/*
 * Copyright (c) 2000-2006 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_BMAP_H__
#define __XFS_BMAP_H__

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

extern kmem_zone_t      *xfs_bmap_free_item_zone;

/*
 * List of extents to be free "later".
 * The list is kept sorted on xbf_startblock.
 */
typedef struct xfs_bmap_free_item
{
        xfs_fsblock_t           xbfi_startblock;/* starting fs block number */
        xfs_extlen_t            xbfi_blockcount;/* number of blocks in extent */
        struct xfs_bmap_free_item *xbfi_next;   /* link to next entry */
} xfs_bmap_free_item_t;

/*
 * Header for free extent list.
 *
 * xbf_low is used by the allocator to activate the lowspace algorithm -
 * when free space is running low the extent allocator may choose to
 * allocate an extent from an AG without leaving sufficient space for
 * a btree split when inserting the new extent.  In this case the allocator
 * will enable the lowspace algorithm which is supposed to allow further
 * allocations (such as btree splits and newroots) to allocate from
 * sequential AGs.  In order to avoid locking AGs out of order the lowspace
 * algorithm will start searching for free space from AG 0.  If the correct
 * transaction reservations have been made then this algorithm will eventually
 * find all the space it needs.
 */
typedef struct xfs_bmap_free
{
        xfs_bmap_free_item_t    *xbf_first;     /* list of to-be-free extents */
        int                     xbf_count;      /* count of items on list */
        int                     xbf_low;        /* alloc in low mode */
} xfs_bmap_free_t;

#define XFS_BMAP_MAX_NMAP       4

/*
 * Flags for xfs_bmapi_*
 */
#define XFS_BMAPI_ENTIRE        0x001   /* return entire extent, not trimmed */
#define XFS_BMAPI_METADATA      0x002   /* mapping metadata not user data */
#define XFS_BMAPI_ATTRFORK      0x004   /* use attribute fork not data */
#define XFS_BMAPI_PREALLOC      0x008   /* preallocation op: unwritten space */
#define XFS_BMAPI_IGSTATE       0x010   /* Ignore state - */
                                        /* combine contig. space */
#define XFS_BMAPI_CONTIG        0x020   /* 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       0x040

#define XFS_BMAPI_FLAGS \
        { XFS_BMAPI_ENTIRE,     "ENTIRE" }, \
        { XFS_BMAPI_METADATA,   "METADATA" }, \
        { XFS_BMAPI_ATTRFORK,   "ATTRFORK" }, \
        { XFS_BMAPI_PREALLOC,   "PREALLOC" }, \
        { XFS_BMAPI_IGSTATE,    "IGSTATE" }, \
        { XFS_BMAPI_CONTIG,     "CONTIG" }, \
        { XFS_BMAPI_CONVERT,    "CONVERT" }


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

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

static inline void xfs_bmap_init(xfs_bmap_free_t *flp, xfs_fsblock_t *fbp)
{
        ((flp)->xbf_first = NULL, (flp)->xbf_count = 0, \
                (flp)->xbf_low = 0, *(fbp) = NULLFSBLOCK);
}

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

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


/*
 * This macro is used to determine how many extents will be shifted
 * in one write transaction. We could require two splits,
 * an extent move on the first and an extent merge on the second,
 * So it is proper that one extent is shifted inside write transaction
 * at a time.
 */
#define XFS_BMAP_MAX_SHIFT_EXTENTS      1

#ifdef DEBUG
void    xfs_bmap_trace_exlist(struct xfs_inode *ip, xfs_extnum_t cnt,
                int whichfork, unsigned long caller_ip);
#define XFS_BMAP_TRACE_EXLIST(ip,c,w)   \
        xfs_bmap_trace_exlist(ip,c,w, _THIS_IP_)
#else
#define XFS_BMAP_TRACE_EXLIST(ip,c,w)
#endif

int     xfs_bmap_add_attrfork(struct xfs_inode *ip, int size, int rsvd);
void    xfs_bmap_local_to_extents_empty(struct xfs_inode *ip, int whichfork);
void    xfs_bmap_add_free(xfs_fsblock_t bno, xfs_filblks_t len,
                struct xfs_bmap_free *flist, struct xfs_mount *mp);
void    xfs_bmap_cancel(struct xfs_bmap_free *flist);
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_bmap_one_block(struct xfs_inode *ip, int whichfork);
int     xfs_bmap_read_extents(struct xfs_trans *tp, struct xfs_inode *ip,
                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, int flags);
int     xfs_bmapi_delay(struct xfs_inode *ip, xfs_fileoff_t bno,
                xfs_filblks_t len, struct xfs_bmbt_irec *mval,
                int *nmap, int flags);
int     xfs_bmapi_write(struct xfs_trans *tp, struct xfs_inode *ip,
                xfs_fileoff_t bno, xfs_filblks_t len, int flags,
                xfs_fsblock_t *firstblock, xfs_extlen_t total,
                struct xfs_bmbt_irec *mval, int *nmap,
                struct xfs_bmap_free *flist);
int     xfs_bunmapi(struct xfs_trans *tp, struct xfs_inode *ip,
                xfs_fileoff_t bno, xfs_filblks_t len, int flags,
                xfs_extnum_t nexts, xfs_fsblock_t *firstblock,
                struct xfs_bmap_free *flist, int *done);
int     xfs_check_nostate_extents(struct xfs_ifork *ifp, xfs_extnum_t idx,
                xfs_extnum_t num);
uint    xfs_default_attroffset(struct xfs_inode *ip);
int     xfs_bmap_shift_extents(struct xfs_trans *tp, struct xfs_inode *ip,
                int *done, xfs_fileoff_t start_fsb,
                xfs_fileoff_t offset_shift_fsb, xfs_extnum_t *current_ext,
                xfs_fsblock_t *firstblock, struct xfs_bmap_free *flist,
                int num_exts);

#endif  /* __XFS_BMAP_H__ */