aboutsummaryrefslogtreecommitdiffstats
path: root/fs
diff options
context:
space:
mode:
authorJoe Peterson <joe@skyrush.com>2008-07-25 04:46:47 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2008-07-25 13:53:34 -0400
commitb271e067c896ad4082b15e96077675d08db40625 (patch)
tree1837d1c988226116e277c4f71b7f57aed5a7df05 /fs
parente8938a62a85d1f487e02c3b01955b47c9598f6d2 (diff)
fatfs: add UTC timestamp option
Provide a new mount option ("tz=UTC") for DOS (vfat/msdos) filesystems, allowing timestamps to be in coordinated universal time (UTC) rather than local time in applications where doing this is advantageous. In particular, portable devices that use fat/vfat (such as digital cameras) can benefit from using UTC in their internal clocks, thus avoiding daylight saving time errors and general time ambiguity issues. The user of the device does not have to worry about changing the time when moving from place or when daylight saving changes. The new mount option, when set, disables the counter-adjustment that Linux currently makes to FAT timestamp info in anticipation of the normal userspace time zone correction. When used in this new mode, all daylight saving time and time zone handling is done in userspace as is normal for many other filesystems (like ext3). The default mode, which remains unchanged, is still appropriate when mounting volumes written in Windows (because of its use of local time). I originally based this patch on one submitted last year by Paul Collins, but I updated it to work with current source and changed variable/option naming. Ogawa Hirofumi (who maintains these filesystems) and I discussed this patch at length on lkml, and he suggested using the option name in the attached version of the patch. Barry Bouwsma pointed out a good addition to the patch as well. Signed-off-by: Joe Peterson <joe@skyrush.com> Signed-off-by: Paul Collins <paul@ondioline.org> Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Cc: Barry Bouwsma <free_beer_for_all@yahoo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs')
-rw-r--r--fs/fat/dir.c2
-rw-r--r--fs/fat/inode.c27
-rw-r--r--fs/fat/misc.c10
-rw-r--r--fs/msdos/namei.c3
-rw-r--r--fs/vfat/namei.c2
5 files changed, 30 insertions, 14 deletions
diff --git a/fs/fat/dir.c b/fs/fat/dir.c
index 4c35477bc94c..cd4a0162e10d 100644
--- a/fs/fat/dir.c
+++ b/fs/fat/dir.c
@@ -1101,7 +1101,7 @@ int fat_alloc_new_dir(struct inode *dir, struct timespec *ts)
1101 goto error_free; 1101 goto error_free;
1102 } 1102 }
1103 1103
1104 fat_date_unix2dos(ts->tv_sec, &time, &date); 1104 fat_date_unix2dos(ts->tv_sec, &time, &date, sbi->options.tz_utc);
1105 1105
1106 de = (struct msdos_dir_entry *)bhs[0]->b_data; 1106 de = (struct msdos_dir_entry *)bhs[0]->b_data;
1107 /* filling the new directory slots ("." and ".." entries) */ 1107 /* filling the new directory slots ("." and ".." entries) */
diff --git a/fs/fat/inode.c b/fs/fat/inode.c
index 60deb5fd1188..23676f9d79ce 100644
--- a/fs/fat/inode.c
+++ b/fs/fat/inode.c
@@ -382,17 +382,20 @@ static int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de)
382 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1)) 382 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
383 & ~((loff_t)sbi->cluster_size - 1)) >> 9; 383 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
384 inode->i_mtime.tv_sec = 384 inode->i_mtime.tv_sec =
385 date_dos2unix(le16_to_cpu(de->time), le16_to_cpu(de->date)); 385 date_dos2unix(le16_to_cpu(de->time), le16_to_cpu(de->date),
386 sbi->options.tz_utc);
386 inode->i_mtime.tv_nsec = 0; 387 inode->i_mtime.tv_nsec = 0;
387 if (sbi->options.isvfat) { 388 if (sbi->options.isvfat) {
388 int secs = de->ctime_cs / 100; 389 int secs = de->ctime_cs / 100;
389 int csecs = de->ctime_cs % 100; 390 int csecs = de->ctime_cs % 100;
390 inode->i_ctime.tv_sec = 391 inode->i_ctime.tv_sec =
391 date_dos2unix(le16_to_cpu(de->ctime), 392 date_dos2unix(le16_to_cpu(de->ctime),
392 le16_to_cpu(de->cdate)) + secs; 393 le16_to_cpu(de->cdate),
394 sbi->options.tz_utc) + secs;
393 inode->i_ctime.tv_nsec = csecs * 10000000; 395 inode->i_ctime.tv_nsec = csecs * 10000000;
394 inode->i_atime.tv_sec = 396 inode->i_atime.tv_sec =
395 date_dos2unix(0, le16_to_cpu(de->adate)); 397 date_dos2unix(0, le16_to_cpu(de->adate),
398 sbi->options.tz_utc);
396 inode->i_atime.tv_nsec = 0; 399 inode->i_atime.tv_nsec = 0;
397 } else 400 } else
398 inode->i_ctime = inode->i_atime = inode->i_mtime; 401 inode->i_ctime = inode->i_atime = inode->i_mtime;
@@ -591,11 +594,14 @@ retry:
591 raw_entry->attr = fat_attr(inode); 594 raw_entry->attr = fat_attr(inode);
592 raw_entry->start = cpu_to_le16(MSDOS_I(inode)->i_logstart); 595 raw_entry->start = cpu_to_le16(MSDOS_I(inode)->i_logstart);
593 raw_entry->starthi = cpu_to_le16(MSDOS_I(inode)->i_logstart >> 16); 596 raw_entry->starthi = cpu_to_le16(MSDOS_I(inode)->i_logstart >> 16);
594 fat_date_unix2dos(inode->i_mtime.tv_sec, &raw_entry->time, &raw_entry->date); 597 fat_date_unix2dos(inode->i_mtime.tv_sec, &raw_entry->time,
598 &raw_entry->date, sbi->options.tz_utc);
595 if (sbi->options.isvfat) { 599 if (sbi->options.isvfat) {
596 __le16 atime; 600 __le16 atime;
597 fat_date_unix2dos(inode->i_ctime.tv_sec,&raw_entry->ctime,&raw_entry->cdate); 601 fat_date_unix2dos(inode->i_ctime.tv_sec, &raw_entry->ctime,
598 fat_date_unix2dos(inode->i_atime.tv_sec,&atime,&raw_entry->adate); 602 &raw_entry->cdate, sbi->options.tz_utc);
603 fat_date_unix2dos(inode->i_atime.tv_sec, &atime,
604 &raw_entry->adate, sbi->options.tz_utc);
599 raw_entry->ctime_cs = (inode->i_ctime.tv_sec & 1) * 100 + 605 raw_entry->ctime_cs = (inode->i_ctime.tv_sec & 1) * 100 +
600 inode->i_ctime.tv_nsec / 10000000; 606 inode->i_ctime.tv_nsec / 10000000;
601 } 607 }
@@ -836,6 +842,8 @@ static int fat_show_options(struct seq_file *m, struct vfsmount *mnt)
836 } 842 }
837 if (sbi->options.flush) 843 if (sbi->options.flush)
838 seq_puts(m, ",flush"); 844 seq_puts(m, ",flush");
845 if (opts->tz_utc)
846 seq_puts(m, ",tz=UTC");
839 847
840 return 0; 848 return 0;
841} 849}
@@ -848,7 +856,7 @@ enum {
848 Opt_charset, Opt_shortname_lower, Opt_shortname_win95, 856 Opt_charset, Opt_shortname_lower, Opt_shortname_win95,
849 Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes, 857 Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes,
850 Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes, 858 Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes,
851 Opt_obsolate, Opt_flush, Opt_err, 859 Opt_obsolate, Opt_flush, Opt_tz_utc, Opt_err,
852}; 860};
853 861
854static match_table_t fat_tokens = { 862static match_table_t fat_tokens = {
@@ -883,6 +891,7 @@ static match_table_t fat_tokens = {
883 {Opt_obsolate, "cvf_options=%100s"}, 891 {Opt_obsolate, "cvf_options=%100s"},
884 {Opt_obsolate, "posix"}, 892 {Opt_obsolate, "posix"},
885 {Opt_flush, "flush"}, 893 {Opt_flush, "flush"},
894 {Opt_tz_utc, "tz=UTC"},
886 {Opt_err, NULL}, 895 {Opt_err, NULL},
887}; 896};
888static match_table_t msdos_tokens = { 897static match_table_t msdos_tokens = {
@@ -947,6 +956,7 @@ static int parse_options(char *options, int is_vfat, int silent, int *debug,
947 opts->utf8 = opts->unicode_xlate = 0; 956 opts->utf8 = opts->unicode_xlate = 0;
948 opts->numtail = 1; 957 opts->numtail = 1;
949 opts->usefree = opts->nocase = 0; 958 opts->usefree = opts->nocase = 0;
959 opts->tz_utc = 0;
950 *debug = 0; 960 *debug = 0;
951 961
952 if (!options) 962 if (!options)
@@ -1036,6 +1046,9 @@ static int parse_options(char *options, int is_vfat, int silent, int *debug,
1036 case Opt_flush: 1046 case Opt_flush:
1037 opts->flush = 1; 1047 opts->flush = 1;
1038 break; 1048 break;
1049 case Opt_tz_utc:
1050 opts->tz_utc = 1;
1051 break;
1039 1052
1040 /* msdos specific */ 1053 /* msdos specific */
1041 case Opt_dots: 1054 case Opt_dots:
diff --git a/fs/fat/misc.c b/fs/fat/misc.c
index 61f23511eacf..79fb98ad36d4 100644
--- a/fs/fat/misc.c
+++ b/fs/fat/misc.c
@@ -142,7 +142,7 @@ static int day_n[] = {
142}; 142};
143 143
144/* Convert a MS-DOS time/date pair to a UNIX date (seconds since 1 1 70). */ 144/* Convert a MS-DOS time/date pair to a UNIX date (seconds since 1 1 70). */
145int date_dos2unix(unsigned short time, unsigned short date) 145int date_dos2unix(unsigned short time, unsigned short date, int tz_utc)
146{ 146{
147 int month, year, secs; 147 int month, year, secs;
148 148
@@ -156,16 +156,18 @@ int date_dos2unix(unsigned short time, unsigned short date)
156 ((date & 31)-1+day_n[month]+(year/4)+year*365-((year & 3) == 0 && 156 ((date & 31)-1+day_n[month]+(year/4)+year*365-((year & 3) == 0 &&
157 month < 2 ? 1 : 0)+3653); 157 month < 2 ? 1 : 0)+3653);
158 /* days since 1.1.70 plus 80's leap day */ 158 /* days since 1.1.70 plus 80's leap day */
159 secs += sys_tz.tz_minuteswest*60; 159 if (!tz_utc)
160 secs += sys_tz.tz_minuteswest*60;
160 return secs; 161 return secs;
161} 162}
162 163
163/* Convert linear UNIX date to a MS-DOS time/date pair. */ 164/* Convert linear UNIX date to a MS-DOS time/date pair. */
164void fat_date_unix2dos(int unix_date, __le16 *time, __le16 *date) 165void fat_date_unix2dos(int unix_date, __le16 *time, __le16 *date, int tz_utc)
165{ 166{
166 int day, year, nl_day, month; 167 int day, year, nl_day, month;
167 168
168 unix_date -= sys_tz.tz_minuteswest*60; 169 if (!tz_utc)
170 unix_date -= sys_tz.tz_minuteswest*60;
169 171
170 /* Jan 1 GMT 00:00:00 1980. But what about another time zone? */ 172 /* Jan 1 GMT 00:00:00 1980. But what about another time zone? */
171 if (unix_date < 315532800) 173 if (unix_date < 315532800)
diff --git a/fs/msdos/namei.c b/fs/msdos/namei.c
index e4ad6c6b753e..e844b9809d27 100644
--- a/fs/msdos/namei.c
+++ b/fs/msdos/namei.c
@@ -237,6 +237,7 @@ static int msdos_add_entry(struct inode *dir, const unsigned char *name,
237 int is_dir, int is_hid, int cluster, 237 int is_dir, int is_hid, int cluster,
238 struct timespec *ts, struct fat_slot_info *sinfo) 238 struct timespec *ts, struct fat_slot_info *sinfo)
239{ 239{
240 struct msdos_sb_info *sbi = MSDOS_SB(dir->i_sb);
240 struct msdos_dir_entry de; 241 struct msdos_dir_entry de;
241 __le16 time, date; 242 __le16 time, date;
242 int err; 243 int err;
@@ -246,7 +247,7 @@ static int msdos_add_entry(struct inode *dir, const unsigned char *name,
246 if (is_hid) 247 if (is_hid)
247 de.attr |= ATTR_HIDDEN; 248 de.attr |= ATTR_HIDDEN;
248 de.lcase = 0; 249 de.lcase = 0;
249 fat_date_unix2dos(ts->tv_sec, &time, &date); 250 fat_date_unix2dos(ts->tv_sec, &time, &date, sbi->options.tz_utc);
250 de.cdate = de.adate = 0; 251 de.cdate = de.adate = 0;
251 de.ctime = 0; 252 de.ctime = 0;
252 de.ctime_cs = 0; 253 de.ctime_cs = 0;
diff --git a/fs/vfat/namei.c b/fs/vfat/namei.c
index b546ba69be82..155c10b4adbd 100644
--- a/fs/vfat/namei.c
+++ b/fs/vfat/namei.c
@@ -621,7 +621,7 @@ shortname:
621 memcpy(de->name, msdos_name, MSDOS_NAME); 621 memcpy(de->name, msdos_name, MSDOS_NAME);
622 de->attr = is_dir ? ATTR_DIR : ATTR_ARCH; 622 de->attr = is_dir ? ATTR_DIR : ATTR_ARCH;
623 de->lcase = lcase; 623 de->lcase = lcase;
624 fat_date_unix2dos(ts->tv_sec, &time, &date); 624 fat_date_unix2dos(ts->tv_sec, &time, &date, sbi->options.tz_utc);
625 de->time = de->ctime = time; 625 de->time = de->ctime = time;
626 de->date = de->cdate = de->adate = date; 626 de->date = de->cdate = de->adate = date;
627 de->ctime_cs = 0; 627 de->ctime_cs = 0;