diff options
Diffstat (limited to 'fs/fat/misc.c')
| -rw-r--r-- | fs/fat/misc.c | 91 |
1 files changed, 84 insertions, 7 deletions
diff --git a/fs/fat/misc.c b/fs/fat/misc.c index 573836dcaefc..fce0a76f3f1e 100644 --- a/fs/fat/misc.c +++ b/fs/fat/misc.c @@ -7,6 +7,7 @@ */ #include "fat.h" +#include <linux/iversion.h> /* * fat_fs_error reports a file system problem that might indicate fa data @@ -185,6 +186,13 @@ static long days_in_year[] = { 0, 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 0, 0, 0, }; +static inline int fat_tz_offset(struct msdos_sb_info *sbi) +{ + return (sbi->options.tz_set ? + -sbi->options.time_offset : + sys_tz.tz_minuteswest) * SECS_PER_MIN; +} + /* Convert a FAT time/date pair to a UNIX date (seconds since 1 1 70). */ void fat_time_fat2unix(struct msdos_sb_info *sbi, struct timespec64 *ts, __le16 __time, __le16 __date, u8 time_cs) @@ -210,10 +218,7 @@ void fat_time_fat2unix(struct msdos_sb_info *sbi, struct timespec64 *ts, + days_in_year[month] + day + DAYS_DELTA) * SECS_PER_DAY; - if (!sbi->options.tz_set) - second += sys_tz.tz_minuteswest * SECS_PER_MIN; - else - second -= sbi->options.time_offset * SECS_PER_MIN; + second += fat_tz_offset(sbi); if (time_cs) { ts->tv_sec = second + (time_cs / 100); @@ -229,9 +234,7 @@ void fat_time_unix2fat(struct msdos_sb_info *sbi, struct timespec64 *ts, __le16 *time, __le16 *date, u8 *time_cs) { struct tm tm; - time64_to_tm(ts->tv_sec, - (sbi->options.tz_set ? sbi->options.time_offset : - -sys_tz.tz_minuteswest) * SECS_PER_MIN, &tm); + time64_to_tm(ts->tv_sec, -fat_tz_offset(sbi), &tm); /* FAT can only support year between 1980 to 2107 */ if (tm.tm_year < 1980 - 1900) { @@ -263,6 +266,80 @@ void fat_time_unix2fat(struct msdos_sb_info *sbi, struct timespec64 *ts, } EXPORT_SYMBOL_GPL(fat_time_unix2fat); +static inline struct timespec64 fat_timespec64_trunc_2secs(struct timespec64 ts) +{ + return (struct timespec64){ ts.tv_sec & ~1ULL, 0 }; +} +/* + * truncate the various times with appropriate granularity: + * root inode: + * all times always 0 + * all other inodes: + * mtime - 2 seconds + * ctime + * msdos - 2 seconds + * vfat - 10 milliseconds + * atime - 24 hours (00:00:00 in local timezone) + */ +int fat_truncate_time(struct inode *inode, struct timespec64 *now, int flags) +{ + struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); + struct timespec64 ts; + + if (inode->i_ino == MSDOS_ROOT_INO) + return 0; + + if (now == NULL) { + now = &ts; + ts = current_time(inode); + } + + if (flags & S_ATIME) { + /* to localtime */ + time64_t seconds = now->tv_sec - fat_tz_offset(sbi); + s32 remainder; + + div_s64_rem(seconds, SECS_PER_DAY, &remainder); + /* to day boundary, and back to unix time */ + seconds = seconds + fat_tz_offset(sbi) - remainder; + + inode->i_atime = (struct timespec64){ seconds, 0 }; + } + if (flags & S_CTIME) { + if (sbi->options.isvfat) + inode->i_ctime = timespec64_trunc(*now, 10000000); + else + inode->i_ctime = fat_timespec64_trunc_2secs(*now); + } + if (flags & S_MTIME) + inode->i_mtime = fat_timespec64_trunc_2secs(*now); + + return 0; +} +EXPORT_SYMBOL_GPL(fat_truncate_time); + +int fat_update_time(struct inode *inode, struct timespec64 *now, int flags) +{ + int iflags = I_DIRTY_TIME; + bool dirty = false; + + if (inode->i_ino == MSDOS_ROOT_INO) + return 0; + + fat_truncate_time(inode, now, flags); + if (flags & S_VERSION) + dirty = inode_maybe_inc_iversion(inode, false); + if ((flags & (S_ATIME | S_CTIME | S_MTIME)) && + !(inode->i_sb->s_flags & SB_LAZYTIME)) + dirty = true; + + if (dirty) + iflags |= I_DIRTY_SYNC; + __mark_inode_dirty(inode, iflags); + return 0; +} +EXPORT_SYMBOL_GPL(fat_update_time); + int fat_sync_bhs(struct buffer_head **bhs, int nr_bhs) { int i, err = 0; |