From 08f36d9d2cbe95df935378c220215791fc1dd111 Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Tue, 15 Apr 2014 08:44:12 -0400 Subject: locks: allow __break_lease to sleep even when break_time is 0 commit 4991a628a789dc5954e98e79476d9808812292ec upstream. A fl->fl_break_time of 0 has a special meaning to the lease break code that basically means "never break the lease". knfsd uses this to ensure that leases don't disappear out from under it. Unfortunately, the code in __break_lease can end up passing this value to wait_event_interruptible as a timeout, which prevents it from going to sleep at all. This causes __break_lease to spin in a tight loop and causes soft lockups. Fix this by ensuring that we pass a minimum value of 1 as a timeout instead. Cc: J. Bruce Fields Reported-by: Terry Barnaby Signed-off-by: Jeff Layton Signed-off-by: J. Bruce Fields Signed-off-by: Greg Kroah-Hartman --- fs/locks.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/fs/locks.c b/fs/locks.c index fcc50ab71cc6..d4f1d89d9bc6 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -1253,11 +1253,10 @@ int __break_lease(struct inode *inode, unsigned int mode) restart: break_time = flock->fl_break_time; - if (break_time != 0) { + if (break_time != 0) break_time -= jiffies; - if (break_time == 0) - break_time++; - } + if (break_time == 0) + break_time++; locks_insert_block(flock, new_fl); unlock_flocks(); error = wait_event_interruptible_timeout(new_fl->fl_wait, -- cgit v1.2.3