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 unsigned int s_inodes_per_block; /* number of inodes per block */
27 unsigned int s_inodes_per_block_1; /* inodes_per_block - 1 */
28 unsigned int s_inodes_per_block_bits; /* log2(inodes_per_block) */
29 unsigned int s_ind_per_block; /* number of indirections per block */
30 unsigned int s_ind_per_block_bits; /* log2(ind_per_block) */
31 unsigned int s_ind_per_block_2; /* ind_per_block ^ 2 */
32 unsigned int s_toobig_block; /* 10 + ipb + ipb^2 + ipb^3 */
33 unsigned int s_block_base; /* physical block number of block 0 */
34 unsigned short s_fic_size; /* free inode cache size, NICINOD */
35 unsigned short s_flc_size; /* free block list chunk size, NICFREE */
36 /* The superblock is kept in one or two disk buffers: */
37 struct buffer_head *s_bh1;
38 struct buffer_head *s_bh2;
39 /* These are pointers into the disk buffer, to compensate for
40 different superblock layout. */
41 char * s_sbd1; /* entire superblock data, for part 1 */
42 char * s_sbd2; /* entire superblock data, for part 2 */
43 __fs16 *s_sb_fic_count; /* pointer to s_sbd->s_ninode */
44 sysv_ino_t *s_sb_fic_inodes; /* pointer to s_sbd->s_inode */
45 __fs16 *s_sb_total_free_inodes; /* pointer to s_sbd->s_tinode */
46 __fs16 *s_bcache_count; /* pointer to s_sbd->s_nfree */
47 sysv_zone_t *s_bcache; /* pointer to s_sbd->s_free */
48 __fs32 *s_free_blocks; /* pointer to s_sbd->s_tfree */
49 __fs32 *s_sb_time; /* pointer to s_sbd->s_time */
50 __fs32 *s_sb_state; /* pointer to s_sbd->s_state, only FSTYPE_SYSV */
51 /* We keep those superblock entities that don't change here;
52 this saves us an indirection and perhaps a conversion. */
53 u32 s_firstinodezone; /* index of first inode zone */
54 u32 s_firstdatazone; /* same as s_sbd->s_isize */
55 u32 s_ninodes; /* total number of inodes */
56 u32 s_ndatazones; /* total number of data zones */
57 u32 s_nzones; /* same as s_sbd->s_fsize */
58 u16 s_namelen; /* max length of dir entry */
59 int s_forced_ro;
60 struct mutex s_lock;
61 };
62
63 /*
64 * SystemV/V7/Coherent FS inode data in memory
65 */
66 struct sysv_inode_info {
67 __fs32 i_data[13];
68 u32 i_dir_start_lookup;
69 struct inode vfs_inode;
70 };
71
72
SYSV_I(struct inode * inode)73 static inline struct sysv_inode_info *SYSV_I(struct inode *inode)
74 {
75 return container_of(inode, struct sysv_inode_info, vfs_inode);
76 }
77
SYSV_SB(struct super_block * sb)78 static inline struct sysv_sb_info *SYSV_SB(struct super_block *sb)
79 {
80 return sb->s_fs_info;
81 }
82
83
84 /* identify the FS in memory */
85 enum {
86 FSTYPE_NONE = 0,
87 FSTYPE_XENIX,
88 FSTYPE_SYSV4,
89 FSTYPE_SYSV2,
90 FSTYPE_COH,
91 FSTYPE_V7,
92 FSTYPE_AFS,
93 FSTYPE_END,
94 };
95
96 #define SYSV_MAGIC_BASE 0x012FF7B3
97
98 #define XENIX_SUPER_MAGIC (SYSV_MAGIC_BASE+FSTYPE_XENIX)
99 #define SYSV4_SUPER_MAGIC (SYSV_MAGIC_BASE+FSTYPE_SYSV4)
100 #define SYSV2_SUPER_MAGIC (SYSV_MAGIC_BASE+FSTYPE_SYSV2)
101 #define COH_SUPER_MAGIC (SYSV_MAGIC_BASE+FSTYPE_COH)
102
103
104 /* Admissible values for i_nlink: 0.._LINK_MAX */
105 enum {
106 XENIX_LINK_MAX = 126, /* ?? */
107 SYSV_LINK_MAX = 126, /* 127? 251? */
108 V7_LINK_MAX = 126, /* ?? */
109 COH_LINK_MAX = 10000,
110 };
111
112
dirty_sb(struct super_block * sb)113 static inline void dirty_sb(struct super_block *sb)
114 {
115 struct sysv_sb_info *sbi = SYSV_SB(sb);
116
117 mark_buffer_dirty(sbi->s_bh1);
118 if (sbi->s_bh1 != sbi->s_bh2)
119 mark_buffer_dirty(sbi->s_bh2);
120 }
121
122
123 /* ialloc.c */
124 extern struct sysv_inode *sysv_raw_inode(struct super_block *, unsigned,
125 struct buffer_head **);
126 extern struct inode * sysv_new_inode(const struct inode *, umode_t);
127 extern void sysv_free_inode(struct inode *);
128 extern unsigned long sysv_count_free_inodes(struct super_block *);
129
130 /* balloc.c */
131 extern sysv_zone_t sysv_new_block(struct super_block *);
132 extern void sysv_free_block(struct super_block *, sysv_zone_t);
133 extern unsigned long sysv_count_free_blocks(struct super_block *);
134
135 /* itree.c */
136 extern void sysv_truncate(struct inode *);
137 extern int sysv_prepare_chunk(struct page *page, loff_t pos, unsigned len);
138
139 /* inode.c */
140 extern struct inode *sysv_iget(struct super_block *, unsigned int);
141 extern int sysv_write_inode(struct inode *, struct writeback_control *wbc);
142 extern int sysv_sync_inode(struct inode *);
143 extern void sysv_set_inode(struct inode *, dev_t);
144 extern int sysv_getattr(const struct path *, struct kstat *, u32, unsigned int);
145 extern int sysv_init_icache(void);
146 extern void sysv_destroy_icache(void);
147
148
149 /* dir.c */
150 extern struct sysv_dir_entry *sysv_find_entry(struct dentry *, struct page **);
151 extern int sysv_add_link(struct dentry *, struct inode *);
152 extern int sysv_delete_entry(struct sysv_dir_entry *, struct page *);
153 extern int sysv_make_empty(struct inode *, struct inode *);
154 extern int sysv_empty_dir(struct inode *);
155 extern void sysv_set_link(struct sysv_dir_entry *, struct page *,
156 struct inode *);
157 extern struct sysv_dir_entry *sysv_dotdot(struct inode *, struct page **);
158 extern ino_t sysv_inode_by_name(struct dentry *);
159
160
161 extern const struct inode_operations sysv_file_inode_operations;
162 extern const struct inode_operations sysv_dir_inode_operations;
163 extern const struct file_operations sysv_file_operations;
164 extern const struct file_operations sysv_dir_operations;
165 extern const struct address_space_operations sysv_aops;
166 extern const struct super_operations sysv_sops;
167
168
169 enum {
170 BYTESEX_LE,
171 BYTESEX_PDP,
172 BYTESEX_BE,
173 };
174
PDP_swab(u32 x)175 static inline u32 PDP_swab(u32 x)
176 {
177 #ifdef __LITTLE_ENDIAN
178 return ((x & 0xffff) << 16) | ((x & 0xffff0000) >> 16);
179 #else
180 #ifdef __BIG_ENDIAN
181 return ((x & 0xff00ff) << 8) | ((x & 0xff00ff00) >> 8);
182 #else
183 #error BYTESEX
184 #endif
185 #endif
186 }
187
fs32_to_cpu(struct sysv_sb_info * sbi,__fs32 n)188 static inline __u32 fs32_to_cpu(struct sysv_sb_info *sbi, __fs32 n)
189 {
190 if (sbi->s_bytesex == BYTESEX_PDP)
191 return PDP_swab((__force __u32)n);
192 else if (sbi->s_bytesex == BYTESEX_LE)
193 return le32_to_cpu((__force __le32)n);
194 else
195 return be32_to_cpu((__force __be32)n);
196 }
197
cpu_to_fs32(struct sysv_sb_info * sbi,__u32 n)198 static inline __fs32 cpu_to_fs32(struct sysv_sb_info *sbi, __u32 n)
199 {
200 if (sbi->s_bytesex == BYTESEX_PDP)
201 return (__force __fs32)PDP_swab(n);
202 else if (sbi->s_bytesex == BYTESEX_LE)
203 return (__force __fs32)cpu_to_le32(n);
204 else
205 return (__force __fs32)cpu_to_be32(n);
206 }
207
fs32_add(struct sysv_sb_info * sbi,__fs32 * n,int d)208 static inline __fs32 fs32_add(struct sysv_sb_info *sbi, __fs32 *n, int d)
209 {
210 if (sbi->s_bytesex == BYTESEX_PDP)
211 *(__u32*)n = PDP_swab(PDP_swab(*(__u32*)n)+d);
212 else if (sbi->s_bytesex == BYTESEX_LE)
213 le32_add_cpu((__le32 *)n, d);
214 else
215 be32_add_cpu((__be32 *)n, d);
216 return *n;
217 }
218
fs16_to_cpu(struct sysv_sb_info * sbi,__fs16 n)219 static inline __u16 fs16_to_cpu(struct sysv_sb_info *sbi, __fs16 n)
220 {
221 if (sbi->s_bytesex != BYTESEX_BE)
222 return le16_to_cpu((__force __le16)n);
223 else
224 return be16_to_cpu((__force __be16)n);
225 }
226
cpu_to_fs16(struct sysv_sb_info * sbi,__u16 n)227 static inline __fs16 cpu_to_fs16(struct sysv_sb_info *sbi, __u16 n)
228 {
229 if (sbi->s_bytesex != BYTESEX_BE)
230 return (__force __fs16)cpu_to_le16(n);
231 else
232 return (__force __fs16)cpu_to_be16(n);
233 }
234
fs16_add(struct sysv_sb_info * sbi,__fs16 * n,int d)235 static inline __fs16 fs16_add(struct sysv_sb_info *sbi, __fs16 *n, int d)
236 {
237 if (sbi->s_bytesex != BYTESEX_BE)
238 le16_add_cpu((__le16 *)n, d);
239 else
240 be16_add_cpu((__be16 *)n, d);
241 return *n;
242 }
243
244 #endif /* _SYSV_H */
245
