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_fmode;
  55         mode_t s_dmode;
  56         gid_t s_gid;
  57         uid_t s_uid;
  58         struct nls_table *s_nls_iocharset; /* Native language support table */
  59 };
  60
  61 static inline struct isofs_sb_info *ISOFS_SB(struct super_block *sb)
  62 {
  63         return sb->s_fs_info;
  64 }
  65
  66 static inline struct iso_inode_info *ISOFS_I(struct inode *inode)
  67 {
  68         return container_of(inode, struct iso_inode_info, vfs_inode);
  69 }
  70
  71 static inline int isonum_711(char *p)
  72 {
  73         return *(u8 *)p;
  74 }
  75 static inline int isonum_712(char *p)
  76 {
  77         return *(s8 *)p;
  78 }
  79 static inline unsigned int isonum_721(char *p)
  80 {
  81         return get_unaligned_le16(p);
  82 }
  83 static inline unsigned int isonum_722(char *p)
  84 {
  85         return get_unaligned_be16(p);
  86 }
  87 static inline unsigned int isonum_723(char *p)
  88 {
  89         /* Ignore bigendian datum due to broken mastering programs */
  90         return get_unaligned_le16(p);
  91 }
  92 static inline unsigned int isonum_731(char *p)
  93 {
  94         return get_unaligned_le32(p);
  95 }
  96 static inline unsigned int isonum_732(char *p)
  97 {
  98         return get_unaligned_be32(p);
  99 }
 100 static inline unsigned int isonum_733(char *p)
 101 {
 102         /* Ignore bigendian datum due to broken mastering programs */
 103         return get_unaligned_le32(p);
 104 }
 105 extern int iso_date(char *, int);
 106
 107 struct inode;           /* To make gcc happy */
 108
 109 extern int parse_rock_ridge_inode(struct iso_directory_record *, struct inode *);
 110 extern int get_rock_ridge_filename(struct iso_directory_record *, char *, struct inode *);
 111 extern int isofs_name_translate(struct iso_directory_record *, char *, struct inode *);
 112
 113 int get_joliet_filename(struct iso_directory_record *, unsigned char *, struct inode *);
 114 int get_acorn_filename(struct iso_directory_record *, char *, struct inode *);
 115
 116 extern struct dentry *isofs_lookup(struct inode *, struct dentry *, struct nameidata *);
 117 extern struct buffer_head *isofs_bread(struct inode *, sector_t);
 118 extern int isofs_get_blocks(struct inode *, sector_t, struct buffer_head **, unsigned long);
 119
 120 extern struct inode *isofs_iget(struct super_block *sb,
 121                                 unsigned long block,
 122                                 unsigned long offset);
 123
 124 /* Because the inode number is no longer relevant to finding the
 125  * underlying meta-data for an inode, we are free to choose a more
 126  * convenient 32-bit number as the inode number.  The inode numbering
 127  * scheme was recommended by Sergey Vlasov and Eric Lammerts. */
 128 static inline unsigned long isofs_get_ino(unsigned long block,
 129                                           unsigned long offset,
 130                                           unsigned long bufbits)
 131 {
 132         return (block << (bufbits - 5)) | (offset >> 5);
 133 }
 134
 135 /* Every directory can have many redundant directory entries scattered
 136  * throughout the directory tree.  First there is the directory entry
 137  * with the name of the directory stored in the parent directory.
 138  * Then, there is the "." directory entry stored in the directory
 139  * itself.  Finally, there are possibly many ".." directory entries
 140  * stored in all the subdirectories.
 141  *
 142  * In order for the NFS get_parent() method to work and for the
 143  * general consistency of the dcache, we need to make sure the
 144  * "i_iget5_block" and "i_iget5_offset" all point to exactly one of
 145  * the many redundant entries for each directory.  We normalize the
 146  * block and offset by always making them point to the "."  directory.
 147  *
 148  * Notice that we do not use the entry for the directory with the name
 149  * that is located in the parent directory.  Even though choosing this
 150  * first directory is more natural, it is much easier to find the "."
 151  * entry in the NFS get_parent() method because it is implicitly
 152  * encoded in the "extent + ext_attr_length" fields of _all_ the
 153  * redundant entries for the directory.  Thus, it can always be
 154  * reached regardless of which directory entry you have in hand.
 155  *
 156  * This works because the "." entry is simply the first directory
 157  * record when you start reading the file that holds all the directory
 158  * records, and this file starts at "extent + ext_attr_length" blocks.
 159  * Because the "." entry is always the first entry listed in the
 160  * directories file, the normalized "offset" value is always 0.
 161  *
 162  * You should pass the directory entry in "de".  On return, "block"
 163  * and "offset" will hold normalized values.  Only directories are
 164  * affected making it safe to call even for non-directory file
 165  * types. */
 166 static inline void
 167 isofs_normalize_block_and_offset(struct iso_directory_record* de,
 168                                  unsigned long *block,
 169                                  unsigned long *offset)
 170 {
 171         /* Only directories are normalized. */
 172         if (de->flags[0] & 2) {
 173                 *offset = 0;
 174                 *block = (unsigned long)isonum_733(de->extent)
 175                         + (unsigned long)isonum_711(de->ext_attr_length);
 176         }
 177 }
 178
 179 extern const struct inode_operations isofs_dir_inode_operations;
 180 extern const struct file_operations isofs_dir_operations;
 181 extern const struct address_space_operations isofs_symlink_aops;
 182 extern const struct export_operations isofs_export_ops;