zswap: make zswap_store() take a folio

Patch series "Followup folio conversions for zswap".

With frontswap killed, it's worth converting the zswap_load() and
zswap_store() functions to take a folio instead of a page pointer.  They
aren't converted to support large folios, but there are a lot of
unnecessary calls to compound_head() that are removed by these patches.

This patch (of 4):

Only convert a few easy parts of this function to use the folio passed in;
convert back to struct page for the majority of it.  This does remove a
few hidden calls to compound_head().

Link: https://lkml.kernel.org/r/20230715042343.434588-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20230715042343.434588-3-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/include/linux/zswap.h b/include/linux/zswap.h
index 850c377..9f318c8 100644 (file)
--- a/include/linux/zswap.h
+++ b/include/linux/zswap.h
@@ -10,7 +10,7 @@ extern atomic_t zswap_stored_pages;
 
 #ifdef CONFIG_ZSWAP
 
-bool zswap_store(struct page *page);
+bool zswap_store(struct folio *folio);
 bool zswap_load(struct page *page);
 void zswap_invalidate(int type, pgoff_t offset);
 void zswap_swapon(int type);
@@ -18,7 +18,7 @@ void zswap_swapoff(int type);
 
 #else
 
-static inline bool zswap_store(struct page *page)
+static inline bool zswap_store(struct folio *folio)
 {
        return false;
 }

diff --git a/mm/page_io.c b/mm/page_io.c
index 5d0baba..ac89685 100644 (file)
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -195,7 +195,7 @@ int swap_writepage(struct page *page, struct writeback_control *wbc)
                folio_unlock(folio);
                return ret;
        }
-       if (zswap_store(&folio->page)) {
+       if (zswap_store(folio)) {
                folio_start_writeback(folio);
                folio_unlock(folio);
                folio_end_writeback(folio);

diff --git a/mm/zswap.c b/mm/zswap.c
index be1b641..df3054e 100644 (file)
--- a/mm/zswap.c
+++ b/mm/zswap.c
@@ -1223,11 +1223,12 @@ static void zswap_fill_page(void *ptr, unsigned long value)
        memset_l(page, value, PAGE_SIZE / sizeof(unsigned long));
 }
 
-bool zswap_store(struct page *page)
+bool zswap_store(struct folio *folio)
 {
-       swp_entry_t swp = { .val = page_private(page), };
+       swp_entry_t swp = folio_swap_entry(folio);
        int type = swp_type(swp);
        pgoff_t offset = swp_offset(swp);
+       struct page *page = &folio->page;
        struct zswap_tree *tree = zswap_trees[type];
        struct zswap_entry *entry, *dupentry;
        struct scatterlist input, output;
@@ -1242,11 +1243,11 @@ bool zswap_store(struct page *page)
        gfp_t gfp;
        int ret;
 
-       VM_WARN_ON_ONCE(!PageLocked(page));
-       VM_WARN_ON_ONCE(!PageSwapCache(page));
+       VM_WARN_ON_ONCE(!folio_test_locked(folio));
+       VM_WARN_ON_ONCE(!folio_test_swapcache(folio));
 
-       /* THP isn't supported */
-       if (PageTransHuge(page))
+       /* Large folios aren't supported */
+       if (folio_test_large(folio))
                return false;
 
        if (!zswap_enabled || !tree)