ratelimit: Use nolock_ret label to collapse lock-failure code

Now that we have a nolock_ret label that handles ->missed correctly
based on the value of ret, we can eliminate a local variable and collapse
several "if" statements on the lock-acquisition-failure code path.

Link: https://lore.kernel.org/all/fbe93a52-365e-47fe-93a4-44a44547d601@paulmck-laptop/
Link: https://lore.kernel.org/all/20250423115409.3425-1-spasswolf@web.de/
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Kuniyuki Iwashima <kuniyu@amazon.com>
Cc: Mateusz Guzik <mjguzik@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>

diff --git a/lib/ratelimit.c b/lib/ratelimit.c
index e7101a79c697393d824fe000e7b1f31c3e3a893f..bcda7c61fc6ff433d594dbf26a4b29ef233975e6 100644 (file)
--- a/lib/ratelimit.c
+++ b/lib/ratelimit.c
@@ -58,20 +58,10 @@ int ___ratelimit(struct ratelimit_state *rs, const char *func)
         * the current lock owner is just about to reset it.
         */
        if (!raw_spin_trylock_irqsave(&rs->lock, flags)) {
-               unsigned int rs_flags = READ_ONCE(rs->flags);
-
-               if (rs_flags & RATELIMIT_INITIALIZED && burst) {
-                       int n_left = atomic_read(&rs->rs_n_left);
-
-                       if (n_left <= 0)
-                               return 0;
-                       n_left = atomic_dec_return(&rs->rs_n_left);
-                       if (n_left >= 0)
-                               return 1;
-               }
-
-               ratelimit_state_inc_miss(rs);
-               return 0;
+               if (READ_ONCE(rs->flags) & RATELIMIT_INITIALIZED && burst &&
+                   atomic_read(&rs->rs_n_left) > 0 && atomic_dec_return(&rs->rs_n_left) >= 0)
+                       ret = 1;
+               goto nolock_ret;
        }
 
        if (!(rs->flags & RATELIMIT_INITIALIZED)) {