4 * Written 1992,1993 by Werner Almesberger
5 * 22/11/2000 - Fixed fat_date_unix2dos for dates earlier than 01/01/1980
6 * and date_dos2unix for date==0 by Igor Zhbanov(bsg@uniyar.ac.ru)
9 #include <linux/module.h>
11 #include <linux/buffer_head.h>
15 * fat_fs_error reports a file system problem that might indicate fa data
16 * corruption/inconsistency. Depending on 'errors' mount option the
17 * panic() is called, or error message is printed FAT and nothing is done,
18 * or filesystem is remounted read-only (default behavior).
19 * In case the file system is remounted read-only, it can be made writable
20 * again by remounting it.
22 void fat_fs_error(struct super_block
*s
, const char *fmt
, ...)
24 struct fat_mount_options
*opts
= &MSDOS_SB(s
)->options
;
27 printk(KERN_ERR
"FAT: Filesystem error (dev %s)\n", s
->s_id
);
35 if (opts
->errors
== FAT_ERRORS_PANIC
)
36 panic(" FAT fs panic from previous error\n");
37 else if (opts
->errors
== FAT_ERRORS_RO
&& !(s
->s_flags
& MS_RDONLY
)) {
38 s
->s_flags
|= MS_RDONLY
;
39 printk(KERN_ERR
" File system has been set read-only\n");
42 EXPORT_SYMBOL_GPL(fat_fs_error
);
44 /* Flushes the number of free clusters on FAT32 */
45 /* XXX: Need to write one per FSINFO block. Currently only writes 1 */
46 void fat_clusters_flush(struct super_block
*sb
)
48 struct msdos_sb_info
*sbi
= MSDOS_SB(sb
);
49 struct buffer_head
*bh
;
50 struct fat_boot_fsinfo
*fsinfo
;
52 if (sbi
->fat_bits
!= 32)
55 bh
= sb_bread(sb
, sbi
->fsinfo_sector
);
57 printk(KERN_ERR
"FAT: bread failed in fat_clusters_flush\n");
61 fsinfo
= (struct fat_boot_fsinfo
*)bh
->b_data
;
63 if (!IS_FSINFO(fsinfo
)) {
64 printk(KERN_ERR
"FAT: Invalid FSINFO signature: "
65 "0x%08x, 0x%08x (sector = %lu)\n",
66 le32_to_cpu(fsinfo
->signature1
),
67 le32_to_cpu(fsinfo
->signature2
),
70 if (sbi
->free_clusters
!= -1)
71 fsinfo
->free_clusters
= cpu_to_le32(sbi
->free_clusters
);
72 if (sbi
->prev_free
!= -1)
73 fsinfo
->next_cluster
= cpu_to_le32(sbi
->prev_free
);
74 mark_buffer_dirty(bh
);
80 * fat_chain_add() adds a new cluster to the chain of clusters represented
83 int fat_chain_add(struct inode
*inode
, int new_dclus
, int nr_cluster
)
85 struct super_block
*sb
= inode
->i_sb
;
86 struct msdos_sb_info
*sbi
= MSDOS_SB(sb
);
87 int ret
, new_fclus
, last
;
90 * We must locate the last cluster of the file to add this new
91 * one (new_dclus) to the end of the link list (the FAT).
94 if (MSDOS_I(inode
)->i_start
) {
97 ret
= fat_get_cluster(inode
, FAT_ENT_EOF
, &fclus
, &dclus
);
100 new_fclus
= fclus
+ 1;
104 /* add new one to the last of the cluster chain */
106 struct fat_entry fatent
;
108 fatent_init(&fatent
);
109 ret
= fat_ent_read(inode
, &fatent
, last
);
111 int wait
= inode_needs_sync(inode
);
112 ret
= fat_ent_write(inode
, &fatent
, new_dclus
, wait
);
113 fatent_brelse(&fatent
);
117 // fat_cache_add(inode, new_fclus, new_dclus);
119 MSDOS_I(inode
)->i_start
= new_dclus
;
120 MSDOS_I(inode
)->i_logstart
= new_dclus
;
122 * Since generic_write_sync() synchronizes regular files later,
123 * we sync here only directories.
125 if (S_ISDIR(inode
->i_mode
) && IS_DIRSYNC(inode
)) {
126 ret
= fat_sync_inode(inode
);
130 mark_inode_dirty(inode
);
132 if (new_fclus
!= (inode
->i_blocks
>> (sbi
->cluster_bits
- 9))) {
133 fat_fs_error(sb
, "clusters badly computed (%d != %llu)",
135 (llu
)(inode
->i_blocks
>> (sbi
->cluster_bits
- 9)));
136 fat_cache_inval_inode(inode
);
138 inode
->i_blocks
+= nr_cluster
<< (sbi
->cluster_bits
- 9);
143 extern struct timezone sys_tz
;
146 * The epoch of FAT timestamp is 1980.
148 * date: 0 - 4: day (1 - 31)
149 * date: 5 - 8: month (1 - 12)
150 * date: 9 - 15: year (0 - 127) from 1980
151 * time: 0 - 4: sec (0 - 29) 2sec counts
152 * time: 5 - 10: min (0 - 59)
153 * time: 11 - 15: hour (0 - 23)
155 #define SECS_PER_MIN 60
156 #define SECS_PER_HOUR (60 * 60)
157 #define SECS_PER_DAY (SECS_PER_HOUR * 24)
158 #define UNIX_SECS_1980 315532800L
159 #if BITS_PER_LONG == 64
160 #define UNIX_SECS_2108 4354819200L
162 /* days between 1.1.70 and 1.1.80 (2 leap days) */
163 #define DAYS_DELTA (365 * 10 + 2)
164 /* 120 (2100 - 1980) isn't leap year */
165 #define YEAR_2100 120
166 #define IS_LEAP_YEAR(y) (!((y) & 3) && (y) != YEAR_2100)
168 /* Linear day numbers of the respective 1sts in non-leap years. */
169 static time_t days_in_year
[] = {
170 /* Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec */
171 0, 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 0, 0, 0,
174 /* Convert a FAT time/date pair to a UNIX date (seconds since 1 1 70). */
175 void fat_time_fat2unix(struct msdos_sb_info
*sbi
, struct timespec
*ts
,
176 __le16 __time
, __le16 __date
, u8 time_cs
)
178 u16 time
= le16_to_cpu(__time
), date
= le16_to_cpu(__date
);
179 time_t second
, day
, leap_day
, month
, year
;
182 month
= max(1, (date
>> 5) & 0xf);
183 day
= max(1, date
& 0x1f) - 1;
185 leap_day
= (year
+ 3) / 4;
186 if (year
> YEAR_2100
) /* 2100 isn't leap year */
188 if (IS_LEAP_YEAR(year
) && month
> 2)
191 second
= (time
& 0x1f) << 1;
192 second
+= ((time
>> 5) & 0x3f) * SECS_PER_MIN
;
193 second
+= (time
>> 11) * SECS_PER_HOUR
;
194 second
+= (year
* 365 + leap_day
195 + days_in_year
[month
] + day
196 + DAYS_DELTA
) * SECS_PER_DAY
;
198 if (!sbi
->options
.tz_utc
)
199 second
+= sys_tz
.tz_minuteswest
* SECS_PER_MIN
;
202 ts
->tv_sec
= second
+ (time_cs
/ 100);
203 ts
->tv_nsec
= (time_cs
% 100) * 10000000;
210 /* Convert linear UNIX date to a FAT time/date pair. */
211 void fat_time_unix2fat(struct msdos_sb_info
*sbi
, struct timespec
*ts
,
212 __le16
*time
, __le16
*date
, u8
*time_cs
)
214 time_t second
= ts
->tv_sec
;
215 time_t day
, leap_day
, month
, year
;
217 if (!sbi
->options
.tz_utc
)
218 second
-= sys_tz
.tz_minuteswest
* SECS_PER_MIN
;
220 /* Jan 1 GMT 00:00:00 1980. But what about another time zone? */
221 if (second
< UNIX_SECS_1980
) {
223 *date
= cpu_to_le16((0 << 9) | (1 << 5) | 1);
228 #if BITS_PER_LONG == 64
229 if (second
>= UNIX_SECS_2108
) {
230 *time
= cpu_to_le16((23 << 11) | (59 << 5) | 29);
231 *date
= cpu_to_le16((127 << 9) | (12 << 5) | 31);
238 day
= second
/ SECS_PER_DAY
- DAYS_DELTA
;
240 leap_day
= (year
+ 3) / 4;
241 if (year
> YEAR_2100
) /* 2100 isn't leap year */
243 if (year
* 365 + leap_day
> day
)
245 leap_day
= (year
+ 3) / 4;
246 if (year
> YEAR_2100
) /* 2100 isn't leap year */
248 day
-= year
* 365 + leap_day
;
250 if (IS_LEAP_YEAR(year
) && day
== days_in_year
[3]) {
253 if (IS_LEAP_YEAR(year
) && day
> days_in_year
[3])
255 for (month
= 1; month
< 12; month
++) {
256 if (days_in_year
[month
+ 1] > day
)
260 day
-= days_in_year
[month
];
262 *time
= cpu_to_le16(((second
/ SECS_PER_HOUR
) % 24) << 11
263 | ((second
/ SECS_PER_MIN
) % 60) << 5
264 | (second
% SECS_PER_MIN
) >> 1);
265 *date
= cpu_to_le16((year
<< 9) | (month
<< 5) | (day
+ 1));
267 *time_cs
= (ts
->tv_sec
& 1) * 100 + ts
->tv_nsec
/ 10000000;
269 EXPORT_SYMBOL_GPL(fat_time_unix2fat
);
271 int fat_sync_bhs(struct buffer_head
**bhs
, int nr_bhs
)
275 ll_rw_block(SWRITE
, nr_bhs
, bhs
);
276 for (i
= 0; i
< nr_bhs
; i
++) {
277 wait_on_buffer(bhs
[i
]);
278 if (buffer_eopnotsupp(bhs
[i
])) {
279 clear_buffer_eopnotsupp(bhs
[i
]);
281 } else if (!err
&& !buffer_uptodate(bhs
[i
]))
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