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Commit e93f3152 authored by Alex Elder's avatar Alex Elder
Browse files

rbd: define parent image request routines 



Define rbd_parent_request_create() and rbd_parent_request_destroy()
to handle the creation of parent image requests submitted for
layered image objects.  For simplicity, let rbd_img_request_put()
handle dropping the reference to any image request (parent or not),
and call whichever destructor is appropriate on the last put.

Signed-off-by: default avatarAlex Elder <elder@inktank.com>
Reviewed-by: default avatarJosh Durgin <josh.durgin@inktank.com>
parent fb65d228

drivers/block/rbd.c

+55 −23
Original line number Diff line number Diff line
@@ -1359,12 +1359,17 @@ static void rbd_obj_request_put(struct rbd_obj_request *obj_request) 
	kref_put(&obj_request->kref, rbd_obj_request_destroy);

}



static bool img_request_child_test(struct rbd_img_request *img_request);

static void rbd_parent_request_destroy(struct kref *kref);

static void rbd_img_request_destroy(struct kref *kref);

static void rbd_img_request_put(struct rbd_img_request *img_request)

{

	rbd_assert(img_request != NULL);

	dout("%s: img %p (was %d)\n", __func__, img_request,

		atomic_read(&img_request->kref.refcount));

	if (img_request_child_test(img_request))

		kref_put(&img_request->kref, rbd_parent_request_destroy);

	else

		kref_put(&img_request->kref, rbd_img_request_destroy);

}
@@ -1482,6 +1487,12 @@ static void img_request_child_set(struct rbd_img_request *img_request) 
	smp_mb();

}



static void img_request_child_clear(struct rbd_img_request *img_request)

{

	clear_bit(IMG_REQ_CHILD, &img_request->flags);

	smp_mb();

}



static bool img_request_child_test(struct rbd_img_request *img_request)

{

	smp_mb();
@@ -1856,8 +1867,7 @@ static void rbd_dev_unparent(struct rbd_device *rbd_dev) 
static struct rbd_img_request *rbd_img_request_create(

					struct rbd_device *rbd_dev,

					u64 offset, u64 length,

					bool write_request,

					bool child_request)

					bool write_request)

{

	struct rbd_img_request *img_request;
@@ -1882,8 +1892,6 @@ static struct rbd_img_request *rbd_img_request_create( 
	} else {

		img_request->snap_id = rbd_dev->spec->snap_id;

	}

	if (child_request)

		img_request_child_set(img_request);

	if (rbd_dev->parent_overlap)

		img_request_layered_set(img_request);

	spin_lock_init(&img_request->completion_lock);
@@ -1918,12 +1926,46 @@ static void rbd_img_request_destroy(struct kref *kref) 
	if (img_request_write_test(img_request))

		ceph_put_snap_context(img_request->snapc);



	if (img_request_child_test(img_request))

		rbd_obj_request_put(img_request->obj_request);



	kmem_cache_free(rbd_img_request_cache, img_request);

}



static struct rbd_img_request *rbd_parent_request_create(

					struct rbd_obj_request *obj_request,

					u64 img_offset, u64 length)

{

	struct rbd_img_request *parent_request;

	struct rbd_device *rbd_dev;



	rbd_assert(obj_request->img_request);

	rbd_dev = obj_request->img_request->rbd_dev;



	parent_request = rbd_img_request_create(rbd_dev->parent,

						img_offset, length, false);

	if (!parent_request)

		return NULL;



	img_request_child_set(parent_request);

	rbd_obj_request_get(obj_request);

	parent_request->obj_request = obj_request;



	return parent_request;

}



static void rbd_parent_request_destroy(struct kref *kref)

{

	struct rbd_img_request *parent_request;

	struct rbd_obj_request *orig_request;



	parent_request = container_of(kref, struct rbd_img_request, kref);

	orig_request = parent_request->obj_request;



	parent_request->obj_request = NULL;

	rbd_obj_request_put(orig_request);

	img_request_child_clear(parent_request);



	rbd_img_request_destroy(kref);

}



static bool rbd_img_obj_end_request(struct rbd_obj_request *obj_request)

{

	struct rbd_img_request *img_request;
@@ -2321,13 +2363,10 @@ static int rbd_img_obj_parent_read_full(struct rbd_obj_request *obj_request) 
	}



	result = -ENOMEM;

	parent_request = rbd_img_request_create(rbd_dev->parent,

						img_offset, length,

						false, true);

	parent_request = rbd_parent_request_create(obj_request,

						img_offset, length);

	if (!parent_request)

		goto out_err;

	rbd_obj_request_get(obj_request);

	parent_request->obj_request = obj_request;



	result = rbd_img_request_fill(parent_request, OBJ_REQUEST_PAGES, pages);

	if (result)
@@ -2580,7 +2619,6 @@ out: 


static void rbd_img_parent_read(struct rbd_obj_request *obj_request)

{

	struct rbd_device *rbd_dev;

	struct rbd_img_request *img_request;

	int result;
@@ -2589,20 +2627,14 @@ static void rbd_img_parent_read(struct rbd_obj_request *obj_request) 
	rbd_assert(obj_request->result == (s32) -ENOENT);

	rbd_assert(obj_request_type_valid(obj_request->type));



	rbd_dev = obj_request->img_request->rbd_dev;

	rbd_assert(rbd_dev->parent != NULL);

	/* rbd_read_finish(obj_request, obj_request->length); */

	img_request = rbd_img_request_create(rbd_dev->parent,

	img_request = rbd_parent_request_create(obj_request,

						obj_request->img_offset,

						obj_request->length,

						false, true);

						obj_request->length);

	result = -ENOMEM;

	if (!img_request)

		goto out_err;



	rbd_obj_request_get(obj_request);

	img_request->obj_request = obj_request;



	if (obj_request->type == OBJ_REQUEST_BIO)

		result = rbd_img_request_fill(img_request, OBJ_REQUEST_BIO,

						obj_request->bio_list);
@@ -2913,7 +2945,7 @@ static void rbd_request_fn(struct request_queue *q) 


		result = -ENOMEM;

		img_request = rbd_img_request_create(rbd_dev, offset, length,

							write_request, false);

							write_request);

		if (!img_request)

			goto end_request;