tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
25struct 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 */
58struct 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 struct inode *fsinfo_inode;
86
87 struct ratelimit_state ratelimit;
88
89 spinlock_t inode_hash_lock;
90 struct hlist_head inode_hashtable[FAT_HASH_SIZE];
91};
92
93#define FAT_CACHE_VALID 0 /* special case for valid cache */
94
95/*
96 * MS-DOS file system inode data in memory
97 */
98struct msdos_inode_info {
99 spinlock_t cache_lru_lock;
100 struct list_head cache_lru;
101 int nr_caches;
102 /* for avoiding the race between fat_free() and fat_get_cluster() */
103 unsigned int cache_valid_id;
104
105 /* NOTE: mmu_private is 64bits, so must hold ->i_mutex to access */
106 loff_t mmu_private; /* physically allocated size */
107
108 int i_start; /* first cluster or 0 */
109 int i_logstart; /* logical first cluster */
110 int i_attrs; /* unused attribute bits */
111 loff_t i_pos; /* on-disk position of directory entry or 0 */
112 struct hlist_node i_fat_hash; /* hash by i_location */
113 struct rw_semaphore truncate_lock; /* protect bmap against truncate */
114 struct inode vfs_inode;
115};
116
117struct fat_slot_info {
118 loff_t i_pos; /* on-disk position of directory entry */
119 loff_t slot_off; /* offset for slot or de start */
120 int nr_slots; /* number of slots + 1(de) in filename */
121 struct msdos_dir_entry *de;
122 struct buffer_head *bh;
123};
124
125static inline struct msdos_sb_info *MSDOS_SB(struct super_block *sb)
126{
127 return sb->s_fs_info;
128}
129
130static inline struct msdos_inode_info *MSDOS_I(struct inode *inode)
131{
132 return container_of(inode, struct msdos_inode_info, vfs_inode);
133}
134
135/*
136 * If ->i_mode can't hold S_IWUGO (i.e. ATTR_RO), we use ->i_attrs to
137 * save ATTR_RO instead of ->i_mode.
138 *
139 * If it's directory and !sbi->options.rodir, ATTR_RO isn't read-only
140 * bit, it's just used as flag for app.
141 */
142static inline int fat_mode_can_hold_ro(struct inode *inode)
143{
144 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
145 umode_t mask;
146
147 if (S_ISDIR(inode->i_mode)) {
148 if (!sbi->options.rodir)
149 return 0;
150 mask = ~sbi->options.fs_dmask;
151 } else
152 mask = ~sbi->options.fs_fmask;
153
154 if (!(mask & S_IWUGO))
155 return 0;
156 return 1;
157}
158
159/* Convert attribute bits and a mask to the UNIX mode. */
160static inline umode_t fat_make_mode(struct msdos_sb_info *sbi,
161 u8 attrs, umode_t mode)
162{
163 if (attrs & ATTR_RO && !((attrs & ATTR_DIR) && !sbi->options.rodir))
164 mode &= ~S_IWUGO;
165
166 if (attrs & ATTR_DIR)
167 return (mode & ~sbi->options.fs_dmask) | S_IFDIR;
168 else
169 return (mode & ~sbi->options.fs_fmask) | S_IFREG;
170}
171
172/* Return the FAT attribute byte for this inode */
173static inline u8 fat_make_attrs(struct inode *inode)
174{
175 u8 attrs = MSDOS_I(inode)->i_attrs;
176 if (S_ISDIR(inode->i_mode))
177 attrs |= ATTR_DIR;
178 if (fat_mode_can_hold_ro(inode) && !(inode->i_mode & S_IWUGO))
179 attrs |= ATTR_RO;
180 return attrs;
181}
182
183static inline void fat_save_attrs(struct inode *inode, u8 attrs)
184{
185 if (fat_mode_can_hold_ro(inode))
186 MSDOS_I(inode)->i_attrs = attrs & ATTR_UNUSED;
187 else
188 MSDOS_I(inode)->i_attrs = attrs & (ATTR_UNUSED | ATTR_RO);
189}
190
191static inline unsigned char fat_checksum(const __u8 *name)
192{
193 unsigned char s = name[0];
194 s = (s<<7) + (s>>1) + name[1]; s = (s<<7) + (s>>1) + name[2];
195 s = (s<<7) + (s>>1) + name[3]; s = (s<<7) + (s>>1) + name[4];
196 s = (s<<7) + (s>>1) + name[5]; s = (s<<7) + (s>>1) + name[6];
197 s = (s<<7) + (s>>1) + name[7]; s = (s<<7) + (s>>1) + name[8];
198 s = (s<<7) + (s>>1) + name[9]; s = (s<<7) + (s>>1) + name[10];
199 return s;
200}
201
202static inline sector_t fat_clus_to_blknr(struct msdos_sb_info *sbi, int clus)
203{
204 return ((sector_t)clus - FAT_START_ENT) * sbi->sec_per_clus
205 + sbi->data_start;
206}
207
208static inline void fat16_towchar(wchar_t *dst, const __u8 *src, size_t len)
209{
210#ifdef __BIG_ENDIAN
211 while (len--) {
212 *dst++ = src[0] | (src[1] << 8);
213 src += 2;
214 }
215#else
216 memcpy(dst, src, len * 2);
217#endif
218}
219
220static inline void fatwchar_to16(__u8 *dst, const wchar_t *src, size_t len)
221{
222#ifdef __BIG_ENDIAN
223 while (len--) {
224 dst[0] = *src & 0x00FF;
225 dst[1] = (*src & 0xFF00) >> 8;
226 dst += 2;
227 src++;
228 }
229#else
230 memcpy(dst, src, len * 2);
231#endif
232}
233
234/* fat/cache.c */
235extern void fat_cache_inval_inode(struct inode *inode);
236extern int fat_get_cluster(struct inode *inode, int cluster,
237 int *fclus, int *dclus);
238extern int fat_bmap(struct inode *inode, sector_t sector, sector_t *phys,
239 unsigned long *mapped_blocks, int create);
240
241/* fat/dir.c */
242extern const struct file_operations fat_dir_operations;
243extern int fat_search_long(struct inode *inode, const unsigned char *name,
244 int name_len, struct fat_slot_info *sinfo);
245extern int fat_dir_empty(struct inode *dir);
246extern int fat_subdirs(struct inode *dir);
247extern int fat_scan(struct inode *dir, const unsigned char *name,
248 struct fat_slot_info *sinfo);
249extern int fat_get_dotdot_entry(struct inode *dir, struct buffer_head **bh,
250 struct msdos_dir_entry **de, loff_t *i_pos);
251extern int fat_alloc_new_dir(struct inode *dir, struct timespec *ts);
252extern int fat_add_entries(struct inode *dir, void *slots, int nr_slots,
253 struct fat_slot_info *sinfo);
254extern int fat_remove_entries(struct inode *dir, struct fat_slot_info *sinfo);
255
256/* fat/fatent.c */
257struct fat_entry {
258 int entry;
259 union {
260 u8 *ent12_p[2];
261 __le16 *ent16_p;
262 __le32 *ent32_p;
263 } u;
264 int nr_bhs;
265 struct buffer_head *bhs[2];
266 struct inode *fat_inode;
267};
268
269static inline void fatent_init(struct fat_entry *fatent)
270{
271 fatent->nr_bhs = 0;
272 fatent->entry = 0;
273 fatent->u.ent32_p = NULL;
274 fatent->bhs[0] = fatent->bhs[1] = NULL;
275 fatent->fat_inode = NULL;
276}
277
278static inline void fatent_set_entry(struct fat_entry *fatent, int entry)
279{
280 fatent->entry = entry;
281 fatent->u.ent32_p = NULL;
282}
283
284static inline void fatent_brelse(struct fat_entry *fatent)
285{
286 int i;
287 fatent->u.ent32_p = NULL;
288 for (i = 0; i < fatent->nr_bhs; i++)
289 brelse(fatent->bhs[i]);
290 fatent->nr_bhs = 0;
291 fatent->bhs[0] = fatent->bhs[1] = NULL;
292 fatent->fat_inode = NULL;
293}
294
295extern void fat_ent_access_init(struct super_block *sb);
296extern int fat_ent_read(struct inode *inode, struct fat_entry *fatent,
297 int entry);
298extern int fat_ent_write(struct inode *inode, struct fat_entry *fatent,
299 int new, int wait);
300extern int fat_alloc_clusters(struct inode *inode, int *cluster,
301 int nr_cluster);
302extern int fat_free_clusters(struct inode *inode, int cluster);
303extern int fat_count_free_clusters(struct super_block *sb);
304
305/* fat/file.c */
306extern long fat_generic_ioctl(struct file *filp, unsigned int cmd,
307 unsigned long arg);
308extern const struct file_operations fat_file_operations;
309extern const struct inode_operations fat_file_inode_operations;
310extern int fat_setattr(struct dentry * dentry, struct iattr * attr);
311extern void fat_truncate_blocks(struct inode *inode, loff_t offset);
312extern int fat_getattr(struct vfsmount *mnt, struct dentry *dentry,
313 struct kstat *stat);
314extern int fat_file_fsync(struct file *file, loff_t start, loff_t end,
315 int datasync);
316
317/* fat/inode.c */
318extern void fat_attach(struct inode *inode, loff_t i_pos);
319extern void fat_detach(struct inode *inode);
320extern struct inode *fat_iget(struct super_block *sb, loff_t i_pos);
321extern struct inode *fat_build_inode(struct super_block *sb,
322 struct msdos_dir_entry *de, loff_t i_pos);
323extern int fat_sync_inode(struct inode *inode);
324extern int fat_fill_super(struct super_block *sb, void *data, int silent,
325 int isvfat, void (*setup)(struct super_block *));
326
327extern int fat_flush_inodes(struct super_block *sb, struct inode *i1,
328 struct inode *i2);
329/* fat/misc.c */
330extern __printf(3, 4) __cold
331void __fat_fs_error(struct super_block *sb, int report, const char *fmt, ...);
332#define fat_fs_error(sb, fmt, args...) \
333 __fat_fs_error(sb, 1, fmt , ## args)
334#define fat_fs_error_ratelimit(sb, fmt, args...) \
335 __fat_fs_error(sb, __ratelimit(&MSDOS_SB(sb)->ratelimit), fmt , ## args)
336__printf(3, 4) __cold
337void fat_msg(struct super_block *sb, const char *level, const char *fmt, ...);
338#define fat_msg_ratelimit(sb, level, fmt, args...) \
339 do { \
340 if (__ratelimit(&MSDOS_SB(sb)->ratelimit)) \
341 fat_msg(sb, level, fmt, ## args); \
342 } while (0)
343extern int fat_clusters_flush(struct super_block *sb);
344extern int fat_chain_add(struct inode *inode, int new_dclus, int nr_cluster);
345extern void fat_time_fat2unix(struct msdos_sb_info *sbi, struct timespec *ts,
346 __le16 __time, __le16 __date, u8 time_cs);
347extern void fat_time_unix2fat(struct msdos_sb_info *sbi, struct timespec *ts,
348 __le16 *time, __le16 *date, u8 *time_cs);
349extern int fat_sync_bhs(struct buffer_head **bhs, int nr_bhs);
350
351int fat_cache_init(void);
352void fat_cache_destroy(void);
353
354/* helper for printk */
355typedef unsigned long long llu;
356
357#endif /* !_FAT_H */