Re: [rfc][patch 3/4] fs: new truncate sequence

Nick Piggin
2009-07-13T14:05:19Z

On Mon, Jul 13, 2009 at 09:53:24AM -0400, Christoph Hellwig wrote:
> On Mon, Jul 13, 2009 at 08:59:17AM +0200, Nick Piggin wrote:
> > Agreed, if it is a common sequence / requirement for filesystems
> > then of course I will not object to a helper to make things clearer
> > or share code.
> >
> > I would like to see inode_setattr renamed into simple_setattr, and
> > then also .setattr made mandatory, so I don't like to cut code out
> > of inode_setattr which makes it unable to be the simple_setattr
> > after the old truncate code is removed.
>
> But inode_setattr isn't anything like simple_setattr. Except for
> the truncate special case it's really just a helper to copy values
> into the inode. It doesn't even even have the same prototype as
> ->setattr.
>
> A simple_setattr would look like the following:

OK that's kind of what I imagine inode_setattr becomes, but now
that you make me look at it in that perspective, it is better to
say inode_setattr returns to a plain helper to copy values into
the inode once we move the truncate code out of there.

It would be good to add your simple_setattr and factor it out
from fnotify_change, then. I guess this is what you plan to do
after my patchset?

>
> int simple_setattr(struct dentry *dentry, struct iattr *iattr)
> {
> struct inode *inode = dentry->d_inode;
> int error;
>
> error = inode_change_ok(inode, iattr);
> if (error)
> return error;
>
> if ((iattr->ia_valid & ATTR_UID && iattr->ia_uid != inode->i_uid) ||
> (iattr->ia_valid & ATTR_GID && iattr->ia_gid != inode->i_gid)) {
> if (vfs_dq_transfer(inode, iattr))
> return -EDQUOT;
> }
>
> if (iattr->ia_valid & ATTR_ATTR_SIZE &&
> iattr->ia_size !== i_size_read(inode) &&
> inode->i_op->new_truncate) {
> error = simple_setsize(inode, attr->ia_size);
> if (error)
> return error;
> }
>
> return inode_setattr(inode, attr);
> }