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
26#define FAT_NFS_STALE_RW 1 /* NFS RW support, can cause ESTALE */
27#define FAT_NFS_NOSTALE_RO 2 /* NFS RO support, no ESTALE issue */
28
29struct fat_mount_options {
30 kuid_t fs_uid;
31 kgid_t fs_gid;
32 unsigned short fs_fmask;
33 unsigned short fs_dmask;
34 unsigned short codepage; /* Codepage for shortname conversions */
35 int time_offset; /* Offset of timestamps from UTC (in minutes) */
36 char *iocharset; /* Charset used for filename input/display */
37 unsigned short shortname; /* flags for shortname display/create rule */
38 unsigned char name_check; /* r = relaxed, n = normal, s = strict */
39 unsigned char errors; /* On error: continue, panic, remount-ro */
40 unsigned char nfs; /* NFS support: nostale_ro, stale_rw */
41 unsigned short allow_utime;/* permission for setting the [am]time */
42 unsigned quiet:1, /* set = fake successful chmods and chowns */
43 showexec:1, /* set = only set x bit for com/exe/bat */
44 sys_immutable:1, /* set = system files are immutable */
45 dotsOK:1, /* set = hidden and system files are named '.filename' */
46 isvfat:1, /* 0=no vfat long filename support, 1=vfat support */
47 utf8:1, /* Use of UTF-8 character set (Default) */
48 unicode_xlate:1, /* create escape sequences for unhandled Unicode */
49 numtail:1, /* Does first alias have a numeric '~1' type tail? */
50 flush:1, /* write things quickly */
51 nocase:1, /* Does this need case conversion? 0=need case conversion*/
52 usefree:1, /* Use free_clusters for FAT32 */
53 tz_set:1, /* Filesystem timestamps' offset set */
54 rodir:1, /* allow ATTR_RO for directory */
55 discard:1, /* Issue discard requests on deletions */
56 dos1xfloppy:1; /* Assume default BPB for DOS 1.x floppies */
57};
58
59#define FAT_HASH_BITS 8
60#define FAT_HASH_SIZE (1UL << FAT_HASH_BITS)
61
62/*
63 * MS-DOS file system in-core superblock data
64 */
65struct msdos_sb_info {
66 unsigned short sec_per_clus; /* sectors/cluster */
67 unsigned short cluster_bits; /* log2(cluster_size) */
68 unsigned int cluster_size; /* cluster size */
69 unsigned char fats, fat_bits; /* number of FATs, FAT bits (12 or 16) */
70 unsigned short fat_start;
71 unsigned long fat_length; /* FAT start & length (sec.) */
72 unsigned long dir_start;
73 unsigned short dir_entries; /* root dir start & entries */
74 unsigned long data_start; /* first data sector */
75 unsigned long max_cluster; /* maximum cluster number */
76 unsigned long root_cluster; /* first cluster of the root directory */
77 unsigned long fsinfo_sector; /* sector number of FAT32 fsinfo */
78 struct mutex fat_lock;
79 struct mutex nfs_build_inode_lock;
80 struct mutex s_lock;
81 unsigned int prev_free; /* previously allocated cluster number */
82 unsigned int free_clusters; /* -1 if undefined */
83 unsigned int free_clus_valid; /* is free_clusters valid? */
84 struct fat_mount_options options;
85 struct nls_table *nls_disk; /* Codepage used on disk */
86 struct nls_table *nls_io; /* Charset used for input and display */
87 const void *dir_ops; /* Opaque; default directory operations */
88 int dir_per_block; /* dir entries per block */
89 int dir_per_block_bits; /* log2(dir_per_block) */
90 unsigned int vol_id; /*volume ID*/
91
92 int fatent_shift;
93 struct fatent_operations *fatent_ops;
94 struct inode *fat_inode;
95 struct inode *fsinfo_inode;
96
97 struct ratelimit_state ratelimit;
98
99 spinlock_t inode_hash_lock;
100 struct hlist_head inode_hashtable[FAT_HASH_SIZE];
101
102 spinlock_t dir_hash_lock;
103 struct hlist_head dir_hashtable[FAT_HASH_SIZE];
104
105 unsigned int dirty; /* fs state before mount */
106 struct rcu_head rcu;
107};
108
109#define FAT_CACHE_VALID 0 /* special case for valid cache */
110
111/*
112 * MS-DOS file system inode data in memory
113 */
114struct msdos_inode_info {
115 spinlock_t cache_lru_lock;
116 struct list_head cache_lru;
117 int nr_caches;
118 /* for avoiding the race between fat_free() and fat_get_cluster() */
119 unsigned int cache_valid_id;
120
121 /* NOTE: mmu_private is 64bits, so must hold ->i_mutex to access */
122 loff_t mmu_private; /* physically allocated size */
123
124 int i_start; /* first cluster or 0 */
125 int i_logstart; /* logical first cluster */
126 int i_attrs; /* unused attribute bits */
127 loff_t i_pos; /* on-disk position of directory entry or 0 */
128 struct hlist_node i_fat_hash; /* hash by i_location */
129 struct hlist_node i_dir_hash; /* hash by i_logstart */
130 struct rw_semaphore truncate_lock; /* protect bmap against truncate */
131 struct inode vfs_inode;
132};
133
134struct fat_slot_info {
135 loff_t i_pos; /* on-disk position of directory entry */
136 loff_t slot_off; /* offset for slot or de start */
137 int nr_slots; /* number of slots + 1(de) in filename */
138 struct msdos_dir_entry *de;
139 struct buffer_head *bh;
140};
141
142static inline struct msdos_sb_info *MSDOS_SB(struct super_block *sb)
143{
144 return sb->s_fs_info;
145}
146
147static inline struct msdos_inode_info *MSDOS_I(struct inode *inode)
148{
149 return container_of(inode, struct msdos_inode_info, vfs_inode);
150}
151
152/*
153 * If ->i_mode can't hold S_IWUGO (i.e. ATTR_RO), we use ->i_attrs to
154 * save ATTR_RO instead of ->i_mode.
155 *
156 * If it's directory and !sbi->options.rodir, ATTR_RO isn't read-only
157 * bit, it's just used as flag for app.
158 */
159static inline int fat_mode_can_hold_ro(struct inode *inode)
160{
161 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
162 umode_t mask;
163
164 if (S_ISDIR(inode->i_mode)) {
165 if (!sbi->options.rodir)
166 return 0;
167 mask = ~sbi->options.fs_dmask;
168 } else
169 mask = ~sbi->options.fs_fmask;
170
171 if (!(mask & S_IWUGO))
172 return 0;
173 return 1;
174}
175
176/* Convert attribute bits and a mask to the UNIX mode. */
177static inline umode_t fat_make_mode(struct msdos_sb_info *sbi,
178 u8 attrs, umode_t mode)
179{
180 if (attrs & ATTR_RO && !((attrs & ATTR_DIR) && !sbi->options.rodir))
181 mode &= ~S_IWUGO;
182
183 if (attrs & ATTR_DIR)
184 return (mode & ~sbi->options.fs_dmask) | S_IFDIR;
185 else
186 return (mode & ~sbi->options.fs_fmask) | S_IFREG;
187}
188
189/* Return the FAT attribute byte for this inode */
190static inline u8 fat_make_attrs(struct inode *inode)
191{
192 u8 attrs = MSDOS_I(inode)->i_attrs;
193 if (S_ISDIR(inode->i_mode))
194 attrs |= ATTR_DIR;
195 if (fat_mode_can_hold_ro(inode) && !(inode->i_mode & S_IWUGO))
196 attrs |= ATTR_RO;
197 return attrs;
198}
199
200static inline void fat_save_attrs(struct inode *inode, u8 attrs)
201{
202 if (fat_mode_can_hold_ro(inode))
203 MSDOS_I(inode)->i_attrs = attrs & ATTR_UNUSED;
204 else
205 MSDOS_I(inode)->i_attrs = attrs & (ATTR_UNUSED | ATTR_RO);
206}
207
208static inline unsigned char fat_checksum(const __u8 *name)
209{
210 unsigned char s = name[0];
211 s = (s<<7) + (s>>1) + name[1]; s = (s<<7) + (s>>1) + name[2];
212 s = (s<<7) + (s>>1) + name[3]; s = (s<<7) + (s>>1) + name[4];
213 s = (s<<7) + (s>>1) + name[5]; s = (s<<7) + (s>>1) + name[6];
214 s = (s<<7) + (s>>1) + name[7]; s = (s<<7) + (s>>1) + name[8];
215 s = (s<<7) + (s>>1) + name[9]; s = (s<<7) + (s>>1) + name[10];
216 return s;
217}
218
219static inline sector_t fat_clus_to_blknr(struct msdos_sb_info *sbi, int clus)
220{
221 return ((sector_t)clus - FAT_START_ENT) * sbi->sec_per_clus
222 + sbi->data_start;
223}
224
225static inline void fat_get_blknr_offset(struct msdos_sb_info *sbi,
226 loff_t i_pos, sector_t *blknr, int *offset)
227{
228 *blknr = i_pos >> sbi->dir_per_block_bits;
229 *offset = i_pos & (sbi->dir_per_block - 1);
230}
231
232static inline loff_t fat_i_pos_read(struct msdos_sb_info *sbi,
233 struct inode *inode)
234{
235 loff_t i_pos;
236#if BITS_PER_LONG == 32
237 spin_lock(&sbi->inode_hash_lock);
238#endif
239 i_pos = MSDOS_I(inode)->i_pos;
240#if BITS_PER_LONG == 32
241 spin_unlock(&sbi->inode_hash_lock);
242#endif
243 return i_pos;
244}
245
246static inline void fat16_towchar(wchar_t *dst, const __u8 *src, size_t len)
247{
248#ifdef __BIG_ENDIAN
249 while (len--) {
250 *dst++ = src[0] | (src[1] << 8);
251 src += 2;
252 }
253#else
254 memcpy(dst, src, len * 2);
255#endif
256}
257
258static inline int fat_get_start(const struct msdos_sb_info *sbi,
259 const struct msdos_dir_entry *de)
260{
261 int cluster = le16_to_cpu(de->start);
262 if (sbi->fat_bits == 32)
263 cluster |= (le16_to_cpu(de->starthi) << 16);
264 return cluster;
265}
266
267static inline void fat_set_start(struct msdos_dir_entry *de, int cluster)
268{
269 de->start = cpu_to_le16(cluster);
270 de->starthi = cpu_to_le16(cluster >> 16);
271}
272
273static inline void fatwchar_to16(__u8 *dst, const wchar_t *src, size_t len)
274{
275#ifdef __BIG_ENDIAN
276 while (len--) {
277 dst[0] = *src & 0x00FF;
278 dst[1] = (*src & 0xFF00) >> 8;
279 dst += 2;
280 src++;
281 }
282#else
283 memcpy(dst, src, len * 2);
284#endif
285}
286
287/* fat/cache.c */
288extern void fat_cache_inval_inode(struct inode *inode);
289extern int fat_get_cluster(struct inode *inode, int cluster,
290 int *fclus, int *dclus);
291extern int fat_bmap(struct inode *inode, sector_t sector, sector_t *phys,
292 unsigned long *mapped_blocks, int create);
293
294/* fat/dir.c */
295extern const struct file_operations fat_dir_operations;
296extern int fat_search_long(struct inode *inode, const unsigned char *name,
297 int name_len, struct fat_slot_info *sinfo);
298extern int fat_dir_empty(struct inode *dir);
299extern int fat_subdirs(struct inode *dir);
300extern int fat_scan(struct inode *dir, const unsigned char *name,
301 struct fat_slot_info *sinfo);
302extern int fat_scan_logstart(struct inode *dir, int i_logstart,
303 struct fat_slot_info *sinfo);
304extern int fat_get_dotdot_entry(struct inode *dir, struct buffer_head **bh,
305 struct msdos_dir_entry **de);
306extern int fat_alloc_new_dir(struct inode *dir, struct timespec *ts);
307extern int fat_add_entries(struct inode *dir, void *slots, int nr_slots,
308 struct fat_slot_info *sinfo);
309extern int fat_remove_entries(struct inode *dir, struct fat_slot_info *sinfo);
310
311/* fat/fatent.c */
312struct fat_entry {
313 int entry;
314 union {
315 u8 *ent12_p[2];
316 __le16 *ent16_p;
317 __le32 *ent32_p;
318 } u;
319 int nr_bhs;
320 struct buffer_head *bhs[2];
321 struct inode *fat_inode;
322};
323
324static inline void fatent_init(struct fat_entry *fatent)
325{
326 fatent->nr_bhs = 0;
327 fatent->entry = 0;
328 fatent->u.ent32_p = NULL;
329 fatent->bhs[0] = fatent->bhs[1] = NULL;
330 fatent->fat_inode = NULL;
331}
332
333static inline void fatent_set_entry(struct fat_entry *fatent, int entry)
334{
335 fatent->entry = entry;
336 fatent->u.ent32_p = NULL;
337}
338
339static inline void fatent_brelse(struct fat_entry *fatent)
340{
341 int i;
342 fatent->u.ent32_p = NULL;
343 for (i = 0; i < fatent->nr_bhs; i++)
344 brelse(fatent->bhs[i]);
345 fatent->nr_bhs = 0;
346 fatent->bhs[0] = fatent->bhs[1] = NULL;
347 fatent->fat_inode = NULL;
348}
349
350extern void fat_ent_access_init(struct super_block *sb);
351extern int fat_ent_read(struct inode *inode, struct fat_entry *fatent,
352 int entry);
353extern int fat_ent_write(struct inode *inode, struct fat_entry *fatent,
354 int new, int wait);
355extern int fat_alloc_clusters(struct inode *inode, int *cluster,
356 int nr_cluster);
357extern int fat_free_clusters(struct inode *inode, int cluster);
358extern int fat_count_free_clusters(struct super_block *sb);
359
360/* fat/file.c */
361extern long fat_generic_ioctl(struct file *filp, unsigned int cmd,
362 unsigned long arg);
363extern const struct file_operations fat_file_operations;
364extern const struct inode_operations fat_file_inode_operations;
365extern int fat_setattr(struct dentry *dentry, struct iattr *attr);
366extern void fat_truncate_blocks(struct inode *inode, loff_t offset);
367extern int fat_getattr(struct vfsmount *mnt, struct dentry *dentry,
368 struct kstat *stat);
369extern int fat_file_fsync(struct file *file, loff_t start, loff_t end,
370 int datasync);
371
372/* fat/inode.c */
373extern void fat_attach(struct inode *inode, loff_t i_pos);
374extern void fat_detach(struct inode *inode);
375extern struct inode *fat_iget(struct super_block *sb, loff_t i_pos);
376extern struct inode *fat_build_inode(struct super_block *sb,
377 struct msdos_dir_entry *de, loff_t i_pos);
378extern int fat_sync_inode(struct inode *inode);
379extern int fat_fill_super(struct super_block *sb, void *data, int silent,
380 int isvfat, void (*setup)(struct super_block *));
381extern int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de);
382
383extern int fat_flush_inodes(struct super_block *sb, struct inode *i1,
384 struct inode *i2);
385static inline unsigned long fat_dir_hash(int logstart)
386{
387 return hash_32(logstart, FAT_HASH_BITS);
388}
389
390/* fat/misc.c */
391extern __printf(3, 4) __cold
392void __fat_fs_error(struct super_block *sb, int report, const char *fmt, ...);
393#define fat_fs_error(sb, fmt, args...) \
394 __fat_fs_error(sb, 1, fmt , ## args)
395#define fat_fs_error_ratelimit(sb, fmt, args...) \
396 __fat_fs_error(sb, __ratelimit(&MSDOS_SB(sb)->ratelimit), fmt , ## args)
397__printf(3, 4) __cold
398void fat_msg(struct super_block *sb, const char *level, const char *fmt, ...);
399#define fat_msg_ratelimit(sb, level, fmt, args...) \
400 do { \
401 if (__ratelimit(&MSDOS_SB(sb)->ratelimit)) \
402 fat_msg(sb, level, fmt, ## args); \
403 } while (0)
404extern int fat_clusters_flush(struct super_block *sb);
405extern int fat_chain_add(struct inode *inode, int new_dclus, int nr_cluster);
406extern void fat_time_fat2unix(struct msdos_sb_info *sbi, struct timespec *ts,
407 __le16 __time, __le16 __date, u8 time_cs);
408extern void fat_time_unix2fat(struct msdos_sb_info *sbi, struct timespec *ts,
409 __le16 *time, __le16 *date, u8 *time_cs);
410extern int fat_sync_bhs(struct buffer_head **bhs, int nr_bhs);
411
412int fat_cache_init(void);
413void fat_cache_destroy(void);
414
415/* fat/nfs.c */
416extern const struct export_operations fat_export_ops;
417extern const struct export_operations fat_export_ops_nostale;
418
419/* helper for printk */
420typedef unsigned long long llu;
421
422#endif /* !_FAT_H */