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 	int           s_rock_offset; /* offset of SUSP fields within SU area */
39 	unsigned char s_joliet_level;
40 	unsigned char s_mapping;
41 	unsigned int  s_high_sierra:1;
42 	unsigned int  s_rock:2;
43 	unsigned int  s_utf8:1;
44 	unsigned int  s_cruft:1; /* Broken disks with high byte of length
45 				  * containing junk */
46 	unsigned int  s_nocompress:1;
47 	unsigned int  s_hide:1;
48 	unsigned int  s_showassoc:1;
49 	unsigned int  s_overriderockperm:1;
50 	unsigned int  s_uid_set:1;
51 	unsigned int  s_gid_set:1;
52 
53 	mode_t s_fmode;
54 	mode_t s_dmode;
55 	gid_t s_gid;
56 	uid_t s_uid;
57 	struct nls_table *s_nls_iocharset; /* Native language support table */
58 	struct mutex s_mutex; /* replaces BKL, please remove if possible */
59 };
60 
61 #define ISOFS_INVALID_MODE ((mode_t) -1)
62 
ISOFS_SB(struct super_block * sb)63 static inline struct isofs_sb_info *ISOFS_SB(struct super_block *sb)
64 {
65 	return sb->s_fs_info;
66 }
67 
ISOFS_I(struct inode * inode)68 static inline struct iso_inode_info *ISOFS_I(struct inode *inode)
69 {
70 	return container_of(inode, struct iso_inode_info, vfs_inode);
71 }
72 
isonum_711(char * p)73 static inline int isonum_711(char *p)
74 {
75 	return *(u8 *)p;
76 }
isonum_712(char * p)77 static inline int isonum_712(char *p)
78 {
79 	return *(s8 *)p;
80 }
isonum_721(char * p)81 static inline unsigned int isonum_721(char *p)
82 {
83 	return get_unaligned_le16(p);
84 }
isonum_722(char * p)85 static inline unsigned int isonum_722(char *p)
86 {
87 	return get_unaligned_be16(p);
88 }
isonum_723(char * p)89 static inline unsigned int isonum_723(char *p)
90 {
91 	/* Ignore bigendian datum due to broken mastering programs */
92 	return get_unaligned_le16(p);
93 }
isonum_731(char * p)94 static inline unsigned int isonum_731(char *p)
95 {
96 	return get_unaligned_le32(p);
97 }
isonum_732(char * p)98 static inline unsigned int isonum_732(char *p)
99 {
100 	return get_unaligned_be32(p);
101 }
isonum_733(char * p)102 static inline unsigned int isonum_733(char *p)
103 {
104 	/* Ignore bigendian datum due to broken mastering programs */
105 	return get_unaligned_le32(p);
106 }
107 extern int iso_date(char *, int);
108 
109 struct inode;		/* To make gcc happy */
110 
111 extern int parse_rock_ridge_inode(struct iso_directory_record *, struct inode *);
112 extern int get_rock_ridge_filename(struct iso_directory_record *, char *, struct inode *);
113 extern int isofs_name_translate(struct iso_directory_record *, char *, struct inode *);
114 
115 int get_joliet_filename(struct iso_directory_record *, unsigned char *, struct inode *);
116 int get_acorn_filename(struct iso_directory_record *, char *, struct inode *);
117 
118 extern struct dentry *isofs_lookup(struct inode *, struct dentry *, struct nameidata *);
119 extern struct buffer_head *isofs_bread(struct inode *, sector_t);
120 extern int isofs_get_blocks(struct inode *, sector_t, struct buffer_head **, unsigned long);
121 
122 extern struct inode *isofs_iget(struct super_block *sb,
123                                 unsigned long block,
124                                 unsigned long offset);
125 
126 /* Because the inode number is no longer relevant to finding the
127  * underlying meta-data for an inode, we are free to choose a more
128  * convenient 32-bit number as the inode number.  The inode numbering
129  * scheme was recommended by Sergey Vlasov and Eric Lammerts. */
isofs_get_ino(unsigned long block,unsigned long offset,unsigned long bufbits)130 static inline unsigned long isofs_get_ino(unsigned long block,
131 					  unsigned long offset,
132 					  unsigned long bufbits)
133 {
134 	return (block << (bufbits - 5)) | (offset >> 5);
135 }
136 
137 /* Every directory can have many redundant directory entries scattered
138  * throughout the directory tree.  First there is the directory entry
139  * with the name of the directory stored in the parent directory.
140  * Then, there is the "." directory entry stored in the directory
141  * itself.  Finally, there are possibly many ".." directory entries
142  * stored in all the subdirectories.
143  *
144  * In order for the NFS get_parent() method to work and for the
145  * general consistency of the dcache, we need to make sure the
146  * "i_iget5_block" and "i_iget5_offset" all point to exactly one of
147  * the many redundant entries for each directory.  We normalize the
148  * block and offset by always making them point to the "."  directory.
149  *
150  * Notice that we do not use the entry for the directory with the name
151  * that is located in the parent directory.  Even though choosing this
152  * first directory is more natural, it is much easier to find the "."
153  * entry in the NFS get_parent() method because it is implicitly
154  * encoded in the "extent + ext_attr_length" fields of _all_ the
155  * redundant entries for the directory.  Thus, it can always be
156  * reached regardless of which directory entry you have in hand.
157  *
158  * This works because the "." entry is simply the first directory
159  * record when you start reading the file that holds all the directory
160  * records, and this file starts at "extent + ext_attr_length" blocks.
161  * Because the "." entry is always the first entry listed in the
162  * directories file, the normalized "offset" value is always 0.
163  *
164  * You should pass the directory entry in "de".  On return, "block"
165  * and "offset" will hold normalized values.  Only directories are
166  * affected making it safe to call even for non-directory file
167  * types. */
168 static inline void
isofs_normalize_block_and_offset(struct iso_directory_record * de,unsigned long * block,unsigned long * offset)169 isofs_normalize_block_and_offset(struct iso_directory_record* de,
170 				 unsigned long *block,
171 				 unsigned long *offset)
172 {
173 	/* Only directories are normalized. */
174 	if (de->flags[0] & 2) {
175 		*offset = 0;
176 		*block = (unsigned long)isonum_733(de->extent)
177 			+ (unsigned long)isonum_711(de->ext_attr_length);
178 	}
179 }
180 
181 extern const struct inode_operations isofs_dir_inode_operations;
182 extern const struct file_operations isofs_dir_operations;
183 extern const struct address_space_operations isofs_symlink_aops;
184 extern const struct export_operations isofs_export_ops;
185