Re: [PATCH v6 6/7] kernfs: add kernfs_need_inode_refresh()

[Miklos Szeredi]

On Wed, 9 Jun 2021 at 10:52, Ian Kent <raven@xxxxxxxxxx> wrote:
>
> Now the kernfs_rwsem read lock is held for kernfs_refresh_inode() and
> the i_lock taken to protect inode updates there can be some contention
> introduced when .permission() is called with concurrent path walks in
> progress.
>
> Since .permission() is called frequently during path walks it's worth
> checking if the update is actually needed before taking the lock and
> performing the update.
>
> Signed-off-by: Ian Kent <raven@xxxxxxxxxx>

Reviewed-by: Miklos Szeredi <mszeredi@xxxxxxxxxx>