[PATCH-RESEND 3/8] staging/lustre: fix 'data race condition' issues in at_reset()

[Peng Tao <bergwolf@gmail.com>]

From: Sebastien Buisson <sebastien.buisson@bull.net>

Fix 'data race condition' defects found by Coverity version
6.5.0:
Data race condition (MISSING_LOCK)
Accessing variable without holding lock. Elsewhere,
this variable is accessed with lock held.

at_reset() needs to take at->at_lock before modifying its members.

Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-2744
Lustre-change: http://review.whamcloud.com/6569
Signed-off-by: Sebastien Buisson <sebastien.buisson@bull.net>
Reviewed-by: Bob Glossman <bob.glossman@intel.com>
Reviewed-by: Keith Mannthey <keith.mannthey@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: Peng Tao <tao.peng@emc.com>
Signed-off-by: Andreas Dilger <andreas.dilger@intel.com>
---
 .../staging/lustre/lustre/include/lustre_import.h  |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/drivers/staging/lustre/lustre/include/lustre_import.h b/drivers/staging/lustre/lustre/include/lustre_import.h
index 3a5dd6a..67259eb 100644
--- a/drivers/staging/lustre/lustre/include/lustre_import.h
+++ b/drivers/staging/lustre/lustre/include/lustre_import.h
@@ -336,9 +336,11 @@ static inline unsigned int at_timeout2est(unsigned int val)
 }
 
 static inline void at_reset(struct adaptive_timeout *at, int val) {
+	spin_lock(&at->at_lock);
 	at->at_current = val;
 	at->at_worst_ever = val;
 	at->at_worst_time = cfs_time_current_sec();
+	spin_unlock(&at->at_lock);
 }
 static inline void at_init(struct adaptive_timeout *at, int val, int flags) {
 	memset(at, 0, sizeof(*at));
-- 
1.7.1