watchdog/core: Split out cpumask write function

Split the write part of the cpumask proc handler out into a separate helper
to avoid deep indentation. This also reduces the patch complexity in the
following cleanups.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Don Zickus <dzickus@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Ulrich Obergfell <uobergfe@redhat.com>
Link: http://lkml.kernel.org/r/20170912194147.218075991@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index a9bdfde73e4b2a10c699876d1e712fe903e7ad57..cedf45ab4d81e2a8fdefd6a892c4308a1defe123 100644 (file)
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -792,10 +792,29 @@ static int watchdog_update_cpus(void)
        if (IS_ENABLED(CONFIG_SOFTLOCKUP_DETECTOR)) {
                return smpboot_update_cpumask_percpu_thread(&watchdog_threads,
                                                            &watchdog_cpumask);
+               __lockup_detector_cleanup();
        }
        return 0;
 }
 
+static void proc_watchdog_cpumask_update(void)
+{
+       /* Remove impossible cpus to keep sysctl output clean. */
+       cpumask_and(&watchdog_cpumask, &watchdog_cpumask, cpu_possible_mask);
+
+       if (watchdog_running) {
+               /*
+                * Failure would be due to being unable to allocate a
+                * temporary cpumask, so we are likely not in a position to
+                * do much else to make things better.
+                */
+               if (watchdog_update_cpus() != 0)
+                       pr_err("cpumask update failed\n");
+       }
+
+       watchdog_nmi_reconfigure();
+}
+
 /*
  * The cpumask is the mask of possible cpus that the watchdog can run
  * on, not the mask of cpus it is actually running on.  This allows the
@@ -811,30 +830,13 @@ int proc_watchdog_cpumask(struct ctl_table *table, int write,
        mutex_lock(&watchdog_mutex);
 
        err = proc_do_large_bitmap(table, write, buffer, lenp, ppos);
-       if (!err && write) {
-               /* Remove impossible cpus to keep sysctl output cleaner. */
-               cpumask_and(&watchdog_cpumask, &watchdog_cpumask,
-                           cpu_possible_mask);
-
-               if (watchdog_running) {
-                       /*
-                        * Failure would be due to being unable to allocate
-                        * a temporary cpumask, so we are likely not in a
-                        * position to do much else to make things better.
-                        */
-                       if (watchdog_update_cpus() != 0)
-                               pr_err("cpumask update failed\n");
-               }
-
-               watchdog_nmi_reconfigure();
-               __lockup_detector_cleanup();
-       }
+       if (!err && write)
+               proc_watchdog_cpumask_update();
 
        mutex_unlock(&watchdog_mutex);
        cpu_hotplug_enable();
        return err;
 }
-
 #endif /* CONFIG_SYSCTL */
 
 void __init lockup_detector_init(void)