f2fs: merge read IOs at ra_nat_pages()

Change log from v1:
  o add mark_page_accessed() not to reclaim the nat pages.

This patch changes the policy of submitting read bios at ra_nat_pages.

Previously, f2fs submits small read bios with block plugging.
But, with this patch, f2fs itself merges read bios first and then submits a
large bio, which can reduce the bio handling overheads.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

1 files changed, 4 insertions, 7 deletions

diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index b843a5b3d5ee..b212599b0da4 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -89,13 +89,10 @@ static void ra_nat_pages(struct f2fs_sb_info *sbi, int nid)
 {
         struct address_space *mapping = sbi->meta_inode->i_mapping;
         struct f2fs_nm_info *nm_i = NM_I(sbi);
-        struct blk_plug plug;
         struct page *page;
         pgoff_t index;
         int i;
 
-        blk_start_plug(&plug);
-
         for (i = 0; i < FREE_NID_PAGES; i++, nid += NAT_ENTRY_PER_BLOCK) {
                 if (nid >= nm_i->max_nid)
                         nid = 0;
@@ -105,15 +102,15 @@ static void ra_nat_pages(struct f2fs_sb_info *sbi, int nid)
                 if (!page)
                         continue;
                 if (PageUptodate(page)) {
+                        mark_page_accessed(page);
                         f2fs_put_page(page, 1);
                         continue;
                 }
-                if (f2fs_readpage(sbi, page, index, READ))
-                        continue;
-
+                submit_read_page(sbi, page, index, READ_SYNC);
+                mark_page_accessed(page);
                 f2fs_put_page(page, 0);
         }
-        blk_finish_plug(&plug);
+        f2fs_submit_read_bio(sbi, READ_SYNC);
 }
 
 static struct nat_entry *__lookup_nat_cache(struct f2fs_nm_info *nm_i, nid_t n)