1 /* SPDX-License-Identifier: GPL-2.0-only */
5  * Generic code for various authentication-related caches
22  *  - A 'struct cache_detail' which contains information specific to the cache
24  *  - An item structure that must contain a "struct cache_head"
25  *  - A lookup function defined using DefineCacheLookup
26  *  - A 'put' function that can release a cache item. It will only
29  *  - A function to calculate a hash of an item's key.
49 	time64_t	expiry_time;	/* After time expiry_time, don't use
54 					 * be *after* ->flush_time.
63 	CACHE_NEGATIVE,		/* Negative entry - there is no match for the key */
117 	atomic_t		writers;		/* how many time is /channel open */
140  * delayed awaiting cache-fill
154  * since boot.  This is the best for measuring differences in
155  * real time.
163 	struct timespec64 boot;  in seconds_since_boot()  local
164 	getboottime64(&boot);  in seconds_since_boot()
165 	return ktime_get_real_seconds() - boot.tv_sec;  in seconds_since_boot()
170 	struct timespec64 boot;  in convert_to_wallclock()  local
171 	getboottime64(&boot);  in convert_to_wallclock()
172 	return boot.tv_sec + sinceboot;  in convert_to_wallclock()
197 	kref_get(&h->ref);  in cache_get()
203 	if (kref_get_unless_zero(&h->ref))  in cache_get_rcu()
210 	if (kref_read(&h->ref) <= 2 &&  in cache_put()
211 	    h->expiry_time < cd->nextcheck)  in cache_put()
212 		cd->nextcheck = h->expiry_time;  in cache_put()
213 	kref_put(&h->ref, cd->cache_put);  in cache_put()
218 	if (h->expiry_time < seconds_since_boot())  in cache_is_expired()
220 	if (!test_bit(CACHE_VALID, &h->flags))  in cache_is_expired()
222 	return detail->flush_time >= h->last_refresh;  in cache_is_expired()
246 /* Must store cache_detail in seq_file->private if using next three functions */
263 		return -EINVAL;  in get_int()
265 		return -ENOENT;  in get_int()
269 		return -EINVAL;  in get_int()
281 		return -EINVAL;  in get_uint()
283 		return -ENOENT;  in get_uint()
286 		return -EINVAL;  in get_uint()
291 static inline int get_time(char **bpp, time64_t *time)  in get_time()  argument
298 		return -EINVAL;  in get_time()
300 		return -ENOENT;  in get_time()
303 		return -EINVAL;  in get_time()
305 	*time = ll;  in get_time()
312 	struct timespec64 boot;  in get_expiry()  local
318 	getboottime64(&boot);  in get_expiry()
319 	(*rvp) -= boot.tv_sec;  in get_expiry()