include/xfs_bmap.h

   1 /*
   2  * Copyright (c) 2000-2003 Silicon Graphics, Inc.  All Rights Reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms of version 2 of the GNU General Public License as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it would be useful, but
   9  * WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  11  *
  12  * Further, this software is distributed without any warranty that it is
  13  * free of the rightful claim of any third person regarding infringement
  14  * or the like.  Any license provided herein, whether implied or
  15  * otherwise, applies only to this software file.  Patent licenses, if
  16  * any, provided herein do not apply to combinations of this program with
  17  * other software, or any other product whatsoever.
  18  *
  19  * You should have received a copy of the GNU General Public License along
  20  * with this program; if not, write the Free Software Foundation, Inc., 59
  21  * Temple Place - Suite 330, Boston MA 02111-1307, USA.
  22  *
  23  * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
  24  * Mountain View, CA  94043, or:
  25  *
  26  * http://www.sgi.com
  27  *
  28  * For further information regarding this notice, see:
  29  *
  30  * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
  31  */
  32 #ifndef __XFS_BMAP_H__
  33 #define __XFS_BMAP_H__
  34
  35 struct getbmap;
  36 struct xfs_bmbt_irec;
  37 struct xfs_inode;
  38 struct xfs_mount;
  39 struct xfs_trans;
  40
  41 /*
  42  * List of extents to be free "later".
  43  * The list is kept sorted on xbf_startblock.
  44  */
  45 typedef struct xfs_bmap_free_item
  46 {
  47         xfs_fsblock_t           xbfi_startblock;/* starting fs block number */
  48         xfs_extlen_t            xbfi_blockcount;/* number of blocks in extent */
  49         struct xfs_bmap_free_item *xbfi_next;   /* link to next entry */
  50 } xfs_bmap_free_item_t;
  51
  52 /*
  53  * Header for free extent list.
  54  */
  55 typedef 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;        /* kludge: 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_WRITE         0x001   /* write operation: allocate space */
  68 #define XFS_BMAPI_DELAY         0x002   /* delayed write operation */
  69 #define XFS_BMAPI_ENTIRE        0x004   /* return entire extent, not trimmed */
  70 #define XFS_BMAPI_METADATA      0x008   /* mapping metadata not user data */
  71 #define XFS_BMAPI_EXACT         0x010   /* allocate only to spec'd bounds */
  72 #define XFS_BMAPI_ATTRFORK      0x020   /* use attribute fork not data */
  73 #define XFS_BMAPI_ASYNC         0x040   /* bunmapi xactions can be async */
  74 #define XFS_BMAPI_RSVBLOCKS     0x080   /* OK to alloc. reserved data blocks */
  75 #define XFS_BMAPI_PREALLOC      0x100   /* preallocation op: unwritten space */
  76 #define XFS_BMAPI_IGSTATE       0x200   /* Ignore state - */
  77                                         /* combine contig. space */
  78 #define XFS_BMAPI_CONTIG        0x400   /* must allocate only one extent */
  79
  80 #if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_BMAPI_AFLAG)
  81 int xfs_bmapi_aflag(int w);
  82 #define XFS_BMAPI_AFLAG(w)      xfs_bmapi_aflag(w)
  83 #else
  84 #define XFS_BMAPI_AFLAG(w)      ((w) == XFS_ATTR_FORK ? XFS_BMAPI_ATTRFORK : 0)
  85 #endif
  86
  87 /*
  88  * Special values for xfs_bmbt_irec_t br_startblock field.
  89  */
  90 #define DELAYSTARTBLOCK         ((xfs_fsblock_t)-1LL)
  91 #define HOLESTARTBLOCK          ((xfs_fsblock_t)-2LL)
  92
  93 /*
  94  * Trace operations for bmap extent tracing
  95  */
  96 #define XFS_BMAP_KTRACE_DELETE  1
  97 #define XFS_BMAP_KTRACE_INSERT  2
  98 #define XFS_BMAP_KTRACE_PRE_UP  3
  99 #define XFS_BMAP_KTRACE_POST_UP 4
 100
 101 #define XFS_BMAP_TRACE_SIZE     4096    /* size of global trace buffer */
 102 #define XFS_BMAP_KTRACE_SIZE    32      /* size of per-inode trace buffer */
 103
 104 #if defined(XFS_ALL_TRACE)
 105 #define XFS_BMAP_TRACE
 106 #endif
 107
 108 #if !defined(DEBUG)
 109 #undef  XFS_BMAP_TRACE
 110 #endif
 111
 112
 113 #if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_BMAP_INIT)
 114 void xfs_bmap_init(xfs_bmap_free_t *flp, xfs_fsblock_t *fbp);
 115 #define XFS_BMAP_INIT(flp,fbp)  xfs_bmap_init(flp,fbp)
 116 #else
 117 #define XFS_BMAP_INIT(flp,fbp)  \
 118         ((flp)->xbf_first = NULL, (flp)->xbf_count = 0, \
 119          (flp)->xbf_low = 0, *(fbp) = NULLFSBLOCK)
 120 #endif
 121
 122 /*
 123  * Argument structure for xfs_bmap_alloc.
 124  */
 125 typedef struct xfs_bmalloca {
 126         xfs_fsblock_t           firstblock; /* i/o first block allocated */
 127         xfs_fsblock_t           rval;   /* starting block of new extent */
 128         xfs_fileoff_t           off;    /* offset in file filling in */
 129         struct xfs_trans        *tp;    /* transaction pointer */
 130         struct xfs_inode        *ip;    /* incore inode pointer */
 131         struct xfs_bmbt_irec    *prevp; /* extent before the new one */
 132         struct xfs_bmbt_irec    *gotp;  /* extent after, or delayed */
 133         xfs_extlen_t            alen;   /* i/o length asked/allocated */
 134         xfs_extlen_t            total;  /* total blocks needed for xaction */
 135         xfs_extlen_t            minlen; /* mininum allocation size (blocks) */
 136         xfs_extlen_t            minleft; /* amount must be left after alloc */
 137         char                    eof;    /* set if allocating past last extent */
 138         char                    wasdel; /* replacing a delayed allocation */
 139         char                    userdata;/* set if is user data */
 140         char                    low;    /* low on space, using seq'l ags */
 141         char                    aeof;   /* allocated space at eof */
 142 } xfs_bmalloca_t;
 143
 144 #ifdef __KERNEL__
 145 /*
 146  * Convert inode from non-attributed to attributed.
 147  * Must not be in a transaction, ip must not be locked.
 148  */
 149 int                                     /* error code */
 150 xfs_bmap_add_attrfork(
 151         struct xfs_inode        *ip,    /* incore inode pointer */
 152         int                                     rsvd);  /* flag for reserved block allocation */
 153
 154 /*
 155  * Add the extent to the list of extents to be free at transaction end.
 156  * The list is maintained sorted (by block number).
 157  */
 158 void
 159 xfs_bmap_add_free(
 160         xfs_fsblock_t           bno,            /* fs block number of extent */
 161         xfs_filblks_t           len,            /* length of extent */
 162         xfs_bmap_free_t         *flist,         /* list of extents */
 163         struct xfs_mount        *mp);           /* mount point structure */
 164
 165 /*
 166  * Routine to clean up the free list data structure when
 167  * an error occurs during a transaction.
 168  */
 169 void
 170 xfs_bmap_cancel(
 171         xfs_bmap_free_t         *flist);        /* free list to clean up */
 172
 173 /*
 174  * Routine to check if a specified inode is swap capable.
 175  */
 176 int
 177 xfs_bmap_check_swappable(
 178         struct xfs_inode        *ip);           /* incore inode */
 179
 180 /*
 181  * Compute and fill in the value of the maximum depth of a bmap btree
 182  * in this filesystem.  Done once, during mount.
 183  */
 184 void
 185 xfs_bmap_compute_maxlevels(
 186         struct xfs_mount        *mp,    /* file system mount structure */
 187         int                     whichfork);     /* data or attr fork */
 188
 189 /*
 190  * Routine to be called at transaction's end by xfs_bmapi, xfs_bunmapi
 191  * caller.  Frees all the extents that need freeing, which must be done
 192  * last due to locking considerations.
 193  *
 194  * Return 1 if the given transaction was committed and a new one allocated,
 195  * and 0 otherwise.
 196  */
 197 int                                             /* error */
 198 xfs_bmap_finish(
 199         struct xfs_trans        **tp,           /* transaction pointer addr */
 200         xfs_bmap_free_t         *flist,         /* i/o: list extents to free */
 201         xfs_fsblock_t           firstblock,     /* controlled a.g. for allocs */
 202         int                     *committed);    /* xact committed or not */
 203
 204 /*
 205  * Returns the file-relative block number of the first unused block in the file.
 206  * This is the lowest-address hole if the file has holes, else the first block
 207  * past the end of file.
 208  */
 209 int                                             /* error */
 210 xfs_bmap_first_unused(
 211         struct xfs_trans        *tp,            /* transaction pointer */
 212         struct xfs_inode        *ip,            /* incore inode */
 213         xfs_extlen_t            len,            /* size of hole to find */
 214         xfs_fileoff_t           *unused,        /* unused block num */
 215         int                     whichfork);     /* data or attr fork */
 216
 217 /*
 218  * Returns the file-relative block number of the last block + 1 before
 219  * last_block (input value) in the file.
 220  * This is not based on i_size, it is based on the extent list.
 221  * Returns 0 for local files, as they do not have an extent list.
 222  */
 223 int                                             /* error */
 224 xfs_bmap_last_before(
 225         struct xfs_trans        *tp,            /* transaction pointer */
 226         struct xfs_inode        *ip,            /* incore inode */
 227         xfs_fileoff_t           *last_block,    /* last block */
 228         int                     whichfork);     /* data or attr fork */
 229
 230 /*
 231  * Returns the file-relative block number of the first block past eof in
 232  * the file.  This is not based on i_size, it is based on the extent list.
 233  * Returns 0 for local files, as they do not have an extent list.
 234  */
 235 int                                             /* error */
 236 xfs_bmap_last_offset(
 237         struct xfs_trans        *tp,            /* transaction pointer */
 238         struct xfs_inode        *ip,            /* incore inode */
 239         xfs_fileoff_t           *unused,        /* last block num */
 240         int                     whichfork);     /* data or attr fork */
 241
 242 /*
 243  * Returns whether the selected fork of the inode has exactly one
 244  * block or not.  For the data fork we check this matches di_size,
 245  * implying the file's range is 0..bsize-1.
 246  */
 247 int
 248 xfs_bmap_one_block(
 249         struct xfs_inode        *ip,            /* incore inode */
 250         int                     whichfork);     /* data or attr fork */
 251
 252 /*
 253  * Read in the extents to iu_extents.
 254  * All inode fields are set up by caller, we just traverse the btree
 255  * and copy the records in.
 256  */
 257 int                                             /* error */
 258 xfs_bmap_read_extents(
 259         struct xfs_trans        *tp,            /* transaction pointer */
 260         struct xfs_inode        *ip,            /* incore inode */
 261         int                     whichfork);     /* data or attr fork */
 262
 263 #if defined(XFS_BMAP_TRACE)
 264 /*
 265  * Add bmap trace insert entries for all the contents of the extent list.
 266  */
 267 void
 268 xfs_bmap_trace_exlist(
 269         char                    *fname,         /* function name */
 270         struct xfs_inode        *ip,            /* incore inode pointer */
 271         xfs_extnum_t            cnt,            /* count of entries in list */
 272         int                     whichfork);     /* data or attr fork */
 273 #else
 274 #define xfs_bmap_trace_exlist(f,ip,c,w)
 275 #endif
 276
 277 /*
 278  * Map file blocks to filesystem blocks.
 279  * File range is given by the bno/len pair.
 280  * Adds blocks to file if a write ("flags & XFS_BMAPI_WRITE" set)
 281  * into a hole or past eof.
 282  * Only allocates blocks from a single allocation group,
 283  * to avoid locking problems.
 284  * The returned value in "firstblock" from the first call in a transaction
 285  * must be remembered and presented to subsequent calls in "firstblock".
 286  * An upper bound for the number of blocks to be allocated is supplied to
 287  * the first call in "total"; if no allocation group has that many free
 288  * blocks then the call will fail (return NULLFSBLOCK in "firstblock").
 289  */
 290 int                                             /* error */
 291 xfs_bmapi(
 292         struct xfs_trans        *tp,            /* transaction pointer */
 293         struct xfs_inode        *ip,            /* incore inode */
 294         xfs_fileoff_t           bno,            /* starting file offs. mapped */
 295         xfs_filblks_t           len,            /* length to map in file */
 296         int                     flags,          /* XFS_BMAPI_... */
 297         xfs_fsblock_t           *firstblock,    /* first allocated block
 298                                                    controls a.g. for allocs */
 299         xfs_extlen_t            total,          /* total blocks needed */
 300         struct xfs_bmbt_irec    *mval,          /* output: map values */
 301         int                     *nmap,          /* i/o: mval size/count */
 302         xfs_bmap_free_t         *flist);        /* i/o: list extents to free */
 303
 304 /*
 305  * Map file blocks to filesystem blocks, simple version.
 306  * One block only, read-only.
 307  * For flags, only the XFS_BMAPI_ATTRFORK flag is examined.
 308  * For the other flag values, the effect is as if XFS_BMAPI_METADATA
 309  * was set and all the others were clear.
 310  */
 311 int                                             /* error */
 312 xfs_bmapi_single(
 313         struct xfs_trans        *tp,            /* transaction pointer */
 314         struct xfs_inode        *ip,            /* incore inode */
 315         int                     whichfork,      /* data or attr fork */
 316         xfs_fsblock_t           *fsb,           /* output: mapped block */
 317         xfs_fileoff_t           bno);           /* starting file offs. mapped */
 318
 319 /*
 320  * Unmap (remove) blocks from a file.
 321  * If nexts is nonzero then the number of extents to remove is limited to
 322  * that value.  If not all extents in the block range can be removed then
 323  * *done is set.
 324  */
 325 int                                             /* error */
 326 xfs_bunmapi(
 327         struct xfs_trans        *tp,            /* transaction pointer */
 328         struct xfs_inode        *ip,            /* incore inode */
 329         xfs_fileoff_t           bno,            /* starting offset to unmap */
 330         xfs_filblks_t           len,            /* length to unmap in file */
 331         int                     flags,          /* XFS_BMAPI_... */
 332         xfs_extnum_t            nexts,          /* number of extents max */
 333         xfs_fsblock_t           *firstblock,    /* first allocated block
 334                                                    controls a.g. for allocs */
 335         xfs_bmap_free_t         *flist,         /* i/o: list extents to free */
 336         int                     *done);         /* set if not done yet */
 337
 338 /*
 339  * Fcntl interface to xfs_bmapi.
 340  */
 341 int                                             /* error code */
 342 xfs_getbmap(
 343         bhv_desc_t              *bdp,           /* XFS behavior descriptor*/
 344         struct getbmap          *bmv,           /* user bmap structure */
 345         void                    *ap,            /* pointer to user's array */
 346         int                     iflags);        /* interface flags */
 347
 348 /*
 349  * Check the last inode extent to determine whether this allocation will result
 350  * in blocks being allocated at the end of the file. When we allocate new data
 351  * blocks at the end of the file which do not start at the previous data block,
 352  * we will try to align the new blocks at stripe unit boundaries.
 353  */
 354 int
 355 xfs_bmap_isaeof(
 356         struct xfs_inode        *ip,
 357         xfs_fileoff_t           off,
 358         int                     whichfork,
 359         char                    *aeof);
 360
 361 /*
 362  * Check if the endoff is outside the last extent. If so the caller will grow
 363  * the allocation to a stripe unit boundary
 364  */
 365 int
 366 xfs_bmap_eof(
 367         struct xfs_inode        *ip,
 368         xfs_fileoff_t           endoff,
 369         int                     whichfork,
 370         int                     *eof);
 371
 372 /*
 373  * Count fsblocks of the given fork.
 374  */
 375 int
 376 xfs_bmap_count_blocks(
 377         xfs_trans_t             *tp,
 378         xfs_inode_t             *ip,
 379         int                     whichfork,
 380         int                     *count);
 381
 382 /*
 383  * Check an extent list, which has just been read, for
 384  * any bit in the extent flag field.
 385  */
 386 int
 387 xfs_check_nostate_extents(
 388         xfs_bmbt_rec_t          *ep,
 389         xfs_extnum_t            num);
 390
 391 #endif  /* __KERNEL__ */
 392
 393 #endif  /* __XFS_BMAP_H__ */