Re: [PATCH 2/2] kernfs: dont take i_lock on revalidate

[Ian Kent]

On 1/11/22 15:46, Amir Goldstein wrote:
> On Tue, Oct 18, 2022 at 5:58 AM Ian Kent <raven@xxxxxxxxxx> wrote:
> > In kernfs_dop_revalidate() when the passed in dentry is negative the
> > dentry directory is checked to see if it has changed and if so the
> > negative dentry is discarded so it can refreshed. During this check
> > the dentry inode i_lock is taken to mitigate against a possible
> > concurrent rename.
> >
> > But if it's racing with a rename, becuase the dentry is negative, it
> > can't be the source it must be the target and it must be going to do
> > a d_move() otherwise the rename will return an error.
> >
> > In this case the parent dentry of the target will not change, it will
> > be the same over the d_move(), only the source dentry parent may change
> > so the inode i_lock isn't needed.
> You meant d_lock.
> Same for the commit title.

Ha, well how do you like that, such an obvious mistake, how

did I not see it?


Not sure what to do about it now though ...

Any suggestions anyone?


Ian