switch jfs to ->s_d_op, close exportfs races

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/jfs/namei.c

@@ -1465,9 +1465,6 @@ static struct dentry *jfs_lookup(struct inode *dip, struct dentry *dentry, struc
 
 	jfs_info("jfs_lookup: name = %s", name);
 
-	if (JFS_SBI(dip->i_sb)->mntflag & JFS_OS2)
-		d_set_d_op(dentry, &jfs_ci_dentry_operations);
-
 	if ((name[0] == '.') && (len == 1))
 		inum = dip->i_ino;
 	else if (strcmp(name, "..") == 0)
@@ -1492,12 +1489,7 @@ static struct dentry *jfs_lookup(struct inode *dip, struct dentry *dentry, struc
 		return ERR_CAST(ip);
 	}
 
-	dentry = d_splice_alias(ip, dentry);
-
-	if (dentry && (JFS_SBI(dip->i_sb)->mntflag & JFS_OS2))
-		d_set_d_op(dentry, &jfs_ci_dentry_operations);
-
-	return dentry;
+	return d_splice_alias(ip, dentry);
 }
 
 static struct inode *jfs_nfs_get_inode(struct super_block *sb,

fs/jfs/super.c

@@ -515,6 +515,9 @@ static int jfs_fill_super(struct super_block *sb, void *data, int silent)
 
 	sb->s_magic = JFS_SUPER_MAGIC;
 
+	if (sbi->mntflag & JFS_OS2)
+		sb->s_d_op = &jfs_ci_dentry_operations;
+
 	inode = jfs_iget(sb, ROOT_I);
 	if (IS_ERR(inode)) {
 		ret = PTR_ERR(inode);
@@ -524,9 +527,6 @@ static int jfs_fill_super(struct super_block *sb, void *data, int silent)
 	if (!sb->s_root)
 		goto out_no_root;
 
-	if (sbi->mntflag & JFS_OS2)
-		d_set_d_op(sb->s_root, &jfs_ci_dentry_operations);
-
 	/* logical blocks are represented by 40 bits in pxd_t, etc. */
 	sb->s_maxbytes = ((u64) sb->s_blocksize) << 40;
 #if BITS_PER_LONG == 32