linux/fs/afs/rxrpc.c
Linus Torvalds 9daa0a27a0 AFS Changes
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Merge tag 'afs-next-20200604' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs

Pull AFS updates from David Howells:
 "There's some core VFS changes which affect a couple of filesystems:

   - Make the inode hash table RCU safe and providing some RCU-safe
     accessor functions. The search can then be done without taking the
     inode_hash_lock. Care must be taken because the object may be being
     deleted and no wait is made.

   - Allow iunique() to avoid taking the inode_hash_lock.

   - Allow AFS's callback processing to avoid taking the inode_hash_lock
     when using the inode table to find an inode to notify.

   - Improve Ext4's time updating. Konstantin Khlebnikov said "For now,
     I've plugged this issue with try-lock in ext4 lazy time update.
     This solution is much better."

  Then there's a set of changes to make a number of improvements to the
  AFS driver:

   - Improve callback (ie. third party change notification) processing
     by:

      (a) Relying more on the fact we're doing this under RCU and by
          using fewer locks. This makes use of the RCU-based inode
          searching outlined above.

      (b) Moving to keeping volumes in a tree indexed by volume ID
          rather than a flat list.

      (c) Making the server and volume records logically part of the
          cell. This means that a server record now points directly at
          the cell and the tree of volumes is there. This removes an N:M
          mapping table, simplifying things.

   - Improve keeping NAT or firewall channels open for the server
     callbacks to reach the client by actively polling the fileserver on
     a timed basis, instead of only doing it when we have an operation
     to process.

   - Improving detection of delayed or lost callbacks by including the
     parent directory in the list of file IDs to be queried when doing a
     bulk status fetch from lookup. We can then check to see if our copy
     of the directory has changed under us without us getting notified.

   - Determine aliasing of cells (such as a cell that is pointed to be a
     DNS alias). This allows us to avoid having ambiguity due to
     apparently different cells using the same volume and file servers.

   - Improve the fileserver rotation to do more probing when it detects
     that all of the addresses to a server are listed as non-responsive.
     It's possible that an address that previously stopped responding
     has become responsive again.

  Beyond that, lay some foundations for making some calls asynchronous:

   - Turn the fileserver cursor struct into a general operation struct
     and hang the parameters off of that rather than keeping them in
     local variables and hang results off of that rather than the call
     struct.

   - Implement some general operation handling code and simplify the
     callers of operations that affect a volume or a volume component
     (such as a file). Most of the operation is now done by core code.

   - Operations are supplied with a table of operations to issue
     different variants of RPCs and to manage the completion, where all
     the required data is held in the operation object, thereby allowing
     these to be called from a workqueue.

   - Put the standard "if (begin), while(select), call op, end" sequence
     into a canned function that just emulates the current behaviour for
     now.

  There are also some fixes interspersed:

   - Don't let the EACCES from ICMP6 mapping reach the user as such,
     since it's confusing as to whether it's a filesystem error. Convert
     it to EHOSTUNREACH.

   - Don't use the epoch value acquired through probing a server. If we
     have two servers with the same UUID but in different cells, it's
     hard to draw conclusions from them having different epoch values.

   - Don't interpret the argument to the CB.ProbeUuid RPC as a
     fileserver UUID and look up a fileserver from it.

   - Deal with servers in different cells having the same UUIDs. In the
     event that a CB.InitCallBackState3 RPC is received, we have to
     break the callback promises for every server record matching that
     UUID.

   - Don't let afs_statfs return values that go below 0.

   - Don't use running fileserver probe state to make server selection
     and address selection decisions on. Only make decisions on final
     state as the running state is cleared at the start of probing"

Acked-by: Al Viro <viro@zeniv.linux.org.uk> (fs/inode.c part)

* tag 'afs-next-20200604' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs: (27 commits)
  afs: Adjust the fileserver rotation algorithm to reprobe/retry more quickly
  afs: Show more a bit more server state in /proc/net/afs/servers
  afs: Don't use probe running state to make decisions outside probe code
  afs: Fix afs_statfs() to not let the values go below zero
  afs: Fix the by-UUID server tree to allow servers with the same UUID
  afs: Reorganise volume and server trees to be rooted on the cell
  afs: Add a tracepoint to track the lifetime of the afs_volume struct
  afs: Detect cell aliases 3 - YFS Cells with a canonical cell name op
  afs: Detect cell aliases 2 - Cells with no root volumes
  afs: Detect cell aliases 1 - Cells with root volumes
  afs: Implement client support for the YFSVL.GetCellName RPC op
  afs: Retain more of the VLDB record for alias detection
  afs: Fix handling of CB.ProbeUuid cache manager op
  afs: Don't get epoch from a server because it may be ambiguous
  afs: Build an abstraction around an "operation" concept
  afs: Rename struct afs_fs_cursor to afs_operation
  afs: Remove the error argument from afs_protocol_error()
  afs: Set error flag rather than return error from file status decode
  afs: Make callback processing more efficient.
  afs: Show more information in /proc/net/afs/servers
  ...
2020-06-05 16:26:36 -07:00

973 lines
24 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/* 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)
*/
#include <linux/slab.h>
#include <linux/sched/signal.h>
#include <net/sock.h>
#include <net/af_rxrpc.h>
#include "internal.h"
#include "afs_cm.h"
#include "protocol_yfs.h"
struct workqueue_struct *afs_async_calls;
static void afs_wake_up_call_waiter(struct sock *, struct rxrpc_call *, unsigned long);
static void afs_wake_up_async_call(struct sock *, struct rxrpc_call *, unsigned long);
static void afs_process_async_call(struct work_struct *);
static void afs_rx_new_call(struct sock *, struct rxrpc_call *, unsigned long);
static void afs_rx_discard_new_call(struct rxrpc_call *, unsigned long);
static int afs_deliver_cm_op_id(struct afs_call *);
/* asynchronous incoming call initial processing */
static const struct afs_call_type afs_RXCMxxxx = {
.name = "CB.xxxx",
.deliver = afs_deliver_cm_op_id,
};
/*
* 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(struct afs_net *net)
{
struct sockaddr_rxrpc srx;
struct socket *socket;
int ret;
_enter("");
ret = sock_create_kern(net->net, AF_RXRPC, SOCK_DGRAM, PF_INET6, &socket);
if (ret < 0)
goto error_1;
socket->sk->sk_allocation = GFP_NOFS;
/* bind the callback manager's address to make this a server socket */
memset(&srx, 0, sizeof(srx));
srx.srx_family = AF_RXRPC;
srx.srx_service = CM_SERVICE;
srx.transport_type = SOCK_DGRAM;
srx.transport_len = sizeof(srx.transport.sin6);
srx.transport.sin6.sin6_family = AF_INET6;
srx.transport.sin6.sin6_port = htons(AFS_CM_PORT);
ret = rxrpc_sock_set_min_security_level(socket->sk,
RXRPC_SECURITY_ENCRYPT);
if (ret < 0)
goto error_2;
ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
if (ret == -EADDRINUSE) {
srx.transport.sin6.sin6_port = 0;
ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
}
if (ret < 0)
goto error_2;
srx.srx_service = YFS_CM_SERVICE;
ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
if (ret < 0)
goto error_2;
/* Ideally, we'd turn on service upgrade here, but we can't because
* OpenAFS is buggy and leaks the userStatus field from packet to
* packet and between FS packets and CB packets - so if we try to do an
* upgrade on an FS packet, OpenAFS will leak that into the CB packet
* it sends back to us.
*/
rxrpc_kernel_new_call_notification(socket, afs_rx_new_call,
afs_rx_discard_new_call);
ret = kernel_listen(socket, INT_MAX);
if (ret < 0)
goto error_2;
net->socket = socket;
afs_charge_preallocation(&net->charge_preallocation_work);
_leave(" = 0");
return 0;
error_2:
sock_release(socket);
error_1:
_leave(" = %d", ret);
return ret;
}
/*
* close the RxRPC socket AFS was using
*/
void afs_close_socket(struct afs_net *net)
{
_enter("");
kernel_listen(net->socket, 0);
flush_workqueue(afs_async_calls);
if (net->spare_incoming_call) {
afs_put_call(net->spare_incoming_call);
net->spare_incoming_call = NULL;
}
_debug("outstanding %u", atomic_read(&net->nr_outstanding_calls));
wait_var_event(&net->nr_outstanding_calls,
!atomic_read(&net->nr_outstanding_calls));
_debug("no outstanding calls");
kernel_sock_shutdown(net->socket, SHUT_RDWR);
flush_workqueue(afs_async_calls);
sock_release(net->socket);
_debug("dework");
_leave("");
}
/*
* Allocate a call.
*/
static struct afs_call *afs_alloc_call(struct afs_net *net,
const struct afs_call_type *type,
gfp_t gfp)
{
struct afs_call *call;
int o;
call = kzalloc(sizeof(*call), gfp);
if (!call)
return NULL;
call->type = type;
call->net = net;
call->debug_id = atomic_inc_return(&rxrpc_debug_id);
atomic_set(&call->usage, 1);
INIT_WORK(&call->async_work, afs_process_async_call);
init_waitqueue_head(&call->waitq);
spin_lock_init(&call->state_lock);
call->iter = &call->def_iter;
o = atomic_inc_return(&net->nr_outstanding_calls);
trace_afs_call(call, afs_call_trace_alloc, 1, o,
__builtin_return_address(0));
return call;
}
/*
* Dispose of a reference on a call.
*/
void afs_put_call(struct afs_call *call)
{
struct afs_net *net = call->net;
int n = atomic_dec_return(&call->usage);
int o = atomic_read(&net->nr_outstanding_calls);
trace_afs_call(call, afs_call_trace_put, n, o,
__builtin_return_address(0));
ASSERTCMP(n, >=, 0);
if (n == 0) {
ASSERT(!work_pending(&call->async_work));
ASSERT(call->type->name != NULL);
if (call->rxcall) {
rxrpc_kernel_end_call(net->socket, call->rxcall);
call->rxcall = NULL;
}
if (call->type->destructor)
call->type->destructor(call);
afs_unuse_server_notime(call->net, call->server, afs_server_trace_put_call);
afs_put_addrlist(call->alist);
kfree(call->request);
trace_afs_call(call, afs_call_trace_free, 0, o,
__builtin_return_address(0));
kfree(call);
o = atomic_dec_return(&net->nr_outstanding_calls);
if (o == 0)
wake_up_var(&net->nr_outstanding_calls);
}
}
static struct afs_call *afs_get_call(struct afs_call *call,
enum afs_call_trace why)
{
int u = atomic_inc_return(&call->usage);
trace_afs_call(call, why, u,
atomic_read(&call->net->nr_outstanding_calls),
__builtin_return_address(0));
return call;
}
/*
* Queue the call for actual work.
*/
static void afs_queue_call_work(struct afs_call *call)
{
if (call->type->work) {
INIT_WORK(&call->work, call->type->work);
afs_get_call(call, afs_call_trace_work);
if (!queue_work(afs_wq, &call->work))
afs_put_call(call);
}
}
/*
* allocate a call with flat request and reply buffers
*/
struct afs_call *afs_alloc_flat_call(struct afs_net *net,
const struct afs_call_type *type,
size_t request_size, size_t reply_max)
{
struct afs_call *call;
call = afs_alloc_call(net, type, GFP_NOFS);
if (!call)
goto nomem_call;
if (request_size) {
call->request_size = request_size;
call->request = kmalloc(request_size, GFP_NOFS);
if (!call->request)
goto nomem_free;
}
if (reply_max) {
call->reply_max = reply_max;
call->buffer = kmalloc(reply_max, GFP_NOFS);
if (!call->buffer)
goto nomem_free;
}
afs_extract_to_buf(call, call->reply_max);
call->operation_ID = type->op;
init_waitqueue_head(&call->waitq);
return call;
nomem_free:
afs_put_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;
}
#define AFS_BVEC_MAX 8
/*
* Load the given bvec with the next few pages.
*/
static void afs_load_bvec(struct afs_call *call, struct msghdr *msg,
struct bio_vec *bv, pgoff_t first, pgoff_t last,
unsigned offset)
{
struct afs_operation *op = call->op;
struct page *pages[AFS_BVEC_MAX];
unsigned int nr, n, i, to, bytes = 0;
nr = min_t(pgoff_t, last - first + 1, AFS_BVEC_MAX);
n = find_get_pages_contig(op->store.mapping, first, nr, pages);
ASSERTCMP(n, ==, nr);
msg->msg_flags |= MSG_MORE;
for (i = 0; i < nr; i++) {
to = PAGE_SIZE;
if (first + i >= last) {
to = op->store.last_to;
msg->msg_flags &= ~MSG_MORE;
}
bv[i].bv_page = pages[i];
bv[i].bv_len = to - offset;
bv[i].bv_offset = offset;
bytes += to - offset;
offset = 0;
}
iov_iter_bvec(&msg->msg_iter, WRITE, bv, nr, bytes);
}
/*
* Advance the AFS call state when the RxRPC call ends the transmit phase.
*/
static void afs_notify_end_request_tx(struct sock *sock,
struct rxrpc_call *rxcall,
unsigned long call_user_ID)
{
struct afs_call *call = (struct afs_call *)call_user_ID;
afs_set_call_state(call, AFS_CALL_CL_REQUESTING, AFS_CALL_CL_AWAIT_REPLY);
}
/*
* 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 afs_operation *op = call->op;
struct bio_vec bv[AFS_BVEC_MAX];
unsigned int bytes, nr, loop, offset;
pgoff_t first = op->store.first, last = op->store.last;
int ret;
offset = op->store.first_offset;
op->store.first_offset = 0;
do {
afs_load_bvec(call, msg, bv, first, last, offset);
trace_afs_send_pages(call, msg, first, last, offset);
offset = 0;
bytes = msg->msg_iter.count;
nr = msg->msg_iter.nr_segs;
ret = rxrpc_kernel_send_data(op->net->socket, call->rxcall, msg,
bytes, afs_notify_end_request_tx);
for (loop = 0; loop < nr; loop++)
put_page(bv[loop].bv_page);
if (ret < 0)
break;
first += nr;
} while (first <= last);
trace_afs_sent_pages(call, op->store.first, last, first, ret);
return ret;
}
/*
* Initiate a call and synchronously queue up the parameters for dispatch. Any
* error is stored into the call struct, which the caller must check for.
*/
void afs_make_call(struct afs_addr_cursor *ac, struct afs_call *call, gfp_t gfp)
{
struct sockaddr_rxrpc *srx = &ac->alist->addrs[ac->index];
struct rxrpc_call *rxcall;
struct msghdr msg;
struct kvec iov[1];
s64 tx_total_len;
int ret;
_enter(",{%pISp},", &srx->transport);
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(&call->net->nr_outstanding_calls));
call->addr_ix = ac->index;
call->alist = afs_get_addrlist(ac->alist);
/* Work out the length we're going to transmit. This is awkward for
* calls such as FS.StoreData where there's an extra injection of data
* after the initial fixed part.
*/
tx_total_len = call->request_size;
if (call->send_pages) {
struct afs_operation *op = call->op;
if (op->store.last == op->store.first) {
tx_total_len += op->store.last_to - op->store.first_offset;
} else {
/* It looks mathematically like you should be able to
* combine the following lines with the ones above, but
* unsigned arithmetic is fun when it wraps...
*/
tx_total_len += PAGE_SIZE - op->store.first_offset;
tx_total_len += op->store.last_to;
tx_total_len += (op->store.last - op->store.first - 1) * PAGE_SIZE;
}
}
/* If the call is going to be asynchronous, we need an extra ref for
* the call to hold itself so the caller need not hang on to its ref.
*/
if (call->async) {
afs_get_call(call, afs_call_trace_get);
call->drop_ref = true;
}
/* create a call */
rxcall = rxrpc_kernel_begin_call(call->net->socket, srx, call->key,
(unsigned long)call,
tx_total_len, gfp,
(call->async ?
afs_wake_up_async_call :
afs_wake_up_call_waiter),
call->upgrade,
(call->intr ? RXRPC_PREINTERRUPTIBLE :
RXRPC_UNINTERRUPTIBLE),
call->debug_id);
if (IS_ERR(rxcall)) {
ret = PTR_ERR(rxcall);
call->error = ret;
goto error_kill_call;
}
call->rxcall = rxcall;
if (call->max_lifespan)
rxrpc_kernel_set_max_life(call->net->socket, rxcall,
call->max_lifespan);
/* 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, iov, 1, call->request_size);
msg.msg_control = NULL;
msg.msg_controllen = 0;
msg.msg_flags = MSG_WAITALL | (call->send_pages ? MSG_MORE : 0);
ret = rxrpc_kernel_send_data(call->net->socket, rxcall,
&msg, call->request_size,
afs_notify_end_request_tx);
if (ret < 0)
goto error_do_abort;
if (call->send_pages) {
ret = afs_send_pages(call, &msg);
if (ret < 0)
goto error_do_abort;
}
/* Note that at this point, we may have received the reply or an abort
* - and an asynchronous call may already have completed.
*
* afs_wait_for_call_to_complete(call, ac)
* must be called to synchronously clean up.
*/
return;
error_do_abort:
if (ret != -ECONNABORTED) {
rxrpc_kernel_abort_call(call->net->socket, rxcall,
RX_USER_ABORT, ret, "KSD");
} else {
iov_iter_kvec(&msg.msg_iter, READ, NULL, 0, 0);
rxrpc_kernel_recv_data(call->net->socket, rxcall,
&msg.msg_iter, false,
&call->abort_code, &call->service_id);
ac->abort_code = call->abort_code;
ac->responded = true;
}
call->error = ret;
trace_afs_call_done(call);
error_kill_call:
if (call->type->done)
call->type->done(call);
/* We need to dispose of the extra ref we grabbed for an async call.
* The call, however, might be queued on afs_async_calls and we need to
* make sure we don't get any more notifications that might requeue it.
*/
if (call->rxcall) {
rxrpc_kernel_end_call(call->net->socket, call->rxcall);
call->rxcall = NULL;
}
if (call->async) {
if (cancel_work_sync(&call->async_work))
afs_put_call(call);
afs_put_call(call);
}
ac->error = ret;
call->state = AFS_CALL_COMPLETE;
_leave(" = %d", ret);
}
/*
* deliver messages to a call
*/
static void afs_deliver_to_call(struct afs_call *call)
{
enum afs_call_state state;
u32 abort_code, remote_abort = 0;
int ret;
_enter("%s", call->type->name);
while (state = READ_ONCE(call->state),
state == AFS_CALL_CL_AWAIT_REPLY ||
state == AFS_CALL_SV_AWAIT_OP_ID ||
state == AFS_CALL_SV_AWAIT_REQUEST ||
state == AFS_CALL_SV_AWAIT_ACK
) {
if (state == AFS_CALL_SV_AWAIT_ACK) {
iov_iter_kvec(&call->def_iter, READ, NULL, 0, 0);
ret = rxrpc_kernel_recv_data(call->net->socket,
call->rxcall, &call->def_iter,
false, &remote_abort,
&call->service_id);
trace_afs_receive_data(call, &call->def_iter, false, ret);
if (ret == -EINPROGRESS || ret == -EAGAIN)
return;
if (ret < 0 || ret == 1) {
if (ret == 1)
ret = 0;
goto call_complete;
}
return;
}
if (!call->have_reply_time &&
rxrpc_kernel_get_reply_time(call->net->socket,
call->rxcall,
&call->reply_time))
call->have_reply_time = true;
ret = call->type->deliver(call);
state = READ_ONCE(call->state);
if (ret == 0 && call->unmarshalling_error)
ret = -EBADMSG;
switch (ret) {
case 0:
afs_queue_call_work(call);
if (state == AFS_CALL_CL_PROC_REPLY) {
if (call->op)
set_bit(AFS_SERVER_FL_MAY_HAVE_CB,
&call->op->server->flags);
goto call_complete;
}
ASSERTCMP(state, >, AFS_CALL_CL_PROC_REPLY);
goto done;
case -EINPROGRESS:
case -EAGAIN:
goto out;
case -ECONNABORTED:
ASSERTCMP(state, ==, AFS_CALL_COMPLETE);
goto done;
case -ENOTSUPP:
abort_code = RXGEN_OPCODE;
rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
abort_code, ret, "KIV");
goto local_abort;
case -EIO:
pr_err("kAFS: Call %u in bad state %u\n",
call->debug_id, state);
/* Fall through */
case -ENODATA:
case -EBADMSG:
case -EMSGSIZE:
abort_code = RXGEN_CC_UNMARSHAL;
if (state != AFS_CALL_CL_AWAIT_REPLY)
abort_code = RXGEN_SS_UNMARSHAL;
rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
abort_code, ret, "KUM");
goto local_abort;
default:
abort_code = RX_USER_ABORT;
rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
abort_code, ret, "KER");
goto local_abort;
}
}
done:
if (call->type->done)
call->type->done(call);
out:
_leave("");
return;
local_abort:
abort_code = 0;
call_complete:
afs_set_call_complete(call, ret, remote_abort);
state = AFS_CALL_COMPLETE;
goto done;
}
/*
* Wait synchronously for a call to complete and clean up the call struct.
*/
long afs_wait_for_call_to_complete(struct afs_call *call,
struct afs_addr_cursor *ac)
{
long ret;
bool rxrpc_complete = false;
DECLARE_WAITQUEUE(myself, current);
_enter("");
ret = call->error;
if (ret < 0)
goto out;
add_wait_queue(&call->waitq, &myself);
for (;;) {
set_current_state(TASK_UNINTERRUPTIBLE);
/* deliver any messages that are in the queue */
if (!afs_check_call_state(call, AFS_CALL_COMPLETE) &&
call->need_attention) {
call->need_attention = false;
__set_current_state(TASK_RUNNING);
afs_deliver_to_call(call);
continue;
}
if (afs_check_call_state(call, AFS_CALL_COMPLETE))
break;
if (!rxrpc_kernel_check_life(call->net->socket, call->rxcall)) {
/* rxrpc terminated the call. */
rxrpc_complete = true;
break;
}
schedule();
}
remove_wait_queue(&call->waitq, &myself);
__set_current_state(TASK_RUNNING);
if (!afs_check_call_state(call, AFS_CALL_COMPLETE)) {
if (rxrpc_complete) {
afs_set_call_complete(call, call->error, call->abort_code);
} else {
/* Kill off the call if it's still live. */
_debug("call interrupted");
if (rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
RX_USER_ABORT, -EINTR, "KWI"))
afs_set_call_complete(call, -EINTR, 0);
}
}
spin_lock_bh(&call->state_lock);
ac->abort_code = call->abort_code;
ac->error = call->error;
spin_unlock_bh(&call->state_lock);
ret = ac->error;
switch (ret) {
case 0:
ret = call->ret0;
call->ret0 = 0;
/* Fall through */
case -ECONNABORTED:
ac->responded = true;
break;
}
out:
_debug("call complete");
afs_put_call(call);
_leave(" = %p", (void *)ret);
return ret;
}
/*
* wake up a waiting call
*/
static void afs_wake_up_call_waiter(struct sock *sk, struct rxrpc_call *rxcall,
unsigned long call_user_ID)
{
struct afs_call *call = (struct afs_call *)call_user_ID;
call->need_attention = true;
wake_up(&call->waitq);
}
/*
* wake up an asynchronous call
*/
static void afs_wake_up_async_call(struct sock *sk, struct rxrpc_call *rxcall,
unsigned long call_user_ID)
{
struct afs_call *call = (struct afs_call *)call_user_ID;
int u;
trace_afs_notify_call(rxcall, call);
call->need_attention = true;
u = atomic_fetch_add_unless(&call->usage, 1, 0);
if (u != 0) {
trace_afs_call(call, afs_call_trace_wake, u + 1,
atomic_read(&call->net->nr_outstanding_calls),
__builtin_return_address(0));
if (!queue_work(afs_async_calls, &call->async_work))
afs_put_call(call);
}
}
/*
* Perform I/O processing on an asynchronous call. The work item carries a ref
* to the call struct that we either need to release or to pass on.
*/
static void afs_process_async_call(struct work_struct *work)
{
struct afs_call *call = container_of(work, struct afs_call, async_work);
_enter("");
if (call->state < AFS_CALL_COMPLETE && call->need_attention) {
call->need_attention = false;
afs_deliver_to_call(call);
}
afs_put_call(call);
_leave("");
}
static void afs_rx_attach(struct rxrpc_call *rxcall, unsigned long user_call_ID)
{
struct afs_call *call = (struct afs_call *)user_call_ID;
call->rxcall = rxcall;
}
/*
* Charge the incoming call preallocation.
*/
void afs_charge_preallocation(struct work_struct *work)
{
struct afs_net *net =
container_of(work, struct afs_net, charge_preallocation_work);
struct afs_call *call = net->spare_incoming_call;
for (;;) {
if (!call) {
call = afs_alloc_call(net, &afs_RXCMxxxx, GFP_KERNEL);
if (!call)
break;
call->drop_ref = true;
call->async = true;
call->state = AFS_CALL_SV_AWAIT_OP_ID;
init_waitqueue_head(&call->waitq);
afs_extract_to_tmp(call);
}
if (rxrpc_kernel_charge_accept(net->socket,
afs_wake_up_async_call,
afs_rx_attach,
(unsigned long)call,
GFP_KERNEL,
call->debug_id) < 0)
break;
call = NULL;
}
net->spare_incoming_call = call;
}
/*
* Discard a preallocated call when a socket is shut down.
*/
static void afs_rx_discard_new_call(struct rxrpc_call *rxcall,
unsigned long user_call_ID)
{
struct afs_call *call = (struct afs_call *)user_call_ID;
call->rxcall = NULL;
afs_put_call(call);
}
/*
* Notification of an incoming call.
*/
static void afs_rx_new_call(struct sock *sk, struct rxrpc_call *rxcall,
unsigned long user_call_ID)
{
struct afs_net *net = afs_sock2net(sk);
queue_work(afs_wq, &net->charge_preallocation_work);
}
/*
* Grab the operation ID from an incoming cache manager call. The socket
* buffer is discarded on error or if we don't yet have sufficient data.
*/
static int afs_deliver_cm_op_id(struct afs_call *call)
{
int ret;
_enter("{%zu}", iov_iter_count(call->iter));
/* the operation ID forms the first four bytes of the request data */
ret = afs_extract_data(call, true);
if (ret < 0)
return ret;
call->operation_ID = ntohl(call->tmp);
afs_set_call_state(call, AFS_CALL_SV_AWAIT_OP_ID, AFS_CALL_SV_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;
trace_afs_cb_call(call);
/* pass responsibility for the remainer of this message off to the
* cache manager op */
return call->type->deliver(call);
}
/*
* Advance the AFS call state when an RxRPC service call ends the transmit
* phase.
*/
static void afs_notify_end_reply_tx(struct sock *sock,
struct rxrpc_call *rxcall,
unsigned long call_user_ID)
{
struct afs_call *call = (struct afs_call *)call_user_ID;
afs_set_call_state(call, AFS_CALL_SV_REPLYING, AFS_CALL_SV_AWAIT_ACK);
}
/*
* send an empty reply
*/
void afs_send_empty_reply(struct afs_call *call)
{
struct afs_net *net = call->net;
struct msghdr msg;
_enter("");
rxrpc_kernel_set_tx_length(net->socket, call->rxcall, 0);
msg.msg_name = NULL;
msg.msg_namelen = 0;
iov_iter_kvec(&msg.msg_iter, WRITE, NULL, 0, 0);
msg.msg_control = NULL;
msg.msg_controllen = 0;
msg.msg_flags = 0;
switch (rxrpc_kernel_send_data(net->socket, call->rxcall, &msg, 0,
afs_notify_end_reply_tx)) {
case 0:
_leave(" [replied]");
return;
case -ENOMEM:
_debug("oom");
rxrpc_kernel_abort_call(net->socket, call->rxcall,
RX_USER_ABORT, -ENOMEM, "KOO");
/* Fall through */
default:
_leave(" [error]");
return;
}
}
/*
* send a simple reply
*/
void afs_send_simple_reply(struct afs_call *call, const void *buf, size_t len)
{
struct afs_net *net = call->net;
struct msghdr msg;
struct kvec iov[1];
int n;
_enter("");
rxrpc_kernel_set_tx_length(net->socket, call->rxcall, len);
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, iov, 1, len);
msg.msg_control = NULL;
msg.msg_controllen = 0;
msg.msg_flags = 0;
n = rxrpc_kernel_send_data(net->socket, call->rxcall, &msg, len,
afs_notify_end_reply_tx);
if (n >= 0) {
/* Success */
_leave(" [replied]");
return;
}
if (n == -ENOMEM) {
_debug("oom");
rxrpc_kernel_abort_call(net->socket, call->rxcall,
RX_USER_ABORT, -ENOMEM, "KOO");
}
_leave(" [error]");
}
/*
* Extract a piece of data from the received data socket buffers.
*/
int afs_extract_data(struct afs_call *call, bool want_more)
{
struct afs_net *net = call->net;
struct iov_iter *iter = call->iter;
enum afs_call_state state;
u32 remote_abort = 0;
int ret;
_enter("{%s,%zu},%d", call->type->name, iov_iter_count(iter), want_more);
ret = rxrpc_kernel_recv_data(net->socket, call->rxcall, iter,
want_more, &remote_abort,
&call->service_id);
if (ret == 0 || ret == -EAGAIN)
return ret;
state = READ_ONCE(call->state);
if (ret == 1) {
switch (state) {
case AFS_CALL_CL_AWAIT_REPLY:
afs_set_call_state(call, state, AFS_CALL_CL_PROC_REPLY);
break;
case AFS_CALL_SV_AWAIT_REQUEST:
afs_set_call_state(call, state, AFS_CALL_SV_REPLYING);
break;
case AFS_CALL_COMPLETE:
kdebug("prem complete %d", call->error);
return afs_io_error(call, afs_io_error_extract);
default:
break;
}
return 0;
}
afs_set_call_complete(call, ret, remote_abort);
return ret;
}
/*
* Log protocol error production.
*/
noinline int afs_protocol_error(struct afs_call *call,
enum afs_eproto_cause cause)
{
trace_afs_protocol_error(call, cause);
if (call)
call->unmarshalling_error = true;
return -EBADMSG;
}