fat: Fix and cleanup timestamp conversion

This cleans date_dos2unix()/fat_date_unix2dos() up. New code should be
much more readable.

And this fixes those old functions. Those doesn't handle 2100
correctly. 2100 isn't leap year, but old one handles it as leap year.
Also, with this, centi sec is handled and is fixed.

Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 4 insertions, 2 deletions

diff --git a/fs/fat/dir.c b/fs/fat/dir.c
index 08b23ad25f1c..a601c6d45bc0 100644
--- a/fs/fat/dir.c
+++ b/fs/fat/dir.c
@@ -1089,6 +1089,7 @@ int fat_alloc_new_dir(struct inode *dir, struct timespec *ts)
         struct msdos_dir_entry *de;
         sector_t blknr;
         __le16 date, time;
+        u8 time_cs;
         int err, cluster;
 
         err = fat_alloc_clusters(dir, &cluster, 1);
@@ -1102,7 +1103,7 @@ int fat_alloc_new_dir(struct inode *dir, struct timespec *ts)
                 goto error_free;
         }
 
-        fat_date_unix2dos(ts->tv_sec, &time, &date, sbi->options.tz_utc);
+        fat_time_unix2fat(sbi, ts, &time, &date, &time_cs);
 
         de = (struct msdos_dir_entry *)bhs[0]->b_data;
         /* filling the new directory slots ("." and ".." entries) */
@@ -1112,13 +1113,14 @@ int fat_alloc_new_dir(struct inode *dir, struct timespec *ts)
         de[0].lcase = de[1].lcase = 0;
         de[0].time = de[1].time = time;
         de[0].date = de[1].date = date;
-        de[0].ctime_cs = de[1].ctime_cs = 0;
         if (sbi->options.isvfat) {
                 /* extra timestamps */
                 de[0].ctime = de[1].ctime = time;
+                de[0].ctime_cs = de[1].ctime_cs = time_cs;
                 de[0].adate = de[0].cdate = de[1].adate = de[1].cdate = date;
         } else {
                 de[0].ctime = de[1].ctime = 0;
+                de[0].ctime_cs = de[1].ctime_cs = 0;
                 de[0].adate = de[0].cdate = de[1].adate = de[1].cdate = 0;
         }
         de[0].start = cpu_to_le16(cluster);