locks: convert lease handling to file_lock_context

Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Acked-by: Christoph Hellwig <hch@lst.de>

include/linux/fs.h

@@ -969,6 +969,7 @@ struct file_lock {
 struct file_lock_context {
 	struct list_head	flc_flock;
 	struct list_head	flc_posix;
+	struct list_head	flc_lease;
 };
 
 /* The following constant reflects the upper bound of the file/locking space */
@@ -1990,7 +1991,7 @@ static inline int break_lease(struct inode *inode, unsigned int mode)
 	 * end up racing with tasks trying to set a new lease on this file.
 	 */
 	smp_mb();
-	if (inode->i_flock)
+	if (inode->i_flctx && !list_empty_careful(&inode->i_flctx->flc_lease))
 		return __break_lease(inode, mode, FL_LEASE);
 	return 0;
 }
@@ -2003,7 +2004,7 @@ static inline int break_deleg(struct inode *inode, unsigned int mode)
 	 * end up racing with tasks trying to set a new lease on this file.
 	 */
 	smp_mb();
-	if (inode->i_flock)
+	if (inode->i_flctx && !list_empty_careful(&inode->i_flctx->flc_lease))
 		return __break_lease(inode, mode, FL_DELEG);
 	return 0;
 }