On Mon, Jul 29, 2019 at 06:49:09PM -0700, Deepa Dinamani wrote:
> POSIX is ambiguous on the behavior of timestamps for
> futimens, utimensat and utimes. Whether to return an
> error or silently clamp a timestamp beyond the range
> supported by the underlying filesystems is not clear.
> 
> POSIX.1 section for futimens, utimensat and utimes says:
> (http://pubs.opengroup.org/onlinepubs/9699919799/functions/futimens.html)
> 
> The file's relevant timestamp shall be set to the greatest
> value supported by the file system that is not greater
> than the specified time.
> 
> If the tv_nsec field of a timespec structure has the special
> value UTIME_NOW, the file's relevant timestamp shall be set
> to the greatest value supported by the file system that is
> not greater than the current time.
> 
> [EINVAL]
>     A new file timestamp would be a value whose tv_sec
>     component is not a value supported by the file system.
> 
> The patch chooses to clamp the timestamps according to the
> filesystem timestamp ranges and does not return an error.
> This is in line with the behavior of utime syscall also
> since the POSIX 
> page(http://pubs.opengroup.org/onlinepubs/009695399/functions/utime.html)
> for utime does not mention returning an error or clamping like above.
> 
> Same for utimes 
> http://pubs.opengroup.org/onlinepubs/009695399/functions/utimes.html
> 
> Signed-off-by: Deepa Dinamani <deepa.ker...@gmail.com>
> ---
>  fs/utimes.c | 17 +++++++++++++----
>  1 file changed, 13 insertions(+), 4 deletions(-)
> 
> diff --git a/fs/utimes.c b/fs/utimes.c
> index 350c9c16ace1..4c1a2ce90bbc 100644
> --- a/fs/utimes.c
> +++ b/fs/utimes.c
> @@ -21,6 +21,7 @@ static int utimes_common(const struct path *path, struct 
> timespec64 *times)
>       int error;
>       struct iattr newattrs;
>       struct inode *inode = path->dentry->d_inode;
> +     struct super_block *sb = inode->i_sb;
>       struct inode *delegated_inode = NULL;
>  
>       error = mnt_want_write(path->mnt);
> @@ -36,16 +37,24 @@ static int utimes_common(const struct path *path, struct 
> timespec64 *times)
>               if (times[0].tv_nsec == UTIME_OMIT)
>                       newattrs.ia_valid &= ~ATTR_ATIME;
>               else if (times[0].tv_nsec != UTIME_NOW) {
> -                     newattrs.ia_atime.tv_sec = times[0].tv_sec;
> -                     newattrs.ia_atime.tv_nsec = times[0].tv_nsec;
> +                     newattrs.ia_atime.tv_sec =
> +                             clamp(times[0].tv_sec, sb->s_time_min, 
> sb->s_time_max);
> +                     if (times[0].tv_sec == sb->s_time_max || 
> times[0].tv_sec == sb->s_time_min)
> +                             newattrs.ia_atime.tv_nsec = 0;
> +                     else
> +                             newattrs.ia_atime.tv_nsec = times[0].tv_nsec;
>                       newattrs.ia_valid |= ATTR_ATIME_SET;
>               }
>  
>               if (times[1].tv_nsec == UTIME_OMIT)
>                       newattrs.ia_valid &= ~ATTR_MTIME;
>               else if (times[1].tv_nsec != UTIME_NOW) {
> -                     newattrs.ia_mtime.tv_sec = times[1].tv_sec;
> -                     newattrs.ia_mtime.tv_nsec = times[1].tv_nsec;
> +                     newattrs.ia_mtime.tv_sec =
> +                             clamp(times[1].tv_sec, sb->s_time_min, 
> sb->s_time_max);
> +                     if (times[1].tv_sec >= sb->s_time_max || 
> times[1].tv_sec == sb->s_time_min)

Line length.

Also, didn't you just introduce a function to clamp tv_sec and fix
granularity?  Why not just use it here?  I think this is the third time
I've seen this open-coded logic.

--D

> +                             newattrs.ia_mtime.tv_nsec = 0;
> +                     else
> +                             newattrs.ia_mtime.tv_nsec = times[1].tv_nsec;
>                       newattrs.ia_valid |= ATTR_MTIME_SET;
>               }
>               /*
> -- 
> 2.17.1
> 
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