xref: /openbmc/linux/fs/isofs/isofs.h (revision 7211ec63)
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 	s32           s_sbsector;
40 	unsigned char s_joliet_level;
41 	unsigned char s_mapping;
42 	unsigned char s_check;
43 	unsigned char s_session;
44 	unsigned int  s_high_sierra:1;
45 	unsigned int  s_rock:2;
46 	unsigned int  s_utf8:1;
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 
65 static inline struct isofs_sb_info *ISOFS_SB(struct super_block *sb)
66 {
67 	return sb->s_fs_info;
68 }
69 
70 static inline struct iso_inode_info *ISOFS_I(struct inode *inode)
71 {
72 	return container_of(inode, struct iso_inode_info, vfs_inode);
73 }
74 
75 static inline int isonum_711(char *p)
76 {
77 	return *(u8 *)p;
78 }
79 static inline int isonum_712(char *p)
80 {
81 	return *(s8 *)p;
82 }
83 static inline unsigned int isonum_721(char *p)
84 {
85 	return get_unaligned_le16(p);
86 }
87 static inline unsigned int isonum_722(char *p)
88 {
89 	return get_unaligned_be16(p);
90 }
91 static inline unsigned int isonum_723(char *p)
92 {
93 	/* Ignore bigendian datum due to broken mastering programs */
94 	return get_unaligned_le16(p);
95 }
96 static inline unsigned int isonum_731(char *p)
97 {
98 	return get_unaligned_le32(p);
99 }
100 static inline unsigned int isonum_732(char *p)
101 {
102 	return get_unaligned_be32(p);
103 }
104 static inline unsigned int isonum_733(char *p)
105 {
106 	/* Ignore bigendian datum due to broken mastering programs */
107 	return get_unaligned_le32(p);
108 }
109 extern int iso_date(char *, int);
110 
111 struct inode;		/* To make gcc happy */
112 
113 extern int parse_rock_ridge_inode(struct iso_directory_record *, struct inode *, int relocated);
114 extern int get_rock_ridge_filename(struct iso_directory_record *, char *, struct inode *);
115 extern int isofs_name_translate(struct iso_directory_record *, char *, struct inode *);
116 
117 int get_joliet_filename(struct iso_directory_record *, unsigned char *, struct inode *);
118 int get_acorn_filename(struct iso_directory_record *, char *, struct inode *);
119 
120 extern struct dentry *isofs_lookup(struct inode *, struct dentry *, unsigned int flags);
121 extern struct buffer_head *isofs_bread(struct inode *, sector_t);
122 extern int isofs_get_blocks(struct inode *, sector_t, struct buffer_head **, unsigned long);
123 
124 struct inode *__isofs_iget(struct super_block *sb,
125 			   unsigned long block,
126 			   unsigned long offset,
127 			   int relocated);
128 
129 static inline struct inode *isofs_iget(struct super_block *sb,
130 				       unsigned long block,
131 				       unsigned long offset)
132 {
133 	return __isofs_iget(sb, block, offset, 0);
134 }
135 
136 static inline struct inode *isofs_iget_reloc(struct super_block *sb,
137 					     unsigned long block,
138 					     unsigned long offset)
139 {
140 	return __isofs_iget(sb, block, offset, 1);
141 }
142 
143 /* Because the inode number is no longer relevant to finding the
144  * underlying meta-data for an inode, we are free to choose a more
145  * convenient 32-bit number as the inode number.  The inode numbering
146  * scheme was recommended by Sergey Vlasov and Eric Lammerts. */
147 static inline unsigned long isofs_get_ino(unsigned long block,
148 					  unsigned long offset,
149 					  unsigned long bufbits)
150 {
151 	return (block << (bufbits - 5)) | (offset >> 5);
152 }
153 
154 /* Every directory can have many redundant directory entries scattered
155  * throughout the directory tree.  First there is the directory entry
156  * with the name of the directory stored in the parent directory.
157  * Then, there is the "." directory entry stored in the directory
158  * itself.  Finally, there are possibly many ".." directory entries
159  * stored in all the subdirectories.
160  *
161  * In order for the NFS get_parent() method to work and for the
162  * general consistency of the dcache, we need to make sure the
163  * "i_iget5_block" and "i_iget5_offset" all point to exactly one of
164  * the many redundant entries for each directory.  We normalize the
165  * block and offset by always making them point to the "."  directory.
166  *
167  * Notice that we do not use the entry for the directory with the name
168  * that is located in the parent directory.  Even though choosing this
169  * first directory is more natural, it is much easier to find the "."
170  * entry in the NFS get_parent() method because it is implicitly
171  * encoded in the "extent + ext_attr_length" fields of _all_ the
172  * redundant entries for the directory.  Thus, it can always be
173  * reached regardless of which directory entry you have in hand.
174  *
175  * This works because the "." entry is simply the first directory
176  * record when you start reading the file that holds all the directory
177  * records, and this file starts at "extent + ext_attr_length" blocks.
178  * Because the "." entry is always the first entry listed in the
179  * directories file, the normalized "offset" value is always 0.
180  *
181  * You should pass the directory entry in "de".  On return, "block"
182  * and "offset" will hold normalized values.  Only directories are
183  * affected making it safe to call even for non-directory file
184  * types. */
185 static inline void
186 isofs_normalize_block_and_offset(struct iso_directory_record* de,
187 				 unsigned long *block,
188 				 unsigned long *offset)
189 {
190 	/* Only directories are normalized. */
191 	if (de->flags[0] & 2) {
192 		*offset = 0;
193 		*block = (unsigned long)isonum_733(de->extent)
194 			+ (unsigned long)isonum_711(de->ext_attr_length);
195 	}
196 }
197 
198 extern const struct inode_operations isofs_dir_inode_operations;
199 extern const struct file_operations isofs_dir_operations;
200 extern const struct address_space_operations isofs_symlink_aops;
201 extern const struct export_operations isofs_export_ops;
202