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