Re: [PATCH 14/38] fallthru: ext2 fallthru support

From: Valerie Aurora
Date: Sun Aug 08 2010 - 12:41:18 EST


On Fri, Aug 06, 2010 at 06:28:29PM -0600, Andreas Dilger wrote:
> On 2010-08-06, at 16:35, Valerie Aurora wrote:
> > XXX What to do for d_ino for fallthrus? If we return the inode from
> > the the underlying file system, it comes from a different inode
> > "namespace" and that will produce spurious matches. This argues for
> > implementation of fallthrus as symlinks because they have to allocate
> > an inode (and inode number) anyway, and we can later reuse it if we
> > copy the file up.
> >
> > @@ -342,6 +344,24 @@ ext2_readdir (struct file * filp, void * dirent, + /* XXX We don't know the inode number
> > + * of the directory entry in the
> > + * underlying file system. Should
> > + * look it up, either on fallthru
> > + * creation at first readdir or now at
> > + * filldir time. */
> > + over = filldir(dirent, de->name, de->name_len,
> > + (n<<PAGE_CACHE_SHIFT) | offset,
> > + 123 /* Made up ino */, d_type);
>
> I don't think it makes sense to use "123" for the inode number. This is a valid inode number, and almost certainly one that will be in use in most filesystems. One option for extN is to use EXT2_BAD_INO (1).

The next version (Subject: Union mounts - return d_ino from lower fs)
fixed this. Take a look and tell me what you think?

-VAL
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