Subject: Re: [PATCH 1/4] inotify: Add infrastructure to account inotify limits per-namespace

From: Cyrill Gorcunov <[email-masked]>
Date: Mon, 6 Jun 2016 11:05:57 +0300

On Wed, Jun 01, 2016 at 10:52:57AM +0300, Nikolay Borisov wrote:
> This patch adds the necessary members to user_struct. The idea behind
> the solution is really simple - user the userns pointers as keys into
> a hash table which holds the inotify instances/watches counts. This
> allows to account the limits per userns rather than per real user,
> which makes certain scenarios such as a single mapped user in a
> container deplete the inotify resources for all other users, which
> map to the exact same real user.
> 
> Signed-off-by: Nikolay Borisov <[email-masked]>
...
> +static inline unsigned long inotify_dec_return_dev(struct user_struct *user,
> +						   void *key)
> +{
> +	struct inotify_state *state;
> +	unsigned long ret;
> +
> +	spin_lock(&user->inotify_lock);
> +	state = __find_inotify_state(user, key);
> +	ret = --state->inotify_devs;
> +	spin_unlock(&user->inotify_lock);
> +
> +	return ret;
> +}

Hi Nikolay! Could you please explain why this new function is not used anywhere
in other patches or I miss something obvious?