repair/bmap.h

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (c) 2000-2001,2005 Silicon Graphics, Inc.
   4  * All Rights Reserved.
   5  */
   6
   7 #ifndef _XFS_REPAIR_BMAP_H
   8 #define _XFS_REPAIR_BMAP_H
   9
  10 /*
  11  * Extent descriptor.
  12  */
  13 typedef struct bmap_ext {
  14         xfs_fileoff_t   startoff;
  15         xfs_fsblock_t   startblock;
  16         xfs_filblks_t   blockcount;
  17 } bmap_ext_t;
  18
  19 /*
  20  * Block map.
  21  */
  22 typedef struct blkmap {
  23         int             naexts;
  24         int             nexts;
  25         bmap_ext_t      exts[1];
  26 } blkmap_t;
  27
  28 #define BLKMAP_SIZE(n)  \
  29         (offsetof(blkmap_t, exts) + (sizeof(bmap_ext_t) * (n)))
  30
  31 /*
  32  * For 32 bit platforms, we are limited to extent arrays of 2^31 bytes, which
  33  * limits the number of extents in an inode we can check. If we don't limit the
  34  * valid range, we can overflow the BLKMAP_SIZE() calculation and allocate less
  35  * memory than we think we needed, and hence walk off the end of the array and
  36  * corrupt memory.
  37  */
  38 #if BITS_PER_LONG == 32
  39 #define BLKMAP_NEXTS_MAX        ((INT_MAX / sizeof(bmap_ext_t)) - 1)
  40 #else
  41 #define BLKMAP_NEXTS_MAX        INT_MAX
  42 #endif
  43
  44 extern pthread_key_t dblkmap_key;
  45 extern pthread_key_t ablkmap_key;
  46
  47 blkmap_t        *blkmap_alloc(xfs_extnum_t nex, int whichfork);
  48 void            blkmap_free(blkmap_t *blkmap);
  49 void            blkmap_free_final(void);
  50
  51 int             blkmap_set_ext(blkmap_t **blkmapp, xfs_fileoff_t o,
  52                                xfs_fsblock_t b, xfs_filblks_t c);
  53
  54 xfs_fsblock_t   blkmap_get(blkmap_t *blkmap, xfs_fileoff_t o);
  55 int             blkmap_getn(blkmap_t *blkmap, xfs_fileoff_t o,
  56                             xfs_filblks_t nb, bmap_ext_t **bmpp,
  57                             bmap_ext_t *bmpp_single);
  58 xfs_fileoff_t   blkmap_last_off(blkmap_t *blkmap);
  59 xfs_fileoff_t   blkmap_next_off(blkmap_t *blkmap, xfs_fileoff_t o, int *t);
  60
  61 #endif /* _XFS_REPAIR_BMAP_H */