Line data Source code
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 0 : static inline struct isofs_sb_info *ISOFS_SB(struct super_block *sb)
67 : {
68 0 : return sb->s_fs_info;
69 : }
70 :
71 0 : static inline struct iso_inode_info *ISOFS_I(struct inode *inode)
72 : {
73 0 : return container_of(inode, struct iso_inode_info, vfs_inode);
74 : }
75 :
76 0 : static inline int isonum_711(u8 *p)
77 : {
78 0 : return *p;
79 : }
80 : static inline int isonum_712(s8 *p)
81 : {
82 : return *p;
83 : }
84 0 : static inline unsigned int isonum_721(u8 *p)
85 : {
86 0 : return get_unaligned_le16(p);
87 : }
88 : static inline unsigned int isonum_722(u8 *p)
89 : {
90 : return get_unaligned_be16(p);
91 : }
92 0 : static inline unsigned int isonum_723(u8 *p)
93 : {
94 : /* Ignore bigendian datum due to broken mastering programs */
95 0 : 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 0 : static inline unsigned int isonum_733(u8 *p)
106 : {
107 : /* Ignore bigendian datum due to broken mastering programs */
108 0 : 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 0 : static inline struct inode *isofs_iget(struct super_block *sb,
131 : unsigned long block,
132 : unsigned long offset)
133 : {
134 0 : return __isofs_iget(sb, block, offset, 0);
135 : }
136 :
137 0 : static inline struct inode *isofs_iget_reloc(struct super_block *sb,
138 : unsigned long block,
139 : unsigned long offset)
140 : {
141 0 : 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 0 : static inline unsigned long isofs_get_ino(unsigned long block,
149 : unsigned long offset,
150 : unsigned long bufbits)
151 : {
152 0 : 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 0 : 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 0 : if (de->flags[0] & 2) {
193 0 : *offset = 0;
194 0 : *block = (unsigned long)isonum_733(de->extent)
195 0 : + (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;
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