xref: /openbmc/linux/fs/sysv/sysv.h (revision 9cdb81c7)
1 #ifndef _SYSV_H
2 #define _SYSV_H
3 
4 #include <linux/buffer_head.h>
5 
6 typedef __u16 __bitwise __fs16;
7 typedef __u32 __bitwise __fs32;
8 
9 #include <linux/sysv_fs.h>
10 
11 /*
12  * SystemV/V7/Coherent super-block data in memory
13  *
14  * The SystemV/V7/Coherent superblock contains dynamic data (it gets modified
15  * while the system is running). This is in contrast to the Minix and Berkeley
16  * filesystems (where the superblock is never modified). This affects the
17  * sync() operation: we must keep the superblock in a disk buffer and use this
18  * one as our "working copy".
19  */
20 
21 struct sysv_sb_info {
22 	struct super_block *s_sb;	/* VFS superblock */
23 	int	       s_type;		/* file system type: FSTYPE_{XENIX|SYSV|COH} */
24 	char	       s_bytesex;	/* bytesex (le/be/pdp) */
25 	char	       s_truncate;	/* if 1: names > SYSV_NAMELEN chars are truncated */
26 					/* if 0: they are disallowed (ENAMETOOLONG) */
27 	unsigned int   s_inodes_per_block;	/* number of inodes per block */
28 	unsigned int   s_inodes_per_block_1;	/* inodes_per_block - 1 */
29 	unsigned int   s_inodes_per_block_bits;	/* log2(inodes_per_block) */
30 	unsigned int   s_ind_per_block;		/* number of indirections per block */
31 	unsigned int   s_ind_per_block_bits;	/* log2(ind_per_block) */
32 	unsigned int   s_ind_per_block_2;	/* ind_per_block ^ 2 */
33 	unsigned int   s_toobig_block;		/* 10 + ipb + ipb^2 + ipb^3 */
34 	unsigned int   s_block_base;	/* physical block number of block 0 */
35 	unsigned short s_fic_size;	/* free inode cache size, NICINOD */
36 	unsigned short s_flc_size;	/* free block list chunk size, NICFREE */
37 	/* The superblock is kept in one or two disk buffers: */
38 	struct buffer_head *s_bh1;
39 	struct buffer_head *s_bh2;
40 	/* These are pointers into the disk buffer, to compensate for
41 	   different superblock layout. */
42 	char *         s_sbd1;		/* entire superblock data, for part 1 */
43 	char *         s_sbd2;		/* entire superblock data, for part 2 */
44 	__fs16         *s_sb_fic_count;	/* pointer to s_sbd->s_ninode */
45         sysv_ino_t     *s_sb_fic_inodes; /* pointer to s_sbd->s_inode */
46 	__fs16         *s_sb_total_free_inodes; /* pointer to s_sbd->s_tinode */
47 	__fs16         *s_bcache_count;	/* pointer to s_sbd->s_nfree */
48 	sysv_zone_t    *s_bcache;	/* pointer to s_sbd->s_free */
49 	__fs32         *s_free_blocks;	/* pointer to s_sbd->s_tfree */
50 	__fs32         *s_sb_time;	/* pointer to s_sbd->s_time */
51 	__fs32         *s_sb_state;	/* pointer to s_sbd->s_state, only FSTYPE_SYSV */
52 	/* We keep those superblock entities that don't change here;
53 	   this saves us an indirection and perhaps a conversion. */
54 	u32            s_firstinodezone; /* index of first inode zone */
55 	u32            s_firstdatazone;	/* same as s_sbd->s_isize */
56 	u32            s_ninodes;	/* total number of inodes */
57 	u32            s_ndatazones;	/* total number of data zones */
58 	u32            s_nzones;	/* same as s_sbd->s_fsize */
59 	u16	       s_namelen;       /* max length of dir entry */
60 	int	       s_forced_ro;
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 
73 static inline struct sysv_inode_info *SYSV_I(struct inode *inode)
74 {
75 	return list_entry(inode, struct sysv_inode_info, vfs_inode);
76 }
77 
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 
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 	sb->s_dirt = 1;
121 }
122 
123 
124 /* ialloc.c */
125 extern struct sysv_inode *sysv_raw_inode(struct super_block *, unsigned,
126 			struct buffer_head **);
127 extern struct inode * sysv_new_inode(const struct inode *, umode_t);
128 extern void sysv_free_inode(struct inode *);
129 extern unsigned long sysv_count_free_inodes(struct super_block *);
130 
131 /* balloc.c */
132 extern sysv_zone_t sysv_new_block(struct super_block *);
133 extern void sysv_free_block(struct super_block *, sysv_zone_t);
134 extern unsigned long sysv_count_free_blocks(struct super_block *);
135 
136 /* itree.c */
137 extern void sysv_truncate(struct inode *);
138 extern int sysv_prepare_chunk(struct page *page, loff_t pos, unsigned len);
139 
140 /* inode.c */
141 extern struct inode *sysv_iget(struct super_block *, unsigned int);
142 extern int sysv_write_inode(struct inode *, struct writeback_control *wbc);
143 extern int sysv_sync_inode(struct inode *);
144 extern void sysv_set_inode(struct inode *, dev_t);
145 extern int sysv_getattr(struct vfsmount *, struct dentry *, struct kstat *);
146 extern int sysv_init_icache(void);
147 extern void sysv_destroy_icache(void);
148 
149 
150 /* dir.c */
151 extern struct sysv_dir_entry *sysv_find_entry(struct dentry *, struct page **);
152 extern int sysv_add_link(struct dentry *, struct inode *);
153 extern int sysv_delete_entry(struct sysv_dir_entry *, struct page *);
154 extern int sysv_make_empty(struct inode *, struct inode *);
155 extern int sysv_empty_dir(struct inode *);
156 extern void sysv_set_link(struct sysv_dir_entry *, struct page *,
157 			struct inode *);
158 extern struct sysv_dir_entry *sysv_dotdot(struct inode *, struct page **);
159 extern ino_t sysv_inode_by_name(struct dentry *);
160 
161 
162 extern const struct inode_operations sysv_file_inode_operations;
163 extern const struct inode_operations sysv_dir_inode_operations;
164 extern const struct inode_operations sysv_fast_symlink_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 
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 
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 
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 
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 
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 
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 
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