ratelimit: Create functions to handle ratelimit_state internals

A number of ratelimit use cases do open-coded access to the
ratelimit_state structure's ->missed field.  This works, but is a bit
messy and makes it more annoying to make changes to this field.

Therefore, provide a ratelimit_state_inc_miss() function that increments
the ->missed field, a ratelimit_state_get_miss() function that reads
out the ->missed field, and a ratelimit_state_reset_miss() function
that reads out that field, but that also resets its value to zero.
These functions will replace client-code open-coded uses of ->missed.

In addition, a new ratelimit_state_reset_interval() function encapsulates
what was previously open-coded lock acquisition and direct field updates.

[ paulmck: Apply kernel test robot feedback. ]

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/include/linux/ratelimit.h b/include/linux/ratelimit.h
index b17e0cd0a30cfb9fc15c23bad511ef82007f7414..8400c5356c187b089cf84c5f4c6c04cc98476d4d 100644 (file)
--- a/include/linux/ratelimit.h
+++ b/include/linux/ratelimit.h
@@ -22,16 +22,46 @@ static inline void ratelimit_default_init(struct ratelimit_state *rs)
                                        DEFAULT_RATELIMIT_BURST);
 }
 
+static inline void ratelimit_state_inc_miss(struct ratelimit_state *rs)
+{
+       rs->missed++;
+}
+
+static inline int ratelimit_state_get_miss(struct ratelimit_state *rs)
+{
+       return rs->missed;
+}
+
+static inline int ratelimit_state_reset_miss(struct ratelimit_state *rs)
+{
+       int ret = rs->missed;
+
+       rs->missed = 0;
+       return ret;
+}
+
+static inline void ratelimit_state_reset_interval(struct ratelimit_state *rs, int interval_init)
+{
+       unsigned long flags;
+
+       raw_spin_lock_irqsave(&rs->lock, flags);
+       rs->interval = interval_init;
+       rs->begin = 0;
+       rs->printed = 0;
+       ratelimit_state_reset_miss(rs);
+       raw_spin_unlock_irqrestore(&rs->lock, flags);
+}
+
 static inline void ratelimit_state_exit(struct ratelimit_state *rs)
 {
+       int m;
+
        if (!(rs->flags & RATELIMIT_MSG_ON_RELEASE))
                return;
 
-       if (rs->missed) {
-               pr_warn("%s: %d output lines suppressed due to ratelimiting\n",
-                       current->comm, rs->missed);
-               rs->missed = 0;
-       }
+       m = ratelimit_state_reset_miss(rs);
+       if (m)
+               pr_warn("%s: %d output lines suppressed due to ratelimiting\n", current->comm, m);
 }
 
 static inline void

diff --git a/lib/ratelimit.c b/lib/ratelimit.c
index ce945c17980b9b8addd4c044e1080f73f21a4f3d..85e22f00180c5bdd180647514e289fb51ef21034 100644 (file)
--- a/lib/ratelimit.c
+++ b/lib/ratelimit.c
@@ -51,12 +51,12 @@ int ___ratelimit(struct ratelimit_state *rs, const char *func)
                rs->begin = jiffies;
 
        if (time_is_before_jiffies(rs->begin + interval)) {
-               if (rs->missed) {
+               int m = ratelimit_state_reset_miss(rs);
+
+               if (m) {
                        if (!(rs->flags & RATELIMIT_MSG_ON_RELEASE)) {
                                printk_deferred(KERN_WARNING
-                                               "%s: %d callbacks suppressed\n",
-                                               func, rs->missed);
-                               rs->missed = 0;
+                                               "%s: %d callbacks suppressed\n", func, m);
                        }
                }
                rs->begin   = jiffies;