[f2fs-dev] [PATCH 1/2] f2fs: clean up node page updating flow

[Chao Yu]

If read_node_page return LOCKED_PAGE, in its caller it's better a) skip
unneeded 'Update' flag and mapping info verfication; b) check nid value
stored in footer structure of node page.

Signed-off-by: Chao Yu <chao2...@samsung.com>
---
 fs/f2fs/node.c | 26 +++++++++++++++-----------
 1 file changed, 15 insertions(+), 11 deletions(-)

diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index 7bcbc6e..d842b19 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -1063,12 +1063,13 @@ repeat:
        if (err < 0) {
                f2fs_put_page(page, 1);
                return ERR_PTR(err);
-       } else if (err != LOCKED_PAGE) {
-               lock_page(page);
+       } else if (err == LOCKED_PAGE) {
+               goto page_hit;
        }
 
-       if (unlikely(!PageUptodate(page) || nid != nid_of_node(page))) {
-               ClearPageUptodate(page);
+       lock_page(page);
+
+       if (unlikely(!PageUptodate(page))) {
                f2fs_put_page(page, 1);
                return ERR_PTR(-EIO);
        }
@@ -1076,6 +1077,8 @@ repeat:
                f2fs_put_page(page, 1);
                goto repeat;
        }
+page_hit:
+       f2fs_bug_on(sbi, nid != nid_of_node(page));
        return page;
 }
 
@@ -1114,24 +1117,25 @@ repeat:
        end = start + MAX_RA_NODE;
        end = min(end, NIDS_PER_BLOCK);
        for (i = start + 1; i < end; i++) {
-               nid = get_nid(parent, i, false);
-               if (!nid)
+               nid_t tnid = get_nid(parent, i, false);
+               if (!tnid)
                        continue;
-               ra_node_page(sbi, nid);
+               ra_node_page(sbi, tnid);
        }
 
        blk_finish_plug(&plug);
 
        lock_page(page);
+       if (unlikely(!PageUptodate(page))) {
+               f2fs_put_page(page, 1);
+               return ERR_PTR(-EIO);
+       }
        if (unlikely(page->mapping != NODE_MAPPING(sbi))) {
                f2fs_put_page(page, 1);
                goto repeat;
        }
 page_hit:
-       if (unlikely(!PageUptodate(page))) {
-               f2fs_put_page(page, 1);
-               return ERR_PTR(-EIO);
-       }
+       f2fs_bug_on(sbi, nid != nid_of_node(page));
        return page;
 }
 
-- 
2.6.3



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