diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 22b282409a16..9d21f90f93f0 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -1495,6 +1495,8 @@ static bool rbd_obj_is_tail(struct rbd_obj_request *obj_req)
  */
 static void rbd_obj_set_copyup_enabled(struct rbd_obj_request *obj_req)
 {
+	rbd_assert(obj_req->img_request->snapc);
+
 	if (obj_req->img_request->op_type == OBJ_OP_DISCARD) {
 		dout("%s %p objno %llu discard\n", __func__, obj_req,
 		     obj_req->ex.oe_objno);
@@ -1613,6 +1615,7 @@ __rbd_obj_add_osd_request(struct rbd_obj_request *obj_req,
 static struct ceph_osd_request *
 rbd_obj_add_osd_request(struct rbd_obj_request *obj_req, int num_ops)
 {
+	rbd_assert(obj_req->img_request->snapc);
 	return __rbd_obj_add_osd_request(obj_req, obj_req->img_request->snapc,
 					 num_ops);
 }
@@ -1741,11 +1744,14 @@ static bool rbd_dev_parent_get(struct rbd_device *rbd_dev)
  * Caller is responsible for filling in the list of object requests
  * that comprises the image request, and the Linux request pointer
  * (if there is one).
+ *
+ * Only snap_id is captured here, for reads.  For writes, snapshot
+ * context is captured in rbd_img_object_requests() after exclusive
+ * lock is ensured to be held.
  */
 static struct rbd_img_request *rbd_img_request_create(
 					struct rbd_device *rbd_dev,
-					enum obj_operation_type op_type,
-					struct ceph_snap_context *snapc)
+					enum obj_operation_type op_type)
 {
 	struct rbd_img_request *img_request;
 
@@ -1757,8 +1763,6 @@ static struct rbd_img_request *rbd_img_request_create(
 	img_request->op_type = op_type;
 	if (!rbd_img_is_write(img_request))
 		img_request->snap_id = rbd_dev->spec->snap_id;
-	else
-		img_request->snapc = snapc;
 
 	if (rbd_dev_parent_get(rbd_dev))
 		img_request_layered_set(img_request);
@@ -2944,7 +2948,7 @@ static int rbd_obj_read_from_parent(struct rbd_obj_request *obj_req)
 	int ret;
 
 	child_img_req = rbd_img_request_create(img_req->rbd_dev->parent,
-					       OBJ_OP_READ, NULL);
+					       OBJ_OP_READ);
 	if (!child_img_req)
 		return -ENOMEM;
 
@@ -3635,9 +3639,19 @@ static int rbd_img_exclusive_lock(struct rbd_img_request *img_req)
 
 static void rbd_img_object_requests(struct rbd_img_request *img_req)
 {
+	struct rbd_device *rbd_dev = img_req->rbd_dev;
 	struct rbd_obj_request *obj_req;
 
 	rbd_assert(!img_req->pending.result && !img_req->pending.num_pending);
+	rbd_assert(!need_exclusive_lock(img_req) ||
+		   __rbd_is_lock_owner(rbd_dev));
+
+	if (rbd_img_is_write(img_req)) {
+		rbd_assert(!img_req->snapc);
+		down_read(&rbd_dev->header_rwsem);
+		img_req->snapc = ceph_get_snap_context(rbd_dev->header.snapc);
+		up_read(&rbd_dev->header_rwsem);
+	}
 
 	for_each_obj_request(img_req, obj_req) {
 		int result = 0;
@@ -3655,7 +3669,6 @@ static void rbd_img_object_requests(struct rbd_img_request *img_req)
 
 static bool rbd_img_advance(struct rbd_img_request *img_req, int *result)
 {
-	struct rbd_device *rbd_dev = img_req->rbd_dev;
 	int ret;
 
 again:
@@ -3676,9 +3689,6 @@ again:
 		if (*result)
 			return true;
 
-		rbd_assert(!need_exclusive_lock(img_req) ||
-			   __rbd_is_lock_owner(rbd_dev));
-
 		rbd_img_object_requests(img_req);
 		if (!img_req->pending.num_pending) {
 			*result = img_req->pending.result;
@@ -4140,6 +4150,10 @@ static int rbd_post_acquire_action(struct rbd_device *rbd_dev)
 {
 	int ret;
 
+	ret = rbd_dev_refresh(rbd_dev);
+	if (ret)
+		return ret;
+
 	if (rbd_dev->header.features & RBD_FEATURE_OBJECT_MAP) {
 		ret = rbd_object_map_open(rbd_dev);
 		if (ret)
@@ -4798,7 +4812,6 @@ static void rbd_queue_workfn(struct work_struct *work)
 	struct request *rq = blk_mq_rq_from_pdu(work);
 	struct rbd_device *rbd_dev = rq->q->queuedata;
 	struct rbd_img_request *img_request;
-	struct ceph_snap_context *snapc = NULL;
 	u64 offset = (u64)blk_rq_pos(rq) << SECTOR_SHIFT;
 	u64 length = blk_rq_bytes(rq);
 	enum obj_operation_type op_type;
@@ -4863,10 +4876,6 @@ static void rbd_queue_workfn(struct work_struct *work)
 
 	down_read(&rbd_dev->header_rwsem);
 	mapping_size = rbd_dev->mapping.size;
-	if (op_type != OBJ_OP_READ) {
-		snapc = rbd_dev->header.snapc;
-		ceph_get_snap_context(snapc);
-	}
 	up_read(&rbd_dev->header_rwsem);
 
 	if (offset + length > mapping_size) {
@@ -4876,13 +4885,12 @@ static void rbd_queue_workfn(struct work_struct *work)
 		goto err_rq;
 	}
 
-	img_request = rbd_img_request_create(rbd_dev, op_type, snapc);
+	img_request = rbd_img_request_create(rbd_dev, op_type);
 	if (!img_request) {
 		result = -ENOMEM;
 		goto err_rq;
 	}
 	img_request->rq = rq;
-	snapc = NULL; /* img_request consumes a ref */
 
 	dout("%s rbd_dev %p img_req %p %s %llu~%llu\n", __func__, rbd_dev,
 	     img_request, obj_op_name(op_type), offset, length);
@@ -4904,7 +4912,6 @@ err_rq:
 	if (result)
 		rbd_warn(rbd_dev, "%s %llx at %llx result %d",
 			 obj_op_name(op_type), length, offset, result);
-	ceph_put_snap_context(snapc);
 err:
 	blk_mq_end_request(rq, errno_to_blk_status(result));
 }