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, relocated: 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, relocated: 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(p: de->extent) |
194 | + (unsigned long)isonum_711(p: 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 | |