fs/xfs/xfs_bmap.h

   1 /*
   2  * Copyright (c) 2000-2003,2005 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_inode;
  24 struct xfs_mount;
  25 struct xfs_trans;
  26
  27 /*
  28  * List of extents to be free "later".
  29  * The list is kept sorted on xbf_startblock.
  30  */
  31 typedef struct xfs_bmap_free_item
  32 {
  33         xfs_fsblock_t           xbfi_startblock;/* starting fs block number */
  34         xfs_extlen_t            xbfi_blockcount;/* number of blocks in extent */
  35         struct xfs_bmap_free_item *xbfi_next;   /* link to next entry */
  36 } xfs_bmap_free_item_t;
  37
  38 /*
  39  * Header for free extent list.
  40  */
  41 typedef struct xfs_bmap_free
  42 {
  43         xfs_bmap_free_item_t    *xbf_first;     /* list of to-be-free extents */
  44         int                     xbf_count;      /* count of items on list */
  45         int                     xbf_low;        /* kludge: alloc in low mode */
  46 } xfs_bmap_free_t;
  47
  48 #define XFS_BMAP_MAX_NMAP       4
  49
  50 /*
  51  * Flags for xfs_bmapi
  52  */
  53 #define XFS_BMAPI_WRITE         0x001   /* write operation: allocate space */
  54 #define XFS_BMAPI_DELAY         0x002   /* delayed write operation */
  55 #define XFS_BMAPI_ENTIRE        0x004   /* return entire extent, not trimmed */
  56 #define XFS_BMAPI_METADATA      0x008   /* mapping metadata not user data */
  57 #define XFS_BMAPI_EXACT         0x010   /* allocate only to spec'd bounds */
  58 #define XFS_BMAPI_ATTRFORK      0x020   /* use attribute fork not data */
  59 #define XFS_BMAPI_ASYNC         0x040   /* bunmapi xactions can be async */
  60 #define XFS_BMAPI_RSVBLOCKS     0x080   /* OK to alloc. reserved data blocks */
  61 #define XFS_BMAPI_PREALLOC      0x100   /* preallocation op: unwritten space */
  62 #define XFS_BMAPI_IGSTATE       0x200   /* Ignore state - */
  63                                         /* combine contig. space */
  64 #define XFS_BMAPI_CONTIG        0x400   /* must allocate only one extent */
  65 /*      XFS_BMAPI_DIRECT_IO     0x800   */
  66 #define XFS_BMAPI_CONVERT       0x1000  /* unwritten extent conversion - */
  67                                         /* need write cache flushing and no */
  68                                         /* additional allocation alignments */
  69
  70 #define XFS_BMAPI_AFLAG(w)      xfs_bmapi_aflag(w)
  71 static inline int xfs_bmapi_aflag(int w)
  72 {
  73         return (w == XFS_ATTR_FORK ? XFS_BMAPI_ATTRFORK : 0);
  74 }
  75
  76 /*
  77  * Special values for xfs_bmbt_irec_t br_startblock field.
  78  */
  79 #define DELAYSTARTBLOCK         ((xfs_fsblock_t)-1LL)
  80 #define HOLESTARTBLOCK          ((xfs_fsblock_t)-2LL)
  81
  82 #define XFS_BMAP_INIT(flp,fbp)  xfs_bmap_init(flp,fbp)
  83 static inline void xfs_bmap_init(xfs_bmap_free_t *flp, xfs_fsblock_t *fbp)
  84 {
  85         ((flp)->xbf_first = NULL, (flp)->xbf_count = 0, \
  86                 (flp)->xbf_low = 0, *(fbp) = NULLFSBLOCK);
  87 }
  88
  89 /*
  90  * Argument structure for xfs_bmap_alloc.
  91  */
  92 typedef struct xfs_bmalloca {
  93         xfs_fsblock_t           firstblock; /* i/o first block allocated */
  94         xfs_fsblock_t           rval;   /* starting block of new extent */
  95         xfs_fileoff_t           off;    /* offset in file filling in */
  96         struct xfs_trans        *tp;    /* transaction pointer */
  97         struct xfs_inode        *ip;    /* incore inode pointer */
  98         struct xfs_bmbt_irec    *prevp; /* extent before the new one */
  99         struct xfs_bmbt_irec    *gotp;  /* extent after, or delayed */
 100         xfs_extlen_t            alen;   /* i/o length asked/allocated */
 101         xfs_extlen_t            total;  /* total blocks needed for xaction */
 102         xfs_extlen_t            minlen; /* mininum allocation size (blocks) */
 103         xfs_extlen_t            minleft; /* amount must be left after alloc */
 104         char                    eof;    /* set if allocating past last extent */
 105         char                    wasdel; /* replacing a delayed allocation */
 106         char                    userdata;/* set if is user data */
 107         char                    low;    /* low on space, using seq'l ags */
 108         char                    aeof;   /* allocated space at eof */
 109         char                    conv;   /* overwriting unwritten extents */
 110 } xfs_bmalloca_t;
 111
 112 #ifdef __KERNEL__
 113
 114 #if defined(XFS_BMAP_TRACE)
 115 /*
 116  * Trace operations for bmap extent tracing
 117  */
 118 #define XFS_BMAP_KTRACE_DELETE  1
 119 #define XFS_BMAP_KTRACE_INSERT  2
 120 #define XFS_BMAP_KTRACE_PRE_UP  3
 121 #define XFS_BMAP_KTRACE_POST_UP 4
 122
 123 #define XFS_BMAP_TRACE_SIZE     4096    /* size of global trace buffer */
 124 #define XFS_BMAP_KTRACE_SIZE    32      /* size of per-inode trace buffer */
 125 extern ktrace_t *xfs_bmap_trace_buf;
 126
 127 /*
 128  * Add bmap trace insert entries for all the contents of the extent list.
 129  */
 130 void
 131 xfs_bmap_trace_exlist(
 132         char                    *fname,         /* function name */
 133         struct xfs_inode        *ip,            /* incore inode pointer */
 134         xfs_extnum_t            cnt,            /* count of entries in list */
 135         int                     whichfork);     /* data or attr fork */
 136 #else
 137 #define xfs_bmap_trace_exlist(f,ip,c,w)
 138 #endif
 139
 140 /*
 141  * Convert inode from non-attributed to attributed.
 142  * Must not be in a transaction, ip must not be locked.
 143  */
 144 int                                     /* error code */
 145 xfs_bmap_add_attrfork(
 146         struct xfs_inode        *ip,    /* incore inode pointer */
 147         int                     size,   /* space needed for new attribute */
 148         int                     rsvd);  /* flag for reserved block allocation */
 149
 150 /*
 151  * Add the extent to the list of extents to be free at transaction end.
 152  * The list is maintained sorted (by block number).
 153  */
 154 void
 155 xfs_bmap_add_free(
 156         xfs_fsblock_t           bno,            /* fs block number of extent */
 157         xfs_filblks_t           len,            /* length of extent */
 158         xfs_bmap_free_t         *flist,         /* list of extents */
 159         struct xfs_mount        *mp);           /* mount point structure */
 160
 161 /*
 162  * Routine to clean up the free list data structure when
 163  * an error occurs during a transaction.
 164  */
 165 void
 166 xfs_bmap_cancel(
 167         xfs_bmap_free_t         *flist);        /* free list to clean up */
 168
 169 /*
 170  * Compute and fill in the value of the maximum depth of a bmap btree
 171  * in this filesystem.  Done once, during mount.
 172  */
 173 void
 174 xfs_bmap_compute_maxlevels(
 175         struct xfs_mount        *mp,    /* file system mount structure */
 176         int                     whichfork);     /* data or attr fork */
 177
 178 /*
 179  * Routine to be called at transaction's end by xfs_bmapi, xfs_bunmapi
 180  * caller.  Frees all the extents that need freeing, which must be done
 181  * last due to locking considerations.
 182  *
 183  * Return 1 if the given transaction was committed and a new one allocated,
 184  * and 0 otherwise.
 185  */
 186 int                                             /* error */
 187 xfs_bmap_finish(
 188         struct xfs_trans        **tp,           /* transaction pointer addr */
 189         xfs_bmap_free_t         *flist,         /* i/o: list extents to free */
 190         xfs_fsblock_t           firstblock,     /* controlled a.g. for allocs */
 191         int                     *committed);    /* xact committed or not */
 192
 193 /*
 194  * Returns the file-relative block number of the first unused block in the file.
 195  * This is the lowest-address hole if the file has holes, else the first block
 196  * past the end of file.
 197  */
 198 int                                             /* error */
 199 xfs_bmap_first_unused(
 200         struct xfs_trans        *tp,            /* transaction pointer */
 201         struct xfs_inode        *ip,            /* incore inode */
 202         xfs_extlen_t            len,            /* size of hole to find */
 203         xfs_fileoff_t           *unused,        /* unused block num */
 204         int                     whichfork);     /* data or attr fork */
 205
 206 /*
 207  * Returns the file-relative block number of the last block + 1 before
 208  * last_block (input value) in the file.
 209  * This is not based on i_size, it is based on the extent list.
 210  * Returns 0 for local files, as they do not have an extent list.
 211  */
 212 int                                             /* error */
 213 xfs_bmap_last_before(
 214         struct xfs_trans        *tp,            /* transaction pointer */
 215         struct xfs_inode        *ip,            /* incore inode */
 216         xfs_fileoff_t           *last_block,    /* last block */
 217         int                     whichfork);     /* data or attr fork */
 218
 219 /*
 220  * Returns the file-relative block number of the first block past eof in
 221  * the file.  This is not based on i_size, it is based on the extent list.
 222  * Returns 0 for local files, as they do not have an extent list.
 223  */
 224 int                                             /* error */
 225 xfs_bmap_last_offset(
 226         struct xfs_trans        *tp,            /* transaction pointer */
 227         struct xfs_inode        *ip,            /* incore inode */
 228         xfs_fileoff_t           *unused,        /* last block num */
 229         int                     whichfork);     /* data or attr fork */
 230
 231 /*
 232  * Returns whether the selected fork of the inode has exactly one
 233  * block or not.  For the data fork we check this matches di_size,
 234  * implying the file's range is 0..bsize-1.
 235  */
 236 int
 237 xfs_bmap_one_block(
 238         struct xfs_inode        *ip,            /* incore inode */
 239         int                     whichfork);     /* data or attr fork */
 240
 241 /*
 242  * Read in the extents to iu_extents.
 243  * All inode fields are set up by caller, we just traverse the btree
 244  * and copy the records in.
 245  */
 246 int                                             /* error */
 247 xfs_bmap_read_extents(
 248         struct xfs_trans        *tp,            /* transaction pointer */
 249         struct xfs_inode        *ip,            /* incore inode */
 250         int                     whichfork);     /* data or attr fork */
 251
 252 /*
 253  * Map file blocks to filesystem blocks.
 254  * File range is given by the bno/len pair.
 255  * Adds blocks to file if a write ("flags & XFS_BMAPI_WRITE" set)
 256  * into a hole or past eof.
 257  * Only allocates blocks from a single allocation group,
 258  * to avoid locking problems.
 259  * The returned value in "firstblock" from the first call in a transaction
 260  * must be remembered and presented to subsequent calls in "firstblock".
 261  * An upper bound for the number of blocks to be allocated is supplied to
 262  * the first call in "total"; if no allocation group has that many free
 263  * blocks then the call will fail (return NULLFSBLOCK in "firstblock").
 264  */
 265 int                                             /* error */
 266 xfs_bmapi(
 267         struct xfs_trans        *tp,            /* transaction pointer */
 268         struct xfs_inode        *ip,            /* incore inode */
 269         xfs_fileoff_t           bno,            /* starting file offs. mapped */
 270         xfs_filblks_t           len,            /* length to map in file */
 271         int                     flags,          /* XFS_BMAPI_... */
 272         xfs_fsblock_t           *firstblock,    /* first allocated block
 273                                                    controls a.g. for allocs */
 274         xfs_extlen_t            total,          /* total blocks needed */
 275         struct xfs_bmbt_irec    *mval,          /* output: map values */
 276         int                     *nmap,          /* i/o: mval size/count */
 277         xfs_bmap_free_t         *flist);        /* i/o: list extents to free */
 278
 279 /*
 280  * Map file blocks to filesystem blocks, simple version.
 281  * One block only, read-only.
 282  * For flags, only the XFS_BMAPI_ATTRFORK flag is examined.
 283  * For the other flag values, the effect is as if XFS_BMAPI_METADATA
 284  * was set and all the others were clear.
 285  */
 286 int                                             /* error */
 287 xfs_bmapi_single(
 288         struct xfs_trans        *tp,            /* transaction pointer */
 289         struct xfs_inode        *ip,            /* incore inode */
 290         int                     whichfork,      /* data or attr fork */
 291         xfs_fsblock_t           *fsb,           /* output: mapped block */
 292         xfs_fileoff_t           bno);           /* starting file offs. mapped */
 293
 294 /*
 295  * Unmap (remove) blocks from a file.
 296  * If nexts is nonzero then the number of extents to remove is limited to
 297  * that value.  If not all extents in the block range can be removed then
 298  * *done is set.
 299  */
 300 int                                             /* error */
 301 xfs_bunmapi(
 302         struct xfs_trans        *tp,            /* transaction pointer */
 303         struct xfs_inode        *ip,            /* incore inode */
 304         xfs_fileoff_t           bno,            /* starting offset to unmap */
 305         xfs_filblks_t           len,            /* length to unmap in file */
 306         int                     flags,          /* XFS_BMAPI_... */
 307         xfs_extnum_t            nexts,          /* number of extents max */
 308         xfs_fsblock_t           *firstblock,    /* first allocated block
 309                                                    controls a.g. for allocs */
 310         xfs_bmap_free_t         *flist,         /* i/o: list extents to free */
 311         int                     *done);         /* set if not done yet */
 312
 313 /*
 314  * Fcntl interface to xfs_bmapi.
 315  */
 316 int                                             /* error code */
 317 xfs_getbmap(
 318         bhv_desc_t              *bdp,           /* XFS behavior descriptor*/
 319         struct getbmap          *bmv,           /* user bmap structure */
 320         void                    __user *ap,     /* pointer to user's array */
 321         int                     iflags);        /* interface flags */
 322
 323 /*
 324  * Check if the endoff is outside the last extent. If so the caller will grow
 325  * the allocation to a stripe unit boundary
 326  */
 327 int
 328 xfs_bmap_eof(
 329         struct xfs_inode        *ip,
 330         xfs_fileoff_t           endoff,
 331         int                     whichfork,
 332         int                     *eof);
 333
 334 /*
 335  * Count fsblocks of the given fork.
 336  */
 337 int
 338 xfs_bmap_count_blocks(
 339         xfs_trans_t             *tp,
 340         struct xfs_inode        *ip,
 341         int                     whichfork,
 342         int                     *count);
 343
 344 /*
 345  * Check an extent list, which has just been read, for
 346  * any bit in the extent flag field.
 347  */
 348 int
 349 xfs_check_nostate_extents(
 350         xfs_bmbt_rec_t          *ep,
 351         xfs_extnum_t            num);
 352
 353 #endif  /* __KERNEL__ */
 354
 355 #endif  /* __XFS_BMAP_H__ */