android_kernel_xiaomi_sm8350/fs/nfs/callback.c

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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/smp_lock.h>
#include <linux/sunrpc/svc.h>
#include <linux/sunrpc/svcsock.h>
#include <linux/nfs_fs.h>
#include <linux/mutex.h>
#include <linux/freezer.h>
#include <linux/kthread.h>
#include <linux/sunrpc/svcauth_gss.h>
nfs41: Implement NFSv4.1 callback service process. nfs41_callback_up() initializes the necessary queues and creates the new nfs41_callback_svc thread. This thread executes the callback service which waits for requests to arrive on the svc_serv->sv_cb_list. NFS41_BC_MIN_CALLBACKS is set to 1 because we expect callbacks to not cause substantial latency. The actual processing of the callback will be implemented as a separate patch. There is only one NFSv4.1 callback service. The first caller of nfs4_callback_up() creates the service, subsequent callers increment a reference count on the service. The service is destroyed when the last caller invokes nfs_callback_down(). The transport needs to hold a reference to the callback service in order to invoke it during callback processing. Currently this reference is only obtained when the service is first created. This is incorrect, since subsequent registrations for other transports will leave the xprt->serv pointer uninitialized, leading to an oops when a callback arrives on the "unreferenced" transport. This patch fixes the problem by ensuring that a reference to the service is saved in xprt->serv, either because the service is created by this invocation to nfs4_callback_up() or by a prior invocation. Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com> Signed-off-by: Benny Halevy <bhalevy@panasas.com> [nfs41: Add a reference to svc_serv during callback service bring up] Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com> Signed-off-by: Benny Halevy <bhalevy@panasas.com> [Type check arguments of nfs_callback_up] Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com> Signed-off-by: Benny Halevy <bhalevy@panasas.com> [nfs41: save svc_serv in nfs_callback_info] Signed-off-by: Benny Halevy <bhalevy@panasas.com> [Removal of ugly #ifdefs] [nfs41: Update to removal of ugly #ifdefs] Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com> Signed-off-by: Benny Halevy <bhalevy@panasas.com>
2009-04-01 09:23:08 -04:00
#if defined(CONFIG_NFS_V4_1)
#include <linux/sunrpc/bc_xprt.h>
#endif
#include <net/inet_sock.h>
#include "nfs4_fs.h"
#include "callback.h"
#include "internal.h"
#define NFSDBG_FACILITY NFSDBG_CALLBACK
struct nfs_callback_data {
unsigned int users;
nfs41: Implement NFSv4.1 callback service process. nfs41_callback_up() initializes the necessary queues and creates the new nfs41_callback_svc thread. This thread executes the callback service which waits for requests to arrive on the svc_serv->sv_cb_list. NFS41_BC_MIN_CALLBACKS is set to 1 because we expect callbacks to not cause substantial latency. The actual processing of the callback will be implemented as a separate patch. There is only one NFSv4.1 callback service. The first caller of nfs4_callback_up() creates the service, subsequent callers increment a reference count on the service. The service is destroyed when the last caller invokes nfs_callback_down(). The transport needs to hold a reference to the callback service in order to invoke it during callback processing. Currently this reference is only obtained when the service is first created. This is incorrect, since subsequent registrations for other transports will leave the xprt->serv pointer uninitialized, leading to an oops when a callback arrives on the "unreferenced" transport. This patch fixes the problem by ensuring that a reference to the service is saved in xprt->serv, either because the service is created by this invocation to nfs4_callback_up() or by a prior invocation. Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com> Signed-off-by: Benny Halevy <bhalevy@panasas.com> [nfs41: Add a reference to svc_serv during callback service bring up] Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com> Signed-off-by: Benny Halevy <bhalevy@panasas.com> [Type check arguments of nfs_callback_up] Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com> Signed-off-by: Benny Halevy <bhalevy@panasas.com> [nfs41: save svc_serv in nfs_callback_info] Signed-off-by: Benny Halevy <bhalevy@panasas.com> [Removal of ugly #ifdefs] [nfs41: Update to removal of ugly #ifdefs] Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com> Signed-off-by: Benny Halevy <bhalevy@panasas.com>
2009-04-01 09:23:08 -04:00
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;
unsigned int nfs_callback_set_tcpport;
unsigned short nfs_callback_tcpport;
unsigned short nfs_callback_tcpport6;
#define NFS_CALLBACK_MAXPORTNR (65535U)
static int param_set_portnr(const char *val, struct kernel_param *kp)
{
unsigned long num;
int ret;
if (!val)
return -EINVAL;
ret = strict_strtoul(val, 0, &num);
if (ret == -EINVAL || num > NFS_CALLBACK_MAXPORTNR)
return -EINVAL;
*((unsigned int *)kp->arg) = num;
return 0;
}
static int param_get_portnr(char *buffer, struct kernel_param *kp)
{
return param_get_uint(buffer, kp);
}
#define param_check_portnr(name, p) __param_check(name, p, unsigned int);
module_param_named(callback_tcpport, nfs_callback_set_tcpport, portnr, 0644);
/*
* This is the NFSv4 callback kernel thread.
*/
static int
nfs4_callback_svc(void *vrqstp)
{
int err, preverr = 0;
struct svc_rqst *rqstp = vrqstp;
set_freezable();
/*
* FIXME: do we really need to run this under the BKL? If so, please
* add a comment about what it's intended to protect.
*/
lock_kernel();
while (!kthread_should_stop()) {
/*
* Listen for a request on the socket
*/
err = svc_recv(rqstp, MAX_SCHEDULE_TIMEOUT);
if (err == -EAGAIN || err == -EINTR) {
preverr = err;
continue;
}
if (err < 0) {
if (err != preverr) {
printk(KERN_WARNING "%s: unexpected error "
"from svc_recv (%d)\n", __func__, err);
preverr = err;
}
schedule_timeout_uninterruptible(HZ);
continue;
}
preverr = err;
svc_process(rqstp);
}
unlock_kernel();
return 0;
}
/*
* Prepare to bring up the NFSv4 callback service
*/
struct svc_rqst *
nfs4_callback_up(struct svc_serv *serv)
{
int ret;
ret = svc_create_xprt(serv, "tcp", PF_INET,
nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
if (ret <= 0)
goto out_err;
nfs_callback_tcpport = ret;
dprintk("NFS: Callback listener port = %u (af %u)\n",
nfs_callback_tcpport, PF_INET);
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
ret = svc_create_xprt(serv, "tcp", PF_INET6,
nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
if (ret > 0) {
nfs_callback_tcpport6 = ret;
dprintk("NFS: Callback listener port = %u (af %u)\n",
nfs_callback_tcpport6, PF_INET6);
} else if (ret == -EAFNOSUPPORT)
ret = 0;
else
goto out_err;
#endif /* defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) */
return svc_prepare_thread(serv, &serv->sv_pools[0]);
out_err:
if (ret == 0)
ret = -ENOMEM;
return ERR_PTR(ret);
}
nfs41: Implement NFSv4.1 callback service process. nfs41_callback_up() initializes the necessary queues and creates the new nfs41_callback_svc thread. This thread executes the callback service which waits for requests to arrive on the svc_serv->sv_cb_list. NFS41_BC_MIN_CALLBACKS is set to 1 because we expect callbacks to not cause substantial latency. The actual processing of the callback will be implemented as a separate patch. There is only one NFSv4.1 callback service. The first caller of nfs4_callback_up() creates the service, subsequent callers increment a reference count on the service. The service is destroyed when the last caller invokes nfs_callback_down(). The transport needs to hold a reference to the callback service in order to invoke it during callback processing. Currently this reference is only obtained when the service is first created. This is incorrect, since subsequent registrations for other transports will leave the xprt->serv pointer uninitialized, leading to an oops when a callback arrives on the "unreferenced" transport. This patch fixes the problem by ensuring that a reference to the service is saved in xprt->serv, either because the service is created by this invocation to nfs4_callback_up() or by a prior invocation. Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com> Signed-off-by: Benny Halevy <bhalevy@panasas.com> [nfs41: Add a reference to svc_serv during callback service bring up] Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com> Signed-off-by: Benny Halevy <bhalevy@panasas.com> [Type check arguments of nfs_callback_up] Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com> Signed-off-by: Benny Halevy <bhalevy@panasas.com> [nfs41: save svc_serv in nfs_callback_info] Signed-off-by: Benny Halevy <bhalevy@panasas.com> [Removal of ugly #ifdefs] [nfs41: Update to removal of ugly #ifdefs] Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com> Signed-off-by: Benny Halevy <bhalevy@panasas.com>
2009-04-01 09:23:08 -04:00
#if defined(CONFIG_NFS_V4_1)
/*
* 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();
/*
* FIXME: do we really need to run this under the BKL? If so, please
* add a comment about what it's intended to protect.
*/
lock_kernel();
while (!kthread_should_stop()) {
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);
}
unlock_kernel();
return 0;
}
/*
* Bring up the NFSv4.1 callback service
*/
struct svc_rqst *
nfs41_callback_up(struct svc_serv *serv, struct rpc_xprt *xprt)
{
struct svc_xprt *bc_xprt;
struct svc_rqst *rqstp = ERR_PTR(-ENOMEM);
dprintk("--> %s\n", __func__);
/* Create a svc_sock for the service */
bc_xprt = svc_sock_create(serv, xprt->prot);
if (!bc_xprt)
goto out;
nfs41: Implement NFSv4.1 callback service process. nfs41_callback_up() initializes the necessary queues and creates the new nfs41_callback_svc thread. This thread executes the callback service which waits for requests to arrive on the svc_serv->sv_cb_list. NFS41_BC_MIN_CALLBACKS is set to 1 because we expect callbacks to not cause substantial latency. The actual processing of the callback will be implemented as a separate patch. There is only one NFSv4.1 callback service. The first caller of nfs4_callback_up() creates the service, subsequent callers increment a reference count on the service. The service is destroyed when the last caller invokes nfs_callback_down(). The transport needs to hold a reference to the callback service in order to invoke it during callback processing. Currently this reference is only obtained when the service is first created. This is incorrect, since subsequent registrations for other transports will leave the xprt->serv pointer uninitialized, leading to an oops when a callback arrives on the "unreferenced" transport. This patch fixes the problem by ensuring that a reference to the service is saved in xprt->serv, either because the service is created by this invocation to nfs4_callback_up() or by a prior invocation. Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com> Signed-off-by: Benny Halevy <bhalevy@panasas.com> [nfs41: Add a reference to svc_serv during callback service bring up] Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com> Signed-off-by: Benny Halevy <bhalevy@panasas.com> [Type check arguments of nfs_callback_up] Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com> Signed-off-by: Benny Halevy <bhalevy@panasas.com> [nfs41: save svc_serv in nfs_callback_info] Signed-off-by: Benny Halevy <bhalevy@panasas.com> [Removal of ugly #ifdefs] [nfs41: Update to removal of ugly #ifdefs] Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com> Signed-off-by: Benny Halevy <bhalevy@panasas.com>
2009-04-01 09:23:08 -04:00
/*
* Save the svc_serv in the transport so that it can
* be referenced when the session backchannel is initialized
*/
serv->bc_xprt = bc_xprt;
nfs41: Implement NFSv4.1 callback service process. nfs41_callback_up() initializes the necessary queues and creates the new nfs41_callback_svc thread. This thread executes the callback service which waits for requests to arrive on the svc_serv->sv_cb_list. NFS41_BC_MIN_CALLBACKS is set to 1 because we expect callbacks to not cause substantial latency. The actual processing of the callback will be implemented as a separate patch. There is only one NFSv4.1 callback service. The first caller of nfs4_callback_up() creates the service, subsequent callers increment a reference count on the service. The service is destroyed when the last caller invokes nfs_callback_down(). The transport needs to hold a reference to the callback service in order to invoke it during callback processing. Currently this reference is only obtained when the service is first created. This is incorrect, since subsequent registrations for other transports will leave the xprt->serv pointer uninitialized, leading to an oops when a callback arrives on the "unreferenced" transport. This patch fixes the problem by ensuring that a reference to the service is saved in xprt->serv, either because the service is created by this invocation to nfs4_callback_up() or by a prior invocation. Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com> Signed-off-by: Benny Halevy <bhalevy@panasas.com> [nfs41: Add a reference to svc_serv during callback service bring up] Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com> Signed-off-by: Benny Halevy <bhalevy@panasas.com> [Type check arguments of nfs_callback_up] Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com> Signed-off-by: Benny Halevy <bhalevy@panasas.com> [nfs41: save svc_serv in nfs_callback_info] Signed-off-by: Benny Halevy <bhalevy@panasas.com> [Removal of ugly #ifdefs] [nfs41: Update to removal of ugly #ifdefs] Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com> Signed-off-by: Benny Halevy <bhalevy@panasas.com>
2009-04-01 09:23:08 -04:00
xprt->bc_serv = serv;
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]);
if (IS_ERR(rqstp))
svc_sock_destroy(bc_xprt);
out:
dprintk("--> %s return %p\n", __func__, rqstp);
return rqstp;
nfs41: Implement NFSv4.1 callback service process. nfs41_callback_up() initializes the necessary queues and creates the new nfs41_callback_svc thread. This thread executes the callback service which waits for requests to arrive on the svc_serv->sv_cb_list. NFS41_BC_MIN_CALLBACKS is set to 1 because we expect callbacks to not cause substantial latency. The actual processing of the callback will be implemented as a separate patch. There is only one NFSv4.1 callback service. The first caller of nfs4_callback_up() creates the service, subsequent callers increment a reference count on the service. The service is destroyed when the last caller invokes nfs_callback_down(). The transport needs to hold a reference to the callback service in order to invoke it during callback processing. Currently this reference is only obtained when the service is first created. This is incorrect, since subsequent registrations for other transports will leave the xprt->serv pointer uninitialized, leading to an oops when a callback arrives on the "unreferenced" transport. This patch fixes the problem by ensuring that a reference to the service is saved in xprt->serv, either because the service is created by this invocation to nfs4_callback_up() or by a prior invocation. Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com> Signed-off-by: Benny Halevy <bhalevy@panasas.com> [nfs41: Add a reference to svc_serv during callback service bring up] Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com> Signed-off-by: Benny Halevy <bhalevy@panasas.com> [Type check arguments of nfs_callback_up] Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com> Signed-off-by: Benny Halevy <bhalevy@panasas.com> [nfs41: save svc_serv in nfs_callback_info] Signed-off-by: Benny Halevy <bhalevy@panasas.com> [Removal of ugly #ifdefs] [nfs41: Update to removal of ugly #ifdefs] Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com> Signed-off-by: Benny Halevy <bhalevy@panasas.com>
2009-04-01 09:23:08 -04:00
}
static inline int nfs_minorversion_callback_svc_setup(u32 minorversion,
struct svc_serv *serv, struct rpc_xprt *xprt,
struct svc_rqst **rqstpp, int (**callback_svc)(void *vrqstp))
{
if (minorversion) {
*rqstpp = nfs41_callback_up(serv, xprt);
*callback_svc = nfs41_callback_svc;
}
return minorversion;
}
static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
struct nfs_callback_data *cb_info)
{
if (minorversion)
xprt->bc_serv = cb_info->serv;
}
#else
static inline int nfs_minorversion_callback_svc_setup(u32 minorversion,
struct svc_serv *serv, struct rpc_xprt *xprt,
struct svc_rqst **rqstpp, int (**callback_svc)(void *vrqstp))
{
return 0;
}
static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
struct nfs_callback_data *cb_info)
{
}
#endif /* CONFIG_NFS_V4_1 */
/*
* Bring up the callback thread if it is not already up.
*/
int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
{
struct svc_serv *serv = NULL;
struct svc_rqst *rqstp;
int (*callback_svc)(void *vrqstp);
struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
char svc_name[12];
int ret = 0;
nfs41: Implement NFSv4.1 callback service process. nfs41_callback_up() initializes the necessary queues and creates the new nfs41_callback_svc thread. This thread executes the callback service which waits for requests to arrive on the svc_serv->sv_cb_list. NFS41_BC_MIN_CALLBACKS is set to 1 because we expect callbacks to not cause substantial latency. The actual processing of the callback will be implemented as a separate patch. There is only one NFSv4.1 callback service. The first caller of nfs4_callback_up() creates the service, subsequent callers increment a reference count on the service. The service is destroyed when the last caller invokes nfs_callback_down(). The transport needs to hold a reference to the callback service in order to invoke it during callback processing. Currently this reference is only obtained when the service is first created. This is incorrect, since subsequent registrations for other transports will leave the xprt->serv pointer uninitialized, leading to an oops when a callback arrives on the "unreferenced" transport. This patch fixes the problem by ensuring that a reference to the service is saved in xprt->serv, either because the service is created by this invocation to nfs4_callback_up() or by a prior invocation. Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com> Signed-off-by: Benny Halevy <bhalevy@panasas.com> [nfs41: Add a reference to svc_serv during callback service bring up] Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com> Signed-off-by: Benny Halevy <bhalevy@panasas.com> [Type check arguments of nfs_callback_up] Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com> Signed-off-by: Benny Halevy <bhalevy@panasas.com> [nfs41: save svc_serv in nfs_callback_info] Signed-off-by: Benny Halevy <bhalevy@panasas.com> [Removal of ugly #ifdefs] [nfs41: Update to removal of ugly #ifdefs] Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com> Signed-off-by: Benny Halevy <bhalevy@panasas.com>
2009-04-01 09:23:08 -04:00
int minorversion_setup;
mutex_lock(&nfs_callback_mutex);
if (cb_info->users++ || cb_info->task != NULL) {
nfs_callback_bc_serv(minorversion, xprt, cb_info);
goto out;
nfs41: Implement NFSv4.1 callback service process. nfs41_callback_up() initializes the necessary queues and creates the new nfs41_callback_svc thread. This thread executes the callback service which waits for requests to arrive on the svc_serv->sv_cb_list. NFS41_BC_MIN_CALLBACKS is set to 1 because we expect callbacks to not cause substantial latency. The actual processing of the callback will be implemented as a separate patch. There is only one NFSv4.1 callback service. The first caller of nfs4_callback_up() creates the service, subsequent callers increment a reference count on the service. The service is destroyed when the last caller invokes nfs_callback_down(). The transport needs to hold a reference to the callback service in order to invoke it during callback processing. Currently this reference is only obtained when the service is first created. This is incorrect, since subsequent registrations for other transports will leave the xprt->serv pointer uninitialized, leading to an oops when a callback arrives on the "unreferenced" transport. This patch fixes the problem by ensuring that a reference to the service is saved in xprt->serv, either because the service is created by this invocation to nfs4_callback_up() or by a prior invocation. Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com> Signed-off-by: Benny Halevy <bhalevy@panasas.com> [nfs41: Add a reference to svc_serv during callback service bring up] Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com> Signed-off-by: Benny Halevy <bhalevy@panasas.com> [Type check arguments of nfs_callback_up] Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com> Signed-off-by: Benny Halevy <bhalevy@panasas.com> [nfs41: save svc_serv in nfs_callback_info] Signed-off-by: Benny Halevy <bhalevy@panasas.com> [Removal of ugly #ifdefs] [nfs41: Update to removal of ugly #ifdefs] Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com> Signed-off-by: Benny Halevy <bhalevy@panasas.com>
2009-04-01 09:23:08 -04:00
}
serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, NULL);
if (!serv) {
ret = -ENOMEM;
goto out_err;
}
nfs41: Implement NFSv4.1 callback service process. nfs41_callback_up() initializes the necessary queues and creates the new nfs41_callback_svc thread. This thread executes the callback service which waits for requests to arrive on the svc_serv->sv_cb_list. NFS41_BC_MIN_CALLBACKS is set to 1 because we expect callbacks to not cause substantial latency. The actual processing of the callback will be implemented as a separate patch. There is only one NFSv4.1 callback service. The first caller of nfs4_callback_up() creates the service, subsequent callers increment a reference count on the service. The service is destroyed when the last caller invokes nfs_callback_down(). The transport needs to hold a reference to the callback service in order to invoke it during callback processing. Currently this reference is only obtained when the service is first created. This is incorrect, since subsequent registrations for other transports will leave the xprt->serv pointer uninitialized, leading to an oops when a callback arrives on the "unreferenced" transport. This patch fixes the problem by ensuring that a reference to the service is saved in xprt->serv, either because the service is created by this invocation to nfs4_callback_up() or by a prior invocation. Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com> Signed-off-by: Benny Halevy <bhalevy@panasas.com> [nfs41: Add a reference to svc_serv during callback service bring up] Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com> Signed-off-by: Benny Halevy <bhalevy@panasas.com> [Type check arguments of nfs_callback_up] Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com> Signed-off-by: Benny Halevy <bhalevy@panasas.com> [nfs41: save svc_serv in nfs_callback_info] Signed-off-by: Benny Halevy <bhalevy@panasas.com> [Removal of ugly #ifdefs] [nfs41: Update to removal of ugly #ifdefs] Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com> Signed-off-by: Benny Halevy <bhalevy@panasas.com>
2009-04-01 09:23:08 -04:00
minorversion_setup = nfs_minorversion_callback_svc_setup(minorversion,
serv, xprt, &rqstp, &callback_svc);
if (!minorversion_setup) {
/* v4.0 callback setup */
rqstp = nfs4_callback_up(serv);
callback_svc = nfs4_callback_svc;
}
if (IS_ERR(rqstp)) {
ret = PTR_ERR(rqstp);
goto out_err;
}
svc_sock_update_bufs(serv);
sprintf(svc_name, "nfsv4.%u-svc", minorversion);
cb_info->serv = serv;
cb_info->rqst = rqstp;
cb_info->task = kthread_run(callback_svc, cb_info->rqst, svc_name);
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;
goto out_err;
}
out:
/*
* svc_create creates the svc_serv with sv_nrthreads == 1, and then
* svc_prepare_thread increments that. So we need to call svc_destroy
* on both success and failure so that the refcount is 1 when the
* thread exits.
*/
if (serv)
svc_destroy(serv);
mutex_unlock(&nfs_callback_mutex);
return ret;
out_err:
dprintk("NFS: Couldn't create callback socket or server thread; "
"err = %d\n", ret);
cb_info->users--;
goto out;
}
/*
* Kill the callback thread if it's no longer being used.
*/
void nfs_callback_down(int minorversion)
{
struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
mutex_lock(&nfs_callback_mutex);
cb_info->users--;
if (cb_info->users == 0 && cb_info->task != NULL) {
kthread_stop(cb_info->task);
svc_exit_thread(cb_info->rqst);
cb_info->serv = NULL;
cb_info->rqst = NULL;
cb_info->task = NULL;
}
mutex_unlock(&nfs_callback_mutex);
}
static int check_gss_callback_principal(struct nfs_client *clp,
struct svc_rqst *rqstp)
{
struct rpc_clnt *r = clp->cl_rpcclient;
char *p = svc_gss_principal(rqstp);
/*
* It might just be a normal user principal, in which case
* userspace won't bother to tell us the name at all.
*/
if (p == NULL)
return SVC_DENIED;
/* Expect a GSS_C_NT_HOSTBASED_NAME like "nfs@serverhostname" */
if (memcmp(p, "nfs@", 4) != 0)
return SVC_DENIED;
p += 4;
if (strcmp(p, r->cl_server) != 0)
return SVC_DENIED;
return SVC_OK;
}
static int nfs_callback_authenticate(struct svc_rqst *rqstp)
{
struct nfs_client *clp;
RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
int ret = SVC_OK;
/* Don't talk to strangers */
clp = nfs_find_client(svc_addr(rqstp), 4);
if (clp == NULL)
return SVC_DROP;
dprintk("%s: %s NFSv4 callback!\n", __func__,
svc_print_addr(rqstp, buf, sizeof(buf)));
switch (rqstp->rq_authop->flavour) {
case RPC_AUTH_NULL:
if (rqstp->rq_proc != CB_NULL)
ret = SVC_DENIED;
break;
case RPC_AUTH_UNIX:
break;
case RPC_AUTH_GSS:
ret = check_gss_callback_principal(clp, rqstp);
break;
default:
ret = SVC_DENIED;
}
nfs_put_client(clp);
return ret;
}
/*
* Define NFS4 callback program
*/
static struct svc_version *nfs4_callback_version[] = {
[1] = &nfs4_callback_version1,
};
static struct svc_stat nfs4_callback_stats;
static struct svc_program nfs4_callback_program = {
.pg_prog = NFS4_CALLBACK, /* RPC service number */
.pg_nvers = ARRAY_SIZE(nfs4_callback_version), /* Number of entries */
.pg_vers = nfs4_callback_version, /* version table */
.pg_name = "NFSv4 callback", /* service name */
.pg_class = "nfs", /* authentication class */
.pg_stats = &nfs4_callback_stats,
.pg_authenticate = nfs_callback_authenticate,
};