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bonding: remove bonding read/write semaphore

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The whole read/write semaphore locking can be removed. It doesn't add any
protection that isn't already done by using the RTNL mutex properly.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Stephen Hemminger 2009-06-12 19:02:46 +00:00 committed by David S. Miller
parent d93216051a
commit 7e08384045
3 changed files with 6 additions and 36 deletions
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16
drivers/net/bonding/bond_main.c
View File

@ -3489,10 +3489,10 @@ static int bond_event_changename(struct bonding *bond)
{
bond_remove_proc_entry(bond);
bond_create_proc_entry(bond);
down_write(&(bonding_rwsem));
bond_destroy_sysfs_entry(bond);
bond_create_sysfs_entry(bond);
up_write(&(bonding_rwsem));
return NOTIFY_DONE;
}
@ -4015,7 +4015,6 @@ static int bond_do_ioctl(struct net_device *bond_dev, struct ifreq *ifr, int cmd
return -EPERM;
}
down_write(&(bonding_rwsem));
slave_dev = dev_get_by_name(&init_net, ifr->ifr_slave);
pr_debug("slave_dev=%p: \n", slave_dev);
@ -4048,7 +4047,6 @@ static int bond_do_ioctl(struct net_device *bond_dev, struct ifreq *ifr, int cmd
dev_put(slave_dev);
}
up_write(&(bonding_rwsem));
return res;
}
@ -5123,8 +5121,6 @@ int bond_create(const char *name)
int res;
rtnl_lock();
down_write(&bonding_rwsem);
/* Check to see if the bond already exists. */
if (name) {
list_for_each_entry(bond, &bond_dev_list, bond_list)
@ -5173,24 +5169,20 @@ int bond_create(const char *name)
goto out_bond;
}
up_write(&bonding_rwsem);
rtnl_unlock(); /* allows sysfs registration of net device */
res = bond_create_sysfs_entry(netdev_priv(bond_dev));
if (res < 0)
goto out_unreg;
rtnl_unlock();
return 0;
out_unreg:
rtnl_lock();
down_write(&bonding_rwsem);
unregister_netdevice(bond_dev);
out_bond:
bond_deinit(bond_dev);
out_netdev:
free_netdev(bond_dev);
out_rtnl:
up_write(&bonding_rwsem);
rtnl_unlock();
return res;
}
@ -5209,8 +5201,6 @@ static int __init bonding_init(void)
bond_create_proc_dir();
init_rwsem(&bonding_rwsem);
for (i = 0; i < max_bonds; i++) {
res = bond_create(NULL);
if (res)

23
drivers/net/bonding/bond_sysfs.c
View File

@ -44,20 +44,6 @@
/*---------------------------- Declarations -------------------------------*/
static int expected_refcount = -1;
/*--------------------------- Data Structures -----------------------------*/
/* Bonding sysfs lock. Why can't we just use the subsystem lock?
* Because kobject_register tries to acquire the subsystem lock. If
* we already hold the lock (which we would if the user was creating
* a new bond through the sysfs interface), we deadlock.
* This lock is only needed when deleting a bond - we need to make sure
* that we don't collide with an ongoing ioctl.
*/
struct rw_semaphore bonding_rwsem;
/*------------------------------ Functions --------------------------------*/
@ -70,7 +56,7 @@ static ssize_t bonding_show_bonds(struct class *cls, char *buf)
int res = 0;
struct bonding *bond;
down_read(&(bonding_rwsem));
rtnl_lock();
list_for_each_entry(bond, &bond_dev_list, bond_list) {
if (res > (PAGE_SIZE - IFNAMSIZ)) {
@ -84,7 +70,8 @@ static ssize_t bonding_show_bonds(struct class *cls, char *buf)
}
if (res)
buf[res-1] = '\n'; /* eat the leftover space */
up_read(&(bonding_rwsem));
rtnl_unlock();
return res;
}
@ -122,7 +109,6 @@ static ssize_t bonding_store_bonds(struct class *cls, const char *buffer, size_t
if (command[0] == '-') {
rtnl_lock();
down_write(&bonding_rwsem);
list_for_each_entry(bond, &bond_dev_list, bond_list)
if (strnicmp(bond->dev->name, ifname, IFNAMSIZ) == 0) {
@ -157,7 +143,6 @@ err_no_cmd:
return -EPERM;
out_unlock:
up_write(&bonding_rwsem);
rtnl_unlock();
/* Always return either count or an error. If you return 0, you'll
@ -253,7 +238,6 @@ static ssize_t bonding_store_slaves(struct device *d,
if (!rtnl_trylock())
return restart_syscall();
down_write(&(bonding_rwsem));
sscanf(buffer, "%16s", command); /* IFNAMSIZ*/
ifname = command + 1;
@ -357,7 +341,6 @@ err_no_cmd:
ret = -EPERM;
out:
up_write(&(bonding_rwsem));
rtnl_unlock();
return ret;
}

3
drivers/net/bonding/bonding.h
View File

@ -351,9 +351,6 @@ extern const struct bond_parm_tbl arp_validate_tbl[];
extern const struct bond_parm_tbl fail_over_mac_tbl[];
extern struct bond_parm_tbl ad_select_tbl[];
/* exported from bond_sysfs.c */
extern struct rw_semaphore bonding_rwsem;
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
void bond_send_unsolicited_na(struct bonding *bond);
void bond_register_ipv6_notifier(void);