f2fs: remove inmem radix tree

Previously, we use radix tree to index all registered page entries for
atomic file, but now we only use radix tree to see whether current page
is indexed or not, since the other user of radix tree is gone in commit
042b7816aaeb ("f2fs: remove unnecessary call to invalidate inmemory pages").

So in this patch, we try to use one more efficient way:
Introducing a macro ATOMIC_WRITTEN_PAGE, and setting it as page private
value to indicate page indexing status. By using this way, we can save
memory and lookup time.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

1 files changed, 18 insertions, 2 deletions

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 7ea8eda8f137..cad9ebe45692 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -1558,6 +1558,11 @@ void f2fs_invalidate_page(struct page *page, unsigned int offset,
 		else
 			inode_dec_dirty_pages(inode);
 	}
+
+	/* This is atomic written page, keep Private */
+	if (IS_ATOMIC_WRITTEN_PAGE(page))
+		return;
+
 	ClearPagePrivate(page);
 }
 
@@ -1567,6 +1572,10 @@ int f2fs_release_page(struct page *page, gfp_t wait)
 	if (PageDirty(page))
 		return 0;
 
+	/* This is atomic written page, keep Private */
+	if (IS_ATOMIC_WRITTEN_PAGE(page))
+		return 0;
+
 	ClearPagePrivate(page);
 	return 1;
 }
@@ -1581,8 +1590,15 @@ static int f2fs_set_data_page_dirty(struct page *page)
 	SetPageUptodate(page);
 
 	if (f2fs_is_atomic_file(inode)) {
-		register_inmem_page(inode, page);
-		return 1;
+		if (!IS_ATOMIC_WRITTEN_PAGE(page)) {
+			register_inmem_page(inode, page);
+			return 1;
+		}
+		/*
+		 * Previously, this page has been registered, we just
+		 * return here.
+		 */
+		return 0;
 	}
 
 	if (!PageDirty(page)) {