Fedora kernel-2.6.17-1.2142_FC4 patched with stable patch-2.6.17.4-vs2.0.2-rc26.diff
[linux-2.6.git] / fs / lockd / clntproc.c
index a440761..ece5c5a 100644 (file)
 #include <linux/sunrpc/svc.h>
 #include <linux/lockd/lockd.h>
 #include <linux/lockd/sm_inter.h>
+#include <linux/vs_cvirt.h>
 
 #define NLMDBG_FACILITY                NLMDBG_CLIENT
 #define NLMCLNT_GRACE_WAIT     (5*HZ)
+#define NLMCLNT_POLL_TIMEOUT   (30*HZ)
+#define NLMCLNT_MAX_RETRIES    3
 
 static int     nlmclnt_test(struct nlm_rqst *, struct file_lock *);
 static int     nlmclnt_lock(struct nlm_rqst *, struct file_lock *);
 static int     nlmclnt_unlock(struct nlm_rqst *, struct file_lock *);
-static void    nlmclnt_unlock_callback(struct rpc_task *);
-static void    nlmclnt_cancel_callback(struct rpc_task *);
 static int     nlm_stat_to_errno(u32 stat);
 static void    nlmclnt_locks_init_private(struct file_lock *fl, struct nlm_host *host);
+static int     nlmclnt_cancel(struct nlm_host *, int , struct file_lock *);
+
+static const struct rpc_call_ops nlmclnt_unlock_ops;
+static const struct rpc_call_ops nlmclnt_cancel_ops;
 
 /*
  * Cookie counter for NLM requests
@@ -111,8 +116,7 @@ static struct nlm_lockowner *nlm_find_lockowner(struct nlm_host *host, fl_owner_
                }
        }
        spin_unlock(&host->h_lock);
-       if (new != NULL)
-               kfree(new);
+       kfree(new);
        return res;
 }
 
@@ -127,61 +131,20 @@ static void nlmclnt_setlockargs(struct nlm_rqst *req, struct file_lock *fl)
        nlmclnt_next_cookie(&argp->cookie);
        argp->state   = nsm_local_state;
        memcpy(&lock->fh, NFS_FH(fl->fl_file->f_dentry->d_inode), sizeof(struct nfs_fh));
-       lock->caller  = system_utsname.nodename;
+       lock->caller  = vx_new_uts(nodename);
        lock->oh.data = req->a_owner;
-       lock->oh.len  = sprintf(req->a_owner, "%d@%s",
-                               current->pid, system_utsname.nodename);
-       locks_copy_lock(&lock->fl, fl);
+       lock->oh.len  = snprintf(req->a_owner, sizeof(req->a_owner), "%u@%s",
+                               (unsigned int)fl->fl_u.nfs_fl.owner->pid,
+                               vx_new_uts(nodename));
+       lock->svid = fl->fl_u.nfs_fl.owner->pid;
+       lock->fl.fl_start = fl->fl_start;
+       lock->fl.fl_end = fl->fl_end;
+       lock->fl.fl_type = fl->fl_type;
 }
 
 static void nlmclnt_release_lockargs(struct nlm_rqst *req)
 {
-       struct file_lock *fl = &req->a_args.lock.fl;
-
-       if (fl->fl_ops && fl->fl_ops->fl_release_private)
-               fl->fl_ops->fl_release_private(fl);
-}
-
-/*
- * Initialize arguments for GRANTED call. The nlm_rqst structure
- * has been cleared already.
- */
-int
-nlmclnt_setgrantargs(struct nlm_rqst *call, struct nlm_lock *lock)
-{
-       locks_copy_lock(&call->a_args.lock.fl, &lock->fl);
-       memcpy(&call->a_args.lock.fh, &lock->fh, sizeof(call->a_args.lock.fh));
-       call->a_args.lock.caller = system_utsname.nodename;
-       call->a_args.lock.oh.len = lock->oh.len;
-
-       /* set default data area */
-       call->a_args.lock.oh.data = call->a_owner;
-
-       if (lock->oh.len > NLMCLNT_OHSIZE) {
-               void *data = kmalloc(lock->oh.len, GFP_KERNEL);
-               if (!data) {
-                       nlmclnt_freegrantargs(call);
-                       return 0;
-               }
-               call->a_args.lock.oh.data = (u8 *) data;
-       }
-
-       memcpy(call->a_args.lock.oh.data, lock->oh.data, lock->oh.len);
-       return 1;
-}
-
-void
-nlmclnt_freegrantargs(struct nlm_rqst *call)
-{
-       struct file_lock *fl = &call->a_args.lock.fl;
-       /*
-        * Check whether we allocated memory for the owner.
-        */
-       if (call->a_args.lock.oh.data != (u8 *) call->a_owner) {
-               kfree(call->a_args.lock.oh.data);
-       }
-       if (fl->fl_ops && fl->fl_ops->fl_release_private)
-               fl->fl_ops->fl_release_private(fl);
+       BUG_ON(req->a_args.lock.fl.fl_ops != NULL);
 }
 
 /*
@@ -190,9 +153,8 @@ nlmclnt_freegrantargs(struct nlm_rqst *call)
 int
 nlmclnt_proc(struct inode *inode, int cmd, struct file_lock *fl)
 {
-       struct nfs_server       *nfssrv = NFS_SERVER(inode);
        struct nlm_host         *host;
-       struct nlm_rqst         reqst, *call = &reqst;
+       struct nlm_rqst         *call;
        sigset_t                oldset;
        unsigned long           flags;
        int                     status, proto, vers;
@@ -206,24 +168,17 @@ nlmclnt_proc(struct inode *inode, int cmd, struct file_lock *fl)
        /* Retrieve transport protocol from NFS client */
        proto = NFS_CLIENT(inode)->cl_xprt->prot;
 
-       if (!(host = nlmclnt_lookup_host(NFS_ADDR(inode), proto, vers)))
+       host = nlmclnt_lookup_host(NFS_ADDR(inode), proto, vers);
+       if (host == NULL)
                return -ENOLCK;
 
-       /* Create RPC client handle if not there, and copy soft
-        * and intr flags from NFS client. */
-       if (host->h_rpcclnt == NULL) {
-               struct rpc_clnt *clnt;
+       call = nlm_alloc_call(host);
+       if (call == NULL)
+               return -ENOMEM;
 
-               /* Bind an rpc client to this host handle (does not
-                * perform a portmapper lookup) */
-               if (!(clnt = nlm_bind_host(host))) {
-                       status = -ENOLCK;
-                       goto done;
-               }
-               clnt->cl_softrtry = nfssrv->client->cl_softrtry;
-               clnt->cl_intr     = nfssrv->client->cl_intr;
-               clnt->cl_chatty   = nfssrv->client->cl_chatty;
-       }
+       nlmclnt_locks_init_private(fl, host);
+       /* Set up the argument struct */
+       nlmclnt_setlockargs(call, fl);
 
        /* Keep the old signal mask */
        spin_lock_irqsave(&current->sighand->siglock, flags);
@@ -236,26 +191,10 @@ nlmclnt_proc(struct inode *inode, int cmd, struct file_lock *fl)
            && (current->flags & PF_EXITING)) {
                sigfillset(&current->blocked);  /* Mask all signals */
                recalc_sigpending();
-               spin_unlock_irqrestore(&current->sighand->siglock, flags);
 
-               call = nlmclnt_alloc_call();
-               if (!call) {
-                       status = -ENOMEM;
-                       goto out_restore;
-               }
                call->a_flags = RPC_TASK_ASYNC;
-       } else {
-               spin_unlock_irqrestore(&current->sighand->siglock, flags);
-               memset(call, 0, sizeof(*call));
-               locks_init_lock(&call->a_args.lock.fl);
-               locks_init_lock(&call->a_res.lock.fl);
        }
-       call->a_host = host;
-
-       nlmclnt_locks_init_private(fl, host);
-
-       /* Set up the argument struct */
-       nlmclnt_setlockargs(call, fl);
+       spin_unlock_irqrestore(&current->sighand->siglock, flags);
 
        if (IS_SETLK(cmd) || IS_SETLKW(cmd)) {
                if (fl->fl_type != F_UNLCK) {
@@ -268,42 +207,58 @@ nlmclnt_proc(struct inode *inode, int cmd, struct file_lock *fl)
        else
                status = -EINVAL;
 
- out_restore:
+       fl->fl_ops->fl_release_private(fl);
+       fl->fl_ops = NULL;
+
        spin_lock_irqsave(&current->sighand->siglock, flags);
        current->blocked = oldset;
        recalc_sigpending();
        spin_unlock_irqrestore(&current->sighand->siglock, flags);
 
-done:
        dprintk("lockd: clnt proc returns %d\n", status);
-       nlm_release_host(host);
        return status;
 }
 EXPORT_SYMBOL(nlmclnt_proc);
 
 /*
  * Allocate an NLM RPC call struct
+ *
+ * Note: the caller must hold a reference to host. In case of failure,
+ * this reference will be released.
  */
-struct nlm_rqst *
-nlmclnt_alloc_call(void)
+struct nlm_rqst *nlm_alloc_call(struct nlm_host *host)
 {
        struct nlm_rqst *call;
 
-       while (!signalled()) {
-               call = (struct nlm_rqst *) kmalloc(sizeof(struct nlm_rqst), GFP_KERNEL);
-               if (call) {
-                       memset(call, 0, sizeof(*call));
+       for(;;) {
+               call = kzalloc(sizeof(*call), GFP_KERNEL);
+               if (call != NULL) {
                        locks_init_lock(&call->a_args.lock.fl);
                        locks_init_lock(&call->a_res.lock.fl);
+                       call->a_host = host;
                        return call;
                }
-               printk("nlmclnt_alloc_call: failed, waiting for memory\n");
-               current->state = TASK_INTERRUPTIBLE;
-               schedule_timeout(5*HZ);
+               if (signalled())
+                       break;
+               printk("nlm_alloc_call: failed, waiting for memory\n");
+               schedule_timeout_interruptible(5*HZ);
        }
+       nlm_release_host(host);
        return NULL;
 }
 
+void nlm_release_call(struct nlm_rqst *call)
+{
+       nlm_release_host(call->a_host);
+       nlmclnt_release_lockargs(call);
+       kfree(call);
+}
+
+static void nlmclnt_rpc_release(void *data)
+{
+       return nlm_release_call(data);
+}
+
 static int nlm_wait_on_grace(wait_queue_head_t *queue)
 {
        DEFINE_WAIT(wait);
@@ -312,7 +267,7 @@ static int nlm_wait_on_grace(wait_queue_head_t *queue)
        prepare_to_wait(queue, &wait, TASK_INTERRUPTIBLE);
        if (!signalled ()) {
                schedule_timeout(NLMCLNT_GRACE_WAIT);
-               try_to_freeze(PF_FREEZE);
+               try_to_freeze();
                if (!signalled ())
                        status = 0;
        }
@@ -400,59 +355,45 @@ in_grace_period:
 /*
  * Generic NLM call, async version.
  */
-int
-nlmsvc_async_call(struct nlm_rqst *req, u32 proc, rpc_action callback)
+static int __nlm_async_call(struct nlm_rqst *req, u32 proc, struct rpc_message *msg, const struct rpc_call_ops *tk_ops)
 {
        struct nlm_host *host = req->a_host;
        struct rpc_clnt *clnt;
-       struct rpc_message msg = {
-               .rpc_argp       = &req->a_args,
-               .rpc_resp       = &req->a_res,
-       };
-       int             status;
+       int status = -ENOLCK;
 
        dprintk("lockd: call procedure %d on %s (async)\n",
                        (int)proc, host->h_name);
 
        /* If we have no RPC client yet, create one. */
-       if ((clnt = nlm_bind_host(host)) == NULL)
-               return -ENOLCK;
-       msg.rpc_proc = &clnt->cl_procinfo[proc];
+       clnt = nlm_bind_host(host);
+       if (clnt == NULL)
+               goto out_err;
+       msg->rpc_proc = &clnt->cl_procinfo[proc];
 
         /* bootstrap and kick off the async RPC call */
-        status = rpc_call_async(clnt, &msg, RPC_TASK_ASYNC, callback, req);
-
+        status = rpc_call_async(clnt, msg, RPC_TASK_ASYNC, tk_ops, req);
+       if (status == 0)
+               return 0;
+out_err:
+       nlm_release_call(req);
        return status;
 }
 
-static int
-nlmclnt_async_call(struct nlm_rqst *req, u32 proc, rpc_action callback)
+int nlm_async_call(struct nlm_rqst *req, u32 proc, const struct rpc_call_ops *tk_ops)
 {
-       struct nlm_host *host = req->a_host;
-       struct rpc_clnt *clnt;
-       struct nlm_args *argp = &req->a_args;
-       struct nlm_res  *resp = &req->a_res;
        struct rpc_message msg = {
-               .rpc_argp       = argp,
-               .rpc_resp       = resp,
+               .rpc_argp       = &req->a_args,
+               .rpc_resp       = &req->a_res,
        };
-       int             status;
-
-       dprintk("lockd: call procedure %d on %s (async)\n",
-                       (int)proc, host->h_name);
-
-       /* If we have no RPC client yet, create one. */
-       if ((clnt = nlm_bind_host(host)) == NULL)
-               return -ENOLCK;
-       msg.rpc_proc = &clnt->cl_procinfo[proc];
+       return __nlm_async_call(req, proc, &msg, tk_ops);
+}
 
-       /* Increment host refcount */
-       nlm_get_host(host);
-        /* bootstrap and kick off the async RPC call */
-        status = rpc_call_async(clnt, &msg, RPC_TASK_ASYNC, callback, req);
-       if (status < 0)
-               nlm_release_host(host);
-       return status;
+int nlm_async_reply(struct nlm_rqst *req, u32 proc, const struct rpc_call_ops *tk_ops)
+{
+       struct rpc_message msg = {
+               .rpc_argp       = &req->a_res,
+       };
+       return __nlm_async_call(req, proc, &msg, tk_ops);
 }
 
 /*
@@ -464,36 +405,41 @@ nlmclnt_test(struct nlm_rqst *req, struct file_lock *fl)
        int     status;
 
        status = nlmclnt_call(req, NLMPROC_TEST);
-       nlmclnt_release_lockargs(req);
        if (status < 0)
-               return status;
+               goto out;
 
-       status = req->a_res.status;
-       if (status == NLM_LCK_GRANTED) {
-               fl->fl_type = F_UNLCK;
-       } if (status == NLM_LCK_DENIED) {
-               /*
-                * Report the conflicting lock back to the application.
-                */
-               locks_copy_lock(fl, &req->a_res.lock.fl);
-               fl->fl_pid = 0;
-       } else {
-               return nlm_stat_to_errno(req->a_res.status);
+       switch (req->a_res.status) {
+               case NLM_LCK_GRANTED:
+                       fl->fl_type = F_UNLCK;
+                       break;
+               case NLM_LCK_DENIED:
+                       /*
+                        * Report the conflicting lock back to the application.
+                        */
+                       fl->fl_start = req->a_res.lock.fl.fl_start;
+                       fl->fl_end = req->a_res.lock.fl.fl_start;
+                       fl->fl_type = req->a_res.lock.fl.fl_type;
+                       fl->fl_pid = 0;
+                       break;
+               default:
+                       status = nlm_stat_to_errno(req->a_res.status);
        }
-
-       return 0;
+out:
+       nlm_release_call(req);
+       return status;
 }
 
 static void nlmclnt_locks_copy_lock(struct file_lock *new, struct file_lock *fl)
 {
-       memcpy(&new->fl_u.nfs_fl, &fl->fl_u.nfs_fl, sizeof(new->fl_u.nfs_fl));
-       nlm_get_lockowner(new->fl_u.nfs_fl.owner);
+       new->fl_u.nfs_fl.state = fl->fl_u.nfs_fl.state;
+       new->fl_u.nfs_fl.owner = nlm_get_lockowner(fl->fl_u.nfs_fl.owner);
+       list_add_tail(&new->fl_u.nfs_fl.list, &fl->fl_u.nfs_fl.owner->host->h_granted);
 }
 
 static void nlmclnt_locks_release_private(struct file_lock *fl)
 {
+       list_del(&fl->fl_u.nfs_fl.list);
        nlm_put_lockowner(fl->fl_u.nfs_fl.owner);
-       fl->fl_ops = NULL;
 }
 
 static struct file_lock_operations nlmclnt_lock_ops = {
@@ -505,8 +451,8 @@ static void nlmclnt_locks_init_private(struct file_lock *fl, struct nlm_host *ho
 {
        BUG_ON(fl->fl_ops != NULL);
        fl->fl_u.nfs_fl.state = 0;
-       fl->fl_u.nfs_fl.flags = 0;
        fl->fl_u.nfs_fl.owner = nlm_find_lockowner(host, fl->fl_owner);
+       INIT_LIST_HEAD(&fl->fl_u.nfs_fl.list);
        fl->fl_ops = &nlmclnt_lock_ops;
 }
 
@@ -553,34 +499,52 @@ nlmclnt_lock(struct nlm_rqst *req, struct file_lock *fl)
 {
        struct nlm_host *host = req->a_host;
        struct nlm_res  *resp = &req->a_res;
-       int             status;
+       struct nlm_wait *block = NULL;
+       int status = -ENOLCK;
 
        if (!host->h_monitored && nsm_monitor(host) < 0) {
                printk(KERN_NOTICE "lockd: failed to monitor %s\n",
                                        host->h_name);
-               status = -ENOLCK;
                goto out;
        }
 
-       do {
-               if ((status = nlmclnt_call(req, NLMPROC_LOCK)) >= 0) {
-                       if (resp->status != NLM_LCK_BLOCKED)
-                               break;
-                       status = nlmclnt_block(host, fl, &resp->status);
-               }
+       block = nlmclnt_prepare_block(host, fl);
+       for(;;) {
+               status = nlmclnt_call(req, NLMPROC_LOCK);
+               if (status < 0)
+                       goto out_unblock;
+               if (!req->a_args.block)
+                       break;
+               /* Did a reclaimer thread notify us of a server reboot? */
+               if (resp->status ==  NLM_LCK_DENIED_GRACE_PERIOD)
+                       continue;
+               if (resp->status != NLM_LCK_BLOCKED)
+                       break;
+               /* Wait on an NLM blocking lock */
+               status = nlmclnt_block(block, req, NLMCLNT_POLL_TIMEOUT);
+               /* if we were interrupted. Send a CANCEL request to the server
+                * and exit
+                */
                if (status < 0)
-                       goto out;
-       } while (resp->status == NLM_LCK_BLOCKED && req->a_args.block);
+                       goto out_unblock;
+               if (resp->status != NLM_LCK_BLOCKED)
+                       break;
+       }
 
        if (resp->status == NLM_LCK_GRANTED) {
                fl->fl_u.nfs_fl.state = host->h_state;
-               fl->fl_u.nfs_fl.flags |= NFS_LCK_GRANTED;
                fl->fl_flags |= FL_SLEEP;
+               /* Ensure the resulting lock will get added to granted list */
                do_vfs_lock(fl);
        }
        status = nlm_stat_to_errno(resp->status);
+out_unblock:
+       nlmclnt_finish_block(block);
+       /* Cancel the blocked request if it is still pending */
+       if (resp->status == NLM_LCK_BLOCKED)
+               nlmclnt_cancel(host, req->a_args.block, fl);
 out:
-       nlmclnt_release_lockargs(req);
+       nlm_release_call(req);
        return status;
 }
 
@@ -636,44 +600,36 @@ nlmclnt_unlock(struct nlm_rqst *req, struct file_lock *fl)
        struct nlm_res  *resp = &req->a_res;
        int             status;
 
-       /* Clean the GRANTED flag now so the lock doesn't get
-        * reclaimed while we're stuck in the unlock call. */
-       fl->fl_u.nfs_fl.flags &= ~NFS_LCK_GRANTED;
+       /*
+        * Note: the server is supposed to either grant us the unlock
+        * request, or to deny it with NLM_LCK_DENIED_GRACE_PERIOD. In either
+        * case, we want to unlock.
+        */
+       do_vfs_lock(fl);
 
-       if (req->a_flags & RPC_TASK_ASYNC) {
-               status = nlmclnt_async_call(req, NLMPROC_UNLOCK,
-                                       nlmclnt_unlock_callback);
-               /* Hrmf... Do the unlock early since locks_remove_posix()
-                * really expects us to free the lock synchronously */
-               do_vfs_lock(fl);
-               if (status < 0) {
-                       nlmclnt_release_lockargs(req);
-                       kfree(req);
-               }
-               return status;
-       }
+       if (req->a_flags & RPC_TASK_ASYNC)
+               return nlm_async_call(req, NLMPROC_UNLOCK, &nlmclnt_unlock_ops);
 
        status = nlmclnt_call(req, NLMPROC_UNLOCK);
-       nlmclnt_release_lockargs(req);
        if (status < 0)
-               return status;
+               goto out;
 
-       do_vfs_lock(fl);
+       status = 0;
        if (resp->status == NLM_LCK_GRANTED)
-               return 0;
+               goto out;
 
        if (resp->status != NLM_LCK_DENIED_NOLOCKS)
                printk("lockd: unexpected unlock status: %d\n", resp->status);
-
        /* What to do now? I'm out of my depth... */
-
-       return -ENOLCK;
+       status = -ENOLCK;
+out:
+       nlm_release_call(req);
+       return status;
 }
 
-static void
-nlmclnt_unlock_callback(struct rpc_task *task)
+static void nlmclnt_unlock_callback(struct rpc_task *task, void *data)
 {
-       struct nlm_rqst *req = (struct nlm_rqst *) task->tk_calldata;
+       struct nlm_rqst *req = data;
        int             status = req->a_res.status;
 
        if (RPC_ASSASSINATED(task))
@@ -690,9 +646,6 @@ nlmclnt_unlock_callback(struct rpc_task *task)
        if (status != NLM_LCK_GRANTED)
                printk(KERN_WARNING "lockd: unexpected unlock status: %d\n", status);
 die:
-       nlm_release_host(req->a_host);
-       nlmclnt_release_lockargs(req);
-       kfree(req);
        return;
  retry_rebind:
        nlm_rebind_host(req->a_host);
@@ -700,13 +653,17 @@ die:
        rpc_restart_call(task);
 }
 
+static const struct rpc_call_ops nlmclnt_unlock_ops = {
+       .rpc_call_done = nlmclnt_unlock_callback,
+       .rpc_release = nlmclnt_rpc_release,
+};
+
 /*
  * Cancel a blocked lock request.
  * We always use an async RPC call for this in order not to hang a
  * process that has been Ctrl-C'ed.
  */
-int
-nlmclnt_cancel(struct nlm_host *host, struct file_lock *fl)
+static int nlmclnt_cancel(struct nlm_host *host, int block, struct file_lock *fl)
 {
        struct nlm_rqst *req;
        unsigned long   flags;
@@ -720,20 +677,15 @@ nlmclnt_cancel(struct nlm_host *host, struct file_lock *fl)
        recalc_sigpending();
        spin_unlock_irqrestore(&current->sighand->siglock, flags);
 
-       req = nlmclnt_alloc_call();
+       req = nlm_alloc_call(nlm_get_host(host));
        if (!req)
                return -ENOMEM;
-       req->a_host  = host;
        req->a_flags = RPC_TASK_ASYNC;
 
        nlmclnt_setlockargs(req, fl);
+       req->a_args.block = block;
 
-       status = nlmclnt_async_call(req, NLMPROC_CANCEL,
-                                       nlmclnt_cancel_callback);
-       if (status < 0) {
-               nlmclnt_release_lockargs(req);
-               kfree(req);
-       }
+       status = nlm_async_call(req, NLMPROC_CANCEL, &nlmclnt_cancel_ops);
 
        spin_lock_irqsave(&current->sighand->siglock, flags);
        current->blocked = oldset;
@@ -743,10 +695,9 @@ nlmclnt_cancel(struct nlm_host *host, struct file_lock *fl)
        return status;
 }
 
-static void
-nlmclnt_cancel_callback(struct rpc_task *task)
+static void nlmclnt_cancel_callback(struct rpc_task *task, void *data)
 {
-       struct nlm_rqst *req = (struct nlm_rqst *) task->tk_calldata;
+       struct nlm_rqst *req = data;
 
        if (RPC_ASSASSINATED(task))
                goto die;
@@ -763,6 +714,7 @@ nlmclnt_cancel_callback(struct rpc_task *task)
        switch (req->a_res.status) {
        case NLM_LCK_GRANTED:
        case NLM_LCK_DENIED_GRACE_PERIOD:
+       case NLM_LCK_DENIED:
                /* Everything's good */
                break;
        case NLM_LCK_DENIED_NOLOCKS:
@@ -774,17 +726,22 @@ nlmclnt_cancel_callback(struct rpc_task *task)
        }
 
 die:
-       nlm_release_host(req->a_host);
-       nlmclnt_release_lockargs(req);
-       kfree(req);
        return;
 
 retry_cancel:
+       /* Don't ever retry more than 3 times */
+       if (req->a_retries++ >= NLMCLNT_MAX_RETRIES)
+               goto die;
        nlm_rebind_host(req->a_host);
        rpc_restart_call(task);
        rpc_delay(task, 30 * HZ);
 }
 
+static const struct rpc_call_ops nlmclnt_cancel_ops = {
+       .rpc_call_done = nlmclnt_cancel_callback,
+       .rpc_release = nlmclnt_rpc_release,
+};
+
 /*
  * Convert an NLM status code to a generic kernel errno
  */