1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _SYSV_H
3 #define _SYSV_H
4 
5 #include <linux/buffer_head.h>
6 
7 typedef __u16 __bitwise __fs16;
8 typedef __u32 __bitwise __fs32;
9 
10 #include <linux/sysv_fs.h>
11 
12 /*
13  * SystemV/V7/Coherent super-block data in memory
14  *
15  * The SystemV/V7/Coherent superblock contains dynamic data (it gets modified
16  * while the system is running). This is in contrast to the Minix and Berkeley
17  * filesystems (where the superblock is never modified). This affects the
18  * sync() operation: we must keep the superblock in a disk buffer and use this
19  * one as our "working copy".
20  */
21 
22 struct sysv_sb_info {
23 	struct super_block *s_sb;	/* VFS superblock */
24 	int	       s_type;		/* file system type: FSTYPE_{XENIX|SYSV|COH} */
25 	char	       s_bytesex;	/* bytesex (le/be/pdp) */
26 	char	       s_truncate;	/* if 1: names > SYSV_NAMELEN chars are truncated */
27 					/* if 0: they are disallowed (ENAMETOOLONG) */
28 	unsigned int   s_inodes_per_block;	/* number of inodes per block */
29 	unsigned int   s_inodes_per_block_1;	/* inodes_per_block - 1 */
30 	unsigned int   s_inodes_per_block_bits;	/* log2(inodes_per_block) */
31 	unsigned int   s_ind_per_block;		/* number of indirections per block */
32 	unsigned int   s_ind_per_block_bits;	/* log2(ind_per_block) */
33 	unsigned int   s_ind_per_block_2;	/* ind_per_block ^ 2 */
34 	unsigned int   s_toobig_block;		/* 10 + ipb + ipb^2 + ipb^3 */
35 	unsigned int   s_block_base;	/* physical block number of block 0 */
36 	unsigned short s_fic_size;	/* free inode cache size, NICINOD */
37 	unsigned short s_flc_size;	/* free block list chunk size, NICFREE */
38 	/* The superblock is kept in one or two disk buffers: */
39 	struct buffer_head *s_bh1;
40 	struct buffer_head *s_bh2;
41 	/* These are pointers into the disk buffer, to compensate for
42 	   different superblock layout. */
43 	char *         s_sbd1;		/* entire superblock data, for part 1 */
44 	char *         s_sbd2;		/* entire superblock data, for part 2 */
45 	__fs16         *s_sb_fic_count;	/* pointer to s_sbd->s_ninode */
46         sysv_ino_t     *s_sb_fic_inodes; /* pointer to s_sbd->s_inode */
47 	__fs16         *s_sb_total_free_inodes; /* pointer to s_sbd->s_tinode */
48 	__fs16         *s_bcache_count;	/* pointer to s_sbd->s_nfree */
49 	sysv_zone_t    *s_bcache;	/* pointer to s_sbd->s_free */
50 	__fs32         *s_free_blocks;	/* pointer to s_sbd->s_tfree */
51 	__fs32         *s_sb_time;	/* pointer to s_sbd->s_time */
52 	__fs32         *s_sb_state;	/* pointer to s_sbd->s_state, only FSTYPE_SYSV */
53 	/* We keep those superblock entities that don't change here;
54 	   this saves us an indirection and perhaps a conversion. */
55 	u32            s_firstinodezone; /* index of first inode zone */
56 	u32            s_firstdatazone;	/* same as s_sbd->s_isize */
57 	u32            s_ninodes;	/* total number of inodes */
58 	u32            s_ndatazones;	/* total number of data zones */
59 	u32            s_nzones;	/* same as s_sbd->s_fsize */
60 	u16	       s_namelen;       /* max length of dir entry */
61 	int	       s_forced_ro;
62 	struct mutex s_lock;
63 };
64 
65 /*
66  * SystemV/V7/Coherent FS inode data in memory
67  */
68 struct sysv_inode_info {
69 	__fs32		i_data[13];
70 	u32		i_dir_start_lookup;
71 	struct inode	vfs_inode;
72 };
73 
74 
SYSV_I(struct inode * inode)75 static inline struct sysv_inode_info *SYSV_I(struct inode *inode)
76 {
77 	return container_of(inode, struct sysv_inode_info, vfs_inode);
78 }
79 
SYSV_SB(struct super_block * sb)80 static inline struct sysv_sb_info *SYSV_SB(struct super_block *sb)
81 {
82 	return sb->s_fs_info;
83 }
84 
85 
86 /* identify the FS in memory */
87 enum {
88 	FSTYPE_NONE = 0,
89 	FSTYPE_XENIX,
90 	FSTYPE_SYSV4,
91 	FSTYPE_SYSV2,
92 	FSTYPE_COH,
93 	FSTYPE_V7,
94 	FSTYPE_AFS,
95 	FSTYPE_END,
96 };
97 
98 #define SYSV_MAGIC_BASE		0x012FF7B3
99 
100 #define XENIX_SUPER_MAGIC	(SYSV_MAGIC_BASE+FSTYPE_XENIX)
101 #define SYSV4_SUPER_MAGIC	(SYSV_MAGIC_BASE+FSTYPE_SYSV4)
102 #define SYSV2_SUPER_MAGIC	(SYSV_MAGIC_BASE+FSTYPE_SYSV2)
103 #define COH_SUPER_MAGIC		(SYSV_MAGIC_BASE+FSTYPE_COH)
104 
105 
106 /* Admissible values for i_nlink: 0.._LINK_MAX */
107 enum {
108 	XENIX_LINK_MAX	=	126,	/* ?? */
109 	SYSV_LINK_MAX	=	126,	/* 127? 251? */
110 	V7_LINK_MAX     =	126,	/* ?? */
111 	COH_LINK_MAX	=	10000,
112 };
113 
114 
dirty_sb(struct super_block * sb)115 static inline void dirty_sb(struct super_block *sb)
116 {
117 	struct sysv_sb_info *sbi = SYSV_SB(sb);
118 
119 	mark_buffer_dirty(sbi->s_bh1);
120 	if (sbi->s_bh1 != sbi->s_bh2)
121 		mark_buffer_dirty(sbi->s_bh2);
122 }
123 
124 
125 /* ialloc.c */
126 extern struct sysv_inode *sysv_raw_inode(struct super_block *, unsigned,
127 			struct buffer_head **);
128 extern struct inode * sysv_new_inode(const struct inode *, umode_t);
129 extern void sysv_free_inode(struct inode *);
130 extern unsigned long sysv_count_free_inodes(struct super_block *);
131 
132 /* balloc.c */
133 extern sysv_zone_t sysv_new_block(struct super_block *);
134 extern void sysv_free_block(struct super_block *, sysv_zone_t);
135 extern unsigned long sysv_count_free_blocks(struct super_block *);
136 
137 /* itree.c */
138 extern void sysv_truncate(struct inode *);
139 extern int sysv_prepare_chunk(struct page *page, loff_t pos, unsigned len);
140 
141 /* inode.c */
142 extern struct inode *sysv_iget(struct super_block *, unsigned int);
143 extern int sysv_write_inode(struct inode *, struct writeback_control *wbc);
144 extern int sysv_sync_inode(struct inode *);
145 extern void sysv_set_inode(struct inode *, dev_t);
146 extern int sysv_getattr(const struct path *, struct kstat *, u32, unsigned int);
147 extern int sysv_init_icache(void);
148 extern void sysv_destroy_icache(void);
149 
150 
151 /* dir.c */
152 extern struct sysv_dir_entry *sysv_find_entry(struct dentry *, struct page **);
153 extern int sysv_add_link(struct dentry *, struct inode *);
154 extern int sysv_delete_entry(struct sysv_dir_entry *, struct page *);
155 extern int sysv_make_empty(struct inode *, struct inode *);
156 extern int sysv_empty_dir(struct inode *);
157 extern void sysv_set_link(struct sysv_dir_entry *, struct page *,
158 			struct inode *);
159 extern struct sysv_dir_entry *sysv_dotdot(struct inode *, struct page **);
160 extern ino_t sysv_inode_by_name(struct dentry *);
161 
162 
163 extern const struct inode_operations sysv_file_inode_operations;
164 extern const struct inode_operations sysv_dir_inode_operations;
165 extern const struct file_operations sysv_file_operations;
166 extern const struct file_operations sysv_dir_operations;
167 extern const struct address_space_operations sysv_aops;
168 extern const struct super_operations sysv_sops;
169 extern const struct dentry_operations sysv_dentry_operations;
170 
171 
172 enum {
173 	BYTESEX_LE,
174 	BYTESEX_PDP,
175 	BYTESEX_BE,
176 };
177 
PDP_swab(u32 x)178 static inline u32 PDP_swab(u32 x)
179 {
180 #ifdef __LITTLE_ENDIAN
181 	return ((x & 0xffff) << 16) | ((x & 0xffff0000) >> 16);
182 #else
183 #ifdef __BIG_ENDIAN
184 	return ((x & 0xff00ff) << 8) | ((x & 0xff00ff00) >> 8);
185 #else
186 #error BYTESEX
187 #endif
188 #endif
189 }
190 
fs32_to_cpu(struct sysv_sb_info * sbi,__fs32 n)191 static inline __u32 fs32_to_cpu(struct sysv_sb_info *sbi, __fs32 n)
192 {
193 	if (sbi->s_bytesex == BYTESEX_PDP)
194 		return PDP_swab((__force __u32)n);
195 	else if (sbi->s_bytesex == BYTESEX_LE)
196 		return le32_to_cpu((__force __le32)n);
197 	else
198 		return be32_to_cpu((__force __be32)n);
199 }
200 
cpu_to_fs32(struct sysv_sb_info * sbi,__u32 n)201 static inline __fs32 cpu_to_fs32(struct sysv_sb_info *sbi, __u32 n)
202 {
203 	if (sbi->s_bytesex == BYTESEX_PDP)
204 		return (__force __fs32)PDP_swab(n);
205 	else if (sbi->s_bytesex == BYTESEX_LE)
206 		return (__force __fs32)cpu_to_le32(n);
207 	else
208 		return (__force __fs32)cpu_to_be32(n);
209 }
210 
fs32_add(struct sysv_sb_info * sbi,__fs32 * n,int d)211 static inline __fs32 fs32_add(struct sysv_sb_info *sbi, __fs32 *n, int d)
212 {
213 	if (sbi->s_bytesex == BYTESEX_PDP)
214 		*(__u32*)n = PDP_swab(PDP_swab(*(__u32*)n)+d);
215 	else if (sbi->s_bytesex == BYTESEX_LE)
216 		le32_add_cpu((__le32 *)n, d);
217 	else
218 		be32_add_cpu((__be32 *)n, d);
219 	return *n;
220 }
221 
fs16_to_cpu(struct sysv_sb_info * sbi,__fs16 n)222 static inline __u16 fs16_to_cpu(struct sysv_sb_info *sbi, __fs16 n)
223 {
224 	if (sbi->s_bytesex != BYTESEX_BE)
225 		return le16_to_cpu((__force __le16)n);
226 	else
227 		return be16_to_cpu((__force __be16)n);
228 }
229 
cpu_to_fs16(struct sysv_sb_info * sbi,__u16 n)230 static inline __fs16 cpu_to_fs16(struct sysv_sb_info *sbi, __u16 n)
231 {
232 	if (sbi->s_bytesex != BYTESEX_BE)
233 		return (__force __fs16)cpu_to_le16(n);
234 	else
235 		return (__force __fs16)cpu_to_be16(n);
236 }
237 
fs16_add(struct sysv_sb_info * sbi,__fs16 * n,int d)238 static inline __fs16 fs16_add(struct sysv_sb_info *sbi, __fs16 *n, int d)
239 {
240 	if (sbi->s_bytesex != BYTESEX_BE)
241 		le16_add_cpu((__le16 *)n, d);
242 	else
243 		be16_add_cpu((__be16 *)n, d);
244 	return *n;
245 }
246 
247 #endif /* _SYSV_H */
248