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
   8 enum 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  */
  17 struct 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  */
  32 struct 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
  66 static inline struct isofs_sb_info *ISOFS_SB(struct super_block *sb)
  67 {
  68         return sb->s_fs_info;
  69 }
  70
  71 static inline struct iso_inode_info *ISOFS_I(struct inode *inode)
  72 {
  73         return container_of(inode, struct iso_inode_info, vfs_inode);
  74 }
  75
  76 static inline int isonum_711(char *p)
  77 {
  78         return *(u8 *)p;
  79 }
  80 static inline int isonum_712(char *p)
  81 {
  82         return *(s8 *)p;
  83 }
  84 static inline unsigned int isonum_721(char *p)
  85 {
  86         return get_unaligned_le16(p);
  87 }
  88 static inline unsigned int isonum_722(char *p)
  89 {
  90         return get_unaligned_be16(p);
  91 }
  92 static inline unsigned int isonum_723(char *p)
  93 {
  94         /* Ignore bigendian datum due to broken mastering programs */
  95         return get_unaligned_le16(p);
  96 }
  97 static inline unsigned int isonum_731(char *p)
  98 {
  99         return get_unaligned_le32(p);
 100 }
 101 static inline unsigned int isonum_732(char *p)
 102 {
 103         return get_unaligned_be32(p);
 104 }
 105 static inline unsigned int isonum_733(char *p)
 106 {
 107         /* Ignore bigendian datum due to broken mastering programs */
 108         return get_unaligned_le32(p);
 109 }
 110 extern int iso_date(char *, int);
 111
 112 struct inode;           /* To make gcc happy */
 113
 114 extern int parse_rock_ridge_inode(struct iso_directory_record *, struct inode *, int relocated);
 115 extern int get_rock_ridge_filename(struct iso_directory_record *, char *, struct inode *);
 116 extern int isofs_name_translate(struct iso_directory_record *, char *, struct inode *);
 117
 118 int get_joliet_filename(struct iso_directory_record *, unsigned char *, struct inode *);
 119 int get_acorn_filename(struct iso_directory_record *, char *, struct inode *);
 120
 121 extern struct dentry *isofs_lookup(struct inode *, struct dentry *, unsigned int flags);
 122 extern struct buffer_head *isofs_bread(struct inode *, sector_t);
 123 extern int isofs_get_blocks(struct inode *, sector_t, struct buffer_head **, unsigned long);
 124
 125 struct inode *__isofs_iget(struct super_block *sb,
 126                            unsigned long block,
 127                            unsigned long offset,
 128                            int relocated);
 129
 130 static 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
 137 static 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. */
 148 static 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. */
 186 static inline void
 187 isofs_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
 199 extern const struct inode_operations isofs_dir_inode_operations;
 200 extern const struct file_operations isofs_dir_operations;
 201 extern const struct address_space_operations isofs_symlink_aops;
 202 extern const struct export_operations isofs_export_ops;