1 #ifndef _LINUX_MSDOS_FS_H
2 #define _LINUX_MSDOS_FS_H
3
4 #include <linux/magic.h>
5
6 /*
7 * The MS-DOS filesystem constants/structures
8 */
9 #include <asm/byteorder.h>
10
11 #define SECTOR_SIZE 512 /* sector size (bytes) */
12 #define SECTOR_BITS 9 /* log2(SECTOR_SIZE) */
13 #define MSDOS_DPB (MSDOS_DPS) /* dir entries per block */
14 #define MSDOS_DPB_BITS 4 /* log2(MSDOS_DPB) */
15 #define MSDOS_DPS (SECTOR_SIZE / sizeof(struct msdos_dir_entry))
16 #define MSDOS_DPS_BITS 4 /* log2(MSDOS_DPS) */
17 #define CF_LE_W(v) le16_to_cpu(v)
18 #define CF_LE_L(v) le32_to_cpu(v)
19 #define CT_LE_W(v) cpu_to_le16(v)
20 #define CT_LE_L(v) cpu_to_le32(v)
21
22
23 #define MSDOS_ROOT_INO 1 /* == MINIX_ROOT_INO */
24 #define MSDOS_DIR_BITS 5 /* log2(sizeof(struct msdos_dir_entry)) */
25
26 /* directory limit */
27 #define FAT_MAX_DIR_ENTRIES (65536)
28 #define FAT_MAX_DIR_SIZE (FAT_MAX_DIR_ENTRIES << MSDOS_DIR_BITS)
29
30 #define ATTR_NONE 0 /* no attribute bits */
31 #define ATTR_RO 1 /* read-only */
32 #define ATTR_HIDDEN 2 /* hidden */
33 #define ATTR_SYS 4 /* system */
34 #define ATTR_VOLUME 8 /* volume label */
35 #define ATTR_DIR 16 /* directory */
36 #define ATTR_ARCH 32 /* archived */
37
38 /* attribute bits that are copied "as is" */
39 #define ATTR_UNUSED (ATTR_VOLUME | ATTR_ARCH | ATTR_SYS | ATTR_HIDDEN)
40 /* bits that are used by the Windows 95/Windows NT extended FAT */
41 #define ATTR_EXT (ATTR_RO | ATTR_HIDDEN | ATTR_SYS | ATTR_VOLUME)
42
43 #define CASE_LOWER_BASE 8 /* base is lower case */
44 #define CASE_LOWER_EXT 16 /* extension is lower case */
45
46 #define DELETED_FLAG 0xe5 /* marks file as deleted when in name[0] */
47 #define IS_FREE(n) (!*(n) || *(n) == DELETED_FLAG)
48
49 /* valid file mode bits */
50 #define MSDOS_VALID_MODE (S_IFREG | S_IFDIR | S_IRWXU | S_IRWXG | S_IRWXO)
51 /* Convert attribute bits and a mask to the UNIX mode. */
52 #define MSDOS_MKMODE(a, m) (m & (a & ATTR_RO ? S_IRUGO|S_IXUGO : S_IRWXUGO))
53
54 #define MSDOS_NAME 11 /* maximum name length */
55 #define MSDOS_LONGNAME 256 /* maximum name length */
56 #define MSDOS_SLOTS 21 /* max # of slots for short and long names */
57 #define MSDOS_DOT ". " /* ".", padded to MSDOS_NAME chars */
58 #define MSDOS_DOTDOT ".. " /* "..", padded to MSDOS_NAME chars */
59
60 /* media of boot sector */
61 #define FAT_VALID_MEDIA(x) ((0xF8 <= (x) && (x) <= 0xFF) || (x) == 0xF0)
62 #define FAT_FIRST_ENT(s, x) ((MSDOS_SB(s)->fat_bits == 32 ? 0x0FFFFF00 : \
63 MSDOS_SB(s)->fat_bits == 16 ? 0xFF00 : 0xF00) | (x))
64
65 /* start of data cluster's entry (number of reserved clusters) */
66 #define FAT_START_ENT 2
67
68 /* maximum number of clusters */
69 #define MAX_FAT12 0xFF4
70 #define MAX_FAT16 0xFFF4
71 #define MAX_FAT32 0x0FFFFFF6
72 #define MAX_FAT(s) (MSDOS_SB(s)->fat_bits == 32 ? MAX_FAT32 : \
73 MSDOS_SB(s)->fat_bits == 16 ? MAX_FAT16 : MAX_FAT12)
74
75 /* bad cluster mark */
76 #define BAD_FAT12 0xFF7
77 #define BAD_FAT16 0xFFF7
78 #define BAD_FAT32 0x0FFFFFF7
79
80 /* standard EOF */
81 #define EOF_FAT12 0xFFF
82 #define EOF_FAT16 0xFFFF
83 #define EOF_FAT32 0x0FFFFFFF
84
85 #define FAT_ENT_FREE (0)
86 #define FAT_ENT_BAD (BAD_FAT32)
87 #define FAT_ENT_EOF (EOF_FAT32)
88
89 #define FAT_FSINFO_SIG1 0x41615252
90 #define FAT_FSINFO_SIG2 0x61417272
91 #define IS_FSINFO(x) (le32_to_cpu((x)->signature1) == FAT_FSINFO_SIG1 \
92 && le32_to_cpu((x)->signature2) == FAT_FSINFO_SIG2)
93
94 /*
95 * ioctl commands
96 */
97 #define VFAT_IOCTL_READDIR_BOTH _IOR('r', 1, struct dirent [2])
98 #define VFAT_IOCTL_READDIR_SHORT _IOR('r', 2, struct dirent [2])
99 /* <linux/videotext.h> has used 0x72 ('r') in collision, so skip a few */
100 #define FAT_IOCTL_GET_ATTRIBUTES _IOR('r', 0x10, __u32)
101 #define FAT_IOCTL_SET_ATTRIBUTES _IOW('r', 0x11, __u32)
102 #define VFAT_IOCTL_GET_VOLUME_ID _IOR('r', 0x12, __u32)
103
104 /*
105 * vfat shortname flags
106 */
107 #define VFAT_SFN_DISPLAY_LOWER 0x0001 /* convert to lowercase for display */
108 #define VFAT_SFN_DISPLAY_WIN95 0x0002 /* emulate win95 rule for display */
109 #define VFAT_SFN_DISPLAY_WINNT 0x0004 /* emulate winnt rule for display */
110 #define VFAT_SFN_CREATE_WIN95 0x0100 /* emulate win95 rule for create */
111 #define VFAT_SFN_CREATE_WINNT 0x0200 /* emulate winnt rule for create */
112
113 struct fat_boot_sector {
114 __u8 ignored[3]; /* Boot strap short or near jump */
115 __u8 system_id[8]; /* Name - can be used to special case
116 partition manager volumes */
117 __u8 sector_size[2]; /* bytes per logical sector */
118 __u8 sec_per_clus; /* sectors/cluster */
119 __le16 reserved; /* reserved sectors */
120 __u8 fats; /* number of FATs */
121 __u8 dir_entries[2]; /* root directory entries */
122 __u8 sectors[2]; /* number of sectors */
123 __u8 media; /* media code */
124 __le16 fat_length; /* sectors/FAT */
125 __le16 secs_track; /* sectors per track */
126 __le16 heads; /* number of heads */
127 __le32 hidden; /* hidden sectors (unused) */
128 __le32 total_sect; /* number of sectors (if sectors == 0) */
129
130 /* The following fields are only used by FAT32 */
131 __le32 fat32_length; /* sectors/FAT */
132 __le16 flags; /* bit 8: fat mirroring, low 4: active fat */
133 __u8 version[2]; /* major, minor filesystem version */
134 __le32 root_cluster; /* first cluster in root directory */
135 __le16 info_sector; /* filesystem info sector */
136 __le16 backup_boot; /* backup boot sector */
137 __le16 reserved2[6]; /* Unused */
138 };
139
140 struct fat_boot_fsinfo {
141 __le32 signature1; /* 0x41615252L */
142 __le32 reserved1[120]; /* Nothing as far as I can tell */
143 __le32 signature2; /* 0x61417272L */
144 __le32 free_clusters; /* Free cluster count. -1 if unknown */
145 __le32 next_cluster; /* Most recently allocated cluster */
146 __le32 reserved2[4];
147 };
148
149 struct fat_boot_bsx {
150 __u8 drive; /* drive number */
151 __u8 reserved1;
152 __u8 signature; /* extended boot signature */
153 __u8 vol_id[4]; /* volume ID */
154 __u8 vol_label[11]; /* volume label */
155 __u8 type[8]; /* file system type */
156 };
157 #define FAT16_BSX_OFFSET 36 /* offset of fat_boot_bsx in FAT12 and FAT16 */
158 #define FAT32_BSX_OFFSET 64 /* offset of fat_boot_bsx in FAT32 */
159
160 struct msdos_dir_entry {
161 __u8 name[MSDOS_NAME];/* name and extension */
162 __u8 attr; /* attribute bits */
163 __u8 lcase; /* Case for base and extension */
164 __u8 ctime_cs; /* Creation time, centiseconds (0-199) */
165 __le16 ctime; /* Creation time */
166 __le16 cdate; /* Creation date */
167 __le16 adate; /* Last access date */
168 __le16 starthi; /* High 16 bits of cluster in FAT32 */
169 __le16 time,date,start;/* time, date and first cluster */
170 __le32 size; /* file size (in bytes) */
171 };
172
173 /* Up to 13 characters of the name */
174 struct msdos_dir_slot {
175 __u8 id; /* sequence number for slot */
176 __u8 name0_4[10]; /* first 5 characters in name */
177 __u8 attr; /* attribute byte */
178 __u8 reserved; /* always 0 */
179 __u8 alias_checksum; /* checksum for 8.3 alias */
180 __u8 name5_10[12]; /* 6 more characters in name */
181 __le16 start; /* starting cluster number, 0 in long slots */
182 __u8 name11_12[4]; /* last 2 characters in name */
183 };
184
185 struct fat_slot_info {
186 loff_t i_pos; /* on-disk position of directory entry */
187 loff_t slot_off; /* offset for slot or de start */
188 int nr_slots; /* number of slots + 1(de) in filename */
189 struct msdos_dir_entry *de;
190 struct buffer_head *bh;
191 };
192
193 #ifdef __KERNEL__
194
195 #include <linux/buffer_head.h>
196 #include <linux/string.h>
197 #include <linux/nls.h>
198 #include <linux/fs.h>
199 #include <linux/mutex.h>
200
201 struct fat_mount_options {
202 uid_t fs_uid;
203 gid_t fs_gid;
204 unsigned short fs_fmask;
205 unsigned short fs_dmask;
206 unsigned short codepage; /* Codepage for shortname conversions */
207 char *iocharset; /* Charset used for filename input/display */
208 unsigned short shortname; /* flags for shortname display/create rule */
209 unsigned char name_check; /* r = relaxed, n = normal, s = strict */
210 unsigned quiet:1, /* set = fake successful chmods and chowns */
211 showexec:1, /* set = only set x bit for com/exe/bat */
212 sys_immutable:1, /* set = system files are immutable */
213 dotsOK:1, /* set = hidden and system files are named '.filename' */
214 isvfat:1, /* 0=no vfat long filename support, 1=vfat support */
215 utf8:1, /* Use of UTF-8 character set (Default) */
216 unicode_xlate:1, /* create escape sequences for unhandled Unicode */
217 numtail:1, /* Does first alias have a numeric '~1' type tail? */
218 atari:1, /* Use Atari GEMDOS variation of MS-DOS fs */
219 flush:1, /* write things quickly */
220 nocase:1, /* Does this need case conversion? 0=need case conversion*/
221 usefree:1; /* Use free_clusters for FAT32 */
222 };
223
224 #define FAT_HASH_BITS 8
225 #define FAT_HASH_SIZE (1UL << FAT_HASH_BITS)
226 #define FAT_HASH_MASK (FAT_HASH_SIZE-1)
227
228 /*
229 * MS-DOS file system in-core superblock data
230 */
231 struct msdos_sb_info {
232 unsigned short sec_per_clus; /* sectors/cluster */
233 unsigned short cluster_bits; /* log2(cluster_size) */
234 unsigned int cluster_size; /* cluster size */
235 unsigned char fats,fat_bits; /* number of FATs, FAT bits (12 or 16) */
236 unsigned short fat_start;
237 unsigned long fat_length; /* FAT start & length (sec.) */
238 unsigned long dir_start;
239 unsigned short dir_entries; /* root dir start & entries */
240 unsigned long data_start; /* first data sector */
241 unsigned long max_cluster; /* maximum cluster number */
242 unsigned long root_cluster; /* first cluster of the root directory */
243 unsigned long fsinfo_sector; /* sector number of FAT32 fsinfo */
244 struct mutex fat_lock;
245 unsigned int prev_free; /* previously allocated cluster number */
246 unsigned int free_clusters; /* -1 if undefined */
247 struct fat_mount_options options;
248 struct nls_table *nls_disk; /* Codepage used on disk */
249 struct nls_table *nls_io; /* Charset used for input and display */
250 const void *dir_ops; /* Opaque; default directory operations */
251 int dir_per_block; /* dir entries per block */
252 int dir_per_block_bits; /* log2(dir_per_block) */
253 unsigned long vol_id; /* volume ID */
254
255 int fatent_shift;
256 struct fatent_operations *fatent_ops;
257
258 spinlock_t inode_hash_lock;
259 struct hlist_head inode_hashtable[FAT_HASH_SIZE];
260 };
261
262 #define FAT_CACHE_VALID 0 /* special case for valid cache */
263
264 /*
265 * MS-DOS file system inode data in memory
266 */
267 struct msdos_inode_info {
268 spinlock_t cache_lru_lock;
269 struct list_head cache_lru;
270 int nr_caches;
271 /* for avoiding the race between fat_free() and fat_get_cluster() */
272 unsigned int cache_valid_id;
273
274 loff_t mmu_private;
275 int i_start; /* first cluster or 0 */
276 int i_logstart; /* logical first cluster */
277 int i_attrs; /* unused attribute bits */
278 loff_t i_pos; /* on-disk position of directory entry or 0 */
279 struct hlist_node i_fat_hash; /* hash by i_location */
280 struct inode vfs_inode;
281 };
282
MSDOS_SB(struct super_block * sb)283 static inline struct msdos_sb_info *MSDOS_SB(struct super_block *sb)
284 {
285 return sb->s_fs_info;
286 }
287
MSDOS_I(struct inode * inode)288 static inline struct msdos_inode_info *MSDOS_I(struct inode *inode)
289 {
290 return container_of(inode, struct msdos_inode_info, vfs_inode);
291 }
292
293 /* Return the FAT attribute byte for this inode */
fat_attr(struct inode * inode)294 static inline u8 fat_attr(struct inode *inode)
295 {
296 return ((inode->i_mode & S_IWUGO) ? ATTR_NONE : ATTR_RO) |
297 (S_ISDIR(inode->i_mode) ? ATTR_DIR : ATTR_NONE) |
298 MSDOS_I(inode)->i_attrs;
299 }
300
fat_checksum(const __u8 * name)301 static inline unsigned char fat_checksum(const __u8 *name)
302 {
303 unsigned char s = name[0];
304 s = (s<<7) + (s>>1) + name[1]; s = (s<<7) + (s>>1) + name[2];
305 s = (s<<7) + (s>>1) + name[3]; s = (s<<7) + (s>>1) + name[4];
306 s = (s<<7) + (s>>1) + name[5]; s = (s<<7) + (s>>1) + name[6];
307 s = (s<<7) + (s>>1) + name[7]; s = (s<<7) + (s>>1) + name[8];
308 s = (s<<7) + (s>>1) + name[9]; s = (s<<7) + (s>>1) + name[10];
309 return s;
310 }
311
fat_clus_to_blknr(struct msdos_sb_info * sbi,int clus)312 static inline sector_t fat_clus_to_blknr(struct msdos_sb_info *sbi, int clus)
313 {
314 return ((sector_t)clus - FAT_START_ENT) * sbi->sec_per_clus
315 + sbi->data_start;
316 }
317
fat16_towchar(wchar_t * dst,const __u8 * src,size_t len)318 static inline void fat16_towchar(wchar_t *dst, const __u8 *src, size_t len)
319 {
320 #ifdef __BIG_ENDIAN
321 while (len--) {
322 *dst++ = src[0] | (src[1] << 8);
323 src += 2;
324 }
325 #else
326 memcpy(dst, src, len * 2);
327 #endif
328 }
329
fatwchar_to16(__u8 * dst,const wchar_t * src,size_t len)330 static inline void fatwchar_to16(__u8 *dst, const wchar_t *src, size_t len)
331 {
332 #ifdef __BIG_ENDIAN
333 while (len--) {
334 dst[0] = *src & 0x00FF;
335 dst[1] = (*src & 0xFF00) >> 8;
336 dst += 2;
337 src++;
338 }
339 #else
340 memcpy(dst, src, len * 2);
341 #endif
342 }
343
344 /* fat/cache.c */
345 extern void fat_cache_inval_inode(struct inode *inode);
346 extern int fat_get_cluster(struct inode *inode, int cluster,
347 int *fclus, int *dclus);
348 extern int fat_bmap(struct inode *inode, sector_t sector, sector_t *phys,
349 unsigned long *mapped_blocks);
350
351 /* fat/dir.c */
352 extern const struct file_operations fat_dir_operations;
353 extern int fat_search_long(struct inode *inode, const unsigned char *name,
354 int name_len, struct fat_slot_info *sinfo);
355 extern int fat_dir_empty(struct inode *dir);
356 extern int fat_subdirs(struct inode *dir);
357 extern int fat_scan(struct inode *dir, const unsigned char *name,
358 struct fat_slot_info *sinfo);
359 extern int fat_get_dotdot_entry(struct inode *dir, struct buffer_head **bh,
360 struct msdos_dir_entry **de, loff_t *i_pos);
361 extern int fat_alloc_new_dir(struct inode *dir, struct timespec *ts);
362 extern int fat_add_entries(struct inode *dir, void *slots, int nr_slots,
363 struct fat_slot_info *sinfo);
364 extern int fat_remove_entries(struct inode *dir, struct fat_slot_info *sinfo);
365
366 /* fat/fatent.c */
367 struct fat_entry {
368 int entry;
369 union {
370 u8 *ent12_p[2];
371 __le16 *ent16_p;
372 __le32 *ent32_p;
373 } u;
374 int nr_bhs;
375 struct buffer_head *bhs[2];
376 };
377
fatent_init(struct fat_entry * fatent)378 static inline void fatent_init(struct fat_entry *fatent)
379 {
380 fatent->nr_bhs = 0;
381 fatent->entry = 0;
382 fatent->u.ent32_p = NULL;
383 fatent->bhs[0] = fatent->bhs[1] = NULL;
384 }
385
fatent_set_entry(struct fat_entry * fatent,int entry)386 static inline void fatent_set_entry(struct fat_entry *fatent, int entry)
387 {
388 fatent->entry = entry;
389 fatent->u.ent32_p = NULL;
390 }
391
fatent_brelse(struct fat_entry * fatent)392 static inline void fatent_brelse(struct fat_entry *fatent)
393 {
394 int i;
395 fatent->u.ent32_p = NULL;
396 for (i = 0; i < fatent->nr_bhs; i++)
397 brelse(fatent->bhs[i]);
398 fatent->nr_bhs = 0;
399 fatent->bhs[0] = fatent->bhs[1] = NULL;
400 }
401
402 extern void fat_ent_access_init(struct super_block *sb);
403 extern int fat_ent_read(struct inode *inode, struct fat_entry *fatent,
404 int entry);
405 extern int fat_ent_write(struct inode *inode, struct fat_entry *fatent,
406 int new, int wait);
407 extern int fat_alloc_clusters(struct inode *inode, int *cluster,
408 int nr_cluster);
409 extern int fat_free_clusters(struct inode *inode, int cluster);
410 extern int fat_count_free_clusters(struct super_block *sb);
411
412 /* fat/file.c */
413 extern int fat_generic_ioctl(struct inode *inode, struct file *filp,
414 unsigned int cmd, unsigned long arg);
415 extern const struct file_operations fat_file_operations;
416 extern const struct inode_operations fat_file_inode_operations;
417 extern int fat_notify_change(struct dentry * dentry, struct iattr * attr);
418 extern void fat_truncate(struct inode *inode);
419 extern int fat_getattr(struct vfsmount *mnt, struct dentry *dentry,
420 struct kstat *stat);
421
422 /* fat/inode.c */
423 extern void fat_attach(struct inode *inode, loff_t i_pos);
424 extern void fat_detach(struct inode *inode);
425 extern struct inode *fat_iget(struct super_block *sb, loff_t i_pos);
426 extern struct inode *fat_build_inode(struct super_block *sb,
427 struct msdos_dir_entry *de, loff_t i_pos);
428 extern int fat_sync_inode(struct inode *inode);
429 extern int fat_fill_super(struct super_block *sb, void *data, int silent,
430 const struct inode_operations *fs_dir_inode_ops, int isvfat);
431
432 extern int fat_flush_inodes(struct super_block *sb, struct inode *i1,
433 struct inode *i2);
434 /* fat/misc.c */
435 extern void fat_fs_panic(struct super_block *s, const char *fmt, ...);
436 extern void fat_clusters_flush(struct super_block *sb);
437 extern int fat_chain_add(struct inode *inode, int new_dclus, int nr_cluster);
438 extern int date_dos2unix(unsigned short time, unsigned short date);
439 extern void fat_date_unix2dos(int unix_date, __le16 *time, __le16 *date);
440 extern int fat_sync_bhs(struct buffer_head **bhs, int nr_bhs);
441
442 int fat_cache_init(void);
443 void fat_cache_destroy(void);
444
445 #endif /* __KERNEL__ */
446
447 #endif
448