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rxrpc: Don't expose skbs to in-kernel users [ver #2]

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Don't expose skbs to in-kernel users, such as the AFS filesystem, but
instead provide a notification hook the indicates that a call needs
attention and another that indicates that there's a new call to be
collected.

This makes the following possibilities more achievable:

 (1) Call refcounting can be made simpler if skbs don't hold refs to calls.

 (2) skbs referring to non-data events will be able to be freed much sooner
     rather than being queued for AFS to pick up as rxrpc_kernel_recv_data
     will be able to consult the call state.

 (3) We can shortcut the receive phase when a call is remotely aborted
     because we don't have to go through all the packets to get to the one
     cancelling the operation.

 (4) It makes it easier to do encryption/decryption directly between AFS's
     buffers and sk_buffs.

 (5) Encryption/decryption can more easily be done in the AFS's thread
     contexts - usually that of the userspace process that issued a syscall
     - rather than in one of rxrpc's background threads on a workqueue.

 (6) AFS will be able to wait synchronously on a call inside AF_RXRPC.

To make this work, the following interface function has been added:

     int rxrpc_kernel_recv_data(
		struct socket *sock, struct rxrpc_call *call,
		void *buffer, size_t bufsize, size_t *_offset,
		bool want_more, u32 *_abort_code);

This is the recvmsg equivalent.  It allows the caller to find out about the
state of a specific call and to transfer received data into a buffer
piecemeal.

afs_extract_data() and rxrpc_kernel_recv_data() now do all the extraction
logic between them.  They don't wait synchronously yet because the socket
lock needs to be dealt with.

Five interface functions have been removed:

	rxrpc_kernel_is_data_last()
    	rxrpc_kernel_get_abort_code()
    	rxrpc_kernel_get_error_number()
    	rxrpc_kernel_free_skb()
    	rxrpc_kernel_data_consumed()

As a temporary hack, sk_buffs going to an in-kernel call are queued on the
rxrpc_call struct (->knlrecv_queue) rather than being handed over to the
in-kernel user.  To process the queue internally, a temporary function,
temp_deliver_data() has been added.  This will be replaced with common code
between the rxrpc_recvmsg() path and the kernel_rxrpc_recv_data() path in a
future patch.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David Howells
2016-08-30 20:42:14 +01:00
committed by David S. Miller
parent 95ac399451
commit d001648ec7
16 changed files with 566 additions and 587 deletions
Download Patch File Download Diff File Expand all files Collapse all files

437
fs/afs/rxrpc.c
View File

@@ -19,31 +19,31 @@
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 void afs_free_call(struct afs_call *);
static void afs_wake_up_call_waiter(struct sock *, struct rxrpc_call *, unsigned long);
static int afs_wait_for_call_to_complete(struct afs_call *);
static void afs_wake_up_async_call(struct afs_call *);
static void afs_wake_up_async_call(struct sock *, struct rxrpc_call *, unsigned long);
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);
static void afs_process_async_call(struct work_struct *);
static void afs_rx_new_call(struct sock *);
static int afs_deliver_cm_op_id(struct afs_call *);
/* synchronous call management */
const struct afs_wait_mode afs_sync_call = {
.rx_wakeup = afs_wake_up_call_waiter,
.notify_rx = 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,
.notify_rx = 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,
.notify_rx = afs_wake_up_async_call,
};
/* asynchronous incoming call initial processing */
@@ -55,16 +55,8 @@ static const struct afs_call_type afs_RXCMxxxx = {
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);
}
static int afs_wait_atomic_t(atomic_t *p)
{
schedule();
@@ -83,8 +75,6 @@ int afs_open_socket(void)
_enter("");
skb_queue_head_init(&afs_incoming_calls);
ret = -ENOMEM;
afs_async_calls = create_singlethread_workqueue("kafsd");
if (!afs_async_calls)
@@ -110,12 +100,12 @@ int afs_open_socket(void)
if (ret < 0)
goto error_2;
rxrpc_kernel_new_call_notification(socket, afs_rx_new_call);
ret = kernel_listen(socket, INT_MAX);
if (ret < 0)
goto error_2;
rxrpc_kernel_intercept_rx_messages(socket, afs_rx_interceptor);
afs_socket = socket;
_leave(" = 0");
return 0;
@@ -136,51 +126,19 @@ void afs_close_socket(void)
{
_enter("");
_debug("outstanding %u", atomic_read(&afs_outstanding_calls));
wait_on_atomic_t(&afs_outstanding_calls, afs_wait_atomic_t,
TASK_UNINTERRUPTIBLE);
_debug("no outstanding calls");
flush_workqueue(afs_async_calls);
sock_release(afs_socket);
_debug("dework");
destroy_workqueue(afs_async_calls);
ASSERTCMP(atomic_read(&afs_outstanding_skbs), ==, 0);
_leave("");
}
/*
* Note that the data in a socket buffer is now consumed.
*/
void afs_data_consumed(struct afs_call *call, 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));
rxrpc_kernel_data_consumed(call->rxcall, 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
*/
@@ -191,7 +149,6 @@ static void afs_free_call(struct afs_call *call)
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);
@@ -227,7 +184,7 @@ static void afs_end_call(struct afs_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)
size_t request_size, size_t reply_max)
{
struct afs_call *call;
@@ -241,7 +198,7 @@ struct afs_call *afs_alloc_flat_call(const struct afs_call_type *type,
call->type = type;
call->request_size = request_size;
call->reply_max = reply_size;
call->reply_max = reply_max;
if (request_size) {
call->request = kmalloc(request_size, GFP_NOFS);
@@ -249,14 +206,13 @@ struct afs_call *afs_alloc_flat_call(const struct afs_call_type *type,
goto nomem_free;
}
if (reply_size) {
call->buffer = kmalloc(reply_size, GFP_NOFS);
if (reply_max) {
call->buffer = kmalloc(reply_max, GFP_NOFS);
if (!call->buffer)
goto nomem_free;
}
init_waitqueue_head(&call->waitq);
skb_queue_head_init(&call->rx_queue);
return call;
nomem_free:
@@ -354,7 +310,6 @@ int afs_make_call(struct in_addr *addr, struct afs_call *call, gfp_t gfp,
struct msghdr msg;
struct kvec iov[1];
int ret;
struct sk_buff *skb;
_enter("%x,{%d},", addr->s_addr, ntohs(call->port));
@@ -366,8 +321,7 @@ int afs_make_call(struct in_addr *addr, struct afs_call *call, gfp_t gfp,
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);
INIT_WORK(&call->async_work, afs_process_async_call);
memset(&srx, 0, sizeof(srx));
srx.srx_family = AF_RXRPC;
@@ -380,7 +334,8 @@ int afs_make_call(struct in_addr *addr, struct afs_call *call, gfp_t gfp,
/* create a call */
rxcall = rxrpc_kernel_begin_call(afs_socket, &srx, call->key,
(unsigned long) call, gfp);
(unsigned long) call, gfp,
wait_mode->notify_rx);
call->key = NULL;
if (IS_ERR(rxcall)) {
ret = PTR_ERR(rxcall);
@@ -423,150 +378,84 @@ int afs_make_call(struct in_addr *addr, struct afs_call *call, gfp_t gfp,
error_do_abort:
rxrpc_kernel_abort_call(afs_socket, 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 from the AF_RXRPC call processor in waitqueue process context. For
* each call, it is guaranteed this will be called in order of packet to be
* delivered.
*/
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("");
_enter("%s", call->type->name);
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 -EAGAIN:
if (last) {
_debug("short data");
goto unmarshal_error;
}
break;
case 0:
ASSERT(last);
if (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:
unmarshal_error:
abort_code = RXGEN_CC_UNMARSHAL;
if (call->state != AFS_CALL_AWAIT_REPLY)
abort_code = RXGEN_SS_UNMARSHAL;
do_abort:
rxrpc_kernel_abort_call(afs_socket,
call->rxcall,
abort_code);
call->error = ret;
call->state = AFS_CALL_ERROR;
break;
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
) {
if (call->state == AFS_CALL_AWAIT_ACK) {
size_t offset = 0;
ret = rxrpc_kernel_recv_data(afs_socket, call->rxcall,
NULL, 0, &offset, false,
&call->abort_code);
if (ret == -EINPROGRESS || ret == -EAGAIN)
return;
if (ret == 1) {
call->state = AFS_CALL_COMPLETE;
goto done;
}
break;
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_LOCAL_ABORT:
abort_code = rxrpc_kernel_get_abort_code(skb);
call->error = call->type->abort_to_error(abort_code);
call->state = AFS_CALL_ABORTED;
_debug("Loc 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;
return;
}
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);
ret = call->type->deliver(call);
switch (ret) {
case 0:
if (call->state == AFS_CALL_AWAIT_REPLY)
call->state = AFS_CALL_COMPLETE;
goto done;
case -EINPROGRESS:
case -EAGAIN:
goto out;
case -ENOTCONN:
abort_code = RX_CALL_DEAD;
rxrpc_kernel_abort_call(afs_socket, call->rxcall,
abort_code);
goto do_abort;
case -ENOTSUPP:
abort_code = RX_INVALID_OPERATION;
rxrpc_kernel_abort_call(afs_socket, call->rxcall,
abort_code);
goto do_abort;
case -ENODATA:
case -EBADMSG:
case -EMSGSIZE:
default:
abort_code = RXGEN_CC_UNMARSHAL;
if (call->state != AFS_CALL_AWAIT_REPLY)
abort_code = RXGEN_SS_UNMARSHAL;
rxrpc_kernel_abort_call(afs_socket, call->rxcall,
abort_code);
goto do_abort;
}
}
done:
if (call->state == AFS_CALL_COMPLETE && call->incoming)
afs_end_call(call);
out:
_leave("");
return;
do_abort:
call->error = ret;
call->state = AFS_CALL_COMPLETE;
goto done;
}
/*
@@ -574,7 +463,6 @@ static void afs_deliver_to_call(struct afs_call *call)
*/
static int afs_wait_for_call_to_complete(struct afs_call *call)
{
struct sk_buff *skb;
int ret;
DECLARE_WAITQUEUE(myself, current);
@@ -586,14 +474,15 @@ static int afs_wait_for_call_to_complete(struct afs_call *call)
set_current_state(TASK_INTERRUPTIBLE);
/* deliver any messages that are in the queue */
if (!skb_queue_empty(&call->rx_queue)) {
if (call->state < AFS_CALL_COMPLETE && call->need_attention) {
call->need_attention = false;
__set_current_state(TASK_RUNNING);
afs_deliver_to_call(call);
continue;
}
ret = call->error;
if (call->state >= AFS_CALL_COMPLETE)
if (call->state == AFS_CALL_COMPLETE)
break;
ret = -EINTR;
if (signal_pending(current))
@@ -607,9 +496,8 @@ static int afs_wait_for_call_to_complete(struct afs_call *call)
/* kill the call */
if (call->state < AFS_CALL_COMPLETE) {
_debug("call incomplete");
rxrpc_kernel_abort_call(afs_socket, call->rxcall, RX_CALL_DEAD);
while ((skb = skb_dequeue(&call->rx_queue)))
afs_free_skb(skb);
rxrpc_kernel_abort_call(afs_socket, call->rxcall,
RX_CALL_DEAD);
}
_debug("call complete");
@@ -621,17 +509,24 @@ static int afs_wait_for_call_to_complete(struct afs_call *call)
/*
* wake up a waiting call
*/
static void afs_wake_up_call_waiter(struct afs_call *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 afs_call *call)
static void afs_wake_up_async_call(struct sock *sk, struct rxrpc_call *rxcall,
unsigned long call_user_ID)
{
_enter("");
struct afs_call *call = (struct afs_call *)call_user_ID;
call->need_attention = true;
queue_work(afs_async_calls, &call->async_work);
}
@@ -649,8 +544,10 @@ static int afs_dont_wait_for_call_to_complete(struct afs_call *call)
/*
* delete an asynchronous call
*/
static void afs_delete_async_call(struct afs_call *call)
static void afs_delete_async_call(struct work_struct *work)
{
struct afs_call *call = container_of(work, struct afs_call, async_work);
_enter("");
afs_free_call(call);
@@ -660,17 +557,19 @@ static void afs_delete_async_call(struct afs_call *call)
/*
* 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)
static void afs_process_async_call(struct work_struct *work)
{
struct afs_call *call = container_of(work, struct afs_call, async_work);
_enter("");
if (!skb_queue_empty(&call->rx_queue))
if (call->state < AFS_CALL_COMPLETE && call->need_attention) {
call->need_attention = false;
afs_deliver_to_call(call);
}
if (call->state >= AFS_CALL_COMPLETE && call->wait_mode) {
if (call->state == AFS_CALL_COMPLETE && call->wait_mode) {
if (call->wait_mode->async_complete)
call->wait_mode->async_complete(call->reply,
call->error);
@@ -681,45 +580,13 @@ static void afs_process_async_call(struct afs_call *call)
/* we can't just delete the call because the work item may be
* queued */
call->async_workfn = afs_delete_async_call;
call->async_work.func = afs_delete_async_call;
queue_work(afs_async_calls, &call->async_work);
}
_leave("");
}
/*
* Empty a socket buffer into a flat reply buffer.
*/
int afs_transfer_reply(struct afs_call *call, struct sk_buff *skb, bool last)
{
size_t len = skb->len;
if (len > call->reply_max - call->reply_size) {
_leave(" = -EBADMSG [%zu > %u]",
len, call->reply_max - call->reply_size);
return -EBADMSG;
}
if (len > 0) {
if (skb_copy_bits(skb, 0, call->buffer + call->reply_size,
len) < 0)
BUG();
call->reply_size += len;
}
afs_data_consumed(call, skb);
if (!last)
return -EAGAIN;
if (call->reply_size != call->reply_max) {
_leave(" = -EBADMSG [%u != %u]",
call->reply_size, call->reply_max);
return -EBADMSG;
}
return 0;
}
/*
* accept the backlog of incoming calls
*/
@@ -727,14 +594,10 @@ 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);
_enter("");
do {
if (!call) {
call = kzalloc(sizeof(struct afs_call), GFP_KERNEL);
if (!call) {
@@ -742,12 +605,10 @@ static void afs_collect_incoming_call(struct work_struct *work)
return;
}
call->async_workfn = afs_process_async_call;
INIT_WORK(&call->async_work, afs_async_workfn);
INIT_WORK(&call->async_work, afs_process_async_call);
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]",
@@ -757,46 +618,47 @@ static void afs_collect_incoming_call(struct work_struct *work)
}
rxcall = rxrpc_kernel_accept_call(afs_socket,
(unsigned long) call);
(unsigned long)call,
afs_wake_up_async_call);
if (!IS_ERR(rxcall)) {
call->rxcall = rxcall;
call->need_attention = true;
queue_work(afs_async_calls, &call->async_work);
call = NULL;
}
}
} while (!call);
if (call)
afs_free_call(call);
}
/*
* Notification of an incoming call.
*/
static void afs_rx_new_call(struct sock *sk)
{
queue_work(afs_wq, &afs_collect_incoming_call_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, struct sk_buff *skb,
bool last)
static int afs_deliver_cm_op_id(struct afs_call *call)
{
size_t len = skb->len;
void *oibuf = (void *) &call->operation_ID;
int ret;
_enter("{%u},{%zu},%d", call->offset, len, last);
_enter("{%zu}", call->offset);
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) {
afs_data_consumed(call, skb);
_leave(" = -EAGAIN");
return -EAGAIN;
}
ret = afs_extract_data(call, &call->operation_ID, 4, true);
if (ret < 0)
return ret;
call->state = AFS_CALL_AWAIT_REQUEST;
call->offset = 0;
/* ask the cache manager to route the call (it'll change the call type
* if successful) */
@@ -805,7 +667,7 @@ static int afs_deliver_cm_op_id(struct afs_call *call, struct sk_buff *skb,
/* pass responsibility for the remainer of this message off to the
* cache manager op */
return call->type->deliver(call, skb, last);
return call->type->deliver(call);
}
/*
@@ -881,25 +743,40 @@ void afs_send_simple_reply(struct afs_call *call, const void *buf, size_t len)
/*
* 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)
int afs_extract_data(struct afs_call *call, void *buf, size_t count,
bool want_more)
{
size_t len = skb->len;
int ret;
_enter("{%u},{%zu},%d,,%zu", call->offset, len, last, count);
_enter("{%s,%zu},,%zu,%d",
call->type->name, call->offset, count, want_more);
ASSERTCMP(call->offset, <, 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;
ret = rxrpc_kernel_recv_data(afs_socket, call->rxcall,
buf, count, &call->offset,
want_more, &call->abort_code);
if (ret == 0 || ret == -EAGAIN)
return ret;
if (call->offset < count) {
afs_data_consumed(call, skb);
_leave(" = -EAGAIN");
return -EAGAIN;
if (ret == 1) {
switch (call->state) {
case AFS_CALL_AWAIT_REPLY:
call->state = AFS_CALL_COMPLETE;
break;
case AFS_CALL_AWAIT_REQUEST:
call->state = AFS_CALL_REPLYING;
break;
default:
break;
}
return 0;
}
return 0;
if (ret == -ECONNABORTED)
call->error = call->type->abort_to_error(call->abort_code);
else
call->error = ret;
call->state = AFS_CALL_COMPLETE;
return ret;
}