403 lines
9.7 KiB
C
403 lines
9.7 KiB
C
/*
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* linux/fs/nfs/callback.c
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*
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* Copyright (C) 2004 Trond Myklebust
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*
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* NFSv4 callback handling
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*/
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#include <linux/completion.h>
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#include <linux/ip.h>
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#include <linux/module.h>
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#include <linux/smp_lock.h>
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#include <linux/sunrpc/svc.h>
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#include <linux/sunrpc/svcsock.h>
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#include <linux/nfs_fs.h>
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#include <linux/mutex.h>
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#include <linux/freezer.h>
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#include <linux/kthread.h>
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#include <linux/sunrpc/svcauth_gss.h>
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#if defined(CONFIG_NFS_V4_1)
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#include <linux/sunrpc/bc_xprt.h>
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#endif
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#include <net/inet_sock.h>
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#include "nfs4_fs.h"
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#include "callback.h"
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#include "internal.h"
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#define NFSDBG_FACILITY NFSDBG_CALLBACK
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struct nfs_callback_data {
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unsigned int users;
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struct svc_serv *serv;
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struct svc_rqst *rqst;
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struct task_struct *task;
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};
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static struct nfs_callback_data nfs_callback_info[NFS4_MAX_MINOR_VERSION + 1];
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static DEFINE_MUTEX(nfs_callback_mutex);
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static struct svc_program nfs4_callback_program;
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unsigned int nfs_callback_set_tcpport;
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unsigned short nfs_callback_tcpport;
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unsigned short nfs_callback_tcpport6;
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static const int nfs_set_port_min = 0;
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static const int nfs_set_port_max = 65535;
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static int param_set_port(const char *val, struct kernel_param *kp)
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{
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char *endp;
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int num = simple_strtol(val, &endp, 0);
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if (endp == val || *endp || num < nfs_set_port_min || num > nfs_set_port_max)
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return -EINVAL;
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*((int *)kp->arg) = num;
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return 0;
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}
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module_param_call(callback_tcpport, param_set_port, param_get_int,
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&nfs_callback_set_tcpport, 0644);
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/*
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* This is the NFSv4 callback kernel thread.
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*/
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static int
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nfs4_callback_svc(void *vrqstp)
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{
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int err, preverr = 0;
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struct svc_rqst *rqstp = vrqstp;
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set_freezable();
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/*
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* FIXME: do we really need to run this under the BKL? If so, please
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* add a comment about what it's intended to protect.
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*/
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lock_kernel();
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while (!kthread_should_stop()) {
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/*
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* Listen for a request on the socket
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*/
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err = svc_recv(rqstp, MAX_SCHEDULE_TIMEOUT);
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if (err == -EAGAIN || err == -EINTR) {
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preverr = err;
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continue;
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}
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if (err < 0) {
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if (err != preverr) {
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printk(KERN_WARNING "%s: unexpected error "
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"from svc_recv (%d)\n", __func__, err);
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preverr = err;
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}
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schedule_timeout_uninterruptible(HZ);
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continue;
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}
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preverr = err;
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svc_process(rqstp);
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}
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unlock_kernel();
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return 0;
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}
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/*
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* Prepare to bring up the NFSv4 callback service
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*/
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struct svc_rqst *
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nfs4_callback_up(struct svc_serv *serv)
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{
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int ret;
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ret = svc_create_xprt(serv, "tcp", PF_INET,
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nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
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if (ret <= 0)
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goto out_err;
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nfs_callback_tcpport = ret;
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dprintk("NFS: Callback listener port = %u (af %u)\n",
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nfs_callback_tcpport, PF_INET);
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#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
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ret = svc_create_xprt(serv, "tcp", PF_INET6,
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nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
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if (ret > 0) {
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nfs_callback_tcpport6 = ret;
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dprintk("NFS: Callback listener port = %u (af %u)\n",
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nfs_callback_tcpport6, PF_INET6);
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} else if (ret != -EAFNOSUPPORT)
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goto out_err;
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#endif /* defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) */
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return svc_prepare_thread(serv, &serv->sv_pools[0]);
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out_err:
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if (ret == 0)
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ret = -ENOMEM;
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return ERR_PTR(ret);
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}
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#if defined(CONFIG_NFS_V4_1)
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/*
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* The callback service for NFSv4.1 callbacks
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*/
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static int
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nfs41_callback_svc(void *vrqstp)
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{
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struct svc_rqst *rqstp = vrqstp;
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struct svc_serv *serv = rqstp->rq_server;
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struct rpc_rqst *req;
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int error;
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DEFINE_WAIT(wq);
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set_freezable();
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/*
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* FIXME: do we really need to run this under the BKL? If so, please
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* add a comment about what it's intended to protect.
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*/
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lock_kernel();
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while (!kthread_should_stop()) {
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prepare_to_wait(&serv->sv_cb_waitq, &wq, TASK_INTERRUPTIBLE);
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spin_lock_bh(&serv->sv_cb_lock);
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if (!list_empty(&serv->sv_cb_list)) {
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req = list_first_entry(&serv->sv_cb_list,
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struct rpc_rqst, rq_bc_list);
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list_del(&req->rq_bc_list);
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spin_unlock_bh(&serv->sv_cb_lock);
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dprintk("Invoking bc_svc_process()\n");
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error = bc_svc_process(serv, req, rqstp);
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dprintk("bc_svc_process() returned w/ error code= %d\n",
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error);
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} else {
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spin_unlock_bh(&serv->sv_cb_lock);
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schedule();
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}
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finish_wait(&serv->sv_cb_waitq, &wq);
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}
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unlock_kernel();
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return 0;
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}
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/*
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* Bring up the NFSv4.1 callback service
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*/
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struct svc_rqst *
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nfs41_callback_up(struct svc_serv *serv, struct rpc_xprt *xprt)
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{
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struct svc_xprt *bc_xprt;
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struct svc_rqst *rqstp = ERR_PTR(-ENOMEM);
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dprintk("--> %s\n", __func__);
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/* Create a svc_sock for the service */
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bc_xprt = svc_sock_create(serv, xprt->prot);
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if (!bc_xprt)
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goto out;
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/*
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* Save the svc_serv in the transport so that it can
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* be referenced when the session backchannel is initialized
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*/
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serv->bc_xprt = bc_xprt;
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xprt->bc_serv = serv;
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INIT_LIST_HEAD(&serv->sv_cb_list);
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spin_lock_init(&serv->sv_cb_lock);
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init_waitqueue_head(&serv->sv_cb_waitq);
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rqstp = svc_prepare_thread(serv, &serv->sv_pools[0]);
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if (IS_ERR(rqstp))
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svc_sock_destroy(bc_xprt);
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out:
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dprintk("--> %s return %p\n", __func__, rqstp);
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return rqstp;
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}
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static inline int nfs_minorversion_callback_svc_setup(u32 minorversion,
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struct svc_serv *serv, struct rpc_xprt *xprt,
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struct svc_rqst **rqstpp, int (**callback_svc)(void *vrqstp))
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{
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if (minorversion) {
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*rqstpp = nfs41_callback_up(serv, xprt);
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*callback_svc = nfs41_callback_svc;
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}
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return minorversion;
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}
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static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
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struct nfs_callback_data *cb_info)
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{
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if (minorversion)
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xprt->bc_serv = cb_info->serv;
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}
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#else
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static inline int nfs_minorversion_callback_svc_setup(u32 minorversion,
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struct svc_serv *serv, struct rpc_xprt *xprt,
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struct svc_rqst **rqstpp, int (**callback_svc)(void *vrqstp))
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{
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return 0;
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}
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static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
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struct nfs_callback_data *cb_info)
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{
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}
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#endif /* CONFIG_NFS_V4_1 */
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/*
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* Bring up the callback thread if it is not already up.
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*/
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int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
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{
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struct svc_serv *serv = NULL;
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struct svc_rqst *rqstp;
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int (*callback_svc)(void *vrqstp);
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struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
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char svc_name[12];
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int ret = 0;
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int minorversion_setup;
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mutex_lock(&nfs_callback_mutex);
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if (cb_info->users++ || cb_info->task != NULL) {
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nfs_callback_bc_serv(minorversion, xprt, cb_info);
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goto out;
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}
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serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, NULL);
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if (!serv) {
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ret = -ENOMEM;
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goto out_err;
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}
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minorversion_setup = nfs_minorversion_callback_svc_setup(minorversion,
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serv, xprt, &rqstp, &callback_svc);
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if (!minorversion_setup) {
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/* v4.0 callback setup */
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rqstp = nfs4_callback_up(serv);
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callback_svc = nfs4_callback_svc;
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}
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if (IS_ERR(rqstp)) {
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ret = PTR_ERR(rqstp);
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goto out_err;
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}
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svc_sock_update_bufs(serv);
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sprintf(svc_name, "nfsv4.%u-svc", minorversion);
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cb_info->serv = serv;
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cb_info->rqst = rqstp;
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cb_info->task = kthread_run(callback_svc, cb_info->rqst, svc_name);
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if (IS_ERR(cb_info->task)) {
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ret = PTR_ERR(cb_info->task);
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svc_exit_thread(cb_info->rqst);
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cb_info->rqst = NULL;
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cb_info->task = NULL;
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goto out_err;
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}
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out:
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/*
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* svc_create creates the svc_serv with sv_nrthreads == 1, and then
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* svc_prepare_thread increments that. So we need to call svc_destroy
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* on both success and failure so that the refcount is 1 when the
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* thread exits.
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*/
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if (serv)
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svc_destroy(serv);
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mutex_unlock(&nfs_callback_mutex);
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return ret;
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out_err:
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dprintk("NFS: Couldn't create callback socket or server thread; "
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"err = %d\n", ret);
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cb_info->users--;
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goto out;
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}
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/*
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* Kill the callback thread if it's no longer being used.
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*/
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void nfs_callback_down(int minorversion)
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{
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struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
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mutex_lock(&nfs_callback_mutex);
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cb_info->users--;
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if (cb_info->users == 0 && cb_info->task != NULL) {
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kthread_stop(cb_info->task);
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svc_exit_thread(cb_info->rqst);
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cb_info->serv = NULL;
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cb_info->rqst = NULL;
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cb_info->task = NULL;
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}
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mutex_unlock(&nfs_callback_mutex);
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}
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static int check_gss_callback_principal(struct nfs_client *clp,
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struct svc_rqst *rqstp)
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{
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struct rpc_clnt *r = clp->cl_rpcclient;
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char *p = svc_gss_principal(rqstp);
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/*
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* It might just be a normal user principal, in which case
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* userspace won't bother to tell us the name at all.
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*/
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if (p == NULL)
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return SVC_DENIED;
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/* Expect a GSS_C_NT_HOSTBASED_NAME like "nfs@serverhostname" */
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if (memcmp(p, "nfs@", 4) != 0)
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return SVC_DENIED;
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p += 4;
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if (strcmp(p, r->cl_server) != 0)
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return SVC_DENIED;
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return SVC_OK;
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}
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static int nfs_callback_authenticate(struct svc_rqst *rqstp)
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{
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struct nfs_client *clp;
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RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
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int ret = SVC_OK;
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/* Don't talk to strangers */
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clp = nfs_find_client(svc_addr(rqstp), 4);
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if (clp == NULL)
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return SVC_DROP;
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dprintk("%s: %s NFSv4 callback!\n", __func__,
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svc_print_addr(rqstp, buf, sizeof(buf)));
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switch (rqstp->rq_authop->flavour) {
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case RPC_AUTH_NULL:
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if (rqstp->rq_proc != CB_NULL)
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ret = SVC_DENIED;
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break;
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case RPC_AUTH_UNIX:
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break;
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case RPC_AUTH_GSS:
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ret = check_gss_callback_principal(clp, rqstp);
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break;
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default:
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ret = SVC_DENIED;
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}
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nfs_put_client(clp);
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return ret;
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}
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/*
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* Define NFS4 callback program
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*/
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static struct svc_version *nfs4_callback_version[] = {
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[1] = &nfs4_callback_version1,
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};
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static struct svc_stat nfs4_callback_stats;
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static struct svc_program nfs4_callback_program = {
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.pg_prog = NFS4_CALLBACK, /* RPC service number */
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.pg_nvers = ARRAY_SIZE(nfs4_callback_version), /* Number of entries */
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.pg_vers = nfs4_callback_version, /* version table */
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.pg_name = "NFSv4 callback", /* service name */
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.pg_class = "nfs", /* authentication class */
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.pg_stats = &nfs4_callback_stats,
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.pg_authenticate = nfs_callback_authenticate,
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};
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