isofs.h 6.0 KB

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  1. #include <linux/fs.h>
  2. #include <linux/buffer_head.h>
  3. #include <linux/exportfs.h>
  4. #include <linux/iso_fs.h>
  5. #include <asm/unaligned.h>
  6. enum isofs_file_format {
  7. isofs_file_normal = 0,
  8. isofs_file_sparse = 1,
  9. isofs_file_compressed = 2,
  10. };
  11. /*
  12. * iso fs inode data in memory
  13. */
  14. struct iso_inode_info {
  15. unsigned long i_iget5_block;
  16. unsigned long i_iget5_offset;
  17. unsigned int i_first_extent;
  18. unsigned char i_file_format;
  19. unsigned char i_format_parm[3];
  20. unsigned long i_next_section_block;
  21. unsigned long i_next_section_offset;
  22. off_t i_section_size;
  23. struct inode vfs_inode;
  24. };
  25. /*
  26. * iso9660 super-block data in memory
  27. */
  28. struct isofs_sb_info {
  29. unsigned long s_ninodes;
  30. unsigned long s_nzones;
  31. unsigned long s_firstdatazone;
  32. unsigned long s_log_zone_size;
  33. unsigned long s_max_size;
  34. unsigned char s_high_sierra; /* A simple flag */
  35. unsigned char s_mapping;
  36. int s_rock_offset; /* offset of SUSP fields within SU area */
  37. unsigned char s_rock;
  38. unsigned char s_joliet_level;
  39. unsigned char s_utf8;
  40. unsigned char s_cruft; /* Broken disks with high
  41. byte of length containing
  42. junk */
  43. unsigned char s_unhide;
  44. unsigned char s_nosuid;
  45. unsigned char s_nodev;
  46. unsigned char s_nocompress;
  47. unsigned char s_hide;
  48. unsigned char s_showassoc;
  49. mode_t s_mode;
  50. gid_t s_gid;
  51. uid_t s_uid;
  52. struct nls_table *s_nls_iocharset; /* Native language support table */
  53. };
  54. static inline struct isofs_sb_info *ISOFS_SB(struct super_block *sb)
  55. {
  56. return sb->s_fs_info;
  57. }
  58. static inline struct iso_inode_info *ISOFS_I(struct inode *inode)
  59. {
  60. return container_of(inode, struct iso_inode_info, vfs_inode);
  61. }
  62. static inline int isonum_711(char *p)
  63. {
  64. return *(u8 *)p;
  65. }
  66. static inline int isonum_712(char *p)
  67. {
  68. return *(s8 *)p;
  69. }
  70. static inline unsigned int isonum_721(char *p)
  71. {
  72. return le16_to_cpu(get_unaligned((__le16 *)p));
  73. }
  74. static inline unsigned int isonum_722(char *p)
  75. {
  76. return be16_to_cpu(get_unaligned((__le16 *)p));
  77. }
  78. static inline unsigned int isonum_723(char *p)
  79. {
  80. /* Ignore bigendian datum due to broken mastering programs */
  81. return le16_to_cpu(get_unaligned((__le16 *)p));
  82. }
  83. static inline unsigned int isonum_731(char *p)
  84. {
  85. return le32_to_cpu(get_unaligned((__le32 *)p));
  86. }
  87. static inline unsigned int isonum_732(char *p)
  88. {
  89. return be32_to_cpu(get_unaligned((__le32 *)p));
  90. }
  91. static inline unsigned int isonum_733(char *p)
  92. {
  93. /* Ignore bigendian datum due to broken mastering programs */
  94. return le32_to_cpu(get_unaligned((__le32 *)p));
  95. }
  96. extern int iso_date(char *, int);
  97. struct inode; /* To make gcc happy */
  98. extern int parse_rock_ridge_inode(struct iso_directory_record *, struct inode *);
  99. extern int get_rock_ridge_filename(struct iso_directory_record *, char *, struct inode *);
  100. extern int isofs_name_translate(struct iso_directory_record *, char *, struct inode *);
  101. int get_joliet_filename(struct iso_directory_record *, unsigned char *, struct inode *);
  102. int get_acorn_filename(struct iso_directory_record *, char *, struct inode *);
  103. extern struct dentry *isofs_lookup(struct inode *, struct dentry *, struct nameidata *);
  104. extern struct buffer_head *isofs_bread(struct inode *, sector_t);
  105. extern int isofs_get_blocks(struct inode *, sector_t, struct buffer_head **, unsigned long);
  106. extern struct inode *isofs_iget(struct super_block *sb,
  107. unsigned long block,
  108. unsigned long offset);
  109. /* Because the inode number is no longer relevant to finding the
  110. * underlying meta-data for an inode, we are free to choose a more
  111. * convenient 32-bit number as the inode number. The inode numbering
  112. * scheme was recommended by Sergey Vlasov and Eric Lammerts. */
  113. static inline unsigned long isofs_get_ino(unsigned long block,
  114. unsigned long offset,
  115. unsigned long bufbits)
  116. {
  117. return (block << (bufbits - 5)) | (offset >> 5);
  118. }
  119. /* Every directory can have many redundant directory entries scattered
  120. * throughout the directory tree. First there is the directory entry
  121. * with the name of the directory stored in the parent directory.
  122. * Then, there is the "." directory entry stored in the directory
  123. * itself. Finally, there are possibly many ".." directory entries
  124. * stored in all the subdirectories.
  125. *
  126. * In order for the NFS get_parent() method to work and for the
  127. * general consistency of the dcache, we need to make sure the
  128. * "i_iget5_block" and "i_iget5_offset" all point to exactly one of
  129. * the many redundant entries for each directory. We normalize the
  130. * block and offset by always making them point to the "." directory.
  131. *
  132. * Notice that we do not use the entry for the directory with the name
  133. * that is located in the parent directory. Even though choosing this
  134. * first directory is more natural, it is much easier to find the "."
  135. * entry in the NFS get_parent() method because it is implicitly
  136. * encoded in the "extent + ext_attr_length" fields of _all_ the
  137. * redundant entries for the directory. Thus, it can always be
  138. * reached regardless of which directory entry you have in hand.
  139. *
  140. * This works because the "." entry is simply the first directory
  141. * record when you start reading the file that holds all the directory
  142. * records, and this file starts at "extent + ext_attr_length" blocks.
  143. * Because the "." entry is always the first entry listed in the
  144. * directories file, the normalized "offset" value is always 0.
  145. *
  146. * You should pass the directory entry in "de". On return, "block"
  147. * and "offset" will hold normalized values. Only directories are
  148. * affected making it safe to call even for non-directory file
  149. * types. */
  150. static inline void
  151. isofs_normalize_block_and_offset(struct iso_directory_record* de,
  152. unsigned long *block,
  153. unsigned long *offset)
  154. {
  155. /* Only directories are normalized. */
  156. if (de->flags[0] & 2) {
  157. *offset = 0;
  158. *block = (unsigned long)isonum_733(de->extent)
  159. + (unsigned long)isonum_711(de->ext_attr_length);
  160. }
  161. }
  162. extern const struct inode_operations isofs_dir_inode_operations;
  163. extern const struct file_operations isofs_dir_operations;
  164. extern const struct address_space_operations isofs_symlink_aops;
  165. extern struct export_operations isofs_export_ops;