2009-03-24 14:18:58

by David Teigland

[permalink] [raw]
Subject: [PATCH 4/7] dlm: replace idr with hash table for connections

From: Christine Caulfield <[email protected]>

Integer nodeids can be too large for the idr code; use a hash
table instead.

Signed-off-by: Christine Caulfield <[email protected]>
Signed-off-by: David Teigland <[email protected]>
---
fs/dlm/lowcomms.c | 171 ++++++++++++++++++++++++++++------------------------
1 files changed, 92 insertions(+), 79 deletions(-)

diff --git a/fs/dlm/lowcomms.c b/fs/dlm/lowcomms.c
index 982314c..609108a 100644
--- a/fs/dlm/lowcomms.c
+++ b/fs/dlm/lowcomms.c
@@ -2,7 +2,7 @@
*******************************************************************************
**
** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
-** Copyright (C) 2004-2007 Red Hat, Inc. All rights reserved.
+** Copyright (C) 2004-2009 Red Hat, Inc. All rights reserved.
**
** This copyrighted material is made available to anyone wishing to use,
** modify, copy, or redistribute it subject to the terms and conditions
@@ -48,7 +48,6 @@
#include <net/sock.h>
#include <net/tcp.h>
#include <linux/pagemap.h>
-#include <linux/idr.h>
#include <linux/file.h>
#include <linux/mutex.h>
#include <linux/sctp.h>
@@ -61,6 +60,7 @@
#include "config.h"

#define NEEDED_RMEM (4*1024*1024)
+#define CONN_HASH_SIZE 32

struct cbuf {
unsigned int base;
@@ -115,6 +115,7 @@ struct connection {
int retries;
#define MAX_CONNECT_RETRIES 3
int sctp_assoc;
+ struct hlist_node list;
struct connection *othercon;
struct work_struct rwork; /* Receive workqueue */
struct work_struct swork; /* Send workqueue */
@@ -139,14 +140,37 @@ static int dlm_local_count;
static struct workqueue_struct *recv_workqueue;
static struct workqueue_struct *send_workqueue;

-static DEFINE_IDR(connections_idr);
+static struct hlist_head connection_hash[CONN_HASH_SIZE];
static DEFINE_MUTEX(connections_lock);
-static int max_nodeid;
static struct kmem_cache *con_cache;

static void process_recv_sockets(struct work_struct *work);
static void process_send_sockets(struct work_struct *work);

+
+/* This is deliberately very simple because most clusters have simple
+ sequential nodeids, so we should be able to go straight to a connection
+ struct in the array */
+static inline int nodeid_hash(int nodeid)
+{
+ return nodeid & (CONN_HASH_SIZE-1);
+}
+
+static struct connection *__find_con(int nodeid)
+{
+ int r;
+ struct hlist_node *h;
+ struct connection *con;
+
+ r = nodeid_hash(nodeid);
+
+ hlist_for_each_entry(con, h, &connection_hash[r], list) {
+ if (con->nodeid == nodeid)
+ return con;
+ }
+ return NULL;
+}
+
/*
* If 'allocation' is zero then we don't attempt to create a new
* connection structure for this node.
@@ -155,31 +179,17 @@ static struct connection *__nodeid2con(int nodeid, gfp_t alloc)
{
struct connection *con = NULL;
int r;
- int n;

- con = idr_find(&connections_idr, nodeid);
+ con = __find_con(nodeid);
if (con || !alloc)
return con;

- r = idr_pre_get(&connections_idr, alloc);
- if (!r)
- return NULL;
-
con = kmem_cache_zalloc(con_cache, alloc);
if (!con)
return NULL;

- r = idr_get_new_above(&connections_idr, con, nodeid, &n);
- if (r) {
- kmem_cache_free(con_cache, con);
- return NULL;
- }
-
- if (n != nodeid) {
- idr_remove(&connections_idr, n);
- kmem_cache_free(con_cache, con);
- return NULL;
- }
+ r = nodeid_hash(nodeid);
+ hlist_add_head(&con->list, &connection_hash[r]);

con->nodeid = nodeid;
mutex_init(&con->sock_mutex);
@@ -190,19 +200,30 @@ static struct connection *__nodeid2con(int nodeid, gfp_t alloc)

/* Setup action pointers for child sockets */
if (con->nodeid) {
- struct connection *zerocon = idr_find(&connections_idr, 0);
+ struct connection *zerocon = __find_con(0);

con->connect_action = zerocon->connect_action;
if (!con->rx_action)
con->rx_action = zerocon->rx_action;
}

- if (nodeid > max_nodeid)
- max_nodeid = nodeid;
-
return con;
}

+/* Loop round all connections */
+static void foreach_conn(void (*conn_func)(struct connection *c))
+{
+ int i;
+ struct hlist_node *h, *n;
+ struct connection *con;
+
+ for (i = 0; i < CONN_HASH_SIZE; i++) {
+ hlist_for_each_entry_safe(con, h, n, &connection_hash[i], list){
+ conn_func(con);
+ }
+ }
+}
+
static struct connection *nodeid2con(int nodeid, gfp_t allocation)
{
struct connection *con;
@@ -218,14 +239,17 @@ static struct connection *nodeid2con(int nodeid, gfp_t allocation)
static struct connection *assoc2con(int assoc_id)
{
int i;
+ struct hlist_node *h;
struct connection *con;

mutex_lock(&connections_lock);
- for (i=0; i<=max_nodeid; i++) {
- con = __nodeid2con(i, 0);
- if (con && con->sctp_assoc == assoc_id) {
- mutex_unlock(&connections_lock);
- return con;
+
+ for (i = 0 ; i < CONN_HASH_SIZE; i++) {
+ hlist_for_each_entry(con, h, &connection_hash[i], list) {
+ if (con && con->sctp_assoc == assoc_id) {
+ mutex_unlock(&connections_lock);
+ return con;
+ }
}
}
mutex_unlock(&connections_lock);
@@ -376,25 +400,23 @@ static void sctp_send_shutdown(sctp_assoc_t associd)
log_print("send EOF to node failed: %d", ret);
}

+static void sctp_init_failed_foreach(struct connection *con)
+{
+ con->sctp_assoc = 0;
+ if (test_and_clear_bit(CF_CONNECT_PENDING, &con->flags)) {
+ if (!test_and_set_bit(CF_WRITE_PENDING, &con->flags))
+ queue_work(send_workqueue, &con->swork);
+ }
+}
+
/* INIT failed but we don't know which node...
restart INIT on all pending nodes */
static void sctp_init_failed(void)
{
- int i;
- struct connection *con;
-
mutex_lock(&connections_lock);
- for (i=1; i<=max_nodeid; i++) {
- con = __nodeid2con(i, 0);
- if (!con)
- continue;
- con->sctp_assoc = 0;
- if (test_and_clear_bit(CF_CONNECT_PENDING, &con->flags)) {
- if (!test_and_set_bit(CF_WRITE_PENDING, &con->flags)) {
- queue_work(send_workqueue, &con->swork);
- }
- }
- }
+
+ foreach_conn(sctp_init_failed_foreach);
+
mutex_unlock(&connections_lock);
}

@@ -1313,13 +1335,10 @@ out_connect:

static void clean_one_writequeue(struct connection *con)
{
- struct list_head *list;
- struct list_head *temp;
+ struct writequeue_entry *e, *safe;

spin_lock(&con->writequeue_lock);
- list_for_each_safe(list, temp, &con->writequeue) {
- struct writequeue_entry *e =
- list_entry(list, struct writequeue_entry, list);
+ list_for_each_entry_safe(e, safe, &con->writequeue, list) {
list_del(&e->list);
free_entry(e);
}
@@ -1369,14 +1388,7 @@ static void process_send_sockets(struct work_struct *work)
/* Discard all entries on the write queues */
static void clean_writequeues(void)
{
- int nodeid;
-
- for (nodeid = 1; nodeid <= max_nodeid; nodeid++) {
- struct connection *con = __nodeid2con(nodeid, 0);
-
- if (con)
- clean_one_writequeue(con);
- }
+ foreach_conn(clean_one_writequeue);
}

static void work_stop(void)
@@ -1406,23 +1418,29 @@ static int work_start(void)
return 0;
}

-void dlm_lowcomms_stop(void)
+static void stop_conn(struct connection *con)
{
- int i;
- struct connection *con;
+ con->flags |= 0x0F;
+ if (con->sock)
+ con->sock->sk->sk_user_data = NULL;
+}

+static void free_conn(struct connection *con)
+{
+ close_connection(con, true);
+ if (con->othercon)
+ kmem_cache_free(con_cache, con->othercon);
+ hlist_del(&con->list);
+ kmem_cache_free(con_cache, con);
+}
+
+void dlm_lowcomms_stop(void)
+{
/* Set all the flags to prevent any
socket activity.
*/
mutex_lock(&connections_lock);
- for (i = 0; i <= max_nodeid; i++) {
- con = __nodeid2con(i, 0);
- if (con) {
- con->flags |= 0x0F;
- if (con->sock)
- con->sock->sk->sk_user_data = NULL;
- }
- }
+ foreach_conn(stop_conn);
mutex_unlock(&connections_lock);

work_stop();
@@ -1430,25 +1448,20 @@ void dlm_lowcomms_stop(void)
mutex_lock(&connections_lock);
clean_writequeues();

- for (i = 0; i <= max_nodeid; i++) {
- con = __nodeid2con(i, 0);
- if (con) {
- close_connection(con, true);
- if (con->othercon)
- kmem_cache_free(con_cache, con->othercon);
- kmem_cache_free(con_cache, con);
- }
- }
- max_nodeid = 0;
+ foreach_conn(free_conn);
+
mutex_unlock(&connections_lock);
kmem_cache_destroy(con_cache);
- idr_init(&connections_idr);
}

int dlm_lowcomms_start(void)
{
int error = -EINVAL;
struct connection *con;
+ int i;
+
+ for (i = 0; i < CONN_HASH_SIZE; i++)
+ INIT_HLIST_HEAD(&connection_hash[i]);

init_local();
if (!dlm_local_count) {
--
1.5.5.6