From 7e74e54f08294a81b82b686e86b9d784ad65a5f9 Mon Sep 17 00:00:00 2001 From: Bruno Faccini Date: Tue, 12 Apr 2016 16:14:03 -0400 Subject: [PATCH] staging: lustre: ldlm: Fix a race during FLock handling Protect against race where lock could have been just destroyed due to overlap, in ldlm_process_flock_lock(). Easy reproducer is BULL's NFS Locktests in pthread mode. (http://nfsv4.bullopensource.org/tools/tests/locktest.php) Signed-off-by: Bruno Faccini Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-1126 Reviewed-on: http://review.whamcloud.com/7134 Reviewed-by: Oleg Drokin Reviewed-by: John L. Hammond Signed-off-by: James Simmons Signed-off-by: Greg Kroah-Hartman --- drivers/staging/lustre/lustre/ldlm/ldlm_flock.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/drivers/staging/lustre/lustre/ldlm/ldlm_flock.c b/drivers/staging/lustre/lustre/ldlm/ldlm_flock.c index 3f97e1c..5102d78 100644 --- a/drivers/staging/lustre/lustre/ldlm/ldlm_flock.c +++ b/drivers/staging/lustre/lustre/ldlm/ldlm_flock.c @@ -520,11 +520,6 @@ ldlm_flock_completion_ast(struct ldlm_lock *lock, __u64 flags, void *data) granted: OBD_FAIL_TIMEOUT(OBD_FAIL_LDLM_CP_CB_WAIT, 10); - if (lock->l_flags & LDLM_FL_DESTROYED) { - LDLM_DEBUG(lock, "client-side enqueue waking up: destroyed"); - return 0; - } - if (lock->l_flags & LDLM_FL_FAILED) { LDLM_DEBUG(lock, "client-side enqueue waking up: failed"); return -EIO; @@ -534,6 +529,16 @@ granted: lock_res_and_lock(lock); + /* + * Protect against race where lock could have been just destroyed + * due to overlap in ldlm_process_flock_lock(). + */ + if (lock->l_flags & LDLM_FL_DESTROYED) { + unlock_res_and_lock(lock); + LDLM_DEBUG(lock, "client-side enqueue waking up: destroyed"); + return 0; + } + /* ldlm_lock_enqueue() has already placed lock on the granted list. */ list_del_init(&lock->l_res_link); -- 2.7.4