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