[PATCHv4 dlm/next 10/15] dlm: convert res_lock to spinlock

[Alexander Aring <aahringo@redhat.com>]

This patch converts the per dlm rsb res_lock from a mutex to a spinlock.
To prepare switching to a softirq context when parsing DLM messages.

Signed-off-by: Alexander Aring <aahringo@redhat.com>
---
 fs/dlm/dlm_internal.h | 2 +-
 fs/dlm/lock.c         | 2 +-
 fs/dlm/lock.h         | 4 ++--
 3 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/fs/dlm/dlm_internal.h b/fs/dlm/dlm_internal.h
index 98029fd5cd2b..9f98a815f935 100644
--- a/fs/dlm/dlm_internal.h
+++ b/fs/dlm/dlm_internal.h
@@ -320,7 +320,7 @@ struct dlm_lkb {
 struct dlm_rsb {
 	struct dlm_ls		*res_ls;	/* the lockspace */
 	struct kref		res_ref;
-	struct mutex		res_mutex;
+	spinlock_t		res_lock;
 	unsigned long		res_flags;
 	int			res_length;	/* length of rsb name */
 	int			res_nodeid;
diff --git a/fs/dlm/lock.c b/fs/dlm/lock.c
index af677add4f5f..7b309231eebd 100644
--- a/fs/dlm/lock.c
+++ b/fs/dlm/lock.c
@@ -415,7 +415,7 @@ static int get_rsb_struct(struct dlm_ls *ls, const void *name, int len,
 	r->res_ls = ls;
 	r->res_length = len;
 	memcpy(r->res_name, name, len);
-	mutex_init(&r->res_mutex);
+	spin_lock_init(&r->res_lock);
 
 	INIT_LIST_HEAD(&r->res_lookup);
 	INIT_LIST_HEAD(&r->res_grantqueue);
diff --git a/fs/dlm/lock.h b/fs/dlm/lock.h
index b2fd74a2f8eb..0f6b2700c0da 100644
--- a/fs/dlm/lock.h
+++ b/fs/dlm/lock.h
@@ -69,12 +69,12 @@ static inline int is_master(struct dlm_rsb *r)
 
 static inline void lock_rsb(struct dlm_rsb *r)
 {
-	mutex_lock(&r->res_mutex);
+	spin_lock(&r->res_lock);
 }
 
 static inline void unlock_rsb(struct dlm_rsb *r)
 {
-	mutex_unlock(&r->res_mutex);
+	spin_unlock(&r->res_lock);
 }
 
 #endif
-- 
2.43.0