Re: [RFC][PATCH 13/14] ext3 whiteout support

Jan Blunck
2007-05-15T08:31:59Z

On 5/15/07, Bharata B Rao <bharata@linux.vnet.ibm.com> wrote:
> On Mon, May 14, 2007 at 01:16:57PM -0700, Badari Pulavarty wrote:
> > On Mon, 2007-05-14 at 15:14 +0530, Bharata B Rao wrote:
> > > From: Bharata B Rao <bharata@linux.vnet.ibm.com>
> > >
> > > +static int ext3_whiteout(struct inode *dir, struct dentry *dentry)
> > > +{
> > > + struct inode * inode;
> > > + int err, retries = 0;
> > > + handle_t *handle;
> > > +
> > > +retry:
> > > + handle = ext3_journal_start(dir, EXT3_DATA_TRANS_BLOCKS(dir->i_sb) +
> > > + EXT3_INDEX_EXTRA_TRANS_BLOCKS + 3 +
> > > + 2*EXT3_QUOTA_INIT_BLOCKS(dir->i_sb));
> > > + if (IS_ERR(handle))
> > > + return PTR_ERR(handle);
> > > +
> > > + if (IS_DIRSYNC(dir))
> > > + handle->h_sync = 1;
> > > +
> > > + inode = ext3_new_inode (handle, dir, S_IFWHT | S_IRUGO);
> > > + err = PTR_ERR(inode);
> > > + if (IS_ERR(inode))
> > > + goto out_stop;
> >
> > Don't you need to call init_special_inode() here ?
> > Or this is handled somewhere else ?
>
> Whiteout doesn't have any attributes and hence we are not explicitly
> doing init_special_inode() on this. Accesses to whiteout files are trapped
> at the VFS lookup itself and creation and deletion of whiteouts are handled
> automatically by VFS. So I believe init_special_inode() isn't necessary
> on a whiteout file.
>

I added default whiteout file operations. So calling
init_special_inode() seems to make sense.

I know the ext2/ext3 whiteout patches are not really where they should
be. I plan to use a reserved inode number to reflect the case that the
inode itself doesn't have any attributes itself. It makes sense to
have a singleton whiteout inode per superblock.