staging: lustre: replace libcfs_register_ioctl with a blocking notifier_chain

libcfs allows other modules to register handlers for ioctls.
The implementation it uses for this is nearly identical to a
blocking notifier chain, so change to use that.

The biggest difference is that the return value from notifier has a
defined format, where libcfs_register_ioctl uses -EINVAL to mean
"continue".  This requires a little bit of conversion.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 25 insertions, 13 deletions

diff --git a/drivers/staging/lustre/lnet/lnet/module.c b/drivers/staging/lustre/lnet/lnet/module.c
index f6e912e..9d06664 100644
--- a/drivers/staging/lustre/lnet/lnet/module.c
+++ b/drivers/staging/lustre/lnet/lnet/module.c
@@ -136,30 +136,37 @@ out_unlock:
 }
 
 static int
-lnet_ioctl(unsigned int cmd, struct libcfs_ioctl_hdr *hdr)
+lnet_ioctl(struct notifier_block *nb,
+	   unsigned long cmd, void *vdata)
 {
 	int rc;
+	struct libcfs_ioctl_hdr *hdr = vdata;
 
 	switch (cmd) {
 	case IOC_LIBCFS_CONFIGURE: {
 		struct libcfs_ioctl_data *data =
 			(struct libcfs_ioctl_data *)hdr;
 
-		if (data->ioc_hdr.ioc_len < sizeof(*data))
-			return -EINVAL;
-
-		the_lnet.ln_nis_from_mod_params = data->ioc_flags;
-		return lnet_configure(NULL);
+		if (data->ioc_hdr.ioc_len < sizeof(*data)) {
+			rc = -EINVAL;
+		} else {
+			the_lnet.ln_nis_from_mod_params = data->ioc_flags;
+			rc = lnet_configure(NULL);
+		}
+		break;
 	}
 
 	case IOC_LIBCFS_UNCONFIGURE:
-		return lnet_unconfigure();
+		rc = lnet_unconfigure();
+		break;
 
 	case IOC_LIBCFS_ADD_NET:
-		return lnet_dyn_configure(hdr);
+		rc = lnet_dyn_configure(hdr);
+		break;
 
 	case IOC_LIBCFS_DEL_NET:
-		return lnet_dyn_unconfigure(hdr);
+		rc = lnet_dyn_unconfigure(hdr);
+		break;
 
 	default:
 		/*
@@ -172,11 +179,14 @@ lnet_ioctl(unsigned int cmd, struct libcfs_ioctl_hdr *hdr)
 			rc = LNetCtl(cmd, hdr);
 			LNetNIFini();
 		}
-		return rc;
+		break;
 	}
+	return notifier_from_ioctl_errno(rc);
 }
 
-static DECLARE_IOCTL_HANDLER(lnet_ioctl_handler, lnet_ioctl);
+static struct notifier_block lnet_ioctl_handler = {
+	.notifier_call = lnet_ioctl,
+};
 
 static int __init lnet_init(void)
 {
@@ -194,7 +204,8 @@ static int __init lnet_init(void)
 		return rc;
 	}
 
-	rc = libcfs_register_ioctl(&lnet_ioctl_handler);
+	rc = blocking_notifier_chain_register(&libcfs_ioctl_list,
+					      &lnet_ioctl_handler);
 	LASSERT(!rc);
 
 	if (config_on_load) {
@@ -212,7 +223,8 @@ static void __exit lnet_exit(void)
 {
 	int rc;
 
-	rc = libcfs_deregister_ioctl(&lnet_ioctl_handler);
+	rc = blocking_notifier_chain_unregister(&libcfs_ioctl_list,
+						&lnet_ioctl_handler);
 	LASSERT(!rc);
 
 	lnet_lib_exit();