1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
|
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Written 1992,1993 by Werner Almesberger
* 22/11/2000 - Fixed fat_date_unix2dos for dates earlier than 01/01/1980
* and date_dos2unix for date==0 by Igor Zhbanov(bsg@uniyar.ac.ru)
* Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.
*/
#include <linux/time.h>
#include <linux/fs.h>
#include <linux/slab.h>
#include <linux/buffer_head.h>
#include "exfat_raw.h"
#include "exfat_fs.h"
/*
* exfat_fs_error reports a file system problem that might indicate fa data
* corruption/inconsistency. Depending on 'errors' mount option the
* panic() is called, or error message is printed FAT and nothing is done,
* or filesystem is remounted read-only (default behavior).
* In case the file system is remounted read-only, it can be made writable
* again by remounting it.
*/
void __exfat_fs_error(struct super_block *sb, int report, const char *fmt, ...)
{
struct exfat_mount_options *opts = &EXFAT_SB(sb)->options;
va_list args;
struct va_format vaf;
if (report) {
va_start(args, fmt);
vaf.fmt = fmt;
vaf.va = &args;
exfat_msg(sb, KERN_ERR, "error, %pV\n", &vaf);
va_end(args);
}
if (opts->errors == EXFAT_ERRORS_PANIC) {
panic("exFAT-fs (%s): fs panic from previous error\n",
sb->s_id);
} else if (opts->errors == EXFAT_ERRORS_RO && !sb_rdonly(sb)) {
sb->s_flags |= SB_RDONLY;
exfat_msg(sb, KERN_ERR, "Filesystem has been set read-only");
}
}
/*
* exfat_msg() - print preformated EXFAT specific messages.
* All logs except what uses exfat_fs_error() should be written by exfat_msg()
*/
void exfat_msg(struct super_block *sb, const char *level, const char *fmt, ...)
{
struct va_format vaf;
va_list args;
va_start(args, fmt);
vaf.fmt = fmt;
vaf.va = &args;
/* level means KERN_ pacility level */
printk("%sexFAT-fs (%s): %pV\n", level, sb->s_id, &vaf);
va_end(args);
}
#define SECS_PER_MIN (60)
#define TIMEZONE_SEC(x) ((x) * 15 * SECS_PER_MIN)
static void exfat_adjust_tz(struct timespec64 *ts, u8 tz_off)
{
if (tz_off <= 0x3F)
ts->tv_sec -= TIMEZONE_SEC(tz_off);
else /* 0x40 <= (tz_off & 0x7F) <=0x7F */
ts->tv_sec += TIMEZONE_SEC(0x80 - tz_off);
}
/* Convert a EXFAT time/date pair to a UNIX date (seconds since 1 1 70). */
void exfat_get_entry_time(struct exfat_sb_info *sbi, struct timespec64 *ts,
u8 tz, __le16 time, __le16 date, u8 time_ms)
{
u16 t = le16_to_cpu(time);
u16 d = le16_to_cpu(date);
ts->tv_sec = mktime64(1980 + (d >> 9), d >> 5 & 0x000F, d & 0x001F,
t >> 11, (t >> 5) & 0x003F, (t & 0x001F) << 1);
/* time_ms field represent 0 ~ 199(1990 ms) */
if (time_ms) {
ts->tv_sec += time_ms / 100;
ts->tv_nsec = (time_ms % 100) * 10 * NSEC_PER_MSEC;
} else
ts->tv_nsec = 0;
if (tz & EXFAT_TZ_VALID)
/* Adjust timezone to UTC0. */
exfat_adjust_tz(ts, tz & ~EXFAT_TZ_VALID);
else
/* Convert from local time to UTC using time_offset. */
ts->tv_sec -= sbi->options.time_offset * SECS_PER_MIN;
}
/* Convert linear UNIX date to a EXFAT time/date pair. */
void exfat_set_entry_time(struct exfat_sb_info *sbi, struct timespec64 *ts,
u8 *tz, __le16 *time, __le16 *date, u8 *time_ms)
{
struct tm tm;
u16 t, d;
time64_to_tm(ts->tv_sec, 0, &tm);
t = (tm.tm_hour << 11) | (tm.tm_min << 5) | (tm.tm_sec >> 1);
d = ((tm.tm_year - 80) << 9) | ((tm.tm_mon + 1) << 5) | tm.tm_mday;
*time = cpu_to_le16(t);
*date = cpu_to_le16(d);
/* time_ms field represent 0 ~ 199(1990 ms) */
if (time_ms)
*time_ms = (tm.tm_sec & 1) * 100 +
ts->tv_nsec / (10 * NSEC_PER_MSEC);
/*
* Record 00h value for OffsetFromUtc field and 1 value for OffsetValid
* to indicate that local time and UTC are the same.
*/
*tz = EXFAT_TZ_VALID;
}
/*
* The timestamp for access_time has double seconds granularity.
* (There is no 10msIncrement field for access_time unlike create/modify_time)
* atime also has only a 2-second resolution.
*/
void exfat_truncate_atime(struct timespec64 *ts)
{
ts->tv_sec = round_down(ts->tv_sec, 2);
ts->tv_nsec = 0;
}
unsigned short exfat_calc_chksum_2byte(void *data, int len,
unsigned short chksum, int type)
{
int i;
unsigned char *c = (unsigned char *)data;
for (i = 0; i < len; i++, c++) {
if (((i == 2) || (i == 3)) && (type == CS_DIR_ENTRY))
continue;
chksum = (((chksum & 1) << 15) | ((chksum & 0xFFFE) >> 1)) +
(unsigned short)*c;
}
return chksum;
}
void exfat_update_bh(struct super_block *sb, struct buffer_head *bh, int sync)
{
set_bit(EXFAT_SB_DIRTY, &EXFAT_SB(sb)->s_state);
set_buffer_uptodate(bh);
mark_buffer_dirty(bh);
if (sync)
sync_dirty_buffer(bh);
}
void exfat_chain_set(struct exfat_chain *ec, unsigned int dir,
unsigned int size, unsigned char flags)
{
ec->dir = dir;
ec->size = size;
ec->flags = flags;
}
void exfat_chain_dup(struct exfat_chain *dup, struct exfat_chain *ec)
{
return exfat_chain_set(dup, ec->dir, ec->size, ec->flags);
}
|
