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/recovery.c b/fs/f2fs/recovery.c
index 9a93a6e..9160a37 100644
--- a/fs/f2fs/recovery.c
+++ b/fs/f2fs/recovery.c
@@ -170,13 +170,15 @@
 	curseg = CURSEG_I(sbi, CURSEG_WARM_NODE);
 	blkaddr = NEXT_FREE_BLKADDR(sbi, curseg);
 
+	ra_meta_pages(sbi, blkaddr, 1, META_POR);
+
 	while (1) {
 		struct fsync_inode_entry *entry;
 
 		if (blkaddr < MAIN_BLKADDR(sbi) || blkaddr >= MAX_BLKADDR(sbi))
 			return 0;
 
-		page = get_meta_page_ra(sbi, blkaddr);
+		page = get_meta_page(sbi, blkaddr);
 
 		if (cp_ver != cpver_of_node(page))
 			break;
@@ -227,6 +229,8 @@
 		/* check next segment */
 		blkaddr = next_blkaddr_of_node(page);
 		f2fs_put_page(page, 1);
+
+		ra_meta_pages_cond(sbi, blkaddr);
 	}
 	f2fs_put_page(page, 1);
 	return err;
@@ -436,7 +440,9 @@
 		if (blkaddr < MAIN_BLKADDR(sbi) || blkaddr >= MAX_BLKADDR(sbi))
 			break;
 
-		page = get_meta_page_ra(sbi, blkaddr);
+		ra_meta_pages_cond(sbi, blkaddr);
+
+		page = get_meta_page(sbi, blkaddr);
 
 		if (cp_ver != cpver_of_node(page)) {
 			f2fs_put_page(page, 1);