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>

diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index b843a5b..b212599 100644 (file)
--- 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)