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         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         kgid_t s_gid;
  56         kuid_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
  62 static inline struct isofs_sb_info *ISOFS_SB(struct super_block *sb)
  63 {
  64         return sb->s_fs_info;
  65 }
  66
  67 static inline struct iso_inode_info *ISOFS_I(struct inode *inode)
  68 {
  69         return container_of(inode, struct iso_inode_info, vfs_inode);
  70 }
  71
  72 static inline int isonum_711(char *p)
  73 {
  74         return *(u8 *)p;
  75 }
  76 static inline int isonum_712(char *p)
  77 {
  78         return *(s8 *)p;
  79 }
  80 static inline unsigned int isonum_721(char *p)
  81 {
  82         return get_unaligned_le16(p);
  83 }
  84 static inline unsigned int isonum_722(char *p)
  85 {
  86         return get_unaligned_be16(p);
  87 }
  88 static inline unsigned int isonum_723(char *p)
  89 {
  90         /* Ignore bigendian datum due to broken mastering programs */
  91         return get_unaligned_le16(p);
  92 }
  93 static inline unsigned int isonum_731(char *p)
  94 {
  95         return get_unaligned_le32(p);
  96 }
  97 static inline unsigned int isonum_732(char *p)
  98 {
  99         return get_unaligned_be32(p);
 100 }
 101 static inline unsigned int isonum_733(char *p)
 102 {
 103         /* Ignore bigendian datum due to broken mastering programs */
 104         return get_unaligned_le32(p);
 105 }
 106 extern int iso_date(char *, int);
 107
 108 struct inode;           /* To make gcc happy */
 109
 110 extern int parse_rock_ridge_inode(struct iso_directory_record *, struct inode *);
 111 extern int get_rock_ridge_filename(struct iso_directory_record *, char *, struct inode *);
 112 extern int isofs_name_translate(struct iso_directory_record *, char *, struct inode *);
 113
 114 int get_joliet_filename(struct iso_directory_record *, unsigned char *, struct inode *);
 115 int get_acorn_filename(struct iso_directory_record *, char *, struct inode *);
 116
 117 extern struct dentry *isofs_lookup(struct inode *, struct dentry *, unsigned int flags);
 118 extern struct buffer_head *isofs_bread(struct inode *, sector_t);
 119 extern int isofs_get_blocks(struct inode *, sector_t, struct buffer_head **, unsigned long);
 120
 121 extern 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. */
 129 static 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. */
 167 static inline void
 168 isofs_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
 180 extern const struct inode_operations isofs_dir_inode_operations;
 181 extern const struct file_operations isofs_dir_operations;
 182 extern const struct address_space_operations isofs_symlink_aops;
 183 extern const struct export_operations isofs_export_ops;