[PATCH v3 1/3] mm: zswap: convert zswap_invalidate() to take a range

[Kefeng Wang <wangkefeng.wang@huawei.com>]

zswap_invalidate() takes a swp_entry_t only to unpack it right back
into type and offset, and both callers already have those values in
hand. Pass type, offset, and nr_entries directly so swap_range_free()
can invalidate an entire range in one call instead of looping in the
caller.

Suggested-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
---
 include/linux/zswap.h |  8 ++++++--
 mm/swapfile.c         |  4 +---
 mm/zswap.c            | 29 +++++++++++++++++++----------
 3 files changed, 26 insertions(+), 15 deletions(-)

diff --git a/include/linux/zswap.h b/include/linux/zswap.h
index 30c193a1207e..df6cafbe95dc 100644
--- a/include/linux/zswap.h
+++ b/include/linux/zswap.h
@@ -27,7 +27,7 @@ struct zswap_lruvec_state {
 unsigned long zswap_total_pages(void);
 bool zswap_store(struct folio *folio);
 int zswap_load(struct folio *folio);
-void zswap_invalidate(swp_entry_t swp);
+void zswap_invalidate(int type, pgoff_t offset, unsigned long nr_entries);
 int zswap_swapon(int type, unsigned long nr_pages);
 void zswap_swapoff(int type);
 void zswap_memcg_offline_cleanup(struct mem_cgroup *memcg);
@@ -49,7 +49,11 @@ static inline int zswap_load(struct folio *folio)
 	return -ENOENT;
 }
 
-static inline void zswap_invalidate(swp_entry_t swp) {}
+static inline void zswap_invalidate(int type, pgoff_t offset,
+		unsigned long nr_entries)
+{
+}
+
 static inline int zswap_swapon(int type, unsigned long nr_pages)
 {
 	return 0;
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 05d3408396f9..891379c95a01 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -1316,10 +1316,8 @@ static void swap_range_free(struct swap_info_struct *si, unsigned long offset,
 {
 	unsigned long end = offset + nr_entries - 1;
 	void (*swap_slot_free_notify)(struct block_device *, unsigned long);
-	unsigned int i;
 
-	for (i = 0; i < nr_entries; i++)
-		zswap_invalidate(swp_entry(si->type, offset + i));
+	zswap_invalidate(si->type, offset, nr_entries);
 
 	if (si->flags & SWP_BLKDEV)
 		swap_slot_free_notify =
diff --git a/mm/zswap.c b/mm/zswap.c
index a12b6452a225..79a66093d7ec 100644
--- a/mm/zswap.c
+++ b/mm/zswap.c
@@ -228,10 +228,15 @@ static bool zswap_has_pool;
 /* One swap address space for each 64M swap space */
 #define ZSWAP_ADDRESS_SPACE_SHIFT 14
 #define ZSWAP_ADDRESS_SPACE_PAGES (1 << ZSWAP_ADDRESS_SPACE_SHIFT)
+
+static inline struct xarray *zswap_tree(int type, pgoff_t offset)
+{
+	return &zswap_trees[type][offset >> ZSWAP_ADDRESS_SPACE_SHIFT];
+}
+
 static inline struct xarray *swap_zswap_tree(swp_entry_t swp)
 {
-	return &zswap_trees[swp_type(swp)][swp_offset(swp)
-		>> ZSWAP_ADDRESS_SPACE_SHIFT];
+	return zswap_tree(swp_type(swp), swp_offset(swp));
 }
 
 #define zswap_pool_debug(msg, p)			\
@@ -1659,18 +1664,22 @@ int zswap_load(struct folio *folio)
 	return 0;
 }
 
-void zswap_invalidate(swp_entry_t swp)
+void zswap_invalidate(int type, pgoff_t offset, unsigned long nr_entries)
 {
-	pgoff_t offset = swp_offset(swp);
-	struct xarray *tree = swap_zswap_tree(swp);
 	struct zswap_entry *entry;
+	struct xarray *tree;
+	unsigned long i;
 
-	if (xa_empty(tree))
-		return;
+	for (i = 0; i < nr_entries; i++) {
+		tree = zswap_tree(type, offset + i);
 
-	entry = xa_erase(tree, offset);
-	if (entry)
-		zswap_entry_free(entry);
+		if (xa_empty(tree))
+			continue;
+
+		entry = xa_erase(tree, offset + i);
+		if (entry)
+			zswap_entry_free(entry);
+	}
 }
 
 int zswap_swapon(int type, unsigned long nr_pages)
-- 
2.55.0