fs/isofs/isofs.h

   1 #include <linux/fs.h>
   2 #include <linux/buffer_head.h>
   3 #include <linux/iso_fs.h>
   4 #include <asm/unaligned.h>
   5
   6 enum isofs_file_format {
   7         isofs_file_normal = 0,
   8         isofs_file_sparse = 1,
   9         isofs_file_compressed = 2,
  10 };
  11
  12 /*
  13  * iso fs inode data in memory
  14  */
  15 struct iso_inode_info {
  16         unsigned long i_iget5_block;
  17         unsigned long i_iget5_offset;
  18         unsigned int i_first_extent;
  19         unsigned char i_file_format;
  20         unsigned char i_format_parm[3];
  21         unsigned long i_next_section_block;
  22         unsigned long i_next_section_offset;
  23         off_t i_section_size;
  24         struct inode vfs_inode;
  25 };
  26
  27 /*
  28  * iso9660 super-block data in memory
  29  */
  30 struct isofs_sb_info {
  31         unsigned long s_ninodes;
  32         unsigned long s_nzones;
  33         unsigned long s_firstdatazone;
  34         unsigned long s_log_zone_size;
  35         unsigned long s_max_size;
  36
  37         unsigned char s_high_sierra; /* A simple flag */
  38         unsigned char s_mapping;
  39         int           s_rock_offset; /* offset of SUSP fields within SU area */
  40         unsigned char s_rock;
  41         unsigned char s_joliet_level;
  42         unsigned char s_utf8;
  43         unsigned char s_cruft; /* Broken disks with high
  44                                   byte of length containing
  45                                   junk */
  46         unsigned char s_unhide;
  47         unsigned char s_nosuid;
  48         unsigned char s_nodev;
  49         unsigned char s_nocompress;
  50         unsigned char s_hide;
  51         unsigned char s_showassoc;
  52
  53         mode_t s_mode;
  54         gid_t s_gid;
  55         uid_t s_uid;
  56         struct nls_table *s_nls_iocharset; /* Native language support table */
  57 };
  58
  59 static inline struct isofs_sb_info *ISOFS_SB(struct super_block *sb)
  60 {
  61         return sb->s_fs_info;
  62 }
  63
  64 static inline struct iso_inode_info *ISOFS_I(struct inode *inode)
  65 {
  66         return container_of(inode, struct iso_inode_info, vfs_inode);
  67 }
  68
  69 static inline int isonum_711(char *p)
  70 {
  71         return *(u8 *)p;
  72 }
  73 static inline int isonum_712(char *p)
  74 {
  75         return *(s8 *)p;
  76 }
  77 static inline unsigned int isonum_721(char *p)
  78 {
  79         return le16_to_cpu(get_unaligned((__le16 *)p));
  80 }
  81 static inline unsigned int isonum_722(char *p)
  82 {
  83         return be16_to_cpu(get_unaligned((__le16 *)p));
  84 }
  85 static inline unsigned int isonum_723(char *p)
  86 {
  87         /* Ignore bigendian datum due to broken mastering programs */
  88         return le16_to_cpu(get_unaligned((__le16 *)p));
  89 }
  90 static inline unsigned int isonum_731(char *p)
  91 {
  92         return le32_to_cpu(get_unaligned((__le32 *)p));
  93 }
  94 static inline unsigned int isonum_732(char *p)
  95 {
  96         return be32_to_cpu(get_unaligned((__le32 *)p));
  97 }
  98 static inline unsigned int isonum_733(char *p)
  99 {
 100         /* Ignore bigendian datum due to broken mastering programs */
 101         return le32_to_cpu(get_unaligned((__le32 *)p));
 102 }
 103 extern int iso_date(char *, int);
 104
 105 struct inode;           /* To make gcc happy */
 106
 107 extern int parse_rock_ridge_inode(struct iso_directory_record *, struct inode *);
 108 extern int get_rock_ridge_filename(struct iso_directory_record *, char *, struct inode *);
 109 extern int isofs_name_translate(struct iso_directory_record *, char *, struct inode *);
 110
 111 int get_joliet_filename(struct iso_directory_record *, unsigned char *, struct inode *);
 112 int get_acorn_filename(struct iso_directory_record *, char *, struct inode *);
 113
 114 extern struct dentry *isofs_lookup(struct inode *, struct dentry *, struct nameidata *);
 115 extern struct buffer_head *isofs_bread(struct inode *, sector_t);
 116 extern int isofs_get_blocks(struct inode *, sector_t, struct buffer_head **, unsigned long);
 117
 118 extern struct inode *isofs_iget(struct super_block *sb,
 119                                 unsigned long block,
 120                                 unsigned long offset);
 121
 122 /* Because the inode number is no longer relevant to finding the
 123  * underlying meta-data for an inode, we are free to choose a more
 124  * convenient 32-bit number as the inode number.  The inode numbering
 125  * scheme was recommended by Sergey Vlasov and Eric Lammerts. */
 126 static inline unsigned long isofs_get_ino(unsigned long block,
 127                                           unsigned long offset,
 128                                           unsigned long bufbits)
 129 {
 130         return (block << (bufbits - 5)) | (offset >> 5);
 131 }
 132
 133 /* Every directory can have many redundant directory entries scattered
 134  * throughout the directory tree.  First there is the directory entry
 135  * with the name of the directory stored in the parent directory.
 136  * Then, there is the "." directory entry stored in the directory
 137  * itself.  Finally, there are possibly many ".." directory entries
 138  * stored in all the subdirectories.
 139  *
 140  * In order for the NFS get_parent() method to work and for the
 141  * general consistency of the dcache, we need to make sure the
 142  * "i_iget5_block" and "i_iget5_offset" all point to exactly one of
 143  * the many redundant entries for each directory.  We normalize the
 144  * block and offset by always making them point to the "."  directory.
 145  *
 146  * Notice that we do not use the entry for the directory with the name
 147  * that is located in the parent directory.  Even though choosing this
 148  * first directory is more natural, it is much easier to find the "."
 149  * entry in the NFS get_parent() method because it is implicitly
 150  * encoded in the "extent + ext_attr_length" fields of _all_ the
 151  * redundant entries for the directory.  Thus, it can always be
 152  * reached regardless of which directory entry you have in hand.
 153  *
 154  * This works because the "." entry is simply the first directory
 155  * record when you start reading the file that holds all the directory
 156  * records, and this file starts at "extent + ext_attr_length" blocks.
 157  * Because the "." entry is always the first entry listed in the
 158  * directories file, the normalized "offset" value is always 0.
 159  *
 160  * You should pass the directory entry in "de".  On return, "block"
 161  * and "offset" will hold normalized values.  Only directories are
 162  * affected making it safe to call even for non-directory file
 163  * types. */
 164 static inline void
 165 isofs_normalize_block_and_offset(struct iso_directory_record* de,
 166                                  unsigned long *block,
 167                                  unsigned long *offset)
 168 {
 169         /* Only directories are normalized. */
 170         if (de->flags[0] & 2) {
 171                 *offset = 0;
 172                 *block = (unsigned long)isonum_733(de->extent)
 173                         + (unsigned long)isonum_711(de->ext_attr_length);
 174         }
 175 }
 176
 177 extern struct inode_operations isofs_dir_inode_operations;
 178 extern const struct file_operations isofs_dir_operations;
 179 extern const struct address_space_operations isofs_symlink_aops;
 180 extern struct export_operations isofs_export_ops;