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/ratelimit.h>
10 #include <linux/msdos_fs.h>
11
12 /*
13 * vfat shortname flags
14 */
15 #define VFAT_SFN_DISPLAY_LOWER 0x0001 /* convert to lowercase for display */
16 #define VFAT_SFN_DISPLAY_WIN95 0x0002 /* emulate win95 rule for display */
17 #define VFAT_SFN_DISPLAY_WINNT 0x0004 /* emulate winnt rule for display */
18 #define VFAT_SFN_CREATE_WIN95 0x0100 /* emulate win95 rule for create */
19 #define VFAT_SFN_CREATE_WINNT 0x0200 /* emulate winnt rule for create */
20
21 #define FAT_ERRORS_CONT 1 /* ignore error and continue */
22 #define FAT_ERRORS_PANIC 2 /* panic on error */
23 #define FAT_ERRORS_RO 3 /* remount r/o on error */
24
25 struct fat_mount_options {
26 uid_t fs_uid;
27 gid_t fs_gid;
28 unsigned short fs_fmask;
29 unsigned short fs_dmask;
30 unsigned short codepage; /* Codepage for shortname conversions */
31 char *iocharset; /* Charset used for filename input/display */
32 unsigned short shortname; /* flags for shortname display/create rule */
33 unsigned char name_check; /* r = relaxed, n = normal, s = strict */
34 unsigned char errors; /* On error: continue, panic, remount-ro */
35 unsigned short allow_utime;/* permission for setting the [am]time */
36 unsigned quiet:1, /* set = fake successful chmods and chowns */
37 showexec:1, /* set = only set x bit for com/exe/bat */
38 sys_immutable:1, /* set = system files are immutable */
39 dotsOK:1, /* set = hidden and system files are named '.filename' */
40 isvfat:1, /* 0=no vfat long filename support, 1=vfat support */
41 utf8:1, /* Use of UTF-8 character set (Default) */
42 unicode_xlate:1, /* create escape sequences for unhandled Unicode */
43 numtail:1, /* Does first alias have a numeric '~1' type tail? */
44 flush:1, /* write things quickly */
45 nocase:1, /* Does this need case conversion? 0=need case conversion*/
46 usefree:1, /* Use free_clusters for FAT32 */
47 tz_utc:1, /* Filesystem timestamps are in UTC */
48 rodir:1, /* allow ATTR_RO for directory */
49 discard:1; /* Issue discard requests on deletions */
50 };
51
52 #define FAT_HASH_BITS 8
53 #define FAT_HASH_SIZE (1UL << FAT_HASH_BITS)
54
55 /*
56 * MS-DOS file system in-core superblock data
57 */
58 struct msdos_sb_info {
59 unsigned short sec_per_clus; /* sectors/cluster */
60 unsigned short cluster_bits; /* log2(cluster_size) */
61 unsigned int cluster_size; /* cluster size */
62 unsigned char fats,fat_bits; /* number of FATs, FAT bits (12 or 16) */
63 unsigned short fat_start;
64 unsigned long fat_length; /* FAT start & length (sec.) */
65 unsigned long dir_start;
66 unsigned short dir_entries; /* root dir start & entries */
67 unsigned long data_start; /* first data sector */
68 unsigned long max_cluster; /* maximum cluster number */
69 unsigned long root_cluster; /* first cluster of the root directory */
70 unsigned long fsinfo_sector; /* sector number of FAT32 fsinfo */
71 struct mutex fat_lock;
72 unsigned int prev_free; /* previously allocated cluster number */
73 unsigned int free_clusters; /* -1 if undefined */
74 unsigned int free_clus_valid; /* is free_clusters valid? */
75 struct fat_mount_options options;
76 struct nls_table *nls_disk; /* Codepage used on disk */
77 struct nls_table *nls_io; /* Charset used for input and display */
78 const void *dir_ops; /* Opaque; default directory operations */
79 int dir_per_block; /* dir entries per block */
80 int dir_per_block_bits; /* log2(dir_per_block) */
81
82 int fatent_shift;
83 struct fatent_operations *fatent_ops;
84 struct inode *fat_inode;
85
86 struct ratelimit_state ratelimit;
87
88 spinlock_t inode_hash_lock;
89 struct hlist_head inode_hashtable[FAT_HASH_SIZE];
90 };
91
92 #define FAT_CACHE_VALID 0 /* special case for valid cache */
93
94 /*
95 * MS-DOS file system inode data in memory
96 */
97 struct msdos_inode_info {
98 spinlock_t cache_lru_lock;
99 struct list_head cache_lru;
100 int nr_caches;
101 /* for avoiding the race between fat_free() and fat_get_cluster() */
102 unsigned int cache_valid_id;
103
104 /* NOTE: mmu_private is 64bits, so must hold ->i_mutex to access */
105 loff_t mmu_private; /* physically allocated size */
106
107 int i_start; /* first cluster or 0 */
108 int i_logstart; /* logical first cluster */
109 int i_attrs; /* unused attribute bits */
110 loff_t i_pos; /* on-disk position of directory entry or 0 */
111 struct hlist_node i_fat_hash; /* hash by i_location */
112 struct rw_semaphore truncate_lock; /* protect bmap against truncate */
113 struct inode vfs_inode;
114 };
115
116 struct fat_slot_info {
117 loff_t i_pos; /* on-disk position of directory entry */
118 loff_t slot_off; /* offset for slot or de start */
119 int nr_slots; /* number of slots + 1(de) in filename */
120 struct msdos_dir_entry *de;
121 struct buffer_head *bh;
122 };
123
MSDOS_SB(struct super_block * sb)124 static inline struct msdos_sb_info *MSDOS_SB(struct super_block *sb)
125 {
126 return sb->s_fs_info;
127 }
128
MSDOS_I(struct inode * inode)129 static inline struct msdos_inode_info *MSDOS_I(struct inode *inode)
130 {
131 return container_of(inode, struct msdos_inode_info, vfs_inode);
132 }
133
134 /*
135 * If ->i_mode can't hold S_IWUGO (i.e. ATTR_RO), we use ->i_attrs to
136 * save ATTR_RO instead of ->i_mode.
137 *
138 * If it's directory and !sbi->options.rodir, ATTR_RO isn't read-only
139 * bit, it's just used as flag for app.
140 */
fat_mode_can_hold_ro(struct inode * inode)141 static inline int fat_mode_can_hold_ro(struct inode *inode)
142 {
143 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
144 umode_t mask;
145
146 if (S_ISDIR(inode->i_mode)) {
147 if (!sbi->options.rodir)
148 return 0;
149 mask = ~sbi->options.fs_dmask;
150 } else
151 mask = ~sbi->options.fs_fmask;
152
153 if (!(mask & S_IWUGO))
154 return 0;
155 return 1;
156 }
157
158 /* Convert attribute bits and a mask to the UNIX mode. */
fat_make_mode(struct msdos_sb_info * sbi,u8 attrs,umode_t mode)159 static inline umode_t fat_make_mode(struct msdos_sb_info *sbi,
160 u8 attrs, umode_t mode)
161 {
162 if (attrs & ATTR_RO && !((attrs & ATTR_DIR) && !sbi->options.rodir))
163 mode &= ~S_IWUGO;
164
165 if (attrs & ATTR_DIR)
166 return (mode & ~sbi->options.fs_dmask) | S_IFDIR;
167 else
168 return (mode & ~sbi->options.fs_fmask) | S_IFREG;
169 }
170
171 /* Return the FAT attribute byte for this inode */
fat_make_attrs(struct inode * inode)172 static inline u8 fat_make_attrs(struct inode *inode)
173 {
174 u8 attrs = MSDOS_I(inode)->i_attrs;
175 if (S_ISDIR(inode->i_mode))
176 attrs |= ATTR_DIR;
177 if (fat_mode_can_hold_ro(inode) && !(inode->i_mode & S_IWUGO))
178 attrs |= ATTR_RO;
179 return attrs;
180 }
181
fat_save_attrs(struct inode * inode,u8 attrs)182 static inline void fat_save_attrs(struct inode *inode, u8 attrs)
183 {
184 if (fat_mode_can_hold_ro(inode))
185 MSDOS_I(inode)->i_attrs = attrs & ATTR_UNUSED;
186 else
187 MSDOS_I(inode)->i_attrs = attrs & (ATTR_UNUSED | ATTR_RO);
188 }
189
fat_checksum(const __u8 * name)190 static inline unsigned char fat_checksum(const __u8 *name)
191 {
192 unsigned char s = name[0];
193 s = (s<<7) + (s>>1) + name[1]; s = (s<<7) + (s>>1) + name[2];
194 s = (s<<7) + (s>>1) + name[3]; s = (s<<7) + (s>>1) + name[4];
195 s = (s<<7) + (s>>1) + name[5]; s = (s<<7) + (s>>1) + name[6];
196 s = (s<<7) + (s>>1) + name[7]; s = (s<<7) + (s>>1) + name[8];
197 s = (s<<7) + (s>>1) + name[9]; s = (s<<7) + (s>>1) + name[10];
198 return s;
199 }
200
fat_clus_to_blknr(struct msdos_sb_info * sbi,int clus)201 static inline sector_t fat_clus_to_blknr(struct msdos_sb_info *sbi, int clus)
202 {
203 return ((sector_t)clus - FAT_START_ENT) * sbi->sec_per_clus
204 + sbi->data_start;
205 }
206
fat16_towchar(wchar_t * dst,const __u8 * src,size_t len)207 static inline void fat16_towchar(wchar_t *dst, const __u8 *src, size_t len)
208 {
209 #ifdef __BIG_ENDIAN
210 while (len--) {
211 *dst++ = src[0] | (src[1] << 8);
212 src += 2;
213 }
214 #else
215 memcpy(dst, src, len * 2);
216 #endif
217 }
218
fatwchar_to16(__u8 * dst,const wchar_t * src,size_t len)219 static inline void fatwchar_to16(__u8 *dst, const wchar_t *src, size_t len)
220 {
221 #ifdef __BIG_ENDIAN
222 while (len--) {
223 dst[0] = *src & 0x00FF;
224 dst[1] = (*src & 0xFF00) >> 8;
225 dst += 2;
226 src++;
227 }
228 #else
229 memcpy(dst, src, len * 2);
230 #endif
231 }
232
233 /* fat/cache.c */
234 extern void fat_cache_inval_inode(struct inode *inode);
235 extern int fat_get_cluster(struct inode *inode, int cluster,
236 int *fclus, int *dclus);
237 extern int fat_bmap(struct inode *inode, sector_t sector, sector_t *phys,
238 unsigned long *mapped_blocks, int create);
239
240 /* fat/dir.c */
241 extern const struct file_operations fat_dir_operations;
242 extern int fat_search_long(struct inode *inode, const unsigned char *name,
243 int name_len, struct fat_slot_info *sinfo);
244 extern int fat_dir_empty(struct inode *dir);
245 extern int fat_subdirs(struct inode *dir);
246 extern int fat_scan(struct inode *dir, const unsigned char *name,
247 struct fat_slot_info *sinfo);
248 extern int fat_get_dotdot_entry(struct inode *dir, struct buffer_head **bh,
249 struct msdos_dir_entry **de, loff_t *i_pos);
250 extern int fat_alloc_new_dir(struct inode *dir, struct timespec *ts);
251 extern int fat_add_entries(struct inode *dir, void *slots, int nr_slots,
252 struct fat_slot_info *sinfo);
253 extern int fat_remove_entries(struct inode *dir, struct fat_slot_info *sinfo);
254
255 /* fat/fatent.c */
256 struct fat_entry {
257 int entry;
258 union {
259 u8 *ent12_p[2];
260 __le16 *ent16_p;
261 __le32 *ent32_p;
262 } u;
263 int nr_bhs;
264 struct buffer_head *bhs[2];
265 struct inode *fat_inode;
266 };
267
fatent_init(struct fat_entry * fatent)268 static inline void fatent_init(struct fat_entry *fatent)
269 {
270 fatent->nr_bhs = 0;
271 fatent->entry = 0;
272 fatent->u.ent32_p = NULL;
273 fatent->bhs[0] = fatent->bhs[1] = NULL;
274 fatent->fat_inode = NULL;
275 }
276
fatent_set_entry(struct fat_entry * fatent,int entry)277 static inline void fatent_set_entry(struct fat_entry *fatent, int entry)
278 {
279 fatent->entry = entry;
280 fatent->u.ent32_p = NULL;
281 }
282
fatent_brelse(struct fat_entry * fatent)283 static inline void fatent_brelse(struct fat_entry *fatent)
284 {
285 int i;
286 fatent->u.ent32_p = NULL;
287 for (i = 0; i < fatent->nr_bhs; i++)
288 brelse(fatent->bhs[i]);
289 fatent->nr_bhs = 0;
290 fatent->bhs[0] = fatent->bhs[1] = NULL;
291 fatent->fat_inode = NULL;
292 }
293
294 extern void fat_ent_access_init(struct super_block *sb);
295 extern int fat_ent_read(struct inode *inode, struct fat_entry *fatent,
296 int entry);
297 extern int fat_ent_write(struct inode *inode, struct fat_entry *fatent,
298 int new, int wait);
299 extern int fat_alloc_clusters(struct inode *inode, int *cluster,
300 int nr_cluster);
301 extern int fat_free_clusters(struct inode *inode, int cluster);
302 extern int fat_count_free_clusters(struct super_block *sb);
303
304 /* fat/file.c */
305 extern long fat_generic_ioctl(struct file *filp, unsigned int cmd,
306 unsigned long arg);
307 extern const struct file_operations fat_file_operations;
308 extern const struct inode_operations fat_file_inode_operations;
309 extern int fat_setattr(struct dentry * dentry, struct iattr * attr);
310 extern void fat_truncate_blocks(struct inode *inode, loff_t offset);
311 extern int fat_getattr(struct vfsmount *mnt, struct dentry *dentry,
312 struct kstat *stat);
313 extern int fat_file_fsync(struct file *file, loff_t start, loff_t end,
314 int datasync);
315
316 /* fat/inode.c */
317 extern void fat_attach(struct inode *inode, loff_t i_pos);
318 extern void fat_detach(struct inode *inode);
319 extern struct inode *fat_iget(struct super_block *sb, loff_t i_pos);
320 extern struct inode *fat_build_inode(struct super_block *sb,
321 struct msdos_dir_entry *de, loff_t i_pos);
322 extern int fat_sync_inode(struct inode *inode);
323 extern int fat_fill_super(struct super_block *sb, void *data, int silent,
324 int isvfat, void (*setup)(struct super_block *));
325
326 extern int fat_flush_inodes(struct super_block *sb, struct inode *i1,
327 struct inode *i2);
328 /* fat/misc.c */
329 extern __printf(3, 4) __cold
330 void __fat_fs_error(struct super_block *sb, int report, const char *fmt, ...);
331 #define fat_fs_error(sb, fmt, args...) \
332 __fat_fs_error(sb, 1, fmt , ## args)
333 #define fat_fs_error_ratelimit(sb, fmt, args...) \
334 __fat_fs_error(sb, __ratelimit(&MSDOS_SB(sb)->ratelimit), fmt , ## args)
335 __printf(3, 4) __cold
336 void fat_msg(struct super_block *sb, const char *level, const char *fmt, ...);
337 extern int fat_clusters_flush(struct super_block *sb);
338 extern int fat_chain_add(struct inode *inode, int new_dclus, int nr_cluster);
339 extern void fat_time_fat2unix(struct msdos_sb_info *sbi, struct timespec *ts,
340 __le16 __time, __le16 __date, u8 time_cs);
341 extern void fat_time_unix2fat(struct msdos_sb_info *sbi, struct timespec *ts,
342 __le16 *time, __le16 *date, u8 *time_cs);
343 extern int fat_sync_bhs(struct buffer_head **bhs, int nr_bhs);
344
345 int fat_cache_init(void);
346 void fat_cache_destroy(void);
347
348 /* helper for printk */
349 typedef unsigned long long llu;
350
351 #endif /* !_FAT_H */
352