Re: BIG files & file systems

From: Stephen Lord (lord@sgi.com)
Date: Thu Aug 01 2002 - 19:09:37 EST


On Wed, 2002-07-31 at 22:51, Jan Harkes wrote:
> On Wed, Jul 31, 2002 at 05:13:46PM -0400, Alexander Viro wrote:
> > On Wed, 31 Jul 2002, Jan Harkes wrote:
> > > On Wed, Jul 31, 2002 at 01:16:20PM -0600, Peter J. Braam wrote:
> > > > I've just been told that some "limitations" of the following kind will
> > > > remain:
> > > > page index = unsigned long
> > > > ino_t = unsigned long
> > >
> > > The number of files is not limited by ino_t, just look at the
> > > iget5_locked operation in fs/inode.c. It is possible to have your own
> > > n-bit file identifier, and simply provide your own comparison function.
> > > The ino_t then becomes the 'hash-bucket' in which the actual inode is
> > > looked up.
> >
> > You _do_ need unique ->st_ino from stat(2), though - otherwise tar(1)
> > and friends will break in all sorts of amusing ways. And there's
> > nothing kernel can do about that - applications expect 32bit st_ino
> > (compare them as 32bit values, etc.)
>
> Which is why "tar and friends" are to different extents already broken
> on various filesystems like Coda, NFS, NTFS, ReiserFS, and probably XFS.
> (i.e. anything that currently uses iget5_locked instead of iget to grab
> the inode).

Why are they broken? In the case of XFS at least you still get a unique
and stable inode number back - and it fits in 32 bits too.

Steve

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/



This archive was generated by hypermail 2b29 : Wed Aug 07 2002 - 22:00:17 EST