rbd: refactor rbd_wait_state_locked()

In preparation for lock_timeout option, make rbd_wait_state_locked()
return error codes.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

1 files changed, 26 insertions, 17 deletions

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 07dc5419bd63..f4b1b91e6d4d 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -3533,9 +3533,21 @@ static int rbd_obj_method_sync(struct rbd_device *rbd_dev,
 /*
  * lock_rwsem must be held for read
  */
-static void rbd_wait_state_locked(struct rbd_device *rbd_dev)
+static int rbd_wait_state_locked(struct rbd_device *rbd_dev, bool may_acquire)
 {
         DEFINE_WAIT(wait);
+        int ret = 0;
+
+        if (test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags))
+                return -EBLACKLISTED;
+
+        if (rbd_dev->lock_state == RBD_LOCK_STATE_LOCKED)
+                return 0;
+
+        if (!may_acquire) {
+                rbd_warn(rbd_dev, "exclusive lock required");
+                return -EROFS;
+        }
 
         do {
                 /*
@@ -3549,10 +3561,14 @@ static void rbd_wait_state_locked(struct rbd_device *rbd_dev)
                 up_read(&rbd_dev->lock_rwsem);
                 schedule();
                 down_read(&rbd_dev->lock_rwsem);
-        } while (rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED &&
-                 !test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags));
+                if (test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags)) {
+                        ret = -EBLACKLISTED;
+                        break;
+                }
+        } while (rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED);
 
         finish_wait(&rbd_dev->lock_waitq, &wait);
+        return ret;
 }
 
 static void rbd_queue_workfn(struct work_struct *work)
@@ -3638,19 +3654,10 @@ static void rbd_queue_workfn(struct work_struct *work)
             (op_type != OBJ_OP_READ || rbd_dev->opts->lock_on_read);
         if (must_be_locked) {
                 down_read(&rbd_dev->lock_rwsem);
-                if (rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED &&
-                    !test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags)) {
-                        if (rbd_dev->opts->exclusive) {
-                                rbd_warn(rbd_dev, "exclusive lock required");
-                                result = -EROFS;
-                                goto err_unlock;
-                        }
-                        rbd_wait_state_locked(rbd_dev);
-                }
-                if (test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags)) {
-                        result = -EBLACKLISTED;
+                result = rbd_wait_state_locked(rbd_dev,
+                                               !rbd_dev->opts->exclusive);
+                if (result)
                         goto err_unlock;
-                }
         }
 
         img_request = rbd_img_request_create(rbd_dev, op_type, snapc);
@@ -5216,6 +5223,8 @@ static void rbd_dev_image_unlock(struct rbd_device *rbd_dev)
 
 static int rbd_add_acquire_lock(struct rbd_device *rbd_dev)
 {
+        int ret;
+
         if (!(rbd_dev->header.features & RBD_FEATURE_EXCLUSIVE_LOCK)) {
                 rbd_warn(rbd_dev, "exclusive-lock feature is not enabled");
                 return -EINVAL;
@@ -5223,9 +5232,9 @@ static int rbd_add_acquire_lock(struct rbd_device *rbd_dev)
 
         /* FIXME: "rbd map --exclusive" should be in interruptible */
         down_read(&rbd_dev->lock_rwsem);
-        rbd_wait_state_locked(rbd_dev);
+        ret = rbd_wait_state_locked(rbd_dev, true);
         up_read(&rbd_dev->lock_rwsem);
-        if (test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags)) {
+        if (ret) {
                 rbd_warn(rbd_dev, "failed to acquire exclusive lock");
                 return -EROFS;
         }