xfs_bmap.h

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/*
 * 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_STACK_SWITCH  0x080

#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" }, \
    { XFS_BMAPI_STACK_SWITCH, "STACK_SWITCH" }


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);
}

/*
 * Argument structure for xfs_bmap_alloc.
 */
typedef struct xfs_bmalloca {
    xfs_fsblock_t       *firstblock; /* i/o first block allocated */
    struct xfs_bmap_free    *flist; /* bmap freelist */
    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 */
    xfs_extnum_t        idx;    /* current extent index */
    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 */
    char            eof;    /* set if allocating past last extent */
    char            wasdel; /* replacing a delayed allocation */
    char            userdata;/* set if is user data */
    char            aeof;   /* allocated space at eof */
    char            conv;   /* overwriting unwritten extents */
    char            stack_switch;
    int         flags;
    struct completion   *done;
    struct work_struct  work;
    int         result;
} xfs_bmalloca_t;

/*
 * 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" }

#if defined(__KERNEL) && defined(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_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_trans *tp, 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);

#ifdef __KERNEL__
/* bmap to userspace formatter - copy to user & advance pointer */
typedef int (*xfs_bmap_format_t)(void **, struct getbmapx *, int *);

int xfs_bmap_finish(struct xfs_trans **tp, struct xfs_bmap_free *flist,
        int *committed);
int xfs_getbmap(struct xfs_inode *ip, struct getbmapx *bmv,
        xfs_bmap_format_t formatter, void *arg);
int xfs_bmap_eof(struct xfs_inode *ip, xfs_fileoff_t endoff,
        int whichfork, int *eof);
int xfs_bmap_count_blocks(struct xfs_trans *tp, struct xfs_inode *ip,
        int whichfork, int *count);
int xfs_bmap_punch_delalloc_range(struct xfs_inode *ip,
        xfs_fileoff_t start_fsb, xfs_fileoff_t length);

xfs_daddr_t xfs_fsb_to_db(struct xfs_inode *ip, xfs_fsblock_t fsb);

#endif  /* __KERNEL__ */

#endif  /* __XFS_BMAP_H__ */