[PATCH 5/5] zswap: Make zswap_load() take a folio

From: Matthew Wilcox (Oracle)
Date: Sat Jul 15 2023 - 00:24:03 EST


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. Removes three
hidden calls to compound_head().

Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
---
include/linux/zswap.h | 4 ++--
mm/page_io.c | 2 +-
mm/zswap.c | 11 ++++++-----
3 files changed, 9 insertions(+), 8 deletions(-)

diff --git a/include/linux/zswap.h b/include/linux/zswap.h
index 9f318c8bc367..2a60ce39cfde 100644
--- a/include/linux/zswap.h
+++ b/include/linux/zswap.h
@@ -11,7 +11,7 @@ extern atomic_t zswap_stored_pages;
#ifdef CONFIG_ZSWAP

bool zswap_store(struct folio *folio);
-bool zswap_load(struct page *page);
+bool zswap_load(struct folio *folio);
void zswap_invalidate(int type, pgoff_t offset);
void zswap_swapon(int type);
void zswap_swapoff(int type);
@@ -23,7 +23,7 @@ static inline bool zswap_store(struct folio *folio)
return false;
}

-static inline bool zswap_load(struct page *page)
+static inline bool zswap_load(struct folio *folio)
{
return false;
}
diff --git a/mm/page_io.c b/mm/page_io.c
index e5b6f1402506..8741d3a0d48a 100644
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -516,7 +516,7 @@ void swap_readpage(struct page *page, bool synchronous, struct swap_iocb **plug)
}
delayacct_swapin_start();

- if (zswap_load(page)) {
+ if (zswap_load(folio)) {
folio_mark_uptodate(folio);
folio_unlock(folio);
} else if (data_race(sis->flags & SWP_FS_OPS)) {
diff --git a/mm/zswap.c b/mm/zswap.c
index 69d097d14255..4287f8551841 100644
--- a/mm/zswap.c
+++ b/mm/zswap.c
@@ -1381,11 +1381,12 @@ bool zswap_store(struct folio *folio)
goto reject;
}

-bool zswap_load(struct page *page)
+bool zswap_load(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;
struct scatterlist input, output;
@@ -1394,8 +1395,8 @@ bool zswap_load(struct page *page)
unsigned int dlen;
bool 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));

/* find */
spin_lock(&tree->lock);
@@ -1457,7 +1458,7 @@ bool zswap_load(struct page *page)
spin_lock(&tree->lock);
if (ret && zswap_exclusive_loads_enabled) {
zswap_invalidate_entry(tree, entry);
- SetPageDirty(page);
+ folio_mark_dirty(folio);
} else if (entry->length) {
spin_lock(&entry->pool->lru_lock);
list_move(&entry->lru, &entry->pool->lru);
--
2.39.2