From: Patrick Caulfield Date: Tue, 17 Apr 2007 14:39:57 +0000 (+0100) Subject: [DLM] Consolidate transport protocols X-Git-Tag: v2.6.22-rc1~820^2~12 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6ed7257b46709e87d79ac2b6b819b7e0c9184998;p=linux-2.6 [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 Signed-off-by: Steven Whitehouse --- diff --git a/fs/dlm/Kconfig b/fs/dlm/Kconfig index 6fa7b0d5c0..69a94690e4 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 65388944eb..604cf7dc5f 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 8665c88e5a..822abdcd14 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 1e978611a9..967cc3d72e 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 dc83a9d979..0000000000 --- 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 -#include -#include -#include -#include -#include -#include - -#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.c similarity index 55% rename from fs/dlm/lowcomms-tcp.c rename to fs/dlm/lowcomms.c index 919e92a6ae..76399b7819 100644 --- a/fs/dlm/lowcomms-tcp.c +++ b/fs/dlm/lowcomms.c @@ -36,30 +36,36 @@ * 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. + * 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 #include #include #include +#include +#include +#include +#include #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; }; -#define NODE_INCREMENT 32 static void cbuf_add(struct cbuf *cb, int n) { cb->len += n; @@ -88,28 +94,25 @@ 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 */ + unsigned long flags; #define CF_READ_PENDING 1 #define CF_WRITE_PENDING 2 #define CF_CONNECT_PENDING 3 -#define CF_IS_OTHERCON 4 +#define CF_INIT_PENDING 4 +#define CF_IS_OTHERCON 5 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 */ + 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 */ @@ -127,68 +130,136 @@ struct writequeue_entry { struct connection *con; }; -static struct sockaddr_storage dlm_local_addr; +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; -/* An array of pointers to connections, indexed by NODEID */ -static struct connection **connections; +static DEFINE_IDR(connections_idr); static DECLARE_MUTEX(connections_lock); +static int max_nodeid; 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) +/* + * 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; - down(&connections_lock); - if (nodeid >= conn_array_size) { - int new_size = nodeid + NODE_INCREMENT; - struct connection **new_conns; + con = idr_find(&connections_idr, nodeid); + if (con || !alloc) + return con; - new_conns = kzalloc(sizeof(struct connection *) * - new_size, allocation); - if (!new_conns) - goto finish; + r = idr_pre_get(&connections_idr, alloc); + if (!r) + return NULL; + + con = kmem_cache_zalloc(con_cache, alloc); + if (!con) + return NULL; - memcpy(new_conns, connections, sizeof(struct connection *) * conn_array_size); - conn_array_size = new_size; - kfree(connections); - connections = new_conns; + 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 = 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); - 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); - connections[nodeid] = con; + con->connect_action = zerocon->connect_action; + if (!con->rx_action) + con->rx_action = zerocon->rx_action; } -finish: + 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; isctp_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); } @@ -222,20 +293,21 @@ static int add_sock(struct socket *sock, struct connection *con) 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 IP6 or 4 sockaddr and return the address +/* 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.ss_family; + 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); @@ -264,6 +336,192 @@ static void close_connection(struct connection *con, bool and_other) 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; isn_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) { @@ -274,6 +532,7 @@ static int receive_from_sock(struct connection *con) int r; int call_again_soon = 0; int nvec; + char incmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))]; mutex_lock(&con->sock_mutex); @@ -293,6 +552,11 @@ static int receive_from_sock(struct connection *con) 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. @@ -316,10 +580,22 @@ static int receive_from_sock(struct connection *con) 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); @@ -367,7 +643,7 @@ out_close: } /* Listening socket is busy, accept a connection */ -static int accept_from_sock(struct connection *con) +static int tcp_accept_from_sock(struct connection *con) { int result; struct sockaddr_storage peeraddr; @@ -378,7 +654,7 @@ static int accept_from_sock(struct connection *con) struct connection *addcon; memset(&peeraddr, 0, sizeof(peeraddr)); - result = sock_create_kern(dlm_local_addr.ss_family, SOCK_STREAM, + result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_STREAM, IPPROTO_TCP, &newsock); if (result < 0) return -ENOMEM; @@ -418,7 +694,6 @@ static int accept_from_sock(struct connection *con) /* 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); @@ -480,8 +755,102 @@ accept_err: 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 connect_to_sock(struct connection *con) +static void tcp_connect_to_sock(struct connection *con) { int result = -EHOSTUNREACH; struct sockaddr_storage saddr; @@ -504,7 +873,7 @@ static void connect_to_sock(struct connection *con) } /* Create a socket to communicate with */ - result = sock_create_kern(dlm_local_addr.ss_family, SOCK_STREAM, + result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_STREAM, IPPROTO_TCP, &sock); if (result < 0) goto out_err; @@ -515,11 +884,11 @@ static void connect_to_sock(struct connection *con) 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); - add_sock(sock, con); - log_print("connecting to %d", con->nodeid); result = sock->ops->connect(sock, (struct sockaddr *)&saddr, addr_len, @@ -549,38 +918,36 @@ out: return; } -static struct socket *create_listen_sock(struct connection *con, - struct sockaddr_storage *saddr) +static struct socket *tcp_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) + 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.ss_family, SOCK_STREAM, IPPROTO_TCP, &sock); + 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; } - fs = get_fs(); - set_fs(get_ds()); - result = sock_setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, - (char *)&one, sizeof(one)); - set_fs(fs); + 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 = accept_from_sock; + con->rx_action = tcp_accept_from_sock; + con->connect_action = tcp_connect_to_sock; con->sock = sock; /* Bind to our port */ @@ -593,13 +960,8 @@ static struct socket *create_listen_sock(struct connection *con, con->sock = NULL; goto create_out; } - - fs = get_fs(); - set_fs(get_ds()); - - result = sock_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE, + result = kernel_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE, (char *)&one, sizeof(one)); - set_fs(fs); if (result < 0) { printk("dlm: Set keepalive failed: %d\n", result); } @@ -616,18 +978,141 @@ 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; +} -/* Listen on all interfaces */ -static int listen_for_all(void) +/* 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 = create_listen_sock(con, &dlm_local_addr); + sock = tcp_create_listen_sock(con, dlm_local_addr[0]); if (sock) { add_sock(sock, con); result = 0; @@ -734,12 +1219,6 @@ out: 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) { @@ -806,7 +1285,8 @@ send_error: out_connect: mutex_unlock(&con->sock_mutex); - connect_to_sock(con); + if (!test_bit(CF_INIT_PENDING, &con->flags)) + lowcomms_connect_sock(con); return; } @@ -831,9 +1311,6 @@ 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) { @@ -841,12 +1318,9 @@ int dlm_lowcomms_close(int nodeid) close_connection(con, true); } return 0; - -out: - return -1; } -/* Look for activity on active sockets */ +/* Receive workqueue function */ static void process_recv_sockets(struct work_struct *work) { struct connection *con = container_of(work, struct connection, rwork); @@ -858,15 +1332,14 @@ static void process_recv_sockets(struct work_struct *work) } 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)) { - connect_to_sock(con); + con->connect_action(con); } - clear_bit(CF_WRITE_PENDING, &con->flags); send_to_sock(con); } @@ -877,7 +1350,7 @@ static void clean_writequeues(void) { int nodeid; - for (nodeid = 1; nodeid < conn_array_size; nodeid++) { + for (nodeid = 1; nodeid < max_nodeid; nodeid++) { struct connection *con = nodeid2con(nodeid, 0); if (con) @@ -915,64 +1388,64 @@ static int work_start(void) void dlm_lowcomms_stop(void) { int i; + struct connection *con; /* Set all the flags to prevent any socket activity. */ - for (i = 0; i < conn_array_size; i++) { - if (connections[i]) - connections[i]->flags |= 0xFF; + 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 < 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]); + 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); } } - - kfree(connections); - connections = NULL; - + up(&connections_lock); 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; + int error = -EINVAL; + struct connection *con; - if (dlm_our_addr(&dlm_local_addr, 0)) { + init_local(); + if (!dlm_local_count) { 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; + goto out; } + error = -ENOMEM; con_cache = kmem_cache_create("dlm_conn", sizeof(struct connection), __alignof__(struct connection), 0, NULL, NULL); if (!con_cache) - goto fail_free_conn; + goto out; + /* Set some sysctl minima */ + if (sysctl_rmem_max < NEEDED_RMEM) + sysctl_rmem_max = NEEDED_RMEM; /* Start listening */ - error = listen_for_all(); + if (dlm_config.ci_protocol == 0) + error = tcp_listen_for_all(); + else + error = sctp_listen_for_all(); if (error) goto fail_unlisten; @@ -983,24 +1456,13 @@ int dlm_lowcomms_start(void) return 0; fail_unlisten: - close_connection(connections[0], false); - kmem_cache_free(con_cache, connections[0]); + con = nodeid2con(0,0); + if (con) { + close_connection(con, false); + kmem_cache_free(con_cache, con); + } 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: - */