f2fs: introduce ra_meta_pages to readahead CP/NAT/SIT pages

This patch help us to cleanup the readahead code by merging ra_{sit,nat}_pages
function into ra_meta_pages.
Additionally the new function is used to readahead cp block in
recover_orphan_inodes.

Change log from v1:
 o fix a deadloop bug pointed by Jaegeuk Kim.

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

1 files changed, 78 insertions, 0 deletions

diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index 427dd55cfd5a..deb60356f7cf 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -75,6 +75,82 @@ out:
 	return page;
 }
 
+inline int get_max_meta_blks(struct f2fs_sb_info *sbi, int type)
+{
+	switch (type) {
+	case META_NAT:
+		return NM_I(sbi)->max_nid / NAT_ENTRY_PER_BLOCK;
+	case META_SIT:
+		return SIT_BLK_CNT(sbi);
+	case META_CP:
+		return 0;
+	default:
+		BUG();
+	}
+}
+
+/*
+ * Readahead CP/NAT/SIT pages
+ */
+int ra_meta_pages(struct f2fs_sb_info *sbi, int start, int nrpages, int type)
+{
+	block_t prev_blk_addr = 0;
+	struct page *page;
+	int blkno = start;
+	int max_blks = get_max_meta_blks(sbi, type);
+
+	struct f2fs_io_info fio = {
+		.type = META,
+		.rw = READ_SYNC | REQ_META | REQ_PRIO
+	};
+
+	for (; nrpages-- > 0; blkno++) {
+		block_t blk_addr;
+
+		switch (type) {
+		case META_NAT:
+			/* get nat block addr */
+			if (unlikely(blkno >= max_blks))
+				blkno = 0;
+			blk_addr = current_nat_addr(sbi,
+					blkno * NAT_ENTRY_PER_BLOCK);
+			break;
+		case META_SIT:
+			/* get sit block addr */
+			if (unlikely(blkno >= max_blks))
+				goto out;
+			blk_addr = current_sit_addr(sbi,
+					blkno * SIT_ENTRY_PER_BLOCK);
+			if (blkno != start && prev_blk_addr + 1 != blk_addr)
+				goto out;
+			prev_blk_addr = blk_addr;
+			break;
+		case META_CP:
+			/* get cp block addr */
+			blk_addr = blkno;
+			break;
+		default:
+			BUG();
+		}
+
+		page = grab_cache_page(META_MAPPING(sbi), blk_addr);
+		if (!page)
+			continue;
+		if (PageUptodate(page)) {
+			mark_page_accessed(page);
+			f2fs_put_page(page, 1);
+			continue;
+		}
+
+		f2fs_submit_page_mbio(sbi, page, blk_addr, &fio);
+		mark_page_accessed(page);
+		f2fs_put_page(page, 0);
+	}
+out:
+	f2fs_submit_merged_bio(sbi, META, READ);
+	return blkno - start;
+}
+
 static int f2fs_write_meta_page(struct page *page,
 				struct writeback_control *wbc)
 {
@@ -298,6 +374,8 @@ void recover_orphan_inodes(struct f2fs_sb_info *sbi)
 	start_blk = __start_cp_addr(sbi) + 1;
 	orphan_blkaddr = __start_sum_addr(sbi) - 1;
 
+	ra_meta_pages(sbi, start_blk, orphan_blkaddr, META_CP);
+
 	for (i = 0; i < orphan_blkaddr; i++) {
 		struct page *page = get_meta_page(sbi, start_blk + i);
 		struct f2fs_orphan_block *orphan_blk;