On Mon, 2019-07-29 at 18:49 -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.kernel@xxxxxxxxx> > --- > 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) This is testing the un-clamped value. > + 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) Similarly here, for the minimum. I suggest testing for clamping like this: if (newattrs.ia_atime.tv_sec != times[0].tv_sec) ... if (newattrs.ia_mtime.tv_sec != times[1].tv_sec) ... Ben. > + newattrs.ia_mtime.tv_nsec = 0; > + else > + newattrs.ia_mtime.tv_nsec = times[1].tv_nsec; > newattrs.ia_valid |= ATTR_MTIME_SET; > } > /* -- Ben Hutchings, Software Developer Codethink Ltd https://www.codethink.co.uk/ Dale House, 35 Dale Street Manchester, M1 2HF, United Kingdom
