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From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
To: akpm@linux-foundation.org
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>,
	linux-fsdevel@vger.kernel.org, linux-mm@kvack.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH v2 45/46] mm/filemap: Add filemap_get_folio
Date: Tue, 22 Jun 2021 13:15:50 +0100	[thread overview]
Message-ID: <20210622121551.3398730-46-willy@infradead.org> (raw)
In-Reply-To: <20210622121551.3398730-1-willy@infradead.org>

filemap_get_folio() is a replacement for find_get_page().
Turn pagecache_get_page() into a wrapper around __filemap_get_folio().
Remove find_lock_head() as this use case is now covered by
filemap_get_folio().

Reduces overall kernel size by 209 bytes.  __filemap_get_folio() is
316 bytes shorter than pagecache_get_page() was, but the new
pagecache_get_page() is 99 bytes.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
 include/linux/pagemap.h | 41 +++++++++----------
 mm/filemap.c            | 90 +++++++++++++++++++----------------------
 mm/folio-compat.c       | 12 ++++++
 3 files changed, 74 insertions(+), 69 deletions(-)

diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index b0c1d24fb01b..669bdebe2861 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -302,8 +302,26 @@ pgoff_t page_cache_prev_miss(struct address_space *mapping,
 #define FGP_HEAD		0x00000080
 #define FGP_ENTRY		0x00000100
 
-struct page *pagecache_get_page(struct address_space *mapping, pgoff_t offset,
-		int fgp_flags, gfp_t cache_gfp_mask);
+struct folio *__filemap_get_folio(struct address_space *mapping, pgoff_t index,
+		int fgp_flags, gfp_t gfp);
+struct page *pagecache_get_page(struct address_space *mapping, pgoff_t index,
+		int fgp_flags, gfp_t gfp);
+
+/**
+ * filemap_get_folio - Find and get a folio.
+ * @mapping: The address_space to search.
+ * @index: The page index.
+ *
+ * Looks up the page cache entry at @mapping & @index.  If a folio is
+ * present, it is returned with an increased refcount.
+ *
+ * Otherwise, %NULL is returned.
+ */
+static inline struct folio *filemap_get_folio(struct address_space *mapping,
+					pgoff_t index)
+{
+	return __filemap_get_folio(mapping, index, 0, 0);
+}
 
 /**
  * find_get_page - find and get a page reference
@@ -346,25 +364,6 @@ static inline struct page *find_lock_page(struct address_space *mapping,
 	return pagecache_get_page(mapping, index, FGP_LOCK, 0);
 }
 
-/**
- * find_lock_head - Locate, pin and lock a pagecache page.
- * @mapping: The address_space to search.
- * @index: The page index.
- *
- * Looks up the page cache entry at @mapping & @index.  If there is a
- * page cache page, its head page is returned locked and with an increased
- * refcount.
- *
- * Context: May sleep.
- * Return: A struct page which is !PageTail, or %NULL if there is no page
- * in the cache for this index.
- */
-static inline struct page *find_lock_head(struct address_space *mapping,
-					pgoff_t index)
-{
-	return pagecache_get_page(mapping, index, FGP_LOCK | FGP_HEAD, 0);
-}
-
 /**
  * find_or_create_page - locate or add a pagecache page
  * @mapping: the page's address_space
diff --git a/mm/filemap.c b/mm/filemap.c
index 7d0b51f30223..e431461279c3 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1794,95 +1794,89 @@ static struct folio *mapping_get_entry(struct address_space *mapping,
 }
 
 /**
- * pagecache_get_page - Find and get a reference to a page.
+ * __filemap_get_folio - Find and get a reference to a folio.
  * @mapping: The address_space to search.
  * @index: The page index.
- * @fgp_flags: %FGP flags modify how the page is returned.
- * @gfp_mask: Memory allocation flags to use if %FGP_CREAT is specified.
+ * @fgp_flags: %FGP flags modify how the folio is returned.
+ * @gfp: Memory allocation flags to use if %FGP_CREAT is specified.
  *
  * Looks up the page cache entry at @mapping & @index.
  *
  * @fgp_flags can be zero or more of these flags:
  *
- * * %FGP_ACCESSED - The page will be marked accessed.
- * * %FGP_LOCK - The page is returned locked.
- * * %FGP_HEAD - If the page is present and a THP, return the head page
- *   rather than the exact page specified by the index.
+ * * %FGP_ACCESSED - The folio will be marked accessed.
+ * * %FGP_LOCK - The folio is returned locked.
  * * %FGP_ENTRY - If there is a shadow / swap / DAX entry, return it
- *   instead of allocating a new page to replace it.
+ *   instead of allocating a new folio to replace it.
  * * %FGP_CREAT - If no page is present then a new page is allocated using
- *   @gfp_mask and added to the page cache and the VM's LRU list.
+ *   @gfp and added to the page cache and the VM's LRU list.
  *   The page is returned locked and with an increased refcount.
  * * %FGP_FOR_MMAP - The caller wants to do its own locking dance if the
  *   page is already in cache.  If the page was allocated, unlock it before
  *   returning so the caller can do the same dance.
- * * %FGP_WRITE - The page will be written
- * * %FGP_NOFS - __GFP_FS will get cleared in gfp mask
- * * %FGP_NOWAIT - Don't get blocked by page lock
+ * * %FGP_WRITE - The page will be written to by the caller.
+ * * %FGP_NOFS - __GFP_FS will get cleared in gfp.
+ * * %FGP_NOWAIT - Don't get blocked by page lock.
  *
  * If %FGP_LOCK or %FGP_CREAT are specified then the function may sleep even
  * if the %GFP flags specified for %FGP_CREAT are atomic.
  *
  * If there is a page cache page, it is returned with an increased refcount.
  *
- * Return: The found page or %NULL otherwise.
+ * Return: The found folio or %NULL otherwise.
  */
-struct page *pagecache_get_page(struct address_space *mapping, pgoff_t index,
-		int fgp_flags, gfp_t gfp_mask)
+struct folio *__filemap_get_folio(struct address_space *mapping, pgoff_t index,
+		int fgp_flags, gfp_t gfp)
 {
 	struct folio *folio;
-	struct page *page;
 
 repeat:
 	folio = mapping_get_entry(mapping, index);
-	page = &folio->page;
-	if (xa_is_value(page)) {
+	if (xa_is_value(folio)) {
 		if (fgp_flags & FGP_ENTRY)
-			return page;
-		page = NULL;
+			return folio;
+		folio = NULL;
 	}
-	if (!page)
+	if (!folio)
 		goto no_page;
 
 	if (fgp_flags & FGP_LOCK) {
 		if (fgp_flags & FGP_NOWAIT) {
-			if (!trylock_page(page)) {
-				put_page(page);
+			if (!folio_trylock(folio)) {
+				folio_put(folio);
 				return NULL;
 			}
 		} else {
-			lock_page(page);
+			folio_lock(folio);
 		}
 
 		/* Has the page been truncated? */
-		if (unlikely(page->mapping != mapping)) {
-			unlock_page(page);
-			put_page(page);
+		if (unlikely(folio->mapping != mapping)) {
+			folio_unlock(folio);
+			folio_put(folio);
 			goto repeat;
 		}
-		VM_BUG_ON_PAGE(!thp_contains(page, index), page);
+		VM_BUG_ON_FOLIO(!folio_contains(folio, index), folio);
 	}
 
 	if (fgp_flags & FGP_ACCESSED)
-		mark_page_accessed(page);
+		folio_mark_accessed(folio);
 	else if (fgp_flags & FGP_WRITE) {
 		/* Clear idle flag for buffer write */
-		if (page_is_idle(page))
-			clear_page_idle(page);
+		if (folio_idle(folio))
+			folio_clear_idle_flag(folio);
 	}
-	if (!(fgp_flags & FGP_HEAD))
-		page = find_subpage(page, index);
 
 no_page:
-	if (!page && (fgp_flags & FGP_CREAT)) {
+	if (!folio && (fgp_flags & FGP_CREAT)) {
 		int err;
 		if ((fgp_flags & FGP_WRITE) && mapping_can_writeback(mapping))
-			gfp_mask |= __GFP_WRITE;
+			gfp |= __GFP_WRITE;
 		if (fgp_flags & FGP_NOFS)
-			gfp_mask &= ~__GFP_FS;
+			gfp &= ~__GFP_FS;
 
-		page = __page_cache_alloc(gfp_mask);
-		if (!page)
+		folio = filemap_alloc_folio(gfp, 0);
+		if (!folio)
 			return NULL;
 
 		if (WARN_ON_ONCE(!(fgp_flags & (FGP_LOCK | FGP_FOR_MMAP))))
@@ -1890,27 +1884,27 @@ struct page *pagecache_get_page(struct address_space *mapping, pgoff_t index,
 
 		/* Init accessed so avoid atomic mark_page_accessed later */
 		if (fgp_flags & FGP_ACCESSED)
-			__SetPageReferenced(page);
+			__folio_set_referenced_flag(folio);
 
-		err = add_to_page_cache_lru(page, mapping, index, gfp_mask);
+		err = filemap_add_folio(mapping, folio, index, gfp);
 		if (unlikely(err)) {
-			put_page(page);
-			page = NULL;
+			folio_put(folio);
+			folio = NULL;
 			if (err == -EEXIST)
 				goto repeat;
 		}
 
 		/*
-		 * add_to_page_cache_lru locks the page, and for mmap we expect
-		 * an unlocked page.
+		 * filemap_add_folio locks the page, and for mmap
+		 * we expect an unlocked page.
 		 */
-		if (page && (fgp_flags & FGP_FOR_MMAP))
-			unlock_page(page);
+		if (folio && (fgp_flags & FGP_FOR_MMAP))
+			folio_unlock(folio);
 	}
 
-	return page;
+	return folio;
 }
-EXPORT_SYMBOL(pagecache_get_page);
+EXPORT_SYMBOL(__filemap_get_folio);
 
 static inline struct page *find_get_entry(struct xa_state *xas, pgoff_t max,
 		xa_mark_t mark)
diff --git a/mm/folio-compat.c b/mm/folio-compat.c
index 0a8bdd3f8d91..78365eaee7d3 100644
--- a/mm/folio-compat.c
+++ b/mm/folio-compat.c
@@ -114,3 +114,15 @@ void lru_cache_add(struct page *page)
 	folio_add_lru(page_folio(page));
 }
 EXPORT_SYMBOL(lru_cache_add);
+
+struct page *pagecache_get_page(struct address_space *mapping, pgoff_t index,
+		int fgp_flags, gfp_t gfp)
+{
+	struct folio *folio;
+
+	folio = __filemap_get_folio(mapping, index, fgp_flags, gfp);
+	if ((fgp_flags & FGP_HEAD) || !folio || xa_is_value(folio))
+		return &folio->page;
+	return folio_file_page(folio, index);
+}
+EXPORT_SYMBOL(pagecache_get_page);
-- 
2.30.2


  parent reply	other threads:[~2021-06-22 12:56 UTC|newest]

Thread overview: 128+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-22 12:15 [PATCH v2 00/46] Folio-enabling the page cache Matthew Wilcox (Oracle)
2021-06-22 12:15 ` [PATCH v2 01/46] mm: Add folio_to_pfn() Matthew Wilcox (Oracle)
2021-06-23  7:49   ` Christoph Hellwig
2021-06-24 15:12     ` Matthew Wilcox
2021-06-28  6:18       ` Christoph Hellwig
2021-06-22 12:15 ` [PATCH v2 02/46] mm: Add folio_rmapping() Matthew Wilcox (Oracle)
2021-06-23  7:56   ` Christoph Hellwig
2021-06-24 15:51     ` Matthew Wilcox
2021-06-22 12:15 ` [PATCH v2 03/46] mm: Add kmap_local_folio() Matthew Wilcox (Oracle)
2021-06-23  7:58   ` Christoph Hellwig
2021-06-22 12:15 ` [PATCH v2 04/46] mm: Add flush_dcache_folio() Matthew Wilcox (Oracle)
2021-06-22 12:15 ` [PATCH v2 05/46] mm: Add arch_make_folio_accessible() Matthew Wilcox (Oracle)
2021-06-23  8:00   ` Christoph Hellwig
2021-06-24 15:57     ` Matthew Wilcox
2021-06-28  6:21       ` Christoph Hellwig
2021-06-28 14:07         ` Matthew Wilcox
2021-06-22 12:15 ` [PATCH v2 06/46] mm: Add folio_young() and folio_idle() Matthew Wilcox (Oracle)
2021-06-22 12:15 ` [PATCH v2 07/46] mm/workingset: Convert workingset_activation to take a folio Matthew Wilcox (Oracle)
2021-06-23  8:02   ` Christoph Hellwig
2021-06-22 12:15 ` [PATCH v2 08/46] mm/swap: Add folio_activate() Matthew Wilcox (Oracle)
2021-06-23  8:04   ` Christoph Hellwig
2021-06-22 12:15 ` [PATCH v2 09/46] mm/swap: Add folio_mark_accessed() Matthew Wilcox (Oracle)
2021-06-23  8:07   ` Christoph Hellwig
2021-06-22 12:15 ` [PATCH v2 10/46] mm/rmap: Add folio_mkclean() Matthew Wilcox (Oracle)
2021-06-23  8:08   ` Christoph Hellwig
2021-06-22 12:15 ` [PATCH v2 11/46] mm/memcg: Remove 'page' parameter to mem_cgroup_charge_statistics() Matthew Wilcox (Oracle)
2021-06-23  8:09   ` Christoph Hellwig
2021-06-25  7:58   ` Michal Hocko
2021-06-22 12:15 ` [PATCH v2 12/46] mm/memcg: Use the node id in mem_cgroup_update_tree() Matthew Wilcox (Oracle)
2021-06-23  8:12   ` Christoph Hellwig
2021-06-24 16:19     ` Matthew Wilcox
2021-06-25  8:05       ` Michal Hocko
2021-06-22 12:15 ` [PATCH v2 13/46] mm/memcg: Convert commit_charge() to take a folio Matthew Wilcox (Oracle)
2021-06-23  8:13   ` Christoph Hellwig
2021-06-25  8:11   ` Michal Hocko
2021-06-22 12:15 ` [PATCH v2 14/46] mm/memcg: Add folio_charge_cgroup() Matthew Wilcox (Oracle)
2021-06-23  8:15   ` Christoph Hellwig
2021-06-24 16:42     ` Matthew Wilcox
2021-06-25  8:22       ` Michal Hocko
2021-06-25 11:34         ` Matthew Wilcox
2021-06-22 12:15 ` [PATCH v2 15/46] mm/memcg: Add folio_uncharge_cgroup() Matthew Wilcox (Oracle)
2021-06-23  8:16   ` Christoph Hellwig
2021-06-25  8:25   ` Michal Hocko
2021-06-25 11:21     ` Matthew Wilcox
2021-06-25 13:21       ` Michal Hocko
2021-06-22 12:15 ` [PATCH v2 16/46] mm/memcg: Add folio_migrate_cgroup() Matthew Wilcox (Oracle)
2021-06-23  8:19   ` Christoph Hellwig
2021-06-22 12:15 ` [PATCH v2 17/46] mm/memcg: Convert mem_cgroup_track_foreign_dirty_slowpath() to folio Matthew Wilcox (Oracle)
2021-06-23  8:21   ` Christoph Hellwig
2021-06-24 17:37     ` Matthew Wilcox
2021-06-28  6:24       ` Christoph Hellwig
2021-06-22 12:15 ` [PATCH v2 18/46] mm/migrate: Add folio_migrate_mapping() Matthew Wilcox (Oracle)
2021-06-23  8:22   ` Christoph Hellwig
2021-06-22 12:15 ` [PATCH v2 19/46] mm/migrate: Add folio_migrate_flags() Matthew Wilcox (Oracle)
2021-06-23  8:28   ` Christoph Hellwig
2021-06-24 17:55     ` Matthew Wilcox
2021-06-22 12:15 ` [PATCH v2 20/46] mm/migrate: Add folio_migrate_copy() Matthew Wilcox (Oracle)
2021-06-23  8:35   ` Christoph Hellwig
2021-06-24 18:02     ` Matthew Wilcox
2021-06-28  6:26       ` Christoph Hellwig
2021-06-22 12:15 ` [PATCH v2 21/46] mm/writeback: Rename __add_wb_stat() to wb_stat_mod() Matthew Wilcox (Oracle)
2021-06-23  8:37   ` Christoph Hellwig
2021-06-22 12:15 ` [PATCH v2 22/46] flex_proportions: Allow N events instead of 1 Matthew Wilcox (Oracle)
2021-06-23  8:41   ` Christoph Hellwig
2021-06-22 12:15 ` [PATCH v2 23/46] mm/writeback: Change __wb_writeout_inc() to __wb_writeout_add() Matthew Wilcox (Oracle)
2021-06-23  8:45   ` Christoph Hellwig
2021-06-22 12:15 ` [PATCH v2 24/46] mm/writeback: Add __folio_end_writeback() Matthew Wilcox (Oracle)
2021-06-23  9:15   ` Christoph Hellwig
2021-06-24 18:20     ` Matthew Wilcox
2021-06-28  6:33       ` Christoph Hellwig
2021-06-22 12:15 ` [PATCH v2 25/46] mm/writeback: Add folio_start_writeback() Matthew Wilcox (Oracle)
2021-06-23  9:18   ` Christoph Hellwig
2021-06-24 18:33     ` Matthew Wilcox
2021-06-22 12:15 ` [PATCH v2 26/46] mm/writeback: Add folio_mark_dirty() Matthew Wilcox (Oracle)
2021-06-23  9:21   ` Christoph Hellwig
2021-06-22 12:15 ` [PATCH v2 27/46] mm/writeback: Add __folio_mark_dirty() Matthew Wilcox (Oracle)
2021-06-23  9:27   ` Christoph Hellwig
2021-06-24 18:37     ` Matthew Wilcox
2021-06-28  6:03       ` Christoph Hellwig
2021-06-28 15:43         ` Matthew Wilcox
2021-06-22 12:15 ` [PATCH v2 28/46] mm/writeback: Add filemap_dirty_folio() Matthew Wilcox (Oracle)
2021-06-23  9:32   ` Christoph Hellwig
2021-06-22 12:15 ` [PATCH v2 29/46] mm/writeback: Add folio_account_cleaned() Matthew Wilcox (Oracle)
2021-06-23  9:36   ` Christoph Hellwig
2021-06-24 20:06     ` Matthew Wilcox
2021-06-22 12:15 ` [PATCH v2 30/46] mm/writeback: Add folio_cancel_dirty() Matthew Wilcox (Oracle)
2021-06-23  9:39   ` Christoph Hellwig
2021-06-22 12:15 ` [PATCH v2 31/46] mm/writeback: Add folio_clear_dirty_for_io() Matthew Wilcox (Oracle)
2021-06-23  9:43   ` Christoph Hellwig
2021-06-24 20:09     ` Matthew Wilcox
2021-06-22 12:15 ` [PATCH v2 32/46] mm/writeback: Add folio_account_redirty() Matthew Wilcox (Oracle)
2021-06-23  9:44   ` Christoph Hellwig
2021-06-22 12:15 ` [PATCH v2 33/46] mm/writeback: Add folio_redirty_for_writepage() Matthew Wilcox (Oracle)
2021-06-23  9:45   ` Christoph Hellwig
2021-06-22 12:15 ` [PATCH v2 34/46] mm/filemap: Add i_blocks_per_folio() Matthew Wilcox (Oracle)
2021-06-23  9:46   ` Christoph Hellwig
2021-06-22 12:15 ` [PATCH v2 35/46] mm/filemap: Add folio_mkwrite_check_truncate() Matthew Wilcox (Oracle)
2021-06-23  9:47   ` Christoph Hellwig
2021-06-23 13:19     ` Matthew Wilcox
2021-06-22 12:15 ` [PATCH v2 36/46] mm/filemap: Add readahead_folio() Matthew Wilcox (Oracle)
2021-06-23  9:50   ` Christoph Hellwig
2021-06-24 23:46     ` Matthew Wilcox
2021-06-22 12:15 ` [PATCH v2 37/46] mm/workingset: Convert workingset_refault() to take a folio Matthew Wilcox (Oracle)
2021-06-23  9:52   ` Christoph Hellwig
2021-06-22 12:15 ` [PATCH v2 38/46] mm: Add folio_evictable() Matthew Wilcox (Oracle)
2021-06-23  9:54   ` Christoph Hellwig
2021-06-24 23:50     ` Matthew Wilcox
2021-06-22 12:15 ` [PATCH v2 39/46] mm/lru: Convert __pagevec_lru_add_fn to take a folio Matthew Wilcox (Oracle)
2021-06-23  9:55   ` Christoph Hellwig
2021-06-22 12:15 ` [PATCH v2 40/46] mm/lru: Add folio_add_lru() Matthew Wilcox (Oracle)
2021-06-23  9:56   ` Christoph Hellwig
2021-06-22 12:15 ` [PATCH v2 41/46] mm/page_alloc: Add folio allocation functions Matthew Wilcox (Oracle)
2021-06-23  9:58   ` Christoph Hellwig
2021-06-25  1:06     ` Matthew Wilcox
2021-06-22 12:15 ` [PATCH v2 42/46] mm/filemap: Add filemap_alloc_folio Matthew Wilcox (Oracle)
2021-06-23  9:59   ` Christoph Hellwig
2021-06-22 12:15 ` [PATCH v2 43/46] mm/filemap: Add filemap_add_folio Matthew Wilcox (Oracle)
2021-06-23 11:30   ` Christoph Hellwig
2021-06-25  1:57     ` Matthew Wilcox
2021-06-22 12:15 ` [PATCH v2 44/46] mm/filemap: Convert mapping_get_entry to return a folio Matthew Wilcox (Oracle)
2021-06-23 11:32   ` Christoph Hellwig
2021-06-25  3:29     ` Matthew Wilcox
2021-06-28  6:07       ` Christoph Hellwig
2021-06-22 12:15 ` Matthew Wilcox (Oracle) [this message]
2021-06-23 11:39   ` [PATCH v2 45/46] mm/filemap: Add filemap_get_folio Christoph Hellwig
2021-06-22 12:15 ` [PATCH v2 46/46] mm/filemap: Add FGP_STABLE Matthew Wilcox (Oracle)
2021-06-23 11:43   ` Christoph Hellwig
2021-06-23 12:15     ` Matthew Wilcox

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