1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef FS_MINIX_H
3 #define FS_MINIX_H
4 
5 #include <linux/fs.h>
6 #include <linux/pagemap.h>
7 #include <linux/minix_fs.h>
8 
9 #define INODE_VERSION(inode)	minix_sb(inode->i_sb)->s_version
10 #define MINIX_V1		0x0001		/* original minix fs */
11 #define MINIX_V2		0x0002		/* minix V2 fs */
12 #define MINIX_V3		0x0003		/* minix V3 fs */
13 
14 /*
15  * minix fs inode data in memory
16  */
17 struct minix_inode_info {
18 	union {
19 		__u16 i1_data[16];
20 		__u32 i2_data[16];
21 	} u;
22 	struct inode vfs_inode;
23 };
24 
25 /*
26  * minix super-block data in memory
27  */
28 struct minix_sb_info {
29 	unsigned long s_ninodes;
30 	unsigned long s_nzones;
31 	unsigned long s_imap_blocks;
32 	unsigned long s_zmap_blocks;
33 	unsigned long s_firstdatazone;
34 	unsigned long s_log_zone_size;
35 	unsigned long s_max_size;
36 	int s_dirsize;
37 	int s_namelen;
38 	struct buffer_head ** s_imap;
39 	struct buffer_head ** s_zmap;
40 	struct buffer_head * s_sbh;
41 	struct minix_super_block * s_ms;
42 	unsigned short s_mount_state;
43 	unsigned short s_version;
44 };
45 
46 extern struct inode *minix_iget(struct super_block *, unsigned long);
47 extern struct minix_inode * minix_V1_raw_inode(struct super_block *, ino_t, struct buffer_head **);
48 extern struct minix2_inode * minix_V2_raw_inode(struct super_block *, ino_t, struct buffer_head **);
49 extern struct inode * minix_new_inode(const struct inode *, umode_t, int *);
50 extern void minix_free_inode(struct inode * inode);
51 extern unsigned long minix_count_free_inodes(struct super_block *sb);
52 extern int minix_new_block(struct inode * inode);
53 extern void minix_free_block(struct inode *inode, unsigned long block);
54 extern unsigned long minix_count_free_blocks(struct super_block *sb);
55 extern int minix_getattr(const struct path *, struct kstat *, u32, unsigned int);
56 extern int minix_prepare_chunk(struct page *page, loff_t pos, unsigned len);
57 
58 extern void V1_minix_truncate(struct inode *);
59 extern void V2_minix_truncate(struct inode *);
60 extern void minix_truncate(struct inode *);
61 extern void minix_set_inode(struct inode *, dev_t);
62 extern int V1_minix_get_block(struct inode *, long, struct buffer_head *, int);
63 extern int V2_minix_get_block(struct inode *, long, struct buffer_head *, int);
64 extern unsigned V1_minix_blocks(loff_t, struct super_block *);
65 extern unsigned V2_minix_blocks(loff_t, struct super_block *);
66 
67 extern struct minix_dir_entry *minix_find_entry(struct dentry*, struct page**);
68 extern int minix_add_link(struct dentry*, struct inode*);
69 extern int minix_delete_entry(struct minix_dir_entry*, struct page*);
70 extern int minix_make_empty(struct inode*, struct inode*);
71 extern int minix_empty_dir(struct inode*);
72 extern void minix_set_link(struct minix_dir_entry*, struct page*, struct inode*);
73 extern struct minix_dir_entry *minix_dotdot(struct inode*, struct page**);
74 extern ino_t minix_inode_by_name(struct dentry*);
75 
76 extern const struct inode_operations minix_file_inode_operations;
77 extern const struct inode_operations minix_dir_inode_operations;
78 extern const struct file_operations minix_file_operations;
79 extern const struct file_operations minix_dir_operations;
80 
minix_sb(struct super_block * sb)81 static inline struct minix_sb_info *minix_sb(struct super_block *sb)
82 {
83 	return sb->s_fs_info;
84 }
85 
minix_i(struct inode * inode)86 static inline struct minix_inode_info *minix_i(struct inode *inode)
87 {
88 	return container_of(inode, struct minix_inode_info, vfs_inode);
89 }
90 
minix_blocks_needed(unsigned bits,unsigned blocksize)91 static inline unsigned minix_blocks_needed(unsigned bits, unsigned blocksize)
92 {
93 	return DIV_ROUND_UP(bits, blocksize * 8);
94 }
95 
96 #if defined(CONFIG_MINIX_FS_NATIVE_ENDIAN) && \
97 	defined(CONFIG_MINIX_FS_BIG_ENDIAN_16BIT_INDEXED)
98 
99 #error Minix file system byte order broken
100 
101 #elif defined(CONFIG_MINIX_FS_NATIVE_ENDIAN)
102 
103 /*
104  * big-endian 32 or 64 bit indexed bitmaps on big-endian system or
105  * little-endian bitmaps on little-endian system
106  */
107 
108 #define minix_test_and_set_bit(nr, addr)	\
109 	__test_and_set_bit((nr), (unsigned long *)(addr))
110 #define minix_set_bit(nr, addr)		\
111 	__set_bit((nr), (unsigned long *)(addr))
112 #define minix_test_and_clear_bit(nr, addr) \
113 	__test_and_clear_bit((nr), (unsigned long *)(addr))
114 #define minix_test_bit(nr, addr)		\
115 	test_bit((nr), (unsigned long *)(addr))
116 #define minix_find_first_zero_bit(addr, size) \
117 	find_first_zero_bit((unsigned long *)(addr), (size))
118 
119 #elif defined(CONFIG_MINIX_FS_BIG_ENDIAN_16BIT_INDEXED)
120 
121 /*
122  * big-endian 16bit indexed bitmaps
123  */
124 
minix_find_first_zero_bit(const void * vaddr,unsigned size)125 static inline int minix_find_first_zero_bit(const void *vaddr, unsigned size)
126 {
127 	const unsigned short *p = vaddr, *addr = vaddr;
128 	unsigned short num;
129 
130 	if (!size)
131 		return 0;
132 
133 	size >>= 4;
134 	while (*p++ == 0xffff) {
135 		if (--size == 0)
136 			return (p - addr) << 4;
137 	}
138 
139 	num = *--p;
140 	return ((p - addr) << 4) + ffz(num);
141 }
142 
143 #define minix_test_and_set_bit(nr, addr)	\
144 	__test_and_set_bit((nr) ^ 16, (unsigned long *)(addr))
145 #define minix_set_bit(nr, addr)	\
146 	__set_bit((nr) ^ 16, (unsigned long *)(addr))
147 #define minix_test_and_clear_bit(nr, addr)	\
148 	__test_and_clear_bit((nr) ^ 16, (unsigned long *)(addr))
149 
minix_test_bit(int nr,const void * vaddr)150 static inline int minix_test_bit(int nr, const void *vaddr)
151 {
152 	const unsigned short *p = vaddr;
153 	return (p[nr >> 4] & (1U << (nr & 15))) != 0;
154 }
155 
156 #else
157 
158 /*
159  * little-endian bitmaps
160  */
161 
162 #define minix_test_and_set_bit	__test_and_set_bit_le
163 #define minix_set_bit		__set_bit_le
164 #define minix_test_and_clear_bit	__test_and_clear_bit_le
165 #define minix_test_bit	test_bit_le
166 #define minix_find_first_zero_bit	find_first_zero_bit_le
167 
168 #endif
169 
170 #endif /* FS_MINIX_H */
171