This is a note to let you know that I've just added the patch titled
net: devlink: take RTNL in port_fill() function only if it is not held
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
net-devlink-take-rtnl-in-port_fill-function-only-if-.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 68d81614aec1851d3e794c9cc8a5ad703d0234ad
Author: Jiri Pirko <jiri@xxxxxxxxxxx>
Date: Wed Nov 2 17:02:02 2022 +0100
net: devlink: take RTNL in port_fill() function only if it is not held
[ Upstream commit d41c9dbd12745cfc1cb2946cd99016d83c2c5364 ]
Follow-up patch is going to introduce a netdevice notifier event
processing which is called with RTNL mutex held. Processing of this will
eventually lead to call to port_notity() and port_fill() which currently
takes RTNL mutex internally. So as a temporary solution, propagate a
bool indicating if the mutex is already held. This will go away in one
of the follow-up patches.
Signed-off-by: Jiri Pirko <jiri@xxxxxxxxxx>
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Stable-dep-of: fef5b228dd38 ("rtnetlink: move IFLA_GSO_ tb check to validate_linkmsg")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/net/core/devlink.c b/net/core/devlink.c
index 7d7fc61a62553..79cfba316438c 100644
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -1278,7 +1278,8 @@ devlink_nl_port_function_attrs_put(struct sk_buff *msg, struct devlink_port *por
static int devlink_nl_port_fill(struct sk_buff *msg,
struct devlink_port *devlink_port,
enum devlink_command cmd, u32 portid, u32 seq,
- int flags, struct netlink_ext_ack *extack)
+ int flags, struct netlink_ext_ack *extack,
+ bool rtnl_held)
{
struct devlink *devlink = devlink_port->devlink;
void *hdr;
@@ -1293,7 +1294,8 @@ static int devlink_nl_port_fill(struct sk_buff *msg,
goto nla_put_failure;
/* Hold rtnl lock while accessing port's netdev attributes. */
- rtnl_lock();
+ if (!rtnl_held)
+ rtnl_lock();
spin_lock_bh(&devlink_port->type_lock);
if (nla_put_u16(msg, DEVLINK_ATTR_PORT_TYPE, devlink_port->type))
goto nla_put_failure_type_locked;
@@ -1321,7 +1323,8 @@ static int devlink_nl_port_fill(struct sk_buff *msg,
goto nla_put_failure_type_locked;
}
spin_unlock_bh(&devlink_port->type_lock);
- rtnl_unlock();
+ if (!rtnl_held)
+ rtnl_unlock();
if (devlink_nl_port_attrs_put(msg, devlink_port))
goto nla_put_failure;
if (devlink_nl_port_function_attrs_put(msg, devlink_port, extack))
@@ -1336,14 +1339,15 @@ static int devlink_nl_port_fill(struct sk_buff *msg,
nla_put_failure_type_locked:
spin_unlock_bh(&devlink_port->type_lock);
- rtnl_unlock();
+ if (!rtnl_held)
+ rtnl_unlock();
nla_put_failure:
genlmsg_cancel(msg, hdr);
return -EMSGSIZE;
}
-static void devlink_port_notify(struct devlink_port *devlink_port,
- enum devlink_command cmd)
+static void __devlink_port_notify(struct devlink_port *devlink_port,
+ enum devlink_command cmd, bool rtnl_held)
{
struct devlink *devlink = devlink_port->devlink;
struct sk_buff *msg;
@@ -1358,7 +1362,8 @@ static void devlink_port_notify(struct devlink_port *devlink_port,
if (!msg)
return;
- err = devlink_nl_port_fill(msg, devlink_port, cmd, 0, 0, 0, NULL);
+ err = devlink_nl_port_fill(msg, devlink_port, cmd, 0, 0, 0, NULL,
+ rtnl_held);
if (err) {
nlmsg_free(msg);
return;
@@ -1368,6 +1373,12 @@ static void devlink_port_notify(struct devlink_port *devlink_port,
0, DEVLINK_MCGRP_CONFIG, GFP_KERNEL);
}
+static void devlink_port_notify(struct devlink_port *devlink_port,
+ enum devlink_command cmd)
+{
+ __devlink_port_notify(devlink_port, cmd, false);
+}
+
static void devlink_rate_notify(struct devlink_rate *devlink_rate,
enum devlink_command cmd)
{
@@ -1534,7 +1545,7 @@ static int devlink_nl_cmd_port_get_doit(struct sk_buff *skb,
err = devlink_nl_port_fill(msg, devlink_port, DEVLINK_CMD_PORT_NEW,
info->snd_portid, info->snd_seq, 0,
- info->extack);
+ info->extack, false);
if (err) {
nlmsg_free(msg);
return err;
@@ -1564,7 +1575,8 @@ static int devlink_nl_cmd_port_get_dumpit(struct sk_buff *msg,
DEVLINK_CMD_NEW,
NETLINK_CB(cb->skb).portid,
cb->nlh->nlmsg_seq,
- NLM_F_MULTI, cb->extack);
+ NLM_F_MULTI, cb->extack,
+ false);
if (err) {
devl_unlock(devlink);
devlink_put(devlink);
@@ -1776,7 +1788,8 @@ static int devlink_port_new_notify(struct devlink *devlink,
}
err = devlink_nl_port_fill(msg, devlink_port, DEVLINK_CMD_NEW,
- info->snd_portid, info->snd_seq, 0, NULL);
+ info->snd_portid, info->snd_seq, 0, NULL,
+ false);
if (err)
goto out;
@@ -10036,7 +10049,7 @@ static void devlink_port_type_netdev_checks(struct devlink_port *devlink_port,
static void __devlink_port_type_set(struct devlink_port *devlink_port,
enum devlink_port_type type,
- void *type_dev)
+ void *type_dev, bool rtnl_held)
{
struct net_device *netdev = type_dev;
@@ -10063,7 +10076,7 @@ static void __devlink_port_type_set(struct devlink_port *devlink_port,
break;
}
spin_unlock_bh(&devlink_port->type_lock);
- devlink_port_notify(devlink_port, DEVLINK_CMD_PORT_NEW);
+ __devlink_port_notify(devlink_port, DEVLINK_CMD_PORT_NEW, rtnl_held);
}
/**
@@ -10080,7 +10093,8 @@ void devlink_port_type_eth_set(struct devlink_port *devlink_port,
"devlink port type for port %d set to Ethernet without a software interface reference, device type not supported by the kernel?\n",
devlink_port->index);
- __devlink_port_type_set(devlink_port, DEVLINK_PORT_TYPE_ETH, netdev);
+ __devlink_port_type_set(devlink_port, DEVLINK_PORT_TYPE_ETH, netdev,
+ false);
}
EXPORT_SYMBOL_GPL(devlink_port_type_eth_set);
@@ -10093,7 +10107,8 @@ EXPORT_SYMBOL_GPL(devlink_port_type_eth_set);
void devlink_port_type_ib_set(struct devlink_port *devlink_port,
struct ib_device *ibdev)
{
- __devlink_port_type_set(devlink_port, DEVLINK_PORT_TYPE_IB, ibdev);
+ __devlink_port_type_set(devlink_port, DEVLINK_PORT_TYPE_IB, ibdev,
+ false);
}
EXPORT_SYMBOL_GPL(devlink_port_type_ib_set);
@@ -10104,7 +10119,8 @@ EXPORT_SYMBOL_GPL(devlink_port_type_ib_set);
*/
void devlink_port_type_clear(struct devlink_port *devlink_port)
{
- __devlink_port_type_set(devlink_port, DEVLINK_PORT_TYPE_NOTSET, NULL);
+ __devlink_port_type_set(devlink_port, DEVLINK_PORT_TYPE_NOTSET, NULL,
+ false);
}
EXPORT_SYMBOL_GPL(devlink_port_type_clear);
