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