Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932478AbaFJTxY (ORCPT ); Tue, 10 Jun 2014 15:53:24 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:35502 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753790AbaFJTxU (ORCPT ); Tue, 10 Jun 2014 15:53:20 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: "J. Bruce Fields" , Jeff Layton , Kamal Mostafa Subject: [PATCH 3.13 063/160] locks: allow __break_lease to sleep even when break_time is 0 Date: Tue, 10 Jun 2014 12:45:03 -0700 Message-Id: <1402429600-20477-64-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1402429600-20477-1-git-send-email-kamal@canonical.com> References: <1402429600-20477-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.13 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.13.11.3 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Jeff Layton commit f1c6bb2cb8b81013e8979806f8e15e3d53efb96d 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 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: J. Bruce Fields Reported-by: Terry Barnaby Signed-off-by: Jeff Layton Signed-off-by: Kamal Mostafa --- fs/locks.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/fs/locks.c b/fs/locks.c index 92a0f0a..4dd39b9 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -1376,11 +1376,10 @@ 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, -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/