fs/isofs/isofs.h

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