[Bug-tar] Re: Check nano seconds (nsec) to accurate; extract of sym-links fails

[Raphael Bossek]

On Tue, Sep 19, 2006 at 02:26:00PM -0700, Paul Eggert wrote:
> "Raphael Bossek" <address@hidden> writes:
> 
> > --- tar-1.15.91.orig/src/extract.c
> > +++ tar-1.15.91/src/extract.c
> > @@ -918,7 +918,7 @@
> >             for (; ds; ds = ds->next)
> >               if (ds->dev == st1.st_dev
> >                   && ds->ino == st1.st_ino
> > -                 && timespec_cmp (ds->mtime, get_stat_mtime (&st1)) == 0)
> > +                 && tar_timespec_cmp (ds->mtime, get_stat_mtime (&st1)) == 
> > 0)
> >                 {
> >                   struct string_list *p =  xmalloc (offsetof (struct 
> > string_list, string)
> >                                                     + strlen (file_name) + 
> > 1);
> 
> That sort of patch doesn't look correct to me, as it is comparing two
> time stamps both gotten by 'stat' or 'lstat'.  They should be
> consistent, even if the underlying file system does not have
> full timestamp resolution.
> 
> Possibly your kernel temporarily remembers subsecond time stamp
> resolution, so long as the inode is cached, but forgets it once it's
> sent to disk?  That might explain the problem.  But that would be a
> kernel bug, not a tar bug.
This may be a kernel bug because I'm used User-Mode-Linux which is not
as stable/accurate as it should be. The problem occurs only in this
environment for me.

-- 
Raphael Bossek