mm: swap: factor out helper to drop cache of entries within a single cluster

Factor out helper swap_entries_put_cache() from put_swap_folio() to serve
as a general-purpose routine for dropping cache flag of entries within a
single cluster.

Link: https://lkml.kernel.org/r/20250325162528.68385-8-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 4f4fc74239d6d4b082224cf778cb157c84921171..953dcd99006edae697b57a76bd8d7d177e8b560b 100644 (file)
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -1463,6 +1463,22 @@ put_out:
        return NULL;
 }
 
+static void swap_entries_put_cache(struct swap_info_struct *si,
+                                  swp_entry_t entry, int nr)
+{
+       unsigned long offset = swp_offset(entry);
+       struct swap_cluster_info *ci;
+
+       ci = lock_cluster(si, offset);
+       if (swap_only_has_cache(si, offset, nr))
+               swap_entries_free(si, ci, entry, nr);
+       else {
+               for (int i = 0; i < nr; i++, entry.val++)
+                       swap_entry_put_locked(si, ci, entry, SWAP_HAS_CACHE);
+       }
+       unlock_cluster(ci);
+}
+
 static bool swap_entries_put_map(struct swap_info_struct *si,
                                 swp_entry_t entry, int nr)
 {
@@ -1607,8 +1623,6 @@ void swap_free_nr(swp_entry_t entry, int nr_pages)
  */
 void put_swap_folio(struct folio *folio, swp_entry_t entry)
 {
-       unsigned long offset = swp_offset(entry);
-       struct swap_cluster_info *ci;
        struct swap_info_struct *si;
        int size = 1 << swap_entry_order(folio_order(folio));
 
@@ -1616,14 +1630,7 @@ void put_swap_folio(struct folio *folio, swp_entry_t entry)
        if (!si)
                return;
 
-       ci = lock_cluster(si, offset);
-       if (swap_only_has_cache(si, offset, size))
-               swap_entries_free(si, ci, entry, size);
-       else {
-               for (int i = 0; i < size; i++, entry.val++)
-                       swap_entry_put_locked(si, ci, entry, SWAP_HAS_CACHE);
-       }
-       unlock_cluster(ci);
+       swap_entries_put_cache(si, entry, size);
 }
 
 int __swap_count(swp_entry_t entry)