f2fs: avoid to ra unneeded blocks in recover flow

To improve recovery speed, f2fs try to readahead many contiguous blocks in warm
node segment, but for most time, abnormal power-off do not occur frequently, so
when mount a normal power-off f2fs image, by contrary ra so many blocks and then
invalid them will hurt the performance of mount.
It's better to just ra the first next-block for normal condition.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index b2d5431..e6c271f 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -72,21 +72,6 @@
 	return page;
 }
 
-struct page *get_meta_page_ra(struct f2fs_sb_info *sbi, pgoff_t index)
-{
-	bool readahead = false;
-	struct page *page;
-
-	page = find_get_page(META_MAPPING(sbi), index);
-	if (!page || (page && !PageUptodate(page)))
-		readahead = true;
-	f2fs_put_page(page, 0);
-
-	if (readahead)
-		ra_meta_pages(sbi, index, MAX_BIO_BLOCKS(sbi), META_POR);
-	return get_meta_page(sbi, index);
-}
-
 static inline bool is_valid_blkaddr(struct f2fs_sb_info *sbi,
 						block_t blkaddr, int type)
 {
@@ -181,6 +166,20 @@
 	return blkno - start;
 }
 
+void ra_meta_pages_cond(struct f2fs_sb_info *sbi, pgoff_t index)
+{
+	struct page *page;
+	bool readahead = false;
+
+	page = find_get_page(META_MAPPING(sbi), index);
+	if (!page || (page && !PageUptodate(page)))
+		readahead = true;
+	f2fs_put_page(page, 0);
+
+	if (readahead)
+		ra_meta_pages(sbi, index, MAX_BIO_BLOCKS(sbi), META_POR);
+}
+
 static int f2fs_write_meta_page(struct page *page,
 				struct writeback_control *wbc)
 {