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-rw-r--r--fs/fat/fat.h329
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diff --git a/fs/fat/fat.h b/fs/fat/fat.h
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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
20struct fat_mount_options {
21 uid_t fs_uid;
22 gid_t fs_gid;
23 unsigned short fs_fmask;
24 unsigned short fs_dmask;
25 unsigned short codepage; /* Codepage for shortname conversions */
26 char *iocharset; /* Charset used for filename input/display */
27 unsigned short shortname; /* flags for shortname display/create rule */
28 unsigned char name_check; /* r = relaxed, n = normal, s = strict */
29 unsigned short allow_utime;/* permission for setting the [am]time */
30 unsigned quiet:1, /* set = fake successful chmods and chowns */
31 showexec:1, /* set = only set x bit for com/exe/bat */
32 sys_immutable:1, /* set = system files are immutable */
33 dotsOK:1, /* set = hidden and system files are named '.filename' */
34 isvfat:1, /* 0=no vfat long filename support, 1=vfat support */
35 utf8:1, /* Use of UTF-8 character set (Default) */
36 unicode_xlate:1, /* create escape sequences for unhandled Unicode */
37 numtail:1, /* Does first alias have a numeric '~1' type tail? */
38 flush:1, /* write things quickly */
39 nocase:1, /* Does this need case conversion? 0=need case conversion*/
40 usefree:1, /* Use free_clusters for FAT32 */
41 tz_utc:1, /* Filesystem timestamps are in UTC */
42 rodir:1; /* allow ATTR_RO for directory */
43};
44
45#define FAT_HASH_BITS 8
46#define FAT_HASH_SIZE (1UL << FAT_HASH_BITS)
47
48/*
49 * MS-DOS file system in-core superblock data
50 */
51struct msdos_sb_info {
52 unsigned short sec_per_clus; /* sectors/cluster */
53 unsigned short cluster_bits; /* log2(cluster_size) */
54 unsigned int cluster_size; /* cluster size */
55 unsigned char fats,fat_bits; /* number of FATs, FAT bits (12 or 16) */
56 unsigned short fat_start;
57 unsigned long fat_length; /* FAT start & length (sec.) */
58 unsigned long dir_start;
59 unsigned short dir_entries; /* root dir start & entries */
60 unsigned long data_start; /* first data sector */
61 unsigned long max_cluster; /* maximum cluster number */
62 unsigned long root_cluster; /* first cluster of the root directory */
63 unsigned long fsinfo_sector; /* sector number of FAT32 fsinfo */
64 struct mutex fat_lock;
65 unsigned int prev_free; /* previously allocated cluster number */
66 unsigned int free_clusters; /* -1 if undefined */
67 unsigned int free_clus_valid; /* is free_clusters valid? */
68 struct fat_mount_options options;
69 struct nls_table *nls_disk; /* Codepage used on disk */
70 struct nls_table *nls_io; /* Charset used for input and display */
71 const void *dir_ops; /* Opaque; default directory operations */
72 int dir_per_block; /* dir entries per block */
73 int dir_per_block_bits; /* log2(dir_per_block) */
74
75 int fatent_shift;
76 struct fatent_operations *fatent_ops;
77
78 spinlock_t inode_hash_lock;
79 struct hlist_head inode_hashtable[FAT_HASH_SIZE];
80};
81
82#define FAT_CACHE_VALID 0 /* special case for valid cache */
83
84/*
85 * MS-DOS file system inode data in memory
86 */
87struct msdos_inode_info {
88 spinlock_t cache_lru_lock;
89 struct list_head cache_lru;
90 int nr_caches;
91 /* for avoiding the race between fat_free() and fat_get_cluster() */
92 unsigned int cache_valid_id;
93
94 /* NOTE: mmu_private is 64bits, so must hold ->i_mutex to access */
95 loff_t mmu_private; /* physically allocated size */
96
97 int i_start; /* first cluster or 0 */
98 int i_logstart; /* logical first cluster */
99 int i_attrs; /* unused attribute bits */
100 loff_t i_pos; /* on-disk position of directory entry or 0 */
101 struct hlist_node i_fat_hash; /* hash by i_location */
102 struct inode vfs_inode;
103};
104
105struct fat_slot_info {
106 loff_t i_pos; /* on-disk position of directory entry */
107 loff_t slot_off; /* offset for slot or de start */
108 int nr_slots; /* number of slots + 1(de) in filename */
109 struct msdos_dir_entry *de;
110 struct buffer_head *bh;
111};
112
113static inline struct msdos_sb_info *MSDOS_SB(struct super_block *sb)
114{
115 return sb->s_fs_info;
116}
117
118static inline struct msdos_inode_info *MSDOS_I(struct inode *inode)
119{
120 return container_of(inode, struct msdos_inode_info, vfs_inode);
121}
122
123/*
124 * If ->i_mode can't hold S_IWUGO (i.e. ATTR_RO), we use ->i_attrs to
125 * save ATTR_RO instead of ->i_mode.
126 *
127 * If it's directory and !sbi->options.rodir, ATTR_RO isn't read-only
128 * bit, it's just used as flag for app.
129 */
130static inline int fat_mode_can_hold_ro(struct inode *inode)
131{
132 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
133 mode_t mask;
134
135 if (S_ISDIR(inode->i_mode)) {
136 if (!sbi->options.rodir)
137 return 0;
138 mask = ~sbi->options.fs_dmask;
139 } else
140 mask = ~sbi->options.fs_fmask;
141
142 if (!(mask & S_IWUGO))
143 return 0;
144 return 1;
145}
146
147/* Convert attribute bits and a mask to the UNIX mode. */
148static inline mode_t fat_make_mode(struct msdos_sb_info *sbi,
149 u8 attrs, mode_t mode)
150{
151 if (attrs & ATTR_RO && !((attrs & ATTR_DIR) && !sbi->options.rodir))
152 mode &= ~S_IWUGO;
153
154 if (attrs & ATTR_DIR)
155 return (mode & ~sbi->options.fs_dmask) | S_IFDIR;
156 else
157 return (mode & ~sbi->options.fs_fmask) | S_IFREG;
158}
159
160/* Return the FAT attribute byte for this inode */
161static inline u8 fat_make_attrs(struct inode *inode)
162{
163 u8 attrs = MSDOS_I(inode)->i_attrs;
164 if (S_ISDIR(inode->i_mode))
165 attrs |= ATTR_DIR;
166 if (fat_mode_can_hold_ro(inode) && !(inode->i_mode & S_IWUGO))
167 attrs |= ATTR_RO;
168 return attrs;
169}
170
171static inline void fat_save_attrs(struct inode *inode, u8 attrs)
172{
173 if (fat_mode_can_hold_ro(inode))
174 MSDOS_I(inode)->i_attrs = attrs & ATTR_UNUSED;
175 else
176 MSDOS_I(inode)->i_attrs = attrs & (ATTR_UNUSED | ATTR_RO);
177}
178
179static inline unsigned char fat_checksum(const __u8 *name)
180{
181 unsigned char s = name[0];
182 s = (s<<7) + (s>>1) + name[1]; s = (s<<7) + (s>>1) + name[2];
183 s = (s<<7) + (s>>1) + name[3]; s = (s<<7) + (s>>1) + name[4];
184 s = (s<<7) + (s>>1) + name[5]; s = (s<<7) + (s>>1) + name[6];
185 s = (s<<7) + (s>>1) + name[7]; s = (s<<7) + (s>>1) + name[8];
186 s = (s<<7) + (s>>1) + name[9]; s = (s<<7) + (s>>1) + name[10];
187 return s;
188}
189
190static inline sector_t fat_clus_to_blknr(struct msdos_sb_info *sbi, int clus)
191{
192 return ((sector_t)clus - FAT_START_ENT) * sbi->sec_per_clus
193 + sbi->data_start;
194}
195
196static inline void fat16_towchar(wchar_t *dst, const __u8 *src, size_t len)
197{
198#ifdef __BIG_ENDIAN
199 while (len--) {
200 *dst++ = src[0] | (src[1] << 8);
201 src += 2;
202 }
203#else
204 memcpy(dst, src, len * 2);
205#endif
206}
207
208static inline void fatwchar_to16(__u8 *dst, const wchar_t *src, size_t len)
209{
210#ifdef __BIG_ENDIAN
211 while (len--) {
212 dst[0] = *src & 0x00FF;
213 dst[1] = (*src & 0xFF00) >> 8;
214 dst += 2;
215 src++;
216 }
217#else
218 memcpy(dst, src, len * 2);
219#endif
220}
221
222/* fat/cache.c */
223extern void fat_cache_inval_inode(struct inode *inode);
224extern int fat_get_cluster(struct inode *inode, int cluster,
225 int *fclus, int *dclus);
226extern int fat_bmap(struct inode *inode, sector_t sector, sector_t *phys,
227 unsigned long *mapped_blocks, int create);
228
229/* fat/dir.c */
230extern const struct file_operations fat_dir_operations;
231extern int fat_search_long(struct inode *inode, const unsigned char *name,
232 int name_len, struct fat_slot_info *sinfo);
233extern int fat_dir_empty(struct inode *dir);
234extern int fat_subdirs(struct inode *dir);
235extern int fat_scan(struct inode *dir, const unsigned char *name,
236 struct fat_slot_info *sinfo);
237extern int fat_get_dotdot_entry(struct inode *dir, struct buffer_head **bh,
238 struct msdos_dir_entry **de, loff_t *i_pos);
239extern int fat_alloc_new_dir(struct inode *dir, struct timespec *ts);
240extern int fat_add_entries(struct inode *dir, void *slots, int nr_slots,
241 struct fat_slot_info *sinfo);
242extern int fat_remove_entries(struct inode *dir, struct fat_slot_info *sinfo);
243
244/* fat/fatent.c */
245struct fat_entry {
246 int entry;
247 union {
248 u8 *ent12_p[2];
249 __le16 *ent16_p;
250 __le32 *ent32_p;
251 } u;
252 int nr_bhs;
253 struct buffer_head *bhs[2];
254};
255
256static inline void fatent_init(struct fat_entry *fatent)
257{
258 fatent->nr_bhs = 0;
259 fatent->entry = 0;
260 fatent->u.ent32_p = NULL;
261 fatent->bhs[0] = fatent->bhs[1] = NULL;
262}
263
264static inline void fatent_set_entry(struct fat_entry *fatent, int entry)
265{
266 fatent->entry = entry;
267 fatent->u.ent32_p = NULL;
268}
269
270static inline void fatent_brelse(struct fat_entry *fatent)
271{
272 int i;
273 fatent->u.ent32_p = NULL;
274 for (i = 0; i < fatent->nr_bhs; i++)
275 brelse(fatent->bhs[i]);
276 fatent->nr_bhs = 0;
277 fatent->bhs[0] = fatent->bhs[1] = NULL;
278}
279
280extern void fat_ent_access_init(struct super_block *sb);
281extern int fat_ent_read(struct inode *inode, struct fat_entry *fatent,
282 int entry);
283extern int fat_ent_write(struct inode *inode, struct fat_entry *fatent,
284 int new, int wait);
285extern int fat_alloc_clusters(struct inode *inode, int *cluster,
286 int nr_cluster);
287extern int fat_free_clusters(struct inode *inode, int cluster);
288extern int fat_count_free_clusters(struct super_block *sb);
289
290/* fat/file.c */
291extern int fat_generic_ioctl(struct inode *inode, struct file *filp,
292 unsigned int cmd, unsigned long arg);
293extern const struct file_operations fat_file_operations;
294extern const struct inode_operations fat_file_inode_operations;
295extern int fat_setattr(struct dentry * dentry, struct iattr * attr);
296extern void fat_truncate(struct inode *inode);
297extern int fat_getattr(struct vfsmount *mnt, struct dentry *dentry,
298 struct kstat *stat);
299
300/* fat/inode.c */
301extern void fat_attach(struct inode *inode, loff_t i_pos);
302extern void fat_detach(struct inode *inode);
303extern struct inode *fat_iget(struct super_block *sb, loff_t i_pos);
304extern struct inode *fat_build_inode(struct super_block *sb,
305 struct msdos_dir_entry *de, loff_t i_pos);
306extern int fat_sync_inode(struct inode *inode);
307extern int fat_fill_super(struct super_block *sb, void *data, int silent,
308 const struct inode_operations *fs_dir_inode_ops, int isvfat);
309
310extern int fat_flush_inodes(struct super_block *sb, struct inode *i1,
311 struct inode *i2);
312/* fat/misc.c */
313extern void fat_fs_panic(struct super_block *s, const char *fmt, ...)
314 __attribute__ ((format (printf, 2, 3))) __cold;
315extern void fat_clusters_flush(struct super_block *sb);
316extern int fat_chain_add(struct inode *inode, int new_dclus, int nr_cluster);
317extern void fat_time_fat2unix(struct msdos_sb_info *sbi, struct timespec *ts,
318 __le16 __time, __le16 __date, u8 time_cs);
319extern void fat_time_unix2fat(struct msdos_sb_info *sbi, struct timespec *ts,
320 __le16 *time, __le16 *date, u8 *time_cs);
321extern int fat_sync_bhs(struct buffer_head **bhs, int nr_bhs);
322
323int fat_cache_init(void);
324void fat_cache_destroy(void);
325
326/* helper for printk */
327typedef unsigned long long llu;
328
329#endif /* !_FAT_H */
generated by cgit v1.2.2 (git 2.25.0) at 2026-01-09 03:31:15 -0500