4 #include <linux/buffer_head.h>
5 #include <linux/string.h>
8 #include <linux/hash.h>
9 #include <linux/mutex.h>
10 #include <linux/ratelimit.h>
11 #include <linux/msdos_fs.h>
14 * vfat shortname flags
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 */
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 */
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 */
29 struct fat_mount_options {
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 */
58 #define FAT_HASH_BITS 8
59 #define FAT_HASH_SIZE (1UL << FAT_HASH_BITS)
62 * MS-DOS file system in-core superblock data
64 struct msdos_sb_info {
65 unsigned short sec_per_clus; /* sectors/cluster */
66 unsigned short cluster_bits; /* log2(cluster_size) */
67 unsigned int cluster_size; /* cluster size */
68 unsigned char fats, fat_bits; /* number of FATs, FAT bits (12 or 16) */
69 unsigned short fat_start;
70 unsigned long fat_length; /* FAT start & length (sec.) */
71 unsigned long dir_start;
72 unsigned short dir_entries; /* root dir start & entries */
73 unsigned long data_start; /* first data sector */
74 unsigned long max_cluster; /* maximum cluster number */
75 unsigned long root_cluster; /* first cluster of the root directory */
76 unsigned long fsinfo_sector; /* sector number of FAT32 fsinfo */
77 struct mutex fat_lock;
79 unsigned int prev_free; /* previously allocated cluster number */
80 unsigned int free_clusters; /* -1 if undefined */
81 unsigned int free_clus_valid; /* is free_clusters valid? */
82 struct fat_mount_options options;
83 struct nls_table *nls_disk; /* Codepage used on disk */
84 struct nls_table *nls_io; /* Charset used for input and display */
85 const void *dir_ops; /* Opaque; default directory operations */
86 int dir_per_block; /* dir entries per block */
87 int dir_per_block_bits; /* log2(dir_per_block) */
90 struct fatent_operations *fatent_ops;
91 struct inode *fat_inode;
92 struct inode *fsinfo_inode;
94 struct ratelimit_state ratelimit;
96 spinlock_t inode_hash_lock;
97 struct hlist_head inode_hashtable[FAT_HASH_SIZE];
99 spinlock_t dir_hash_lock;
100 struct hlist_head dir_hashtable[FAT_HASH_SIZE];
102 unsigned int dirty; /* fs state before mount */
105 #define FAT_CACHE_VALID 0 /* special case for valid cache */
108 * MS-DOS file system inode data in memory
110 struct msdos_inode_info {
111 spinlock_t cache_lru_lock;
112 struct list_head cache_lru;
114 /* for avoiding the race between fat_free() and fat_get_cluster() */
115 unsigned int cache_valid_id;
117 /* NOTE: mmu_private is 64bits, so must hold ->i_mutex to access */
118 loff_t mmu_private; /* physically allocated size */
120 int i_start; /* first cluster or 0 */
121 int i_logstart; /* logical first cluster */
122 int i_attrs; /* unused attribute bits */
123 loff_t i_pos; /* on-disk position of directory entry or 0 */
124 struct hlist_node i_fat_hash; /* hash by i_location */
125 struct hlist_node i_dir_hash; /* hash by i_logstart */
126 struct rw_semaphore truncate_lock; /* protect bmap against truncate */
127 struct inode vfs_inode;
130 struct fat_slot_info {
131 loff_t i_pos; /* on-disk position of directory entry */
132 loff_t slot_off; /* offset for slot or de start */
133 int nr_slots; /* number of slots + 1(de) in filename */
134 struct msdos_dir_entry *de;
135 struct buffer_head *bh;
138 static inline struct msdos_sb_info *MSDOS_SB(struct super_block *sb)
140 return sb->s_fs_info;
143 static inline struct msdos_inode_info *MSDOS_I(struct inode *inode)
145 return container_of(inode, struct msdos_inode_info, vfs_inode);
149 * If ->i_mode can't hold S_IWUGO (i.e. ATTR_RO), we use ->i_attrs to
150 * save ATTR_RO instead of ->i_mode.
152 * If it's directory and !sbi->options.rodir, ATTR_RO isn't read-only
153 * bit, it's just used as flag for app.
155 static inline int fat_mode_can_hold_ro(struct inode *inode)
157 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
160 if (S_ISDIR(inode->i_mode)) {
161 if (!sbi->options.rodir)
163 mask = ~sbi->options.fs_dmask;
165 mask = ~sbi->options.fs_fmask;
167 if (!(mask & S_IWUGO))
172 /* Convert attribute bits and a mask to the UNIX mode. */
173 static inline umode_t fat_make_mode(struct msdos_sb_info *sbi,
174 u8 attrs, umode_t mode)
176 if (attrs & ATTR_RO && !((attrs & ATTR_DIR) && !sbi->options.rodir))
179 if (attrs & ATTR_DIR)
180 return (mode & ~sbi->options.fs_dmask) | S_IFDIR;
182 return (mode & ~sbi->options.fs_fmask) | S_IFREG;
185 /* Return the FAT attribute byte for this inode */
186 static inline u8 fat_make_attrs(struct inode *inode)
188 u8 attrs = MSDOS_I(inode)->i_attrs;
189 if (S_ISDIR(inode->i_mode))
191 if (fat_mode_can_hold_ro(inode) && !(inode->i_mode & S_IWUGO))
196 static inline void fat_save_attrs(struct inode *inode, u8 attrs)
198 if (fat_mode_can_hold_ro(inode))
199 MSDOS_I(inode)->i_attrs = attrs & ATTR_UNUSED;
201 MSDOS_I(inode)->i_attrs = attrs & (ATTR_UNUSED | ATTR_RO);
204 static inline unsigned char fat_checksum(const __u8 *name)
206 unsigned char s = name[0];
207 s = (s<<7) + (s>>1) + name[1]; s = (s<<7) + (s>>1) + name[2];
208 s = (s<<7) + (s>>1) + name[3]; s = (s<<7) + (s>>1) + name[4];
209 s = (s<<7) + (s>>1) + name[5]; s = (s<<7) + (s>>1) + name[6];
210 s = (s<<7) + (s>>1) + name[7]; s = (s<<7) + (s>>1) + name[8];
211 s = (s<<7) + (s>>1) + name[9]; s = (s<<7) + (s>>1) + name[10];
215 static inline sector_t fat_clus_to_blknr(struct msdos_sb_info *sbi, int clus)
217 return ((sector_t)clus - FAT_START_ENT) * sbi->sec_per_clus
221 static inline loff_t fat_i_pos_read(struct msdos_sb_info *sbi,
225 #if BITS_PER_LONG == 32
226 spin_lock(&sbi->inode_hash_lock);
228 i_pos = MSDOS_I(inode)->i_pos;
229 #if BITS_PER_LONG == 32
230 spin_unlock(&sbi->inode_hash_lock);
235 static inline void fat16_towchar(wchar_t *dst, const __u8 *src, size_t len)
239 *dst++ = src[0] | (src[1] << 8);
243 memcpy(dst, src, len * 2);
247 static inline int fat_get_start(const struct msdos_sb_info *sbi,
248 const struct msdos_dir_entry *de)
250 int cluster = le16_to_cpu(de->start);
251 if (sbi->fat_bits == 32)
252 cluster |= (le16_to_cpu(de->starthi) << 16);
256 static inline void fat_set_start(struct msdos_dir_entry *de, int cluster)
258 de->start = cpu_to_le16(cluster);
259 de->starthi = cpu_to_le16(cluster >> 16);
262 static inline void fatwchar_to16(__u8 *dst, const wchar_t *src, size_t len)
266 dst[0] = *src & 0x00FF;
267 dst[1] = (*src & 0xFF00) >> 8;
272 memcpy(dst, src, len * 2);
277 extern void fat_cache_inval_inode(struct inode *inode);
278 extern int fat_get_cluster(struct inode *inode, int cluster,
279 int *fclus, int *dclus);
280 extern int fat_bmap(struct inode *inode, sector_t sector, sector_t *phys,
281 unsigned long *mapped_blocks, int create);
284 extern const struct file_operations fat_dir_operations;
285 extern int fat_search_long(struct inode *inode, const unsigned char *name,
286 int name_len, struct fat_slot_info *sinfo);
287 extern int fat_dir_empty(struct inode *dir);
288 extern int fat_subdirs(struct inode *dir);
289 extern int fat_scan(struct inode *dir, const unsigned char *name,
290 struct fat_slot_info *sinfo);
291 extern int fat_get_dotdot_entry(struct inode *dir, struct buffer_head **bh,
292 struct msdos_dir_entry **de);
293 extern int fat_alloc_new_dir(struct inode *dir, struct timespec *ts);
294 extern int fat_add_entries(struct inode *dir, void *slots, int nr_slots,
295 struct fat_slot_info *sinfo);
296 extern int fat_remove_entries(struct inode *dir, struct fat_slot_info *sinfo);
307 struct buffer_head *bhs[2];
308 struct inode *fat_inode;
311 static inline void fatent_init(struct fat_entry *fatent)
315 fatent->u.ent32_p = NULL;
316 fatent->bhs[0] = fatent->bhs[1] = NULL;
317 fatent->fat_inode = NULL;
320 static inline void fatent_set_entry(struct fat_entry *fatent, int entry)
322 fatent->entry = entry;
323 fatent->u.ent32_p = NULL;
326 static inline void fatent_brelse(struct fat_entry *fatent)
329 fatent->u.ent32_p = NULL;
330 for (i = 0; i < fatent->nr_bhs; i++)
331 brelse(fatent->bhs[i]);
333 fatent->bhs[0] = fatent->bhs[1] = NULL;
334 fatent->fat_inode = NULL;
337 extern void fat_ent_access_init(struct super_block *sb);
338 extern int fat_ent_read(struct inode *inode, struct fat_entry *fatent,
340 extern int fat_ent_write(struct inode *inode, struct fat_entry *fatent,
342 extern int fat_alloc_clusters(struct inode *inode, int *cluster,
344 extern int fat_free_clusters(struct inode *inode, int cluster);
345 extern int fat_count_free_clusters(struct super_block *sb);
348 extern long fat_generic_ioctl(struct file *filp, unsigned int cmd,
350 extern const struct file_operations fat_file_operations;
351 extern const struct inode_operations fat_file_inode_operations;
352 extern int fat_setattr(struct dentry *dentry, struct iattr *attr);
353 extern void fat_truncate_blocks(struct inode *inode, loff_t offset);
354 extern int fat_getattr(struct vfsmount *mnt, struct dentry *dentry,
356 extern int fat_file_fsync(struct file *file, loff_t start, loff_t end,
360 extern void fat_attach(struct inode *inode, loff_t i_pos);
361 extern void fat_detach(struct inode *inode);
362 extern struct inode *fat_iget(struct super_block *sb, loff_t i_pos);
363 extern struct inode *fat_build_inode(struct super_block *sb,
364 struct msdos_dir_entry *de, loff_t i_pos);
365 extern int fat_sync_inode(struct inode *inode);
366 extern int fat_fill_super(struct super_block *sb, void *data, int silent,
367 int isvfat, void (*setup)(struct super_block *));
369 extern int fat_flush_inodes(struct super_block *sb, struct inode *i1,
371 static inline unsigned long fat_dir_hash(int logstart)
373 return hash_32(logstart, FAT_HASH_BITS);
377 extern __printf(3, 4) __cold
378 void __fat_fs_error(struct super_block *sb, int report, const char *fmt, ...);
379 #define fat_fs_error(sb, fmt, args...) \
380 __fat_fs_error(sb, 1, fmt , ## args)
381 #define fat_fs_error_ratelimit(sb, fmt, args...) \
382 __fat_fs_error(sb, __ratelimit(&MSDOS_SB(sb)->ratelimit), fmt , ## args)
383 __printf(3, 4) __cold
384 void fat_msg(struct super_block *sb, const char *level, const char *fmt, ...);
385 #define fat_msg_ratelimit(sb, level, fmt, args...) \
387 if (__ratelimit(&MSDOS_SB(sb)->ratelimit)) \
388 fat_msg(sb, level, fmt, ## args); \
390 extern int fat_clusters_flush(struct super_block *sb);
391 extern int fat_chain_add(struct inode *inode, int new_dclus, int nr_cluster);
392 extern void fat_time_fat2unix(struct msdos_sb_info *sbi, struct timespec *ts,
393 __le16 __time, __le16 __date, u8 time_cs);
394 extern void fat_time_unix2fat(struct msdos_sb_info *sbi, struct timespec *ts,
395 __le16 *time, __le16 *date, u8 *time_cs);
396 extern int fat_sync_bhs(struct buffer_head **bhs, int nr_bhs);
398 int fat_cache_init(void);
399 void fat_cache_destroy(void);
403 extern struct dentry *fat_fh_to_dentry(struct super_block *sb, struct fid *fid,
404 int fh_len, int fh_type);
405 extern struct dentry *fat_fh_to_parent(struct super_block *sb, struct fid *fid,
406 int fh_len, int fh_type);
407 extern struct dentry *fat_get_parent(struct dentry *child_dir);
409 /* helper for printk */
410 typedef unsigned long long llu;