include/xfs_bmap.h

   1 /*
   2  * Copyright (c) 2000 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 #define XFS_BMAPI_DIRECT_IO     0x800   /* Flag from cxfs client, not used
  80                                          * by xfs directly. Indicates alloc
  81                                          * request is for direct I/O not
  82                                          * extent conversion by server */
  83
  84 #if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_BMAPI_AFLAG)
  85 int xfs_bmapi_aflag(int w);
  86 #define XFS_BMAPI_AFLAG(w)      xfs_bmapi_aflag(w)
  87 #else
  88 #define XFS_BMAPI_AFLAG(w)      ((w) == XFS_ATTR_FORK ? XFS_BMAPI_ATTRFORK : 0)
  89 #endif
  90
  91 /*
  92  * Special values for xfs_bmbt_irec_t br_startblock field.
  93  */
  94 #define DELAYSTARTBLOCK         ((xfs_fsblock_t)-1LL)
  95 #define HOLESTARTBLOCK          ((xfs_fsblock_t)-2LL)
  96
  97 /*
  98  * Trace operations for bmap extent tracing
  99  */
 100 #define XFS_BMAP_KTRACE_DELETE  1
 101 #define XFS_BMAP_KTRACE_INSERT  2
 102 #define XFS_BMAP_KTRACE_PRE_UP  3
 103 #define XFS_BMAP_KTRACE_POST_UP 4
 104
 105 #define XFS_BMAP_TRACE_SIZE     4096    /* size of global trace buffer */
 106 #define XFS_BMAP_KTRACE_SIZE    32      /* size of per-inode trace buffer */
 107
 108 #if defined(XFS_ALL_TRACE)
 109 #define XFS_BMAP_TRACE
 110 #endif
 111
 112 #if !defined(DEBUG)
 113 #undef  XFS_BMAP_TRACE
 114 #endif
 115
 116
 117 #if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_BMAP_INIT)
 118 void xfs_bmap_init(xfs_bmap_free_t *flp, xfs_fsblock_t *fbp);
 119 #define XFS_BMAP_INIT(flp,fbp)  xfs_bmap_init(flp,fbp)
 120 #else
 121 #define XFS_BMAP_INIT(flp,fbp)  \
 122         ((flp)->xbf_first = NULL, (flp)->xbf_count = 0, \
 123          (flp)->xbf_low = 0, *(fbp) = NULLFSBLOCK)
 124 #endif
 125
 126 /*
 127  * Argument structure for xfs_bmap_alloc.
 128  */
 129 typedef struct xfs_bmalloca {
 130         xfs_fsblock_t           firstblock; /* i/o first block allocated */
 131         xfs_fsblock_t           rval;   /* starting block of new extent */
 132         xfs_fileoff_t           off;    /* offset in file filling in */
 133         struct xfs_trans        *tp;    /* transaction pointer */
 134         struct xfs_inode        *ip;    /* incore inode pointer */
 135         struct xfs_bmbt_irec    *prevp; /* extent before the new one */
 136         struct xfs_bmbt_irec    *gotp;  /* extent after, or delayed */
 137         xfs_extlen_t            alen;   /* i/o length asked/allocated */
 138         xfs_extlen_t            total;  /* total blocks needed for xaction */
 139         xfs_extlen_t            minlen; /* mininum allocation size (blocks) */
 140         xfs_extlen_t            minleft; /* amount must be left after alloc */
 141         int                     eof;    /* set if allocating past last extent */
 142         int                     wasdel; /* replacing a delayed allocation */
 143         int                     userdata;/* set if is user data */
 144         int                     low;    /* low on space, using seq'l ags */
 145         int                     aeof;   /* allocated space at eof */
 146 } xfs_bmalloca_t;
 147
 148 #ifdef __KERNEL__
 149 /*
 150  * Convert inode from non-attributed to attributed.
 151  * Must not be in a transaction, ip must not be locked.
 152  */
 153 int                                     /* error code */
 154 xfs_bmap_add_attrfork(
 155         struct xfs_inode        *ip,    /* incore inode pointer */
 156         int                                     rsvd);  /* flag for reserved block allocation */
 157
 158 /*
 159  * Add the extent to the list of extents to be free at transaction end.
 160  * The list is maintained sorted (by block number).
 161  */
 162 void
 163 xfs_bmap_add_free(
 164         xfs_fsblock_t           bno,            /* fs block number of extent */
 165         xfs_filblks_t           len,            /* length of extent */
 166         xfs_bmap_free_t         *flist,         /* list of extents */
 167         struct xfs_mount        *mp);           /* mount point structure */
 168
 169 /*
 170  * Routine to clean up the free list data structure when
 171  * an error occurs during a transaction.
 172  */
 173 void
 174 xfs_bmap_cancel(
 175         xfs_bmap_free_t         *flist);        /* free list to clean up */
 176
 177 /*
 178  * Routine to check if a specified inode is swap capable.
 179  */
 180 int
 181 xfs_bmap_check_swappable(
 182         struct xfs_inode        *ip);           /* incore inode */
 183
 184 /*
 185  * Compute and fill in the value of the maximum depth of a bmap btree
 186  * in this filesystem.  Done once, during mount.
 187  */
 188 void
 189 xfs_bmap_compute_maxlevels(
 190         struct xfs_mount        *mp,    /* file system mount structure */
 191         int                     whichfork);     /* data or attr fork */
 192
 193 /*
 194  * Routine to be called at transaction's end by xfs_bmapi, xfs_bunmapi
 195  * caller.  Frees all the extents that need freeing, which must be done
 196  * last due to locking considerations.
 197  *
 198  * Return 1 if the given transaction was committed and a new one allocated,
 199  * and 0 otherwise.
 200  */
 201 int                                             /* error */
 202 xfs_bmap_finish(
 203         struct xfs_trans        **tp,           /* transaction pointer addr */
 204         xfs_bmap_free_t         *flist,         /* i/o: list extents to free */
 205         xfs_fsblock_t           firstblock,     /* controlled a.g. for allocs */
 206         int                     *committed);    /* xact committed or not */
 207
 208 /*
 209  * Returns the file-relative block number of the first unused block in the file.
 210  * This is the lowest-address hole if the file has holes, else the first block
 211  * past the end of file.
 212  */
 213 int                                             /* error */
 214 xfs_bmap_first_unused(
 215         struct xfs_trans        *tp,            /* transaction pointer */
 216         struct xfs_inode        *ip,            /* incore inode */
 217         xfs_extlen_t            len,            /* size of hole to find */
 218         xfs_fileoff_t           *unused,        /* unused block num */
 219         int                     whichfork);     /* data or attr fork */
 220
 221 /*
 222  * Returns the file-relative block number of the last block + 1 before
 223  * last_block (input value) in the file.
 224  * This is not based on i_size, it is based on the extent list.
 225  * Returns 0 for local files, as they do not have an extent list.
 226  */
 227 int                                             /* error */
 228 xfs_bmap_last_before(
 229         struct xfs_trans        *tp,            /* transaction pointer */
 230         struct xfs_inode        *ip,            /* incore inode */
 231         xfs_fileoff_t           *last_block,    /* last block */
 232         int                     whichfork);     /* data or attr fork */
 233
 234 /*
 235  * Returns the file-relative block number of the first block past eof in
 236  * the file.  This is not based on i_size, it is based on the extent list.
 237  * Returns 0 for local files, as they do not have an extent list.
 238  */
 239 int                                             /* error */
 240 xfs_bmap_last_offset(
 241         struct xfs_trans        *tp,            /* transaction pointer */
 242         struct xfs_inode        *ip,            /* incore inode */
 243         xfs_fileoff_t           *unused,        /* last block num */
 244         int                     whichfork);     /* data or attr fork */
 245
 246 /*
 247  * Returns whether the selected fork of the inode has exactly one
 248  * block or not.  For the data fork we check this matches di_size,
 249  * implying the file's range is 0..bsize-1.
 250  */
 251 int
 252 xfs_bmap_one_block(
 253         struct xfs_inode        *ip,            /* incore inode */
 254         int                     whichfork);     /* data or attr fork */
 255
 256 /*
 257  * Read in the extents to iu_extents.
 258  * All inode fields are set up by caller, we just traverse the btree
 259  * and copy the records in.
 260  */
 261 int                                             /* error */
 262 xfs_bmap_read_extents(
 263         struct xfs_trans        *tp,            /* transaction pointer */
 264         struct xfs_inode        *ip,            /* incore inode */
 265         int                     whichfork);     /* data or attr fork */
 266
 267 #if defined(XFS_BMAP_TRACE)
 268 /*
 269  * Add bmap trace insert entries for all the contents of the extent list.
 270  */
 271 void
 272 xfs_bmap_trace_exlist(
 273         char                    *fname,         /* function name */
 274         struct xfs_inode        *ip,            /* incore inode pointer */
 275         xfs_extnum_t            cnt,            /* count of entries in list */
 276         int                     whichfork);     /* data or attr fork */
 277 #else
 278 #define xfs_bmap_trace_exlist(f,ip,c,w)
 279 #endif
 280
 281 /*
 282  * Map file blocks to filesystem blocks.
 283  * File range is given by the bno/len pair.
 284  * Adds blocks to file if a write ("flags & XFS_BMAPI_WRITE" set)
 285  * into a hole or past eof.
 286  * Only allocates blocks from a single allocation group,
 287  * to avoid locking problems.
 288  * The returned value in "firstblock" from the first call in a transaction
 289  * must be remembered and presented to subsequent calls in "firstblock".
 290  * An upper bound for the number of blocks to be allocated is supplied to
 291  * the first call in "total"; if no allocation group has that many free
 292  * blocks then the call will fail (return NULLFSBLOCK in "firstblock").
 293  */
 294 int                                             /* error */
 295 xfs_bmapi(
 296         struct xfs_trans        *tp,            /* transaction pointer */
 297         struct xfs_inode        *ip,            /* incore inode */
 298         xfs_fileoff_t           bno,            /* starting file offs. mapped */
 299         xfs_filblks_t           len,            /* length to map in file */
 300         int                     flags,          /* XFS_BMAPI_... */
 301         xfs_fsblock_t           *firstblock,    /* first allocated block
 302                                                    controls a.g. for allocs */
 303         xfs_extlen_t            total,          /* total blocks needed */
 304         struct xfs_bmbt_irec    *mval,          /* output: map values */
 305         int                     *nmap,          /* i/o: mval size/count */
 306         xfs_bmap_free_t         *flist);        /* i/o: list extents to free */
 307
 308 /*
 309  * Map file blocks to filesystem blocks, simple version.
 310  * One block only, read-only.
 311  * For flags, only the XFS_BMAPI_ATTRFORK flag is examined.
 312  * For the other flag values, the effect is as if XFS_BMAPI_METADATA
 313  * was set and all the others were clear.
 314  */
 315 int                                             /* error */
 316 xfs_bmapi_single(
 317         struct xfs_trans        *tp,            /* transaction pointer */
 318         struct xfs_inode        *ip,            /* incore inode */
 319         int                     whichfork,      /* data or attr fork */
 320         xfs_fsblock_t           *fsb,           /* output: mapped block */
 321         xfs_fileoff_t           bno);           /* starting file offs. mapped */
 322
 323 /*
 324  * Unmap (remove) blocks from a file.
 325  * If nexts is nonzero then the number of extents to remove is limited to
 326  * that value.  If not all extents in the block range can be removed then
 327  * *done is set.
 328  */
 329 int                                             /* error */
 330 xfs_bunmapi(
 331         struct xfs_trans        *tp,            /* transaction pointer */
 332         struct xfs_inode        *ip,            /* incore inode */
 333         xfs_fileoff_t           bno,            /* starting offset to unmap */
 334         xfs_filblks_t           len,            /* length to unmap in file */
 335         int                     flags,          /* XFS_BMAPI_... */
 336         xfs_extnum_t            nexts,          /* number of extents max */
 337         xfs_fsblock_t           *firstblock,    /* first allocated block
 338                                                    controls a.g. for allocs */
 339         xfs_bmap_free_t         *flist,         /* i/o: list extents to free */
 340         int                     *done);         /* set if not done yet */
 341
 342 /*
 343  * Fcntl interface to xfs_bmapi.
 344  */
 345 int                                             /* error code */
 346 xfs_getbmap(
 347         bhv_desc_t              *bdp,           /* XFS behavior descriptor*/
 348         struct getbmap          *bmv,           /* user bmap structure */
 349         void                    *ap,            /* pointer to user's array */
 350         int                     iflags);        /* interface flags */
 351
 352 /*
 353  * Check the last inode extent to determine whether this allocation will result
 354  * in blocks being allocated at the end of the file. When we allocate new data
 355  * blocks at the end of the file which do not start at the previous data block,
 356  * we will try to align the new blocks at stripe unit boundaries.
 357  */
 358 int
 359 xfs_bmap_isaeof(
 360         struct xfs_inode        *ip,
 361         xfs_fileoff_t           off,
 362         int                     whichfork,
 363         int                     *aeof);
 364
 365 /*
 366  * Check if the endoff is outside the last extent. If so the caller will grow
 367  * the allocation to a stripe unit boundary
 368  */
 369 int
 370 xfs_bmap_eof(
 371         struct xfs_inode        *ip,
 372         xfs_fileoff_t           endoff,
 373         int                     whichfork,
 374         int                     *eof);
 375
 376 /*
 377  * Count fsblocks of the given fork.
 378  */
 379 int
 380 xfs_bmap_count_blocks(
 381         xfs_trans_t             *tp,
 382         xfs_inode_t             *ip,
 383         int                     whichfork,
 384         int                     *count);
 385
 386 /*
 387  * Check an extent list, which has just been read, for
 388  * any bit in the extent flag field.
 389  */
 390 int
 391 xfs_check_nostate_extents(
 392         xfs_bmbt_rec_t          *ep,
 393         xfs_extnum_t            num);
 394
 395 #endif  /* __KERNEL__ */
 396
 397 #endif  /* __XFS_BMAP_H__ */