mm: swap: use swap_entries_free() drop last ref count in swap_entries_put_nr()

Use swap_entries_free() to directly free swap entries when the swap
entries are not cached and referenced, without needing to set swap entries
to set intermediate SWAP_HAS_CACHE state.

Link: https://lkml.kernel.org/r/20250325162528.68385-5-shikemeng@huaweicloud.com
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Tim Chen <tim.c.chen@linux.intel.com>
Reviewed-by: Baoquan He <bhe@redhat.com>
Cc: Kairui Song <kasong@tencent.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/swapfile.c b/mm/swapfile.c
index f0ba27db9b3edbf844ce87d3c6a52dc4ef55ef30..f8fe507be4f3525277e79890354ee3af02ff5ec2 100644 (file)
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -1498,10 +1498,11 @@ static bool swap_entries_put_nr(struct swap_info_struct *si,
                unlock_cluster(ci);
                goto fallback;
        }
-       for (i = 0; i < nr; i++)
-               WRITE_ONCE(si->swap_map[offset + i], SWAP_HAS_CACHE);
        if (!has_cache)
                swap_entries_free(si, ci, entry, nr);
+       else
+               for (i = 0; i < nr; i++)
+                       WRITE_ONCE(si->swap_map[offset + i], SWAP_HAS_CACHE);
        unlock_cluster(ci);
 
        return has_cache;