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
ISOFS_SB(struct super_block * sb)66 static inline struct isofs_sb_info *ISOFS_SB(struct super_block *sb)
67 {
68 return sb->s_fs_info;
69 }
70
ISOFS_I(struct inode * inode)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
isonum_711(u8 * p)76 static inline int isonum_711(u8 *p)
77 {
78 return *p;
79 }
isonum_712(s8 * p)80 static inline int isonum_712(s8 *p)
81 {
82 return *p;
83 }
isonum_721(u8 * p)84 static inline unsigned int isonum_721(u8 *p)
85 {
86 return get_unaligned_le16(p);
87 }
isonum_722(u8 * p)88 static inline unsigned int isonum_722(u8 *p)
89 {
90 return get_unaligned_be16(p);
91 }
isonum_723(u8 * p)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 }
isonum_731(u8 * p)97 static inline unsigned int isonum_731(u8 *p)
98 {
99 return get_unaligned_le32(p);
100 }
isonum_732(u8 * p)101 static inline unsigned int isonum_732(u8 *p)
102 {
103 return get_unaligned_be32(p);
104 }
isonum_733(u8 * p)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
isofs_iget(struct super_block * sb,unsigned long block,unsigned long offset)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
isofs_iget_reloc(struct super_block * sb,unsigned long block,unsigned long offset)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. */
isofs_get_ino(unsigned long block,unsigned long offset,unsigned long bufbits)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
isofs_normalize_block_and_offset(struct iso_directory_record * de,unsigned long * block,unsigned long * offset)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