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From: Kairui Song <ryncsn@gmail.com>
To: linux-mm@kvack.org
Cc: "Huang, Ying" <ying.huang@intel.com>,
	Chris Li <chrisl@kernel.org>,
	Minchan Kim <minchan@kernel.org>,
	Barry Song <v-songbaohua@oppo.com>,
	Ryan Roberts <ryan.roberts@arm.com>,
	Yu Zhao <yuzhao@google.com>,
	SeongJae Park <sj@kernel.org>,
	David Hildenbrand <david@redhat.com>,
	Yosry Ahmed <yosryahmed@google.com>,
	Johannes Weiner <hannes@cmpxchg.org>,
	Matthew Wilcox <willy@infradead.org>,
	Nhat Pham <nphamcs@gmail.com>,
	Chengming Zhou <zhouchengming@bytedance.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	linux-kernel@vger.kernel.org,
	Kairui Song <kasong@tencent.com>
Subject: [RFC PATCH 07/10] mm/swap: rename __read_swap_cache_async to swap_cache_alloc_or_get
Date: Wed, 27 Mar 2024 02:50:29 +0800
Message-ID: <20240326185032.72159-8-ryncsn@gmail.com>
In-Reply-To: <20240326185032.72159-1-ryncsn@gmail.com>
References: <20240326185032.72159-1-ryncsn@gmail.com>
Reply-To: Kairui Song <kasong@tencent.com>
Precedence: bulk
MIME-Version: 1.0
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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. Rename it to
better present the usage.

Signed-off-by: Kairui Song <kasong@tencent.com>
---
 mm/swap.h       |  2 +-
 mm/swap_state.c | 22 +++++++++++-----------
 mm/swapfile.c   |  2 +-
 mm/zswap.c      |  2 +-
 4 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/mm/swap.h b/mm/swap.h
index 7721ddb3bdbc..5fbbc4a42787 100644
--- a/mm/swap.h
+++ b/mm/swap.h
@@ -48,7 +48,7 @@ struct folio *filemap_get_incore_folio(struct address_space *mapping,
 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 *swap_cache_alloc_or_get(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 caf69696f47c..cd1a16afcd9f 100644
--- a/mm/swap_state.c
+++ b/mm/swap_state.c
@@ -385,7 +385,7 @@ struct folio *filemap_get_incore_folio(struct address_space *mapping,
 	return folio;
 }
 
-struct folio *__read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask,
+struct folio *swap_cache_alloc_or_get(swp_entry_t entry, gfp_t gfp_mask,
 		struct mempolicy *mpol, pgoff_t ilx, bool *new_page_allocated,
 		bool skip_if_exists)
 {
@@ -443,12 +443,12 @@ struct folio *__read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask,
 			goto fail_put_swap;
 
 		/*
-		 * Protect against a recursive call to __read_swap_cache_async()
+		 * Protect against a recursive call to swap_cache_alloc_or_get()
 		 * 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.
+		 * swap_cache_alloc_or_get() in the writeback path.
 		 */
 		if (skip_if_exists)
 			goto fail_put_swap;
@@ -457,7 +457,7 @@ struct folio *__read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask,
 		 * We might race against __delete_from_swap_cache(), 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
+		 * swap_cache_alloc_or_get(), which has set SWAP_HAS_CACHE
 		 * in swap_map, but not yet added its folio to swap cache.
 		 */
 		schedule_timeout_uninterruptible(1);
@@ -505,7 +505,7 @@ 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
+ * swap_cache_alloc_or_get() 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,
@@ -518,7 +518,7 @@ struct folio *read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask,
 	struct folio *folio;
 
 	mpol = get_vma_policy(vma, addr, 0, &ilx);
-	folio = __read_swap_cache_async(entry, gfp_mask, mpol, ilx,
+	folio = swap_cache_alloc_or_get(entry, gfp_mask, mpol, ilx,
 					&page_allocated, false);
 	mpol_cond_put(mpol);
 
@@ -634,7 +634,7 @@ 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 = swap_cache_alloc_or_get(
 				swp_entry(swp_type(entry), offset),
 				gfp_mask, mpol, ilx, &page_allocated, false);
 		if (!folio)
@@ -653,7 +653,7 @@ 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 = swap_cache_alloc_or_get(entry, gfp_mask, mpol, ilx,
 					&page_allocated, false);
 	if (unlikely(page_allocated)) {
 		zswap_folio_swapin(folio);
@@ -809,7 +809,7 @@ 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 = swap_cache_alloc_or_get(entry, gfp_mask, mpol, ilx,
 						&page_allocated, false);
 		if (!folio)
 			continue;
@@ -829,7 +829,7 @@ 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 = swap_cache_alloc_or_get(targ_entry, gfp_mask, mpol, targ_ilx,
 					&page_allocated, false);
 	if (unlikely(page_allocated)) {
 		zswap_folio_swapin(folio);
@@ -855,7 +855,7 @@ struct folio *swapin_direct(swp_entry_t entry, gfp_t gfp_mask,
 	pgoff_t ilx;
 
 	mpol = get_vma_policy(vmf->vma, vmf->address, 0, &ilx);
-	folio = __read_swap_cache_async(entry, gfp_mask, mpol, ilx,
+	folio = swap_cache_alloc_or_get(entry, gfp_mask, mpol, ilx,
 					&page_allocated, false);
 	mpol_cond_put(mpol);
 
diff --git a/mm/swapfile.c b/mm/swapfile.c
index bafae23c0f26..332ce4e578e8 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -1249,7 +1249,7 @@ static unsigned char __swap_entry_free_locked(struct swap_info_struct *p,
  *   CPU1				CPU2
  *   do_swap_page()
  *     ...				swapoff+swapon
- *     __read_swap_cache_async()
+ *     swap_cache_alloc_or_get()
  *       swapcache_prepare()
  *         __swap_duplicate()
  *           // check swap_map
diff --git a/mm/zswap.c b/mm/zswap.c
index 9dec853647c8..e4d96816be70 100644
--- a/mm/zswap.c
+++ b/mm/zswap.c
@@ -1126,7 +1126,7 @@ static int zswap_writeback_entry(struct zswap_entry *entry,
 
 	/* try to allocate swap cache folio */
 	mpol = get_task_policy(current);
-	folio = __read_swap_cache_async(swpentry, GFP_KERNEL, mpol,
+	folio = swap_cache_alloc_or_get(swpentry, GFP_KERNEL, mpol,
 				NO_INTERLEAVE_INDEX, &folio_was_allocated, true);
 	if (!folio)
 		return -ENOMEM;
-- 
2.43.0