locks: plumb a "priv" pointer into the setlease routines

In later patches, we're going to add a new lock_manager_operation to
finish setting up the lease while still holding the i_lock.  To do
this, we'll need to pass a little bit of info in the fcntl setlease
case (primarily an fasync structure). Plumb the extra pointer into
there in advance of that.

We declare this pointer as a void ** to make it clear that this is
private info, and that the caller isn't required to set this unless
the lm_setup specifically requires it.

Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
diff --git a/fs/locks.c b/fs/locks.c
index e16c2c6..4fa269b 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -1297,7 +1297,6 @@
 	}
 	return 0;
 }
-
 EXPORT_SYMBOL(lease_modify);
 
 static bool past_time(unsigned long then)
@@ -1543,7 +1542,8 @@
 	return ret;
 }
 
-static int generic_add_lease(struct file *filp, long arg, struct file_lock **flp)
+static int
+generic_add_lease(struct file *filp, long arg, struct file_lock **flp, void **priv)
 {
 	struct file_lock *fl, **before, **my_before = NULL, *lease;
 	struct dentry *dentry = filp->f_path.dentry;
@@ -1630,11 +1630,14 @@
 	smp_mb();
 	error = check_conflicting_open(dentry, arg);
 	if (error)
-		locks_unlink_lock(before);
+		goto out_unlink;
 out:
 	if (is_deleg)
 		mutex_unlock(&inode->i_mutex);
 	return error;
+out_unlink:
+	locks_unlink_lock(before);
+	goto out;
 }
 
 static int generic_delete_lease(struct file *filp)
@@ -1661,13 +1664,15 @@
  *	@filp: file pointer
  *	@arg: type of lease to obtain
  *	@flp: input - file_lock to use, output - file_lock inserted
+ *	@priv: private data for lm_setup
  *
  *	The (input) flp->fl_lmops->lm_break function is required
  *	by break_lease().
  *
  *	Called with inode->i_lock held.
  */
-int generic_setlease(struct file *filp, long arg, struct file_lock **flp)
+int generic_setlease(struct file *filp, long arg, struct file_lock **flp,
+			void **priv)
 {
 	struct dentry *dentry = filp->f_path.dentry;
 	struct inode *inode = dentry->d_inode;
@@ -1692,19 +1697,20 @@
 			WARN_ON_ONCE(1);
 			return -ENOLCK;
 		}
-		return generic_add_lease(filp, arg, flp);
+		return generic_add_lease(filp, arg, flp, priv);
 	default:
 		return -EINVAL;
 	}
 }
 EXPORT_SYMBOL(generic_setlease);
 
-static int __vfs_setlease(struct file *filp, long arg, struct file_lock **lease)
+static int
+__vfs_setlease(struct file *filp, long arg, struct file_lock **lease, void **priv)
 {
 	if (filp->f_op->setlease)
-		return filp->f_op->setlease(filp, arg, lease);
+		return filp->f_op->setlease(filp, arg, lease, priv);
 	else
-		return generic_setlease(filp, arg, lease);
+		return generic_setlease(filp, arg, lease, priv);
 }
 
 /**
@@ -1712,6 +1718,7 @@
  * @filp: file pointer
  * @arg: type of lease to obtain
  * @lease: file_lock to use when adding a lease
+ * @priv: private info for lm_setup when adding a lease
  *
  * Call this to establish a lease on the file. The "lease" argument is not
  * used for F_UNLCK requests and may be NULL. For commands that set or alter
@@ -1720,13 +1727,14 @@
  * stack trace).
  */
 
-int vfs_setlease(struct file *filp, long arg, struct file_lock **lease)
+int
+vfs_setlease(struct file *filp, long arg, struct file_lock **lease, void **priv)
 {
 	struct inode *inode = file_inode(filp);
 	int error;
 
 	spin_lock(&inode->i_lock);
-	error = __vfs_setlease(filp, arg, lease);
+	error = __vfs_setlease(filp, arg, lease, priv);
 	spin_unlock(&inode->i_lock);
 
 	return error;
@@ -1751,7 +1759,7 @@
 	}
 	ret = fl;
 	spin_lock(&inode->i_lock);
-	error = __vfs_setlease(filp, arg, &ret);
+	error = __vfs_setlease(filp, arg, &ret, NULL);
 	if (error)
 		goto out_unlock;
 	if (ret == fl)
@@ -1789,7 +1797,7 @@
 int fcntl_setlease(unsigned int fd, struct file *filp, long arg)
 {
 	if (arg == F_UNLCK)
-		return vfs_setlease(filp, F_UNLCK, NULL);
+		return vfs_setlease(filp, F_UNLCK, NULL, NULL);
 	return do_fcntl_add_lease(fd, filp, arg);
 }