Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
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#define FAT_FIRST_ENT(s, x) ((MSDOS_SB(s)->fat_bits == 32 ? 0x0FFFFF00 : \
61 MSDOS_SB(s)->fat_bits == 16 ? 0xFF00 : 0xF00) | (x))
62
63/* start of data cluster's entry (number of reserved clusters) */
64#define FAT_START_ENT 2
65
66/* maximum number of clusters */
67#define MAX_FAT12 0xFF4
68#define MAX_FAT16 0xFFF4
69#define MAX_FAT32 0x0FFFFFF6
70#define MAX_FAT(s) (MSDOS_SB(s)->fat_bits == 32 ? MAX_FAT32 : \
71 MSDOS_SB(s)->fat_bits == 16 ? MAX_FAT16 : MAX_FAT12)
72
73/* bad cluster mark */
74#define BAD_FAT12 0xFF7
75#define BAD_FAT16 0xFFF7
76#define BAD_FAT32 0x0FFFFFF7
77
78/* standard EOF */
79#define EOF_FAT12 0xFFF
80#define EOF_FAT16 0xFFFF
81#define EOF_FAT32 0x0FFFFFFF
82
83#define FAT_ENT_FREE (0)
84#define FAT_ENT_BAD (BAD_FAT32)
85#define FAT_ENT_EOF (EOF_FAT32)
86
87#define FAT_FSINFO_SIG1 0x41615252
88#define FAT_FSINFO_SIG2 0x61417272
89#define IS_FSINFO(x) (le32_to_cpu((x)->signature1) == FAT_FSINFO_SIG1 \
90 && le32_to_cpu((x)->signature2) == FAT_FSINFO_SIG2)
91
92/*
93 * ioctl commands
94 */
95#define VFAT_IOCTL_READDIR_BOTH _IOR('r', 1, struct dirent [2])
96#define VFAT_IOCTL_READDIR_SHORT _IOR('r', 2, struct dirent [2])
97/* <linux/videotext.h> has used 0x72 ('r') in collision, so skip a few */
98#define FAT_IOCTL_GET_ATTRIBUTES _IOR('r', 0x10, __u32)
99#define FAT_IOCTL_SET_ATTRIBUTES _IOW('r', 0x11, __u32)
100
101/*
102 * vfat shortname flags
103 */
104#define VFAT_SFN_DISPLAY_LOWER 0x0001 /* convert to lowercase for display */
105#define VFAT_SFN_DISPLAY_WIN95 0x0002 /* emulate win95 rule for display */
106#define VFAT_SFN_DISPLAY_WINNT 0x0004 /* emulate winnt rule for display */
107#define VFAT_SFN_CREATE_WIN95 0x0100 /* emulate win95 rule for create */
108#define VFAT_SFN_CREATE_WINNT 0x0200 /* emulate winnt rule for create */
109
110struct fat_boot_sector {
111 __u8 ignored[3]; /* Boot strap short or near jump */
112 __u8 system_id[8]; /* Name - can be used to special case
113 partition manager volumes */
114 __u8 sector_size[2]; /* bytes per logical sector */
115 __u8 sec_per_clus; /* sectors/cluster */
116 __le16 reserved; /* reserved sectors */
117 __u8 fats; /* number of FATs */
118 __u8 dir_entries[2]; /* root directory entries */
119 __u8 sectors[2]; /* number of sectors */
120 __u8 media; /* media code */
121 __le16 fat_length; /* sectors/FAT */
122 __le16 secs_track; /* sectors per track */
123 __le16 heads; /* number of heads */
124 __le32 hidden; /* hidden sectors (unused) */
125 __le32 total_sect; /* number of sectors (if sectors == 0) */
126
127 /* The following fields are only used by FAT32 */
128 __le32 fat32_length; /* sectors/FAT */
129 __le16 flags; /* bit 8: fat mirroring, low 4: active fat */
130 __u8 version[2]; /* major, minor filesystem version */
131 __le32 root_cluster; /* first cluster in root directory */
132 __le16 info_sector; /* filesystem info sector */
133 __le16 backup_boot; /* backup boot sector */
134 __le16 reserved2[6]; /* Unused */
135};
136
137struct fat_boot_fsinfo {
138 __le32 signature1; /* 0x41615252L */
139 __le32 reserved1[120]; /* Nothing as far as I can tell */
140 __le32 signature2; /* 0x61417272L */
141 __le32 free_clusters; /* Free cluster count. -1 if unknown */
142 __le32 next_cluster; /* Most recently allocated cluster */
143 __le32 reserved2[4];
144};
145
146struct msdos_dir_entry {
147 __u8 name[MSDOS_NAME];/* name and extension */
148 __u8 attr; /* attribute bits */
149 __u8 lcase; /* Case for base and extension */
150 __u8 ctime_cs; /* Creation time, centiseconds (0-199) */
151 __le16 ctime; /* Creation time */
152 __le16 cdate; /* Creation date */
153 __le16 adate; /* Last access date */
154 __le16 starthi; /* High 16 bits of cluster in FAT32 */
155 __le16 time,date,start;/* time, date and first cluster */
156 __le32 size; /* file size (in bytes) */
157};
158
159/* Up to 13 characters of the name */
160struct msdos_dir_slot {
161 __u8 id; /* sequence number for slot */
162 __u8 name0_4[10]; /* first 5 characters in name */
163 __u8 attr; /* attribute byte */
164 __u8 reserved; /* always 0 */
165 __u8 alias_checksum; /* checksum for 8.3 alias */
166 __u8 name5_10[12]; /* 6 more characters in name */
167 __le16 start; /* starting cluster number, 0 in long slots */
168 __u8 name11_12[4]; /* last 2 characters in name */
169};
170
171struct fat_slot_info {
172 loff_t i_pos; /* on-disk position of directory entry */
173 loff_t slot_off; /* offset for slot or de start */
174 int nr_slots; /* number of slots + 1(de) in filename */
175 struct msdos_dir_entry *de;
176 struct buffer_head *bh;
177};
178
179#ifdef __KERNEL__
180
181#include <linux/buffer_head.h>
182#include <linux/string.h>
183#include <linux/nls.h>
184#include <linux/fs.h>
185#include <linux/mutex.h>
186
187struct fat_mount_options {
188 uid_t fs_uid;
189 gid_t fs_gid;
190 unsigned short fs_fmask;
191 unsigned short fs_dmask;
192 unsigned short codepage; /* Codepage for shortname conversions */
193 char *iocharset; /* Charset used for filename input/display */
194 unsigned short shortname; /* flags for shortname display/create rule */
195 unsigned char name_check; /* r = relaxed, n = normal, s = strict */
196 unsigned short allow_utime;/* permission for setting the [am]time */
197 unsigned quiet:1, /* set = fake successful chmods and chowns */
198 showexec:1, /* set = only set x bit for com/exe/bat */
199 sys_immutable:1, /* set = system files are immutable */
200 dotsOK:1, /* set = hidden and system files are named '.filename' */
201 isvfat:1, /* 0=no vfat long filename support, 1=vfat support */
202 utf8:1, /* Use of UTF-8 character set (Default) */
203 unicode_xlate:1, /* create escape sequences for unhandled Unicode */
204 numtail:1, /* Does first alias have a numeric '~1' type tail? */
205 atari:1, /* Use Atari GEMDOS variation of MS-DOS fs */
206 flush:1, /* write things quickly */
207 nocase:1, /* Does this need case conversion? 0=need case conversion*/
208 usefree:1; /* Use free_clusters for FAT32 */
209};
210
211#define FAT_HASH_BITS 8
212#define FAT_HASH_SIZE (1UL << FAT_HASH_BITS)
213#define FAT_HASH_MASK (FAT_HASH_SIZE-1)
214
215/*
216 * MS-DOS file system in-core superblock data
217 */
218struct msdos_sb_info {
219 unsigned short sec_per_clus; /* sectors/cluster */
220 unsigned short cluster_bits; /* log2(cluster_size) */
221 unsigned int cluster_size; /* cluster size */
222 unsigned char fats,fat_bits; /* number of FATs, FAT bits (12 or 16) */
223 unsigned short fat_start;
224 unsigned long fat_length; /* FAT start & length (sec.) */
225 unsigned long dir_start;
226 unsigned short dir_entries; /* root dir start & entries */
227 unsigned long data_start; /* first data sector */
228 unsigned long max_cluster; /* maximum cluster number */
229 unsigned long root_cluster; /* first cluster of the root directory */
230 unsigned long fsinfo_sector; /* sector number of FAT32 fsinfo */
231 struct mutex fat_lock;
232 unsigned int prev_free; /* previously allocated cluster number */
233 unsigned int free_clusters; /* -1 if undefined */
234 unsigned int free_clus_valid; /* is free_clusters valid? */
235 struct fat_mount_options options;
236 struct nls_table *nls_disk; /* Codepage used on disk */
237 struct nls_table *nls_io; /* Charset used for input and display */
238 const void *dir_ops; /* Opaque; default directory operations */
239 int dir_per_block; /* dir entries per block */
240 int dir_per_block_bits; /* log2(dir_per_block) */
241
242 int fatent_shift;
243 struct fatent_operations *fatent_ops;
244
245 spinlock_t inode_hash_lock;
246 struct hlist_head inode_hashtable[FAT_HASH_SIZE];
247};
248
249#define FAT_CACHE_VALID 0 /* special case for valid cache */
250
251/*
252 * MS-DOS file system inode data in memory
253 */
254struct msdos_inode_info {
255 spinlock_t cache_lru_lock;
256 struct list_head cache_lru;
257 int nr_caches;
258 /* for avoiding the race between fat_free() and fat_get_cluster() */
259 unsigned int cache_valid_id;
260
261 loff_t mmu_private;
262 int i_start; /* first cluster or 0 */
263 int i_logstart; /* logical first cluster */
264 int i_attrs; /* unused attribute bits */
265 loff_t i_pos; /* on-disk position of directory entry or 0 */
266 struct hlist_node i_fat_hash; /* hash by i_location */
267 struct inode vfs_inode;
268};
269
270static inline struct msdos_sb_info *MSDOS_SB(struct super_block *sb)
271{
272 return sb->s_fs_info;
273}
274
275static inline struct msdos_inode_info *MSDOS_I(struct inode *inode)
276{
277 return container_of(inode, struct msdos_inode_info, vfs_inode);
278}
279
280/* Return the FAT attribute byte for this inode */
281static inline u8 fat_attr(struct inode *inode)
282{
283 return ((inode->i_mode & S_IWUGO) ? ATTR_NONE : ATTR_RO) |
284 (S_ISDIR(inode->i_mode) ? ATTR_DIR : ATTR_NONE) |
285 MSDOS_I(inode)->i_attrs;
286}
287
288static inline unsigned char fat_checksum(const __u8 *name)
289{
290 unsigned char s = name[0];
291 s = (s<<7) + (s>>1) + name[1]; s = (s<<7) + (s>>1) + name[2];
292 s = (s<<7) + (s>>1) + name[3]; s = (s<<7) + (s>>1) + name[4];
293 s = (s<<7) + (s>>1) + name[5]; s = (s<<7) + (s>>1) + name[6];
294 s = (s<<7) + (s>>1) + name[7]; s = (s<<7) + (s>>1) + name[8];
295 s = (s<<7) + (s>>1) + name[9]; s = (s<<7) + (s>>1) + name[10];
296 return s;
297}
298
299static inline sector_t fat_clus_to_blknr(struct msdos_sb_info *sbi, int clus)
300{
301 return ((sector_t)clus - FAT_START_ENT) * sbi->sec_per_clus
302 + sbi->data_start;
303}
304
305static inline void fat16_towchar(wchar_t *dst, const __u8 *src, size_t len)
306{
307#ifdef __BIG_ENDIAN
308 while (len--) {
309 *dst++ = src[0] | (src[1] << 8);
310 src += 2;
311 }
312#else
313 memcpy(dst, src, len * 2);
314#endif
315}
316
317static inline void fatwchar_to16(__u8 *dst, const wchar_t *src, size_t len)
318{
319#ifdef __BIG_ENDIAN
320 while (len--) {
321 dst[0] = *src & 0x00FF;
322 dst[1] = (*src & 0xFF00) >> 8;
323 dst += 2;
324 src++;
325 }
326#else
327 memcpy(dst, src, len * 2);
328#endif
329}
330
331/* media of boot sector */
332static inline int fat_valid_media(u8 media)
333{
334 return 0xf8 <= media || media == 0xf0;
335}
336
337/* fat/cache.c */
338extern void fat_cache_inval_inode(struct inode *inode);
339extern int fat_get_cluster(struct inode *inode, int cluster,
340 int *fclus, int *dclus);
341extern int fat_bmap(struct inode *inode, sector_t sector, sector_t *phys,
342 unsigned long *mapped_blocks);
343
344/* fat/dir.c */
345extern const struct file_operations fat_dir_operations;
346extern int fat_search_long(struct inode *inode, const unsigned char *name,
347 int name_len, struct fat_slot_info *sinfo);
348extern int fat_dir_empty(struct inode *dir);
349extern int fat_subdirs(struct inode *dir);
350extern int fat_scan(struct inode *dir, const unsigned char *name,
351 struct fat_slot_info *sinfo);
352extern int fat_get_dotdot_entry(struct inode *dir, struct buffer_head **bh,
353 struct msdos_dir_entry **de, loff_t *i_pos);
354extern int fat_alloc_new_dir(struct inode *dir, struct timespec *ts);
355extern int fat_add_entries(struct inode *dir, void *slots, int nr_slots,
356 struct fat_slot_info *sinfo);
357extern int fat_remove_entries(struct inode *dir, struct fat_slot_info *sinfo);
358
359/* fat/fatent.c */
360struct fat_entry {
361 int entry;
362 union {
363 u8 *ent12_p[2];
364 __le16 *ent16_p;
365 __le32 *ent32_p;
366 } u;
367 int nr_bhs;
368 struct buffer_head *bhs[2];
369};
370
371static inline void fatent_init(struct fat_entry *fatent)
372{
373 fatent->nr_bhs = 0;
374 fatent->entry = 0;
375 fatent->u.ent32_p = NULL;
376 fatent->bhs[0] = fatent->bhs[1] = NULL;
377}
378
379static inline void fatent_set_entry(struct fat_entry *fatent, int entry)
380{
381 fatent->entry = entry;
382 fatent->u.ent32_p = NULL;
383}
384
385static inline void fatent_brelse(struct fat_entry *fatent)
386{
387 int i;
388 fatent->u.ent32_p = NULL;
389 for (i = 0; i < fatent->nr_bhs; i++)
390 brelse(fatent->bhs[i]);
391 fatent->nr_bhs = 0;
392 fatent->bhs[0] = fatent->bhs[1] = NULL;
393}
394
395extern void fat_ent_access_init(struct super_block *sb);
396extern int fat_ent_read(struct inode *inode, struct fat_entry *fatent,
397 int entry);
398extern int fat_ent_write(struct inode *inode, struct fat_entry *fatent,
399 int new, int wait);
400extern int fat_alloc_clusters(struct inode *inode, int *cluster,
401 int nr_cluster);
402extern int fat_free_clusters(struct inode *inode, int cluster);
403extern int fat_count_free_clusters(struct super_block *sb);
404
405/* fat/file.c */
406extern int fat_generic_ioctl(struct inode *inode, struct file *filp,
407 unsigned int cmd, unsigned long arg);
408extern const struct file_operations fat_file_operations;
409extern const struct inode_operations fat_file_inode_operations;
410extern int fat_setattr(struct dentry * dentry, struct iattr * attr);
411extern void fat_truncate(struct inode *inode);
412extern int fat_getattr(struct vfsmount *mnt, struct dentry *dentry,
413 struct kstat *stat);
414
415/* fat/inode.c */
416extern void fat_attach(struct inode *inode, loff_t i_pos);
417extern void fat_detach(struct inode *inode);
418extern struct inode *fat_iget(struct super_block *sb, loff_t i_pos);
419extern struct inode *fat_build_inode(struct super_block *sb,
420 struct msdos_dir_entry *de, loff_t i_pos);
421extern int fat_sync_inode(struct inode *inode);
422extern int fat_fill_super(struct super_block *sb, void *data, int silent,
423 const struct inode_operations *fs_dir_inode_ops, int isvfat);
424
425extern int fat_flush_inodes(struct super_block *sb, struct inode *i1,
426 struct inode *i2);
427/* fat/misc.c */
428extern void fat_fs_panic(struct super_block *s, const char *fmt, ...);
429extern void fat_clusters_flush(struct super_block *sb);
430extern int fat_chain_add(struct inode *inode, int new_dclus, int nr_cluster);
431extern int date_dos2unix(unsigned short time, unsigned short date);
432extern void fat_date_unix2dos(int unix_date, __le16 *time, __le16 *date);
433extern int fat_sync_bhs(struct buffer_head **bhs, int nr_bhs);
434
435int fat_cache_init(void);
436void fat_cache_destroy(void);
437
438#endif /* __KERNEL__ */
439
440#endif