drbd: Removed drbd_state_lock() and drbd_state_unlock()

The lock they constructed is only taken when the state_mutex
was already taken. It is superficial.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>

4 files changed, 8 insertions, 29 deletions

diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h
index f718124c5c82..2dbcd13ba2af 100644
--- a/drivers/block/drbd/drbd_int.h
+++ b/drivers/block/drbd/drbd_int.h
@@ -764,7 +764,6 @@ enum {
         UNPLUG_REMOTE,          /* sending a "UnplugRemote" could help */
         MD_DIRTY,               /* current uuids and flags not yet on disk */
         USE_DEGR_WFC_T,         /* degr-wfc-timeout instead of wfc-timeout. */
-        CLUSTER_ST_CHANGE,      /* Cluster wide state change going on... */
         CL_ST_CHG_SUCCESS,
         CL_ST_CHG_FAIL,
         CRASHED_PRIMARY,        /* This node was a crashed primary.
@@ -1664,23 +1663,6 @@ static inline int drbd_ee_has_active_page(struct drbd_peer_request *peer_req)
         return 0;
 }
 
-
-
-
-
-
-static inline void drbd_state_lock(struct drbd_conf *mdev)
-{
-        wait_event(mdev->misc_wait,
-                   !test_and_set_bit(CLUSTER_ST_CHANGE, &mdev->flags));
-}
-
-static inline void drbd_state_unlock(struct drbd_conf *mdev)
-{
-        clear_bit(CLUSTER_ST_CHANGE, &mdev->flags);
-        wake_up(&mdev->misc_wait);
-}
-
 static inline enum drbd_state_rv
 _drbd_set_state(struct drbd_conf *mdev, union drbd_state ns,
                 enum chg_state_flags flags, struct completion *done)
diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index 27e1eb7ce540..423e4dd2d53e 100644
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -3167,7 +3167,8 @@ static int receive_uuids(struct drbd_conf *mdev, enum drbd_packet cmd,
            ongoing cluster wide state change is finished. That is important if
            we are primary and are detaching from our disk. We need to see the
            new disk state... */
-        wait_event(mdev->misc_wait, !test_bit(CLUSTER_ST_CHANGE, &mdev->flags));
+        mutex_lock(&mdev->state_mutex);
+        mutex_unlock(&mdev->state_mutex);
         if (mdev->state.conn >= C_CONNECTED && mdev->state.disk < D_INCONSISTENT)
                 updated_uuids |= drbd_set_ed_uuid(mdev, p_uuid[UI_CURRENT]);
 
@@ -3218,7 +3219,7 @@ static int receive_req_state(struct drbd_conf *mdev, enum drbd_packet cmd,
         val.i = be32_to_cpu(p->val);
 
         if (test_bit(DISCARD_CONCURRENT, &mdev->tconn->flags) &&
-            test_bit(CLUSTER_ST_CHANGE, &mdev->flags)) {
+            mutex_is_locked(&mdev->state_mutex)) {
                 drbd_send_sr_reply(mdev, SS_CONCURRENT_ST_CHG);
                 return true;
         }
diff --git a/drivers/block/drbd/drbd_state.c b/drivers/block/drbd/drbd_state.c
index 7376d9dc0bc7..91433168e1d4 100644
--- a/drivers/block/drbd/drbd_state.c
+++ b/drivers/block/drbd/drbd_state.c
@@ -184,9 +184,7 @@ drbd_req_state(struct drbd_conf *mdev, union drbd_state mask,
                         goto abort;
                 }
 
-                drbd_state_lock(mdev);
                 if (!drbd_send_state_req(mdev, mask, val)) {
-                        drbd_state_unlock(mdev);
                         rv = SS_CW_FAILED_BY_PEER;
                         if (f & CS_VERBOSE)
                                 print_st_err(mdev, os, ns, rv);
@@ -197,7 +195,6 @@ drbd_req_state(struct drbd_conf *mdev, union drbd_state mask,
                         (rv = _req_st_cond(mdev, mask, val)));
 
                 if (rv < SS_SUCCESS) {
-                        drbd_state_unlock(mdev);
                         if (f & CS_VERBOSE)
                                 print_st_err(mdev, os, ns, rv);
                         goto abort;
@@ -205,7 +202,6 @@ drbd_req_state(struct drbd_conf *mdev, union drbd_state mask,
                 spin_lock_irqsave(&mdev->tconn->req_lock, flags);
                 ns = apply_mask_val(mdev->state, mask, val);
                 rv = _drbd_set_state(mdev, ns, f, &done);
-                drbd_state_unlock(mdev);
         } else {
                 rv = _drbd_set_state(mdev, ns, f, &done);
         }
diff --git a/drivers/block/drbd/drbd_worker.c b/drivers/block/drbd/drbd_worker.c
index eee017dd6d7d..e8448712b958 100644
--- a/drivers/block/drbd/drbd_worker.c
+++ b/drivers/block/drbd/drbd_worker.c
@@ -1536,21 +1536,21 @@ void drbd_start_resync(struct drbd_conf *mdev, enum drbd_conns side)
         }
 
         if (current == mdev->tconn->worker.task) {
-                /* The worker should not sleep waiting for drbd_state_lock(),
+                /* The worker should not sleep waiting for state_mutex,
                    that can take long */
-                if (test_and_set_bit(CLUSTER_ST_CHANGE, &mdev->flags)) {
+                if (!mutex_trylock(&mdev->state_mutex)) {
                         set_bit(B_RS_H_DONE, &mdev->flags);
                         mdev->start_resync_timer.expires = jiffies + HZ/5;
                         add_timer(&mdev->start_resync_timer);
                         return;
                 }
         } else {
-                drbd_state_lock(mdev);
+                mutex_lock(&mdev->state_mutex);
         }
         clear_bit(B_RS_H_DONE, &mdev->flags);
 
         if (!get_ldev_if_state(mdev, D_NEGOTIATING)) {
-                drbd_state_unlock(mdev);
+                mutex_unlock(&mdev->state_mutex);
                 return;
         }
 
@@ -1639,7 +1639,7 @@ void drbd_start_resync(struct drbd_conf *mdev, enum drbd_conns side)
                 drbd_md_sync(mdev);
         }
         put_ldev(mdev);
-        drbd_state_unlock(mdev);
+        mutex_unlock(&mdev->state_mutex);
 }
 
 static int _worker_dying(int vnr, void *p, void *data)