Re: Linux 2.6.38-rc5

[Al Viro <viro@ZenIV.linux.org.uk>]

On Wed, Feb 16, 2011 at 08:33:32AM -0800, Linus Torvalds wrote:
> Does it make tons of conceptual sense to pass in 'inode' to
> do_follow_link? No, it's clearly redundant information, which is the
> whole point of the BUG_ON(). But it does allow that extra shared
> sanity test, and we _could_ also then do
> 
>   -       if (!IS_ERR(cookie) && path->dentry->d_inode->i_op->put_link)
>   -               path->dentry->d_inode->i_op->put_link(path->dentry,
> nd, cookie);
>   +       if (!IS_ERR(cookie) && inode->i_op->put_link)
>   +               inode->i_op->put_link(path->dentry, nd, cookie);
> 
> since we've verified that 'inode' is 'path->dentry->d_inode', and all
> of those should be stable over all the calls (in the non-RCU case,
> which we are in).
> 
> I dunno. I don't care _deeply_, but I do have to say that I much liked
> how you moved the
> 
>     if (nameidata_dentry_drop_rcu_maybe(nd, path->dentry))
>       ..
> 
> into do_follow_link(). I think it made it clearer that do_follow_link
> (and __do_follow_link()) aren't done with RCU.

OK, I can live with that.  Consider me convinced, let's go with your variant.
Speaking of ugliness: Nick, why the _fuck_ have you reverted non-create case
in do_filp_open() to do_path_lookup()?