trans *tp, struct xfs_bmap_intent *bi);
void    xfs_bmap_map_extent(struct xfs_trans *tp, struct xfs_inode *ip,
                int whichfork, struct xfs_bmbt_irec *imap);
void    xfs_bmap_unmap_extent(struct xfs_trans *tp, struct xfs_inode *ip,
                int whichfork, struct xfs_bmbt_irec *imap);

static inline uint32_t xfs_bmap_fork_to_state(int whichfork)
{
        switch (whichfork) {
        case XFS_ATTR_FORK:
                return BMAP_ATTRFORK;
        case XFS_COW_FORK:
                return BMAP_COWFORK;
        default:
                return 0;
        }
}

xfs_failaddr_t xfs_bmap_validate_extent_raw(struct xfs_mount *mp, bool rtfile,
                int whichfork, struct xfs_bmbt_irec *irec);
xfs_failaddr_t xfs_bmap_validate_extent(struct xfs_inode *ip, int whichfork,
                struct xfs_bmbt_irec *irec);
int xfs_bmap_complain_bad_rec(struct xfs_inode *ip, int whichfork,
                xfs_failaddr_t fa, const struct xfs_bmbt_irec *irec);

int     xfs_bmapi_remap(struct xfs_trans *tp, struct xfs_inode *ip,
                xfs_fileoff_t bno, xfs_filblks_t len, xfs_fsblock_t startblock,
                uint32_t flags);
int     xfs_bunmapi_range(struct xfs_trans **tpp, struct xfs_inode *ip,
                uint32_t flags, xfs_fileoff_t startoff, xfs_fileoff_t endoff);

extern struct kmem_cache        *xfs_bmap_intent_cache;

int __init xfs_bmap_intent_init_cache(void);
void xfs_bmap_intent_destroy_cache(void);

typedef int (*xfs_bmap_query_range_fn)(
        struct xfs_btree_cur    *cur,
        struct xfs_bmbt_irec    *rec,
        void                    *priv);

int xfs_bmap_query_all(struct xfs_btree_cur *cur, xfs_bmap_query_range_fn fn,
                void *priv);

xfs_extlen_t    xfs_get_extsz_hint(struct xfs_inode *ip);
xfs_extlen_t    xfs_get_cowextsz_hint(struct xfs_inode *ip);

#endif  /* __XFS_BMAP_H__ */