From: Tariq Toukan <tariqt@nvidia.com>
To: Eric Dumazet <edumazet@google.com>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
Andrew Lunn <andrew+netdev@lunn.ch>,
"David S. Miller" <davem@davemloft.net>
Cc: Donald Hunter <donald.hunter@gmail.com>,
Jiri Pirko <jiri@resnulli.us>, Jonathan Corbet <corbet@lwn.net>,
Saeed Mahameed <saeedm@nvidia.com>,
"Leon Romanovsky" <leon@kernel.org>,
Tariq Toukan <tariqt@nvidia.com>, Mark Bloch <mbloch@nvidia.com>,
<netdev@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
<linux-doc@vger.kernel.org>, <linux-rdma@vger.kernel.org>,
Gal Pressman <gal@nvidia.com>, Moshe Shemesh <moshe@nvidia.com>,
Carolina Jubran <cjubran@nvidia.com>,
Cosmin Ratiu <cratiu@nvidia.com>, Jiri Pirko <jiri@nvidia.com>,
Randy Dunlap <rdunlap@infradead.org>,
Simon Horman <horms@kernel.org>,
Krzysztof Kozlowski <krzk@kernel.org>
Subject: [PATCH net-next V5 07/15] devlink: Add parent dev to devlink API
Date: Tue, 20 Jan 2026 09:57:50 +0200 [thread overview]
Message-ID: <1768895878-1637182-8-git-send-email-tariqt@nvidia.com> (raw)
In-Reply-To: <1768895878-1637182-1-git-send-email-tariqt@nvidia.com>
From: Cosmin Ratiu <cratiu@nvidia.com>
Upcoming changes to the rate commands need the parent devlink specified.
This change adds a nested 'parent-dev' attribute to the API and helpers
to obtain and put a reference to the parent devlink instance in
info->user_ptr[1].
To avoid deadlocks, the parent devlink is unlocked before obtaining the
main devlink instance that is the target of the request.
A reference to the parent is kept until the end of the request to avoid
it suddenly disappearing.
This means that this reference is of limited use without additional
protection.
Signed-off-by: Cosmin Ratiu <cratiu@nvidia.com>
Reviewed-by: Carolina Jubran <cjubran@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
---
Documentation/netlink/specs/devlink.yaml | 12 +++++
include/uapi/linux/devlink.h | 2 +
net/devlink/devl_internal.h | 2 +
net/devlink/netlink.c | 67 ++++++++++++++++++++++--
net/devlink/netlink_gen.c | 5 ++
net/devlink/netlink_gen.h | 8 +++
6 files changed, 91 insertions(+), 5 deletions(-)
diff --git a/Documentation/netlink/specs/devlink.yaml b/Documentation/netlink/specs/devlink.yaml
index 837112da6738..a8fd0a815c0d 100644
--- a/Documentation/netlink/specs/devlink.yaml
+++ b/Documentation/netlink/specs/devlink.yaml
@@ -867,6 +867,10 @@ attribute-sets:
type: flag
doc: Request restoring parameter to its default value.
value: 183
+
+ - name: parent-dev
+ type: nest
+ nested-attributes: dl-parent-dev
-
name: dl-dev-stats
subset-of: devlink
@@ -1289,6 +1293,14 @@ attribute-sets:
Specifies the bandwidth share assigned to the Traffic Class.
The bandwidth for the traffic class is determined
in proportion to the sum of the shares of all configured classes.
+ -
+ name: dl-parent-dev
+ subset-of: devlink
+ attributes:
+ -
+ name: bus-name
+ -
+ name: dev-name
operations:
enum-model: directional
diff --git a/include/uapi/linux/devlink.h b/include/uapi/linux/devlink.h
index e7d6b6d13470..94b8a4437bac 100644
--- a/include/uapi/linux/devlink.h
+++ b/include/uapi/linux/devlink.h
@@ -642,6 +642,8 @@ enum devlink_attr {
DEVLINK_ATTR_PARAM_VALUE_DEFAULT, /* dynamic */
DEVLINK_ATTR_PARAM_RESET_DEFAULT, /* flag */
+ DEVLINK_ATTR_PARENT_DEV, /* nested */
+
/* Add new attributes above here, update the spec in
* Documentation/netlink/specs/devlink.yaml and re-generate
* net/devlink/netlink_gen.c.
diff --git a/net/devlink/devl_internal.h b/net/devlink/devl_internal.h
index 8374c9cab6ce..3ca4cc8517cd 100644
--- a/net/devlink/devl_internal.h
+++ b/net/devlink/devl_internal.h
@@ -162,6 +162,8 @@ typedef int devlink_nl_dump_one_func_t(struct sk_buff *msg,
struct devlink *
devlink_get_from_attrs_lock(struct net *net, struct nlattr **attrs,
bool dev_lock);
+struct devlink *
+devlink_get_parent_from_attrs_lock(struct net *net, struct nlattr **attrs);
int devlink_nl_dumpit(struct sk_buff *msg, struct netlink_callback *cb,
devlink_nl_dump_one_func_t *dump_one);
diff --git a/net/devlink/netlink.c b/net/devlink/netlink.c
index 593605c1b1ef..781758b8632c 100644
--- a/net/devlink/netlink.c
+++ b/net/devlink/netlink.c
@@ -12,6 +12,7 @@
#define DEVLINK_NL_FLAG_NEED_PORT BIT(0)
#define DEVLINK_NL_FLAG_NEED_DEVLINK_OR_PORT BIT(1)
#define DEVLINK_NL_FLAG_NEED_DEV_LOCK BIT(2)
+#define DEVLINK_NL_FLAG_OPTIONAL_PARENT_DEV BIT(3)
static const struct genl_multicast_group devlink_nl_mcgrps[] = {
[DEVLINK_MCGRP_CONFIG] = { .name = DEVLINK_GENL_MCGRP_CONFIG_NAME },
@@ -206,19 +207,51 @@ devlink_get_from_attrs_lock(struct net *net, struct nlattr **attrs,
return ERR_PTR(-ENODEV);
}
+struct devlink *
+devlink_get_parent_from_attrs_lock(struct net *net, struct nlattr **attrs)
+{
+ struct nlattr *tb[DEVLINK_ATTR_DEV_NAME + 1];
+ int err;
+
+ if (!attrs[DEVLINK_ATTR_PARENT_DEV])
+ return ERR_PTR(-EINVAL);
+
+ err = nla_parse_nested(tb, DEVLINK_ATTR_DEV_NAME,
+ attrs[DEVLINK_ATTR_PARENT_DEV],
+ devlink_dl_parent_dev_nl_policy, NULL);
+ if (err)
+ return ERR_PTR(err);
+
+ return devlink_get_from_attrs_lock(net, tb, false);
+}
+
static int __devlink_nl_pre_doit(struct sk_buff *skb, struct genl_info *info,
u8 flags)
{
+ bool parent_dev = flags & DEVLINK_NL_FLAG_OPTIONAL_PARENT_DEV;
bool dev_lock = flags & DEVLINK_NL_FLAG_NEED_DEV_LOCK;
+ struct devlink *devlink, *parent_devlink = NULL;
+ struct net *net = genl_info_net(info);
+ struct nlattr **attrs = info->attrs;
struct devlink_port *devlink_port;
- struct devlink *devlink;
int err;
- devlink = devlink_get_from_attrs_lock(genl_info_net(info), info->attrs,
- dev_lock);
- if (IS_ERR(devlink))
- return PTR_ERR(devlink);
+ if (parent_dev && attrs[DEVLINK_ATTR_PARENT_DEV]) {
+ parent_devlink = devlink_get_parent_from_attrs_lock(net, attrs);
+ if (IS_ERR(parent_devlink))
+ return PTR_ERR(parent_devlink);
+ info->user_ptr[1] = parent_devlink;
+ /* Drop the parent devlink lock but don't release the reference.
+ * This will keep it alive until the end of the request.
+ */
+ devl_unlock(parent_devlink);
+ }
+ devlink = devlink_get_from_attrs_lock(net, attrs, dev_lock);
+ if (IS_ERR(devlink)) {
+ err = PTR_ERR(devlink);
+ goto parent_put;
+ }
info->user_ptr[0] = devlink;
if (flags & DEVLINK_NL_FLAG_NEED_PORT) {
devlink_port = devlink_port_get_from_info(devlink, info);
@@ -237,6 +270,9 @@ static int __devlink_nl_pre_doit(struct sk_buff *skb, struct genl_info *info,
unlock:
devl_dev_unlock(devlink, dev_lock);
devlink_put(devlink);
+parent_put:
+ if (parent_dev && parent_devlink)
+ devlink_put(parent_devlink);
return err;
}
@@ -265,6 +301,14 @@ int devlink_nl_pre_doit_port_optional(const struct genl_split_ops *ops,
return __devlink_nl_pre_doit(skb, info, DEVLINK_NL_FLAG_NEED_DEVLINK_OR_PORT);
}
+int devlink_nl_pre_doit_parent_dev_optional(const struct genl_split_ops *ops,
+ struct sk_buff *skb,
+ struct genl_info *info)
+{
+ return __devlink_nl_pre_doit(skb, info,
+ DEVLINK_NL_FLAG_OPTIONAL_PARENT_DEV);
+}
+
static void __devlink_nl_post_doit(struct sk_buff *skb, struct genl_info *info,
u8 flags)
{
@@ -274,6 +318,11 @@ static void __devlink_nl_post_doit(struct sk_buff *skb, struct genl_info *info,
devlink = info->user_ptr[0];
devl_dev_unlock(devlink, dev_lock);
devlink_put(devlink);
+ if ((flags & DEVLINK_NL_FLAG_OPTIONAL_PARENT_DEV) &&
+ info->user_ptr[1]) {
+ devlink = info->user_ptr[1];
+ devlink_put(devlink);
+ }
}
void devlink_nl_post_doit(const struct genl_split_ops *ops,
@@ -289,6 +338,14 @@ devlink_nl_post_doit_dev_lock(const struct genl_split_ops *ops,
__devlink_nl_post_doit(skb, info, DEVLINK_NL_FLAG_NEED_DEV_LOCK);
}
+void
+devlink_nl_post_doit_parent_dev_optional(const struct genl_split_ops *ops,
+ struct sk_buff *skb,
+ struct genl_info *info)
+{
+ __devlink_nl_post_doit(skb, info, DEVLINK_NL_FLAG_OPTIONAL_PARENT_DEV);
+}
+
static int devlink_nl_inst_single_dumpit(struct sk_buff *msg,
struct netlink_callback *cb, int flags,
devlink_nl_dump_one_func_t *dump_one,
diff --git a/net/devlink/netlink_gen.c b/net/devlink/netlink_gen.c
index f4c61c2b4f22..6b691bdbf037 100644
--- a/net/devlink/netlink_gen.c
+++ b/net/devlink/netlink_gen.c
@@ -39,6 +39,11 @@ devlink_attr_param_type_validate(const struct nlattr *attr,
}
/* Common nested types */
+const struct nla_policy devlink_dl_parent_dev_nl_policy[DEVLINK_ATTR_DEV_NAME + 1] = {
+ [DEVLINK_ATTR_BUS_NAME] = { .type = NLA_NUL_STRING, },
+ [DEVLINK_ATTR_DEV_NAME] = { .type = NLA_NUL_STRING, },
+};
+
const struct nla_policy devlink_dl_port_function_nl_policy[DEVLINK_PORT_FN_ATTR_CAPS + 1] = {
[DEVLINK_PORT_FUNCTION_ATTR_HW_ADDR] = { .type = NLA_BINARY, },
[DEVLINK_PORT_FN_ATTR_STATE] = NLA_POLICY_MAX(NLA_U8, 1),
diff --git a/net/devlink/netlink_gen.h b/net/devlink/netlink_gen.h
index 2817d53a0eba..d4db82a00522 100644
--- a/net/devlink/netlink_gen.h
+++ b/net/devlink/netlink_gen.h
@@ -13,6 +13,7 @@
#include <uapi/linux/devlink.h>
/* Common nested types */
+extern const struct nla_policy devlink_dl_parent_dev_nl_policy[DEVLINK_ATTR_DEV_NAME + 1];
extern const struct nla_policy devlink_dl_port_function_nl_policy[DEVLINK_PORT_FN_ATTR_CAPS + 1];
extern const struct nla_policy devlink_dl_rate_tc_bws_nl_policy[DEVLINK_RATE_TC_ATTR_BW + 1];
extern const struct nla_policy devlink_dl_selftest_id_nl_policy[DEVLINK_ATTR_SELFTEST_ID_FLASH + 1];
@@ -29,12 +30,19 @@ int devlink_nl_pre_doit_dev_lock(const struct genl_split_ops *ops,
int devlink_nl_pre_doit_port_optional(const struct genl_split_ops *ops,
struct sk_buff *skb,
struct genl_info *info);
+int devlink_nl_pre_doit_parent_dev_optional(const struct genl_split_ops *ops,
+ struct sk_buff *skb,
+ struct genl_info *info);
void
devlink_nl_post_doit(const struct genl_split_ops *ops, struct sk_buff *skb,
struct genl_info *info);
void
devlink_nl_post_doit_dev_lock(const struct genl_split_ops *ops,
struct sk_buff *skb, struct genl_info *info);
+void
+devlink_nl_post_doit_parent_dev_optional(const struct genl_split_ops *ops,
+ struct sk_buff *skb,
+ struct genl_info *info);
int devlink_nl_get_doit(struct sk_buff *skb, struct genl_info *info);
int devlink_nl_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb);
--
2.44.0
next prev parent reply other threads:[~2026-01-20 7:59 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-01-20 7:57 [PATCH net-next V5 00/15] devlink and mlx5: Support cross-function rate scheduling Tariq Toukan
2026-01-20 7:57 ` [PATCH net-next V5 01/15] documentation: networking: add shared devlink documentation Tariq Toukan
2026-01-20 7:57 ` [PATCH net-next V5 02/15] devlink: introduce shared devlink instance for PFs on same chip Tariq Toukan
2026-01-20 7:57 ` [PATCH net-next V5 03/15] devlink: Reverse locking order for nested instances Tariq Toukan
2026-01-20 7:57 ` [PATCH net-next V5 04/15] devlink: Add helpers to lock nested-in instances Tariq Toukan
2026-01-20 7:57 ` [PATCH net-next V5 05/15] devlink: Refactor devlink_rate_nodes_check Tariq Toukan
2026-01-20 7:57 ` [PATCH net-next V5 06/15] devlink: Decouple rate storage from associated devlink object Tariq Toukan
2026-01-22 3:39 ` [net-next,V5,06/15] " Jakub Kicinski
2026-01-22 11:18 ` Cosmin Ratiu
2026-01-20 7:57 ` Tariq Toukan [this message]
2026-01-20 7:57 ` [PATCH net-next V5 08/15] devlink: Allow parent dev for rate-set and rate-new Tariq Toukan
2026-01-20 7:57 ` [PATCH net-next V5 09/15] devlink: Allow rate node parents from other devlinks Tariq Toukan
2026-01-20 7:57 ` [PATCH net-next V5 10/15] net/mlx5: Add a shared devlink instance for PFs on same chip Tariq Toukan
2026-01-22 3:39 ` [net-next,V5,10/15] " Jakub Kicinski
2026-01-22 3:41 ` Jakub Kicinski
2026-01-22 7:42 ` [PATCH net-next V5 10/15] " Krzysztof Kozlowski
2026-01-22 11:13 ` Cosmin Ratiu
2026-01-20 7:57 ` [PATCH net-next V5 11/15] net/mlx5: Expose a function to clear a vport's parent Tariq Toukan
2026-01-22 3:40 ` [net-next,V5,11/15] " Jakub Kicinski
2026-01-22 3:42 ` Jakub Kicinski
2026-01-20 7:57 ` [PATCH net-next V5 12/15] net/mlx5: Store QoS sched nodes in the sh_devlink Tariq Toukan
2026-01-22 3:40 ` [net-next,V5,12/15] " Jakub Kicinski
2026-01-22 11:15 ` Cosmin Ratiu
2026-01-20 7:57 ` [PATCH net-next V5 13/15] net/mlx5: qos: Support cross-device tx scheduling Tariq Toukan
2026-01-20 7:57 ` [PATCH net-next V5 14/15] net/mlx5: qos: Enable cross-device scheduling Tariq Toukan
2026-01-20 7:57 ` [PATCH net-next V5 15/15] net/mlx5: Document devlink rates Tariq Toukan
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