Linux Kernel  3.7.1
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sysv.h
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1 #ifndef _SYSV_H
2 #define _SYSV_H
3 
4 #include <linux/buffer_head.h>
5 
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 */
61  struct mutex s_lock;
62 };
63 
64 /*
65  * SystemV/V7/Coherent FS inode data in memory
66  */
70  struct inode vfs_inode;
71 };
72 
73 
74 static inline struct sysv_inode_info *SYSV_I(struct inode *inode)
75 {
76  return list_entry(inode, struct sysv_inode_info, vfs_inode);
77 }
78 
79 static inline struct sysv_sb_info *SYSV_SB(struct super_block *sb)
80 {
81  return sb->s_fs_info;
82 }
83 
84 
85 /* identify the FS in memory */
86 enum {
95 };
96 
97 #define SYSV_MAGIC_BASE 0x012FF7B3
98 
99 #define XENIX_SUPER_MAGIC (SYSV_MAGIC_BASE+FSTYPE_XENIX)
100 #define SYSV4_SUPER_MAGIC (SYSV_MAGIC_BASE+FSTYPE_SYSV4)
101 #define SYSV2_SUPER_MAGIC (SYSV_MAGIC_BASE+FSTYPE_SYSV2)
102 #define COH_SUPER_MAGIC (SYSV_MAGIC_BASE+FSTYPE_COH)
103 
104 
105 /* Admissible values for i_nlink: 0.._LINK_MAX */
106 enum {
107  XENIX_LINK_MAX = 126, /* ?? */
108  SYSV_LINK_MAX = 126, /* 127? 251? */
109  V7_LINK_MAX = 126, /* ?? */
110  COH_LINK_MAX = 10000,
111 };
112 
113 
114 static inline void dirty_sb(struct super_block *sb)
115 {
116  struct sysv_sb_info *sbi = SYSV_SB(sb);
117 
118  mark_buffer_dirty(sbi->s_bh1);
119  if (sbi->s_bh1 != sbi->s_bh2)
120  mark_buffer_dirty(sbi->s_bh2);
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;
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 {
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 */