diff options
Diffstat (limited to 'fs/afs/rxrpc.c')
| -rw-r--r-- | fs/afs/rxrpc.c | 862 |
1 files changed, 862 insertions, 0 deletions
diff --git a/fs/afs/rxrpc.c b/fs/afs/rxrpc.c new file mode 100644 index 000000000..3a57a1b0f --- /dev/null +++ b/fs/afs/rxrpc.c @@ -0,0 +1,862 @@ +/* Maintain an RxRPC server socket to do AFS communications through + * + * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#include <linux/slab.h> +#include <net/sock.h> +#include <net/af_rxrpc.h> +#include <rxrpc/packet.h> +#include "internal.h" +#include "afs_cm.h" + +static struct socket *afs_socket; /* my RxRPC socket */ +static struct workqueue_struct *afs_async_calls; +static atomic_t afs_outstanding_calls; +static atomic_t afs_outstanding_skbs; + +static void afs_wake_up_call_waiter(struct afs_call *); +static int afs_wait_for_call_to_complete(struct afs_call *); +static void afs_wake_up_async_call(struct afs_call *); +static int afs_dont_wait_for_call_to_complete(struct afs_call *); +static void afs_process_async_call(struct afs_call *); +static void afs_rx_interceptor(struct sock *, unsigned long, struct sk_buff *); +static int afs_deliver_cm_op_id(struct afs_call *, struct sk_buff *, bool); + +/* synchronous call management */ +const struct afs_wait_mode afs_sync_call = { + .rx_wakeup = afs_wake_up_call_waiter, + .wait = afs_wait_for_call_to_complete, +}; + +/* asynchronous call management */ +const struct afs_wait_mode afs_async_call = { + .rx_wakeup = afs_wake_up_async_call, + .wait = afs_dont_wait_for_call_to_complete, +}; + +/* asynchronous incoming call management */ +static const struct afs_wait_mode afs_async_incoming_call = { + .rx_wakeup = afs_wake_up_async_call, +}; + +/* asynchronous incoming call initial processing */ +static const struct afs_call_type afs_RXCMxxxx = { + .name = "CB.xxxx", + .deliver = afs_deliver_cm_op_id, + .abort_to_error = afs_abort_to_error, +}; + +static void afs_collect_incoming_call(struct work_struct *); + +static struct sk_buff_head afs_incoming_calls; +static DECLARE_WORK(afs_collect_incoming_call_work, afs_collect_incoming_call); + +static void afs_async_workfn(struct work_struct *work) +{ + struct afs_call *call = container_of(work, struct afs_call, async_work); + + call->async_workfn(call); +} + +/* + * open an RxRPC socket and bind it to be a server for callback notifications + * - the socket is left in blocking mode and non-blocking ops use MSG_DONTWAIT + */ +int afs_open_socket(void) +{ + struct sockaddr_rxrpc srx; + struct socket *socket; + int ret; + + _enter(""); + + skb_queue_head_init(&afs_incoming_calls); + + afs_async_calls = create_singlethread_workqueue("kafsd"); + if (!afs_async_calls) { + _leave(" = -ENOMEM [wq]"); + return -ENOMEM; + } + + ret = sock_create_kern(AF_RXRPC, SOCK_DGRAM, PF_INET, &socket); + if (ret < 0) { + destroy_workqueue(afs_async_calls); + _leave(" = %d [socket]", ret); + return ret; + } + + socket->sk->sk_allocation = GFP_NOFS; + + /* bind the callback manager's address to make this a server socket */ + srx.srx_family = AF_RXRPC; + srx.srx_service = CM_SERVICE; + srx.transport_type = SOCK_DGRAM; + srx.transport_len = sizeof(srx.transport.sin); + srx.transport.sin.sin_family = AF_INET; + srx.transport.sin.sin_port = htons(AFS_CM_PORT); + memset(&srx.transport.sin.sin_addr, 0, + sizeof(srx.transport.sin.sin_addr)); + + ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx)); + if (ret < 0) { + sock_release(socket); + destroy_workqueue(afs_async_calls); + _leave(" = %d [bind]", ret); + return ret; + } + + rxrpc_kernel_intercept_rx_messages(socket, afs_rx_interceptor); + + afs_socket = socket; + _leave(" = 0"); + return 0; +} + +/* + * close the RxRPC socket AFS was using + */ +void afs_close_socket(void) +{ + _enter(""); + + sock_release(afs_socket); + + _debug("dework"); + destroy_workqueue(afs_async_calls); + + ASSERTCMP(atomic_read(&afs_outstanding_skbs), ==, 0); + ASSERTCMP(atomic_read(&afs_outstanding_calls), ==, 0); + _leave(""); +} + +/* + * note that the data in a socket buffer is now delivered and that the buffer + * should be freed + */ +static void afs_data_delivered(struct sk_buff *skb) +{ + if (!skb) { + _debug("DLVR NULL [%d]", atomic_read(&afs_outstanding_skbs)); + dump_stack(); + } else { + _debug("DLVR %p{%u} [%d]", + skb, skb->mark, atomic_read(&afs_outstanding_skbs)); + if (atomic_dec_return(&afs_outstanding_skbs) == -1) + BUG(); + rxrpc_kernel_data_delivered(skb); + } +} + +/* + * free a socket buffer + */ +static void afs_free_skb(struct sk_buff *skb) +{ + if (!skb) { + _debug("FREE NULL [%d]", atomic_read(&afs_outstanding_skbs)); + dump_stack(); + } else { + _debug("FREE %p{%u} [%d]", + skb, skb->mark, atomic_read(&afs_outstanding_skbs)); + if (atomic_dec_return(&afs_outstanding_skbs) == -1) + BUG(); + rxrpc_kernel_free_skb(skb); + } +} + +/* + * free a call + */ +static void afs_free_call(struct afs_call *call) +{ + _debug("DONE %p{%s} [%d]", + call, call->type->name, atomic_read(&afs_outstanding_calls)); + if (atomic_dec_return(&afs_outstanding_calls) == -1) + BUG(); + + ASSERTCMP(call->rxcall, ==, NULL); + ASSERT(!work_pending(&call->async_work)); + ASSERT(skb_queue_empty(&call->rx_queue)); + ASSERT(call->type->name != NULL); + + kfree(call->request); + kfree(call); +} + +/* + * End a call but do not free it + */ +static void afs_end_call_nofree(struct afs_call *call) +{ + if (call->rxcall) { + rxrpc_kernel_end_call(call->rxcall); + call->rxcall = NULL; + } + if (call->type->destructor) + call->type->destructor(call); +} + +/* + * End a call and free it + */ +static void afs_end_call(struct afs_call *call) +{ + afs_end_call_nofree(call); + afs_free_call(call); +} + +/* + * allocate a call with flat request and reply buffers + */ +struct afs_call *afs_alloc_flat_call(const struct afs_call_type *type, + size_t request_size, size_t reply_size) +{ + struct afs_call *call; + + call = kzalloc(sizeof(*call), GFP_NOFS); + if (!call) + goto nomem_call; + + _debug("CALL %p{%s} [%d]", + call, type->name, atomic_read(&afs_outstanding_calls)); + atomic_inc(&afs_outstanding_calls); + + call->type = type; + call->request_size = request_size; + call->reply_max = reply_size; + + if (request_size) { + call->request = kmalloc(request_size, GFP_NOFS); + if (!call->request) + goto nomem_free; + } + + if (reply_size) { + call->buffer = kmalloc(reply_size, GFP_NOFS); + if (!call->buffer) + goto nomem_free; + } + + init_waitqueue_head(&call->waitq); + skb_queue_head_init(&call->rx_queue); + return call; + +nomem_free: + afs_free_call(call); +nomem_call: + return NULL; +} + +/* + * clean up a call with flat buffer + */ +void afs_flat_call_destructor(struct afs_call *call) +{ + _enter(""); + + kfree(call->request); + call->request = NULL; + kfree(call->buffer); + call->buffer = NULL; +} + +/* + * attach the data from a bunch of pages on an inode to a call + */ +static int afs_send_pages(struct afs_call *call, struct msghdr *msg, + struct kvec *iov) +{ + struct page *pages[8]; + unsigned count, n, loop, offset, to; + pgoff_t first = call->first, last = call->last; + int ret; + + _enter(""); + + offset = call->first_offset; + call->first_offset = 0; + + do { + _debug("attach %lx-%lx", first, last); + + count = last - first + 1; + if (count > ARRAY_SIZE(pages)) + count = ARRAY_SIZE(pages); + n = find_get_pages_contig(call->mapping, first, count, pages); + ASSERTCMP(n, ==, count); + + loop = 0; + do { + msg->msg_flags = 0; + to = PAGE_SIZE; + if (first + loop >= last) + to = call->last_to; + else + msg->msg_flags = MSG_MORE; + iov->iov_base = kmap(pages[loop]) + offset; + iov->iov_len = to - offset; + offset = 0; + + _debug("- range %u-%u%s", + offset, to, msg->msg_flags ? " [more]" : ""); + iov_iter_kvec(&msg->msg_iter, WRITE | ITER_KVEC, + iov, 1, to - offset); + + /* have to change the state *before* sending the last + * packet as RxRPC might give us the reply before it + * returns from sending the request */ + if (first + loop >= last) + call->state = AFS_CALL_AWAIT_REPLY; + ret = rxrpc_kernel_send_data(call->rxcall, msg, + to - offset); + kunmap(pages[loop]); + if (ret < 0) + break; + } while (++loop < count); + first += count; + + for (loop = 0; loop < count; loop++) + put_page(pages[loop]); + if (ret < 0) + break; + } while (first <= last); + + _leave(" = %d", ret); + return ret; +} + +/* + * initiate a call + */ +int afs_make_call(struct in_addr *addr, struct afs_call *call, gfp_t gfp, + const struct afs_wait_mode *wait_mode) +{ + struct sockaddr_rxrpc srx; + struct rxrpc_call *rxcall; + struct msghdr msg; + struct kvec iov[1]; + int ret; + struct sk_buff *skb; + + _enter("%x,{%d},", addr->s_addr, ntohs(call->port)); + + ASSERT(call->type != NULL); + ASSERT(call->type->name != NULL); + + _debug("____MAKE %p{%s,%x} [%d]____", + call, call->type->name, key_serial(call->key), + atomic_read(&afs_outstanding_calls)); + + call->wait_mode = wait_mode; + call->async_workfn = afs_process_async_call; + INIT_WORK(&call->async_work, afs_async_workfn); + + memset(&srx, 0, sizeof(srx)); + srx.srx_family = AF_RXRPC; + srx.srx_service = call->service_id; + srx.transport_type = SOCK_DGRAM; + srx.transport_len = sizeof(srx.transport.sin); + srx.transport.sin.sin_family = AF_INET; + srx.transport.sin.sin_port = call->port; + memcpy(&srx.transport.sin.sin_addr, addr, 4); + + /* create a call */ + rxcall = rxrpc_kernel_begin_call(afs_socket, &srx, call->key, + (unsigned long) call, gfp); + call->key = NULL; + if (IS_ERR(rxcall)) { + ret = PTR_ERR(rxcall); + goto error_kill_call; + } + + call->rxcall = rxcall; + + /* send the request */ + iov[0].iov_base = call->request; + iov[0].iov_len = call->request_size; + + msg.msg_name = NULL; + msg.msg_namelen = 0; + iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, iov, 1, + call->request_size); + msg.msg_control = NULL; + msg.msg_controllen = 0; + msg.msg_flags = (call->send_pages ? MSG_MORE : 0); + + /* have to change the state *before* sending the last packet as RxRPC + * might give us the reply before it returns from sending the + * request */ + if (!call->send_pages) + call->state = AFS_CALL_AWAIT_REPLY; + ret = rxrpc_kernel_send_data(rxcall, &msg, call->request_size); + if (ret < 0) + goto error_do_abort; + + if (call->send_pages) { + ret = afs_send_pages(call, &msg, iov); + if (ret < 0) + goto error_do_abort; + } + + /* at this point, an async call may no longer exist as it may have + * already completed */ + return wait_mode->wait(call); + +error_do_abort: + rxrpc_kernel_abort_call(rxcall, RX_USER_ABORT); + while ((skb = skb_dequeue(&call->rx_queue))) + afs_free_skb(skb); +error_kill_call: + afs_end_call(call); + _leave(" = %d", ret); + return ret; +} + +/* + * handles intercepted messages that were arriving in the socket's Rx queue + * - called with the socket receive queue lock held to ensure message ordering + * - called with softirqs disabled + */ +static void afs_rx_interceptor(struct sock *sk, unsigned long user_call_ID, + struct sk_buff *skb) +{ + struct afs_call *call = (struct afs_call *) user_call_ID; + + _enter("%p,,%u", call, skb->mark); + + _debug("ICPT %p{%u} [%d]", + skb, skb->mark, atomic_read(&afs_outstanding_skbs)); + + ASSERTCMP(sk, ==, afs_socket->sk); + atomic_inc(&afs_outstanding_skbs); + + if (!call) { + /* its an incoming call for our callback service */ + skb_queue_tail(&afs_incoming_calls, skb); + queue_work(afs_wq, &afs_collect_incoming_call_work); + } else { + /* route the messages directly to the appropriate call */ + skb_queue_tail(&call->rx_queue, skb); + call->wait_mode->rx_wakeup(call); + } + + _leave(""); +} + +/* + * deliver messages to a call + */ +static void afs_deliver_to_call(struct afs_call *call) +{ + struct sk_buff *skb; + bool last; + u32 abort_code; + int ret; + + _enter(""); + + while ((call->state == AFS_CALL_AWAIT_REPLY || + call->state == AFS_CALL_AWAIT_OP_ID || + call->state == AFS_CALL_AWAIT_REQUEST || + call->state == AFS_CALL_AWAIT_ACK) && + (skb = skb_dequeue(&call->rx_queue))) { + switch (skb->mark) { + case RXRPC_SKB_MARK_DATA: + _debug("Rcv DATA"); + last = rxrpc_kernel_is_data_last(skb); + ret = call->type->deliver(call, skb, last); + switch (ret) { + case 0: + if (last && + call->state == AFS_CALL_AWAIT_REPLY) + call->state = AFS_CALL_COMPLETE; + break; + case -ENOTCONN: + abort_code = RX_CALL_DEAD; + goto do_abort; + case -ENOTSUPP: + abort_code = RX_INVALID_OPERATION; + goto do_abort; + default: + abort_code = RXGEN_CC_UNMARSHAL; + if (call->state != AFS_CALL_AWAIT_REPLY) + abort_code = RXGEN_SS_UNMARSHAL; + do_abort: + rxrpc_kernel_abort_call(call->rxcall, + abort_code); + call->error = ret; + call->state = AFS_CALL_ERROR; + break; + } + afs_data_delivered(skb); + skb = NULL; + continue; + case RXRPC_SKB_MARK_FINAL_ACK: + _debug("Rcv ACK"); + call->state = AFS_CALL_COMPLETE; + break; + case RXRPC_SKB_MARK_BUSY: + _debug("Rcv BUSY"); + call->error = -EBUSY; + call->state = AFS_CALL_BUSY; + break; + case RXRPC_SKB_MARK_REMOTE_ABORT: + abort_code = rxrpc_kernel_get_abort_code(skb); + call->error = call->type->abort_to_error(abort_code); + call->state = AFS_CALL_ABORTED; + _debug("Rcv ABORT %u -> %d", abort_code, call->error); + break; + case RXRPC_SKB_MARK_NET_ERROR: + call->error = -rxrpc_kernel_get_error_number(skb); + call->state = AFS_CALL_ERROR; + _debug("Rcv NET ERROR %d", call->error); + break; + case RXRPC_SKB_MARK_LOCAL_ERROR: + call->error = -rxrpc_kernel_get_error_number(skb); + call->state = AFS_CALL_ERROR; + _debug("Rcv LOCAL ERROR %d", call->error); + break; + default: + BUG(); + break; + } + + afs_free_skb(skb); + } + + /* make sure the queue is empty if the call is done with (we might have + * aborted the call early because of an unmarshalling error) */ + if (call->state >= AFS_CALL_COMPLETE) { + while ((skb = skb_dequeue(&call->rx_queue))) + afs_free_skb(skb); + if (call->incoming) + afs_end_call(call); + } + + _leave(""); +} + +/* + * wait synchronously for a call to complete + */ +static int afs_wait_for_call_to_complete(struct afs_call *call) +{ + struct sk_buff *skb; + int ret; + + DECLARE_WAITQUEUE(myself, current); + + _enter(""); + + add_wait_queue(&call->waitq, &myself); + for (;;) { + set_current_state(TASK_INTERRUPTIBLE); + + /* deliver any messages that are in the queue */ + if (!skb_queue_empty(&call->rx_queue)) { + __set_current_state(TASK_RUNNING); + afs_deliver_to_call(call); + continue; + } + + ret = call->error; + if (call->state >= AFS_CALL_COMPLETE) + break; + ret = -EINTR; + if (signal_pending(current)) + break; + schedule(); + } + + remove_wait_queue(&call->waitq, &myself); + __set_current_state(TASK_RUNNING); + + /* kill the call */ + if (call->state < AFS_CALL_COMPLETE) { + _debug("call incomplete"); + rxrpc_kernel_abort_call(call->rxcall, RX_CALL_DEAD); + while ((skb = skb_dequeue(&call->rx_queue))) + afs_free_skb(skb); + } + + _debug("call complete"); + afs_end_call(call); + _leave(" = %d", ret); + return ret; +} + +/* + * wake up a waiting call + */ +static void afs_wake_up_call_waiter(struct afs_call *call) +{ + wake_up(&call->waitq); +} + +/* + * wake up an asynchronous call + */ +static void afs_wake_up_async_call(struct afs_call *call) +{ + _enter(""); + queue_work(afs_async_calls, &call->async_work); +} + +/* + * put a call into asynchronous mode + * - mustn't touch the call descriptor as the call my have completed by the + * time we get here + */ +static int afs_dont_wait_for_call_to_complete(struct afs_call *call) +{ + _enter(""); + return -EINPROGRESS; +} + +/* + * delete an asynchronous call + */ +static void afs_delete_async_call(struct afs_call *call) +{ + _enter(""); + + afs_free_call(call); + + _leave(""); +} + +/* + * perform processing on an asynchronous call + * - on a multiple-thread workqueue this work item may try to run on several + * CPUs at the same time + */ +static void afs_process_async_call(struct afs_call *call) +{ + _enter(""); + + if (!skb_queue_empty(&call->rx_queue)) + afs_deliver_to_call(call); + + if (call->state >= AFS_CALL_COMPLETE && call->wait_mode) { + if (call->wait_mode->async_complete) + call->wait_mode->async_complete(call->reply, + call->error); + call->reply = NULL; + + /* kill the call */ + afs_end_call_nofree(call); + + /* we can't just delete the call because the work item may be + * queued */ + call->async_workfn = afs_delete_async_call; + queue_work(afs_async_calls, &call->async_work); + } + + _leave(""); +} + +/* + * empty a socket buffer into a flat reply buffer + */ +void afs_transfer_reply(struct afs_call *call, struct sk_buff *skb) +{ + size_t len = skb->len; + + if (skb_copy_bits(skb, 0, call->buffer + call->reply_size, len) < 0) + BUG(); + call->reply_size += len; +} + +/* + * accept the backlog of incoming calls + */ +static void afs_collect_incoming_call(struct work_struct *work) +{ + struct rxrpc_call *rxcall; + struct afs_call *call = NULL; + struct sk_buff *skb; + + while ((skb = skb_dequeue(&afs_incoming_calls))) { + _debug("new call"); + + /* don't need the notification */ + afs_free_skb(skb); + + if (!call) { + call = kzalloc(sizeof(struct afs_call), GFP_KERNEL); + if (!call) { + rxrpc_kernel_reject_call(afs_socket); + return; + } + + call->async_workfn = afs_process_async_call; + INIT_WORK(&call->async_work, afs_async_workfn); + call->wait_mode = &afs_async_incoming_call; + call->type = &afs_RXCMxxxx; + init_waitqueue_head(&call->waitq); + skb_queue_head_init(&call->rx_queue); + call->state = AFS_CALL_AWAIT_OP_ID; + + _debug("CALL %p{%s} [%d]", + call, call->type->name, + atomic_read(&afs_outstanding_calls)); + atomic_inc(&afs_outstanding_calls); + } + + rxcall = rxrpc_kernel_accept_call(afs_socket, + (unsigned long) call); + if (!IS_ERR(rxcall)) { + call->rxcall = rxcall; + call = NULL; + } + } + + if (call) + afs_free_call(call); +} + +/* + * grab the operation ID from an incoming cache manager call + */ +static int afs_deliver_cm_op_id(struct afs_call *call, struct sk_buff *skb, + bool last) +{ + size_t len = skb->len; + void *oibuf = (void *) &call->operation_ID; + + _enter("{%u},{%zu},%d", call->offset, len, last); + + ASSERTCMP(call->offset, <, 4); + + /* the operation ID forms the first four bytes of the request data */ + len = min_t(size_t, len, 4 - call->offset); + if (skb_copy_bits(skb, 0, oibuf + call->offset, len) < 0) + BUG(); + if (!pskb_pull(skb, len)) + BUG(); + call->offset += len; + + if (call->offset < 4) { + if (last) { + _leave(" = -EBADMSG [op ID short]"); + return -EBADMSG; + } + _leave(" = 0 [incomplete]"); + return 0; + } + + call->state = AFS_CALL_AWAIT_REQUEST; + + /* ask the cache manager to route the call (it'll change the call type + * if successful) */ + if (!afs_cm_incoming_call(call)) + return -ENOTSUPP; + + /* pass responsibility for the remainer of this message off to the + * cache manager op */ + return call->type->deliver(call, skb, last); +} + +/* + * send an empty reply + */ +void afs_send_empty_reply(struct afs_call *call) +{ + struct msghdr msg; + + _enter(""); + + msg.msg_name = NULL; + msg.msg_namelen = 0; + iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, NULL, 0, 0); + msg.msg_control = NULL; + msg.msg_controllen = 0; + msg.msg_flags = 0; + + call->state = AFS_CALL_AWAIT_ACK; + switch (rxrpc_kernel_send_data(call->rxcall, &msg, 0)) { + case 0: + _leave(" [replied]"); + return; + + case -ENOMEM: + _debug("oom"); + rxrpc_kernel_abort_call(call->rxcall, RX_USER_ABORT); + default: + afs_end_call(call); + _leave(" [error]"); + return; + } +} + +/* + * send a simple reply + */ +void afs_send_simple_reply(struct afs_call *call, const void *buf, size_t len) +{ + struct msghdr msg; + struct kvec iov[1]; + int n; + + _enter(""); + + iov[0].iov_base = (void *) buf; + iov[0].iov_len = len; + msg.msg_name = NULL; + msg.msg_namelen = 0; + iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, iov, 1, len); + msg.msg_control = NULL; + msg.msg_controllen = 0; + msg.msg_flags = 0; + + call->state = AFS_CALL_AWAIT_ACK; + n = rxrpc_kernel_send_data(call->rxcall, &msg, len); + if (n >= 0) { + /* Success */ + _leave(" [replied]"); + return; + } + + if (n == -ENOMEM) { + _debug("oom"); + rxrpc_kernel_abort_call(call->rxcall, RX_USER_ABORT); + } + afs_end_call(call); + _leave(" [error]"); +} + +/* + * extract a piece of data from the received data socket buffers + */ +int afs_extract_data(struct afs_call *call, struct sk_buff *skb, + bool last, void *buf, size_t count) +{ + size_t len = skb->len; + + _enter("{%u},{%zu},%d,,%zu", call->offset, len, last, count); + + ASSERTCMP(call->offset, <, count); + + len = min_t(size_t, len, count - call->offset); + if (skb_copy_bits(skb, 0, buf + call->offset, len) < 0 || + !pskb_pull(skb, len)) + BUG(); + call->offset += len; + + if (call->offset < count) { + if (last) { + _leave(" = -EBADMSG [%d < %zu]", call->offset, count); + return -EBADMSG; + } + _leave(" = -EAGAIN"); + return -EAGAIN; + } + return 0; +} |