From fef75d4c76745e8cd35df36e4691ed66c9e5902f Mon Sep 17 00:00:00 2001 From: Andriy Skulysh Date: Thu, 16 May 2013 13:10:41 +0300 Subject: [PATCH 1/1] LU-2835 ptlrpc: Fix race during exp_flock_hash creation During race exp_flock_hash can be created 2 times. It is created & assigned without any lock. Move hash initialization from ldlm_flock_blocking_link() to ldlm_init_export() Xyratex-bug-id: MRP-855 Signed-off-by: Andriy Skulysh Reviewed-by: Alexander Boyko Reviewed-by: Vitaly Fertman Tested-by: Kyrylo Shatskyy Change-Id: Iaec171eb628396b69dede973260a59ac345b7e8c Reviewed-on: http://review.whamcloud.com/5471 Tested-by: Hudson Reviewed-by: Keith Mannthey Tested-by: Maloo Reviewed-by: Prakash Surya Reviewed-by: Oleg Drokin --- lustre/ldlm/ldlm_flock.c | 28 ++++++++-------------------- lustre/ldlm/ldlm_lockd.c | 8 ++++++++ 2 files changed, 16 insertions(+), 20 deletions(-) diff --git a/lustre/ldlm/ldlm_flock.c b/lustre/ldlm/ldlm_flock.c index 5b40b3e..a765cc7 100644 --- a/lustre/ldlm/ldlm_flock.c +++ b/lustre/ldlm/ldlm_flock.c @@ -100,20 +100,12 @@ ldlm_flocks_overlap(struct ldlm_lock *lock, struct ldlm_lock *new) lock->l_policy_data.l_flock.start)); } -static inline int ldlm_flock_blocking_link(struct ldlm_lock *req, - struct ldlm_lock *lock) +static inline void ldlm_flock_blocking_link(struct ldlm_lock *req, + struct ldlm_lock *lock) { - int rc = 0; - /* For server only */ if (req->l_export == NULL) - return 0; - - if (unlikely(req->l_export->exp_flock_hash == NULL)) { - rc = ldlm_init_flock_export(req->l_export); - if (rc) - goto error; - } + return; LASSERT(cfs_hlist_unhashed(&req->l_exp_flock_hash)); @@ -126,8 +118,6 @@ static inline int ldlm_flock_blocking_link(struct ldlm_lock *req, cfs_hash_add(req->l_export->exp_flock_hash, &req->l_policy_data.l_flock.owner, &req->l_exp_flock_hash); -error: - return rc; } static inline void ldlm_flock_blocking_unlink(struct ldlm_lock *req) @@ -258,7 +248,6 @@ ldlm_process_flock_lock(struct ldlm_lock *req, __u64 *flags, int first_enq, int overlaps = 0; int splitted = 0; const struct ldlm_callback_suite null_cbs = { NULL }; - int rc; ENTRY; CDEBUG(D_DLMTRACE, "flags %#llx owner "LPU64" pid %u mode %u start " @@ -337,12 +326,8 @@ reprocess: /* add lock to blocking list before deadlock * check to prevent race */ - rc = ldlm_flock_blocking_link(req, lock); - if (rc) { - ldlm_flock_destroy(req, mode, *flags); - *err = rc; - RETURN(LDLM_ITER_STOP); - } + ldlm_flock_blocking_link(req, lock); + if (ldlm_flock_deadlock(req, lock)) { ldlm_flock_blocking_unlink(req); ldlm_flock_destroy(req, mode, *flags); @@ -862,6 +847,9 @@ static cfs_hash_ops_t ldlm_export_flock_ops = { int ldlm_init_flock_export(struct obd_export *exp) { + if( strcmp(exp->exp_obd->obd_type->typ_name, LUSTRE_MDT_NAME) != 0) + RETURN(0); + exp->exp_flock_hash = cfs_hash_create(obd_uuid2str(&exp->exp_client_uuid), HASH_EXP_LOCK_CUR_BITS, diff --git a/lustre/ldlm/ldlm_lockd.c b/lustre/ldlm/ldlm_lockd.c index 2f11b93..1cfd813 100644 --- a/lustre/ldlm/ldlm_lockd.c +++ b/lustre/ldlm/ldlm_lockd.c @@ -2775,6 +2775,7 @@ static cfs_hash_ops_t ldlm_export_lock_ops = { int ldlm_init_export(struct obd_export *exp) { + int rc; ENTRY; exp->exp_lock_hash = @@ -2790,7 +2791,14 @@ int ldlm_init_export(struct obd_export *exp) if (!exp->exp_lock_hash) RETURN(-ENOMEM); + rc = ldlm_init_flock_export(exp); + if (rc) + GOTO(err, rc); + RETURN(0); +err: + ldlm_destroy_export(exp); + RETURN(rc); } EXPORT_SYMBOL(ldlm_init_export); -- 1.8.3.1