xref: /linux/fs/isofs/isofs.h (revision 2b8232ce512105e28453f301d1510de8363bccd1)
1 #include <linux/fs.h>
2 #include <linux/buffer_head.h>
3 #include <linux/exportfs.h>
4 #include <linux/iso_fs.h>
5 #include <asm/unaligned.h>
6 
7 enum isofs_file_format {
8 	isofs_file_normal = 0,
9 	isofs_file_sparse = 1,
10 	isofs_file_compressed = 2,
11 };
12 
13 /*
14  * iso fs inode data in memory
15  */
16 struct iso_inode_info {
17 	unsigned long i_iget5_block;
18 	unsigned long i_iget5_offset;
19 	unsigned int i_first_extent;
20 	unsigned char i_file_format;
21 	unsigned char i_format_parm[3];
22 	unsigned long i_next_section_block;
23 	unsigned long i_next_section_offset;
24 	off_t i_section_size;
25 	struct inode vfs_inode;
26 };
27 
28 /*
29  * iso9660 super-block data in memory
30  */
31 struct isofs_sb_info {
32 	unsigned long s_ninodes;
33 	unsigned long s_nzones;
34 	unsigned long s_firstdatazone;
35 	unsigned long s_log_zone_size;
36 	unsigned long s_max_size;
37 
38 	unsigned char s_high_sierra; /* A simple flag */
39 	unsigned char s_mapping;
40 	int           s_rock_offset; /* offset of SUSP fields within SU area */
41 	unsigned char s_rock;
42 	unsigned char s_joliet_level;
43 	unsigned char s_utf8;
44 	unsigned char s_cruft; /* Broken disks with high
45 				  byte of length containing
46 				  junk */
47 	unsigned char s_unhide;
48 	unsigned char s_nosuid;
49 	unsigned char s_nodev;
50 	unsigned char s_nocompress;
51 	unsigned char s_hide;
52 	unsigned char s_showassoc;
53 
54 	mode_t s_mode;
55 	gid_t s_gid;
56 	uid_t s_uid;
57 	struct nls_table *s_nls_iocharset; /* Native language support table */
58 };
59 
60 static inline struct isofs_sb_info *ISOFS_SB(struct super_block *sb)
61 {
62 	return sb->s_fs_info;
63 }
64 
65 static inline struct iso_inode_info *ISOFS_I(struct inode *inode)
66 {
67 	return container_of(inode, struct iso_inode_info, vfs_inode);
68 }
69 
70 static inline int isonum_711(char *p)
71 {
72 	return *(u8 *)p;
73 }
74 static inline int isonum_712(char *p)
75 {
76 	return *(s8 *)p;
77 }
78 static inline unsigned int isonum_721(char *p)
79 {
80 	return le16_to_cpu(get_unaligned((__le16 *)p));
81 }
82 static inline unsigned int isonum_722(char *p)
83 {
84 	return be16_to_cpu(get_unaligned((__le16 *)p));
85 }
86 static inline unsigned int isonum_723(char *p)
87 {
88 	/* Ignore bigendian datum due to broken mastering programs */
89 	return le16_to_cpu(get_unaligned((__le16 *)p));
90 }
91 static inline unsigned int isonum_731(char *p)
92 {
93 	return le32_to_cpu(get_unaligned((__le32 *)p));
94 }
95 static inline unsigned int isonum_732(char *p)
96 {
97 	return be32_to_cpu(get_unaligned((__le32 *)p));
98 }
99 static inline unsigned int isonum_733(char *p)
100 {
101 	/* Ignore bigendian datum due to broken mastering programs */
102 	return le32_to_cpu(get_unaligned((__le32 *)p));
103 }
104 extern int iso_date(char *, int);
105 
106 struct inode;		/* To make gcc happy */
107 
108 extern int parse_rock_ridge_inode(struct iso_directory_record *, struct inode *);
109 extern int get_rock_ridge_filename(struct iso_directory_record *, char *, struct inode *);
110 extern int isofs_name_translate(struct iso_directory_record *, char *, struct inode *);
111 
112 int get_joliet_filename(struct iso_directory_record *, unsigned char *, struct inode *);
113 int get_acorn_filename(struct iso_directory_record *, char *, struct inode *);
114 
115 extern struct dentry *isofs_lookup(struct inode *, struct dentry *, struct nameidata *);
116 extern struct buffer_head *isofs_bread(struct inode *, sector_t);
117 extern int isofs_get_blocks(struct inode *, sector_t, struct buffer_head **, unsigned long);
118 
119 extern struct inode *isofs_iget(struct super_block *sb,
120                                 unsigned long block,
121                                 unsigned long offset);
122 
123 /* Because the inode number is no longer relevant to finding the
124  * underlying meta-data for an inode, we are free to choose a more
125  * convenient 32-bit number as the inode number.  The inode numbering
126  * scheme was recommended by Sergey Vlasov and Eric Lammerts. */
127 static inline unsigned long isofs_get_ino(unsigned long block,
128 					  unsigned long offset,
129 					  unsigned long bufbits)
130 {
131 	return (block << (bufbits - 5)) | (offset >> 5);
132 }
133 
134 /* Every directory can have many redundant directory entries scattered
135  * throughout the directory tree.  First there is the directory entry
136  * with the name of the directory stored in the parent directory.
137  * Then, there is the "." directory entry stored in the directory
138  * itself.  Finally, there are possibly many ".." directory entries
139  * stored in all the subdirectories.
140  *
141  * In order for the NFS get_parent() method to work and for the
142  * general consistency of the dcache, we need to make sure the
143  * "i_iget5_block" and "i_iget5_offset" all point to exactly one of
144  * the many redundant entries for each directory.  We normalize the
145  * block and offset by always making them point to the "."  directory.
146  *
147  * Notice that we do not use the entry for the directory with the name
148  * that is located in the parent directory.  Even though choosing this
149  * first directory is more natural, it is much easier to find the "."
150  * entry in the NFS get_parent() method because it is implicitly
151  * encoded in the "extent + ext_attr_length" fields of _all_ the
152  * redundant entries for the directory.  Thus, it can always be
153  * reached regardless of which directory entry you have in hand.
154  *
155  * This works because the "." entry is simply the first directory
156  * record when you start reading the file that holds all the directory
157  * records, and this file starts at "extent + ext_attr_length" blocks.
158  * Because the "." entry is always the first entry listed in the
159  * directories file, the normalized "offset" value is always 0.
160  *
161  * You should pass the directory entry in "de".  On return, "block"
162  * and "offset" will hold normalized values.  Only directories are
163  * affected making it safe to call even for non-directory file
164  * types. */
165 static inline void
166 isofs_normalize_block_and_offset(struct iso_directory_record* de,
167 				 unsigned long *block,
168 				 unsigned long *offset)
169 {
170 	/* Only directories are normalized. */
171 	if (de->flags[0] & 2) {
172 		*offset = 0;
173 		*block = (unsigned long)isonum_733(de->extent)
174 			+ (unsigned long)isonum_711(de->ext_attr_length);
175 	}
176 }
177 
178 extern const struct inode_operations isofs_dir_inode_operations;
179 extern const struct file_operations isofs_dir_operations;
180 extern const struct address_space_operations isofs_symlink_aops;
181 extern struct export_operations isofs_export_ops;
182