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Commit c809195f authored by Sowmini Varadhan's avatar Sowmini Varadhan Committed by David S. Miller
Browse files

rds: clean up loopback rds_connections on netns deletion 



The RDS core module creates rds_connections based on callbacks
from rds_loop_transport when sending/receiving packets to local
addresses.

These connections will need to be cleaned up when they are
created from a netns that is not init_net, and that netns is deleted.

Add the changes aligned with the changes from
commit ebeeb1ad ("rds: tcp: use rds_destroy_pending() to synchronize
netns/module teardown and rds connection/workq management") for
rds_loop_transport

Reported-and-tested-by: default avatar <syzbot+4c20b3866171ce8441d2@syzkaller.appspotmail.com>
Acked-by: default avatarSantosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: default avatarSowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 094bdadd

net/rds/connection.c

+10 −1
Original line number Diff line number Diff line
@@ -659,11 +659,19 @@ static void rds_conn_info(struct socket *sock, unsigned int len, 


int rds_conn_init(void)

{

	int ret;



	ret = rds_loop_net_init(); /* register pernet callback */

	if (ret)

		return ret;



	rds_conn_slab = kmem_cache_create("rds_connection",

					  sizeof(struct rds_connection),

					  0, 0, NULL);

	if (!rds_conn_slab)

	if (!rds_conn_slab) {

		rds_loop_net_exit();

		return -ENOMEM;

	}



	rds_info_register_func(RDS_INFO_CONNECTIONS, rds_conn_info);

	rds_info_register_func(RDS_INFO_SEND_MESSAGES,
@@ -676,6 +684,7 @@ int rds_conn_init(void) 


void rds_conn_exit(void)

{

	rds_loop_net_exit(); /* unregister pernet callback */

	rds_loop_exit();



	WARN_ON(!hlist_empty(rds_conn_hash));

net/rds/loop.c

+56 −0
Original line number Diff line number Diff line
@@ -33,6 +33,8 @@ 
#include <linux/kernel.h>

#include <linux/slab.h>

#include <linux/in.h>

#include <net/net_namespace.h>

#include <net/netns/generic.h>



#include "rds_single_path.h"

#include "rds.h"
@@ -40,6 +42,17 @@ 


static DEFINE_SPINLOCK(loop_conns_lock);

static LIST_HEAD(loop_conns);

static atomic_t rds_loop_unloading = ATOMIC_INIT(0);



static void rds_loop_set_unloading(void)

{

	atomic_set(&rds_loop_unloading, 1);

}



static bool rds_loop_is_unloading(struct rds_connection *conn)

{

	return atomic_read(&rds_loop_unloading) != 0;

}



/*

 * This 'loopback' transport is a special case for flows that originate
@@ -165,6 +178,8 @@ void rds_loop_exit(void) 
	struct rds_loop_connection *lc, *_lc;

	LIST_HEAD(tmp_list);



	rds_loop_set_unloading();

	synchronize_rcu();

	/* avoid calling conn_destroy with irqs off */

	spin_lock_irq(&loop_conns_lock);

	list_splice(&loop_conns, &tmp_list);
@@ -177,6 +192,46 @@ void rds_loop_exit(void) 
	}

}



static void rds_loop_kill_conns(struct net *net)

{

	struct rds_loop_connection *lc, *_lc;

	LIST_HEAD(tmp_list);



	spin_lock_irq(&loop_conns_lock);

	list_for_each_entry_safe(lc, _lc, &loop_conns, loop_node)  {

		struct net *c_net = read_pnet(&lc->conn->c_net);



		if (net != c_net)

			continue;

		list_move_tail(&lc->loop_node, &tmp_list);

	}

	spin_unlock_irq(&loop_conns_lock);



	list_for_each_entry_safe(lc, _lc, &tmp_list, loop_node) {

		WARN_ON(lc->conn->c_passive);

		rds_conn_destroy(lc->conn);

	}

}



static void __net_exit rds_loop_exit_net(struct net *net)

{

	rds_loop_kill_conns(net);

}



static struct pernet_operations rds_loop_net_ops = {

	.exit = rds_loop_exit_net,

};



int rds_loop_net_init(void)

{

	return register_pernet_device(&rds_loop_net_ops);

}



void rds_loop_net_exit(void)

{

	unregister_pernet_device(&rds_loop_net_ops);

}



/*

 * This is missing .xmit_* because loop doesn't go through generic

 * rds_send_xmit() and doesn't call rds_recv_incoming().  .listen_stop and
@@ -194,4 +249,5 @@ struct rds_transport rds_loop_transport = { 
	.inc_free		= rds_loop_inc_free,

	.t_name			= "loopback",

	.t_type			= RDS_TRANS_LOOP,

	.t_unloading		= rds_loop_is_unloading,

};

net/rds/loop.h

+2 −0
Original line number Diff line number Diff line
@@ -5,6 +5,8 @@ 
/* loop.c */

extern struct rds_transport rds_loop_transport;



int rds_loop_net_init(void);

void rds_loop_net_exit(void);

void rds_loop_exit(void);



#endif