block: drbd: Convert semaphore to mutex

The bm_change semaphore is semantically a mutex. Convert it to a real
mutex.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>

1 files changed, 5 insertions, 5 deletions

diff --git a/drivers/block/drbd/drbd_bitmap.c b/drivers/block/drbd/drbd_bitmap.c
index b61057e77882..f58e76581c4b 100644
--- a/drivers/block/drbd/drbd_bitmap.c
+++ b/drivers/block/drbd/drbd_bitmap.c
@@ -66,7 +66,7 @@ struct drbd_bitmap {
         size_t   bm_words;
         size_t   bm_number_of_pages;
         sector_t bm_dev_capacity;
-        struct semaphore bm_change; /* serializes resize operations */
+        struct mutex bm_change; /* serializes resize operations */
 
         atomic_t bm_async_io;
         wait_queue_head_t bm_io_wait;
@@ -114,7 +114,7 @@ void drbd_bm_lock(struct drbd_conf *mdev, char *why)
                 return;
         }
 
-        trylock_failed = down_trylock(&b->bm_change);
+        trylock_failed = !mutex_trylock(&b->bm_change);
 
         if (trylock_failed) {
                 dev_warn(DEV, "%s going to '%s' but bitmap already locked for '%s' by %s\n",
@@ -125,7 +125,7 @@ void drbd_bm_lock(struct drbd_conf *mdev, char *why)
                     b->bm_task == mdev->receiver.task ? "receiver" :
                     b->bm_task == mdev->asender.task  ? "asender"  :
                     b->bm_task == mdev->worker.task   ? "worker"   : "?");
-                down(&b->bm_change);
+                mutex_lock(&b->bm_change);
         }
         if (__test_and_set_bit(BM_LOCKED, &b->bm_flags))
                 dev_err(DEV, "FIXME bitmap already locked in bm_lock\n");
@@ -147,7 +147,7 @@ void drbd_bm_unlock(struct drbd_conf *mdev)
 
         b->bm_why  = NULL;
         b->bm_task = NULL;
-        up(&b->bm_change);
+        mutex_unlock(&b->bm_change);
 }
 
 /* word offset to long pointer */
@@ -295,7 +295,7 @@ int drbd_bm_init(struct drbd_conf *mdev)
         if (!b)
                 return -ENOMEM;
         spin_lock_init(&b->bm_lock);
-        init_MUTEX(&b->bm_change);
+        mutex_init(&b->bm_change);
         init_waitqueue_head(&b->bm_io_wait);
 
         mdev->bitmap = b;