kernel-aes67/net/bridge/br_sysfs_if.c
Eric W. Biederman af38f29895 net: Fix bridgeing sysfs handling of rtnl_lock
Holding rtnl_lock when we are unregistering the sysfs files can
deadlock if we unconditionally take rtnl_lock in a sysfs file.  So fix
it with the now familiar patter of: rtnl_trylock and syscall_restart()

Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-05-18 22:15:59 -07:00

237 lines
6.4 KiB
C

/*
* Sysfs attributes of bridge ports
* Linux ethernet bridge
*
* Authors:
* Stephen Hemminger <shemminger@osdl.org>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/capability.h>
#include <linux/kernel.h>
#include <linux/netdevice.h>
#include <linux/if_bridge.h>
#include <linux/rtnetlink.h>
#include <linux/spinlock.h>
#include "br_private.h"
struct brport_attribute {
struct attribute attr;
ssize_t (*show)(struct net_bridge_port *, char *);
ssize_t (*store)(struct net_bridge_port *, unsigned long);
};
#define BRPORT_ATTR(_name,_mode,_show,_store) \
struct brport_attribute brport_attr_##_name = { \
.attr = {.name = __stringify(_name), \
.mode = _mode }, \
.show = _show, \
.store = _store, \
};
static ssize_t show_path_cost(struct net_bridge_port *p, char *buf)
{
return sprintf(buf, "%d\n", p->path_cost);
}
static ssize_t store_path_cost(struct net_bridge_port *p, unsigned long v)
{
br_stp_set_path_cost(p, v);
return 0;
}
static BRPORT_ATTR(path_cost, S_IRUGO | S_IWUSR,
show_path_cost, store_path_cost);
static ssize_t show_priority(struct net_bridge_port *p, char *buf)
{
return sprintf(buf, "%d\n", p->priority);
}
static ssize_t store_priority(struct net_bridge_port *p, unsigned long v)
{
if (v >= (1<<(16-BR_PORT_BITS)))
return -ERANGE;
br_stp_set_port_priority(p, v);
return 0;
}
static BRPORT_ATTR(priority, S_IRUGO | S_IWUSR,
show_priority, store_priority);
static ssize_t show_designated_root(struct net_bridge_port *p, char *buf)
{
return br_show_bridge_id(buf, &p->designated_root);
}
static BRPORT_ATTR(designated_root, S_IRUGO, show_designated_root, NULL);
static ssize_t show_designated_bridge(struct net_bridge_port *p, char *buf)
{
return br_show_bridge_id(buf, &p->designated_bridge);
}
static BRPORT_ATTR(designated_bridge, S_IRUGO, show_designated_bridge, NULL);
static ssize_t show_designated_port(struct net_bridge_port *p, char *buf)
{
return sprintf(buf, "%d\n", p->designated_port);
}
static BRPORT_ATTR(designated_port, S_IRUGO, show_designated_port, NULL);
static ssize_t show_designated_cost(struct net_bridge_port *p, char *buf)
{
return sprintf(buf, "%d\n", p->designated_cost);
}
static BRPORT_ATTR(designated_cost, S_IRUGO, show_designated_cost, NULL);
static ssize_t show_port_id(struct net_bridge_port *p, char *buf)
{
return sprintf(buf, "0x%x\n", p->port_id);
}
static BRPORT_ATTR(port_id, S_IRUGO, show_port_id, NULL);
static ssize_t show_port_no(struct net_bridge_port *p, char *buf)
{
return sprintf(buf, "0x%x\n", p->port_no);
}
static BRPORT_ATTR(port_no, S_IRUGO, show_port_no, NULL);
static ssize_t show_change_ack(struct net_bridge_port *p, char *buf)
{
return sprintf(buf, "%d\n", p->topology_change_ack);
}
static BRPORT_ATTR(change_ack, S_IRUGO, show_change_ack, NULL);
static ssize_t show_config_pending(struct net_bridge_port *p, char *buf)
{
return sprintf(buf, "%d\n", p->config_pending);
}
static BRPORT_ATTR(config_pending, S_IRUGO, show_config_pending, NULL);
static ssize_t show_port_state(struct net_bridge_port *p, char *buf)
{
return sprintf(buf, "%d\n", p->state);
}
static BRPORT_ATTR(state, S_IRUGO, show_port_state, NULL);
static ssize_t show_message_age_timer(struct net_bridge_port *p,
char *buf)
{
return sprintf(buf, "%ld\n", br_timer_value(&p->message_age_timer));
}
static BRPORT_ATTR(message_age_timer, S_IRUGO, show_message_age_timer, NULL);
static ssize_t show_forward_delay_timer(struct net_bridge_port *p,
char *buf)
{
return sprintf(buf, "%ld\n", br_timer_value(&p->forward_delay_timer));
}
static BRPORT_ATTR(forward_delay_timer, S_IRUGO, show_forward_delay_timer, NULL);
static ssize_t show_hold_timer(struct net_bridge_port *p,
char *buf)
{
return sprintf(buf, "%ld\n", br_timer_value(&p->hold_timer));
}
static BRPORT_ATTR(hold_timer, S_IRUGO, show_hold_timer, NULL);
static ssize_t store_flush(struct net_bridge_port *p, unsigned long v)
{
br_fdb_delete_by_port(p->br, p, 0); // Don't delete local entry
return 0;
}
static BRPORT_ATTR(flush, S_IWUSR, NULL, store_flush);
static struct brport_attribute *brport_attrs[] = {
&brport_attr_path_cost,
&brport_attr_priority,
&brport_attr_port_id,
&brport_attr_port_no,
&brport_attr_designated_root,
&brport_attr_designated_bridge,
&brport_attr_designated_port,
&brport_attr_designated_cost,
&brport_attr_state,
&brport_attr_change_ack,
&brport_attr_config_pending,
&brport_attr_message_age_timer,
&brport_attr_forward_delay_timer,
&brport_attr_hold_timer,
&brport_attr_flush,
NULL
};
#define to_brport_attr(_at) container_of(_at, struct brport_attribute, attr)
#define to_brport(obj) container_of(obj, struct net_bridge_port, kobj)
static ssize_t brport_show(struct kobject * kobj,
struct attribute * attr, char * buf)
{
struct brport_attribute * brport_attr = to_brport_attr(attr);
struct net_bridge_port * p = to_brport(kobj);
return brport_attr->show(p, buf);
}
static ssize_t brport_store(struct kobject * kobj,
struct attribute * attr,
const char * buf, size_t count)
{
struct brport_attribute * brport_attr = to_brport_attr(attr);
struct net_bridge_port * p = to_brport(kobj);
ssize_t ret = -EINVAL;
char *endp;
unsigned long val;
if (!capable(CAP_NET_ADMIN))
return -EPERM;
val = simple_strtoul(buf, &endp, 0);
if (endp != buf) {
if (!rtnl_trylock())
return restart_syscall();
if (p->dev && p->br && brport_attr->store) {
spin_lock_bh(&p->br->lock);
ret = brport_attr->store(p, val);
spin_unlock_bh(&p->br->lock);
if (ret == 0)
ret = count;
}
rtnl_unlock();
}
return ret;
}
struct sysfs_ops brport_sysfs_ops = {
.show = brport_show,
.store = brport_store,
};
/*
* Add sysfs entries to ethernet device added to a bridge.
* Creates a brport subdirectory with bridge attributes.
* Puts symlink in bridge's brport subdirectory
*/
int br_sysfs_addif(struct net_bridge_port *p)
{
struct net_bridge *br = p->br;
struct brport_attribute **a;
int err;
err = sysfs_create_link(&p->kobj, &br->dev->dev.kobj,
SYSFS_BRIDGE_PORT_LINK);
if (err)
goto out2;
for (a = brport_attrs; *a; ++a) {
err = sysfs_create_file(&p->kobj, &((*a)->attr));
if (err)
goto out2;
}
err = sysfs_create_link(br->ifobj, &p->kobj, p->dev->name);
out2:
return err;
}