[PATCH 06/15] net,9p: use new hashtable implementation

[PATCH 06/15] net,9p: use new hashtable implementation

[Sasha Levin]

Switch 9p error table to use the new hashtable implementation. This reduces
the amount of generic unrelated code in 9p.

This patch depends on d9b482c ("hashtable: introduce a small and naive
hashtable") which was merged in v3.6.

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
---
 net/9p/error.c | 21 +++++++++------------
 1 file changed, 9 insertions(+), 12 deletions(-)

diff --git a/net/9p/error.c b/net/9p/error.c
index 2ab2de7..a394b37 100644
--- a/net/9p/error.c
+++ b/net/9p/error.c
@@ -34,6 +34,7 @@
 #include <linux/jhash.h>
 #include <linux/errno.h>
 #include <net/9p/9p.h>
+#include <linux/hashtable.h>
 
 /**
  * struct errormap - map string errors from Plan 9 to Linux numeric ids
@@ -50,8 +51,8 @@ struct errormap {
 	struct hlist_node list;
 };
 
-#define ERRHASHSZ		32
-static struct hlist_head hash_errmap[ERRHASHSZ];
+#define ERR_HASH_BITS 5
+static DEFINE_HASHTABLE(hash_errmap, ERR_HASH_BITS);
 
 /* FixMe - reduce to a reasonable size */
 static struct errormap errmap[] = {
@@ -193,18 +194,14 @@ static struct errormap errmap[] = {
 int p9_error_init(void)
 {
 	struct errormap *c;
-	int bucket;
-
-	/* initialize hash table */
-	for (bucket = 0; bucket < ERRHASHSZ; bucket++)
-		INIT_HLIST_HEAD(&hash_errmap[bucket]);
+	u32 hash;
 
 	/* load initial error map into hash table */
 	for (c = errmap; c->name != NULL; c++) {
 		c->namelen = strlen(c->name);
-		bucket = jhash(c->name, c->namelen, 0) % ERRHASHSZ;
+		hash = jhash(c->name, c->namelen, 0);
 		INIT_HLIST_NODE(&c->list);
-		hlist_add_head(&c->list, &hash_errmap[bucket]);
+		hash_add(hash_errmap, &c->list, hash);
 	}
 
 	return 1;
@@ -223,13 +220,13 @@ int p9_errstr2errno(char *errstr, int len)
 	int errno;
 	struct hlist_node *p;
 	struct errormap *c;
-	int bucket;
+	u32 hash;
 
 	errno = 0;
 	p = NULL;
 	c = NULL;
-	bucket = jhash(errstr, len, 0) % ERRHASHSZ;
-	hlist_for_each_entry(c, p, &hash_errmap[bucket], list) {
+	hash = jhash(errstr, len, 0);
+	hash_for_each_possible(hash_errmap, c, p, list, hash) {
 		if (c->namelen == len && !memcmp(c->name, errstr, len)) {
 			errno = c->val;
 			break;
-- 
1.8.0

[PATCH 08/15] SUNRPC/cache: use new hashtable implementation

[Sasha Levin]

Switch cache to use the new hashtable implementation. This reduces the amount
of generic unrelated code in the cache implementation.

This patch depends on d9b482c ("hashtable: introduce a small and naive
hashtable") which was merged in v3.6.

Tested-by: J. Bruce Fields <bfields@fieldses.org>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
---
 net/sunrpc/cache.c | 18 +++++++-----------
 1 file changed, 7 insertions(+), 11 deletions(-)

diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c
index 9afa439..d4539b6 100644
--- a/net/sunrpc/cache.c
+++ b/net/sunrpc/cache.c
@@ -28,6 +28,7 @@
 #include <linux/workqueue.h>
 #include <linux/mutex.h>
 #include <linux/pagemap.h>
+#include <linux/hashtable.h>
 #include <asm/ioctls.h>
 #include <linux/sunrpc/types.h>
 #include <linux/sunrpc/cache.h>
@@ -524,19 +525,18 @@ EXPORT_SYMBOL_GPL(cache_purge);
  * it to be revisited when cache info is available
  */
 
-#define	DFR_HASHSIZE	(PAGE_SIZE/sizeof(struct list_head))
-#define	DFR_HASH(item)	((((long)item)>>4 ^ (((long)item)>>13)) % DFR_HASHSIZE)
+#define	DFR_HASH_BITS	9
 
 #define	DFR_MAX	300	/* ??? */
 
 static DEFINE_SPINLOCK(cache_defer_lock);
 static LIST_HEAD(cache_defer_list);
-static struct hlist_head cache_defer_hash[DFR_HASHSIZE];
+static DEFINE_HASHTABLE(cache_defer_hash, DFR_HASH_BITS);
 static int cache_defer_cnt;
 
 static void __unhash_deferred_req(struct cache_deferred_req *dreq)
 {
-	hlist_del_init(&dreq->hash);
+	hash_del(&dreq->hash);
 	if (!list_empty(&dreq->recent)) {
 		list_del_init(&dreq->recent);
 		cache_defer_cnt--;
@@ -545,10 +545,7 @@ static void __unhash_deferred_req(struct cache_deferred_req *dreq)
 
 static void __hash_deferred_req(struct cache_deferred_req *dreq, struct cache_head *item)
 {
-	int hash = DFR_HASH(item);
-
-	INIT_LIST_HEAD(&dreq->recent);
-	hlist_add_head(&dreq->hash, &cache_defer_hash[hash]);
+	hash_add(cache_defer_hash, &dreq->hash, (unsigned long)item);
 }
 
 static void setup_deferral(struct cache_deferred_req *dreq,
@@ -600,7 +597,7 @@ static void cache_wait_req(struct cache_req *req, struct cache_head *item)
 		 * to clean up
 		 */
 		spin_lock(&cache_defer_lock);
-		if (!hlist_unhashed(&sleeper.handle.hash)) {
+		if (hash_hashed(&sleeper.handle.hash)) {
 			__unhash_deferred_req(&sleeper.handle);
 			spin_unlock(&cache_defer_lock);
 		} else {
@@ -671,12 +668,11 @@ static void cache_revisit_request(struct cache_head *item)
 	struct cache_deferred_req *dreq;
 	struct list_head pending;
 	struct hlist_node *lp, *tmp;
-	int hash = DFR_HASH(item);
 
 	INIT_LIST_HEAD(&pending);
 	spin_lock(&cache_defer_lock);
 
-	hlist_for_each_entry_safe(dreq, lp, tmp, &cache_defer_hash[hash], hash)
+	hash_for_each_possible_safe(cache_defer_hash, dreq, lp, tmp, hash, (unsigned long)item)
 		if (dreq->item == item) {
 			__unhash_deferred_req(dreq);
 			list_add(&dreq->recent, &pending);
-- 
1.8.0

[PATCH 10/15] net,l2tp: use new hashtable implementation

[Sasha Levin]

Switch l2tp to use the new hashtable implementation. This reduces the amount
of generic unrelated code in l2tp.

This patch depends on d9b482c ("hashtable: introduce a small and naive
hashtable") which was merged in v3.6.

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
---
 net/l2tp/l2tp_core.c    | 140 +++++++++++++++++++-----------------------------
 net/l2tp/l2tp_core.h    |  15 ++++--
 net/l2tp/l2tp_debugfs.c |  19 +++----
 3 files changed, 74 insertions(+), 100 deletions(-)

diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c
index 1a9f372..0b369e4 100644
--- a/net/l2tp/l2tp_core.c
+++ b/net/l2tp/l2tp_core.c
@@ -44,6 +44,7 @@
 #include <linux/udp.h>
 #include <linux/l2tp.h>
 #include <linux/hash.h>
+#include <linux/hashtable.h>
 #include <linux/sort.h>
 #include <linux/file.h>
 #include <linux/nsproxy.h>
@@ -107,8 +108,14 @@ static unsigned int l2tp_net_id;
 struct l2tp_net {
 	struct list_head l2tp_tunnel_list;
 	spinlock_t l2tp_tunnel_list_lock;
-	struct hlist_head l2tp_session_hlist[L2TP_HASH_SIZE_2];
-	spinlock_t l2tp_session_hlist_lock;
+/*
+ * Session hash global list for L2TPv3.
+ * The session_id SHOULD be random according to RFC3931, but several
+ * L2TP implementations use incrementing session_ids.  So we do a real
+ * hash on the session_id, rather than a simple bitmask.
+ */
+	DECLARE_HASHTABLE(l2tp_session_hash, L2TP_HASH_BITS_2);
+	spinlock_t l2tp_session_hash_lock;
 };
 
 static void l2tp_session_set_header_len(struct l2tp_session *session, int version);
@@ -156,30 +163,17 @@ do {									\
 #define l2tp_tunnel_dec_refcount(t) l2tp_tunnel_dec_refcount_1(t)
 #endif
 
-/* Session hash global list for L2TPv3.
- * The session_id SHOULD be random according to RFC3931, but several
- * L2TP implementations use incrementing session_ids.  So we do a real
- * hash on the session_id, rather than a simple bitmask.
- */
-static inline struct hlist_head *
-l2tp_session_id_hash_2(struct l2tp_net *pn, u32 session_id)
-{
-	return &pn->l2tp_session_hlist[hash_32(session_id, L2TP_HASH_BITS_2)];
-
-}
-
 /* Lookup a session by id in the global session list
  */
 static struct l2tp_session *l2tp_session_find_2(struct net *net, u32 session_id)
 {
 	struct l2tp_net *pn = l2tp_pernet(net);
-	struct hlist_head *session_list =
-		l2tp_session_id_hash_2(pn, session_id);
 	struct l2tp_session *session;
 	struct hlist_node *walk;
 
 	rcu_read_lock_bh();
-	hlist_for_each_entry_rcu(session, walk, session_list, global_hlist) {
+	hash_for_each_possible_rcu(pn->l2tp_session_hash, session, walk,
+					global_hlist, session_id) {
 		if (session->session_id == session_id) {
 			rcu_read_unlock_bh();
 			return session;
@@ -190,23 +184,10 @@ static struct l2tp_session *l2tp_session_find_2(struct net *net, u32 session_id)
 	return NULL;
 }
 
-/* Session hash list.
- * The session_id SHOULD be random according to RFC2661, but several
- * L2TP implementations (Cisco and Microsoft) use incrementing
- * session_ids.  So we do a real hash on the session_id, rather than a
- * simple bitmask.
- */
-static inline struct hlist_head *
-l2tp_session_id_hash(struct l2tp_tunnel *tunnel, u32 session_id)
-{
-	return &tunnel->session_hlist[hash_32(session_id, L2TP_HASH_BITS)];
-}
-
 /* Lookup a session by id
  */
 struct l2tp_session *l2tp_session_find(struct net *net, struct l2tp_tunnel *tunnel, u32 session_id)
 {
-	struct hlist_head *session_list;
 	struct l2tp_session *session;
 	struct hlist_node *walk;
 
@@ -217,15 +198,14 @@ struct l2tp_session *l2tp_session_find(struct net *net, struct l2tp_tunnel *tunn
 	if (tunnel == NULL)
 		return l2tp_session_find_2(net, session_id);
 
-	session_list = l2tp_session_id_hash(tunnel, session_id);
-	read_lock_bh(&tunnel->hlist_lock);
-	hlist_for_each_entry(session, walk, session_list, hlist) {
+	read_lock_bh(&tunnel->hash_lock);
+	hash_for_each_possible(tunnel->session_hash, session, walk, hlist, session_id) {
 		if (session->session_id == session_id) {
-			read_unlock_bh(&tunnel->hlist_lock);
+			read_unlock_bh(&tunnel->hash_lock);
 			return session;
 		}
 	}
-	read_unlock_bh(&tunnel->hlist_lock);
+	read_unlock_bh(&tunnel->hash_lock);
 
 	return NULL;
 }
@@ -238,17 +218,15 @@ struct l2tp_session *l2tp_session_find_nth(struct l2tp_tunnel *tunnel, int nth)
 	struct l2tp_session *session;
 	int count = 0;
 
-	read_lock_bh(&tunnel->hlist_lock);
-	for (hash = 0; hash < L2TP_HASH_SIZE; hash++) {
-		hlist_for_each_entry(session, walk, &tunnel->session_hlist[hash], hlist) {
-			if (++count > nth) {
-				read_unlock_bh(&tunnel->hlist_lock);
-				return session;
-			}
+	read_lock_bh(&tunnel->hash_lock);
+	hash_for_each(tunnel->session_hash, hash, walk, session, hlist) {
+		if (++count > nth) {
+			read_unlock_bh(&tunnel->hash_lock);
+			return session;
 		}
 	}
 
-	read_unlock_bh(&tunnel->hlist_lock);
+	read_unlock_bh(&tunnel->hash_lock);
 
 	return NULL;
 }
@@ -265,12 +243,10 @@ struct l2tp_session *l2tp_session_find_by_ifname(struct net *net, char *ifname)
 	struct l2tp_session *session;
 
 	rcu_read_lock_bh();
-	for (hash = 0; hash < L2TP_HASH_SIZE_2; hash++) {
-		hlist_for_each_entry_rcu(session, walk, &pn->l2tp_session_hlist[hash], global_hlist) {
-			if (!strcmp(session->ifname, ifname)) {
-				rcu_read_unlock_bh();
-				return session;
-			}
+	hash_for_each_rcu(pn->l2tp_session_hash, hash, walk, session, global_hlist) {
+		if (!strcmp(session->ifname, ifname)) {
+			rcu_read_unlock_bh();
+			return session;
 		}
 	}
 
@@ -1272,7 +1248,7 @@ end:
  */
 static void l2tp_tunnel_closeall(struct l2tp_tunnel *tunnel)
 {
-	int hash;
+	int hash, found = 0;
 	struct hlist_node *walk;
 	struct hlist_node *tmp;
 	struct l2tp_session *session;
@@ -1282,16 +1258,14 @@ static void l2tp_tunnel_closeall(struct l2tp_tunnel *tunnel)
 	l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: closing all sessions...\n",
 		  tunnel->name);
 
-	write_lock_bh(&tunnel->hlist_lock);
-	for (hash = 0; hash < L2TP_HASH_SIZE; hash++) {
-again:
-		hlist_for_each_safe(walk, tmp, &tunnel->session_hlist[hash]) {
-			session = hlist_entry(walk, struct l2tp_session, hlist);
-
+	write_lock_bh(&tunnel->hash_lock);
+	do {
+		found = 0;
+		hash_for_each_safe(tunnel->session_hash, hash, walk, tmp, session, hlist) {
 			l2tp_info(session, L2TP_MSG_CONTROL,
 				  "%s: closing session\n", session->name);
 
-			hlist_del_init(&session->hlist);
+			hash_del(&session->hlist);
 
 			/* Since we should hold the sock lock while
 			 * doing any unbinding, we need to release the
@@ -1302,14 +1276,14 @@ again:
 			if (session->ref != NULL)
 				(*session->ref)(session);
 
-			write_unlock_bh(&tunnel->hlist_lock);
+			write_unlock_bh(&tunnel->hash_lock);
 
 			if (tunnel->version != L2TP_HDR_VER_2) {
 				struct l2tp_net *pn = l2tp_pernet(tunnel->l2tp_net);
 
-				spin_lock_bh(&pn->l2tp_session_hlist_lock);
-				hlist_del_init_rcu(&session->global_hlist);
-				spin_unlock_bh(&pn->l2tp_session_hlist_lock);
+				spin_lock_bh(&pn->l2tp_session_hash_lock);
+				hash_del_rcu(&session->global_hlist);
+				spin_unlock_bh(&pn->l2tp_session_hash_lock);
 				synchronize_rcu();
 			}
 
@@ -1319,17 +1293,17 @@ again:
 			if (session->deref != NULL)
 				(*session->deref)(session);
 
-			write_lock_bh(&tunnel->hlist_lock);
+			write_lock_bh(&tunnel->hash_lock);
 
 			/* Now restart from the beginning of this hash
 			 * chain.  We always remove a session from the
 			 * list so we are guaranteed to make forward
 			 * progress.
 			 */
-			goto again;
+			found = 1;
 		}
-	}
-	write_unlock_bh(&tunnel->hlist_lock);
+	} while (found);
+	write_unlock_bh(&tunnel->hash_lock);
 }
 
 /* Really kill the tunnel.
@@ -1576,7 +1550,7 @@ int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id, u32
 
 	tunnel->magic = L2TP_TUNNEL_MAGIC;
 	sprintf(&tunnel->name[0], "tunl %u", tunnel_id);
-	rwlock_init(&tunnel->hlist_lock);
+	rwlock_init(&tunnel->hash_lock);
 
 	/* The net we belong to */
 	tunnel->l2tp_net = net;
@@ -1613,6 +1587,8 @@ int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id, u32
 
 	/* Add tunnel to our list */
 	INIT_LIST_HEAD(&tunnel->list);
+
+	hash_init(tunnel->session_hash);
 	atomic_inc(&l2tp_tunnel_count);
 
 	/* Bump the reference count. The tunnel context is deleted
@@ -1677,17 +1653,17 @@ void l2tp_session_free(struct l2tp_session *session)
 		BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC);
 
 		/* Delete the session from the hash */
-		write_lock_bh(&tunnel->hlist_lock);
-		hlist_del_init(&session->hlist);
-		write_unlock_bh(&tunnel->hlist_lock);
+		write_lock_bh(&tunnel->hash_lock);
+		hash_del(&session->hlist);
+		write_unlock_bh(&tunnel->hash_lock);
 
 		/* Unlink from the global hash if not L2TPv2 */
 		if (tunnel->version != L2TP_HDR_VER_2) {
 			struct l2tp_net *pn = l2tp_pernet(tunnel->l2tp_net);
 
-			spin_lock_bh(&pn->l2tp_session_hlist_lock);
-			hlist_del_init_rcu(&session->global_hlist);
-			spin_unlock_bh(&pn->l2tp_session_hlist_lock);
+			spin_lock_bh(&pn->l2tp_session_hash_lock);
+			hash_del_rcu(&session->global_hlist);
+			spin_unlock_bh(&pn->l2tp_session_hash_lock);
 			synchronize_rcu();
 		}
 
@@ -1800,19 +1776,17 @@ struct l2tp_session *l2tp_session_create(int priv_size, struct l2tp_tunnel *tunn
 		sock_hold(tunnel->sock);
 
 		/* Add session to the tunnel's hash list */
-		write_lock_bh(&tunnel->hlist_lock);
-		hlist_add_head(&session->hlist,
-			       l2tp_session_id_hash(tunnel, session_id));
-		write_unlock_bh(&tunnel->hlist_lock);
+		write_lock_bh(&tunnel->hash_lock);
+		hash_add(tunnel->session_hash, &session->hlist, session_id);
+		write_unlock_bh(&tunnel->hash_lock);
 
 		/* And to the global session list if L2TPv3 */
 		if (tunnel->version != L2TP_HDR_VER_2) {
 			struct l2tp_net *pn = l2tp_pernet(tunnel->l2tp_net);
 
-			spin_lock_bh(&pn->l2tp_session_hlist_lock);
-			hlist_add_head_rcu(&session->global_hlist,
-					   l2tp_session_id_hash_2(pn, session_id));
-			spin_unlock_bh(&pn->l2tp_session_hlist_lock);
+			spin_lock_bh(&pn->l2tp_session_hash_lock);
+			hash_add(pn->l2tp_session_hash, &session->global_hlist, session_id);
+			spin_unlock_bh(&pn->l2tp_session_hash_lock);
 		}
 
 		/* Ignore management session in session count value */
@@ -1831,15 +1805,13 @@ EXPORT_SYMBOL_GPL(l2tp_session_create);
 static __net_init int l2tp_init_net(struct net *net)
 {
 	struct l2tp_net *pn = net_generic(net, l2tp_net_id);
-	int hash;
 
 	INIT_LIST_HEAD(&pn->l2tp_tunnel_list);
 	spin_lock_init(&pn->l2tp_tunnel_list_lock);
 
-	for (hash = 0; hash < L2TP_HASH_SIZE_2; hash++)
-		INIT_HLIST_HEAD(&pn->l2tp_session_hlist[hash]);
+	hash_init(pn->l2tp_session_hash);
 
-	spin_lock_init(&pn->l2tp_session_hlist_lock);
+	spin_lock_init(&pn->l2tp_session_hash_lock);
 
 	return 0;
 }
diff --git a/net/l2tp/l2tp_core.h b/net/l2tp/l2tp_core.h
index 56d583e..fc58c85 100644
--- a/net/l2tp/l2tp_core.h
+++ b/net/l2tp/l2tp_core.h
@@ -11,17 +11,17 @@
 #ifndef _L2TP_CORE_H_
 #define _L2TP_CORE_H_
 
+#include <linux/hashtable.h>
+
 /* Just some random numbers */
 #define L2TP_TUNNEL_MAGIC	0x42114DDA
 #define L2TP_SESSION_MAGIC	0x0C04EB7D
 
 /* Per tunnel, session hash table size */
 #define L2TP_HASH_BITS	4
-#define L2TP_HASH_SIZE	(1 << L2TP_HASH_BITS)
 
 /* System-wide, session hash table size */
 #define L2TP_HASH_BITS_2	8
-#define L2TP_HASH_SIZE_2	(1 << L2TP_HASH_BITS_2)
 
 /* Debug message categories for the DEBUG socket option */
 enum {
@@ -164,8 +164,15 @@ struct l2tp_tunnel_cfg {
 struct l2tp_tunnel {
 	int			magic;		/* Should be L2TP_TUNNEL_MAGIC */
 	struct rcu_head rcu;
-	rwlock_t		hlist_lock;	/* protect session_hlist */
-	struct hlist_head	session_hlist[L2TP_HASH_SIZE];
+	rwlock_t		hash_lock;	/* protect session_hash */
+/*
+ * Session hash list.
+ * The session_id SHOULD be random according to RFC2661, but several
+ * L2TP implementations (Cisco and Microsoft) use incrementing
+ * session_ids.  So we do a real hash on the session_id, rather than a
+ * simple bitmask.
+*/
+	DECLARE_HASHTABLE(session_hash, L2TP_HASH_BITS);
 						/* hashed list of sessions,
 						 * hashed by id */
 	u32			tunnel_id;
diff --git a/net/l2tp/l2tp_debugfs.c b/net/l2tp/l2tp_debugfs.c
index c3813bc..655f1fa 100644
--- a/net/l2tp/l2tp_debugfs.c
+++ b/net/l2tp/l2tp_debugfs.c
@@ -105,21 +105,16 @@ static void l2tp_dfs_seq_tunnel_show(struct seq_file *m, void *v)
 	int session_count = 0;
 	int hash;
 	struct hlist_node *walk;
-	struct hlist_node *tmp;
+	struct l2tp_session *session;
 
-	read_lock_bh(&tunnel->hlist_lock);
-	for (hash = 0; hash < L2TP_HASH_SIZE; hash++) {
-		hlist_for_each_safe(walk, tmp, &tunnel->session_hlist[hash]) {
-			struct l2tp_session *session;
+	read_lock_bh(&tunnel->hash_lock);
+	hash_for_each(tunnel->session_hash, hash, walk, session, hlist) {
+		if (session->session_id == 0)
+			continue;
 
-			session = hlist_entry(walk, struct l2tp_session, hlist);
-			if (session->session_id == 0)
-				continue;
-
-			session_count++;
-		}
+		session_count++;
 	}
-	read_unlock_bh(&tunnel->hlist_lock);
+	read_unlock_bh(&tunnel->hash_lock);
 
 	seq_printf(m, "\nTUNNEL %u peer %u", tunnel->tunnel_id, tunnel->peer_tunnel_id);
 	if (tunnel->sock) {
-- 
1.8.0

[PATCH 13/15] net,rds: use new hashtable implementation

[Sasha Levin]

Switch rds to use the new hashtable implementation. This reduces the amount of
generic unrelated code in rds.

This patch depends on d9b482c ("hashtable: introduce a small and naive
hashtable") which was merged in v3.6.

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
---
 net/rds/bind.c       |  20 +++++------
 net/rds/connection.c | 100 ++++++++++++++++++++++-----------------------------
 2 files changed, 53 insertions(+), 67 deletions(-)

diff --git a/net/rds/bind.c b/net/rds/bind.c
index 637bde5..a99e524 100644
--- a/net/rds/bind.c
+++ b/net/rds/bind.c
@@ -36,16 +36,16 @@
 #include <linux/if_arp.h>
 #include <linux/jhash.h>
 #include <linux/ratelimit.h>
+#include <linux/hashtable.h>
 #include "rds.h"
 
-#define BIND_HASH_SIZE 1024
-static struct hlist_head bind_hash_table[BIND_HASH_SIZE];
+#define BIND_HASH_BITS 10
+static DEFINE_HASHTABLE(bind_hash_table, BIND_HASH_BITS);
 static DEFINE_SPINLOCK(rds_bind_lock);
 
-static struct hlist_head *hash_to_bucket(__be32 addr, __be16 port)
+static u32 rds_hash(__be32 addr, __be16 port)
 {
-	return bind_hash_table + (jhash_2words((u32)addr, (u32)port, 0) &
-				  (BIND_HASH_SIZE - 1));
+	return jhash_2words((u32)addr, (u32)port, 0);
 }
 
 static struct rds_sock *rds_bind_lookup(__be32 addr, __be16 port,
@@ -53,12 +53,12 @@ static struct rds_sock *rds_bind_lookup(__be32 addr, __be16 port,
 {
 	struct rds_sock *rs;
 	struct hlist_node *node;
-	struct hlist_head *head = hash_to_bucket(addr, port);
+	u32 key = rds_hash(addr, port);
 	u64 cmp;
 	u64 needle = ((u64)be32_to_cpu(addr) << 32) | be16_to_cpu(port);
 
 	rcu_read_lock();
-	hlist_for_each_entry_rcu(rs, node, head, rs_bound_node) {
+	hash_for_each_possible_rcu(bind_hash_table, rs, node, rs_bound_node, key) {
 		cmp = ((u64)be32_to_cpu(rs->rs_bound_addr) << 32) |
 		      be16_to_cpu(rs->rs_bound_port);
 
@@ -74,13 +74,13 @@ static struct rds_sock *rds_bind_lookup(__be32 addr, __be16 port,
 		 * make sure our addr and port are set before
 		 * we are added to the list, other people
 		 * in rcu will find us as soon as the
-		 * hlist_add_head_rcu is done
+		 * hash_add_rcu is done
 		 */
 		insert->rs_bound_addr = addr;
 		insert->rs_bound_port = port;
 		rds_sock_addref(insert);
 
-		hlist_add_head_rcu(&insert->rs_bound_node, head);
+		hash_add_rcu(bind_hash_table, &insert->rs_bound_node, key);
 	}
 	return NULL;
 }
@@ -152,7 +152,7 @@ void rds_remove_bound(struct rds_sock *rs)
 		  rs, &rs->rs_bound_addr,
 		  ntohs(rs->rs_bound_port));
 
-		hlist_del_init_rcu(&rs->rs_bound_node);
+		hash_del_rcu(&rs->rs_bound_node);
 		rds_sock_put(rs);
 		rs->rs_bound_addr = 0;
 	}
diff --git a/net/rds/connection.c b/net/rds/connection.c
index 9e07c75..a9afcb8 100644
--- a/net/rds/connection.c
+++ b/net/rds/connection.c
@@ -34,28 +34,24 @@
 #include <linux/list.h>
 #include <linux/slab.h>
 #include <linux/export.h>
+#include <linux/hashtable.h>
 #include <net/inet_hashtables.h>
 
 #include "rds.h"
 #include "loop.h"
 
 #define RDS_CONNECTION_HASH_BITS 12
-#define RDS_CONNECTION_HASH_ENTRIES (1 << RDS_CONNECTION_HASH_BITS)
-#define RDS_CONNECTION_HASH_MASK (RDS_CONNECTION_HASH_ENTRIES - 1)
 
 /* converting this to RCU is a chore for another day.. */
 static DEFINE_SPINLOCK(rds_conn_lock);
 static unsigned long rds_conn_count;
-static struct hlist_head rds_conn_hash[RDS_CONNECTION_HASH_ENTRIES];
+static DEFINE_HASHTABLE(rds_conn_hash, RDS_CONNECTION_HASH_BITS);
 static struct kmem_cache *rds_conn_slab;
 
-static struct hlist_head *rds_conn_bucket(__be32 laddr, __be32 faddr)
+static unsigned long rds_conn_hashfn(__be32 laddr, __be32 faddr)
 {
 	/* Pass NULL, don't need struct net for hash */
-	unsigned long hash = inet_ehashfn(NULL,
-					  be32_to_cpu(laddr), 0,
-					  be32_to_cpu(faddr), 0);
-	return &rds_conn_hash[hash & RDS_CONNECTION_HASH_MASK];
+	return inet_ehashfn(NULL,  be32_to_cpu(laddr), 0,  be32_to_cpu(faddr), 0);
 }
 
 #define rds_conn_info_set(var, test, suffix) do {		\
@@ -64,14 +60,14 @@ static struct hlist_head *rds_conn_bucket(__be32 laddr, __be32 faddr)
 } while (0)
 
 /* rcu read lock must be held or the connection spinlock */
-static struct rds_connection *rds_conn_lookup(struct hlist_head *head,
-					      __be32 laddr, __be32 faddr,
+static struct rds_connection *rds_conn_lookup(__be32 laddr, __be32 faddr,
 					      struct rds_transport *trans)
 {
 	struct rds_connection *conn, *ret = NULL;
 	struct hlist_node *pos;
+	unsigned long key = rds_conn_hashfn(laddr, faddr);
 
-	hlist_for_each_entry_rcu(conn, pos, head, c_hash_node) {
+	hash_for_each_possible_rcu(rds_conn_hash, conn, pos, c_hash_node, key) {
 		if (conn->c_faddr == faddr && conn->c_laddr == laddr &&
 				conn->c_trans == trans) {
 			ret = conn;
@@ -117,13 +113,12 @@ static struct rds_connection *__rds_conn_create(__be32 laddr, __be32 faddr,
 				       int is_outgoing)
 {
 	struct rds_connection *conn, *parent = NULL;
-	struct hlist_head *head = rds_conn_bucket(laddr, faddr);
 	struct rds_transport *loop_trans;
 	unsigned long flags;
 	int ret;
 
 	rcu_read_lock();
-	conn = rds_conn_lookup(head, laddr, faddr, trans);
+	conn = rds_conn_lookup(laddr, faddr, trans);
 	if (conn && conn->c_loopback && conn->c_trans != &rds_loop_transport &&
 	    !is_outgoing) {
 		/* This is a looped back IB connection, and we're
@@ -224,13 +219,15 @@ static struct rds_connection *__rds_conn_create(__be32 laddr, __be32 faddr,
 		/* Creating normal conn */
 		struct rds_connection *found;
 
-		found = rds_conn_lookup(head, laddr, faddr, trans);
+		found = rds_conn_lookup(laddr, faddr, trans);
 		if (found) {
 			trans->conn_free(conn->c_transport_data);
 			kmem_cache_free(rds_conn_slab, conn);
 			conn = found;
 		} else {
-			hlist_add_head_rcu(&conn->c_hash_node, head);
+			unsigned long key = rds_conn_hashfn(laddr, faddr);
+
+			hash_add_rcu(rds_conn_hash, &conn->c_hash_node, key);
 			rds_cong_add_conn(conn);
 			rds_conn_count++;
 		}
@@ -303,7 +300,7 @@ void rds_conn_shutdown(struct rds_connection *conn)
 	 * conn - the reconnect is always triggered by the active peer. */
 	cancel_delayed_work_sync(&conn->c_conn_w);
 	rcu_read_lock();
-	if (!hlist_unhashed(&conn->c_hash_node)) {
+	if (hash_hashed(&conn->c_hash_node)) {
 		rcu_read_unlock();
 		rds_queue_reconnect(conn);
 	} else {
@@ -329,7 +326,7 @@ void rds_conn_destroy(struct rds_connection *conn)
 
 	/* Ensure conn will not be scheduled for reconnect */
 	spin_lock_irq(&rds_conn_lock);
-	hlist_del_init_rcu(&conn->c_hash_node);
+	hash_del(&conn->c_hash_node);
 	spin_unlock_irq(&rds_conn_lock);
 	synchronize_rcu();
 
@@ -375,7 +372,6 @@ static void rds_conn_message_info(struct socket *sock, unsigned int len,
 				  struct rds_info_lengths *lens,
 				  int want_send)
 {
-	struct hlist_head *head;
 	struct hlist_node *pos;
 	struct list_head *list;
 	struct rds_connection *conn;
@@ -388,27 +384,24 @@ static void rds_conn_message_info(struct socket *sock, unsigned int len,
 
 	rcu_read_lock();
 
-	for (i = 0, head = rds_conn_hash; i < ARRAY_SIZE(rds_conn_hash);
-	     i++, head++) {
-		hlist_for_each_entry_rcu(conn, pos, head, c_hash_node) {
-			if (want_send)
-				list = &conn->c_send_queue;
-			else
-				list = &conn->c_retrans;
-
-			spin_lock_irqsave(&conn->c_lock, flags);
-
-			/* XXX too lazy to maintain counts.. */
-			list_for_each_entry(rm, list, m_conn_item) {
-				total++;
-				if (total <= len)
-					rds_inc_info_copy(&rm->m_inc, iter,
-							  conn->c_laddr,
-							  conn->c_faddr, 0);
-			}
-
-			spin_unlock_irqrestore(&conn->c_lock, flags);
+	hash_for_each_rcu(rds_conn_hash, i, pos, conn, c_hash_node) {
+		if (want_send)
+			list = &conn->c_send_queue;
+		else
+			list = &conn->c_retrans;
+
+		spin_lock_irqsave(&conn->c_lock, flags);
+
+		/* XXX too lazy to maintain counts.. */
+		list_for_each_entry(rm, list, m_conn_item) {
+			total++;
+			if (total <= len)
+				rds_inc_info_copy(&rm->m_inc, iter,
+						  conn->c_laddr,
+						  conn->c_faddr, 0);
 		}
+
+		spin_unlock_irqrestore(&conn->c_lock, flags);
 	}
 	rcu_read_unlock();
 
@@ -438,7 +431,6 @@ void rds_for_each_conn_info(struct socket *sock, unsigned int len,
 			  size_t item_len)
 {
 	uint64_t buffer[(item_len + 7) / 8];
-	struct hlist_head *head;
 	struct hlist_node *pos;
 	struct rds_connection *conn;
 	size_t i;
@@ -448,23 +440,19 @@ void rds_for_each_conn_info(struct socket *sock, unsigned int len,
 	lens->nr = 0;
 	lens->each = item_len;
 
-	for (i = 0, head = rds_conn_hash; i < ARRAY_SIZE(rds_conn_hash);
-	     i++, head++) {
-		hlist_for_each_entry_rcu(conn, pos, head, c_hash_node) {
-
-			/* XXX no c_lock usage.. */
-			if (!visitor(conn, buffer))
-				continue;
-
-			/* We copy as much as we can fit in the buffer,
-			 * but we count all items so that the caller
-			 * can resize the buffer. */
-			if (len >= item_len) {
-				rds_info_copy(iter, buffer, item_len);
-				len -= item_len;
-			}
-			lens->nr++;
+	hash_for_each_rcu(rds_conn_hash, i, pos, conn, c_hash_node) {
+		/* XXX no c_lock usage.. */
+		if (!visitor(conn, buffer))
+			continue;
+
+		/* We copy as much as we can fit in the buffer,
+		 * but we count all items so that the caller
+		 * can resize the buffer. */
+		if (len >= item_len) {
+			rds_info_copy(iter, buffer, item_len);
+			len -= item_len;
 		}
+		lens->nr++;
 	}
 	rcu_read_unlock();
 }
@@ -525,8 +513,6 @@ void rds_conn_exit(void)
 {
 	rds_loop_exit();
 
-	WARN_ON(!hlist_empty(rds_conn_hash));
-
 	kmem_cache_destroy(rds_conn_slab);
 
 	rds_info_deregister_func(RDS_INFO_CONNECTIONS, rds_conn_info);
-- 
1.8.0

[PATCH 14/15] openvswitch: use new hashtable implementation

[Sasha Levin]

Switch openvswitch to use the new hashtable implementation. This reduces the
amount of generic unrelated code in openvswitch.

This patch depends on d9b482c ("hashtable: introduce a small and naive
hashtable") which was merged in v3.6.

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
---
 net/openvswitch/vport.c | 35 ++++++++++++-----------------------
 1 file changed, 12 insertions(+), 23 deletions(-)

diff --git a/net/openvswitch/vport.c b/net/openvswitch/vport.c
index 70af0be..a946529 100644
--- a/net/openvswitch/vport.c
+++ b/net/openvswitch/vport.c
@@ -28,6 +28,7 @@
 #include <linux/rtnetlink.h>
 #include <linux/compat.h>
 #include <net/net_namespace.h>
+#include <linux/hashtable.h>
 
 #include "datapath.h"
 #include "vport.h"
@@ -41,8 +42,8 @@ static const struct vport_ops *vport_ops_list[] = {
 };
 
 /* Protected by RCU read lock for reading, RTNL lock for writing. */
-static struct hlist_head *dev_table;
-#define VPORT_HASH_BUCKETS 1024
+#define VPORT_HASH_BITS 10
+static DEFINE_HASHTABLE(dev_table, VPORT_HASH_BITS);
 
 /**
  *	ovs_vport_init - initialize vport subsystem
@@ -51,11 +52,6 @@ static struct hlist_head *dev_table;
  */
 int ovs_vport_init(void)
 {
-	dev_table = kzalloc(VPORT_HASH_BUCKETS * sizeof(struct hlist_head),
-			    GFP_KERNEL);
-	if (!dev_table)
-		return -ENOMEM;
-
 	return 0;
 }
 
@@ -66,13 +62,6 @@ int ovs_vport_init(void)
  */
 void ovs_vport_exit(void)
 {
-	kfree(dev_table);
-}
-
-static struct hlist_head *hash_bucket(struct net *net, const char *name)
-{
-	unsigned int hash = jhash(name, strlen(name), (unsigned long) net);
-	return &dev_table[hash & (VPORT_HASH_BUCKETS - 1)];
 }
 
 /**
@@ -84,13 +73,12 @@ static struct hlist_head *hash_bucket(struct net *net, const char *name)
  */
 struct vport *ovs_vport_locate(struct net *net, const char *name)
 {
-	struct hlist_head *bucket = hash_bucket(net, name);
 	struct vport *vport;
 	struct hlist_node *node;
+	int key = full_name_hash(name, strlen(name));
 
-	hlist_for_each_entry_rcu(vport, node, bucket, hash_node)
-		if (!strcmp(name, vport->ops->get_name(vport)) &&
-		    net_eq(ovs_dp_get_net(vport->dp), net))
+	hash_for_each_possible_rcu(dev_table, vport, node, hash_node, key)
+		if (!strcmp(name, vport->ops->get_name(vport)))
 			return vport;
 
 	return NULL;
@@ -174,7 +162,8 @@ struct vport *ovs_vport_add(const struct vport_parms *parms)
 
 	for (i = 0; i < ARRAY_SIZE(vport_ops_list); i++) {
 		if (vport_ops_list[i]->type == parms->type) {
-			struct hlist_head *bucket;
+			int key;
+			const char *name;
 
 			vport = vport_ops_list[i]->create(parms);
 			if (IS_ERR(vport)) {
@@ -182,9 +171,9 @@ struct vport *ovs_vport_add(const struct vport_parms *parms)
 				goto out;
 			}
 
-			bucket = hash_bucket(ovs_dp_get_net(vport->dp),
-					     vport->ops->get_name(vport));
-			hlist_add_head_rcu(&vport->hash_node, bucket);
+			name = vport->ops->get_name(vport);
+			key = full_name_hash(name, strlen(name));
+			hash_add_rcu(dev_table, &vport->hash_node, key);
 			return vport;
 		}
 	}
@@ -225,7 +214,7 @@ void ovs_vport_del(struct vport *vport)
 {
 	ASSERT_RTNL();
 
-	hlist_del_rcu(&vport->hash_node);
+	hash_del_rcu(&vport->hash_node);
 
 	vport->ops->destroy(vport);
 }
-- 
1.8.0