From 941f841c8d396d957381fcd4de003d8f2201e741 Mon Sep 17 00:00:00 2001
From: David Disseldorp <ddiss@suse.de>
Date: Wed, 15 Jan 2020 13:33:50 +0100
Subject: [PATCH] rbd: add img_request done callback
References: fate#318836
Patch-mainline: Not yet, SES clustered LIO/RBD

This allows LIO to properly handle SCSI command completion.

Signed-off-by: David Disseldorp <ddiss@suse.de>
---
 drivers/block/rbd.c         |   29 ++++++++++++++++++++---------
 include/linux/ceph/librbd.h |    6 +++++-
 2 files changed, 25 insertions(+), 10 deletions(-)

--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -1354,7 +1354,8 @@ static bool rbd_dev_parent_get(struct rb
 
 static void rbd_img_request_init(struct rbd_img_request *img_request,
 				 struct rbd_device *rbd_dev,
-				 enum obj_operation_type op_type)
+				 enum obj_operation_type op_type,
+				 rbd_img_request_end_cb_t end_cb)
 {
 	memset(img_request, 0, sizeof(*img_request));
 
@@ -1364,12 +1365,14 @@ static void rbd_img_request_init(struct
 	INIT_LIST_HEAD(&img_request->lock_item);
 	INIT_LIST_HEAD(&img_request->object_extents);
 	mutex_init(&img_request->state_mutex);
+	img_request->callback = end_cb;
 }
 
 /* This is for use by LIO RBD so we don't export the caches directly */
 struct rbd_img_request *rbd_img_request_create(
 					struct rbd_device *rbd_dev,
-					enum obj_operation_type op_type)
+					enum obj_operation_type op_type,
+					rbd_img_request_end_cb_t end_cb)
 {
 	struct rbd_img_request *img_request;
 
@@ -1377,7 +1380,7 @@ struct rbd_img_request *rbd_img_request_
 	if (!img_request)
 		return NULL;
 
-	rbd_img_request_init(img_request, rbd_dev, op_type);
+	rbd_img_request_init(img_request, rbd_dev, op_type, end_cb);
 	return img_request;
 }
 EXPORT_SYMBOL(rbd_img_request_create);
@@ -2579,6 +2582,8 @@ static int rbd_obj_read_object(struct rb
 	return 0;
 }
 
+static void rbd_img_end_request(struct rbd_img_request *img_req, int result);
+
 static int rbd_obj_read_from_parent(struct rbd_obj_request *obj_req)
 {
 	struct rbd_img_request *img_req = obj_req->img_request;
@@ -2590,7 +2595,8 @@ static int rbd_obj_read_from_parent(stru
 	if (!child_img_req)
 		return -ENOMEM;
 
-	rbd_img_request_init(child_img_req, parent, OBJ_OP_READ);
+	rbd_img_request_init(child_img_req, parent, OBJ_OP_READ,
+			    rbd_img_end_request);
 	__set_bit(IMG_REQ_CHILD, &child_img_req->flags);
 	child_img_req->obj_request = obj_req;
 
@@ -3376,6 +3382,14 @@ static bool __rbd_img_handle_request(str
 	return done;
 }
 
+static void rbd_img_end_request(struct rbd_img_request *img_req, int result)
+{
+	struct request *rq = blk_mq_rq_from_pdu(img_req);
+
+	rbd_img_request_destroy(img_req);
+	blk_mq_end_request(rq, errno_to_blk_status(result));
+}
+
 void rbd_img_handle_request(struct rbd_img_request *img_req, int result)
 {
 again:
@@ -3391,10 +3405,7 @@ again:
 			goto again;
 		}
 	} else {
-		struct request *rq = blk_mq_rq_from_pdu(img_req);
-
-		rbd_img_request_destroy(img_req);
-		blk_mq_end_request(rq, errno_to_blk_status(result));
+		img_req->callback(img_req, result);
 	}
 }
 EXPORT_SYMBOL(rbd_img_handle_request);
@@ -4528,7 +4539,7 @@ static blk_status_t rbd_queue_rq(struct
 		return BLK_STS_IOERR;
 	}
 
-	rbd_img_request_init(img_req, rbd_dev, op_type);
+	rbd_img_request_init(img_req, rbd_dev, op_type, rbd_img_end_request);
 
 	if (rbd_img_is_write(img_req)) {
 		if (rbd_is_ro(rbd_dev)) {
--- a/include/linux/ceph/librbd.h
+++ b/include/linux/ceph/librbd.h
@@ -101,6 +101,8 @@ enum rbd_img_state {
 };
 
 struct rbd_obj_request;
+typedef void (*rbd_img_request_end_cb_t)(struct rbd_img_request *img_request,
+					 int result);
 
 struct rbd_img_request {
 	struct rbd_device	*rbd_dev;
@@ -113,6 +115,7 @@ struct rbd_img_request {
 		struct ceph_snap_context *snapc;	/* for writes */
 	};
 	struct rbd_obj_request	*obj_request;	/* obj req initiator */
+	rbd_img_request_end_cb_t callback;
 
 	struct list_head	lock_item;
 	struct list_head	object_extents;	/* obj_req.ex structs */
@@ -234,7 +237,8 @@ enum rbd_dev_flags {
 
 extern struct rbd_img_request *rbd_img_request_create(
 					struct rbd_device *rbd_dev,
-					enum obj_operation_type op_type);
+					enum obj_operation_type op_type,
+					rbd_img_request_end_cb_t end_cb);
 extern int rbd_img_fill_nodata(struct rbd_img_request *img_req,
 			       u64 off, u64 len);
 extern int rbd_img_fill_from_bvecs(struct rbd_img_request *img_req,