lib/flex_proportions.c: remove local_irq_ops in fprop_new_period()

commit e78d4833c03e28> "lib: Fix possible deadlock in flexible proportion
code" adds the local_irq_ops because percpu_counter_{sum |add} ops'lock
can cause deadlock by interrupts.  Now percpu_counter _{sum|add} ops use
raw_spin_(un)lock_irq*, so revert the commit and resolve the conflict.

Link: https://lkml.kernel.org/r/20220604131502.5190-1-wuchi.zero@gmail.com
Signed-off-by: wuchi <wuchi.zero@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/lib/flex_proportions.c b/lib/flex_proportions.c
index 53e7eb1..05cccbc 100644 (file)
--- a/lib/flex_proportions.c
+++ b/lib/flex_proportions.c
@@ -63,18 +63,13 @@ void fprop_global_destroy(struct fprop_global *p)
  */
 bool fprop_new_period(struct fprop_global *p, int periods)
 {
-       s64 events;
-       unsigned long flags;
+       s64 events = percpu_counter_sum(&p->events);
 
-       local_irq_save(flags);
-       events = percpu_counter_sum(&p->events);
        /*
         * Don't do anything if there are no events.
         */
-       if (events <= 1) {
-               local_irq_restore(flags);
+       if (events <= 1)
                return false;
-       }
        write_seqcount_begin(&p->sequence);
        if (periods < 64)
                events -= events >> periods;
@@ -82,7 +77,6 @@ bool fprop_new_period(struct fprop_global *p, int periods)
        percpu_counter_add(&p->events, -events);
        p->period += periods;
        write_seqcount_end(&p->sequence);
-       local_irq_restore(flags);
 
        return true;
 }