Re: [PATCH] dcache: fix d_splice_alias handling of aliases

From: Miklos Szeredi
Date: Thu Jan 16 2014 - 11:13:37 EST


On Thu, Jan 16, 2014 at 4:41 PM, J. Bruce Fields <bfields@xxxxxxxxxxxx> wrote:
> And, sorry, I did miss that you said "non-directory". But I think you
> have that backwards: d_splice_alias looks like:
>
> if (inode && S_ISDIR(inode->i_mode)) {
> ...
> } else {
> d_instantiate(dentry, inode);
> if (d_unhashed(dentry))
> d_rehash(dentry);
> }
>
> So it ignores any existing aliases in the non-directory case.

Okay.

>
> d_materialise_unique by contrast calls __d_instantiate_unique, which
> looks like it should avoid adding duplicates.
>
> So I think switching everyone to d_materialiase_unique would result in
> fewer dentries. But I've never seen any complaint about the issue and
> like you don't see a reason this would matter much either way.

So, yes, d_materialise_unique() looks like it has superior
functionality compared to d_splice_alias().

Thanks,
Miklos
--
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/