LXR linux/fs/isofs/isofs.h

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#include <linux/fs.h>
   3#include <linux/buffer_head.h>
   4#include <linux/exportfs.h>
   5#include <linux/iso_fs.h>
   6#include <asm/unaligned.h>
   7
   8enum isofs_file_format {
   9        isofs_file_normal = 0,
  10        isofs_file_sparse = 1,
  11        isofs_file_compressed = 2,
  12};
  13        
  14/*
  15 * iso fs inode data in memory
  16 */
  17struct iso_inode_info {
  18        unsigned long i_iget5_block;
  19        unsigned long i_iget5_offset;
  20        unsigned int i_first_extent;
  21        unsigned char i_file_format;
  22        unsigned char i_format_parm[3];
  23        unsigned long i_next_section_block;
  24        unsigned long i_next_section_offset;
  25        off_t i_section_size;
  26        struct inode vfs_inode;
  27};
  28
  29/*
  30 * iso9660 super-block data in memory
  31 */
  32struct isofs_sb_info {
  33        unsigned long s_ninodes;
  34        unsigned long s_nzones;
  35        unsigned long s_firstdatazone;
  36        unsigned long s_log_zone_size;
  37        unsigned long s_max_size;
  38        
  39        int           s_rock_offset; /* offset of SUSP fields within SU area */
  40        s32           s_sbsector;
  41        unsigned char s_joliet_level;
  42        unsigned char s_mapping;
  43        unsigned char s_check;
  44        unsigned char s_session;
  45        unsigned int  s_high_sierra:1;
  46        unsigned int  s_rock:2;
  47        unsigned int  s_cruft:1; /* Broken disks with high byte of length
  48                                  * containing junk */
  49        unsigned int  s_nocompress:1;
  50        unsigned int  s_hide:1;
  51        unsigned int  s_showassoc:1;
  52        unsigned int  s_overriderockperm:1;
  53        unsigned int  s_uid_set:1;
  54        unsigned int  s_gid_set:1;
  55
  56        umode_t s_fmode;
  57        umode_t s_dmode;
  58        kgid_t s_gid;
  59        kuid_t s_uid;
  60        struct nls_table *s_nls_iocharset; /* Native language support table */
  61};
  62
  63#define ISOFS_INVALID_MODE ((umode_t) -1)
  64
  65static inline struct isofs_sb_info *ISOFS_SB(struct super_block *sb)
  66{
  67        return sb->s_fs_info;
  68}
  69
  70static inline struct iso_inode_info *ISOFS_I(struct inode *inode)
  71{
  72        return container_of(inode, struct iso_inode_info, vfs_inode);
  73}
  74
  75static inline int isonum_711(u8 *p)
  76{
  77        return *p;
  78}
  79static inline int isonum_712(s8 *p)
  80{
  81        return *p;
  82}
  83static inline unsigned int isonum_721(u8 *p)
  84{
  85        return get_unaligned_le16(p);
  86}
  87static inline unsigned int isonum_722(u8 *p)
  88{
  89        return get_unaligned_be16(p);
  90}
  91static inline unsigned int isonum_723(u8 *p)
  92{
  93        /* Ignore bigendian datum due to broken mastering programs */
  94        return get_unaligned_le16(p);
  95}
  96static inline unsigned int isonum_731(u8 *p)
  97{
  98        return get_unaligned_le32(p);
  99}
 100static inline unsigned int isonum_732(u8 *p)
 101{
 102        return get_unaligned_be32(p);
 103}
 104static inline unsigned int isonum_733(u8 *p)
 105{
 106        /* Ignore bigendian datum due to broken mastering programs */
 107        return get_unaligned_le32(p);
 108}
 109extern int iso_date(u8 *, int);
 110
 111struct inode;           /* To make gcc happy */
 112
 113extern int parse_rock_ridge_inode(struct iso_directory_record *, struct inode *, int relocated);
 114extern int get_rock_ridge_filename(struct iso_directory_record *, char *, struct inode *);
 115extern int isofs_name_translate(struct iso_directory_record *, char *, struct inode *);
 116
 117int get_joliet_filename(struct iso_directory_record *, unsigned char *, struct inode *);
 118int get_acorn_filename(struct iso_directory_record *, char *, struct inode *);
 119
 120extern struct dentry *isofs_lookup(struct inode *, struct dentry *, unsigned int flags);
 121extern struct buffer_head *isofs_bread(struct inode *, sector_t);
 122extern int isofs_get_blocks(struct inode *, sector_t, struct buffer_head **, unsigned long);
 123
 124struct inode *__isofs_iget(struct super_block *sb,
 125                           unsigned long block,
 126                           unsigned long offset,
 127                           int relocated);
 128
 129static inline struct inode *isofs_iget(struct super_block *sb,
 130                                       unsigned long block,
 131                                       unsigned long offset)
 132{
 133        return __isofs_iget(sb, block, offset, 0);
 134}
 135
 136static inline struct inode *isofs_iget_reloc(struct super_block *sb,
 137                                             unsigned long block,
 138                                             unsigned long offset)
 139{
 140        return __isofs_iget(sb, block, offset, 1);
 141}
 142
 143/* Because the inode number is no longer relevant to finding the
 144 * underlying meta-data for an inode, we are free to choose a more
 145 * convenient 32-bit number as the inode number.  The inode numbering
 146 * scheme was recommended by Sergey Vlasov and Eric Lammerts. */
 147static inline unsigned long isofs_get_ino(unsigned long block,
 148                                          unsigned long offset,
 149                                          unsigned long bufbits)
 150{
 151        return (block << (bufbits - 5)) | (offset >> 5);
 152}
 153
 154/* Every directory can have many redundant directory entries scattered
 155 * throughout the directory tree.  First there is the directory entry
 156 * with the name of the directory stored in the parent directory.
 157 * Then, there is the "." directory entry stored in the directory
 158 * itself.  Finally, there are possibly many ".." directory entries
 159 * stored in all the subdirectories.
 160 *
 161 * In order for the NFS get_parent() method to work and for the
 162 * general consistency of the dcache, we need to make sure the
 163 * "i_iget5_block" and "i_iget5_offset" all point to exactly one of
 164 * the many redundant entries for each directory.  We normalize the
 165 * block and offset by always making them point to the "."  directory.
 166 *
 167 * Notice that we do not use the entry for the directory with the name
 168 * that is located in the parent directory.  Even though choosing this
 169 * first directory is more natural, it is much easier to find the "."
 170 * entry in the NFS get_parent() method because it is implicitly
 171 * encoded in the "extent + ext_attr_length" fields of _all_ the
 172 * redundant entries for the directory.  Thus, it can always be
 173 * reached regardless of which directory entry you have in hand.
 174 *
 175 * This works because the "." entry is simply the first directory
 176 * record when you start reading the file that holds all the directory
 177 * records, and this file starts at "extent + ext_attr_length" blocks.
 178 * Because the "." entry is always the first entry listed in the
 179 * directories file, the normalized "offset" value is always 0.
 180 *
 181 * You should pass the directory entry in "de".  On return, "block"
 182 * and "offset" will hold normalized values.  Only directories are
 183 * affected making it safe to call even for non-directory file
 184 * types. */
 185static inline void
 186isofs_normalize_block_and_offset(struct iso_directory_record* de,
 187                                 unsigned long *block,
 188                                 unsigned long *offset)
 189{
 190        /* Only directories are normalized. */
 191        if (de->flags[0] & 2) {
 192                *offset = 0;
 193                *block = (unsigned long)isonum_733(de->extent)
 194                        + (unsigned long)isonum_711(de->ext_attr_length);
 195        }
 196}
 197
 198extern const struct inode_operations isofs_dir_inode_operations;
 199extern const struct file_operations isofs_dir_operations;
 200extern const struct address_space_operations isofs_symlink_aops;
 201extern const struct export_operations isofs_export_ops;
 202