Messages in this thread | | | Date | Tue, 22 Jan 2019 11:35:29 +0100 | From | Jan Kara <> | Subject | Re: [PATCH 1/1] kernel/ucounts: expose current inotify watch count |
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On Mon 21-01-19 17:45:11, Albert Vaca Cintora wrote: > Adds a readonly 'current_inotify_watches' entry to the user sysctl table. > The handler for this entry is a custom function that ends calling > proc_dointvec. > > Signed-off-by: Albert Vaca Cintora <albertvaka@gmail.com>
FWIW this makes sense to me. I'd just copy a lot of the rationale from the cover latter to this commit log so that it gets preseved in git history. Other than that feel free to add:
Acked-by: Jan Kara <jack@suse.cz>
Honza
> --- > kernel/ucount.c | 29 +++++++++++++++++++++++++++++ > 1 file changed, 29 insertions(+) > > diff --git a/kernel/ucount.c b/kernel/ucount.c > index f48d1b6376a4..afa3b89e3373 100644 > --- a/kernel/ucount.c > +++ b/kernel/ucount.c > @@ -57,6 +57,11 @@ static struct ctl_table_root set_root = { > .permissions = set_permissions, > }; > > +#ifdef CONFIG_INOTIFY_USER > +int proc_read_inotify_watches(struct ctl_table *table, int write, > + void __user *buffer, size_t *lenp, loff_t *ppos); > +#endif > + > static int zero = 0; > static int int_max = INT_MAX; > #define UCOUNT_ENTRY(name) \ > @@ -79,6 +84,12 @@ static struct ctl_table user_table[] = { > #ifdef CONFIG_INOTIFY_USER > UCOUNT_ENTRY("max_inotify_instances"), > UCOUNT_ENTRY("max_inotify_watches"), > + { > + .procname = "current_inotify_watches", > + .maxlen = sizeof(int), > + .mode = 0444, > + .proc_handler = proc_read_inotify_watches, > + }, > #endif > { } > }; > @@ -226,6 +237,24 @@ void dec_ucount(struct ucounts *ucounts, enum ucount_type type) > put_ucounts(ucounts); > } > > +#ifdef CONFIG_INOTIFY_USER > +int proc_read_inotify_watches(struct ctl_table *table, int write, > + void __user *buffer, size_t *lenp, loff_t *ppos) > +{ > + struct ucounts *ucounts; > + struct ctl_table fake_table; > + int count; > + > + ucounts = get_ucounts(current_user_ns(), current_euid()); > + count = atomic_read(&ucounts->ucount[UCOUNT_INOTIFY_WATCHES]); > + put_ucounts(ucounts); > + > + fake_table.data = &count; > + fake_table.maxlen = sizeof(count); > + return proc_dointvec(&fake_table, write, buffer, lenp, ppos); > +} > +#endif > + > static __init int user_namespace_sysctl_init(void) > { > #ifdef CONFIG_SYSCTL > -- > 2.20.1 > -- Jan Kara <jack@suse.com> SUSE Labs, CR
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