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/*
* linux/fs/nfs/callback.c
*
* Copyright (C) 2004 Trond Myklebust
*
* NFSv4 callback handling
*/
#include <linux/completion.h>
#include <linux/ip.h>
#include <linux/module.h>
#include <linux/sunrpc/svc.h>
#include <linux/sunrpc/svcsock.h>
#include <linux/nfs_fs.h>
#include <linux/errno.h>
#include <linux/mutex.h>
#include <linux/freezer.h>
#include <linux/kthread.h>
#include <linux/sunrpc/svcauth_gss.h>
#include <linux/sunrpc/bc_xprt.h>
#include <net/inet_sock.h>
#include "nfs4_fs.h"
#include "callback.h"
#include "internal.h"
#include "netns.h"
#define NFSDBG_FACILITY NFSDBG_CALLBACK
struct nfs_callback_data {
unsigned int users;
struct svc_serv *serv;
struct svc_rqst *rqst;
struct task_struct *task;
};
static struct nfs_callback_data nfs_callback_info[NFS4_MAX_MINOR_VERSION + 1];
static DEFINE_MUTEX(nfs_callback_mutex);
static struct svc_program nfs4_callback_program;
static int nfs4_callback_up_net(struct svc_serv *serv, struct net *net)
{
int ret;
struct nfs_net *nn = net_generic(net, nfs_net_id);
ret = svc_create_xprt(serv, "tcp", net, PF_INET,
nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
if (ret <= 0)
goto out_err;
nn->nfs_callback_tcpport = ret;
dprintk("NFS: Callback listener port = %u (af %u, net %p)\n",
nn->nfs_callback_tcpport, PF_INET, net);
ret = svc_create_xprt(serv, "tcp", net, PF_INET6,
nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
if (ret > 0) {
nn->nfs_callback_tcpport6 = ret;
dprintk("NFS: Callback listener port = %u (af %u, net %p)\n",
nn->nfs_callback_tcpport6, PF_INET6, net);
} else if (ret != -EAFNOSUPPORT)
goto out_err;
return 0;
out_err:
return (ret) ? ret : -ENOMEM;
}
/*
* This is the NFSv4 callback kernel thread.
*/
static int
nfs4_callback_svc(void *vrqstp)
{
int err;
struct svc_rqst *rqstp = vrqstp;
set_freezable();
while (!kthread_should_stop()) {
/*
* Listen for a request on the socket
*/
err = svc_recv(rqstp, MAX_SCHEDULE_TIMEOUT);
if (err == -EAGAIN || err == -EINTR)
continue;
svc_process(rqstp);
}
return 0;
}
/*
* Prepare to bring up the NFSv4 callback service
*/
static struct svc_rqst *
nfs4_callback_up(struct svc_serv *serv)
{
return svc_prepare_thread(serv, &serv->sv_pools[0], NUMA_NO_NODE);
}
#if defined(CONFIG_NFS_V4_1)
static int nfs41_callback_up_net(struct svc_serv *serv, struct net *net)
{
/*
* Create an svc_sock for the back channel service that shares the
* fore channel connection.
* Returns the input port (0) and sets the svc_serv bc_xprt on success
*/
return svc_create_xprt(serv, "tcp-bc", net, PF_INET, 0,
SVC_SOCK_ANONYMOUS);
}
/*
* The callback service for NFSv4.1 callbacks
*/
static int
nfs41_callback_svc(void *vrqstp)
{
struct svc_rqst *rqstp = vrqstp;
struct svc_serv *serv = rqstp->rq_server;
struct rpc_rqst *req;
int error;
DEFINE_WAIT(wq);
set_freezable();
while (!kthread_should_stop()) {
if (try_to_freeze())
continue;
prepare_to_wait(&serv->sv_cb_waitq, &wq, TASK_INTERRUPTIBLE);
spin_lock_bh(&serv->sv_cb_lock);
if (!list_empty(&serv->sv_cb_list)) {
req = list_first_entry(&serv->sv_cb_list,
struct rpc_rqst, rq_bc_list);
list_del(&req->rq_bc_list);
spin_unlock_bh(&serv->sv_cb_lock);
dprintk("Invoking bc_svc_process()\n");
error = bc_svc_process(serv, req, rqstp);
dprintk("bc_svc_process() returned w/ error code= %d\n",
error);
} else {
spin_unlock_bh(&serv->sv_cb_lock);
schedule();
}
finish_wait(&serv->sv_cb_waitq, &wq);
}
return 0;
}
/*
* Bring up the NFSv4.1 callback service
*/
static struct svc_rqst *
nfs41_callback_up(struct svc_serv *serv)
{
struct svc_rqst *rqstp;
INIT_LIST_HEAD(&serv->sv_cb_list);
spin_lock_init(&serv->sv_cb_lock);
init_waitqueue_head(&serv->sv_cb_waitq);
rqstp = svc_prepare_thread(serv, &serv->sv_pools[0], NUMA_NO_NODE);
if (IS_ERR(rqstp)) {
svc_xprt_put(serv->sv_bc_xprt);
serv->sv_bc_xprt = NULL;
}
dprintk("--> %s return %d\n", __func__, PTR_ERR_OR_ZERO(rqstp));
return rqstp;
}
static void nfs_minorversion_callback_svc_setup(struct svc_serv *serv,
struct svc_rqst **rqstpp, int (**callback_svc)(void *vrqstp))
{
*rqstpp = nfs41_callback_up(serv);
*callback_svc = nfs41_callback_svc;
}
static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
struct svc_serv *serv)
{
if (minorversion)
/*
* Save the svc_serv in the transport so that it can
* be referenced when the session backchannel is initialized
*/
xprt->bc_serv = serv;
}
#else
static int nfs41_callback_up_net(struct svc_serv *serv, struct net *net)
{
return 0;
}
static void nfs_minorversion_callback_svc_setup(struct svc_serv *serv,
struct svc_rqst **rqstpp, int (**callback_svc)(void *vrqstp))
{
*rqstpp = ERR_PTR(-ENOTSUPP);
*callback_svc = ERR_PTR(-ENOTSUPP);
}
static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
struct svc_serv *serv)
{
}
#endif /* CONFIG_NFS_V4_1 */
static int nfs_callback_start_svc(int minorversion, struct rpc_xprt *xprt,
struct svc_serv *serv)
{
struct svc_rqst *rqstp;
int (*callback_svc)(void *vrqstp);
struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
int ret;
nfs_callback_bc_serv(minorversion, xprt, serv);
if (cb_info->task)
return 0;
switch (minorversion) {
case 0:
/* v4.0 callback setup */
rqstp = nfs4_callback_up(serv);
callback_svc = nfs4_callback_svc;
break;
default:
nfs_minorversion_callback_svc_setup(serv,
&rqstp, &callback_svc);
}
if (IS_ERR(rqstp))
return PTR_ERR(rqstp);
svc_sock_update_bufs(serv);
cb_info->serv = serv;
cb_info->rqst = rqstp;
cb_info->task = kthread_create(callback_svc, cb_info->rqst,
"nfsv4.%u-svc", minorversion);
if (IS_ERR(cb_info->task)) {
ret = PTR_ERR(cb_info->task);
svc_exit_thread(cb_info->rqst);
cb_info->rqst = NULL;
cb_info->task = NULL;
return ret;
}
rqstp->rq_task = cb_info->task;
wake_up_process(cb_info->task);
dprintk("nfs_callback_up: service started\n");
return 0;
}
static void nfs_callback_down_net(u32 minorversion, struct svc_serv *serv, struct net *net)
{
struct nfs_net *nn = net_generic(net, nfs_net_id);
if (--nn->cb_users[minorversion])
return;
dprintk("NFS: destroy per-net callback data; net=%p\n", net);
svc_shutdown
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