vxfs_dir.h 3.2 KB

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  1. /*
  2. * Copyright (c) 2000-2001 Christoph Hellwig.
  3. * All rights reserved.
  4. *
  5. * Redistribution and use in source and binary forms, with or without
  6. * modification, are permitted provided that the following conditions
  7. * are met:
  8. * 1. Redistributions of source code must retain the above copyright
  9. * notice, this list of conditions, and the following disclaimer,
  10. * without modification.
  11. * 2. The name of the author may not be used to endorse or promote products
  12. * derived from this software without specific prior written permission.
  13. *
  14. * Alternatively, this software may be distributed under the terms of the
  15. * GNU General Public License ("GPL").
  16. *
  17. * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  18. * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19. * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20. * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
  21. * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22. * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23. * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24. * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25. * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26. * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27. * SUCH DAMAGE.
  28. *
  29. */
  30. #ifndef _VXFS_DIR_H_
  31. #define _VXFS_DIR_H_
  32. /*
  33. * Veritas filesystem driver - directory structure.
  34. *
  35. * This file contains the definition of the vxfs directory format.
  36. */
  37. /*
  38. * VxFS directory block header.
  39. *
  40. * This entry is the head of every filesystem block in a directory.
  41. * It is used for free space management and additionally includes
  42. * a hash for speeding up directory search (lookup).
  43. *
  44. * The hash may be empty and in fact we do not use it all in the
  45. * Linux driver for now.
  46. */
  47. struct vxfs_dirblk {
  48. __fs16 d_free; /* free space in dirblock */
  49. __fs16 d_nhash; /* no of hash chains */
  50. __fs16 d_hash[1]; /* hash chain */
  51. };
  52. /*
  53. * VXFS_NAMELEN is the maximum length of the d_name field
  54. * of an VxFS directory entry.
  55. */
  56. #define VXFS_NAMELEN 256
  57. /*
  58. * VxFS directory entry.
  59. */
  60. struct vxfs_direct {
  61. __fs32 d_ino; /* inode number */
  62. __fs16 d_reclen; /* record length */
  63. __fs16 d_namelen; /* d_name length */
  64. __fs16 d_hashnext; /* next hash entry */
  65. char d_name[VXFS_NAMELEN]; /* name */
  66. };
  67. /*
  68. * VXFS_DIRPAD defines the directory entry boundaries, is _must_ be
  69. * a multiple of four.
  70. * VXFS_NAMEMIN is the length of a directory entry with a NULL d_name.
  71. * VXFS_DIRROUND is an internal macros that rounds a length to a value
  72. * usable for directory sizes.
  73. * VXFS_DIRLEN calculates the directory entry size for an entry with
  74. * a d_name with size len.
  75. */
  76. #define VXFS_DIRPAD 4
  77. #define VXFS_NAMEMIN offsetof(struct vxfs_direct, d_name)
  78. #define VXFS_DIRROUND(len) ((VXFS_DIRPAD + (len) - 1) & ~(VXFS_DIRPAD -1))
  79. #define VXFS_DIRLEN(len) (VXFS_DIRROUND(VXFS_NAMEMIN + (len)))
  80. /*
  81. * VXFS_DIRBLKOV is the overhead of a specific dirblock.
  82. */
  83. #define VXFS_DIRBLKOV(sbi, dbp) \
  84. ((sizeof(short) * fs16_to_cpu(sbi, dbp->d_nhash)) + 4)
  85. #endif /* _VXFS_DIR_H_ */