xref: /openbmc/linux/fs/isofs/isofs.h (revision 54cbac81)
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 	umode_t s_fmode;
54 	umode_t s_dmode;
55 	kgid_t s_gid;
56 	kuid_t s_uid;
57 	struct nls_table *s_nls_iocharset; /* Native language support table */
58 };
59 
60 #define ISOFS_INVALID_MODE ((umode_t) -1)
61 
62 static inline struct isofs_sb_info *ISOFS_SB(struct super_block *sb)
63 {
64 	return sb->s_fs_info;
65 }
66 
67 static inline struct iso_inode_info *ISOFS_I(struct inode *inode)
68 {
69 	return container_of(inode, struct iso_inode_info, vfs_inode);
70 }
71 
72 static inline int isonum_711(char *p)
73 {
74 	return *(u8 *)p;
75 }
76 static inline int isonum_712(char *p)
77 {
78 	return *(s8 *)p;
79 }
80 static inline unsigned int isonum_721(char *p)
81 {
82 	return get_unaligned_le16(p);
83 }
84 static inline unsigned int isonum_722(char *p)
85 {
86 	return get_unaligned_be16(p);
87 }
88 static inline unsigned int isonum_723(char *p)
89 {
90 	/* Ignore bigendian datum due to broken mastering programs */
91 	return get_unaligned_le16(p);
92 }
93 static inline unsigned int isonum_731(char *p)
94 {
95 	return get_unaligned_le32(p);
96 }
97 static inline unsigned int isonum_732(char *p)
98 {
99 	return get_unaligned_be32(p);
100 }
101 static inline unsigned int isonum_733(char *p)
102 {
103 	/* Ignore bigendian datum due to broken mastering programs */
104 	return get_unaligned_le32(p);
105 }
106 extern int iso_date(char *, int);
107 
108 struct inode;		/* To make gcc happy */
109 
110 extern int parse_rock_ridge_inode(struct iso_directory_record *, struct inode *);
111 extern int get_rock_ridge_filename(struct iso_directory_record *, char *, struct inode *);
112 extern int isofs_name_translate(struct iso_directory_record *, char *, struct inode *);
113 
114 int get_joliet_filename(struct iso_directory_record *, unsigned char *, struct inode *);
115 int get_acorn_filename(struct iso_directory_record *, char *, struct inode *);
116 
117 extern struct dentry *isofs_lookup(struct inode *, struct dentry *, unsigned int flags);
118 extern struct buffer_head *isofs_bread(struct inode *, sector_t);
119 extern int isofs_get_blocks(struct inode *, sector_t, struct buffer_head **, unsigned long);
120 
121 extern struct inode *isofs_iget(struct super_block *sb,
122                                 unsigned long block,
123                                 unsigned long offset);
124 
125 /* Because the inode number is no longer relevant to finding the
126  * underlying meta-data for an inode, we are free to choose a more
127  * convenient 32-bit number as the inode number.  The inode numbering
128  * scheme was recommended by Sergey Vlasov and Eric Lammerts. */
129 static inline unsigned long isofs_get_ino(unsigned long block,
130 					  unsigned long offset,
131 					  unsigned long bufbits)
132 {
133 	return (block << (bufbits - 5)) | (offset >> 5);
134 }
135 
136 /* Every directory can have many redundant directory entries scattered
137  * throughout the directory tree.  First there is the directory entry
138  * with the name of the directory stored in the parent directory.
139  * Then, there is the "." directory entry stored in the directory
140  * itself.  Finally, there are possibly many ".." directory entries
141  * stored in all the subdirectories.
142  *
143  * In order for the NFS get_parent() method to work and for the
144  * general consistency of the dcache, we need to make sure the
145  * "i_iget5_block" and "i_iget5_offset" all point to exactly one of
146  * the many redundant entries for each directory.  We normalize the
147  * block and offset by always making them point to the "."  directory.
148  *
149  * Notice that we do not use the entry for the directory with the name
150  * that is located in the parent directory.  Even though choosing this
151  * first directory is more natural, it is much easier to find the "."
152  * entry in the NFS get_parent() method because it is implicitly
153  * encoded in the "extent + ext_attr_length" fields of _all_ the
154  * redundant entries for the directory.  Thus, it can always be
155  * reached regardless of which directory entry you have in hand.
156  *
157  * This works because the "." entry is simply the first directory
158  * record when you start reading the file that holds all the directory
159  * records, and this file starts at "extent + ext_attr_length" blocks.
160  * Because the "." entry is always the first entry listed in the
161  * directories file, the normalized "offset" value is always 0.
162  *
163  * You should pass the directory entry in "de".  On return, "block"
164  * and "offset" will hold normalized values.  Only directories are
165  * affected making it safe to call even for non-directory file
166  * types. */
167 static inline void
168 isofs_normalize_block_and_offset(struct iso_directory_record* de,
169 				 unsigned long *block,
170 				 unsigned long *offset)
171 {
172 	/* Only directories are normalized. */
173 	if (de->flags[0] & 2) {
174 		*offset = 0;
175 		*block = (unsigned long)isonum_733(de->extent)
176 			+ (unsigned long)isonum_711(de->ext_attr_length);
177 	}
178 }
179 
180 extern const struct inode_operations isofs_dir_inode_operations;
181 extern const struct file_operations isofs_dir_operations;
182 extern const struct address_space_operations isofs_symlink_aops;
183 extern const struct export_operations isofs_export_ops;
184