[PATCH 09/28] mm/swap: rename __read_swap_cache_async to __swapin_cache_alloc

[Kairui Song <ryncsn@gmail.com>]

From: Kairui Song <kasong@tencent.com>

__read_swap_cache_async is widely used to allocate and ensure a folio is
in swapcache, or get the folio if a folio is already there.

It's not async, and it's not doing any read. Rename it to better
present its usage.

Signed-off-by: Kairui Song <kasong@tencent.com>
---
 mm/swap.h       |  2 +-
 mm/swap_state.c | 20 ++++++++++----------
 mm/swapfile.c   |  2 +-
 mm/zswap.c      |  4 ++--
 4 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/mm/swap.h b/mm/swap.h
index 30cd257aecbb..fec7d6e751ae 100644
--- a/mm/swap.h
+++ b/mm/swap.h
@@ -210,7 +210,7 @@ void swapcache_clear(struct swap_info_struct *si, swp_entry_t entry, int nr);
 struct folio *read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask,
 		struct vm_area_struct *vma, unsigned long addr,
 		struct swap_iocb **plug);
-struct folio *__read_swap_cache_async(swp_entry_t entry, gfp_t gfp_flags,
+struct folio *__swapin_cache_alloc(swp_entry_t entry, gfp_t gfp_flags,
 		struct mempolicy *mpol, pgoff_t ilx, bool *new_page_allocated,
 		bool skip_if_exists);
 struct folio *swap_cluster_readahead(swp_entry_t entry, gfp_t flag,
diff --git a/mm/swap_state.c b/mm/swap_state.c
index bef9633533ec..fe71706e29d9 100644
--- a/mm/swap_state.c
+++ b/mm/swap_state.c
@@ -353,7 +353,7 @@ void swap_update_readahead(struct folio *folio,
 	}
 }
 
-struct folio *__read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask,
+struct folio *__swapin_cache_alloc(swp_entry_t entry, gfp_t gfp_mask,
 		struct mempolicy *mpol, pgoff_t ilx, bool *new_page_allocated,
 		bool skip_if_exists)
 {
@@ -403,12 +403,12 @@ struct folio *__read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask,
 			goto put_and_return;
 
 		/*
-		 * Protect against a recursive call to __read_swap_cache_async()
+		 * Protect against a recursive call to __swapin_cache_alloc()
 		 * on the same entry waiting forever here because SWAP_HAS_CACHE
 		 * is set but the folio is not the swap cache yet. This can
 		 * happen today if mem_cgroup_swapin_charge_folio() below
 		 * triggers reclaim through zswap, which may call
-		 * __read_swap_cache_async() in the writeback path.
+		 * __swapin_cache_alloc() in the writeback path.
 		 */
 		if (skip_if_exists)
 			goto put_and_return;
@@ -417,7 +417,7 @@ struct folio *__read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask,
 		 * We might race against __swap_cache_del_folio(), and
 		 * stumble across a swap_map entry whose SWAP_HAS_CACHE
 		 * has not yet been cleared.  Or race against another
-		 * __read_swap_cache_async(), which has set SWAP_HAS_CACHE
+		 * __swapin_cache_alloc(), which has set SWAP_HAS_CACHE
 		 * in swap_map, but not yet added its folio to swap cache.
 		 */
 		schedule_timeout_uninterruptible(1);
@@ -464,7 +464,7 @@ struct folio *__read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask,
  * the swap entry is no longer in use.
  *
  * get/put_swap_device() aren't needed to call this function, because
- * __read_swap_cache_async() call them and swap_read_folio() holds the
+ * __swapin_cache_alloc() call them and swap_read_folio() holds the
  * swap cache folio lock.
  */
 struct folio *read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask,
@@ -482,7 +482,7 @@ struct folio *read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask,
 		return NULL;
 
 	mpol = get_vma_policy(vma, addr, 0, &ilx);
-	folio = __read_swap_cache_async(entry, gfp_mask, mpol, ilx,
+	folio = __swapin_cache_alloc(entry, gfp_mask, mpol, ilx,
 					&page_allocated, false);
 	mpol_cond_put(mpol);
 
@@ -600,7 +600,7 @@ struct folio *swap_cluster_readahead(swp_entry_t entry, gfp_t gfp_mask,
 	blk_start_plug(&plug);
 	for (offset = start_offset; offset <= end_offset ; offset++) {
 		/* Ok, do the async read-ahead now */
-		folio = __read_swap_cache_async(
+		folio = __swapin_cache_alloc(
 				swp_entry(swp_type(entry), offset),
 				gfp_mask, mpol, ilx, &page_allocated, false);
 		if (!folio)
@@ -619,7 +619,7 @@ struct folio *swap_cluster_readahead(swp_entry_t entry, gfp_t gfp_mask,
 	lru_add_drain();	/* Push any new pages onto the LRU now */
 skip:
 	/* The page was likely read above, so no need for plugging here */
-	folio = __read_swap_cache_async(entry, gfp_mask, mpol, ilx,
+	folio = __swapin_cache_alloc(entry, gfp_mask, mpol, ilx,
 					&page_allocated, false);
 	if (unlikely(page_allocated))
 		swap_read_folio(folio, NULL);
@@ -714,7 +714,7 @@ static struct folio *swap_vma_readahead(swp_entry_t targ_entry, gfp_t gfp_mask,
 			continue;
 		pte_unmap(pte);
 		pte = NULL;
-		folio = __read_swap_cache_async(entry, gfp_mask, mpol, ilx,
+		folio = __swapin_cache_alloc(entry, gfp_mask, mpol, ilx,
 						&page_allocated, false);
 		if (!folio)
 			continue;
@@ -734,7 +734,7 @@ static struct folio *swap_vma_readahead(swp_entry_t targ_entry, gfp_t gfp_mask,
 	lru_add_drain();
 skip:
 	/* The folio was likely read above, so no need for plugging here */
-	folio = __read_swap_cache_async(targ_entry, gfp_mask, mpol, targ_ilx,
+	folio = __swapin_cache_alloc(targ_entry, gfp_mask, mpol, targ_ilx,
 					&page_allocated, false);
 	if (unlikely(page_allocated))
 		swap_read_folio(folio, NULL);
diff --git a/mm/swapfile.c b/mm/swapfile.c
index aaf7d21eaecb..62af67b6f7c2 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -1390,7 +1390,7 @@ static unsigned char swap_entry_put_locked(struct swap_info_struct *si,
  *   CPU1				CPU2
  *   do_swap_page()
  *     ...				swapoff+swapon
- *     __read_swap_cache_async()
+ *     __swapin_cache_alloc()
  *       swapcache_prepare()
  *         __swap_duplicate()
  *           // check swap_map
diff --git a/mm/zswap.c b/mm/zswap.c
index af954bda0b02..87aebeee11ef 100644
--- a/mm/zswap.c
+++ b/mm/zswap.c
@@ -1084,8 +1084,8 @@ static int zswap_writeback_entry(struct zswap_entry *entry,
 		return -EEXIST;
 
 	mpol = get_task_policy(current);
-	folio = __read_swap_cache_async(swpentry, GFP_KERNEL, mpol,
-			NO_INTERLEAVE_INDEX, &folio_was_allocated, true);
+	folio = __swapin_cache_alloc(swpentry, GFP_KERNEL, mpol,
+				NO_INTERLEAVE_INDEX, &folio_was_allocated, true);
 	put_swap_device(si);
 	if (!folio)
 		return -ENOMEM;
-- 
2.49.0