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_utf8:1;
  48        unsigned int  s_cruft:1; /* Broken disks with high byte of length
  49                                  * containing junk */
  50        unsigned int  s_nocompress:1;
  51        unsigned int  s_hide:1;
  52        unsigned int  s_showassoc:1;
  53        unsigned int  s_overriderockperm:1;
  54        unsigned int  s_uid_set:1;
  55        unsigned int  s_gid_set:1;
  56
  57        umode_t s_fmode;
  58        umode_t s_dmode;
  59        kgid_t s_gid;
  60        kuid_t s_uid;
  61        struct nls_table *s_nls_iocharset; /* Native language support table */
  62};
  63
  64#define ISOFS_INVALID_MODE ((umode_t) -1)
  65
  66static inline struct isofs_sb_info *ISOFS_SB(struct super_block *sb)
  67{
  68        return sb->s_fs_info;
  69}
  70
  71static inline struct iso_inode_info *ISOFS_I(struct inode *inode)
  72{
  73        return container_of(inode, struct iso_inode_info, vfs_inode);
  74}
  75
  76static inline int isonum_711(char *p)
  77{
  78        return *(u8 *)p;
  79}
  80static inline int isonum_712(char *p)
  81{
  82        return *(s8 *)p;
  83}
  84static inline unsigned int isonum_721(char *p)
  85{
  86        return get_unaligned_le16(p);
  87}
  88static inline unsigned int isonum_722(char *p)
  89{
  90        return get_unaligned_be16(p);
  91}
  92static inline unsigned int isonum_723(char *p)
  93{
  94        /* Ignore bigendian datum due to broken mastering programs */
  95        return get_unaligned_le16(p);
  96}
  97static inline unsigned int isonum_731(char *p)
  98{
  99        return get_unaligned_le32(p);
 100}
 101static inline unsigned int isonum_732(char *p)
 102{
 103        return get_unaligned_be32(p);
 104}
 105static inline unsigned int isonum_733(char *p)
 106{
 107        /* Ignore bigendian datum due to broken mastering programs */
 108        return get_unaligned_le32(p);
 109}
 110extern int iso_date(char *, int);
 111
 112struct inode;           /* To make gcc happy */
 113
 114extern int parse_rock_ridge_inode(struct iso_directory_record *, struct inode *, int relocated);
 115extern int get_rock_ridge_filename(struct iso_directory_record *, char *, struct inode *);
 116extern int isofs_name_translate(struct iso_directory_record *, char *, struct inode *);
 117
 118int get_joliet_filename(struct iso_directory_record *, unsigned char *, struct inode *);
 119int get_acorn_filename(struct iso_directory_record *, char *, struct inode *);
 120
 121extern struct dentry *isofs_lookup(struct inode *, struct dentry *, unsigned int flags);
 122extern struct buffer_head *isofs_bread(struct inode *, sector_t);
 123extern int isofs_get_blocks(struct inode *, sector_t, struct buffer_head **, unsigned long);
 124
 125struct inode *__isofs_iget(struct super_block *sb,
 126                           unsigned long block,
 127                           unsigned long offset,
 128                           int relocated);
 129
 130static inline struct inode *isofs_iget(struct super_block *sb,
 131                                       unsigned long block,
 132                                       unsigned long offset)
 133{
 134        return __isofs_iget(sb, block, offset, 0);
 135}
 136
 137static inline struct inode *isofs_iget_reloc(struct super_block *sb,
 138                                             unsigned long block,
 139                                             unsigned long offset)
 140{
 141        return __isofs_iget(sb, block, offset, 1);
 142}
 143
 144/* Because the inode number is no longer relevant to finding the
 145 * underlying meta-data for an inode, we are free to choose a more
 146 * convenient 32-bit number as the inode number.  The inode numbering
 147 * scheme was recommended by Sergey Vlasov and Eric Lammerts. */
 148static inline unsigned long isofs_get_ino(unsigned long block,
 149                                          unsigned long offset,
 150                                          unsigned long bufbits)
 151{
 152        return (block << (bufbits - 5)) | (offset >> 5);
 153}
 154
 155/* Every directory can have many redundant directory entries scattered
 156 * throughout the directory tree.  First there is the directory entry
 157 * with the name of the directory stored in the parent directory.
 158 * Then, there is the "." directory entry stored in the directory
 159 * itself.  Finally, there are possibly many ".." directory entries
 160 * stored in all the subdirectories.
 161 *
 162 * In order for the NFS get_parent() method to work and for the
 163 * general consistency of the dcache, we need to make sure the
 164 * "i_iget5_block" and "i_iget5_offset" all point to exactly one of
 165 * the many redundant entries for each directory.  We normalize the
 166 * block and offset by always making them point to the "."  directory.
 167 *
 168 * Notice that we do not use the entry for the directory with the name
 169 * that is located in the parent directory.  Even though choosing this
 170 * first directory is more natural, it is much easier to find the "."
 171 * entry in the NFS get_parent() method because it is implicitly
 172 * encoded in the "extent + ext_attr_length" fields of _all_ the
 173 * redundant entries for the directory.  Thus, it can always be
 174 * reached regardless of which directory entry you have in hand.
 175 *
 176 * This works because the "." entry is simply the first directory
 177 * record when you start reading the file that holds all the directory
 178 * records, and this file starts at "extent + ext_attr_length" blocks.
 179 * Because the "." entry is always the first entry listed in the
 180 * directories file, the normalized "offset" value is always 0.
 181 *
 182 * You should pass the directory entry in "de".  On return, "block"
 183 * and "offset" will hold normalized values.  Only directories are
 184 * affected making it safe to call even for non-directory file
 185 * types. */
 186static inline void
 187isofs_normalize_block_and_offset(struct iso_directory_record* de,
 188                                 unsigned long *block,
 189                                 unsigned long *offset)
 190{
 191        /* Only directories are normalized. */
 192        if (de->flags[0] & 2) {
 193                *offset = 0;
 194                *block = (unsigned long)isonum_733(de->extent)
 195                        + (unsigned long)isonum_711(de->ext_attr_length);
 196        }
 197}
 198
 199extern const struct inode_operations isofs_dir_inode_operations;
 200extern const struct file_operations isofs_dir_operations;
 201extern const struct address_space_operations isofs_symlink_aops;
 202extern const struct export_operations isofs_export_ops;
 203