kernel/locks-allow-__break_lease-to-sleep-even-when-break_t.patch
Justin M. Forbes 511f256d9f Linux v3.14.3
2014-05-08 07:24:27 -05:00

51 lines
1.6 KiB
Diff

Bugzilla: 1082586
Upstream-status: 3.15 and sent for stable
From f1c6bb2cb8b81013e8979806f8e15e3d53efb96d Mon Sep 17 00:00:00 2001
From: Jeff Layton <jlayton@redhat.com>
Date: Tue, 15 Apr 2014 06:17:49 -0400
Subject: [PATCH] locks: allow __break_lease to sleep even when break_time is 0
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 makes __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: <stable@vger.kernel.org>
Cc: J. Bruce Fields <bfields@fieldses.org>
Reported-by: Terry Barnaby <terry1@beam.ltd.uk>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
---
fs/locks.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)
diff --git a/fs/locks.c b/fs/locks.c
index 13fc7a6d380a..b380f5543614 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -1391,11 +1391,10 @@ int __break_lease(struct inode *inode, unsigned int mode, unsigned int type)
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);
spin_unlock(&inode->i_lock);
error = wait_event_interruptible_timeout(new_fl->fl_wait,
--
1.9.0