On Tue 28-06-22 18:14:13, Guowei Du wrote:
> From: duguowei <duguowei@xxxxxxxxxx>
>
> Add a node of sysctl, which is current_user_instances.
> It shows current initialized group counts of system.
>
> Signed-off-by: duguowei <duguowei@xxxxxxxxxx>
Hum, I'm not sure about a wider context here but the changelog is certainly
missing a motivation of this change - why do you need this counter? In
particular because we already do maintain (and limit) the number of
fanotify groups each user has allocated in a particular namespace...
Honza
> ---
> fs/notify/fanotify/fanotify_user.c | 14 ++++++++++++++
> 1 file changed, 14 insertions(+)
>
> diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
> index c2255b440df9..39674fbffc4f 100644
> --- a/fs/notify/fanotify/fanotify_user.c
> +++ b/fs/notify/fanotify/fanotify_user.c
> @@ -51,6 +51,8 @@
>
> /* configurable via /proc/sys/fs/fanotify/ */
> static int fanotify_max_queued_events __read_mostly;
> +/* current initialized group count */
> +static int fanotify_user_instances __read_mostly;
>
> #ifdef CONFIG_SYSCTL
>
> @@ -86,6 +88,14 @@ static struct ctl_table fanotify_table[] = {
> .proc_handler = proc_dointvec_minmax,
> .extra1 = SYSCTL_ZERO
> },
> + {
> + .procname = "current_user_instances",
> + .data = &fanotify_user_instances,
> + .maxlen = sizeof(int),
> + .mode = 0444,
> + .proc_handler = proc_dointvec_minmax,
> + .extra1 = SYSCTL_ZERO
> + },
> { }
> };
>
> @@ -905,6 +915,8 @@ static int fanotify_release(struct inode *ignored, struct file *file)
> /* matches the fanotify_init->fsnotify_alloc_group */
> fsnotify_destroy_group(group);
>
> + fanotify_user_instances--;
> +
> return 0;
> }
>
> @@ -1459,6 +1471,8 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags)
> if (fd < 0)
> goto out_destroy_group;
>
> + fanotify_user_instances++;
> +
> return fd;
>
> out_destroy_group:
> --
> 2.36.1
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
