Commit cf2ce339 authored by Taehee Yoo's avatar Taehee Yoo Committed by David S. Miller
Browse files

mld: get rid of inet6_dev->mc_lock 



The purpose of mc_lock is to protect inet6_dev->mc_tomb.
But mc_tomb is already protected by RTNL and all functions,
which manipulate mc_tomb are called under RTNL.
So, mc_lock is not needed.
Furthermore, it is spinlock so the critical section is atomic.
In order to reduce atomic context, it should be removed.

Suggested-by: default avatarCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: default avatarTaehee Yoo <ap420073@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 2d9a93b4

include/net/if_inet6.h

+0 −1
Original line number Diff line number Diff line
@@ -167,7 +167,6 @@ struct inet6_dev { 


	struct ifmcaddr6	*mc_list;

	struct ifmcaddr6	*mc_tomb;

	spinlock_t		mc_lock;



	unsigned char		mc_qrv;		/* Query Robustness Variable */

	unsigned char		mc_gq_running;

net/ipv6/mcast.c

+0 −9
Original line number Diff line number Diff line
@@ -752,10 +752,8 @@ static void mld_add_delrec(struct inet6_dev *idev, struct ifmcaddr6 *im) 
	}

	spin_unlock_bh(&im->mca_lock);



	spin_lock_bh(&idev->mc_lock);

	pmc->next = idev->mc_tomb;

	idev->mc_tomb = pmc;

	spin_unlock_bh(&idev->mc_lock);

}



static void mld_del_delrec(struct inet6_dev *idev, struct ifmcaddr6 *im)
@@ -764,7 +762,6 @@ static void mld_del_delrec(struct inet6_dev *idev, struct ifmcaddr6 *im) 
	struct ip6_sf_list *psf;

	struct in6_addr *pmca = &im->mca_addr;



	spin_lock_bh(&idev->mc_lock);

	pmc_prev = NULL;

	for (pmc = idev->mc_tomb; pmc; pmc = pmc->next) {

		if (ipv6_addr_equal(&pmc->mca_addr, pmca))
@@ -777,7 +774,6 @@ static void mld_del_delrec(struct inet6_dev *idev, struct ifmcaddr6 *im) 
		else

			idev->mc_tomb = pmc->next;

	}

	spin_unlock_bh(&idev->mc_lock);



	spin_lock_bh(&im->mca_lock);

	if (pmc) {
@@ -801,10 +797,8 @@ static void mld_clear_delrec(struct inet6_dev *idev) 
{

	struct ifmcaddr6 *pmc, *nextpmc;



	spin_lock_bh(&idev->mc_lock);

	pmc = idev->mc_tomb;

	idev->mc_tomb = NULL;

	spin_unlock_bh(&idev->mc_lock);



	for (; pmc; pmc = nextpmc) {

		nextpmc = pmc->next;
@@ -1907,7 +1901,6 @@ static void mld_send_cr(struct inet6_dev *idev) 
	int type, dtype;



	read_lock_bh(&idev->lock);

	spin_lock(&idev->mc_lock);



	/* deleted MCA's */

	pmc_prev = NULL;
@@ -1941,7 +1934,6 @@ static void mld_send_cr(struct inet6_dev *idev) 
		} else

			pmc_prev = pmc;

	}

	spin_unlock(&idev->mc_lock);



	/* change recs */

	for (pmc = idev->mc_list; pmc; pmc = pmc->next) {
@@ -2582,7 +2574,6 @@ void ipv6_mc_up(struct inet6_dev *idev) 
void ipv6_mc_init_dev(struct inet6_dev *idev)

{

	write_lock_bh(&idev->lock);

	spin_lock_init(&idev->mc_lock);

	idev->mc_gq_running = 0;

	INIT_DELAYED_WORK(&idev->mc_gq_work, mld_gq_work);

	idev->mc_tomb = NULL;