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git.proxmox.com Git - mirror_ubuntu-bionic-kernel.git/blob - fs/fat/misc.c
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>
12 #include <linux/time.h>
16 * fat_fs_error reports a file system problem that might indicate fa data
17 * corruption/inconsistency. Depending on 'errors' mount option the
18 * panic() is called, or error message is printed FAT and nothing is done,
19 * or filesystem is remounted read-only (default behavior).
20 * In case the file system is remounted read-only, it can be made writable
21 * again by remounting it.
23 void __fat_fs_error(struct super_block
*sb
, int report
, const char *fmt
, ...)
25 struct fat_mount_options
*opts
= &MSDOS_SB(sb
)->options
;
33 fat_msg(sb
, KERN_ERR
, "error, %pV", &vaf
);
37 if (opts
->errors
== FAT_ERRORS_PANIC
)
38 panic("FAT-fs (%s): fs panic from previous error\n", sb
->s_id
);
39 else if (opts
->errors
== FAT_ERRORS_RO
&& !(sb
->s_flags
& MS_RDONLY
)) {
40 sb
->s_flags
|= MS_RDONLY
;
41 fat_msg(sb
, KERN_ERR
, "Filesystem has been set read-only");
44 EXPORT_SYMBOL_GPL(__fat_fs_error
);
47 * fat_msg() - print preformated FAT specific messages. Every thing what is
48 * not fat_fs_error() should be fat_msg().
50 void fat_msg(struct super_block
*sb
, const char *level
, const char *fmt
, ...)
58 printk("%sFAT-fs (%s): %pV\n", level
, sb
->s_id
, &vaf
);
62 /* Flushes the number of free clusters on FAT32 */
63 /* XXX: Need to write one per FSINFO block. Currently only writes 1 */
64 int fat_clusters_flush(struct super_block
*sb
)
66 struct msdos_sb_info
*sbi
= MSDOS_SB(sb
);
67 struct buffer_head
*bh
;
68 struct fat_boot_fsinfo
*fsinfo
;
70 if (sbi
->fat_bits
!= 32)
73 bh
= sb_bread(sb
, sbi
->fsinfo_sector
);
75 fat_msg(sb
, KERN_ERR
, "bread failed in fat_clusters_flush");
79 fsinfo
= (struct fat_boot_fsinfo
*)bh
->b_data
;
81 if (!IS_FSINFO(fsinfo
)) {
82 fat_msg(sb
, KERN_ERR
, "Invalid FSINFO signature: "
83 "0x%08x, 0x%08x (sector = %lu)",
84 le32_to_cpu(fsinfo
->signature1
),
85 le32_to_cpu(fsinfo
->signature2
),
88 if (sbi
->free_clusters
!= -1)
89 fsinfo
->free_clusters
= cpu_to_le32(sbi
->free_clusters
);
90 if (sbi
->prev_free
!= -1)
91 fsinfo
->next_cluster
= cpu_to_le32(sbi
->prev_free
);
92 mark_buffer_dirty(bh
);
100 * fat_chain_add() adds a new cluster to the chain of clusters represented
103 int fat_chain_add(struct inode
*inode
, int new_dclus
, int nr_cluster
)
105 struct super_block
*sb
= inode
->i_sb
;
106 struct msdos_sb_info
*sbi
= MSDOS_SB(sb
);
107 int ret
, new_fclus
, last
;
110 * We must locate the last cluster of the file to add this new
111 * one (new_dclus) to the end of the link list (the FAT).
113 last
= new_fclus
= 0;
114 if (MSDOS_I(inode
)->i_start
) {
117 ret
= fat_get_cluster(inode
, FAT_ENT_EOF
, &fclus
, &dclus
);
120 new_fclus
= fclus
+ 1;
124 /* add new one to the last of the cluster chain */
126 struct fat_entry fatent
;
128 fatent_init(&fatent
);
129 ret
= fat_ent_read(inode
, &fatent
, last
);
131 int wait
= inode_needs_sync(inode
);
132 ret
= fat_ent_write(inode
, &fatent
, new_dclus
, wait
);
133 fatent_brelse(&fatent
);
138 * FIXME:Although we can add this cache, fat_cache_add() is
139 * assuming to be called after linear search with fat_cache_id.
141 // fat_cache_add(inode, new_fclus, new_dclus);
143 MSDOS_I(inode
)->i_start
= new_dclus
;
144 MSDOS_I(inode
)->i_logstart
= new_dclus
;
146 * Since generic_write_sync() synchronizes regular files later,
147 * we sync here only directories.
149 if (S_ISDIR(inode
->i_mode
) && IS_DIRSYNC(inode
)) {
150 ret
= fat_sync_inode(inode
);
154 mark_inode_dirty(inode
);
156 if (new_fclus
!= (inode
->i_blocks
>> (sbi
->cluster_bits
- 9))) {
157 fat_fs_error(sb
, "clusters badly computed (%d != %llu)",
159 (llu
)(inode
->i_blocks
>> (sbi
->cluster_bits
- 9)));
160 fat_cache_inval_inode(inode
);
162 inode
->i_blocks
+= nr_cluster
<< (sbi
->cluster_bits
- 9);
168 * The epoch of FAT timestamp is 1980.
170 * date: 0 - 4: day (1 - 31)
171 * date: 5 - 8: month (1 - 12)
172 * date: 9 - 15: year (0 - 127) from 1980
173 * time: 0 - 4: sec (0 - 29) 2sec counts
174 * time: 5 - 10: min (0 - 59)
175 * time: 11 - 15: hour (0 - 23)
177 #define SECS_PER_MIN 60
178 #define SECS_PER_HOUR (60 * 60)
179 #define SECS_PER_DAY (SECS_PER_HOUR * 24)
180 /* days between 1.1.70 and 1.1.80 (2 leap days) */
181 #define DAYS_DELTA (365 * 10 + 2)
182 /* 120 (2100 - 1980) isn't leap year */
183 #define YEAR_2100 120
184 #define IS_LEAP_YEAR(y) (!((y) & 3) && (y) != YEAR_2100)
186 /* Linear day numbers of the respective 1sts in non-leap years. */
187 static time_t days_in_year
[] = {
188 /* Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec */
189 0, 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 0, 0, 0,
192 /* Convert a FAT time/date pair to a UNIX date (seconds since 1 1 70). */
193 void fat_time_fat2unix(struct msdos_sb_info
*sbi
, struct timespec
*ts
,
194 __le16 __time
, __le16 __date
, u8 time_cs
)
196 u16 time
= le16_to_cpu(__time
), date
= le16_to_cpu(__date
);
197 time_t second
, day
, leap_day
, month
, year
;
200 month
= max(1, (date
>> 5) & 0xf);
201 day
= max(1, date
& 0x1f) - 1;
203 leap_day
= (year
+ 3) / 4;
204 if (year
> YEAR_2100
) /* 2100 isn't leap year */
206 if (IS_LEAP_YEAR(year
) && month
> 2)
209 second
= (time
& 0x1f) << 1;
210 second
+= ((time
>> 5) & 0x3f) * SECS_PER_MIN
;
211 second
+= (time
>> 11) * SECS_PER_HOUR
;
212 second
+= (year
* 365 + leap_day
213 + days_in_year
[month
] + day
214 + DAYS_DELTA
) * SECS_PER_DAY
;
216 if (!sbi
->options
.tz_set
)
217 second
+= sys_tz
.tz_minuteswest
* SECS_PER_MIN
;
219 second
-= sbi
->options
.time_offset
* SECS_PER_MIN
;
222 ts
->tv_sec
= second
+ (time_cs
/ 100);
223 ts
->tv_nsec
= (time_cs
% 100) * 10000000;
230 /* Convert linear UNIX date to a FAT time/date pair. */
231 void fat_time_unix2fat(struct msdos_sb_info
*sbi
, struct timespec
*ts
,
232 __le16
*time
, __le16
*date
, u8
*time_cs
)
235 time_to_tm(ts
->tv_sec
,
236 (sbi
->options
.tz_set
? sbi
->options
.time_offset
:
237 -sys_tz
.tz_minuteswest
) * SECS_PER_MIN
, &tm
);
239 /* FAT can only support year between 1980 to 2107 */
240 if (tm
.tm_year
< 1980 - 1900) {
242 *date
= cpu_to_le16((0 << 9) | (1 << 5) | 1);
247 if (tm
.tm_year
> 2107 - 1900) {
248 *time
= cpu_to_le16((23 << 11) | (59 << 5) | 29);
249 *date
= cpu_to_le16((127 << 9) | (12 << 5) | 31);
255 /* from 1900 -> from 1980 */
259 /* 0~59 -> 0~29(2sec counts) */
262 *time
= cpu_to_le16(tm
.tm_hour
<< 11 | tm
.tm_min
<< 5 | tm
.tm_sec
);
263 *date
= cpu_to_le16(tm
.tm_year
<< 9 | tm
.tm_mon
<< 5 | tm
.tm_mday
);
265 *time_cs
= (ts
->tv_sec
& 1) * 100 + ts
->tv_nsec
/ 10000000;
267 EXPORT_SYMBOL_GPL(fat_time_unix2fat
);
269 int fat_sync_bhs(struct buffer_head
**bhs
, int nr_bhs
)
273 for (i
= 0; i
< nr_bhs
; i
++)
274 write_dirty_buffer(bhs
[i
], WRITE
);
276 for (i
= 0; i
< nr_bhs
; i
++) {
277 wait_on_buffer(bhs
[i
]);
278 if (!err
&& !buffer_uptodate(bhs
[i
]))