mm: tidy up swap_writeout

Use a goto label to consolidate the unlock folio and return pattern
and don't bother with an else after a return / goto.

Signed-off-by: Christoph Hellwig <hch@lst.de>

diff --git a/mm/page_io.c b/mm/page_io.c
index f7716b6569fa92f7fb0f525750c2b4c372c57271..c420b0aa0f22d932bf67792ac542cbd8b38b78c5 100644 (file)
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -239,12 +239,11 @@ static void swap_zeromap_folio_clear(struct folio *folio)
  */
 int swap_writeout(struct folio *folio, struct writeback_control *wbc)
 {
-       int ret;
+       int ret = 0;
+
+       if (folio_free_swap(folio))
+               goto out_unlock;
 
-       if (folio_free_swap(folio)) {
-               folio_unlock(folio);
-               return 0;
-       }
        /*
         * Arch code may have to preserve more data than just the page
         * contents, e.g. memory tags.
@@ -252,8 +251,7 @@ int swap_writeout(struct folio *folio, struct writeback_control *wbc)
        ret = arch_prepare_to_swap(folio);
        if (ret) {
                folio_mark_dirty(folio);
-               folio_unlock(folio);
-               return ret;
+               goto out_unlock;
        }
 
        /*
@@ -264,20 +262,19 @@ int swap_writeout(struct folio *folio, struct writeback_control *wbc)
         */
        if (is_folio_zero_filled(folio)) {
                swap_zeromap_folio_set(folio);
-               folio_unlock(folio);
-               return 0;
-       } else {
-               /*
-                * Clear bits this folio occupies in the zeromap to prevent
-                * zero data being read in from any previous zero writes that
-                * occupied the same swap entries.
-                */
-               swap_zeromap_folio_clear(folio);
+               goto out_unlock;
        }
+
+       /*
+        * Clear bits this folio occupies in the zeromap to prevent zero data
+        * being read in from any previous zero writes that occupied the same
+        * swap entries.
+        */
+       swap_zeromap_folio_clear(folio);
+
        if (zswap_store(folio)) {
                count_mthp_stat(folio_order(folio), MTHP_STAT_ZSWPOUT);
-               folio_unlock(folio);
-               return 0;
+               goto out_unlock;
        }
        if (!mem_cgroup_zswap_writeback_enabled(folio_memcg(folio))) {
                folio_mark_dirty(folio);
@@ -286,6 +283,9 @@ int swap_writeout(struct folio *folio, struct writeback_control *wbc)
 
        __swap_writepage(folio, wbc);
        return 0;
+out_unlock:
+       folio_unlock(folio);
+       return ret;
 }
 
 static inline void count_swpout_vm_event(struct folio *folio)