nilfs2: introduce check flag to btree node buffer

nilfs_btree_get_block() now may return untested buffer due to
read-ahead.  This adds a new flag for buffer heads so that the btree
code can check whether the buffer is already verified or not.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

1 files changed, 9 insertions, 1 deletions

diff --git a/fs/nilfs2/btree.c b/fs/nilfs2/btree.c
index 1b5321c0bcac..d3faa0bba171 100644
--- a/fs/nilfs2/btree.c
+++ b/fs/nilfs2/btree.c
@@ -370,8 +370,16 @@ static int nilfs_btree_node_broken(const struct nilfs_btree_node *node,
 
 int nilfs_btree_broken_node_block(struct buffer_head *bh)
 {
-	return nilfs_btree_node_broken((struct nilfs_btree_node *)bh->b_data,
+	int ret;
+
+	if (buffer_nilfs_checked(bh))
+		return 0;
+
+	ret = nilfs_btree_node_broken((struct nilfs_btree_node *)bh->b_data,
 				       bh->b_size, bh->b_blocknr);
+	if (likely(!ret))
+		set_buffer_nilfs_checked(bh);
+	return ret;
 }
 
 static struct nilfs_btree_node *