Commit 962bd40b authored by Jeff Layton's avatar Jeff Layton
Browse files

locks: add missing memory barrier in break_deleg 



break_deleg is subject to the same potential race as break_lease. Add
a memory barrier to prevent it.

Signed-off-by: default avatarJeff Layton <jlayton@primarydata.com>
parent 64b2d1fb

include/linux/fs.h

+6 −0
Original line number Diff line number Diff line
@@ -1914,6 +1914,12 @@ static inline int break_lease(struct inode *inode, unsigned int mode) 


static inline int break_deleg(struct inode *inode, unsigned int mode)

{

	/*

	 * Since this check is lockless, we must ensure that any refcounts

	 * taken are done before checking inode->i_flock. Otherwise, we could

	 * end up racing with tasks trying to set a new lease on this file.

	 */

	smp_mb();

	if (inode->i_flock)

		return __break_lease(inode, mode, FL_DELEG);

	return 0;