diff options
Diffstat (limited to 'fs/dlm/lowcomms.c')
| -rw-r--r-- | fs/dlm/lowcomms.c | 1024 |
1 files changed, 552 insertions, 472 deletions
diff --git a/fs/dlm/lowcomms.c b/fs/dlm/lowcomms.c index c6b91f67a2c2..799d1c36eabf 100644 --- a/fs/dlm/lowcomms.c +++ b/fs/dlm/lowcomms.c @@ -63,35 +63,43 @@ #define NEEDED_RMEM (4*1024*1024) -/* Number of messages to send before rescheduling */ -#define MAX_SEND_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; + /* this semaphore is used to allow parallel recv/send in read + * lock mode. When we release a sock we need to held the write lock. + * + * However this is locking code and not nice. When we remove the + * othercon handling we can look into other mechanism to synchronize + * io handling to call sock_release() at the right time. + */ + struct rw_semaphore sock_lock; unsigned long flags; -#define CF_READ_PENDING 1 -#define CF_WRITE_PENDING 2 -#define CF_INIT_PENDING 4 +#define CF_APP_LIMITED 0 +#define CF_RECV_PENDING 1 +#define CF_SEND_PENDING 2 +#define CF_RECV_INTR 3 +#define CF_IO_STOP 4 #define CF_IS_OTHERCON 5 -#define CF_CLOSE 6 -#define CF_APP_LIMITED 7 -#define CF_CLOSING 8 -#define CF_CONNECTED 9 -#define CF_RECONNECT 10 -#define CF_DELAY_CONNECT 11 struct list_head writequeue; /* List of outgoing writequeue_entries */ spinlock_t writequeue_lock; int retries; -#define MAX_CONNECT_RETRIES 3 struct hlist_node list; + /* due some connect()/accept() races we currently have this cross over + * connection attempt second connection for one node. + * + * There is a solution to avoid the race by introducing a connect + * rule as e.g. our_nodeid > nodeid_to_connect who is allowed to + * connect. Otherside can connect but will only be considered that + * the other side wants to have a reconnect. + * + * However changing to this behaviour will break backwards compatible. + * In a DLM protocol major version upgrade we should remove this! + */ struct connection *othercon; - struct connection *sendcon; - struct work_struct rwork; /* Receive workqueue */ - struct work_struct swork; /* Send workqueue */ - unsigned char *rx_buf; - int rx_buflen; + struct work_struct rwork; /* receive worker */ + struct work_struct swork; /* send worker */ + unsigned char rx_leftover_buf[DLM_MAX_SOCKET_BUFSIZE]; int rx_leftover; int mark; int addr_count; @@ -136,6 +144,14 @@ struct dlm_msg { struct kref ref; }; +struct processqueue_entry { + unsigned char *buf; + int nodeid; + int buflen; + + struct list_head list; +}; + struct dlm_proto_ops { bool try_new_addr; const char *name; @@ -162,8 +178,8 @@ static struct sockaddr_storage dlm_local_addr[DLM_MAX_ADDR_COUNT]; static int dlm_local_count; /* Work queues */ -static struct workqueue_struct *recv_workqueue; -static struct workqueue_struct *send_workqueue; +static struct workqueue_struct *io_workqueue; +static struct workqueue_struct *process_workqueue; static struct hlist_head connection_hash[CONN_HASH_SIZE]; static DEFINE_SPINLOCK(connections_lock); @@ -171,14 +187,44 @@ DEFINE_STATIC_SRCU(connections_srcu); static const struct dlm_proto_ops *dlm_proto_ops; +#define DLM_IO_SUCCESS 0 +#define DLM_IO_END 1 +#define DLM_IO_EOF 2 +#define DLM_IO_RESCHED 3 + static void process_recv_sockets(struct work_struct *work); static void process_send_sockets(struct work_struct *work); +static void process_dlm_messages(struct work_struct *work); + +static DECLARE_WORK(process_work, process_dlm_messages); +static DEFINE_SPINLOCK(processqueue_lock); +static bool process_dlm_messages_pending; +static LIST_HEAD(processqueue); bool dlm_lowcomms_is_running(void) { return !!listen_con.sock; } +static void lowcomms_queue_swork(struct connection *con) +{ + WARN_ON_ONCE(!lockdep_is_held(&con->writequeue_lock)); + + if (!test_bit(CF_IO_STOP, &con->flags) && + !test_bit(CF_APP_LIMITED, &con->flags) && + !test_and_set_bit(CF_SEND_PENDING, &con->flags)) + queue_work(io_workqueue, &con->swork); +} + +static void lowcomms_queue_rwork(struct connection *con) +{ + WARN_ON_ONCE(!lockdep_sock_is_held(con->sock->sk)); + + if (!test_bit(CF_IO_STOP, &con->flags) && + !test_and_set_bit(CF_RECV_PENDING, &con->flags)) + queue_work(io_workqueue, &con->rwork); +} + static void writequeue_entry_ctor(void *data) { struct writequeue_entry *entry = data; @@ -225,21 +271,15 @@ static struct connection *__find_con(int nodeid, int r) return NULL; } -static int dlm_con_init(struct connection *con, int nodeid) +static void dlm_con_init(struct connection *con, int nodeid) { - con->rx_buflen = dlm_config.ci_buffer_size; - con->rx_buf = kmalloc(con->rx_buflen, GFP_NOFS); - if (!con->rx_buf) - return -ENOMEM; - con->nodeid = nodeid; - mutex_init(&con->sock_mutex); + init_rwsem(&con->sock_lock); 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); - - return 0; + spin_lock_init(&con->addrs_lock); } /* @@ -249,7 +289,7 @@ static int dlm_con_init(struct connection *con, int nodeid) static struct connection *nodeid2con(int nodeid, gfp_t alloc) { struct connection *con, *tmp; - int r, ret; + int r; r = nodeid_hash(nodeid); con = __find_con(nodeid, r); @@ -260,11 +300,7 @@ static struct connection *nodeid2con(int nodeid, gfp_t alloc) if (!con) return NULL; - ret = dlm_con_init(con, nodeid); - if (ret) { - kfree(con); - return NULL; - } + dlm_con_init(con, nodeid); spin_lock(&connections_lock); /* Because multiple workqueues/threads calls this function it can @@ -276,7 +312,6 @@ static struct connection *nodeid2con(int nodeid, gfp_t alloc) tmp = __find_con(nodeid, r); if (tmp) { spin_unlock(&connections_lock); - kfree(con->rx_buf); kfree(con); return tmp; } @@ -287,18 +322,6 @@ static struct connection *nodeid2con(int nodeid, gfp_t alloc) return con; } -/* Loop round all connections */ -static void foreach_conn(void (*conn_func)(struct connection *c)) -{ - int i; - struct connection *con; - - for (i = 0; i < CONN_HASH_SIZE; i++) { - hlist_for_each_entry_rcu(con, &connection_hash[i], list) - conn_func(con); - } -} - static int addr_compare(const struct sockaddr_storage *x, const struct sockaddr_storage *y) { @@ -474,56 +497,38 @@ static void lowcomms_data_ready(struct sock *sk) { struct connection *con = sock2con(sk); - if (!test_and_set_bit(CF_READ_PENDING, &con->flags)) - queue_work(recv_workqueue, &con->rwork); -} - -static void lowcomms_listen_data_ready(struct sock *sk) -{ - queue_work(recv_workqueue, &listen_con.rwork); + set_bit(CF_RECV_INTR, &con->flags); + lowcomms_queue_rwork(con); } static void lowcomms_write_space(struct sock *sk) { struct connection *con = sock2con(sk); - if (!test_and_set_bit(CF_CONNECTED, &con->flags)) { - log_print("connected to node %d", con->nodeid); - queue_work(send_workqueue, &con->swork); - return; - } - clear_bit(SOCK_NOSPACE, &con->sock->flags); + spin_lock_bh(&con->writequeue_lock); if (test_and_clear_bit(CF_APP_LIMITED, &con->flags)) { con->sock->sk->sk_write_pending--; clear_bit(SOCKWQ_ASYNC_NOSPACE, &con->sock->flags); } - queue_work(send_workqueue, &con->swork); -} - -static inline void lowcomms_connect_sock(struct connection *con) -{ - if (test_bit(CF_CLOSE, &con->flags)) - return; - queue_work(send_workqueue, &con->swork); - cond_resched(); + lowcomms_queue_swork(con); + spin_unlock_bh(&con->writequeue_lock); } static void lowcomms_state_change(struct sock *sk) { /* SCTP layer is not calling sk_data_ready when the connection - * is done, so we catch the signal through here. Also, it - * doesn't switch socket state when entering shutdown, so we - * skip the write in that case. + * is done, so we catch the signal through here. */ - if (sk->sk_shutdown) { - if (sk->sk_shutdown == RCV_SHUTDOWN) - lowcomms_data_ready(sk); - } else if (sk->sk_state == TCP_ESTABLISHED) { - lowcomms_write_space(sk); - } + if (sk->sk_shutdown == RCV_SHUTDOWN) + lowcomms_data_ready(sk); +} + +static void lowcomms_listen_data_ready(struct sock *sk) +{ + queue_work(io_workqueue, &listen_con.rwork); } int dlm_lowcomms_connect_node(int nodeid) @@ -541,9 +546,16 @@ int dlm_lowcomms_connect_node(int nodeid) return -ENOENT; } - lowcomms_connect_sock(con); + down_read(&con->sock_lock); + if (!con->sock) { + spin_lock_bh(&con->writequeue_lock); + lowcomms_queue_swork(con); + spin_unlock_bh(&con->writequeue_lock); + } + up_read(&con->sock_lock); srcu_read_unlock(&connections_srcu, idx); + cond_resched(); return 0; } @@ -596,39 +608,23 @@ static void lowcomms_error_report(struct sock *sk) "invalid socket family %d set, " "sk_err=%d/%d\n", dlm_our_nodeid(), sk->sk_family, sk->sk_err, sk->sk_err_soft); - goto out; - } - - /* below sendcon only handling */ - if (test_bit(CF_IS_OTHERCON, &con->flags)) - con = con->sendcon; - - switch (sk->sk_err) { - case ECONNREFUSED: - set_bit(CF_DELAY_CONNECT, &con->flags); - break; - default: break; } - if (!test_and_set_bit(CF_RECONNECT, &con->flags)) - queue_work(send_workqueue, &con->swork); + dlm_midcomms_unack_msg_resend(con->nodeid); -out: listen_sock.sk_error_report(sk); } -static void restore_callbacks(struct socket *sock) +static void restore_callbacks(struct sock *sk) { - struct sock *sk = sock->sk; + WARN_ON_ONCE(!lockdep_sock_is_held(sk)); - lock_sock(sk); sk->sk_user_data = NULL; sk->sk_data_ready = listen_sock.sk_data_ready; sk->sk_state_change = listen_sock.sk_state_change; sk->sk_write_space = listen_sock.sk_write_space; sk->sk_error_report = listen_sock.sk_error_report; - release_sock(sk); } /* Make a socket active */ @@ -640,10 +636,10 @@ static void add_sock(struct socket *sock, struct connection *con) con->sock = sock; sk->sk_user_data = con; - /* Install a data_ready callback */ sk->sk_data_ready = lowcomms_data_ready; sk->sk_write_space = lowcomms_write_space; - sk->sk_state_change = lowcomms_state_change; + if (dlm_config.ci_protocol == DLM_PROTO_SCTP) + sk->sk_state_change = lowcomms_state_change; sk->sk_allocation = GFP_NOFS; sk->sk_error_report = lowcomms_error_report; release_sock(sk); @@ -705,37 +701,62 @@ static void free_entry(struct writequeue_entry *e) static void dlm_close_sock(struct socket **sock) { - if (*sock) { - restore_callbacks(*sock); - sock_release(*sock); - *sock = NULL; + lock_sock((*sock)->sk); + restore_callbacks((*sock)->sk); + release_sock((*sock)->sk); + + sock_release(*sock); + *sock = NULL; +} + +static void allow_connection_io(struct connection *con) +{ + if (con->othercon) + clear_bit(CF_IO_STOP, &con->othercon->flags); + clear_bit(CF_IO_STOP, &con->flags); +} + +static void stop_connection_io(struct connection *con) +{ + if (con->othercon) + stop_connection_io(con->othercon); + + down_write(&con->sock_lock); + if (con->sock) { + lock_sock(con->sock->sk); + restore_callbacks(con->sock->sk); + + spin_lock_bh(&con->writequeue_lock); + set_bit(CF_IO_STOP, &con->flags); + spin_unlock_bh(&con->writequeue_lock); + release_sock(con->sock->sk); + } else { + spin_lock_bh(&con->writequeue_lock); + set_bit(CF_IO_STOP, &con->flags); + spin_unlock_bh(&con->writequeue_lock); } + up_write(&con->sock_lock); + + cancel_work_sync(&con->swork); + cancel_work_sync(&con->rwork); } /* Close a remote connection and tidy up */ -static void close_connection(struct connection *con, bool and_other, - bool tx, bool rx) +static void close_connection(struct connection *con, bool and_other) { - bool closing = test_and_set_bit(CF_CLOSING, &con->flags); struct writequeue_entry *e; - if (tx && !closing && cancel_work_sync(&con->swork)) { - log_print("canceled swork for node %d", con->nodeid); - clear_bit(CF_WRITE_PENDING, &con->flags); - } - if (rx && !closing && cancel_work_sync(&con->rwork)) { - log_print("canceled rwork for node %d", con->nodeid); - clear_bit(CF_READ_PENDING, &con->flags); + if (con->othercon && and_other) + close_connection(con->othercon, false); + + down_write(&con->sock_lock); + if (!con->sock) { + up_write(&con->sock_lock); + return; } - mutex_lock(&con->sock_mutex); dlm_close_sock(&con->sock); - if (con->othercon && and_other) { - /* Will only re-enter once. */ - close_connection(con->othercon, false, tx, rx); - } - /* if we send a writequeue entry only a half way, we drop the * whole entry because reconnection and that we not start of the * middle of a msg which will confuse the other end. @@ -747,143 +768,209 @@ static void close_connection(struct connection *con, bool and_other, * our policy is to start on a clean state when disconnects, we don't * know what's send/received on transport layer in this case. */ - spin_lock(&con->writequeue_lock); + spin_lock_bh(&con->writequeue_lock); if (!list_empty(&con->writequeue)) { e = list_first_entry(&con->writequeue, struct writequeue_entry, list); if (e->dirty) free_entry(e); } - spin_unlock(&con->writequeue_lock); + spin_unlock_bh(&con->writequeue_lock); con->rx_leftover = 0; con->retries = 0; clear_bit(CF_APP_LIMITED, &con->flags); - clear_bit(CF_CONNECTED, &con->flags); - clear_bit(CF_DELAY_CONNECT, &con->flags); - clear_bit(CF_RECONNECT, &con->flags); - mutex_unlock(&con->sock_mutex); - clear_bit(CF_CLOSING, &con->flags); + clear_bit(CF_RECV_PENDING, &con->flags); + clear_bit(CF_SEND_PENDING, &con->flags); + up_write(&con->sock_lock); } -static int con_realloc_receive_buf(struct connection *con, int newlen) +static struct processqueue_entry *new_processqueue_entry(int nodeid, + int buflen) { - unsigned char *newbuf; - - newbuf = kmalloc(newlen, GFP_NOFS); - if (!newbuf) - return -ENOMEM; + struct processqueue_entry *pentry; - /* copy any leftover from last receive */ - if (con->rx_leftover) - memmove(newbuf, con->rx_buf, con->rx_leftover); + pentry = kmalloc(sizeof(*pentry), GFP_NOFS); + if (!pentry) + return NULL; - /* swap to new buffer space */ - kfree(con->rx_buf); - con->rx_buflen = newlen; - con->rx_buf = newbuf; + pentry->buf = kmalloc(buflen, GFP_NOFS); + if (!pentry->buf) { + kfree(pentry); + return NULL; + } - return 0; + pentry->nodeid = nodeid; + return pentry; } -/* Data received from remote end */ -static int receive_from_sock(struct connection *con) +static void free_processqueue_entry(struct processqueue_entry *pentry) { - struct msghdr msg; - struct kvec iov; - int ret, buflen; + kfree(pentry->buf); + kfree(pentry); +} + +struct dlm_processed_nodes { + int nodeid; - mutex_lock(&con->sock_mutex); + struct list_head list; +}; - if (con->sock == NULL) { - ret = -EAGAIN; - goto out_close; +static void add_processed_node(int nodeid, struct list_head *processed_nodes) +{ + struct dlm_processed_nodes *n; + + list_for_each_entry(n, processed_nodes, list) { + /* we already remembered this node */ + if (n->nodeid == nodeid) + return; } - /* realloc if we get new buffer size to read out */ - buflen = dlm_config.ci_buffer_size; - if (con->rx_buflen != buflen && con->rx_leftover <= buflen) { - ret = con_realloc_receive_buf(con, buflen); - if (ret < 0) - goto out_resched; + /* if it's fails in worst case we simple don't send an ack back. + * We try it next time. + */ + n = kmalloc(sizeof(*n), GFP_NOFS); + if (!n) + return; + + n->nodeid = nodeid; + list_add(&n->list, processed_nodes); +} + +static void process_dlm_messages(struct work_struct *work) +{ + struct dlm_processed_nodes *n, *n_tmp; + struct processqueue_entry *pentry; + LIST_HEAD(processed_nodes); + + spin_lock(&processqueue_lock); + pentry = list_first_entry_or_null(&processqueue, + struct processqueue_entry, list); + if (WARN_ON_ONCE(!pentry)) { + spin_unlock(&processqueue_lock); + return; } + list_del(&pentry->list); + spin_unlock(&processqueue_lock); + for (;;) { - /* calculate new buffer parameter regarding last receive and - * possible leftover bytes - */ - iov.iov_base = con->rx_buf + con->rx_leftover; - iov.iov_len = con->rx_buflen - con->rx_leftover; - - memset(&msg, 0, sizeof(msg)); - msg.msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL; - ret = kernel_recvmsg(con->sock, &msg, &iov, 1, iov.iov_len, - msg.msg_flags); - trace_dlm_recv(con->nodeid, ret); - if (ret == -EAGAIN) + dlm_process_incoming_buffer(pentry->nodeid, pentry->buf, + pentry->buflen); + add_processed_node(pentry->nodeid, &processed_nodes); + free_processqueue_entry(pentry); + + spin_lock(&processqueue_lock); + pentry = list_first_entry_or_null(&processqueue, + struct processqueue_entry, list); + if (!pentry) { + process_dlm_messages_pending = false; + spin_unlock(&processqueue_lock); break; - else if (ret <= 0) - goto out_close; - - /* new buflen according readed bytes and leftover from last receive */ - buflen = ret + con->rx_leftover; - ret = dlm_process_incoming_buffer(con->nodeid, con->rx_buf, buflen); - if (ret < 0) - goto out_close; - - /* calculate leftover bytes from process and put it into begin of - * the receive buffer, so next receive we have the full message - * at the start address of the receive buffer. - */ - con->rx_leftover = buflen - ret; - if (con->rx_leftover) { - memmove(con->rx_buf, con->rx_buf + ret, - con->rx_leftover); } + + list_del(&pentry->list); + spin_unlock(&processqueue_lock); + } + + /* send ack back after we processed couple of messages */ + list_for_each_entry_safe(n, n_tmp, &processed_nodes, list) { + list_del(&n->list); + dlm_midcomms_receive_done(n->nodeid); + kfree(n); + } +} + +/* Data received from remote end */ +static int receive_from_sock(struct connection *con, int buflen) +{ + struct processqueue_entry *pentry; + int ret, buflen_real; + struct msghdr msg; + struct kvec iov; + + pentry = new_processqueue_entry(con->nodeid, buflen); + if (!pentry) + return DLM_IO_RESCHED; + + memcpy(pentry->buf, con->rx_leftover_buf, con->rx_leftover); + + /* calculate new buffer parameter regarding last receive and + * possible leftover bytes + */ + iov.iov_base = pentry->buf + con->rx_leftover; + iov.iov_len = buflen - con->rx_leftover; + + memset(&msg, 0, sizeof(msg)); + msg.msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL; + clear_bit(CF_RECV_INTR, &con->flags); +again: + ret = kernel_recvmsg(con->sock, &msg, &iov, 1, iov.iov_len, + msg.msg_flags); + trace_dlm_recv(con->nodeid, ret); + if (ret == -EAGAIN) { + lock_sock(con->sock->sk); + if (test_and_clear_bit(CF_RECV_INTR, &con->flags)) { + release_sock(con->sock->sk); + goto again; + } + + clear_bit(CF_RECV_PENDING, &con->flags); + release_sock(con->sock->sk); + free_processqueue_entry(pentry); + return DLM_IO_END; + } else if (ret == 0) { + /* close will clear CF_RECV_PENDING */ + free_processqueue_entry(pentry); + return DLM_IO_EOF; + } else if (ret < 0) { + free_processqueue_entry(pentry); + return ret; } - dlm_midcomms_receive_done(con->nodeid); - mutex_unlock(&con->sock_mutex); - return 0; + /* new buflen according readed bytes and leftover from last receive */ + buflen_real = ret + con->rx_leftover; + ret = dlm_validate_incoming_buffer(con->nodeid, pentry->buf, + buflen_real); + if (ret < 0) { + free_processqueue_entry(pentry); + return ret; + } -out_resched: - if (!test_and_set_bit(CF_READ_PENDING, &con->flags)) - queue_work(recv_workqueue, &con->rwork); - mutex_unlock(&con->sock_mutex); - return -EAGAIN; - -out_close: - if (ret == 0) { - log_print("connection %p got EOF from %d", - con, con->nodeid); - - mutex_unlock(&con->sock_mutex); - close_connection(con, false, true, false); - /* signal to breaking receive worker */ - ret = -1; - } else { - mutex_unlock(&con->sock_mutex); + pentry->buflen = ret; + + /* calculate leftover bytes from process and put it into begin of + * the receive buffer, so next receive we have the full message + * at the start address of the receive buffer. + */ + con->rx_leftover = buflen_real - ret; + memmove(con->rx_leftover_buf, pentry->buf + ret, + con->rx_leftover); + + spin_lock(&processqueue_lock); + list_add_tail(&pentry->list, &processqueue); + if (!process_dlm_messages_pending) { + process_dlm_messages_pending = true; + queue_work(process_workqueue, &process_work); } - return ret; + spin_unlock(&processqueue_lock); + + return DLM_IO_SUCCESS; } /* Listening socket is busy, accept a connection */ -static int accept_from_sock(struct listen_connection *con) +static int accept_from_sock(void) { - int result; struct sockaddr_storage peeraddr; - struct socket *newsock; - int len, idx; - int nodeid; + int len, idx, result, nodeid; struct connection *newcon; - struct connection *addcon; + struct socket *newsock; unsigned int mark; - if (!con->sock) - return -ENOTCONN; - - result = kernel_accept(con->sock, &newsock, O_NONBLOCK); - if (result < 0) + result = kernel_accept(listen_con.sock, &newsock, O_NONBLOCK); + if (result == -EAGAIN) + return DLM_IO_END; + else if (result < 0) goto accept_err; /* Get the connected socket's peer */ @@ -940,7 +1027,7 @@ static int accept_from_sock(struct listen_connection *con) sock_set_mark(newsock->sk, mark); - mutex_lock(&newcon->sock_mutex); + down_write(&newcon->sock_lock); if (newcon->sock) { struct connection *othercon = newcon->othercon; @@ -948,63 +1035,50 @@ static int accept_from_sock(struct listen_connection *con) othercon = kzalloc(sizeof(*othercon), GFP_NOFS); if (!othercon) { log_print("failed to allocate incoming socket"); - mutex_unlock(&newcon->sock_mutex); + up_write(&newcon->sock_lock); srcu_read_unlock(&connections_srcu, idx); result = -ENOMEM; goto accept_err; } - result = dlm_con_init(othercon, nodeid); - if (result < 0) { - kfree(othercon); - mutex_unlock(&newcon->sock_mutex); - srcu_read_unlock(&connections_srcu, idx); - goto accept_err; - } - - lockdep_set_subclass(&othercon->sock_mutex, 1); - set_bit(CF_IS_OTHERCON, &othercon->flags); + dlm_con_init(othercon, nodeid); + lockdep_set_subclass(&othercon->sock_lock, 1); newcon->othercon = othercon; - othercon->sendcon = newcon; + set_bit(CF_IS_OTHERCON, &othercon->flags); } else { /* close other sock con if we have something new */ - close_connection(othercon, false, true, false); + close_connection(othercon, false); } - mutex_lock(&othercon->sock_mutex); + down_write(&othercon->sock_lock); add_sock(newsock, othercon); - addcon = othercon; - mutex_unlock(&othercon->sock_mutex); + + /* check if we receved something while adding */ + lock_sock(othercon->sock->sk); + lowcomms_queue_rwork(othercon); + release_sock(othercon->sock->sk); + up_write(&othercon->sock_lock); } else { /* accept copies the sk after we've saved the callbacks, so we don't want to save them a second time or comm errors will result in calling sk_error_report recursively. */ add_sock(newsock, newcon); - addcon = newcon; - } - - set_bit(CF_CONNECTED, &addcon->flags); - mutex_unlock(&newcon->sock_mutex); - - /* - * Add it to the active queue in case we got data - * between processing the accept adding the socket - * to the read_sockets list - */ - if (!test_and_set_bit(CF_READ_PENDING, &addcon->flags)) - queue_work(recv_workqueue, &addcon->rwork); + /* check if we receved something while adding */ + lock_sock(newcon->sock->sk); + lowcomms_queue_rwork(newcon); + release_sock(newcon->sock->sk); + } + up_write(&newcon->sock_lock); srcu_read_unlock(&connections_srcu, idx); - return 0; + return DLM_IO_SUCCESS; accept_err: if (newsock) sock_release(newsock); - if (result != -EAGAIN) - log_print("error accepting connection from node: %d", result); return result; } @@ -1098,7 +1172,7 @@ static struct writequeue_entry *new_wq_entry(struct connection *con, int len, { struct writequeue_entry *e; - spin_lock(&con->writequeue_lock); + spin_lock_bh(&con->writequeue_lock); if (!list_empty(&con->writequeue)) { e = list_last_entry(&con->writequeue, struct writequeue_entry, list); if (DLM_WQ_REMAIN_BYTES(e) >= len) { @@ -1127,7 +1201,7 @@ static struct writequeue_entry *new_wq_entry(struct connection *con, int len, list_add_tail(&e->list, &con->writequeue); out: - spin_unlock(&con->writequeue_lock); + spin_unlock_bh(&con->writequeue_lock); return e; }; @@ -1176,7 +1250,7 @@ struct dlm_msg *dlm_lowcomms_new_msg(int nodeid, int len, gfp_t allocation, len < sizeof(struct dlm_header)) { BUILD_BUG_ON(PAGE_SIZE < DLM_MAX_SOCKET_BUFSIZE); log_print("failed to allocate a buffer of size %d", len); - WARN_ON(1); + WARN_ON_ONCE(1); return NULL; } @@ -1207,7 +1281,7 @@ static void _dlm_lowcomms_commit_msg(struct dlm_msg *msg) struct connection *con = e->con; int users; - spin_lock(&con->writequeue_lock); + spin_lock_bh(&con->writequeue_lock); kref_get(&msg->ref); list_add(&msg->list, &e->msgs); @@ -1216,13 +1290,11 @@ static void _dlm_lowcomms_commit_msg(struct dlm_msg *msg) goto out; e->len = DLM_WQ_LENGTH_BYTES(e); - spin_unlock(&con->writequeue_lock); - queue_work(send_workqueue, &con->swork); - return; + lowcomms_queue_swork(con); out: - spin_unlock(&con->writequeue_lock); + spin_unlock_bh(&con->writequeue_lock); return; } @@ -1244,7 +1316,7 @@ void dlm_lowcomms_put_msg(struct dlm_msg *msg) kref_put(&msg->ref, dlm_msg_release); } -/* does not held connections_srcu, usage workqueue only */ +/* does not held connections_srcu, usage lowcomms_error_report only */ int dlm_lowcomms_resend_msg(struct dlm_msg *msg) { struct dlm_msg *msg_resend; @@ -1270,88 +1342,78 @@ int dlm_lowcomms_resend_msg(struct dlm_msg *msg) } /* Send a message */ -static void send_to_sock(struct connection *con) +static int send_to_sock(struct connection *con) { const int msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL; struct writequeue_entry *e; int len, offset, ret; - int count; - -again: - count = 0; - mutex_lock(&con->sock_mutex); - if (con->sock == NULL) - goto out_connect; - - spin_lock(&con->writequeue_lock); - for (;;) { - e = con_next_wq(con); - if (!e) - break; - - len = e->len; - offset = e->offset; - BUG_ON(len == 0 && e->users == 0); - spin_unlock(&con->writequeue_lock); - - ret = kernel_sendpage(con->sock, e->page, offset, len, - msg_flags); - trace_dlm_send(con->nodeid, ret); - if (ret == -EAGAIN || ret == 0) { - if (ret == -EAGAIN && - test_bit(SOCKWQ_ASYNC_NOSPACE, &con->sock->flags) && - !test_and_set_bit(CF_APP_LIMITED, &con->flags)) { - /* Notify TCP that we're limited by the - * application window size. - */ - set_bit(SOCK_NOSPACE, &con->sock->flags); - con->sock->sk->sk_write_pending++; - } - cond_resched(); - goto out; - } else if (ret < 0) - goto out; + spin_lock_bh(&con->writequeue_lock); + e = con_next_wq(con); + if (!e) { + clear_bit(CF_SEND_PENDING, &con->flags); + spin_unlock_bh(&con->writequeue_lock); + return DLM_IO_END; + } - spin_lock(&con->writequeue_lock); - writequeue_entry_complete(e, ret); + len = e->len; + offset = e->offset; + WARN_ON_ONCE(len == 0 && e->users == 0); + spin_unlock_bh(&con->writequeue_lock); - /* Don't starve people filling buffers */ - if (++count >= MAX_SEND_MSG_COUNT) { - spin_unlock(&con->writequeue_lock); - mutex_unlock(&con->sock_mutex); - cond_resched(); - goto again; + ret = kernel_sendpage(con->sock, e->page, offset, len, + msg_flags); + trace_dlm_send(con->nodeid, ret); + if (ret == -EAGAIN || ret == 0) { + lock_sock(con->sock->sk); + spin_lock_bh(&con->writequeue_lock); + if (test_bit(SOCKWQ_ASYNC_NOSPACE, &con->sock->flags) && + !test_and_set_bit(CF_APP_LIMITED, &con->flags)) { + /* Notify TCP that we're limited by the + * application window size. + */ + set_bit(SOCK_NOSPACE, &con->sock->sk->sk_socket->flags); + con->sock->sk->sk_write_pending++; + + clear_bit(CF_SEND_PENDING, &con->flags); + spin_unlock_bh(&con->writequeue_lock); + release_sock(con->sock->sk); + + /* wait for write_space() event */ + return DLM_IO_END; } + spin_unlock_bh(&con->writequeue_lock); + release_sock(con->sock->sk); + + return DLM_IO_RESCHED; + } else if (ret < 0) { + return ret; } - spin_unlock(&con->writequeue_lock); -out: - mutex_unlock(&con->sock_mutex); - return; + spin_lock_bh(&con->writequeue_lock); + writequeue_entry_complete(e, ret); + spin_unlock_bh(&con->writequeue_lock); -out_connect: - mutex_unlock(&con->sock_mutex); - queue_work(send_workqueue, &con->swork); - cond_resched(); + return DLM_IO_SUCCESS; } static void clean_one_writequeue(struct connection *con) { struct writequeue_entry *e, *safe; - spin_lock(&con->writequeue_lock); + spin_lock_bh(&con->writequeue_lock); list_for_each_entry_safe(e, safe, &con->writequeue, list) { free_entry(e); } - spin_unlock(&con->writequeue_lock); + spin_unlock_bh(&con->writequeue_lock); } static void connection_release(struct rcu_head *rcu) { struct connection *con = container_of(rcu, struct connection, rcu); - kfree(con->rx_buf); + WARN_ON_ONCE(!list_empty(&con->writequeue)); + WARN_ON_ONCE(con->sock); kfree(con); } @@ -1371,12 +1433,14 @@ int dlm_lowcomms_close(int nodeid) return -ENOENT; } + stop_connection_io(con); + log_print("io handling for node: %d stopped", nodeid); + close_connection(con, true); + spin_lock(&connections_lock); hlist_del_rcu(&con->list); spin_unlock(&connections_lock); - close_connection(con, true, true, true); - clean_one_writequeue(con); call_srcu(&connections_srcu, &con->rcu, connection_release); if (con->othercon) { @@ -1386,148 +1450,238 @@ int dlm_lowcomms_close(int nodeid) } srcu_read_unlock(&connections_srcu, idx); + /* for debugging we print when we are done to compare with other + * messages in between. This function need to be correctly synchronized + * with io handling + */ + log_print("closing connection to node %d done", nodeid); + return 0; } -/* Receive workqueue function */ +/* Receive worker function */ static void process_recv_sockets(struct work_struct *work) { struct connection *con = container_of(work, struct connection, rwork); + int ret, buflen; - clear_bit(CF_READ_PENDING, &con->flags); - receive_from_sock(con); + down_read(&con->sock_lock); + if (!con->sock) { + up_read(&con->sock_lock); + return; + } + + buflen = READ_ONCE(dlm_config.ci_buffer_size); + do { + ret = receive_from_sock(con, buflen); + } while (ret == DLM_IO_SUCCESS); + up_read(&con->sock_lock); + + switch (ret) { + case DLM_IO_END: + /* CF_RECV_PENDING cleared */ + break; + case DLM_IO_EOF: + close_connection(con, false); + /* CF_RECV_PENDING cleared */ + break; + case DLM_IO_RESCHED: + cond_resched(); + queue_work(io_workqueue, &con->rwork); + /* CF_RECV_PENDING not cleared */ + break; + default: + if (ret < 0) { + if (test_bit(CF_IS_OTHERCON, &con->flags)) { + close_connection(con, false); + } else { + spin_lock_bh(&con->writequeue_lock); + lowcomms_queue_swork(con); + spin_unlock_bh(&con->writequeue_lock); + } + + /* CF_RECV_PENDING cleared for othercon + * we trigger send queue if not already done + * and process_send_sockets will handle it + */ + break; + } + + WARN_ON_ONCE(1); + break; + } } static void process_listen_recv_socket(struct work_struct *work) { int ret; + if (WARN_ON_ONCE(!listen_con.sock)) + return; + do { - ret = accept_from_sock(&listen_con); - } while (!ret); + ret = accept_from_sock(); + } while (ret == DLM_IO_SUCCESS); + + if (ret < 0) + log_print("critical error accepting connection: %d", ret); } -static void dlm_connect(struct connection *con) +static int dlm_connect(struct connection *con) { struct sockaddr_storage addr; int result, addr_len; struct socket *sock; unsigned int mark; - /* Some odd races can cause double-connects, ignore them */ - if (con->retries++ > MAX_CONNECT_RETRIES) - return; - - if (con->sock) { - log_print("node %d already connected.", con->nodeid); - return; - } - memset(&addr, 0, sizeof(addr)); result = nodeid_to_addr(con->nodeid, &addr, NULL, dlm_proto_ops->try_new_addr, &mark); if (result < 0) { log_print("no address for nodeid %d", con->nodeid); - return; + return result; } /* Create a socket to communicate with */ result = sock_create_kern(&init_net, dlm_local_addr[0].ss_family, SOCK_STREAM, dlm_proto_ops->proto, &sock); if (result < 0) - goto socket_err; + return result; sock_set_mark(sock->sk, mark); dlm_proto_ops->sockopts(sock); - add_sock(sock, con); - result = dlm_proto_ops->bind(sock); - if (result < 0) - goto add_sock_err; + if (result < 0) { + sock_release(sock); + return result; + } + + add_sock(sock, con); log_print_ratelimited("connecting to %d", con->nodeid); make_sockaddr(&addr, dlm_config.ci_tcp_port, &addr_len); result = dlm_proto_ops->connect(con, sock, (struct sockaddr *)&addr, addr_len); - if (result < 0) - goto add_sock_err; - - return; - -add_sock_err: - dlm_close_sock(&con->sock); + switch (result) { + case -EINPROGRESS: + /* not an error */ + fallthrough; + case 0: + break; + default: + if (result < 0) + dlm_close_sock(&con->sock); -socket_err: - /* - * Some errors are fatal and this list might need adjusting. For other - * errors we try again until the max number of retries is reached. - */ - if (result != -EHOSTUNREACH && - result != -ENETUNREACH && - result != -ENETDOWN && - result != -EINVAL && - result != -EPROTONOSUPPORT) { - log_print("connect %d try %d error %d", con->nodeid, - con->retries, result); - msleep(1000); - lowcomms_connect_sock(con); + break; } + + return result; } -/* Send workqueue function */ +/* Send worker function */ static void process_send_sockets(struct work_struct *work) { struct connection *con = container_of(work, struct connection, swork); + int ret; - WARN_ON(test_bit(CF_IS_OTHERCON, &con->flags)); + WARN_ON_ONCE(test_bit(CF_IS_OTHERCON, &con->flags)); + + down_read(&con->sock_lock); + if (!con->sock) { + up_read(&con->sock_lock); + down_write(&con->sock_lock); + if (!con->sock) { + ret = dlm_connect(con); + switch (ret) { + case 0: + break; + case -EINPROGRESS: + /* avoid spamming resched on connection + * we might can switch to a state_change + * event based mechanism if established + */ + msleep(100); + break; + default: + /* CF_SEND_PENDING not cleared */ + up_write(&con->sock_lock); + log_print("connect to node %d try %d error %d", + con->nodeid, con->retries++, ret); + msleep(1000); + /* For now we try forever to reconnect. In + * future we should send a event to cluster + * manager to fence itself after certain amount + * of retries. + */ + queue_work(io_workqueue, &con->swork); + return; + } + } + downgrade_write(&con->sock_lock); + } - clear_bit(CF_WRITE_PENDING, &con->flags); + do { + ret = send_to_sock(con); + } while (ret == DLM_IO_SUCCESS); + up_read(&con->sock_lock); - if (test_and_clear_bit(CF_RECONNECT, &con->flags)) { - close_connection(con, false, false, true); - dlm_midcomms_unack_msg_resend(con->nodeid); - } + switch (ret) { + case DLM_IO_END: + /* CF_SEND_PENDING cleared */ + break; + case DLM_IO_RESCHED: + /* CF_SEND_PENDING not cleared */ + cond_resched(); + queue_work(io_workqueue, &con->swork); + break; + default: + if (ret < 0) { + close_connection(con, false); - if (con->sock == NULL) { - if (test_and_clear_bit(CF_DELAY_CONNECT, &con->flags)) - msleep(1000); + /* CF_SEND_PENDING cleared */ + spin_lock_bh(&con->writequeue_lock); + lowcomms_queue_swork(con); + spin_unlock_bh(&con->writequeue_lock); + break; + } - mutex_lock(&con->sock_mutex); - dlm_connect(con); - mutex_unlock(&con->sock_mutex); + WARN_ON_ONCE(1); + break; } - - if (!list_empty(&con->writequeue)) - send_to_sock(con); } static void work_stop(void) { - if (recv_workqueue) { - destroy_workqueue(recv_workqueue); - recv_workqueue = NULL; + if (io_workqueue) { + destroy_workqueue(io_workqueue); + io_workqueue = NULL; } - if (send_workqueue) { - destroy_workqueue(send_workqueue); - send_workqueue = NULL; + if (process_workqueue) { + destroy_workqueue(process_workqueue); + process_workqueue = NULL; } } static int work_start(void) { - recv_workqueue = alloc_ordered_workqueue("dlm_recv", WQ_MEM_RECLAIM); - if (!recv_workqueue) { - log_print("can't start dlm_recv"); + io_workqueue = alloc_workqueue("dlm_io", WQ_HIGHPRI | WQ_MEM_RECLAIM, + 0); + if (!io_workqueue) { + log_print("can't start dlm_io"); return -ENOMEM; } - send_workqueue = alloc_ordered_workqueue("dlm_send", WQ_MEM_RECLAIM); - if (!send_workqueue) { - log_print("can't start dlm_send"); - destroy_workqueue(recv_workqueue); - recv_workqueue = NULL; + /* ordered dlm message process queue, + * should be converted to a tasklet + */ + process_workqueue = alloc_ordered_workqueue("dlm_process", + WQ_HIGHPRI | WQ_MEM_RECLAIM); + if (!process_workqueue) { + log_print("can't start dlm_process"); + destroy_workqueue(io_workqueue); + io_workqueue = NULL; return -ENOMEM; } @@ -1543,6 +1697,8 @@ void dlm_lowcomms_shutdown(void) cancel_work_sync(&listen_con.rwork); dlm_close_sock(&listen_con.sock); + + flush_workqueue(process_workqueue); } void dlm_lowcomms_shutdown_node(int nodeid, bool force) @@ -1558,79 +1714,19 @@ void dlm_lowcomms_shutdown_node(int nodeid, bool force) } flush_work(&con->swork); + stop_connection_io(con); WARN_ON_ONCE(!force && !list_empty(&con->writequeue)); + close_connection(con, true); clean_one_writequeue(con); if (con->othercon) clean_one_writequeue(con->othercon); - close_connection(con, true, true, true); + allow_connection_io(con); srcu_read_unlock(&connections_srcu, idx); } -static void _stop_conn(struct connection *con, bool and_other) -{ - mutex_lock(&con->sock_mutex); - set_bit(CF_CLOSE, &con->flags); - set_bit(CF_READ_PENDING, &con->flags); - set_bit(CF_WRITE_PENDING, &con->flags); - if (con->sock && con->sock->sk) { - lock_sock(con->sock->sk); - con->sock->sk->sk_user_data = NULL; - release_sock(con->sock->sk); - } - if (con->othercon && and_other) - _stop_conn(con->othercon, false); - mutex_unlock(&con->sock_mutex); -} - -static void stop_conn(struct connection *con) -{ - _stop_conn(con, true); -} - -static void free_conn(struct connection *con) -{ - close_connection(con, true, true, true); -} - -static void work_flush(void) -{ - int ok; - int i; - struct connection *con; - - do { - ok = 1; - foreach_conn(stop_conn); - if (recv_workqueue) - flush_workqueue(recv_workqueue); - if (send_workqueue) - flush_workqueue(send_workqueue); - for (i = 0; i < CONN_HASH_SIZE && ok; i++) { - hlist_for_each_entry_rcu(con, &connection_hash[i], - list) { - ok &= test_bit(CF_READ_PENDING, &con->flags); - ok &= test_bit(CF_WRITE_PENDING, &con->flags); - if (con->othercon) { - ok &= test_bit(CF_READ_PENDING, - &con->othercon->flags); - ok &= test_bit(CF_WRITE_PENDING, - &con->othercon->flags); - } - } - } - } while (!ok); -} - void dlm_lowcomms_stop(void) { - int idx; - - idx = srcu_read_lock(&connections_srcu); - work_flush(); - foreach_conn(free_conn); - srcu_read_unlock(&connections_srcu, idx); work_stop(); - dlm_proto_ops = NULL; } @@ -1709,17 +1805,7 @@ static int dlm_tcp_bind(struct socket *sock) static int dlm_tcp_connect(struct connection *con, struct socket *sock, struct sockaddr *addr, int addr_len) { - int ret; - - ret = sock->ops->connect(sock, addr, addr_len, O_NONBLOCK); - switch (ret) { - case -EINPROGRESS: - fallthrough; - case 0: - return 0; - } - - return ret; + return sock->ops->connect(sock, addr, addr_len, O_NONBLOCK); } static int dlm_tcp_listen_validate(void) @@ -1784,13 +1870,7 @@ static int dlm_sctp_connect(struct connection *con, struct socket *sock, sock_set_sndtimeo(sock->sk, 5); ret = sock->ops->connect(sock, addr, addr_len, 0); sock_set_sndtimeo(sock->sk, 0); - if (ret < 0) - return ret; - - if (!test_and_set_bit(CF_CONNECTED, &con->flags)) - log_print("connected to node %d", con->nodeid); - - return 0; + return ret; } static int dlm_sctp_listen_validate(void) |