1#ifndef _FAT_H
2#define _FAT_H
3
4#include <linux/buffer_head.h>
5#include <linux/nls.h>
6#include <linux/hash.h>
7#include <linux/ratelimit.h>
8#include <linux/msdos_fs.h>
9
10/*
11 * vfat shortname flags
12 */
13#define VFAT_SFN_DISPLAY_LOWER	0x0001 /* convert to lowercase for display */
14#define VFAT_SFN_DISPLAY_WIN95	0x0002 /* emulate win95 rule for display */
15#define VFAT_SFN_DISPLAY_WINNT	0x0004 /* emulate winnt rule for display */
16#define VFAT_SFN_CREATE_WIN95	0x0100 /* emulate win95 rule for create */
17#define VFAT_SFN_CREATE_WINNT	0x0200 /* emulate winnt rule for create */
18
19#define FAT_ERRORS_CONT		1      /* ignore error and continue */
20#define FAT_ERRORS_PANIC	2      /* panic on error */
21#define FAT_ERRORS_RO		3      /* remount r/o on error */
22
23#define FAT_NFS_STALE_RW	1      /* NFS RW support, can cause ESTALE */
24#define FAT_NFS_NOSTALE_RO	2      /* NFS RO support, no ESTALE issue */
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	int time_offset;	   /* Offset of timestamps from UTC (in minutes) */
33	char *iocharset;           /* Charset used for filename input/display */
34	unsigned short shortname;  /* flags for shortname display/create rule */
35	unsigned char name_check;  /* r = relaxed, n = normal, s = strict */
36	unsigned char errors;	   /* On error: continue, panic, remount-ro */
37	unsigned char nfs;	  /* NFS support: nostale_ro, stale_rw */
38	unsigned short allow_utime;/* permission for setting the [am]time */
39	unsigned quiet:1,          /* set = fake successful chmods and chowns */
40		 showexec:1,       /* set = only set x bit for com/exe/bat */
41		 sys_immutable:1,  /* set = system files are immutable */
42		 dotsOK:1,         /* set = hidden and system files are named '.filename' */
43		 isvfat:1,         /* 0=no vfat long filename support, 1=vfat support */
44		 utf8:1,	   /* Use of UTF-8 character set (Default) */
45		 unicode_xlate:1,  /* create escape sequences for unhandled Unicode */
46		 numtail:1,        /* Does first alias have a numeric '~1' type tail? */
47		 flush:1,	   /* write things quickly */
48		 nocase:1,	   /* Does this need case conversion? 0=need case conversion*/
49		 usefree:1,	   /* Use free_clusters for FAT32 */
50		 tz_set:1,	   /* Filesystem timestamps' offset set */
51		 rodir:1,	   /* allow ATTR_RO for directory */
52		 discard:1,	   /* Issue discard requests on deletions */
53		 dos1xfloppy:1;	   /* Assume default BPB for DOS 1.x floppies */
54};
55
56#define FAT_HASH_BITS	8
57#define FAT_HASH_SIZE	(1UL << FAT_HASH_BITS)
58
59/*
60 * MS-DOS file system in-core superblock data
61 */
62struct msdos_sb_info {
63	unsigned short sec_per_clus;  /* sectors/cluster */
64	unsigned short cluster_bits;  /* log2(cluster_size) */
65	unsigned int cluster_size;    /* cluster size */
66	unsigned char fats, fat_bits; /* number of FATs, FAT bits (12,16 or 32) */
67	unsigned short fat_start;
68	unsigned long fat_length;     /* FAT start & length (sec.) */
69	unsigned long dir_start;
70	unsigned short dir_entries;   /* root dir start & entries */
71	unsigned long data_start;     /* first data sector */
72	unsigned long max_cluster;    /* maximum cluster number */
73	unsigned long root_cluster;   /* first cluster of the root directory */
74	unsigned long fsinfo_sector;  /* sector number of FAT32 fsinfo */
75	struct mutex fat_lock;
76	struct mutex nfs_build_inode_lock;
77	struct mutex s_lock;
78	unsigned int prev_free;      /* previously allocated cluster number */
79	unsigned int free_clusters;  /* -1 if undefined */
80	unsigned int free_clus_valid; /* is free_clusters valid? */
81	struct fat_mount_options options;
82	struct nls_table *nls_disk;   /* Codepage used on disk */
83	struct nls_table *nls_io;     /* Charset used for input and display */
84	const void *dir_ops;	      /* Opaque; default directory operations */
85	int dir_per_block;	      /* dir entries per block */
86	int dir_per_block_bits;	      /* log2(dir_per_block) */
87	unsigned int vol_id;		/*volume ID*/
88
89	int fatent_shift;
90	struct fatent_operations *fatent_ops;
91	struct inode *fat_inode;
92	struct inode *fsinfo_inode;
93
94	struct ratelimit_state ratelimit;
95
96	spinlock_t inode_hash_lock;
97	struct hlist_head inode_hashtable[FAT_HASH_SIZE];
98
99	spinlock_t dir_hash_lock;
100	struct hlist_head dir_hashtable[FAT_HASH_SIZE];
101
102	unsigned int dirty;           /* fs state before mount */
103	struct rcu_head rcu;
104};
105
106#define FAT_CACHE_VALID	0	/* special case for valid cache */
107
108/*
109 * MS-DOS file system inode data in memory
110 */
111struct msdos_inode_info {
112	spinlock_t cache_lru_lock;
113	struct list_head cache_lru;
114	int nr_caches;
115	/* for avoiding the race between fat_free() and fat_get_cluster() */
116	unsigned int cache_valid_id;
117
118	/* NOTE: mmu_private is 64bits, so must hold ->i_mutex to access */
119	loff_t mmu_private;	/* physically allocated size */
120
121	int i_start;		/* first cluster or 0 */
122	int i_logstart;		/* logical first cluster */
123	int i_attrs;		/* unused attribute bits */
124	loff_t i_pos;		/* on-disk position of directory entry or 0 */
125	struct hlist_node i_fat_hash;	/* hash by i_location */
126	struct hlist_node i_dir_hash;	/* hash by i_logstart */
127	struct rw_semaphore truncate_lock; /* protect bmap against truncate */
128	struct inode vfs_inode;
129};
130
131struct fat_slot_info {
132	loff_t i_pos;		/* on-disk position of directory entry */
133	loff_t slot_off;	/* offset for slot or de start */
134	int nr_slots;		/* number of slots + 1(de) in filename */
135	struct msdos_dir_entry *de;
136	struct buffer_head *bh;
137};
138
139static inline struct msdos_sb_info *MSDOS_SB(struct super_block *sb)
140{
141	return sb->s_fs_info;
142}
143
144static inline struct msdos_inode_info *MSDOS_I(struct inode *inode)
145{
146	return container_of(inode, struct msdos_inode_info, vfs_inode);
147}
148
149/*
150 * If ->i_mode can't hold S_IWUGO (i.e. ATTR_RO), we use ->i_attrs to
151 * save ATTR_RO instead of ->i_mode.
152 *
153 * If it's directory and !sbi->options.rodir, ATTR_RO isn't read-only
154 * bit, it's just used as flag for app.
155 */
156static inline int fat_mode_can_hold_ro(struct inode *inode)
157{
158	struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
159	umode_t mask;
160
161	if (S_ISDIR(inode->i_mode)) {
162		if (!sbi->options.rodir)
163			return 0;
164		mask = ~sbi->options.fs_dmask;
165	} else
166		mask = ~sbi->options.fs_fmask;
167
168	if (!(mask & S_IWUGO))
169		return 0;
170	return 1;
171}
172
173/* Convert attribute bits and a mask to the UNIX mode. */
174static inline umode_t fat_make_mode(struct msdos_sb_info *sbi,
175				   u8 attrs, umode_t mode)
176{
177	if (attrs & ATTR_RO && !((attrs & ATTR_DIR) && !sbi->options.rodir))
178		mode &= ~S_IWUGO;
179
180	if (attrs & ATTR_DIR)
181		return (mode & ~sbi->options.fs_dmask) | S_IFDIR;
182	else
183		return (mode & ~sbi->options.fs_fmask) | S_IFREG;
184}
185
186/* Return the FAT attribute byte for this inode */
187static inline u8 fat_make_attrs(struct inode *inode)
188{
189	u8 attrs = MSDOS_I(inode)->i_attrs;
190	if (S_ISDIR(inode->i_mode))
191		attrs |= ATTR_DIR;
192	if (fat_mode_can_hold_ro(inode) && !(inode->i_mode & S_IWUGO))
193		attrs |= ATTR_RO;
194	return attrs;
195}
196
197static inline void fat_save_attrs(struct inode *inode, u8 attrs)
198{
199	if (fat_mode_can_hold_ro(inode))
200		MSDOS_I(inode)->i_attrs = attrs & ATTR_UNUSED;
201	else
202		MSDOS_I(inode)->i_attrs = attrs & (ATTR_UNUSED | ATTR_RO);
203}
204
205static inline unsigned char fat_checksum(const __u8 *name)
206{
207	unsigned char s = name[0];
208	s = (s<<7) + (s>>1) + name[1];	s = (s<<7) + (s>>1) + name[2];
209	s = (s<<7) + (s>>1) + name[3];	s = (s<<7) + (s>>1) + name[4];
210	s = (s<<7) + (s>>1) + name[5];	s = (s<<7) + (s>>1) + name[6];
211	s = (s<<7) + (s>>1) + name[7];	s = (s<<7) + (s>>1) + name[8];
212	s = (s<<7) + (s>>1) + name[9];	s = (s<<7) + (s>>1) + name[10];
213	return s;
214}
215
216static inline sector_t fat_clus_to_blknr(struct msdos_sb_info *sbi, int clus)
217{
218	return ((sector_t)clus - FAT_START_ENT) * sbi->sec_per_clus
219		+ sbi->data_start;
220}
221
222static inline void fat_get_blknr_offset(struct msdos_sb_info *sbi,
223				loff_t i_pos, sector_t *blknr, int *offset)
224{
225	*blknr = i_pos >> sbi->dir_per_block_bits;
226	*offset = i_pos & (sbi->dir_per_block - 1);
227}
228
229static inline loff_t fat_i_pos_read(struct msdos_sb_info *sbi,
230					struct inode *inode)
231{
232	loff_t i_pos;
233#if BITS_PER_LONG == 32
234	spin_lock(&sbi->inode_hash_lock);
235#endif
236	i_pos = MSDOS_I(inode)->i_pos;
237#if BITS_PER_LONG == 32
238	spin_unlock(&sbi->inode_hash_lock);
239#endif
240	return i_pos;
241}
242
243static inline void fat16_towchar(wchar_t *dst, const __u8 *src, size_t len)
244{
245#ifdef __BIG_ENDIAN
246	while (len--) {
247		*dst++ = src[0] | (src[1] << 8);
248		src += 2;
249	}
250#else
251	memcpy(dst, src, len * 2);
252#endif
253}
254
255static inline int fat_get_start(const struct msdos_sb_info *sbi,
256				const struct msdos_dir_entry *de)
257{
258	int cluster = le16_to_cpu(de->start);
259	if (sbi->fat_bits == 32)
260		cluster |= (le16_to_cpu(de->starthi) << 16);
261	return cluster;
262}
263
264static inline void fat_set_start(struct msdos_dir_entry *de, int cluster)
265{
266	de->start   = cpu_to_le16(cluster);
267	de->starthi = cpu_to_le16(cluster >> 16);
268}
269
270static inline void fatwchar_to16(__u8 *dst, const wchar_t *src, size_t len)
271{
272#ifdef __BIG_ENDIAN
273	while (len--) {
274		dst[0] = *src & 0x00FF;
275		dst[1] = (*src & 0xFF00) >> 8;
276		dst += 2;
277		src++;
278	}
279#else
280	memcpy(dst, src, len * 2);
281#endif
282}
283
284/* fat/cache.c */
285extern void fat_cache_inval_inode(struct inode *inode);
286extern int fat_get_cluster(struct inode *inode, int cluster,
287			   int *fclus, int *dclus);
288extern int fat_bmap(struct inode *inode, sector_t sector, sector_t *phys,
289		    unsigned long *mapped_blocks, int create);
290
291/* fat/dir.c */
292extern const struct file_operations fat_dir_operations;
293extern int fat_search_long(struct inode *inode, const unsigned char *name,
294			   int name_len, struct fat_slot_info *sinfo);
295extern int fat_dir_empty(struct inode *dir);
296extern int fat_subdirs(struct inode *dir);
297extern int fat_scan(struct inode *dir, const unsigned char *name,
298		    struct fat_slot_info *sinfo);
299extern int fat_scan_logstart(struct inode *dir, int i_logstart,
300			     struct fat_slot_info *sinfo);
301extern int fat_get_dotdot_entry(struct inode *dir, struct buffer_head **bh,
302				struct msdos_dir_entry **de);
303extern int fat_alloc_new_dir(struct inode *dir, struct timespec *ts);
304extern int fat_add_entries(struct inode *dir, void *slots, int nr_slots,
305			   struct fat_slot_info *sinfo);
306extern int fat_remove_entries(struct inode *dir, struct fat_slot_info *sinfo);
307
308/* fat/fatent.c */
309struct fat_entry {
310	int entry;
311	union {
312		u8 *ent12_p[2];
313		__le16 *ent16_p;
314		__le32 *ent32_p;
315	} u;
316	int nr_bhs;
317	struct buffer_head *bhs[2];
318	struct inode *fat_inode;
319};
320
321static inline void fatent_init(struct fat_entry *fatent)
322{
323	fatent->nr_bhs = 0;
324	fatent->entry = 0;
325	fatent->u.ent32_p = NULL;
326	fatent->bhs[0] = fatent->bhs[1] = NULL;
327	fatent->fat_inode = NULL;
328}
329
330static inline void fatent_set_entry(struct fat_entry *fatent, int entry)
331{
332	fatent->entry = entry;
333	fatent->u.ent32_p = NULL;
334}
335
336static inline void fatent_brelse(struct fat_entry *fatent)
337{
338	int i;
339	fatent->u.ent32_p = NULL;
340	for (i = 0; i < fatent->nr_bhs; i++)
341		brelse(fatent->bhs[i]);
342	fatent->nr_bhs = 0;
343	fatent->bhs[0] = fatent->bhs[1] = NULL;
344	fatent->fat_inode = NULL;
345}
346
347extern void fat_ent_access_init(struct super_block *sb);
348extern int fat_ent_read(struct inode *inode, struct fat_entry *fatent,
349			int entry);
350extern int fat_ent_write(struct inode *inode, struct fat_entry *fatent,
351			 int new, int wait);
352extern int fat_alloc_clusters(struct inode *inode, int *cluster,
353			      int nr_cluster);
354extern int fat_free_clusters(struct inode *inode, int cluster);
355extern int fat_count_free_clusters(struct super_block *sb);
356
357/* fat/file.c */
358extern long fat_generic_ioctl(struct file *filp, unsigned int cmd,
359			      unsigned long arg);
360extern const struct file_operations fat_file_operations;
361extern const struct inode_operations fat_file_inode_operations;
362extern int fat_setattr(struct dentry *dentry, struct iattr *attr);
363extern void fat_truncate_blocks(struct inode *inode, loff_t offset);
364extern int fat_getattr(struct vfsmount *mnt, struct dentry *dentry,
365		       struct kstat *stat);
366extern int fat_file_fsync(struct file *file, loff_t start, loff_t end,
367			  int datasync);
368
369/* fat/inode.c */
370extern int fat_block_truncate_page(struct inode *inode, loff_t from);
371extern void fat_attach(struct inode *inode, loff_t i_pos);
372extern void fat_detach(struct inode *inode);
373extern struct inode *fat_iget(struct super_block *sb, loff_t i_pos);
374extern struct inode *fat_build_inode(struct super_block *sb,
375			struct msdos_dir_entry *de, loff_t i_pos);
376extern int fat_sync_inode(struct inode *inode);
377extern int fat_fill_super(struct super_block *sb, void *data, int silent,
378			  int isvfat, void (*setup)(struct super_block *));
379extern int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de);
380
381extern int fat_flush_inodes(struct super_block *sb, struct inode *i1,
382			    struct inode *i2);
383static inline unsigned long fat_dir_hash(int logstart)
384{
385	return hash_32(logstart, FAT_HASH_BITS);
386}
387
388/* fat/misc.c */
389extern __printf(3, 4) __cold
390void __fat_fs_error(struct super_block *sb, int report, const char *fmt, ...);
391#define fat_fs_error(sb, fmt, args...)		\
392	__fat_fs_error(sb, 1, fmt , ## args)
393#define fat_fs_error_ratelimit(sb, fmt, args...) \
394	__fat_fs_error(sb, __ratelimit(&MSDOS_SB(sb)->ratelimit), fmt , ## args)
395__printf(3, 4) __cold
396void fat_msg(struct super_block *sb, const char *level, const char *fmt, ...);
397#define fat_msg_ratelimit(sb, level, fmt, args...)	\
398	do {	\
399			if (__ratelimit(&MSDOS_SB(sb)->ratelimit))	\
400				fat_msg(sb, level, fmt, ## args);	\
401	 } while (0)
402extern int fat_clusters_flush(struct super_block *sb);
403extern int fat_chain_add(struct inode *inode, int new_dclus, int nr_cluster);
404extern void fat_time_fat2unix(struct msdos_sb_info *sbi, struct timespec *ts,
405			      __le16 __time, __le16 __date, u8 time_cs);
406extern void fat_time_unix2fat(struct msdos_sb_info *sbi, struct timespec *ts,
407			      __le16 *time, __le16 *date, u8 *time_cs);
408extern int fat_sync_bhs(struct buffer_head **bhs, int nr_bhs);
409
410int fat_cache_init(void);
411void fat_cache_destroy(void);
412
413/* fat/nfs.c */
414extern const struct export_operations fat_export_ops;
415extern const struct export_operations fat_export_ops_nostale;
416
417/* helper for printk */
418typedef unsigned long long	llu;
419
420#endif /* !_FAT_H */
421