timespec_trunc() function is used to truncate a filesystem timestamp to the right granularity. But, the function does not clamp tv_sec part of the timestamps according to the filesystem timestamp limits.
The replacement api: timestamp_truncate() also alters the signature of the function to accommodate filesystem timestamp clamping according to flesystem limits.
Note that the tv_nsec part is set to 0 if tv_sec is not within the range supported for the filesystem.
Signed-off-by: Deepa Dinamani deepa.kernel@gmail.com --- fs/inode.c | 33 ++++++++++++++++++++++++++++++++- include/linux/fs.h | 2 ++ 2 files changed, 34 insertions(+), 1 deletion(-)
diff --git a/fs/inode.c b/fs/inode.c index ef33fdf0105f..fef457a42882 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -2169,6 +2169,37 @@ 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. @@ -2190,7 +2221,7 @@ 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);
diff --git a/include/linux/fs.h b/include/linux/fs.h index 93c440d22547..1170d8260aa2 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -737,6 +737,8 @@ struct inode { void *i_private; /* fs or device private pointer */ } __randomize_layout;
+struct timespec64 timestamp_truncate(struct timespec64 t, struct inode *inode); + static inline unsigned int i_blocksize(const struct inode *node) { return (1 << node->i_blkbits);