f2fs: don't check inode's checksum if it was dirtied or writebacked

If another thread already made the page dirtied or writebacked, we must avoid
to verify checksum. If we got an error, we need to remove its uptodate as well.
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/inode.c

@@ -153,7 +153,8 @@ bool f2fs_inode_chksum_verify(struct f2fs_sb_info *sbi, struct page *page)
 	struct f2fs_inode *ri;
 	__u32 provided, calculated;
 
-	if (!f2fs_enable_inode_chksum(sbi, page))
+	if (!f2fs_enable_inode_chksum(sbi, page) ||
+			PageDirty(page) || PageWriteback(page))
 		return true;
 
 	ri = &F2FS_NODE(page)->i;

fs/f2fs/node.c

@@ -1187,9 +1187,9 @@ static struct page *__get_node_page(struct f2fs_sb_info *sbi, pgoff_t nid,
 			nid, nid_of_node(page), ino_of_node(page),
 			ofs_of_node(page), cpver_of_node(page),
 			next_blkaddr_of_node(page));
-		ClearPageUptodate(page);
 		err = -EINVAL;
 out_err:
+		ClearPageUptodate(page);
 		f2fs_put_page(page, 1);
 		return ERR_PTR(err);
 	}