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

- From: Cyrill Gorcunov \<hidden\>
- Date: 2016-06-06 08:06:07 
- List: netdev
- Page: https://ratatoskr.run/netdev/2016/06/4765744
- Thread: https://ratatoskr.run/netdev/2016/06/4761944/t.md

```text
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 <redacted>
...
> +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?
```