mm/swapfile.c: omit a duplicate code by compare tmp and max first

There are two duplicate code to handle the case when there is no available
swap entry.  To avoid this, we can compare tmp and max first and let the
second guard do its job.

No functional change is expected.

Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Hugh Dickins <hughd@google.com>
Link: http://lkml.kernel.org/r/20200421213824.8099-3-richard.weiyang@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/swapfile.c b/mm/swapfile.c
index c74c9e1dc50d5864cf62ed211e350eeef38a805a..1743386d24012045482943a95f12e40fe064da92 100644 (file)
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -629,17 +629,15 @@ new_cluster:
        tmp = cluster->next;
        max = min_t(unsigned long, si->max,
                    (cluster_next(&cluster->index) + 1) * SWAPFILE_CLUSTER);
-       if (tmp >= max) {
-               cluster_set_null(&cluster->index);
-               goto new_cluster;
-       }
-       ci = lock_cluster(si, tmp);
-       while (tmp < max) {
-               if (!si->swap_map[tmp])
-                       break;
-               tmp++;
+       if (tmp < max) {
+               ci = lock_cluster(si, tmp);
+               while (tmp < max) {
+                       if (!si->swap_map[tmp])
+                               break;
+                       tmp++;
+               }
+               unlock_cluster(ci);
        }
-       unlock_cluster(ci);
        if (tmp >= max) {
                cluster_set_null(&cluster->index);
                goto new_cluster;