Commit 07f3af66 authored by Jakub Kicinski's avatar Jakub Kicinski
Browse files

devlink: add by-instance dump infra 



Most dumpit implementations walk the devlink instances.
This requires careful lock taking and reference dropping.
Factor the loop out and provide just a callback to handle
a single instance dump.

Convert one user as an example, other users converted
in the next change.

Slightly inspired by ethtool netlink code.

Reviewed-by: default avatarJacob Keller <jacob.e.keller@intel.com>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent e4d5015b

net/devlink/devl_internal.h

+10 −0
Original line number Diff line number Diff line
@@ -122,6 +122,11 @@ struct devlink_nl_dump_state { 
	};

};



struct devlink_gen_cmd {

	int (*dump_one)(struct sk_buff *msg, struct devlink *devlink,

			struct netlink_callback *cb);

};



/* Iterate over registered devlink instances for devlink dump.

 * devlink_put() needs to be called for each iterated devlink pointer

 * in loop body in order to release the reference.
@@ -140,6 +145,9 @@ struct devlink *devlink_get_from_attrs(struct net *net, struct nlattr **attrs); 
void devlink_notify_unregister(struct devlink *devlink);

void devlink_notify_register(struct devlink *devlink);



int devlink_nl_instance_iter_dump(struct sk_buff *msg,

				  struct netlink_callback *cb);



static inline struct devlink_nl_dump_state *

devlink_dump_state(struct netlink_callback *cb)

{
@@ -175,6 +183,8 @@ devlink_linecard_get_from_info(struct devlink *devlink, struct genl_info *info); 
void devlink_linecard_put(struct devlink_linecard *linecard);



/* Rates */

extern const struct devlink_gen_cmd devl_gen_rate_get;



struct devlink_rate *

devlink_rate_get_from_info(struct devlink *devlink, struct genl_info *info);

struct devlink_rate *

net/devlink/leftover.c

+24 −31
Original line number Diff line number Diff line
@@ -1219,18 +1219,15 @@ static void devlink_rate_notify(struct devlink_rate *devlink_rate, 
				0, DEVLINK_MCGRP_CONFIG, GFP_KERNEL);

}



static int devlink_nl_cmd_rate_get_dumpit(struct sk_buff *msg,

static int

devlink_nl_cmd_rate_get_dump_one(struct sk_buff *msg, struct devlink *devlink,

				 struct netlink_callback *cb)

{

	struct devlink_nl_dump_state *state = devlink_dump_state(cb);

	struct devlink *devlink;

	int err = 0;



	devlink_dump_for_each_instance_get(msg, state, devlink) {

	struct devlink_rate *devlink_rate;

	int idx = 0;

	int err = 0;



		devl_lock(devlink);

	list_for_each_entry(devlink_rate, &devlink->rate_list, list) {

		enum devlink_command cmd = DEVLINK_CMD_RATE_NEW;

		u32 id = NETLINK_CB(cb->skb).portid;
@@ -1243,23 +1240,19 @@ static int devlink_nl_cmd_rate_get_dumpit(struct sk_buff *msg, 
					   cb->nlh->nlmsg_seq,

					   NLM_F_MULTI, NULL);

		if (err) {

				devl_unlock(devlink);

				devlink_put(devlink);

			state->idx = idx;

				goto out;

			break;

		}

		idx++;

	}

		devl_unlock(devlink);

		devlink_put(devlink);

	}

out:

	if (err != -EMSGSIZE)

		return err;



	return msg->len;

	return err;

}



const struct devlink_gen_cmd devl_gen_rate_get = {

	.dump_one		= devlink_nl_cmd_rate_get_dump_one,

};



static int devlink_nl_cmd_rate_get_doit(struct sk_buff *skb,

					struct genl_info *info)

{
@@ -9130,7 +9123,7 @@ const struct genl_small_ops devlink_nl_ops[56] = { 
	{

		.cmd = DEVLINK_CMD_RATE_GET,

		.doit = devlink_nl_cmd_rate_get_doit,

		.dumpit = devlink_nl_cmd_rate_get_dumpit,

		.dumpit = devlink_nl_instance_iter_dump,

		.internal_flags = DEVLINK_NL_FLAG_NEED_RATE,

		/* can be retrieved by unprivileged users */

	},

net/devlink/netlink.c

+34 −0
Original line number Diff line number Diff line
@@ -5,6 +5,7 @@ 
 */



#include <net/genetlink.h>

#include <net/sock.h>



#include "devl_internal.h"
@@ -177,6 +178,39 @@ static void devlink_nl_post_doit(const struct genl_split_ops *ops, 
	devlink_put(devlink);

}



static const struct devlink_gen_cmd *devl_gen_cmds[] = {

	[DEVLINK_CMD_RATE_GET]		= &devl_gen_rate_get,

};



int devlink_nl_instance_iter_dump(struct sk_buff *msg,

				  struct netlink_callback *cb)

{

	const struct genl_dumpit_info *info = genl_dumpit_info(cb);

	struct devlink_nl_dump_state *state = devlink_dump_state(cb);

	const struct devlink_gen_cmd *cmd;

	struct devlink *devlink;

	int err = 0;



	cmd = devl_gen_cmds[info->op.cmd];



	devlink_dump_for_each_instance_get(msg, state, devlink) {

		devl_lock(devlink);

		err = cmd->dump_one(msg, devlink, cb);

		devl_unlock(devlink);

		devlink_put(devlink);



		if (err)

			break;



		/* restart sub-object walk for the next instance */

		state->idx = 0;

	}



	if (err != -EMSGSIZE)

		return err;

	return msg->len;

}



struct genl_family devlink_nl_family __ro_after_init = {

	.name		= DEVLINK_GENL_NAME,

	.version	= DEVLINK_GENL_VERSION,