libxfs/xfs_bmap.h

   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
  21 struct getbmap;
  22 struct xfs_bmbt_irec;
  23 struct xfs_ifork;
  24 struct xfs_inode;
  25 struct xfs_mount;
  26 struct xfs_trans;
  27
  28 extern kmem_zone_t      *xfs_bmap_free_item_zone;
  29
  30 /*
  31  * Argument structure for xfs_bmap_alloc.
  32  */
  33 struct xfs_bmalloca {
  34         xfs_fsblock_t           *firstblock; /* i/o first block allocated */
  35         struct xfs_bmap_free    *flist; /* bmap freelist */
  36         struct xfs_trans        *tp;    /* transaction pointer */
  37         struct xfs_inode        *ip;    /* incore inode pointer */
  38         struct xfs_bmbt_irec    prev;   /* extent before the new one */
  39         struct xfs_bmbt_irec    got;    /* extent after, or delayed */
  40
  41         xfs_fileoff_t           offset; /* offset in file filling in */
  42         xfs_extlen_t            length; /* i/o length asked/allocated */
  43         xfs_fsblock_t           blkno;  /* starting block of new extent */
  44
  45         struct xfs_btree_cur    *cur;   /* btree cursor */
  46         xfs_extnum_t            idx;    /* current extent index */
  47         int                     nallocs;/* number of extents alloc'd */
  48         int                     logflags;/* flags for transaction logging */
  49
  50         xfs_extlen_t            total;  /* total blocks needed for xaction */
  51         xfs_extlen_t            minlen; /* minimum allocation size (blocks) */
  52         xfs_extlen_t            minleft; /* amount must be left after alloc */
  53         bool                    eof;    /* set if allocating past last extent */
  54         bool                    wasdel; /* replacing a delayed allocation */
  55         bool                    aeof;   /* allocated space at eof */
  56         bool                    conv;   /* overwriting unwritten extents */
  57         char                    userdata;/* userdata mask */
  58         int                     flags;
  59 };
  60
  61 /*
  62  * List of extents to be free "later".
  63  * The list is kept sorted on xbf_startblock.
  64  */
  65 typedef struct xfs_bmap_free_item
  66 {
  67         xfs_fsblock_t           xbfi_startblock;/* starting fs block number */
  68         xfs_extlen_t            xbfi_blockcount;/* number of blocks in extent */
  69         struct xfs_bmap_free_item *xbfi_next;   /* link to next entry */
  70 } xfs_bmap_free_item_t;
  71
  72 /*
  73  * Header for free extent list.
  74  *
  75  * xbf_low is used by the allocator to activate the lowspace algorithm -
  76  * when free space is running low the extent allocator may choose to
  77  * allocate an extent from an AG without leaving sufficient space for
  78  * a btree split when inserting the new extent.  In this case the allocator
  79  * will enable the lowspace algorithm which is supposed to allow further
  80  * allocations (such as btree splits and newroots) to allocate from
  81  * sequential AGs.  In order to avoid locking AGs out of order the lowspace
  82  * algorithm will start searching for free space from AG 0.  If the correct
  83  * transaction reservations have been made then this algorithm will eventually
  84  * find all the space it needs.
  85  */
  86 typedef struct xfs_bmap_free
  87 {
  88         xfs_bmap_free_item_t    *xbf_first;     /* list of to-be-free extents */
  89         int                     xbf_count;      /* count of items on list */
  90         int                     xbf_low;        /* alloc in low mode */
  91 } xfs_bmap_free_t;
  92
  93 #define XFS_BMAP_MAX_NMAP       4
  94
  95 /*
  96  * Flags for xfs_bmapi_*
  97  */
  98 #define XFS_BMAPI_ENTIRE        0x001   /* return entire extent, not trimmed */
  99 #define XFS_BMAPI_METADATA      0x002   /* mapping metadata not user data */
 100 #define XFS_BMAPI_ATTRFORK      0x004   /* use attribute fork not data */
 101 #define XFS_BMAPI_PREALLOC      0x008   /* preallocation op: unwritten space */
 102 #define XFS_BMAPI_IGSTATE       0x010   /* Ignore state - */
 103                                         /* combine contig. space */
 104 #define XFS_BMAPI_CONTIG        0x020   /* must allocate only one extent */
 105 /*
 106  * unwritten extent conversion - this needs write cache flushing and no additional
 107  * allocation alignments. When specified with XFS_BMAPI_PREALLOC it converts
 108  * from written to unwritten, otherwise convert from unwritten to written.
 109  */
 110 #define XFS_BMAPI_CONVERT       0x040
 111
 112 /*
 113  * allocate zeroed extents - this requires all newly allocated user data extents
 114  * to be initialised to zero. It will be ignored if XFS_BMAPI_METADATA is set.
 115  * Use in conjunction with XFS_BMAPI_CONVERT to convert unwritten extents found
 116  * during the allocation range to zeroed written extents.
 117  */
 118 #define XFS_BMAPI_ZERO          0x080
 119
 120 #define XFS_BMAPI_FLAGS \
 121         { XFS_BMAPI_ENTIRE,     "ENTIRE" }, \
 122         { XFS_BMAPI_METADATA,   "METADATA" }, \
 123         { XFS_BMAPI_ATTRFORK,   "ATTRFORK" }, \
 124         { XFS_BMAPI_PREALLOC,   "PREALLOC" }, \
 125         { XFS_BMAPI_IGSTATE,    "IGSTATE" }, \
 126         { XFS_BMAPI_CONTIG,     "CONTIG" }, \
 127         { XFS_BMAPI_CONVERT,    "CONVERT" }, \
 128         { XFS_BMAPI_ZERO,       "ZERO" }
 129
 130
 131 static inline int xfs_bmapi_aflag(int w)
 132 {
 133         return (w == XFS_ATTR_FORK ? XFS_BMAPI_ATTRFORK : 0);
 134 }
 135
 136 /*
 137  * Special values for xfs_bmbt_irec_t br_startblock field.
 138  */
 139 #define DELAYSTARTBLOCK         ((xfs_fsblock_t)-1LL)
 140 #define HOLESTARTBLOCK          ((xfs_fsblock_t)-2LL)
 141
 142 static inline void xfs_bmap_init(xfs_bmap_free_t *flp, xfs_fsblock_t *fbp)
 143 {
 144         ((flp)->xbf_first = NULL, (flp)->xbf_count = 0, \
 145                 (flp)->xbf_low = 0, *(fbp) = NULLFSBLOCK);
 146 }
 147
 148 /*
 149  * Flags for xfs_bmap_add_extent*.
 150  */
 151 #define BMAP_LEFT_CONTIG        (1 << 0)
 152 #define BMAP_RIGHT_CONTIG       (1 << 1)
 153 #define BMAP_LEFT_FILLING       (1 << 2)
 154 #define BMAP_RIGHT_FILLING      (1 << 3)
 155 #define BMAP_LEFT_DELAY         (1 << 4)
 156 #define BMAP_RIGHT_DELAY        (1 << 5)
 157 #define BMAP_LEFT_VALID         (1 << 6)
 158 #define BMAP_RIGHT_VALID        (1 << 7)
 159 #define BMAP_ATTRFORK           (1 << 8)
 160
 161 #define XFS_BMAP_EXT_FLAGS \
 162         { BMAP_LEFT_CONTIG,     "LC" }, \
 163         { BMAP_RIGHT_CONTIG,    "RC" }, \
 164         { BMAP_LEFT_FILLING,    "LF" }, \
 165         { BMAP_RIGHT_FILLING,   "RF" }, \
 166         { BMAP_ATTRFORK,        "ATTR" }
 167
 168
 169 /*
 170  * This macro is used to determine how many extents will be shifted
 171  * in one write transaction. We could require two splits,
 172  * an extent move on the first and an extent merge on the second,
 173  * So it is proper that one extent is shifted inside write transaction
 174  * at a time.
 175  */
 176 #define XFS_BMAP_MAX_SHIFT_EXTENTS      1
 177
 178 enum shift_direction {
 179         SHIFT_LEFT = 0,
 180         SHIFT_RIGHT,
 181 };
 182
 183 #ifdef DEBUG
 184 void    xfs_bmap_trace_exlist(struct xfs_inode *ip, xfs_extnum_t cnt,
 185                 int whichfork, unsigned long caller_ip);
 186 #define XFS_BMAP_TRACE_EXLIST(ip,c,w)   \
 187         xfs_bmap_trace_exlist(ip,c,w, _THIS_IP_)
 188 #else
 189 #define XFS_BMAP_TRACE_EXLIST(ip,c,w)
 190 #endif
 191
 192 int     xfs_bmap_add_attrfork(struct xfs_inode *ip, int size, int rsvd);
 193 void    xfs_bmap_local_to_extents_empty(struct xfs_inode *ip, int whichfork);
 194 void    xfs_bmap_add_free(struct xfs_mount *mp, struct xfs_bmap_free *flist,
 195                           xfs_fsblock_t bno, xfs_filblks_t len);
 196 void    xfs_bmap_cancel(struct xfs_bmap_free *flist);
 197 int     xfs_bmap_finish(struct xfs_trans **tp, struct xfs_bmap_free *flist,
 198                         int *committed);
 199 void    xfs_bmap_compute_maxlevels(struct xfs_mount *mp, int whichfork);
 200 int     xfs_bmap_first_unused(struct xfs_trans *tp, struct xfs_inode *ip,
 201                 xfs_extlen_t len, xfs_fileoff_t *unused, int whichfork);
 202 int     xfs_bmap_last_before(struct xfs_trans *tp, struct xfs_inode *ip,
 203                 xfs_fileoff_t *last_block, int whichfork);
 204 int     xfs_bmap_last_offset(struct xfs_inode *ip, xfs_fileoff_t *unused,
 205                 int whichfork);
 206 int     xfs_bmap_one_block(struct xfs_inode *ip, int whichfork);
 207 int     xfs_bmap_read_extents(struct xfs_trans *tp, struct xfs_inode *ip,
 208                 int whichfork);
 209 int     xfs_bmapi_read(struct xfs_inode *ip, xfs_fileoff_t bno,
 210                 xfs_filblks_t len, struct xfs_bmbt_irec *mval,
 211                 int *nmap, int flags);
 212 int     xfs_bmapi_delay(struct xfs_inode *ip, xfs_fileoff_t bno,
 213                 xfs_filblks_t len, struct xfs_bmbt_irec *mval,
 214                 int *nmap, int flags);
 215 int     xfs_bmapi_write(struct xfs_trans *tp, struct xfs_inode *ip,
 216                 xfs_fileoff_t bno, xfs_filblks_t len, int flags,
 217                 xfs_fsblock_t *firstblock, xfs_extlen_t total,
 218                 struct xfs_bmbt_irec *mval, int *nmap,
 219                 struct xfs_bmap_free *flist);
 220 int     xfs_bunmapi(struct xfs_trans *tp, struct xfs_inode *ip,
 221                 xfs_fileoff_t bno, xfs_filblks_t len, int flags,
 222                 xfs_extnum_t nexts, xfs_fsblock_t *firstblock,
 223                 struct xfs_bmap_free *flist, int *done);
 224 int     xfs_check_nostate_extents(struct xfs_ifork *ifp, xfs_extnum_t idx,
 225                 xfs_extnum_t num);
 226 uint    xfs_default_attroffset(struct xfs_inode *ip);
 227 int     xfs_bmap_shift_extents(struct xfs_trans *tp, struct xfs_inode *ip,
 228                 xfs_fileoff_t *next_fsb, xfs_fileoff_t offset_shift_fsb,
 229                 int *done, xfs_fileoff_t stop_fsb, xfs_fsblock_t *firstblock,
 230                 struct xfs_bmap_free *flist, enum shift_direction direction,
 231                 int num_exts);
 232 int     xfs_bmap_split_extent(struct xfs_inode *ip, xfs_fileoff_t split_offset);
 233
 234 struct xfs_bmbt_rec_host *
 235         xfs_bmap_search_extents(struct xfs_inode *ip, xfs_fileoff_t bno,
 236                                 int fork, int *eofp, xfs_extnum_t *lastxp,
 237                                 struct xfs_bmbt_irec *gotp,
 238                                 struct xfs_bmbt_irec *prevp);
 239
 240
 241 #endif  /* __XFS_BMAP_H__ */