Merge tag 'locks-v3.16-2' of git://git.samba.org/jlayton/linux
Pull file locking fixes from Jeff Layton:
"File locking related bugfixes
Nothing too earth-shattering here. A fix for a potential regression
due to a patch in pile #1, and the addition of a memory barrier to
prevent a race condition between break_deleg and generic_add_lease"
* tag 'locks-v3.16-2' of git://git.samba.org/jlayton/linux:
locks: set fl_owner for leases back to current->files
locks: add missing memory barrier in break_deleg
diff --git a/fs/locks.c b/fs/locks.c
index da57c9b..717fbc4 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -431,7 +431,7 @@
if (assign_type(fl, type) != 0)
return -EINVAL;
- fl->fl_owner = (fl_owner_t)filp;
+ fl->fl_owner = (fl_owner_t)current->files;
fl->fl_pid = current->tgid;
fl->fl_file = filp;
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 338e6f7..e11d60c 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1921,6 +1921,12 @@
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;
