nilfs2: separate read method of meta data files on super root block

Will displace nilfs_mdt_read_inode_direct function with an individual
read method: nilfs_dat_read, nilfs_sufile_read, nilfs_cpfile_read.

This provides the opportunity to initialize local variables of each
metadata file after reading the inode.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
diff --git a/fs/nilfs2/the_nilfs.c b/fs/nilfs2/the_nilfs.c
index d4a731f..bc7760c 100644
--- a/fs/nilfs2/the_nilfs.c
+++ b/fs/nilfs2/the_nilfs.c
@@ -204,18 +204,18 @@
 
 	nilfs_mdt_set_shadow(nilfs->ns_dat, nilfs->ns_gc_dat);
 
-	err = nilfs_mdt_read_inode_direct(
-		nilfs->ns_dat, bh_sr, NILFS_SR_DAT_OFFSET(inode_size));
+	err = nilfs_dat_read(nilfs->ns_dat, (void *)bh_sr->b_data +
+			     NILFS_SR_DAT_OFFSET(inode_size));
 	if (unlikely(err))
 		goto failed_sufile;
 
-	err = nilfs_mdt_read_inode_direct(
-		nilfs->ns_cpfile, bh_sr, NILFS_SR_CPFILE_OFFSET(inode_size));
+	err = nilfs_cpfile_read(nilfs->ns_cpfile, (void *)bh_sr->b_data +
+				NILFS_SR_CPFILE_OFFSET(inode_size));
 	if (unlikely(err))
 		goto failed_sufile;
 
-	err = nilfs_mdt_read_inode_direct(
-		nilfs->ns_sufile, bh_sr, NILFS_SR_SUFILE_OFFSET(inode_size));
+	err = nilfs_sufile_read(nilfs->ns_sufile, (void *)bh_sr->b_data +
+				NILFS_SR_SUFILE_OFFSET(inode_size));
 	if (unlikely(err))
 		goto failed_sufile;