Merge branch 'net-devlink-return-the-driver-name-in-devlink_nl_info_fill'

Vincent Mailhol says:

====================
net: devlink: return the driver name in devlink_nl_info_fill

The driver name is available in device_driver::name. Right now,
drivers still have to report this piece of information themselves in
their devlink_ops::info_get callback function.

The goal of this series is to have the devlink core to report this
information instead of the drivers.

The first patch fulfills the actual goal of this series: modify
devlink core to report the driver name and clean-up all drivers. Both
have to be done in an atomic change to avoid attribute
duplication. This same patch also removes the
devlink_info_driver_name_put() function to prevent future drivers from
reporting the driver name themselves.

The second patch allows the core to call devlink_nl_info_fill() even
if the devlink_ops::info_get() callback is NULL. This leads to the
third and final patch which cleans up the drivers which have an empty
info_get().
====================

Link: https://lore.kernel.org/r/20221129095140.3913303-1-mailhol.vincent@wanadoo.fr
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 22 insertions, 13 deletions

diff --git a/net/core/devlink.c b/net/core/devlink.c
index 298041a44aa8..fca3ebee97b0 100644
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -6707,14 +6707,6 @@ out_unlock:
 	return err;
 }
 
-int devlink_info_driver_name_put(struct devlink_info_req *req, const char *name)
-{
-	if (!req->msg)
-		return 0;
-	return nla_put_string(req->msg, DEVLINK_ATTR_INFO_DRIVER_NAME, name);
-}
-EXPORT_SYMBOL_GPL(devlink_info_driver_name_put);
-
 int devlink_info_serial_number_put(struct devlink_info_req *req, const char *sn)
 {
 	if (!req->msg)
@@ -6823,11 +6815,25 @@ int devlink_info_version_running_put_ext(struct devlink_info_req *req,
 }
 EXPORT_SYMBOL_GPL(devlink_info_version_running_put_ext);
 
+static int devlink_nl_driver_info_get(struct device_driver *drv,
+				      struct devlink_info_req *req)
+{
+	if (!drv)
+		return 0;
+
+	if (drv->name[0])
+		return nla_put_string(req->msg, DEVLINK_ATTR_INFO_DRIVER_NAME,
+				      drv->name);
+
+	return 0;
+}
+
 static int
 devlink_nl_info_fill(struct sk_buff *msg, struct devlink *devlink,
 		     enum devlink_command cmd, u32 portid,
 		     u32 seq, int flags, struct netlink_ext_ack *extack)
 {
+	struct device *dev = devlink_to_dev(devlink);
 	struct devlink_info_req req = {};
 	void *hdr;
 	int err;
@@ -6841,7 +6847,13 @@ devlink_nl_info_fill(struct sk_buff *msg, struct devlink *devlink,
 		goto err_cancel_msg;
 
 	req.msg = msg;
-	err = devlink->ops->info_get(devlink, &req, extack);
+	if (devlink->ops->info_get) {
+		err = devlink->ops->info_get(devlink, &req, extack);
+		if (err)
+			goto err_cancel_msg;
+	}
+
+	err = devlink_nl_driver_info_get(dev->driver, &req);
 	if (err)
 		goto err_cancel_msg;
 
@@ -6860,9 +6872,6 @@ static int devlink_nl_cmd_info_get_doit(struct sk_buff *skb,
 	struct sk_buff *msg;
 	int err;
 
-	if (!devlink->ops->info_get)
-		return -EOPNOTSUPP;
-
 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
 	if (!msg)
 		return -ENOMEM;
@@ -6888,7 +6897,7 @@ static int devlink_nl_cmd_info_get_dumpit(struct sk_buff *msg,
 	int err = 0;
 
 	devlinks_xa_for_each_registered_get(sock_net(msg->sk), index, devlink) {
-		if (idx < start || !devlink->ops->info_get)
+		if (idx < start)
 			goto inc;
 
 		devl_lock(devlink);