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/hash.h>
9#include <linux/mutex.h>
10#include <linux/ratelimit.h>
11#include <linux/msdos_fs.h>
12
13/*
14 * vfat shortname flags
15 */
16#define VFAT_SFN_DISPLAY_LOWER 0x0001 /* convert to lowercase for display */
17#define VFAT_SFN_DISPLAY_WIN95 0x0002 /* emulate win95 rule for display */
18#define VFAT_SFN_DISPLAY_WINNT 0x0004 /* emulate winnt rule for display */
19#define VFAT_SFN_CREATE_WIN95 0x0100 /* emulate win95 rule for create */
20#define VFAT_SFN_CREATE_WINNT 0x0200 /* emulate winnt rule for create */
21
22#define FAT_ERRORS_CONT 1 /* ignore error and continue */
23#define FAT_ERRORS_PANIC 2 /* panic on error */
24#define FAT_ERRORS_RO 3 /* remount r/o on error */
25
26struct fat_mount_options {
27 kuid_t fs_uid;
28 kgid_t fs_gid;
29 unsigned short fs_fmask;
30 unsigned short fs_dmask;
31 unsigned short codepage; /* Codepage for shortname conversions */
32 char *iocharset; /* Charset used for filename input/display */
33 unsigned short shortname; /* flags for shortname display/create rule */
34 unsigned char name_check; /* r = relaxed, n = normal, s = strict */
35 unsigned char errors; /* On error: continue, panic, remount-ro */
36 unsigned short allow_utime;/* permission for setting the [am]time */
37 unsigned quiet:1, /* set = fake successful chmods and chowns */
38 showexec:1, /* set = only set x bit for com/exe/bat */
39 sys_immutable:1, /* set = system files are immutable */
40 dotsOK:1, /* set = hidden and system files are named '.filename' */
41 isvfat:1, /* 0=no vfat long filename support, 1=vfat support */
42 utf8:1, /* Use of UTF-8 character set (Default) */
43 unicode_xlate:1, /* create escape sequences for unhandled Unicode */
44 numtail:1, /* Does first alias have a numeric '~1' type tail? */
45 flush:1, /* write things quickly */
46 nocase:1, /* Does this need case conversion? 0=need case conversion*/
47 usefree:1, /* Use free_clusters for FAT32 */
48 tz_utc:1, /* Filesystem timestamps are in UTC */
49 rodir:1, /* allow ATTR_RO for directory */
50 discard:1, /* Issue discard requests on deletions */
51 nfs:1; /* Do extra work needed for NFS export */
52};
53
54#define FAT_HASH_BITS 8
55#define FAT_HASH_SIZE (1UL << FAT_HASH_BITS)
56
57/*
58 * MS-DOS file system in-core superblock data
59 */
60struct msdos_sb_info {
61 unsigned short sec_per_clus; /* sectors/cluster */
62 unsigned short cluster_bits; /* log2(cluster_size) */
63 unsigned int cluster_size; /* cluster size */
64 unsigned char fats, fat_bits; /* number of FATs, FAT bits (12 or 16) */
65 unsigned short fat_start;
66 unsigned long fat_length; /* FAT start & length (sec.) */
67 unsigned long dir_start;
68 unsigned short dir_entries; /* root dir start & entries */
69 unsigned long data_start; /* first data sector */
70 unsigned long max_cluster; /* maximum cluster number */
71 unsigned long root_cluster; /* first cluster of the root directory */
72 unsigned long fsinfo_sector; /* sector number of FAT32 fsinfo */
73 struct mutex fat_lock;
74 struct mutex s_lock;
75 unsigned int prev_free; /* previously allocated cluster number */
76 unsigned int free_clusters; /* -1 if undefined */
77 unsigned int free_clus_valid; /* is free_clusters valid? */
78 struct fat_mount_options options;
79 struct nls_table *nls_disk; /* Codepage used on disk */
80 struct nls_table *nls_io; /* Charset used for input and display */
81 const void *dir_ops; /* Opaque; default directory operations */
82 int dir_per_block; /* dir entries per block */
83 int dir_per_block_bits; /* log2(dir_per_block) */
84
85 int fatent_shift;
86 struct fatent_operations *fatent_ops;
87 struct inode *fat_inode;
88 struct inode *fsinfo_inode;
89
90 struct ratelimit_state ratelimit;
91
92 spinlock_t inode_hash_lock;
93 struct hlist_head inode_hashtable[FAT_HASH_SIZE];
94
95 spinlock_t dir_hash_lock;
96 struct hlist_head dir_hashtable[FAT_HASH_SIZE];
97};
98
99#define FAT_CACHE_VALID 0 /* special case for valid cache */
100
101/*
102 * MS-DOS file system inode data in memory
103 */
104struct msdos_inode_info {
105 spinlock_t cache_lru_lock;
106 struct list_head cache_lru;
107 int nr_caches;
108 /* for avoiding the race between fat_free() and fat_get_cluster() */
109 unsigned int cache_valid_id;
110
111 /* NOTE: mmu_private is 64bits, so must hold ->i_mutex to access */
112 loff_t mmu_private; /* physically allocated size */
113
114 int i_start; /* first cluster or 0 */
115 int i_logstart; /* logical first cluster */
116 int i_attrs; /* unused attribute bits */
117 loff_t i_pos; /* on-disk position of directory entry or 0 */
118 struct hlist_node i_fat_hash; /* hash by i_location */
119 struct hlist_node i_dir_hash; /* hash by i_logstart */
120 struct rw_semaphore truncate_lock; /* protect bmap against truncate */
121 struct inode vfs_inode;
122};
123
124struct fat_slot_info {
125 loff_t i_pos; /* on-disk position of directory entry */
126 loff_t slot_off; /* offset for slot or de start */
127 int nr_slots; /* number of slots + 1(de) in filename */
128 struct msdos_dir_entry *de;
129 struct buffer_head *bh;
130};
131
132static inline struct msdos_sb_info *MSDOS_SB(struct super_block *sb)
133{
134 return sb->s_fs_info;
135}
136
137static inline struct msdos_inode_info *MSDOS_I(struct inode *inode)
138{
139 return container_of(inode, struct msdos_inode_info, vfs_inode);
140}
141
142/*
143 * If ->i_mode can't hold S_IWUGO (i.e. ATTR_RO), we use ->i_attrs to
144 * save ATTR_RO instead of ->i_mode.
145 *
146 * If it's directory and !sbi->options.rodir, ATTR_RO isn't read-only
147 * bit, it's just used as flag for app.
148 */
149static inline int fat_mode_can_hold_ro(struct inode *inode)
150{
151 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
152 umode_t mask;
153
154 if (S_ISDIR(inode->i_mode)) {
155 if (!sbi->options.rodir)
156 return 0;
157 mask = ~sbi->options.fs_dmask;
158 } else
159 mask = ~sbi->options.fs_fmask;
160
161 if (!(mask & S_IWUGO))
162 return 0;
163 return 1;
164}
165
166/* Convert attribute bits and a mask to the UNIX mode. */
167static inline umode_t fat_make_mode(struct msdos_sb_info *sbi,
168 u8 attrs, umode_t mode)
169{
170 if (attrs & ATTR_RO && !((attrs & ATTR_DIR) && !sbi->options.rodir))
171 mode &= ~S_IWUGO;
172
173 if (attrs & ATTR_DIR)
174 return (mode & ~sbi->options.fs_dmask) | S_IFDIR;
175 else
176 return (mode & ~sbi->options.fs_fmask) | S_IFREG;
177}
178
179/* Return the FAT attribute byte for this inode */
180static inline u8 fat_make_attrs(struct inode *inode)
181{
182 u8 attrs = MSDOS_I(inode)->i_attrs;
183 if (S_ISDIR(inode->i_mode))
184 attrs |= ATTR_DIR;
185 if (fat_mode_can_hold_ro(inode) && !(inode->i_mode & S_IWUGO))
186 attrs |= ATTR_RO;
187 return attrs;
188}
189
190static inline void fat_save_attrs(struct inode *inode, u8 attrs)
191{
192 if (fat_mode_can_hold_ro(inode))
193 MSDOS_I(inode)->i_attrs = attrs & ATTR_UNUSED;
194 else
195 MSDOS_I(inode)->i_attrs = attrs & (ATTR_UNUSED | ATTR_RO);
196}
197
198static inline unsigned char fat_checksum(const __u8 *name)
199{
200 unsigned char s = name[0];
201 s = (s<<7) + (s>>1) + name[1]; s = (s<<7) + (s>>1) + name[2];
202 s = (s<<7) + (s>>1) + name[3]; s = (s<<7) + (s>>1) + name[4];
203 s = (s<<7) + (s>>1) + name[5]; s = (s<<7) + (s>>1) + name[6];
204 s = (s<<7) + (s>>1) + name[7]; s = (s<<7) + (s>>1) + name[8];
205 s = (s<<7) + (s>>1) + name[9]; s = (s<<7) + (s>>1) + name[10];
206 return s;
207}
208
209static inline sector_t fat_clus_to_blknr(struct msdos_sb_info *sbi, int clus)
210{
211 return ((sector_t)clus - FAT_START_ENT) * sbi->sec_per_clus
212 + sbi->data_start;
213}
214
215static inline void fat16_towchar(wchar_t *dst, const __u8 *src, size_t len)
216{
217#ifdef __BIG_ENDIAN
218 while (len--) {
219 *dst++ = src[0] | (src[1] << 8);
220 src += 2;
221 }
222#else
223 memcpy(dst, src, len * 2);
224#endif
225}
226
227static inline int fat_get_start(const struct msdos_sb_info *sbi,
228 const struct msdos_dir_entry *de)
229{
230 int cluster = le16_to_cpu(de->start);
231 if (sbi->fat_bits == 32)
232 cluster |= (le16_to_cpu(de->starthi) << 16);
233 return cluster;
234}
235
236static inline void fat_set_start(struct msdos_dir_entry *de, int cluster)
237{
238 de->start = cpu_to_le16(cluster);
239 de->starthi = cpu_to_le16(cluster >> 16);
240}
241
242static inline void fatwchar_to16(__u8 *dst, const wchar_t *src, size_t len)
243{
244#ifdef __BIG_ENDIAN
245 while (len--) {
246 dst[0] = *src & 0x00FF;
247 dst[1] = (*src & 0xFF00) >> 8;
248 dst += 2;
249 src++;
250 }
251#else
252 memcpy(dst, src, len * 2);
253#endif
254}
255
256/* fat/cache.c */
257extern void fat_cache_inval_inode(struct inode *inode);
258extern int fat_get_cluster(struct inode *inode, int cluster,
259 int *fclus, int *dclus);
260extern int fat_bmap(struct inode *inode, sector_t sector, sector_t *phys,
261 unsigned long *mapped_blocks, int create);
262
263/* fat/dir.c */
264extern const struct file_operations fat_dir_operations;
265extern int fat_search_long(struct inode *inode, const unsigned char *name,
266 int name_len, struct fat_slot_info *sinfo);
267extern int fat_dir_empty(struct inode *dir);
268extern int fat_subdirs(struct inode *dir);
269extern int fat_scan(struct inode *dir, const unsigned char *name,
270 struct fat_slot_info *sinfo);
271extern int fat_get_dotdot_entry(struct inode *dir, struct buffer_head **bh,
272 struct msdos_dir_entry **de);
273extern int fat_alloc_new_dir(struct inode *dir, struct timespec *ts);
274extern int fat_add_entries(struct inode *dir, void *slots, int nr_slots,
275 struct fat_slot_info *sinfo);
276extern int fat_remove_entries(struct inode *dir, struct fat_slot_info *sinfo);
277
278/* fat/fatent.c */
279struct fat_entry {
280 int entry;
281 union {
282 u8 *ent12_p[2];
283 __le16 *ent16_p;
284 __le32 *ent32_p;
285 } u;
286 int nr_bhs;
287 struct buffer_head *bhs[2];
288 struct inode *fat_inode;
289};
290
291static inline void fatent_init(struct fat_entry *fatent)
292{
293 fatent->nr_bhs = 0;
294 fatent->entry = 0;
295 fatent->u.ent32_p = NULL;
296 fatent->bhs[0] = fatent->bhs[1] = NULL;
297 fatent->fat_inode = NULL;
298}
299
300static inline void fatent_set_entry(struct fat_entry *fatent, int entry)
301{
302 fatent->entry = entry;
303 fatent->u.ent32_p = NULL;
304}
305
306static inline void fatent_brelse(struct fat_entry *fatent)
307{
308 int i;
309 fatent->u.ent32_p = NULL;
310 for (i = 0; i < fatent->nr_bhs; i++)
311 brelse(fatent->bhs[i]);
312 fatent->nr_bhs = 0;
313 fatent->bhs[0] = fatent->bhs[1] = NULL;
314 fatent->fat_inode = NULL;
315}
316
317extern void fat_ent_access_init(struct super_block *sb);
318extern int fat_ent_read(struct inode *inode, struct fat_entry *fatent,
319 int entry);
320extern int fat_ent_write(struct inode *inode, struct fat_entry *fatent,
321 int new, int wait);
322extern int fat_alloc_clusters(struct inode *inode, int *cluster,
323 int nr_cluster);
324extern int fat_free_clusters(struct inode *inode, int cluster);
325extern int fat_count_free_clusters(struct super_block *sb);
326
327/* fat/file.c */
328extern long fat_generic_ioctl(struct file *filp, unsigned int cmd,
329 unsigned long arg);
330extern const struct file_operations fat_file_operations;
331extern const struct inode_operations fat_file_inode_operations;
332extern int fat_setattr(struct dentry *dentry, struct iattr *attr);
333extern void fat_truncate_blocks(struct inode *inode, loff_t offset);
334extern int fat_getattr(struct vfsmount *mnt, struct dentry *dentry,
335 struct kstat *stat);
336extern int fat_file_fsync(struct file *file, loff_t start, loff_t end,
337 int datasync);
338
339/* fat/inode.c */
340extern void fat_attach(struct inode *inode, loff_t i_pos);
341extern void fat_detach(struct inode *inode);
342extern struct inode *fat_iget(struct super_block *sb, loff_t i_pos);
343extern struct inode *fat_build_inode(struct super_block *sb,
344 struct msdos_dir_entry *de, loff_t i_pos);
345extern int fat_sync_inode(struct inode *inode);
346extern int fat_fill_super(struct super_block *sb, void *data, int silent,
347 int isvfat, void (*setup)(struct super_block *));
348
349extern int fat_flush_inodes(struct super_block *sb, struct inode *i1,
350 struct inode *i2);
351static inline unsigned long fat_dir_hash(int logstart)
352{
353 return hash_32(logstart, FAT_HASH_BITS);
354}
355
356/* fat/misc.c */
357extern __printf(3, 4) __cold
358void __fat_fs_error(struct super_block *sb, int report, const char *fmt, ...);
359#define fat_fs_error(sb, fmt, args...) \
360 __fat_fs_error(sb, 1, fmt , ## args)
361#define fat_fs_error_ratelimit(sb, fmt, args...) \
362 __fat_fs_error(sb, __ratelimit(&MSDOS_SB(sb)->ratelimit), fmt , ## args)
363__printf(3, 4) __cold
364void fat_msg(struct super_block *sb, const char *level, const char *fmt, ...);
365#define fat_msg_ratelimit(sb, level, fmt, args...) \
366 do { \
367 if (__ratelimit(&MSDOS_SB(sb)->ratelimit)) \
368 fat_msg(sb, level, fmt, ## args); \
369 } while (0)
370extern int fat_clusters_flush(struct super_block *sb);
371extern int fat_chain_add(struct inode *inode, int new_dclus, int nr_cluster);
372extern void fat_time_fat2unix(struct msdos_sb_info *sbi, struct timespec *ts,
373 __le16 __time, __le16 __date, u8 time_cs);
374extern void fat_time_unix2fat(struct msdos_sb_info *sbi, struct timespec *ts,
375 __le16 *time, __le16 *date, u8 *time_cs);
376extern int fat_sync_bhs(struct buffer_head **bhs, int nr_bhs);
377
378int fat_cache_init(void);
379void fat_cache_destroy(void);
380
381/* fat/nfs.c */
382struct fid;
383extern struct dentry *fat_fh_to_dentry(struct super_block *sb, struct fid *fid,
384 int fh_len, int fh_type);
385extern struct dentry *fat_fh_to_parent(struct super_block *sb, struct fid *fid,
386 int fh_len, int fh_type);
387extern struct dentry *fat_get_parent(struct dentry *child_dir);
388
389/* helper for printk */
390typedef unsigned long long llu;
391
392#endif /* !_FAT_H */