NLM: Add nlmclnt_release_call

Add a helper function to simplify the freeing of NLM client requests.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 74 insertions, 121 deletions

diff --git a/fs/lockd/clntproc.c b/fs/lockd/clntproc.c
index 7a239864b8bf..3f8ad7c54efa 100644
--- a/fs/lockd/clntproc.c
+++ b/fs/lockd/clntproc.c
@@ -152,9 +152,8 @@ static void nlmclnt_release_lockargs(struct nlm_rqst *req)
 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;
@@ -168,23 +167,17 @@ 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;
-        }
+        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);
@@ -197,26 +190,10 @@ 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) {
@@ -229,24 +206,26 @@ 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;
 
@@ -255,16 +234,30 @@ nlmclnt_alloc_call(void)
                 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;
                 }
                 if (signalled())
                         break;
-                printk("nlmclnt_alloc_call: failed, waiting for memory\n");
+                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);
@@ -361,7 +354,7 @@ in_grace_period:
 /*
  * Generic NLM call, async version.
  */
-int nlmsvc_async_call(struct nlm_rqst *req, u32 proc, const struct rpc_call_ops *tk_ops)
+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;
@@ -369,48 +362,23 @@ int nlmsvc_async_call(struct nlm_rqst *req, u32 proc, const struct rpc_call_ops
                 .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];
-
-        /* bootstrap and kick off the async RPC call */
-        status = rpc_call_async(clnt, &msg, RPC_TASK_ASYNC, tk_ops, req);
-
-        return status;
-}
-
-static int nlmclnt_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,
-        };
-        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;
+        clnt = nlm_bind_host(host);
+        if (clnt == NULL)
+                goto out_err;
         msg.rpc_proc = &clnt->cl_procinfo[proc];
 
-        /* Increment host refcount */
-        nlm_get_host(host);
         /* bootstrap and kick off the async RPC call */
         status = rpc_call_async(clnt, &msg, RPC_TASK_ASYNC, tk_ops, req);
-        if (status < 0)
-                nlm_release_host(host);
+        if (status == 0)
+                return 0;
+out_err:
+        nlm_release_call(req);
         return status;
 }
 
@@ -423,26 +391,28 @@ 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.
-                 */
-                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;
-        } 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)
@@ -560,7 +530,7 @@ out_unblock:
         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;
 }
 
@@ -623,32 +593,24 @@ nlmclnt_unlock(struct nlm_rqst *req, struct file_lock *fl)
          */
         do_vfs_lock(fl);
 
-        if (req->a_flags & RPC_TASK_ASYNC) {
-                status = nlmclnt_async_call(req, NLMPROC_UNLOCK,
-                                        &nlmclnt_unlock_ops);
-                /* Hrmf... Do the unlock early since locks_remove_posix()
-                 * really expects us to free the lock synchronously */
-                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;
 
+        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, void *data)
@@ -670,9 +632,6 @@ static void nlmclnt_unlock_callback(struct rpc_task *task, void *data)
         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);
@@ -682,6 +641,7 @@ die:
 
 static const struct rpc_call_ops nlmclnt_unlock_ops = {
         .rpc_call_done = nlmclnt_unlock_callback,
+        .rpc_release = nlmclnt_rpc_release,
 };
 
 /*
@@ -703,20 +663,15 @@ static int nlmclnt_cancel(struct nlm_host *host, int block, 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_ops);
-        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;
@@ -757,9 +712,6 @@ static void nlmclnt_cancel_callback(struct rpc_task *task, void *data)
         }
 
 die:
-        nlm_release_host(req->a_host);
-        nlmclnt_release_lockargs(req);
-        kfree(req);
         return;
 
 retry_cancel:
@@ -773,6 +725,7 @@ retry_cancel:
 
 static const struct rpc_call_ops nlmclnt_cancel_ops = {
         .rpc_call_done = nlmclnt_cancel_callback,
+        .rpc_release = nlmclnt_rpc_release,
 };
 
 /*