linux/fs/afs/cmservice.c

331 lines
7.5 KiB
C
Raw Normal View History

/* AFS Cache Manager Service
*
* Copyright (C) 2002 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/module.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/ip.h>
#include "internal.h"
#include "afs_cm.h"
struct workqueue_struct *afs_cm_workqueue;
static int afs_deliver_cb_init_call_back_state(struct afs_call *,
struct sk_buff *, bool);
static int afs_deliver_cb_probe(struct afs_call *, struct sk_buff *, bool);
static int afs_deliver_cb_callback(struct afs_call *, struct sk_buff *, bool);
static void afs_cm_destructor(struct afs_call *);
/*
* CB.CallBack operation type
*/
static const struct afs_call_type afs_SRXCBCallBack = {
.name = "CB.CallBack",
.deliver = afs_deliver_cb_callback,
.abort_to_error = afs_abort_to_error,
.destructor = afs_cm_destructor,
};
/*
* CB.InitCallBackState operation type
*/
static const struct afs_call_type afs_SRXCBInitCallBackState = {
.name = "CB.InitCallBackState",
.deliver = afs_deliver_cb_init_call_back_state,
.abort_to_error = afs_abort_to_error,
.destructor = afs_cm_destructor,
};
/*
* CB.Probe operation type
*/
static const struct afs_call_type afs_SRXCBProbe = {
.name = "CB.Probe",
.deliver = afs_deliver_cb_probe,
.abort_to_error = afs_abort_to_error,
.destructor = afs_cm_destructor,
};
/*
* route an incoming cache manager call
* - return T if supported, F if not
*/
bool afs_cm_incoming_call(struct afs_call *call)
{
u32 operation_id = ntohl(call->operation_ID);
_enter("{CB.OP %u}", operation_id);
switch (operation_id) {
case CBCallBack:
call->type = &afs_SRXCBCallBack;
return true;
case CBInitCallBackState:
call->type = &afs_SRXCBInitCallBackState;
return true;
case CBProbe:
call->type = &afs_SRXCBProbe;
return true;
default:
return false;
}
}
/*
* clean up a cache manager call
*/
static void afs_cm_destructor(struct afs_call *call)
{
_enter("");
afs_put_server(call->server);
call->server = NULL;
kfree(call->buffer);
call->buffer = NULL;
}
/*
* allow the fileserver to see if the cache manager is still alive
*/
static void SRXAFSCB_CallBack(struct work_struct *work)
{
struct afs_call *call = container_of(work, struct afs_call, work);
_enter("");
/* be sure to send the reply *before* attempting to spam the AFS server
* with FSFetchStatus requests on the vnodes with broken callbacks lest
* the AFS server get into a vicious cycle of trying to break further
* callbacks because it hadn't received completion of the CBCallBack op
* yet */
afs_send_empty_reply(call);
afs_break_callbacks(call->server, call->count, call->request);
_leave("");
}
/*
* deliver request data to a CB.CallBack call
*/
static int afs_deliver_cb_callback(struct afs_call *call, struct sk_buff *skb,
bool last)
{
struct afs_callback *cb;
struct afs_server *server;
struct in_addr addr;
__be32 *bp;
u32 tmp;
int ret, loop;
_enter("{%u},{%u},%d", call->unmarshall, skb->len, last);
switch (call->unmarshall) {
case 0:
call->offset = 0;
call->unmarshall++;
/* extract the FID array and its count in two steps */
case 1:
_debug("extract FID count");
ret = afs_extract_data(call, skb, last, &call->tmp, 4);
switch (ret) {
case 0: break;
case -EAGAIN: return 0;
default: return ret;
}
call->count = ntohl(call->tmp);
_debug("FID count: %u", call->count);
if (call->count > AFSCBMAX)
return -EBADMSG;
call->buffer = kmalloc(call->count * 3 * 4, GFP_KERNEL);
if (!call->buffer)
return -ENOMEM;
call->offset = 0;
call->unmarshall++;
case 2:
_debug("extract FID array");
ret = afs_extract_data(call, skb, last, call->buffer,
call->count * 3 * 4);
switch (ret) {
case 0: break;
case -EAGAIN: return 0;
default: return ret;
}
_debug("unmarshall FID array");
call->request = kcalloc(call->count,
sizeof(struct afs_callback),
GFP_KERNEL);
if (!call->request)
return -ENOMEM;
cb = call->request;
bp = call->buffer;
for (loop = call->count; loop > 0; loop--, cb++) {
cb->fid.vid = ntohl(*bp++);
cb->fid.vnode = ntohl(*bp++);
cb->fid.unique = ntohl(*bp++);
cb->type = AFSCM_CB_UNTYPED;
}
call->offset = 0;
call->unmarshall++;
/* extract the callback array and its count in two steps */
case 3:
_debug("extract CB count");
ret = afs_extract_data(call, skb, last, &call->tmp, 4);
switch (ret) {
case 0: break;
case -EAGAIN: return 0;
default: return ret;
}
tmp = ntohl(call->tmp);
_debug("CB count: %u", tmp);
if (tmp != call->count && tmp != 0)
return -EBADMSG;
call->offset = 0;
call->unmarshall++;
if (tmp == 0)
goto empty_cb_array;
case 4:
_debug("extract CB array");
ret = afs_extract_data(call, skb, last, call->request,
call->count * 3 * 4);
switch (ret) {
case 0: break;
case -EAGAIN: return 0;
default: return ret;
}
_debug("unmarshall CB array");
cb = call->request;
bp = call->buffer;
for (loop = call->count; loop > 0; loop--, cb++) {
cb->version = ntohl(*bp++);
cb->expiry = ntohl(*bp++);
cb->type = ntohl(*bp++);
}
empty_cb_array:
call->offset = 0;
call->unmarshall++;
case 5:
_debug("trailer");
if (skb->len != 0)
return -EBADMSG;
break;
}
if (!last)
return 0;
call->state = AFS_CALL_REPLYING;
/* we'll need the file server record as that tells us which set of
* vnodes to operate upon */
memcpy(&addr, &ip_hdr(skb)->saddr, 4);
server = afs_find_server(&addr);
if (!server)
return -ENOTCONN;
call->server = server;
INIT_WORK(&call->work, SRXAFSCB_CallBack);
schedule_work(&call->work);
return 0;
}
/*
* allow the fileserver to request callback state (re-)initialisation
*/
static void SRXAFSCB_InitCallBackState(struct work_struct *work)
{
struct afs_call *call = container_of(work, struct afs_call, work);
_enter("{%p}", call->server);
afs_init_callback_state(call->server);
afs_send_empty_reply(call);
_leave("");
}
/*
* deliver request data to a CB.InitCallBackState call
*/
static int afs_deliver_cb_init_call_back_state(struct afs_call *call,
struct sk_buff *skb,
bool last)
{
struct afs_server *server;
struct in_addr addr;
_enter(",{%u},%d", skb->len, last);
if (skb->len > 0)
return -EBADMSG;
if (!last)
return 0;
/* no unmarshalling required */
call->state = AFS_CALL_REPLYING;
/* we'll need the file server record as that tells us which set of
* vnodes to operate upon */
memcpy(&addr, &ip_hdr(skb)->saddr, 4);
server = afs_find_server(&addr);
if (!server)
return -ENOTCONN;
call->server = server;
INIT_WORK(&call->work, SRXAFSCB_InitCallBackState);
schedule_work(&call->work);
return 0;
}
/*
* allow the fileserver to see if the cache manager is still alive
*/
static void SRXAFSCB_Probe(struct work_struct *work)
{
struct afs_call *call = container_of(work, struct afs_call, work);
_enter("");
afs_send_empty_reply(call);
_leave("");
}
/*
* deliver request data to a CB.Probe call
*/
static int afs_deliver_cb_probe(struct afs_call *call, struct sk_buff *skb,
bool last)
{
_enter(",{%u},%d", skb->len, last);
if (skb->len > 0)
return -EBADMSG;
if (!last)
return 0;
/* no unmarshalling required */
call->state = AFS_CALL_REPLYING;
INIT_WORK(&call->work, SRXAFSCB_Probe);
schedule_work(&call->work);
return 0;
}