diff options
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/inode.c | 33 |
1 files changed, 32 insertions, 1 deletions
diff --git a/fs/inode.c b/fs/inode.c index 0f1e3b563c47..64bf28cf05cd 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -2167,6 +2167,37 @@ struct timespec64 timespec64_trunc(struct timespec64 t, unsigned gran) EXPORT_SYMBOL(timespec64_trunc); /** + * timestamp_truncate - Truncate timespec to a granularity + * @t: Timespec + * @inode: inode being updated + * + * Truncate a timespec to the granularity supported by the fs + * containing the inode. Always rounds down. gran must + * not be 0 nor greater than a second (NSEC_PER_SEC, or 10^9 ns). + */ +struct timespec64 timestamp_truncate(struct timespec64 t, struct inode *inode) +{ + struct super_block *sb = inode->i_sb; + unsigned int gran = sb->s_time_gran; + + t.tv_sec = clamp(t.tv_sec, sb->s_time_min, sb->s_time_max); + if (unlikely(t.tv_sec == sb->s_time_max || t.tv_sec == sb->s_time_min)) + t.tv_nsec = 0; + + /* Avoid division in the common cases 1 ns and 1 s. */ + if (gran == 1) + ; /* nothing */ + else if (gran == NSEC_PER_SEC) + t.tv_nsec = 0; + else if (gran > 1 && gran < NSEC_PER_SEC) + t.tv_nsec -= t.tv_nsec % gran; + else + WARN(1, "invalid file time granularity: %u", gran); + return t; +} +EXPORT_SYMBOL(timestamp_truncate); + +/** * current_time - Return FS time * @inode: inode. * @@ -2187,7 +2218,7 @@ struct timespec64 current_time(struct inode *inode) return now; } - return timespec64_trunc(now, inode->i_sb->s_time_gran); + return timestamp_truncate(now, inode); } EXPORT_SYMBOL(current_time); |