NLM,NFSv4: Don't put UNLOCK requests on the wire unless we hold a lock

Use the new behaviour of {flock,posix}_file_lock(F_UNLCK) to determine if
we held a lock, and only send the RPC request to the server if this was the
case.

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

diff --git a/fs/lockd/clntproc.c b/fs/lockd/clntproc.c
index 5980c45..24c691f 100644 (file)
--- a/fs/lockd/clntproc.c
+++ b/fs/lockd/clntproc.c
@@ -454,7 +454,7 @@ static void nlmclnt_locks_init_private(struct file_lock *fl, struct nlm_host *ho
        fl->fl_ops = &nlmclnt_lock_ops;
 }
 
-static void do_vfs_lock(struct file_lock *fl)
+static int do_vfs_lock(struct file_lock *fl)
 {
        int res = 0;
        switch (fl->fl_flags & (FL_POSIX|FL_FLOCK)) {
@@ -467,9 +467,7 @@ static void do_vfs_lock(struct file_lock *fl)
                default:
                        BUG();
        }
-       if (res < 0)
-               printk(KERN_WARNING "%s: VFS is out of sync with lock manager!\n",
-                               __FUNCTION__);
+       return res;
 }
 
 /*
@@ -541,7 +539,8 @@ again:
                }
                fl->fl_flags |= FL_SLEEP;
                /* Ensure the resulting lock will get added to granted list */
-               do_vfs_lock(fl);
+               if (do_vfs_lock(fl) < 0)
+                       printk(KERN_WARNING "%s: VFS is out of sync with lock manager!\n", __FUNCTION__);
                up_read(&host->h_rwsem);
        }
        status = nlm_stat_to_errno(resp->status);
@@ -606,15 +605,19 @@ nlmclnt_unlock(struct nlm_rqst *req, struct file_lock *fl)
 {
        struct nlm_host *host = req->a_host;
        struct nlm_res  *resp = &req->a_res;
-       int             status;
+       int status = 0;
 
        /*
         * 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.
         */
+       fl->fl_flags |= FL_EXISTS;
        down_read(&host->h_rwsem);
-       do_vfs_lock(fl);
+       if (do_vfs_lock(fl) == -ENOENT) {
+               up_read(&host->h_rwsem);
+               goto out;
+       }
        up_read(&host->h_rwsem);
 
        if (req->a_flags & RPC_TASK_ASYNC)
@@ -624,7 +627,6 @@ nlmclnt_unlock(struct nlm_rqst *req, struct file_lock *fl)
        if (status < 0)
                goto out;
 
-       status = 0;
        if (resp->status == NLM_LCK_GRANTED)
                goto out;
 

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index b4916b0..b8c6375 100644 (file)
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -3144,9 +3144,6 @@ static int do_vfs_lock(struct file *file, struct file_lock *fl)
                default:
                        BUG();
        }
-       if (res < 0)
-               printk(KERN_WARNING "%s: VFS is out of sync with lock manager!\n",
-                               __FUNCTION__);
        return res;
 }
 
@@ -3258,8 +3255,6 @@ static struct rpc_task *nfs4_do_unlck(struct file_lock *fl,
                return ERR_PTR(-ENOMEM);
        }
 
-       /* Unlock _before_ we do the RPC call */
-       do_vfs_lock(fl->fl_file, fl);
        return rpc_run_task(NFS_CLIENT(lsp->ls_state->inode), RPC_TASK_ASYNC, &nfs4_locku_ops, data);
 }
 
@@ -3270,30 +3265,28 @@ static int nfs4_proc_unlck(struct nfs4_state *state, int cmd, struct file_lock *
        struct rpc_task *task;
        int status = 0;
 
-       /* Is this a delegated lock? */
-       if (test_bit(NFS_DELEGATED_STATE, &state->flags))
-               goto out_unlock;
-       /* Is this open_owner holding any locks on the server? */
-       if (test_bit(LK_STATE_IN_USE, &state->flags) == 0)
-               goto out_unlock;
-
        status = nfs4_set_lock_state(state, request);
+       /* Unlock _before_ we do the RPC call */
+       request->fl_flags |= FL_EXISTS;
+       if (do_vfs_lock(request->fl_file, request) == -ENOENT)
+               goto out;
        if (status != 0)
-               goto out_unlock;
+               goto out;
+       /* Is this a delegated lock? */
+       if (test_bit(NFS_DELEGATED_STATE, &state->flags))
+               goto out;
        lsp = request->fl_u.nfs4_fl.owner;
-       status = -ENOMEM;
        seqid = nfs_alloc_seqid(&lsp->ls_seqid);
+       status = -ENOMEM;
        if (seqid == NULL)
-               goto out_unlock;
+               goto out;
        task = nfs4_do_unlck(request, request->fl_file->private_data, lsp, seqid);
        status = PTR_ERR(task);
        if (IS_ERR(task))
-               goto out_unlock;
+               goto out;
        status = nfs4_wait_for_completion_rpc_task(task);
        rpc_release_task(task);
-       return status;
-out_unlock:
-       do_vfs_lock(request->fl_file, request);
+out:
        return status;
 }