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Commit 7e083840 authored by Stephen Hemminger's avatar Stephen Hemminger Committed by David S. Miller
Browse files

bonding: remove bonding read/write semaphore 



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: default avatarStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent d9321605

drivers/net/bonding/bond_main.c

+3 −13
Original line number Diff line number Diff line
@@ -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)

drivers/net/bonding/bond_sysfs.c

+3 −20
Original line number Diff line number Diff line
@@ -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 @@ static ssize_t bonding_store_bonds(struct class *cls, const char *buffer, size_t 
	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 @@ static ssize_t bonding_store_slaves(struct device *d, 
	ret = -EPERM;



out:

	up_write(&(bonding_rwsem));

	rtnl_unlock();

	return ret;

}

drivers/net/bonding/bonding.h

+0 −3
Original line number Diff line number Diff line
@@ -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);