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(u8 *p) 77 { 78 return *p; 79 } 80 static inline int isonum_712(s8 *p) 81 { 82 return *p; 83 } 84 static inline unsigned int isonum_721(u8 *p) 85 { 86 return get_unaligned_le16(p); 87 } 88 static inline unsigned int isonum_722(u8 *p) 89 { 90 return get_unaligned_be16(p); 91 } 92 static inline unsigned int isonum_723(u8 *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(u8 *p) 98 { 99 return get_unaligned_le32(p); 100 } 101 static inline unsigned int isonum_732(u8 *p) 102 { 103 return get_unaligned_be32(p); 104 } 105 static inline unsigned int isonum_733(u8 *p) 106 { 107 /* Ignore bigendian datum due to broken mastering programs */ 108 return get_unaligned_le32(p); 109 } 110 extern int iso_date(u8 *, 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; 203