linux/fs/xfs/xfs_bmap.h
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   1/*
   2 * Copyright (c) 2000-2006 Silicon Graphics, Inc.
   3 * All Rights Reserved.
   4 *
   5 * This program is free software; you can redistribute it and/or
   6 * modify it under the terms of the GNU General Public License as
   7 * published by the Free Software Foundation.
   8 *
   9 * This program is distributed in the hope that it would be useful,
  10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 * GNU General Public License for more details.
  13 *
  14 * You should have received a copy of the GNU General Public License
  15 * along with this program; if not, write the Free Software Foundation,
  16 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  17 */
  18#ifndef __XFS_BMAP_H__
  19#define __XFS_BMAP_H__
  20
  21struct getbmap;
  22struct xfs_bmbt_irec;
  23struct xfs_ifork;
  24struct xfs_inode;
  25struct xfs_mount;
  26struct xfs_trans;
  27
  28extern kmem_zone_t      *xfs_bmap_free_item_zone;
  29
  30/*
  31 * List of extents to be free "later".
  32 * The list is kept sorted on xbf_startblock.
  33 */
  34typedef struct xfs_bmap_free_item
  35{
  36        xfs_fsblock_t           xbfi_startblock;/* starting fs block number */
  37        xfs_extlen_t            xbfi_blockcount;/* number of blocks in extent */
  38        struct xfs_bmap_free_item *xbfi_next;   /* link to next entry */
  39} xfs_bmap_free_item_t;
  40
  41/*
  42 * Header for free extent list.
  43 *
  44 * xbf_low is used by the allocator to activate the lowspace algorithm -
  45 * when free space is running low the extent allocator may choose to
  46 * allocate an extent from an AG without leaving sufficient space for
  47 * a btree split when inserting the new extent.  In this case the allocator
  48 * will enable the lowspace algorithm which is supposed to allow further
  49 * allocations (such as btree splits and newroots) to allocate from
  50 * sequential AGs.  In order to avoid locking AGs out of order the lowspace
  51 * algorithm will start searching for free space from AG 0.  If the correct
  52 * transaction reservations have been made then this algorithm will eventually
  53 * find all the space it needs.
  54 */
  55typedef struct xfs_bmap_free
  56{
  57        xfs_bmap_free_item_t    *xbf_first;     /* list of to-be-free extents */
  58        int                     xbf_count;      /* count of items on list */
  59        int                     xbf_low;        /* alloc in low mode */
  60} xfs_bmap_free_t;
  61
  62#define XFS_BMAP_MAX_NMAP       4
  63
  64/*
  65 * Flags for xfs_bmapi_*
  66 */
  67#define XFS_BMAPI_ENTIRE        0x001   /* return entire extent, not trimmed */
  68#define XFS_BMAPI_METADATA      0x002   /* mapping metadata not user data */
  69#define XFS_BMAPI_ATTRFORK      0x004   /* use attribute fork not data */
  70#define XFS_BMAPI_PREALLOC      0x008   /* preallocation op: unwritten space */
  71#define XFS_BMAPI_IGSTATE       0x010   /* Ignore state - */
  72                                        /* combine contig. space */
  73#define XFS_BMAPI_CONTIG        0x020   /* must allocate only one extent */
  74/*
  75 * unwritten extent conversion - this needs write cache flushing and no additional
  76 * allocation alignments. When specified with XFS_BMAPI_PREALLOC it converts
  77 * from written to unwritten, otherwise convert from unwritten to written.
  78 */
  79#define XFS_BMAPI_CONVERT       0x040
  80
  81#define XFS_BMAPI_FLAGS \
  82        { XFS_BMAPI_ENTIRE,     "ENTIRE" }, \
  83        { XFS_BMAPI_METADATA,   "METADATA" }, \
  84        { XFS_BMAPI_ATTRFORK,   "ATTRFORK" }, \
  85        { XFS_BMAPI_PREALLOC,   "PREALLOC" }, \
  86        { XFS_BMAPI_IGSTATE,    "IGSTATE" }, \
  87        { XFS_BMAPI_CONTIG,     "CONTIG" }, \
  88        { XFS_BMAPI_CONVERT,    "CONVERT" }
  89
  90
  91static inline int xfs_bmapi_aflag(int w)
  92{
  93        return (w == XFS_ATTR_FORK ? XFS_BMAPI_ATTRFORK : 0);
  94}
  95
  96/*
  97 * Special values for xfs_bmbt_irec_t br_startblock field.
  98 */
  99#define DELAYSTARTBLOCK         ((xfs_fsblock_t)-1LL)
 100#define HOLESTARTBLOCK          ((xfs_fsblock_t)-2LL)
 101
 102static inline void xfs_bmap_init(xfs_bmap_free_t *flp, xfs_fsblock_t *fbp)
 103{
 104        ((flp)->xbf_first = NULL, (flp)->xbf_count = 0, \
 105                (flp)->xbf_low = 0, *(fbp) = NULLFSBLOCK);
 106}
 107
 108/*
 109 * Argument structure for xfs_bmap_alloc.
 110 */
 111typedef struct xfs_bmalloca {
 112        xfs_fsblock_t           *firstblock; /* i/o first block allocated */
 113        struct xfs_bmap_free    *flist; /* bmap freelist */
 114        struct xfs_trans        *tp;    /* transaction pointer */
 115        struct xfs_inode        *ip;    /* incore inode pointer */
 116        struct xfs_bmbt_irec    prev;   /* extent before the new one */
 117        struct xfs_bmbt_irec    got;    /* extent after, or delayed */
 118
 119        xfs_fileoff_t           offset; /* offset in file filling in */
 120        xfs_extlen_t            length; /* i/o length asked/allocated */
 121        xfs_fsblock_t           blkno;  /* starting block of new extent */
 122
 123        struct xfs_btree_cur    *cur;   /* btree cursor */
 124        xfs_extnum_t            idx;    /* current extent index */
 125        int                     nallocs;/* number of extents alloc'd */
 126        int                     logflags;/* flags for transaction logging */
 127
 128        xfs_extlen_t            total;  /* total blocks needed for xaction */
 129        xfs_extlen_t            minlen; /* minimum allocation size (blocks) */
 130        xfs_extlen_t            minleft; /* amount must be left after alloc */
 131        char                    eof;    /* set if allocating past last extent */
 132        char                    wasdel; /* replacing a delayed allocation */
 133        char                    userdata;/* set if is user data */
 134        char                    aeof;   /* allocated space at eof */
 135        char                    conv;   /* overwriting unwritten extents */
 136} xfs_bmalloca_t;
 137
 138/*
 139 * Flags for xfs_bmap_add_extent*.
 140 */
 141#define BMAP_LEFT_CONTIG        (1 << 0)
 142#define BMAP_RIGHT_CONTIG       (1 << 1)
 143#define BMAP_LEFT_FILLING       (1 << 2)
 144#define BMAP_RIGHT_FILLING      (1 << 3)
 145#define BMAP_LEFT_DELAY         (1 << 4)
 146#define BMAP_RIGHT_DELAY        (1 << 5)
 147#define BMAP_LEFT_VALID         (1 << 6)
 148#define BMAP_RIGHT_VALID        (1 << 7)
 149#define BMAP_ATTRFORK           (1 << 8)
 150
 151#define XFS_BMAP_EXT_FLAGS \
 152        { BMAP_LEFT_CONTIG,     "LC" }, \
 153        { BMAP_RIGHT_CONTIG,    "RC" }, \
 154        { BMAP_LEFT_FILLING,    "LF" }, \
 155        { BMAP_RIGHT_FILLING,   "RF" }, \
 156        { BMAP_ATTRFORK,        "ATTR" }
 157
 158#if defined(__KERNEL) && defined(DEBUG)
 159void    xfs_bmap_trace_exlist(struct xfs_inode *ip, xfs_extnum_t cnt,
 160                int whichfork, unsigned long caller_ip);
 161#define XFS_BMAP_TRACE_EXLIST(ip,c,w)   \
 162        xfs_bmap_trace_exlist(ip,c,w, _THIS_IP_)
 163#else
 164#define XFS_BMAP_TRACE_EXLIST(ip,c,w)
 165#endif
 166
 167int     xfs_bmap_add_attrfork(struct xfs_inode *ip, int size, int rsvd);
 168void    xfs_bmap_add_free(xfs_fsblock_t bno, xfs_filblks_t len,
 169                struct xfs_bmap_free *flist, struct xfs_mount *mp);
 170void    xfs_bmap_cancel(struct xfs_bmap_free *flist);
 171void    xfs_bmap_compute_maxlevels(struct xfs_mount *mp, int whichfork);
 172int     xfs_bmap_first_unused(struct xfs_trans *tp, struct xfs_inode *ip,
 173                xfs_extlen_t len, xfs_fileoff_t *unused, int whichfork);
 174int     xfs_bmap_last_before(struct xfs_trans *tp, struct xfs_inode *ip,
 175                xfs_fileoff_t *last_block, int whichfork);
 176int     xfs_bmap_last_offset(struct xfs_trans *tp, struct xfs_inode *ip,
 177                xfs_fileoff_t *unused, int whichfork);
 178int     xfs_bmap_one_block(struct xfs_inode *ip, int whichfork);
 179int     xfs_bmap_read_extents(struct xfs_trans *tp, struct xfs_inode *ip,
 180                int whichfork);
 181int     xfs_bmapi_read(struct xfs_inode *ip, xfs_fileoff_t bno,
 182                xfs_filblks_t len, struct xfs_bmbt_irec *mval,
 183                int *nmap, int flags);
 184int     xfs_bmapi_delay(struct xfs_inode *ip, xfs_fileoff_t bno,
 185                xfs_filblks_t len, struct xfs_bmbt_irec *mval,
 186                int *nmap, int flags);
 187int     xfs_bmapi_write(struct xfs_trans *tp, struct xfs_inode *ip,
 188                xfs_fileoff_t bno, xfs_filblks_t len, int flags,
 189                xfs_fsblock_t *firstblock, xfs_extlen_t total,
 190                struct xfs_bmbt_irec *mval, int *nmap,
 191                struct xfs_bmap_free *flist);
 192int     xfs_bunmapi(struct xfs_trans *tp, struct xfs_inode *ip,
 193                xfs_fileoff_t bno, xfs_filblks_t len, int flags,
 194                xfs_extnum_t nexts, xfs_fsblock_t *firstblock,
 195                struct xfs_bmap_free *flist, int *done);
 196int     xfs_check_nostate_extents(struct xfs_ifork *ifp, xfs_extnum_t idx,
 197                xfs_extnum_t num);
 198uint    xfs_default_attroffset(struct xfs_inode *ip);
 199
 200#ifdef __KERNEL__
 201/* bmap to userspace formatter - copy to user & advance pointer */
 202typedef int (*xfs_bmap_format_t)(void **, struct getbmapx *, int *);
 203
 204int     xfs_bmap_finish(struct xfs_trans **tp, struct xfs_bmap_free *flist,
 205                int *committed);
 206int     xfs_getbmap(struct xfs_inode *ip, struct getbmapx *bmv,
 207                xfs_bmap_format_t formatter, void *arg);
 208int     xfs_bmap_eof(struct xfs_inode *ip, xfs_fileoff_t endoff,
 209                int whichfork, int *eof);
 210int     xfs_bmap_count_blocks(struct xfs_trans *tp, struct xfs_inode *ip,
 211                int whichfork, int *count);
 212int     xfs_bmap_punch_delalloc_range(struct xfs_inode *ip,
 213                xfs_fileoff_t start_fsb, xfs_fileoff_t length);
 214
 215xfs_daddr_t xfs_fsb_to_db(struct xfs_inode *ip, xfs_fsblock_t fsb);
 216
 217#endif  /* __KERNEL__ */
 218
 219#endif  /* __XFS_BMAP_H__ */
 220
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