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v3.15
 
  1/*
  2 *  linux/fs/fat/misc.c
  3 *
  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)
  7 */
  8
  9#include <linux/module.h>
 10#include <linux/fs.h>
 11#include <linux/buffer_head.h>
 12#include <linux/time.h>
 13#include "fat.h"
 
 14
 15/*
 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.
 22 */
 23void __fat_fs_error(struct super_block *sb, int report, const char *fmt, ...)
 24{
 25	struct fat_mount_options *opts = &MSDOS_SB(sb)->options;
 26	va_list args;
 27	struct va_format vaf;
 28
 29	if (report) {
 30		va_start(args, fmt);
 31		vaf.fmt = fmt;
 32		vaf.va = &args;
 33		fat_msg(sb, KERN_ERR, "error, %pV", &vaf);
 34		va_end(args);
 35	}
 36
 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");
 42	}
 43}
 44EXPORT_SYMBOL_GPL(__fat_fs_error);
 45
 46/**
 47 * fat_msg() - print preformated FAT specific messages. Every thing what is
 48 * not fat_fs_error() should be fat_msg().
 49 */
 50void fat_msg(struct super_block *sb, const char *level, const char *fmt, ...)
 51{
 52	struct va_format vaf;
 53	va_list args;
 54
 55	va_start(args, fmt);
 56	vaf.fmt = fmt;
 57	vaf.va = &args;
 58	printk("%sFAT-fs (%s): %pV\n", level, sb->s_id, &vaf);
 59	va_end(args);
 60}
 61
 62/* Flushes the number of free clusters on FAT32 */
 63/* XXX: Need to write one per FSINFO block.  Currently only writes 1 */
 64int fat_clusters_flush(struct super_block *sb)
 65{
 66	struct msdos_sb_info *sbi = MSDOS_SB(sb);
 67	struct buffer_head *bh;
 68	struct fat_boot_fsinfo *fsinfo;
 69
 70	if (sbi->fat_bits != 32)
 71		return 0;
 72
 73	bh = sb_bread(sb, sbi->fsinfo_sector);
 74	if (bh == NULL) {
 75		fat_msg(sb, KERN_ERR, "bread failed in fat_clusters_flush");
 76		return -EIO;
 77	}
 78
 79	fsinfo = (struct fat_boot_fsinfo *)bh->b_data;
 80	/* Sanity check */
 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),
 86		       sbi->fsinfo_sector);
 87	} else {
 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);
 93	}
 94	brelse(bh);
 95
 96	return 0;
 97}
 98
 99/*
100 * fat_chain_add() adds a new cluster to the chain of clusters represented
101 * by inode.
102 */
103int fat_chain_add(struct inode *inode, int new_dclus, int nr_cluster)
104{
105	struct super_block *sb = inode->i_sb;
106	struct msdos_sb_info *sbi = MSDOS_SB(sb);
107	int ret, new_fclus, last;
108
109	/*
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).
112	 */
113	last = new_fclus = 0;
114	if (MSDOS_I(inode)->i_start) {
115		int fclus, dclus;
116
117		ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus);
118		if (ret < 0)
119			return ret;
120		new_fclus = fclus + 1;
121		last = dclus;
122	}
123
124	/* add new one to the last of the cluster chain */
125	if (last) {
126		struct fat_entry fatent;
127
128		fatent_init(&fatent);
129		ret = fat_ent_read(inode, &fatent, last);
130		if (ret >= 0) {
131			int wait = inode_needs_sync(inode);
132			ret = fat_ent_write(inode, &fatent, new_dclus, wait);
133			fatent_brelse(&fatent);
134		}
135		if (ret < 0)
136			return ret;
137		/*
138		 * FIXME:Although we can add this cache, fat_cache_add() is
139		 * assuming to be called after linear search with fat_cache_id.
140		 */
141//		fat_cache_add(inode, new_fclus, new_dclus);
142	} else {
143		MSDOS_I(inode)->i_start = new_dclus;
144		MSDOS_I(inode)->i_logstart = new_dclus;
145		/*
146		 * Since generic_write_sync() synchronizes regular files later,
147		 * we sync here only directories.
148		 */
149		if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode)) {
150			ret = fat_sync_inode(inode);
151			if (ret)
152				return ret;
153		} else
154			mark_inode_dirty(inode);
155	}
156	if (new_fclus != (inode->i_blocks >> (sbi->cluster_bits - 9))) {
157		fat_fs_error(sb, "clusters badly computed (%d != %llu)",
158			     new_fclus,
159			     (llu)(inode->i_blocks >> (sbi->cluster_bits - 9)));
160		fat_cache_inval_inode(inode);
161	}
162	inode->i_blocks += nr_cluster << (sbi->cluster_bits - 9);
163
164	return 0;
165}
166
167extern struct timezone sys_tz;
168
169/*
170 * The epoch of FAT timestamp is 1980.
171 *     :  bits :     value
172 * date:  0 -  4: day	(1 -  31)
173 * date:  5 -  8: month	(1 -  12)
174 * date:  9 - 15: year	(0 - 127) from 1980
175 * time:  0 -  4: sec	(0 -  29) 2sec counts
176 * time:  5 - 10: min	(0 -  59)
177 * time: 11 - 15: hour	(0 -  23)
178 */
179#define SECS_PER_MIN	60
180#define SECS_PER_HOUR	(60 * 60)
181#define SECS_PER_DAY	(SECS_PER_HOUR * 24)
182/* days between 1.1.70 and 1.1.80 (2 leap days) */
183#define DAYS_DELTA	(365 * 10 + 2)
184/* 120 (2100 - 1980) isn't leap year */
185#define YEAR_2100	120
186#define IS_LEAP_YEAR(y)	(!((y) & 3) && (y) != YEAR_2100)
187
188/* Linear day numbers of the respective 1sts in non-leap years. */
189static time_t days_in_year[] = {
190	/* Jan  Feb  Mar  Apr  May  Jun  Jul  Aug  Sep  Oct  Nov  Dec */
191	0,   0,  31,  59,  90, 120, 151, 181, 212, 243, 273, 304, 334, 0, 0, 0,
192};
193
 
 
 
 
 
 
 
194/* Convert a FAT time/date pair to a UNIX date (seconds since 1 1 70). */
195void fat_time_fat2unix(struct msdos_sb_info *sbi, struct timespec *ts,
196		       __le16 __time, __le16 __date, u8 time_cs)
197{
198	u16 time = le16_to_cpu(__time), date = le16_to_cpu(__date);
199	time_t second, day, leap_day, month, year;
 
200
201	year  = date >> 9;
202	month = max(1, (date >> 5) & 0xf);
203	day   = max(1, date & 0x1f) - 1;
204
205	leap_day = (year + 3) / 4;
206	if (year > YEAR_2100)		/* 2100 isn't leap year */
207		leap_day--;
208	if (IS_LEAP_YEAR(year) && month > 2)
209		leap_day++;
210
211	second =  (time & 0x1f) << 1;
212	second += ((time >> 5) & 0x3f) * SECS_PER_MIN;
213	second += (time >> 11) * SECS_PER_HOUR;
214	second += (year * 365 + leap_day
215		   + days_in_year[month] + day
216		   + DAYS_DELTA) * SECS_PER_DAY;
217
218	if (!sbi->options.tz_set)
219		second += sys_tz.tz_minuteswest * SECS_PER_MIN;
220	else
221		second -= sbi->options.time_offset * SECS_PER_MIN;
222
223	if (time_cs) {
224		ts->tv_sec = second + (time_cs / 100);
225		ts->tv_nsec = (time_cs % 100) * 10000000;
226	} else {
227		ts->tv_sec = second;
228		ts->tv_nsec = 0;
229	}
230}
231
232/* Convert linear UNIX date to a FAT time/date pair. */
233void fat_time_unix2fat(struct msdos_sb_info *sbi, struct timespec *ts,
234		       __le16 *time, __le16 *date, u8 *time_cs)
235{
236	struct tm tm;
237	time_to_tm(ts->tv_sec,
238		   (sbi->options.tz_set ? sbi->options.time_offset :
239		   -sys_tz.tz_minuteswest) * SECS_PER_MIN, &tm);
240
241	/*  FAT can only support year between 1980 to 2107 */
242	if (tm.tm_year < 1980 - 1900) {
243		*time = 0;
244		*date = cpu_to_le16((0 << 9) | (1 << 5) | 1);
245		if (time_cs)
246			*time_cs = 0;
247		return;
248	}
249	if (tm.tm_year > 2107 - 1900) {
250		*time = cpu_to_le16((23 << 11) | (59 << 5) | 29);
251		*date = cpu_to_le16((127 << 9) | (12 << 5) | 31);
252		if (time_cs)
253			*time_cs = 199;
254		return;
255	}
256
257	/* from 1900 -> from 1980 */
258	tm.tm_year -= 80;
259	/* 0~11 -> 1~12 */
260	tm.tm_mon++;
261	/* 0~59 -> 0~29(2sec counts) */
262	tm.tm_sec >>= 1;
263
264	*time = cpu_to_le16(tm.tm_hour << 11 | tm.tm_min << 5 | tm.tm_sec);
265	*date = cpu_to_le16(tm.tm_year << 9 | tm.tm_mon << 5 | tm.tm_mday);
266	if (time_cs)
267		*time_cs = (ts->tv_sec & 1) * 100 + ts->tv_nsec / 10000000;
268}
269EXPORT_SYMBOL_GPL(fat_time_unix2fat);
270
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
271int fat_sync_bhs(struct buffer_head **bhs, int nr_bhs)
272{
273	int i, err = 0;
274
275	for (i = 0; i < nr_bhs; i++)
276		write_dirty_buffer(bhs[i], WRITE);
277
278	for (i = 0; i < nr_bhs; i++) {
279		wait_on_buffer(bhs[i]);
280		if (!err && !buffer_uptodate(bhs[i]))
281			err = -EIO;
282	}
283	return err;
284}
v5.9
  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 *  linux/fs/fat/misc.c
  4 *
  5 *  Written 1992,1993 by Werner Almesberger
  6 *  22/11/2000 - Fixed fat_date_unix2dos for dates earlier than 01/01/1980
  7 *		 and date_dos2unix for date==0 by Igor Zhbanov(bsg@uniyar.ac.ru)
  8 */
  9
 
 
 
 
 10#include "fat.h"
 11#include <linux/iversion.h>
 12
 13/*
 14 * fat_fs_error reports a file system problem that might indicate fa data
 15 * corruption/inconsistency. Depending on 'errors' mount option the
 16 * panic() is called, or error message is printed FAT and nothing is done,
 17 * or filesystem is remounted read-only (default behavior).
 18 * In case the file system is remounted read-only, it can be made writable
 19 * again by remounting it.
 20 */
 21void __fat_fs_error(struct super_block *sb, int report, const char *fmt, ...)
 22{
 23	struct fat_mount_options *opts = &MSDOS_SB(sb)->options;
 24	va_list args;
 25	struct va_format vaf;
 26
 27	if (report) {
 28		va_start(args, fmt);
 29		vaf.fmt = fmt;
 30		vaf.va = &args;
 31		fat_msg(sb, KERN_ERR, "error, %pV", &vaf);
 32		va_end(args);
 33	}
 34
 35	if (opts->errors == FAT_ERRORS_PANIC)
 36		panic("FAT-fs (%s): fs panic from previous error\n", sb->s_id);
 37	else if (opts->errors == FAT_ERRORS_RO && !sb_rdonly(sb)) {
 38		sb->s_flags |= SB_RDONLY;
 39		fat_msg(sb, KERN_ERR, "Filesystem has been set read-only");
 40	}
 41}
 42EXPORT_SYMBOL_GPL(__fat_fs_error);
 43
 44/**
 45 * fat_msg() - print preformated FAT specific messages. Every thing what is
 46 * not fat_fs_error() should be fat_msg().
 47 */
 48void fat_msg(struct super_block *sb, const char *level, const char *fmt, ...)
 49{
 50	struct va_format vaf;
 51	va_list args;
 52
 53	va_start(args, fmt);
 54	vaf.fmt = fmt;
 55	vaf.va = &args;
 56	printk("%sFAT-fs (%s): %pV\n", level, sb->s_id, &vaf);
 57	va_end(args);
 58}
 59
 60/* Flushes the number of free clusters on FAT32 */
 61/* XXX: Need to write one per FSINFO block.  Currently only writes 1 */
 62int fat_clusters_flush(struct super_block *sb)
 63{
 64	struct msdos_sb_info *sbi = MSDOS_SB(sb);
 65	struct buffer_head *bh;
 66	struct fat_boot_fsinfo *fsinfo;
 67
 68	if (!is_fat32(sbi))
 69		return 0;
 70
 71	bh = sb_bread(sb, sbi->fsinfo_sector);
 72	if (bh == NULL) {
 73		fat_msg(sb, KERN_ERR, "bread failed in fat_clusters_flush");
 74		return -EIO;
 75	}
 76
 77	fsinfo = (struct fat_boot_fsinfo *)bh->b_data;
 78	/* Sanity check */
 79	if (!IS_FSINFO(fsinfo)) {
 80		fat_msg(sb, KERN_ERR, "Invalid FSINFO signature: "
 81		       "0x%08x, 0x%08x (sector = %lu)",
 82		       le32_to_cpu(fsinfo->signature1),
 83		       le32_to_cpu(fsinfo->signature2),
 84		       sbi->fsinfo_sector);
 85	} else {
 86		if (sbi->free_clusters != -1)
 87			fsinfo->free_clusters = cpu_to_le32(sbi->free_clusters);
 88		if (sbi->prev_free != -1)
 89			fsinfo->next_cluster = cpu_to_le32(sbi->prev_free);
 90		mark_buffer_dirty(bh);
 91	}
 92	brelse(bh);
 93
 94	return 0;
 95}
 96
 97/*
 98 * fat_chain_add() adds a new cluster to the chain of clusters represented
 99 * by inode.
100 */
101int fat_chain_add(struct inode *inode, int new_dclus, int nr_cluster)
102{
103	struct super_block *sb = inode->i_sb;
104	struct msdos_sb_info *sbi = MSDOS_SB(sb);
105	int ret, new_fclus, last;
106
107	/*
108	 * We must locate the last cluster of the file to add this new
109	 * one (new_dclus) to the end of the link list (the FAT).
110	 */
111	last = new_fclus = 0;
112	if (MSDOS_I(inode)->i_start) {
113		int fclus, dclus;
114
115		ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus);
116		if (ret < 0)
117			return ret;
118		new_fclus = fclus + 1;
119		last = dclus;
120	}
121
122	/* add new one to the last of the cluster chain */
123	if (last) {
124		struct fat_entry fatent;
125
126		fatent_init(&fatent);
127		ret = fat_ent_read(inode, &fatent, last);
128		if (ret >= 0) {
129			int wait = inode_needs_sync(inode);
130			ret = fat_ent_write(inode, &fatent, new_dclus, wait);
131			fatent_brelse(&fatent);
132		}
133		if (ret < 0)
134			return ret;
135		/*
136		 * FIXME:Although we can add this cache, fat_cache_add() is
137		 * assuming to be called after linear search with fat_cache_id.
138		 */
139//		fat_cache_add(inode, new_fclus, new_dclus);
140	} else {
141		MSDOS_I(inode)->i_start = new_dclus;
142		MSDOS_I(inode)->i_logstart = new_dclus;
143		/*
144		 * Since generic_write_sync() synchronizes regular files later,
145		 * we sync here only directories.
146		 */
147		if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode)) {
148			ret = fat_sync_inode(inode);
149			if (ret)
150				return ret;
151		} else
152			mark_inode_dirty(inode);
153	}
154	if (new_fclus != (inode->i_blocks >> (sbi->cluster_bits - 9))) {
155		fat_fs_error(sb, "clusters badly computed (%d != %llu)",
156			     new_fclus,
157			     (llu)(inode->i_blocks >> (sbi->cluster_bits - 9)));
158		fat_cache_inval_inode(inode);
159	}
160	inode->i_blocks += nr_cluster << (sbi->cluster_bits - 9);
161
162	return 0;
163}
164
 
 
165/*
166 * The epoch of FAT timestamp is 1980.
167 *     :  bits :     value
168 * date:  0 -  4: day	(1 -  31)
169 * date:  5 -  8: month	(1 -  12)
170 * date:  9 - 15: year	(0 - 127) from 1980
171 * time:  0 -  4: sec	(0 -  29) 2sec counts
172 * time:  5 - 10: min	(0 -  59)
173 * time: 11 - 15: hour	(0 -  23)
174 */
175#define SECS_PER_MIN	60
176#define SECS_PER_HOUR	(60 * 60)
177#define SECS_PER_DAY	(SECS_PER_HOUR * 24)
178/* days between 1.1.70 and 1.1.80 (2 leap days) */
179#define DAYS_DELTA	(365 * 10 + 2)
180/* 120 (2100 - 1980) isn't leap year */
181#define YEAR_2100	120
182#define IS_LEAP_YEAR(y)	(!((y) & 3) && (y) != YEAR_2100)
183
184/* Linear day numbers of the respective 1sts in non-leap years. */
185static long days_in_year[] = {
186	/* Jan  Feb  Mar  Apr  May  Jun  Jul  Aug  Sep  Oct  Nov  Dec */
187	0,   0,  31,  59,  90, 120, 151, 181, 212, 243, 273, 304, 334, 0, 0, 0,
188};
189
190static inline int fat_tz_offset(struct msdos_sb_info *sbi)
191{
192	return (sbi->options.tz_set ?
193	       -sbi->options.time_offset :
194	       sys_tz.tz_minuteswest) * SECS_PER_MIN;
195}
196
197/* Convert a FAT time/date pair to a UNIX date (seconds since 1 1 70). */
198void fat_time_fat2unix(struct msdos_sb_info *sbi, struct timespec64 *ts,
199		       __le16 __time, __le16 __date, u8 time_cs)
200{
201	u16 time = le16_to_cpu(__time), date = le16_to_cpu(__date);
202	time64_t second;
203	long day, leap_day, month, year;
204
205	year  = date >> 9;
206	month = max(1, (date >> 5) & 0xf);
207	day   = max(1, date & 0x1f) - 1;
208
209	leap_day = (year + 3) / 4;
210	if (year > YEAR_2100)		/* 2100 isn't leap year */
211		leap_day--;
212	if (IS_LEAP_YEAR(year) && month > 2)
213		leap_day++;
214
215	second =  (time & 0x1f) << 1;
216	second += ((time >> 5) & 0x3f) * SECS_PER_MIN;
217	second += (time >> 11) * SECS_PER_HOUR;
218	second += (time64_t)(year * 365 + leap_day
219		   + days_in_year[month] + day
220		   + DAYS_DELTA) * SECS_PER_DAY;
221
222	second += fat_tz_offset(sbi);
 
 
 
223
224	if (time_cs) {
225		ts->tv_sec = second + (time_cs / 100);
226		ts->tv_nsec = (time_cs % 100) * 10000000;
227	} else {
228		ts->tv_sec = second;
229		ts->tv_nsec = 0;
230	}
231}
232
233/* Convert linear UNIX date to a FAT time/date pair. */
234void fat_time_unix2fat(struct msdos_sb_info *sbi, struct timespec64 *ts,
235		       __le16 *time, __le16 *date, u8 *time_cs)
236{
237	struct tm tm;
238	time64_to_tm(ts->tv_sec, -fat_tz_offset(sbi), &tm);
 
 
239
240	/*  FAT can only support year between 1980 to 2107 */
241	if (tm.tm_year < 1980 - 1900) {
242		*time = 0;
243		*date = cpu_to_le16((0 << 9) | (1 << 5) | 1);
244		if (time_cs)
245			*time_cs = 0;
246		return;
247	}
248	if (tm.tm_year > 2107 - 1900) {
249		*time = cpu_to_le16((23 << 11) | (59 << 5) | 29);
250		*date = cpu_to_le16((127 << 9) | (12 << 5) | 31);
251		if (time_cs)
252			*time_cs = 199;
253		return;
254	}
255
256	/* from 1900 -> from 1980 */
257	tm.tm_year -= 80;
258	/* 0~11 -> 1~12 */
259	tm.tm_mon++;
260	/* 0~59 -> 0~29(2sec counts) */
261	tm.tm_sec >>= 1;
262
263	*time = cpu_to_le16(tm.tm_hour << 11 | tm.tm_min << 5 | tm.tm_sec);
264	*date = cpu_to_le16(tm.tm_year << 9 | tm.tm_mon << 5 | tm.tm_mday);
265	if (time_cs)
266		*time_cs = (ts->tv_sec & 1) * 100 + ts->tv_nsec / 10000000;
267}
268EXPORT_SYMBOL_GPL(fat_time_unix2fat);
269
270static inline struct timespec64 fat_timespec64_trunc_2secs(struct timespec64 ts)
271{
272	return (struct timespec64){ ts.tv_sec & ~1ULL, 0 };
273}
274
275static inline struct timespec64 fat_timespec64_trunc_10ms(struct timespec64 ts)
276{
277	if (ts.tv_nsec)
278		ts.tv_nsec -= ts.tv_nsec % 10000000UL;
279	return ts;
280}
281
282/*
283 * truncate the various times with appropriate granularity:
284 *   root inode:
285 *     all times always 0
286 *   all other inodes:
287 *     mtime - 2 seconds
288 *     ctime
289 *       msdos - 2 seconds
290 *       vfat  - 10 milliseconds
291 *     atime - 24 hours (00:00:00 in local timezone)
292 */
293int fat_truncate_time(struct inode *inode, struct timespec64 *now, int flags)
294{
295	struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
296	struct timespec64 ts;
297
298	if (inode->i_ino == MSDOS_ROOT_INO)
299		return 0;
300
301	if (now == NULL) {
302		now = &ts;
303		ts = current_time(inode);
304	}
305
306	if (flags & S_ATIME) {
307		/* to localtime */
308		time64_t seconds = now->tv_sec - fat_tz_offset(sbi);
309		s32 remainder;
310
311		div_s64_rem(seconds, SECS_PER_DAY, &remainder);
312		/* to day boundary, and back to unix time */
313		seconds = seconds + fat_tz_offset(sbi) - remainder;
314
315		inode->i_atime = (struct timespec64){ seconds, 0 };
316	}
317	if (flags & S_CTIME) {
318		if (sbi->options.isvfat)
319			inode->i_ctime = fat_timespec64_trunc_10ms(*now);
320		else
321			inode->i_ctime = fat_timespec64_trunc_2secs(*now);
322	}
323	if (flags & S_MTIME)
324		inode->i_mtime = fat_timespec64_trunc_2secs(*now);
325
326	return 0;
327}
328EXPORT_SYMBOL_GPL(fat_truncate_time);
329
330int fat_update_time(struct inode *inode, struct timespec64 *now, int flags)
331{
332	int iflags = I_DIRTY_TIME;
333	bool dirty = false;
334
335	if (inode->i_ino == MSDOS_ROOT_INO)
336		return 0;
337
338	fat_truncate_time(inode, now, flags);
339	if (flags & S_VERSION)
340		dirty = inode_maybe_inc_iversion(inode, false);
341	if ((flags & (S_ATIME | S_CTIME | S_MTIME)) &&
342	    !(inode->i_sb->s_flags & SB_LAZYTIME))
343		dirty = true;
344
345	if (dirty)
346		iflags |= I_DIRTY_SYNC;
347	__mark_inode_dirty(inode, iflags);
348	return 0;
349}
350EXPORT_SYMBOL_GPL(fat_update_time);
351
352int fat_sync_bhs(struct buffer_head **bhs, int nr_bhs)
353{
354	int i, err = 0;
355
356	for (i = 0; i < nr_bhs; i++)
357		write_dirty_buffer(bhs[i], 0);
358
359	for (i = 0; i < nr_bhs; i++) {
360		wait_on_buffer(bhs[i]);
361		if (!err && !buffer_uptodate(bhs[i]))
362			err = -EIO;
363	}
364	return err;
365}