locks: rename lease functions to reflect locks.c conventions

We've been using the convention that vfs_foo is the function that calls
a filesystem-specific foo method if it exists, or falls back on a
generic method if it doesn't; thus vfs_foo is what is called when some
other part of the kernel (normally lockd or nfsd) wants to get a lock,
whereas foo is what filesystems call to use the underlying local
functionality as part of their lock implementation.

So rename setlease to vfs_setlease (which will call a
filesystem-specific setlease after a later patch) and __setlease to
setlease.

Also, vfs_setlease need only be GPL-exported as long as it's only needed
by lockd and nfsd.

Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu>
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index e4a4c87..6284807 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -256,7 +256,7 @@
 	/* The following nfsd_close may not actually close the file,
 	 * but we want to remove the lease in any case. */
 	if (dp->dl_flock)
-		setlease(filp, F_UNLCK, &dp->dl_flock);
+		vfs_setlease(filp, F_UNLCK, &dp->dl_flock);
 	nfsd_close(filp);
 }
 
@@ -1402,7 +1402,7 @@
 /*
  * Set the delegation file_lock back pointer.
  *
- * Called from __setlease() with lock_kernel() held.
+ * Called from setlease() with lock_kernel() held.
  */
 static
 void nfsd_copy_lock_deleg_cb(struct file_lock *new, struct file_lock *fl)
@@ -1416,7 +1416,7 @@
 }
 
 /*
- * Called from __setlease() with lock_kernel() held
+ * Called from setlease() with lock_kernel() held
  */
 static
 int nfsd_same_client_deleg_cb(struct file_lock *onlist, struct file_lock *try)
@@ -1716,10 +1716,10 @@
 	fl.fl_file = stp->st_vfs_file;
 	fl.fl_pid = current->tgid;
 
-	/* setlease checks to see if delegation should be handed out.
+	/* vfs_setlease checks to see if delegation should be handed out.
 	 * the lock_manager callbacks fl_mylease and fl_change are used
 	 */
-	if ((status = setlease(stp->st_vfs_file,
+	if ((status = vfs_setlease(stp->st_vfs_file,
 		flag == NFS4_OPEN_DELEGATE_READ? F_RDLCK: F_WRLCK, &flp))) {
 		dprintk("NFSD: setlease failed [%d], no delegation\n", status);
 		unhash_delegation(dp);