diff options
Diffstat (limited to 'fs/dlm/lowcomms.c')
| -rw-r--r-- | fs/dlm/lowcomms.c | 1239 |
1 files changed, 0 insertions, 1239 deletions
diff --git a/fs/dlm/lowcomms.c b/fs/dlm/lowcomms.c deleted file mode 100644 index 6da6b14d5a6..00000000000 --- a/fs/dlm/lowcomms.c +++ /dev/null @@ -1,1239 +0,0 @@ -/****************************************************************************** -******************************************************************************* -** -** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. -** Copyright (C) 2004-2005 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; -}; - -static DEFINE_IDR(nodeinfo_idr); -static struct rw_semaphore nodeinfo_lock; -static int max_nodeid; - -struct cbuf { - unsigned base; - unsigned len; - unsigned 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; -}; - -/* 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; -}; - -#define CBUF_ADD(cb, n) do { (cb)->len += n; } while(0) -#define CBUF_EMPTY(cb) ((cb)->len == 0) -#define CBUF_MAY_ADD(cb, n) (((cb)->len + (n)) < ((cb)->mask + 1)) -#define CBUF_DATA(cb) (((cb)->base + (cb)->len) & (cb)->mask) - -#define CBUF_INIT(cb, size) \ -do { \ - (cb)->base = (cb)->len = 0; \ - (cb)->mask = ((size)-1); \ -} while(0) - -#define CBUF_EAT(cb, n) \ -do { \ - (cb)->len -= (n); \ - (cb)->base += (n); \ - (cb)->base &= (cb)->mask; \ -} while(0) - - -/* List of nodes which have writes pending */ -static struct list_head write_nodes; -static spinlock_t write_nodes_lock; - -/* Maximum number of incoming messages to process before - * doing a schedule() - */ -#define MAX_RX_MSG_COUNT 25 - -/* Manage daemons */ -static struct task_struct *recv_task; -static struct task_struct *send_task; -static wait_queue_head_t lowcomms_recv_wait; -static atomic_t accepting; - -/* The SCTP connection */ -static struct connection sctp_con; - - -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; -} - -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) { - 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); - 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) -{ - atomic_inc(&sctp_con.waiting_requests); - if (test_and_set_bit(CF_READ_PENDING, &sctp_con.flags)) - return; - - wake_up_interruptible(&lowcomms_recv_wait); -} - - -/* 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 = (struct sctp_sndrcvinfo *)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); - } - } - } - wake_up_process(send_task); -} - -/* 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 */ - spin_lock(&ni->lock); - ni->assoc_id = sn->sn_assoc_change.sac_assoc_id; - spin_unlock(&ni->lock); - - 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); - } - wake_up_process(send_task); - } - 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)); - - memset(incmsg, 0, sizeof(incmsg)); - 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 = (struct sctp_sndrcvinfo *)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); - } - wake_up_process(send_task); - } - } - - /* INIT sends a message with length of 1 - ignore it */ - if (r == 1) - return 0; - - CBUF_ADD(&sctp_con.cb, ret); - 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; - schedule(); - 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.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.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; - - if (!atomic_read(&accepting)) - return NULL; - - ni = nodeid2nodeinfo(nodeid, allocation); - if (!ni) - return NULL; - - spin_lock(&ni->writequeue_lock); - e = list_entry(ni->writequeue.prev, struct writequeue_entry, list); - if (((struct list_head *) e == &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; - - if (!atomic_read(&accepting)) - return; - - 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); - wake_up_process(send_task); - } - 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.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 = (struct sctp_sndrcvinfo *)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 int 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 0; - } - 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 = (struct sctp_sndrcvinfo *)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 */ - schedule(); - } - - spin_lock(&ni->writequeue_lock); - e->offset += ret; - e->len -= ret; - - if (e->len == 0 && e->users == 0) { - list_del(&e->list); - free_entry(e); - continue; - } - } - spin_unlock(&ni->writequeue_lock); - out: - return ret; - - 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 ret; -} - -/* 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; -} - -static int write_list_empty(void) -{ - int status; - - spin_lock_bh(&write_nodes_lock); - status = list_empty(&write_nodes); - spin_unlock_bh(&write_nodes_lock); - - return status; -} - -static int dlm_recvd(void *data) -{ - DECLARE_WAITQUEUE(wait, current); - - while (!kthread_should_stop()) { - int count = 0; - - set_current_state(TASK_INTERRUPTIBLE); - add_wait_queue(&lowcomms_recv_wait, &wait); - if (!test_bit(CF_READ_PENDING, &sctp_con.flags)) - schedule(); - remove_wait_queue(&lowcomms_recv_wait, &wait); - set_current_state(TASK_RUNNING); - - if (test_and_clear_bit(CF_READ_PENDING, &sctp_con.flags)) { - int ret; - - do { - ret = receive_from_sock(); - - /* Don't starve out everyone else */ - if (++count >= MAX_RX_MSG_COUNT) { - schedule(); - count = 0; - } - } while (!kthread_should_stop() && ret >=0); - } - schedule(); - } - - return 0; -} - -static int dlm_sendd(void *data) -{ - DECLARE_WAITQUEUE(wait, current); - - add_wait_queue(sctp_con.sock->sk->sk_sleep, &wait); - - while (!kthread_should_stop()) { - set_current_state(TASK_INTERRUPTIBLE); - if (write_list_empty()) - schedule(); - set_current_state(TASK_RUNNING); - - if (sctp_con.eagain_flag) { - sctp_con.eagain_flag = 0; - refill_write_queue(); - } - process_output_queue(); - } - - remove_wait_queue(sctp_con.sock->sk->sk_sleep, &wait); - - return 0; -} - -static void daemons_stop(void) -{ - kthread_stop(recv_task); - kthread_stop(send_task); -} - -static int daemons_start(void) -{ - struct task_struct *p; - int error; - - p = kthread_run(dlm_recvd, NULL, "dlm_recvd"); - error = IS_ERR(p); - if (error) { - log_print("can't start dlm_recvd %d", error); - return error; - } - recv_task = p; - - p = kthread_run(dlm_sendd, NULL, "dlm_sendd"); - error = IS_ERR(p); - if (error) { - log_print("can't start dlm_sendd %d", error); - kthread_stop(recv_task); - return error; - } - send_task = p; - - return 0; -} - -/* - * This is quite likely to sleep... - */ -int dlm_lowcomms_start(void) -{ - int error; - - error = init_sock(); - if (error) - goto fail_sock; - error = daemons_start(); - if (error) - goto fail_sock; - atomic_set(&accepting, 1); - return 0; - - fail_sock: - close_connection(); - return error; -} - -/* Set all the activity flags to prevent any socket activity. */ - -void dlm_lowcomms_stop(void) -{ - atomic_set(&accepting, 0); - sctp_con.flags = 0x7; - daemons_stop(); - clean_writequeues(); - close_connection(); - dealloc_nodeinfo(); - max_nodeid = 0; -} - -int dlm_lowcomms_init(void) -{ - init_waitqueue_head(&lowcomms_recv_wait); - spin_lock_init(&write_nodes_lock); - INIT_LIST_HEAD(&write_nodes); - init_rwsem(&nodeinfo_lock); - return 0; -} - -void dlm_lowcomms_exit(void) -{ - int i; - - for (i = 0; i < dlm_local_count; i++) - kfree(dlm_local_addr[i]); - dlm_local_count = 0; - dlm_local_nodeid = 0; -} - |