2015-12-11 08:09:09

by Chao Yu

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

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 <[email protected]>
---
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