linux/fs/isofs/isofs.h
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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
   7enum 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 */
  16struct 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 */
  31struct 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        int           s_rock_offset; /* offset of SUSP fields within SU area */
  39        unsigned char s_joliet_level;
  40        unsigned char s_mapping;
  41        unsigned int  s_high_sierra:1;
  42        unsigned int  s_rock:2;
  43        unsigned int  s_utf8:1;
  44        unsigned int  s_cruft:1; /* Broken disks with high byte of length
  45                                  * containing junk */
  46        unsigned int  s_nocompress:1;
  47        unsigned int  s_hide:1;
  48        unsigned int  s_showassoc:1;
  49        unsigned int  s_overriderockperm:1;
  50        unsigned int  s_uid_set:1;
  51        unsigned int  s_gid_set:1;
  52
  53        umode_t s_fmode;
  54        umode_t s_dmode;
  55        gid_t s_gid;
  56        uid_t s_uid;
  57        struct nls_table *s_nls_iocharset; /* Native language support table */
  58};
  59
  60#define ISOFS_INVALID_MODE ((umode_t) -1)
  61
  62static inline struct isofs_sb_info *ISOFS_SB(struct super_block *sb)
  63{
  64        return sb->s_fs_info;
  65}
  66
  67static inline struct iso_inode_info *ISOFS_I(struct inode *inode)
  68{
  69        return container_of(inode, struct iso_inode_info, vfs_inode);
  70}
  71
  72static inline int isonum_711(char *p)
  73{
  74        return *(u8 *)p;
  75}
  76static inline int isonum_712(char *p)
  77{
  78        return *(s8 *)p;
  79}
  80static inline unsigned int isonum_721(char *p)
  81{
  82        return get_unaligned_le16(p);
  83}
  84static inline unsigned int isonum_722(char *p)
  85{
  86        return get_unaligned_be16(p);
  87}
  88static inline unsigned int isonum_723(char *p)
  89{
  90        /* Ignore bigendian datum due to broken mastering programs */
  91        return get_unaligned_le16(p);
  92}
  93static inline unsigned int isonum_731(char *p)
  94{
  95        return get_unaligned_le32(p);
  96}
  97static inline unsigned int isonum_732(char *p)
  98{
  99        return get_unaligned_be32(p);
 100}
 101static inline unsigned int isonum_733(char *p)
 102{
 103        /* Ignore bigendian datum due to broken mastering programs */
 104        return get_unaligned_le32(p);
 105}
 106extern int iso_date(char *, int);
 107
 108struct inode;           /* To make gcc happy */
 109
 110extern int parse_rock_ridge_inode(struct iso_directory_record *, struct inode *);
 111extern int get_rock_ridge_filename(struct iso_directory_record *, char *, struct inode *);
 112extern int isofs_name_translate(struct iso_directory_record *, char *, struct inode *);
 113
 114int get_joliet_filename(struct iso_directory_record *, unsigned char *, struct inode *);
 115int get_acorn_filename(struct iso_directory_record *, char *, struct inode *);
 116
 117extern struct dentry *isofs_lookup(struct inode *, struct dentry *, unsigned int flags);
 118extern struct buffer_head *isofs_bread(struct inode *, sector_t);
 119extern int isofs_get_blocks(struct inode *, sector_t, struct buffer_head **, unsigned long);
 120
 121extern struct inode *isofs_iget(struct super_block *sb,
 122                                unsigned long block,
 123                                unsigned long offset);
 124
 125/* Because the inode number is no longer relevant to finding the
 126 * underlying meta-data for an inode, we are free to choose a more
 127 * convenient 32-bit number as the inode number.  The inode numbering
 128 * scheme was recommended by Sergey Vlasov and Eric Lammerts. */
 129static inline unsigned long isofs_get_ino(unsigned long block,
 130                                          unsigned long offset,
 131                                          unsigned long bufbits)
 132{
 133        return (block << (bufbits - 5)) | (offset >> 5);
 134}
 135
 136/* Every directory can have many redundant directory entries scattered
 137 * throughout the directory tree.  First there is the directory entry
 138 * with the name of the directory stored in the parent directory.
 139 * Then, there is the "." directory entry stored in the directory
 140 * itself.  Finally, there are possibly many ".." directory entries
 141 * stored in all the subdirectories.
 142 *
 143 * In order for the NFS get_parent() method to work and for the
 144 * general consistency of the dcache, we need to make sure the
 145 * "i_iget5_block" and "i_iget5_offset" all point to exactly one of
 146 * the many redundant entries for each directory.  We normalize the
 147 * block and offset by always making them point to the "."  directory.
 148 *
 149 * Notice that we do not use the entry for the directory with the name
 150 * that is located in the parent directory.  Even though choosing this
 151 * first directory is more natural, it is much easier to find the "."
 152 * entry in the NFS get_parent() method because it is implicitly
 153 * encoded in the "extent + ext_attr_length" fields of _all_ the
 154 * redundant entries for the directory.  Thus, it can always be
 155 * reached regardless of which directory entry you have in hand.
 156 *
 157 * This works because the "." entry is simply the first directory
 158 * record when you start reading the file that holds all the directory
 159 * records, and this file starts at "extent + ext_attr_length" blocks.
 160 * Because the "." entry is always the first entry listed in the
 161 * directories file, the normalized "offset" value is always 0.
 162 *
 163 * You should pass the directory entry in "de".  On return, "block"
 164 * and "offset" will hold normalized values.  Only directories are
 165 * affected making it safe to call even for non-directory file
 166 * types. */
 167static inline void
 168isofs_normalize_block_and_offset(struct iso_directory_record* de,
 169                                 unsigned long *block,
 170                                 unsigned long *offset)
 171{
 172        /* Only directories are normalized. */
 173        if (de->flags[0] & 2) {
 174                *offset = 0;
 175                *block = (unsigned long)isonum_733(de->extent)
 176                        + (unsigned long)isonum_711(de->ext_attr_length);
 177        }
 178}
 179
 180extern const struct inode_operations isofs_dir_inode_operations;
 181extern const struct file_operations isofs_dir_operations;
 182extern const struct address_space_operations isofs_symlink_aops;
 183extern const struct export_operations isofs_export_ops;
 184
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