mm/swap_slots.c: simplify alloc_swap_slot_cache()

Patch series "clean up some functions in mm/swap_slots.c".

When I studied the code of mm/swap_slots.c, I found some places can be
improved.

This patch (of 3):

Both "slots" and "slots_ret" are only need to be freed when cache already
allocated.  Make them closer, seems more clear.

No functional change.

Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Tim Chen <tim.c.chen@linux.intel.com>
Link: http://lkml.kernel.org/r/20200430061143.450-1-thunder.leizhen@huawei.com
Link: http://lkml.kernel.org/r/20200430061143.450-2-thunder.leizhen@huawei.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/swap_slots.c b/mm/swap_slots.c
index 0975adc722532e5e6ddfee770a3ef4848b093866..01609b5f0c55093a63da97ac8f8b39561c1d3704 100644 (file)
--- a/mm/swap_slots.c
+++ b/mm/swap_slots.c
@@ -136,9 +136,16 @@ static int alloc_swap_slot_cache(unsigned int cpu)
 
        mutex_lock(&swap_slots_cache_mutex);
        cache = &per_cpu(swp_slots, cpu);
-       if (cache->slots || cache->slots_ret)
+       if (cache->slots || cache->slots_ret) {
                /* cache already allocated */
-               goto out;
+               mutex_unlock(&swap_slots_cache_mutex);
+
+               kvfree(slots);
+               kvfree(slots_ret);
+
+               return 0;
+       }
+
        if (!cache->lock_initialized) {
                mutex_init(&cache->alloc_lock);
                spin_lock_init(&cache->free_lock);
@@ -155,15 +162,8 @@ static int alloc_swap_slot_cache(unsigned int cpu)
         */
        mb();
        cache->slots = slots;
-       slots = NULL;
        cache->slots_ret = slots_ret;
-       slots_ret = NULL;
-out:
        mutex_unlock(&swap_slots_cache_mutex);
-       if (slots)
-               kvfree(slots);
-       if (slots_ret)
-               kvfree(slots_ret);
        return 0;
 }