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dlm: replace idr with hash table for connections
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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]>
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@chrissie-c @teigland
chrissie-c authored and teigland committed Mar 11, 2009
1 parent 2cf12c0 commit 5e9ccc3
Showing 1 changed file with 92 additions and 79 deletions.
171 changes: 92 additions & 79 deletions fs/dlm/lowcomms.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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
Expand Down Expand Up @@ -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>
Expand All @@ -61,6 +60,7 @@
#include "config.h"

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

struct cbuf {
unsigned int base;
Expand Down Expand Up @@ -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 */
Expand All @@ -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.
Expand All @@ -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);
Expand All @@ -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;
Expand All @@ -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);
Expand Down Expand Up @@ -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);
}

Expand Down Expand Up @@ -1313,13 +1335,10 @@ static void send_to_sock(struct connection *con)

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);
}
Expand Down Expand Up @@ -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)
Expand Down Expand Up @@ -1406,49 +1418,50 @@ 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();

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) {
Expand Down

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