Merge branch 'rhashtable-New-features-in-walk-and-bucket'

Tom Herbert says:

====================
rhashtable: New features in walk and bucket

This patch contains some changes to related rhashtable:

- Above allow rhashtable_walk_start to return void
- Add a functon to peek at the next entry during a walk
- Abstract out function to compute a has for a table
- A library function to alloc a spinlocks bucket array
- Call the above function for rhashtable locks allocation

Tested: Exercised using various operations on an ILA xlat
table.

v2:
 - Apply feedback from Herbert. Don't change semantics of resize
   event reporting and -EAGAIN, just simplify API for callers that
   ignore those.
 - Add end_of_table in iter to reliably tell when the iterator has
   reached to the eno.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

9 files changed, 26 insertions, 70 deletions

diff --git a/net/ipv6/ila/ila_xlat.c b/net/ipv6/ila/ila_xlat.c
index 6eb5e68f112a..44c39c5f0638 100644
--- a/net/ipv6/ila/ila_xlat.c
+++ b/net/ipv6/ila/ila_xlat.c
@@ -512,9 +512,7 @@ static int ila_nl_dump(struct sk_buff *skb, struct netlink_callback *cb)
 	struct ila_map *ila;
 	int ret;
 
-	ret = rhashtable_walk_start(rhiter);
-	if (ret && ret != -EAGAIN)
-		goto done;
+	rhashtable_walk_start(rhiter);
 
 	for (;;) {
 		ila = rhashtable_walk_next(rhiter);
diff --git a/net/ipv6/seg6.c b/net/ipv6/seg6.c
index c81407770956..7f5621d09571 100644
--- a/net/ipv6/seg6.c
+++ b/net/ipv6/seg6.c
@@ -306,9 +306,7 @@ static int seg6_genl_dumphmac(struct sk_buff *skb, struct netlink_callback *cb)
 	struct seg6_hmac_info *hinfo;
 	int ret;
 
-	ret = rhashtable_walk_start(iter);
-	if (ret && ret != -EAGAIN)
-		goto done;
+	rhashtable_walk_start(iter);
 
 	for (;;) {
 		hinfo = rhashtable_walk_next(iter);
diff --git a/net/mac80211/mesh_pathtbl.c b/net/mac80211/mesh_pathtbl.c
index 86c8dfef56a4..a5125624a76d 100644
--- a/net/mac80211/mesh_pathtbl.c
+++ b/net/mac80211/mesh_pathtbl.c
@@ -257,9 +257,7 @@ __mesh_path_lookup_by_idx(struct mesh_table *tbl, int idx)
 	if (ret)
 		return NULL;
 
-	ret = rhashtable_walk_start(&iter);
-	if (ret && ret != -EAGAIN)
-		goto err;
+	rhashtable_walk_start(&iter);
 
 	while ((mpath = rhashtable_walk_next(&iter))) {
 		if (IS_ERR(mpath) && PTR_ERR(mpath) == -EAGAIN)
@@ -269,7 +267,6 @@ __mesh_path_lookup_by_idx(struct mesh_table *tbl, int idx)
 		if (i++ == idx)
 			break;
 	}
-err:
 	rhashtable_walk_stop(&iter);
 	rhashtable_walk_exit(&iter);
 
@@ -513,9 +510,7 @@ void mesh_plink_broken(struct sta_info *sta)
 	if (ret)
 		return;
 
-	ret = rhashtable_walk_start(&iter);
-	if (ret && ret != -EAGAIN)
-		goto out;
+	rhashtable_walk_start(&iter);
 
 	while ((mpath = rhashtable_walk_next(&iter))) {
 		if (IS_ERR(mpath) && PTR_ERR(mpath) == -EAGAIN)
@@ -535,7 +530,6 @@ void mesh_plink_broken(struct sta_info *sta)
 				WLAN_REASON_MESH_PATH_DEST_UNREACHABLE, bcast);
 		}
 	}
-out:
 	rhashtable_walk_stop(&iter);
 	rhashtable_walk_exit(&iter);
 }
@@ -584,9 +578,7 @@ void mesh_path_flush_by_nexthop(struct sta_info *sta)
 	if (ret)
 		return;
 
-	ret = rhashtable_walk_start(&iter);
-	if (ret && ret != -EAGAIN)
-		goto out;
+	rhashtable_walk_start(&iter);
 
 	while ((mpath = rhashtable_walk_next(&iter))) {
 		if (IS_ERR(mpath) && PTR_ERR(mpath) == -EAGAIN)
@@ -597,7 +589,7 @@ void mesh_path_flush_by_nexthop(struct sta_info *sta)
 		if (rcu_access_pointer(mpath->next_hop) == sta)
 			__mesh_path_del(tbl, mpath);
 	}
-out:
+
 	rhashtable_walk_stop(&iter);
 	rhashtable_walk_exit(&iter);
 }
@@ -614,9 +606,7 @@ static void mpp_flush_by_proxy(struct ieee80211_sub_if_data *sdata,
 	if (ret)
 		return;
 
-	ret = rhashtable_walk_start(&iter);
-	if (ret && ret != -EAGAIN)
-		goto out;
+	rhashtable_walk_start(&iter);
 
 	while ((mpath = rhashtable_walk_next(&iter))) {
 		if (IS_ERR(mpath) && PTR_ERR(mpath) == -EAGAIN)
@@ -627,7 +617,7 @@ static void mpp_flush_by_proxy(struct ieee80211_sub_if_data *sdata,
 		if (ether_addr_equal(mpath->mpp, proxy))
 			__mesh_path_del(tbl, mpath);
 	}
-out:
+
 	rhashtable_walk_stop(&iter);
 	rhashtable_walk_exit(&iter);
 }
@@ -642,9 +632,7 @@ static void table_flush_by_iface(struct mesh_table *tbl)
 	if (ret)
 		return;
 
-	ret = rhashtable_walk_start(&iter);
-	if (ret && ret != -EAGAIN)
-		goto out;
+	rhashtable_walk_start(&iter);
 
 	while ((mpath = rhashtable_walk_next(&iter))) {
 		if (IS_ERR(mpath) && PTR_ERR(mpath) == -EAGAIN)
@@ -653,7 +641,7 @@ static void table_flush_by_iface(struct mesh_table *tbl)
 			break;
 		__mesh_path_del(tbl, mpath);
 	}
-out:
+
 	rhashtable_walk_stop(&iter);
 	rhashtable_walk_exit(&iter);
 }
@@ -873,9 +861,7 @@ void mesh_path_tbl_expire(struct ieee80211_sub_if_data *sdata,
 	if (ret)
 		return;
 
-	ret = rhashtable_walk_start(&iter);
-	if (ret && ret != -EAGAIN)
-		goto out;
+	rhashtable_walk_start(&iter);
 
 	while ((mpath = rhashtable_walk_next(&iter))) {
 		if (IS_ERR(mpath) && PTR_ERR(mpath) == -EAGAIN)
@@ -887,7 +873,7 @@ void mesh_path_tbl_expire(struct ieee80211_sub_if_data *sdata,
 		     time_after(jiffies, mpath->exp_time + MESH_PATH_EXPIRE))
 			__mesh_path_del(tbl, mpath);
 	}
-out:
+
 	rhashtable_walk_stop(&iter);
 	rhashtable_walk_exit(&iter);
 }
diff --git a/net/netfilter/nft_set_hash.c b/net/netfilter/nft_set_hash.c
index f8166c1d5430..3f1624ee056f 100644
--- a/net/netfilter/nft_set_hash.c
+++ b/net/netfilter/nft_set_hash.c
@@ -251,11 +251,7 @@ static void nft_rhash_walk(const struct nft_ctx *ctx, struct nft_set *set,
 	if (err)
 		return;
 
-	err = rhashtable_walk_start(&hti);
-	if (err && err != -EAGAIN) {
-		iter->err = err;
-		goto out;
-	}
+	rhashtable_walk_start(&hti);
 
 	while ((he = rhashtable_walk_next(&hti))) {
 		if (IS_ERR(he)) {
@@ -306,9 +302,7 @@ static void nft_rhash_gc(struct work_struct *work)
 	if (err)
 		goto schedule;
 
-	err = rhashtable_walk_start(&hti);
-	if (err && err != -EAGAIN)
-		goto out;
+	rhashtable_walk_start(&hti);
 
 	while ((he = rhashtable_walk_next(&hti))) {
 		if (IS_ERR(he)) {
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index b9e0ee4e22f5..ab325d4d6fef 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -2478,8 +2478,9 @@ static int netlink_walk_start(struct nl_seq_iter *iter)
 		return err;
 	}
 
-	err = rhashtable_walk_start(&iter->hti);
-	return err == -EAGAIN ? 0 : err;
+	rhashtable_walk_start(&iter->hti);
+
+	return 0;
 }
 
 static void netlink_walk_stop(struct nl_seq_iter *iter)
diff --git a/net/netlink/diag.c b/net/netlink/diag.c
index 8faa20b4d457..7dda33b9b784 100644
--- a/net/netlink/diag.c
+++ b/net/netlink/diag.c
@@ -115,11 +115,7 @@ static int __netlink_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
 	if (!s_num)
 		rhashtable_walk_enter(&tbl->hash, hti);
 
-	ret = rhashtable_walk_start(hti);
-	if (ret == -EAGAIN)
-		ret = 0;
-	if (ret)
-		goto stop;
+	rhashtable_walk_start(hti);
 
 	while ((nlsk = rhashtable_walk_next(hti))) {
 		if (IS_ERR(nlsk)) {
@@ -146,8 +142,8 @@ static int __netlink_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
 		}
 	}
 
-stop:
 	rhashtable_walk_stop(hti);
+
 	if (ret)
 		goto done;
 
diff --git a/net/sctp/proc.c b/net/sctp/proc.c
index 26b4be6b4172..4545bc2aff84 100644
--- a/net/sctp/proc.c
+++ b/net/sctp/proc.c
@@ -288,12 +288,8 @@ struct sctp_ht_iter {
 static void *sctp_transport_seq_start(struct seq_file *seq, loff_t *pos)
 {
 	struct sctp_ht_iter *iter = seq->private;
-	int err = sctp_transport_walk_start(&iter->hti);
 
-	if (err) {
-		iter->start_fail = 1;
-		return ERR_PTR(err);
-	}
+	sctp_transport_walk_start(&iter->hti);
 
 	iter->start_fail = 0;
 	return sctp_transport_get_idx(seq_file_net(seq), &iter->hti, *pos);
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index eb17a911aa29..3e55daa37e66 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -4676,20 +4676,11 @@ int sctp_get_sctp_info(struct sock *sk, struct sctp_association *asoc,
 EXPORT_SYMBOL_GPL(sctp_get_sctp_info);
 
 /* use callback to avoid exporting the core structure */
-int sctp_transport_walk_start(struct rhashtable_iter *iter)
+void sctp_transport_walk_start(struct rhashtable_iter *iter)
 {
-	int err;
-
 	rhltable_walk_enter(&sctp_transport_hashtable, iter);
 
-	err = rhashtable_walk_start(iter);
-	if (err && err != -EAGAIN) {
-		rhashtable_walk_stop(iter);
-		rhashtable_walk_exit(iter);
-		return err;
-	}
-
-	return 0;
+	rhashtable_walk_start(iter);
 }
 
 void sctp_transport_walk_stop(struct rhashtable_iter *iter)
@@ -4780,12 +4771,10 @@ int sctp_for_each_transport(int (*cb)(struct sctp_transport *, void *),
 			    struct net *net, int *pos, void *p) {
 	struct rhashtable_iter hti;
 	struct sctp_transport *tsp;
-	int ret;
+	int ret = 0;
 
 again:
-	ret = sctp_transport_walk_start(&hti);
-	if (ret)
-		return ret;
+	sctp_transport_walk_start(&hti);
 
 	tsp = sctp_transport_get_idx(net, &hti, *pos + 1);
 	for (; !IS_ERR_OR_NULL(tsp); tsp = sctp_transport_get_next(net, &hti)) {
diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index 5d18c0caa92b..22c4fd8a9dfe 100644
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -2640,9 +2640,7 @@ void tipc_sk_reinit(struct net *net)
 	rhashtable_walk_enter(&tn->sk_rht, &iter);
 
 	do {
-		tsk = ERR_PTR(rhashtable_walk_start(&iter));
-		if (IS_ERR(tsk))
-			goto walk_stop;
+		rhashtable_walk_start(&iter);
 
 		while ((tsk = rhashtable_walk_next(&iter)) && !IS_ERR(tsk)) {
 			spin_lock_bh(&tsk->sk.sk_lock.slock);
@@ -2651,7 +2649,7 @@ void tipc_sk_reinit(struct net *net)
 			msg_set_orignode(msg, tn->own_addr);
 			spin_unlock_bh(&tsk->sk.sk_lock.slock);
 		}
-walk_stop:
+
 		rhashtable_walk_stop(&iter);
 	} while (tsk == ERR_PTR(-EAGAIN));
 }