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 <linux/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}
109#define ISO_DATE_HIGH_SIERRA (1 << 0)
110#define ISO_DATE_LONG_FORM (1 << 1)
111struct timespec64 iso_date(u8 *p, int flags);
112
113struct inode; /* To make gcc happy */
114
115extern int parse_rock_ridge_inode(struct iso_directory_record *, struct inode *, int relocated);
116extern int get_rock_ridge_filename(struct iso_directory_record *, char *, struct inode *);
117extern int isofs_name_translate(struct iso_directory_record *, char *, struct inode *);
118
119int get_joliet_filename(struct iso_directory_record *, unsigned char *, struct inode *);
120int get_acorn_filename(struct iso_directory_record *, char *, struct inode *);
121
122extern struct dentry *isofs_lookup(struct inode *, struct dentry *, unsigned int flags);
123extern struct buffer_head *isofs_bread(struct inode *, sector_t);
124extern int isofs_get_blocks(struct inode *, sector_t, struct buffer_head **, unsigned long);
125
126struct inode *__isofs_iget(struct super_block *sb,
127 unsigned long block,
128 unsigned long offset,
129 int relocated);
130
131static inline struct inode *isofs_iget(struct super_block *sb,
132 unsigned long block,
133 unsigned long offset)
134{
135 return __isofs_iget(sb, block, offset, relocated: 0);
136}
137
138static inline struct inode *isofs_iget_reloc(struct super_block *sb,
139 unsigned long block,
140 unsigned long offset)
141{
142 return __isofs_iget(sb, block, offset, relocated: 1);
143}
144
145/* Because the inode number is no longer relevant to finding the
146 * underlying meta-data for an inode, we are free to choose a more
147 * convenient 32-bit number as the inode number. The inode numbering
148 * scheme was recommended by Sergey Vlasov and Eric Lammerts. */
149static inline unsigned long isofs_get_ino(unsigned long block,
150 unsigned long offset,
151 unsigned long bufbits)
152{
153 return (block << (bufbits - 5)) | (offset >> 5);
154}
155
156/* Every directory can have many redundant directory entries scattered
157 * throughout the directory tree. First there is the directory entry
158 * with the name of the directory stored in the parent directory.
159 * Then, there is the "." directory entry stored in the directory
160 * itself. Finally, there are possibly many ".." directory entries
161 * stored in all the subdirectories.
162 *
163 * In order for the NFS get_parent() method to work and for the
164 * general consistency of the dcache, we need to make sure the
165 * "i_iget5_block" and "i_iget5_offset" all point to exactly one of
166 * the many redundant entries for each directory. We normalize the
167 * block and offset by always making them point to the "." directory.
168 *
169 * Notice that we do not use the entry for the directory with the name
170 * that is located in the parent directory. Even though choosing this
171 * first directory is more natural, it is much easier to find the "."
172 * entry in the NFS get_parent() method because it is implicitly
173 * encoded in the "extent + ext_attr_length" fields of _all_ the
174 * redundant entries for the directory. Thus, it can always be
175 * reached regardless of which directory entry you have in hand.
176 *
177 * This works because the "." entry is simply the first directory
178 * record when you start reading the file that holds all the directory
179 * records, and this file starts at "extent + ext_attr_length" blocks.
180 * Because the "." entry is always the first entry listed in the
181 * directories file, the normalized "offset" value is always 0.
182 *
183 * You should pass the directory entry in "de". On return, "block"
184 * and "offset" will hold normalized values. Only directories are
185 * affected making it safe to call even for non-directory file
186 * types. */
187static inline void
188isofs_normalize_block_and_offset(struct iso_directory_record* de,
189 unsigned long *block,
190 unsigned long *offset)
191{
192 /* Only directories are normalized. */
193 if (de->flags[0] & 2) {
194 *offset = 0;
195 *block = (unsigned long)isonum_733(p: de->extent)
196 + (unsigned long)isonum_711(p: de->ext_attr_length);
197 }
198}
199
200extern const struct inode_operations isofs_dir_inode_operations;
201extern const struct file_operations isofs_dir_operations;
202extern const struct address_space_operations isofs_symlink_aops;
203extern const struct export_operations isofs_export_ops;
204