[PATCH RFC 2/9] random: Avoid open-coded use of ratelimit_state structure's ->missed field

[Paul E. McKenney]

The _credit_init_bits() function directly accesses the ratelimit_state
structure's ->missed field, which work, but which also makes it
more difficult to change this field.  Therefore, make use of the
ratelimit_state_get_miss() and ratelimit_state_inc_miss() functions
instead of directly accessing the ->missed field.

Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
Cc: "Theodore Ts'o" <tytso@xxxxxxx>
"Jason A. Donenfeld" <Jason@xxxxxxxxx>
---
 drivers/char/random.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/char/random.c b/drivers/char/random.c
index 2581186fa61b7..cbd1692bf3f50 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -726,6 +726,7 @@ static void __cold _credit_init_bits(size_t bits)
 	static DECLARE_WORK(set_ready, crng_set_ready);
 	unsigned int new, orig, add;
 	unsigned long flags;
+	int m;
 
 	if (!bits)
 		return;
@@ -748,9 +749,9 @@ static void __cold _credit_init_bits(size_t bits)
 		wake_up_interruptible(&crng_init_wait);
 		kill_fasync(&fasync, SIGIO, POLL_IN);
 		pr_notice("crng init done\n");
-		if (urandom_warning.missed)
-			pr_notice("%d urandom warning(s) missed due to ratelimiting\n",
-				  urandom_warning.missed);
+		m = ratelimit_state_get_miss(&urandom_warning);
+		if (m)
+			pr_notice("%d urandom warning(s) missed due to ratelimiting\n", m);
 	} else if (orig < POOL_EARLY_BITS && new >= POOL_EARLY_BITS) {
 		spin_lock_irqsave(&base_crng.lock, flags);
 		/* Check if crng_init is CRNG_EMPTY, to avoid race with crng_reseed(). */
@@ -1466,7 +1467,7 @@ static ssize_t urandom_read_iter(struct kiocb *kiocb, struct iov_iter *iter)
 
 	if (!crng_ready()) {
 		if (!ratelimit_disable && maxwarn <= 0)
-			++urandom_warning.missed;
+			ratelimit_state_inc_miss(&urandom_warning);
 		else if (ratelimit_disable || __ratelimit(&urandom_warning)) {
 			--maxwarn;
 			pr_notice("%s: uninitialized urandom read (%zu bytes read)\n",
-- 
2.40.1