1 /* SPDX-License-Identifier: GPL-2.0 */
2 #include <linux/fs.h>
3 #include <linux/adfs_fs.h>
4 
5 /* Internal data structures for ADFS */
6 
7 #define ADFS_FREE_FRAG		 0
8 #define ADFS_BAD_FRAG		 1
9 #define ADFS_ROOT_FRAG		 2
10 
11 #define ADFS_NDA_OWNER_READ	(1 << 0)
12 #define ADFS_NDA_OWNER_WRITE	(1 << 1)
13 #define ADFS_NDA_LOCKED		(1 << 2)
14 #define ADFS_NDA_DIRECTORY	(1 << 3)
15 #define ADFS_NDA_EXECUTE	(1 << 4)
16 #define ADFS_NDA_PUBLIC_READ	(1 << 5)
17 #define ADFS_NDA_PUBLIC_WRITE	(1 << 6)
18 
19 #include "dir_f.h"
20 
21 struct buffer_head;
22 
23 /*
24  * adfs file system inode data in memory
25  */
26 struct adfs_inode_info {
27 	loff_t		mmu_private;
28 	unsigned long	parent_id;	/* object id of parent		*/
29 	__u32		loadaddr;	/* RISC OS load address		*/
30 	__u32		execaddr;	/* RISC OS exec address		*/
31 	unsigned int	filetype;	/* RISC OS file type		*/
32 	unsigned int	attr;		/* RISC OS permissions		*/
33 	unsigned int	stamped:1;	/* RISC OS file has date/time	*/
34 	struct inode vfs_inode;
35 };
36 
37 /*
38  * Forward-declare this
39  */
40 struct adfs_discmap;
41 struct adfs_dir_ops;
42 
43 /*
44  * ADFS file system superblock data in memory
45  */
46 struct adfs_sb_info {
47 	union { struct {
48 		struct adfs_discmap *s_map;	/* bh list containing map */
49 		const struct adfs_dir_ops *s_dir; /* directory operations */
50 		};
51 		struct rcu_head rcu;	/* used only at shutdown time	 */
52 	};
53 	kuid_t		s_uid;		/* owner uid */
54 	kgid_t		s_gid;		/* owner gid */
55 	umode_t		s_owner_mask;	/* ADFS owner perm -> unix perm */
56 	umode_t		s_other_mask;	/* ADFS other perm -> unix perm	*/
57 	int		s_ftsuffix;	/* ,xyz hex filetype suffix option */
58 
59 	__u32		s_ids_per_zone;	/* max. no ids in one zone */
60 	__u32		s_idlen;	/* length of ID in map */
61 	__u32		s_map_size;	/* sector size of a map	*/
62 	unsigned long	s_size;		/* total size (in blocks) of this fs */
63 	signed int	s_map2blk;	/* shift left by this for map->sector*/
64 	unsigned int	s_log2sharesize;/* log2 share size */
65 	__le32		s_version;	/* disc format version */
66 	unsigned int	s_namelen;	/* maximum number of characters in name	 */
67 };
68 
ADFS_SB(struct super_block * sb)69 static inline struct adfs_sb_info *ADFS_SB(struct super_block *sb)
70 {
71 	return sb->s_fs_info;
72 }
73 
ADFS_I(struct inode * inode)74 static inline struct adfs_inode_info *ADFS_I(struct inode *inode)
75 {
76 	return container_of(inode, struct adfs_inode_info, vfs_inode);
77 }
78 
79 /*
80  * Directory handling
81  */
82 struct adfs_dir {
83 	struct super_block	*sb;
84 
85 	int			nr_buffers;
86 	struct buffer_head	*bh[4];
87 
88 	/* big directories need allocated buffers */
89 	struct buffer_head	**bh_fplus;
90 
91 	unsigned int		pos;
92 	unsigned int		parent_id;
93 
94 	struct adfs_dirheader	dirhead;
95 	union  adfs_dirtail	dirtail;
96 };
97 
98 /*
99  * This is the overall maximum name length
100  */
101 #define ADFS_MAX_NAME_LEN	(256 + 4) /* +4 for ,xyz hex filetype suffix */
102 struct object_info {
103 	__u32		parent_id;		/* parent object id	*/
104 	__u32		file_id;		/* object id		*/
105 	__u32		loadaddr;		/* load address		*/
106 	__u32		execaddr;		/* execution address	*/
107 	__u32		size;			/* size			*/
108 	__u8		attr;			/* RISC OS attributes	*/
109 	unsigned int	name_len;		/* name length		*/
110 	char		name[ADFS_MAX_NAME_LEN];/* file name		*/
111 
112 	/* RISC OS file type (12-bit: derived from loadaddr) */
113 	__u16		filetype;
114 };
115 
116 /* RISC OS 12-bit filetype converts to ,xyz hex filename suffix */
append_filetype_suffix(char * buf,__u16 filetype)117 static inline int append_filetype_suffix(char *buf, __u16 filetype)
118 {
119 	if (filetype == 0xffff)	/* no explicit 12-bit file type was set */
120 		return 0;
121 
122 	*buf++ = ',';
123 	*buf++ = hex_asc_lo(filetype >> 8);
124 	*buf++ = hex_asc_lo(filetype >> 4);
125 	*buf++ = hex_asc_lo(filetype >> 0);
126 	return 4;
127 }
128 
129 struct adfs_dir_ops {
130 	int	(*read)(struct super_block *sb, unsigned int id, unsigned int sz, struct adfs_dir *dir);
131 	int	(*setpos)(struct adfs_dir *dir, unsigned int fpos);
132 	int	(*getnext)(struct adfs_dir *dir, struct object_info *obj);
133 	int	(*update)(struct adfs_dir *dir, struct object_info *obj);
134 	int	(*create)(struct adfs_dir *dir, struct object_info *obj);
135 	int	(*remove)(struct adfs_dir *dir, struct object_info *obj);
136 	int	(*sync)(struct adfs_dir *dir);
137 	void	(*free)(struct adfs_dir *dir);
138 };
139 
140 struct adfs_discmap {
141 	struct buffer_head	*dm_bh;
142 	__u32			dm_startblk;
143 	unsigned int		dm_startbit;
144 	unsigned int		dm_endbit;
145 };
146 
147 /* Inode stuff */
148 struct inode *adfs_iget(struct super_block *sb, struct object_info *obj);
149 int adfs_write_inode(struct inode *inode, struct writeback_control *wbc);
150 int adfs_notify_change(struct dentry *dentry, struct iattr *attr);
151 
152 /* map.c */
153 extern int adfs_map_lookup(struct super_block *sb, unsigned int frag_id, unsigned int offset);
154 extern unsigned int adfs_map_free(struct super_block *sb);
155 
156 /* Misc */
157 __printf(3, 4)
158 void __adfs_error(struct super_block *sb, const char *function,
159 		  const char *fmt, ...);
160 #define adfs_error(sb, fmt...) __adfs_error(sb, __func__, fmt)
161 
162 /* super.c */
163 
164 /*
165  * Inodes and file operations
166  */
167 
168 /* dir_*.c */
169 extern const struct inode_operations adfs_dir_inode_operations;
170 extern const struct file_operations adfs_dir_operations;
171 extern const struct dentry_operations adfs_dentry_operations;
172 extern const struct adfs_dir_ops adfs_f_dir_ops;
173 extern const struct adfs_dir_ops adfs_fplus_dir_ops;
174 
175 extern int adfs_dir_update(struct super_block *sb, struct object_info *obj,
176 			   int wait);
177 
178 /* file.c */
179 extern const struct inode_operations adfs_file_inode_operations;
180 extern const struct file_operations adfs_file_operations;
181 
signed_asl(__u32 val,signed int shift)182 static inline __u32 signed_asl(__u32 val, signed int shift)
183 {
184 	if (shift >= 0)
185 		val <<= shift;
186 	else
187 		val >>= -shift;
188 	return val;
189 }
190 
191 /*
192  * Calculate the address of a block in an object given the block offset
193  * and the object identity.
194  *
195  * The root directory ID should always be looked up in the map [3.4]
196  */
197 static inline int
__adfs_block_map(struct super_block * sb,unsigned int object_id,unsigned int block)198 __adfs_block_map(struct super_block *sb, unsigned int object_id,
199 		 unsigned int block)
200 {
201 	if (object_id & 255) {
202 		unsigned int off;
203 
204 		off = (object_id & 255) - 1;
205 		block += off << ADFS_SB(sb)->s_log2sharesize;
206 	}
207 
208 	return adfs_map_lookup(sb, object_id >> 8, block);
209 }
210