Re: vfs-scale, d_revalidate from nfsd

[Nick Piggin]

On Sat, Jan 15, 2011 at 2:47 PM, J. R. Okajima <hooanon05@xxxxxxxxxxx> wrote:
>
> Nick Piggin:
>> Of course. I was discussing it with Miklos yesterday too, but haven't
>> finished getting a proposal together.
>>
>> The main idea here would be to just pass in a flags parameter rather
>> thank poking in nd to get the rcu-walk status. That would solve this
>> problem and also avoid nd for most filesystems that don't care about
>> it.
>
> Let me make sure.
> - add a flag parameter to ->d_revalidate. not remove the panameter nd.
> - FS ->d_revalidate() will (probably) return -ECHILD when LOOKUP_RCU is
>  set.
> Right?
>
>
> Then how about the callers?
> Current sequence is
> - NFSD calls lookup_one_len
> - __lookup_hash
> - do_revalidate
> - d_revalidate
> {
>        status = dentry->d_op->d_revalidate(dentry, nd);
>        if (status == -ECHILD) {
>                ;;;
>                status = dentry->d_op->d_revalidate(dentry, nd);
>        }
> }
>
> There will be no change in NFSD but VFS d_revalidate(), such like this?
> VFS d_revalidate()
> {
>        if (nd) {
>                dentry->d_op->d_revalidate(dentry, nd, nd->flags);
>                if (-ECHILD) {
>                        dentry->d_op->d_revalidate(dentry, nd, nd->flags);
>                }
>        } else
>                return dentry->d_op->d_revalidate(dentry, NULL, 0);
> }

Yes that's the idea. I also want to pass a struct inode * parameter, to
facilitate rcu-walk implementations that want to check the inode
(such as fuse).
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/