[DLM] Consolidate transport protocols [21/34]

From: Steven Whitehouse
Date: Tue May 01 2007 - 06:21:20 EST

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>From 6ed7257b46709e87d79ac2b6b819b7e0c9184998 Mon Sep 17 00:00:00 2001
From: Patrick Caulfield <pcaulfie@xxxxxxxxxx>
Date: Tue, 17 Apr 2007 15:39:57 +0100
Subject: [PATCH] [DLM] Consolidate transport protocols

This patch consolidates the TCP & SCTP protocols for the DLM into a single file
and makes it switchable at run-time (well, at least before the DLM actually
starts up!)

For RHEL5 this patch requires Neil Horman's patch that expands the in-kernel
socket API but that has already been twice ACKed so it should be OK.

The patch adds a new lowcomms.c file that replaces the existing lowcomms-sctp.c
& lowcomms-tcp.c files.

Signed-off-By: Patrick Caulfield <pcaulfie@xxxxxxxxxx>
Signed-off-by: Steven Whitehouse <swhiteho@xxxxxxxxxx>

diff --git a/fs/dlm/Kconfig b/fs/dlm/Kconfig
index 6fa7b0d..69a9469 100644
--- a/fs/dlm/Kconfig
+++ b/fs/dlm/Kconfig
@@ -3,36 +3,19 @@ menu "Distributed Lock Manager"

config DLM
tristate "Distributed Lock Manager (DLM)"
- depends on SYSFS && (IPV6 || IPV6=n)
+ depends on IPV6 || IPV6=n
select CONFIGFS_FS
- select IP_SCTP if DLM_SCTP
+ select IP_SCTP
help
- A general purpose distributed lock manager for kernel or userspace
- applications.
-
-choice
- prompt "Select DLM communications protocol"
- depends on DLM
- default DLM_TCP
- help
- The DLM Can use TCP or SCTP for it's network communications.
- SCTP supports multi-homed operations whereas TCP doesn't.
- However, SCTP seems to have stability problems at the moment.
-
-config DLM_TCP
- bool "TCP/IP"
-
-config DLM_SCTP
- bool "SCTP"
-
-endchoice
+ A general purpose distributed lock manager for kernel or userspace
+ applications.

config DLM_DEBUG
bool "DLM debugging"
depends on DLM
help
- Under the debugfs mount point, the name of each lockspace will
- appear as a file in the "dlm" directory. The output is the
- list of resource and locks the local node knows about.
+ Under the debugfs mount point, the name of each lockspace will
+ appear as a file in the "dlm" directory. The output is the
+ list of resource and locks the local node knows about.

endmenu
diff --git a/fs/dlm/Makefile b/fs/dlm/Makefile
index 6538894..604cf7d 100644
--- a/fs/dlm/Makefile
+++ b/fs/dlm/Makefile
@@ -8,14 +8,12 @@ dlm-y := ast.o \
member.o \
memory.o \
midcomms.o \
+ lowcomms.o \
rcom.o \
recover.o \
recoverd.o \
requestqueue.o \
user.o \
- util.o
+ util.o
dlm-$(CONFIG_DLM_DEBUG) += debug_fs.o

-dlm-$(CONFIG_DLM_TCP) += lowcomms-tcp.o
-
-dlm-$(CONFIG_DLM_SCTP) += lowcomms-sctp.o
\ No newline at end of file
diff --git a/fs/dlm/config.c b/fs/dlm/config.c
index 8665c88..822abdc 100644
--- a/fs/dlm/config.c
+++ b/fs/dlm/config.c
@@ -2,7 +2,7 @@
*******************************************************************************
**
** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
-** Copyright (C) 2004-2005 Red Hat, Inc. All rights reserved.
+** Copyright (C) 2004-2007 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
@@ -89,6 +89,7 @@ struct cluster {
unsigned int cl_toss_secs;
unsigned int cl_scan_secs;
unsigned int cl_log_debug;
+ unsigned int cl_protocol;
};

enum {
@@ -101,6 +102,7 @@ enum {
CLUSTER_ATTR_TOSS_SECS,
CLUSTER_ATTR_SCAN_SECS,
CLUSTER_ATTR_LOG_DEBUG,
+ CLUSTER_ATTR_PROTOCOL,
};

struct cluster_attribute {
@@ -159,6 +161,7 @@ CLUSTER_ATTR(recover_timer, 1);
CLUSTER_ATTR(toss_secs, 1);
CLUSTER_ATTR(scan_secs, 1);
CLUSTER_ATTR(log_debug, 0);
+CLUSTER_ATTR(protocol, 0);

static struct configfs_attribute *cluster_attrs[] = {
[CLUSTER_ATTR_TCP_PORT] = &cluster_attr_tcp_port.attr,
@@ -170,6 +173,7 @@ static struct configfs_attribute *cluster_attrs[] = {
[CLUSTER_ATTR_TOSS_SECS] = &cluster_attr_toss_secs.attr,
[CLUSTER_ATTR_SCAN_SECS] = &cluster_attr_scan_secs.attr,
[CLUSTER_ATTR_LOG_DEBUG] = &cluster_attr_log_debug.attr,
+ [CLUSTER_ATTR_PROTOCOL] = &cluster_attr_protocol.attr,
NULL,
};

@@ -904,6 +908,7 @@ int dlm_our_addr(struct sockaddr_storage *addr, int num)
#define DEFAULT_TOSS_SECS 10
#define DEFAULT_SCAN_SECS 5
#define DEFAULT_LOG_DEBUG 0
+#define DEFAULT_PROTOCOL 0

struct dlm_config_info dlm_config = {
.ci_tcp_port = DEFAULT_TCP_PORT,
@@ -914,6 +919,7 @@ struct dlm_config_info dlm_config = {
.ci_recover_timer = DEFAULT_RECOVER_TIMER,
.ci_toss_secs = DEFAULT_TOSS_SECS,
.ci_scan_secs = DEFAULT_SCAN_SECS,
- .ci_log_debug = DEFAULT_LOG_DEBUG
+ .ci_log_debug = DEFAULT_LOG_DEBUG,
+ .ci_protocol = DEFAULT_PROTOCOL
};

diff --git a/fs/dlm/config.h b/fs/dlm/config.h
index 1e97861..967cc3d 100644
--- a/fs/dlm/config.h
+++ b/fs/dlm/config.h
@@ -2,7 +2,7 @@
*******************************************************************************
**
** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
-** Copyright (C) 2004-2005 Red Hat, Inc. All rights reserved.
+** Copyright (C) 2004-2007 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
@@ -26,6 +26,7 @@ struct dlm_config_info {
int ci_toss_secs;
int ci_scan_secs;
int ci_log_debug;
+ int ci_protocol;
};

extern struct dlm_config_info dlm_config;
diff --git a/fs/dlm/lowcomms-sctp.c b/fs/dlm/lowcomms-sctp.c
deleted file mode 100644
index dc83a9d..0000000
--- a/fs/dlm/lowcomms-sctp.c
+++ /dev/null
@@ -1,1210 +0,0 @@
-/******************************************************************************
-*******************************************************************************
-**
-** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
-** Copyright (C) 2004-2006 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
-** of the GNU General Public License v.2.
-**
-*******************************************************************************
-******************************************************************************/
-
-/*
- * lowcomms.c
- *
- * This is the "low-level" comms layer.
- *
- * It is responsible for sending/receiving messages
- * from other nodes in the cluster.
- *
- * Cluster nodes are referred to by their nodeids. nodeids are
- * simply 32 bit numbers to the locking module - if they need to
- * be expanded for the cluster infrastructure then that is it's
- * responsibility. It is this layer's
- * responsibility to resolve these into IP address or
- * whatever it needs for inter-node communication.
- *
- * The comms level is two kernel threads that deal mainly with
- * the receiving of messages from other nodes and passing them
- * up to the mid-level comms layer (which understands the
- * message format) for execution by the locking core, and
- * a send thread which does all the setting up of connections
- * to remote nodes and the sending of data. Threads are not allowed
- * to send their own data because it may cause them to wait in times
- * of high load. Also, this way, the sending thread can collect together
- * messages bound for one node and send them in one block.
- *
- * I don't see any problem with the recv thread executing the locking
- * code on behalf of remote processes as the locking code is
- * short, efficient and never (well, hardly ever) waits.
- *
- */
-
-#include <asm/ioctls.h>
-#include <net/sock.h>
-#include <net/tcp.h>
-#include <net/sctp/user.h>
-#include <linux/pagemap.h>
-#include <linux/socket.h>
-#include <linux/idr.h>
-
-#include "dlm_internal.h"
-#include "lowcomms.h"
-#include "config.h"
-#include "midcomms.h"
-
-static struct sockaddr_storage *dlm_local_addr[DLM_MAX_ADDR_COUNT];
-static int dlm_local_count;
-static int dlm_local_nodeid;
-
-/* One of these per connected node */
-
-#define NI_INIT_PENDING 1
-#define NI_WRITE_PENDING 2
-
-struct nodeinfo {
- spinlock_t lock;
- sctp_assoc_t assoc_id;
- unsigned long flags;
- struct list_head write_list; /* nodes with pending writes */
- struct list_head writequeue; /* outgoing writequeue_entries */
- spinlock_t writequeue_lock;
- int nodeid;
- struct work_struct swork; /* Send workqueue */
- struct work_struct lwork; /* Locking workqueue */
-};
-
-static DEFINE_IDR(nodeinfo_idr);
-static DECLARE_RWSEM(nodeinfo_lock);
-static int max_nodeid;
-
-struct cbuf {
- unsigned int base;
- unsigned int len;
- unsigned int mask;
-};
-
-/* Just the one of these, now. But this struct keeps
- the connection-specific variables together */
-
-#define CF_READ_PENDING 1
-
-struct connection {
- struct socket *sock;
- unsigned long flags;
- struct page *rx_page;
- atomic_t waiting_requests;
- struct cbuf cb;
- int eagain_flag;
- struct work_struct work; /* Send workqueue */
-};
-
-/* An entry waiting to be sent */
-
-struct writequeue_entry {
- struct list_head list;
- struct page *page;
- int offset;
- int len;
- int end;
- int users;
- struct nodeinfo *ni;
-};
-
-static void cbuf_add(struct cbuf *cb, int n)
-{
- cb->len += n;
-}
-
-static int cbuf_data(struct cbuf *cb)
-{
- return ((cb->base + cb->len) & cb->mask);
-}
-
-static void cbuf_init(struct cbuf *cb, int size)
-{
- cb->base = cb->len = 0;
- cb->mask = size-1;
-}
-
-static void cbuf_eat(struct cbuf *cb, int n)
-{
- cb->len -= n;
- cb->base += n;
- cb->base &= cb->mask;
-}
-
-/* List of nodes which have writes pending */
-static LIST_HEAD(write_nodes);
-static DEFINE_SPINLOCK(write_nodes_lock);
-
-
-/* Maximum number of incoming messages to process before
- * doing a schedule()
- */
-#define MAX_RX_MSG_COUNT 25
-
-/* Work queues */
-static struct workqueue_struct *recv_workqueue;
-static struct workqueue_struct *send_workqueue;
-static struct workqueue_struct *lock_workqueue;
-
-/* The SCTP connection */
-static struct connection sctp_con;
-
-static void process_send_sockets(struct work_struct *work);
-static void process_recv_sockets(struct work_struct *work);
-static void process_lock_request(struct work_struct *work);
-
-static int nodeid_to_addr(int nodeid, struct sockaddr *retaddr)
-{
- struct sockaddr_storage addr;
- int error;
-
- if (!dlm_local_count)
- return -1;
-
- error = dlm_nodeid_to_addr(nodeid, &addr);
- if (error)
- return error;
-
- if (dlm_local_addr[0]->ss_family == AF_INET) {
- struct sockaddr_in *in4 = (struct sockaddr_in *) &addr;
- struct sockaddr_in *ret4 = (struct sockaddr_in *) retaddr;
- ret4->sin_addr.s_addr = in4->sin_addr.s_addr;
- } else {
- struct sockaddr_in6 *in6 = (struct sockaddr_in6 *) &addr;
- struct sockaddr_in6 *ret6 = (struct sockaddr_in6 *) retaddr;
- memcpy(&ret6->sin6_addr, &in6->sin6_addr,
- sizeof(in6->sin6_addr));
- }
-
- return 0;
-}
-
-/* If alloc is 0 here we will not attempt to allocate a new
- nodeinfo struct */
-static struct nodeinfo *nodeid2nodeinfo(int nodeid, gfp_t alloc)
-{
- struct nodeinfo *ni;
- int r;
- int n;
-
- down_read(&nodeinfo_lock);
- ni = idr_find(&nodeinfo_idr, nodeid);
- up_read(&nodeinfo_lock);
-
- if (ni || !alloc)
- return ni;
-
- down_write(&nodeinfo_lock);
-
- ni = idr_find(&nodeinfo_idr, nodeid);
- if (ni)
- goto out_up;
-
- r = idr_pre_get(&nodeinfo_idr, alloc);
- if (!r)
- goto out_up;
-
- ni = kmalloc(sizeof(struct nodeinfo), alloc);
- if (!ni)
- goto out_up;
-
- r = idr_get_new_above(&nodeinfo_idr, ni, nodeid, &n);
- if (r) {
- kfree(ni);
- ni = NULL;
- goto out_up;
- }
- if (n != nodeid) {
- idr_remove(&nodeinfo_idr, n);
- kfree(ni);
- ni = NULL;
- goto out_up;
- }
- memset(ni, 0, sizeof(struct nodeinfo));
- spin_lock_init(&ni->lock);
- INIT_LIST_HEAD(&ni->writequeue);
- spin_lock_init(&ni->writequeue_lock);
- INIT_WORK(&ni->lwork, process_lock_request);
- INIT_WORK(&ni->swork, process_send_sockets);
- ni->nodeid = nodeid;
-
- if (nodeid > max_nodeid)
- max_nodeid = nodeid;
-out_up:
- up_write(&nodeinfo_lock);
-
- return ni;
-}
-
-/* Don't call this too often... */
-static struct nodeinfo *assoc2nodeinfo(sctp_assoc_t assoc)
-{
- int i;
- struct nodeinfo *ni;
-
- for (i=1; i<=max_nodeid; i++) {
- ni = nodeid2nodeinfo(i, 0);
- if (ni && ni->assoc_id == assoc)
- return ni;
- }
- return NULL;
-}
-
-/* Data or notification available on socket */
-static void lowcomms_data_ready(struct sock *sk, int count_unused)
-{
- if (test_and_set_bit(CF_READ_PENDING, &sctp_con.flags))
- queue_work(recv_workqueue, &sctp_con.work);
-}
-
-
-/* Add the port number to an IP6 or 4 sockaddr and return the address length.
- Also padd out the struct with zeros to make comparisons meaningful */
-
-static void make_sockaddr(struct sockaddr_storage *saddr, uint16_t port,
- int *addr_len)
-{
- struct sockaddr_in *local4_addr;
- struct sockaddr_in6 *local6_addr;
-
- if (!dlm_local_count)
- return;
-
- if (!port) {
- if (dlm_local_addr[0]->ss_family == AF_INET) {
- local4_addr = (struct sockaddr_in *)dlm_local_addr[0];
- port = be16_to_cpu(local4_addr->sin_port);
- } else {
- local6_addr = (struct sockaddr_in6 *)dlm_local_addr[0];
- port = be16_to_cpu(local6_addr->sin6_port);
- }
- }
-
- saddr->ss_family = dlm_local_addr[0]->ss_family;
- if (dlm_local_addr[0]->ss_family == AF_INET) {
- struct sockaddr_in *in4_addr = (struct sockaddr_in *)saddr;
- in4_addr->sin_port = cpu_to_be16(port);
- memset(&in4_addr->sin_zero, 0, sizeof(in4_addr->sin_zero));
- memset(in4_addr+1, 0, sizeof(struct sockaddr_storage) -
- sizeof(struct sockaddr_in));
- *addr_len = sizeof(struct sockaddr_in);
- } else {
- struct sockaddr_in6 *in6_addr = (struct sockaddr_in6 *)saddr;
- in6_addr->sin6_port = cpu_to_be16(port);
- memset(in6_addr+1, 0, sizeof(struct sockaddr_storage) -
- sizeof(struct sockaddr_in6));
- *addr_len = sizeof(struct sockaddr_in6);
- }
-}
-
-/* Close the connection and tidy up */
-static void close_connection(void)
-{
- if (sctp_con.sock) {
- sock_release(sctp_con.sock);
- sctp_con.sock = NULL;
- }
-
- if (sctp_con.rx_page) {
- __free_page(sctp_con.rx_page);
- sctp_con.rx_page = NULL;
- }
-}
-
-/* We only send shutdown messages to nodes that are not part of the cluster */
-static void send_shutdown(sctp_assoc_t associd)
-{
- static char outcmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))];
- struct msghdr outmessage;
- struct cmsghdr *cmsg;
- struct sctp_sndrcvinfo *sinfo;
- int ret;
-
- outmessage.msg_name = NULL;
- outmessage.msg_namelen = 0;
- outmessage.msg_control = outcmsg;
- outmessage.msg_controllen = sizeof(outcmsg);
- outmessage.msg_flags = MSG_EOR;
-
- cmsg = CMSG_FIRSTHDR(&outmessage);
- cmsg->cmsg_level = IPPROTO_SCTP;
- cmsg->cmsg_type = SCTP_SNDRCV;
- cmsg->cmsg_len = CMSG_LEN(sizeof(struct sctp_sndrcvinfo));
- outmessage.msg_controllen = cmsg->cmsg_len;
- sinfo = CMSG_DATA(cmsg);
- memset(sinfo, 0x00, sizeof(struct sctp_sndrcvinfo));
-
- sinfo->sinfo_flags |= MSG_EOF;
- sinfo->sinfo_assoc_id = associd;
-
- ret = kernel_sendmsg(sctp_con.sock, &outmessage, NULL, 0, 0);
-
- if (ret != 0)
- log_print("send EOF to node failed: %d", ret);
-}
-
-
-/* INIT failed but we don't know which node...
- restart INIT on all pending nodes */
-static void init_failed(void)
-{
- int i;
- struct nodeinfo *ni;
-
- for (i=1; i<=max_nodeid; i++) {
- ni = nodeid2nodeinfo(i, 0);
- if (!ni)
- continue;
-
- if (test_and_clear_bit(NI_INIT_PENDING, &ni->flags)) {
- ni->assoc_id = 0;
- if (!test_and_set_bit(NI_WRITE_PENDING, &ni->flags)) {
- spin_lock_bh(&write_nodes_lock);
- list_add_tail(&ni->write_list, &write_nodes);
- spin_unlock_bh(&write_nodes_lock);
- queue_work(send_workqueue, &ni->swork);
- }
- }
- }
-}
-
-/* Something happened to an association */
-static void process_sctp_notification(struct msghdr *msg, char *buf)
-{
- union sctp_notification *sn = (union sctp_notification *)buf;
-
- if (sn->sn_header.sn_type == SCTP_ASSOC_CHANGE) {
- switch (sn->sn_assoc_change.sac_state) {
-
- case SCTP_COMM_UP:
- case SCTP_RESTART:
- {
- /* Check that the new node is in the lockspace */
- struct sctp_prim prim;
- mm_segment_t fs;
- int nodeid;
- int prim_len, ret;
- int addr_len;
- struct nodeinfo *ni;
-
- /* This seems to happen when we received a connection
- * too early... or something... anyway, it happens but
- * we always seem to get a real message too, see
- * receive_from_sock */
-
- if ((int)sn->sn_assoc_change.sac_assoc_id <= 0) {
- log_print("COMM_UP for invalid assoc ID %d",
- (int)sn->sn_assoc_change.sac_assoc_id);
- init_failed();
- return;
- }
- memset(&prim, 0, sizeof(struct sctp_prim));
- prim_len = sizeof(struct sctp_prim);
- prim.ssp_assoc_id = sn->sn_assoc_change.sac_assoc_id;
-
- fs = get_fs();
- set_fs(get_ds());
- ret = sctp_con.sock->ops->getsockopt(sctp_con.sock,
- IPPROTO_SCTP,
- SCTP_PRIMARY_ADDR,
- (char*)&prim,
- &prim_len);
- set_fs(fs);
- if (ret < 0) {
- struct nodeinfo *ni;
-
- log_print("getsockopt/sctp_primary_addr on "
- "new assoc %d failed : %d",
- (int)sn->sn_assoc_change.sac_assoc_id,
- ret);
-
- /* Retry INIT later */
- ni = assoc2nodeinfo(sn->sn_assoc_change.sac_assoc_id);
- if (ni)
- clear_bit(NI_INIT_PENDING, &ni->flags);
- return;
- }
- make_sockaddr(&prim.ssp_addr, 0, &addr_len);
- if (dlm_addr_to_nodeid(&prim.ssp_addr, &nodeid)) {
- log_print("reject connect from unknown addr");
- send_shutdown(prim.ssp_assoc_id);
- return;
- }
-
- ni = nodeid2nodeinfo(nodeid, GFP_KERNEL);
- if (!ni)
- return;
-
- /* Save the assoc ID */
- ni->assoc_id = sn->sn_assoc_change.sac_assoc_id;
-
- log_print("got new/restarted association %d nodeid %d",
- (int)sn->sn_assoc_change.sac_assoc_id, nodeid);
-
- /* Send any pending writes */
- clear_bit(NI_INIT_PENDING, &ni->flags);
- if (!test_and_set_bit(NI_WRITE_PENDING, &ni->flags)) {
- spin_lock_bh(&write_nodes_lock);
- list_add_tail(&ni->write_list, &write_nodes);
- spin_unlock_bh(&write_nodes_lock);
- queue_work(send_workqueue, &ni->swork);
- }
- }
- break;
-
- case SCTP_COMM_LOST:
- case SCTP_SHUTDOWN_COMP:
- {
- struct nodeinfo *ni;
-
- ni = assoc2nodeinfo(sn->sn_assoc_change.sac_assoc_id);
- if (ni) {
- spin_lock(&ni->lock);
- ni->assoc_id = 0;
- spin_unlock(&ni->lock);
- }
- }
- break;
-
- /* We don't know which INIT failed, so clear the PENDING flags
- * on them all. if assoc_id is zero then it will then try
- * again */
-
- case SCTP_CANT_STR_ASSOC:
- {
- log_print("Can't start SCTP association - retrying");
- init_failed();
- }
- break;
-
- default:
- log_print("unexpected SCTP assoc change id=%d state=%d",
- (int)sn->sn_assoc_change.sac_assoc_id,
- sn->sn_assoc_change.sac_state);
- }
- }
-}
-
-/* Data received from remote end */
-static int receive_from_sock(void)
-{
- int ret = 0;
- struct msghdr msg;
- struct kvec iov[2];
- unsigned len;
- int r;
- struct sctp_sndrcvinfo *sinfo;
- struct cmsghdr *cmsg;
- struct nodeinfo *ni;
-
- /* These two are marginally too big for stack allocation, but this
- * function is (currently) only called by dlm_recvd so static should be
- * OK.
- */
- static struct sockaddr_storage msgname;
- static char incmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))];
-
- if (sctp_con.sock == NULL)
- goto out;
-
- if (sctp_con.rx_page == NULL) {
- /*
- * This doesn't need to be atomic, but I think it should
- * improve performance if it is.
- */
- sctp_con.rx_page = alloc_page(GFP_ATOMIC);
- if (sctp_con.rx_page == NULL)
- goto out_resched;
- cbuf_init(&sctp_con.cb, PAGE_CACHE_SIZE);
- }
-
- memset(&incmsg, 0, sizeof(incmsg));
- memset(&msgname, 0, sizeof(msgname));
-
- msg.msg_name = &msgname;
- msg.msg_namelen = sizeof(msgname);
- msg.msg_flags = 0;
- msg.msg_control = incmsg;
- msg.msg_controllen = sizeof(incmsg);
- msg.msg_iovlen = 1;
-
- /* I don't see why this circular buffer stuff is necessary for SCTP
- * which is a packet-based protocol, but the whole thing breaks under
- * load without it! The overhead is minimal (and is in the TCP lowcomms
- * anyway, of course) so I'll leave it in until I can figure out what's
- * really happening.
- */
-
- /*
- * iov[0] is the bit of the circular buffer between the current end
- * point (cb.base + cb.len) and the end of the buffer.
- */
- iov[0].iov_len = sctp_con.cb.base - cbuf_data(&sctp_con.cb);
- iov[0].iov_base = page_address(sctp_con.rx_page) +
- cbuf_data(&sctp_con.cb);
- iov[1].iov_len = 0;
-
- /*
- * iov[1] is the bit of the circular buffer between the start of the
- * buffer and the start of the currently used section (cb.base)
- */
- if (cbuf_data(&sctp_con.cb) >= sctp_con.cb.base) {
- iov[0].iov_len = PAGE_CACHE_SIZE - cbuf_data(&sctp_con.cb);
- iov[1].iov_len = sctp_con.cb.base;
- iov[1].iov_base = page_address(sctp_con.rx_page);
- msg.msg_iovlen = 2;
- }
- len = iov[0].iov_len + iov[1].iov_len;
-
- r = ret = kernel_recvmsg(sctp_con.sock, &msg, iov, msg.msg_iovlen, len,
- MSG_NOSIGNAL | MSG_DONTWAIT);
- if (ret <= 0)
- goto out_close;
-
- msg.msg_control = incmsg;
- msg.msg_controllen = sizeof(incmsg);
- cmsg = CMSG_FIRSTHDR(&msg);
- sinfo = CMSG_DATA(cmsg);
-
- if (msg.msg_flags & MSG_NOTIFICATION) {
- process_sctp_notification(&msg, page_address(sctp_con.rx_page));
- return 0;
- }
-
- /* Is this a new association ? */
- ni = nodeid2nodeinfo(le32_to_cpu(sinfo->sinfo_ppid), GFP_KERNEL);
- if (ni) {
- ni->assoc_id = sinfo->sinfo_assoc_id;
- if (test_and_clear_bit(NI_INIT_PENDING, &ni->flags)) {
-
- if (!test_and_set_bit(NI_WRITE_PENDING, &ni->flags)) {
- spin_lock_bh(&write_nodes_lock);
- list_add_tail(&ni->write_list, &write_nodes);
- spin_unlock_bh(&write_nodes_lock);
- queue_work(send_workqueue, &ni->swork);
- }
- }
- }
-
- /* INIT sends a message with length of 1 - ignore it */
- if (r == 1)
- return 0;
-
- cbuf_add(&sctp_con.cb, ret);
- // PJC: TODO: Add to node's workqueue....can we ??
- ret = dlm_process_incoming_buffer(cpu_to_le32(sinfo->sinfo_ppid),
- page_address(sctp_con.rx_page),
- sctp_con.cb.base, sctp_con.cb.len,
- PAGE_CACHE_SIZE);
- if (ret < 0)
- goto out_close;
- cbuf_eat(&sctp_con.cb, ret);
-
-out:
- ret = 0;
- goto out_ret;
-
-out_resched:
- lowcomms_data_ready(sctp_con.sock->sk, 0);
- ret = 0;
- cond_resched();
- goto out_ret;
-
-out_close:
- if (ret != -EAGAIN)
- log_print("error reading from sctp socket: %d", ret);
-out_ret:
- return ret;
-}
-
-/* Bind to an IP address. SCTP allows multiple address so it can do multi-homing */
-static int add_bind_addr(struct sockaddr_storage *addr, int addr_len, int num)
-{
- mm_segment_t fs;
- int result = 0;
-
- fs = get_fs();
- set_fs(get_ds());
- if (num == 1)
- result = sctp_con.sock->ops->bind(sctp_con.sock,
- (struct sockaddr *) addr,
- addr_len);
- else
- result = sctp_con.sock->ops->setsockopt(sctp_con.sock, SOL_SCTP,
- SCTP_SOCKOPT_BINDX_ADD,
- (char *)addr, addr_len);
- set_fs(fs);
-
- if (result < 0)
- log_print("Can't bind to port %d addr number %d",
- dlm_config.ci_tcp_port, num);
-
- return result;
-}
-
-static void init_local(void)
-{
- struct sockaddr_storage sas, *addr;
- int i;
-
- dlm_local_nodeid = dlm_our_nodeid();
-
- for (i = 0; i < DLM_MAX_ADDR_COUNT - 1; i++) {
- if (dlm_our_addr(&sas, i))
- break;
-
- addr = kmalloc(sizeof(*addr), GFP_KERNEL);
- if (!addr)
- break;
- memcpy(addr, &sas, sizeof(*addr));
- dlm_local_addr[dlm_local_count++] = addr;
- }
-}
-
-/* Initialise SCTP socket and bind to all interfaces */
-static int init_sock(void)
-{
- mm_segment_t fs;
- struct socket *sock = NULL;
- struct sockaddr_storage localaddr;
- struct sctp_event_subscribe subscribe;
- int result = -EINVAL, num = 1, i, addr_len;
-
- if (!dlm_local_count) {
- init_local();
- if (!dlm_local_count) {
- log_print("no local IP address has been set");
- goto out;
- }
- }
-
- result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_SEQPACKET,
- IPPROTO_SCTP, &sock);
- if (result < 0) {
- log_print("Can't create comms socket, check SCTP is loaded");
- goto out;
- }
-
- /* Listen for events */
- memset(&subscribe, 0, sizeof(subscribe));
- subscribe.sctp_data_io_event = 1;
- subscribe.sctp_association_event = 1;
- subscribe.sctp_send_failure_event = 1;
- subscribe.sctp_shutdown_event = 1;
- subscribe.sctp_partial_delivery_event = 1;
-
- fs = get_fs();
- set_fs(get_ds());
- result = sock->ops->setsockopt(sock, SOL_SCTP, SCTP_EVENTS,
- (char *)&subscribe, sizeof(subscribe));
- set_fs(fs);
-
- if (result < 0) {
- log_print("Failed to set SCTP_EVENTS on socket: result=%d",
- result);
- goto create_delsock;
- }
-
- /* Init con struct */
- sock->sk->sk_user_data = &sctp_con;
- sctp_con.sock = sock;
- sctp_con.sock->sk->sk_data_ready = lowcomms_data_ready;
-
- /* Bind to all interfaces. */
- for (i = 0; i < dlm_local_count; i++) {
- memcpy(&localaddr, dlm_local_addr[i], sizeof(localaddr));
- make_sockaddr(&localaddr, dlm_config.ci_tcp_port, &addr_len);
-
- result = add_bind_addr(&localaddr, addr_len, num);
- if (result)
- goto create_delsock;
- ++num;
- }
-
- result = sock->ops->listen(sock, 5);
- if (result < 0) {
- log_print("Can't set socket listening");
- goto create_delsock;
- }
-
- return 0;
-
-create_delsock:
- sock_release(sock);
- sctp_con.sock = NULL;
-out:
- return result;
-}
-
-
-static struct writequeue_entry *new_writequeue_entry(gfp_t allocation)
-{
- struct writequeue_entry *entry;
-
- entry = kmalloc(sizeof(struct writequeue_entry), allocation);
- if (!entry)
- return NULL;
-
- entry->page = alloc_page(allocation);
- if (!entry->page) {
- kfree(entry);
- return NULL;
- }
-
- entry->offset = 0;
- entry->len = 0;
- entry->end = 0;
- entry->users = 0;
-
- return entry;
-}
-
-void *dlm_lowcomms_get_buffer(int nodeid, int len, gfp_t allocation, char **ppc)
-{
- struct writequeue_entry *e;
- int offset = 0;
- int users = 0;
- struct nodeinfo *ni;
-
- ni = nodeid2nodeinfo(nodeid, allocation);
- if (!ni)
- return NULL;
-
- spin_lock(&ni->writequeue_lock);
- e = list_entry(ni->writequeue.prev, struct writequeue_entry, list);
- if ((&e->list == &ni->writequeue) ||
- (PAGE_CACHE_SIZE - e->end < len)) {
- e = NULL;
- } else {
- offset = e->end;
- e->end += len;
- users = e->users++;
- }
- spin_unlock(&ni->writequeue_lock);
-
- if (e) {
- got_one:
- if (users == 0)
- kmap(e->page);
- *ppc = page_address(e->page) + offset;
- return e;
- }
-
- e = new_writequeue_entry(allocation);
- if (e) {
- spin_lock(&ni->writequeue_lock);
- offset = e->end;
- e->end += len;
- e->ni = ni;
- users = e->users++;
- list_add_tail(&e->list, &ni->writequeue);
- spin_unlock(&ni->writequeue_lock);
- goto got_one;
- }
- return NULL;
-}
-
-void dlm_lowcomms_commit_buffer(void *arg)
-{
- struct writequeue_entry *e = (struct writequeue_entry *) arg;
- int users;
- struct nodeinfo *ni = e->ni;
-
- spin_lock(&ni->writequeue_lock);
- users = --e->users;
- if (users)
- goto out;
- e->len = e->end - e->offset;
- kunmap(e->page);
- spin_unlock(&ni->writequeue_lock);
-
- if (!test_and_set_bit(NI_WRITE_PENDING, &ni->flags)) {
- spin_lock_bh(&write_nodes_lock);
- list_add_tail(&ni->write_list, &write_nodes);
- spin_unlock_bh(&write_nodes_lock);
-
- queue_work(send_workqueue, &ni->swork);
- }
- return;
-
-out:
- spin_unlock(&ni->writequeue_lock);
- return;
-}
-
-static void free_entry(struct writequeue_entry *e)
-{
- __free_page(e->page);
- kfree(e);
-}
-
-/* Initiate an SCTP association. In theory we could just use sendmsg() on
- the first IP address and it should work, but this allows us to set up the
- association before sending any valuable data that we can't afford to lose.
- It also keeps the send path clean as it can now always use the association ID */
-static void initiate_association(int nodeid)
-{
- struct sockaddr_storage rem_addr;
- static char outcmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))];
- struct msghdr outmessage;
- struct cmsghdr *cmsg;
- struct sctp_sndrcvinfo *sinfo;
- int ret;
- int addrlen;
- char buf[1];
- struct kvec iov[1];
- struct nodeinfo *ni;
-
- log_print("Initiating association with node %d", nodeid);
-
- ni = nodeid2nodeinfo(nodeid, GFP_KERNEL);
- if (!ni)
- return;
-
- if (nodeid_to_addr(nodeid, (struct sockaddr *)&rem_addr)) {
- log_print("no address for nodeid %d", nodeid);
- return;
- }
-
- make_sockaddr(&rem_addr, dlm_config.ci_tcp_port, &addrlen);
-
- outmessage.msg_name = &rem_addr;
- outmessage.msg_namelen = addrlen;
- outmessage.msg_control = outcmsg;
- outmessage.msg_controllen = sizeof(outcmsg);
- outmessage.msg_flags = MSG_EOR;
-
- iov[0].iov_base = buf;
- iov[0].iov_len = 1;
-
- /* Real INIT messages seem to cause trouble. Just send a 1 byte message
- we can afford to lose */
- cmsg = CMSG_FIRSTHDR(&outmessage);
- cmsg->cmsg_level = IPPROTO_SCTP;
- cmsg->cmsg_type = SCTP_SNDRCV;
- cmsg->cmsg_len = CMSG_LEN(sizeof(struct sctp_sndrcvinfo));
- sinfo = CMSG_DATA(cmsg);
- memset(sinfo, 0x00, sizeof(struct sctp_sndrcvinfo));
- sinfo->sinfo_ppid = cpu_to_le32(dlm_local_nodeid);
-
- outmessage.msg_controllen = cmsg->cmsg_len;
- ret = kernel_sendmsg(sctp_con.sock, &outmessage, iov, 1, 1);
- if (ret < 0) {
- log_print("send INIT to node failed: %d", ret);
- /* Try again later */
- clear_bit(NI_INIT_PENDING, &ni->flags);
- }
-}
-
-/* Send a message */
-static void send_to_sock(struct nodeinfo *ni)
-{
- int ret = 0;
- struct writequeue_entry *e;
- int len, offset;
- struct msghdr outmsg;
- static char outcmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))];
- struct cmsghdr *cmsg;
- struct sctp_sndrcvinfo *sinfo;
- struct kvec iov;
-
- /* See if we need to init an association before we start
- sending precious messages */
- spin_lock(&ni->lock);
- if (!ni->assoc_id && !test_and_set_bit(NI_INIT_PENDING, &ni->flags)) {
- spin_unlock(&ni->lock);
- initiate_association(ni->nodeid);
- return;
- }
- spin_unlock(&ni->lock);
-
- outmsg.msg_name = NULL; /* We use assoc_id */
- outmsg.msg_namelen = 0;
- outmsg.msg_control = outcmsg;
- outmsg.msg_controllen = sizeof(outcmsg);
- outmsg.msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL | MSG_EOR;
-
- cmsg = CMSG_FIRSTHDR(&outmsg);
- cmsg->cmsg_level = IPPROTO_SCTP;
- cmsg->cmsg_type = SCTP_SNDRCV;
- cmsg->cmsg_len = CMSG_LEN(sizeof(struct sctp_sndrcvinfo));
- sinfo = CMSG_DATA(cmsg);
- memset(sinfo, 0x00, sizeof(struct sctp_sndrcvinfo));
- sinfo->sinfo_ppid = cpu_to_le32(dlm_local_nodeid);
- sinfo->sinfo_assoc_id = ni->assoc_id;
- outmsg.msg_controllen = cmsg->cmsg_len;
-
- spin_lock(&ni->writequeue_lock);
- for (;;) {
- if (list_empty(&ni->writequeue))
- break;
- e = list_entry(ni->writequeue.next, struct writequeue_entry,
- list);
- len = e->len;
- offset = e->offset;
- BUG_ON(len == 0 && e->users == 0);
- spin_unlock(&ni->writequeue_lock);
- kmap(e->page);
-
- ret = 0;
- if (len) {
- iov.iov_base = page_address(e->page)+offset;
- iov.iov_len = len;
-
- ret = kernel_sendmsg(sctp_con.sock, &outmsg, &iov, 1,
- len);
- if (ret == -EAGAIN) {
- sctp_con.eagain_flag = 1;
- goto out;
- } else if (ret < 0)
- goto send_error;
- } else {
- /* Don't starve people filling buffers */
- cond_resched();
- }
-
- spin_lock(&ni->writequeue_lock);
- e->offset += ret;
- e->len -= ret;
-
- if (e->len == 0 && e->users == 0) {
- list_del(&e->list);
- kunmap(e->page);
- free_entry(e);
- continue;
- }
- }
- spin_unlock(&ni->writequeue_lock);
-out:
- return;
-
-send_error:
- log_print("Error sending to node %d %d", ni->nodeid, ret);
- spin_lock(&ni->lock);
- if (!test_and_set_bit(NI_INIT_PENDING, &ni->flags)) {
- ni->assoc_id = 0;
- spin_unlock(&ni->lock);
- initiate_association(ni->nodeid);
- } else
- spin_unlock(&ni->lock);
-
- return;
-}
-
-/* Try to send any messages that are pending */
-static void process_output_queue(void)
-{
- struct list_head *list;
- struct list_head *temp;
-
- spin_lock_bh(&write_nodes_lock);
- list_for_each_safe(list, temp, &write_nodes) {
- struct nodeinfo *ni =
- list_entry(list, struct nodeinfo, write_list);
- clear_bit(NI_WRITE_PENDING, &ni->flags);
- list_del(&ni->write_list);
-
- spin_unlock_bh(&write_nodes_lock);
-
- send_to_sock(ni);
- spin_lock_bh(&write_nodes_lock);
- }
- spin_unlock_bh(&write_nodes_lock);
-}
-
-/* Called after we've had -EAGAIN and been woken up */
-static void refill_write_queue(void)
-{
- int i;
-
- for (i=1; i<=max_nodeid; i++) {
- struct nodeinfo *ni = nodeid2nodeinfo(i, 0);
-
- if (ni) {
- if (!test_and_set_bit(NI_WRITE_PENDING, &ni->flags)) {
- spin_lock_bh(&write_nodes_lock);
- list_add_tail(&ni->write_list, &write_nodes);
- spin_unlock_bh(&write_nodes_lock);
- }
- }
- }
-}
-
-static void clean_one_writequeue(struct nodeinfo *ni)
-{
- struct list_head *list;
- struct list_head *temp;
-
- spin_lock(&ni->writequeue_lock);
- list_for_each_safe(list, temp, &ni->writequeue) {
- struct writequeue_entry *e =
- list_entry(list, struct writequeue_entry, list);
- list_del(&e->list);
- free_entry(e);
- }
- spin_unlock(&ni->writequeue_lock);
-}
-
-static void clean_writequeues(void)
-{
- int i;
-
- for (i=1; i<=max_nodeid; i++) {
- struct nodeinfo *ni = nodeid2nodeinfo(i, 0);
- if (ni)
- clean_one_writequeue(ni);
- }
-}
-
-
-static void dealloc_nodeinfo(void)
-{
- int i;
-
- for (i=1; i<=max_nodeid; i++) {
- struct nodeinfo *ni = nodeid2nodeinfo(i, 0);
- if (ni) {
- idr_remove(&nodeinfo_idr, i);
- kfree(ni);
- }
- }
-}
-
-int dlm_lowcomms_close(int nodeid)
-{
- struct nodeinfo *ni;
-
- ni = nodeid2nodeinfo(nodeid, 0);
- if (!ni)
- return -1;
-
- spin_lock(&ni->lock);
- if (ni->assoc_id) {
- ni->assoc_id = 0;
- /* Don't send shutdown here, sctp will just queue it
- till the node comes back up! */
- }
- spin_unlock(&ni->lock);
-
- clean_one_writequeue(ni);
- clear_bit(NI_INIT_PENDING, &ni->flags);
- return 0;
-}
-
-// PJC: The work queue function for receiving.
-static void process_recv_sockets(struct work_struct *work)
-{
- if (test_and_clear_bit(CF_READ_PENDING, &sctp_con.flags)) {
- int ret;
- int count = 0;
-
- do {
- ret = receive_from_sock();
-
- /* Don't starve out everyone else */
- if (++count >= MAX_RX_MSG_COUNT) {
- cond_resched();
- count = 0;
- }
- } while (!kthread_should_stop() && ret >=0);
- }
- cond_resched();
-}
-
-// PJC: the work queue function for sending
-static void process_send_sockets(struct work_struct *work)
-{
- if (sctp_con.eagain_flag) {
- sctp_con.eagain_flag = 0;
- refill_write_queue();
- }
- process_output_queue();
-}
-
-// PJC: Process lock requests from a particular node.
-// TODO: can we optimise this out on UP ??
-static void process_lock_request(struct work_struct *work)
-{
-}
-
-static void daemons_stop(void)
-{
- destroy_workqueue(recv_workqueue);
- destroy_workqueue(send_workqueue);
- destroy_workqueue(lock_workqueue);
-}
-
-static int daemons_start(void)
-{
- int error;
- recv_workqueue = create_workqueue("dlm_recv");
- error = IS_ERR(recv_workqueue);
- if (error) {
- log_print("can't start dlm_recv %d", error);
- return error;
- }
-
- send_workqueue = create_singlethread_workqueue("dlm_send");
- error = IS_ERR(send_workqueue);
- if (error) {
- log_print("can't start dlm_send %d", error);
- destroy_workqueue(recv_workqueue);
- return error;
- }
-
- lock_workqueue = create_workqueue("dlm_rlock");
- error = IS_ERR(lock_workqueue);
- if (error) {
- log_print("can't start dlm_rlock %d", error);
- destroy_workqueue(send_workqueue);
- destroy_workqueue(recv_workqueue);
- return error;
- }
-
- return 0;
-}
-
-/*
- * This is quite likely to sleep...
- */
-int dlm_lowcomms_start(void)
-{
- int error;
-
- INIT_WORK(&sctp_con.work, process_recv_sockets);
-
- error = init_sock();
- if (error)
- goto fail_sock;
- error = daemons_start();
- if (error)
- goto fail_sock;
- return 0;
-
-fail_sock:
- close_connection();
- return error;
-}
-
-void dlm_lowcomms_stop(void)
-{
- int i;
-
- sctp_con.flags = 0x7;
- daemons_stop();
- clean_writequeues();
- close_connection();
- dealloc_nodeinfo();
- max_nodeid = 0;
-
- dlm_local_count = 0;
- dlm_local_nodeid = 0;
-
- for (i = 0; i < dlm_local_count; i++)
- kfree(dlm_local_addr[i]);
-}
diff --git a/fs/dlm/lowcomms-tcp.c b/fs/dlm/lowcomms-tcp.c
deleted file mode 100644
index 919e92a..0000000
--- a/fs/dlm/lowcomms-tcp.c
+++ /dev/null
@@ -1,1006 +0,0 @@
-/******************************************************************************
-*******************************************************************************
-**
-** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
-** Copyright (C) 2004-2007 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
-** of the GNU General Public License v.2.
-**
-*******************************************************************************
-******************************************************************************/
-
-/*
- * lowcomms.c
- *
- * This is the "low-level" comms layer.
- *
- * It is responsible for sending/receiving messages
- * from other nodes in the cluster.
- *
- * Cluster nodes are referred to by their nodeids. nodeids are
- * simply 32 bit numbers to the locking module - if they need to
- * be expanded for the cluster infrastructure then that is it's
- * responsibility. It is this layer's
- * responsibility to resolve these into IP address or
- * whatever it needs for inter-node communication.
- *
- * The comms level is two kernel threads that deal mainly with
- * the receiving of messages from other nodes and passing them
- * up to the mid-level comms layer (which understands the
- * message format) for execution by the locking core, and
- * a send thread which does all the setting up of connections
- * to remote nodes and the sending of data. Threads are not allowed
- * to send their own data because it may cause them to wait in times
- * of high load. Also, this way, the sending thread can collect together
- * messages bound for one node and send them in one block.
- *
- * I don't see any problem with the recv thread executing the locking
- * code on behalf of remote processes as the locking code is
- * short, efficient and never waits.
- *
- */
-
-
-#include <asm/ioctls.h>
-#include <net/sock.h>
-#include <net/tcp.h>
-#include <linux/pagemap.h>
-
-#include "dlm_internal.h"
-#include "lowcomms.h"
-#include "midcomms.h"
-#include "config.h"
-
-struct cbuf {
- unsigned int base;
- unsigned int len;
- unsigned int mask;
-};
-
-#define NODE_INCREMENT 32
-static void cbuf_add(struct cbuf *cb, int n)
-{
- cb->len += n;
-}
-
-static int cbuf_data(struct cbuf *cb)
-{
- return ((cb->base + cb->len) & cb->mask);
-}
-
-static void cbuf_init(struct cbuf *cb, int size)
-{
- cb->base = cb->len = 0;
- cb->mask = size-1;
-}
-
-static void cbuf_eat(struct cbuf *cb, int n)
-{
- cb->len -= n;
- cb->base += n;
- cb->base &= cb->mask;
-}
-
-static bool cbuf_empty(struct cbuf *cb)
-{
- return cb->len == 0;
-}
-
-/* Maximum number of incoming messages to process before
- doing a cond_resched()
-*/
-#define MAX_RX_MSG_COUNT 25
-
-struct connection {
- struct socket *sock; /* NULL if not connected */
- uint32_t nodeid; /* So we know who we are in the list */
- struct mutex sock_mutex;
- unsigned long flags; /* bit 1,2 = We are on the read/write lists */
-#define CF_READ_PENDING 1
-#define CF_WRITE_PENDING 2
-#define CF_CONNECT_PENDING 3
-#define CF_IS_OTHERCON 4
- struct list_head writequeue; /* List of outgoing writequeue_entries */
- struct list_head listenlist; /* List of allocated listening sockets */
- spinlock_t writequeue_lock;
- int (*rx_action) (struct connection *); /* What to do when active */
- struct page *rx_page;
- struct cbuf cb;
- int retries;
-#define MAX_CONNECT_RETRIES 3
- struct connection *othercon;
- struct work_struct rwork; /* Receive workqueue */
- struct work_struct swork; /* Send workqueue */
-};
-#define sock2con(x) ((struct connection *)(x)->sk_user_data)
-
-/* An entry waiting to be sent */
-struct writequeue_entry {
- struct list_head list;
- struct page *page;
- int offset;
- int len;
- int end;
- int users;
- struct connection *con;
-};
-
-static struct sockaddr_storage dlm_local_addr;
-
-/* Work queues */
-static struct workqueue_struct *recv_workqueue;
-static struct workqueue_struct *send_workqueue;
-
-/* An array of pointers to connections, indexed by NODEID */
-static struct connection **connections;
-static DECLARE_MUTEX(connections_lock);
-static struct kmem_cache *con_cache;
-static int conn_array_size;
-
-static void process_recv_sockets(struct work_struct *work);
-static void process_send_sockets(struct work_struct *work);
-
-static struct connection *nodeid2con(int nodeid, gfp_t allocation)
-{
- struct connection *con = NULL;
-
- down(&connections_lock);
- if (nodeid >= conn_array_size) {
- int new_size = nodeid + NODE_INCREMENT;
- struct connection **new_conns;
-
- new_conns = kzalloc(sizeof(struct connection *) *
- new_size, allocation);
- if (!new_conns)
- goto finish;
-
- memcpy(new_conns, connections, sizeof(struct connection *) * conn_array_size);
- conn_array_size = new_size;
- kfree(connections);
- connections = new_conns;
-
- }
-
- con = connections[nodeid];
- if (con == NULL && allocation) {
- con = kmem_cache_zalloc(con_cache, allocation);
- if (!con)
- goto finish;
-
- con->nodeid = nodeid;
- mutex_init(&con->sock_mutex);
- INIT_LIST_HEAD(&con->writequeue);
- spin_lock_init(&con->writequeue_lock);
- INIT_WORK(&con->swork, process_send_sockets);
- INIT_WORK(&con->rwork, process_recv_sockets);
-
- connections[nodeid] = con;
- }
-
-finish:
- up(&connections_lock);
- return con;
-}
-
-/* Data available on socket or listen socket received a connect */
-static void lowcomms_data_ready(struct sock *sk, int count_unused)
-{
- struct connection *con = sock2con(sk);
-
- if (!test_and_set_bit(CF_READ_PENDING, &con->flags))
- queue_work(recv_workqueue, &con->rwork);
-}
-
-static void lowcomms_write_space(struct sock *sk)
-{
- struct connection *con = sock2con(sk);
-
- if (!test_and_set_bit(CF_WRITE_PENDING, &con->flags))
- queue_work(send_workqueue, &con->swork);
-}
-
-static inline void lowcomms_connect_sock(struct connection *con)
-{
- if (!test_and_set_bit(CF_CONNECT_PENDING, &con->flags))
- queue_work(send_workqueue, &con->swork);
-}
-
-static void lowcomms_state_change(struct sock *sk)
-{
- if (sk->sk_state == TCP_ESTABLISHED)
- lowcomms_write_space(sk);
-}
-
-/* Make a socket active */
-static int add_sock(struct socket *sock, struct connection *con)
-{
- con->sock = sock;
-
- /* Install a data_ready callback */
- con->sock->sk->sk_data_ready = lowcomms_data_ready;
- con->sock->sk->sk_write_space = lowcomms_write_space;
- con->sock->sk->sk_state_change = lowcomms_state_change;
-
- return 0;
-}
-
-/* Add the port number to an IP6 or 4 sockaddr and return the address
- length */
-static void make_sockaddr(struct sockaddr_storage *saddr, uint16_t port,
- int *addr_len)
-{
- saddr->ss_family = dlm_local_addr.ss_family;
- if (saddr->ss_family == AF_INET) {
- struct sockaddr_in *in4_addr = (struct sockaddr_in *)saddr;
- in4_addr->sin_port = cpu_to_be16(port);
- *addr_len = sizeof(struct sockaddr_in);
- } else {
- struct sockaddr_in6 *in6_addr = (struct sockaddr_in6 *)saddr;
- in6_addr->sin6_port = cpu_to_be16(port);
- *addr_len = sizeof(struct sockaddr_in6);
- }
-}
-
-/* Close a remote connection and tidy up */
-static void close_connection(struct connection *con, bool and_other)
-{
- mutex_lock(&con->sock_mutex);
-
- if (con->sock) {
- sock_release(con->sock);
- con->sock = NULL;
- }
- if (con->othercon && and_other) {
- /* Will only re-enter once. */
- close_connection(con->othercon, false);
- }
- if (con->rx_page) {
- __free_page(con->rx_page);
- con->rx_page = NULL;
- }
- con->retries = 0;
- mutex_unlock(&con->sock_mutex);
-}
-
-/* Data received from remote end */
-static int receive_from_sock(struct connection *con)
-{
- int ret = 0;
- struct msghdr msg = {};
- struct kvec iov[2];
- unsigned len;
- int r;
- int call_again_soon = 0;
- int nvec;
-
- mutex_lock(&con->sock_mutex);
-
- if (con->sock == NULL) {
- ret = -EAGAIN;
- goto out_close;
- }
-
- if (con->rx_page == NULL) {
- /*
- * This doesn't need to be atomic, but I think it should
- * improve performance if it is.
- */
- con->rx_page = alloc_page(GFP_ATOMIC);
- if (con->rx_page == NULL)
- goto out_resched;
- cbuf_init(&con->cb, PAGE_CACHE_SIZE);
- }
-
- /*
- * iov[0] is the bit of the circular buffer between the current end
- * point (cb.base + cb.len) and the end of the buffer.
- */
- iov[0].iov_len = con->cb.base - cbuf_data(&con->cb);
- iov[0].iov_base = page_address(con->rx_page) + cbuf_data(&con->cb);
- iov[1].iov_len = 0;
- nvec = 1;
-
- /*
- * iov[1] is the bit of the circular buffer between the start of the
- * buffer and the start of the currently used section (cb.base)
- */
- if (cbuf_data(&con->cb) >= con->cb.base) {
- iov[0].iov_len = PAGE_CACHE_SIZE - cbuf_data(&con->cb);
- iov[1].iov_len = con->cb.base;
- iov[1].iov_base = page_address(con->rx_page);
- nvec = 2;
- }
- len = iov[0].iov_len + iov[1].iov_len;
-
- r = ret = kernel_recvmsg(con->sock, &msg, iov, nvec, len,
- MSG_DONTWAIT | MSG_NOSIGNAL);
-
- if (ret <= 0)
- goto out_close;
-
- if (ret == len)
- call_again_soon = 1;
- cbuf_add(&con->cb, ret);
- ret = dlm_process_incoming_buffer(con->nodeid,
- page_address(con->rx_page),
- con->cb.base, con->cb.len,
- PAGE_CACHE_SIZE);
- if (ret == -EBADMSG) {
- printk(KERN_INFO "dlm: lowcomms: addr=%p, base=%u, len=%u, "
- "iov_len=%u, iov_base[0]=%p, read=%d\n",
- page_address(con->rx_page), con->cb.base, con->cb.len,
- len, iov[0].iov_base, r);
- }
- if (ret < 0)
- goto out_close;
- cbuf_eat(&con->cb, ret);
-
- if (cbuf_empty(&con->cb) && !call_again_soon) {
- __free_page(con->rx_page);
- con->rx_page = NULL;
- }
-
- if (call_again_soon)
- goto out_resched;
- mutex_unlock(&con->sock_mutex);
- return 0;
-
-out_resched:
- if (!test_and_set_bit(CF_READ_PENDING, &con->flags))
- queue_work(recv_workqueue, &con->rwork);
- mutex_unlock(&con->sock_mutex);
- return -EAGAIN;
-
-out_close:
- mutex_unlock(&con->sock_mutex);
- if (ret != -EAGAIN && !test_bit(CF_IS_OTHERCON, &con->flags)) {
- close_connection(con, false);
- /* Reconnect when there is something to send */
- }
- /* Don't return success if we really got EOF */
- if (ret == 0)
- ret = -EAGAIN;
-
- return ret;
-}
-
-/* Listening socket is busy, accept a connection */
-static int accept_from_sock(struct connection *con)
-{
- int result;
- struct sockaddr_storage peeraddr;
- struct socket *newsock;
- int len;
- int nodeid;
- struct connection *newcon;
- struct connection *addcon;
-
- memset(&peeraddr, 0, sizeof(peeraddr));
- result = sock_create_kern(dlm_local_addr.ss_family, SOCK_STREAM,
- IPPROTO_TCP, &newsock);
- if (result < 0)
- return -ENOMEM;
-
- mutex_lock_nested(&con->sock_mutex, 0);
-
- result = -ENOTCONN;
- if (con->sock == NULL)
- goto accept_err;
-
- newsock->type = con->sock->type;
- newsock->ops = con->sock->ops;
-
- result = con->sock->ops->accept(con->sock, newsock, O_NONBLOCK);
- if (result < 0)
- goto accept_err;
-
- /* Get the connected socket's peer */
- memset(&peeraddr, 0, sizeof(peeraddr));
- if (newsock->ops->getname(newsock, (struct sockaddr *)&peeraddr,
- &len, 2)) {
- result = -ECONNABORTED;
- goto accept_err;
- }
-
- /* Get the new node's NODEID */
- make_sockaddr(&peeraddr, 0, &len);
- if (dlm_addr_to_nodeid(&peeraddr, &nodeid)) {
- printk("dlm: connect from non cluster node\n");
- sock_release(newsock);
- mutex_unlock(&con->sock_mutex);
- return -1;
- }
-
- log_print("got connection from %d", nodeid);
-
- /* Check to see if we already have a connection to this node. This
- * could happen if the two nodes initiate a connection at roughly
- * the same time and the connections cross on the wire.
- * TEMPORARY FIX:
- * In this case we store the incoming one in "othercon"
- */
- newcon = nodeid2con(nodeid, GFP_KERNEL);
- if (!newcon) {
- result = -ENOMEM;
- goto accept_err;
- }
- mutex_lock_nested(&newcon->sock_mutex, 1);
- if (newcon->sock) {
- struct connection *othercon = newcon->othercon;
-
- if (!othercon) {
- othercon = kmem_cache_zalloc(con_cache, GFP_KERNEL);
- if (!othercon) {
- printk("dlm: failed to allocate incoming socket\n");
- mutex_unlock(&newcon->sock_mutex);
- result = -ENOMEM;
- goto accept_err;
- }
- othercon->nodeid = nodeid;
- othercon->rx_action = receive_from_sock;
- mutex_init(&othercon->sock_mutex);
- INIT_WORK(&othercon->swork, process_send_sockets);
- INIT_WORK(&othercon->rwork, process_recv_sockets);
- set_bit(CF_IS_OTHERCON, &othercon->flags);
- newcon->othercon = othercon;
- }
- othercon->sock = newsock;
- newsock->sk->sk_user_data = othercon;
- add_sock(newsock, othercon);
- addcon = othercon;
- }
- else {
- newsock->sk->sk_user_data = newcon;
- newcon->rx_action = receive_from_sock;
- add_sock(newsock, newcon);
- addcon = newcon;
- }
-
- mutex_unlock(&newcon->sock_mutex);
-
- /*
- * Add it to the active queue in case we got data
- * beween processing the accept adding the socket
- * to the read_sockets list
- */
- if (!test_and_set_bit(CF_READ_PENDING, &addcon->flags))
- queue_work(recv_workqueue, &addcon->rwork);
- mutex_unlock(&con->sock_mutex);
-
- return 0;
-
-accept_err:
- mutex_unlock(&con->sock_mutex);
- sock_release(newsock);
-
- if (result != -EAGAIN)
- printk("dlm: error accepting connection from node: %d\n", result);
- return result;
-}
-
-/* Connect a new socket to its peer */
-static void connect_to_sock(struct connection *con)
-{
- int result = -EHOSTUNREACH;
- struct sockaddr_storage saddr;
- int addr_len;
- struct socket *sock;
-
- if (con->nodeid == 0) {
- log_print("attempt to connect sock 0 foiled");
- return;
- }
-
- mutex_lock(&con->sock_mutex);
- if (con->retries++ > MAX_CONNECT_RETRIES)
- goto out;
-
- /* Some odd races can cause double-connects, ignore them */
- if (con->sock) {
- result = 0;
- goto out;
- }
-
- /* Create a socket to communicate with */
- result = sock_create_kern(dlm_local_addr.ss_family, SOCK_STREAM,
- IPPROTO_TCP, &sock);
- if (result < 0)
- goto out_err;
-
- memset(&saddr, 0, sizeof(saddr));
- if (dlm_nodeid_to_addr(con->nodeid, &saddr))
- goto out_err;
-
- sock->sk->sk_user_data = con;
- con->rx_action = receive_from_sock;
-
- make_sockaddr(&saddr, dlm_config.ci_tcp_port, &addr_len);
-
- add_sock(sock, con);
-
- log_print("connecting to %d", con->nodeid);
- result =
- sock->ops->connect(sock, (struct sockaddr *)&saddr, addr_len,
- O_NONBLOCK);
- if (result == -EINPROGRESS)
- result = 0;
- if (result == 0)
- goto out;
-
-out_err:
- if (con->sock) {
- sock_release(con->sock);
- con->sock = NULL;
- }
- /*
- * Some errors are fatal and this list might need adjusting. For other
- * errors we try again until the max number of retries is reached.
- */
- if (result != -EHOSTUNREACH && result != -ENETUNREACH &&
- result != -ENETDOWN && result != EINVAL
- && result != -EPROTONOSUPPORT) {
- lowcomms_connect_sock(con);
- result = 0;
- }
-out:
- mutex_unlock(&con->sock_mutex);
- return;
-}
-
-static struct socket *create_listen_sock(struct connection *con,
- struct sockaddr_storage *saddr)
-{
- struct socket *sock = NULL;
- mm_segment_t fs;
- int result = 0;
- int one = 1;
- int addr_len;
-
- if (dlm_local_addr.ss_family == AF_INET)
- addr_len = sizeof(struct sockaddr_in);
- else
- addr_len = sizeof(struct sockaddr_in6);
-
- /* Create a socket to communicate with */
- result = sock_create_kern(dlm_local_addr.ss_family, SOCK_STREAM, IPPROTO_TCP, &sock);
- if (result < 0) {
- printk("dlm: Can't create listening comms socket\n");
- goto create_out;
- }
-
- fs = get_fs();
- set_fs(get_ds());
- result = sock_setsockopt(sock, SOL_SOCKET, SO_REUSEADDR,
- (char *)&one, sizeof(one));
- set_fs(fs);
- if (result < 0) {
- printk("dlm: Failed to set SO_REUSEADDR on socket: result=%d\n",
- result);
- }
- sock->sk->sk_user_data = con;
- con->rx_action = accept_from_sock;
- con->sock = sock;
-
- /* Bind to our port */
- make_sockaddr(saddr, dlm_config.ci_tcp_port, &addr_len);
- result = sock->ops->bind(sock, (struct sockaddr *) saddr, addr_len);
- if (result < 0) {
- printk("dlm: Can't bind to port %d\n", dlm_config.ci_tcp_port);
- sock_release(sock);
- sock = NULL;
- con->sock = NULL;
- goto create_out;
- }
-
- fs = get_fs();
- set_fs(get_ds());
-
- result = sock_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
- (char *)&one, sizeof(one));
- set_fs(fs);
- if (result < 0) {
- printk("dlm: Set keepalive failed: %d\n", result);
- }
-
- result = sock->ops->listen(sock, 5);
- if (result < 0) {
- printk("dlm: Can't listen on port %d\n", dlm_config.ci_tcp_port);
- sock_release(sock);
- sock = NULL;
- goto create_out;
- }
-
-create_out:
- return sock;
-}
-
-
-/* Listen on all interfaces */
-static int listen_for_all(void)
-{
- struct socket *sock = NULL;
- struct connection *con = nodeid2con(0, GFP_KERNEL);
- int result = -EINVAL;
-
- /* We don't support multi-homed hosts */
- set_bit(CF_IS_OTHERCON, &con->flags);
-
- sock = create_listen_sock(con, &dlm_local_addr);
- if (sock) {
- add_sock(sock, con);
- result = 0;
- }
- else {
- result = -EADDRINUSE;
- }
-
- return result;
-}
-
-
-
-static struct writequeue_entry *new_writequeue_entry(struct connection *con,
- gfp_t allocation)
-{
- struct writequeue_entry *entry;
-
- entry = kmalloc(sizeof(struct writequeue_entry), allocation);
- if (!entry)
- return NULL;
-
- entry->page = alloc_page(allocation);
- if (!entry->page) {
- kfree(entry);
- return NULL;
- }
-
- entry->offset = 0;
- entry->len = 0;
- entry->end = 0;
- entry->users = 0;
- entry->con = con;
-
- return entry;
-}
-
-void *dlm_lowcomms_get_buffer(int nodeid, int len,
- gfp_t allocation, char **ppc)
-{
- struct connection *con;
- struct writequeue_entry *e;
- int offset = 0;
- int users = 0;
-
- con = nodeid2con(nodeid, allocation);
- if (!con)
- return NULL;
-
- spin_lock(&con->writequeue_lock);
- e = list_entry(con->writequeue.prev, struct writequeue_entry, list);
- if ((&e->list == &con->writequeue) ||
- (PAGE_CACHE_SIZE - e->end < len)) {
- e = NULL;
- } else {
- offset = e->end;
- e->end += len;
- users = e->users++;
- }
- spin_unlock(&con->writequeue_lock);
-
- if (e) {
- got_one:
- if (users == 0)
- kmap(e->page);
- *ppc = page_address(e->page) + offset;
- return e;
- }
-
- e = new_writequeue_entry(con, allocation);
- if (e) {
- spin_lock(&con->writequeue_lock);
- offset = e->end;
- e->end += len;
- users = e->users++;
- list_add_tail(&e->list, &con->writequeue);
- spin_unlock(&con->writequeue_lock);
- goto got_one;
- }
- return NULL;
-}
-
-void dlm_lowcomms_commit_buffer(void *mh)
-{
- struct writequeue_entry *e = (struct writequeue_entry *)mh;
- struct connection *con = e->con;
- int users;
-
- spin_lock(&con->writequeue_lock);
- users = --e->users;
- if (users)
- goto out;
- e->len = e->end - e->offset;
- kunmap(e->page);
- spin_unlock(&con->writequeue_lock);
-
- if (!test_and_set_bit(CF_WRITE_PENDING, &con->flags)) {
- queue_work(send_workqueue, &con->swork);
- }
- return;
-
-out:
- spin_unlock(&con->writequeue_lock);
- return;
-}
-
-static void free_entry(struct writequeue_entry *e)
-{
- __free_page(e->page);
- kfree(e);
-}
-
-/* Send a message */
-static void send_to_sock(struct connection *con)
-{
- int ret = 0;
- ssize_t(*sendpage) (struct socket *, struct page *, int, size_t, int);
- const int msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL;
- struct writequeue_entry *e;
- int len, offset;
-
- mutex_lock(&con->sock_mutex);
- if (con->sock == NULL)
- goto out_connect;
-
- sendpage = con->sock->ops->sendpage;
-
- spin_lock(&con->writequeue_lock);
- for (;;) {
- e = list_entry(con->writequeue.next, struct writequeue_entry,
- list);
- if ((struct list_head *) e == &con->writequeue)
- break;
-
- len = e->len;
- offset = e->offset;
- BUG_ON(len == 0 && e->users == 0);
- spin_unlock(&con->writequeue_lock);
- kmap(e->page);
-
- ret = 0;
- if (len) {
- ret = sendpage(con->sock, e->page, offset, len,
- msg_flags);
- if (ret == -EAGAIN || ret == 0)
- goto out;
- if (ret <= 0)
- goto send_error;
- }
- else {
- /* Don't starve people filling buffers */
- cond_resched();
- }
-
- spin_lock(&con->writequeue_lock);
- e->offset += ret;
- e->len -= ret;
-
- if (e->len == 0 && e->users == 0) {
- list_del(&e->list);
- kunmap(e->page);
- free_entry(e);
- continue;
- }
- }
- spin_unlock(&con->writequeue_lock);
-out:
- mutex_unlock(&con->sock_mutex);
- return;
-
-send_error:
- mutex_unlock(&con->sock_mutex);
- close_connection(con, false);
- lowcomms_connect_sock(con);
- return;
-
-out_connect:
- mutex_unlock(&con->sock_mutex);
- connect_to_sock(con);
- return;
-}
-
-static void clean_one_writequeue(struct connection *con)
-{
- struct list_head *list;
- struct list_head *temp;
-
- 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_del(&e->list);
- free_entry(e);
- }
- spin_unlock(&con->writequeue_lock);
-}
-
-/* Called from recovery when it knows that a node has
- left the cluster */
-int dlm_lowcomms_close(int nodeid)
-{
- struct connection *con;
-
- if (!connections)
- goto out;
-
- log_print("closing connection to node %d", nodeid);
- con = nodeid2con(nodeid, 0);
- if (con) {
- clean_one_writequeue(con);
- close_connection(con, true);
- }
- return 0;
-
-out:
- return -1;
-}
-
-/* Look for activity on active sockets */
-static void process_recv_sockets(struct work_struct *work)
-{
- struct connection *con = container_of(work, struct connection, rwork);
- int err;
-
- clear_bit(CF_READ_PENDING, &con->flags);
- do {
- err = con->rx_action(con);
- } while (!err);
-}
-
-
-static void process_send_sockets(struct work_struct *work)
-{
- struct connection *con = container_of(work, struct connection, swork);
-
- if (test_and_clear_bit(CF_CONNECT_PENDING, &con->flags)) {
- connect_to_sock(con);
- }
-
- clear_bit(CF_WRITE_PENDING, &con->flags);
- send_to_sock(con);
-}
-
-
-/* Discard all entries on the write queues */
-static void clean_writequeues(void)
-{
- int nodeid;
-
- for (nodeid = 1; nodeid < conn_array_size; nodeid++) {
- struct connection *con = nodeid2con(nodeid, 0);
-
- if (con)
- clean_one_writequeue(con);
- }
-}
-
-static void work_stop(void)
-{
- destroy_workqueue(recv_workqueue);
- destroy_workqueue(send_workqueue);
-}
-
-static int work_start(void)
-{
- int error;
- recv_workqueue = create_workqueue("dlm_recv");
- error = IS_ERR(recv_workqueue);
- if (error) {
- log_print("can't start dlm_recv %d", error);
- return error;
- }
-
- send_workqueue = create_singlethread_workqueue("dlm_send");
- error = IS_ERR(send_workqueue);
- if (error) {
- log_print("can't start dlm_send %d", error);
- destroy_workqueue(recv_workqueue);
- return error;
- }
-
- return 0;
-}
-
-void dlm_lowcomms_stop(void)
-{
- int i;
-
- /* Set all the flags to prevent any
- socket activity.
- */
- for (i = 0; i < conn_array_size; i++) {
- if (connections[i])
- connections[i]->flags |= 0xFF;
- }
-
- work_stop();
- clean_writequeues();
-
- for (i = 0; i < conn_array_size; i++) {
- if (connections[i]) {
- close_connection(connections[i], true);
- if (connections[i]->othercon)
- kmem_cache_free(con_cache, connections[i]->othercon);
- kmem_cache_free(con_cache, connections[i]);
- }
- }
-
- kfree(connections);
- connections = NULL;
-
- kmem_cache_destroy(con_cache);
-}
-
-/* This is quite likely to sleep... */
-int dlm_lowcomms_start(void)
-{
- int error = 0;
-
- error = -ENOMEM;
- connections = kzalloc(sizeof(struct connection *) *
- NODE_INCREMENT, GFP_KERNEL);
- if (!connections)
- goto out;
-
- conn_array_size = NODE_INCREMENT;
-
- if (dlm_our_addr(&dlm_local_addr, 0)) {
- log_print("no local IP address has been set");
- goto fail_free_conn;
- }
- if (!dlm_our_addr(&dlm_local_addr, 1)) {
- log_print("This dlm comms module does not support multi-homed clustering");
- goto fail_free_conn;
- }
-
- con_cache = kmem_cache_create("dlm_conn", sizeof(struct connection),
- __alignof__(struct connection), 0,
- NULL, NULL);
- if (!con_cache)
- goto fail_free_conn;
-
-
- /* Start listening */
- error = listen_for_all();
- if (error)
- goto fail_unlisten;
-
- error = work_start();
- if (error)
- goto fail_unlisten;
-
- return 0;
-
-fail_unlisten:
- close_connection(connections[0], false);
- kmem_cache_free(con_cache, connections[0]);
- kmem_cache_destroy(con_cache);
-
-fail_free_conn:
- kfree(connections);
-
-out:
- return error;
-}
-
-/*
- * Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only. This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */
diff --git a/fs/dlm/lowcomms.c b/fs/dlm/lowcomms.c
new file mode 100644
index 0000000..76399b7
--- /dev/null
+++ b/fs/dlm/lowcomms.c
@@ -0,0 +1,1468 @@
+/******************************************************************************
+*******************************************************************************
+**
+** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
+** Copyright (C) 2004-2007 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
+** of the GNU General Public License v.2.
+**
+*******************************************************************************
+******************************************************************************/
+
+/*
+ * lowcomms.c
+ *
+ * This is the "low-level" comms layer.
+ *
+ * It is responsible for sending/receiving messages
+ * from other nodes in the cluster.
+ *
+ * Cluster nodes are referred to by their nodeids. nodeids are
+ * simply 32 bit numbers to the locking module - if they need to
+ * be expanded for the cluster infrastructure then that is it's
+ * responsibility. It is this layer's
+ * responsibility to resolve these into IP address or
+ * whatever it needs for inter-node communication.
+ *
+ * The comms level is two kernel threads that deal mainly with
+ * the receiving of messages from other nodes and passing them
+ * up to the mid-level comms layer (which understands the
+ * message format) for execution by the locking core, and
+ * a send thread which does all the setting up of connections
+ * to remote nodes and the sending of data. Threads are not allowed
+ * to send their own data because it may cause them to wait in times
+ * of high load. Also, this way, the sending thread can collect together
+ * messages bound for one node and send them in one block.
+ *
+ * lowcomms will choose to use wither TCP or SCTP as its transport layer
+ * depending on the configuration variable 'protocol'. This should be set
+ * to 0 (default) for TCP or 1 for SCTP. It shouldbe configured using a
+ * cluster-wide mechanism as it must be the same on all nodes of the cluster
+ * for the DLM to function.
+ *
+ */
+
+#include <asm/ioctls.h>
+#include <net/sock.h>
+#include <net/tcp.h>
+#include <linux/pagemap.h>
+#include <linux/idr.h>
+#include <linux/file.h>
+#include <linux/sctp.h>
+#include <net/sctp/user.h>
+
+#include "dlm_internal.h"
+#include "lowcomms.h"
+#include "midcomms.h"
+#include "config.h"
+
+#define NEEDED_RMEM (4*1024*1024)
+
+struct cbuf {
+ unsigned int base;
+ unsigned int len;
+ unsigned int mask;
+};
+
+static void cbuf_add(struct cbuf *cb, int n)
+{
+ cb->len += n;
+}
+
+static int cbuf_data(struct cbuf *cb)
+{
+ return ((cb->base + cb->len) & cb->mask);
+}
+
+static void cbuf_init(struct cbuf *cb, int size)
+{
+ cb->base = cb->len = 0;
+ cb->mask = size-1;
+}
+
+static void cbuf_eat(struct cbuf *cb, int n)
+{
+ cb->len -= n;
+ cb->base += n;
+ cb->base &= cb->mask;
+}
+
+static bool cbuf_empty(struct cbuf *cb)
+{
+ return cb->len == 0;
+}
+
+struct connection {
+ struct socket *sock; /* NULL if not connected */
+ uint32_t nodeid; /* So we know who we are in the list */
+ struct mutex sock_mutex;
+ unsigned long flags;
+#define CF_READ_PENDING 1
+#define CF_WRITE_PENDING 2
+#define CF_CONNECT_PENDING 3
+#define CF_INIT_PENDING 4
+#define CF_IS_OTHERCON 5
+ struct list_head writequeue; /* List of outgoing writequeue_entries */
+ spinlock_t writequeue_lock;
+ int (*rx_action) (struct connection *); /* What to do when active */
+ void (*connect_action) (struct connection *); /* What to do to connect */
+ struct page *rx_page;
+ struct cbuf cb;
+ int retries;
+#define MAX_CONNECT_RETRIES 3
+ int sctp_assoc;
+ struct connection *othercon;
+ struct work_struct rwork; /* Receive workqueue */
+ struct work_struct swork; /* Send workqueue */
+};
+#define sock2con(x) ((struct connection *)(x)->sk_user_data)
+
+/* An entry waiting to be sent */
+struct writequeue_entry {
+ struct list_head list;
+ struct page *page;
+ int offset;
+ int len;
+ int end;
+ int users;
+ struct connection *con;
+};
+
+static struct sockaddr_storage *dlm_local_addr[DLM_MAX_ADDR_COUNT];
+static int dlm_local_count;
+
+/* Work queues */
+static struct workqueue_struct *recv_workqueue;
+static struct workqueue_struct *send_workqueue;
+
+static DEFINE_IDR(connections_idr);
+static DECLARE_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);
+
+/*
+ * If 'allocation' is zero then we don't attempt to create a new
+ * connection structure for this node.
+ */
+static struct connection *__nodeid2con(int nodeid, gfp_t alloc)
+{
+ struct connection *con = NULL;
+ int r;
+ int n;
+
+ con = idr_find(&connections_idr, 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;
+ }
+
+ con->nodeid = nodeid;
+ mutex_init(&con->sock_mutex);
+ INIT_LIST_HEAD(&con->writequeue);
+ spin_lock_init(&con->writequeue_lock);
+ INIT_WORK(&con->swork, process_send_sockets);
+ INIT_WORK(&con->rwork, process_recv_sockets);
+
+ /* Setup action pointers for child sockets */
+ if (con->nodeid) {
+ struct connection *zerocon = idr_find(&connections_idr, 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;
+}
+
+static struct connection *nodeid2con(int nodeid, gfp_t allocation)
+{
+ struct connection *con;
+
+ down(&connections_lock);
+ con = __nodeid2con(nodeid, allocation);
+ up(&connections_lock);
+
+ return con;
+}
+
+/* This is a bit drastic, but only called when things go wrong */
+static struct connection *assoc2con(int assoc_id)
+{
+ int i;
+ struct connection *con;
+
+ down(&connections_lock);
+ for (i=0; i<max_nodeid; i++) {
+ con = __nodeid2con(i, 0);
+ if (con && con->sctp_assoc == assoc_id) {
+ up(&connections_lock);
+ return con;
+ }
+ }
+ up(&connections_lock);
+ return NULL;
+}
+
+static int nodeid_to_addr(int nodeid, struct sockaddr *retaddr)
+{
+ struct sockaddr_storage addr;
+ int error;
+
+ if (!dlm_local_count)
+ return -1;
+
+ error = dlm_nodeid_to_addr(nodeid, &addr);
+ if (error)
+ return error;
+
+ if (dlm_local_addr[0]->ss_family == AF_INET) {
+ struct sockaddr_in *in4 = (struct sockaddr_in *) &addr;
+ struct sockaddr_in *ret4 = (struct sockaddr_in *) retaddr;
+ ret4->sin_addr.s_addr = in4->sin_addr.s_addr;
+ } else {
+ struct sockaddr_in6 *in6 = (struct sockaddr_in6 *) &addr;
+ struct sockaddr_in6 *ret6 = (struct sockaddr_in6 *) retaddr;
+ memcpy(&ret6->sin6_addr, &in6->sin6_addr,
+ sizeof(in6->sin6_addr));
+ }
+
+ return 0;
+}
+
+/* Data available on socket or listen socket received a connect */
+static void lowcomms_data_ready(struct sock *sk, int count_unused)
+{
+ struct connection *con = sock2con(sk);
+ if (!test_and_set_bit(CF_READ_PENDING, &con->flags))
+ queue_work(recv_workqueue, &con->rwork);
+}
+
+static void lowcomms_write_space(struct sock *sk)
+{
+ struct connection *con = sock2con(sk);
+
+ if (!test_and_set_bit(CF_WRITE_PENDING, &con->flags))
+ queue_work(send_workqueue, &con->swork);
+}
+
+static inline void lowcomms_connect_sock(struct connection *con)
+{
+ if (!test_and_set_bit(CF_CONNECT_PENDING, &con->flags))
+ queue_work(send_workqueue, &con->swork);
+}
+
+static void lowcomms_state_change(struct sock *sk)
+{
+ if (sk->sk_state == TCP_ESTABLISHED)
+ lowcomms_write_space(sk);
+}
+
+/* Make a socket active */
+static int add_sock(struct socket *sock, struct connection *con)
+{
+ con->sock = sock;
+
+ /* Install a data_ready callback */
+ con->sock->sk->sk_data_ready = lowcomms_data_ready;
+ con->sock->sk->sk_write_space = lowcomms_write_space;
+ con->sock->sk->sk_state_change = lowcomms_state_change;
+ con->sock->sk->sk_user_data = con;
+ return 0;
+}
+
+/* Add the port number to an IPv6 or 4 sockaddr and return the address
+ length */
+static void make_sockaddr(struct sockaddr_storage *saddr, uint16_t port,
+ int *addr_len)
+{
+ saddr->ss_family = dlm_local_addr[0]->ss_family;
+ if (saddr->ss_family == AF_INET) {
+ struct sockaddr_in *in4_addr = (struct sockaddr_in *)saddr;
+ in4_addr->sin_port = cpu_to_be16(port);
+ *addr_len = sizeof(struct sockaddr_in);
+ memset(&in4_addr->sin_zero, 0, sizeof(in4_addr->sin_zero));
+ } else {
+ struct sockaddr_in6 *in6_addr = (struct sockaddr_in6 *)saddr;
+ in6_addr->sin6_port = cpu_to_be16(port);
+ *addr_len = sizeof(struct sockaddr_in6);
+ }
+}
+
+/* Close a remote connection and tidy up */
+static void close_connection(struct connection *con, bool and_other)
+{
+ mutex_lock(&con->sock_mutex);
+
+ if (con->sock) {
+ sock_release(con->sock);
+ con->sock = NULL;
+ }
+ if (con->othercon && and_other) {
+ /* Will only re-enter once. */
+ close_connection(con->othercon, false);
+ }
+ if (con->rx_page) {
+ __free_page(con->rx_page);
+ con->rx_page = NULL;
+ }
+ con->retries = 0;
+ mutex_unlock(&con->sock_mutex);
+}
+
+/* We only send shutdown messages to nodes that are not part of the cluster */
+static void sctp_send_shutdown(sctp_assoc_t associd)
+{
+ static char outcmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))];
+ struct msghdr outmessage;
+ struct cmsghdr *cmsg;
+ struct sctp_sndrcvinfo *sinfo;
+ int ret;
+ struct connection *con;
+
+ con = nodeid2con(0,0);
+ BUG_ON(con == NULL);
+
+ outmessage.msg_name = NULL;
+ outmessage.msg_namelen = 0;
+ outmessage.msg_control = outcmsg;
+ outmessage.msg_controllen = sizeof(outcmsg);
+ outmessage.msg_flags = MSG_EOR;
+
+ cmsg = CMSG_FIRSTHDR(&outmessage);
+ cmsg->cmsg_level = IPPROTO_SCTP;
+ cmsg->cmsg_type = SCTP_SNDRCV;
+ cmsg->cmsg_len = CMSG_LEN(sizeof(struct sctp_sndrcvinfo));
+ outmessage.msg_controllen = cmsg->cmsg_len;
+ sinfo = CMSG_DATA(cmsg);
+ memset(sinfo, 0x00, sizeof(struct sctp_sndrcvinfo));
+
+ sinfo->sinfo_flags |= MSG_EOF;
+ sinfo->sinfo_assoc_id = associd;
+
+ ret = kernel_sendmsg(con->sock, &outmessage, NULL, 0, 0);
+
+ if (ret != 0)
+ log_print("send EOF to node failed: %d", ret);
+}
+
+/* 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;
+
+ down(&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);
+ }
+ }
+ }
+ up(&connections_lock);
+}
+
+/* Something happened to an association */
+static void process_sctp_notification(struct connection *con, struct msghdr *msg, char *buf)
+{
+ union sctp_notification *sn = (union sctp_notification *)buf;
+
+ if (sn->sn_header.sn_type == SCTP_ASSOC_CHANGE) {
+ switch (sn->sn_assoc_change.sac_state) {
+
+ case SCTP_COMM_UP:
+ case SCTP_RESTART:
+ {
+ /* Check that the new node is in the lockspace */
+ struct sctp_prim prim;
+ int nodeid;
+ int prim_len, ret;
+ int addr_len;
+ struct connection *new_con;
+ struct file *file;
+ sctp_peeloff_arg_t parg;
+ int parglen = sizeof(parg);
+
+ /*
+ * We get this before any data for an association.
+ * We verify that the node is in the cluster and
+ * then peel off a socket for it.
+ */
+ if ((int)sn->sn_assoc_change.sac_assoc_id <= 0) {
+ log_print("COMM_UP for invalid assoc ID %d",
+ (int)sn->sn_assoc_change.sac_assoc_id);
+ sctp_init_failed();
+ return;
+ }
+ memset(&prim, 0, sizeof(struct sctp_prim));
+ prim_len = sizeof(struct sctp_prim);
+ prim.ssp_assoc_id = sn->sn_assoc_change.sac_assoc_id;
+
+ ret = kernel_getsockopt(con->sock,
+ IPPROTO_SCTP,
+ SCTP_PRIMARY_ADDR,
+ (char*)&prim,
+ &prim_len);
+ if (ret < 0) {
+ log_print("getsockopt/sctp_primary_addr on "
+ "new assoc %d failed : %d",
+ (int)sn->sn_assoc_change.sac_assoc_id,
+ ret);
+
+ /* Retry INIT later */
+ new_con = assoc2con(sn->sn_assoc_change.sac_assoc_id);
+ if (new_con)
+ clear_bit(CF_CONNECT_PENDING, &con->flags);
+ return;
+ }
+ make_sockaddr(&prim.ssp_addr, 0, &addr_len);
+ if (dlm_addr_to_nodeid(&prim.ssp_addr, &nodeid)) {
+ int i;
+ unsigned char *b=(unsigned char *)&prim.ssp_addr;
+ log_print("reject connect from unknown addr");
+ for (i=0; i<sizeof(struct sockaddr_storage);i++)
+ printk("%02x ", b[i]);
+ printk("\n");
+ sctp_send_shutdown(prim.ssp_assoc_id);
+ return;
+ }
+
+ new_con = nodeid2con(nodeid, GFP_KERNEL);
+ if (!new_con)
+ return;
+
+ /* Peel off a new sock */
+ parg.associd = sn->sn_assoc_change.sac_assoc_id;
+ ret = kernel_getsockopt(con->sock, IPPROTO_SCTP, SCTP_SOCKOPT_PEELOFF,
+ (void *)&parg, &parglen);
+ if (ret < 0) {
+ log_print("Can't peel off a socket for connection %d to node %d: err=%d\n",
+ parg.associd, nodeid, ret);
+ return;
+ }
+
+ file = fget(parg.sd);
+ new_con->sock = SOCKET_I(file->f_dentry->d_inode);
+ add_sock(new_con->sock, new_con);
+ fput(file);
+ put_unused_fd(parg.sd);
+
+ log_print("got new/restarted association %d nodeid %d",
+ (int)sn->sn_assoc_change.sac_assoc_id, nodeid);
+
+ /* Send any pending writes */
+ clear_bit(CF_CONNECT_PENDING, &new_con->flags);
+ clear_bit(CF_INIT_PENDING, &con->flags);
+ if (!test_and_set_bit(CF_WRITE_PENDING, &new_con->flags)) {
+ queue_work(send_workqueue, &new_con->swork);
+ }
+ if (!test_and_set_bit(CF_READ_PENDING, &new_con->flags))
+ queue_work(recv_workqueue, &new_con->rwork);
+ }
+ break;
+
+ case SCTP_COMM_LOST:
+ case SCTP_SHUTDOWN_COMP:
+ {
+ con = assoc2con(sn->sn_assoc_change.sac_assoc_id);
+ if (con) {
+ con->sctp_assoc = 0;
+ }
+ }
+ break;
+
+ /* We don't know which INIT failed, so clear the PENDING flags
+ * on them all. if assoc_id is zero then it will then try
+ * again */
+
+ case SCTP_CANT_STR_ASSOC:
+ {
+ log_print("Can't start SCTP association - retrying");
+ sctp_init_failed();
+ }
+ break;
+
+ default:
+ log_print("unexpected SCTP assoc change id=%d state=%d",
+ (int)sn->sn_assoc_change.sac_assoc_id,
+ sn->sn_assoc_change.sac_state);
+ }
+ }
+}
+
+/* Data received from remote end */
+static int receive_from_sock(struct connection *con)
+{
+ int ret = 0;
+ struct msghdr msg = {};
+ struct kvec iov[2];
+ unsigned len;
+ int r;
+ int call_again_soon = 0;
+ int nvec;
+ char incmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))];
+
+ mutex_lock(&con->sock_mutex);
+
+ if (con->sock == NULL) {
+ ret = -EAGAIN;
+ goto out_close;
+ }
+
+ if (con->rx_page == NULL) {
+ /*
+ * This doesn't need to be atomic, but I think it should
+ * improve performance if it is.
+ */
+ con->rx_page = alloc_page(GFP_ATOMIC);
+ if (con->rx_page == NULL)
+ goto out_resched;
+ cbuf_init(&con->cb, PAGE_CACHE_SIZE);
+ }
+
+ /* Only SCTP needs these really */
+ memset(&incmsg, 0, sizeof(incmsg));
+ msg.msg_control = incmsg;
+ msg.msg_controllen = sizeof(incmsg);
+
+ /*
+ * iov[0] is the bit of the circular buffer between the current end
+ * point (cb.base + cb.len) and the end of the buffer.
+ */
+ iov[0].iov_len = con->cb.base - cbuf_data(&con->cb);
+ iov[0].iov_base = page_address(con->rx_page) + cbuf_data(&con->cb);
+ iov[1].iov_len = 0;
+ nvec = 1;
+
+ /*
+ * iov[1] is the bit of the circular buffer between the start of the
+ * buffer and the start of the currently used section (cb.base)
+ */
+ if (cbuf_data(&con->cb) >= con->cb.base) {
+ iov[0].iov_len = PAGE_CACHE_SIZE - cbuf_data(&con->cb);
+ iov[1].iov_len = con->cb.base;
+ iov[1].iov_base = page_address(con->rx_page);
+ nvec = 2;
+ }
+ len = iov[0].iov_len + iov[1].iov_len;
+
+ r = ret = kernel_recvmsg(con->sock, &msg, iov, nvec, len,
+ MSG_DONTWAIT | MSG_NOSIGNAL);
+ if (ret <= 0)
+ goto out_close;
+
+ /* Process SCTP notifications */
+ if (msg.msg_flags & MSG_NOTIFICATION) {
+ BUG_ON(con->nodeid != 0);
+ msg.msg_control = incmsg;
+ msg.msg_controllen = sizeof(incmsg);
+
+ process_sctp_notification(con, &msg,
+ page_address(con->rx_page) + con->cb.base);
+ mutex_unlock(&con->sock_mutex);
+ return 0;
+ }
+ BUG_ON(con->nodeid == 0);
+
+ if (ret == len)
+ call_again_soon = 1;
+ cbuf_add(&con->cb, ret);
+ ret = dlm_process_incoming_buffer(con->nodeid,
+ page_address(con->rx_page),
+ con->cb.base, con->cb.len,
+ PAGE_CACHE_SIZE);
+ if (ret == -EBADMSG) {
+ printk(KERN_INFO "dlm: lowcomms: addr=%p, base=%u, len=%u, "
+ "iov_len=%u, iov_base[0]=%p, read=%d\n",
+ page_address(con->rx_page), con->cb.base, con->cb.len,
+ len, iov[0].iov_base, r);
+ }
+ if (ret < 0)
+ goto out_close;
+ cbuf_eat(&con->cb, ret);
+
+ if (cbuf_empty(&con->cb) && !call_again_soon) {
+ __free_page(con->rx_page);
+ con->rx_page = NULL;
+ }
+
+ if (call_again_soon)
+ goto out_resched;
+ mutex_unlock(&con->sock_mutex);
+ return 0;
+
+out_resched:
+ if (!test_and_set_bit(CF_READ_PENDING, &con->flags))
+ queue_work(recv_workqueue, &con->rwork);
+ mutex_unlock(&con->sock_mutex);
+ return -EAGAIN;
+
+out_close:
+ mutex_unlock(&con->sock_mutex);
+ if (ret != -EAGAIN && !test_bit(CF_IS_OTHERCON, &con->flags)) {
+ close_connection(con, false);
+ /* Reconnect when there is something to send */
+ }
+ /* Don't return success if we really got EOF */
+ if (ret == 0)
+ ret = -EAGAIN;
+
+ return ret;
+}
+
+/* Listening socket is busy, accept a connection */
+static int tcp_accept_from_sock(struct connection *con)
+{
+ int result;
+ struct sockaddr_storage peeraddr;
+ struct socket *newsock;
+ int len;
+ int nodeid;
+ struct connection *newcon;
+ struct connection *addcon;
+
+ memset(&peeraddr, 0, sizeof(peeraddr));
+ result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_STREAM,
+ IPPROTO_TCP, &newsock);
+ if (result < 0)
+ return -ENOMEM;
+
+ mutex_lock_nested(&con->sock_mutex, 0);
+
+ result = -ENOTCONN;
+ if (con->sock == NULL)
+ goto accept_err;
+
+ newsock->type = con->sock->type;
+ newsock->ops = con->sock->ops;
+
+ result = con->sock->ops->accept(con->sock, newsock, O_NONBLOCK);
+ if (result < 0)
+ goto accept_err;
+
+ /* Get the connected socket's peer */
+ memset(&peeraddr, 0, sizeof(peeraddr));
+ if (newsock->ops->getname(newsock, (struct sockaddr *)&peeraddr,
+ &len, 2)) {
+ result = -ECONNABORTED;
+ goto accept_err;
+ }
+
+ /* Get the new node's NODEID */
+ make_sockaddr(&peeraddr, 0, &len);
+ if (dlm_addr_to_nodeid(&peeraddr, &nodeid)) {
+ printk("dlm: connect from non cluster node\n");
+ sock_release(newsock);
+ mutex_unlock(&con->sock_mutex);
+ return -1;
+ }
+
+ log_print("got connection from %d", nodeid);
+
+ /* Check to see if we already have a connection to this node. This
+ * could happen if the two nodes initiate a connection at roughly
+ * the same time and the connections cross on the wire.
+ * In this case we store the incoming one in "othercon"
+ */
+ newcon = nodeid2con(nodeid, GFP_KERNEL);
+ if (!newcon) {
+ result = -ENOMEM;
+ goto accept_err;
+ }
+ mutex_lock_nested(&newcon->sock_mutex, 1);
+ if (newcon->sock) {
+ struct connection *othercon = newcon->othercon;
+
+ if (!othercon) {
+ othercon = kmem_cache_zalloc(con_cache, GFP_KERNEL);
+ if (!othercon) {
+ printk("dlm: failed to allocate incoming socket\n");
+ mutex_unlock(&newcon->sock_mutex);
+ result = -ENOMEM;
+ goto accept_err;
+ }
+ othercon->nodeid = nodeid;
+ othercon->rx_action = receive_from_sock;
+ mutex_init(&othercon->sock_mutex);
+ INIT_WORK(&othercon->swork, process_send_sockets);
+ INIT_WORK(&othercon->rwork, process_recv_sockets);
+ set_bit(CF_IS_OTHERCON, &othercon->flags);
+ newcon->othercon = othercon;
+ }
+ othercon->sock = newsock;
+ newsock->sk->sk_user_data = othercon;
+ add_sock(newsock, othercon);
+ addcon = othercon;
+ }
+ else {
+ newsock->sk->sk_user_data = newcon;
+ newcon->rx_action = receive_from_sock;
+ add_sock(newsock, newcon);
+ addcon = newcon;
+ }
+
+ mutex_unlock(&newcon->sock_mutex);
+
+ /*
+ * Add it to the active queue in case we got data
+ * beween processing the accept adding the socket
+ * to the read_sockets list
+ */
+ if (!test_and_set_bit(CF_READ_PENDING, &addcon->flags))
+ queue_work(recv_workqueue, &addcon->rwork);
+ mutex_unlock(&con->sock_mutex);
+
+ return 0;
+
+accept_err:
+ mutex_unlock(&con->sock_mutex);
+ sock_release(newsock);
+
+ if (result != -EAGAIN)
+ printk("dlm: error accepting connection from node: %d\n", result);
+ return result;
+}
+
+static void free_entry(struct writequeue_entry *e)
+{
+ __free_page(e->page);
+ kfree(e);
+}
+
+/* Initiate an SCTP association.
+ This is a special case of send_to_sock() in that we don't yet have a
+ peeled-off socket for this association, so we use the listening socket
+ and add the primary IP address of the remote node.
+ */
+static void sctp_init_assoc(struct connection *con)
+{
+ struct sockaddr_storage rem_addr;
+ char outcmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))];
+ struct msghdr outmessage;
+ struct cmsghdr *cmsg;
+ struct sctp_sndrcvinfo *sinfo;
+ struct connection *base_con;
+ struct writequeue_entry *e;
+ int len, offset;
+ int ret;
+ int addrlen;
+ struct kvec iov[1];
+
+ if (test_and_set_bit(CF_INIT_PENDING, &con->flags))
+ return;
+
+ if (con->retries++ > MAX_CONNECT_RETRIES)
+ return;
+
+ log_print("Initiating association with node %d", con->nodeid);
+
+ if (nodeid_to_addr(con->nodeid, (struct sockaddr *)&rem_addr)) {
+ log_print("no address for nodeid %d", con->nodeid);
+ return;
+ }
+ base_con = nodeid2con(0, 0);
+ BUG_ON(base_con == NULL);
+
+ make_sockaddr(&rem_addr, dlm_config.ci_tcp_port, &addrlen);
+
+ outmessage.msg_name = &rem_addr;
+ outmessage.msg_namelen = addrlen;
+ outmessage.msg_control = outcmsg;
+ outmessage.msg_controllen = sizeof(outcmsg);
+ outmessage.msg_flags = MSG_EOR;
+
+ spin_lock(&con->writequeue_lock);
+ e = list_entry(con->writequeue.next, struct writequeue_entry,
+ list);
+
+ BUG_ON((struct list_head *) e == &con->writequeue);
+
+ len = e->len;
+ offset = e->offset;
+ spin_unlock(&con->writequeue_lock);
+ kmap(e->page);
+
+ /* Send the first block off the write queue */
+ iov[0].iov_base = page_address(e->page)+offset;
+ iov[0].iov_len = len;
+
+ cmsg = CMSG_FIRSTHDR(&outmessage);
+ cmsg->cmsg_level = IPPROTO_SCTP;
+ cmsg->cmsg_type = SCTP_SNDRCV;
+ cmsg->cmsg_len = CMSG_LEN(sizeof(struct sctp_sndrcvinfo));
+ sinfo = CMSG_DATA(cmsg);
+ memset(sinfo, 0x00, sizeof(struct sctp_sndrcvinfo));
+ sinfo->sinfo_ppid = cpu_to_le32(dlm_our_nodeid());
+ outmessage.msg_controllen = cmsg->cmsg_len;
+
+ ret = kernel_sendmsg(base_con->sock, &outmessage, iov, 1, len);
+ if (ret < 0) {
+ log_print("Send first packet to node %d failed: %d", con->nodeid, ret);
+
+ /* Try again later */
+ clear_bit(CF_CONNECT_PENDING, &con->flags);
+ clear_bit(CF_INIT_PENDING, &con->flags);
+ }
+ else {
+ spin_lock(&con->writequeue_lock);
+ e->offset += ret;
+ e->len -= ret;
+
+ if (e->len == 0 && e->users == 0) {
+ list_del(&e->list);
+ kunmap(e->page);
+ free_entry(e);
+ }
+ spin_unlock(&con->writequeue_lock);
+ }
+}
+
+/* Connect a new socket to its peer */
+static void tcp_connect_to_sock(struct connection *con)
+{
+ int result = -EHOSTUNREACH;
+ struct sockaddr_storage saddr;
+ int addr_len;
+ struct socket *sock;
+
+ if (con->nodeid == 0) {
+ log_print("attempt to connect sock 0 foiled");
+ return;
+ }
+
+ mutex_lock(&con->sock_mutex);
+ if (con->retries++ > MAX_CONNECT_RETRIES)
+ goto out;
+
+ /* Some odd races can cause double-connects, ignore them */
+ if (con->sock) {
+ result = 0;
+ goto out;
+ }
+
+ /* Create a socket to communicate with */
+ result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_STREAM,
+ IPPROTO_TCP, &sock);
+ if (result < 0)
+ goto out_err;
+
+ memset(&saddr, 0, sizeof(saddr));
+ if (dlm_nodeid_to_addr(con->nodeid, &saddr))
+ goto out_err;
+
+ sock->sk->sk_user_data = con;
+ con->rx_action = receive_from_sock;
+ con->connect_action = tcp_connect_to_sock;
+ add_sock(sock, con);
+
+ make_sockaddr(&saddr, dlm_config.ci_tcp_port, &addr_len);
+
+ log_print("connecting to %d", con->nodeid);
+ result =
+ sock->ops->connect(sock, (struct sockaddr *)&saddr, addr_len,
+ O_NONBLOCK);
+ if (result == -EINPROGRESS)
+ result = 0;
+ if (result == 0)
+ goto out;
+
+out_err:
+ if (con->sock) {
+ sock_release(con->sock);
+ con->sock = NULL;
+ }
+ /*
+ * Some errors are fatal and this list might need adjusting. For other
+ * errors we try again until the max number of retries is reached.
+ */
+ if (result != -EHOSTUNREACH && result != -ENETUNREACH &&
+ result != -ENETDOWN && result != EINVAL
+ && result != -EPROTONOSUPPORT) {
+ lowcomms_connect_sock(con);
+ result = 0;
+ }
+out:
+ mutex_unlock(&con->sock_mutex);
+ return;
+}
+
+static struct socket *tcp_create_listen_sock(struct connection *con,
+ struct sockaddr_storage *saddr)
+{
+ struct socket *sock = NULL;
+ int result = 0;
+ int one = 1;
+ int addr_len;
+
+ if (dlm_local_addr[0]->ss_family == AF_INET)
+ addr_len = sizeof(struct sockaddr_in);
+ else
+ addr_len = sizeof(struct sockaddr_in6);
+
+ /* Create a socket to communicate with */
+ result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_STREAM, IPPROTO_TCP, &sock);
+ if (result < 0) {
+ printk("dlm: Can't create listening comms socket\n");
+ goto create_out;
+ }
+
+ result = kernel_setsockopt(sock, SOL_SOCKET, SO_REUSEADDR,
+ (char *)&one, sizeof(one));
+
+ if (result < 0) {
+ printk("dlm: Failed to set SO_REUSEADDR on socket: result=%d\n",
+ result);
+ }
+ sock->sk->sk_user_data = con;
+ con->rx_action = tcp_accept_from_sock;
+ con->connect_action = tcp_connect_to_sock;
+ con->sock = sock;
+
+ /* Bind to our port */
+ make_sockaddr(saddr, dlm_config.ci_tcp_port, &addr_len);
+ result = sock->ops->bind(sock, (struct sockaddr *) saddr, addr_len);
+ if (result < 0) {
+ printk("dlm: Can't bind to port %d\n", dlm_config.ci_tcp_port);
+ sock_release(sock);
+ sock = NULL;
+ con->sock = NULL;
+ goto create_out;
+ }
+ result = kernel_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
+ (char *)&one, sizeof(one));
+ if (result < 0) {
+ printk("dlm: Set keepalive failed: %d\n", result);
+ }
+
+ result = sock->ops->listen(sock, 5);
+ if (result < 0) {
+ printk("dlm: Can't listen on port %d\n", dlm_config.ci_tcp_port);
+ sock_release(sock);
+ sock = NULL;
+ goto create_out;
+ }
+
+create_out:
+ return sock;
+}
+
+/* Get local addresses */
+static void init_local(void)
+{
+ struct sockaddr_storage sas, *addr;
+ int i;
+
+ for (i = 0; i < DLM_MAX_ADDR_COUNT - 1; i++) {
+ if (dlm_our_addr(&sas, i))
+ break;
+
+ addr = kmalloc(sizeof(*addr), GFP_KERNEL);
+ if (!addr)
+ break;
+ memcpy(addr, &sas, sizeof(*addr));
+ dlm_local_addr[dlm_local_count++] = addr;
+ }
+}
+
+/* Bind to an IP address. SCTP allows multiple address so it can do multi-homing */
+static int add_sctp_bind_addr(struct connection *sctp_con, struct sockaddr_storage *addr, int addr_len, int num)
+{
+ int result = 0;
+
+ if (num == 1)
+ result = kernel_bind(sctp_con->sock,
+ (struct sockaddr *) addr,
+ addr_len);
+ else
+ result = kernel_setsockopt(sctp_con->sock, SOL_SCTP,
+ SCTP_SOCKOPT_BINDX_ADD,
+ (char *)addr, addr_len);
+
+ if (result < 0)
+ log_print("Can't bind to port %d addr number %d",
+ dlm_config.ci_tcp_port, num);
+
+ return result;
+}
+
+/* Initialise SCTP socket and bind to all interfaces */
+static int sctp_listen_for_all(void)
+{
+ struct socket *sock = NULL;
+ struct sockaddr_storage localaddr;
+ struct sctp_event_subscribe subscribe;
+ int result = -EINVAL, num = 1, i, addr_len;
+ struct connection *con = nodeid2con(0, GFP_KERNEL);
+ int bufsize = NEEDED_RMEM;
+
+ if (!con)
+ return -ENOMEM;
+
+ log_print("Using SCTP for communications");
+
+ result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_SEQPACKET,
+ IPPROTO_SCTP, &sock);
+ if (result < 0) {
+ log_print("Can't create comms socket, check SCTP is loaded");
+ goto out;
+ }
+
+ /* Listen for events */
+ memset(&subscribe, 0, sizeof(subscribe));
+ subscribe.sctp_data_io_event = 1;
+ subscribe.sctp_association_event = 1;
+ subscribe.sctp_send_failure_event = 1;
+ subscribe.sctp_shutdown_event = 1;
+ subscribe.sctp_partial_delivery_event = 1;
+
+ result = kernel_setsockopt(sock, SOL_SOCKET, SO_RCVBUF,
+ (char *)&bufsize, sizeof(bufsize));
+ if (result)
+ log_print("Error increasing buffer space on socket: %d", result);
+
+ result = kernel_setsockopt(sock, SOL_SCTP, SCTP_EVENTS,
+ (char *)&subscribe, sizeof(subscribe));
+ if (result < 0) {
+ log_print("Failed to set SCTP_EVENTS on socket: result=%d",
+ result);
+ goto create_delsock;
+ }
+
+ /* Init con struct */
+ sock->sk->sk_user_data = con;
+ con->sock = sock;
+ con->sock->sk->sk_data_ready = lowcomms_data_ready;
+ con->rx_action = receive_from_sock;
+ con->connect_action = sctp_init_assoc;
+
+ /* Bind to all interfaces. */
+ for (i = 0; i < dlm_local_count; i++) {
+ memcpy(&localaddr, dlm_local_addr[i], sizeof(localaddr));
+ make_sockaddr(&localaddr, dlm_config.ci_tcp_port, &addr_len);
+
+ result = add_sctp_bind_addr(con, &localaddr, addr_len, num);
+ if (result)
+ goto create_delsock;
+ ++num;
+ }
+
+ result = sock->ops->listen(sock, 5);
+ if (result < 0) {
+ log_print("Can't set socket listening");
+ goto create_delsock;
+ }
+
+ return 0;
+
+create_delsock:
+ sock_release(sock);
+ con->sock = NULL;
+out:
+ return result;
+}
+
+static int tcp_listen_for_all(void)
+{
+ struct socket *sock = NULL;
+ struct connection *con = nodeid2con(0, GFP_KERNEL);
+ int result = -EINVAL;
+
+ if (!con)
+ return -ENOMEM;
+
+ /* We don't support multi-homed hosts */
+ if (dlm_local_addr[1] != NULL) {
+ log_print("TCP protocol can't handle multi-homed hosts, try SCTP");
+ return -EINVAL;
+ }
+
+ log_print("Using TCP for communications");
+
+ set_bit(CF_IS_OTHERCON, &con->flags);
+
+ sock = tcp_create_listen_sock(con, dlm_local_addr[0]);
+ if (sock) {
+ add_sock(sock, con);
+ result = 0;
+ }
+ else {
+ result = -EADDRINUSE;
+ }
+
+ return result;
+}
+
+
+
+static struct writequeue_entry *new_writequeue_entry(struct connection *con,
+ gfp_t allocation)
+{
+ struct writequeue_entry *entry;
+
+ entry = kmalloc(sizeof(struct writequeue_entry), allocation);
+ if (!entry)
+ return NULL;
+
+ entry->page = alloc_page(allocation);
+ if (!entry->page) {
+ kfree(entry);
+ return NULL;
+ }
+
+ entry->offset = 0;
+ entry->len = 0;
+ entry->end = 0;
+ entry->users = 0;
+ entry->con = con;
+
+ return entry;
+}
+
+void *dlm_lowcomms_get_buffer(int nodeid, int len,
+ gfp_t allocation, char **ppc)
+{
+ struct connection *con;
+ struct writequeue_entry *e;
+ int offset = 0;
+ int users = 0;
+
+ con = nodeid2con(nodeid, allocation);
+ if (!con)
+ return NULL;
+
+ spin_lock(&con->writequeue_lock);
+ e = list_entry(con->writequeue.prev, struct writequeue_entry, list);
+ if ((&e->list == &con->writequeue) ||
+ (PAGE_CACHE_SIZE - e->end < len)) {
+ e = NULL;
+ } else {
+ offset = e->end;
+ e->end += len;
+ users = e->users++;
+ }
+ spin_unlock(&con->writequeue_lock);
+
+ if (e) {
+ got_one:
+ if (users == 0)
+ kmap(e->page);
+ *ppc = page_address(e->page) + offset;
+ return e;
+ }
+
+ e = new_writequeue_entry(con, allocation);
+ if (e) {
+ spin_lock(&con->writequeue_lock);
+ offset = e->end;
+ e->end += len;
+ users = e->users++;
+ list_add_tail(&e->list, &con->writequeue);
+ spin_unlock(&con->writequeue_lock);
+ goto got_one;
+ }
+ return NULL;
+}
+
+void dlm_lowcomms_commit_buffer(void *mh)
+{
+ struct writequeue_entry *e = (struct writequeue_entry *)mh;
+ struct connection *con = e->con;
+ int users;
+
+ spin_lock(&con->writequeue_lock);
+ users = --e->users;
+ if (users)
+ goto out;
+ e->len = e->end - e->offset;
+ kunmap(e->page);
+ spin_unlock(&con->writequeue_lock);
+
+ if (!test_and_set_bit(CF_WRITE_PENDING, &con->flags)) {
+ queue_work(send_workqueue, &con->swork);
+ }
+ return;
+
+out:
+ spin_unlock(&con->writequeue_lock);
+ return;
+}
+
+/* Send a message */
+static void send_to_sock(struct connection *con)
+{
+ int ret = 0;
+ ssize_t(*sendpage) (struct socket *, struct page *, int, size_t, int);
+ const int msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL;
+ struct writequeue_entry *e;
+ int len, offset;
+
+ mutex_lock(&con->sock_mutex);
+ if (con->sock == NULL)
+ goto out_connect;
+
+ sendpage = con->sock->ops->sendpage;
+
+ spin_lock(&con->writequeue_lock);
+ for (;;) {
+ e = list_entry(con->writequeue.next, struct writequeue_entry,
+ list);
+ if ((struct list_head *) e == &con->writequeue)
+ break;
+
+ len = e->len;
+ offset = e->offset;
+ BUG_ON(len == 0 && e->users == 0);
+ spin_unlock(&con->writequeue_lock);
+ kmap(e->page);
+
+ ret = 0;
+ if (len) {
+ ret = sendpage(con->sock, e->page, offset, len,
+ msg_flags);
+ if (ret == -EAGAIN || ret == 0)
+ goto out;
+ if (ret <= 0)
+ goto send_error;
+ }
+ else {
+ /* Don't starve people filling buffers */
+ cond_resched();
+ }
+
+ spin_lock(&con->writequeue_lock);
+ e->offset += ret;
+ e->len -= ret;
+
+ if (e->len == 0 && e->users == 0) {
+ list_del(&e->list);
+ kunmap(e->page);
+ free_entry(e);
+ continue;
+ }
+ }
+ spin_unlock(&con->writequeue_lock);
+out:
+ mutex_unlock(&con->sock_mutex);
+ return;
+
+send_error:
+ mutex_unlock(&con->sock_mutex);
+ close_connection(con, false);
+ lowcomms_connect_sock(con);
+ return;
+
+out_connect:
+ mutex_unlock(&con->sock_mutex);
+ if (!test_bit(CF_INIT_PENDING, &con->flags))
+ lowcomms_connect_sock(con);
+ return;
+}
+
+static void clean_one_writequeue(struct connection *con)
+{
+ struct list_head *list;
+ struct list_head *temp;
+
+ 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_del(&e->list);
+ free_entry(e);
+ }
+ spin_unlock(&con->writequeue_lock);
+}
+
+/* Called from recovery when it knows that a node has
+ left the cluster */
+int dlm_lowcomms_close(int nodeid)
+{
+ struct connection *con;
+
+ log_print("closing connection to node %d", nodeid);
+ con = nodeid2con(nodeid, 0);
+ if (con) {
+ clean_one_writequeue(con);
+ close_connection(con, true);
+ }
+ return 0;
+}
+
+/* Receive workqueue function */
+static void process_recv_sockets(struct work_struct *work)
+{
+ struct connection *con = container_of(work, struct connection, rwork);
+ int err;
+
+ clear_bit(CF_READ_PENDING, &con->flags);
+ do {
+ err = con->rx_action(con);
+ } while (!err);
+}
+
+/* Send workqueue function */
+static void process_send_sockets(struct work_struct *work)
+{
+ struct connection *con = container_of(work, struct connection, swork);
+
+ if (test_and_clear_bit(CF_CONNECT_PENDING, &con->flags)) {
+ con->connect_action(con);
+ }
+ clear_bit(CF_WRITE_PENDING, &con->flags);
+ send_to_sock(con);
+}
+
+
+/* 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);
+ }
+}
+
+static void work_stop(void)
+{
+ destroy_workqueue(recv_workqueue);
+ destroy_workqueue(send_workqueue);
+}
+
+static int work_start(void)
+{
+ int error;
+ recv_workqueue = create_workqueue("dlm_recv");
+ error = IS_ERR(recv_workqueue);
+ if (error) {
+ log_print("can't start dlm_recv %d", error);
+ return error;
+ }
+
+ send_workqueue = create_singlethread_workqueue("dlm_send");
+ error = IS_ERR(send_workqueue);
+ if (error) {
+ log_print("can't start dlm_send %d", error);
+ destroy_workqueue(recv_workqueue);
+ return error;
+ }
+
+ return 0;
+}
+
+void dlm_lowcomms_stop(void)
+{
+ int i;
+ struct connection *con;
+
+ /* Set all the flags to prevent any
+ socket activity.
+ */
+ down(&connections_lock);
+ for (i = 0; i < max_nodeid; i++) {
+ con = __nodeid2con(i, 0);
+ if (con)
+ con->flags |= 0xFF;
+ }
+ up(&connections_lock);
+
+ work_stop();
+
+ down(&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);
+ }
+ }
+ up(&connections_lock);
+ kmem_cache_destroy(con_cache);
+}
+
+int dlm_lowcomms_start(void)
+{
+ int error = -EINVAL;
+ struct connection *con;
+
+ init_local();
+ if (!dlm_local_count) {
+ log_print("no local IP address has been set");
+ goto out;
+ }
+
+ error = -ENOMEM;
+ con_cache = kmem_cache_create("dlm_conn", sizeof(struct connection),
+ __alignof__(struct connection), 0,
+ NULL, NULL);
+ if (!con_cache)
+ goto out;
+
+ /* Set some sysctl minima */
+ if (sysctl_rmem_max < NEEDED_RMEM)
+ sysctl_rmem_max = NEEDED_RMEM;
+
+ /* Start listening */
+ if (dlm_config.ci_protocol == 0)
+ error = tcp_listen_for_all();
+ else
+ error = sctp_listen_for_all();
+ if (error)
+ goto fail_unlisten;
+
+ error = work_start();
+ if (error)
+ goto fail_unlisten;
+
+ return 0;
+
+fail_unlisten:
+ con = nodeid2con(0,0);
+ if (con) {
+ close_connection(con, false);
+ kmem_cache_free(con_cache, con);
+ }
+ kmem_cache_destroy(con_cache);
+
+out:
+ return error;
+}
--
1.5.1.2

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