1 #ifndef _FAT_H
2 #define _FAT_H
3
4 #include <linux/buffer_head.h>
5 #include <linux/string.h>
6 #include <linux/nls.h>
7 #include <linux/fs.h>
8 #include <linux/mutex.h>
9 #include <linux/msdos_fs.h>
10
11 /*
12 * vfat shortname flags
13 */
14 #define VFAT_SFN_DISPLAY_LOWER 0x0001 /* convert to lowercase for display */
15 #define VFAT_SFN_DISPLAY_WIN95 0x0002 /* emulate win95 rule for display */
16 #define VFAT_SFN_DISPLAY_WINNT 0x0004 /* emulate winnt rule for display */
17 #define VFAT_SFN_CREATE_WIN95 0x0100 /* emulate win95 rule for create */
18 #define VFAT_SFN_CREATE_WINNT 0x0200 /* emulate winnt rule for create */
19
20 #define FAT_ERRORS_CONT 1 /* ignore error and continue */
21 #define FAT_ERRORS_PANIC 2 /* panic on error */
22 #define FAT_ERRORS_RO 3 /* remount r/o on error */
23
24 struct fat_mount_options {
25 uid_t fs_uid;
26 gid_t fs_gid;
27 unsigned short fs_fmask;
28 unsigned short fs_dmask;
29 unsigned short codepage; /* Codepage for shortname conversions */
30 char *iocharset; /* Charset used for filename input/display */
31 unsigned short shortname; /* flags for shortname display/create rule */
32 unsigned char name_check; /* r = relaxed, n = normal, s = strict */
33 unsigned char errors; /* On error: continue, panic, remount-ro */
34 unsigned short allow_utime;/* permission for setting the [am]time */
35 unsigned quiet:1, /* set = fake successful chmods and chowns */
36 showexec:1, /* set = only set x bit for com/exe/bat */
37 sys_immutable:1, /* set = system files are immutable */
38 dotsOK:1, /* set = hidden and system files are named '.filename' */
39 isvfat:1, /* 0=no vfat long filename support, 1=vfat support */
40 utf8:1, /* Use of UTF-8 character set (Default) */
41 unicode_xlate:1, /* create escape sequences for unhandled Unicode */
42 numtail:1, /* Does first alias have a numeric '~1' type tail? */
43 flush:1, /* write things quickly */
44 nocase:1, /* Does this need case conversion? 0=need case conversion*/
45 usefree:1, /* Use free_clusters for FAT32 */
46 tz_utc:1, /* Filesystem timestamps are in UTC */
47 rodir:1; /* allow ATTR_RO for directory */
48 };
49
50 #define FAT_HASH_BITS 8
51 #define FAT_HASH_SIZE (1UL << FAT_HASH_BITS)
52
53 /*
54 * MS-DOS file system in-core superblock data
55 */
56 struct msdos_sb_info {
57 unsigned short sec_per_clus; /* sectors/cluster */
58 unsigned short cluster_bits; /* log2(cluster_size) */
59 unsigned int cluster_size; /* cluster size */
60 unsigned char fats,fat_bits; /* number of FATs, FAT bits (12 or 16) */
61 unsigned short fat_start;
62 unsigned long fat_length; /* FAT start & length (sec.) */
63 unsigned long dir_start;
64 unsigned short dir_entries; /* root dir start & entries */
65 unsigned long data_start; /* first data sector */
66 unsigned long max_cluster; /* maximum cluster number */
67 unsigned long root_cluster; /* first cluster of the root directory */
68 unsigned long fsinfo_sector; /* sector number of FAT32 fsinfo */
69 struct mutex fat_lock;
70 unsigned int prev_free; /* previously allocated cluster number */
71 unsigned int free_clusters; /* -1 if undefined */
72 unsigned int free_clus_valid; /* is free_clusters valid? */
73 struct fat_mount_options options;
74 struct nls_table *nls_disk; /* Codepage used on disk */
75 struct nls_table *nls_io; /* Charset used for input and display */
76 const void *dir_ops; /* Opaque; default directory operations */
77 int dir_per_block; /* dir entries per block */
78 int dir_per_block_bits; /* log2(dir_per_block) */
79 unsigned long vol_id; /* volume ID */
80
81 int fatent_shift;
82 struct fatent_operations *fatent_ops;
83
84 spinlock_t inode_hash_lock;
85 struct hlist_head inode_hashtable[FAT_HASH_SIZE];
86 };
87
88 #define FAT_CACHE_VALID 0 /* special case for valid cache */
89
90 /*
91 * MS-DOS file system inode data in memory
92 */
93 struct msdos_inode_info {
94 spinlock_t cache_lru_lock;
95 struct list_head cache_lru;
96 int nr_caches;
97 /* for avoiding the race between fat_free() and fat_get_cluster() */
98 unsigned int cache_valid_id;
99
100 /* NOTE: mmu_private is 64bits, so must hold ->i_mutex to access */
101 loff_t mmu_private; /* physically allocated size */
102
103 int i_start; /* first cluster or 0 */
104 int i_logstart; /* logical first cluster */
105 int i_attrs; /* unused attribute bits */
106 loff_t i_pos; /* on-disk position of directory entry or 0 */
107 struct hlist_node i_fat_hash; /* hash by i_location */
108 struct inode vfs_inode;
109 };
110
111 struct fat_slot_info {
112 loff_t i_pos; /* on-disk position of directory entry */
113 loff_t slot_off; /* offset for slot or de start */
114 int nr_slots; /* number of slots + 1(de) in filename */
115 struct msdos_dir_entry *de;
116 struct buffer_head *bh;
117 };
118
MSDOS_SB(struct super_block * sb)119 static inline struct msdos_sb_info *MSDOS_SB(struct super_block *sb)
120 {
121 return sb->s_fs_info;
122 }
123
MSDOS_I(struct inode * inode)124 static inline struct msdos_inode_info *MSDOS_I(struct inode *inode)
125 {
126 return container_of(inode, struct msdos_inode_info, vfs_inode);
127 }
128
129 /*
130 * If ->i_mode can't hold S_IWUGO (i.e. ATTR_RO), we use ->i_attrs to
131 * save ATTR_RO instead of ->i_mode.
132 *
133 * If it's directory and !sbi->options.rodir, ATTR_RO isn't read-only
134 * bit, it's just used as flag for app.
135 */
fat_mode_can_hold_ro(struct inode * inode)136 static inline int fat_mode_can_hold_ro(struct inode *inode)
137 {
138 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
139 mode_t mask;
140
141 if (S_ISDIR(inode->i_mode)) {
142 if (!sbi->options.rodir)
143 return 0;
144 mask = ~sbi->options.fs_dmask;
145 } else
146 mask = ~sbi->options.fs_fmask;
147
148 if (!(mask & S_IWUGO))
149 return 0;
150 return 1;
151 }
152
153 /* Convert attribute bits and a mask to the UNIX mode. */
fat_make_mode(struct msdos_sb_info * sbi,u8 attrs,mode_t mode)154 static inline mode_t fat_make_mode(struct msdos_sb_info *sbi,
155 u8 attrs, mode_t mode)
156 {
157 if (attrs & ATTR_RO && !((attrs & ATTR_DIR) && !sbi->options.rodir))
158 mode &= ~S_IWUGO;
159
160 if (attrs & ATTR_DIR)
161 return (mode & ~sbi->options.fs_dmask) | S_IFDIR;
162 else
163 return (mode & ~sbi->options.fs_fmask) | S_IFREG;
164 }
165
166 /* Return the FAT attribute byte for this inode */
fat_make_attrs(struct inode * inode)167 static inline u8 fat_make_attrs(struct inode *inode)
168 {
169 u8 attrs = MSDOS_I(inode)->i_attrs;
170 if (S_ISDIR(inode->i_mode))
171 attrs |= ATTR_DIR;
172 if (fat_mode_can_hold_ro(inode) && !(inode->i_mode & S_IWUGO))
173 attrs |= ATTR_RO;
174 return attrs;
175 }
176
fat_save_attrs(struct inode * inode,u8 attrs)177 static inline void fat_save_attrs(struct inode *inode, u8 attrs)
178 {
179 if (fat_mode_can_hold_ro(inode))
180 MSDOS_I(inode)->i_attrs = attrs & ATTR_UNUSED;
181 else
182 MSDOS_I(inode)->i_attrs = attrs & (ATTR_UNUSED | ATTR_RO);
183 }
184
fat_checksum(const __u8 * name)185 static inline unsigned char fat_checksum(const __u8 *name)
186 {
187 unsigned char s = name[0];
188 s = (s<<7) + (s>>1) + name[1]; s = (s<<7) + (s>>1) + name[2];
189 s = (s<<7) + (s>>1) + name[3]; s = (s<<7) + (s>>1) + name[4];
190 s = (s<<7) + (s>>1) + name[5]; s = (s<<7) + (s>>1) + name[6];
191 s = (s<<7) + (s>>1) + name[7]; s = (s<<7) + (s>>1) + name[8];
192 s = (s<<7) + (s>>1) + name[9]; s = (s<<7) + (s>>1) + name[10];
193 return s;
194 }
195
fat_clus_to_blknr(struct msdos_sb_info * sbi,int clus)196 static inline sector_t fat_clus_to_blknr(struct msdos_sb_info *sbi, int clus)
197 {
198 return ((sector_t)clus - FAT_START_ENT) * sbi->sec_per_clus
199 + sbi->data_start;
200 }
201
fat16_towchar(wchar_t * dst,const __u8 * src,size_t len)202 static inline void fat16_towchar(wchar_t *dst, const __u8 *src, size_t len)
203 {
204 #ifdef __BIG_ENDIAN
205 while (len--) {
206 *dst++ = src[0] | (src[1] << 8);
207 src += 2;
208 }
209 #else
210 memcpy(dst, src, len * 2);
211 #endif
212 }
213
fatwchar_to16(__u8 * dst,const wchar_t * src,size_t len)214 static inline void fatwchar_to16(__u8 *dst, const wchar_t *src, size_t len)
215 {
216 #ifdef __BIG_ENDIAN
217 while (len--) {
218 dst[0] = *src & 0x00FF;
219 dst[1] = (*src & 0xFF00) >> 8;
220 dst += 2;
221 src++;
222 }
223 #else
224 memcpy(dst, src, len * 2);
225 #endif
226 }
227
228 /* fat/cache.c */
229 extern void fat_cache_inval_inode(struct inode *inode);
230 extern int fat_get_cluster(struct inode *inode, int cluster,
231 int *fclus, int *dclus);
232 extern int fat_bmap(struct inode *inode, sector_t sector, sector_t *phys,
233 unsigned long *mapped_blocks, int create);
234
235 /* fat/dir.c */
236 extern const struct file_operations fat_dir_operations;
237 extern int fat_search_long(struct inode *inode, const unsigned char *name,
238 int name_len, struct fat_slot_info *sinfo);
239 extern int fat_dir_empty(struct inode *dir);
240 extern int fat_subdirs(struct inode *dir);
241 extern int fat_scan(struct inode *dir, const unsigned char *name,
242 struct fat_slot_info *sinfo);
243 extern int fat_get_dotdot_entry(struct inode *dir, struct buffer_head **bh,
244 struct msdos_dir_entry **de, loff_t *i_pos);
245 extern int fat_alloc_new_dir(struct inode *dir, struct timespec *ts);
246 extern int fat_add_entries(struct inode *dir, void *slots, int nr_slots,
247 struct fat_slot_info *sinfo);
248 extern int fat_remove_entries(struct inode *dir, struct fat_slot_info *sinfo);
249
250 /* fat/fatent.c */
251 struct fat_entry {
252 int entry;
253 union {
254 u8 *ent12_p[2];
255 __le16 *ent16_p;
256 __le32 *ent32_p;
257 } u;
258 int nr_bhs;
259 struct buffer_head *bhs[2];
260 };
261
fatent_init(struct fat_entry * fatent)262 static inline void fatent_init(struct fat_entry *fatent)
263 {
264 fatent->nr_bhs = 0;
265 fatent->entry = 0;
266 fatent->u.ent32_p = NULL;
267 fatent->bhs[0] = fatent->bhs[1] = NULL;
268 }
269
fatent_set_entry(struct fat_entry * fatent,int entry)270 static inline void fatent_set_entry(struct fat_entry *fatent, int entry)
271 {
272 fatent->entry = entry;
273 fatent->u.ent32_p = NULL;
274 }
275
fatent_brelse(struct fat_entry * fatent)276 static inline void fatent_brelse(struct fat_entry *fatent)
277 {
278 int i;
279 fatent->u.ent32_p = NULL;
280 for (i = 0; i < fatent->nr_bhs; i++)
281 brelse(fatent->bhs[i]);
282 fatent->nr_bhs = 0;
283 fatent->bhs[0] = fatent->bhs[1] = NULL;
284 }
285
286 extern void fat_ent_access_init(struct super_block *sb);
287 extern int fat_ent_read(struct inode *inode, struct fat_entry *fatent,
288 int entry);
289 extern int fat_ent_write(struct inode *inode, struct fat_entry *fatent,
290 int new, int wait);
291 extern int fat_alloc_clusters(struct inode *inode, int *cluster,
292 int nr_cluster);
293 extern int fat_free_clusters(struct inode *inode, int cluster);
294 extern int fat_count_free_clusters(struct super_block *sb);
295
296 /* fat/file.c */
297 extern int fat_generic_ioctl(struct inode *inode, struct file *filp,
298 unsigned int cmd, unsigned long arg);
299 extern const struct file_operations fat_file_operations;
300 extern const struct inode_operations fat_file_inode_operations;
301 extern int fat_setattr(struct dentry * dentry, struct iattr * attr);
302 extern void fat_truncate(struct inode *inode);
303 extern int fat_getattr(struct vfsmount *mnt, struct dentry *dentry,
304 struct kstat *stat);
305
306 /* fat/inode.c */
307 extern void fat_attach(struct inode *inode, loff_t i_pos);
308 extern void fat_detach(struct inode *inode);
309 extern struct inode *fat_iget(struct super_block *sb, loff_t i_pos);
310 extern struct inode *fat_build_inode(struct super_block *sb,
311 struct msdos_dir_entry *de, loff_t i_pos);
312 extern int fat_sync_inode(struct inode *inode);
313 extern int fat_fill_super(struct super_block *sb, void *data, int silent,
314 const struct inode_operations *fs_dir_inode_ops, int isvfat);
315
316 extern int fat_flush_inodes(struct super_block *sb, struct inode *i1,
317 struct inode *i2);
318 /* fat/misc.c */
319 extern void fat_fs_error(struct super_block *s, const char *fmt, ...)
320 __attribute__ ((format (printf, 2, 3))) __cold;
321 extern void fat_clusters_flush(struct super_block *sb);
322 extern int fat_chain_add(struct inode *inode, int new_dclus, int nr_cluster);
323 extern void fat_time_fat2unix(struct msdos_sb_info *sbi, struct timespec *ts,
324 __le16 __time, __le16 __date, u8 time_cs);
325 extern void fat_time_unix2fat(struct msdos_sb_info *sbi, struct timespec *ts,
326 __le16 *time, __le16 *date, u8 *time_cs);
327 extern int fat_sync_bhs(struct buffer_head **bhs, int nr_bhs);
328
329 int fat_cache_init(void);
330 void fat_cache_destroy(void);
331
332 /* helper for printk */
333 typedef unsigned long long llu;
334
335 #endif /* !_FAT_H */
336