1/* SPDX-License-Identifier: GPL-2.0 */
2#include <linux/buffer_head.h>
3#include <linux/fs.h>
4#include <linux/adfs_fs.h>
5
6/* Internal data structures for ADFS */
7
8#define ADFS_FREE_FRAG		 0
9#define ADFS_BAD_FRAG		 1
10#define ADFS_ROOT_FRAG		 2
11
12#define ADFS_FILETYPE_NONE	((u16)~0)
13
14/* RISC OS 12-bit filetype is stored in load_address[19:8] */
15static inline u16 adfs_filetype(u32 loadaddr)
16{
17	return (loadaddr & 0xfff00000) == 0xfff00000 ?
18	       (loadaddr >> 8) & 0xfff : ADFS_FILETYPE_NONE;
19}
20
21#define ADFS_NDA_OWNER_READ	(1 << 0)
22#define ADFS_NDA_OWNER_WRITE	(1 << 1)
23#define ADFS_NDA_LOCKED		(1 << 2)
24#define ADFS_NDA_DIRECTORY	(1 << 3)
25#define ADFS_NDA_EXECUTE	(1 << 4)
26#define ADFS_NDA_PUBLIC_READ	(1 << 5)
27#define ADFS_NDA_PUBLIC_WRITE	(1 << 6)
28
29/*
30 * adfs file system inode data in memory
31 */
32struct adfs_inode_info {
33	loff_t		mmu_private;
34	__u32		parent_id;	/* parent indirect disc address	*/
35	__u32		indaddr;	/* object indirect disc address	*/
36	__u32		loadaddr;	/* RISC OS load address		*/
37	__u32		execaddr;	/* RISC OS exec address		*/
38	unsigned int	attr;		/* RISC OS permissions		*/
39	struct inode vfs_inode;
40};
41
42static inline struct adfs_inode_info *ADFS_I(struct inode *inode)
43{
44	return container_of(inode, struct adfs_inode_info, vfs_inode);
45}
46
47static inline bool adfs_inode_is_stamped(struct inode *inode)
48{
49	return (ADFS_I(inode)->loadaddr & 0xfff00000) == 0xfff00000;
50}
51
52/*
53 * Forward-declare this
54 */
55struct adfs_discmap;
56struct adfs_dir_ops;
57
58/*
59 * ADFS file system superblock data in memory
60 */
61struct adfs_sb_info {
62	union { struct {
63		struct adfs_discmap *s_map;	/* bh list containing map */
64		const struct adfs_dir_ops *s_dir; /* directory operations */
65		};
66		struct rcu_head rcu;	/* used only at shutdown time	 */
67	};
68	kuid_t		s_uid;		/* owner uid */
69	kgid_t		s_gid;		/* owner gid */
70	umode_t		s_owner_mask;	/* ADFS owner perm -> unix perm */
71	umode_t		s_other_mask;	/* ADFS other perm -> unix perm	*/
72	int		s_ftsuffix;	/* ,xyz hex filetype suffix option */
73
74	__u32		s_ids_per_zone;	/* max. no ids in one zone */
75	__u32		s_idlen;	/* length of ID in map */
76	__u32		s_map_size;	/* sector size of a map	*/
77	signed int	s_map2blk;	/* shift left by this for map->sector*/
78	unsigned int	s_log2sharesize;/* log2 share size */
79	unsigned int	s_namelen;	/* maximum number of characters in name	 */
80};
81
82static inline struct adfs_sb_info *ADFS_SB(struct super_block *sb)
83{
84	return sb->s_fs_info;
85}
86
87/*
88 * Directory handling
89 */
90struct adfs_dir {
91	struct super_block	*sb;
92
93	int			nr_buffers;
94	struct buffer_head	*bh[4];
95	struct buffer_head	**bhs;
96
97	unsigned int		pos;
98	__u32			parent_id;
99
100	union {
101		struct adfs_dirheader	*dirhead;
102		struct adfs_bigdirheader *bighead;
103	};
104	union {
105		struct adfs_newdirtail	*newtail;
106		struct adfs_bigdirtail	*bigtail;
107	};
108};
109
110/*
111 * This is the overall maximum name length
112 */
113#define ADFS_MAX_NAME_LEN	(256 + 4) /* +4 for ,xyz hex filetype suffix */
114struct object_info {
115	__u32		parent_id;		/* parent object id	*/
116	__u32		indaddr;		/* indirect disc addr	*/
117	__u32		loadaddr;		/* load address		*/
118	__u32		execaddr;		/* execution address	*/
119	__u32		size;			/* size			*/
120	__u8		attr;			/* RISC OS attributes	*/
121	unsigned int	name_len;		/* name length		*/
122	char		name[ADFS_MAX_NAME_LEN];/* file name		*/
123};
124
125struct adfs_dir_ops {
126	int	(*read)(struct super_block *sb, unsigned int indaddr,
127			unsigned int size, struct adfs_dir *dir);
128	int	(*iterate)(struct adfs_dir *dir, struct dir_context *ctx);
129	int	(*setpos)(struct adfs_dir *dir, unsigned int fpos);
130	int	(*getnext)(struct adfs_dir *dir, struct object_info *obj);
131	int	(*update)(struct adfs_dir *dir, struct object_info *obj);
132	int	(*create)(struct adfs_dir *dir, struct object_info *obj);
133	int	(*remove)(struct adfs_dir *dir, struct object_info *obj);
134	int	(*commit)(struct adfs_dir *dir);
135};
136
137struct adfs_discmap {
138	struct buffer_head	*dm_bh;
139	__u32			dm_startblk;
140	unsigned int		dm_startbit;
141	unsigned int		dm_endbit;
142};
143
144/* Inode stuff */
145struct inode *adfs_iget(struct super_block *sb, struct object_info *obj);
146int adfs_write_inode(struct inode *inode, struct writeback_control *wbc);
147int adfs_notify_change(struct mnt_idmap *idmap, struct dentry *dentry,
148		       struct iattr *attr);
149
150/* map.c */
151int adfs_map_lookup(struct super_block *sb, u32 frag_id, unsigned int offset);
152void adfs_map_statfs(struct super_block *sb, struct kstatfs *buf);
153struct adfs_discmap *adfs_read_map(struct super_block *sb, struct adfs_discrecord *dr);
154void adfs_free_map(struct super_block *sb);
155
156/* Misc */
157__printf(3, 4)
158void __adfs_error(struct super_block *sb, const char *function,
159		  const char *fmt, ...);
160#define adfs_error(sb, fmt...) __adfs_error(sb, __func__, fmt)
161void adfs_msg(struct super_block *sb, const char *pfx, const char *fmt, ...);
162
163/* super.c */
164
165/*
166 * Inodes and file operations
167 */
168
169/* dir_*.c */
170extern const struct inode_operations adfs_dir_inode_operations;
171extern const struct file_operations adfs_dir_operations;
172extern const struct dentry_operations adfs_dentry_operations;
173extern const struct adfs_dir_ops adfs_f_dir_ops;
174extern const struct adfs_dir_ops adfs_fplus_dir_ops;
175
176int adfs_dir_copyfrom(void *dst, struct adfs_dir *dir, unsigned int offset,
177		      size_t len);
178int adfs_dir_copyto(struct adfs_dir *dir, unsigned int offset, const void *src,
179		    size_t len);
180void adfs_dir_relse(struct adfs_dir *dir);
181int adfs_dir_read_buffers(struct super_block *sb, u32 indaddr,
182			  unsigned int size, struct adfs_dir *dir);
183void adfs_object_fixup(struct adfs_dir *dir, struct object_info *obj);
184extern int adfs_dir_update(struct super_block *sb, struct object_info *obj,
185			   int wait);
186
187/* file.c */
188extern const struct inode_operations adfs_file_inode_operations;
189extern const struct file_operations adfs_file_operations;
190
191static inline __u32 signed_asl(__u32 val, signed int shift)
192{
193	if (shift >= 0)
194		val <<= shift;
195	else
196		val >>= -shift;
197	return val;
198}
199
200/*
201 * Calculate the address of a block in an object given the block offset
202 * and the object identity.
203 *
204 * The root directory ID should always be looked up in the map [3.4]
205 */
206static inline int __adfs_block_map(struct super_block *sb, u32 indaddr,
207				   unsigned int block)
208{
209	if (indaddr & 255) {
210		unsigned int off;
211
212		off = (indaddr & 255) - 1;
213		block += off << ADFS_SB(sb)->s_log2sharesize;
214	}
215
216	return adfs_map_lookup(sb, indaddr >> 8, block);
217}
218
219/* Return the disc record from the map */
220static inline
221struct adfs_discrecord *adfs_map_discrecord(struct adfs_discmap *dm)
222{
223	return (void *)(dm[0].dm_bh->b_data + 4);
224}
225
226static inline u64 adfs_disc_size(const struct adfs_discrecord *dr)
227{
228	return (u64)le32_to_cpu(dr->disc_size_high) << 32 |
229		    le32_to_cpu(dr->disc_size);
230}
231