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From:   Moshe Shemesh <moshe@mellanox.com>
To:     "David S. Miller" <davem@davemloft.net>
Cc:     Jiri Pirko <jiri@mellanox.com>, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        Vladyslav Tarasiuk <vladyslavt@mellanox.com>
Subject: [PATCH net-next v2 4/7] devlink: Implement devlink health reporters on per-port basis
Date:   Fri,  3 Jul 2020 06:27:35 +0300
Message-Id: <1593746858-6548-5-git-send-email-moshe@mellanox.com>
In-Reply-To: <1593746858-6548-1-git-send-email-moshe@mellanox.com>
References: <1593746858-6548-1-git-send-email-moshe@mellanox.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

From: Vladyslav Tarasiuk <vladyslavt@mellanox.com>

Add devlink-health reporter support on per-port basis.
The main difference existing devlink-health is that port reporters are
stored in per-devlink_port lists. Upon creation of such health reporter the
reference to a port it belongs to is stored in reporter struct.

Fill the port index attribute in devlink-health response to
allow devlink userspace utility to distinguish between device and port
reporters.

Signed-off-by: Vladyslav Tarasiuk <vladyslavt@mellanox.com>
Reviewed-by: Moshe Shemesh <moshe@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
---
 include/net/devlink.h |  2 ++
 net/core/devlink.c    | 94 +++++++++++++++++++++++++++++++++++++++++----------
 2 files changed, 79 insertions(+), 17 deletions(-)

diff --git a/include/net/devlink.h b/include/net/devlink.h
index 428f55f..d3ac152 100644
--- a/include/net/devlink.h
+++ b/include/net/devlink.h
@@ -91,6 +91,8 @@ struct devlink_port {
 	void *type_dev;
 	struct devlink_port_attrs attrs;
 	struct delayed_work type_warn_dw;
+	struct list_head reporter_list;
+	struct mutex reporters_lock; /* Protects reporter_list */
 };
 
 struct devlink_sb_pool_info {
diff --git a/net/core/devlink.c b/net/core/devlink.c
index 98e6911..8aedd20 100644
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -386,19 +386,21 @@ struct devlink_snapshot {
 	return NULL;
 }
 
-#define DEVLINK_NL_FLAG_NEED_DEVLINK	BIT(0)
-#define DEVLINK_NL_FLAG_NEED_PORT	BIT(1)
-#define DEVLINK_NL_FLAG_NEED_SB		BIT(2)
+#define DEVLINK_NL_FLAG_NEED_DEVLINK		BIT(0)
+#define DEVLINK_NL_FLAG_NEED_PORT		BIT(1)
+#define DEVLINK_NL_FLAG_NEED_DEVLINK_OR_PORT	BIT(2)
+#define DEVLINK_NL_FLAG_NEED_SB			BIT(3)
 
 /* The per devlink instance lock is taken by default in the pre-doit
  * operation, yet several commands do not require this. The global
  * devlink lock is taken and protects from disruption by user-calls.
  */
-#define DEVLINK_NL_FLAG_NO_LOCK		BIT(3)
+#define DEVLINK_NL_FLAG_NO_LOCK			BIT(4)
 
 static int devlink_nl_pre_doit(const struct genl_ops *ops,
 			       struct sk_buff *skb, struct genl_info *info)
 {
+	struct devlink_port *devlink_port;
 	struct devlink *devlink;
 	int err;
 
@@ -413,14 +415,17 @@ static int devlink_nl_pre_doit(const struct genl_ops *ops,
 	if (ops->internal_flags & DEVLINK_NL_FLAG_NEED_DEVLINK) {
 		info->user_ptr[0] = devlink;
 	} else if (ops->internal_flags & DEVLINK_NL_FLAG_NEED_PORT) {
-		struct devlink_port *devlink_port;
-
 		devlink_port = devlink_port_get_from_info(devlink, info);
 		if (IS_ERR(devlink_port)) {
 			err = PTR_ERR(devlink_port);
 			goto unlock;
 		}
 		info->user_ptr[0] = devlink_port;
+	} else if (ops->internal_flags & DEVLINK_NL_FLAG_NEED_DEVLINK_OR_PORT) {
+		info->user_ptr[0] = devlink;
+		devlink_port = devlink_port_get_from_info(devlink, info);
+		if (!IS_ERR(devlink_port))
+			info->user_ptr[1] = devlink_port;
 	}
 	if (ops->internal_flags & DEVLINK_NL_FLAG_NEED_SB) {
 		struct devlink_sb *devlink_sb;
@@ -5261,6 +5266,7 @@ struct devlink_health_reporter {
 	void *priv;
 	const struct devlink_health_reporter_ops *ops;
 	struct devlink *devlink;
+	struct devlink_port *devlink_port;
 	struct devlink_fmsg *dump_fmsg;
 	struct mutex dump_lock; /* lock parallel read/write from dump buffers */
 	u64 graceful_period;
@@ -5306,6 +5312,15 @@ struct devlink_health_reporter {
 }
 
 static struct devlink_health_reporter *
+devlink_port_health_reporter_find_by_name(struct devlink_port *devlink_port,
+					  const char *reporter_name)
+{
+	return __devlink_health_reporter_find_by_name(&devlink_port->reporter_list,
+						      &devlink_port->reporters_lock,
+						      reporter_name);
+}
+
+static struct devlink_health_reporter *
 __devlink_health_reporter_create(struct devlink *devlink,
 				 const struct devlink_health_reporter_ops *ops,
 				 u64 graceful_period, void *priv)
@@ -5417,6 +5432,10 @@ struct devlink_health_reporter *
 	if (devlink_nl_put_handle(msg, devlink))
 		goto genlmsg_cancel;
 
+	if (reporter->devlink_port) {
+		if (nla_put_u32(msg, DEVLINK_ATTR_PORT_INDEX, reporter->devlink_port->index))
+			goto genlmsg_cancel;
+	}
 	reporter_attr = nla_nest_start_noflag(msg,
 					      DEVLINK_ATTR_HEALTH_REPORTER);
 	if (!reporter_attr)
@@ -5624,17 +5643,28 @@ int devlink_health_report(struct devlink_health_reporter *reporter,
 				       struct nlattr **attrs)
 {
 	struct devlink_health_reporter *reporter;
+	struct devlink_port *devlink_port;
 	char *reporter_name;
 
 	if (!attrs[DEVLINK_ATTR_HEALTH_REPORTER_NAME])
 		return NULL;
 
 	reporter_name = nla_data(attrs[DEVLINK_ATTR_HEALTH_REPORTER_NAME]);
-	mutex_lock(&devlink->reporters_lock);
-	reporter = devlink_health_reporter_find_by_name(devlink, reporter_name);
-	if (reporter)
-		refcount_inc(&reporter->refcount);
-	mutex_unlock(&devlink->reporters_lock);
+	devlink_port = devlink_port_get_from_attrs(devlink, attrs);
+	if (IS_ERR(devlink_port)) {
+		mutex_lock(&devlink->reporters_lock);
+		reporter = devlink_health_reporter_find_by_name(devlink, reporter_name);
+		if (reporter)
+			refcount_inc(&reporter->refcount);
+		mutex_unlock(&devlink->reporters_lock);
+	} else {
+		mutex_lock(&devlink_port->reporters_lock);
+		reporter = devlink_port_health_reporter_find_by_name(devlink_port, reporter_name);
+		if (reporter)
+			refcount_inc(&reporter->refcount);
+		mutex_unlock(&devlink_port->reporters_lock);
+	}
+
 	return reporter;
 }
 
@@ -5722,6 +5752,7 @@ static int devlink_nl_cmd_health_reporter_get_doit(struct sk_buff *skb,
 					  struct netlink_callback *cb)
 {
 	struct devlink_health_reporter *reporter;
+	struct devlink_port *port;
 	struct devlink *devlink;
 	int start = cb->args[0];
 	int idx = 0;
@@ -5752,6 +5783,31 @@ static int devlink_nl_cmd_health_reporter_get_doit(struct sk_buff *skb,
 		}
 		mutex_unlock(&devlink->reporters_lock);
 	}
+
+	list_for_each_entry(devlink, &devlink_list, list) {
+		if (!net_eq(devlink_net(devlink), sock_net(msg->sk)))
+			continue;
+		list_for_each_entry(port, &devlink->port_list, list) {
+			mutex_lock(&port->reporters_lock);
+			list_for_each_entry(reporter, &port->reporter_list, list) {
+				if (idx < start) {
+					idx++;
+					continue;
+				}
+				err = devlink_nl_health_reporter_fill(msg, devlink, reporter,
+								      DEVLINK_CMD_HEALTH_REPORTER_GET,
+								      NETLINK_CB(cb->skb).portid,
+								      cb->nlh->nlmsg_seq,
+								      NLM_F_MULTI);
+				if (err) {
+					mutex_unlock(&port->reporters_lock);
+					goto out;
+				}
+				idx++;
+			}
+			mutex_unlock(&port->reporters_lock);
+		}
+	}
 out:
 	mutex_unlock(&devlink_mutex);
 
@@ -7131,7 +7187,7 @@ static int devlink_nl_cmd_trap_policer_set_doit(struct sk_buff *skb,
 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 		.doit = devlink_nl_cmd_health_reporter_get_doit,
 		.dumpit = devlink_nl_cmd_health_reporter_get_dumpit,
-		.internal_flags = DEVLINK_NL_FLAG_NEED_DEVLINK |
+		.internal_flags = DEVLINK_NL_FLAG_NEED_DEVLINK_OR_PORT |
 				  DEVLINK_NL_FLAG_NO_LOCK,
 		/* can be retrieved by unprivileged users */
 	},
@@ -7140,7 +7196,7 @@ static int devlink_nl_cmd_trap_policer_set_doit(struct sk_buff *skb,
 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 		.doit = devlink_nl_cmd_health_reporter_set_doit,
 		.flags = GENL_ADMIN_PERM,
-		.internal_flags = DEVLINK_NL_FLAG_NEED_DEVLINK |
+		.internal_flags = DEVLINK_NL_FLAG_NEED_DEVLINK_OR_PORT |
 				  DEVLINK_NL_FLAG_NO_LOCK,
 	},
 	{
@@ -7148,7 +7204,7 @@ static int devlink_nl_cmd_trap_policer_set_doit(struct sk_buff *skb,
 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 		.doit = devlink_nl_cmd_health_reporter_recover_doit,
 		.flags = GENL_ADMIN_PERM,
-		.internal_flags = DEVLINK_NL_FLAG_NEED_DEVLINK |
+		.internal_flags = DEVLINK_NL_FLAG_NEED_DEVLINK_OR_PORT |
 				  DEVLINK_NL_FLAG_NO_LOCK,
 	},
 	{
@@ -7156,7 +7212,7 @@ static int devlink_nl_cmd_trap_policer_set_doit(struct sk_buff *skb,
 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 		.doit = devlink_nl_cmd_health_reporter_diagnose_doit,
 		.flags = GENL_ADMIN_PERM,
-		.internal_flags = DEVLINK_NL_FLAG_NEED_DEVLINK |
+		.internal_flags = DEVLINK_NL_FLAG_NEED_DEVLINK_OR_PORT |
 				  DEVLINK_NL_FLAG_NO_LOCK,
 	},
 	{
@@ -7165,7 +7221,7 @@ static int devlink_nl_cmd_trap_policer_set_doit(struct sk_buff *skb,
 			    GENL_DONT_VALIDATE_DUMP_STRICT,
 		.dumpit = devlink_nl_cmd_health_reporter_dump_get_dumpit,
 		.flags = GENL_ADMIN_PERM,
-		.internal_flags = DEVLINK_NL_FLAG_NEED_DEVLINK |
+		.internal_flags = DEVLINK_NL_FLAG_NEED_DEVLINK_OR_PORT |
 				  DEVLINK_NL_FLAG_NO_LOCK,
 	},
 	{
@@ -7173,7 +7229,7 @@ static int devlink_nl_cmd_trap_policer_set_doit(struct sk_buff *skb,
 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 		.doit = devlink_nl_cmd_health_reporter_dump_clear_doit,
 		.flags = GENL_ADMIN_PERM,
-		.internal_flags = DEVLINK_NL_FLAG_NEED_DEVLINK |
+		.internal_flags = DEVLINK_NL_FLAG_NEED_DEVLINK_OR_PORT |
 				  DEVLINK_NL_FLAG_NO_LOCK,
 	},
 	{
@@ -7433,6 +7489,8 @@ int devlink_port_register(struct devlink *devlink,
 	list_add_tail(&devlink_port->list, &devlink->port_list);
 	INIT_LIST_HEAD(&devlink_port->param_list);
 	mutex_unlock(&devlink->lock);
+	INIT_LIST_HEAD(&devlink_port->reporter_list);
+	mutex_init(&devlink_port->reporters_lock);
 	INIT_DELAYED_WORK(&devlink_port->type_warn_dw, &devlink_port_type_warn);
 	devlink_port_type_warn_schedule(devlink_port);
 	devlink_port_notify(devlink_port, DEVLINK_CMD_PORT_NEW);
@@ -7449,6 +7507,8 @@ void devlink_port_unregister(struct devlink_port *devlink_port)
 {
 	struct devlink *devlink = devlink_port->devlink;
 
+	WARN_ON(!list_empty(&devlink_port->reporter_list));
+	mutex_destroy(&devlink_port->reporters_lock);
 	devlink_port_type_warn_cancel(devlink_port);
 	devlink_port_notify(devlink_port, DEVLINK_CMD_PORT_DEL);
 	mutex_lock(&devlink->lock);
-- 
1.8.3.1