Commit a68d5398 authored by David S. Miller's avatar David S. Miller
Browse files

Merge branch 'rhash-raw-walkers-remove-part-1' 



Herbert Xu says:

====================
rhashtable: Get rid of raw table walkers part 1

This series starts the process of getting rid of all raw rhashtable
walkers (e.g., using any of the rht_for_each helpers) from the
kernel.

We need to do this before I can fix the resize kmalloc failure issue
by using multi-layered tables.

We should do this anyway because almost all raw table walkers are
already buggy in that they don't handle multiple rhashtables during
a resize.
====================

Dave/Tomas, please keep an eye out for any new patches that try
to introduce raw table walkers and nack them.

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents 363dc396 ad202074

MAINTAINERS

+1 −0
Original line number Diff line number Diff line
@@ -9936,6 +9936,7 @@ F: net/rfkill/ 


RHASHTABLE

M:	Thomas Graf <tgraf@suug.ch>

M:	Herbert Xu <herbert@gondor.apana.org.au>

L:	netdev@vger.kernel.org

S:	Maintained

F:	lib/rhashtable.c

include/linux/rhashtable.h

+11 −3
Original line number Diff line number Diff line
@@ -173,7 +173,7 @@ struct rhashtable_walker { 
struct rhashtable_iter {

	struct rhashtable *ht;

	struct rhash_head *p;

	struct rhashtable_walker *walker;

	struct rhashtable_walker walker;

	unsigned int slot;

	unsigned int skip;

};
@@ -346,8 +346,8 @@ struct bucket_table *rhashtable_insert_slow(struct rhashtable *ht, 
					    struct bucket_table *old_tbl);

int rhashtable_insert_rehash(struct rhashtable *ht, struct bucket_table *tbl);



int rhashtable_walk_init(struct rhashtable *ht, struct rhashtable_iter *iter,

			 gfp_t gfp);

void rhashtable_walk_enter(struct rhashtable *ht,

			   struct rhashtable_iter *iter);

void rhashtable_walk_exit(struct rhashtable_iter *iter);

int rhashtable_walk_start(struct rhashtable_iter *iter) __acquires(RCU);

void *rhashtable_walk_next(struct rhashtable_iter *iter);
@@ -906,4 +906,12 @@ static inline int rhashtable_replace_fast( 
	return err;

}



/* Obsolete function, do not use in new code. */

static inline int rhashtable_walk_init(struct rhashtable *ht,

				       struct rhashtable_iter *iter, gfp_t gfp)

{

	rhashtable_walk_enter(ht, iter);

	return 0;

}



#endif /* _LINUX_RHASHTABLE_H */

lib/rhashtable.c

+18 −28
Original line number Diff line number Diff line
@@ -489,10 +489,9 @@ exit: 
EXPORT_SYMBOL_GPL(rhashtable_insert_slow);



/**

 * rhashtable_walk_init - Initialise an iterator

 * rhashtable_walk_enter - Initialise an iterator

 * @ht:		Table to walk over

 * @iter:	Hash table Iterator

 * @gfp:	GFP flags for allocations

 *

 * This function prepares a hash table walk.

 *
@@ -507,30 +506,22 @@ EXPORT_SYMBOL_GPL(rhashtable_insert_slow); 
 * This function may sleep so you must not call it from interrupt

 * context or with spin locks held.

 *

 * You must call rhashtable_walk_exit if this function returns

 * successfully.

 * You must call rhashtable_walk_exit after this function returns.

 */

int rhashtable_walk_init(struct rhashtable *ht, struct rhashtable_iter *iter,

			 gfp_t gfp)

void rhashtable_walk_enter(struct rhashtable *ht, struct rhashtable_iter *iter)

{

	iter->ht = ht;

	iter->p = NULL;

	iter->slot = 0;

	iter->skip = 0;



	iter->walker = kmalloc(sizeof(*iter->walker), gfp);

	if (!iter->walker)

		return -ENOMEM;



	spin_lock(&ht->lock);

	iter->walker->tbl =

	iter->walker.tbl =

		rcu_dereference_protected(ht->tbl, lockdep_is_held(&ht->lock));

	list_add(&iter->walker->list, &iter->walker->tbl->walkers);

	list_add(&iter->walker.list, &iter->walker.tbl->walkers);

	spin_unlock(&ht->lock);



	return 0;

}

EXPORT_SYMBOL_GPL(rhashtable_walk_init);

EXPORT_SYMBOL_GPL(rhashtable_walk_enter);



/**

 * rhashtable_walk_exit - Free an iterator
@@ -541,10 +532,9 @@ EXPORT_SYMBOL_GPL(rhashtable_walk_init); 
void rhashtable_walk_exit(struct rhashtable_iter *iter)

{

	spin_lock(&iter->ht->lock);

	if (iter->walker->tbl)

		list_del(&iter->walker->list);

	if (iter->walker.tbl)

		list_del(&iter->walker.list);

	spin_unlock(&iter->ht->lock);

	kfree(iter->walker);

}

EXPORT_SYMBOL_GPL(rhashtable_walk_exit);
@@ -570,12 +560,12 @@ int rhashtable_walk_start(struct rhashtable_iter *iter) 
	rcu_read_lock();



	spin_lock(&ht->lock);

	if (iter->walker->tbl)

		list_del(&iter->walker->list);

	if (iter->walker.tbl)

		list_del(&iter->walker.list);

	spin_unlock(&ht->lock);



	if (!iter->walker->tbl) {

		iter->walker->tbl = rht_dereference_rcu(ht->tbl, ht);

	if (!iter->walker.tbl) {

		iter->walker.tbl = rht_dereference_rcu(ht->tbl, ht);

		return -EAGAIN;

	}
@@ -597,7 +587,7 @@ EXPORT_SYMBOL_GPL(rhashtable_walk_start); 
 */

void *rhashtable_walk_next(struct rhashtable_iter *iter)

{

	struct bucket_table *tbl = iter->walker->tbl;

	struct bucket_table *tbl = iter->walker.tbl;

	struct rhashtable *ht = iter->ht;

	struct rhash_head *p = iter->p;
@@ -630,8 +620,8 @@ next: 
	/* Ensure we see any new tables. */

	smp_rmb();



	iter->walker->tbl = rht_dereference_rcu(tbl->future_tbl, ht);

	if (iter->walker->tbl) {

	iter->walker.tbl = rht_dereference_rcu(tbl->future_tbl, ht);

	if (iter->walker.tbl) {

		iter->slot = 0;

		iter->skip = 0;

		return ERR_PTR(-EAGAIN);
@@ -651,7 +641,7 @@ void rhashtable_walk_stop(struct rhashtable_iter *iter) 
	__releases(RCU)

{

	struct rhashtable *ht;

	struct bucket_table *tbl = iter->walker->tbl;

	struct bucket_table *tbl = iter->walker.tbl;



	if (!tbl)

		goto out;
@@ -660,9 +650,9 @@ void rhashtable_walk_stop(struct rhashtable_iter *iter) 


	spin_lock(&ht->lock);

	if (tbl->rehash < tbl->size)

		list_add(&iter->walker->list, &tbl->walkers);

		list_add(&iter->walker.list, &tbl->walkers);

	else

		iter->walker->tbl = NULL;

		iter->walker.tbl = NULL;

	spin_unlock(&ht->lock);



	iter->p = NULL;

net/netlink/diag.c

+73 −30
Original line number Diff line number Diff line
@@ -63,29 +63,53 @@ out_nlmsg_trim: 
static int __netlink_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,

				int protocol, int s_num)

{

	struct rhashtable_iter *hti = (void *)cb->args[2];

	struct netlink_table *tbl = &nl_table[protocol];

	struct rhashtable *ht = &tbl->hash;

	const struct bucket_table *htbl = rht_dereference_rcu(ht->tbl, ht);

	struct net *net = sock_net(skb->sk);

	struct netlink_diag_req *req;

	struct netlink_sock *nlsk;

	struct sock *sk;

	int ret = 0, num = 0, i;

	int num = 2;

	int ret = 0;



	req = nlmsg_data(cb->nlh);



	for (i = 0; i < htbl->size; i++) {

		struct rhash_head *pos;

	if (s_num > 1)

		goto mc_list;



	num--;



	if (!hti) {

		hti = kmalloc(sizeof(*hti), GFP_KERNEL);

		if (!hti)

			return -ENOMEM;



		cb->args[2] = (long)hti;

	}



	if (!s_num)

		rhashtable_walk_enter(&tbl->hash, hti);



	ret = rhashtable_walk_start(hti);

	if (ret == -EAGAIN)

		ret = 0;

	if (ret)

		goto stop;



	while ((nlsk = rhashtable_walk_next(hti))) {

		if (IS_ERR(nlsk)) {

			ret = PTR_ERR(nlsk);

			if (ret == -EAGAIN) {

				ret = 0;

				continue;

			}

			break;

		}



		rht_for_each_entry_rcu(nlsk, pos, htbl, i, node) {

		sk = (struct sock *)nlsk;



		if (!net_eq(sock_net(sk), net))

			continue;

			if (num < s_num) {

				num++;

				continue;

			}



		if (sk_diag_fill(sk, skb, req,

				 NETLINK_CB(cb->skb).portid,
@@ -93,13 +117,21 @@ static int __netlink_diag_dump(struct sk_buff *skb, struct netlink_callback *cb, 
				 NLM_F_MULTI,

				 sock_i_ino(sk)) < 0) {

			ret = 1;

				goto done;

			break;

		}

	}



stop:

	rhashtable_walk_stop(hti);

	if (ret)

		goto done;



	rhashtable_walk_exit(hti);

	cb->args[2] = 0;

	num++;

		}

	}



mc_list:

	read_lock(&nl_table_lock);

	sk_for_each_bound(sk, &tbl->mc_list) {

		if (sk_hashed(sk))

			continue;
@@ -116,13 +148,14 @@ static int __netlink_diag_dump(struct sk_buff *skb, struct netlink_callback *cb, 
				 NLM_F_MULTI,

				 sock_i_ino(sk)) < 0) {

			ret = 1;

			goto done;

			break;

		}

		num++;

	}

	read_unlock(&nl_table_lock);



done:

	cb->args[0] = num;

	cb->args[1] = protocol;



	return ret;

}
@@ -131,20 +164,20 @@ static int netlink_diag_dump(struct sk_buff *skb, struct netlink_callback *cb) 
{

	struct netlink_diag_req *req;

	int s_num = cb->args[0];

	int err = 0;



	req = nlmsg_data(cb->nlh);



	rcu_read_lock();

	read_lock(&nl_table_lock);



	if (req->sdiag_protocol == NDIAG_PROTO_ALL) {

		int i;



		for (i = cb->args[1]; i < MAX_LINKS; i++) {

			if (__netlink_diag_dump(skb, cb, i, s_num))

			err = __netlink_diag_dump(skb, cb, i, s_num);

			if (err)

				break;

			s_num = 0;

		}

		cb->args[1] = i;

	} else {

		if (req->sdiag_protocol >= MAX_LINKS) {

			read_unlock(&nl_table_lock);
@@ -152,13 +185,22 @@ static int netlink_diag_dump(struct sk_buff *skb, struct netlink_callback *cb) 
			return -ENOENT;

		}



		__netlink_diag_dump(skb, cb, req->sdiag_protocol, s_num);

		err = __netlink_diag_dump(skb, cb, req->sdiag_protocol, s_num);

	}



	read_unlock(&nl_table_lock);

	rcu_read_unlock();

	return err < 0 ? err : skb->len;

}



	return skb->len;

static int netlink_diag_dump_done(struct netlink_callback *cb)

{

	struct rhashtable_iter *hti = (void *)cb->args[2];



	if (cb->args[0] == 1)

		rhashtable_walk_exit(hti);



	kfree(hti);



	return 0;

}



static int netlink_diag_handler_dump(struct sk_buff *skb, struct nlmsghdr *h)
@@ -172,6 +214,7 @@ static int netlink_diag_handler_dump(struct sk_buff *skb, struct nlmsghdr *h) 
	if (h->nlmsg_flags & NLM_F_DUMP) {

		struct netlink_dump_control c = {

			.dump = netlink_diag_dump,

			.done = netlink_diag_dump_done,

		};

		return netlink_dump_start(net->diag_nlsk, skb, h, &c);

	} else

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